The role of specific SOX genes and microRNAs in reactivation and senescence of human astrocytes derived from pluripotent NT2/D1 cells

Astrocytes are the main homeostatic cells in the brain with important roles both in physiological and pathological conditions. They have a unique ability to become reactivated in response to different types of brain pathologies, which serves as a compensatory response that modulates tissue damage and recovery. Also, senescent astrocytes have profound implications in age-related neurodegenerative disorders. The molecular mechanisms underlying astrocyte reactivation and senescence are still not well understood. To investigate the roles of SOX2 and SOX9 transcription factors and miR-21 in these phenotypic alternations of astroglia, astrocytes derived from NT2/D1 cell line (NT2/A) were used as a model system. Western blot analyses showed that the expression of both SOX2 and SOX9 decreases during the maturation of NT2/A and they are re-expressed upon in vitro induced injury. Further modulation of the SOX2 and SOX9 expression will reveal their roles in the regulation of astrocytes reactivation. Down-regulation of mir-21 in both immature and mature NT2/A by using the antisense technology, induced the decline in cell proliferation revealed by Ki67 proliferation marker. Also the premature cellular senescence was induced as indicated by increase in SA-ß-gal activity and the expression of p21 and p53. Additionally, in silico analysis predicted many of the genes, previously shown to be upregulated in senescent astrocytes, as miR-21 targets. Clarifying the roles of SOX genes and miRNAs in astrocyte reactivation and senescence would contribute to better understanding of the functions of these cells at the molecular level, which holds promise for development of new therapeutic strategies.BOOK OF ABSTRACTS: 8th CONGRESS OF SERBIAN NEUROSCIENCE SOCIETY with international participation 31 May – 2 June 2023. Belgrade, Serbi