These new results "challenge the most popular hypothesis of how stem cells work in kidney protection and repair, which holds that administered stem cells enter an injured organ where they differentiate into those cells that have been destroyed, and thus replace them both anatomically and functionally," Westenfelder said.
MSC paracrine effects prompt a positive cascade, halt inflammatory response
Rather, the Utah team found that "administered stem cells don't stay in the kidney that has ARF long enough to differentiate into kidney cells, but rather appear to alter the course of ARF by a number of identifiable and some still unexplored paracrine mechanisms. The former include the induction of organ-protective and repair-supporting genes in surviving renal cells, robust suppression of proinflammatory cytokines in the ARF kidney and upregulation of anti-inflammatory genes, as well as the delivery and release at the site of injury of organ-protective and other beneficial gene products by the stem cells per se. Collectively, these and as yet unidentified mechanisms represent a highly potent intervention in ARF," Westenfelder stated.
The study, "Administered mesenchymal stem cells protect against ischemic acute renal failure through differentiation-independent mechanisms," appears in the American Journal of Physiology-Renal Physiology, published by the American Physiological Society. Research was conducted by Florian Tögel, Zhuma Hu, Kathleen Weiss, and Christof Westenfelder of the University of Utah and the Veterans Affairs Medical Center; Jorge Isaac, University of Utah; and Claudia Lange, Bone Marrow Transplantation Center, Hamburg.
Stem cell time in the kidney: about two hours
At first, Westenfelder conceded, the researchers experienced "substantial frustration because the cells were detectable in the kidney for only two hours and
Source:American Physiological Society