Background/Purpose:

Synovial fibroblasts (SF) with aberrant expression of microRNAs (miRNA) are critical pathogenic regulators of rheumatoid joint, and studies examining the effect of overexpressing or silencing miRNA expression levels in arthritis models can contribute to the development of miRNA-based therapeutics in rheumatoid arthritis (RA). We hypothesized that miR-140-3p and -5p are involved in the RA pathogenesis, and examined whether targeting SF by the intra-articular (i.a.) delivery of these molecules can ameliorate autoimmune arthritis in mice.

Methods:

Synovial tissues were obtained from RA and osteoarthritis patients, and two experimental models in mice were used in this study, collagen-induced arthritis (CIA) and collagen antibody-induced arthritis (CAIA). Recombinant lentiviral vectors were produced by transfecting 293T cells with pre-miR-140, the miR-140 precursor molecule cloned downstream of a CMV promoter, the packaging plasmid psPAX2 and the envelope plasmid pMD2.G by using a calcium phosphate precipitation method. Overexpressing miR-140-3p and -5p in SF and joints was performed by the lentivirus (LV)-mediated transfer of pre-miR-140 with a precursor scramble construct as the negative control. Quantitative real-time PCR was used to examine the expression levels of miR-140-3p and miR-140-5p in SF and synovial tissues. Clinical, histopathological and radiological scores were evaluated in CIA and CAIA joints receiving the i.a. delivery of miR-140-3p and -5p lentiviral vectors. Quantitation of sirtuin 1 (SIRT1) and stromal cell-derived factor-1 (SDF-1), target molecules of miR-140-3p and miR-140-5p, respectively, was carried out by immunoblot/ELISA and real-time PCR in SF, and by immunohistochemical staining and real-time PCR in synovial tissues. For in vitro experiments with SF, cell migration, apoptosis and proliferation were analyzed with Boyden chamber, TUNEL and WST-1 assays, respectively.    

Results:

Lower expression levels of miR-140-3p and -5p were detected in SF and synovial tissues from RA patients and two arthritis models. In both CIA and CAIA mice, the LV-mediated i.a. transfer of miR-140-3p and -5p significantly ameliorated arthritis by clinical, histopathological and radiological evaluations with reduced densities in SF. Overexpressing miR-140 resulted in lower expression levels with correlated kinetic patterns of SIRT1 and SDF-1 in SF and joints. In vitro overexpressing miR-140 in SF enhanced apoptosis, reduced migration and proliferation, and regulated the expression of miR-140 in the presence of pro-inflammatory cytokines.

Conclusion:

Our results demonstrate that targeting SF by the i.a. delivery of miR-140-3p and -5p can ameliorate autoimmune arthritis, and these findings might facilitate the pharmacological development of miRNA-based molecular therapeutics in RA.

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/targeting-synovial-fibroblasts-by-the-intra-articular-delivery-of-microrna-140-3p-and-5p-ameliorates-experimental-autoimmune-arthritis/