HIF1A knockdown in MSCs affects the regulation of histone H3K9 methylation under hypoxia in vitro Тезисы доклада
Конференция |
TERMIS-AP Conference 16-19 окт. 2023 , Гонконг |
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Сборник | TERMIS-AP Conference Сборник, 2023. |
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Вых. Данные | Год: 2023, Номер: 632, | ||
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Реферат:
Background: realization of the regenerative potential of MSCs is associated with their functioning under conditions of ischemia, while a reduced level of O2 modifies a number of properties of MSCs due to the HIF-1-dependent mechanism. At the same time, other oxygen-sensitive molecules, particularly histone methylases and demethylases, including EHMT2/G9A, KDM3 and KDM4, which regulate the degree of chromatin accessibility by the mean of histone methylation, also control MSC functions. The study aims to reveal the patterns of functioning of the oxygen-dependent regulators HIF-1α and histone methylases/demethylases (EHMT2/G9A, KDM3 and KDM4) in MSCs, which is essential for understanding the fundamental mechanisms of cellular response to hypoxic conditions. Methods: The experiments were performed in vitro using MSCs from human umbilical cord. In order to evaluate the effects of HIF-1α, HIF1A mRNA was inhibited by RNA interference technique. Then, the MSCs were exposed to hypoxia (1% O2) for 1 h and 24 h. After that quantitative PCR was performed to assess the effects of HIF1A inhibition and hypoxic conditions on the expression of genes encoding epigenetic regulatory factors, such as KDM3A, KDM4A, EHMT2. The levels of KDM3A, KDM4A, EHMT2/G9a proteins and mono-/dimethylated forms of histone H3K9 were analyzed using flow cytometry. Results: The transcriptional response of umbilical cord MSC genes involved in epigenetic regulation through H3K9 methylation was more pronounced after 24 h incubation at pathological hypoxia (1% O2) compared with acute (1 h) hypoxic exposure, with KDM4A and EHMT2 but not KDM4A regulated HIF-1-dependently, both in hypoxia and in normoxia. The levels of KDM3A, KDM4A, and EHMT2/G9a proteins determining H3K9 methylation were HIF-1-dependently upregulated in MSCs during 24 h exposure to pathological hypoxia and were less regulated during acute hypoxia. HIF-1-dependent regulation of KDM3A, KDM4A, and EHMT2/G9a in MSCs also took place under normoxia. Pathological hypoxia stimulated mono- and dimethylation of H3K9 in MSCs, in the case of monomethylation it was HIF-1-dependent and more pronounced at 24 h of hypoxic exposure than at acute (1 h) hypoxia. HIF-1 also regulated mono- and dimethylation of H3K9 in MSCs from the umbilical cord under normoxic conditions. Discussion and Conclusion: Thus, oxygen-dependent regulation involving HIF-1 mediates the control of umbilical cord MSC transcriptional activity by engaging in the regulation of H3K9 repressive methylation through modification of the levels of mRNA and the corresponding methylase and demethylase proteins. Along with this, the HIF-1-independent mechanism regulating H3K9 dimethylation plays a significant role. For the examined cells, HIF-1-dependent regulation of methylation occurs not only under hypoxic conditions, but also in normoxia. Acknowledgement: This work was supported by RSCF Grant # 22-25-00749
Библиографическая ссылка:
BOBYLEVA P.
, TYRINA E.
HIF1A knockdown in MSCs affects the regulation of histone H3K9 methylation under hypoxia in vitro
В сборнике TERMIS-AP Conference. 2023.
HIF1A knockdown in MSCs affects the regulation of histone H3K9 methylation under hypoxia in vitro
В сборнике TERMIS-AP Conference. 2023.
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