Pilose antler aqueous extract promotes the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells by stimulating the BMP-2/Smad1, 5/Runx2 signaling pathway

Peptides from Pilose antler aqueous extract(PAAE) have been shown to stimulate the proliferation and differentiation of bone marrow mesenchymal stem cells(BMSCs). However, the underlying molecular mechanisms are not well understood. Here, PAAE was isolated and purified to explore the molecular mechanisms underlying PAAE’s effects on BMSCs as well as its osteoprotective effects in ovariectomized rats. Our results showed that PAAE promoted proliferation and differentiation of BMSCs to become osteoblasts by enhancing ALP activity and increasing extracellular matrix mineralization. The trabecular microarchitecture of ovariectomized rats was also found to be protected by PAAE. Quantitative reverse transcription-polymerase chain reaction(Quantitative RT-PCR) results suggest that PAAE also increased the expression of osteogenic markers including, alkaline phosphatase(ALP), runt-related transcription factor 2(Runx2), osteocalcin(OCN), bone morphogenetic protein-2(BMP-2), and collagen I(COL-I). Immunoblotting results indicated that PAAE upregulated the levels of BMP-2 and Runx2 and was associated with Smad1/5 phosphorylation. PAAE A at the concentration of 200μg·mL^-1 showed the strongest effect on proliferation and osteogenic differentiation of BMSCs after 48 h. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF MS), we identified the molecular weight of PAAE A and found that it is less than 3000 Da and showed several significant peaks. In conclusion, PAAE activates the BMP-2/Smad1, 5/Runx2 pathway to induce osteoblastic differentiation and mineralization in BMSCs and can inhibit OVX-induced bone loss. These mechanisms are likely responsible for its therapeutic effect on postmenopausal osteoporosis.

基于JAK2/STAT3信号通路探讨三棱-莪术含药血清对人异位子宫内膜间质细胞增殖、凋亡和迁移的影响

基于酪氨酸蛋白激酶(Janus kinase, JAK)2/信号传导及转录激活因子(signal transducer and activator of transcription, STAT)3信号通路,研究三棱-莪术含药血清对异位的子宫内膜间质细胞(ectopic endometrial stromal cells, ESCs)增殖、凋亡、迁移和炎症因子分泌的影响。原代培养ESCs,噻唑蓝法(methyl thiazolyl tetrazolium, MTT)检测不同质量分数(5%、10%、20%)三棱、莪术、两药配伍的含药血清和AG490溶液(50μmol·L^(-1))对ESCs增殖的影响,并由此选择最优剂量用于后续实验;将细胞分为空白血清组、三棱组(10%)、莪术组(10%)、配伍组(10%)和AG490组,以流式细胞术检测ESCs凋亡水平,细胞划痕实验检测细胞迁移能力,酶联免疫吸附测定法(enzyme linked immunosorbent assay, ELISA)检测细胞白细胞介素(interleukin, IL)-1β、IL-6和肿瘤坏死因子(tumor necrosis factor, TNF)-α分泌水平,蛋白质印迹法(Western blot)检测含半胱氨酸的天冬氨酸蛋白水解酶(cysteinyl aspartate specific proteinase, caspase)-3、B淋巴细胞瘤(B-cell lymphoma, Bcl)-2、Bcl-2相关X蛋白(Bcl-2 associated X protein, Bax)的蛋白表达以及JAK2、STAT3蛋白的磷酸化水平。结果显示,与空白血清组相比,各给药组均能使ESCs的活力显著降低(P<0.01),尤其10%含药血清细胞活力低于其他组,因此后续实验采用10%的含药血清进行观察。10%的三棱、莪术和两药配伍的含药血清均能使细胞凋亡率显著增加(P<0.01),细胞中caspase-3和Bax蛋白表达均显著升高(P<0.05或P<0.01),Bcl-2蛋白表达显著降低(P<0.01),细胞迁移率显著降低(P<0.05或P<0.01),细胞分泌的IL-1β、IL-6和TNF-α显著减少(P<0.05或P<0.01),JAK2和STAT3的磷酸化水平显著降低(P<0.05或P<0.01)。与三棱、莪术组相比,10%配伍组含药血清孵育后细胞活力更低(P<0.01),caspase-3和Bax蛋白表达较高(P<0.05或P<0.01),Bcl-2蛋白表达更低(P<0.05),JAK2蛋白磷酸化程度较低(P<0.05)。10%配伍组含药血清孵育后,细胞凋亡率明显高于莪术组(P<0.05),细胞的迁移率明显低于莪术组(P<0.01),对STAT3蛋白磷酸化的抑制作用明显强于三棱组(P<0.05)。三棱、莪术及其配伍应用改善子宫内膜异位症的作用机制可能与阻断JAK2/STAT3信号通路,抑制ESCs增殖,促进细胞凋亡,减弱其迁移能力,减少炎症因子的分泌有关,并且三棱-莪术等比配伍效果优于两药单用。