miR-21 通过激活 PI3K/Akt 信号通路促进骨折愈合。

MiR-21 promotes fracture healing by activating the PI3K/Akt signaling pathway.

机构信息

Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

出版信息

Eur Rev Med Pharmacol Sci. 2019 Apr;23(7):2727-2733. doi: 10.26355/eurrev_201904_17544.

DOI:10.26355/eurrev_201904_17544

PMID:31002122

Abstract

OBJECTIVE

This study aims to elucidate the potential mechanism of micro ribonucleic acid (miR)-21 in promoting fracture healing.

MATERIALS AND METHODS

30 male Sprague-Dawley rats were randomly divided into group A (phosphate-buffered saline, PBS, n=10), group B (AntagomiR-21, n=10) and group C (AntagomiR-NC, n=10) according to the different treatments. The femoral fracture operation was performed in every rat, which was pathologically diagnosed via X-ray. After the successful modeling, 50 μL (2 nmoL) PBS, 50 μL AntagomiR-21 or 50 μL AntagomiR-NC was intraperitoneally injected into rats in group A, B or C, respectively. The above agents were injected once a week for 6 weeks. At 6 weeks, 3 rats were executed in each group, and the tissue at the fracture end was observed via hematoxylin-eosin (HE) staining. The fracture healing of rats was evaluated via imaging at 1 and 7 weeks. At the same time, the expression of miR-21 in the three groups was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR), and the expression of phosphatidylinositol 3-hydroxy kinase (PI3K) and phosphorylated-serine/threonine-protein kinase B (p-Akt) in the three groups was detected via Western blotting.

RESULTS

According to the histological staining, the bone repair at the fracture end of rats in group B was not significant with fracture and poor continuity compared with those in group A and group C. The imaging evaluation revealed that in group B, the callus tissues were significantly reduced, the fracture line had undesirable healing. There were no displacement and loosening of internal fixation compared with group A and group C. Besides, RT-PCR showed that the miR-21 expression declined markedly in group B compared with that in group A and group C, and the differences were statistically significant (p<0.05). Western blotting manifested that the protein levels of PI3K and p-Akt also declined in group B compared with those in group A and group C, and there were statistically significant differences (p<0.05).

CONCLUSIONS

MiR-21 promotes the fracture healing in fractured rats by activating the PI3K/Akt signaling pathway.

摘要

目的

本研究旨在阐明微小 RNA（miR）-21 促进骨折愈合的潜在机制。

材料和方法

30 只雄性 Sprague-Dawley 大鼠随机分为 A 组（磷酸盐缓冲液，PBS，n=10）、B 组（AntagomiR-21，n=10）和 C 组（AntagomiR-NC，n=10），根据不同的处理方式。每只大鼠均进行股骨骨折手术，通过 X 线进行病理诊断。建模成功后，A、B、C 组大鼠分别腹腔内注射 50μL（2nmoL）PBS、50μL AntagomiR-21 或 50μL AntagomiR-NC。每周注射一次，共 6 周。6 周时，每组处死 3 只大鼠，通过苏木精-伊红（HE）染色观察骨折端组织。通过 1 周和 7 周的影像学检查评估大鼠骨折愈合情况。同时，通过逆转录-聚合酶链反应（RT-PCR）检测三组大鼠 miR-21 的表达，通过 Western blot 检测三组大鼠磷脂酰肌醇 3-羟激酶（PI3K）和磷酸化丝氨酸/苏氨酸蛋白激酶 B（p-Akt）的表达。

结果

根据组织学染色，B 组大鼠骨折端骨修复不明显，骨折连续性差，与 A、C 组相比。影像学评价显示，B 组大鼠骨痂组织明显减少，骨折线愈合不良。与 A、C 组相比，内固定无移位和松动。此外，RT-PCR 显示 B 组大鼠 miR-21 表达明显低于 A、C 组，差异有统计学意义（p<0.05）。Western blot 显示 B 组大鼠 PI3K 和 p-Akt 蛋白水平也明显低于 A、C 组，差异有统计学意义（p<0.05）。