eDNA-Mediated Cutaneous Protection Against UVB Damage Conferred by Staphylococcal Epidermal Colonization

Abstract

The human skin is a lush microbial habitat which is occupied by a wide array of microorganisms. Among the most common inhabitants are Staphylococcus spp., namely Staphylococcus epidermidis and, in ≈20% of healthy individuals, Staphylococcus aureus. Both bacteria have been associated with cutaneous maladies, where they mostly arrange in a biofilm, thus achieving improved surface adhesion and stability. Moreover, our skin is constantly exposed to numerous oxidative environmental stressors, such as UV-irradiation. Thus, skin cells are equipped with an important antioxidant defense mechanism, the Nrf2–Keap1 pathway. In this work, we aimed to explore the morphology of S. aureus and S. epidermidis as they adhered to healthy human skin and characterize their matrix composition. Furthermore, we hypothesized that the localization of both types of bacteria on a healthy skin surface may provide protective effects against oxidative stressors, such as UV-irradiation. Our results indicate for the first time that S. aureus and S. epidermidis assume a biofilm-like morphology as they adhere to ex vivo healthy human skin and that the cultures’ extracellular matrix (ECM) is composed of extracellular polysaccharides (EPS) and extracellular DNA (eDNA). Both bacterial cultures, as well as isolated S. aureus biofilm eDNA, conferred cutaneous protection against UVB-induced apoptosis. This work emphasized the importance of skin microbiota representatives in the maintenance of a healthy cutaneous redox balance by activating the skin’s natural defense mechanism.

Circadian Oscillations of Minimal Erythema Dose (MED) are Also Influenced by Diet in Patients with Psoriasis: A Chronomedical Study

“…Interestingly, after NB-UVB treatment, MED circadian oscillations are modified and increase from morning to evening only in vegan psoriatic patients. In fact, NB-UVB treatment modifies the cutaneous reactivity to external exposures via (a) the migration of Langerhans cells to lymph nodes [ 84 ] and (b) regularizing the skin microbiome dysregulation due to psoriatic inflammation [ 36 , 85 ], and these effects are magnified by quantities of furocumarins ingested, as seen in the vegan diet. Circadian re-set of MED after treatment also suggests that cutaneous psoriasis should always be treated with the principal of chronomedicine to avoid immunological dysfunction.…”

Exploitation of alternative skin models from academia to industry: proposed functional categories to answer needs and regulation demands

“…Studying skin microbiota through alternative models is very challenging as skin microbiota is a complex and diverse community of microorganisms that play a critical role in maintaining skin health and protecting against harmful pathogens (Ron-Doitch et al, 2021a;Ron-Doitch et al, 2021b). Understanding the skin microbiota profile as a function of varying conditions can be a platform for novel treatment strategies for drugs and skincare products in the industry (Gueniche et al, 2022).…”

Exploring associations between skin, the dermal microbiome, and ultraviolet radiation: advancing possibilities for next-generation sunscreens

“…Despite the pathogenic tendencies of S. aureus, studies have demonstrated its ability to contribute to skin defence against UVB exposure (Ron-Doitch et al, 2021). The eDNA component of its extracellular matrix is suggested to be a key contributor to preventing UVB-induced skin damage.…”

“…The eDNA component of its extracellular matrix is suggested to be a key contributor to preventing UVB-induced skin damage. This is probably because of a subsequent activation of the Nrf2-Keap1 pathway which is known to be crucial in cell defence (Ron-Doitch et al, 2021).…”