Mesenchymal stem cells promote human melanocytes proliferation and resistance to apoptosis through PTEN pathway in vitiligo

BACKGROUND: Vitiligo is an acquired chronic and recurrent skin disease that causes a depigmentation disorder, resulting in selective destruction of melanocytes (MC). However, the mechanism that leads to melanocyte dysfunction and death remains unclear. METHODS: We performed RNA sequencing, immunohistochemistry, and immunoblotting to characterize the patterns of phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway activation in vitiligo. We also cocultured primary melanocytes with mesenchymal stem cells (MSCs) in a Transwell system to explore how MSCs inhibit the PTEN/PI3K/AKT pathway in melanocytes. RESULTS: We identified that vitiligo normal-lesional junction skin presented with high expression of PTEN, which led to the inhibition of AKT phosphorylation (p-AKT) at S(-473). Furthermore, PTEN overexpression led to oxidative stress-induced apoptosis in melanocytes. Coculturing with MSCs enhanced the cell proliferation of human melanocytes and repressed PTEN expression, which inhibited oxidative stress-induced apoptosis. CONCLUSION: We report that vitiligo patients present with high PTEN expression, which may play a role in the impairment of melanocytes. Furthermore, our study provides evidence that MSCs target the PTEN/PI3K/AKT pathway to regulate cell proliferation and apoptosis in human melanocytes, indicating that MSCs may serve as a promising therapy for vitiligo.