Effects of Psoriasis-Like Inflammation on Mitochondrial Functions in Human Keratinocytes and Fibroblasts

Introduction Psoriasis is a chronic skin disease driven by pro-inflammatory cytokines such as TNF-α, IL-17, and IL-22, which, along with psoriasis-affected fibroblasts, induce keratinocyte hyperproliferation and inflammation [1]. In vivo studies suggest that psoriatic inflammation triggers oxidative stress and mitochondrial dysfunction, including mtROS overproduction and disrupted cellular respiration [2]. Although, mitochondrial dysfunction is known to contribute to tissue damage and disease progression in skin cells during psoriasis [3], the time-dependent effects of psoriatic inflammation on mitochondrial functions in keratinocytes and fibroblasts remain inadequately explored. Aim This study investigates how psoriasis-like inflammation (PLI) over 24, 48, and 72 hours alters mitochondrial functions, including mitochondrial membrane potential, mtROS production, and cellular respiration, in human keratinocytes and fibroblasts. Methods Keratinocytes and fibroblasts were stimulated with a cytokine mixture (TNF-α, IL-17, and IL-22) to induce PLI. Mitochondrial membrane potential and mtROS levels were measured at 24, 48, and 72 hours using TMRM and MitoSOX Red staining with fluorescence microscopy (Olympus APX100) and Fiji software analysis. Cellular respiration was assessed at 24 and 72 hours using the Seahorse XFp Analyzer and Mito Stress Test Kit, normalized to total protein content via the Bradford assay and analyzed with the Infinite 200 Pro Nano Plex reader. Results Keratinocytes induced with PLI exhibited temporary increase in mitochondrial membrane potential at 24 and 48 hours, accompanied by elevated mtROS production, which peaked early at 24 hours and stabilized over time. These changes were associated with significant reductions in mitochondrial respiration, ATP synthesis, and glycolytic activity at 24 hours, all of which returned to baseline by 72 hours. In PLI affected fibroblasts, mitochondrial membrane potential also showed an initial rise at 24 hours, followed by normalization at 72 hours, while mtROS production progressively increased, peaking at 72 hours. Unlike keratinocytes, cellular respiration and glycolysis in fibroblasts remained stable initially but exhibited declines at 72 hours, alongside an increase in glycolytic efficiency. Conclusions The study reveals distinct cell-specific and temporal responses to PLI, with keratinocytes exhibiting rapid mitochondrial dysfunction associated with a decline in cellular respiration, both of which resolved as mtROS levels and membrane potential normalized. In contrast, fibroblasts displayed delayed mtROS accumulation, resulting in later impaired mitochondrial respiration and ATP synthesis. These findings provide critical insights into psoriasis pathogenesis and contribute to the identification of therapeutic targets for restoring mitochondrial function.