CHARACTERIZATION OF ENDOTHELIAL CELLS DYSFUNCTION ASSOCIATED TO ACUTE MYOCARDIAL INFARCTION: MODULATION OF METABOLIC PATHWAYS AS A NEW THERAPEUTIC APPROACH

The endothelium plays a pivotal role in the development of cardiovascular disease (CVD), and emerging evidences indicate that the onset of the pathological blood vessels and endothelial dysfunctions are associated with metabolic alterations in endothelial cells (ECs). This project aims at performing a complete characterization of the metabolic profiles of an endothelial pathological Acute Myocardial Infarction (AMI) cell model from 8 patients. The results discussed throughout this thesis are part of this attempt, and brought to the identification of the causes of the AMI pathology, as a consequence of the metabolic alterations related to the endothelium dysfunction. Patients-derived cells displayed a low proliferation rate and unveiled a dependence on mitochondrial metabolism, which results in increased ROS-oxidative stress. Patients-derived cells displayed slow growth, poor migration, and defective tubulogenesis, associated with less glucose consumption and higher lactate efflux in AMI patient-derived endothelial cells. Moreover, these cells showed also a glutamine-dependent metabolism to proliferate, and glutamine plays an important role as a precursor for the synthesis of glutathione to counter the high level of ROS detected in patients-derived cells. Additionally, the high content of glutaminase C (GAC) identified is fundamental to neutralize the acidic pH, which results from the lactate production. The previous observations indicate a profound metabolic reprogramming in AMI patient-derived endothelial cells. This suggests the occurrence of a broad and complex dysfunction in these cells, that should be reflected in global processes. Systematic analysis by RNA-seq led us to discover that the adaptor protein RAP80, a critical actor in homology-directed repair (HDR), is regulated by ESRP1/2 and controls cell growth and response to genotoxic stress. RAP80 presents two isoforms, which express differentially in epithelial or in mesenchymal phenotypes. Our analysis of the expression of these two isoforms in breast cancer demonstrates the clinical relevance of the alternative splicing event in the early prognosis of cancer disease. So we propose RAP80 as a possible target to reduce aggressive phenotypes in breast and prostate cancers, and we hypothesize a possible direct implication of this gene in the DNA-damage associated to some endothelial dysfunction.