Staphylococcus epidermidis WF2R11 Suppresses PM2.5-Mediated Activation of the Aryl Hydrocarbon Receptor in HaCaT Keratinocytes

Abstract

The skin supports a diverse microbiome whose imbalance is related to skin inflammation and diseases. Exposure to fine particulate matter (PM2.5), a major air pollutant, can adversely affect the skin microbiota equilibrium. In this study, the effect and mechanism of PM2.5 exposure in HaCaT keratinocytes were investigated. PM2.5 stimulated the aryl hydrocarbon receptor (AhR) to produce reactive oxygen species (ROS) in HaCaT cells, leading to mitochondrial dysfunction and intrinsic mitochondrial apoptosis. We observed that the culture medium derived from a particular skin microbe, Staphylococcus epidermidis WF2R11, remarkably reduced oxidative stress in HaCaT cells caused by PM2.5-mediated activation of the AhR pathway. Staphylococcus epidermidis WF2R11 also exhibited inhibition of ROS-induced inflammatory cytokine secretion. Herein, we demonstrated that S. epidermidis WF2R11 could act as a suppressor of AhRs, affect cell proliferation, and inhibit apoptosis. Our results highlight the importance of the clinical application of skin microbiome interventions in the treatment of inflammatory skin diseases.

Microbiota, Oxidative Stress, and Skin Cancer: An Unexpected Triangle

“…This air pollutant was able to stimulate AhR to produce ROS and inflammatory cytokines, eliciting apoptosis. These authors found out that the supernatant derived specifically from the S. epidermidis WF2R11 was able to revert these PM2.5-induced effects by inhibiting AhR activation [ 149 ].…”

“…For example, the administration of L. casei YIT9018 or L. reuteri , two well-known probiotics with anti-inflammatory and antioxidant properties, reduced the incidence of melanoma, metastatic lesion, and significantly prolonged survival in B16 melanoma-bearing animals [ 177 , 178 ]. A diminished content of the skin commensal C. acnes and its secreted product RoxP, with antioxidant properties, has been found in BCC tissues [ 149 ]. Moreover, intra-tumoral injection of C. acnes in a melanoma mouse model significantly decreased melanoma growth and size [ 66 ].…”