Secretion of β chemokine from the adult rat astrocytes stimulated by LPS, proinflammatory cytokines and immunoregulatory cytokines
Objective To investigate factor(s) regulating astrocyte chemokine expression, we examined the induction of β chemokine mRNA expression in adult rat astrocytes. Methods By in situ hybridization, we determined the β family chemokine mRNA expression in the astrocytes which were cultivated in vitro and stimulated with different agents. Results Astrocyte derived MCP 1, RANTES, MIP 1α and MIP 1β mRNA were easily induced by IFN γ. TNF α induced RANTES and MIP 1β mRNA expression, and LPS induced MIP 1α and MIP 1β mRNA expression in astrocytes. LPS induced MCP 1 and RANTES mRNA expression by astrocytes were antagonized by TGF β and IL 10. TGF β and IL 10 also down regulated MCP 1 mRNA expression induced by TNF α, and IL 10, but not TGF β, inhibited MIP 1β mRNA expression induced by TNF α. Conclusions The results of this in vitro study suggest that β chemokine mRNA expression by adult rat astrocytes can be induced by LPS or proinflammatory cytokines, while regulatory cytokines, such as TGF β and IL 10, down regulate the induction of astrocyte derived β family chemokine mRNA expression induced by LPS, IFN γ and TNF α.