Isosibiricin inhibits microglial activation by targeting the dopamine D1/D2 receptor-dependent NLRP3/caspase-1 inflammasome pathway.

ABSTRACT: Microglia-mediated neuroinflammation is a crucial risk factor for neurological disorders. Recently, dopamine receptors have been found to be involved in multiple immunopathological processes and considered as valuable therapeutic targets for inflammation-associated neurologic diseases. In this study we investigated the anti-neuroinflammation effect of isosibiricin, a natural coumarin compound isolated from medicinal plant Murraya exotica. We showed that isosibiricin (10-50??M) dose-dependently inhibited lipopolysaccharide (LPS)-induced BV-2 microglia activation, evidenced by the decreased expression of inflammatory mediators, including nitrite oxide (NO), tumour necrosis factor-? (TNF-?), interleukin-6 (IL-6), interleukin-1? (IL-1?) and interleukin-18 (IL-18). By using transcriptomics coupled with bioinformatics analysis, we revealed that isosibiricin treatment mainly affect dopamine receptor signalling pathway. We further demonstrated that isosibiricin upregulated the expression of dopamine D1/2 receptors in LPS-treated BV-2 cells, resulting in inhibitory effect on nucleotide binding domain-like receptor protein 3 (NLRP3)/caspase-1 inflammasome pathway. Treatment with dopamine D1/2 receptor antagonists SCH 23390 (1??M) or sultopride (1??M) could reverse the inhibitory effects of isosibiricin on NLRP3 expression as well as the cleavages of caspase-1 and IL-1?. Collectively, this study demonstrates a promising therapeutic strategy for neuroinflammation by targeting dopamine D1/2 receptors.

SUBMITTER: Wang YH 

PROVIDER: S-EPMC7471458 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature