| BackgroundPreeclampsia(PE)is a unique hypertensive disease that involves all organs during pregnancy,which is often clinically manifested as hypertension,proteinuria,nausea and vomiting.The pre-eclampsia continues to increase convulsions or loss of consciousness is called eclampsia.People with eclampsia often have serious brain complications.Once eclampsia occurs in pregnant women,it is often necessary to terminate the pregnancy early.In some severe cases,it will cause maternal death and poor neonatal outcomes,which seriously threatens the health of mothers and infants.Nervous system symptoms caused by eclampsia is one of the main causes of death of patients.A large number of studies have shown that the inflammatory reaction plays an important role in the occurrence and development of eclampsia.And some studies have confirmed that seizures of eclampsia are often associated with the upregulation of inflammatory factors in the hippocampus.High mobility group protein 1(HMGB1)can be used as an inflammatory cytokine to respond to epileptic injury,HMGB1 binds to the transmembrane protein toll-like receptor 4(TLR4),activates the nuclear transcription factor Kappa B(NF-k B)by various pathways,promote the occurrence of inflammation and play a role in many diseases.Studies have found that both HMGB1 and TLR4 play important roles in central nervous system diseases such as cerebral infarction,cerebral hemorrhage,encephalitis,epilepsy,etc.However,at present,there are still few studies on HMGB1 / TLR4 pathway and eclamptic brain injury.We try to investigate the role of HMGB1 / TLR4 pathway in brain injury of eclampsia,and to provide new ideas for elucidating the mechanisms of brain injury of eclampsia.ObjectiveTo explore the role of HMGB1 / TLR4 pathway in brain injury of eclampsiaMethods1.Animal groups:40 female SD rats(2--3 months,200--250g)were randomly divided into the following 5 groups:1)non-pregnant group(n=5);2)normal pregnancy group(n=5);3)preeclampsia group(n=10): subcutaneously injected with the nitric oxide synthase(NOS)inhibitor--nitro-L-Arg-methyl ester(L-NAME)200 mg/kg/d from day 12 to day 16 of gestation;4)eclampsia-like group(n=10): receive PTZ 40mg/kg/d induced seizure by intraperitoneal injection from day 16 to day 18 of gestation;5)ethyl pyruvate(EP)treatment group(n=10): receive PTZ induced seizure by intraperitoneal injection and EP treatment.2.Observation indicactor:Rats were sacrificed on the 20 th day of gestation,and serum and hippocampus were collected.The serum levels of HMGB1,TLR4 and NF-κB p65 in rats were detected by ELISA.Hematoxylin-eosin(HE)staining was used to detect the pathological changes of brain tissues of the rats in each group.The expression levels of HMGB1,TLR4 and NF-κB p65 in hippocampal tissues were detected by immunohistochemistry,q RT-PCR and Western blot.Results1.Systolic blood pressure and 24-hour urinary protein: before pregnancy,there was no significant difference in blood pressure among the groups,but on the 16 th and 18 th days of gestation,the systolic blood pressure in eclampsia-like group was significantly higher than non-pregnancy group and normal pregnancy group(P <0.05),and there was no significant difference among the eclampsia-like group,the EP treatment group and the preeclampsia group(P> 0.05).The level of 24-hour urine protein in eclampsia-like group was significantly higher than non-pregnancy group and normal pregnancy group(P <0.05),and there was no significant difference among the eclampsia-like group,the EP treatment group and the preeclampsia group(P> 0.05).2.Convulsions behavior of rats: convulsions occurring within 30 minutes after intraperitoneal injection of pentaerythritol.The kindling rate in the eclampsia-like group(5/5)was 100%,which was higher than that in the EP treatment group(2/5,40%)(P>0.05)3.HE staining of hippocampal: compared with the control groups,the brain tissue of the eclampsia-like group showed tissue disorder,neuronal nucleus contraction,apoptosis and other pathological changes;compared with the eclampsia-like,brain tissue pathological changes was alleviated in EP treatment group.4.ELISA results showed that the expression of HMGB1 in the EP treatment group,the preeclampsia group and the eclampsia-like group were significantly higher than those in the normal pregnancy group and the normal non-pregnancy group(P <0.05).Among them,the expression of HMGB1 in the eclampsia-like group was the highest,which was significantly higher than those in the preeclampsia group and the EP treatment group(P <0.05).And there is no significantly difference between normal pregnancy group and normal non-pregnant group(P> 0.05).No significantly differences in HMGB1 expression were observed between the preeclampsia group and the EP treatment group.TLR4 and NF-κB p65 have the same trend.5.Immunohistochemistry results showed that HMGB1 protein positive staining showed tan or brown yellow,mainly expressed in the nucleus.The positive staining particles in the non-pregnant group were relatively rare.The positive staining of HMGB1 in the normal pregnancy group were more than that in the non-pregnant group.And the expression of HMGB1 in the preeclampsia group and eclampsia group were obviously increased.TLR4 and NF-κB p65 have the same trend.6.QPCR results showed that the expression of HMGB1 in the preeclampsia group and the eclampsia-like group were significantly higher than those in the normal pregnancy group and the non-pregnancy group(P <0.05),while the normal pregnancy group and normal non-pregnant group had no significantly difference of HMGB1 RNA expression.And there is no significantly difference between eclampsia-like group and preeclampsia group(P> 0.05).TLR4 and NF-κB p65 have the same trend.7.Western blot results showed that the expression of HMGB1 protein in the eclampsia-like group was significantly higher than the non-pregnancy group(P < 0.05),while the normal pregnancy group and normal non-pregnant group had no significantly difference of HMGB1 protein expression.And there is no significantly difference between eclampsia-like group and preeclampsia group(P> 0.05).TLR4 and NF-κB p65 have the same trend.Conclusion:HMGB1 / TLR4 pathway may be involved in the occurrence of brain injury of eclampsia by mediating inflammatory response. |
