Objective:To preliminarily explore the role of silent information regulator 3 (SIRT3) in ferroptosis induced by high glucose in renal tubular epithelial cells, and to provide a new theoretical basis and treatment ideas for renal tubular injury in diabetic kidney disease patients.Methods:The single-cell transcriptomic analysis from "Tabula-muris" database was used to evaluate the expression of SIRT3 gene in different cellular subtypes of kidney tissues. HK-2 cells, a human immortalized proximal tubule epithelial cell line, were cultured in vitro and divided into following groups: (1) control group, mannitol group and high glucose group; (2) control group, negative control group, SIRT3 overexpression group, high glucose group and SIRT3 overexpression + high glucose group; (3) control group, negative control group, SIRT3 knockdown group, high glucose group and SIRT3 knockdown + high glucose group; (4) control group, Erastin intervention group and SIRT3 overexpression + Erastin intervention group. Normal glucose was 5.5 mmol/L, high glucose was 30 mmol/L, mannitol was 24.5 mmol/L, Erastin was 10 μmol/L, and the intervention time was 48 h. Cell counting kit-8 proliferation and cytotoxicity assay was used to determine cell viability. Real-time quantitative PCR and Western blotting were performed to assess the expression of SIRT3, kidney injury molecule-1 (KIM-1), and ferroptosis-related proteins acyl-CoA synthetase long chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) at the mRNA and protein levels. The malondialdehyde, glutathione, and iron levels were measured to evaluate the degree of cellular ferroptosis. DCFH-DA was used to analyze the intracellular reactive oxygen species level, while the JC-1 staining method was employed to evaluate alterations of mitochondrial membrane potential in HK-2 cells. Results:(1) The results of single-cell transcriptomic database analysis demonstrated that SIRT3 gene was expressed at the highest level in the subtypes of proximal tubule epithelial cells of kidney tissues. (2) Compared with the control group, the expression levels of KIM-1 and ACSL4 were higher, and the expression levels of SIRT3 and GPX4 and cell viability were lower in the high glucose group (all P<0.05), while there was no statistically significant difference of the aforementioned indicators between the mannitol group and the control group (all P>0.05). (3) Compared with the high glucose group, HK-2 cell vitality, GPX4 expression and intracellular glutathione were higher, ACSL4 expression, intracellular iron, malondialdehyde and reactive oxygen species were lower, mitochondrial membrane potential partially recovered in SIRT3 overexpression + high glucose group (all P<0.05). Compared with the high glucose group, HK-2 cell vitality and GPX4 expression were lower, ACSL4 expression was higher in SIRT3 knockdown + high glucose group (all P<0.05), and there were no statistically significant differences in intracellular iron, malondialdehyde and glutathione (all P>0.05). (4) Compared with the control group, Erastin intervention group had upregulated ACSL4 expression and downregulated GPX4 expression in HK-2 cells (all P<0.05). Compared with the Erastin intervention group, SIRT3 overexpression + Erastin intervention group had upregulated GPX4 expression and downregulated ACSL4 expression (all P<0.05). Conclusions:High glucose can decrease SIRT3 expression and mitochondrial membrane potential, and increase oxidative stress and ferroptosis in HK-2 cells. Overexpression of SIRT3 may reduce oxidative stress and alleviate mitochondrial dysfunction, thereby mitigating glucose-induced ferroptosis in HK-2 cells.