The Mechanism Of PPAR? Receptor Regulates Pyroptosis In The Cerebral Ischemia-Reperfusion Injury Through Targeting MicroRNA-124

Objectives To investigate the mechanism of peroxisome proliferator activated receptor gamma(PPAR?)activation mediating the micro RNA-124 inhibiting pyroptosis in rats with cerebral ischemia-reperfusion injury.Methods Sprague-Dawley rats(8 weeks,SPF grade)were randomly divided into sham group,the middle cerebral artery occlusion(MCAO)model group(3h,6h,12 h,24h and48 h after reperfusion),the dimethyl sulfoxide(DMSO)vehicle group,the pioglitazone group(doses of 10mg/kg PGZ,20mg/kg PGZ and 30mg/kg PGZ),the pioglitazone+GW9662 group,the pioglitazone+micro RNA-124 antagomir group;The damages of cerebral were evaluated by neurological deficits and 2,3,5-triphenyltetrazolium chloride(TTC)staining.The expression changes of PPAR?,RXR?and micro RNA-124 were detected with Western blot and RT-q PCR respectively.The expressions of proteins and inflammatory factors associated with pyroptosis,including cysteinyl aspartate specific proteinase-1(Pro-caspase-1),cleaved cysteinyl aspartate specific proteinase-1(caspase-1p20),Gasdermin D(GSDMD),N-terminal fragment Gasdermin D(NT-GSDMD),interleukin-1?(IL-1?)and interleukin-18(IL-18)were detected by Western blot.Luciferase assays analyse the regulatory relations between PPAR? and micro RNA-124;Chromatin Immunoprecipitation(CHIP)assays demonstrated that the PPAR? bound directly to peroxisome proliferator response elements(PPRE)in the micro RNA-124 promoter region.Results 1 Compared with the sham group,the expression of GSDMD,NT-GSDMD,IL-1? and IL-18 increased and the maximum value peaked 24 hours(P<0.001)except that the Pro-caspase-1 and caspase-1p20 peaked at 12 hours(P<0.001).2 Compared with model group,the expression of PPAR? and micro RNA-124 were increased after the PPAR? was activated by pioglitazone(P<0.05).However,the expression of Pro-caspase-1,Caspase-1p20,GSDMD,NT-GSDMD,IL-1? and IL-18 were decreased(P<0.05).Meanwhile,the infarct volume of cerebral was reduced and the neurological function was improvedhe(P<0.05).The function of activated PPAR? was greater with the increase of pioglitazone(P<0.05).In the pioglitazone+GW9662 group,the effect of PPAR? was reversed.3 In luciferase reporter assays,the luciferase activity of mutant were decreased compared with the wild group(P<0.01).CHIP assay showed that there were PCR products in the experimental group.4 In the pioglitazone+micro RNA-124 antagomir group,the effect of micro RNA-124 was blocked significantly.Compared with pioglitazone group,the expression of Pro-caspase-1,caspase-1p20,GSDMD,NT-GSDMD,IL-1? and IL-18 increased significantly(P<0.001).Conclusions 1 Pyroptosis pays an important role in the cerebral ischemia-reperfusion injury.2 PPAR? may play a neuroprotective role by mediating micro RNA-124 to inhibit pyroptosis.Figure 34;Table 18;Reference 177...