Iguratimod ameliorates rheumatoid arthritis progression through regulating miR-146a mediated IRAK1 expression and TRAF6/JNK1 pathway: an in vivo and in vitro study.

OBJECTIVES: This study aimed to evaluate the therapeutic effect of iguratimod and its regulatory role on microRNA (miR-146a) and the downstream genes in treating rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) and collagen-induced arthritis (CIA) rat model. METHODS: RA-FLS was isolated from knee synovial tissue of an active RA patient. In vitro, the effect of miR-146a mimic/inhibition on RA-FLS functions was investigated. Then the effect of Iguratimod on cell viability, proliferation, apoptosis, migration, invasion, inflammatory cytokines, miR-146a and its downstream gene/pathway in RA-FLS was evaluated. In vivo, the collagen induced arthritis (CIA) rat model was constructed, then the effects of iguratimod, miR-146a inhibition and their combination on treating CIA rat were assessed. RESULTS: Iguratimod treatment increased miR-146a while decreased cell proliferation, IRAK1 and TRAF6/JNK1 pathway in RA-FLS in a dose-dependent manner. Notably, iguratimod treatment repressed cell proliferation, migration, invasion, TNF-α, IL-1ß, IL-6, IL-17, IRAK1 and TRAF6/JNK1 pathway in RA-FLS, while miR-146a inhibition alleviated the abovementioned effects of Iguratimod on RA-FLS. The in vivo experiments disclosed that iguratimod reduced systemic arthritis score, and decreased TNF-α, IL-1ß, IL-6, IL-17, IRAK1 as well as TRAF6/JNK1 pathway, while enhanced apoptosis in synovial tissue of CIA rat model; and in miR-146a inhibition treated CIA rat model, the effect of iguratimod was diminished. CONCLUSIONS: Iguratimod ameliorates RA progression via regulating miR-146a mediated IRAK1 expression and TRAF6/JNK1 pathway.

TRIM50 Suppresses Pancreatic Cancer Progression and Reverses the Epithelial-Mesenchymal Transition via Facilitating the Ubiquitous Degradation of Snail1.

Emerging evidence suggests that the tripartite motif (TRIM) family play important roles in tumor development and progression. Tripartite motif-containing 50 (TRIM50) is a member of the TRIM family, but little is known regarding its expression and potential functional roles in cancer. In this study, we first analyzed the expression pattern and clinical significance of TRIM50 in pancreatic cancer and found that TRIM50 expression is significantly reduced in pancreatic cancer tissues and its downregulation is associated with poor survival for pancreatic cancer patients. Functionally, TRIM50 overexpression in pancreatic cancer cells decreases their proliferation and motility capabilities and reverses the epithelial-mesenchymal transition (EMT) process, whereas TRIM50 depletion had the opposite effects. Mechanically, TRIM50 directly interacts with Snail1, a key regulator of EMT, and acts as an E3 ubiquitin ligase to target Snail1 for ubiquitous degradation. The function of TRIM50 in suppressing cell migration and EMT depends on TRIM50-promoted Snail1 degradation. In conclusion, our findings identify TRIM50 as a tumor suppressor that inhibits pancreatic cancer progression and reverses EMT via degrading Snail1 and provide new insights into the progression of pancreatic cancer.