DEVELOPMENTAL REGULATION OF CYTOKINE EXPRESSION IN THE MOUSE-BRAIN

Expression of four cytokine genes, transforming growth factor (TGF) be ta(2) tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), a nd macrophage colony-stimulating factor (CSF-1 also known as M-CSF) wa s examined to determine whether these genes are developmentally regula ted in the brain. Northern blots were performed on RNA isolated from t he mouse brain from embryonic day 15 (E15) through postnatal day 9. TG F beta(2), gene expression was relatively high in the earliest embryos studied and decreased after E16-E17, and the three transcripts were d evelopmentally regulated. TNF-alpha and IL-6 were detected in total RN A on all days studied. CSF-1 was detected only in polyadenylated RNA. The data suggest that expression of these cytokines is related to spec ific developmental events that share cellular functions with regenerat ive or inflammatory processes.