RRM2 attenuates the renal tubular ferroptosis in diabetic kidney disease through PI3K/Akt/Nrf2 pathway

Figure 3 Ribonucleotide reductase regulatory subunit M2 overexpression activates the PI3K/Akt pathway and suppresses apoptosis in high glucose-treated renal tubular cells. A: Representative gel blots of phosphorylated PI3K (p-PI3K, p85, Tyr458) and Akt (p-Akt, Ser473); B and C: Quantification of p-PI3K (normalized to total PI3K) and p-Akt (normalized to total Akt) levels. HK-2 cells were transfected with pCDH-CMV-ribonucleotide reductase regulatory subunit M2 (RRM2) or an empty vector and co-treated with the PI3K/Akt pathway inhibitor LY294002 (10 μM) and high glucose (HG; 30 mmol/L) for 48 hours; D: Cell apoptosis was assessed by Annexin V-FITC double staining and analyzed using flow cytometry; E: Apoptotic rate was calculated by summing the number of early apoptotic cells (lower right quadrant) and late apoptotic cells (upper right quadrant). Data are presented as mean ± SD in triplicate and analyzed using one-way ANOVA. ^aP < 0.001 vs control group; ^bP < 0.001 vs HG group; ^cP < 0.001 vs HG + OE-RRM2 group. HG: High glucose; OE-RRM2: Overexpressing ribonucleotide reductase regulatory subunit M2.