Preliminary Study On The Role Of NLRP3 Inflammasomes And Oxidative Stress In Placenta In Patient With Neonatal Hypoxic-ischemic Encephalopathy

ObjectiveIn this study,the correlation between NLRP3 inflammasome expression withsuperoxide dismutase(SOD)andmalondialdehyde(MDA)was analyzed in the placenta of the fetus with hypoxic-ischemic encephalopathy(HIE),so as to investigate the changes of NLRP3 inflammasome expression and oxidative stress in placenta.MethodsThe expression of NLRP3 protein in placenta was measured by immunohistochemistry and western blot,and compared between 30 cases with HIE and 30 normal fetuses.The concentration of SOD and MDA in placenon kept at -80°C was measured and compared between 10 normal fetuses and 10 fetuses who developed HIE.The correlation among NLRP3,SOD,MDA was analyzed by statistical analysis software.Then,the pathological assessment of placenta tissues was performed.Results(1)There was no significant difference in the general pathological features of placenta between fetuses with HIE and normal fetuses.Microscopic analysis of the morphology of the pathological tissue showed that the number of cytotrophoblast nodules and terminal villi in the placenta of the fetus with HIE were(30.10±5.82)/HPF and(10.33±3.25)/HPF,respectively,which were higher than that of normal placenta(20.40±5.56)/HPF and(4.93±2.13)/HPF(t=5.88,P=0.00;t=7.61,P=0.00,respectively).The number of terminal villi with vasculo-syncytial membrane in placental tissues of fetuses with HIE was lower(10.83±3.52)/HPF vs.(18.57±4.93)/HPF)(t=6.99,P=0.00).(2)Immunohistochemistry results showed that NLRP3 was expressed in all 30placenta tissues of fetuses with HIE(100%),while it was expressed in 9 of normal fetuses(30%)(χ~2=-44.831,P=0.000).Western blot results showedthat the expression of NLRP3 protein in the placenta tissues of fetuses with HIE was higher.Gray values were read by Image J software to calculate relative protein expression.Gray values of placenta tissues of fetuses with HIE and normal fetuses were 0.186±0.084 and0.008±0.005,respectively,and the expression level of NLRP3 protein in HIE fetuses was 23.25 times higher(t=6.666,P=0.000).(3)The activity of SOD in placenta tissues of fetuses with HIE waslower((6.40±1.40)U/mgprotvs.(12.13±3.37)U/mgprot)(t=-4.955,P=0.000).The activity of MDA in placenta tissues of fetuses with HIE washigher((11.45±3.21)nmo l/mgprot vs.(4.89±1.66)nmol/mgprot)(t=5.747,P=0.000).(4)After the expression of NLRP3 was detected by immunohistochemistry,Spearman’s correlation analysis found that NLRP3 protein was positively correlated with MDA(r=0.74,P=0.000),and negatively correlated with SOD activity(R=-0.66,P=0.000).After NLRP3 expression was detected by Western blot,Spearman’s correlation analysis found that NLRP3 expression was positively correlated with MDA(R=0.612,P=0.004),and negatively correlated with SOD activity(R=-0.649,P=0.002).Conclusion(1)There are different degrees of pathological changes in placenta tissues.These pathological changes were consistent with the histological morphology resulting from hypoxia.(2)NLRP3 inflammasome expression in the placenta tissue of fetus with HIE increases significantly.(3)There was abnormal oxidative stress in placental tissues of HIE.(4)There are inflammatory reaction and oxidative stress in placenta tissues of fetuses with HIE,which is correlated with each other.