Ni Ming, Rui Yunfeng, Chen Qiming, Wang Yan, Li Gang
Department of Orthopaedics, General Hospital of Chinese PLA, Beijing 100853, PR China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2011 Sep;25(9):1103-9.
To investigate the effect of growth differentiation factor 7 (GDF-7) on the tenogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro, to provide evidence for improving the efficacy of BMSCs on tendon repair.
BMSCs were isolated from bone marrow tissue of green fluorescent protein rats by density gradient centrifugation method. Chondrogenic, osteogenic, and adipogenic differentiation assays were used to demonstrate the multi-differentiation potential of the BMSCs. BMSCs at passage 3 were cultured and divided into 4 groups according to different concentrations of GDF-7 (0, 12.5, 25.0, and 50.0 ng/mL): group A, B, C, and D, respectively. After cultured for 2 weeks in vitro, the mRNA expressions of scleraxis, tenomodulin, tenascin C, and collagen type I were detected by real-time fluorescent quantitative PCR method, the protein expressions of tenomodulin, tenascin C, and collagen type I by immunocytochemistry staining in 4 groups, and the protein expressions of tenomodulin by Western blot in groups A and C.
BMSCs had osteogenic, chondrogenic, and adipogenic differentiation potentials. The mRNA expressions of tenomodulin in groups B, C, and D were 2.85, 3.41, and 3.07 times higher than that in group A, respectively; the mRNA expressions of scleraxis in groups B, C, and D were 2.13, 1.50, and 2.56 times higher than that in group A, respectively; and the mRNA expressions of tenascin C in groups B, C, and D were 2.45, 2.86, and 1.88 times higher than that in group A, respectively. There were significant differences between groups B, C, D and group A (P < 0.05), while there was no significant difference among groups B, C, and D (P > 0.05). The mRNA expressions of collagen type I in groups B and C were 1.92 and 2.45 times higher than that in group A, showing significant differences between groups B, C and group A (P < 0.05), but no significant difference between groups A and D (P > 0.05). Immunocytochemistry staining showed that the protein expressions of tenomodulin, tenascin C, and collagen type I were detected in groups B, C, and D but not in group A. The results were further confirmed by Western blot results which showed higher protein expression of tenomodulin in group C than in group A.
GDF-7 can be used to promote tenogenic differentiation of rat BMSCs in vitro.
探讨生长分化因子7（GDF-7）对体外骨髓间充质干细胞（BMSCs）向肌腱分化的影响，为提高BMSCs修复肌腱的疗效提供依据。
采用密度梯度离心法从绿色荧光蛋白大鼠骨髓组织中分离BMSCs。通过软骨分化、成骨分化及脂肪分化实验验证BMSCs的多向分化潜能。将第3代BMSCs培养后，根据不同浓度的GDF-7（0、12.5、25.0和50.0 ng/mL）分为4组：A组、B组、C组和D组。体外培养2周后，采用实时荧光定量PCR法检测4组中scleraxis、腱调蛋白、腱生蛋白C及Ⅰ型胶原的mRNA表达；采用免疫细胞化学染色法检测4组中腱调蛋白、腱生蛋白C及Ⅰ型胶原的蛋白表达；采用蛋白质印迹法检测A组和C组中腱调蛋白的蛋白表达。
BMSCs具有成骨、成软骨及成脂肪分化潜能。B组、C组和D组中腱调蛋白的mRNA表达分别是A组的2.85倍、3.41倍和3.07倍；B组、C组和D组中scleraxis的mRNA表达分别是A组的2.13倍、1.50倍和2.56倍；B组、C组和D组中腱生蛋白C的mRNA表达分别是A组的2.45倍、2.86倍和1.88倍。B组、C组、D组与A组比较差异有统计学意义（P<0.05），而B组、C组和D组之间差异无统计学意义（P>0.05）。B组和C组中Ⅰ型胶原的mRNA表达分别是A组的1.92倍和2.45倍，B组、C组与A组比较差异有统计学意义（P<0.05），A组和D组之间差异无统计学意义（P>0.05）。免疫细胞化学染色显示，B组、C组和D组可检测到腱调蛋白、腱生蛋白C及Ⅰ型胶原的蛋白表达，A组未检测到。蛋白质印迹结果进一步证实C组腱调蛋白的蛋白表达高于A组。
GDF-7可用于促进大鼠BMSCs体外向肌腱分化。
