MIT identifies cells for spinal-cord repairJuly 22, 2008Could lead to nonsurgical treatment for injuries CAMBRIDGE, Mass. - A researcher at MIT's Picower Institute for Learning and Memory has pinpointed stem cells within the spinal cord that, if persuaded to differentiate into more healing cells and fewer scarring cells following an injury, may lead to a new, non-surgical treatment for debilitating spinal-cord injuries. The work, reported in the July issue of the journal PLoS (Public Library of Science) Biology, is by Konstantinos Meletis, a postdoctoral fellow at the Picower Institute, and colleagues at the Karolinska Institute in Sweden. Their results could lead to drugs that might restore some degree of mobility to the 30,000 people worldwide afflicted each year with spinal-cord injuries.
In a developing embryo, stem cells differentiate into all the specialized tissues of the body. In adults, stem cells act as a repair system, replenishing specialized cells, but also maintaining the normal turnover of regenerative organs such as blood, skin or intestinal tissues. The tiny number of stem cells in the adult spinal cord proliferate slowly or rarely, and fail to promote regeneration on their own. But recent experiments show that these same cells, grown in the lab and returned to the injury site, can restore some function in paralyzed rodents and primates. The researchers at MIT and the Karolinska Institute found that neural stem cells in the adult spinal cord are limited to a layer of cube- or column-shaped, cilia-covered cells called ependymal cells. These cells make up the thin membrane lining the inner-brain ventricles and the connecting central column of the spinal cord. "We have been able to genetically mark this neural stem cell population and then follow their behavior," Meletis said. "We find that these cells proliferate upon spinal cord injury, migrate toward the injury site and differentiate over several months." The study uncovers the molecular mechanism underlying the tantalizing results of the rodent and primate and goes one step further: By identifying for the first time where this subpopulation of cells is found, they pave a path toward manipulating them with drugs to boost their inborn ability to repair damaged nerve cells. "The ependymal cells' ability to turn into several different cell types upon injury makes them very interesting from an intervention aspect: Imagine if we could regulate the behavior of this stem cell population to repair damaged nerve cells," Meletis said. Upon injury, ependymal cells proliferate and migrate to the injured area, producing a mass of scar-forming cells, plus fewer cells called oligodendrocytes. The oligodendrocytes restore the myelin, or coating, on nerve cells' long, slender, electrical impulse-carrying projections called axons. Myelin is like the layer of plastic insulation on an electrical wire; without it, nerve cells don't function properly. "The limited functional recovery typically associated with central nervous system injuries is in part due to the failure of severed axons to regrow and reconnect with their target cells in the peripheral nervous system that extends to our arms, hands, legs and feet," Meletis said. "The function of axons that remain intact after injury in humans is often compromised without insulating sheaths of myelin." If scientists could genetically manipulate ependymal cells to produce more myelin and less scar tissue after a spinal cord injury, they could potentially avoid or reverse many of the debilitating effects of this type of injury, the researchers said. Massachusetts Institute of Technology | |||||||||||||||||||||
|
Related Spinal Cord News Articles Alcohol consumption can cause too much cell death, fetal abnormalities The initial signs of fetal alcohol syndrome are slight but classic: facial malformations such as a flat and high upper lip, small eye openings and a short nose. New hope for stroke patients If a stroke patient doesn't get treatment within approximately the first three hours of symptoms, there's not much doctors can do to limit damage to the brain. Teens underestimate risk, overestimate vehicle, highway safety in motor vehicle accidents Most teens' attitudes regarding trauma-related injuries, particularly those due to motor vehicle crashes, reflect an sense of invincibility and focus on fate rather than choice, according to new research published in the August issue of the Journal of the American College of Surgeons. Multiple Sclerosis: new MRI contrast medium enables early diagnosis in animal model In an animal model of multiple sclerosis (MS), neuroradiologists and neurologists of the University hospitals of Heidelberg and Würzburg have been able to visualize inflammatory tissue damage, most of which had remained unrecognized up to now, with the aid of a new contrast medium, Gadofluorine M, in magnetic resonance imaging. Protein plays Jekyll and Hyde role in Lou Gehrig's disease Amyotrophic lateral sclerosis (ALS), more commonly known as Lou Gehrig's disease, is a fatal neurodegenerative disease caused by the death of motor neurons in the brain and spinal cord that control muscle movements from walking and swallowing to breathing. In a groundbreaking study this week in PLoS Biology, Brandeis and Harvard Medical School scientists report key findings about the cause and occurrence of the familial form of ALS. Adult stem cells activated in mammalian brain Adult stem cells originate in a different part of the brain than is commonly believed, and with proper stimulation they can produce new brain cells to replace those lost to disease or injury, a study by UC Irvine scientists has shown. Stanford researchers take first look at working muscle fiber Using an unusual microscope with a tip the size of a needle, Stanford researchers are now able to look at tiny fibers of working muscles in live humans, with minimum discomfort to the patient-a development patients are sure to welcome. Pitt-led Research Provides Insight Into Development of Common Congenital Circulatory Defects University of Pittsburgh-led researchers could provide new insight into how two common congenital circulatory problems-aortic arch deformity and arteriovenous malformations (AVMs)-develop in humans, as reported in the June 15 edition of Developmental Biology. Best treatment for MS may depend on disease subtype Animal studies by University of Michigan scientists suggest that people who experience the same clinical signs of multiple sclerosis (MS) may have different forms of the disease that require different kinds of treatment. Tongue Drive system lets persons with disabilities operate powered wheelchairs, computers A new assistive technology developed by engineers at the Georgia Institute of Technology could help individuals with severe disabilities lead more independent lives. More Spinal Cord News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||