RNA-seq Reveals Dysregulation of Novel Melanocyte Genes upon Oxidative Stress: Implications in Vitiligo Pathogenesis

Konduru Seetharama Sastry,Haroon Naeem,Younes Mokrab,Aouatef Ismail Chouchane

doi:10.1155/2019/2841814

Konduru Seetharama Sastry, Haroon Naeem + Show 2 more

Open Access

https://doi.org/10.1155/2019/2841814

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Abstract

Oxidative stress is known to induce melanocyte death, but the underlying mechanisms are incompletely understood. To identify oxidative stress-induced global gene expression changes in melanocytes, we treated PIG1 melanocytes with H2O2 in a dose- and time-dependent manner and performed RNA-seq. This approach allowed us to capture the events occurring early as well as late phase after treatment with H2O2. Our bioinformatics analysis identified differentially expressed genes involved in various biological processes of melanocytes which are known to contribute to the vitiligo development, such as apoptosis, autophagy, cell cycle regulation, cell adhesion, immune and inflammatory responses, melanocyte pluripotency, and developmental signaling such as WNT and NOTCH pathways. We uncovered several novel genes that are not previously described to be involved in melanocytic response to stress nor in vitiligo pathogenesis. Quantitative PCR and western blot analysis of selected proteins, performed on PIG1 and primary human epidermal melanocytes, confirmed the RNA-seq data. Interestingly, we discovered an aberrant regulation of several transcription factors that are involved in diabetes, neurological, and psychiatric diseases, all of which are comorbid conditions in patients with vitiligo. Our results may lead to a better understanding of the molecular mechanisms underlying vitiligo pathogenesis and help developing new drug targets for effective treatment.

Highlights

Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide anion radical, and hydroxyl radical are generated in the cells endogenously as well as through exposure to extrinsic factors
ROS are continuously generated during the melanogenesis process in epidermal melanocytes, and this excessive ROS can lead to melanocyte cell death, resulting in skin conditions such as vitiligo [2]
Various batches of isolated primary human epidermal melanocytes (HEM) respond differently to same treatments with various drugs including H2O2

Summary

Introduction

Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide anion radical, and hydroxyl radical are generated in the cells endogenously as well as through exposure to extrinsic factors. Cells can maintain the intracellular redox homeostasis by scavenging the ROS. Excessive ROS production disrupts the redox homeostasis and damages the organelles and biomolecules, resulting in the manifestation of a variety of diseases including skin conditions. ROS can affect diverse biological processes through multiple mechanisms [1]. ROS are continuously generated during the melanogenesis process in epidermal melanocytes, and this excessive ROS can lead to melanocyte cell death, resulting in skin conditions such as vitiligo [2]. Numerous hypotheses about the etiology of vitiligo have been proposed, but it remains unclear what causes damage or death of melanocytes

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