ABSTRACT
Objective To explore the mechanism that Staphylococcus aureus(S.aureus) α-toxin(Hla) regulate miR-142 expression and inhibit macrophage phagocytosis.Methods BALB/C mice and RAW264.7 cells were infected with wild type S.aureus(WT S.aureus),Hla deletion S.aureus(△HlaS.aureus) or phosphate buffered saline(PBS),and the expression level of miR-142 of skin tissues and cells were detected.miR-142 mimics and inhibitor were then applied in the RAW264.7 culture to examine the effect on phagocytosis.Direct targeting of miR-142 on protein kinase Cα(PKCα) was assessed by luciferase assay and western blotting.Results miR-142 expression in △HlaS.aureus group were significantly down-regulated than WT S.aureus group(P<0.05).MiR-142 mimics inhibited RAW264.7 phagocytosis ability and inhibitor enhanced RAW264.7 phagocytosis ability.PKCα was directly targeted by miR-142.MiR-142 mimics significantly decreased the mRNA expression levels of PKCα in RAW264.7 cells(P<0.05).Conclusion Hla could promote miR-142 expression in macrophages.MiR-142 could inhibit macrophage phagocytosis through down-regulated PKCα.