血管内皮祖细胞改善骨质疏松大鼠骨髓间充质干细胞的增殖及凋亡

Indirect co-culture with endothelial progenitor cells improves proliferation and apoptosis of bone marrow mesenchymal stem cells of osteoporosis rats

背景:研究发现雌激素缺乏骨髓间充质干细胞的活性降低。目的:观察血管内皮祖细胞对去势骨髓间充质干细胞增殖及凋亡特性的影响。方法:1选用6周龄健康雌性SD大鼠行双侧卵巢切除术,建立骨质疏松症动物模型,假手术组仅切除卵巢周围等量脂肪组织;2采用密度梯度离心结合差速贴壁法分离、培养大鼠骨髓间充质干细胞;采用密度梯度离心法结合差速贴壁法利用促进内皮细胞生长的条件培养基诱导培养血管内皮祖细胞;3利用Transwell小室建立血管内皮祖细胞、去势骨髓间充质干细胞间接共培养体系,另设置正常骨髓间充质干细胞-骨髓间充质干细胞组,去势骨髓间充质干细胞-骨髓间充质干细胞组;4采用流式细胞术检测血管内皮祖细胞对去势骨髓间充质干细胞增殖和凋亡的影响。结果与结论:(1)间接共培养第3天,血管内皮祖细胞与去势骨髓间充质干细胞共培养组的S期细胞比例显著大于去势骨髓间充质干细胞组和正常骨髓间充质干细胞组,差异均有显著性意义(P<0.05);(2)间接共培养第10天,血管内皮祖细胞与去势骨髓间充质干细胞共培养组骨髓间充质干细胞凋亡率显著小于去势骨髓间充质干细胞组和正常骨髓间充质干细胞组,差异均有显著性意义(P<0.05);(3)通过血管内皮祖细胞和去势骨髓间充质干细胞间接共培养,发现血管内皮祖细胞可逆转体外去势骨髓间充质干细胞的增殖能力并且抑制其凋亡。

BACKGROUND： Previous studies have found that estrogen deficiency causes a reduction in the activity of bone marrow mesenchymal stem cells（BMSCs）.OBJECTIVE： To explore the effect of endothelial progenitor cells（EPCs） on the BMSCs proliferation and apoptosis ability of osteoporosis rats. METHODS： Healthy female Sprague-Dawley rats, 6 weeks old, were enrolled 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, cell proliferation and immunocytochemistry in vitro. We used Transwell 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.