Assessment of Mitochondrial Function and Membrane Potential in PK1 Cells Treated with Gentamicin and MitoQ

Abstract

Objectives: Determine the effects of concurrent treatment with the aminoglycoside antibiotic gentamicin and mitoquinone (MitoQ), a mitochondria-targeted derivative of the antioxidant ubiquinone that may protect against aminoglycoside ototoxicity, on mitochondrial function and membrane potential. Methods: This study was prospective and controlled. Mitochondrial membrane potential (MMP) was assessed by flow cytometry using MitoProbeTM JC-1 Kit in untreated PK1 cells and cells exposed to low (100 µM) or high (2000 µM) dose gentamicin for 24 hours, with and without 0.5 µM each of MitoQ or idebenone (an untargeted ubiquinone). Mitochondrial function was determined using the Seahorse XF-24TM flux analyzer. Results: MMP was not different in untreated cells and cells co-incubated with low-dose gentamicin and MitoQ or idebenone ( P > .05). Co-incubation with high-dose gentamicin and MitoQ or idebenone decreased MMP ( P < .0001), with MitoQ co-incubation decreasing MMP to a greater extent compared with idebenone ( P = .0001). Basal oxygen consumption rate (OCR) was not different between treatments ( P = .15). Maximal OCR was not different between untreated cells and cells treated with MitoQ alone, low dose gentamicin alone, or the combination of MitoQ and low dose gentamicin ( P > .05). In contrast, cells treated with high dose gentamicin and in combination with MitoQ have reduced maximal OCR ( P = .037 and .026). Conclusions: The combination of gentamicin and MitoQ holds the potential to disrupt mitochondrial function and membrane potential. This suggests a heightened need to monitor for toxicity in patients receiving both agents.