Staphylococcal LTA-Induced miR-143 Inhibits Propionibacterium acnes-Mediated Inflammatory Response in Skin

Abstract

Staphylococcus epidermidis (S.epidermidis) plays a critical role in modulating cutaneous inflammatory responses in skin. Although S.epidermidis has been shown to co-colonize with Propionibacterium acnes (P.acnes) in acne lesions, it is unclear whether S.epidermidis is involved in the regulation of P.acnes-induced inflammatory responses. In this study, we demonstrated that S.epidermidis inhibited P.acnes-induced inflammation in skin. P.acnes induced the expression of interleukin-6 and tumor necrosis factor-α via the activation of toll-like receptor (TLR) 2 in both keratinocytes and mouse ears. Staphylococcal lipoteichoic acid activated TLR2 to induce miR-143 in keratinocytes, and miR-143, in turn, directly targeted 3' UTR of TLR2 to decrease the stability of TLR2 mRNA and then decreased TLR2 protein, thus inhibiting P.acnes-induced proinflammatory cytokines. The inhibitory effect of miR-143 was further confirmed invivo as the administration of miR-143 antagomir into mouse ears abrogated the inhibitory effect of lipoteichoic acid on P.acnes-induced inflammation in skin. Taken together, these observations demonstrate that staphylococcal lipoteichoic acid inhibits P.acnes-induced inflammation via the induction of miR-143, and suggest that local modulation of inflammatory responses by S.epidermidis at the site of acne vulgaris might be a beneficial therapeutic strategy for management of P.acnes-induced inflammation.