Therapeutic effects of methotrexate encapsulated in hyaluronic acid-coated exosomes derived from Wharton's jelly mesenchymal stem cells in a rat model of rheumatoid arthritis.

Abstract

BACKGROUND: Methotrexate (MTX) is widely used for treating rheumatoid arthritis (RA); however, its clinical application is limited because of its nonspecific distribution and significant long-term adverse effects. We developed a hyaluronic acid (HA)-modified exosome (Exo) encapsulating MTX to enhance therapeutic efficacy in a rat RA model. METHODS: Exosomes were isolated from Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) and loaded with MTX, then coated with HA. Exo/MTX/HA characterized using UV-visible spectrophotometry, and Fourier transform infrared (FTIR) spectroscopy. Encapsulation efficiency, in vitro drug release, and cytotoxicity were assessed. Serum levels of tumor necrosis factor-alpha (TNF-&#x3b1;), interleukin-17 (IL-17), transforming growth factor-beta (TGF-&#x3b2;), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), C-reactive protein (CRP), and rheumatoid factor (RF) were measured by ELISA and commercial kits. Gene expression of T-bet, GATA3, Foxp3, ROR&#x3b3;t, matrix metalloproteinases (MMPs), lincRNA-p21, and MALAT1 was quantified by real-time PCR. RESULTS: The Exo/MTX/HA treatment group showed significantly decreased serum levels of TNF-&#x3b1;, IL-17, CRP, and RF but increased TGF-&#x3b2; levels (p&#xa0;<&#xa0;0.001). Furthermore, Exo/MTX/HA significantly downregulated T-bet, ROR&#x3b3;t, MALAT1, MMP-9, and MMP-13, and upregulated Foxp3, GATA3, and LncRNA-p21 expression (p&#xa0;<&#xa0;0.001). Hematoxylin and Eosin (H&E) staining revealed that, compared with the other treatments, Exo/MTX/HA markedly reduced joint cell infiltration (p&#xa0;<&#xa0;0.01). Safety assessments showed no hepatotoxicity in the Exo/MTX/HA, Exo/MTX, or Exo/HA groups compared to the MTX group. CONCLUSION: This study presents a method to improve the therapeutic effect of methotrexate against rheumatoid arthritis using the Exo/MTX/HA.