Recent evidence indicates that the SARS-CoV-2 spike protein affects mitochondria with a cell type-dependent outcome. We elucidate the effect of the SARS-CoV-2 receptor binding domain (RBD) on the mitochondrial network and cristae morphology, oxygen consumption, mitoROS production, and inflammatory cytokine expression in cultured human lung microvascular (HLMVECs), coronary artery endothelial (HCAECs), and bronchial epithelial cells (HBECs). Live Mito Orange staining, STED microscopy, and Fiji MiNa analysis were used for mitochondrial cristae and network morphometry; an Agilent XFp analyser for mitochondrial/glycolytic activity; MitoSOX fluorescence for mitochondrial ROS; and qRT-PCR plus Luminex for cytokines. HLMVEC exposure to SARS-CoV-2 RBD resulted in the fragmentation of the mitochondrial network, mitochondrial swelling, increased cristae area, reduced cristae density, and suppressed mitochondrial oxygen consumption and glycolysis. No significant mitochondrial morphology or oxygen consumption changes were observed in HCAECs and HBECs. SARS-CoV-2 RBD induced mitoROS-mediated expression of cytokines GM-CSF and IL-1β in all three investigated cell types, along with IL-8 expression in both endothelial cell types. The findings suggest mitochondrial ROS control SARS-CoV-2 RBD-induced inflammation in HLMVECs, HCAECs, and HBECs, with the mitochondria of HLMVECs being more sensitive to SARS-CoV-2 RBD.

Mitochondrial structural and functional changes accompany psoriasis, yet the mitochondrial response to psoriatic inflammation in keratinocytes and fibroblasts remains unexplored. In this study, we investigated the effect of psoriasis-like inflammation (PLI) induced by a cytokine cocktail (interleukin (IL)-17A, IL-22 and tumour necrosis factor (TNF)-α) on mitochondrial network morphology and function in cultured keratinocytes (HaCaT) and fibroblasts (BJ-5ta). In both cell types, PLI triggered expression of psoriasis-related Elafin and high amounts of cytokines (IL-1, IL-6), interferons (IFN-α, IFN-β, IFN-γ) and chemokines (C-C motif chemokine 5 (CCL5) and IL-8), accompanied by increased mitochondrial membrane potential, reactive oxygen species (ROS) production, respiration suppression, network fragmentation, swelling, and cristae disassembly. Stimulated emission depletion (STED) nanoscopy revealed the disappearance of mitochondrial cristae in response to PLI, with the process starting more quickly and being more pronounced in keratinocytes than in fibroblasts. These findings highlight cell-specific mitochondrial responses to psoriatic inflammation, guiding future investigations towards new pharmacological targets for managing psoriasis.