Role and characteristics of hippocampal region microglial activation in poststroke depression

Abstract Aims To study the role and characteristics of activated microglia in poststroke depression (PSD) . Methods Twenty-four male Wistar rats were randomly divided into three groups: the poststroke (PS) group, PSD group, and Sham group. Neurobehavioral testing was performed 24 h postoperation. The body weights of the rats were regularly recorded, and behavioral testing was regularly performed at 1, 2 and 3 weeks postmodeling. Immunofluorescent staining was used to detect the microglial marker OX42. Real-time PCR was used to analyze the relative gene expression of microglial activation markers (TNF-a, IL-10, IL-1, TGF-β, CD86, iNOS, CD206, IL-1β, and Arg1) . Results The relative gene expression of proinflammatory markers (IL-1, TNF-a, iNOS, and IL1β) and anti-inflammatory markers (CD206 and Arg1) significantly increased in the hippocampal region compared with that in the right cerebral and left cerebral hemispheres in the PSD group. The relative gene expression of proinflammatory markers (TNF-a, IL-1, iNOS, and CD86) in the hippocampal region was significantly increased in the PSD group compared with that in the Sham and PS groups. The anti-inflammatory markers (TGF-β and CD206) in the hippocampal region were significantly increased in the PSD group compared with that in the Sham group, and the M2 marker Arg1 was significantly increased in the PSD group compared with that in the PS group. Correlation analysis showed that IL-1 was strongly negatively correlated with PSD . Conclusions Most microglia in the hippocampal region of PSD had a proinflammatory status and an anti-inflammatory status. IL-1 showed a strong negative correlation with PSD.