Lipopolysaccharide-evoked HSPA12B expression by activation of MAPK cascade in microglial cells of the spinal cord

The 70-kDa family of heat shock proteins (HSP70), in particular, plays a vital role in cellular protection and has been detected in various tissues subject to stress. HSPA12B is the newest member of the HSP70 family but is distinct from the HSP70 family. In this study, we elucidated the dynamic expression changes and localization of HSPA12B in lipopolysaccharide (LPS)-induced neuroinflammatory processes in adult rats. HSPA12B expression was strongly induced in active microglial cells in inflamed spinal cord. In vitro studies indicated that the up-regulation of HSPA12B may be involved in the subsequent microglia activation following LPS challenge. The elevated HSPA12B expression was regulated by activation of MAPK-p38 and ERK1/2 pathways, less contribution of the SAPK/JNK pathway in microglial cells. Collectively, these results suggested HSPA12B may be important for host defense in microglia-mediated immune response. Understanding the cell signal pathway may provide a novel strategy against inflammatory and immune reaction in neuroinflammtion in CNS.