Right-To-Left Ventricular Differences in the Expression of Mitochondrial Hexokinase and Phosphorylation of Akt

Cellular Physiology and Biochemistry

关键词: Hexokinase isoforms;    Akt kinase;    Left ventricle;    Right ventricle;    Mitochondria co-localization;   

DOI  :  10.1159/000343350

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

Background/Aims Hexokinase (HK) is a key glycolytic enzyme which promotes the maintenance of glucose homeostasis in cardiomyocytes. HK1 isoform is predominantly bound to the outer mitochondrial membrane and highly supports oxidative phosphorylation by increasing the availability of ADP for complex V of the respiratory chain. HK2 isoform is under physiological conditions predominantly localized in the cytosol and upon stimulation of PI3K/ Akt pathway associates with mitochondria and thus can prevent apoptosis. The purpose of this study was to investigate expression and subcellular localization of both HK isoforms in left (LV) and right (RV) heart ventricles of adult male Wistar rats. Methods Real-Time RT-PCR, Western blotting, and quantitative immunofluorescence microscopy were used. Results Our results showed a significantly higher expression of both HK1 and HK2 at mRNA and protein levels in the RV compared to the LV. These findings were corroborated by immunofluorescence staining which revealed substantially higher fluorescence signals of both HKs in the RV than in the LV. The ratios of phospho-Ser473-Akt/non-phospho-Akt and phospho-Thr308-Akt/non-phospho-Akt were also markedly higher in the RV than in the LV. Conclusion These results suggest that the RV has a higher activity of aerobic glycolytic metabolism and may be able to respond faster and more powerfully to stressful stimuli than the LV.

【 授权许可】

CC BY-NC-ND