OBJECTIVES: To explore the role of C1q, the promoter of the classical pathway of the complement system, in regulating postpartum depressive-like behaviors in mice and the therapeutic mechanism of C1q-neutralizing antibodies. METHODS: Female C57BL/6 mouse models of postpartum depression established by hormone-simulated pregnancy (HSP) were evaluated for depression-like behaviors, and peripheral blood levels and hippocampal expressions of C1q were detected using ELISA and Western blotting. Immunofluorescence staining was used for detecting co-labeling of C1q and microglia, and the differentially expressed mRNAs in the hippocampus of HSP mice were analyzed using RNA sequencing. The Edinburgh Postnatal Depression Scale was used to screen patients with postpartum depression, from whom peripheral blood mononuclear cells were extracted for detecting C1q expression levels with Western blotting. The HSP mice were subjected to stereotactic injection of C1q-neutralizing antibody or a control IgG in the hippocampus, and the changes in depressive-like behaviors and hippocampal expression of C3 were examined. RESULTS: The HSP mice exhibited obvious depressive behaviors, demonstrated by significantly decreased preference for sugar water and increased forced swimming and tail suspension time. The mouse models showed significantly increased peripheral blood C1q level and hippocampal expression level of C1q, accompanied by an increase in Iba1 and C1q co-labeling in the hippocampus. The expression level of C1q in peripheral monocytes was also significantly increased in patients with postpartum depression. In HSP mice, stereotactic injection of C1q-neutralizing antibody, but not the control IgG, obviously alleviated depressive-like behaviors, shown by significantly increased preference for sugar water and decreased forced swimming and tail suspension time, resulting also in decreased expression of C3 in the hippocampus and lowered serum levels of IL-6 and TNF-α. CONCLUSIONS C1q-neutralizing antibodies improve postpartum depressive-like behaviors in mice possibly by regulating the C1q/C3 signaling pathway.
Animals ; Female ; Depression, Postpartum ; Complement C1q/metabolism* ; Antibodies, Neutralizing/pharmacology* ; Mice, Inbred C57BL ; Mice ; Hippocampus/metabolism* ; Pregnancy ; Disease Models, Animal

Objective To investigate the protective effect of ginsenoside Rg3 on lipopolysaccharide-induced galial-neuronal interaction injury model.Methods Primary microglia cells and HT-22 cell lines were cultured,and the cells were divided into the control group(CON),the 100 ng/mL LPS group(LPS),the control inflammation model group(CM),the ginsenoside Rg3 group,and the inflammation model plus ginsenoside Rg3 treatment group(CM+Rg3).Ginsenoside Rg3 was administered in the ginsenoside Rg3 group and the CM+Rg3 group at the doses of 2.5,5,10,and 20 μmol/L.Galial-neuronal interaction modeling was performed in the CM group and the CM+Rg3 group.The purity of the primary microglia cells was assessed by immunofluorescence,the viability of the HT-22 cells in each group was assessed by CCK-8,and changes in the levels of inflammatory cytokines,including interleukin(IL)-1β,IL-6,tumor necrosis factor α(TNF-α),and IL-10,in the cell samples of each group were assessed with the ELISA kits.The level of cellular oxidative damage was measured with a ROS kit,and the expression of apoptosis-related proteins,including Bax and Bcl-2,was assessed by Western blot.The activity of Caspase-3 enzyme in each group was measured with a Caspase-3 enzyme activity kit.Results The purity of the microglia cultured reached over 95％and was suitable for subsequent experiments.After ginsenoside Rg3 stimulation at different doses,the survival rate of HT-22 was not much different from that of the CON group.The survival rate of neurons after 100 ng/mL LPS stimulation was 98％,indicating that Rg3 and LPS had no effect on the survival of neurons.Compared with that of the CON group,the survival rate of HT-22 cells in the CM group was significantly decreased(P＜0.01).Compared with the CM group,the CM+Rg3 group showed a significant increase in the viability of neurons(P＜0.0l),indicating that the glia-neuron interaction model was successfully constructed.When Rg3 dose was 10 μmol/L,the HT-22 cells in CM+Rg3 group showed the highest viability(P＜0.05).Hence,10 μmol/L Rg3 was selected for further experiments.After 100 ng/mL LPS stimulation,the concentrations of IL-1 β,IL-6,TNF-α,and IL-10 in HT-22 cells were not significantly different from those in the CON group.After 100 ng/mL LPS stimulation,the concentrations of IL-lβ and TNF-α in microglia were higher than those in the CON group(P＜0.05),but the concentrations of IL-1 β and TNF-α in the LPS+Rg3 group were lower than those in the LPS group(P＜0.05).The concentration of reactive oxygen species in the CM+Rg3 group was slightly higher than that in the CON group,and significantly lower than that in the CM group(P＜0.01).The expression of Bax in the CM+Rg3 group was higher than that in the CON group,and lower than that in the CM group.The expression of Bcl-2 was lower in the CON group,and higher than that in the CM group(P＜0.01).The Caspase-3 enzyme activity in the CM group was significantly higher than that in the CON group(P＜0.01).The Caspase-3 enzyme activity in the CM+Rg3 group was significantly lower than that in the CM group(P＜0.01).Conclusion Ginsenoside Rg3 may play a role in the alleviation of neuronal apoptosis by regulating glial cell damage,reducing the secretion of inflammatory factors,and inhibiting neuronal apoptosis.