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Category Archives: Stem Cell Research

Stem Cell Science and Human Research Studies Ahead of Cargo Arrival – NASA Blogs

Posted: February 21, 2024 at 2:32 am

Stem Cell Science and Human Research Studies Ahead of Cargo Arrival  NASA Blogs

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Stem Cell Science and Human Research Studies Ahead of Cargo Arrival - NASA Blogs

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Harvard Stem Cell Institute (HSCI)

Posted: December 29, 2023 at 2:36 am

HSCI bridges the gaps in traditional research funding to encourage bold thinking and launch scientific careers.

Through our disease programs, we channel world-class resources, both intellectual and technological, toward some of the most prevalent, devastating diseases for which stem cell research holds promise.

In addition, our seed grants and junior faculty programs provide funding for innovative, early-stage projects in stem cell research. This allows up-and-comingscientists to pursue "high risk/high reward" avenues of research that might be difficult to fund from other sources.

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Harvard Stem Cell Institute (HSCI)

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Stem cell – Wikipedia

Posted: December 29, 2023 at 2:36 am

In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage.[1] They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type.

In mammals, roughly 50150 cells make up the inner cell mass during the blastocyst stage of embryonic development, around days 514. These have stem-cell capability. In vivo, they eventually differentiate into all of the body's cell types (making them pluripotent). This process starts with the differentiation into the three germ layers the ectoderm, mesoderm and endoderm at the gastrulation stage. However, when they are isolated and cultured in vitro, they can be kept in the stem-cell stage and are known as embryonic stem cells (ESCs).

Adult stem cells are found in a few select locations in the body, known as niches, such as those in the bone marrow or gonads. They exist to replenish rapidly lost cell types and are multipotent or unipotent, meaning they only differentiate into a few cell types or one type of cell. In mammals, they include, among others, hematopoietic stem cells, which replenish blood and immune cells, basal cells, which maintain the skin epithelium, and mesenchymal stem cells, which maintain bone, cartilage, muscle and fat cells. Adult stem cells are a small minority of cells; they are vastly outnumbered by the progenitor cells and terminally differentiated cells that they differentiate into.[1]

Research into stem cells grew out of findings by Canadian biologists Ernest McCulloch, James Till and Andrew J. Becker at the University of Toronto and the Ontario Cancer Institute in the 1960s.[2][3] As of 2016[update], the only established medical therapy using stem cells is hematopoietic stem cell transplantation,[4] first performed in 1958 by French oncologist Georges Math. Since 1998 however, it has been possible to culture and differentiate human embryonic stem cells (in stem-cell lines). The process of isolating these cells has been controversial, because it typically results in the destruction of the embryo. Sources for isolating ESCs have been restricted in some European countries and Canada, but others such as the UK and China have promoted the research.[5] Somatic cell nuclear transfer is a cloning method that can be used to create a cloned embryo for the use of its embryonic stem cells in stem cell therapy.[6] In 2006, a Japanese team led by Shinya Yamanaka discovered a method to convert mature body cells back into stem cells. These were termed induced pluripotent stem cells (iPSCs).[7]

The term stem cell was coined by Theodor Boveri and Valentin Haecker in late 19th century.[8] Pioneering works in theory of blood stem cell were conducted in the beginning of 20th century by Artur Pappenheim, Alexander Maximow, Franz Ernst Christian Neumann.[8]

The key properties of a stem cell were first defined by Ernest McCulloch and James Till at the University of Toronto and the Ontario Cancer Institute in the early 1960s. They discovered the blood-forming stem cell, the hematopoietic stem cell (HSC), through their pioneering work in mice. McCulloch and Till began a series of experiments in which bone marrow cells were injected into irradiated mice. They observed lumps in the spleens of the mice that were linearly proportional to the number of bone marrow cells injected. They hypothesized that each lump (colony) was a clone arising from a single marrow cell (stem cell). In subsequent work, McCulloch and Till, joined by graduate student Andrew John Becker and senior scientist Louis Siminovitch, confirmed that each lump did in fact arise from a single cell. Their results were published in Nature in 1963. In that same year, Siminovitch was a lead investigator for studies that found colony-forming cells were capable of self-renewal, which is a key defining property of stem cells that Till and McCulloch had theorized.[9]

The first therapy using stem cells was a bone marrow transplant performed by French oncologist Georges Math in 1958 on five workers at the Vina Nuclear Institute in Yugoslavia who had been affected by a criticality accident. The workers all survived.[10]

In 1981, embryonic stem (ES) cells were first isolated and successfully cultured using mouse blastocysts by British biologists Martin Evans and Matthew Kaufman. This allowed the formation of murine genetic models, a system in which the genes of mice are deleted or altered in order to study their function in pathology. By 1998, human embryonic stem cells were first isolated by American biologist James Thomson, which made it possible to have new transplantation methods or various cell types for testing new treatments. In 2006, Shinya Yamanaka's team in Kyoto, Japan converted fibroblasts into pluripotent stem cells by modifying the expression of only four genes. The feat represents the origin of induced pluripotent stem cells, known as iPS cells.[7]

In 2011, a female maned wolf, run over by a truck, underwent stem cell treatment at the Zoo Braslia, this being the first recorded case of the use of stem cells to heal injuries in a wild animal.[11][12]

The classical definition of a stem cell requires that it possesses two properties:

Two mechanisms ensure that a stem cell population is maintained (doesn't shrink in size):

1. Asymmetric cell division: a stem cell divides into one mother cell, which is identical to the original stem cell, and another daughter cell, which is differentiated.

When a stem cell self-renews, it divides and does not disrupt the undifferentiated state. This self-renewal demands control of cell cycle as well as upkeep of multipotency or pluripotency, which all depends on the stem cell.[13]

2. Stochastic differentiation: when one stem cell grows and divides into two differentiated daughter cells, another stem cell undergoes mitosis and produces two stem cells identical to the original.

Stem cells use telomerase, a protein that restores telomeres, to protect their DNA and extend their cell division limit (the Hayflick limit).[14]

Potency specifies the differentiation potential (the potential to differentiate into different cell types) of the stem cell.[15]

In practice, stem cells are identified by whether they can regenerate tissue. For example, the defining test for bone marrow or hematopoietic stem cells (HSCs) is the ability to transplant the cells and save an individual without HSCs. This demonstrates that the cells can produce new blood cells over a long term. It should also be possible to isolate stem cells from the transplanted individual, which can themselves be transplanted into another individual without HSCs, demonstrating that the stem cell was able to self-renew.

Properties of stem cells can be illustrated in vitro, using methods such as clonogenic assays, in which single cells are assessed for their ability to differentiate and self-renew.[18][19] Stem cells can also be isolated by their possession of a distinctive set of cell surface markers. However, in vitro culture conditions can alter the behavior of cells, making it unclear whether the cells shall behave in a similar manner in vivo. There is considerable debate as to whether some proposed adult cell populations are truly stem cells.[20]

Embryonic stem cells (ESCs) are the cells of the inner cell mass of a blastocyst, formed prior to implantation in the uterus.[21] In human embryonic development the blastocyst stage is reached 45 days after fertilization, at which time it consists of 50150 cells. ESCs are pluripotent and give rise during development to all derivatives of the three germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extraembryonic membranes or to the placenta.

During embryonic development the cells of the inner cell mass continuously divide and become more specialized. For example, a portion of the ectoderm in the dorsal part of the embryo specializes as 'neurectoderm', which will become the future central nervous system.[22] Later in development, neurulation causes the neurectoderm to form the neural tube. At the neural tube stage, the anterior portion undergoes encephalization to generate or 'pattern' the basic form of the brain. At this stage of development, the principal cell type of the CNS is considered a neural stem cell.

The neural stem cells self-renew and at some point transition into radial glial progenitor cells (RGPs). Early-formed RGPs self-renew by symmetrical division to form a reservoir group of progenitor cells. These cells transition to a neurogenic state and start to divide asymmetrically to produce a large diversity of many different neuron types, each with unique gene expression, morphological, and functional characteristics. The process of generating neurons from radial glial cells is called neurogenesis. The radial glial cell, has a distinctive bipolar morphology with highly elongated processes spanning the thickness of the neural tube wall. It shares some glial characteristics, most notably the expression of glial fibrillary acidic protein (GFAP).[23][24] The radial glial cell is the primary neural stem cell of the developing vertebrate CNS, and its cell body resides in the ventricular zone, adjacent to the developing ventricular system. Neural stem cells are committed to the neuronal lineages (neurons, astrocytes, and oligodendrocytes), and thus their potency is restricted.[22]

Nearly all research to date has made use of mouse embryonic stem cells (mES) or human embryonic stem cells (hES) derived from the early inner cell mass. Both have the essential stem cell characteristics, yet they require very different environments in order to maintain an undifferentiated state. Mouse ES cells are grown on a layer of gelatin as an extracellular matrix (for support) and require the presence of leukemia inhibitory factor (LIF) in serum media. A drug cocktail containing inhibitors to GSK3B and the MAPK/ERK pathway, called 2i, has also been shown to maintain pluripotency in stem cell culture.[25] Human ESCs are grown on a feeder layer of mouse embryonic fibroblasts and require the presence of basic fibroblast growth factor (bFGF or FGF-2).[26] Without optimal culture conditions or genetic manipulation,[27] embryonic stem cells will rapidly differentiate.

A human embryonic stem cell is also defined by the expression of several transcription factors and cell surface proteins. The transcription factors Oct-4, Nanog, and Sox2 form the core regulatory network that ensures the suppression of genes that lead to differentiation and the maintenance of pluripotency.[28] The cell surface antigens most commonly used to identify hES cells are the glycolipids stage specific embryonic antigen 3 and 4, and the keratan sulfate antigens Tra-1-60 and Tra-1-81. The molecular definition of a stem cell includes many more proteins and continues to be a topic of research.[29]

By using human embryonic stem cells to produce specialized cells like nerve cells or heart cells in the lab, scientists can gain access to adult human cells without taking tissue from patients. They can then study these specialized adult cells in detail to try to discern complications of diseases, or to study cell reactions to proposed new drugs.

Because of their combined abilities of unlimited expansion and pluripotency, embryonic stem cells remain a theoretically potential source for regenerative medicine and tissue replacement after injury or disease.,[30] however, there are currently no approved treatments using ES cells. The first human trial was approved by the US Food and Drug Administration in January 2009.[31] However, the human trial was not initiated until October 13, 2010 in Atlanta for spinal cord injury research. On November 14, 2011 the company conducting the trial (Geron Corporation) announced that it will discontinue further development of its stem cell programs.[32] Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face.[33] Embryonic stem cells, being pluripotent, require specific signals for correct differentiation if injected directly into another body, ES cells will differentiate into many different types of cells, causing a teratoma. Ethical considerations regarding the use of unborn human tissue are another reason for the lack of approved treatments using embryonic stem cells. Many nations currently have moratoria or limitations on either human ES cell research or the production of new human ES cell lines.

Mesenchymal stem cells (MSC) or mesenchymal stromal cells, also known as medicinal signaling cells are known to be multipotent, which can be found in adult tissues, for example, in the muscle, liver, bone marrow and adipose tissue. Mesenchymal stem cells usually function as structural support in various organs as mentioned above, and control the movement of substances. MSC can differentiate into numerous cell categories as an illustration of adipocytes, osteocytes, and chondrocytes, derived by the mesodermal layer.[34] Where the mesoderm layer provides an increase to the body's skeletal elements, such as relating to the cartilage or bone. The term "meso" means middle, infusion originated from the Greek, signifying that mesenchymal cells are able to range and travel in early embryonic growth among the ectodermal and endodermal layers. This mechanism helps with space-filling thus, key for repairing wounds in adult organisms that have to do with mesenchymal cells in the dermis (skin), bone, or muscle.[35]

Mesenchymal stem cells are known to be essential for regenerative medicine. They are broadly studied in clinical trials. Since they are easily isolated and obtain high yield, high plasticity, which makes able to facilitate inflammation and encourage cell growth, cell differentiation, and restoring tissue derived from immunomodulation and immunosuppression. MSC comes from the bone marrow, which requires an aggressive procedure when it comes to isolating the quantity and quality of the isolated cell, and it varies by how old the donor. When comparing the rates of MSC in the bone marrow aspirates and bone marrow stroma, the aspirates tend to have lower rates of MSC than the stroma. MSC are known to be heterogeneous, and they express a high level of pluripotent markers when compared to other types of stem cells, such as embryonic stem cells.[34] MSCs injection leads to wound healing primarily through stimulation of angiogenesis.[36]

Embryonic stem cells (ESCs) have the ability to divide indefinitely while keeping their pluripotency, which is made possible through specialized mechanisms of cell cycle control.[37] Compared to proliferating somatic cells, ESCs have unique cell cycle characteristicssuch as rapid cell division caused by shortened G1 phase, absent G0 phase, and modifications in cell cycle checkpointswhich leaves the cells mostly in S phase at any given time.[37][38] ESCs' rapid division is demonstrated by their short doubling time, which ranges from 8 to 10 hours, whereas somatic cells have doubling time of approximately 20 hours or longer.[39] As cells differentiate, these properties change: G1 and G2 phases lengthen, leading to longer cell division cycles. This suggests that a specific cell cycle structure may contribute to the establishment of pluripotency.[37]

Particularly because G1 phase is the phase in which cells have increased sensitivity to differentiation, shortened G1 is one of the key characteristics of ESCs and plays an important role in maintaining undifferentiated phenotype. Although the exact molecular mechanism remains only partially understood, several studies have shown insight on how ESCs progress through G1and potentially other phasesso rapidly.[38]

The cell cycle is regulated by complex network of cyclins, cyclin-dependent kinases (Cdk), cyclin-dependent kinase inhibitors (Cdkn), pocket proteins of the retinoblastoma (Rb) family, and other accessory factors.[39] Foundational insight into the distinctive regulation of ESC cell cycle was gained by studies on mouse ESCs (mESCs).[38] mESCs showed a cell cycle with highly abbreviated G1 phase, which enabled cells to rapidly alternate between M phase and S phase. In a somatic cell cycle, oscillatory activity of Cyclin-Cdk complexes is observed in sequential action, which controls crucial regulators of the cell cycle to induce unidirectional transitions between phases: Cyclin D and Cdk4/6 are active in the G1 phase, while Cyclin E and Cdk2 are active during the late G1 phase and S phase; and Cyclin A and Cdk2 are active in the S phase and G2, while Cyclin B and Cdk1 are active in G2 and M phase.[39] However, in mESCs, this typically ordered and oscillatory activity of Cyclin-Cdk complexes is absent. Rather, the Cyclin E/Cdk2 complex is constitutively active throughout the cycle, keeping retinoblastoma protein (pRb) hyperphosphorylated and thus inactive. This allows for direct transition from M phase to the late G1 phase, leading to absence of D-type cyclins and therefore a shortened G1 phase.[38] Cdk2 activity is crucial for both cell cycle regulation and cell-fate decisions in mESCs; downregulation of Cdk2 activity prolongs G1 phase progression, establishes a somatic cell-like cell cycle, and induces expression of differentiation markers.[40]

In human ESCs (hESCs), the duration of G1 is dramatically shortened. This has been attributed to high mRNA levels of G1-related Cyclin D2 and Cdk4 genes and low levels of cell cycle regulatory proteins that inhibit cell cycle progression at G1, such as p21CipP1, p27Kip1, and p57Kip2.[37][41] Furthermore, regulators of Cdk4 and Cdk6 activity, such as members of the Ink family of inhibitors (p15, p16, p18, and p19), are expressed at low levels or not at all. Thus, similar to mESCs, hESCs show high Cdk activity, with Cdk2 exhibiting the highest kinase activity. Also similar to mESCs, hESCs demonstrate the importance of Cdk2 in G1 phase regulation by showing that G1 to S transition is delayed when Cdk2 activity is inhibited and G1 is arrest when Cdk2 is knocked down.[37] However unlike mESCs, hESCs have a functional G1 phase. hESCs show that the activities of Cyclin E/Cdk2 and Cyclin A/Cdk2 complexes are cell cycle-dependent and the Rb checkpoint in G1 is functional.[39]

ESCs are also characterized by G1 checkpoint non-functionality, even though the G1 checkpoint is crucial for maintaining genomic stability. In response to DNA damage, ESCs do not stop in G1 to repair DNA damages but instead, depend on S and G2/M checkpoints or undergo apoptosis. The absence of G1 checkpoint in ESCs allows for the removal of cells with damaged DNA, hence avoiding potential mutations from inaccurate DNA repair.[37] Consistent with this idea, ESCs are hypersensitive to DNA damage to minimize mutations passed onto the next generation.[39]

The primitive stem cells located in the organs of fetuses are referred to as fetal stem cells.[42]

There are two types of fetal stem cells:

Adult stem cells, also called somatic (from Greek , "of the body") stem cells, are stem cells which maintain and repair the tissue in which they are found.[44] They can be found in children, as well as adults.[45]

There are three known accessible sources of autologous adult stem cells in humans:

Stem cells can also be taken from umbilical cord blood just after birth. Of all stem cell types, autologous harvesting involves the least risk. By definition, autologous cells are obtained from one's own body, just as one may bank their own blood for elective surgical procedures.[citation needed]

Pluripotent adult stem cells are rare and generally small in number, but they can be found in umbilical cord blood and other tissues.[49] Bone marrow is a rich source of adult stem cells,[50] which have been used in treating several conditions including liver cirrhosis,[51] chronic limb ischemia[52] and endstage heart failure.[53] The quantity of bone marrow stem cells declines with age and is greater in males than females during reproductive years.[54] Much adult stem cell research to date has aimed to characterize their potency and self-renewal capabilities.[55] DNA damage accumulates with age in both stem cells and the cells that comprise the stem cell environment. This accumulation is considered to be responsible, at least in part, for increasing stem cell dysfunction with aging (see DNA damage theory of aging).[56]

Most adult stem cells are lineage-restricted (multipotent) and are generally referred to by their tissue origin (mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, dental pulp stem cell, etc.).[57][58] Muse cells (multi-lineage differentiating stress enduring cells) are a recently discovered pluripotent stem cell type found in multiple adult tissues, including adipose, dermal fibroblasts, and bone marrow. While rare, muse cells are identifiable by their expression of SSEA-3, a marker for undifferentiated stem cells, and general mesenchymal stem cells markers such as CD90, CD105. When subjected to single cell suspension culture, the cells will generate clusters that are similar to embryoid bodies in morphology as well as gene expression, including canonical pluripotency markers Oct4, Sox2, and Nanog.[59]

Adult stem cell treatments have been successfully used for many years to treat leukemia and related bone/blood cancers through bone marrow transplants.[60] Adult stem cells are also used in veterinary medicine to treat tendon and ligament injuries in horses.[61]

The use of adult stem cells in research and therapy is not as controversial as the use of embryonic stem cells, because the production of adult stem cells does not require the destruction of an embryo. Additionally, in instances where adult stem cells are obtained from the intended recipient (an autograft), the risk of rejection is essentially non-existent. Consequently, more US government funding is being provided for adult stem cell research.[62]

With the increasing demand of human adult stem cells for both research and clinical purposes (typically 15 million cells per kg of body weight are required per treatment) it becomes of utmost importance to bridge the gap between the need to expand the cells in vitro and the capability of harnessing the factors underlying replicative senescence. Adult stem cells are known to have a limited lifespan in vitro and to enter replicative senescence almost undetectably upon starting in vitro culturing.[63]

Hematopoietic stem cells (HSCs) are vulnerable to DNA damage and mutations that increase with age.[64] This vulnerability may explain the increased risk of slow growing blood cancers (myeloid malignancies) in the elderly.[64] Several factors appear to influence HSC aging including responses to the production of reactive oxygen species that may cause DNA damage and genetic mutations as well as altered epigenetic profiling.[65]

Also called perinatal stem cells, these multipotent stem cells are found in amniotic fluid and umbilical cord blood. These stem cells are very active, expand extensively without feeders and are not tumorigenic. Amniotic stem cells are multipotent and can differentiate in cells of adipogenic, osteogenic, myogenic, endothelial, hepatic and also neuronal lines.[66] Amniotic stem cells are a topic of active research.

Use of stem cells from amniotic fluid overcomes the ethical objections to using human embryos as a source of cells. Roman Catholic teaching forbids the use of embryonic stem cells in experimentation; accordingly, the Vatican newspaper "Osservatore Romano" called amniotic stem cells "the future of medicine".[67]

It is possible to collect amniotic stem cells for donors or for autologous use: the first US amniotic stem cells bank[68][69] was opened in 2009 in Medford, MA, by Biocell Center Corporation[70][71][72] and collaborates with various hospitals and universities all over the world.[73]

Adult stem cells have limitations with their potency; unlike embryonic stem cells (ESCs), they are not able to differentiate into cells from all three germ layers. As such, they are deemed multipotent.

However, reprogramming allows for the creation of pluripotent cells, induced pluripotent stem cells (iPSCs), from adult cells. These are not adult stem cells, but somatic cells (e.g. epithelial cells) reprogrammed to give rise to cells with pluripotent capabilities. Using genetic reprogramming with protein transcription factors, pluripotent stem cells with ESC-like capabilities have been derived.[74][75][76] The first demonstration of induced pluripotent stem cells was conducted by Shinya Yamanaka and his colleagues at Kyoto University.[77] They used the transcription factors Oct3/4, Sox2, c-Myc, and Klf4 to reprogram mouse fibroblast cells into pluripotent cells.[74][78] Subsequent work used these factors to induce pluripotency in human fibroblast cells.[79] Junying Yu, James Thomson, and their colleagues at the University of WisconsinMadison used a different set of factors, Oct4, Sox2, Nanog and Lin28, and carried out their experiments using cells from human foreskin.[74][80] However, they were able to replicate Yamanaka's finding that inducing pluripotency in human cells was possible.

Induced pluripotent stem cells differ from embryonic stem cells. They share many similar properties, such as pluripotency and differentiation potential, the expression of pluripotency genes, epigenetic patterns, embryoid body and teratoma formation, and viable chimera formation,[77][78] but there are many differences within these properties. The chromatin of iPSCs appears to be more "closed" or methylated than that of ESCs.[77][78] Similarly, the gene expression pattern between ESCs and iPSCs, or even iPSCs sourced from different origins.[77] There are thus questions about the "completeness" of reprogramming and the somatic memory of induced pluripotent stem cells. Despite this, inducing somatic cells to be pluripotent appears to be viable.

As a result of the success of these experiments, Ian Wilmut, who helped create the first cloned animal Dolly the Sheep, has announced that he will abandon somatic cell nuclear transfer as an avenue of research.[81]

IPSCs has helped the field of medicine significantly by finding numerous ways to cure diseases. Since human IPSCc has given the advantage to make in vitro models to study toxins and pathogenesis.[82]

Furthermore, induced pluripotent stem cells provide several therapeutic advantages. Like ESCs, they are pluripotent. They thus have great differentiation potential; theoretically, they could produce any cell within the human body (if reprogramming to pluripotency was "complete").[77] Moreover, unlike ESCs, they potentially could allow doctors to create a pluripotent stem cell line for each individual patient.[83] Frozen blood samples can be used as a valuable source of induced pluripotent stem cells.[84] Patient specific stem cells allow for the screening for side effects before drug treatment, as well as the reduced risk of transplantation rejection.[83] Despite their current limited use therapeutically, iPSCs hold great potential for future use in medical treatment and research.

The key factors controlling the cell cycle also regulate pluripotency. Thus, manipulation of relevant genes can maintain pluripotency and reprogram somatic cells to an induced pluripotent state.[39] However, reprogramming of somatic cells is often low in efficiency and considered stochastic.[85]

With the idea that a more rapid cell cycle is a key component of pluripotency, reprogramming efficiency can be improved. Methods for improving pluripotency through manipulation of cell cycle regulators include: overexpression of Cyclin D/Cdk4, phosphorylation of Sox2 at S39 and S253, overexpression of Cyclin A and Cyclin E, knockdown of Rb, and knockdown of members of the Cip/Kip family or the Ink family.[39] Furthermore, reprogramming efficiency is correlated with the number of cell divisions happened during the stochastic phase, which is suggested by the growing inefficiency of reprogramming of older or slow diving cells.[86]

Lineage is an important procedure to analyze developing embryos. Since cell lineages shows the relationship between cells at each division. This helps in analyzing stem cell lineages along the way which helps recognize stem cell effectiveness, lifespan, and other factors. With the technique of cell lineage mutant genes can be analyzed in stem cell clones that can help in genetic pathways. These pathways can regulate how the stem cell perform.[87]

To ensure self-renewal, stem cells undergo two types of cell division (see Stem cell division and differentiation diagram). Symmetric division gives rise to two identical daughter cells both endowed with stem cell properties. Asymmetric division, on the other hand, produces only one stem cell and a progenitor cell with limited self-renewal potential. Progenitors can go through several rounds of cell division before terminally differentiating into a mature cell. It is possible that the molecular distinction between symmetric and asymmetric divisions lies in differential segregation of cell membrane proteins (such as receptors) between the daughter cells.[88]

An alternative theory is that stem cells remain undifferentiated due to environmental cues in their particular niche. Stem cells differentiate when they leave that niche or no longer receive those signals. Studies in Drosophila germarium have identified the signals decapentaplegic and adherens junctions that prevent germarium stem cells from differentiating.[89][90]

In the United States, Executive Order 13505 established that federal money can be used for research in which approved human embryonic stem-cell (hESC) lines are used, but it cannot be used to derive new lines.[91] The National Institutes of Health (NIH) Guidelines on Human Stem Cell Research, effective July 7, 2009, implemented the Executive Order 13505 by establishing criteria which hESC lines must meet to be approved for funding.[92] The NIH Human Embryonic Stem Cell Registry can be accessed online and has updated information on cell lines eligible for NIH funding.[93] There are 486 approved lines as of January 2022.[94]

Stem cell therapy is the use of stem cells to treat or prevent a disease or condition. Bone marrow transplant is a form of stem cell therapy that has been used for many years because it has proven to be effective in clinical trials.[95][96] Stem cell implantation may help in strengthening the left-ventricle of the heart, as well as retaining the heart tissue to patients who have suffered from heart attacks in the past.[97]

For over 90 years, hematopoietic stem cell transplantation (HSCT) has been used to treat people with conditions such as leukaemia and lymphoma; this is the only widely practiced form of stem-cell therapy.[98][99][100] As of 2016[update], the only established therapy using stem cells is hematopoietic stem cell transplantation.[101] This usually takes the form of a bone-marrow transplantation, but the cells can also be derived from umbilical cord blood. Research is underway to develop various sources for stem cells as well as to apply stem-cell treatments for neurodegenerative diseases[102][103][104] and conditions such as diabetes and heart disease.

Stem cell treatments may lower symptoms of the disease or condition that is being treated. The lowering of symptoms may allow patients to reduce the drug intake of the disease or condition. Stem cell treatment may also provide knowledge for society to further stem cell understanding and future treatments.[105] The physicians' creed would be to do no injury, and stem cells make that simpler than ever before. Surgical processes by their character are harmful. Tissue has to be dropped as a way to reach a successful outcome. One may prevent the dangers of surgical interventions using stem cells. Additionally, there's a possibility of disease, and whether the procedure fails, further surgery may be required. Risks associated with anesthesia can also be eliminated with stem cells.[106] On top of that, stem cells have been harvested from the patient's body and redeployed in which they're wanted. Since they come from the patient's own body, this is referred to as an autologous treatment. Autologous remedies are thought to be the safest because there's likely zero probability of donor substance rejection.

Stem cell treatments may require immunosuppression because of a requirement for radiation before the transplant to remove the person's previous cells, or because the patient's immune system may target the stem cells. One approach to avoid the second possibility is to use stem cells from the same patient who is being treated.

Pluripotency in certain stem cells could also make it difficult to obtain a specific cell type. It is also difficult to obtain the exact cell type needed, because not all cells in a population differentiate uniformly. Undifferentiated cells can create tissues other than desired types.[107]

Some stem cells form tumors after transplantation;[108] pluripotency is linked to tumor formation especially in embryonic stem cells, fetal proper stem cells, induced pluripotent stem cells. Fetal proper stem cells form tumors despite multipotency.[109]

Ethical concerns are also raised about the practice of using or researching embryonic stem cells. Harvesting cells from the blastocyst result in the death of the blastocyst. The concern is whether or not the blastocyst should be considered as a human life.[110] The debate on this issue is mainly a philosophical one, not a scientific one.

Stem cell tourism is the part of the medical tourism industry in which patients travel to obtain stem cell procedures.[111]

The United States has had an explosion of "stem cell clinics".[112] Stem cell procedures are highly profitable for clinics. The advertising sounds authoritative but the efficacy and safety of the procedures is unproven. Patients sometimes experience complications, such as spinal tumors[113] and death. The high expense can also lead to financial problems.[113] According to researchers, there is a need to educate the public, patients, and doctors about this issue.[114]

According to the International Society for Stem Cell Research, the largest academic organization that advocates for stem cell research, stem cell therapies are under development and cannot yet be said to be proven.[115][116] Doctors should inform patients that clinical trials continue to investigate whether these therapies are safe and effective but that unethical clinics present them as proven.[117]

Some of the fundamental patents covering human embryonic stem cells are owned by the Wisconsin Alumni Research Foundation (WARF) they are patents 5,843,780, 6,200,806, and 7,029,913 invented by James A. Thomson. WARF does not enforce these patents against academic scientists, but does enforce them against companies.[118]

In 2006, a request for the US Patent and Trademark Office (USPTO) to re-examine the three patents was filed by the Public Patent Foundation on behalf of its client, the non-profit patent-watchdog group Consumer Watchdog (formerly the Foundation for Taxpayer and Consumer Rights).[118] In the re-examination process, which involves several rounds of discussion between the USPTO and the parties, the USPTO initially agreed with Consumer Watchdog and rejected all the claims in all three patents,[119] however in response, WARF amended the claims of all three patents to make them more narrow, and in 2008 the USPTO found the amended claims in all three patents to be patentable. The decision on one of the patents (7,029,913) was appealable, while the decisions on the other two were not.[120][121] Consumer Watchdog appealed the granting of the '913 patent to the USPTO's Board of Patent Appeals and Interferences (BPAI) which granted the appeal, and in 2010 the BPAI decided that the amended claims of the '913 patent were not patentable.[122] However, WARF was able to re-open prosecution of the case and did so, amending the claims of the '913 patent again to make them more narrow, and in January 2013 the amended claims were allowed.[123]

In July 2013, Consumer Watchdog announced that it would appeal the decision to allow the claims of the '913 patent to the US Court of Appeals for the Federal Circuit (CAFC), the federal appeals court that hears patent cases.[124] At a hearing in December 2013, the CAFC raised the question of whether Consumer Watchdog had legal standing to appeal; the case could not proceed until that issue was resolved.[125]

Diseases and conditions where stem cell treatment is being investigated include:

Research is underway to develop various sources for stem cells, and to apply stem cell treatments for neurodegenerative diseases and conditions, diabetes, heart disease, and other conditions.[146] Research is also underway in generating organoids using stem cells, which would allow for further understanding of human development, organogenesis, and modeling of human diseases.[147]

In more recent years, with the ability of scientists to isolate and culture embryonic stem cells, and with scientists' growing ability to create stem cells using somatic cell nuclear transfer and techniques to create induced pluripotent stem cells, controversy has crept in, both related to abortion politics and to human cloning.

Hepatotoxicity and drug-induced liver injury account for a substantial number of failures of new drugs in development and market withdrawal, highlighting the need for screening assays such as stem cell-derived hepatocyte-like cells, that are capable of detecting toxicity early in the drug development process.[148]

In August 2021, researchers in the Princess Margaret Cancer Centre at the University Health Network published their discovery of a dormancy mechanism in key stem cells which could help develop cancer treatments in the future.[149]

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A Look Inside Stem Cells Helps Create Personalized Regenerative …

Posted: May 17, 2023 at 12:12 am

In two papers, researchers examined a specific type of stem cell with an intracellular toolkit to determine which cells are most likely to create effective cell therapies.

Nicholas Zhang, Georgia Tech Ph.D. candidate 

Organelles the bits and pieces of RNA and protein within a cell play important roles in human health and disease, such as maintaining homeostasis, regulating growth and aging, and generating energy. Organelle diversity in cells not only exists between cell types but also individual cells. Studying these differences helps researchers better understand cell function, leading to improved therapeutics to treat various diseases.

In two papers out of the lab of Ahmet F. Coskun, a Bernie Marcus Early Career professor in the Coulter Department of Biomedical Engineering at the Georgia Institute of Technology and Emory University, researchers examined a specific type of stem cell with an intracellular toolkit to determine which cells are most likely to create effective cell therapies.

We are studying the placement of organelles within cells and how they communicate to help better treat disease, said Coskun. Our recent work proposes the use of an intracellular toolkit to map organelle bio-geography in stem cells that could lead to more precise therapies.

Creating the Subcellular Omics Toolkit

The first study published in Scientific Reports, a Nature portfolio journal looked at mesenchymal stem cells (MSCs) that have historically offered promising treatments for repairing defective cells or modulating the immune response in patients. In a series of experiments, the researchers were able to create a data-driven, single-cell approach through rapid subcellular proteomic imaging that enabled personalized stem cell therapeutics.

The researchers then implemented a rapid multiplexed immunofluorescence technique in which they used antibodies designed to target specific organelles. By fluorescing antibodies, they tracked wavelengths and signals to compile images of many different cells, creating maps. These maps then enabled researchers to see the spatial organization of organelle contacts and geographical spread in similar cells to determine which cell types would best treat various diseases.

Usually, the stem cells are used to repair defective cells or treat immune diseases, but our micro-study of these specific cells showed just how different they can be from one another, said Coskun. This proved that patient treatment population and customized isolation of the stem cells identities and their bioenergetic organelle function should be considered when selecting the tissue source. In other words, in treating a specific disease, it might be better to harvest the same type of cell from different locations depending on the patients needs.

RNA-RNA Proximity Matters

In the next study published this week in Cell Reports Methods, the researchers took the toolkit a step further, studying the spatial organization of multiple neighboring RNA molecules in single cells, which are important to cellular function. The researchers evolved the tool by combining machine learning and spatial transcriptomics. They found that analyzing the variations of gene proximity for classification of cell types was more accurate that analyzing gene expression only.

The physical interactions between molecules create life; therefore, the physical locations and proximity of these molecules play important roles, said Coskun. We created an intracellular toolkit of subcellular gene neighborhood networks in each cell's different geographical parts to take a closer look at this.

The experiment consisted of two parts: the development of computational methods and experiments at the lab bench. The researchers examined published datasets and an algorithm to group RNA molecules based on their physical location. This nearest neighbor algorithm helped determine gene groupings. On the bench, researchers then labeled RNA molecules with fluorescents to easily locate them in single cells. They then uncovered many features from the distribution of RNA molecules, such as how genes are likely to be in similar subcellular locations.

Cell therapy requires many cells with highly similar phenotypes, and if there are subtypes of unknown cells in therapeutic cells, researchers cannot predict the behavior of these cells once injected into patients. With these tools, more cells of the same type can be identified, and distinct stem cell subsets with uncommon gene programs can be isolated.

We are expanding the toolkit for the subcellular spatial organization of molecules a Swiss Army Knife for the subcellular spatial omics field, if you will, said Coskun. The goal is to measure, quantify, and model multiple independent but also interrelated molecular events in each cell with multiple functionalities. The end purpose is to define a cells function that can achieve high energy, Lego-like modular gene neighborhood networks and diverse cellular decisions.

This research is funded by Regenerative Engineering and Medicine at Georgia Tech, as well as the NSF Engineering Research Center for Cell Manufacturing Technologies (CMaT).

CITATION: Venkatesan, M., Zhang, N., Marteau, B., Yajima, Y., Ortiz De Zarate Garcia, N., Fang, Z., Hu, T., Cai, S., Ford, A. Olszewski, H., Borst, A., and Coskun, A. F. Spatial subcellular organelle networks in single cells.Scientific Reports13, 5374 (2023). doi.org/10.1038/s41598-023-32474-y

CITATION: Fang, Z., Ford, A., Hu, T., Zhang, N., Mantalaris, A., Coskun, A.F. Subcellular spatially resolved gene neighborhood networks in single cells. Cell Reports Methods. May 12, 2023. doi.org/10.1016/j.crmeth.2023.100476

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Heart disease study shows hope for stem cell treatment

Posted: March 4, 2023 at 12:10 am

Researchers have tried for decades to use stem cells to restore a damaged heart.

A new study shows they still haven't succeeded, but it offers the first glimmers of hope for heartdisease, whichis blamed for about 1 in 5 deaths in the United States, killingnearly 700,000 people a year.

The trial, by the Texas Heart Institute, showed that a one-time treatment of cells didn't keep heart failurepatients out of the hospital. But it dramatically reduced the risk of stroke or recurrent heart attack for the nearly three years of the study, particularly among people who also had high levels of inflammation.

"At a year, the hearts were pumping stronger," said Dr. Emerson Perin, who led the research.

While he will have to conduct another clinical trial before winning approval for his approach, he has a path forward, Perin said.

"I now have the recipe," he said. "I know who I have to give (the cells) to, how I have to give them and in what dose."

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Stem cells are cellsthat can turn into a variety of other cells.

Every person arises from the combination of an egg and a sperm. Once fused, this combination of cells divides repeatedly, leadingto every other cell in the body, from brain to gut cells.

Early cells with the ability to become every other cell are called "embryonic stem cells."

The human bodyalso produces stem cells later in development that are less versatile than embryonic ones, but still may be useful in medicine. So-called mesenchymal stem cells can turn intobone, cartilage, muscle and fat.

In this study, researchers used precursor mesenchymal stem cells taken from three young, adult donorswithout heart disease. The goal was to alter the environment around the patients'hearts to decrease inflammation.

In the study of 565 heart failure patients from 52 treatment centers, half were given high doses of these mesenchymal stem cells and the other half a sham procedure.

The study was designed to measure hospitalization and time until death, neither of which were statistically improved by the treatment.

But those who received the cells had a 58% reduced risk of heart attack or stroke, and among patients with high levels of inflammation the risk reduction rose to 75%.

These patients were already heavily treated with medication, so the improvements came on top of those therapies.

For years, Perin said, he's been seeing patients with heart failure get better when he gave them mesenchymal stem cells.

"Until now we didn't know why," Perin said. "Cell therapy has been this black hole. ... We now have insights into how it works."

Dr. Richard Lee, a stem cell biologist at Harvard University, said he found the study usefulbut thinks this type of stem cell has a long way to go to becomea treatment for heart failure.

Drugs already available to treat heart failure are underused, he said, and doctors shouldn't wait around for newer therapies. "We should be doing better now," Leesaid.

Despite these other therapies, heart failure continues to be a major problem for patients, saidDr. Roberto Bolli, who holds the distinguished chair in cardiology at the Jewish Hospital Heart and Lung Institute in Louisville, Kentucky.

"We can improve the symptoms of these patients, but still, their long-term outcome is not good. They will inexorably get worse and worse over time," said Bolli, who was not involved in the new research.

Also, the new study showed that the treatment was safe. None of the patients in this trial or in others over the years have suffered serious problems after receiving stem cells for heart disease.

This is first large study of stem cell therapy in heart disease to show an improvement for patients, Bolli said."That's very significant."

Four other smaller trialshave also shown promise in heart failure, including one he led, co-authored by Perin.

"I would say cell therapy is a promising treatment for chronic heart failure," Bolli said.

Researchers have been working for decades to get stem cells to benefit heart disease patients.

Dr. Joshua Hare, a cardiologist at the University of Miami who does stem cell research but was not involved in the current study, said he thinks the field would have moved faster if it had been better funded.

He hopes the new finding, though technically a failure, will encourage more investment.

Stem cell clinics, which "steal people's money" for procedures that don't help cardiac patients, havealso created problems for the field, said Dr. Timothy Henry, a cardiologist and director of the Lindner Center at Christ Hospital inCincinnati, Ohio.

Bolli said research has been so slow in partbecause itfocused for 15 years on treating patients after heart attacks, hoping the cells would rebuild a damaged heart when given within a few days. At least 10 trials have shown that doesn't work.

Instead,the new trialand the four smaller ones suggest that stem cells are best at helping patients with long-standingheart failure, by reducing inflammation around the heart, which continues to damage its function.

Bolli said the new findings strongly suggest the need for a follow-up study concentrating on patients who also have inflammation. (Henry, who was on the steering committee for the new study, said he is optimistic thatMesoblast, the Australian company that funded the trial, will go forward with another study.)

"If that trial confirms these results, that will be a major advance in cardiovascular medicine," Bolli said. "We don't know of any other treatment that does that."

Contact Karen Weintraub at kweintraub@usatoday.com.

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.

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Focus On Stem Cell Research | National Institute of Neurological …

Posted: March 4, 2023 at 12:10 am

Stem cells possess the unique ability to differentiate into many distinct cell types in the body, including brain cells, but they also retain the ability to produce more stem cells, a process termed self-renewal. There are multiple types of stem cell, such as embryonic stem (ES) cells, induced pluripotent stem (iPS) cells, and adult or somatic stem cells. While various types of stem cells share similar properties there are differences as well. For example, ES cells and iPS cells are able to differentiate into any type of cell, whereas adult stem cells are more restricted in their potential. The promise of all stem cells for use in future therapies is exciting, but significant technical hurdles remain that will only be overcome through years of intensive research.

NINDS supports a diverse array of research on stem cells, from studies of the basic biology of stem cells in the developing and adult mammalian brain, to studies focusing on nervous system disorders such as ALS or spinal cord injury. Other examples of NINDS funded research include using iPS cells to derive dopamine-producing neurons that might alleviate symptoms in patients with Parkinsons disease, and using ES cells to generate cerebral organoids to model Zika virus infection.

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Stem Cell Research: Argumentative Essay – Free Essay Example – Edubirdie

Posted: March 4, 2023 at 12:10 am

What if there was a chance of curing degenerative diseases such as Parkinsons and Alzheimers? Everyone should be in favor of ending the suffering of the thousands of people who have these diseases and their families that have to be brought in by such a curse. These diseases and a surplus more can be cured with the potential results of stem cell research. Embryotic stem cells are undifferentiated cells in the womb. The factor of being undifferentiated is crucial to embryotic, and in disease cures, tissue development. Through each stage of fetal development, the embryo will have its stem cells differentiated into different cells. Examples will include muscle, neural, intestinal, cardiac, liver, and blood cells. Research using these undifferentiated cells requires the destruction of an embryo, making the practice an immoral undertone. Some will argue that the embryos in the womb do not deserve disrespect, based on the idea of not harming any form of life. While the other side, in favor of stem cell research, will overlook such unethicality for the benefit of future cures that could save many other out-of-womb lives. Nations around the world should fund stem cell research due to the possible cures in the future.

Stem cells are our baseline for development in the womb and can build 260 different kinds of cells in the human body. Sadly, this research involves using and destroying embryos and possible lives, to save lives and make them easier. Using embryonic cells can result in negative outcomes, and has been greatly associated with causing brain tumors and cancer. In addition to governmental reinforcements, many limitations, including immune rejection which can cause death and tumor possibility, are factors that convince the public that the research should not be advanced. Others can see this research as playing god. As described by Peter Lachmann, playing god carries with it the proposition that there is knowledge that may be too dangerous for the mankind to know (2). Later in his work, Lachmann digs up an ancient code of conduct still used today, the Hippocratic oath. The Hippocratic oath swears that by your own hands every Ph.D. shall not knowingly cause harm to another life. Reaching back to morals, the scientists and doctors involved are breaking the Hippocratic oath, by tearing apart the fetuses in the womb, whether natural or lab-made.

On the other hand, the scientists who see eye-to-eye with stem cell research are currently restricted by the amount of federal funding and embryonic cells available for research. The reason for this is the fact that everyone sees that any products and medication put forth from this medical boom would be far too expensive. Some scientists worry that if strict regulations of stem cell research continue, private companies may bypass the standards put in place by the National Institute of Health and conduct unregulated research. If the United States wishes to remain a premiere country in biomedical research and maintain order and control of embryonic research being performed, action must be taken to address this issue.

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Barack Obama says that we have been given the capacity and will to pursue this research and the humanity and conscience to do so responsibly. Governments around the globe have passed legislation to regulate stem cell research. In the United States, laws prohibit the creation of embryos for research purposes. Scientists instead receive leftover embryos from fertility clinics with consent from donors. Most people agree that these guidelines are appropriate. Disagreements surface, however, when political parties debate about how to fund stem cell research. The federal government allocates billions of dollars each year to biomedical research. Legislators have had the unique challenge of encouraging advances in science and medicine while preserving respect for life. U.S. President Bush, for example, limited federal funding to a study of 70 or so hES cell lines back in 2001. While this did slow the destruction of human embryos, many believe the restrictions set back the progress of stem cell research. President Obama overturned Bushs stem cell policy in 2009 to expand the number of stem cell lines available to researchers.

Despite the moral issues, these cells show an overpoweringly higher possibility to heal illness. Embryonic stem cell study contributes drastically to the systematic grasp of stem cells. An imperative factor in stem cell therapy treatments is the ability to use the patients own stem cells to generate the most effective medical therapies. Such therapies will not be redundant to the bodys immune mechanism. New therapies employing adult stem cells like those initiated in bone marrow and teeth are important for medicinal research. Pro research advancement researchers hope that by controlling stem cells in the lab, they can be employed to treat Parkinsons disease, heart disease, diabetes, and some disorders (Hug 114). The main clinical supply is the aborted fetus and unexploited embryos presently housed in frozen stores at IVF facilities. An advanced stem cell line originates from a solitary embryo, rotating into a collection of cells that reproduces nonstop. Even if one cannot point to a precise separating line in human growth when personhood is acquired, it may be debated that every time the transition happens, early pre-implantation period embryos do not encompass the physiological, psychological, expressive, or intellectual characteristics that are associated with a persons identity. It, consequently, follows that if the embryo does not accomplish the principle of personhood, it does not contain any happiness to be confined and thus may be employed instrumentally for the advantage of human beings. The supporters of embryonic stem cell advancement argue about the point that it will assist to alleviate some agonies.

Overall, though the destruction of a life is typically seen to be unethical, the moral status of an embryo in the blastocyst stage is unclear and therefore cannot be equated to the moral status of an adult human being. Also, ethical sources of embryonic stem cells exist that do not take the life of future beings (i.e. unwanted frozen embryos produced via in vitro fertilization, donated egg cells fertilized in a laboratory). For these reasons, in combination with the possibility of reducing suffering for future beings, embryonic stem cell research is ethical under certain circumstances. As long as the stem cells are isolated in a manner that does not harm an embryo with the plan of developing into an adult human, the subsequent research is ethically justified. With this in mind, embryonic stem cell research should receive greater government funding so that continued progress can be made.

The debate over embryonic stem cell research is a scientific, moral, and political issue. Embryonic stem cells, hold important value for scientific researchers in search of cures for untreatable diseases, medicine to regenerate an assortment of tissues, or a better understanding of early human development. As a consequence, if they are stopped, many people will keep on suffering from terrible diseases that could be cured. In fact, the throbbing and damaging consequences might be alleviated by technologies and therapies attained from embryonic stem cell studies.

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Automated Cell Culture Systems Market Size to Hit USD 12.43 Billion by 2033; Growing Stem Cell Research & Development and Increasing Prevalence of…

Posted: October 21, 2022 at 2:36 am

Automated Cell Culture Systems Market Size to Hit USD 12.43 Billion by 2033; Growing Stem Cell Research & Development and Increasing Prevalence of Non-Communicable Diseases to Elevate Market Growth Research Nester  GlobeNewswire

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NIH Guidelines for Human Stem Cell Research

Posted: October 13, 2022 at 2:04 am

SUMMARY: The National Institutes of Health (NIH) is hereby publishing final "National Institutes of Health Guidelines for Human Stem Cell Research" (Guidelines).

On March 9, 2009, President Barack H. Obama issued Executive Order 13505: Removing Barriers to Responsible Scientific Research Involving Human Stem Cells. The Executive Order states that the Secretary of Health and Human Services, through the Director of NIH, may support and conduct responsible, scientifically worthy human stem cell research, including human embryonic stem cell (hESC) research, to the extent permitted by law.

These Guidelines implement Executive Order 13505, as it pertains to extramural NIH-funded stem cell research, establish policy and procedures under which the NIH will fund such research, and helps ensure that NIH-funded research in this area is ethically responsible, scientifically worthy, and conducted in accordance with applicable law. Internal NIH policies and procedures, consistent with Executive Order 13505 and these Guidelines, will govern the conduct of intramural NIH stem cell research.

EFFECTIVE DATE: These Guidelines are effective on July 7, 2009.

SUMMARY OF PUBLIC COMMENTS ON DRAFT GUIDELINES: On April 23, 2009 the NIH published draft Guidelines for research involving hESCs in the Federal Register for public comment, 74 Fed. Reg. 18578 (April 23, 2009). The comment period ended on May 26, 2009.

The NIH received approximately 49,000 comments from patient advocacy groups, scientists and scientific societies, academic institutions, medical organizations, religious organizations, and private citizens. The NIH also received comments from members of Congress. This Notice presents the final Guidelines together with the NIH response to public comments that addressed provisions of the Guidelines.

Title of the Guidelines, Terminology, and Background:

Respondents felt the title of the NIH draft guidelines was misleading, in that it is entitled "National Institutes of Health Guidelines for Human Stem Cell Research," yet addresses only one type of human stem cell. The NIH notes that although the Guidelines pertain primarily to the donation of embryos for the derivation of hESCs, one Section also applies to certain uses of both hESCs and human induced pluripotent stem cells. Also, the Guidelines discuss applicable regulatory standards when research involving human adult stem cells or induced pluripotent stem cells constitutes human subject research. Therefore, the title of the Guidelines was not changed.

Respondents also disagreed with the definition of human embryonic stem cells in the draft Guidelines, and asked that the NIH define them as originating from the inner cell mass of the blastocyst. The NIH modified the definition to say that human embryonic stem cells "are cells that are derived from the inner cell mass of blastocyst stage human embryos, are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers."

Financial Gain

Respondents expressed concern that derivers of stem cells might profit from the development of hESCs. Others noted that because the stem cells eligible for use in research using NIH funding under the draft Guidelines are those cells that are subject to existing patents, there will be insufficient competition in the licensing of such rights. These respondents suggested that this could inhibit research, as well as increase the cost of any future clinical benefits. The Guidelines do not address the distribution of stem cell research material. It is, however, the NIH's expectation that stem cell research materials developed with NIH funds, as well as associated intellectual property and data, will be distributed in accordance with the NIHs existing policies and guidance, including "Sharing Biomedical Research Resources, Principles and Guidelines for Recipients of NIH Grants and Contracts" and "Best Practices for the Licensing of Genomic Inventions." http://www.ott.nih.gov/policy/policies_and_guidelines.aspx Even where such policies are not directly applicable, the NIH encourages others to refrain from imposing on the transfer of research tools, such as stem cells, any conditions that hinder further biomedical research. In addition, the Guidelines were revised to state that there should be documentation that "no payments, cash or in kind, were offered for the donated embryos."

Respondents were concerned that donor(s) be clearly "apprised up front by any researchers that financial gain may come from the donation and that the donor(s) should know up front if he/she will share in the financial gain." The Guidelines address this concern by asking that donor(s) was/were informed during the consent process that the donation was made without any restriction or direction regarding the individual(s) who may receive medical benefit from the use of the stem cells, such as who may be the recipients of cell transplants. The Guidelines also require that the donor(s) receive(s) information that the research was not intended to provide direct medical benefit to the donor(s); that the results of research using the hESCs may have commercial potential, and that the donor(s) would not receive financial or any other benefits from any such commercial development.

IRB Review under the Common Rule

Respondents suggested that the current regulatory structure of IRB review under the Common Rule (45 C.F.R. Part 46, Subpart A) addresses the core ethical principles needed for appropriate oversight of hESC derivation. They noted that IRB review includes a full review of the informed consent process, as well as a determination of whether individuals were coerced to participate in the research and whether any undue inducements were offered to secure their participation. These respondents urged the NIH to replace the specific standards to assure voluntary and informed consent in the draft Guidelines with a requirement that hESC research be reviewed and approved by an IRB, in conformance with 45 C.F.R. Part 46, Subpart A, as a prerequisite to NIH funding. Respondents also requested that the NIH create a registry of eligible hESC lines to avoid burdensome and repetitive assurances from multiple funding applicants. The NIH agrees that the IRB system of review under the Common Rule provides a comprehensive framework for the review of the donation of identifiable human biological materials for research. However, in the last several years, guidelines on hESC research have been issued by a number of different organizations and governments, and different practices have arisen around the country and worldwide, resulting in a patchwork of standards. The NIH concluded that employing the IRB review system for the donation of embryos would not ameliorate stated concerns about variations in standards for hESC research and would preclude the establishment of an NIH registry of hESCs eligible for NIH funding, because there would be no NIH approval of particular hESCs. To this end and response to comments, these Guidelines articulate policies and procedures that will allow the NIH to create a Registry. These Guidelines also provide scientists who apply for NIH funding with a specific set of standards reflecting currently recognized ethical principles and practices specific to embryo donation that took place on or after the issuance of the Guidelines, while also establishing procedures for the review of donations that took place before the effective date of the Guidelines.

Federal Funding Eligibility of Human Pluripotent Cells from Other Sources

Respondents suggested that the allowable sources of hESCs potentially available for federal funding be expanded to include hESC lines from embryos created expressly for research purposes, and lines created, or pluripotent cells derived, following parthenogenesis or somatic cell nuclear transfer (SCNT). The Guidelines allow for funding of research using hESCs derived from embryos created using in vitro fertilization (IVF) for reproductive purposes and no longer needed for these purposes, assuming the research has scientific merit and the embryos were donated after proper informed consent was obtained from the donor(s). The Guidelines reflect the broad public support for federal funding of research using hESCs created from such embryos based on wide and diverse debate on the topic in Congress and elsewhere. The use of additional sources of human pluripotent stem cells proposed by the respondents involve complex ethical and scientific issues on which a similar consensus has not emerged. For example, the embryo-like entities created by parthenogenesis and SCNT require women to donate oocytes, a procedure that has health and ethical implications, including the health risk to the donor from the course of hormonal treatments needed to induce oocyte production.

Respondents noted that many embryos undergo Pre-implantation Genetic Diagnosis (PGD). This may result in the identification of chromosomal abnormalities that would make the embryos medically unsuitable for clinical use. In addition, the IVF process may also produce embryos that are not transferred into the uterus of a woman because they are determined to be not appropriate for clinical use. Respondents suggested that hESCs derived from such embryos may be extremely valuable for scientific study, and should be considered embryos that were created for reproductive purposes and were no longer needed for this purpose. The NIH agrees with these comments. As in the draft, the final Guidelines allow for the donation of embryos that have undergone PGD.

Donation and Informed Consent

Respondents commented in numerous ways that the draft Guidelines are too procedurally proscriptive in articulating the elements of appropriate informed consent documentation. This over-reliance on the specific details and format of the informed consent document, respondents argued, coupled with the retroactive application of the Guidelines to embryos already donated for research, would result in a framework that fails to appreciate the full range of factors contributing to the complexity of the informed consent process. For example, respondents pointed to several factors that were precluded from consideration by the proposed Guidelines, such as contextual evidence of the consent process, other established governmental frameworks (representing local and community influences), and the changing standards for informed consent in this area of research over time. Respondents argued that the Guidelines should be revised to allow for a fuller array of factors to be considered in determining whether the underlying ethical principle of voluntary informed consent had been met. In addition to these general issues, many respondents made the specific recommendation that all hESCs derived before the final Guidelines were issued be automatically eligible for Federal funding without further review, especially those eligible under prior Presidential policy, i.e., "grandfathered." The final Guidelines seek to implement the Executive Order by issuing clear guidance to assist this field of science to advance and reach its full potential while ensuring adherence to strict ethical standards. To this end, the NIH is establishing a set of conditions that will maximize ethical oversight, while ensuring that the greatest number of ethically derived hESCs are eligible for federal funding. Specifically, for embryos donated in the U.S. on or after the effective date of the Guidelines, the only way to establish eligibility will be to either use hESCs listed on the NIH Registry, or demonstrate compliance with the specific procedural requirements of the Guidelines by submitting an assurance with supporting information for administrative review by the NIH. Thus, for future embryo donations in the United States, the Guidelines articulate one set of procedural requirements. This responds to concerns regarding the patchwork of requirements and guidelines that currently exist.

However, the NIH is also cognizant that in the more than a decade between the discovery of hESCs and today, many lines were derived consistent with ethical standards and/or guidelines developed by various states, countries, and other entities such as the International Society for Stem Cell Research (ISSCR) and the National Academy of Sciences (NAS). These various policies have many common features, rely on a consistent ethical base, and require an informed consent process, but they differ in details of implementation. For example, some require specific wording in a written informed consent document, while others do not. It is important to recognize that the principles of ethical research, e.g., voluntary informed consent to participation, have not varied in this time period, but the requirements for implementation and procedural safeguards employed to demonstrate compliance have evolved. In response to these concerns, the Guidelines state that applicant institutions wishing to use hESCs derived from embryos donated prior to the effective date of the Guidelines may either comply with Section II (A) of the Guidelines or undergo review by a Working Group of the Advisory Committee to the Director (ACD). The ACD, which is a chartered Federal Advisory Committee Act (FACA) committee, will advise NIH on whether the core ethical principles and procedures used in the process for obtaining informed consent for the donation of the embryo were such that the cell line should be eligible for NIH funding. This Working Group will not undertake a de novo evaluation of ethical standards, but will consider the materials submitted in light of the principles and points to consider in the Guidelines, as well as 45 C.F.R. Part 46 Subpart A. Rather than grandfathering, ACD Working Group review will enable pre-existing hESCs derived in a responsible manner to be eligible for use in NIH funded research.

In addition, for embryos donated outside the United States prior to the effective date of these Guidelines, applicants may comply with either Section II (A) or (B). For embryos donated outside of the United States on or after the effective date of the Guidelines, applicants seeking to determine eligibility for NIH research funding may submit an assurance that the hESCs fully comply with Section II (A) or submit an assurance along with supporting information, that the alternative procedural standards of the foreign country where the embryo was donated provide protections at least equivalent to those provided by Section II (A) of these Guidelines. These materials will be reviewed by the NIH ACD Working Group, which will recommend to the ACD whether such equivalence exists. Final decisions will be made by the NIH Director. This special consideration for embryos donated outside the United States is needed because donation of embryos in foreign countries is governed by the laws and policies of the respective governments of those nations. Although such donations may be responsibly conducted, such governments may not or cannot change their national donation requirements to precisely comply with the NIH Guidelines. The NIH believes it is reasonable to provide a means for reviewing such hESCs because ethically derived foreign hESCs constitute an important scientific asset for the U.S.

Respondents expressed concern that it might be difficult in some cases to provide assurance that there was a "clear separation" between the prospective donor(s) decision to create embryos for reproductive purposes and the donor(s) decision to donate the embryos for research purposes. These respondents noted that policies vary at IVF clinics, especially with respect to the degree to which connections with researchers exist. Respondents noted that a particular clinics role may be limited to the provision of contact information for researchers. A clinic that does not have any particular connection with research would not necessarily have in place a written policy articulating the separation contemplated by the Guidelines. Other respondents noted that embryos that are determined not to be suitable for medical purposes, either because of genetic defects or other concerns, may be donated prior to being frozen. In these cases, it is possible that the informed consent process for the donation might be concurrent with the consent process for IVF treatment. Respondents also noted that the initial consent for IVF may contain a general authorization for donating embryos in excess of clinical need, even though a more detailed consent is provided at the actual time of donation. The NIH notes that the Guidelines specifically state that consent should have been obtained at the time of donation, even if the potential donor(s) had given prior indication of a general intent to donate embryos in excess of clinical need for the purposes of research. Accordingly, a general authorization for research donation when consenting for reproductive treatment would comply with the Guidelines, so long as specific consent for the donation is obtained at the time of donation. In response to comments regarding documentation necessary to establish a separation between clinical and research decisions, the NIH has changed the language of the Guidelines to permit applicant institutions to submit consent forms, written policies or other documentation to demonstrate compliance with the provisions of the Guidelines. This change should provide the flexibility to accommodate a range of practices, while adhering to the ethical principles intended.

Some respondents want to require that the IVF physician and the hESC researcher should be different individuals, to prevent conflict of interest. Others say they should be the same person, because people in both roles need to have detailed knowledge of both areas (IVF treatment and hESC research). There is also a concern that the IVF doctor will create extra embryos if he/she is also the researcher. As a general matter, the NIH believes that the doctor and the researcher seeking donation should be different individuals. However, this is not always possible, nor is it required, in the NIH's view, for ethical donation.

Some respondents want explicit language (in the Guidelines and/or in the consent) stating that the embryo will be destroyed when the inner cell mass is removed. In the process of developing guidelines, the NIH reviewed a variety of consent forms that have been used in responsible derivations. Several had extensive descriptions of the process and the research to be done, going well beyond the minimum expected, yet they did not use these exact words. Given the wide variety and diversity of forms, as well as the various policy, statutory and regulatory obligations individual institutions face, the NIH declines to provide exact wording for consent forms, and instead endorses a robust informed consent process where all necessary details are explained and understood in an ongoing, trusting relationship between the clinic and the donor(s).

Respondents asked for clarification regarding the people who must give informed consent for the donation of embryos for research. Some commenters suggested that NIH should require consent from the gamete donors, in cases where those individuals may be different than the individuals seeking reproductive treatment. The NIH requests consent from the individual(s) who sought reproductive treatment because this/these individual(s) is/are responsible for the creation of the embryo(s) and, therefore, its/their disposition. With regard to gamete donation, the risks are associated with privacy and, as such, are governed by requirements of the Common Rule, where applicable.

Respondents also requested clarification on the statement in the draft Guidelines noting that "although human embryonic stem cells are derived from embryos, such stem cells are not themselves human embryos." For the purpose of NIH funding, an embryo is defined by Section 509, Omnibus Appropriations Act, 2009, Pub. L. 111-8, 3/11/09, otherwise known as the Dickey Amendment, as any organism not protected as a human subject under 45 C.F.R. Part 46 that is derived by fertilization, parthenogenesis, cloning or any other means from one or more human gametes or human diploid cells. Since 1999, the Department of Health and Human Services (HHS) has consistently interpreted this provision as not applicable to research using hESCs, because hESCs are not embryos as defined by Section 509. This long-standing interpretation has been left unchanged by Congress, which has annually reenacted the Dickey Amendment with full knowledge that HHS has been funding hESC research since 2001. These guidelines therefore recognize the distinction, accepted by Congress, between the derivation of stem cells from an embryo that results in the embryos destruction, for which federal funding is prohibited, and research involving hESCs that does not involve an embryo nor result in an embryos destruction, for which federal funding is permitted.

Some respondents wanted to ensure that potential donor(s) are either required to put their "extra" embryos up for adoption before donating them for research, or are at least offered this option. The Guidelines require that all the options available in the health care facility where treatment was sought pertaining to the use of embryos no longer needed for reproductive purposes were explained to the potential donor(s). Since not all IVF clinics offer the same services, the healthcare facility is only required to explain the options available to the donor(s) at that particular facility.

Commenters asked that donor(s) be made aware of the point at which their donation decision becomes irrevocable. This is necessary because if the embryo is de-identified, it may be impossible to stop its use beyond a certain point. The NIH agrees with these comments and revised the Guidelines to require that donor(s) should have been informed that they retained the right to withdraw consent for the donation of the embryo until the embryos were actually used to derive embryonic stem cells or until information which could link the identity of the donor(s) with the embryo was no longer retained, if applicable.

Medical Benefits of Donation

Regarding medical benefit, respondents were concerned that the language of the Guidelines should not somehow eliminate a donor's chances of benefitting from results of stem cell research. Respondents noted that although hESCs are not currently being used clinically, it is possible that in the future such cells might be used for the medical benefit of the person donating them. The Guidelines are meant to preclude individuals from donating embryos strictly for use in treating themselves only or from donating but identifying individuals or groups they do or do not want to potentially benefit from medical intervention using their donated cells. While treatment with hESCs is one of the goals of this research, in practice, years of experimental work must still be done before such treatment might become routinely available. The Guidelines are designed to make it clear that immediate medical benefit from a donation is highly unlikely at this time. Importantly, it is critical to note that the Guidelines in no way disqualify a donor from benefitting from the medical outcomes of stem cell research and treatments that may be developed in the future.

Monitoring and Enforcement Actions

Respondents have expressed concern about the monitoring of funded research and the invocation of possible penalties for researchers who do not follow the Guidelines. A grantee's failure to comply with the terms and conditions of award, including confirmed instances of research misconduct, may cause the NIH to take one or more enforcement actions, depending on the severity and duration of the non-compliance. For example, the following actions may be taken by the NIH when there is a failure to comply with the terms and conditions of any award: (1) Under 45 CFR 74.14, the NIH can impose special conditions on an award, including but not limited to increased oversight/monitoring/reporting requirements for an institution, project, or investigator; and (2) under 45 CFR 74.62 the NIH may impose enforcement actions, including but not limited to withholding funds pending correction of the problem, disallowing all or part of the costs of the activity that was not in compliance, withholding further awards for the project, or suspending or terminating all or part of the funding for the project. Individuals and institutions may be debarred from eligibility for all Federal financial assistance and contracts under 2 CFR Part 376 and 48 CFR Subpart 9.4, respectively. The NIH will undertake all enforcement actions in accordance with applicable statutes, regulations, and policies.

These Guidelines apply to the expenditure of National Institutes of Health (NIH) funds for research using human embryonic stem cells (hESCs) and certain uses of induced pluripotent stem cells (See Section IV). The Guidelines implement Executive Order 13505.

Long-standing HHS regulations for Protection of Human Subjects, 45 C.F.R. 46, Subpart A establish safeguards for individuals who are the sources of many human tissues used in research, including non-embryonic human adult stem cells and human induced pluripotent stem cells. When research involving human adult stem cells or induced pluripotent stem cells constitutes human subject research, Institutional Review Board review may be required and informed consent may need to be obtained per the requirements detailed in 45 C.F.R. 46, Subpart A. Applicants should consult http://www.hhs.gov/ohrp/humansubjects/guidance/45cfr46.html .

It is also important to note that the HHS regulation, Protection of Human Subjects, 45 C.F.R. Part 46, Subpart A, may apply to certain research using hESCs. This regulation applies, among other things, to research involving individually identifiable private information about a living individual, 45 C.F.R. 46.102(f). The HHS Office for Human Research Protections (OHRP) considers biological material, such as cells derived from human embryos, to be individually identifiable when they can be linked to specific living individuals by the investigators either directly or indirectly through coding systems. Thus, in certain circumstances, IRB review may be required, in addition to compliance with these Guidelines. Applicant institutions are urged to consult OHRP guidances at http://www.hhs.gov/ohrp/humansubjects/guidance/45cfr46.html

To ensure that the greatest number of responsibly derived hESCs are eligible for research using NIH funding, these Guidelines are divided into several sections, which apply specifically to embryos donated in the U.S. and foreign countries, both before and on or after the effective date of these Guidelines. Section II (A) and (B) describe the conditions and review processes for determining hESC eligibility for NIH funds. Further information on these review processes may be found at http://www.NIH.gov . Sections IV and V describe research that is not eligible for NIH funding.

These guidelines are based on the following principles:

As directed by Executive Order 13505, the NIH shall review and update these Guidelines periodically, as appropriate.

For the purpose of these Guidelines, "human embryonic stem cells (hESCs)" are cells that are derived from the inner cell mass of blastocyst stage human embryos, are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers. Although hESCs are derived from embryos, such stem cells are not themselves human embryos. All of the processes and procedures for review of the eligibility of hESCs will be centralized at the NIH as follows:

The materials submitted must demonstrate that the hESCs were derived from human embryos: 1) that were created using in vitro fertilization for reproductive purposes and were no longer needed for this purpose; and 2) that were donated by donor(s) who gave voluntary written consent for the human embryos to be used for research purposes.

The Working Group will review submitted materials, e.g., consent forms, written policies or other documentation, taking into account the principles articulated in Section II (A), 45 C.F.R. Part 46, Subpart A, and the following additional points to consider. That is, during the informed consent process, including written or oral communications, whether the donor(s) were: (1) informed of other available options pertaining to the use of the embryos; (2) offered any inducements for the donation of the embryos; and (3) informed about what would happen to the embryos after the donation for research.

Prior to the use of NIH funds, funding recipients should provide assurances, when endorsing applications and progress reports submitted to NIH for projects using hESCs, that the hESCs are listed on the NIH registry.

This section governs research using hESCs and human induced pluripotent stem cells, i.e., human cells that are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers. Although the cells may come from eligible sources, the following uses of these cells are nevertheless ineligible for NIH funding, as follows:

Raynard S Kington, M.D., Ph.D.Acting Director, NIH

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NIH Guidelines for Human Stem Cell Research

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Ethics of Stem Cell Research – Blue Marble Space Institute of Science

Posted: October 13, 2022 at 2:04 am

Submitted by Bsra Elkatmis to fulfill the ethics in science requirement for theYoung Scientist Programat BMSIS.

Cells are the smallest known building blocks of living organisms. All of the cells in the human body have different functions. For example, white blood cells fight infection in the body while red blood cells carry oxygen, and heart muscle cells make the heart beat while neurons are used to transmit signals through the body and for the functions of the brain. On the other hand, stem cells are special cells with self-renewal and differentiation functions. Thanks to self-renewal property, stem cells can divide and produce more stem cells [1].

They are known as undifferentiated cells, which means that they can convert into specialized cell types. Stem cells can be classified according to how much they can differentiate into new cell types. The four main classifications are: totipotent, pluripotent, multipotent, and unipotent. Totipotent stem cells can turn into any other cell type. For example, the zygote, which is a fertilized egg cell, and the cells of the embryo up to the eight-cell stage are totipotent cells. These cells can form a complete and normal individual in the womb.

Pluripotent stem cells have the potential to differentiate into almost all cell types. For example, embryonic stem cells are formed from the inner cell mass of the blastocyst, which is a later stage of embryonic development.

Multipotent stem cells can differentiate into small groups of cells. For example, somatic stem cells are multipotent. This means that their differentiation potential is limited to a number of related cell types. Also, mesenchymal stem cells can be an example of multipotent stem cells. They have the potential to differentiate into cartilage cells, bone cells, and muscle cells [2]. The neural stem cells originate from the central nervous system. They can differentiate into nerve cells. The hematopoietic stem cells are another type of multipotent stem cell. They can differentiate into white blood cells and red blood cells.

Lastly, unipotent stem cells can only produce one type of cell. Even though they have a quite limited differentiation capacity, theyre still stem cells because of their self-renewal property. In this concept, they can maintain the undifferentiated stem cell pool as a result of this property.

Beyond these four main classifications, newly discovered induced pluripotent stem cells (also called iPS cells), are somatic cells that have reverted back to pluripotent stem cells under laboratory conditions.

Stem cell research is an open area to scientific development and has the power to treat people with destructive diseases such as Parkinsons, spinal cord injury, and more. For example, stem cell transplantation can be a good treatment for nervous system injuries, because they can maintain the function of damaged cells or tissues [3]. Despite this, there have been ethical questions raised as to the nature of stem cell research. One major question arises because of the methods used to obtain embryonic stem cells that in turn destroy the embryo.

Some people support that although the embryo is still under development, it is considered a potential person. The major problem with this is that the personhood criteria cannot be fully defined. It is claimed that the embryo should have respect and dignity since it would be human even if it did not have human characteristics yet. Others support that the fertilized egg is only an organic material just like our body parts until it can survive independently. If we destroy the blastocyst before it is attached to the womb, it cannot be mentioned of any harm or destruction, as it has no faith, desire, expectation, and purpose. Although both sides of the debate are interested in protecting human life, the position of the human blastula causes ethical problems [4].

Embryonic stem cells are obtained from cells within the blastula, one of the early stages of human formation. Just before the fertilized egg is implanted into the wall of the womb, it turns into a blastula that can survive for a short time. Blastula are harvested, isolated, and cultivated in a laboratory to use in stem cell research. They may even believe that when the egg is fertilized by sperm naturally or in vitro, personhood begins for blastocysts. Therefore, a moral dilemma arises in embryonic stem cell research.

The deontological approach is symbolized by Immanuel Kants principle of the Categorical Imperative, which underlined that persons must be treated as ends rather than as means. Individuals, as expressed in the Declaration of Independence, have been endowed by their Creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness. This argues that a persons life cannot be sacrificed to achieve better things. Some people who assume both a deontological approach and the position that human life begins at conception may then argue that blastocysts are persons who have rights [5]. According to such a position, the destruction of the blastocyst to obtain stem cells is unethical.

During in vitro fertilization, many spare embryos are created that will not be implanted within the womb. These spare embryos may then be used in stem cell studies. This may also be incompatible with Kants Categorical Imperative ethical perspective for someone who believes that human life begins at conception since the destruction of these spare embryos to obtain stem cells means sacrificing human life. Proponents of this position may argue that spare embryos are still persons. Another important point here is stem cell lines. The use of stem cell lines that were created by destroying blastocysts is morally wrong from the Categorical Imperative standpoint because it represents the act of destroying human life.

However, some who argue from a deontological perspective while also supporting the concept that human life begins at conception may actually consider it ethical to use stem cell lines in research because they suggest that stem cell lines were created in the past and we cant change that now. However, those arguing from that position may still be against creating new stem cell lines.

What about those with the deontological perspective, but who do not consider human life to begin at conception (and thus the blastocyst to not be a person)? In such a case, even though they accept the Categorical Imperative, they may see there being no personhood rights for blastocysts, and so no issue with recovery of stem cells at that stage. Meanwhile, for those who take such a stance, they may hold positions that human life begins at a variety of later stages of development (such as the development of the primitive streak or even at birth).

In either case (human life beginning at conception or at a time later in development), some will still take that position that even if it can be argued that blastocysts are not yet human, they are still part of human life, and thus they may still find that destroying blastocysts for stem cell research is unethical. For instance, U.S. President George Bushs Council on Bioethics in 2001 reminds one of such positions and of Kants Categorical Imperative as it stated that it is morally wrong to exploit and destroy developing human life, even for good reason [6].

Virtue ethics is an approach that tells us what kind of people we should strive to be and how we can be such people. For example, using something known as the eudaimonia perspective can be useful for this topic. Eudaimonia can be described as achieving self-realization and happiness. People struggle to improve their character and prevent suffering on the way to eudaimonia.

Applying eudaimonia to stem cell research may go something like this:

Stem cell research offers a curative way to treat destructive diseases such as spinal cord injury, Parkinsons, Alzheimers, and more.Having these disease conditions does not match the ideal of eudaimonia, as achieving this state is not possible with the pain and burden of these diseases.As we are trying to improve our character, we must eliminate situations that prevent eudaimonia.If the treatment of these diseases will be improved through stem cell research, then virtue ethics may find this research ethical from the point of view of eudaimonia and achieving a virtuous state.

Conversely, some virtue ethicists find it unethical to terminate embryo life for stem cell research. The argument they support for this can be described as a duty to respect the value of human life. Based on this concept, they consider that not harming human life is a virtuous human behavior. And they believe that people should strive accordingly.

The basis of utilitarianism is the greatest happiness. The fraction of the population suffering from diseases such as Alzheimers, Parkinsons, and diabetes increases every year. It can be argued that these diseases cause pain, discomfort, suffering, and burdens for those who have the disease as well as for their families and communities. Thus, for a utilitarian approach, it may be worth sacrificing embryos to save these peoples lives and reduce the prevalence of disease through conducting further stem cell research.

In the big picture, utilitarianism focuses on the maximum benefit that all of humanity will achieve through some action. The important thing here is to save as much life as possible, and it is very important to have lives that can be saved. When we look at stem cell research from this point of view, there is no problem in using embryos. Stem cell research provides for the greatest happiness by saving lives while reducing overall suffering.

After examining the purpose of stem cell research, it can be stated that it has a morally right consequence from a utilitarian approach. Stem cell treatment contributes to saving many peoples lives, prolonging human life, reducing health care costs, and more. Since the research and treatments carried out will serve the benefit of many people, they are supported by the utilitarian perspective.

Stem cell research has been a controversial topic for some time. When this topic is analyzed by different ethical approaches, all of them reveal different ethical results, and may even be used to argue both for and against this type of research. It is important to understand the ethical implications of stem cell research to respect the benefit and fundamental humanity of all interested sides. Although stem cell research has provided improvements for the quality of life of some, these actions can still be questioned morally. In addition, stem cell research continues to be an ethical dilemma within both political and religious ideologies. For example, each country has different legal regulations on stem cell research based often on their own internal dialogue on what is right. While reaching a common understanding about when personhood begins may cause this issue to be more tractable within an ethical framework, it is likely that questions will still persist as to the moral right to conduct embryonic stem cell research.

Bsra Elkatmis is an undergraduate student studying molecular biology and genetics at Gebze Technical University and a Research Associate in the BMSIS Young Scientist Program. Shes interested in plant science and the origin of life and enjoys growing plants in her spare time.

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