Effect of FBXL4 on HFpEF-induced changes in mitochondrial dynamics and Ca2+ transport. A: Representative immunoblots depicting pan and phosphorylated (Ser616/637) Drp1; B: Drp1; C–D: Phosphorylated Drp1 (p-Drp1 Ser616, Ser637); E: p-Drp1 Ser616-to-Drp1 ratio; F: Representative immunoblots depicting FIS1 and MFF using specific antibodies; G: FIS1; H: MFF; I: Representative immunoblots of OPA1, MFN1 and MFN2 using specific antibodies; J: OPA1; K: MFN1; L: MFN2; M: Representative immunoblots of SERCA2a, PLN and NCX using specific antibodies; N: Sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2a (SERCA2a); O: Phospholamban (PLN); P: Na+-Ca2+ exchanger (NCX); Q: Representative immunoblots of inositol 1,4,5-trisphosphate receptor 1 (IP3R1), IP3R3, and ryanodine receptor 1 (RYR1) using specific antibodies; R: IP3R1; S: IP3R3; and T: RYR1. Mean ± SEM, n = 10 mice per group (panel A–E), n = 6 mice per group (panel F–T). Statistical significance was estimated by one-way ANOVA followed by Tukey's multiple comparison test. *p < 0.05, ***p < 0.001, ****p < 0.0001 between indicated groups.