Researchers in Brazil Establish the First Line of Human Embryonic Stem Cells

Researchers in Brazil Establish the First Line of Human Embryonic Stem Cells
Tuesday, 03 May 2011

Brazilian researchers, reporting in the current issue of Cell Transplantation, discovered difficulties in establishing a genetically diverse line of human embryonic stem cells (hESC) to serve the therapeutic stem cell transplantation needs of the diverse ethnic and genetic Brazilian population.

According to the study's corresponding author, Dr. Lygia V. Pereira of the Molecular Genetics Laboratory at the University of Sao Paulo, Brazil, pluripotent human embryonic stem cells are an important tool for basic and applied stem cell transplantation research. However, immunocompatibility is an issue, especially in a genetically diverse population such as that in Brazil where the population is comprised of European, African and Native South American ancestry.

In their study, the researchers developed an hES cell line (the first in South America) they called "BR-1" derived from a Brazilian population with embryos donated by couples who had sought assistance from private fertility clinics. Their research was compatible with the 2005 Brazilian national legal, ethical and clinical guidelines for embryonic stem cell research using tissue that had been frozen for the legally mandated time of at least three years, and that had been produced for reproductive reasons.

Their results showed that the hES cell lines they established were a "worse match" to the Brazilian population than hESC lines developed elsewhere, particularly those developed in the U.S. and Singapore.

The reasons for that may be several, said Dr. Pereira.

"The Brazilian population is one of the most heterogeneous in the world, and the genes of Brazilians are mosaics," said Dr. Pereira.

"However, an analysis of BR-1 showed that it is mostly European in origin. The reproductive assistance offered by the Brazilian public health system does not include cryopreservation of surplus embryos, meaning that the only research material available came from private clinics where couples with above-average incomes could afford the high cost of assisted reproduction."

According to the researchers, that segment of the Brazilian population is mostly composed of people self-identified as white - of European ancestry - and so is not representative of Brazilian ethnic admixture and, thus, is unable to be widely compatible with Brazil's diverse population genetics.

"Although we have successfully established the first line of hESCs from the Brazilian population that adds to the pool of genetically different pluripotent cells available, it will be important to have access to embryos from the more mixed population and assistance from the Public Health System," concluded Dr. Pereira.

"Use of embryonic stem cells (ES) in regenerative medicine is very promising, but the potential problems of tumour development, cell rejection due to histo-incompatibility, and contamination with animal products employed in the cell culture need to be overcome," said Dr. Julio Voltarelli, professor of Clinical Medicine and Clinical Immunology at the University of Sao Pãulo, Brazil and section editor for Cell Transplantation.

"In this study, Dr Pereira and colleagues compared the HLA compatibility between their ESC line, the first established in Brazil, and a sample of the Brazilian population who volunteered as donors for hematopoietic stem cell transplantation (REDOME). They found few matches for the ESC line in the representative population, which was attributed to the great genetic heterogeneity of the Brazilian population. This finding may add another difficulty to the clinical use of ESC in Brazil and other mixed populations even once the safety issues of ESC lines are resolved."

Source: Florida Science Communications
Contact: Randolph Fillmore

Reference:
Establishment Of A Brazilian Line Of Human Embryonic Stem Cells In Defined Medium – Implications For Cell Therapy In An Ethnically Diverse Population
Fraga, A. M.; Sukoyan, M.; Rajan, P.; Braga, D. P. F.; Iaconelli, A., Jr.; Franco, J. G., Jr.; Borges, E., Jr.; Pereira, L. V.
Cell Transplant. 20(3):431-440; 2011.
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ZenMaster

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For more on stem cells and cloning, go to CellNEWS at
http://cellnews-blog.blogspot.com/

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US Appeals Court Lift Ban of Federal Funding for Stem Cell Research

US Appeals Court Lift Ban of Federal Funding for Stem Cell Research
Saturday, 30 April 2011

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“Stem cells are thought to have properties that can cure many diseases that other treatments cannot. However, because the cells often come from embryos, the issue is hotly debated. This recent Court of Appeals decision has been heralded a victory for those who wish to continue research; public colleges are now eligible to receive Federal funding. This influx of stem cell research will be a huge benefit to the health science community and are likely to lead less traditional programs, like online PhD programs, to contribute as well."

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US Court of Appeals for the District of Columbia Circuit, on Friday ruled the Obama administration can continue using federal money to fund human embryonic stem cell research.
The appeals court overturned the ruling by the District Judge Royce Lamberth, who found that the US National Institutes of Health (NIH) guidelines on such research violated the law because embryos were destroyed and it put other researchers working with adult stem cells at a disadvantage to win federal grants.

The US Court of Appeals in Washington ruled 2-1 on Friday that a 1996 US law against federal funding of embryo destruction was "ambiguous", and "did not prohibit funding a research project in which an ESC (embryonic stem cell) will be used".

"This is a momentous day – not only for science, but for the hopes of thousands of patients and their families who are relying on NIH-funded scientists to pursue life-saving discoveries and therapies that could come from stem cell research," NIH Director Francis Collins said in a statement.

White House spokesperson Nick Papas said the decision was a victory for scientists and patients.

"Responsible stem cell research has the potential to treat some of our most devastating diseases and conditions and offers hope to families across the country and around the world," he said.

“This is a victory not only for the scientists, but for the patients who are waiting for treatments and cures for terrible diseases,” Arnold Kriegstein, MD, PhD, said. Kriegstein is director of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF.

“This ruling allows critical research to move forward, enabling scientists to compare human embryonic stem cells to other forms of stem cells, such as the cell lines which are derived from skin cells, and to pursue potentially life-saving therapies based on that research.”

Kriegstein was one of two University of California scientists to file a Declaration in September 2010 in support of the UC Board of Regents’ motion to intervene in the August lawsuit, Sherley v. Sebelius.

Sherly v. Sebelius had argued that when the Obama Administration lifted a ban on federal funding for the research in March 2009, it had violated the 1996 Dickey-Wicker Amendment, which barred using taxpayer funds in research that destroyed embryos.

“I am very happy with this decision, although I am surprised that it wasn’t a unanimous vote,” Kriegstein said.

“In my opinion, the evidence in favour of pursuing this research is overwhelming compared to the arguments submitted to stop the research.”

UCSF launched the nation’s first stem cell PhD program in 2010, for which the first class already has been chosen and will begin in fall 2011.

“This is an important day for stem cell research and the nation’s scientific community. Most importantly, this is a victory for the patients around the world suffering from incurable diseases,” says Susan L. Solomon, CEO of the New York Stem Cell Foundation (NYSCF).

“The time has come for our leaders to put progress before politics on this issue and remove all of the remaining, unnecessary limitations on human embryonic stem cell research conducted with the best ethical and medical practices. We need to put an end to the constant uncertainty facing the field of embryonic stem cell research so scientists can get on with the serious business of research and maintain the kind of momentum that will lead to cures for the most intractable diseases facing mankind.”

OnlinePhD supports writing about continued stem cell research in higher education.

Reference:
Read the full court ruling
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ZenMaster

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For more on stem cells and cloning, go to CellNEWS at
http://cellnews-blog.blogspot.com/

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Scientists Create Stable, Self-renewing Neural Stem Cells

Abundant precursor cells can become many types of neurons without introducing tumour risk Monday, 25 April 2011

Researchers at the University of California, San Diego School of Medicine, the Gladstone Institutes in San Francisco and colleagues report a game-changing advance in stem cell science. They have created long-term, self-renewing, and primitive neural precursor cells from human embryonic stem cells (hESCs) that can be directed to become many types of neuron without increased risk of tumour formation. The results are published in a paper in the April 25 early online edition of the Proceedings of the National Academy of Sciences.

"It's a big step forward," said Kang Zhang, MD, PhD, professor of ophthalmology and human genetics at Shiley Eye Center and director of the Institute for Genomic Medicine, both at UC San Diego.

"It means we can generate stable, renewable neural stem cells or downstream products quickly, in great quantities and in a clinical grade – millions in less than a week – that can be used for clinical trials and, eventually, for clinical treatments. Until now, that has not been possible."


Depicts cultured, self-renewing primitive

neural precursors derived from human

embryonic stem cells using molecule

inhibitors. Credit: UC San Diego School

of Medicine.

Human embryonic stem cells hold great promise in regenerative medicine due to their ability to become any kind of cell needed to repair and restore damaged tissues. But the potential of hESCs has been constrained by a number of practical problems, not least among them the difficulty of growing sufficient quantities of stable, usable cells and the risk that some of these cells might form tumours.

To produce the neural stem cells, Zhang, with co-senior author Sheng Ding, PhD, a former professor of chemistry at The Scripps Research Institute and now at the Gladstone Institutes, and colleagues added small molecules in a chemically defined culture condition that induces hESCs to become primitive neural precursor cells, but then halts the further differentiation process.

"And because it doesn't use any gene transfer technologies or exogenous cell products, there's minimal risk of introducing mutations or outside contamination," Zhang said. Assays of these neural precursor cells found no evidence of tumour formation when introduced into laboratory mice.

By adding other chemicals, the scientists are able to then direct the precursor cells to differentiate into different types of mature neurons, "which means you can explore potential clinical applications for a wide range of neurodegenerative diseases," said Zhang.

Depicts stained mature neurons, derived

from precursor cells, expressing the

neurotransmitter dopamine. Credit: UC

San Diego School of Medicine.

"You can generate neurons for specific conditions like amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), Parkinson's disease or, in the case of my particular research area, eye-specific neurons that are lost in macular degeneration, retinitis pigmentosa or glaucoma."

The new process promises to have broad applications in stem cell research. The same method can be used to push induce pluripotent stem cells (stem cells artificially derived from adult, differentiated mature cells) to become neural stem cells, Zhang said.

"And in principle, by altering the combination of small molecules, you may be able to create other types of stem cells capable of becoming heart, pancreas, or muscle cells, to name a few."

The next step, according to Zhang, is to use these stem cells to treat different types of neurodegenerative diseases, such as macular degeneration or glaucoma in animal models.

Source: University of California at San Diego
Contact: Scott LaFee
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ZenMaster

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For more on stem cells and cloning, go to CellNEWS at
http://cellnews-blog.blogspot.com/

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