骨形态发生蛋白2及碱性成纤维生长因子2对大鼠骨髓间充质干细胞膜片增殖和成骨分化的影响

文题释义： 细胞膜片技术：是在体外接种培养高密度的细胞，使其相互融合生长至100%而形成的透明致密膜状物。该技术不需要胰酶消化即可收集细胞，因此保留了大量的胞外基质、细胞间连接以及细胞-基质连接等结构。目前细胞膜片技术已成为组织工程领域的研究热点，已被推广应用于牙周膜、角膜、心脏、软骨、食管等多种组织器官修复。 成骨细胞：主要由内外骨膜和间充质始祖细胞分化而来，在复杂的骨形成过程中发挥着主要的功能，承担着骨基质的合成、分泌和矿化。骨髓间充质干细胞具有多向分化潜能，能定向分化为成骨细胞，其成骨分化过程可受多种因素的影响，如细胞因子的调控、遗传因素和激素水平等。背景：现阶段骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖、成骨分化的影响和作用机制还尚未可知，如何将生长因子与组织工程细胞膜片技术相整合，最终将其用于骨缺损修复具有重要意义。 目的：探讨单独及联合应用骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖和成骨分化的影响。 方法：体外分离培养鉴定SD大鼠骨髓间充质干细胞并构建细胞膜片，选用不同质量浓度的骨形态发生蛋白2和碱性成纤维生长因子2单独及联合诱导骨髓间充质干细胞膜片，CCK-8法结合碱性磷酸酶活性检测确定2种因子促进膜片增殖和成骨分化的最佳有效质量浓度；然后对骨髓间充质干细胞膜片进行成骨诱导，通过大体及显微镜观察、Vonkossa染色、茜素红染色、RT-PCR检测相关成骨标志物来评估诱导效果。 结果与结论：单独应用骨形态发生蛋白2可增强骨髓间充质干细胞膜片的碱性磷酸酶活性，最佳质量浓度为100 μg/L(P < 0.001)，单独应用碱性成纤维生长因子2能加速骨髓间充质干细胞膜片的增殖，最佳质量浓度为20 μg/L(P < 0.001)，而联合应用既可以促进膜片增殖又能提高其碱性磷酸酶活性(P < 0.001)；经成骨诱导后，4组膜片在形态学上无明显差异，均能诱导骨髓间充质干细胞膜片的成骨分化，其中联合组钙结节最明显(P < 0.001)，可显著促进膜片晚期成骨分化并抑制其早期成骨分化，具有明显的协同促进作用(P < 0.001)。结果表明，骨形态发生蛋白2和碱性成纤维生长因子2联合应用时具有协同作用，既可以促进骨髓间充质干细胞膜片增殖，又能显著增强其成骨诱导能力。ORCID: 0000-0003-1918-579X(何惠宇) 中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程

Effects of bone morphogenetic protein 2 and basic fibroblast growth factor 2 on proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cell sheet

BACKGROUND:The effects and mechanisms of bone morphogenetic protein 2 and basic fibroblast growth factor 2 on the proliferation and osteogenic differentiation of bone mesenchymal stem cells still remain unknown.How to combine the growth factors with tissue-engineered cell patch clamp techniques is of great significance for bone defect repair.OBJECTIVE:To explore the effects of bone morphogenetic protein 2 and basic fibroblast growth factor 2 applied alone or in combination on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cell sheet.METHODS:Bone marrow mesenchymal stem cells from Sprague-Dawley rats were isolated,cultured and identified in vitro to construct cell sheet.Bone morphogenetic protein 2 and basic fibroblast growth factor 2 at different concentrations were individually or jointly used to induce bone marrow mesenchymal stem cell sheet.The cell counting kit-8 assay combined with alkaline phosphatase activity assay was used to determine the optimal concentration of the two factors in promoting cell proliferation and osteogenic differentiation.Osteogenic induction of bone marrow mesenchymal stem cell sheet was assessed by gross and microscopic observations,Vonkossa staining,alizarin red staining,and RT-PCR detection.RESULTS AND CONCLUSION:The single application of bone morphogenetic protein 2 enhanced the alkaline phosphatase activity of the bone marrow mesenchymal stem cell sheet,and the optimal concentration was 100μg/L(P<0.001).The single application of basic fibroblast growth factor 2 accelerated the proliferation of bone marrow mesenchymal stem cell sheet,and the optimal concentration was 20μg/L(P<0.001).Their combination facilitated the proliferation of the cell sheet,and boosted the alkaline phosphatase activities(P<0.001).The four groups of cell sheet showed no significant morphological difference,and the osteogenic differentiation of the bone marrow mesenchymal stem cell sheet could all be induced through the osteogenic induction.Calcium nodules were most significant in the combination group(P<0.001),suggesting that the combination significantly facilitated late osteogenic differentiation,suppressed early osteogenic differentiation of the sheet and showed significant synergistic effect(P<0.001).In summary,the application of bone morphogenetic protein 2 combined with basic fibroblast growth factor 2 plays a synergistic role in promoting the proliferation of bone marrow mesenchymal stem cell sheet and significantly enhances the osteogenic induction.