骨缺损对脂肪源干细胞骨形态发生蛋白信号通路相关分子的影响

Effect of bone defect on expression of molecules related to bone morphogenetic protein signalingpathway in adipose-derived stem cells

目的探讨脂肪源干细胞（ADSCs）是否存在骨形态发生蛋白（BMP）信号通路，以及骨缺损对大鼠内源性ADSCs中BMP信号通路分子表达的影响。方法取30只Wistar大鼠随机分为空白对照组（A组5只）和实验组（B组25只）。A组不做处理，直接取腹股沟脂肪垫进行ADSCs培养。B组制造骨缺损模型，分别于造模后1、3、7、14、21d取腹股沟脂肪组织进行ADSCs培养，每一时间点取5只大鼠。原代培养7d，提取ADSCs总RNA，采用实时定量逆转录聚合酶链反应技术检测BMP受体（BMPR）和Smads的mRNA表达变化。实验数据用95％可信区间表示。结果实验组骨缺损后1、3、7、14、21dBMPRla表达量均较对照组明显增加，差异有统计学意义（P〈0．05）；骨缺损后7d表达量（2．532，2．552）增加达高峰。实验组骨缺损后1、3、7、14dBMPRlb表达量较对照组明显增加，差异有统计学意义（P〈0．05）；骨缺损后14d表达量（6．628，6．648）增加达高峰。实验组骨缺损3、7、14、21dBMPR2、Smad5、Smad8表达量较对照组明显增加，差异均有统计学意义（P〈0．05）；骨缺损后14dBMPR2、Smad5表达量（3．538，3．658；8．055，8．149）增加达高峰，骨缺损后3dSmad8表达量（3．657，3．759）增加达高峰。实验组骨缺损后7、14、21dSmadl表达量较对照组明显增加，差异均有统计学意义（P〈0．05）；骨缺损后7d表达量（3．641，3．771）增加达高峰。结论ADSCs表达BMPR，可能存在BMP信号通路，骨缺损可引起大鼠ADSCs中BMP信号通路相关分子的表达增加。

Objective To investigate the molecules related to bone morphogenetic protein （BMP）signaling pathway in adipose-derived stem cells （ADSCs） and the effects of bone defect on their expression in rat endogenous ADSCs. Methods Thirty Wistar rats were randomly divided into a control group （group A, n =5） and an experimental group （group B, n =25）. Rats in group A were not treated before their inguinal adipose pads were used to culture ADSCs. Rats in group B were first made into models of bone defect before their inguinal adipose pads were obtained to culture ADSCs in vitro 1, 3, 7, 14 and 21 days after modeling （5 rats for each time）. After 7 days of primary culture, the total RNA was extracted from ADSCs to detect the expressions of BMP receptors and Smads by RT-qPCR. Results The expression of BMPRla was significantly increased in group B at all time points compared with group A （ P 〈 0.05）, and reached the peak at 7 days after bone defect （2. 532, 2. 552）. The expression of BMPRlb was significantly increased in group B at 1, 3, 7 and 14 days compared with group A （P 〈 0.05）, and reached the peak at 14 days after bone defect （6. 628,6. 648）. The expressions of BMPR2, Smad5 and Smad8 were significantly increased in group B at 3, 7, 14 and 21 days compared with group A （ P 〈 0. 05）. The expressions of BMPR2 and Smad5 reached the peak at 14 days after bone defect（3. 538, 3. 658; 8. 055, 8. 149）, and the expression of Smad8 reached the peak at 7 days （3. 657,3. 759）. The expression of Smadl was significantly increased in group B at 7, 14 and 21 days compared with group A （P 〈 0.05）, and reached the peak at 3 days after bone defect （3. 641,3. 771 ）. Conclusions Since ADSCs can express BMP receptors, there may be a BMP signaling pathway in them. A bone defect may possibly induce an increase in expression of the molecules related to BMP signaling pathway in ADSCs.