Department of Joint Surgery, Tianjin Hospital, Tianjin 300211, P.R. China.
Mol Med Rep. 2018 Jun;17(6):7789-7796. doi: 10.3892/mmr.2018.8845. Epub 2018 Apr 5.
The present study aimed to investigate the effect of microRNA‑148a downregulation on osteoporosis by using an ovariectomized rat model. Reverse transcription‑quantitative polymerase chain reaction was used to analyze microRNA‑148a expression levels, MTT and flow cytometry assays were used to examine cytotoxicity and apoptosis, respectively. The gap‑associated proteins were quantified using western blotting. The expression of microRNA‑148a was significantly increased in osteoporosis rat following ovariectomy. Overexpression of microRNA‑148a significantly promoted apoptosis and inhibited cell growth, whereas downregulation of microRNA‑148a significantly reduced apoptosis and increased cell growth. Overexpression of microRNA‑148a significantly reduced estrogen receptor a (ERα) protein expression and suppressed phosphoinositide‑3‑kinase regulatory subunit 1 (PI3K) and phosphorylated‑protein kinase B (AKT) protein expression in osteoblasts in vitro. The inhibition of ERα increased the microRNA‑148a effect on apoptosis in osteoblasts in vitro. Subsequently, LY294002, an PI3K inhibitor, significantly increased the effect of microRNA‑148a on apoptosis in osteoblasts in vitro. The findings of the present study revealed that anti‑microRNA‑148a protected cells against ovariectomy‑induced osteoporosis through ERα by PI3K/AKT signaling.
本研究旨在通过建立去卵巢大鼠模型来研究下调 microRNA-148a 对骨质疏松症的影响。采用反转录-定量聚合酶链反应（RT-qPCR）分析 microRNA-148a 表达水平，采用 MTT 法和流式细胞术分别检测细胞毒性和细胞凋亡。采用蛋白质印迹法检测缝隙连接蛋白。结果显示，去卵巢大鼠骨质疏松症时 microRNA-148a 表达显著增加。过表达 microRNA-148a 可显著促进细胞凋亡并抑制细胞生长，而下调 microRNA-148a 则可显著减少细胞凋亡并促进细胞生长。过表达 microRNA-148a 可显著降低体外成骨细胞中雌激素受体 α（ERα）蛋白表达，并抑制磷酸肌醇 3-激酶（PI3K）调节亚基 1（PI3K）和磷酸化蛋白激酶 B（AKT）蛋白表达。抑制 ERα 可增加 microRNA-148a 对体外成骨细胞凋亡的影响。随后，PI3K 抑制剂 LY294002 可显著增加 microRNA-148a 对体外成骨细胞凋亡的影响。本研究结果表明，抗 microRNA-148a 通过 PI3K/AKT 信号通路通过 ERα 保护细胞免受去卵巢诱导的骨质疏松症。
