Gene reactivated to rejuvenate tissue repair, promote stem cell self-renewal

Date: Nov-11-2013Two groups of scientists at the Children's Medical Center Research Institute at UT Southwestern (CRI) have made complementary discoveries that break new ground on efforts to turn back the body's clock on cellular activity, paving the way for a better understanding of stem cells, tissue growth, and regeneration.

A team led by Dr. Sean Morrison, Director of CRI and Professor of Pediatrics at UT Southwestern Medical Center, has identified an RNA-binding protein called IMP1 that promotes stem cell self-renewal during fetal development. Self-renewal is the process by which stem cells divide to make more stem cells, which is important for the growth of tissues during fetal development and the regeneration of tissues throughout adult life.

At the same time, researchers including Dr. Hao Zhu, who also directs a lab at CRI and is Assistant Professor of Pediatrics and Internal Medicine at UT Southwestern, have shown that another RNA-binding protein, Lin28a, also promotes tissue repair by reactivating a metabolic state reminiscent of the juvenile developmental stage.

Dr. Zhu's research, published in Cell, showed that reactivation of Lin28a - a gene that is normally turned on in fetal but not adult tissues - substantially improved hair regrowth and accelerated tissue repair after ear and digit injuries.

"Our work found that Lin28a promotes regeneration through a metabolic mechanism," said Dr. Zhu. "This finding opens up an exciting possibility that metabolism could be modulated to improve tissue repair, whereby metabolic drugs could be employed to promote regeneration."

Dr. Morrison's investigation, published in the online journal eLife, identified a set of genes including IMP1 that are turned on only within time-limited windows, and control developmental switches in stem cell properties between fetal development and adulthood.

IMP1 is turned off during late fetal development, partly as a consequence of increasing expression of a third family of RNA-binding molecules called let-7 microRNAs. Importantly, let-7 microRNAs are turned on during late fetal development in part due to declining expression of Lin28a.

Drs. Morrison and Zhu's laboratories both studied molecules at different ends of the same pathway - one that regulates stem cell self-renewal and tissue regeneration by modulating the expression of a network of RNA-binding proteins.

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.