Fig. 1.

Skin exposure to UVB light triggers kidney inflammatory responses, transient proteinuria, and up-regulation of kidney injury markers. (A) Following skin exposure to a single dose of UVB light (500 mJ/cm²), urine and kidney samples were collected at the time points shown (D = day) following cardiac perfusion. (B–G) Gene expression of (B and C) adhesion molecules vcam-1 and e-selectin and (D–G) inflammatory mediators s100a9, s100a6, il1b, and cxcl12 on different days following exposure to UVB light relative to the non-UV–irradiated controls (D-1) was determined by qPCR. Significance was determined by one-way ANOVA with Tukey’s post hoc (n = 3 to 6 per group; *P < 0.05, **P < 0.01, ***P < 0.001). (H and I) Proteinuria was quantified by (H) Bradford assay and (I) urine albumin/creatinine ratio (UACR) at the times shown after exposure to UV light. Significant differences in proteinuria/UACR were determined relative to measurements from the urine of nonirradiated controls (D-1) using (H) one-way ANOVA with Tukey’s post hoc or (I) Student’s t test (n = 10 per time frame; **P < 0.01). (J and K) Gene expression of renal endothelial injury markers (J) lipocalin-2 and (K) kim-1 over time following skin exposure to UV light was compared to non-UV–exposed controls (D-1). Significance was determined by one-way ANOVA with Tukey’s post hoc (n = 3 to 6 per group; *P < 0.05, **P < 0.01, ***P < 0.001).