MiR-718-mediated inhibition of prohibitin 1 influences mitochondrial dynamics, proliferation, and migration of keratinocytes

Abstract

Keratinocyte hyperproliferation is a key characteristic of psoriasis. Prohibitins (PHB) are known to be associated with keratinocyte proliferation and cell cycle regulation, influenced by mitochondrial processes. The objective of this study was to examine the impact of miR-718 overexpression and downregulation on the various PHB1-mitochondria-driven activities in HaCaT keratinocytes. We demonstrated that PHB1 expression is downregulated through direct targeting by miR-718, which then leads to a reduction in the expression of MFN1, MFN2, and OPA1 in miR-718-transfected cells, as evidenced by western blot analysis. Mitochondrial fusion and DRP1-mediated fission, as indicated by western blot results, were further validated using confocal imaging with CMXRoS labeling, contrasting with the effects of AM-718. JC-1 dye staining results demonstrated the miR-718 overexpression facilitates the mitochondrial membrane depolarization that highlighting the PHB1-OPA1 mediated depolarization. Moreover, OPA1 maintains mitochondrial cristae structure and its dysfunction can trigger cell death. Further PHB1 is known to regulate OPA1 function, alters mitochondrial morphology and significantly influences epithelial cell migration. Herein, our data demonstrated a reduction in keratinocyte proliferation and migration, as evidenced by the CCK assay and wound healing assay, respectively, following 24 h of transfection. Ultimately, our data indicates the potential involvement of miR-718 in the mitochondria-mediated suppression of cell proliferation and migration in HaCaT keratinocytes, likely due to modified mitochondrial processes via PHB1.