Activin A, p15INK4b Signaling, and Cell Competition Promote Stem/Progenitor Cell Repopulation of Livers in Aging Rats

FLSPCs, resistant to activin A signaling, repopulate livers of older rats; hepatocytes in older rats have less proliferation because of increased activin A and p15INK4b levels and increased apoptosis than younger rats. These factors and cell types might be manipulated to improve liver cell transplantation strategies in patients with liver diseases in which activin A levels are increased.