Epidermidibacterium keratini gen. nov., sp. nov., a member of the family Sporichthyaceae, isolated from keratin epidermis.

A novel actinobacterial strain, designated EPI-7T, was isolated on R2A agar from human skin (keratinocytes) and subjected to a taxonomic study using a polyphasic approach. Strain EPI-7T showed a Gram-positive reaction, was non-motile, non-spore-forming, and cells had a rod-shape. Colonies were round, convex and pale yellow. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel isolate formed a cluster with several uncultured bacterial clones and with cultured members of the genera Modestobacter and Sporichthya. The 16S rRNA gene sequence similarities with respect to the type strains of recognized species from the above genera and other phylogenetic neighbours ranged from 92.6 to 93.4 %. The G+C content of the genomic DNA was 68.9 mol%. The only isoprenoid quinone was MK-9(H4), and the major fatty acids detected were C17 : 1ω8c, C16 : 0, iso-C15 : 0 and summed feature 3. The major polar lipids were found to be phosphatidylethanolamine, phosphatidylinositol, three unidentified phospholipids, phosphatidylglycerol, phosphatidylcholine, two unidentified amino lipids and three unidentified lipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine. Whole-cell sugars present included rhamnose, glucose and galactose. The combination of the genotypic and phenotypic data allowed differentiation of strain EPI-7T from its closest phylogenetic neighbours and provided evidence that strain EPI-7T represents a novel genus and species in the family Sporichthyaceae. The name Epidermidibacterium keratini gen. nov., sp. nov. is proposed with the type strain being EPI-7T (=KCCM 90264T=JCM 31644T).

Ultraviolet- and infrared-induced 11 beta-hydroxysteroid dehydrogenase type 1 activating skin photoaging is inhibited by red ginseng extract containing high concentration of ginsenoside Rg3(S).

BACKGROUND: Sun irradiation is one of major extrinsic stressors responsible for premature skin aging through activation and expression of 11 beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD1), which converts inactive cortisone to active cortisol. The aim of this study was to evaluate the inhibitory effects of red ginseng extract containing high concentrations of ginsenoside Rg3 (S) (GERg3) on 11ß-HSD1-induced skin photoaging. METHODS: To evaluate the inhibitory effects of GERg3 on ultraviolet- (UV) or infrared (IR)-induced skin photoaging, human dermal fibroblasts or a normal human 3D skin model was exposed to UV or an IR. RT-PCR, ELISA, Western blot, and H&E staining were used for evaluations. GERg3 was isolated from crude red ginseng. RESULTS: GERg3 inhibited the increased expressions of 11ß-HSD1, interleukin (IL)-6, and matrix metalloproteinase-1 (MMP-1) in UVB- or IR-exposed Hs68 cells. Additionally, the increased cortisol, IL-6, and MMP-1 expressions were effectively reduced by GERg3 in UVA-exposed 3D skin models. The photoinduced decrease in type 1 procollagen also recovered as a result of GERg3 treatment in Hs68 cells and the 3D skin model. In addition, the UVA-exposed dermal thickness was decreased in comparison with the UVA-protected 3D skin model, recovered with GERg3 treatment. CONCLUSION: GERg3 had antiphotoaging effects in UV- or IR-exposed human dermal fibroblasts and normal human 3D skin model.

A synthetic C16 omega-hydroxyphytoceramide improves skin barrier functions from diversely perturbed epidermal conditions.

Omega-hydroxyceramides (ω-OH-Cer) play a crucial role in maintaining the integrity of skin barrier. ω-OH-Cer are the primary lipid constituents of the corneocyte lipid envelope (CLE) covalently attached to the outer surface of the cornified envelope linked to involucrin to become bound form lipids in stratum corneum (SC). CLE becomes a hydrophobic impermeable layer of matured corneocyte preventing loss of natural moisturizing factor inside the corneocytes. More importantly, CLE may also play an important role in the formation of proper orientation of intercellular lipid lamellar structure by interdigitating with the intercellular lipids in a comb-like fashion. Abnormal barrier conditions associated with atopic dermatitis but also UVB-irradiated skins are known to have lowered level of bound lipids, especially ω-OH-Cer, which indicate that ω-OH-Cer play an important role in maintaining the integrity of skin barrier. In this study, protective effects of a novel synthetic C16 omega-hydroxyphytoceramides (ω-OH-phytoceramide) on skin barrier function were investigated. Epidermal barrier disruption was induced by UVB irradiation, tape-stripping in hairless mouse and human skin. Protective effect of damaged epidermis was evaluated using the measurement of transepidermal water loss and cohesion of SC. Increased keratinocyte differentiation was verified using cultured keratinocyte through western blot. Results clearly demonstrated that a synthetic C16 ω-OH-phytoceramide enhanced the integrity of SC and accelerated the recovery of damaged skin barrier function by stimulating differentiation process. In a conclusion, a synthetic C16 ω-OH-phytoceramide treatment improved epidermal homeostasis in several disrupted conditions.