Inhibition of microRNA-34a ameliorates murine collagen-induced arthritis
Qiujie Dang1, Fan Yang1, Hongwei Lei1
1Department of Rheumatology and Immunology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, P.R. China.
Abstract:
Rheumatoid arthritis (RA) is one of the most frequently occurring autoimmne diseases, with symptoms including synovium hyperplasia, immune disorder, cartilage damage and bone resorption. It has previously been demonstrated that microRNA-34a (miR-34a) may participate in cell apoptosis, immune activation and bone metabolism, therefore the present study investigated the effects of miR-34a on RA. Collagen-induced arthritic (CIA) mice were employed as a murine model of experimental arthritis, and it was demonstrated that the level of miR-34a in the spleens, lymph nodes and synovium was increased in the CIA mice compared with normal DBA/1j mice. Administration of miR-34a antagomir, the chemically modified inhibitor, ameliorated CIA and delayed the onset of symptoms. Arthritis scores decreased and joint swelling was alleviated with the miR-34a antagomir treatment and the expression of inflammatory cytokines was decreased. miR-34a antagomir delivery significantly decreased the percentage of T cells present including T helper (Th) 1, Th2, Th17 and regulatory T cells. Furthermore miR-34a antagomir-treated CIA mice demonstrated decreased inflammatory-induced bone loss. Overall, it was observed that inhibition of miR-34a ameliorated murine arthritis, downregulated T cell percentage and cytokine expression, and suppressed bone loss. The experimental results suggest that inhibition of miR-34a may offer a novel alternative for the treatment of RA.
Insights
Inhibiting microRNA-34a (miR-34a) reduced symptoms and bone loss in rheumatoid arthritis (RA) mouse models. This suggests targeting miR-34a could be a new treatment strategy for RA patients.
Area of Science:
- Immunology
- Molecular Biology
- Rheumatology
Background:
- Rheumatoid arthritis (RA) is a prevalent autoimmune disease characterized by synovium hyperplasia, immune dysregulation, cartilage degradation, and bone resorption.
- MicroRNA-34a (miR-34a) has been implicated in apoptosis, immune activation, and bone metabolism, suggesting a potential role in RA pathogenesis.
Purpose of the Study:
- To investigate the role of miR-34a in rheumatoid arthritis (RA).
- To evaluate the therapeutic potential of inhibiting miR-34a in a murine model of RA.
Main Methods:
- A collagen-induced arthritis (CIA) mouse model was used to mimic human RA.
- Mice were treated with a miR-34a antagomir, a chemical inhibitor of miR-34a.
- Levels of miR-34a, T cell populations (Th1, Th2, Th17, Treg), inflammatory cytokines, and bone loss were assessed.
Main Results:
- miR-34a levels were elevated in CIA mice compared to controls.
- miR-34a antagomir treatment ameliorated arthritis, reduced disease scores, and alleviated joint swelling.
- Inhibition of miR-34a decreased inflammatory cytokine expression and suppressed T cell populations.
- Treatment with miR-34a antagomir significantly reduced inflammatory-induced bone loss in CIA mice.
Conclusions:
- Inhibition of miR-34a effectively ameliorated murine arthritis, reduced T cell activation, and suppressed bone loss.
- Targeting miR-34a presents a promising novel therapeutic strategy for rheumatoid arthritis.
