ABSTRACT
OBJECTIVE Mitochondria plays a crucial role in cellular homeostasis by regulating various pro-cesses,including calcium signaling and mitophagy.This study aimed to explore the involvement of prohibitin 2(PHB2),an inner mitochondrial membrane protein,in the modulation of mitochondrial calcium dynamics and mitoph-agy.METHODS HEK293T cells were used as the experi-mental cells and were divided into control,PHB2 knock-down,and PHB2 overexpression groups.To evaluate mitochondrial calcium dynamics,Rhod-2 AM and Mito-Tracker Green fluorescence dyesrhod-2 staining and laser confocal microscopy were employed to visualize mito-chondrial calcium imaging.Additionally,Green-5N was utilized to measure the rate of mitochondrial calcium uptake.The mitochondrial membrane potential was assessed using JC-10 staining and laser confocal micros-copy,while cellular ATP levels were determined using ATP assay kits.Furthermore,mitochondrial autophagy was induced by treatment with CCCP,and the expression lev-els of TOM20,LC3,and PARKIN,key mitophagy-related proteins,were analyzed using Western blotting.RESULTS The results demonstrated that compared to the control group,the overexpression of PHB2 increased mitochon-drial calcium concentration,mitochondrial calcium uptake rate,ATP level and expression levels of LC3 and PAR-KIN,but decreased mitochondrial membrane potential and TOM20 expression.In contrast,PHB2 knockdown reduced mitochondrial calcium concentration,ATP level and expression levels of LC3 and PARKIN,but elevated mitochondrial membrane potential,and TOM20 expres-sion.CONCLUSION This study provides evidence that PHB2 plays a vital role in regulating mitochondrial calci-um dynamics,which in turn influences mitochondrial func-tion and modulates mitochondrial autophagy.These find-ings contribute to our understanding of the molecular mechanisms underlying the interplay between PHB2,mitochondrial calcium signaling,and mitophagy.