A new understanding of the role played by the protein cdk9-55 in muscle regeneration and differentiation may lead to novel therapies to rebuild muscle tissue damaged by disease, injury and aging, according to researchers at the Sbarro Institute for Cancer Research and Molecular Medicine at Temple University in Philadelphia and the University of Siena, Italy.

The research results were  reported in the Journal of Cellular Physiology. Adult skeletal muscle tissue can regenerate in response to direct injury, neurological dysfunction and genetic defects. This healing process begins with an activation of muscle stem cells, known as satellite cells. Once activated, the satellite cells multiply and then differentiate into specific types of muscle fibers that eventually fuse to reconstitute muscle tissue.

The researchers discovered that cdk9-55, a variation of the gene cdk9, is induced specifically when satellite cells begin differentiation and is necessary for the genetic reprogramming required to complete the muscle tissue regeneration process.

Researchers also found that cdk9-55 can be used to increase muscle tissues in healthy tissue. Dr Antonio Giordano, Director of the Sbarro Institute said this discovery has important implications for tissue regeneration in muscle tissue damaged by disease and injury, genetic disorders such as muscular dystrophy, chronic disorders like cancer or HIV that may impair muscle regeneration, and diseases related to aging.