Figure 7

Melanosome transfer from melanocytes to TRP1 siRNA transfected keratinocytes. (a) Transcriptional expression of TRP1 in Normal human epidermal keratinocytes (NHEKs) transfected with TRP1 siRNA in 3 samples compared with scrambled control (NC). (b) Western blots for expression of TRP1 protein in the same 3 NHEK samples transfected with TRP1 siRNA (full gel pictures are shown in Supplementary Fig. 20. (c) Densitometric plots for TRP1 expression as compared with NC normalized with endogenous control β-Actin, confirm downregulation of TRP1 in siRNA transfected keratinocytes. (d) Representative image for pellet color in pure keratinocytes, TRP1 siRNA transfected keratinocytes that were co-cultured with melanocytes and harvested by differential trypsinization. Pellet color of keratinocytes transfected with siRNA and co-cultured with melanocytes, is lighter as compared to the keratinocytes transfected with scrambled control (NC) co-cultured with melanocytes. (e,f) Bar graphs showing percentage decrease in melanin and total melanin content in keratinocytes transfected with siRNA compared with that of keratinocytes transfected with scrambled control after co-culture with melanocytes. The melanin content in TRP1 siRNA transfected keratinocytes co-cultured with melanocytes was reduced from 100% (11.13 ± 2.87 µg) in NC to 71.68 ± 10.06% (8.53 ± 3.19 µg). While there is about 29% decrease, the percent decrease does not show statistically significant difference since for all the samples the reduction was calculated from 100%. However, absolute melanin content clearly shows significant reduction in melanin content in siRNA transfected keratinocytes.