Dexmedetomidine Attenuates Neuroinflammation In LPS-Stimulated BV2 Microglia Cells Through Upregulation Of miR-340

Background: Dexmedetomidine (Dex) was reported to exhibit anti-inflammatory effect in the nervous system. However, the mechanism by which Dex exhibits anti-inflammation effects on LPS-stimulated BV2 microglia cells remains unclear. Thus, this study aimed to investigate the role of Dex in LPS-stimulated BV2 cells. Methods: The BV2 cells were stimulated by lipopolysaccharides (LPS). BV2 cells were infected with short-hairpin RNAs targeting NF-kappa B (NF-kappa B-shRNAs) and NF-kappa B overexpression lentivirus, respectively. In addition, miR-340 mimics or miR-340 inhibitor was transfected into BV2 cells, respectively. Meanwhile, the dual-luciferase reporter system assay was used to explore the interaction of miR-340 and NF-kappa B in BV2 cells. CCK-8 was used to detect the viability of BV2 cells. In addition, Western blotting was used to detect the level of NF-kappa B in LPS-stimulated BV2 cells. The levels of TNF-alpha, IL-6, IL-1 beta, IL-2, IL-12, IL-10 and MCP-1 in LPS-stimulated BV2 cells were measured with ELISA. Results: The level of miR-340 was significantly upregulated in Dex-treated BV2 cells. Meanwhile, the level of NF-kappa B was significantly increased in BV2 cells following infection with lenti-NF-kappa B, which was markedly reversed by Dex. LPS markedly increased the expression of NF-kappa B and proinflammatory cytokines in BV2 cells, which were reversed in the presence of Dex. Moreover, miR-340 mimics enhanced the anti-inflammatory effects of Dex in LPS-stimulated BV2 cells via inhibiting NF-kappa B and proinflammatory cytokines. Furthermore, Dex obviously inhibited LPS-induced phagocytosis in BV2 cells. Conclusion: Taken together, our results suggested that Dex might exert anti-inflammatory effects in LPS-stimulated BV2 cells via upregulation of miR-340. Therefore, Dex might serve as a potential agent for the treatment of neuroinflammation.