MicroRNAs and genes regulating responses to hypoxia and inflammation expression levels in blood leukocytes as potential biomarkers of initial oxygen deficiency tolerance.

Introduction: Hypoxia-inducible factors (HIFs) play central roles in evoking responses to hypoxia, and their activities are regulated by numerous molecules, including microRNAs. Organisms typically show differing tolerances to oxygen deficiency; the most common method of determining such tolerance involves examining the effects of sublethal hypoxic exposure (SHE) in a decompression chamber, which can lead to pathological changes in the internal organs. The aim of the present study was to investigate the microRNAs and genes regulating cellular responses to hypoxia and inflammation expression levels in the peripheral blood leukocytes of laboratory animals before and 1 month following determination of hypoxia tolerance. Methods: In animals not exposed to hypoxic exposure, blood was collected from the tail vein. One month later, the rats' resistance to hypoxia was determined at a critical altitude (11,500 m) in a single test in a decompression chamber, based on the "gasping time" before assuming a lateral position and the appearance of signs of asphyxia. Two groups of rats were identified - tolerant and susceptible to hypoxia. The expression of Results: Compared to tolerant rats, the susceptible animals demonstrated an initial high proinflammatory potential characterized by high Discussion: SHE has extended effects on organisms that last for at least a month. The indicators identified herein, which differ between the hypoxia-tolerant and hypoxia-susceptible animals before sublethal hypoxic exposure, can therefore be considered as biomarkers of the initial hypoxia tolerance potential.