Effect Of Shengui Ren Mixture On Expression Of ERα,ERβ And RSK1 In Postpartum Depression Model Rats

Objective:In this study,postpartum depression model rats（PPD）were used as the object,and Shenguiren mixture,which has the effect of tonifying deficiency and removing blood stasis,was used for intervention.By observing the behavior,serum estradiol level（E₂）,and examining the expression of estrogen receptor（ERα,ERβ）mRNA in the hypothalamus,and p90 ribosomal S6 kinase（RSK1）protein in the hypothalamus,hippocampus and frontal lobe of PPD model rats,the relationship between ERα,ERβ,RSK1 and PPD was investigated.Furthermore,we explain the mechanism of the Shenguiren mixture in treating PPD.Methods:1.Sprague-Dawley（SD）rats were divided into two groups randomly by openfield test（OFT）,namely the control group（Ctl group）and the model group（PPD group）,in which the Ctl group was not treated with any treatment.After ovariectomy（OVX）),the PPD group was subjected to continuous hormone injection to simulate the"pregnancy".After 23 days,the hormone was abruptly withdrawn and the PPD rat model was prepared.2.After modeling,both the Ctl group and the PPD group were subjected to the Sugar Water Preference Test（SPT）,OFT and Forced Swim Test（FST）to perform model evaluation.According to the OFT total score,the PPD group was randomly divided into 6 groups:model group（Mdl group）,high dose group of Shenguiren mixture（S-H group）,middle dose group of Shenguiren mixture（S-M group）,low dose group of Shenguiren mixture（S-L group）,estradiol benzoate group（EB group）,and sertraline hydrochloride group（Ser group）.3.After 4 weeks of intervention,behavioral tests were performed again after 2weeks and 4 weeks of administration respectively:SPT,OFT and FST.4.After 4 weeks of drug intervention,and completing the animal behavior test,related indicators were detected:（1）detecting serum E₂ by radioimmunoassa y;（2）using Quantitative Real-Time PCR（RT-RCR）to detect the expression of ERαand ERβmRNA in hypothalamus,calculating the ratio of ERα/ERβmRNA;（3）using Western blotting（WB）todeterminetheexpressionofRSK1proteinin hypothalamus,hippocampus and frontal lobe.Results:1.Behavior observation after modeling:compared with Ctl group,sucrose water consumption decreased significantly（P<0.01）,level score and vertical score of OFT decreased significantly（P<0.01）,and the immobility time of FST increased significantly（P<0.01）.2.Behavioral observation after drug intervention,the scores of sucrose water consumption and sucrose water consumption in Mdl group were significantly lower than those in Ctl group（P<0.01）and the immobility time of FST was significa ntly higher than that in Ctl group（P<0.01）.The scores of sucrose water consumption in S-M group were significantly higher than those in Ctl group（P<0.01）.Compared with Mdl group,the FST immobility time of S-L group and EB group decreased significa ntly（P<0.01）and P<0.01（P<0.05）.3.Results of serum estradiol:compared with Mdl group,serum E₂ level in S-L group was increased（P<0.05）;serum E₂ level in S-M group and EB group was significantly increased（P<0.01）.Serum E₂ levels in the Mdl group were lower than those in the Ctl group,but the difference was not statistically significant（P>0.05）.4.Changes in ER expression:Compared with the Ctl group,the expression of ERαand ERβmRNA in the hypothalamus of rats with PPD was significantly down-regulated（P<0.05）.Compared with Mdl group,the expression of ERαmRNA in hypothalamus of EB group was up-regulated（P<0.05）.The expression of ERαmRNA in hypothalamus of rats in other drug intervention group was higher than that in Mdl group,but the difference was not statistically significant（P>0.05）.The mRNA expression of ERβin hypothalamus was significantly up-regulated in S-M and EB groups（P<0.05,P<0.01）.5.Results of ERα/ERβratio:Compared with Ctl group,the ratio of ERα/ERβmRNA in hypothalamus of Mdl group was up-regulated（P<0.05）.Compared with Mdl group,except for EB group,the ratio of ERα/ERβmRNA in hypothalamus of each treatment group was down-regulated（P<0.05,P<0.01）.6.Results of RSK1 expression:Compared with Ctl group,RSK1 protein expression in hypothalamus,hippocampus and frontal lobe of Mdl group was significantly down-regulated（P<0.05,P<0.01）.Compared with Mdl group,RSK1 protein expression was up-regulated in different degrees in hypothalamus and hippocampus（P<0.05,P<0.01）;In frontal lobe,except S-M group,RSK1 protein expression was up-regulated in each treatment group.（P<0.05）.Conclusion:1.The hormone withdrawal after HSP was performed in the rats and then the behavioral tests were performed.The rats showed a marked depressive state and the PPD rat models were successfully duplicated.2.As a kind of estrogen-like agent,Shenguiren mixture can increase serum E₂ level in PPD rats and improve“postpartum rats”low estrogen level and depression state.3.The decreased expression of ERαand ERβmRNA in hypothalamus of PPD rats may be related to the pathogenesis of PPD,while the activation of ERβhas antidepressant effect.4.The relative balance of ERαand ERβis crucial for postpartum mood.The up-regulation of ERα/ERβmRNA relative ratio may be involved in the development of PPD,and Shenguiren mixture may exert its anti-depressant effect by down-regula ting the relative ratio of ERα/ERβmRNA.5.Shenguiren mixture,a prescription of tonifying deficiency and removing blood stasis,may increase the antidepressant ability of PPD rats by regulating the expression of RSK1 protein,activating MAPK signaling pathway.