Wip1 phosphatase involved in lipopolysaccharide-induced neuroinflammation.

Wild type p53-induced phosphatase 1 (Wip1) is a phosphatase which belongs to protein phosphatase type 2C family, which have been predominantly linked to cell growth and to cellular stress signaling. Numerous downstream targets of Wip1 have been identified, and genetic studies confirm that some play a part in tumorigenesis. Recent evidence highlights a new role for Wip1 in the regulation of NF-κB p65, which indicated that it might play a critical role in immune system. However, its regulation role in central nervous system (CNS) remains poorly understood. To elaborate whether Wip1 was involved in CNS injury, we performed a neuroinflammatory model by lipopolysaccharide (LPS) lateral–ventral injection in adult rats. Wip1 expression was strongly upregulated in active astrocytes in inflamed brain cortex. In vitro studies indicated that the upregulation of Wip1 may be involved in the subsequent astrocytic activation following LPS exposure, and knockdown of Wip1 in primary astrocytes by siRNA showed that Wip1 inhibited the synthesis of TNF-α. Collectively, these results suggested that Wip1 may be important in host defense in CNS immune response, which might provide a potent therapeutic target of neuroinflammation.