Effects of bone marrow mesenchymal stem cells on ovarian and testicular function in aging Sprague-Dawley rats induced by D-galactose

To investigate the effect of bone marrow mesenchymal stem cells (MSCs) on ovarian and testicular function of aging Sprague-Dawley (SD) rats induced by D-galactose (D-gal) and try to clarify the underlying functional mechanism. Adherent culture was used to isolate and purify rat MSCs. The status, proliferation and differentiation of MSCs were detected by hematoxylin-eosin staining, MTT, colony formation, flow cytometry and directional differentiation. The aging rat model was established by subcutaneous injection of D-gal, and the homing of MSCs was detected by fluorescence microscope after infusion of GFP-labeled MSCs through caudal vein. ELISA was used to detect the content of sex hormone in serum, and HE staining was used to observe the structure and morphology of testis and ovary. The isolated and purified MSCs were in good condition, and most of the cells were in G1 phase, which had strong abilities of cell proliferation, colony formation and differentiation. After GFP-labeled MSCs were infused, MSCs could be homed into the testis and ovary of rats. MSCs infusion could significantly improve the morphology of testis and ovary, increase the contents of P and E2 while decrease the contents of LH and FSH in female rats, and increase the content of testosterone in male rats (P < 0.01). It also increased the activity of superoxide dismutase (SOD) in serum of ovary and testis and significantly decreased the content of malondialdehyde (MDA). MSCs affected the content of MDA and the activity of SOD by reducing the expression of cyclin-dependent kinase inhibitor 2A (p16) and increasing proliferating cell nuclear antigen (PCNA), consequently improving the aging and injury of reproductive organs.