Chaijin-Jieyu-Anshen tablet-medicated serum protects rat ACC neurons from synaptic damage via GR/CX3CR1 double signaling in an in vitro de-pression model
AIM:To explore the mechanism by which Chaijin-Jieyu-Anshen tablet(CJJY)-medicated serum prevents synaptic injury in rat anterior cingulate cortex(ACC)neurons using an in vitro depression model.METHODS:Cells(astrocytes,microglia and neurons)were isolated from the ACC of SD rats.The isolated cells were characterized by immunofluorescence staining.An in vitro depression model was developed using 1 mg/L lipopolysaccharide(LPS)com-bined with 200 μmol/L corticosterone(CORT).These cells were divided into control group,model group(CORT+LPS),glucocorticoid receptor(GR)blocker(GR-)group(CORT+LPS+RU486),GR agonist(GR+)group(CORT+LPS+dexa-methasone),CX3C chemokine receptor 1(CX3CR1)blocker(CX3-)group(CORT+LPS+AZD8797),CX3CR1 agonist(CX3+)group(CORT+LPS+fractalkine),CJJY group(CORT+LPS+CJJY-medicated serum),CJJY/GR+group(CORT+LPS+CJJY-medicated serum+dexamethasone),and CJJY/CX3+group(CORT+LPS+CJJY-mediated serum+fractalkine).The morphological characteristics of all ACC cells were observed by high-content analysis.The levels of neuroendocrine-related factors,adrenocorticotropic hormone(ACTH),corticotropin-releasing hormone(CRH)and CORT,and neuroin-flammatory mediators,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6 and glutamate(Glu),in the cell supernatants were quantified by ELISA.Immunofluorescence staining was used to analyze the protein expression of GR and vesicular glutamate transporter 1(VGluT1)in astrocytes,as well as CX3CR1 and adenosine A2A receptor(A2AR)in microglia.Immunofluorescence staining with Nissl and β-tubulin was performed to evaluate synaptic damage in ACC neurons.RESULTS:In an in vitro model of depression,CJJY-medicated serum prevented morphological damage to ACC neurons,microglia and astrocytes.Moreover,CJJY-medicated serum reversed abnormal increases in the levels of ACTH,CRH,CORT,TNF-α,IL-1β,IL-6 and Glu in cell supernatants(P<0.05 or P<0.01).It was also found that CJJY-medi-cated serum reduced abnormal expression of GR,VGluT1,CX3CR1 and A2AR(P<0.05 or P<0.01),alleviating damage to the neuronal dendrites and dendritic spines of ACC neurons.CONCLUSION:The CJJY-medicated serum regulates GR/CX3CR1 double signaling in glia,and attenuates rat ACC neuronal synaptic damage in an in vitro depression model,indicating that CJJY-medicated serum controls depression by affecting the GR/CX3CR1 double signaling.