Harvard Stem Cell Institute scientists at Brigham and Women’s Hospital have found the cellular origin of the tissue scarring caused by organ damage associated with diabetes, lung disease, high blood pressure, kidney disease, and other conditions. The buildup of scar tissue is known as fibrosis.
Fibrosis has a number of consequences, including inflammation, and reduced blood and oxygen delivery to the organ. In the long term, the scar tissue can lead to organ failure and eventually death. It is estimated that fibrosis contributes to 45 percent of all deaths in the developed world.
The researchers, led by Benjamin Humphreys, MD, PhD, found that a rare population of stem cells located outside of blood vessels in mice become myofibroblast cells that secrete proteins that cause scar tissue.
Killing these stem cells prevents the deadly complications of fibrosis, the researchers report in the journal Cell Stem Cell online. Rafael Kramann, MD, a postdoctoral fellow in Humphreys’ lab, is the first author on the paper.
Rare stem cells (in red) that give rise to scar-tissue secreting myofibroblast cells, here found near the blood vessels of a mouse kidney (in green).
Credit: Rafael Kramann, M.D.
The research was supported by the Harvard Stem Cell Institute, the National Institutes of Health, the National Institute of Diabetes and Digestive and Kidney Diseases, the American Heart Association, and the Deutsche Forschungsgemeinschaft.
Cited: Humphreys, B. D., and Kramann, R. et al. Perivascular Gli1+ Progenitors Are Key Contributors to Injury-Induced Organ Fibrosis. Cell Stem Cell. January 8, 2015. Advanced online publication November 18, 2014. DOI: 10.1016/j.stem.2014.11.004