Abstract
Chemokines and chemokine receptors play important roles in differentiation, migration and localization of immune cells. In this study, we introduce the profile of chemokines and its receptors gene expression induced by lipopolysaccharide (LPS) in rat microglia (MG) using a cDNA microarray. When MG were isolated from the primary mixed glial cultures (MGC) prepared from newborn rats and incubated with LPS for 24 h, the upregulation of CXCL7, CXCL15, and SDF-2 and the downregulation of CCL25, CCL28, and CX3CR1 were detected in response to LPS. When MGC were treated with LPS for 24 h, MG in the MGC changed their expression more divergently than the isolated MG, increasing CCL2, CCL3, CCL4, CXCL1, CXCL2 and CXCR5 expression and decreasing CCL25, CCR3 and CX3CR1 expression. These results suggested that the microenvironment surrounding MG, for example the glial network, is an important factor for the expressional regulation of microglial chemokines and its receptors in the immune responses. Treatment of MG in the MGC with LPS for 2 h increased the expression of 13 chemokines and 16 chemokine receptors, suggesting that acute and transient production of chemokines and its receptors in LPS-stimulated MG might be required at the early immune responses. Taken together, these evidences indicated that the divergent expression of chemokines and its receptors in MG might mediate a series of immune reactions induced by microglial activation. [Jpn J Physiol 55 Suppl:S205 (2005)]
