Hydrogen sulfide improves keratinocytes migration and diabetic skin wound healing via plakophilin 4

This study aimed to investigate whether plakophilin 4 (PKP4) mediates the effects of hydrogen sulfide (H₂S) in promoting diabetic wound healing.

Human keratinocytes were cultured under high-glucose conditions to evaluate cell function. Cell viability was assessed using the CCK-8 assay, proliferation was measured by BrdU incorporation. Cell migration was assessed by scratch wound assay, and cell polarity was quantified by GM130-based Golgi orientation. PKP4 overexpression and knockdown models were used to validate the role of PKP4 in regulating keratinocyte function. In vivo, PKP4 knockout C57BL/6 J mice were used to establish a Type 1 diabetic (T1D) mouse model and full-thickness, excisional skin-wound-healing assay was performed. Sodium hydrosulfide (NaHS) was administered to explore the effects of H₂S on keratinocyte function and diabetic wound healing.

High-glucose stimulation inhibited keratinocyte viability, proliferation, migration, and polarity, while increasing PKP4 expression. NaHS treatment increased keratinocyte viability, promoted proliferation, and enhanced polarity, along with a decrease in PKP4 level. PKP4 knockdown reduced cell adhesion and accelerated scratch wound healing, whereas PKP4 overexpression increased cell adhesion and inhibited scratch wound healing. In T1D mice, NaHS treatment enhanced skin wound healing, decreased TNF-α expression, and promoted collagen deposition in the dermis. PKP4 knockout diminished the effects of NaHS on skin wound healing.

Elevated PKP4 levels in keratinocytes enhance cell adhesion and inhibit migration, contributing to delayed scratch wound healing under high-glucose conditions. NaHS treatment reduces PKP4 expression in keratinocytes and promotes diabetic skin wound healing. PKP4 mediates the beneficial effects of H₂S in diabetic skin wound repair, providing new insights into the molecular mechanisms of diabetic skin wound healing.