Effects of Apelin-13 on Rat Bone Marrow-Derived Mesenchymal Stem Cell Proliferation Through the AKT/GSK3β/Cyclin D1 Pathway

The migration and proliferation of bone marrow-derived mesenchymal stem cells (BMSC) is critical to treatment of ischemic injury. Apelin is a recently discovered vasoactive peptide, which has been demonstrated to be the endogenous ligand for the previously orphaned G protein-coupled receptor, angiotensin-like 1 receptor. Apelin has mitogenic effects on a wide variety of cell types. However, the effects of apelin on BMSC proliferation have not been evaluated. We hypothesize that the peptide apelin-13 may enhance BMSC proliferation. Rat BMSC obtain from the bone marrow of 3- to 4-month-old SD rats. There are novel data suggesting that apelin-13 significantly simulates BMSC proliferation and promotes the expression of p-AKT, p-GSK3 beta and cyclin D1 in a concentration-dependent manner. Apelin-13-induced the increases of p-AKT, p-GSK3 beta and cyclin D1 could be abolished by LY294002 (AKT inhibitor) which prevents apelin-13-induced BMSC proliferation. However, LiCl (GSK inhibitor) up-regulates the expression of p-GSK3 beta and cyclin D1, promotes BMSC proliferation, which enhances the proliferation effect of apelin-13 obviously. In conclusion, the AKT/GSK3 beta/cyclin D1 signaling pathway is involved in apelin-13-induced BMSC proliferation.