Journal: Frontiers in Immunology
Article Title: Staphylococcus epidermidis prevents UV-induced skin aging by suppressing TLR3-mediated senescence
doi: 10.3389/fimmu.2026.1796085
Figure Lengend Snippet: Staphylococcus epidermidis inhibits UVB-induced senescence in keratinocytes. (A) Neonatal human epidermal keratinocytes (NHEKs) at 90% confluence were irradiated with 10 mJ/cm 2 UVB, followed by treatment with 75 μg/mL ≤10kDa S. epi . β-gal staining was performed 24 hours post-treatment. The proportion of senescent cells was quantified using Image (J, B) After UVB irradiation, different concentrations of ≤10kDa S. epi were added to NHEKs. RNA was isolated 24 hours later, and P16 expression was measured by quantitative RT-PCR with β-actin as the internal control. (C) NHEKs at 90% confluence were irradiated with 10mJ/cm 2 UVB, followed by treatment with 75μg/mL ≤10kDa S. epi . Six hours later, intracellular ROS were labeled with DCFH-DA and visualized using fluorescence microscope (excitation: 488 nm; emission: 525 nm), and fluorescence intensity was quantified using Image (J, D) NHEKs were treated with different concentrations of ≤10kDa S. epi . Six hours later, proteins were extracted for γH2Ax analysis, and densitometric analysis of protein bands were quantified by Image (J) Immunoblotting results are representative of three independent experiments performed with independent cultured keratinocytes. (E) NHEKs were irradiated with 10mJ/cm 2 UVB and treated with 75μg/mL ≤10kDa S. epi . Six hours post-treatment, γH2Ax expression was visualized by immunofluorescence, and fluorescence intensity was quantified using Image (J, F) After UVB exposure (10mJ/cm 2 ), NHEKs were treated with different concentrations of ≤10kDa S. epi . RNA was isolated 24 hours later, and the expressions of IL-6 , TNFα and IL-1β was analyzed by quantitative RT-PCR using β-actin as internal control. (G) Following UVB irradiation (10mJ/cm 2 ), NHEKs were treated with different concentrations of ≤10kDa S. epi . 24 hours later, cell culture supernatants were collected, and IL-6 and IL-1β secretion was measured by ELISA. Data represent mean ± SEM from independent biological replicates ( n = 3). All the experiments have been repeated three times. Statistical significances were evaluated by One-way ANOVA. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, n.s., no significance.
Article Snippet: Neonatal human epidermal keratinocytes (NHEKs) and neonatal human fibroblasts were purchased from Lifeline Cell Technology.
Techniques: Irradiation, Staining, Isolation, Expressing, Quantitative RT-PCR, Control, Labeling, Fluorescence, Microscopy, Western Blot, Cell Culture, Immunofluorescence, Enzyme-linked Immunosorbent Assay