Effect Of NLRP3/GSDMD/IL-1β Pathway On Depressive Behavior In Developing Rats After Epilepsy And Its Intervention Study

PART I RESEARCH ON POST-EPILEPTIC RELATEDDEPRESSIVE BEHAVIOR IN DEVELOPING RATSObjective: To identity the occurrence of depressive behavior and therapeutic effect of glucocorticoid in developing rats after epilepsy.Methods: Twenty-one day SD male rats were randomly divided into three groups(n=20): negative control group(control group),status epilepticus(SE group);status epilepticus +dexamethasone(SE+DEX group).The animal model of temporal lobe epilepsy(TLE)was established by intraperitoneal injection of lithium chloride-pilocarpine(LiclPilocarpine).SE+DEX group was given DEX[3mg/(kg/d)] by intraperitoneal injection for seven days in a row,while SE group and the control group were given equal amount of saline at the same time points.Sugar preference test(SPT)was used to detect depressive behavior for three weeks after status epilepticus,and then,the open field test(OPT)and forced swimming test(FST)were alsp performed.Results:(1)Compared with control group,the consumption rate of sucrose decreased significantly in SE group for three weeks(86.5±3.02% vs.71.63±10.18%,88.25±2.82%vs.69.75±8.24%,87.13±3.31%vs.68.50±8.65%,p<0.05);Sucrose consumption in SE+DEX group was similar to that in SE group in the first and second week,while the the consumption in SE+DEX group was significantly higher than the SE group in the third week(78.8±2.80% vs.68.50±8.65% respectively,p<0.05);(2)Compared with the control group,the center time of SE group was decreased(4.725±2.566%vs.1.250±0.553%,p < 0.05),There was no significant difference between the SE+DEX group and control groups.Compared with the control group,the center time of SE+DEX group significantly prolong(4.0±2.349 s vs.1.250±0.553 s,p<0.05).The activity track of rats in SE group was more concentrated in the open field edges and corners than that in Control group,the movement distance of SE group was decreased(7.343±1.475%vs.11.008±1.939%,p < 0.05).(3)FST test the immobile time(IMT),SE group increased significantly longer than Control group(53.738±22.544 s vs.27.175±11.858 s,p < 0.05);SE+DEX group was significantly shorter than SE group(22.850±7.845 s vs.53.738±22.544 s,p<0.01).Conclusion:(1)The depressive symptoms occurred after SE and the depressive behavior may sustain to the chronic stage of TLE;(2)Adminstration of dexamethasone for a short time may be effctive to control the depressive behavior after epilepsy in the developing stage rats.PART II NLRP3/GSDMD/IL-1β PATHWAY IN POST-EPILEPTIC DEPRESSION BEHAVIOR DURING DEVELOPMENTObjective: To investigate the role of NLRP3/GSDMD/IL-1β pathway in post-epileptic depressive behavior during development.Methods: SD rats aged 21 d were randomly divided into negative control group(Control group),epileptic seizure group(SE group),epileptic seizure group + dexamethasone group(SE+DEX group).The expression of inflammatory corpuscles NLRP3,GSDMD proteins and m RNA in hippocampus was measured by both Western blot and RT-q PCR methods after the Behavioral test.The IL-1β level of hippocampus was measured by ELISA.Results:(1)Western blot analysis showed,compare to the expression level of NLRP3 protein in Control groups,SE+DEX and SE groups was(0.692±0.257 vs.0.139±0.144,0.624±0.185 vs.0.139±0.144,P < 0.05)significantly higher,but no significant different between SE+DEX group and SE group.Compared with Control group,the expression level of GSDMD protein in SE group increased significantly(0.719±0.031 vs.0.291±0.154,P < 0.05),there was no significant difference between SE+DEX group and Control group.The expression level of GSDMD protein in SE+DEX group was significantly lower than that in SE group(0.383±0.112 vs.0.719±0.031,P <0.05).(2)RT-q PCR detection revealed that compared with Control group,the relative expression of NLRP3 m RNA in SE group increased significantly(2.697±0.220 vs.1.058±0.043 P <0.05).There was no significant difference between SE+DEX group and Control group,while SE+DEX group was significantly lower than SE group(1.397±0.655 vs.2.697±0.220,P<0.05).Compared with Control group,the relative expression of GSDMD m RNA in SE group increased significantly(1.798±0.077 vs.1.107±0.085,P <0.05).There was no significant difference between SE+DEX group and Control group.meanwhile SE+DEX group was significantly lower than SE group(1.143±0.437 vs.1.798±0.077,P<0.05).(3)ELISA detection showed,compared with Control group,The IL-1βlevel of hippocampus of rats in SE group increased significantly(571.37±18.48 pg/ml vs.221.98±87.16 pg/ml,P <0.001).There was no significant difference between SE+DEX group and Control group(299.44±119.35pg/ml vs.221.98±87.16 pg/ml).The expression IL-1β hippocampus in SE+DEX group was lower than that in SE groupwith statistically significant(P <0.01).Conclusion:(1)NLRP3/GSDMD/IL-1β inflammasome may be involved in the pathological process of post-epileptic depression.(2)Dexamethasone short course intervention may improve post-epileptic depressive behavior in developmental rats by down-regulating GSDMD/IL-1β expression.