CysLT2 receptor mediates lipopolysaccharide-induced microglial inflammation and consequent neurotoxicity in vitro

Abstract Neuroinflammation induced by microglial activation plays a critical role in many neurodegenerative diseases, including Parkinson׳s disease (PD). Recent studies have indicated that cysteinyl leukotriene receptor 2 (CysLT 2 R) is involved in inflammation and brain injury after cerebral ischemia. However, the role of CysLT 2 R in microglial responses associated with PD remains unclear. In the present study, we determined the regulatory roles of CysLT 2 R in microglial inflammation and subsequent neurotoxicity in an in vitro brain inflammation model induced by the microglial activator lipopolysaccharide (LPS). We found that LPS induced phagocytosis of a murine microglial cell line (BV-2 cells) and increased production of the proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β). The expression of CysLT 2 R protein was up-regulated and the nuclear translocation of CysLT 2 R was induced in LPS-activated BV-2 cells. CysLT 2 R selective antagonist HAMI 3379 significantly inhibited LPS-induced phagocytosis and overproduction of the cytokines in BV-2 cells. Similarly, the CysLT 2 R silencing by specific short hairpin RNA (shRNA) had the same effects as those of HAMI 3379, suggesting that the effect might be CysLT 2 R-dependent. Furthermore, the conditioned medium (CM) derived from LPS-treated BV-2 cells induced the cell death of a rat adrenal pheochromocytoma cell line (PC12). HAMI 3379 and CysLT 2 R shRNA attenuated neuronal death by suppressing the production of neurotoxic cytokines released from LPS-activated microglia. Collectively, these results suggest that CysLT 2 R mediates LPS-induced microglial inflammation and consequent neurotoxicity. CysLT 2 R may be a promising molecular target that modulates microglia-related neuroinflammation in neurodegenerative disorders, such as PD.