Tag Archives: embryonic

Scientists Find Differences in Embryonic Stem Cells and Reprogrammed Skin Cells

From Newswise.com

UCLA researchers have found that embryonic stem cells and skin cells reprogrammed into embryonic-like cells have inherent molecular differences, demonstrating for the first time that the two cell types are clearly distinguishable from one another.

The data from the study suggest that embryonic stem cells and the reprogrammed cells, known as induced pluripotent stem (iPS) cells, have overlapping but still distinct gene expression signatures. The differing signatures were evident regardless of where the cell lines were generated, the methods by which they were derived or the species from which they were isolated, said Bill Lowry, a researcher with the Broad Stem Cell Research Center and a study author.

“We need to keep in mind that iPS cells are not perfectly similar to embryonic stem cells,” said Lowry, an assistant professor of molecular, cell and developmental biology. “We’re not sure what this means with regard to the biology of pluripotent stem cells. At this point our analyses comprise just an observation. It could be biologically irrelevant, or it could be manifested as an advantage or a disadvantage.”

The study appears in the July 2, 2009 issue of the journal Cell Stem Cell.

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New York Becomes First State To Allow Payment For Donating Eggs For Stem Cell Research

From MedicalNewsToday.com

New York’s Empire State Stem Cell Board earlier this month decided to allow embryonic stem cell researchers who receive state funding to compensate women for donating their eggs for use in research, making New York the first state to enact such a policy, the Washington Post reports (Stein, Washington Post, 6/26). According to the New York Times, the New York state Legislature in 2007 allotted $600 million for an 11-year stem cell research plan (Nelson, New York Times, 6/26). Under the board’s decisions, researchers receiving the state funding may pay women up to $10,000 to compensate them for the time, discomfort and expenses associated with egg donation. David Hohn, vice chair of the board’s two committees that endorsed the decision, said that the board “could not distinguish ethically between the payment for in vitro fertilization, which is very well precedented, and the compensation for donation for research.” The board said researchers should follow the same guidelines as infertility clinics that receive donated eggs for infertile couples. Under those guidelines, payments exceeding $5,000 must be justified, and those exceeding $10,000 are considered excessive (Washington Post, 6/26). Robert Klitzman, director of the master’s degree program in bioethics at Columbia University and a member of the stem cell board’s ethics committee, said the payments will be carefully evaluated by an institutional review board (New York Times, 6/26).

The Post reports that the decision goes against policies in other states that offer funding for embryonic stem cell research, as well as against current guidelines from scientific organizations like the National Academy of Sciences (Washington Post, 6/26). NAS guidelines, for example, prohibit paying women for eggs used in stem cell research. Similarly, the internal guidelines for New York-based groups like Rockefeller University, Cornell University and the Sloan-Kettering Institute prohibit financial compensation for donated eggs. However, researchers say that efforts to recruit unpaid donors have been unsuccessful and that the board’s decision will give New York an advantage in stem cell research (New York Times, 6/26).

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Scientists Find New Way to Create Stem Cells

‘Chemical’ programming avoids problems genetic manipulation poses, study finds
From Forbes.com

April 23 (HealthDay News) — Scientists have converted adult cells into embryonic-like stem cells by using chemical programming instead of genetic manipulation.

Gene manipulation is an older method that has posed the risk of serious health problems such as cancer, the researchers explained.

The ability to make stem cells without genetically altering them could lead to the development of many new types of therapies for a wide range of diseases, including type 1 diabetes and Parkinson’s disease, the team noted.

“We are very excited about this breakthrough in generating embryonic-like cells from fibroblasts [cells that give rise to connective tissue] without using any genetic material. Scientists have been dreaming about this for years,” research leader Sheng Ding, an associate professor at the Scripps Research Institute in La Jolla, Calif., said in a Scripps news release.

Ding and his colleagues reprogrammed adult cells by engineering and using recombinant proteins, which are proteins made from the recombination of fragments of DNA from different organisms. They experimented with these proteins until they found the exact mix that enabled them to gradually reprogram the adult cells.

The reprogrammed embryonic-like cells from fibroblasts behaved the same as embryonic stem cells in terms of molecular and functional features, including differentiation into various cell types, such as neurons, pancreatic cells and beating cardiac muscle cells.

The study, published online April 23 in the journal Cell Stem Cell, was supported by Fate Therapeutics.

Guidelines for broader stem cell research unveiled

By Saundra Young, CNN.com

The Obama administration released a draft of guidelines for federal funding of human embryonic stem cell research Friday.

Under the new guidelines, federal funding would be allowed only for research using human embryonic stem cells from embryos created solely for reproductive purposes by in vitro fertilization. The embryos would have to no longer be needed for reproduction, and the donors would have to consent to their use for research.

Funding for research using adult stem cells and induced pluripotent stem cells will continue. Funding will not be allowed for stem cells obtained from other sources, including somatic cell nuclear transfer, also known as cloning; in vitro fertilization embryos created specifically for research purposes; and parthenogenesis, the development of an unfertilized egg.

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UW researchers find safer way to reprogram cells

By Mark Johnson of the Journal Sentinel

Having mastered the ability to roll back a cell’s clock to its embryonic origin, scientists at the University of Wisconsin-Madison cleared a major technical hurdle this week, raising hopes that the technique could usher in a new kind of medicine that exploits the body’s own repair system.

Stem cell pioneer James Thomson and his colleagues reported Thursday that they have developed a safer way of turning cells from the foreskins of newborns into something very similar to embryonic stem cells.

Previous methods accomplished the trick but left behind viruses and outside genes, remnants of which could cause mutations, block the cells from growing into more specific types and even lead to tumors.

The UW team bypassed this obstacle by delivering the special genes with a plasmid, a small, very stable circle of DNA. This package reprogrammed the skin cells and was eventually diluted out of them. What remained were cells that appear to have the healing potential of embryonic stem cells, Thomson and his colleagues reported in the journal Science.

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Bedford researcher IDs genes separating adult, embryonic stem cells

By Marc Songini, MassHighTech.com

Scientists at the Bedford Research Foundation (BRF) believe they may have discovered the key genetic differences between embryonic stem cells and adult stem cells.

Working with a team of clinician scientists at the University of Athens in Greece, the Bedford-based BRF researchers found a connection between cell multiplication and a set of genes. It’s well known that stem cells have a widespread use in many therapies. The more controversial embryonic stem cells are capable of virtual endless multiplication and can replicate into any cell in the body. However, adult stem cells have proved they are limited in their scalability and adaptability.

For years, scientists have been trying to understand just what sets the two stem cell types apart. Now, according to BRF stem cell researcher Ann Kiessling, it appears that early human embryo cells have circadian genes — that is, genes that have a roughly 24-hour cycle. This was surprising; although scientists have learned that some human tissues cycle every 24 hours (in phase with a master pacemaker in the brain that responds to light and dark), it was assumed that early embryos were too small to function like fully-grown tissue.

Additionally, Kiessling saw that the RB gene, a powerful cell blockade, was de-activated in the early embryo cells. Because RB is a well-studied blockade that prevents cells from multiplying unless required, this also was surprising. The lack of RB and the presence of a circadian oscillator are unique characteristics that enable independent, continuous cell duplication, she claimed.

To understand the cell machinery needed for independent, highly accurate cell multiplication, it’s necessary to understand early embryos, “because they are the true stem cells,” she stated.

Early Stem Cell Mutation Linked To Autism

From Oneindia.in

A breakthrough study on mice has shown that mutations in neural stem cell development may be linked to autism.

Reported in the Proceedings of the National Academy of Sciences by experts at the Burnham Institute for Medical Research, the study showed that mice lacking the myocyte enhancer factor 2C (MEF2C) protein in neural stem cells had smaller brains, fewer nerve cells and showed behaviours similar to those seen in humans with a form of autism known as Rett Syndrome.

Dr. Stuart A. Lipton, a clinical neurologist who led the study, claims that his team”s study represents the first direct link between a developmental disorder of neural stem cells and the subsequent onset of autism.

“These results give us a good hint of how to look at Rett Syndrome and potentially other forms of autism in humans. Having identified a mutation that causes this defect, we can track what happens. Perhaps we can correct it in a mouse, and if so, eventually correct it in humans,” said Dr. Lipton.

Working in Dr. Lipton’s laboratory, the research team observed that MEF2C turns on specific genes, which drive stem cells to become nerve cells.

The researchers also observed a faulty distribution of neurons, accompanied by severe developmental problems, when they deleted MEF2C from neural stem cells in the animals.

They have revealed that adult mice lacking MEF2C in their brains displayed abnormal anxiety-like behaviours, decreased cognitive function, and marked paw clasping, a behaviour which may be analogous to hand wringing, a notable feature in humans with Rett syndrome.

“There’s a yin and yang to this MEF2C protein. My laboratory recently showed that MEF2C induces embryonic stem cells to become neurons. In this new research, we show that knocking out MEFC2 in the brain results in mice with smaller brains, fewer neurons and reduced neuronal activity. The commonality is the protein’s association in making new neurons,” said Dr. Lipton.

Obama Issues Executive Order To Lift Some Federal Restrictions On Embryonic Stem Cell Research

President Obama on Monday at an event with Democratic and Republican lawmakers is expected to announce that he will reverse restrictions put in place by former President George W. Bush on federal funding for embryonic stem cell research, in keeping with campaign promises to “separate science and politics,” the New York Times reports. Although the decision to reverse the restrictions is “not surprising,” it is “nonetheless of great interest, involving a long-controversial intersection of science and personal moral beliefs,” the Times reports (Stout/Harris, New York Times, 3/7). According to the Washington Post, Bush imposed restrictions in August 2001 that limited federal funding to studies involving stem cell lines that were already in existence — about 21 lines. By lifting the restrictions, Obama will “allow thousands of scientists to study hundreds” of stem cell lines that have been developed during the last eight years, the Post reports. Researchers also will be able to “dismantle cumbersome bureaucracies constructed to work around the constraints and let them exchange scientific ideas more easily,” the Post reports (Stein, Washington Post, 3/7).

Obama’s announcement that he intends to lift the restrictions “is not likely to lead to any immediate change in government policy,” the Times reports. It may take many months for NIH to develop new guidelines for the research, but advocates are expected “to push for the process to go as quickly as possible” so universities can have adequate time to submit grant proposals before September 2010, when NIH must give out the last of the $10.4 billion allotted to the agency in the economic stimulus law.

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Creating Embryonic Stem Cell Lines

Brought to you by http://www.AllThingsScience.com/

The inner cell mass (ICM) cells of blastocyst-stage early human embryos can be removed and cultured. These cells can be grown in the lab indefinitely. Various growth factors cause these cells to develop into a variety of differentiated cells, such as muscle or nerve cells.

Geron gets FDA OK for embryonic stem-cell based therapy

From BizJournals.com

The U.S. Food and Drug Administration has granted clearance of an investigational new drug application that lets Geron Corp. move forward with the world’s first study of a human embryonic stem cell based therapy in man, the company said late Thursday.

Menlo Park-based Geron (NASDAQ:GERN) said it plans to initiate a Phase I multi-center trial that is designed to establish the safety of the drug GRNOPC1 in patients with “complete” American Spinal Injury Association grade A subacute thoracic spinal cord injuries.

“The FDA’s clearance of our GRNOPC1 IND is one of Geron’s most significant accomplishments to date,” said Dr. Thomas B. Okarma, Geron’s president and CEO. “This marks the beginning of what is potentially a new chapter in medical therapeutics — one that reaches beyond pills to a new level of healing: the restoration of organ and tissue function achieved by the injection of healthy replacement cells.”

The ultimate goal for the use of GRNOPC1 is restore spinal cord function by injecting hESC-derived oligodendrocyte progenitor cells directly into the patient’s injured spinal cord.”

Geron funded the original research at the University of Wisconsin-Madison that led to the first isolation of hESCs. The production of oligodendrocytes from hESCs is covered by patent rights licensed to Geron from the University of California.