The altered expression of autophagy-related genes participates in heart failure: NRBP2 and CALCOCO2 are associated with left ventricular dysfunction parameters in human dilated cardiomyopathy

This study aimed to analyze changes in the expression of autophagy- and phagocytosis-related genes in patients with dilated cardiomyopathy (DCM), especially in relation to left ventricular (LV) dysfunction. Furthermore, transmission electron microscopy of the diseased tissue was carried out to investigate if the gene expression changes are translated into ultrastructural alterations. LV tissue samples from patients with DCM (n = 13) and from controls (CNT; n = 10) were analyzed by RNA-sequencing, whereupon the altered expression (P < 0.05) of 13 autophagy- and 3 phagocytosis-related genes was observed. The expression changes of the autophagy-related genes NRBP2 and CALCOCO2 were associated with cardiac dysfunction and remodeling (P < 0.05). The affected patients had a higher activity of these degradation processes, as evidenced by the greater number of autophagic structures in the DCM tissue (P < 0.001). Differences in the ultrastructural distribution were also found between the DCM and CNT tissues. These results show that in patients with DCM, the altered expression of NRBP2 and CALCOCO2 is related to LV dysfunction and remodeling. Clarification of the molecular mechanisms of cardiac autophagy would help in the future development of therapies to improve LV performance.