Researchers reveal repressor protein blocks neural stem cell developmentOctober 11, 2007A protein known to repress gene transcription at the molecular level in a variety of processes also blocks embryonic neural stem cells from differentiating into neurons, according to a study by University of California, San Diego and Howard Hughes Medical Institute (HHMI) researchers published online October 10 in Nature. The research team focused on a repressor protein called SMRT (silencing mediator of retinoic acid and thyroid hormone receptor), which has been shown to repress gene expression in a number of molecular pathways. By creating a strain of "knock-out" mice missing the SMRT gene, the team was able to pinpoint significant alterations in brain development in the absence of SMRT. These findings demonstrate the important role of this protein in preventing premature differentiation of specific brain cells from undifferentiated neural stem cells in utero. "By showing that SMRT prevents differentiation by maintaining neural stem cells in a basic stem cell state, we now have a target to study further how stem cells restrict themselves from differentiating," said first author Kristen Jepsen, Ph.D., an assistant research scientist at the UC San Diego School of Medicine. The research team also noted that in the SMRT-deficient mice, the brain exhibited signs of excessive exposure to retinoic acid--naturally occurring vitamin A--which is a known teratogen (an agent which causes birth defects). This finding suggests that in addition to maintaining neural stem cells in a pre-differentiated state, the SMRT protein controls retinoic-acid induced differentiation and, when missing, abnormalities that mimic vitamin A exposure occur. This finding provides scientists with one more important key to understanding how stem cells maintain their potential to grow into specific cells. "Incremental steps such as this lay the groundwork for continuing studies investigating the potential of stem cells to be used therapeutically to replace damaged or deficient cells associated with disease," said Jepsen. University of California - San Diego |
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| Related Stem Cells Current Events and Stem Cells News Articles Gene mismatch influences success of bone marrow transplants A commonly inherited gene deletion can increase the likelihood of immune complications following bone marrow transplantation, an international team of researchers reports in the November 22 advance online issue of Nature Genetics. New research shows versatility of amniotic fluid stem cells For the first time, scientists have demonstrated that stem cells found in amniotic fluid meet an important test of potential to become specialized cell types, which suggests they may be useful for treating a wider array of diseases and conditions than scientists originally thought. First reconstitution of an epidermis from human embryonic stem cells Stem cell research is making great strides. This is yet again illustrated by a study carried out by the I-STEM* Institute (I-STEM/ Inserm UEVE U861/AFM), published in the Lancet on 21 November 2009. The I-STEM team, directed by Marc Peschanski has just succeeded in recreating a whole epidermis from human embryonic stem cells. Bone Implant Offers Hope for Skull Deformities A synthetic bone matrix offers hope for babies born with craniosynostosis, a condition that causes the plates in the skull to fuse too soon. Your Own Stem Cells Can Treat Heart Disease The largest national stem cell study for heart disease showed the first evidence that transplanting a potent form of adult stem cells into the heart muscle of subjects with severe angina results in less pain and an improved ability to walk. The transplant subjects also experienced fewer deaths than those who didn't receive stem cells. Is hepatic differentiation of embryonic stem cells induced by valproic acid and cytokines? Embryonic stem (ES) cells, known for their capacity to proliferate indefinitely and differentiate into almost all types of cells including hepatocytes, have raised the hope of cellular replacement therapy for liver failure. Paradoxical protein might prevent cancer One difficulty with fighting cancer cells is that they are similar in many respects to the body's stem cells. By focusing on the differences, researchers at Karolinska Institutet have found a new way of tackling colon cancer. The study is presented in the prestigious journal Cell. U of M researchers find 2 units of umbilical cord blood reduce risk of leukemia recurrence A new study from the Masonic Cancer Center, University of Minnesota shows that patients who have acute leukemia and are transplanted with two units of umbilical cord blood (UCB) have significantly reduced risk of the disease returning. The use of stem cells in regenerative medicine may also be detrimental for health The use of stem cells in regenerative medicine is not always beneficial for human health, it may even be harmful according to a work done by the University of Granada and University of León. Scientists have demonstrated that transplantation of human mononuclear cells isolated from umbilical cord blood exerted a deleterious effect in rats with liver cirrhosis. Penn Study Provides First Clear Idea of How Rare Bone Disease Progresses An international team of scientists, led by researchers at the University of Pennsylvania School of Medicine, is taking the first step in developing a treatment for a rare genetic disorder called fibrodysplasia ossificans progressiva (FOP), in which the body's skeletal muscles and soft connective tissue turns to bone, immobilizing patients over a lifetime with a second skeleton. More Stem Cells Current Events and Stem Cells News Articles |
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