Empagliflozin targets microtubule-Cx43 axis to alleviate electromechanical remodeling in murine pressure overload-induced heart failure

Background/Introduction Empagliflozin(Empa), a highly selective sodium-glucose co-transported 2 (SGLT2) inhibitors, improved systolic function and reduced ventricular arrhythmia events in our previous trans-aortic coarctation (TAC)-induced murine HF model. connexin43 (Cx43) expression and localization—a key gap junction protein essential to form intercalated disc for cardiomyocyte coupling—in pressure overload-induced HF remains unexplored. Microtubule network regulates abnormal Cx43 forward translocation to intercalated discs and distribution in cell lateral sides during HF condition is also under microtubule regulation. In this study, microtubules and Cx43 are focused to explore its role in mediating empagliflozin's beneficial effects on both systolic and arrhythmogenesis in TAC-induced HF. Purpose We explore that whether empagliflozin mitigates both mechanical and electrical remodeling by modulating the microtubule-Cx43 axis in TAC- induced HF model. Methods Mice subjected to TAC surgery were randomized into TAC and TAC+empagliflozin groups after two weeks, with sham-operated controls monitored for six weeks. We measured the electrical remodeling by optical mapping and Electron microscope. And we explore the process of treatment in HF by gene ontology analysis of other published RNA sequencing and our proteomic data from sham, TAC, and TAC+empagliflozin hearts. Results TEM observations in Fig. 1a showed that well-organized intercalated discs morphology-critical structure for electromechanical coupling-in sham hearts became damaged and disordered in TAC hearts while empagliflozin treatment preserved intercalated disc integrity, restoring their structural alignment. Empagliflozin treatment prevented this aberrant redistribution , maintaining Cx43 at its physiological location (Fig. 1b). Optical mapping of Langendorff-perfused hearts revealed that significantly slowed conduction velocities in TAC hearts compared to sham hearts (62.69 ± 0.93 cm/s vs 74.56 ± 1.90 cm/s, P < 0.001) while empagliflozin treatment restored conduction velocity in failing hearts (70.39 ± 0.59 cm/s, P < 0.05 vs TAC, Fig. 1c). GO analysis was performed and significantly changed cellular components between TAC only and TAC with empagliflozin mice revealed enrichment of cytoskeletal system, of which was microtubule network (Fig. 2a-b). To validate these findings, proteomic profiling among sham, TAC and TAC+empagliflozin hearts in our study were performed. Principal component analysis, Vene were shown (Fig. 2c-d). Then, GO analysis based on the interested DEPs and protein expression heat map also support upper conclusion (Fig. 2e-f). Conclusion(s) We report that empagliflozin inhibits both mechanical and electrical remodeling during pressure overload-induced HF by modulating the microtubule-Cx43 axis.For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text.