Role of miR-423-5p targeted-regulating glutathione S-transferase mu 1 in sub-hypothermia alleviating cerebral ischemia/reperfusion injury in rats
LIU Jinhao
SUN Yan
ZHU Huijie
SUN Xuehua
DONG Rui
YUAN Yang
ZHANG Gaofeng
Abstract：Objective To investigate the role of microRNA-423-5p(miR-423-5p)targeted-regulating glutathione S-transferase mu 1(GSTM1)in sub-hypothermia alleviating cerebral ischemia/reperfusion injury(CIRI)of rats.Methods A total of 100 8-week-old SD rats were randomly divided into 5 groups:sham operation group,cerebral ischemia/reperfusion group(IR),sub-hypothermia group,miR-423-5p agonist+sub-hypothermia group(AGH),miR-423-5p negative control+sub-hypothermia group(NCH),with 20 rats in each group.Rat CIRI model was established by inserting a thread bolt to block blood flow.In sham operation group,only the vessels were isolated without blocking.In the subhypothermia group,75%ethanol was used to cool the brain temperature at 32-33℃ for 3 h during reperfusion.The AGH and NCH groups were treated with intracerebroventricular injection of miR-423-5p agonist or negative control at 2 d before modeling.In 24 h of reperfusion,modified neurological defect scale score(mNSS)was scored,and the cerebral cortex samples in ischemic penumbra of brain tissue were removed to determine the protein expression of GSTM1,inducible nitric oxide synthase(iNOS),arginase-1(Arg-1),and the mRNA expression of GSTM1 and miR-423-5p,detect neuronal apoptotic rate and oberve morphological changes in the cerebral cortex samples.Dual luciferase reporter gene assay was applied to determine the targeting relationship between miR-423-5p and GSTM1 in vitro.Results Compared with the sham operation group,the other four groups exhibited significantly enhanced expression of iNOS,Arg-1 and miR-423-5p,increased mNSS and apoptotic rate,and notably decreased mRNA expression of GSTM1 and GSTM1(P<0.05).In the mild hypothermia group,the expression of iNOS(1.75±0.44 vs 4.06±1.08),miR-423-5p(1.83±0.21 vs 3.48±0.36),mNSS(4.05±1.15 vs 10.25±2.0)and apoptotic rate[(19.56±1.51)%vs(59.90±2.31)%]were significantly lower(P<0.05),the protein levels of Arg-1(15.30±4.05 vs 6.27±1.74),GSTM1(0.60±0.07 vs 0.26±0.04)and the mRNA level of GSTM1(0.72±0.07 vs 0.45±0.08)were notably higher when compared with the IR group(P<0.05).The AGH group had significantly enhanced expression of iNOS and miR-423-5p,increased mNSS and apoptotic rate,while reduced expression of Arg-1 and GSTM1 at a protein level and GSTM1 at a mRNA level than the sub-hypothermia group(P<0.05).HE staining displayed that a large number of damaged cells in the IR group,alleviated cell damage in the sub-hypothermia group,and weakened protective effect in the AGH group.Dual-luciferase reporter gene assay indicated that miR-423-5p targeted and bound to GSTM1.Conclusion Sub-hypothermia may promote the microglia polarization from M1 to M2 by down-regulating miR-423-5p and up-regulating GSTM1,and thereby alleviate CIRI.
Keywords：hypothermiainducedreperfusion injurybrainglutathione transferase
Publication Date：2026-02-15
Online Publishing Date：2026-03-11(First online date of this platform, not the publication date of the document)
Pages：6( 250-255 )