Department of Orthopaedics Traumatology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China.
Eur Rev Med Pharmacol Sci. 2019 Jan;23(2):449-455. doi: 10.26355/eurrev_201901_16854.
The purpose of this study was to explore the mechanism of micro-ribonucleic acid (miR)-214-3p in regulating fracture healing in rats with osteoporosis.
A total of 30 female Sprague-Dawley rats were selected and randomly divided into 3 groups, including group A [phosphate-buffered saline (PBS), n=10], group B (AntagomiR-NC, n=10), and group C (AntagomiR-214-3p, n=10). All rats underwent ovariectomy, and the osteoporosis rat model was verified by dual-energy X-ray absorptiometry 8 weeks after the operation. Then the osteoporotic fracture was established in rats via a second operation. From the successful modeling until the 6th week, 50 μL PBS (2 nmoL) was intraperitoneally injected in group A, an equal amount of AntagomiR-NC was injected in group B, and an equal amount of AntagomiR-214-3p was injected in group C once a week. At the 6th week, fracture healing of osteoporosis rats was evaluated. At the same time, the expression of miR-214-3p in the three groups was detected via reverse Transcription-Polymerase Chain Reaction (RT-PCR). Furthermore, the protein expressions of bone morphogenetic protein 2 (BMP2) and Smad4 in the three groups were detected via Western blotting (WB).
After ovariectomy, the bone mineral density in each group was significantly lower than that before ovariectomy, and the differences were statistically significant (p<0.05). Imaging evaluation demonstrated that compared with group A and B, there were significantly more callus tissues in group C. Meanwhile, the fracture line healing was better and blurred, and the internal fixation had no displacement and loosening. RT-PCR results indicated that the expression level of miR-214-3p in group C was significantly lower than that of the other two groups (p<0.05). WB results showed that the protein expression levels of BMP2 and Smad4 in group C were significantly higher than those of group A and group B (p<0.05).
MiR-214-3p delays fracture healing in rats with osteoporotic fracture by inhibiting the BMP/Smad signaling pathway.
本研究旨在探讨微小 RNA（miR）-214-3p 在调节骨质疏松症大鼠骨折愈合中的作用机制。
选择 30 只雌性 Sprague-Dawley 大鼠，随机分为 3 组，包括 A 组（磷酸盐缓冲液（PBS），n=10）、B 组（AntagomiR-NC，n=10）和 C 组（AntagomiR-214-3p，n=10）。所有大鼠均接受卵巢切除术，术后 8 周通过双能 X 射线吸收仪验证骨质疏松症大鼠模型。然后通过第二次手术在大鼠中建立骨质疏松性骨折。从成功建模到第 6 周，A 组大鼠腹腔内注射 50 μL PBS（2 nmoL），B 组大鼠注射等量的 AntagomiR-NC，C 组大鼠每周注射等量的 AntagomiR-214-3p。第 6 周时，评估骨质疏松症大鼠的骨折愈合情况。同时，通过逆转录聚合酶链反应（RT-PCR）检测三组大鼠 miR-214-3p 的表达。此外，通过 Western 印迹（WB）检测三组大鼠骨形态发生蛋白 2（BMP2）和 Smad4 的蛋白表达。
卵巢切除后，各组大鼠的骨密度均明显低于切除前，差异有统计学意义（p<0.05）。影像学评估显示，与 A 组和 B 组相比，C 组的骨痂组织明显更多。同时，骨折线愈合较好且模糊，内固定无移位和松动。RT-PCR 结果显示，C 组 miR-214-3p 的表达水平明显低于其他两组（p<0.05）。WB 结果显示，C 组大鼠 BMP2 和 Smad4 的蛋白表达水平明显高于 A 组和 B 组（p<0.05）。
miR-214-3p 通过抑制 BMP/Smad 信号通路延迟骨质疏松性骨折大鼠的骨折愈合。
