Implication of microRNA regulation in para-phenylenediamine-induced cell death and senescence in normal human hair dermal papilla cells

The study investigated the effects of para-phenylenediamine (PPD), a common ingredient in hair dyes, on normal human hair dermal papilla cells (nHHDPCs). The researchers found that PPD caused significant cytotoxicity in these cells, leading to cell death and G2 phase cell cycle arrest in a dose-dependent manner. Additionally, PPD treatment induced cellular senescence by promoting oxidative stress. The study also revealed that PPD exposure altered the expression of 74 microRNAs (miRNAs) in nHHDPCs, with 16 being upregulated and 58 downregulated. Bioinformatics analysis suggested that these miRNAs are likely involved in processes such as cell growth, cell cycle arrest, cell death, senescence, and oxidative stress induction. The study concluded that PPD can induce cytotoxic effects by changing miRNA expression levels in nHHDPCs.