Influence of Circ_HECTD1 on OGD/R-induced hippocampal neuronal damage by regulating the miR-135a-5p/TP53INP1 axis / 中风与神经疾病杂志

ABSTRACT

@#Objective　To observe the influences of circular RNA HECT domain E3 ubiquitin ligase 1 (Circ_HECTD1) on the proliferation and apoptosis of HT22 cells and its regulatory mechanism on the microRNA-135a-5p (miR-135a-5p)/tumor protein 53-induced nuclear protein 1 (TP53INP1) axis by in vitro oxygen-glucose deprivation/reoxygenation (OGD/R)-induced hippocampal neuron damage.Methods　HT22 cells were routinely cultured,and the cells were separated into Con group,OGD/R group,si-NC group,and si-Circ_HECTD1 group,miR-NC group,miR-135a-5p group,si-Circ_HECTD1+anti-miR-NC group,and si-Circ_HECTD1+anti-miR-135a-5p group.qRT-PCR method was used to detect the expression of Circ_HECTD1,miR-135a-5p and TP53INP1 mRNA;MTT was used to detect cell viability;flow cytometry was used to detect apoptosis;dual-luciferase reporter gene experiment was applied to verify the targeting relationship between Circ_HECTD1 and miR-135a-5p,miR-135a-5p and TP53INP1;Western blot was applied to measure the protein expressions of Bax,Bcl-2 and TP53INP1.Results　After OGD/R induction,the expressions of Circ_HECTD1 and TP53INP1 in HT22 cells were up-regulated,the expression of miR-135a-5p was down-regulated,the cell survival rate and the expression of Bcl-2 protein were remarkably decreased,the apoptosis rate and the expression of Bax protein were remarkably increased (all P<0.05).Silencing the expression of Circ_HECTD1 could remarkably up-regulate the expression of miR-135a-5p in OGD/R-induced HT22 cells,down-regulate the expression of TP53INP1,increase cell survival rate and Bax protein expression,decrease cell apoptosis rate and Bcl-2 protein expression (all P<0.05).There was a targeting relationship between Circ_HECTD1 and miR-135a-5p,between miR-135a-5p and TP53INP1.Overexpression of miR-135a-5p could remarkably down-regulate the expression of TP53INP1,increase cell survival rate and Bcl-2 protein expression,decrease cell apoptosis rate and Bax protein expression (all P<0.05).Inhibition of miR-135a-5p expression could partially reverse the protective effect of silencing Circ_HECTD1 on HT22 cell damage.Conclusion　Silencing Circ_HECTD1 can regulate the miR-135a-5p/TP53INP1 axis and promote cell survival,inhibit cell apoptosis,and protect against OGD/R-induced hippocampal neuron damage.