Molecular and biochemical studies of succinate dehydrogenase in rat liver under conditions of alloxan diabetes

Experimental alloxan diabetes in rats causes an increase in the activity of liver succinate dehydrogenase (SDH) without changes in its isozyme composition. The observed increase in the catalytic activity of SDH clearly correlates with the intensification of transcription of the genes encoding catalytic dimer of SDH. Analysis of the methyl status of the promoters of the genes, encoding the catalytic dimer of SDH in rats under normal and experimental conditions did not reveal any dependence on the level of their expression. The obtained results of bisulfite sequencing indicate a passive role of the epigenetic mechanism of regulation of SDH gene expression in the development of alloxan diabetes. The transcription factor CREB, responsible for of gluconeogenesis in diabetes, may play an important role in the control of the transcriptional activity of the sdha and sdhb genes.Éksperimental'nyĭ alloksanovyĭ diabet vyzyvaet uvelichenie aktivnosti suktsinatdegidrogenazy (SDG) v pecheni krys, ne sviazannoe s izmeneniem ee izofermentnogo sostava. Éto uvelichenie aktivnosti SDG korreliruet s intensifikatsieĭ transkriptsii genov, kodiruiushchikh kataliticheskiĭ dimer SDG. Analiz metil'nogo statusa promotorov genov, kodiruiushchikh kataliticheskiĭ dimer SDG, u krys v norme i pri diabete ne vyiavil zavisimosti s urovnem ikh ékspressii. Poluchennye rezul'taty bisul'fitnogo sekvenirovaniia svidetel'stvuiut o passivnoĭ roli épigeneticheskogo mekhanizma reguliatsii ékspressii genov SDG pri razvitii alloksanovogo diabeta. Bol'shoe znachenie v kontrole transkriptsionnoĭ aktivnosti genov sdha i sdhb mozhet igrat' transkriptsionnyĭ faktor CREB, obespechivaiushchiĭ aktivatsiiu gliukoneogeneza pri diabete.