Cellular Physiology and Biochemistry (May 2017)

Effect of 1,25-(OH)2D3 on Proliferation of Fibroblast-Like Synoviocytes and Expressions of Pro-Inflammatory Cytokines through Regulating MicroRNA-22 in a Rat Model of Rheumatoid Arthritis

  • Ping Fan,
  • Lan He,
  • Nan Hu,
  • Jing Luo,
  • Jing Zhang,
  • Ling-Fei Mo,
  • Yan-Hua Wang,
  • Dan Pu,
  • Xiao-Hong Lv,
  • Zhi-Ming Hao,
  • Chang-Hai Ding,
  • Wu-Jun Xue,
  • Yang Li

DOI
https://doi.org/10.1159/000477123
Journal volume & issue
Vol. 42, no. 1
pp. 145 – 155

Abstract

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Objective: This study aims to investigate the regulatory mechanism of 1,25-(OH)2D3 on the proliferation of fibroblast-like synoviocytes (FLS) and expressions of pro-inflammatory cytokines in rheumatoid arthritis (RA) rats via microRNA-22 (miR-22). Methods: A rat model of RA was established with a subcutaneous injection of type II collagen. After treated with different concentrations of 1,25-(OH)2D3 the proliferation of FLS was estimated by the MTT method, and the optimal concentration of 1,25-(OH)2D3 was selected for further experiments. Cell proliferation was detected by MTT. Cell cycle and apoptosis were analyzed by FCM. The IL-1β, IL-6, IL-8, and PGE2 protein expressions were determined by ELISA, and MMP-3, INOS, and Cox-2 mRNA expressions were measured by qRT-PCR. Results: The rat model of RA was successfully established. Compared with the blank group, the 1,25-(OH)2D3 and miR-22 inhibitors groups exhibited higher proliferation inhibition and apoptosis rates, lower levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and PGE2), and decreased mRNA expressions of MMP-3, INOS, and Cox-2. The miR-22 mimics group had lower proliferation inhibition and apoptosis rates, elevated expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 than the blank group. In contrast to the 1,25-(OH)2D3 group, the proliferation inhibition and apoptosis rates were down-regulated, and the expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 were up-regulated in the 1,25-(OH)2D3 + miR-22 mimics group. Conclusion: Our study demonstrated that 1,25-(OH)2D3 inhibits the proliferation of FLS and alleviates inflammatory response in RA rats by down-regulating miR-22.

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