RegeneRx Biopharmaceuticals, Inc. has announced that Thymosin Beta 4 (TB4) can activate a unique sub-population of resident adult epicardial stem cells such that they recapture embryonic potential, proliferate, migrate and differentiate into functional heart muscle (cardiomyocytes), according to a research paper published online in Nature. The study animals treated with TB4 prior to injury had increased activation of these resident stem cells that functionally integrated into new heart muscle, suggesting that these cells needed to be "primed" prior to injury to effect activation.

Paul R Riley, Ph.D., Professor of Molecular Cardiology at the UCL-Institute of Child Health and the senior author of the publication stated, “Stem cell transplantation is not required,so this would avoid problems with which cells to use, immune rejection, cell survival, mode of delivery, reaching the site of injury, etc. In our study we stimulate resident (epicardial) progenitor cells, which are already in the right environment and poised to respond to the injury signals once activated by Thymosin B4.”

“It is clear that the adult heart can respond to injury with an increase in these stem cells and that TB4 enhances this response,” stated Deepak Srivastava, MD, director of the Gladstone Institute of Cardiovascular Disease, San Francisco, CA and a member of RegeneRx's Scientific Advisory Board. This is one of a number of mechanisms by which TB4 regenerates injured heart tissue beyond increased angiogenesis, decreased inflammation, increased cell survival, and decreased scar formation. Such findings point to the potential of using the patient's resident adult stem-cell population (rather than embryonic stem cells) after acute heart attack, congestive heart failure, cardiac ischemia, and reperfusion injury.” The research was conducted by Professor Riley and his colleagues at the Molecular Medicine Unit, UCL Institute of Child Health, London, UK; Harvard Stem Cell Institute and Department of Cardiology, Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA; Institute for Nutritional Sciences, Chinese Academy of Sciences, Shanghai, China; and several other institutes and medical centers in the UK. The work was funded by the British Heart Foundation and published in Nature, doi:10.1038/nature10188.

RegeneRx is focused on the development of a novel therapeutic peptide, Thymosin beta 4, or TB4, for tissue and organ protection, repair and regeneration and currently has three drug candidates in clinical development and has an extensive worldwide patent portfolio covering its product candidates.