Pharmacological inhibition of Nampt and Parp1 alleviates skin oxidative stress and inflammation and keratinocyte cell death, hyperproliferation and DNA damage in Spint1a-deficient larvae.

Analysis of neutrophil distribution (A, E) and NFKB transcriptional activity in the skin (C) of wild-type and Spint1a-deficient larvae treated with olaparib (A, C) , and veliparib or talazoparib (E) . Representative images (brightfield and red channel in B, F; green channel in D) of lyz : dsRED and nfkb : eGFP zebrafish larvae of every group are shown. Determination of BrdU positive cells from 48 hpf wild-type and Spint1a-deficient zebrafish larvae treated for 24 hours with 10 μM FK-866 or 100 μM olaparib (G, H) . Representative merge images maximum intensity projection of a confocal Z stack from zebrafish larvae of every group are shown (I) . WIHC with anti-BrdU (green, arrows), anti-p63 (red, basal keratinocyte marker) were counterstained with DAPI (blue). Quantification of TUNEL positive cells from 48 hpf wild-type and Spint1a-deficient zebrafish larvae treated for 24 hours with 100 μM olaparib (J) . Representative images of zebrafish larvae of every group are shown (K) . Quantification of pγH2Ax positive cells from 48 hpf wild-type and Spint1a-deficient zebrafish larvae treated for 24 hours with 10 μM FK-866 or 100 μM olaparib (L) . Similarly, around 60 zebrafish tail folds (red boxed area) were amputated and disaggregated into cells for comet assay analysis in alkaline conditions (N) . Representative merge images of maximum intensity projection of an apotome Z stack from zebrafish larvae of every group are shown (M) . WIHC with anti-pγH2Ax (green, arrows), anti-P63 (basal keratinocyte marker, red) were counterstained with DAPI (blue). Scale bars, 100 μm. Each dot represents one individual. The mean ± SEM (A-L) and median (N) for each group is shown. p -Values were calculated using 1-way ANOVA and Tukey multiple range test (A-L) and Kruskal–Wallis test and Dunn multiple comparisons test (N). * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001, **** p ≤ 0.0001. The data underlying this figure can be found in S1 Data . ANOVA, analysis of variance; Nampt, nicotinamide phosphoribosyltransferase; Parp1, Poly(ADP-Ribose) ...