MiR-20a regulates ASK1 expression and TLR4-dependent cytokine release in rheumatoid fibroblast-like synoviocytes.
Fiche publication
Date publication
juin 2013
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BAHRAM Siamak, Dr FRISCH Benoit, Dr PFEFFER Sébastien, Dr ZUBER Guy
Tous les auteurs :
Philippe L, Alsaleh G, Pichot A, Ostermann E, Zuber G, Frisch B, Sibilia J, Pfeffer S, Bahram S, Wachsmann D, Georgel P
Lien Pubmed
Résumé
OBJECTIVE: To evaluate whether miR-20a belonging to the cluster miR-17-92 is a negative regulator of inflammation in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) by modulating expression of apoptosis signal-regulating kinase (ASK) 1, a key component of the toll-like receptors 4 pathway, upstream of p38 mitogen-activated protein kinase. METHODS: Evaluation of miR-20a and ASK1 mRNA was performed by RT-qPCR. ASK1 protein expression was assessed by western blotting. Overexpression of miR-20a was performed by transfection of RA FLS and THP-1 cells with miR-20a mimics. Interleukin (IL)-6, CXCL-10, IL-1beta and TNF-alpha release were measured by ELISA. The role of miR-20a in vivo was assessed by IL-6 release from macrophages obtained from mice injected intraperitoneally with vectorised miR-20a mimics. RESULTS: We showed that stimulation of RA FLS with lipopolysacharide (LPS) and bacterial lipoproteins (BLP) induces a drop in expression of miR-20a and that this decrease is associated with an upregulation of ASK1 expression. Using transfection of Ask1 3'UTR reporters, we demonstrate that Ask1 is a direct target of miR-20a. Overexpression of miR-20a led to a global decrease in ASK1 protein in BLP- and LPS-activated cells indicating that miR-20a regulates the expression of ASK1 at the translational level. Transfection of miR-20a mimics decreases IL-6 and CXCL10 release by RA FLS and IL-1beta and TNF-alpha by activated THP-1 cells but only in response to LPS. Last, injection of vectorised miR-20a mimics to mice led to a global decrease in ASK1 protein expression and IL-6 secretion in LPS-activated macrophages. CONCLUSIONS: Our data point toward an important role for miR-20a in the regulation of pro-inflammatory cytokines release, by controlling ASK1 expression in RA FLS.
Référence
Ann Rheum Dis. 2013 Jun;72(6):1071-9