Effect of sinomenine on activation of rat mast cells RBL-2H3 and its mechanism

SHI Dong-liang; GUO Hui-qing

Abstract：Objective To explore the effect of sinomenine on activation of rat mast cells RBL-2H3 and the un-derlying mechanism.Methods Cultured RBL-2H3 cells were randomly assigned to the controlⅠgroup and the sinome-nine group.Cells in the sinomenine group were treated with sinomenine, while those in the controlⅠ group were treated with PBS.β-hexosaminidase release in the supernatants of these two groups were determined by biochemical methods. The mRNA and protein expression levels of signal regulatory protein α( SIRPα) in these cells were analyzed by qRT-PCR and Western blot.Recombinant plasmids with SIRPαoverexpression or SIRPαsiRNAs were established.Further-more, RBL-2H3 cells were divided into the controlⅡ group, blank vector group, overexpression group, control Ⅲgroup, mock group, and knockdown group.Transfection was not performed in cells of the controlⅡand controlⅢgroups. Cells of the blank vector group were transfected with blank vectors, while cells of the overexpression group were transfected with SIRPαrecombinant vectors.Cells of the mock group were transfected with non-specific siRNA, while cells of the knockdown group were transfected with SIRPαsiRNA.After transfection, sinomenine was added into the controlⅢgroup, mock group, and knockdown group, and expression of SIRPαas well as the levels of interleukin(IL)-4 , IL-6, tumor necrosis factor-α( TNF-α) were determined.Results Compared with the controlⅠ group, β-hexosaminidase re-lease in cells of the sinomenine group was significantly decreased ( P=0.000) and SIRPαmRNA and protein expressions were upregulated ( P=0.000) .Compared with the controlⅡgroup and blank vector group, SIRPαmRNA expression was significantly upregulated (P=0.000) and levels of IL-4, IL-6 and TNF-αwere significantly decreased (P=0.000) in cells of the overexpression group.In contrast, compared with the controlⅢgroup and mock group, SIRPαmRNA ex-pression was significantly downregulated (P=0.000) and levels of IL-4, IL-6 and TNF-αwere significantly higher ( P=0.000) in cells of the knockdown group.Conclusion Sinomenine treatment significantly inhibits activation of rat RBL-2H3 cells and upregulates SIRPαexpression, which mediates the inhibitory effect on RBL-2H3 cells.