Indirect co-culture with endothelial progenitor cells improves proliferation and apoptosis of bone marrow mesenchymal stem cells of osteoporosis rats / 中国组织工程研究

ABSTRACT

BACKGROUND:Previous studies have found that estrogen deficiency causes a reduction in the activity of bone marrow mesenchymal stem cel s (BMSCs). OBJECTIVE:To explore the effect of endothelial progenitor cel s (EPCs) on the BMSCs proliferation and apoptosis ability of osteoporosis rats. METHODS:Healthy female Sprague-Dawley rats, 6 weeks old, were enrol ed and subjected to bilateral ovariectomy to make osteoporosis models. BMSCs and EPCs were isolated using density gradient centrifugation combined with adhesion method, and identified with surface markers, cel proliferation and immunocytochemistry in vitro. We used Transwel inserts to establish EPCs and OVX-BMSCs indirect co-culture system. Control groups were OVX-BMSCs group and sham-BMSCs group in which rats were only subjected to remove the equal amount of fat tissues around the ovary. Flow cytometry was applied to detect BMSCs proliferation and apoptosis ability. RESULTS AND CONCLUSION:Compared with the control groups, the results of flow cytometry test showed that the proportion of OVX-BMSCs at S phase was significantly increased at 3 days of indirect co-culture with EPCs and the apoptosis rate was significanty reduced at 10 days of indirect co-culture with EPCs (both P<0.05). These results suggest that EPCs can promote the proliferation but inhibit the apoptosis of OVX-BMSCs.