RUDN biologists have determined how the body’s response to lack of oxygen at the molecular level changes with age

Reduced oxygen content (hypoxia) is one of the main factors that can change the functional state of the whole organism. To some extent, the body is able to withstand hypoxia, but if its strength exceeds the adaptive capabilities of the body, then irreversible changes begin in the tissues. The main “conductor” that determines the level of cell adaptation to hypoxia is HIF proteins. Until now, there have been no studies that would determine how HIF activity changes with age. PFUR biologists conducted research on rats and determined what happens to the level of this and other proteins during hypoxia in different age groups.

“Age plays an important role in the body’s resistance to hypoxia. Back in 1870, it was found that newborn animals are more resistant to low oxygen levels compared to adults. However, little is known about HIF expression in organisms of different ages,” Anna Kosyreva, Doctor of Biology, Associate Professor of the Department of Histology, Cytology and Embryology, RUDN University.

Biologists conducted an experiment on rats (36 males) from different age categories: 12 newborns (two days from birth), 12 prepubertal rats (10 days) and 12 adults (three months). 18 rats of all ages were placed in an oxygen-deficient chamber under conditions corresponding to an altitude of 11.5 thousand meters, and measured after what time the first signs of asphyxia appeared — suffocation. The biologists measured the levels of HIF and other proteins in the rats that passed through the pressure chamber and those that remained under normal conditions.

Prepubertal rats were the most sensitive to hypoxia. They began to lack air after 30–40 seconds. It took 60–120 seconds for adult and newborn rats. The number of genes that are responsible for HIF was found to be significantly higher in prepubertal and neonatal rats than in adults. And the HIF level was minimal in rats from the two “younger” groups and maximal in adults. RUDN biologists explained this by the action of another protein — PHD2, which causes the breakdown of HIF

“In prepubertal animals, the expression level of the HIF-1α gene was significantly higher than in adult animals. Simultaneously, PHD2 activity in prepubertal animals was significantly reduced compared to neonatal rats, but the level of HIF-1α protein did not change. Further studies need to identify additional mechanisms that determine the regulation of HIF-1α protein levels in prepubertal animals. This study will give a new insight into age-related differences in resistance to hypoxia,” — Candidate of Biological Sciences Polina Vishnyakova, Research and Educational Laboratory of Medical Biotechnologies, RUDN University.

Research published in the journal Helion.