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McKenna S, Gossling M, Bugarini A, Hill E, Anderson AL, Rancourt RC, Balasubramaniyan N, El Kasmi KC, Wright CJ. Endotoxemia Induces IκBβ/NF-κB-Dependent Endothelin-1 Expression in Hepatic Macrophages. THE JOURNAL OF IMMUNOLOGY 2015; 195:3866-79. [PMID: 26342031 DOI: 10.4049/jimmunol.1501017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 08/03/2015] [Indexed: 12/20/2022]
Abstract
Elevated serum concentrations of the vasoactive protein endothelin-1 (ET-1) occur in the setting of systemic inflammatory response syndrome and contribute to distal organ hypoperfusion and pulmonary hypertension. Thus, understanding the cellular source and transcriptional regulation of systemic inflammatory stress-induced ET-1 expression may reveal therapeutic targets. Using a murine model of LPS-induced septic shock, we demonstrate that the hepatic macrophage is the primary source of elevated circulating ET-1, rather than the endothelium as previously proposed. Using pharmacologic inhibitors, ET-1 promoter luciferase assays, and by silencing and overexpressing NF-κB inhibitory protein IκB expression, we demonstrate that LPS-induced ET-1 expression occurs via an NF-κB-dependent pathway. Finally, the specific role of the cRel/p65 inhibitory protein IκBβ was evaluated. Although cytoplasmic IκBβ inhibits activity of cRel-containing NF-κB dimers, nuclear IκBβ stabilizes NF-κB/DNA binding and enhances gene expression. Using targeted pharmacologic therapies to specifically prevent IκBβ/NF-κB signaling, as well as mice genetically modified to overexpress IκBβ, we show that nuclear IκBβ is both necessary and sufficient to drive LPS-induced ET-1 expression. Together, these results mechanistically link the innate immune response mediated by IκBβ/NF-κB to ET-1 expression and potentially reveal therapeutic targets for patients with Gram-negative septic shock.
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Affiliation(s)
- Sarah McKenna
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045
| | - Megan Gossling
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045
| | - Alejandro Bugarini
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045
| | - Elizabeth Hill
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045
| | - Aimee L Anderson
- Hepatology and Nutrition, Digestive Health Institute, Section of Gastroenterology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045; and
| | - Raymond C Rancourt
- Pediatric Airway Research Center, Section of Pulmonology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045
| | - Natarajan Balasubramaniyan
- Hepatology and Nutrition, Digestive Health Institute, Section of Gastroenterology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045; and
| | - Karim C El Kasmi
- Hepatology and Nutrition, Digestive Health Institute, Section of Gastroenterology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045; and
| | - Clyde J Wright
- Section of Neonatology, Department of Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045;
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Kalambokis GN, Mouzaki A, Rodi M, Pappas K, Korantzopoulos P, Tsianos EV. Circulating endotoxin and interleukin-6 levels are associated with Doppler-evaluated pulmonary vascular resistance in cirrhotic patients. Hepatol Int 2012. [PMID: 26201526 DOI: 10.1007/s12072-011-9337-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE Endotoxin and interleukin-6 levels (IL-6) have been involved in the development of pulmonary hypertension (PH) in non-cirrhotic experimental models and subjects. High circulating levels of both substances have been detected in cirrhosis. The association between circulating endotoxin and IL-6 levels and echocardiographically evaluated pulmonary vascular resistance (PVR) in cirrhotic patients are investigated. METHODS Thirty-seven cirrhotic patients were studied: 25 with PVR <120 dynes s cm(-5) (group 1) and 12 with PVR >120 dynes s cm(-5) (group 2). Plasma endotoxin and serum IL-6 levels were measured. The PVR and cardiac output (CO) by Doppler ultrasound, mean arterial pressure (MAP), and systemic vascular resistance (SVR) as the ratio MAP/CO were evaluated. RESULTS Child-Pugh scores, MAP, CO, and SVR were similar in both groups. Endotoxin levels were correlated significantly with IL-6 levels (r = 0.342; P = 0.03). Endotoxin and IL-6 levels were significantly higher in group 2 compared to group 1 (2.26 [0.39-8.4] vs. 0.85 [0.37-7.6] EU/mL; P = 0.04 and 37.4 [7.85-106.5] vs. 8.36 [3.15-53.7] pg/mL; P < 0.001, respectively). The PVR was correlated significantly with endotoxin levels in group 2 (r = 0.587; P = 0.04) and with IL-6 levels in group 1 (r = 0.529; P = 0.01) and group 2 (r = 0.760; P = 0.004), respectively. CONCLUSIONS Our results suggest that endotoxin and IL-6 may contribute to cirrhosis-associated PH. In this regard, modulation of these substances could improve pulmonary pressures in cirrhotic patients.
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Affiliation(s)
- Georgios N Kalambokis
- First Division of Internal Medicine and Hepato-Gastroenterology Unit, Medical School of Ioannina, University Hospital, 45110, Ioannina, Greece.
| | - Athanasia Mouzaki
- Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras, Greece
| | - Maria Rodi
- Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras, Greece
| | | | | | - Epameinondas V Tsianos
- First Division of Internal Medicine and Hepato-Gastroenterology Unit, Medical School of Ioannina, University Hospital, 45110, Ioannina, Greece.
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Yokoyama Y, Toth B, Kitchens WC, Schwacha MG, Bland KI, Chaudry IH. Role of thromboxane in producing portal hypertension following trauma-hemorrhage. Am J Physiol Gastrointest Liver Physiol 2003; 285:G1293-9. [PMID: 14613921 DOI: 10.1152/ajpgi.00268.2003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Thromboxane A2 (TXA2) and endothelin-1 (ET-1) have been proposed as the important vasoconstrictors that increase portal venous resistance in paracrine or autocrine fashion. We hypothesized that the hepatic damage following trauma-hemorrhage (T-H) is induced by the impaired hepatic circulation due to the increased production of vasoconstrictors such as ET-1 and TXA2 by the liver. To test this, male Sprague-Dawley rats (n = 6/group) were subjected to trauma (i.e., midline laparotomy) and hemorrhage (35-40 mmHg for 90 min followed by fluid resuscitation) or sham operation. At 2 or 5 h after the end of resuscitation, the liver was isolated and perfused and portal inflow pressure, bile flow, and release of ET-1 and thromboxane B2 (TXB2; a stable metabolite of TXA2) into the perfusate were measured. The level of portal pressure was higher at 5 h following T-H compared with 2 h after T-H and sham. The portal pressure was inversely correlated to the amount of bile production. Furthermore, the bile flow was significantly correlated to the hepatic damage as evidenced by release of lactate dehydrogenase into the perfusate. The level of ET-1 at 5 h following T-H in the perfusate after 30 min of recirculation did not show any difference from sham. However, the levels of TXB2 in the T-H group were significantly higher than those in sham at that interval. These results indicate that the increased release of TXA2 but not ET-1 following T-H might be responsible for producing the increased portal resistance, decreased bile production, and hepatic damage.
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Affiliation(s)
- Yukihiro Yokoyama
- Center for Surgical Research and Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA
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Oktar BK, Coşkun T, Bozkurt A, Yegen BC, Yüksel M, Haklar G, Bilsel S, Aksungar FB, Cetinel U, Granger DN, Kurtel H. Endothelin-1-induced PMN infiltration and mucosal dysfunction in the rat small intestine. Am J Physiol Gastrointest Liver Physiol 2000; 279:G483-91. [PMID: 10960346 DOI: 10.1152/ajpgi.2000.279.3.g483] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The objectives of this study were to characterize the effects of endothelin (ET)-1 on intestinal mucosal parameters and to assess the contribution of polymorphonuclear leukocytes (PMNs), intercellular adhesion molecule-1 (ICAM-1), and a platelet-activating factor (PAF) to the mucosal dysfunction induced by ET-1. Different concentrations of ET-1 (100, 200, and 400 pmol/kg) were infused into the superior mesenteric artery for 10 min, and tissue samples were obtained 30 min after terminating the infusion. ET-1 administration significantly elevated tissue myeloperoxidase activity, plasma carbonyl content, and tissue chemiluminescence intensity, indicating that ET-1 produces PMN infiltration and oxidant stress. Blood-to-lumen clearance of (51)Cr-EDTA significantly increased after ET-1 infusion (400 pmol/kg). Monoclonal antibodies against ICAM-1 (1A29, 2 mg/kg), antineutrophil serum, and PAF antagonist (WEB-2086, 10 mg/kg) attenuated the mucosal barrier dysfunction induced by ET-1. Overall, our data indicate that ET-1 causes PMN accumulation, oxidant stress, and mucosal dysfunction in the rat small intestine and that ET-1-induced mucosal dysfunction involves a mechanism that includes a role for PMNs, ICAM-1, and PAF.
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Affiliation(s)
- B K Oktar
- Department of Physiology, Marmara University School of Medicine, 81326 Haydarpaşa, Istanbul, Turkey
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Reichen J, Gerbes AL, Steiner MJ, Sägesser H, Clozel M. The effect of endothelin and its antagonist Bosentan on hemodynamics and microvascular exchange in cirrhotic rat liver. J Hepatol 1998; 28:1020-30. [PMID: 9672179 DOI: 10.1016/s0168-8278(98)80352-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND/AIMS To characterize the effects of endothelin-1 and of Bosentan, a mixed endothelin antagonist, on hepatic hemodynamics in cirrhotic animals in vivo and on hepatic microvascular exchange in the perfused rat liver. METHODS Biliary cirrhosis was induced by bile duct ligation, and micronodular cirrhosis by chronic exposure to phenobarbital/CCl4 in male rats. Hepatic hemodynamics were studied under basal conditions and after administration of Bosentan (3-30 mg/kg) by the microsphere technique. Microvascular exchange was assessed in the in situ perfused rat liver by the multiple indicator dilution technique. RESULTS Bosentan lowered portal pressure in a dose-dependent fashion; at the highest dose tested, this decrease averaged -29+/-11 and -26+/-8% in biliary and micronodular cirrhosis, respectively (p<0.01). This was achieved mainly via a marked decrease in hepatic arterial flow. In the perfused liver, endothelin-1 induced a dose-dependent vasoconstriction; up to 10(-9) mol/l; this was not associated with any effect on viability. At this dose, endothelin-1 markedly decreased extravascular albumin space in both controls and micronodular cirrhosis; this could be antagonized by Bosentan 10(-5) mol/l. CONCLUSIONS Endothelin-1 affects hepatic microvascular exchange, presumably by a direct effect on hepatic sinusoidal endothelial cells. A mixed endothelin antagonist lowers portal pressure in vivo, presumably by acting on hepatic stellate cells, and counteracts the microvascular effects of endothelin-1 in vitro. These properties could prove useful in treatment of portal hypertension.
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Affiliation(s)
- J Reichen
- Department of Clinical Pharmacology, University of Berne, Switzerland.
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