Anti-NLRP3 (C-terminal) polyclonal antibody

Viral myocarditis (VMC) commonly triggers heart failure, for which no specific treatments are available. This study aims to explore the specific role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) in VMC. A VMC mouse model was induced byCoxsackievirus B3(CVB3). Then, MEG3 and TNF receptor-associated factor 6 (TRAF6) were silenced and microRNA-223 (miR-223) was over-expressed in the VMC mice, followed by determination of ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS). Dual-luciferase reporter assay was introduced to test the interaction among MEG3, TRAF6 and miR-223. Macrophages were isolated from cardiac tissues and bone marrow, and polarization of M1 or M2 macrophages was induced. Then, the expressions of components of NLRP3 inflammatory body (NLRP3, ASC, Caspase-1), M1 markers (CD86, iNOS and TNF-alpha) and M2 markers (CD206, Arginase-1 and Fizz-1) were measured following MEG3 silencing. In the VMC mouse model, MEG3 and TRAF6 levels were obviously increased, while miR-223 expression was significantly reduced. Down-regulation of MEG3 resulted in the inhibition of TRAF6 by promoting miR-223. TRAF6 was negatively correlated with miR-223, but positively correlated with MEG3 expression. Down-regulations of MEG3 or TRAF6 or up-regulation of miR-223 was observed to increase mouse weight, survival rate, LVEF and LVFS, while inhibiting myocarditis and inflammationviathe NF-kappa B pathway inactivation in VMC mice. Down-regulation of MEG3 decreased M1 macrophage polarization and elevated M2 macrophage polarization by up-regulating miR-223. Collectively, down-regulation of MEG3 leads to the inhibition of inflammation and induces M2 macrophage polarizationviamiR-223/TRAF6/NF-kappa B axis, thus alleviating VMC.

Shikonin (SHI) is an anti-inflammatory agent extracted from natural herbs. It is still unknown whether SHI ameliorates lipopolysaccharide (LPS)-induced cardiac dysfunction. This study aims to explore the protective effects of SHI on LPS-induced myocardial injury and its mechanism. The LPS-induced cardiac dysfunction mouse model was employed to investigate the protective effects of SHI. In the present study, we found that SHI treatment improved the survival rate and cardiac function and remarkably ameliorated the release of inflammatory cytokines and macrophage infiltration in heart tissue of LPS-treated mice. SHI also reduced lactate dehydrogenase (LDH) and cardiac troponin (cTn) release, cell inflammation, and apoptosis in LPS plus adenosine triphosphate (ATP)-treated H9c2 cells. In addition, SHI significantly upregulated silent information regulator 1 (SIRT1) expression and suppressed the upregulation of NOD-like receptor protein 3 (NLRP3), cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Meanwhile, we got the same results in LPS plus ATP-treated H9c2 cells in vitro. Further, SIRT1 inhibitor or siRNA partially blocked SHI-mediated upregulation of SIRT1 expression and downregulation of NLRP3, cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Therefore, we conclude that SHI ameliorates LPS-induced cardiac dysfunction by inhibiting SIRT1-dependent activation of NLRP3 inflammasomes and might be a promising therapeutic strategy for the treatment of LPS-induced cardiac dysfunction.