Effect of orphan nuclear receptor NR4A1 expression on oxygen-glucose deprivation-induced apoptosis in cultured rats cerebellar granule neurons

Objective To investigate the effect of orphan nuclear receptor NR4A1 expression on oxygenglucose deprivation（OGD）-induced apoptosis in cultured rat cerebellar granule neurons and its possible mechanisms. Methods Primary rat cerebellar granule neurons were cultured for 7 to 8 days, and then treated with OGD. The activity of cultured rat cerebellar granule neurons was assessed by methyl thiazolyl tetrazolium （MTT） assay, apoptosis was detected with flow cytometry, the expressions of NR4A1, caspase-3 and cytochrome c were determined by Western blot analysis, NR4A1 mRNA expression was detected with real-time polymemse chain reaction. The rat cerebellar granule neurons were transfected with lentiviml vector-encoding rat NR4A1. The apoptotic rates and expressions of caspase-3 and cytochrome c in rat cerebellar granule neurons transfected with NR4A1 were detected after OGD. Results The activity of rat cerebellar ganule neurons decreased significantly, the apoptotic rate increased sigtificantly, the expressions of NR4A1 mRNA and protein as well as caspase-3 and cytochrome c incrased sigaiiicantly along with the OGD time. NR4A1 was overexpressed, apoptosis rate was sigaificantly reduced in rat cerebellar granule neurons transfeeted with NR4A1. The expressions of caspase-3 and cytochrome c were significantly reduced in the rat cerebeUar granule neurons transfected with NR4A1 after OGD. Conelusiom NR4A1 overexpression may reduce OGD-induced apoptosis in rat cerebellar ganule neurons by downregulating the expressions of caspase-3 and cytochrome c. Key words: Nuclear Receptor Subfamily 4, Group A, Member 1;  Neurons;  Cerebellum;  Ceils, Cultured;  Brain Ischemia;  Oxy~n;  Glucose;  Apoptosis;  Caspase 3;  Cytochromes c;  Neuroprotective Agents;  Rats