Department of Orthopedics, The First Affiliated Hospital of Xiamen University, Xiamen, People's Republic of China.
Connect Tissue Res. 2022 Mar;63(2):112-123. doi: 10.1080/03008207.2021.1882442. Epub 2021 Mar 10.
MicroRNA-151b (miR-151b) showed altered expression in ovariectomized rat model of osteoporosis. This study established an ovariectomy-induced osteoporotic rat model to investigate the role of miR-151b in osteoblasts.
Eighteen female Sprague-Dawley (SD) rats were divided randomly into Sham and OVX group (n = 9). The transfections with different miRNAs and expression vectors were confirmed by RT-qPCR. The protein expression of Msx2 was detected by Western blots. The interaction between miR-151b and Msx2D was evaluated by RNA pull-down and dual luciferase reporter assay.
The expression of miR-151b was significantly increased in femoral tissues of ovariectomy-induced osteoporotic rats. The expression of osteogenesis marker genes including RUNX2, ALP, OCN, OSX, and Msx2 were all significantly increased in osteogenic medium (OM) incubated primary osteoblasts and MC3T3-E1 cells. The interaction between miR-151b and Msx2 was confirmed by luciferase reporter assay and RNA pull-down. Moreover, overexpression of miR-151b significantly inhibited Msx2 in both MC3T3-E1 cells and primary osteoblasts, while miR-151b inhibitor had the opposite effect on the expression of Msx2. In addition, in primary osteoblasts and MC3T3-E1 cells, miR-151b overexpression, or Msx2 silence significantly decreased the expression of OSX, ALP, RUNX2, and OCN.
MiR-151b could inhibit osteoblast proliferation, differentiation, and mineralization via downregulating Msx2 in both MC3T3-E1 cells and primary osteoblasts. MiR-151b might serve as a novel therapeutic target for osteoporosis.
miR-151b: microRNA-151b; miRNAs: microRNAs; Msx2: Msh homeobox 2; MAPK: mitogen-activated protein kinase; STAT: signal transducer and activator of transcription; SD: Sprague-Dawley; BMD: bone mineral density; qRT-PCR: quantitative reverse transcription PCR; MTT: methyl thiazolyl tetrazolium; OVX: ovariectomy; ALP: alkaline phosphatase.
微小 RNA-151b（miR-151b）在去卵巢大鼠骨质疏松模型中表达改变。本研究建立了去卵巢诱导的骨质疏松大鼠模型，以研究 miR-151b 在成骨细胞中的作用。
18 只雌性 Sprague-Dawley（SD）大鼠随机分为假手术（Sham）和去卵巢（OVX）组（n=9）。通过 RT-qPCR 证实了不同 miRNA 和表达载体的转染。通过 Western blot 检测 Msx2 的蛋白表达。通过 RNA 下拉和双荧光素酶报告基因检测评估 miR-151b 与 Msx2D 的相互作用。
去卵巢诱导的骨质疏松大鼠股骨组织中 miR-151b 的表达明显增加。成骨培养基（OM）孵育的原代成骨细胞和 MC3T3-E1 细胞中，成骨标记基因包括 RUNX2、ALP、OCN、OSX 和 Msx2 的表达均明显增加。荧光素酶报告基因检测和 RNA 下拉证实了 miR-151b 与 Msx2 的相互作用。此外，在 MC3T3-E1 细胞和原代成骨细胞中过表达 miR-151b 显著抑制 Msx2，而 miR-151b 抑制剂对 Msx2 的表达则有相反的影响。此外，在原代成骨细胞和 MC3T3-E1 细胞中，miR-151b 过表达或 Msx2 沉默均显著降低 OSX、ALP、RUNX2 和 OCN 的表达。
miR-151b 可通过下调 MC3T3-E1 细胞和原代成骨细胞中的 Msx2 来抑制成骨细胞增殖、分化和矿化。miR-151b 可能成为骨质疏松症的一种新的治疗靶点。
