When smell cells fail they call in stem cell reservesApril 30, 2007Hopkins researchers have identified a backup supply of stem cells that can repair the most severe damage to the nerves responsible for our sense of smell. These reservists normally lie around and do nothing, but when neighboring cells die, the scientists say, the stem cells jump into action. A report on the discovery will appear online next week in Nature Neuroscience. "These stem cells act like the Army Reserves of our nose," explains lead author Randall Reed, Ph.D., a professor of neuroscience at Johns Hopkins, "supporting a class of active-duty stem cells that help repair normal wear and tear. They don't come in until things are really bad." The only nerve cells in the body to run directly from the brain to the outside world, olfactory cells are under constant assault from harsh chemicals that one might happen to catch a whiff of by accident, risking damage or death. To figure out how the olfactory system repairs severely damaged nerve cells, Reed's team exposed mouse olfactory nerves to a cloud of toxic methyl-bromide gas. Methyl bromide kills not only olfactory nerve cells but also neighboring, non-nerve cells in the nasal passage. Three weeks after chemical exposure, the researchers examined nasal cells to see which, if any, had grown back. They discovered that the newly grown cells, both nerve and non-nerve, grew from HBCs-a population of cells not previously known for repair abilities. "We were stunned because HBCs normally don't grow much or do anything," says Reed. "And the most surprising thing is that HBCs can grow into both nerves and non-nerve cells; they do so by generating the other active type of nasal stem cell." The team then went back and looked at nerve repair under less damaging circumstances where only the olfactory nerve cells are killed. In this situation, the HBCs did nothing to repair the damaged cells; rather, they allowed the previously known stem cells to do all the repair work. "The ability to smell is crucial for eating, mating and survival, and it's important that the olfactory system be fully operational all the time," explains Reed. "The HBCs act as a fail-safe to ensure continued function of the sense of smell." The discovery of these two distinct types of stem cells in one neural tissue is a first, says Reed, who is interested to see if other types of nerves in the body have similar repair mechanisms in play. Johns Hopkins Medical Institutions |
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| Related Stem Cells Current Events and Stem Cells News Articles 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. Iowa State University researcher discovers key to vital DNA, protein interaction A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances." Scientists successfully reprogram blood cells Researchers have transplanted genetically modified hematopoietic stem cells into mice so that their developing red blood cells produce a critical lysosomal enzyme -preventing or reducing organ and central nervous system damage from the often-fatal genetic disorder Hurler's syndrome. More Stem Cells Current Events and Stem Cells News Articles |
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