Supervillin contributes to LPS-induced inflammatory response in THP-1 cell-derived macrophages

Abstract Supervillin (SVIL), the largest member of villin/gelsolin family, is an actin-binding and membrane-associated protein, that can also be localized to the nucleus. It has been reported that the mRNA expression of SVIL in neutrophils could be increased by lipopolysaccharide (LPS), but the underlying mechanisms remain unknown. Moreover, SVIL was also observed to be involved in the regulation of macrophages’ movement. However, it is not clear whether SVIL is involved in the LPS-induced inflammatory response in macrophages. This work was to investigate the underlying molecular mechanisms of LPS regulating SVIL expression in macrophages and hence the possible role of SVIL in LPS-induced inflammation. Our data showed that in THP-1-derived macrophages, LPS stimulation significantly increased SVIL mRNA and protein expression. Inhibition of TLR4 by Resatorvid (Res) completely reversed the expression of SVIL and inflammatory cytokines (IL-6, IL-1β and TNF-α) induced by LPS. Additionally, ERK1/2 and NF-κB inhibitors (U0126 and BAY) significantly reduced SVIL and IL-6, IL-1β & TNF-α expression. Furthermore, down-regulation of SVIL by SVIL-specific shRNA significantly attenuated the expression of IL-6, IL-1β & TNF-α induced by LPS. Taken together, as a downstream molecule of TLR4/NF-κB and ERK1/2, SVIL was involved in the inflammatory response of LPS-induced elevated IL-6, IL-1β and TNF-α in macrophages.