Summary of the effects of rosiglitazone on vitiligo.

Differentially expressed genes (DEGs) between the vitiligo lesional skin group and non-lesional skin group among GEO-datasets. a Volcano plot of DEGs among GSE75819 and GSE65127 datasets. The red and blue spots represented relative upregulated and downregulated DEGs based on |fold change| > 1 and adjusted p-value < 0.05. b Cluster heatmap of the top 100 DEGs sorted by log fold change. c Network of GO term enrichment analysis (red frame are pigmentation-related genes; purple frame are lipid biosynthetic process–related genes). d GO terms enrichment analysis of DEGs is presented (each band representing an enriched term or pathway, colored according to a −log10 p-value). e Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment by analysis of all differentially expressed genes (DEGs) (10 potentially vitiligo-relevant pathways and related genes). f Protein–protein interaction (PPI) network between PPAR signing pathway and pigmentation. G Gene-drug prediction of potential compounds.

Melanocyte deficiency in vitiligo lesions is accompanied by impaired expression of PPAR-γ and EDNRB. a Representative images of the melanocytes in healthy skin samples (n = 5) and vitiligo lesions (n = 5) detected by immunofluorescence. Melanocytes were stained with antibodies to TYR (green) and MITF (red). Nuclei were counterstained with DAPI (blue). b Representative images of the expression of PPAR-γ (green) in healthy skin (n = 5) and vitiligo lesions (n = 5) detected using immunofluorescence. Melanocytes were stained with antibodies to MITF (red). Nuclei were counterstained with DAPI (blue). c Representative images of the expression of EDNRB (green) in healthy skin (n = 5) and vitiligo lesions (n = 5) detected using immunofluorescence. Melanocytes were stained with antibodies to MITF (red). Nuclei were counterstained with DAPI (blue).

Effect of PPAR-γ signaling pathway on melanogenesis. a_L-dopa staining of melanoma cells (Mum-2C) treated with rosiglitazone and GW9662 for 48 h. b Quantification of melanogenesis by _L-dopa staining. c Immunofluorescence of TYR in melanoma cells for 48 h. d Immunofluorescence of PPAR-γ in melanoma cells for 48 h. Data represent mean ± 95% confidence interval (CI) ***p < 0.001; ****p < 0.0001; n = 7.

PAPR-γ pathway activation increases melanogenesis in zebrafish. a Melanin granules in the head of zebrafish and melanin granules of zebrafish at 72 hpf. b The area of melanin granules as a percentage of the head area was measured by ImageJ at 72 hpf. c Immunofluorescence analysis of zebrafish at 72 hpf after rosiglitazone and GW9662 treatment. d The expression of ppar-γ, ednrb, mitf, tyr, trp-1, and trp-2 in zebrafish at 72 hpf. Data represent mean ± 95% confidence interval (CI); *p < 0.05; **p < 0.01; ***p < 0.001; n > 3.