MSCs: The Sentinel and Safe-Guards of Injury

J Cell Physiol. 2016 Jul;231(7):1413-6. doi: 10.1002/jcp.25255. Epub 2015 Nov 26.


Mesenchymal stem cells (MSCs) were originally named because they could differentiate in a variety of mesenchymal phenotypes in culture. Evidence indicates that MSCs arise from perivascular cells, pericytes, when the blood vessels are broken or inflamed. These pericyte/MSCs are situated on every blood vessel in the body. The MSCs sense the micro-environment of the injury site and secrete site-specific factors that serve several important reparative functions: first, a curtain of molecules from the front of the MSCs provide a barrier from the interrogation of the over-aggressive immune system. Second, from the back of the MSCs, a different set of bioactive agents inhibit scar formation and establish a regenerative micro-environment. Third, if bacteria are sensed by the MSCs, they produce powerful protein antibiotics that kill the bacteria on contact. Last, the MSCs surround and encyst intruding solid objects like a piece of wood (a "splinter") or other foreign objects. The MSCs act as a combination paramedic and emergency room (ER) staff to survey the damage, isolate foreign components, stabilize the injured tissues, provide antibiotics and encysting protection before a slower, medicinal sequence can be initiated to regenerate the damaged tissue. The MSCs, thus, act as sentinels to safeguard the individual from intrusion and chronic injury. A societal treatment system has evolved, paramedics and ER procedures, which mirror in a macro-sense what MSCs orchestrate in a micro-sense. Key to this new understanding is that MSCs are not "stem cells," but rather as Medicinal Signaling Cells as the therapeutic agents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Blood Vessels / growth & development*
  • Blood Vessels / injuries
  • Blood Vessels / pathology
  • Cell Differentiation / genetics*
  • Cellular Microenvironment / genetics
  • Cicatrix / pathology
  • Humans
  • Mesenchymal Stem Cell Transplantation
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism
  • Pericytes / cytology*
  • Regenerative Medicine