Enriched Environment Regulates Dendritic Cells to Alleviate Inflammation in Cerebral Infarction Lesions

Abstract

Objective. The aim was to investigate the role that enriched environment (EE) plays in the regulation of inflammation in cerebral infarction (CI) lesions and further explore the relationship between this regulation and dendritic cells (DCs). Methods. 72 Sprague-Dawley rats were randomly divided into sham operation group (CON group, $n=24$ ) and CI model group ( $n=48$ ). On completion of the establishment of CI rat models by Longa’s method, rats in the models group were further assigned to standard environment group (NC group, $n=24$ ) and EE group ( $n=24$ ). HE staining was utilized for evaluation of neuronal injury in the lesions. The number of CD74- and integrin αE-positive cells was detected by immunofluorescence. The expression of the IL-1β, IL-6, and TNF-α in the brain tissue and serum of rats was measured by immunohistochemistry and ELISA, respectively. Results. In comparison with the CON group, the NC and EE groups showed significant increases in neuronal injury, CD74- and Integrin αE-positive cells, DC content, as well as IL-1β, IL-6, and TNF-α expression in brain tissue and serum. According to the further comparison between the NC group and EE group, the latter showed decreases in each indicator, and these decreases were in a time-dependent manner. Conclusion. EE avoids the accumulation of DCs in the lesions and reduces the contents of IL-1β, IL-6, and TNF-α, consequently promoting the recovery of CI. And better recovery results can be obtained through increasing the time to stay in EE.