ИСТИНА

Acute kidney injury (AKI) is a widespread disease affecting approximately one in five hospitalized patients. Revealing the mechanisms of AKI in aging organisms remains considerable problem while the mean age of patients with this diagnosis is 64 years. One of the approaches that prevents development of a wide range of age-related pathologies is dietary restriction (DR). The aim of this research was to study the nephroprotective effect of DR on AKI in young and old animals. We performed the model of ischemic AKI and revealed that in young rats after DR levels of AKI markers were 3.5 times lower than in young rats, which were fed ad libitum. In old rats there was no effect of DR on AKI severity. To evaluate DR-mediated activation of autophagy we stained vital kidney slices with LysoTracker Green and also measured LC3II/LC3I ratio in kidney. A significant increase in LysoTracker Green fluorescence intensity and LC3II/LC3I ratio was observed in young rats after DR, but there were no such alterations in old rats underwent DR. We also evaluated the intensity of mitophagy by the level of PINK-1 in mitochondria, and it was decreased in young rats after DR. Thus, DR has a nephroprotective effect on AKI reducing its severity, but only in young rats. This protective effect could be explained by more significant activation of autophagy in kidney tissue of young animals compared to old, as well as by more intensive elimination of the damaged mitochondria.