Correlation Between RIN3/MMP9 Gene Methylation And Transient Ischemic Attack/mild Ischemic Stroke With Early Cognitive Impairment

Background and object:Stroke can lead to neurological and cognitive impairment and about half of stroke patients will progress to post-stroke cognitive impairment(PSCI)in the future,PSCI is a syndrome of cognitive impairment lasting 6 months after transient ischemic attack,ischemic and hemorrhagic stroke.Cognitive impairment can occur in acute stage of stroke,which will increase the risk of progression to PSCI.Dyskinesia caused by transient ischemic attack(TIA)and mild ischemic stroke(MIS)are mild and short-lived,but cognitive impairment can occur in acute phase.The cognitive impairment in acute phase is highly related to the sustained declining of cognitive function in the future.However,because of the mild and rapid recovery of motor symptoms caused by TIA and MIS,the cognitive impairment caused in acute stage is easily overlooked.Early intervention after TIA and MIS can reduce the risk of developing PSCI in the future.DNA methylation is a kind of epigenetics,which can affect gene expression through gene silencing.This process is reversible and does not change gene sequence.DNA methylation has also been widely studied in nervous system diseases,and multiple genes have been found to be related to ischemic cerebrovascular diseases.Abnormal expression of RIN3 gene can affect the metabolism of amyloid β-protein.RIN3 gene is highly expressed in Alzheimer’s disease,and the whole blood RIN3 gene is hypomethylated in early-onset Alzheimer’s disease patients.The destruction of blood-brain barrier(BBB)can affect transportation of myloid β-protein,MMP9 is related to the destruction of BBB,which is elevated in blood of patients with ischemic stroke,and is related to the occurrence of cognitive impairment after ischemic stroke.At present,there is no study on the relationship between RIN3/MMP9 gene methylation and TIA/MIS with early cognitive impairment.The purpose of this study is to investigate the correlation between RIN3/MMP9 gene methylation and TIA/MIS with early cognitive impairment.Methods:a total of 112 subjects were included in this study,including 84 TIA/MIS and 28 non-stroke control subjects.MIS was defined as an acute cerebral infarction with a National Institutes of Health Stroke Scale(NIHSS)score of less than 5.Patients were evaluated within 7 days of TIA/MIS onset using four single-domain cognitive scales(BNT AVLT TMT-A and TMT-B).Cognitive impairment was determined by more than one(≥1)abnormal scale.DNA methylation was also detected in the whole blood of all subjects.The differences of RIN3/MMP9 gene methylation between TIA/MIS and control group,and between TIA/MIS with and without early cognitive impairment group were compared.Result 1:1.Among the 84 patients with TIA/MIS,55 had early cognitive impairment and 29 had no early cognitive impairment.The incidence of cognitive impairment after TIA/MIS was 65.5%2.Compared with control group,RIN3 gene in TIA/MIS group was hypomethylated(Groupdiff<0)and had significant difference.After adjusting for age and gender,there was still significant difference in RIN3 gene(P<0.001).Compared with TIA/MIS without early cognitive impairment group,RIN3 gene in TIA/MIS with early cognitive impairment group was hypomethylated(Groupdiff<0),and had significant difference.There was still significant difference in RIN3 gene after adjusting for age,gender,education level,history of coronary heart disease and DWM score(P<0.05).3.Compared with control group,sites S26-146,S27-25,29,36,38,40,58,61,96,111,116,127,144,146 and 152 in TIA/MIS group were hypomethylated(Groupdiff<0)and had significant differences.After adjusting for age and gender,there were still significant differences(P<0.01);Compared with TIA/MIS without early cognitive impairment group,sites S26-113,S27-25,36,111,116,127,144,146 and 152 in TIA/MIS with early cognitive impairment group were hypomethylated(Groupdiff<0),S26-165 was hypermethylated(Groupdiff>0)and had significant differences.However,after adjusting for age,gender,education level,history of coronary heart disease and DWM score,there were still significant differences in sites S27-25,111,116,144,146 and 152(P<0.05).4.Compared with control group,RIN3-26 and RIN3-27 in TIA/MIS group were hypomethylated(Groupdiff<0),and had significant differences.After adjusting for age and gender,there was still significant difference in RIN3-27(P<0.001).Compared with TIA/MIS without early cognitive impairment group,RIN3-27 in TIA/MIS with early cognitive impairment group was hypomethylated(Groupdiff<0),and had significant difference.After adjusting for age,gender,education level,history of coronary heart disease and DWM score,there was still significant difference in RIN3-27(P<0.05).5.Education level,history of coronary heart disease and S27-146 site methylation showed the highest sensitivity/specificity for predicting TIA/MIS with early cognitive impairment with an area under the curve of 0.808(95%CI:0.7119-0.9044).Result 2:1.Compared with control group,the MMP9 gene in TIA/MIS group was hypomethylated(Groupdiff<0)and had significant difference.After adjusting for age,gender and Fazekas score,there was no significant difference in MMP9 gene(P>0.05).Sites S33-39,53,58,73,79 and 156 in TIA/MIS group were hypomethylated and had significant differences.After adjusting for age,gender and Fazekas score,there was still significant difference in site S33-79(P<0.05).2.Compared with small artery occlusion group,MMP9 gene,S33-25,30,39,53,58,73,79,113 and 131 sites in large artery atherosclerosis group were hypomethylated(Groupdiff<0),and had significant differences.There were still significant differences after adjusting for age,gender and Fazekas score in MMP9 gene and these sites(P<0.05).3.Compared with TIA/MIS without early cognitive impairment group,the MMP9 gene in TIA/MIS with early cognitive impairment group was hypomethylated(Groupdiff<0),but had no significant difference(P>0.05).In TIA/MIS with early cognitive impairment group,sites S33-25 and S33-30 were hypomethylated and had significant differences.After adjusting for age,gender,education level and Fazekas score,there were still significant differences in sites S33-25 and S33-30(P<0.05).Conclusion 1:1.The incidence of early cognitive impairment in acute stage of TIA/MIS is high,so cognitive assessment of these patients can be highly necessary.2.RIN3 gene hypomethylation is associated with TIA/MIS and TIA/MIS with early cognitive impairment,which is a potential therapeutic target.Abnormal methylation site of RIN3 gene combined with clinical information can predict the occurrence of TIA/MIS with early cognitive impairment.Conclusion 2:1.MMP9 gene hypomethylation sites are associated with TIA/MIS and TIA/MIS with early cognitive impairment,and there is a strong correlation between MMP9 gene hypomethylation and atherosclerotic TIA/MIS.MMP9 gene methylation is involved in pathogenesis of TIA/MIS,which can reflect the severity of TIA/MIS.2.MMP9 gene hypomethylation sites can be used as potential biomarkers and therapeutic targets for TIA/MIS and TIA/MIS with early cognitive impairment.