Pioglitazone alleviates cisplatin nephrotoxicity by suppressing mitochondria-mediated apoptosis via SIRT1/p53 signalling

Abstract

Pioglitazone (PIO) attenuates cisplatin nephrotoxicity whereas the underlying mechanism remains unknown. Apoptosis is associated with mitochondrial dysfunction and SIRT1 activation can decrease cell apoptosis in cisplatin nephrotoxicity. Therefore, we explored whether the protective effect of PIO in cisplatin nephrotoxicity is achieved by suppressing mitochondria-mediated apoptosis through SIRT1/p53 signalling regulation. Cell viability, apoptosis, survival rate, renal pathology and function were examined. Moreover, we also analysed the expression of SIRT1, Acetyl-p53, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), mitochondrial permeability transition pore (mPTP) opening, adenosine triphosphate (ATP) and apoptosis-related protein in vivo and in vitro. Pioglitazone treatment significantly increased cell viability, promoted SIRT1-p53 interaction, upregulated Bcl-2 expression, activated SIRT1 and elevated mitochondrial ATP synthesis after cisplatin treatment. However, PIO decreased the generation of ROS, opening of mPTP, dissipation of MMP and translocation of cytochrome c after cisplatin treatment. Pioglitazone also reduced the activation of caspase-3 and caspase-9, lowered the ratio of Bax/Bcl-2, attenuated kidney pathological damage and dysfunction, down-regulated the expression of Acetyl-p53, PUMA-α and Bax and abated cell apoptosis after cisplatin treatment. The SIRT1 inhibitor, EX527, clearly reversed the protective effects of PIO. These results implied PIO attenuated cisplatin nephrotoxicity by suppressing mitochondria-mediated apoptosis through regulating SIRT1/p53 signalling.

Keywords: Pioglitazone; SIRT1; cisplatin nephrotoxicity; mitochondrial.