SIRT3 and acute kidney injury: MSCs play a protective role in mitochondria for renal repair mainly through the following mechanisms: 1) transfer of mitochondria to damaged proximal tubular epithelial cells (Konari et al., 2019); 2) regulation of mitochondrial biogenesis by enhancing PGC1-α expression, NAD + biosynthesis, and SIRT3 activity (Perico et al., 2017); 3) inhibition of mitochondria-mediated apoptosis and mitophagy (in hexavalent chromium-injured kidney) (Yin et al., 2019); and 4) activation of mitophagy (in sepsis- and cisplatin-induced AKI) (Wang et al., 2017; Guo et al., 2021).