Matrine suppresses NLRP3 inflammasome activation via regulating PTPN2/JNK/SREBP2 pathway in sepsis.

BACKGROUND: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Abnormal activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome plays a vital role in the pathogenesis of sepsis. Matrine is proved to show good anti-inflammatory properties, whereas its effect and the underlying molecular machinery on sepsis remains unclear. PURPOSE: The aim of this study is to evaluate the effect and mechanism of Matrine on sepsis. STUDY DESIGN: THP-1 cells and J774A.1 cells were stimulated by lipopolysaccharide (LPS) with nigericin or adenosine triphosphate (ATP) to establish an in vitro model. Cecal ligation and puncture (CLP)-induced sepsis mouse model was used. Matrine was given by gavage. METHODS: To investigate the NLRP3 inflammasome activation, phorbol myristate acetate (PMA)-induced THP-1 cells were first primed with LPS and then stimulated by matrine, followed by treatment with nigericin or ATP. The concentration of interleukin 1ß (IL-1ß) and interleukin 18 (IL-18) in the cell culture supernatant was detected. The mechanism was explored by cell death assay, immunoblots and immunofluorescence in vitro. C57BL/6 mice were intragastrically administered with matrine for 5 days before CLP. The therapeutic effect of matrine was evaluated by symptoms, pathological analysis, ELISA and RT-qPCR. RESULTS: Our results revealed that matrine inhibited IL-1ß and IL-18 secretion, suppressed caspase-1 activation, reduced cell death, and blocked ASC speck formation upon NLRP3 inflammasome activation. Furthermore, matrine restrains NLRP3 inflammasome activation as well as pyroptosis through regulating the protein tyrosine phosphatase non-receptor type 2 (PTPN2)/JNK/SREBP2 signaling. Matrine also prominently improved the symptoms and pathological changes with reduced levels of TNF-α, IL-1ß, and IL-6 in the lung tissues and serum in a dose-dependent manner. CONCLUSION: Matrine effectively alleviates the symptoms of CLP-induced sepsis in mice, restrains NLRP3 inflammasome activation by regulating PTPN2/JNK/SREBP2 signaling pathway, and may become a promising therapeutic agent for sepsis treatment.

IL-37 improves mice myocardial infarction via inhibiting YAP-NLRP3 signaling mediated macrophage programming.

OBJECTIVE: Myocardial infarction is the highest cause of cardiovascular death. Previous studies found that patients with myocardial infarction have elevated serum IL-37 and IL-37 treatment significantly alleviates adverse remodeling in myocardial infarction mice. However, the underlying mechanism of IL-37 in myocardial infarction is still unknown. Here we explored the underlying mechanism of IL-37 in attenuating myocardial infarction. METHODS: The myocardial infarction mice model was constructed by left anterior descending ligation and then submitted to recombinant IL-37 administration. The histology and cardiac function were detected by HE & Masson staining and echocardiography, respectively. The macrophage phenotypes were analyzed by flow cytometry and real-time PCR. The cytokines in serum and cell culture supernatant were determined by ELISA. In addition, THP-1 cells were used in vitro to investigate the underlying mechanisms. RESULTS: Infarcted mice showed increased inflammatory cell infiltration and impaired cardiac function. IL-37 treatment alleviated pro-inflammatory macrophage infiltration, tissue injury, and collagen deposition in hearts on day 3 and 7 after infarction in mice. In addition, IL-37 application modulated the balance between M1 and M2 macrophages in infarcted hearts. In vitro, THP-1 cell line polarization was also regulated by IL-37, companied by YAP phosphorylation and NLRP3 inactivation. Verteporfin, a YAP inhibitor, could abolish IL-37-induced NLRP3 inhibition and M2 macrophage polarization. CONCLUSION: Our results demonstrated that IL-37 achieves a favorable therapeutical function on myocardial infarction by modulating YAP-NLRP3 mediated macrophage programming, providing a promising drug for the treatment of myocardial infarction.