by Laurie Erickson.
Researchers at the Perelman School of Medicine at the University of Pennsylvania found that the chromatin in tedinopathic tenocytes had abnormal organization and were unable to function normally or to repair themselves. Chromatin is found in the nucleus of cells and is made from protein and DNA that form the cell chromosomes. Tenocytes are the cells in tendons that make new collagen, so this study has identified a reason why tenocytes injured by tendinopathy can become unable to produce normal collagen or to heal themselves.
The Penn Medicine News blog reported on this study and included several quotes from some of the authors. The lead author, Su Chin Heo, Ph.D., an assistant professor of orthopedic surgery. said,
"This is really important because the research tells us, for the first time, that diseased connective tissue cells change the physical structure of their genomes and stop responding to normal physical cues from their environment,"
Researchers subjected tenocytes to stresses that simulated the chemical and mechanical changes that might take place during the tendinopathy injury, and these environmental changes brought about the DNA changes observed in the nucleus of the cells. When the environmental stresses were removed, the cells did not return to normal.
Now that this study has identified changes in tenocytes from environmental stresses, researchers hope that they can develop small molecule therapy to avoid the tenocyte damage or to reverse it after it happens. Small molecules are low molecular weight molecules that can often be used orally or topically because they can reach the target tissue without the need for injection.