Dti Study On The Protective Effect Of ShRNA On MMP-9 On Brain In MCAO Rats

Background and purposeIschemic brain injury is one of the common types of cerebrovascular disease,and complications after cerebral infarction are serious threats to human health.Brain edema is an important complication of cerebral infarction,the occurrence and development of cerebral infarction plays an important role.Matrix metalloproteinase-9(MMP-9)is closely related to cerebral edema and blood-brain barrier permeability.Our study was to investigate the relationship between the area of the edema area and the FA and the expression of MMP-9 gene in the cortical region of the ischemic brain tissue through the DTI imaging of the peripheral edema area of the MCAO model,and to investigate the relationship between the expression of MMP-ShRNA down-regulates the expression of MMP-9 and reduces the area of brain edema after acute cerebral infarction,thus protecting the neurological function of the rats and improving their imaging findings.Materials and Methods1?32 healthy male SD rats weighing 260 g to 300 g were randomly divided into the following four groups(each group of eight): group A(sham operation group): separation of external carotid artery after ligation,the bolt line is not inserted into the internal carotid artery intracranial segment,in the neck of the external carotid artery bifurcation field of vision forward 0.5 cm;group B(MCAO group): MCAO model after the success of single cage feeding;group C(saline group): injection of saline 5 ?l two weeks before MCAO;group D(lentivirus intervention group): injection of saline 10 ?l two weeks before MCAO.The neurological function score(mNSS)and magnetic resonance imaging(MRI)were performed at 4h,8h,18 h and 24 h after successful modeling.The magnetic resonance scan was performed by GE Discovery MR 750 3.0T superconducting high field magnet Resonance scanners,Shanghai Chengguang rats,the animals were fixed in the supine position,the head was advanced,with the optic chiasm as the scanning center,the routine T1 WI,T2WI,T2 WI FLAIR,DWI,DTI and other sequence check.The ADC value and FA value of the lesion side were calculated.2?The experimental data were collected from 32 experimental animals(each group of eight)corresponding to the time of MRI examination.The expression of MMP-9 protein in ischemic brain tissue was detected by Western blot.3?Iaddition,32 experimental animals(each group of eight)were subjected to paraffin sections of ischemic brain tissue corresponding to the time of MRI examination.Immunohistochemical staining was performed to observe the expression of MMP-9 protein.4?All datas applications SPSS 17.0 software for statistical analysis,and the quantitative data was expressed as mean ± standard deviation.Test methods were t-test,repeated measures analysis of variance,Pearson correlation analysis,testing standards for ? = 0.05,P <0.05 indicated statistically significant.Results:1?At 4h,8h,12 h,18h,24 h after ischemia,mNSS of NBP group compared with MCAO model group,the difference was statistically significant(P <0.05).2?The ADC value and FA value of the lentivirus intervention group at the4 h,8h,12 h,18h,24 h after ischemia were higher than MCAO model group,the difference was statistically significant.There was significant difference in FA value between the two groups at 4h,8h,12 h,18h,24h(P <0.05)3?The expression of mmp-9 protein in the lentivirus intervention group was significantly higher than that in the MCAO model group at 4h,8h,12 h,18h,24 h.The difference was statistically significant(P <0.05)4?There was a negative correlation between mNSS neurological function score and FA value and MMP-9 protein expression in the core area of ischemic cerebral infarction.Conclusion1?The expression of mmp-9 in brain tissue of cerebral infarction was involved in the formation of edema around cerebral infarction and the occurrence of neurological impairment.2?Lentivirus by inhibiting the expression of mmp-9 gene,reduce vasogenic edema,play a protective role after cerebral infarction.3?The DTI could dynamically monitor The DTI monitor the changes of ischemic cerebral infarction in rats and the changes of the virus after gene suppression.