Transcriptomics of vitiligo melanocytes after hydroxychloroquine treatment

Purpose: In order to explore the mechanism of hydroxychloroquine (HCQ) in treating vitiligo. We report the application of transcriptome profiling (RNA-seq) in human vitiligo melanocytes cell line PIG3V after HCQ treatment. Methods: The PIG3V cells were divided randomly in two groups: HCQ treatment (1 μg/mL, 24 hours) and the cells without treatment (only medium). RNA samples extracted from PIG3V cells were quantified by NanoDrop and Bioanalyzer. After 2 rounds of purification Poly A RNA was extracted then from total RNA by using Dynabeads Oligo. Small pieces of Poly A RNA were returned through Magnesium RNA Fragmentation Module under the condition of 94℃ for 5 minutes. Subsequently, SuperScript Reverse Transcriptase was used to reverse-transcribe the cleaved RNA pieces into cDNA. Then, U-labeled second-stranded DNAs was synthesized. After adding of A-base to each strand, preparing for indexed adapters, and heat-labile UDG enzyme treatment, PCR amplification was performed under (1) 95℃, 3 minutes; (2) 98℃, 15 seconds for 8 cycles; (3) 60℃, 15 seconds, 72℃, 5 minutes. Ultimately, RNA sequencing was performed according to protocol of Illumina Novaseq™ 6000 (LC-Bio Technology CO., Ltd., Hangzhou, China). After calculation, differential expressed genes were screened by fold change (FC)＞2 or FC＜0.5 and p value＜0.05. Results: Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample and identified 60612 genes and 229420 transcripts. Approximately 0.3% of the genes showed differential expression between the HCQ treated PIG3V cells and the cells without HCQ, with a fold change＞2 or＜0.5 , p value＜0.05. Conclusions: Our research showed the first detailed transcriptome analysis of human vitiligo melanocytes PIG3V, with or without HCQ treatment. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic mechanisms of HCQ in treating vitiligo. mRNA profiles of human vitiligo melanocytes PIG3V treated by hydroxycholoroquine, and PIG3V group without hydroxycholoroquine treatment