ag-490 and Sepsis

Sepsis-induced myocardial dysfunction (SIMD) represents one of the serious complications secondary to sepsis, which is a leading cause of the high mortality rate among septic cases. Subsequent cardiomyocyte apoptosis, together with the uncontrolled inflammatory response, has been suggested to be closely related to SIMD. Piceatannol (PIC) is verified with potent anti-apoptotic and anti-inflammatory effects, but its function and molecular mechanism in SIMD remain unknown so far. This study aimed to explore the potential role and mechanism of action of PIC in resisting SIMD. The interaction of PIC with JAK2 proteins was evaluated by molecular docking, molecular dynamics (MD) simulation and surface plasmon resonance imaging (SPRi). The cecal ligation and puncture-induced septicemia mice and the LPS-stimulated H9C2 cardiomyocytes were prepared as the models in vivo and in vitro, separately. Molecular docking showed that JAK2-PIC complex had the -8.279 kcal/mol binding energy. MD simulations showed that JAK2-PIC binding was stable. SPRi analysis also showed that PIC has a strong binding affinity to JAK2. PIC treatment significantly ameliorated the cardiac function, attenuated the sepsis-induced myocardial loss, and suppressed the myocardial inflammatory responses both in vivo and in vitro. Further detection revealed that PIC inhibited the activation of the JAK2/STAT3 signaling, which was tightly associated with apoptosis and inflammation. Importantly, pre-incubation with a JAK2 inhibitor (AG490) partially blocked the cardioprotective effects of PIC. Collectively, the findings demonstrated that PIC restored the impaired cardiac function by attenuating the sepsis-induced apoptosis and inflammation via suppressing the JAK2/STAT3 pathway both in septic mice and H9C2 cardiomyocytes.

Topics: Animals; Apoptosis; Cardiomyopathies; Cardiotonic Agents; Cell Line; Disease Models, Animal; Inflammation; Janus Kinase 2; Male; Mice, Inbred C57BL; Molecular Docking Simulation; Molecular Dynamics Simulation; Myocytes, Cardiac; Rats; Sepsis; Signal Transduction; STAT3 Transcription Factor; Stilbenes; Tyrphostins

Sepsis, a leading cause of death in hospitalized patients, is characterized by lethal systemic inflammatory responses. JAK2 is an essential tyrosine kinase modulating immune responses. However, the implications of JAK2 in infectious disorders remain undetermined. Here, we report that JAK2 inhibitors rescue animals from polymicrobial sepsis in a clinically relevant time frame. JAK2 inhibition with AG490 prevents NF-kappaB activation, modulates macrophage activation, and restrains the production of inflammatory cytokines. The inhibition of JAK2 blunted TNF production in both macrophages and splenocytes in a concentration-dependent manner. JAK2 inhibition specifically prevents LPS-induced STAT3 tyrosine phosphorylation without affecting serine phosphorylation in macrophages. JAK2 inhibitor prevents the activation of the canonical p65RelA/p50NF-kappaB1 pathway but not the other NF-kappaB proteins. In vivo, JAK2 inhibition restrains serum TNF levels by modulating TNF production in the lung and the spleen and protects mice from lethal endotoxemia in a concentration-dependent manner. AG490 also inhibits extracellular release of HMGB1 from macrophages and prevents an increase in serum HMGB1 levels during sepsis. JAK2 inhibition started at 24 h after the onset of sepsis rescued the mice from polymicrobial sepsis. Our study is the first experimental evidence that JAK2 inhibitors may provide a pharmacological advantage for the treatment of sepsis in a clinically relevant time frame.

Topics: Animals; Cell Line; Cytokines; Enzyme Inhibitors; HMGB1 Protein; Humans; Immunity, Innate; Janus Kinase 2; Macrophages; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Sepsis; STAT3 Transcription Factor; Tumor Necrosis Factor-alpha; Tyrphostins

To investigate the role of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in mediating mRNA expression of high mobility group box 1 protein (HMGB1) in the liver in septic rats.. Using a sepsis model of cecal ligation and puncture (CLP), 98 male Wistar rats were randomly divided into normal control group (n=10), CLP group (n=40), AG490 treatment group (n=24), and Rapamycin (RPM) treatment group (n=24). At serial time points animals in each group were sacrificed, and blood as well as hepatic tissue samples were harvested to determine HMGB1 mRNA expression and serum aspartate aminotransferase (AST) as well as alanine aminotransferase (ALT) contents.. Compared with normal controls, HMGB1 mRNA levels were significantly increased in the liver during 6-48 hours after CLP (P<0.01), and serum AST and ALT contents were significantly elevated at different time points respectively (P<0.05 or P<0.01). Treatment with AG490 and RPM could markedly inhibit HMGB1 mRNA expression in the liver at 24 hours, 48 hours, 6 hours and 24 hours after CLP, respectively. In addition, compared to CLP group, serum AST and ALT contents in both treatment groups could be markedly reduced at various intervals after CLP (P<0.05 or P<0.01).. These data suggest that the activation of JAK/STAT pathway might be involved in mediating up-regulation of HMGB1 mRNA expression in the liver in CLP-induced sepsis. Treatment with inhibitors of JAK/STAT pathway could markedly down-regulate HMGB1 mRNA expression and attenuate acute liver injury associated with sepsis.

Topics: Alanine Transaminase; Animals; Anti-Bacterial Agents; Aspartic Acid; Disease Models, Animal; DNA-Binding Proteins; Enzyme Inhibitors; Gene Expression; HMGB1 Protein; Liver; Male; Protein-Tyrosine Kinases; Random Allocation; Rats; Rats, Wistar; RNA, Messenger; Sepsis; Signal Transduction; Sirolimus; Trans-Activators; Transcription, Genetic; Transcriptional Activation; Tyrphostins