Effect of tail vein injection of exogenous BMSCs on osteogenic microenvironment in ovariectomized rats

Abstract

Objective To investigate the effect of tail vein injection of exogenous bone marrow mesenchymal stem cells (BMSCs) on proliferative,osteogenic and adipogenic potential of BMSCs in ovariectomized osteoporotic rats.Methods The animal model of osteoporosis (OP) was established 3 months after ovariectomy (bilateral ovarian resection)in healthy 10-week-old female SD rats with the same batch and weight.The healthy 8-week-old SD GFP rats were selected in the same way as the BMSCs source.The experiment was divided into BMSCs group and control group.The BMSCs (1×106) marked with GFP were injected into BMSCs group rats by tail vein injection.One week after injection,BMSCs were isolated,cultured and purified in vitro to the 3rd,4th passage in all groups.The MTT method was used to detect the growth curves of BMSCs.The oil red O dyeing and alizarin red staining (ARS) were used to compare the adipogenic and osteogenic potential between the two kinds of BMSCs,respectively.The RT-PCR was used to detect the expression of osteogenesis-related genes (Runx2,osteocalcin and osteopontin) and adipogenesis-related genes (PPARγ and LPL) in BMSCs.Results Compared with the control group,the growth curve of BMSCs in BMSCs group rose significantly; the calcified nodule increased significantly after osteogenic induction; the lipid droplet decreased significantly after adipogenic induction.RT-PCR results showed that the Runx2,osteocalcin and osteopontin mRNA expression increased,while the peroxisome PPARγ and LPL mRNA expression decreased in BMSCs group.Conclution By tail vein injection of exogenous BMSCs,the proliferative and osteogenic potential of BMSCs in ovariectomized osteoporotic rats is enhanced,while the adipogenic potential is reduced,which provides a possibility of stem cell therapy for osteoporosis. Key words: Bone marrow; Mesenchymal stem cells; Osteoporosis, postmenopausal; Cell differentiation