Histidine triad nucleotide-binding protein 2 deficiency induce myocardial glucose utilization disorder in mice

Abstract

Abstract Introduction Histidine triad nucleotide-binding protein 2 (HINT2) has been shown to be benefit to energy metabolism after myocardial infarction. However, the exact mechanism of HINT2 in myocardial metabolism remains unclear. Purpose To explore the effect of HINT2 deficiency on cardiac function and metabolic profile. Methods HINT2-/- mice was generated for experiment in vivo by CRISPR/Cas9 technique. Neonatal mouse ventricle myocytes were used for in vitro experiment. Transthoracic echocardiography and histological analyses were performed to assess ventricle structure and function. Transmission electron microscopy was used to observe ultrastructure in ventricle tissues. Conjoint analysis of proteomics and metabolomics was to screen the metabolism profile and signal pathway. Seahorse XFe 96 analysis was performed to detect oxygen consumption rates and glycolysis rate. Immunoprecipitation mass spectrometry was used to explore the HINT2-interacting protein. Co-immunoprecipitation and proximity ligation assay were used to detect the interaction between proteins. Results Comparing to HINT2+/+, HINT2 deficient mice had higher level of left ventricular posterior wall thickness, and lower left ventricular ejection fraction. The heart weight/tibia length, cross-sectional area and cardiac fibrosis area were increased in HINT2 deficient mice. In HINT2 deficient, using transmission electron microscopy, thicker cardiac muscle fibers was observed, with disorganized and disorganized mitochondria. Conjoint analysis of proteomics and metabolomics exhibited the network of differential protein and metabolite, which proved HINT2 deficiency activated the pathway of diabetic cardiomyopathy. Immunoprecipitation showed that the level of glycosylated modification in heart tissues was higher in HINT2 deficient mice. Seahorse analysis showed that the basal and max oxygen consumption rate in HINT2 deficient mice was significantly lower, and so was the mitochondria related Proton efflux. With immunoprecipitation mass spectrometry detection, we found that PDK4 may have interaction with HINT2. Both co-immunoprecipitation and proximity ligation assay proved that HINT2 and PDK4 has interaction and subcellular localization. Conclusions HINT2 plays an important role in cardiac function and glucose metabolism, which is a critical molecule in process of diabetic cardiomy.