Journal: Scientific Reports

Article Title: Carbon dioxide inhibits UVB-induced inflammatory response by activating the proton-sensing receptor, GPR65, in human keratinocytes

doi: 10.1038/s41598-020-79519-0

Figure Lengend Snippet: CO 2 induces extracellular acidification, generating anti-inflammatory effects. ( a ) CO 2 -free (Ctl) and high-CO 2 concentration (CO 2 ) formulations were applied to the surface of the 3D epidermis after exposure to BCECF or BCECF-AM. Intra-epidermal pH was visualized by multiphoton laser microscopy (DermaInspect). Fluorescent images were obtained 0, 1, and 5 min after formulation application. The images shown are representative of three experiments with similar results. ( b ) Representative fluorescence lifetime was calculated from the fluorescent images using SPC Image 2.9.4 ( n = 3, ** P < 0.01 vs. CO 2 0 min, Dunnett’s test). ( c , d ) HEKn were maintained at the indicated pH in an HCl-supplemented medium for 24 h and then irradiated with 20 mJ/cm 2 of UVB. Total RNA was isolated 8 h later, and qRT-PCR was performed to detect TNFα and IL-6 mRNA expression ( n = 3, ** P < 0.01 vs. pH 7.2 UV(+), Dunnett’s test). ( e , f ) HEKn were incubated in 5 or 15% CO 2 for 24 h and then irradiated with 20 mJ/cm 2 of UVB. The low pH (6.9) induced by 15% CO 2 was adjusted to pH 7.2 with NaOH. Total RNA was isolated 8 h later and qRT-PCR was performed to detect TNFα and IL-6 mRNA expression ( n = 3, * P < 0.05, ** P < 0.01, Tukey–Kramer test).

Article Snippet: For intra-epidermal pH imaging, multiphoton laser microscopy (DermaInspect; JenLab, Jena, Germany) was applied.

Techniques: Concentration Assay, Microscopy, Fluorescence, Irradiation, Isolation, Quantitative RT-PCR, Expressing, Incubation