Fig. 4: Caveolae in melanocytes are necessary for melanin transfer in vitro and in tissue.
From: Coupling of melanocyte signaling and mechanics by caveolae is required for human skin pigmentation
a–c Melanocytes treated with Ctrl (control) or Cav1 (caveolin-1) siRNAs, pre-miR-NC (pre-miRNA-negative control) or pre-miR-203a (pre-miRNA-203a) for 5 days were co-cultured with keratinocytes for the last 2 days. a IFM images of the co-culture immunolabeled for Cav1 (caveolin-1, green) and HMB45 (premelanosome protein PMEL, red). Keratinocytes positive for HMB45-transferred melanin, arrows; melanocytes in merge panels, asterisks. Bars, 20 µm. b Quantification of the frequency of keratinocytes positive for HMB45-positive structures in each condition. c Quantification of HMB45 fluorescent intensity in individual keratinocytes positive in b. d Conventional EM micrographs of 9 days 3D-HRPE (human reconstructed pigmented epidermis) composed of keratinocytes and siCtrl- or siCav1-treated melanocytes. Bars, 2 µm. e Quantification of the number of pigmented melanosomes in keratinocytes at the vicinity of melanocytes. Values are the mean ± s.e.m. b, c Four independent experiments for siCtrl and siCav1 and three independent experiments for pre-miR-NC and pre-miR-203a; e one experiment. b Two-tailed paired t-test; c, e, two-tailed unpaired t-test with Welch’s correction. See also Supplementary Table 4.
