Thaliporphine ameliorates cardiac depression in endotoxemic rats through attenuating TLR4 signaling in the downstream of TAK-1 phosphorylation and NF-κB signaling.
Thaliporphine was found to ameliorate endotoxin-induced circulatory failure and mortality in rodents. The aims of the present study were to assess whether thaliporphine could improve cardiac function in endotoxemic rats and to investigate the underlying mechanisms. Cardiac function was evaluated by pressure-volume loop analysis in pentobarbital-anesthetized rats 24 h after intravenous injection of lipopolysaccharide (LPS) (4 mg/kg) with or without thaliporphine (1 mg/kg, iv). The intracellular Ca(2+) transients, nitric oxide (NO), and reactive oxygen species (ROS) in enzymatically isolated ventricular cells were measured by fluorescent indicators. Western blotting was used to analyze the change of protein expression in response to LPS with or without thaliporphine in rat ventricle, H9C2 and Raw264.7 cells. Cardiac depression was found to coincide with the decreased intracellular Ca(2+) transients and the increased expression of nitrotyrosine on SERCA2 in rat ventricles after 24-h endotoxemia. Thaliporphine decreased intracellular NO and ROS level in ventricular cells and the nitrosylation of SERCA2, which resulted in recovering the functional properties of intracellular Ca(2+) handling and cardiac contraction. In H9C2 cells, LPS-induced nuclear translocation of nuclear factor kappa B (NF-κB) could be attenuated by thaliporphine. In Raw264.7 cells, thaliporphine attenuated LPS-induced TAK-1 phosphorylation and IκBα degradation in association with the inhibition of inducible nitric oxide synthase (iNOS) and tumor necrosis factor alpha (TNF-α) expression and the production of NO and ROS. In conclusion, thaliporphine ameliorates LPS-induced cardiac depression through attenuating TLR4 signaling in the downstream of TAK-1 phosphorylation and NF-κB signaling in both cardiomyocytes and macrophage to prevent cardiac SERCA2 from nitrosylation by peroxynitrite via decreasing iNOS and TNF-α expression.
Chen
Wen-Pin
WP
Institute of Pharmacology, College of Medicine, National Taiwan University, No. 1, Sec. 1, Jen-Ai Rd, Taipei, 100, Taiwan.
Tzeng
Hsiao-Jung
HJ
Ku
Hui-Chun
HC
Ho
Yi-Jin
YJ
Lee
Shoei-Sheng
SS
Su
Ming-Jai
MJ
D000818:Animals; D001060:Aporphines / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D019446:Endotoxemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008070:Lipopolysaccharides / Q000494:pharmacology; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism; D014662:Vasoconstrictor Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016277:Ventricular Function, Left / Q000187:drug effects*; D017725:Ventricular Pressure / Q000187:drug effects*; D000099151:MAP Kinase Kinase Kinase 7
D001060:Aporphines; D008070:Lipopolysaccharides; D020930:MAP Kinase Kinase Kinases; D016328:NF-kappa B; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D017382:Reactive Oxygen Species; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D014662:Vasoconstrictor Agents; D000099151:MAP Kinase Kinase Kinase 7; C080702:thaliporphine