Nucleotides in Pathology, Diagnosis and Therapy of Heart Disease

Heart disease represent a major cause of mortality in human population that will escalate further in our ageing population. Several promising treatments are at experimental stage such as cell based therapies, in vitro organ engineering or mechanical devices. These technologies could revolutionize treatment of heart disease in the long term but for Today further development of pharmacological and surgical treatments and discovery of new targets for drugs remains an important field.

Nucleotides and its metabolites have an important role in all aspects of cell function such as mechanical work, ion transport, synthesis and transfer of genetic information. Nucleotides are also extracellular signaling molecules, which are particularly important in regulation of all types of cells involved in immune responses as well as in platelet aggregation. This programme proposes to study pathology as well as therapeutic and diagnostic potential associated with alterations of nucleotide metabolism in cardiovascular disorders.

Based on our preliminary findings indicating protective effect of altered AMP deaminase (AMPD) activity this strategy will be evaluated in experimental models of heart failure, ischemic heart disease, ischemia/reperfusion injury and type II diabetes. Conditional knock-outs of specific isoforms as well as chemical inhibitors of AMPD will be developed and used in the project. Possible rescue effect of the AMPD knock-out will be studied in genetic models of heart failure and ischemic heart disease. Besides practical aspects, these studies will provide basic information on the role, expression patterns and regulation of specific isoforms of AMPD.

Second line of research will address potential associated with changes in expression of enzymes of extracellular nucleotide degradation. Such changes could have major impact on thrombosis, inflammation and immune responses. Effects of increased expression of ecto-5’nucleotidase (e5N) and/or ecto-nucleoside triphosphate diphosphohydrolase 1 (eNTPD1) and heme oxygenase (HO) will be studied in cells used to populate tissue engineered heart valves. Increased expression of e5N/eNTPD1/HO in pig endothelial cells will be evaluated with in vitro models of xenotransplant rejection. In collaboration with international partners, hearts from multi transgene pigs expressing human e5N/eNTPD1/HO developed for xenotransplantation will be tested using ex vivo perfusion system. Besides practical aspects these studies will provide important information on the mechanisms of regulation of extracellular nucleotide concentration and regulation of expression of enzymes involved.