Exploration of the miR-187-3p/CNR2 pathway in modulating osteoblast differentiation and treating postmenopausal osteoporosis through mechanical stress

FASEB J. 2024 Jul 15;38(13):e23776. doi: 10.1096/fj.202400113RR.

Abstract

This study aimed to explore how mechanical stress affects osteogenic differentiation via the miR-187-3p/CNR2 pathway. To conduct this study, 24 female C57BL/6 mice, aged 8 weeks, were used and divided into four groups. The Sham and OVX groups did not undergo treadmill exercise, while the Sham + EX and OVX + EX groups received a 8-week treadmill exercise. Post-training, bone marrow and fresh femur samples were collected for further analysis. Molecular biology analysis, histomorphology analysis, and micro-CT analysis were conducted on these samples. Moreover, primary osteoblasts were cultured under osteogenic conditions and divided into GM group and CTS group. The cells in the CTS group underwent a sinusoidal stretching regimen for either 3 or 7 days. The expression of early osteoblast markers (Runx2, OPN, and ALP) was measured to assess differentiation. The study findings revealed that mechanical stress has a regulatory impact on osteoblast differentiation. The expression of miR-187-3p was observed to decrease, facilitating osteogenic differentiation, while the expression of CNR2 increased significantly. These observations suggest that mechanical stress, miR-187-3p, and CNR2 play crucial roles in regulating osteogenic differentiation. Both in vivo and in vitro experiments have confirmed that mechanical stress downregulates miR-187-3p and upregulates CNR2, which leads to the restoration of distal femoral bone mass and enhancement of osteoblast differentiation. Therefore, mechanical stress promotes osteoblasts, resulting in improved osteoporosis through the miR-187-3p/CNR2 signaling pathway. These findings have broad prospect and provide molecular biology guidance for the basic research and clinical application of exercise in the prevention and treatment of PMOP.

Keywords: CNR2; mechanical stress; miR‐187‐3p; osteogenic differentiation; osteoporosis.

MeSH terms

  • Animals
  • Cell Differentiation*
  • Cells, Cultured
  • Female
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs* / genetics
  • MicroRNAs* / metabolism
  • Osteoblasts* / metabolism
  • Osteogenesis*
  • Osteoporosis, Postmenopausal* / genetics
  • Osteoporosis, Postmenopausal* / metabolism
  • Osteoporosis, Postmenopausal* / pathology
  • Osteoporosis, Postmenopausal* / therapy
  • Signal Transduction
  • Stress, Mechanical*

Substances

  • MicroRNAs