Source: Oregon Health & Science University
Date: February 25, 2013
Summary:
For decades scientists around the world have attempted to regenerate primary liver cells known as hepatocytes because of their numerous biomedical applications, including hepatitis research, drug metabolism and toxicity studies, as well as transplantation for cirrhosis and other chronic liver conditions. But no lab in the world has been successful in identifying and growing liver stem cells in culture -- using any available technique -- until now.
In the journal Nature, physician-scientists in the Papé Family Pediatric Research Institute at Oregon Health & Science University Doernbecher Children's Hospital, Portland, Ore., along with investigators at the Hubrecht Institute for Developmental Biology and Stem Cell Research, Utrecht, Netherlands, describe a new method through which they were able to infinitely expand liver stem cells from a mouse in a dish.
In a previous Nature study, investigators at the Hubrecht Institute, led by Hans Clever, M.D, Ph.D., were the first to identify stem cells in the small intestine and colon by observing the expression of the adult stem cell marker Lgr5 and growth in response to a growth factor called Wnt. They also hypothesized that the unique expression pattern of Lgr5 could mark stem cells in other adult tissues, including the liver, an organ for which stem cell identification remained elusive.
In the current Nature study, Markus Grompe, M.D., study co-author, director of the Papé Family Pediatric Research Institute at OHSU Doernbecher Children's Hospital; and professor of pediatrics, and molecular and medical genetics in the OHSU School of Medicine. Grompe and colleagues in the Papé Family Pediatric Research Institute at OHSU Doernbecher used a modified version of the Clever method and discovered that Wnt-induced Lgr5 expression not only marks stem cell production in the liver, but it also defines a class of stem cells that become active when the liver is damaged.
The scientists were able to grow these liver stem cells exponentially in a dish -- an accomplishment never before achieved -- and then transplant them in a specially designed mouse model of liver disease, where they continued to grow and show a modest therapeutic effect.
Showing posts with label expression analysis. Show all posts
Showing posts with label expression analysis. Show all posts
Monday, February 25, 2013
Wednesday, June 06, 2012
The Real Culprit Behind Hardened Arteries? Stem Cells, Says Landmark Study
Source: University of California - Berkeley
Date: June 6, 2012
Summary:
BERKELEY — One of the top suspects behind killer vascular diseases is the victim of mistaken identity, according to researchers from the University of California, Berkeley, who used genetic tracing to help hunt down the real culprit. The UC Berkeley researchers say that these newly discovered stem cells contribute to artery-hardening vascular diseases that can lead to heart attacks and strokes.
The guilty party is not the smooth muscle cells within blood vessel walls, which for decades was thought to combine with cholesterol and fat that can clog arteries. Blocked vessels can eventually lead to heart attacks and strokes, which account for one in three deaths in the United States.
Instead, a previously unknown type of stem cell — a multipotent vascular stem cell — is to blame, and it should now be the focus in the search for new treatments, the scientists report in a new study appearing June 6 in the journal Nature Communications.
Date: June 6, 2012
Summary:
BERKELEY — One of the top suspects behind killer vascular diseases is the victim of mistaken identity, according to researchers from the University of California, Berkeley, who used genetic tracing to help hunt down the real culprit. The UC Berkeley researchers say that these newly discovered stem cells contribute to artery-hardening vascular diseases that can lead to heart attacks and strokes.
The guilty party is not the smooth muscle cells within blood vessel walls, which for decades was thought to combine with cholesterol and fat that can clog arteries. Blocked vessels can eventually lead to heart attacks and strokes, which account for one in three deaths in the United States.
Instead, a previously unknown type of stem cell — a multipotent vascular stem cell — is to blame, and it should now be the focus in the search for new treatments, the scientists report in a new study appearing June 6 in the journal Nature Communications.
Wednesday, December 07, 2011
Salk researchers develop safe way to repair sickle cell disease genes New gene editing technique would heal patients with their own cells
Source: Salk Institute for Biological Studies
Date: December 7, 2011
Summary:
LA JOLLA, CA—Researchers at the Salk Institute for Biological Studies have developed a way to use patients' own cells to potentially cure sickle cell disease and many other disorders caused by mutations in a gene that helps produce blood hemoglobin. The technique uses cells from a patient's skin to generate induced pluripotent stem cells (iPSCs), which are capable of developing into various types of mature tissues—including blood. The scientists say their method, which repairs the beta-globin gene (HBB), avoids gene therapy techniques that can introduce potentially harmful genes into cells. The new technique, which will soon be tested as a therapy in animals, also appears to be much more efficient than other methods tested to date, the researchers say. The study appears in the December 2011 issue of Cell Research.
Date: December 7, 2011
Summary:
LA JOLLA, CA—Researchers at the Salk Institute for Biological Studies have developed a way to use patients' own cells to potentially cure sickle cell disease and many other disorders caused by mutations in a gene that helps produce blood hemoglobin. The technique uses cells from a patient's skin to generate induced pluripotent stem cells (iPSCs), which are capable of developing into various types of mature tissues—including blood. The scientists say their method, which repairs the beta-globin gene (HBB), avoids gene therapy techniques that can introduce potentially harmful genes into cells. The new technique, which will soon be tested as a therapy in animals, also appears to be much more efficient than other methods tested to date, the researchers say. The study appears in the December 2011 issue of Cell Research.
Thursday, October 13, 2011
Understanding the Beginnings of Embryonic Stem Cells Helps Predict the Future
Source: Baylor College of Medicine
Date: October 13, 2011
Summary:
HOUSTON -- Ordinarily, embryonic stem cells exist only a day or two as they begin the formation of the embryo itself. Then they are gone. In the laboratory dish, however, they act more like perpetual stem cells – renewing themselves and exhibiting the ability to form cells of almost any type, a status called totipotency.
Scientists at Baylor College of Medicine showed that laboratory-grown cells express a protein called Blimp1, which represses differentiation to somatic or regular tissue cells during germ cell development. Studies of these cells show that they also express other genes associated with early germ cell specification. A report on their work published online today in the journal Current Biology. It will appear in the Oct. 25 print edition of the journal.
Date: October 13, 2011
Summary:
HOUSTON -- Ordinarily, embryonic stem cells exist only a day or two as they begin the formation of the embryo itself. Then they are gone. In the laboratory dish, however, they act more like perpetual stem cells – renewing themselves and exhibiting the ability to form cells of almost any type, a status called totipotency.
Scientists at Baylor College of Medicine showed that laboratory-grown cells express a protein called Blimp1, which represses differentiation to somatic or regular tissue cells during germ cell development. Studies of these cells show that they also express other genes associated with early germ cell specification. A report on their work published online today in the journal Current Biology. It will appear in the Oct. 25 print edition of the journal.
Friday, July 22, 2011
Scientists Complete First Mapping of Molecule Found in Human Embryonic Stem Cells
Source: University of California - Los Angeles
Date: July 22, 2011
Summary:
Stem cell researchers at UCLA have generated the first genome-wide mapping of a DNA modification called 5-hydroxymethylcytosine (5hmC) in embryonic stem cells, and discovered that it is predominantly found in genes that are turned on, or active. The finding by researchers with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA may prove to be important in controlling diseases like cancer, where the regulation of certain genes plays a role in disease development. The study appears in the July issue of the journal Genome Biology.
Date: July 22, 2011
Summary:
Stem cell researchers at UCLA have generated the first genome-wide mapping of a DNA modification called 5-hydroxymethylcytosine (5hmC) in embryonic stem cells, and discovered that it is predominantly found in genes that are turned on, or active. The finding by researchers with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA may prove to be important in controlling diseases like cancer, where the regulation of certain genes plays a role in disease development. The study appears in the July issue of the journal Genome Biology.
Monday, July 18, 2011
USC Research: Cancer Cells and Stem Cells Share Same Origin
Source: University of Southern California
Date: July 18, 2011
Summary:
Oncogenes are generally thought to be genes that, when mutated, change healthy cells into cancerous tumor cells. Scientists at the Keck School of Medicine of USC have proven that those genes also can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis and cancer with stem cell therapy.
Zhong and colleagues at the Children’s Hospital of Orange County (CHOC) in California and Good Samaritan Hospital Medical Center in New York successfully converted human skin cells into brain cells by suppressing the expression of p53, a protein encoded by a widely studied oncogene. This suggests that p53 mutation helps determine cell fate — good or bad — rather than only the outcome of cancer.
The study is slated to appear in the online edition of Proceedings of the National Academy of Sciences, a peer-reviewed scientific journal, the week of July 18, 2011.
Date: July 18, 2011
Summary:
Oncogenes are generally thought to be genes that, when mutated, change healthy cells into cancerous tumor cells. Scientists at the Keck School of Medicine of USC have proven that those genes also can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis and cancer with stem cell therapy.
Zhong and colleagues at the Children’s Hospital of Orange County (CHOC) in California and Good Samaritan Hospital Medical Center in New York successfully converted human skin cells into brain cells by suppressing the expression of p53, a protein encoded by a widely studied oncogene. This suggests that p53 mutation helps determine cell fate — good or bad — rather than only the outcome of cancer.
The study is slated to appear in the online edition of Proceedings of the National Academy of Sciences, a peer-reviewed scientific journal, the week of July 18, 2011.
Monday, April 11, 2011
Scientists identify a surprising new source of cancer stem cells
Source: Whitehead Institute for Biomedical Research
Date: April 11, 2011
Summary:
CAMBRIDGE, Mass. – Whitehead Institute researchers have discovered that a differentiated cell type found in breast tissue can spontaneously convert to a stem-cell-like state, the first time such behavior has been observed in mammalian cells. These results refute scientific dogma, which states that differentiation is a one-way path; once cells specialize, they cannot return to the flexible stem-cell state on their own. This surprising finding, published online this week in the Proceedings of the National Academy of Sciences (PNAS), may have implications for the development of cancer therapeutics, particularly those aimed at eradicating cancer stem cells.
Date: April 11, 2011
Summary:
CAMBRIDGE, Mass. – Whitehead Institute researchers have discovered that a differentiated cell type found in breast tissue can spontaneously convert to a stem-cell-like state, the first time such behavior has been observed in mammalian cells. These results refute scientific dogma, which states that differentiation is a one-way path; once cells specialize, they cannot return to the flexible stem-cell state on their own. This surprising finding, published online this week in the Proceedings of the National Academy of Sciences (PNAS), may have implications for the development of cancer therapeutics, particularly those aimed at eradicating cancer stem cells.
Wednesday, February 23, 2011
Aging, interrupted
Source: Salk Institute for Biological Studies
Date: February 23, 2011
Summary:
LA JOLLA, CA—The current pace of population aging is without parallel in human history but surprisingly little is known about the human aging process, because lifespans of eight decades or more make it difficult to study. Now, researchers at the Salk Institute for Biological Studies replicated premature aging in the lab, allowing them to study ageing-related disease in a dish.
In the February 23, 2011 advance online edition of the journal Nature, Juan-Carlos Izpisúa Belmonte, Ph.D. a professor in the Salk Institute's Gene Expression Laboratory, and his team report that they successfully generated induced pluripotent stem (iPS) cells from skin cells obtained from patients with Hutchinson-Gilford progeria-who age eight to 10 times faster than the rest of us-and differentiated them into smooth muscle cells displaying the telltale signs of vascular aging.
The Washington Examiner published a news story today based on this news release.
Date: February 23, 2011
Summary:
LA JOLLA, CA—The current pace of population aging is without parallel in human history but surprisingly little is known about the human aging process, because lifespans of eight decades or more make it difficult to study. Now, researchers at the Salk Institute for Biological Studies replicated premature aging in the lab, allowing them to study ageing-related disease in a dish.
In the February 23, 2011 advance online edition of the journal Nature, Juan-Carlos Izpisúa Belmonte, Ph.D. a professor in the Salk Institute's Gene Expression Laboratory, and his team report that they successfully generated induced pluripotent stem (iPS) cells from skin cells obtained from patients with Hutchinson-Gilford progeria-who age eight to 10 times faster than the rest of us-and differentiated them into smooth muscle cells displaying the telltale signs of vascular aging.
The Washington Examiner published a news story today based on this news release.
Wednesday, December 29, 2010
Activity of Certain Stem Cell Genes Linked With Worse Outcomes in Acute Myeloid Leukemia Patients
Source: Stanford University Medical Center
Date: December 29, 2010
Summary:
Leukemia patients whose cancers express higher levels of genes associated with cancer stem cells have a significantly poorer prognosis than patients with lower levels of the genes, say researchers at the Stanford University School of Medicine. The finding is among the first to show that the cancer stem cell hypothesis -- which posits that some cancers spring from and are replenished by a small, hardy population of self-renewing cells -- can be used to predict outcomes in a large group of patients and one day to tailor treatments in the clinic. Alizadeh is a co-senior author of the research, which will be published Dec. 22 in the Journal of the American Medical Association.
Date: December 29, 2010
Summary:
Leukemia patients whose cancers express higher levels of genes associated with cancer stem cells have a significantly poorer prognosis than patients with lower levels of the genes, say researchers at the Stanford University School of Medicine. The finding is among the first to show that the cancer stem cell hypothesis -- which posits that some cancers spring from and are replenished by a small, hardy population of self-renewing cells -- can be used to predict outcomes in a large group of patients and one day to tailor treatments in the clinic. Alizadeh is a co-senior author of the research, which will be published Dec. 22 in the Journal of the American Medical Association.
Wednesday, December 15, 2010
Study identifies multitude of genetic regions key to embryonic stem cell development
Source: Stanford University School of Medicine
Date: December 15, 2010
Summary;
More than 2,000 genetic regions involved in early human development have been identified by researchers at the Stanford University School of Medicine. The regions, called enhancers, are responsible for triggering the expression of distant genes when embryonic stem cells begin to divide to form the many tissues of a growing embryo. The research is published online Dec. 15 in Nature.
Date: December 15, 2010
Summary;
More than 2,000 genetic regions involved in early human development have been identified by researchers at the Stanford University School of Medicine. The regions, called enhancers, are responsible for triggering the expression of distant genes when embryonic stem cells begin to divide to form the many tissues of a growing embryo. The research is published online Dec. 15 in Nature.
Monday, August 09, 2010
New Strategy to Fix a Broken Heart: Scaffold Supports Stem Cell-Derived Cardiac Muscle Cells
Source: University of Washington
Date: August 9, 2010
Summary:
Stem cells now offer hope for achieving what the body can't do: mending broken hearts. Engineers and physicians at the University of Washington have built a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells. A description of the scaffold, which supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals, is published this week in the Proceedings of the National Academy of Sciences.
The researchers built a tiny tubular porous scaffold that supports and stabilizes the fragile cardiac cells and can be injected into a damaged heart, where it will foster cell growth and eventually dissolve away. The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body's ability to supply oxygen and nutrients to the transplanted tissue. Eventually, the idea is that doctors would seed the scaffold with stem cells from either the patient or a donor, then implant it when the patient is treated for a heart attack, before scar tissue has formed.
Date: August 9, 2010
Summary:
Stem cells now offer hope for achieving what the body can't do: mending broken hearts. Engineers and physicians at the University of Washington have built a scaffold that supports the growth and integration of stem cell-derived cardiac muscle cells. A description of the scaffold, which supports the growth of cardiac cells in the lab and encourages blood vessel growth in living animals, is published this week in the Proceedings of the National Academy of Sciences.
The researchers built a tiny tubular porous scaffold that supports and stabilizes the fragile cardiac cells and can be injected into a damaged heart, where it will foster cell growth and eventually dissolve away. The new scaffold not only supports cardiac muscle growth, but potentially accelerates the body's ability to supply oxygen and nutrients to the transplanted tissue. Eventually, the idea is that doctors would seed the scaffold with stem cells from either the patient or a donor, then implant it when the patient is treated for a heart attack, before scar tissue has formed.
Thursday, August 05, 2010
Human embryonic stem cells and reprogrammed cells virtually identical
Source: Whitehead Institute for Biomedical Research
Date: August 5, 2010
Summary:
Human embryonic stem (ES) cells and adult cells reprogrammed to an embryonic stem cell-like state—so-called induced pluripotent stem or iPS cells—exhibit very few differences in their gene expression signatures and are nearly indistinguishable in their chromatin state, according to Whitehead Institute researchers. Their results are published in the August 6 issue of Cell Stem Cell.
iPS cells are made by introducing three key genes into adult cells. These reprogramming factors push the cells from a mature state to a more flexible embryonic stem cell-like state. Like ES cells, iPS cells can then, in theory, be coaxed to mature into almost any type of cell in the body. Unlike ES cells, iPS cells taken from a patient are not likely to be rejected by that patient’s immune system. This difference overcomes a major hurdle in regenerative medicine.
Date: August 5, 2010
Summary:
Human embryonic stem (ES) cells and adult cells reprogrammed to an embryonic stem cell-like state—so-called induced pluripotent stem or iPS cells—exhibit very few differences in their gene expression signatures and are nearly indistinguishable in their chromatin state, according to Whitehead Institute researchers. Their results are published in the August 6 issue of Cell Stem Cell.
iPS cells are made by introducing three key genes into adult cells. These reprogramming factors push the cells from a mature state to a more flexible embryonic stem cell-like state. Like ES cells, iPS cells can then, in theory, be coaxed to mature into almost any type of cell in the body. Unlike ES cells, iPS cells taken from a patient are not likely to be rejected by that patient’s immune system. This difference overcomes a major hurdle in regenerative medicine.
Wednesday, August 04, 2010
Newts' Ability to Regenerate Tissue Replicated in Mouse Cells
Source: Stanford University
Date: August 4, 2010
Summary:
New research suggests a reason why mammals are unable to re-grow a limb or produce new heart muscle cells: Restricting cells' ability to pop in and out of the cell cycle at will -- a prerequisite for the cell division necessary to make new tissue -- reduces the chances that they'll run amok and form potentially deadly cancers.
Scientists at the Stanford University School of Medicine have taken a big step toward being able to confer this regenerative capacity on mammalian muscle cells; they accomplished this feat in experiments with laboratory mice in which they blocked the expression of just two tumor-suppressing proteins. The finding may move us closer to future regenerative therapies in humans -- surprisingly, by sending us shimmying back down the evolutionary tree. The research will be published in Cell Stem Cell.
Wired magazine published a news story based on this news release.
Date: August 4, 2010
Summary:
New research suggests a reason why mammals are unable to re-grow a limb or produce new heart muscle cells: Restricting cells' ability to pop in and out of the cell cycle at will -- a prerequisite for the cell division necessary to make new tissue -- reduces the chances that they'll run amok and form potentially deadly cancers.
Scientists at the Stanford University School of Medicine have taken a big step toward being able to confer this regenerative capacity on mammalian muscle cells; they accomplished this feat in experiments with laboratory mice in which they blocked the expression of just two tumor-suppressing proteins. The finding may move us closer to future regenerative therapies in humans -- surprisingly, by sending us shimmying back down the evolutionary tree. The research will be published in Cell Stem Cell.
Wired magazine published a news story based on this news release.
Thursday, July 01, 2010
Biologists discover how T cells make a commitment
Source: California Institute of Technology
Date: July 1, 2010
Summary:
PASADENA, Calif.—When does a cell decide its particular identity? According to biologists at the California Institute of Technology (Caltech), in the case of T cells—immune system cells that help destroy invading pathogens—the answer is when the cells begin expressing a particular gene called Bcl11b. The activation of Bcl11b is a "clean, nearly perfect indicator of when cells have decided to go on the T-cell pathway," says Ellen Rothenberg, the Albert Billings Ruddock Professor of Biology at Caltech and senior author of a paper about the discovery that appears in the July 2 issue of the journal Science.
Date: July 1, 2010
Summary:
PASADENA, Calif.—When does a cell decide its particular identity? According to biologists at the California Institute of Technology (Caltech), in the case of T cells—immune system cells that help destroy invading pathogens—the answer is when the cells begin expressing a particular gene called Bcl11b. The activation of Bcl11b is a "clean, nearly perfect indicator of when cells have decided to go on the T-cell pathway," says Ellen Rothenberg, the Albert Billings Ruddock Professor of Biology at Caltech and senior author of a paper about the discovery that appears in the July 2 issue of the journal Science.
Wednesday, June 30, 2010
Melanoma-Initiating Cell Identified
Source: Stanford University School of Medicine
Date: June 30, 2010
Summary:
Scientists at the Stanford University School of Medicine have identified a cancer-initiating cell in human melanomas. The finding is significant because the existence of such a cell in the aggressive skin cancer has been a source of debate. It may also explain why current immunotherapies are largely unsuccessful in preventing disease recurrence in human patients. The research will be published in the July 1 issue of Nature.
Date: June 30, 2010
Summary:
Scientists at the Stanford University School of Medicine have identified a cancer-initiating cell in human melanomas. The finding is significant because the existence of such a cell in the aggressive skin cancer has been a source of debate. It may also explain why current immunotherapies are largely unsuccessful in preventing disease recurrence in human patients. The research will be published in the July 1 issue of Nature.
Thursday, February 25, 2010
Gene-based stem cell therapy specifically removes cell receptor that attracts HIV
Source: University of California - Los Angeles
Date: February 25, 2010
UCLA AIDS Institute researchers successfully removed CCR5 — a cell receptor to which HIV-1 binds for infection but which the human body does not need — from human cells. Individuals who naturally lack the CCR5 receptor have been found to be essentially resistant to HIV. Using a humanized mouse model, the researchers transplanted a small RNA molecule known as short hairpin RNA (shRNA), which induced RNA interference into human blood stem cells to inhibit the expression of CCR5 in human immune cells. The findings provide evidence that this strategy can be an effective way to treat HIV-infected individuals, by prompting long-term and stable reduction of CCR5. The results are being published in Blood, Journal of the American Society of Hematology.
Date: February 25, 2010
UCLA AIDS Institute researchers successfully removed CCR5 — a cell receptor to which HIV-1 binds for infection but which the human body does not need — from human cells. Individuals who naturally lack the CCR5 receptor have been found to be essentially resistant to HIV. Using a humanized mouse model, the researchers transplanted a small RNA molecule known as short hairpin RNA (shRNA), which induced RNA interference into human blood stem cells to inhibit the expression of CCR5 in human immune cells. The findings provide evidence that this strategy can be an effective way to treat HIV-infected individuals, by prompting long-term and stable reduction of CCR5. The results are being published in Blood, Journal of the American Society of Hematology.
Monday, February 15, 2010
New study suggests stem cells sabotage their own DNA to produce new tissues
Source: Ottawa Hospital Research Institute
Date: February 15, 2010
Summary:
A new study from the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa suggests that stem cells intentionally break their own DNA as a way of regulating tissue development. The study, published in Proceedings of the National Academy of Sciences (PNAS), could dramatically change how researchers think about tissue development, stem cells and cancer.
The discovery has important implications for a number of areas. It could help researchers develop better ways to activate stem cells, so that they can produce new tissues for therapeutic purposes. It also suggests that DNA mutations, which can contribute to a variety of diseases, may initially occur as a result of a normal cellular process. And it has implications for researchers developing therapies that inhibit programmed cell death, suggesting that such therapies may also inhibit normal tissue development.
Date: February 15, 2010
Summary:
A new study from the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa suggests that stem cells intentionally break their own DNA as a way of regulating tissue development. The study, published in Proceedings of the National Academy of Sciences (PNAS), could dramatically change how researchers think about tissue development, stem cells and cancer.
The discovery has important implications for a number of areas. It could help researchers develop better ways to activate stem cells, so that they can produce new tissues for therapeutic purposes. It also suggests that DNA mutations, which can contribute to a variety of diseases, may initially occur as a result of a normal cellular process. And it has implications for researchers developing therapies that inhibit programmed cell death, suggesting that such therapies may also inhibit normal tissue development.
Tuesday, December 22, 2009
Study shows immune system protein involved in reprogramming adult cells to express stem cell genes
Source: Stanford University Medical Center
Date: December 22, 2009
Summary:
Scientists have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. Scientists believe there is much promise for induced pluripotent stem cells: normal adult cells that have been manipulated to develop the stem-cell-like ability to differentiate into other types of cells, potentially to be used to repair damaged tissue and treat the ravages of disease.
But making these so-called iPS cells is both time-consuming and inefficient. Now researchers at Stanford’s School of Medicine have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. The finding could eliminate a major bottleneck in the generation of iPS and embryonic stem cells — that of removing molecular tags called methyl groups from specific regions of cellular DNA. Without this process of demethylation, the stem cell genes are silent in adult, or differentiated, cells. The research is published online in the Dec. 21 issue of Nature.
Date: December 22, 2009
Summary:
Scientists have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. Scientists believe there is much promise for induced pluripotent stem cells: normal adult cells that have been manipulated to develop the stem-cell-like ability to differentiate into other types of cells, potentially to be used to repair damaged tissue and treat the ravages of disease.
But making these so-called iPS cells is both time-consuming and inefficient. Now researchers at Stanford’s School of Medicine have discovered a protein required to quickly and efficiently reprogram human skin cells to express embryonic stem cell genes. The finding could eliminate a major bottleneck in the generation of iPS and embryonic stem cells — that of removing molecular tags called methyl groups from specific regions of cellular DNA. Without this process of demethylation, the stem cell genes are silent in adult, or differentiated, cells. The research is published online in the Dec. 21 issue of Nature.
Tuesday, December 15, 2009
Marking Tissue-Specific Genes in Embryonic Stem Cells Crucial to Ensure Proper Function
Source: University of California - Los Angeles
Date: December 15, 2009
Summary:
Tissue-specific genes, thought to be dormant or not marked for activation in embryonic stem cells, are indeed marked by transcription factors, with proper marking potentially crucial for the function of tissues derived from stem cells.
The finding in the study by researchers at the Broad Stem Cell Research Center involves a class of genes whose properties previously were thought to be unimportant for stem cell function. Most research has instead focused on genes that regulate a pluripotency network and genes that regulate differentiation of embryonic stem cells into other cell lineages.
The Broad center researchers focused on a third class of genes, those expressed only in defined cell types or tissues, which generally remain silent until long after embryonic stem cells have differentiated into specific cell lineages. The study is published in the Dec. 15, 2009 issue of the peer-reviewed journal Genes and Development.
Date: December 15, 2009
Summary:
Tissue-specific genes, thought to be dormant or not marked for activation in embryonic stem cells, are indeed marked by transcription factors, with proper marking potentially crucial for the function of tissues derived from stem cells.
The finding in the study by researchers at the Broad Stem Cell Research Center involves a class of genes whose properties previously were thought to be unimportant for stem cell function. Most research has instead focused on genes that regulate a pluripotency network and genes that regulate differentiation of embryonic stem cells into other cell lineages.
The Broad center researchers focused on a third class of genes, those expressed only in defined cell types or tissues, which generally remain silent until long after embryonic stem cells have differentiated into specific cell lineages. The study is published in the Dec. 15, 2009 issue of the peer-reviewed journal Genes and Development.
Thursday, December 03, 2009
UCSB, UCL scientists rescue visual function in rats using induced pluripotent stem cells
Source: University of California - Santa Barbara
Date: December 3, 2009
Summary:
An international team of scientists has rescued visual function in laboratory rats with eye disease by using cells similar to stem cells. The research shows the potential for stem cell-based therapies to treat age-related macular degeneration in humans. A team led by Dennis Clegg, of UC Santa Barbara, and Pete Coffey, of University College London (UCL), published their work in two papers, including one published this week in the journal PloS One. The first paper was published in the October 27 issue of the journal Stem Cells.
The scientists worked with rats that have a mutation which causes a defect in retinal pigmented epithelial (RPE) cells and leads to photoreceptor death and subsequent blindness. Human RPE cells were derived from induced pluripotent stem cells –– embryonic stem cell-like cells that can be made from virtually any cell in the body, thus avoiding the controversy involved in using stem cells derived from embryos. Pluripotent means that the cells can become almost any cell in the body.
In experiments spearheaded by UCL's Amanda Carr, the team found that by surgically inserting stem cell-derived RPE into the retinas of the rats before photoreceptor degeneration, vision was retained. They found that the rats receiving the transplant tracked their visual focus in the direction of moving patterns more efficiently than control groups that did not receive a transplant.
Date: December 3, 2009
Summary:
An international team of scientists has rescued visual function in laboratory rats with eye disease by using cells similar to stem cells. The research shows the potential for stem cell-based therapies to treat age-related macular degeneration in humans. A team led by Dennis Clegg, of UC Santa Barbara, and Pete Coffey, of University College London (UCL), published their work in two papers, including one published this week in the journal PloS One. The first paper was published in the October 27 issue of the journal Stem Cells.
The scientists worked with rats that have a mutation which causes a defect in retinal pigmented epithelial (RPE) cells and leads to photoreceptor death and subsequent blindness. Human RPE cells were derived from induced pluripotent stem cells –– embryonic stem cell-like cells that can be made from virtually any cell in the body, thus avoiding the controversy involved in using stem cells derived from embryos. Pluripotent means that the cells can become almost any cell in the body.
In experiments spearheaded by UCL's Amanda Carr, the team found that by surgically inserting stem cell-derived RPE into the retinas of the rats before photoreceptor degeneration, vision was retained. They found that the rats receiving the transplant tracked their visual focus in the direction of moving patterns more efficiently than control groups that did not receive a transplant.
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