Human Embryonic Stem Cells
Stem cells are undifferentiated cells that are capable of dividing for long periods of time and can give rise to specialized cells under particular conditions. Embryonic stem cells are a particular type of stem cell derived from embryos. According to US National Institutes of Health (NIH), in humans, the term embryo applies to a fertilized egg from the beginning of division up to the end of the eighth week of gestation, when the embryo becomes a fetus. Between fertilization and the eighth week of gestation, the embryo undergoes multiple cell divisions. At the eight-cell stage, roughly the third day of division, all eight cells are considered totipotent, which means the cell has the capability of becoming a fully developed human being. By day four, cells begin to separate and form a spherical layer which eventually becomes the placenta and tissue that support the development of the future fetus. A mass of about thirty cells, called the inner cell mass, forms at one end of the sphere and eventually becomes the body. When the sphere and inner cell mass are fully formed, around day 5, the pre-implantation embryo is referred to as a blastocyst. At this point the cells in the inner cell mass have not yet differentiated, but have the ability to develop into any specialized cell type that makes up the body. This property is known as pluripotency. As of 2009, embryonic stem cells refer to pluripotent cells that are generally derived from the inner cell mass of blastocysts.
In November 1998, two independent publications announced the first successful isolation and culture of pluripotent human stem cells. While working at the Wisconsin National Primate Research Center, located at the University of Wisconsin-Madison, James A. Thomson and his team of researchers cultured human embryonic stem cells from the inner cell mass of donated embryos originally produced for in vitro fertilization. The characteristics of the cultured cells were consistent with previously identified features in animal stem cells. They were capable of long-term self-renewal and thus could remain undifferentiated for long periods of time; they had particular surface markers; and they were able to maintain a normal and stable karyotype. Thomsons team also observed derivatives of all the three germ layersendoderm, mesoderm, and ectoderm. Since the three germ layers precede differentiation into all the cell types in the body, this observation suggested that the cultured cells were pluripotent. The team published Embryonic Stem Cell Lines Derived from Human Blastocysts, in the 6 November Science issue. Soon afterwards, a research team led by John D. Gearhart at the Johns Hopkins School of Medicine, published Derivation of Pluripotent Stem Cells from Cultured Human Primordial Germ Cells in Proceedings of the National Academy of Science. The paper detailed the process by which pluripotent stem cells were derived from gonadal ridges and mesenteries extracted from aborted five-to-nine week old human embryos. Gearhart and his team noted the same observations as Thomsons team. Despite coming from different sources, according to NIH, the resultant cells seem to be the same.
The largest source of blastocysts for stem cell research comes from in vitro fertilization (IVF) clinics. Used for reproductive purposes, IVF usually produces an abundance of viable blastocysts. Excess blastocysts are sometimes donated for research purposes after obtaining informed consent from donors. Another potential method for producing embryonic stem cells is somatic cell nuclear transfer (SCNT). This has been successfully done using animal cells. The nucleus of a differentiated adult cell, such as a skin cell, is removed and fused with an enucleated egg, an egg with the nucleus removed. The egg, now containing the genetic material from the skin cell, is believed to be totipotent and eventually develops into a blastocyst. As of mid-2006, attempts to produce human embryonic stem cells using SCNT have been unsuccessful. Nonetheless, scientists continue to pursue this method because of the medical and scientific implications of embryonic stem cells lines with an identical genetic makeup to particular patients. One problem faced in tissue transplants is immune rejection, where the host body attacks the introduced tissue. SCNT would be a way to overcome the incompatibility problem by using the patients own somatic cells.
Recent discoveries in cultivating human embryonic stem cells may potentially lead to major advancements in understanding human embryogenesis and medical treatments. Previously, limitations in access and environmental control have stunted research initiatives aimed at mapping out the developmental process. Insights into differentiation factors may lead to treatments into such areas as birth defects. Manipulation of the differentiation process may then lead to large supplies of stem cells for cell-based therapies on patients with Parkinsons disease, for example. In theory adult stem cells can also be cultivated for such purposes, but isolating and identifying adult stem cells has been difficult and the prospects for treatment are more limited than using embryonic stem cells.
Despite the potential benefits that may come about through human embryonic stem cell research, not everyone in the public embraces it. Several ethical debates surround this newly developing research field. Much of the debate stems from differing opinions on how we should view embryos: is an embryo a person? Should an embryo be considered property? Ethical concerns in embryonic stem cell research include destroying human blastocysts, laws surrounding informed consent, and particularly for SCNT, misapplication of techniques for reproductive cloning. For the latter concern, SCNT does produce a blastocyst which contains stem cell clones of an adult cell, but the desired application is in growing replacement tissues. Still, a portion of the public fears the hypothetical one day, when someone decides to use SCNT to develop and raise a human clone.
The public debate continues, advancing along with the changes in the field. As of 2006, public opinion polls showed that majority of religious and non-religious Americans now support embryonic stem cell research, but opinions remain divided over whether it is legitimate to create or use human blastocysts solely for research.
Wu, Ke, "Human Embryonic Stem Cells".
(2010-09-13). ISSN: 1940-5030 http://embryo.asu.edu/handle/10776/2055.
Arizona State University. School of Life Sciences. Center for Biology and Society. Embryo Project Encyclopedia.
Arizona Board of Regents Licensed as Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported (CC BY-NC-SA 3.0) http://creativecommons.org/licenses/by-nc-sa/3.0/
Read more:
Human Embryonic Stem Cells - Arizona State University
- Arizona Oncology Cancer Center working with NexCore Group on new cancer treatment center - Yahoo Finance - October 13th, 2022
- Senate Passes 'Inflation Reduction Act' Which Will Likely Make Inflation Worse - Reason - August 14th, 2022
- Reds prospect rankings will shift after trade deadline acquisition of 10 players - The Athletic - August 5th, 2022
- Stem Cell Therapy Pros and Cons - Arizona Pain and Spine Institute - July 11th, 2022
- Bone Anatomy | Ask A Biologist - Arizona State University - July 11th, 2022
- No, "Top Gun" isn't an anti-woke success story, but rather a tribute to aging Tom Cruise and balls - Salon - June 4th, 2022
- Maine health care workers to appeal order to disclose their names in vaccine mandate lawsuit - Lewiston Sun Journal - June 4th, 2022
- BioEclipse Therapeutics Awarded Almost $8 Million Grant by California Institute for Regenerative Medicine (CIRM) to Fund Ongoing Phase 1 CRX100 Cancer... - May 2nd, 2022
- Right to Try 2.0: Ahwatukee family pushes for proposed law after getting medical treatment abroad - FOX 10 News Phoenix - April 6th, 2022
- Inside the real life Noahs Ark designed to save mankind after the apocalypse with a back up vault on t... - The US Sun - January 5th, 2022
- Mindy Kaling's 'The Sex Lives of College Girls' Is a Spot-On Depiction of College - Glamour - November 22nd, 2021
- Bridging the gap between online and on campus - ASU Now - November 22nd, 2021
- Bacterial Infections Linked with Unapproved Stem Cell Treatments - Contagionlive.com - October 28th, 2021
- ASU professor researches origins of Alzheimers to find a cure - Eight, Arizona PBS - October 16th, 2021
- City of Hope to Accelerate Blood Cancer Research Through a Transformational Gift from Leukemia Survivor James Belardi and His Wife Leslie Belardi -... - October 5th, 2021
- Calidi Biotherapeutics Announces Exclusive License Agreement with City of Hope and the University of Chicago for Novel Oncolytic Virotherapy... - August 18th, 2021
- Jim McMahon broke his neck playing for Vikings, and found out about it 17 years later - TwinCities.com-Pioneer Press - December 23rd, 2020
- Want to Know Where The Best Fall Colors Are in Your Area? Check Out This Interactive US Map - Good News Network - October 5th, 2020
- 'Were not your slaves': Alternative health providers bristle at warning letters about their coronavirus treatments - USA TODAY - September 4th, 2020
- Neogene precipitation, vegetation, and elevation history of the Central Andean Plateau - Science Advances - September 4th, 2020
- Research Roundup: Lasting Immunity to COVID-19 and More - BioSpace - August 21st, 2020
- What in the world is 'Project Carpaccio' and which Israeli company is doing business in Abu Dhabi? - CTech - August 21st, 2020
- Viruses have big impacts on ecology and evolution as well as human health - The Economist - August 21st, 2020
- Encouraging News About Coronavirus Immunity | In the Pipeline - Science Magazine - August 21st, 2020
- Scientists are seeing signs of lasting immunity to COVID-19, among survivors with even mild infections - Firstpost - August 21st, 2020
- Studies show positive signs of strong, lasting Covid-19 immunity - The Irish Times - August 21st, 2020
- Coronavirus vaccine will take time, so researchers are hunting for and finding promising new COVID-19 tre - OregonLive - April 6th, 2020
- Penn announces seven 2020 Thouron Award winners - Penn: Office of University Communications - February 24th, 2020
- Unlocking The Secrets Of DNA Help Researchers Understand How to Slow Aging - YouAreUNLTD - January 9th, 2020
- An ESPN reporter was diagnosed with HLH just before he died at age 34. What is it? - ABC15 Arizona - January 2nd, 2020
- 2020s visions: We'll get flying cars just before becoming software-based people - CNET - December 19th, 2019
- Man fights $4,600 surgery bill he was told insurance would cover - KGUN - December 8th, 2019
- Professor Recognized For Cardiac Regeneration Research - WPI News - December 8th, 2019
- Creative Medical Technology Holdings, Inc. Discusses CaverStem and Other Patented Technology with The Stock Day Podcast - Yahoo Finance - October 19th, 2019
- Bone marrow recipient comes face-to-face with CT donor for the first time - WTNH.com - October 19th, 2019
- Positive Study Results of Phase IIa Clinical Trial Using Intravenous Administration of Mesenchymal Stem Cells for Ischemic Stroke Published in... - October 1st, 2019
- Stem Cell Education Center - Stem Cell Treatment | Arizona ... - September 14th, 2019
- Stem Cell Therapy In Scottsdale Arizona | Regenerative ... - September 12th, 2019
- Stem Cell Therapy | Board Certified Orthopedic Surgeon ... - March 16th, 2019
- Stem Cell Lake Havasu City Arizona 86406 - March 8th, 2019
- Stem Cell Therapy for Cancer | Arizona Pain and Spine ... - December 18th, 2018
- Stem Cells | Arizona Pain Specialists - Scottsdale ... - December 11th, 2018
- Arizona Pain Regenerative Institute - Arizona Pain Specialists - December 5th, 2018
- Stem Cell Therapy Phoenix Arizona | Desert Health Specialists - December 4th, 2018
- Southwest Spine and Sports - Pain Management Doctor Arizona - September 24th, 2018
- Celebration Stem Cell Centre - A private umbilical cord ... - August 12th, 2018
- Bone marrow transplant - Mayo Clinic - July 15th, 2018
- About Dr. Nabil Dib - June 27th, 2018
- Around the world - Bend Bulletin - August 30th, 2017
- FDA Cracks Down On Stem-Cell Clinics Selling Unapproved Treatments - KNAU Arizona Public Radio - August 30th, 2017
- BrainStorm Supports Commitment to ALS Patient Community with ... - Markets Insider - August 8th, 2017
- ASU grad students' lab skills help earn funding for cutting-edge biomedical research - Arizona State University - August 8th, 2017
- Will putting leeches on his face help this blind man see? - USA TODAY - August 8th, 2017
- Engineered Skin Cells Control Type 2 Diabetes in Mice: Study ... - Arizona Daily Star - August 8th, 2017
- 'Soft' side of bioengineering poised to make big impacts - Arizona State University - August 4th, 2017
- Tackling hard-to-treat cancers from every angle - Medical Xpress - June 21st, 2017
- ALS Research Forum | To Evaluate Stem Cell Therapies, Think ... - ALS Research Forum - June 20th, 2017
- New book by ASU researcher explores cancer's pervasive mysteries - Arizona State University - June 18th, 2017
- Arizona Supreme Court Clears Way For Adoption of American Indian Child by Non-Native Parents - Reason (blog) - June 15th, 2017
- Can We Cheat Death? US Firm Aims To Resurrect Brain-Dead People Using Stem Cells - International Business Times - June 11th, 2017
- The three cancers Jews need to worry about most and how to reduce the risks - Jewish Post - June 11th, 2017
- Patient-Centered Stem Cell Therapy Bill Passed by Texas Legislature - satPRnews (press release) - May 31st, 2017
- 6 Arizona young women are taking on the STEM gender gap - AZCentral.com - May 28th, 2017
- Scientists wary as Texas mulls allowing sale of unproven drugs - Texas Tribune - May 26th, 2017
- Scientists wary as Texas mulls allowing sale of unproven drugs - Bryan-College Station Eagle - May 24th, 2017
- ASU engineers envision 'guiding' body's cells to help improve health - Arizona State University - May 19th, 2017
- GV Gardeners: Sun-loving saguaro Southwest symbol | Sun Life ... - Sahuarita Sun (subscription) - May 19th, 2017
- Derek McCartney Named To Lott IMPACT Trophy Watch List - KKTV 11 News - May 18th, 2017
- Tucson Tech: University of Arizona startup advances living heart patch - Arizona Daily Star - May 15th, 2017
- Scientists uncover root of graying, thinning hair - Arizona Daily Star - May 15th, 2017
- GV Gardeners: Sun-loving saguaro Southwest symbol - Green Valley News - May 15th, 2017
- 7-year-old Hollis spread joy around U.S. After losing him to rare brain tumor, parents turn to finding cure - AZCentral.com - May 1st, 2017
- Young minds meet new technology at STEM-focused after-school program - USC News - April 19th, 2017
- Applications for Tissue Culture in Cannabis Growing: Part 1 - Cannabis Industry Journal (blog) - April 14th, 2017
- Yankees: James Kaprielian Getting Tommy John Surgery Out of the Way - Yanks Go Yard - April 14th, 2017
- Can Stem Cell 'Patch' Help Heart Failure? - Arizona Daily Star - April 9th, 2017
- Angels' focus is on defense - Reading Eagle - April 2nd, 2017
- Some restoration drama at the Big A as Dodgers top Angels, 3-1 - Los Angeles Times - April 1st, 2017
- Robert Clayton Robbins Top Choice for UA President - Arizona Public Media - March 10th, 2017
- R. William Funk Lands New Leader for University of Arizona - Hunt Scanlon Media (press release) - March 9th, 2017