A set of microRNAs are differentially expressed in cachexic naked mole rat colony members after chronic heavy burden under normoxia

Enrichment of the habitat of captive rodents Heterocephalus glaber (naked mole rats) to implement their innate behavioral pattern of digging dense soil in search of food, paradoxically led to the appearance of unusual animals in the colony. They showed signs of cachexia, distinguished from other animals by a lower temperature (from 31 °C to 26 °C) and body mass index with decreasing proportion of subcutaneous fat. This animal demonstrated aggressive feeding behavior, but didn't gain weight even after finishing experiment with intensive physical activity. In histochemical analysis of tissues from cachexic and normal animals of the same age and sex liver hyperlipofuscinosis was revealed and indicated that animals when being in a habitat with an increased oxygen content for them (21 % versus 8 % in their natural underground habitat), experienced severe oxidative stress during physical exercise. Stress led to a disruption of the body's regulatory systems, a sharp increase in metabolism even at rest, an overload of the cardiovascular and respiratory systems and damage to organs and tissues. To clarify the pathogenetic mechanism of the observed phenomenon, microRNA was extracted from the animal tissues and sequenced. Then bioinformatics analysis of differential expression of microRNAs between groups of healthy animals and animals with idiopathic cachexia was performed.