Cardioprotective effects of autophagy in myocardial ischemia-reperfusion: influence of available energetic substrates

HERMANN R; MESTRE CORDERO, VICTORIA EVANGELINA; F REZNIK; M.G MARINA PRENDES; FERNÁNDEZ PAZOS, MARÍA DE LAS MERCEDES; D VELEZ

Congreso; IMBSCongress 2018; 2018

Autophagy is a self-degradative process that occurs mainly for house-keeping purposes, such as degradation of long-lived proteins or damaged organelles. Although autophagy is a prominent feature of myocardial ischemia and reperfusion, the functional significance is still unclear and controversial. In this study, we explored effects of the autophagy inhibitor 3-methyladenine (3-MA, 5 mM) in isolated rat left atria subjected to 75 min simulated ischemia-75 min reperfusion (R), when atria were incubated in the presence of 10 mM glucose (G) or G and 1.2 mM palmitate (P), condition observed in most clinical situations of acute myocardial infarction and less well established. ANOVA, n=8. The results showed a significant enhance in LC3-II/LC3-I ratio, an established indicator of autophagy, during R, which was achieved more slowly in the presence of P. These results were accompanied by a decrease of p62, a specific substrate degraded through the autophagy-lysosomal pathway, in both metabolic groups. 3-MA prevented LC3 ratio increase [End stabilization period (ESP)+G:0.94±0.10, ESP+P:1.06±0.02, R+G:1.74±0.16*, R+P:1.68±0.08*, R+G+3-MA:1.00±0.09; R+P+3-MA:0.90±0.07AU; *p