Abstract: Objective To determine whether four-and-a-half LIM-only protein 2(FHL2) can affect macrophage foaming by regulating nuclear factor kappa-B(NF-κB) signaling pathway. Methods FHL2 over-expression plasmids and siRNA of FHL2 were constructed and transfected into human monocyte/macrophages cell line THP-1. Western blot was used to detect the expression of FHL2. The cells were stimulated with oxidized low density lipoprotein(ox-LDL) and the expression of IL-6, IL-1β,TNF-α and other cytokines were detected by ELISA. Oil red O staining was used to detect the degree of cell foaming. The protein expression of NF-κB signaling pathway was detected by Western blot. Results The expression of FHL2 increased after transfected with FHL2 over-expression plasmids while decreased in si-FLH2 transfected cells. FHL2 down-regulated secretion of inflammatory cytokines. Down-regulation of FHL2 alleviated THP-1 macrophage foaming. The down-regulation of FHL2 inhibited activation of NF-κB signaling pathway, while the over-expression FHL2 showed an opposite trend. Conclusions FHL2 down-regulation inhibits the activation of NF-κB signaling pathway, reduces the secretion of inflammatory cytokines and alleviates foaming of macrophages.

Key words: four-and-a-half LIM-only protein 2(FHL2 ), NF-κB signaling pathway, THP-1, macrophage foaming