EXPRESSION OF GLIAL MARKERS, CYTOKINES AND MARKERS OF NEUROGENESIS IN THE MOUSE HIPPOCAMPUS DURING AGING AND IN RESPONSE TO LIPOPOLYSACCHARIDE

DOI: https://doi.org/10.29296/24999490-2021-03-06

E.B. Sotnikov(1), N.I. Patlay(1), A.Y. Nikolaeva(2), O.P. Tuchina(1) 1-Immanuel Kant Baltic Federal University, ul. Universitetskaya, 2, Kaliningrad, 236041, Russian Federation; 2-National Research Nuclear University «Moscow Engineering Physics Institute», Center for Biotechnology, Institute for Nuclear Power Engineering, Studencheskij gorodok, 1, Obninsk, 249034, Russian Federation E-mail: [email protected]

Introduction. Aging is associated with a decrease in the neuro- and synaptogenesis as well as hyperactivation of glial cells, which leads to changes in the morphofunctional state of the nervous tissue of the hippocampus and, as a consequence, a deterioration in cognitive abilities. Changes in the concentration of cytokines observed during aging contribute to the hyperactivation of glial cells and negatively affect the processes of neuronal plasticity; however, peripheral inflammation caused by endotoxin can also lead to the same result. The aim of this study was to analyze the expression levels of glial markers GFAP, Iba1, pro- and anti-inflammatory cytokines, as well as markers of proliferation and neurogenesis in the hippocampus of mice of three ages: 2–3 days, 3 months and 1 year in the physiological state, as well as in the case of intraperitoneal lipopolysaccharide injections. Methods. To determine the expression levels, mRNA was isolated from the hippocampal tissue of inbred mice C57BL/6, cDNA was synthesized, followed by real-time PCR. Results. The expression level of GFAP increases with age, while Iba1 does not change. A general tendency to an increase in the expression of proinflammatory cytokines with age was revealed, the expression levels of the anti-inflammatory cytokines IL-4 and IL-10 did not change significantly, and IL-13 increased. In response to injection of lipopolysaccharide, a decrease in the expression of TNF-α, IL-1β, and IL-13 was observed in 1 year-old mice. The level of proliferation of hippocampal cells is significantly reduced in 1-year-old animals, but increases in response to lipopolysaccharide. DCX expression level does not change with age and in response to lipopolysaccharide. Conclusion. The study of changes which occur in the nervous tissue with age, as well as in response to peripheral inflammation, is necessary to create new and effective models for the development of neurodegenerative diseases, as well as to understand the fundamental processes of brain aging.
Keywords: 
hippocampus, neurogenesis, lipopolysaccharide, neuroinflammation
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