Importance of mitochondrial calcium uniporter in high glucose–induced endothelial cell dysfunction

Objective:Mitochondrial Ca2+ overload is implicated in hyperglycaemia-induced endothelial cell dysfunction, but the key molecular events responsible remain unclear. We examined the involvement of mitochondrial calcium uniporter, which mediates mitochondrial Ca2+ uptake, in endothelial cell dysfunction resulting from high-glucose treatment.Methods:Human umbilical vein endothelial cells were exposed to various glucose concentrations and to high glucose (30 mM) following mitochondrial calcium uniporter inhibition or activation with ruthenium red and spermine, respectively. Subsequently, mitochondrial calcium uniporter and mitochondrial calcium uniporter regulator 1 messenger RNA and protein expression was measured by real-time polymerase chain reaction and western blotting. Ca2+ concentrations were analysed by laser confocal microscopy, and cytoplasmic and mitochondrial oxidative stress was detected using 2′,7′-dichlorofluorescein diacetate and MitoSOX Red, respectively. Apoptosis was assessed by annexin V-f...