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Guixé-Muntet S, Quesada-Vázquez S, Gracia-Sancho J. Pathophysiology and therapeutic options for cirrhotic portal hypertension. Lancet Gastroenterol Hepatol 2024; 9:646-663. [PMID: 38642564 DOI: 10.1016/s2468-1253(23)00438-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 04/22/2024]
Abstract
Portal hypertension represents the primary non-neoplastic complication of liver cirrhosis and has life-threatening consequences, such as oesophageal variceal bleeding, ascites, and hepatic encephalopathy. Portal hypertension occurs due to increased resistance of the cirrhotic liver vasculature to portal blood flow and is further aggravated by the hyperdynamic circulatory syndrome. Existing knowledge indicates that the profibrogenic phenotype acquired by sinusoidal cells is the initial factor leading to increased hepatic vascular tone and fibrosis, which cause increased vascular resistance and portal hypertension. Data also suggest that the phenotype of hepatic cells could be further impaired due to the altered mechanical properties of the cirrhotic liver itself, creating a deleterious cycle that worsens portal hypertension in the advanced stages of liver disease. In this Review, we discuss recent discoveries in the pathophysiology and treatment of cirrhotic portal hypertension, a condition with few pharmacological treatment options.
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Affiliation(s)
- Sergi Guixé-Muntet
- Liver Vascular Biology Research Group, IDIBAPS Biomedical Research Institute, CIBEREHD, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Sergio Quesada-Vázquez
- Liver Vascular Biology Research Group, IDIBAPS Biomedical Research Institute, CIBEREHD, Hospital Clínic de Barcelona, Barcelona, Spain
| | - Jordi Gracia-Sancho
- Liver Vascular Biology Research Group, IDIBAPS Biomedical Research Institute, CIBEREHD, Hospital Clínic de Barcelona, Barcelona, Spain; Department of Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
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2
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Bitto N, Ghigliazza G, Lavorato S, Caputo C, La Mura V. Improving Management of Portal Hypertension: The Potential Benefit of Non-Etiological Therapies in Cirrhosis. J Clin Med 2023; 12:jcm12030934. [PMID: 36769582 PMCID: PMC9917703 DOI: 10.3390/jcm12030934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Portal hypertension is the consequence of cirrhosis and results from increased sinusoidal vascular resistance and hepatic blood inflow. Etiological therapies represent the first intervention to prevent a significant increase in portal pressure due to chronic liver damage. However, other superimposed pathophysiological drivers may worsen liver disease, including inflammation, bacterial translocation, endothelial dysfunction, and hyperactivation of hemostasis. These mechanisms can be targeted by a specific class of drugs already used in clinical practice. Albumin, rifaximin, statins, aspirin, and anticoagulants have been tested in cirrhosis and were a topic of discussion in the last Baveno consensus as non-etiological therapies. Based on the pathogenesis of portal hypertension in cirrhosis, our review summarizes the main mechanisms targeted by these drugs as well as the clinical evidence that considers them a valid complementary option to manage patients with cirrhosis and portal hypertension.
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Affiliation(s)
- Niccolò Bitto
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
| | - Gabriele Ghigliazza
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Division of Sub-Intensive Care Medicine, 20122 Milan, Italy
| | - Stanislao Lavorato
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
| | - Camilla Caputo
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
| | - Vincenzo La Mura
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, 20122 Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
- Correspondence:
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Bzdęga W, Żywno H, Kołakowski A, Kurzyna PF, Harasim-Symbor E, Chabowski A, Konstantynowicz-Nowicka K. Coumestrol as a new substance that may diminish lipid precursors of the inflammation in steatotic primary rat hepatocytes. Biochimie 2023; 204:78-91. [PMID: 36084910 DOI: 10.1016/j.biochi.2022.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/23/2022] [Accepted: 09/01/2022] [Indexed: 01/12/2023]
Abstract
Coumestrol is a phytoestrogen found in various plant foods. Increasing evidence ascertained its robust anti-inflammatory, anti-oxidative properties likewise ability to mitigate insulin resistance. Thus, it may be a potential medicine in the treatment of many metabolic disorders, including obesity, type 2 diabetes (T2D) as well as non-alcoholic fatty liver disease (NAFLD). In this study, we aimed to shed some light on its influence on the accumulation of certain lipid fractions and the expression of pro-inflammatory proteins in primary rat hepatocytes during the lipid-overload state. The cells were isolated from the male Wistar rat's liver with the use of collagenase perfusion. It was followed by incubation of the cells with the presence or absence of palmitic acid and/or coumestrol. The accumulation of lipid fractions was assessed by gas-liquid chromatography (GLC) whereas the expression of the proteins was evaluated by the Western blot technique. Treatment with coumestrol in the state of increased fatty acids availability led to the deposition of triacylglycerols rather than diacylglycerols, significantly decreased expression of proinflammatory and profibrotic cytokines, especially interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), as well as transforming growth factor β (TGF-β), and nuclear factor κβ (NF-κβ). Also, we observed a substantial diminution in proinflammatory enzymes expression. Taking into consideration the direction of the aforementioned changes, we may assume that coumestrol can ameliorate the array of factors leading to the development of steatosis, likewise counteracting progression to steatohepatitis, thus it may be a step forward to the long-awaited breakthrough in the treatment of NAFLD.
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Affiliation(s)
- Wiktor Bzdęga
- Department of Physiology, Medical University of Bialystok, 15-089, Bialystok, Poland.
| | - Hubert Żywno
- Department of Physiology, Medical University of Bialystok, 15-089, Bialystok, Poland.
| | - Adrian Kołakowski
- Department of Physiology, Medical University of Bialystok, 15-089, Bialystok, Poland.
| | | | - Ewa Harasim-Symbor
- Department of Physiology, Medical University of Bialystok, 15-089, Bialystok, Poland.
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, 15-089, Bialystok, Poland.
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Li H. Intercellular crosstalk of liver sinusoidal endothelial cells in liver fibrosis, cirrhosis and hepatocellular carcinoma. Dig Liver Dis 2022; 54:598-613. [PMID: 34344577 DOI: 10.1016/j.dld.2021.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022]
Abstract
Intercellular crosstalk among various liver cells plays an important role in liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Capillarization of liver sinusoidal endothelial cells (LSECs) precedes fibrosis and accumulating evidence suggests that the crosstalk between LSECs and other liver cells is critical in the development and progression of liver fibrosis. LSECs dysfunction, a key event in the progression from fibrosis to cirrhosis, and subsequently obstruction of hepatic sinuses and increased intrahepatic vascular resistance (IHVR) contribute to development of portal hypertension (PHT) and cirrhosis. More importantly, immunosuppressive tumor microenvironment (TME), which is closely related to the crosstalk between LSECs and immune liver cells like CD8+ T cells, promotes advances tumorigenesis, especially HCC. However, the connections within the crosstalk between LSECs and other liver cells during the progression from liver fibrosis to cirrhosis to HCC have yet to be discussed. In this review, we first summarize the current knowledge of how different crosstalk between LSECs and other liver cells, including hepatocytes, hepatic stellate cells (HSCs), macrophoges, immune cells in liver and extra cellular matrix (ECM) contribute to the physiological function and the progrssion from liver fibrosis to cirrhosis, or even to HCC. Then we examine current treatment strategies for LSECs crosstalk in liver fibrosis, cirrhosis and HCC.
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Affiliation(s)
- Hui Li
- Central Laboratory, Hospital of Chengdu University of Traditional Chinese Medicine, NO. 39 Shi-er-qiao Road, Chengdu, 610072, Sichuan Province, PR China.
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The Hepatic Sinusoid in Chronic Liver Disease: The Optimal Milieu for Cancer. Cancers (Basel) 2021; 13:cancers13225719. [PMID: 34830874 PMCID: PMC8616349 DOI: 10.3390/cancers13225719] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary During the development of chronic liver disease, the hepatic sinusoid undergoes major changes that further compromise the hepatic function, inducing persistent inflammation and the formation of scar tissue, together with alterations in liver hemodynamics. This diseased background may induce the formation and development of hepatocellular carcinoma (HCC), which is the most common form of primary liver cancer and a major cause of mortality. In this review, we describe the ways in which the dysregulation of hepatic sinusoidal cells—including liver sinusoidal cells, Kupffer cells, and hepatic stellate cells—may have an important role in the development of HCC. Our review summarizes all of the known sinusoidal processes in both health and disease, and possible treatments focusing on the dysregulation of the sinusoid; finally, we discuss how some of these alterations occurring during chronic injury are shared with the pathology of HCC and may contribute to its development. Abstract The liver sinusoids are a unique type of microvascular beds. The specialized phenotype of sinusoidal cells is essential for their communication, and for the function of all hepatic cell types, including hepatocytes. Liver sinusoidal endothelial cells (LSECs) conform the inner layer of the sinusoids, which is permeable due to the fenestrae across the cytoplasm; hepatic stellate cells (HSCs) surround LSECs, regulate the vascular tone, and synthetize the extracellular matrix, and Kupffer cells (KCs) are the liver-resident macrophages. Upon injury, the harmonic equilibrium in sinusoidal communication is disrupted, leading to phenotypic alterations that may affect the function of the whole liver if the damage persists. Understanding how the specialized sinusoidal cells work in coordination with each other in healthy livers and chronic liver disease is of the utmost importance for the discovery of new therapeutic targets and the design of novel pharmacological strategies. In this manuscript, we summarize the current knowledge on the role of sinusoidal cells and their communication both in health and chronic liver diseases, and their potential pharmacologic modulation. Finally, we discuss how alterations occurring during chronic injury may contribute to the development of hepatocellular carcinoma, which is usually developed in the background of chronic liver disease.
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Cao JL, Yan JB, Wu JT, Chen ZY. Research progress of sinusoidal endothelial cells in nonalcoholic fatty liver disease. Shijie Huaren Xiaohua Zazhi 2021; 29:1254-1260. [DOI: 10.11569/wcjd.v29.i21.1254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a growing health problem associated with metabolic syndrome. Liver sinusoidal endothelial cells (LSECs) are highly specialized endothelial cells located between the blood and other liver cell types. They are composed of window pores, have high endocytosis, and play an important role in maintaining the overall liver homeostasis. Under pathological conditions, LSECs may be the key event of a variety of chronic liver diseases. In this review, we introduce the unique physiological structure and function of LSECs, summarize the main changes of LSECs in NAFLD (including sinohepatic capillarization, angiogenesis, vasoconstriction, proinflammatory effect, and fibrosis) and their pathogenesis, and discuss the influence of LSECs on the progression of NAFLD, with an aim to demonstrate the potential efficacy of LSECS targeted therapy for NAFLD.
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Affiliation(s)
- Jie-Lu Cao
- The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou Command, Hangzhou 310006, Zhejiang Province, China
| | - Jun-Bin Yan
- The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou Command, Hangzhou 310006, Zhejiang Province, China
| | - Jin-Ting Wu
- The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou Command, Hangzhou 310006, Zhejiang Province, China
| | - Zhi-Yun Chen
- The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou Command, Hangzhou 310006, Zhejiang Province, China
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The Vascular Involvement in Soft Tissue Fibrosis-Lessons Learned from Pathological Scarring. Int J Mol Sci 2020; 21:ijms21072542. [PMID: 32268503 PMCID: PMC7177855 DOI: 10.3390/ijms21072542] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 02/06/2023] Open
Abstract
Soft tissue fibrosis in important organs such as the heart, liver, lung, and kidney is a serious pathological process that is characterized by excessive connective tissue deposition. It is the result of chronic but progressive accumulation of fibroblasts and their production of extracellular matrix components such as collagens. Research on pathological scars, namely, hypertrophic scars and keloids, may provide important clues about the mechanisms that drive soft tissue fibrosis, in particular the vascular involvement. This is because these dermal fibrotic lesions bear all of the fibrotic characteristics seen in soft tissue fibrosis. Moreover, their location on the skin surface means they are readily observable and directly treatable and therefore more accessible to research. We will focus here on the roles that blood vessel-associated cells play in cutaneous scar pathology and assess from the literature whether these cells also contribute to other soft tissue fibroses. These cells include endothelial cells, which not only exhibit aberrant functions but also differentiate into mesenchymal cells in pathological scars. They also include pericytes, hepatic stellate cells, fibrocytes, and myofibroblasts. This article will review with broad strokes the roles that these cells play in the pathophysiology of different soft tissue fibroses. We hope that this brief but wide-ranging overview of the vascular involvement in fibrosis pathophysiology will aid research into the mechanisms underlying fibrosis and that this will eventually lead to the development of interventions that can prevent, reduce, or even reverse fibrosis formation and/or progression.
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Acute-on-chronic liver disease enhances phenylephrine-induced endothelial nitric oxide release in rat mesenteric resistance arteries through enhanced PKA, PI3K/AKT and cGMP signalling pathways. Sci Rep 2019; 9:6993. [PMID: 31061522 PMCID: PMC6502824 DOI: 10.1038/s41598-019-43513-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 04/15/2019] [Indexed: 12/15/2022] Open
Abstract
Acute-on-chronic liver disease is a clinical syndrome characterized by decompensated liver fibrosis, portal hypertension and splanchnic hyperdynamic circulation. We aimed to determine whether the alpha-1 agonist phenylephrine (Phe) facilitates endothelial nitric oxide (NO) release by mesenteric resistance arteries (MRA) in rats subjected to an experimental microsurgical obstructive liver cholestasis model (LC). Sham-operated (SO) and LC rats were maintained for eight postoperative weeks. Phe-induced vasoconstriction (in the presence/absence of the NO synthase –NOS- inhibitor L-NAME) and vasodilator response to NO donor DEA-NO were analysed. Phe-induced NO release was determined in the presence/absence of either H89 (protein kinase –PK- A inhibitor) or LY 294002 (PI3K inhibitor). PKA and PKG activities, alpha-1 adrenoceptor, endothelial NOS (eNOS), PI3K, AKT and soluble guanylate cyclase (sGC) subunit expressions, as well as eNOS and AKT phosphorylation, were determined. The results show that LC blunted Phe-induced vasoconstriction, and enhanced DEA-NO-induced vasodilation. L-NAME increased the Phe-induced contraction largely in LC animals. The Phe-induced NO release was greater in MRA from LC animals. Both H89 and LY 294002 reduced NO release in LC. Alpha-1 adrenoceptor, eNOS, PI3K and AKT expressions were unchanged, but sGC subunit expression, eNOS and AKT phosphorylation and the activities of PKA and PKG were higher in MRA from LC animals. In summary, these mechanisms may help maintaining splanchnic vasodilation and hypotension observed in decompensated LC.
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Shenoda B, Boselli J. Vascular syndromes in liver cirrhosis. Clin J Gastroenterol 2019; 12:387-397. [PMID: 30980261 DOI: 10.1007/s12328-019-00956-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 02/20/2019] [Indexed: 02/08/2023]
Abstract
Liver cirrhosis is associated with multiple vascular syndromes affecting almost all body systems. Many of these syndromes are directly related to impaired liver function and sometimes reversible after liver transplantation while others arise secondary to portal hypertension and ascites. Altered expression of angiogenic and vasoactive compounds (most importantly nitric oxide), endothelial dysfunction, dysregulated neurohormonal control, and systemic inflammatory state play differential roles in mediating homeostatic instability and abnormal vasogenic response. Important vascular features encountered in liver disease include portal hypertension, splanchnic overflow, abnormal angiogenesis and shunts, portopulmonary syndrome, hepatopulmonary syndrome, and systemic hyperdynamic circulation. Redistribution of effective circulatory volume deviating from vital organs and pooling in splanchnic circulation is also encountered in liver patients which may lead to devastating outcomes as hepatorenal syndrome. Etiologically, vascular syndromes are not isolated phenomena and vascular dysfunction in one system may lead to the development of another in a different system. This review focuses on understanding the pathophysiological factors underlying vascular syndromes related to chronic liver disease and the potential links among them. Many of these syndromes are associated with high mortality, thus it is crucial to look for early biomarkers for these syndromes and develop novel preventive and therapeutic strategies.
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Affiliation(s)
- Botros Shenoda
- Department of Medicine, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Joseph Boselli
- Department of Medicine, Drexel University College of Medicine, Philadelphia, PA, 19102, USA. .,Drexel Internal Medicine, 205 N. Broad Street, Philadelphia, 19107, USA.
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Gracia-Sancho J, Marrone G, Fernández-Iglesias A. Hepatic microcirculation and mechanisms of portal hypertension. Nat Rev Gastroenterol Hepatol 2019; 16:221-234. [PMID: 30568278 DOI: 10.1038/s41575-018-0097-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The liver microcirculatory milieu, mainly composed of liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs) and hepatic macrophages, has an essential role in liver homeostasis, including in preserving hepatocyte function, regulating the vascular tone and controlling inflammation. Liver microcirculatory dysfunction is one of the key mechanisms that promotes the progression of chronic liver disease (also termed cirrhosis) and the development of its major clinical complication, portal hypertension. In the present Review, we describe the current knowledge of liver microcirculatory dysfunction in cirrhotic portal hypertension and appraise the preclinical models used to study the liver circulation. We also provide a comprehensive summary of the promising therapeutic options to target the liver microvasculature in cirrhosis.
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Affiliation(s)
- Jordi Gracia-Sancho
- Liver Vascular Biology Research Group, Barcelona Hepatic Hemodynamic Laboratory, IDIBAPS Biomedical Research Institute, CIBEREHD, Barcelona, Spain. .,Hepatology, Department of Biomedical Research, Inselspital, Bern University, Bern, Switzerland.
| | - Giusi Marrone
- Liver Vascular Biology Research Group, Barcelona Hepatic Hemodynamic Laboratory, IDIBAPS Biomedical Research Institute, CIBEREHD, Barcelona, Spain
| | - Anabel Fernández-Iglesias
- Liver Vascular Biology Research Group, Barcelona Hepatic Hemodynamic Laboratory, IDIBAPS Biomedical Research Institute, CIBEREHD, Barcelona, Spain
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Lin L, Cai M, Deng S, Huang W, Huang J, Huang X, Huang M, Wang Y, Shuai X, Zhu K. Amelioration of cirrhotic portal hypertension by targeted cyclooxygenase-1 siRNA delivery to liver sinusoidal endothelium with polyethylenimine grafted hyaluronic acid. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:2329-2339. [DOI: 10.1016/j.nano.2017.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/13/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
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Vilaseca M, García-Calderó H, Lafoz E, Ruart M, López-Sanjurjo CI, Murphy MP, Deulofeu R, Bosch J, Hernández-Gea V, Gracia-Sancho J, García-Pagán JC. Mitochondria-targeted antioxidant mitoquinone deactivates human and rat hepatic stellate cells and reduces portal hypertension in cirrhotic rats. Liver Int 2017; 37:1002-1012. [PMID: 28371136 DOI: 10.1111/liv.13436] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/24/2017] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS In cirrhosis, activated hepatic stellate cells (HSC) play a major role in increasing intrahepatic vascular resistance and developing portal hypertension. We have shown that cirrhotic livers have increased reactive oxygen species (ROS), and that antioxidant therapy decreases portal pressure. Considering that mitochondria produce many of these ROS, our aim was to assess the effects of the oral mitochondria-targeted antioxidant mitoquinone on hepatic oxidative stress, HSC phenotype, liver fibrosis and portal hypertension. METHODS Ex vivo: Hepatic stellate cells phenotype was analysed in human precision-cut liver slices in response to mitoquinone or vehicle. In vitro: Mitochondrial oxidative stress was analysed in different cell type of livers from control and cirrhotic rats. HSC phenotype, proliferation and viability were assessed in LX2, and in primary human and rat HSC treated with mitoquinone or vehicle. In vivo: CCl4 - and thioacetamide-cirrhotic rats were treated with mitoquinone (5 mg/kg/day) or the vehicle compound, DecylTPP, for 2 weeks, followed by measurement of oxidative stress, systemic and hepatic haemodynamic, liver fibrosis, HSC phenotype and liver inflammation. RESULTS Mitoquinone deactivated human and rat HSC, decreased their proliferation but with no effects on viability. In CCl4 -cirrhotic rats, mitoquinone decreased hepatic oxidative stress, improved HSC phenotype, reduced intrahepatic vascular resistance and diminished liver fibrosis. These effects were associated with a significant reduction in portal pressure without changes in arterial pressure. These results were further confirmed in the thioacetamide-cirrhotic model. CONCLUSION We propose mitochondria-targeted antioxidants as a novel treatment approach against portal hypertension and cirrhosis.
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Affiliation(s)
- Marina Vilaseca
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain
| | - Héctor García-Calderó
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | - Erica Lafoz
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain
| | - Maria Ruart
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain
| | - Cristina Isabel López-Sanjurjo
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | | | - Ramon Deulofeu
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain.,Department of Biochemistry and Chromatography, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Jaume Bosch
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | - Virginia Hernández-Gea
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | - Jordi Gracia-Sancho
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | - Juan Carlos García-Pagán
- Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
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13
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Vilaseca M, García-Calderó H, Lafoz E, García-Irigoyen O, Avila MA, Reverter JC, Bosch J, Hernández-Gea V, Gracia-Sancho J, García-Pagán JC. The anticoagulant rivaroxaban lowers portal hypertension in cirrhotic rats mainly by deactivating hepatic stellate cells. Hepatology 2017; 65:2031-2044. [PMID: 28142199 DOI: 10.1002/hep.29084] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/29/2016] [Accepted: 01/24/2017] [Indexed: 12/12/2022]
Abstract
UNLABELLED In cirrhosis, increased intrahepatic vascular resistance (IHVR) is the primary factor for portal hypertension (PH) development. Hepatic stellate cells (HSCs) play a major role increasing IHVR because, when activated, they are contractile and promote fibrogenesis. Protease-activated receptors (PARs) can activate HSCs through thrombin and factor Xa, which are known PAR agonists, and cause microthrombosis in liver microcirculation. This study investigates the effects of the oral anticoagulant, rivaroxaban (RVXB), a direct antifactor Xa, on HSC phenotype, liver fibrosis (LF), liver microthrombosis, and PH in cirrhotic rats. Hepatic and systemic hemodynamic, nitric oxide (NO) bioavailability, LF, HSC activation, and microthrombosis were evaluated in CCl4 and thioacetamide-cirrhotic rats treated with RVXB (20 mg/kg/day) or its vehicle for 2 weeks. RVXB significantly decreased portal pressure (PP) in both models of cirrhosis without changes in portal blood flow, suggesting a reduction in IHVR. RVXB reduced oxidative stress, improved NO bioavailability, and ameliorated endothelial dysfunction. Rivaroxaban deactivated HSC, with decreased alpha-smooth muscle actin and mRNA expression of other HSC activation markers. Despite this marked improvement in HSC phenotype, no significant changes in LF were identified. RVXB markedly reduced fibrin deposition, suggesting reduced intrahepatic microthrombosis. CONCLUSION RVXB decreases PP in two rat models of cirrhosis. This effect is mostly associated with decreased IHVR, enhanced NO bioavailability, HSC deactivation, and reduced intrahepatic microthrombosis. Our findings suggest that RVXB deserves further evaluation as a potential treatment for cirrhotic PH. (Hepatology 2017;65:2031-2044).
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Affiliation(s)
- Marina Vilaseca
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,University of Barcelona Medical School, Barcelona, Spain
| | - Héctor García-Calderó
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain
| | - Erica Lafoz
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,University of Barcelona Medical School, Barcelona, Spain
| | - Oihane García-Irigoyen
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain.,Centro de Investigación Médica Aplicada (CIMA), Division of Hepatology; University of Navarra, IDISNA (Instituto de Investigacion Sanitaria de Navarra), Pamplona, Spain
| | - Matías A Avila
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain.,Centro de Investigación Médica Aplicada (CIMA), Division of Hepatology; University of Navarra, IDISNA (Instituto de Investigacion Sanitaria de Navarra), Pamplona, Spain
| | | | - Jaume Bosch
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain.,Swiss Liver Centre, Inselspital, Bern University, Switzerland
| | - Virginia Hernández-Gea
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain
| | - Jordi Gracia-Sancho
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain
| | - Joan Carles García-Pagán
- Barcelona Hepatic Hemodynamic Lab, Liver Unit, Hospital Clínic, Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain.,University of Barcelona Medical School, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Spain
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14
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Persico M, Masarone M, Damato A, Ambrosio M, Federico A, Rosato V, Bucci T, Carrizzo A, Vecchione C. "Non alcoholic fatty liver disease and eNOS dysfunction in humans". BMC Gastroenterol 2017; 17:35. [PMID: 28264657 PMCID: PMC5340006 DOI: 10.1186/s12876-017-0592-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Accepted: 03/01/2017] [Indexed: 02/07/2023] Open
Abstract
Background NAFLD is associated to Insulin Resistance (IR). IR is responsible for Endothelial Dysfunction (ED) through the impairment of eNOS function. Although eNOS derangement has been demonstrated in experimental models, no studies have directly shown that eNOS dysfunction is associated with NAFLD in humans. The aim of this study is to investigate eNOS function in NAFLD patients. Methods Fifty-four NAFLD patients were consecutively enrolled. All patients underwent clinical and laboratory evaluation and liver biopsy. Patients were divided into two groups by the presence of NAFL or NASH. We measured vascular reactivity induced by patients’ platelets on isolated mice aorta rings. Immunoblot assays for platelet-derived phosphorylated-eNOS (p-eNOS) and immunohistochemistry for hepatic p-eNOS have been performed to evaluate eNOS function in platelets and liver specimens. Flow-mediated-dilation (FMD) was also performed. Data were compared with healthy controls. Results Twenty-one (38, 8%) patients had NAFL and 33 (61, 7%) NASH. No differences were found between groups and controls except for HOMA and insulin (p < 0.0001). Vascular reactivity demonstrated a reduced function induced from NAFLD platelets as compared with controls (p < 0.001), associated with an impaired p-eNOS in both platelets and liver (p < 0.001). NAFL showed a higher impairment of eNOS phosphorylation in comparison to NASH (p < 0.01). In contrast with what observed in vitro, the vascular response by FMD was worse in NASH as compared with NAFL. Conclusions Our data showed, for the first time in humans, that NAFLD patients show a marked eNOS dysfunction, which may contribute to a higher CV risk. eNOS dysfunction observed in platelets and liver tissue didn’t match with FMD.
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Affiliation(s)
- Marcello Persico
- Internal Medicine and Hepatology Unit, PO G. Da Procida-AOU- San Giovanni e Ruggi D'Aragona, University of Salerno, Via Salvatore Calenda 162, CAP: 84126, Salerno, Italy.
| | - Mario Masarone
- Internal Medicine and Hepatology Unit, PO G. Da Procida-AOU- San Giovanni e Ruggi D'Aragona, University of Salerno, Via Salvatore Calenda 162, CAP: 84126, Salerno, Italy
| | - Antonio Damato
- Vascular Physiopathology Unit IRCCS, INM Neuromed, Pozzilli, IS, Italy
| | | | - Alessandro Federico
- Hepato-Gastroenterology Division, University of Campania "L. Vanvitelli", Naples, Italy
| | - Valerio Rosato
- Internal Medicine and Hepatology Department, University of Campania "L. Vanvitelli", Naples, Italy
| | - Tommaso Bucci
- Internal Medicine and Hepatology Unit, PO G. Da Procida-AOU- San Giovanni e Ruggi D'Aragona, University of Salerno, Via Salvatore Calenda 162, CAP: 84126, Salerno, Italy
| | - Albino Carrizzo
- Vascular Physiopathology Unit IRCCS, INM Neuromed, Pozzilli, IS, Italy
| | - Carmine Vecchione
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
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15
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Gonzalez-Paredes FJ, Hernández Mesa G, Morales Arraez D, Marcelino Reyes R, Abrante B, Diaz-Flores F, Salido E, Quintero E, Hernández-Guerra M. Contribution of Cyclooxygenase End Products and Oxidative Stress to Intrahepatic Endothelial Dysfunction in Early Non-Alcoholic Fatty Liver Disease. PLoS One 2016; 11:e0156650. [PMID: 27227672 PMCID: PMC4882009 DOI: 10.1371/journal.pone.0156650] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/17/2016] [Indexed: 01/02/2023] Open
Abstract
Introduction Metabolic syndrome induces endothelial dysfunction, a surrogate marker of cardiovascular disease. In parallel, metabolic syndrome is frequently associated with non-alcoholic fatty liver disease (NAFLD), which may progress to cirrhosis. The aim of the present study was to evaluate intrahepatic endothelial dysfunction related to cyclooxygenase end products and oxidative stress as possible mechanisms involved in the pathophysiology of NAFLD. Materials and Methods Sprague-Dawley rats were fed standard diet (control-diet, CD) or high-fat-diet (HFD) for 6 weeks. Metabolic syndrome was assessed by recording arterial pressure, lipids, glycemia and rat body weight. Splanchnic hemodynamics were measured, and endothelial dysfunction was evaluated using concentration-effect curves to acetylcholine. Response was assessed with either vehicle, L-NG-Nitroarginine (L-NNA), indomethacin, tempol, or a thromboxane receptor antagonist, SQ 29548. We quantified inflammation, fibrosis, oxidative stress, nitric oxide (NO) bioavailability and thromboxane B2 levels. Results HFD rats exhibited metabolic syndrome together with the presence of NAFLD. Compared to control-diet livers, HFD livers showed increased hepatic vascular resistance unrelated to inflammation or fibrosis, but with decreased NO activity and increased oxidative stress. Endothelial dysfunction was observed in HFD livers compared with CD rats and improved after cyclooxygenase inhibition or tempol pre-incubation. However, pre-incubation with SQ 29548 did not modify acetylcholine response. Conclusions Our study provides evidence that endothelial dysfunction at an early stage of NAFLD is associated with reduced NO bioavailability together with increased cyclooxygenase end products and oxidative stress, which suggests that both pathways are involved in the pathophysiology and may be worth exploring as therapeutic targets to prevent progression of the disease.
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Affiliation(s)
- Francisco Javier Gonzalez-Paredes
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Goretti Hernández Mesa
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Dalia Morales Arraez
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Raquel Marcelino Reyes
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Beatriz Abrante
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Felicitas Diaz-Flores
- Central Laboratory, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
| | - Eduardo Salido
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
| | - Enrique Quintero
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
- Department of Medicine and Psychiatry, University of La Laguna, La Laguna, Tenerife, Spain
| | - Manuel Hernández-Guerra
- Institute of Biomedical Technologies and Center of Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, La Laguna, Tenerife, Spain
- Gastroenterology Department, University Hospital of the Canary Islands, La Laguna, Tenerife, Spain
- Department of Medicine and Psychiatry, University of La Laguna, La Laguna, Tenerife, Spain
- * E-mail:
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16
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Nair H, Berzigotti A, Bosch J. Emerging therapies for portal hypertension in cirrhosis. Expert Opin Emerg Drugs 2016; 21:167-81. [PMID: 27148904 DOI: 10.1080/14728214.2016.1184647] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Counteracting splanchnic vasodilatation and increased portal-collateral blood flow has been the mainstay for the treatment of portal hypertension (PH) over the past three decades. However, there is still large room for improvement in the treatment of PH. AREAS COVERED The basic mechanism leading to portal hypertension is the increased hepatic vascular resistance to portal blood flow caused by liver structural abnormalities inherent to cirrhosis and increased hepatic vascular tone. Molecules modulating microvascular dysfunction which have undergone preclinical and clinical trials are summarized, potential drug development issues are addressed, and situations relevant to design of clinical trials are considered. EXPERT OPINION Experimental and clinical evidence indicates that molecules modulating liver microvascular dysfunction may allow for 30-40% reduction in portal pressure. Several agents could be utilized in the earlier stages of cirrhosis (antifibrotics, antiangiogenics, etiological therapies) may allow reduction of fibrosis and halt progression of PH. This 'nip at the bud' policy, by combining therapies with existing agents used in advanced phase of cirrhosis and novel agents which could be used in early phase of cirrhotic spectrum, which are likely to hit the market soon would be the future strategy for PH therapy.
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Affiliation(s)
- Harikumar Nair
- a Inselspital Universitatsspital Bern , Bern , Switzerland
| | | | - Jaime Bosch
- a Inselspital Universitatsspital Bern , Bern , Switzerland.,b Hospital Clinic de Barcelona , University of Barcelona , Barcelona , Spain
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17
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Abstract
BACKGROUND Microbial infections are a relevant problem for patients with liver cirrhosis. Different types of bacteria are responsible for different kinds of infections: Escherichia coli and Klebsiella pneumoniae are frequently observed in spontaneous bacterial peritonitis or urinary tract infections, and Streptococcus pneumoniae and Mycoplasma pneumoniae in pulmonary infections. Mortality is up to 4-fold higher in infected patients with liver cirrhosis than in patients without infections. Key Messages: Infections in patients with liver cirrhosis are due to three major reasons: bacterial translocation, immune deficiency and an increased incidence of systemic infections. Nonparenchymal liver cells like Kupffer cells, sinusoidal endothelial cells and hepatic stellate cells are the first liver cells to come into contact with microbial products when systemic infection or bacterial translocation occurs. Kupffer cell (KC) activation by Toll-like receptor (TLR) agonists and endothelial sinusoidal dysfunction have been shown to be important mechanisms increasing portal pressure following intraperitoneal lipopolysaccharide pretreatment in cirrhotic rat livers. Reduced intrahepatic vasodilation and increased intrahepatic vasoconstriction are the relevant pathophysiological pathways. Thromboxane A2 and leukotriene (LT) C4/D4 have been identified as important vasoconstrictors. Accordingly, treatment with montelukast to inhibit the cysteinyl-LT1 receptor reduced portal pressure in cirrhotic rat livers. Clinical studies have demonstrated that activation of KCs, estimated by the amount of soluble CD163 in the blood, correlates with the risk for variceal bleeding. Additionally, intestinal decontamination with rifaximin in patients with alcohol-associated liver cirrhosis reduced the portal pressure and the risk for variceal bleeding. CONCLUSIONS TLR activation of nonparenchymal liver cells by pathogens results in portal hypertension. This might explain the pathophysiologic correlation between microbial infections and portal hypertension in patients with liver cirrhosis. These findings are the basis for both better risk stratifying and new treatment options, such as specific inhibition of TLR for patients with liver cirrhosis and portal hypertension.
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Affiliation(s)
- Christian J Steib
- Department of Medicine II, University Hospital LMU Munich, Liver Center Munich, Munich, Germany
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18
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Sacerdoti D, Pesce P, Di Pascoli M, Brocco S, Cecchetto L, Bolognesi M. Arachidonic acid metabolites and endothelial dysfunction of portal hypertension. Prostaglandins Other Lipid Mediat 2015; 120:80-90. [PMID: 26072731 DOI: 10.1016/j.prostaglandins.2015.05.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/20/2015] [Accepted: 05/25/2015] [Indexed: 12/12/2022]
Abstract
Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial growth factor (VEGF) inside the liver and in the portal circulation. Pharmacological manipulation of AA metabolites may be beneficial for cirrhotic portal hypertension.
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Affiliation(s)
- David Sacerdoti
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy.
| | - Paola Pesce
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Marco Di Pascoli
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Silvia Brocco
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Lara Cecchetto
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
| | - Massimo Bolognesi
- Department of Medicine, University of Padova Via Giustiniani, 2, 35100 Padova, Italy
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19
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Ostadhadi S, Rezayat SM, Ejtemaei-Mehr S, Tavangar SM, Nikoui V, Jazaeri F, Eftekhari G, Abdollahi A, Dehpour AR. Mesenteric artery responsiveness to acetylcholine and phenylephrine in cirrhotic rats challenged with endotoxin: the role of TLR4. Can J Physiol Pharmacol 2015; 93:475-83. [PMID: 25978623 DOI: 10.1139/cjpp-2014-0515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cirrhosis is associated with vascular dysfunction and endotoxemia. These experiments were designed to investigate the hypothesis that the administration of a low-dose of lipopolysaccharide (LPS) worsens vascular dysfunction in rats subjected to bile-duct ligation (BDL), and to determine whether LPS initiates changes in vascular Toll-like receptor 4 (TLR4) expression. Four weeks after BDL, the animals were given an intraperitoneal injection of either saline or LPS (1.0 mg/kg body mass). Three hours later, the superior mesenteric artery was isolated, perfused, and then subjected to the vasoconstriction and vasodilatation effects of phenylephrine and acetylcholine, respectively. Our results show that phenylephrine-induced vasoconstriction decreased in the cirrhotic vascular bed (BDL rats) compared with the vascular bed of the sham-operated animals, and that the LPS injections in the cirrhotic (BDL) rats worsened this response. LPS injection administered to the sham-operated animals had no such effect. On the other hand, both the BDL procedure and the LPS injection increased acetylcholine-induced vasorelaxation, but LPS administration to the BDL rats had no effect on this response. The mRNA levels of TLR4 did not change, but immunohistochemical studies showed that TLR4 localization switched from the endothelium to vascular smooth muscle cells following chronic BDL. In conclusion, acute endotoxemia in cirrhotic rats is associated with hyporesponsiveness to phenylephrine and tolerance to the effects of acetylcholine. Altered localization of TLR4 may be responsible for these effects.
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Affiliation(s)
- Sattar Ostadhadi
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran., Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
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20
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Abstract
Progress in the knowledge of the pathophysiology of portal hypertension has disclosed new targets for therapy, resulting in a larger spectrum of drugs with a potential role for clinical practice. This review focuses on pharmacologic treatments already available for reducing portal pressure and summarizes drugs currently under investigation in this field.
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Affiliation(s)
- Annalisa Berzigotti
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clinic-IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), University of Barcelona, c/Villarroel 170, Barcelona 08036, Spain
| | - Jaime Bosch
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clinic-IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), University of Barcelona, c/Villarroel 170, Barcelona 08036, Spain.
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21
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Rosado E, Rodríguez-Vilarrupla A, Gracia-Sancho J, Tripathi D, García-Calderó H, Bosch J, García-Pagán JC. Terutroban, a TP-receptor antagonist, reduces portal pressure in cirrhotic rats. Hepatology 2013; 58:1424-35. [PMID: 23703868 DOI: 10.1002/hep.26520] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 04/12/2013] [Accepted: 05/07/2013] [Indexed: 12/11/2022]
Abstract
UNLABELLED Increased production of vasoconstrictive prostanoids, such as thromboxane A2 (TXA2 ), contributes to endothelial dysfunction and increased hepatic vascular tone in cirrhosis. TXA2 induces vasoconstriction by way of activation of the thromboxane-A2 /prostaglandin-endoperoxide (TP) receptor. This study investigated whether terutroban, a specific TP receptor blocker, decreases hepatic vascular tone and portal pressure in rats with cirrhosis due to carbon tetrachloride (CCl4 ) or bile duct ligation (BDL). Hepatic and systemic hemodynamics, endothelial dysfunction, liver fibrosis, hepatic Rho-kinase activity (a marker of hepatic stellate cell contraction), and the endothelial nitric oxide synthase (eNOS) signaling pathway were measured in CCl4 and BDL cirrhotic rats treated with terutroban (30 mg/kg/day) or its vehicle for 2 weeks. Terutroban reduced portal pressure in both models without producing significant changes in portal blood flow, suggesting a reduction in hepatic vascular resistance. Terutroban did not significantly change arterial pressure in CCl4 -cirrhotic rats but decreased it significantly in BDL-cirrhotic rats. In livers from CCl4 and BDL-cirrhotic terutroban-treated rats, endothelial dysfunction was improved and Rho-kinase activity was significantly reduced. In CCl4 -cirrhotic rats, terutroban reduced liver fibrosis and decreased alpha smooth muscle actin (α-SMA), collagen-I, and transforming growth factor beta messenger RNA (mRNA) expression without significant changes in the eNOS pathway. In contrast, no change in liver fibrosis was observed in BDL-cirrhotic rats but an increase in the eNOS pathway. CONCLUSION Our data indicate that TP-receptor blockade with terutroban decreases portal pressure in cirrhosis. This effect is due to decreased hepatic resistance, which in CCl4 -cirrhotic rats was linked to decreased hepatic fibrosis, but not in BDL rats, in which the main mediator appeared to be an enhanced eNOS-dependent vasodilatation, which was not liver-selective, as it was associated with decreased arterial pressure. The potential use of terutroban for portal hypertension requires further investigation.
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Affiliation(s)
- Eugenio Rosado
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Barcelona, Spain
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22
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Di Pascoli M, Diví M, Rodríguez-Vilarrupla A, Rosado E, Gracia-Sancho J, Vilaseca M, Bosch J, García-Pagán JC. Resveratrol improves intrahepatic endothelial dysfunction and reduces hepatic fibrosis and portal pressure in cirrhotic rats. J Hepatol 2013; 58:904-10. [PMID: 23262250 DOI: 10.1016/j.jhep.2012.12.012] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Resveratrol, a polyphenol found in a variety of fruits, exerts a wide range of beneficial effects on the endothelium, regulates multiple vasoactive substances and decreases oxidative stress, factors involved in the pathophysiology of portal hypertension. Our study aimed at evaluating the effects of resveratrol on hepatic and systemic hemodynamics, hepatic endothelial dysfunction, and hepatic fibrosis in CCl₄ cirrhotic rats. METHODS Resveratrol (10 and 20 mg/kg/day) or its vehicle was administered to cirrhotic rats for two weeks and hepatic and systemic hemodynamics were measured. Moreover, we evaluated endothelial function by dose-relaxation curves to acetylcholine, hepatic NO bioavailability and TXA2 production. We also evaluated liver fibrosis by Sirius Red staining of liver sections, collagen-1, NFκB, TGFβ mRNA expression, and desmin and α-smooth muscle actin (α-SMA) protein expression, as a surrogate of hepatic stellate cell activation. RESULTS Resveratrol administration significantly decreased portal pressure compared to vehicle (12.1 ± 0.9 vs. 14.3 ± 2.2 mmHg; p <0.05) without significant changes in systemic hemodynamics. Reduction in portal pressure was associated with an improved vasodilatory response to acetylcholine, with decreased TXA2 production, increased endothelial NO, and with a significant reduction in liver fibrosis. The decrease in hepatic fibrosis was associated with a reduced collagen-1, TGFβ, NFκB mRNA expression and desmin and α-SMA protein expression. CONCLUSIONS Resveratrol administration reduces portal pressure, hepatic stellate cell activation and liver fibrosis, and improves hepatic endothelial dysfunction in cirrhotic rats, suggesting it may be a useful dietary supplement in the treatment of portal hypertension in patients with cirrhosis.
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Affiliation(s)
- Marco Di Pascoli
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer and Ciberehd, University of Barcelona, Spain
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23
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Rosado E, Rodríguez-Vilarrupla A, Gracia-Sancho J, Monclús M, Bosch J, García-Pagán JC. Interaction between NO and COX pathways modulating hepatic endothelial cells from control and cirrhotic rats. J Cell Mol Med 2013; 16:2461-70. [PMID: 22436078 PMCID: PMC3823440 DOI: 10.1111/j.1582-4934.2012.01563.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Reduced intrahepatic nitric oxide (NO) bioavailability and increased cyclooxygenase-1 (COX-1)-derived vasoconstrictor prostanoids modulate the hepatic vascular tone in cirrhosis. We aimed at investigating the reciprocal interactions between NO and COX in the hepatic endothelium of control and cirrhotic rats. NO bioavailability (DAF-FM-DA staining), superoxide (O2−) content (DHE staining), prostanoid production (PGI2 and TXA2 by enzyme immunoassays) as well as COX expression (Western Blot), were determined in hepatic endothelial cells (HEC) from control and cirrhotic rats submitted to different experimental conditions: COX activation, COX inhibition, NO activation and NO inhibition. In control and cirrhotic HEC, COX activation with arachidonic acid reduced NO bioavailability and increased O2− levels. These effects were abolished by pre-treating HEC with the COX inhibitor indomethacin. In control, but not in cirrhotic HEC, scavenging of O2− by superoxide dismutase (SOD) incubation partially restored the decrease in NO bioavailability promoted by COX activation. NO supplementation produced a significant and parallel reduction in PGI2 and TXA2 production in control HEC, whereas it only reduced TXA2 production in cirrhotic HEC. By contrast, in control and cirrhotic HEC, NO inhibition did not modify COX expression or activity. Our results demonstrate that NO and COX systems are closely interrelated in HEC. This is especially relevant in cirrhotic HEC where COX inhibition increases NO bioavailability and NO supplementation induces a reduction in TXA2. These strategies may have beneficial effects ameliorating the vasoconstrictor/vasodilator imbalance of the intrahepatic circulation of cirrhotic livers.
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Affiliation(s)
- Eugenio Rosado
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Barcelona, Spain
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García-Pagán JC, Gracia-Sancho J, Bosch J. Functional aspects on the pathophysiology of portal hypertension in cirrhosis. J Hepatol 2012; 57:458-61. [PMID: 22504334 DOI: 10.1016/j.jhep.2012.03.007] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/19/2012] [Accepted: 03/26/2012] [Indexed: 02/07/2023]
Affiliation(s)
- Juan-Carlos García-Pagán
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer and CIBERehd, Spain.
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Rodríguez-Vilarrupla A, Laviña B, García-Calderó H, Russo L, Rosado E, Roglans N, Bosch J, García-Pagán JC. PPARα activation improves endothelial dysfunction and reduces fibrosis and portal pressure in cirrhotic rats. J Hepatol 2012; 56:1033-1039. [PMID: 22245887 DOI: 10.1016/j.jhep.2011.12.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Peroxisome proliferator-activated receptor α (PPARα) is a transcription factor activated by ligands that regulates genes related to vascular tone, oxidative stress, and fibrogenesis, pathways implicated in the development of cirrhosis and portal hypertension. This study aims at evaluating the effects of PPARα activation with fenofibrate on hepatic and systemic hemodynamics, hepatic endothelial dysfunction, and hepatic fibrosis in CCl(4)-cirrhotic rats. METHODS Mean arterial pressure (MAP), portal pressure (PP), and portal blood flow (PBF) were measured in cirrhotic rats treated with oral fenofibrate (25mg/kg/day, n=10) or its vehicle (n=12) for 7 days. The liver was then perfused and dose-relaxation curves to acetylcholine (Ach) were performed. We also evaluated Sirius Red staining of liver sections, collagen-I mRNA expression, and smooth muscle actin (α-SMA) protein expression, cyclo-oxygenase-1 (COX-1) protein expression, and cGMP levels in liver homogenates, and TXB(2) production in perfusates. Nitric oxide (NO) bioavailability and eNOS activation were measured in hepatic endothelial cells (HEC) isolated from cirrhotic rat livers. RESULTS CCl(4) cirrhotic rats treated with fenofibrate had a significantly lower PP (-29%) and higher MAP than those treated with vehicle. These effects were associated with a significant reduction in hepatic fibrosis and improved vasodilatory response to acetylcholine. Moreover, a reduction in COX-1 expression and TXB(2) production in rats receiving fenofibrate and a significant increase in NO bioavailability in HEC with fenofibrate were observed. CONCLUSIONS PPARα activation markedly reduced PP and liver fibrosis and improved hepatic endothelial dysfunction in cirrhotic rats, suggesting it may represent a new therapeutic strategy for portal hypertension in cirrhosis.
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Affiliation(s)
- Aina Rodríguez-Vilarrupla
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain.
| | - Bàrbara Laviña
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
| | - Héctor García-Calderó
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
| | - Lucia Russo
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
| | - Eugenio Rosado
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
| | - Núria Roglans
- Pharmacology Unit, Department of Pharmacology and Therapeutic Chemistry, School of Pharmacy, University of Barcelona, Spain
| | - Jaume Bosch
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
| | - Joan Carles García-Pagán
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Ciberehd, University of Barcelona, Spain
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Russo L, Gracia-Sancho J, García-Calderó H, Marrone G, García-Pagán JC, García-Cardeña G, Bosch J. Addition of simvastatin to cold storage solution prevents endothelial dysfunction in explanted rat livers. Hepatology 2012; 55:921-30. [PMID: 22031447 DOI: 10.1002/hep.24755] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 09/29/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Pathophysiological alterations in the endothelial phenotype result in endothelial dysfunction. Flow cessation, occurring during organ procurement for transplantation, triggers the endothelial dysfunction characteristic of ischemia/reperfusion injury, partly due to a reduction in the expression of the vasoprotective transcription factor Kruppel-like Factor 2 (KLF2). We aimed at (1) characterizing the effects of flow cessation and cold storage on hepatic endothelial phenotype, and (2) ascertaining if the consequences of cold stasis on the hepatic endothelium can be pharmacologically modulated, improving liver graft function. Expression of KLF2 and its vasoprotective programs was determined in (i) hepatic endothelial cells (HEC) incubated under cold storage conditions with or without the KLF2-inducer simvastatin, and (ii) rat livers not cold stored or preserved in cold University of Wisconsin solution (UWS) supplemented with simvastatin or its vehicle. In addition, upon warm reperfusion hepatic vascular resistance, endothelial function, nitric oxide vasodilator pathway, apoptosis, inflammation, and liver injury were evaluated in not cold stored livers or livers preserved in cold UWS supplemented with simvastatin or vehicle. Expression of KLF2 and its vasoprotective programs decrease in HEC incubated under cold storage conditions. Cold-stored rat livers exhibit a time-dependent decrease in KLF2 and its target genes, liver injury, increased hepatic vascular resistance, and endothelial dysfunction. The addition of simvastatin to the storage solution, maintained KLF2-dependent vasoprotective programs, prevented liver damage, inflammation, and oxidative stress and improved endothelial dysfunction. CONCLUSION Our results provide a rationale to evaluate the beneficial effects of a vasoprotective preservation solution on human liver procurement for transplantation.
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Affiliation(s)
- Lucia Russo
- Hepatic Hemodynamic Lab, Liver Unit, IMDIM, Hospital Clínic de Barcelona, IDIBAPS, Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBERehd), University of Barcelona, Barcelona, Spain
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Pathophysiology of portal hypertension and esophageal varices. Int J Hepatol 2012; 2012:895787. [PMID: 22666604 PMCID: PMC3362051 DOI: 10.1155/2012/895787] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/02/2012] [Accepted: 03/12/2012] [Indexed: 02/07/2023] Open
Abstract
Esophageal varices are the major complication of portal hypertension. It is detected in about 50% of cirrhosis patients, and approximately 5-15% of cirrhosis patients show newly formed varices or worsening of varices each year. The major therapeutic strategy of esophageal varices consists of primary prevention, treatment for bleeding varices, and secondary prevention, which are provided by pharmacological, endoscopic, interventional and surgical treatments. Optimal management of esophageal varices requires a clear understanding of the pathophysiology and natural history. In this paper, we outline the current knowledge and future prospect in the pathophysiology of esophageal varices and portal hypertension.
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Insulin resistance and liver microcirculation in a rat model of early NAFLD. J Hepatol 2011; 55:1095-102. [PMID: 21356259 DOI: 10.1016/j.jhep.2011.01.053] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 01/14/2011] [Accepted: 01/27/2011] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS Insulin contributes to vascular homeostasis in peripheral circulation, but the effects of insulin in liver microvasculature have never been explored. The aim of this study was to assess the vascular effects of insulin in the healthy and fatty liver. METHODS Wistar rats were fed a control or a high fat diet (HFD) for 3days, while treated with a placebo, the insulin-sensitizer metformin, or the iNOS inhibitor 1400W. Vascular responses to insulin were evaluated in the isolated liver perfusion model. Insulin sensitivity at the sinusoidal endothelium was tested by endothelium-dependent vasodilation in response to acetylcholine in the presence or absence of insulin and by the level of liver P-eNOS after an insulin injection. RESULTS Rats from the HFD groups developed liver steatosis. Livers from the control group showed a dose-dependent hepatic vasodilation in response to insulin, which was blunted in livers from HFD groups. Metformin restored liver vascular insulin-sensitivity. Pre-treatment with insulin enhanced endothelium-dependent vasodilation of the hepatic vasculature and induced hepatic eNOS phosphorylation in control rats but not in HFD rats. Treatment with metformin or 1400W restored the capacity of insulin to enhance endothelium dependent vasodilation and insulin induced eNOS phosphorylation in HFD rats. CONCLUSIONS The administration of a HFD induces insulin resistance in the liver sinusoidal endothelium, which is mediated, at least in part, through iNOS upregulation and can be prevented by the administration of metformin. Insulin resistance at the hepatic vasculature can be detected earlier than inflammation or any other sign of advanced NALFD.
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Sacerdoti D, Jiang H, Gaiani S, McGiff JC, Gatta A, Bolognesi M. 11,12-EET increases porto-sinusoidal resistance and may play a role in endothelial dysfunction of portal hypertension. Prostaglandins Other Lipid Mediat 2011; 96:72-5. [PMID: 21856435 DOI: 10.1016/j.prostaglandins.2011.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 08/03/2011] [Accepted: 08/04/2011] [Indexed: 12/29/2022]
Abstract
CYP450-dependent epoxyeicosatrienoic acids (EETs) are potent arterial vasodilators, while 20-hydroxyeicosatatraenoic acid (20-HETE) is a vasoconstrictor. We evaluated their role in the control of portal circulation in normal and cirrhotic (CCl(4) induced) isolated perfused rat liver. Phenylephrine (PE) and endothelin-1 (ET-1) increased portal perfusion pressure, as did arachidonic acid (AA), 20-HETE, and 11,12-EET. Inhibition of 20-HETE with 12,12-dibromododecenoic acid (DBDD) did not affect basal pressure nor the responses to PE, ET-1, or AA. However, inhibition of epoxygenase with miconazole caused a significant reduction in the response to ET-1 and to AA, without affecting neither basal pressure nor the response to PE. Hepatic vein EETs concentration increased in response to ET-1, and was increased in cirrhotic, compared to control, livers. 20HETE levels were non-measurable. Miconazole decreased portal perfusion pressure in cirrhotic livers. In conclusion, 20HETE and EETs increase portal resistance; EETs, but not 20-HETE, mediate in part the pressure response to ET-1 in the portal circulation and may be involved in pathophysiology of portal hypertension.
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MESH Headings
- 8,11,14-Eicosatrienoic Acid/analogs & derivatives
- 8,11,14-Eicosatrienoic Acid/metabolism
- 8,11,14-Eicosatrienoic Acid/pharmacology
- Animals
- Arachidonic Acid/metabolism
- Carbon Tetrachloride/adverse effects
- Cytochrome P-450 Enzyme System/metabolism
- Endothelin-1/metabolism
- Endothelin-1/pharmacology
- Hepatic Veins/drug effects
- Hepatic Veins/metabolism
- Hydroxyeicosatetraenoic Acids/metabolism
- Hydroxyeicosatetraenoic Acids/pharmacology
- Hypertension, Portal/chemically induced
- Hypertension, Portal/complications
- Hypertension, Portal/metabolism
- Hypertension, Portal/physiopathology
- Infusion Pumps
- Liver/blood supply
- Liver/drug effects
- Liver/metabolism
- Liver/physiopathology
- Liver Cirrhosis, Experimental/chemically induced
- Liver Cirrhosis, Experimental/complications
- Liver Cirrhosis, Experimental/metabolism
- Liver Cirrhosis, Experimental/physiopathology
- Male
- Miconazole/pharmacology
- Organ Culture Techniques
- Oxidoreductases/antagonists & inhibitors
- Oxidoreductases/metabolism
- Phenylephrine/pharmacology
- Portal Pressure/drug effects
- Rats
- Rats, Sprague-Dawley
- Vascular Resistance/drug effects
- Vasoconstriction/drug effects
- Vasodilation/drug effects
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Affiliation(s)
- David Sacerdoti
- Department of Clinical and Experimental Medicine, University of Padova, Via Giustiniani 2, 35100 Padova, Italy.
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Routray C, Liu C, Yaqoob U, Billadeau DD, Bloch KD, Kaibuchi K, Shah VH, Kang N. Protein kinase G signaling disrupts Rac1-dependent focal adhesion assembly in liver specific pericytes. Am J Physiol Cell Physiol 2011; 301:C66-74. [PMID: 21451103 DOI: 10.1152/ajpcell.00038.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Nitric oxide (NO) regulates the function of perivascular cells (pericytes), including hepatic stellate cells (HSC), mainly by activating cGMP and cGMP-dependent kinase (PKG) via NO/cGMP paracrine signaling. Although PKG is implicated in integrin-mediated cell adhesion to extracellular matrix, whether or how PKG signaling regulates the assembly of focal adhesion complexes (FA) and migration of HSC is not known. With the help of complementary molecular and cell biological approaches, we demonstrate here that activation of PKG signaling in HSC inhibits vascular tubulogenesis, migration/chemotaxis, and assembly of mature FA plaques, as assessed by vascular tubulogenesis assays and immunofluorescence localization of FA markers such as vinculin and vasodilator-stimulated phosphoprotein (VASP). To determine whether PKG inhibits FA assembly by phosphorylation of VASP at Ser-157, Ser-239, and Thr-278, we mutated these putative phosphorylation sites to alanine (VASP3A, phosphoresistant mutant) or aspartic acid (VASP3D, phosphomimetic), respectively. Data generated from these two mutants suggest that the effect of PKG on FA is independent of these three phosphorylation sites. In contrast, activation of PKG inhibits the activity of small GTPase Rac1 and its association with the effector protein IQGAP1. Moreover, PKG activation inhibits the formation of a trimeric protein complex containing Rac1, IQGAP1, and VASP. Finally, we found that expression of a constitutively active Rac1 mutant abolishes the inhibitory effects of PKG on FA formation. In summary, our data suggest that activation of PKG signaling in pericytes inhibits FA formation by inhibiting Rac1.
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Affiliation(s)
- Chittaranjan Routray
- GI Research Unit and Cancer Cell Biology Program, Mayo Clinic, Rochester, Minnesota 55905, USA
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Lee JW. [Treatment update on portal hypertension and complications]. THE KOREAN JOURNAL OF GASTROENTEROLOGY 2010; 56:144-54. [PMID: 20847605 DOI: 10.4166/kjg.2010.56.3.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Current understanding of the pathophysiology of portal hypertension has resulted in therapeutic approaches aimed at correcting the increased splanchnic blood flow and some of which have been already used in clinical practice. Recently new perspectives opened and erstwhile paradigm has been changed to focus on increased resistance to portal blood flow and the formation of portosystemic collateralization. Several studies revealed the clear-cut mechanisms of hepatic endothelial dysfunction and abnormal angiogenesis contributing to the development of portal hypertension. Thus the modulations of hyperdynamic circulation or angiogenesis seem to be valuable therapeutic targets. In the current review update, we discuss the multidisciplinary management of modulating hepatic vascular resistance and abnormal angiogenesis associated with portal hypertension. However, these new pharmacological approaches are still under investigation and widescale clinical application are needed to develop effective strategies.
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Affiliation(s)
- Jin Woo Lee
- Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
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Bosch J, Abraldes JG, Fernández M, García-Pagán JC. Hepatic endothelial dysfunction and abnormal angiogenesis: new targets in the treatment of portal hypertension. J Hepatol 2010; 53:558-67. [PMID: 20561700 DOI: 10.1016/j.jhep.2010.03.021] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 03/19/2010] [Accepted: 03/19/2010] [Indexed: 12/12/2022]
Abstract
Portal hypertension is the main cause of complications in patients with chronic liver disease. Over the past 25 years, progress in the understanding of the pathophysiology of portal hypertension was followed by the introduction of an effective pharmacological therapy, consisting mainly of treatments aimed at correcting the increased splanchnic blood flow. It is only recently that this paradigm has been changed. Progress in our knowledge of the mechanisms of increased resistance to portal blood flow, of the formation of portal-systemic collaterals, and of mechanisms other than vasodilatation maintaining the increased splanchnic blood flow have opened entirely new perspectives for developing more effective treatment strategies. This is the aim of the current review, which focuses on: (a) the modulation of hepatic vascular resistance by correcting the increased hepatic vascular tone due to hepatic endothelial dysfunction, and (b) correcting the abnormal angiogenesis associated with portal hypertension, which contributes to liver inflammation and fibrogenesis, to the hyperkinetic splanchnic circulation, and to the formation of portal-systemic collaterals and varices.
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Affiliation(s)
- Jaume Bosch
- Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clínic-IDIBAPS and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Spain.
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Abstract
This study aimed to investigate the effects of reactive oxygen species on the hepatic macrophages, the Kupffer cells (KC), and to identify the relevant targets of vasoconstrictors involved in the regulation of intrahepatic microcirculation and therefore portal pressure. The effects of hydrogen peroxide (H2O2), xanthine/xanthine oxidase or a thromboxane (TX) analogue (U46619; 0.1 microM) were tested in sham-operated and fibrotic livers (bile duct ligation over 4 weeks) during isolated rat liver perfusion and in vivo with or without additional KC blockade (gadolinium chloride, 10 mg kg(-1) body weight, 48 and 24 h, i.p.). To investigate downstream mechanisms, a TXA2 antagonist (BM 13.177; 20 microM) or a Rho kinase inhibitor (Y27632; 10 microM) was infused additionally. TXB2 efflux was measured by enzyme-linked immunosorbent assay. The phosphorylation state of moesin (p-moesin), as indicator for Rho kinase activity, was assessed by Western blot analyses. Portal pressure was dose-dependently increased by H2O2 (maximum, 0.5 mM) and, to a lower extent, by xanthine/xanthine oxidase together with catalase. The portal pressure increase by H2O2 was attenuated by previous KC blockade. TXA2 efflux increased after H2O2 infusion and was reduced by KC blockade. The TXA2 antagonist counteracted the H2O2-induced increase in portal pressure. The Rho kinase inhibitor attenuated portal pressure increase after TXA2 analogue or H2O2 infusion. Hepatic levels of p-moesin were increased after H2O2 infusion. Reactive oxygen species increased portal pressure via stimulation of TXA2 production by KCs and a subsequent Rho kinase-dependent contraction of the intrahepatic vasculature. In conclusion, the KCs that are well known to produce H2O2 could also be activated by H2O2. This vicious cycle may best be interrupted at the earliest time point.
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Poordad FF, Sigal SH, Brown RS. Pathophysiologic basis for the medical management of portal hypertension. Expert Opin Pharmacother 2009; 10:453-67. [PMID: 19191681 DOI: 10.1517/14656560802707853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Portal hypertension is a potentially life-threatening complication of cirrhosis, resulting from increased intrahepatic resistance and portal inflow. OBJECTIVE Given the complex nature of this disorder, a more complete understanding of the pathophysiology of portal hypertension is necessary to develop new therapies that target specific pathways that regulate portal pressure. METHODS This review is based on a literature search of published articles and abstracts on the pathophysiology of portal hypertension, its complications and its treatment. RESULTS/CONCLUSION A number of therapies have been developed or are under investigation for the treatment of portal hypertension and its complications. These agents may reduce mortality and improve quality of life for patients with advanced liver disease.
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Affiliation(s)
- Fred F Poordad
- Cedars-Sinai Medical Center, Center for Liver Disease and Transplantation, 8635 W. Third Street, Suite 1060W, Los Angeles, CA 90048, USA.
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Van Landeghem L, Laleman W, Vander Elst I, Zeegers M, van Pelt J, Cassiman D, Nevens F. Carbon monoxide produced by intrasinusoidally located haem-oxygenase-1 regulates the vascular tone in cirrhotic rat liver. Liver Int 2009; 29:650-60. [PMID: 18795901 DOI: 10.1111/j.1478-3231.2008.01857.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND/OBJECTIVE Carbon monoxide (CO) produced by haem-oxygenase isoforms (HO-1 & HO-2) is involved in the regulation of systemic vascular tone. We aimed to elucidate the vasoregulatory role of CO in the microcirculation in normal and thioacetamide cirrhotic rat livers. METHODS Haem-oxygenase expression was examined by Western blot. Total HO enzymatic activity was measured spectrophotometrically. Sensitivity of hepatic stellate cells (HSCs) to CO-mediated relaxation was studied by a stress-relaxed-collagen-lattice model. To define the relative role of CO, the CO-releasing molecule CORM-2, the HO-inhibitor zinc protoporphyrin-IX and the HO-1 inducer hemin were added to an in situ liver perfusion set-up. The topography of vasoactive CO production was evaluated by applying different CO- and nitric oxide-trapping reagents in the liver perfusion set-up and by immunohistochemistry. RESULTS Western blot showed decreased expression of both HO isoenzymes (P<0.036 for HO-1; P<0.001 for HO-2) in cirrhotic vs normal rat livers, confirmed by the HO-activity assay (P=0.004). HSCs relaxed on exposure to CORM-2 (P=0.013). The increased intrahepatic vascular resistance (IHVR) of cirrhotic rats was attenuated by perfusion with CORM-2 (P=0.016) and pretreatment with hemin (P<0.001). Inhibition of HO caused a dose-related increase in IHVR in normal and cirrhotic liver. In normal liver, the haemodynamically relevant CO production occurred extrasinusoidally, while intrasinusoidally HO-1 predominantly regulated the microcirculation in cirrhotic livers. CONCLUSION We demonstrate a role for CO and HO in the regulation of normal and cirrhotic microcirculation. These findings are of importance in the pathophysiology of portal hypertension and establish CO/HO as novel treatment targets.
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Affiliation(s)
- Lien Van Landeghem
- Department of Hepatology, University Hospital Gasthuisberg, KU Leuven, Belgium
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Superimposed coagulopathic conditions in cirrhosis: infection and endogenous heparinoids, renal failure, and endothelial dysfunction. Clin Liver Dis 2009; 13:33-42. [PMID: 19150307 DOI: 10.1016/j.cld.2008.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In this article, the authors discuss three pathophysiologic mechanisms that influence the coagulation system in patients who have liver disease. First, bacterial infections may play an important role in the cause of variceal bleeding in patients who have liver cirrhosis, affecting coagulation through multiple pathways. One of the pathways through which this occurs is dependent on endogenous heparinoids, on which the authors focus in this article. Secondly, the authors discuss renal failure, a condition that is frequently encountered in patients who have liver cirrhosis. Finally, they review dysfunction of the endothelial system. The role of markers of endothelial function in cirrhotic patients, such as von Willebrand factor and endothelin-1, is discussed.
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Yang YY, Lee KC, Huang YT, Wang YW, Hou MC, Lee FY, Lin HC, Lee SD. Effects of N-acetylcysteine administration in hepatic microcirculation of rats with biliary cirrhosis. J Hepatol 2008; 49:25-33. [PMID: 18490076 DOI: 10.1016/j.jhep.2008.02.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Revised: 01/16/2008] [Accepted: 02/06/2008] [Indexed: 12/17/2022]
Abstract
BACKGROUND/AIMS Increased intrahepatic resistance (IHR) in cirrhosis is due to fibrosis and hepatic endothelial dysfunction (HED). Besides producing fibrosis, increased reactive oxygen species (ROS) promotes ROS-related nitration of anti-oxidative enzymes in cirrhotic livers. Tyrosine nitration (nitrotyrosilation)-related inactivation of anti-oxidative enzymes is increased in cirrhotic livers. This study investigates effects of N-acetylcysteine (NAC) administrations in bile-duct-ligation (BDL) rats. METHODS This study measured portal venous pressure (PVP), IHR, hepatic endothelial function, hepatic levels of anti-oxidants and oxidants, type III procollagen (PIIIP), proteins expression of thromboxane synthase (TXS), nitrotyrosine, manganese superoxide dismutase (MnSOD), and hepatic NOx and thromboxane A(2) (TXA(2)) production in perfusates. RESULTS The improvement of HED was associated with decreased PVP and IHR, hepatic protein and mRNA levels of PIIIP, protein expression of TXS and nitrotyrosine, oxidants and production of TXA(2) in NAC-treated BDL rat livers. Conversely, hepatic NOx production, anti-oxidants, and protein expression of MnSOD were increased in NAC-treated BDL rat livers. CONCLUSIONS In NAC-treated cirrhotic rats, the decrease in IHR was mainly caused by its anti-oxidative effect-related prevention of hepatic fibrogenesis associated with the decrease of oxidants-related nitrotyrosilation and improvement of HED.
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Affiliation(s)
- Ying-Ying Yang
- Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital Taipei, Taiwan
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Xu H, Lee CY, Clemens MG, Zhang JX. Inhibition of TXA synthesis with OKY-046 improves liver preservation by prolonged hypothermic machine perfusion in rats. J Gastroenterol Hepatol 2008; 23:e212-20. [PMID: 17645480 DOI: 10.1111/j.1440-1746.2007.05061.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND AND AIM We previously reported that hypothermic machine perfusion (HMP) for liver preservation is feasible, but hepatic microcirculatory dysfunction and significant liver damage remain major obstacles in its application when the preservation is extended to 24 h. The underlying injury mechanism is not well understood. The present study sought to investigate the role of thromboxane A(2) (TXA(2)) in the pathogenesis of liver injury after prolonged HMP. METHODS Livers isolated from Sprague-Dawley rats were subjected to continuous machine perfusion with University of Wisconsin (UW) solution at a flow rate of 0.4 mL/min/g liver at 4 degrees C for 24 h. A specific TXA(2) synthase inhibitor, OKY-046 (OKY), was added to UW solution during the preservation period and to the Krebs-Henseleit buffer during reperfusion. The performance of the livers after preservation was evaluated using an isolated liver perfusion system with Krebs-Henseleit buffer at a flow rate of 15 mL/min at 37 degrees C for 30 min. RESULTS Prolonged HMP induced a significant release of TXA(2) into the portal circulation as indicated by markedly increased levels of TXB(2) in the perfusate during reperfusion (at 30 min, 1447.4 +/- 163.6 pg/mL vs 50.91 +/- 6.7 pg/mL for control). Inhibition of TXA(2) synthesis with OKY significantly decreased releases of TXA(2) (69.8 +/- 13.4 pg/mL) concomitant with reduced lactate dehydrogenase (LDH) releases (at 30 min, HMP + OKY: 144.9 +/- 27.9 U/L; HMP: 369.3 +/- 68.5 U/L; simple cold storage or SCS: 884.4 +/- 80.3 U/L), decreased liver wet/dry weight ratio (HMP + OKY vs SCS and HMP: 3.6 +/- 0.3 vs 4.4 +/- 0.1 and 3.9 +/- 0.2, respectively) and increased hyaluronic acid uptake (at 30 min, HMP + OKY vs SCS, HMP: 33.1 +/- 2.9% vs 13.9 +/- 3.6%, 18.6 +/- 2.4%, respectively). Liver histology also showed significant improvement in tissue edema and hepatocellular necrosis with OKY compared with HMP without OKY. CONCLUSION The results demonstrate that TXA(2) is involved in the development of hepatocellular injury induced by HMP, and inhibition of TXA(2) synthesis during preservation and reperfusion protects liver hepatocytes and sinusoidal endothelial cells from injuries caused by prolonged HMP.
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Affiliation(s)
- Hongzhi Xu
- Department of Biology, University of North Carolia at Charlotte, Charlotte, North Carolina 28223, USA
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Bosch J, Berzigotti A, Garcia-Pagan JC, Abraldes JG. The management of portal hypertension: rational basis, available treatments and future options. J Hepatol 2008; 48 Suppl 1:S68-92. [PMID: 18304681 DOI: 10.1016/j.jhep.2008.01.021] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Variceal bleeding is the last step in a chain of events initiated by an increase in portal pressure, followed by the development and progressive dilation of varices until these finally rupture and bleed. This sequence of events might be prevented - and reversed - by achieving a sufficient decrease in portal pressure. A different approach is the use of local endoscopic treatments at the varices. This article reviews the rationale for the management of patients with cirrhosis and portal hypertension, the current recommendations for the prevention and treatment of variceal bleeding, and outlines the unsolved issues and the perspectives for the future opened by new research developments.
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Affiliation(s)
- Jaime Bosch
- Hepatic Hemodynamic Laboratory, Liver Unit, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), University of Barcelona, Hospital Clínic, C.Villarroel 170, 08036 Barcelona, Spain.
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Gracia-Sancho J, Laviña B, Rodríguez-Vilarrupla A, García-Calderó H, Fernández M, Bosch J, García-Pagán JC. Increased oxidative stress in cirrhotic rat livers: A potential mechanism contributing to reduced nitric oxide bioavailability. Hepatology 2008; 47:1248-56. [PMID: 18273863 DOI: 10.1002/hep.22166] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED In cirrhotic livers, decreased nitric oxide (NO) bioavailability is a major factor increasing intrahepatic vascular tone. In several vascular disorders, an increase in superoxide (O(2) (-)) has been shown to contribute to reduced NO bioavailability through its reaction with NO to form peroxynitrite. This study was aimed to test the hypothesis that, in cirrhotic livers, increased O(2) (-), by reacting with NO, reduces NO bioavailability. In control and cirrhotic rat livers, NO bioavailability was evaluated by the measurement of cyclic guanosine monophosphate in liver tissue and by 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM-DA) fluorescence in isolated sinusoidal endothelial cells (SEC); the O(2) (-) content was determined by dihydroethidium staining in fresh liver sections. In addition, the role of endothelial nitric oxide synthase (eNOS), xanthine oxidase (XO), and cyclooxygenase (COX) as possible sources of O(2) (-) and the role of superoxide dismutase (SOD) enzymatic activity as an O(2) (-) scavenger were determined in liver homogenates. Protein-nitrotyrosination, a marker of the NO-O(2) (-) reaction, was evaluated in liver homogenates. Furthermore, in control SEC and bovine aortic endothelial cells, NO modulation by O(2) (-) was evaluated. Cirrhotic livers exhibited increased O(2) (-) levels. This was due, at least in part, to increased production by COX and XO but not eNOS and to reduced scavenging by SOD. Increased O(2) (-) was associated with a significant reduction in NO bioavailability and increased nitrotyrosinated proteins. In endothelial cells, an inverse relationship between O(2) (-) levels and NO bioavailability was observed. CONCLUSION Our data show that oxidative stress may contribute to reduced NO bioavailability in cirrhotic livers, supporting the evaluation of O(2) (-) reduction as a potential mechanism to restore NO content.
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Affiliation(s)
- Jorge Gracia-Sancho
- Hepatic Hemodynamic Laboratory, Liver Unit, Institut de Malalties Digestives i Metabòliques (IMDiM), Hospital Clínic, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, University of Barcelona, Spain
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Gracia-Sancho J, Laviña B, Rodríguez-Vilarrupla A, Brandes RP, Fernández M, Bosch J, García-Pagán JC. Evidence against a role for NADPH oxidase modulating hepatic vascular tone in cirrhosis. Gastroenterology 2007; 133:959-66. [PMID: 17854599 DOI: 10.1053/j.gastro.2007.06.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 05/17/2007] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Increased hepatic vascular resistance in cirrhosis is in part due to reduced nitric oxide (NO) bioavailability. This is related to insufficient NO synthesis from endothelial nitric oxide synthase and to enhanced NO scavenging by superoxide radicals (O(2)(-)). Nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase is an important source of O(2)(-) that increases vascular tone in different cardiovascular disorders. Thus, our aims were to study the molecular and biochemical state of NADPH-oxidase in cirrhotic livers and to investigate its possible role in modulating hepatic vascular tone in cirrhosis. METHODS NADPH-oxidase expression and enzymatic activity were determined in control (n = 8) and CCl(4)-cirrhotic (n = 8) rat livers. Additional control (n = 6) and CCl(4)-cirrhotic (n = 10) rats were treated with apocynin (a selective NADPH-oxidase inhibitor) or its vehicle. Mean arterial pressure, portal pressure, and superior mesenteric arterial blood flow were measured in vivo. Moreover, hepatic endothelial function was evaluated in isolated and perfused rat livers by dose-response curves to acetylcholine. In addition, in 6 control and 6 cirrhotic human livers NADPH-oxidase activity and expression were evaluated. RESULTS Rat cirrhotic livers had no increased NADPH-oxidase protein expression or activity in relation to control livers. NADPH-oxidase inhibition did not modify splanchnic or systemic hemodynamics in control or cirrhotic rats and did not improve the impaired endothelial-dependent vasodilatory response to acetylcholine of cirrhotic livers. Human cirrhotic livers also did not exhibit increased NADPH-oxidase expression or activity. CONCLUSIONS Our study shows that NADPH-oxidase activity is decreased in the cirrhotic livers and therefore cannot explain increased hepatic O(2)(-), endothelial dysfunction, and increased vascular tone in cirrhotic livers.
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Affiliation(s)
- Jorge Gracia-Sancho
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Ciberehd and Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Spain
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Gracia-Sancho J, Laviña B, Rodríguez-Vilarrupla A, García-Calderó H, Bosch J, García-Pagán JC. Enhanced vasoconstrictor prostanoid production by sinusoidal endothelial cells increases portal perfusion pressure in cirrhotic rat livers. J Hepatol 2007; 47:220-7. [PMID: 17459512 DOI: 10.1016/j.jhep.2007.03.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 02/14/2007] [Accepted: 03/03/2007] [Indexed: 12/12/2022]
Abstract
BACKGROUND/AIMS Cyclooxygenase-1 (COX-1) is overexpressed in sinusoidal endothelial cells (SEC) of cirrhotic rat livers, and through an enhanced production of vasoconstrictor prostanoids contributes to increase intrahepatic resistance. Our study was aimed at investigating the role of enhanced AA bioavailability modulating the hepatic vascular tone of cirrhotic livers and identifying which prostanoid is involved. METHODS SEC isolated from control and cirrhotic rat livers were incubated with AA, methoxamine or vehicle. TXA(2) was quantified. In addition, portal perfusion pressure (PP) response curves to AA were performed in rat livers pre-incubated with vehicle, SC-560 (COX-1 inhibitor), Furegrelate (inhibitor of TXA(2) synthesis) and SQ-29548 (PGH(2)/TXA(2) receptor blocker). cPLA2 activity was determined in control and cirrhotic livers. RESULTS AA and methoxamine incubation promoted a significant increase in TXA(2) release by Cirrhotic-SEC, but not in Control-SEC. AA produced a dose-dependent increase in the PP, associated with increased TXA(2) release. These responses were significantly greater in cirrhotic livers. COX-1 inhibition and PGH(2)/TXA(2) receptor blockade, but not TXA(2) synthase inhibition, markedly attenuated the PP response to AA of cirrhotic livers. Additionally, cirrhotic livers exhibited significantly increased cPLA2 activity. CONCLUSIONS An enhanced production of vasoconstrictor prostanoids, probably PGH(2), by SEC contributes to increase vascular tone of cirrhotic livers.
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Affiliation(s)
- Jorge Gracia-Sancho
- Hepatic Hemodynamic Laboratory, Liver Unit, IMDIM, Hospital Clínic, Ciberehd and Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Villarroel 170, 08036 Barcelona, Spain
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Rodríguez-Vilarrupla A, Bosch J, García-Pagán JC. Potential role of antioxidants in the treatment of portal hypertension. J Hepatol 2007; 46:193-7. [PMID: 17161493 DOI: 10.1016/j.jhep.2006.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Aina Rodríguez-Vilarrupla
- Hepatic Hemodynamic Laboratory, Liver Unit, Institut Malalties Digestives I Metabòliques, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
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Laleman W, Van Landeghem L, Van der Elst I, Zeegers M, Fevery J, Nevens F. Nitroflurbiprofen, a nitric oxide-releasing cyclooxygenase inhibitor, improves cirrhotic portal hypertension in rats. Gastroenterology 2007; 132:709-19. [PMID: 17258737 DOI: 10.1053/j.gastro.2006.12.041] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 10/26/2006] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS We studied whether administration of nitroflurbiprofen (HCT-1026), a cyclooxygenase inhibitor with nitric oxide (NO)-donating properties, modulates the increased intrahepatic vascular tone in portal hypertensive cirrhotic rats. METHODS In vivo hemodynamic measurements (n = 8/condition) and evaluation of the increased intrahepatic resistance by in situ perfusion (n = 5/condition) were performed in rats with thioacetamide-induced cirrhosis that received either nitroflurbiprofen (45 mg/kg), flurbiprofen (30 mg/kg, equimolar concentration to nitroflurbiprofen), or vehicle by intraperitoneal injection 24 hours and 1 hour prior to the measurements. Additionally, we evaluated the effect of acute administration of both drugs (250 micromol/L) on the intrahepatic vascular tone in the in situ perfused cirrhotic rat liver (endothelial dysfunction and hyperresponsiveness to methoxamine) and on hepatic stellate cell contraction in vitro. Typical systemic adverse effects of nonsteroidal anti-inflammatory drugs, such as gastrointestinal ulceration, renal insufficiency, and hepatotoxicity, were actively explored. RESULTS In vivo, nitroflurbiprofen and flurbiprofen equally decreased portal pressure (8 +/- 0.8 and 8.4 +/- 0.1 mm Hg, respectively, vs 11.8 +/- 0.6 mm Hg) and reduced the total intrahepatic vascular resistance. Systemic hypotension was not aggravated in the different treatment groups (P = .291). In the perfused cirrhotic liver, both drugs improved endothelial dysfunction and hyperresponsiveness. This was associated with a decreased hepatic thromboxane A(2)-production and an increased intrahepatic nitrate/nitrite level. In vitro, nitroflurbiprofen, more than flurbiprofen, decreased hepatic stellate cells contraction. Flurbiprofen-treated rats showed severe gastrointestinal ulcerations (bleeding in 3/8 rats) and nefrotoxicity, which was not observed in nitroflurbiprofen-treated cirrhotic rats. CONCLUSIONS Treatment with nitroflurbiprofen, an NO-releasing cyclooxygenase inhibitor, improves portal hypertension without major adverse effects in thioacetamide-induced cirrhotic rats by attenuating intrahepatic vascular resistance, endothelial dysfunction, and hepatic hyperreactivity to vasoconstrictors.
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MESH Headings
- Animals
- Cyclooxygenase Inhibitors/adverse effects
- Cyclooxygenase Inhibitors/pharmacology
- Cyclooxygenase Inhibitors/therapeutic use
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiopathology
- Flurbiprofen/adverse effects
- Flurbiprofen/analogs & derivatives
- Flurbiprofen/pharmacology
- Flurbiprofen/therapeutic use
- Hypertension, Portal/drug therapy
- Hypertension, Portal/etiology
- Hypertension, Portal/metabolism
- Hypertension, Portal/physiopathology
- Kidney Diseases/chemically induced
- Liver/drug effects
- Liver/metabolism
- Liver Circulation/drug effects
- Liver Cirrhosis, Experimental/chemically induced
- Liver Cirrhosis, Experimental/complications
- Male
- Nitric Oxide/metabolism
- Nitric Oxide Donors/adverse effects
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Donors/therapeutic use
- Peptic Ulcer/chemically induced
- Perfusion
- Portal Pressure/drug effects
- Rats
- Rats, Wistar
- Thioacetamide
- Thromboxane A2/metabolism
- Vascular Resistance/drug effects
- Vasoconstriction/drug effects
- Vasodilation/drug effects
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Affiliation(s)
- Wim Laleman
- Department of Hepatology, University Hospital Gasthuisberg, Leuven, Belgium
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Matei V, Rodríguez-Vilarrupla A, Deulofeu R, Colomer D, Fernández M, Bosch J, Garcia-Pagán JC. The eNOS cofactor tetrahydrobiopterin improves endothelial dysfunction in livers of rats with CCl4 cirrhosis. Hepatology 2006; 44:44-52. [PMID: 16799985 DOI: 10.1002/hep.21228] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In cirrhosis, intrahepatic endothelial dysfunction is one of the mechanisms involved in the increased resistance to portal blood flow and therefore in the development of portal hypertension. Endothelial nitric oxide synthase (eNOS) uncoupling due to deficiency of tetrahydrobiopterin (BH4) results in decreased production of NO and plays a major role in endothelial dysfunction in other conditions. We examined whether eNOS uncoupling is involved in the pathogenesis of endothelial dysfunction of livers with cirrhosis. Basal levels of tetrahydrobiopterin and guanosine triphosphate (GTP)-cyclohydrolase (BH4 rate-limiting enzyme) expression and activity were determined in liver homogenates of control and rats with CCl4 cirrhosis. Thereafter, rats were treated with tetrahydrobiopterin, and eNOS activity, NO bioavailability, assessed with a functional assay, and the vasodilator response to acetylcholine (endothelial function) were evaluated. Livers with cirrhosis showed reduced BH4 levels and decreased GTP-cyclohydrolase activity and expression, which were associated with impaired vasorelaxation to acetylcholine. Tetrahydrobiopterin supplementation increased BH4 hepatic levels and eNOS activity and significantly improved the vasodilator response to acetylcholine in rats with cirrhosis. In conclusion, the impaired response to acetylcholine of livers with cirrhosis is modulated by a reduced availability of the eNOS cofactor, tetrahydrobiopterin. Tetrahydrobiopterin supplementation improved the endothelial dysfunction of cirrhotic livers.
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Affiliation(s)
- Vasilica Matei
- Hepatic Hemodynamic Laboratory, Liver Unit, Institut de Malalties Digestives i Metabòliques, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
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Laleman W, Vander Elst I, Zeegers M, Servaes R, Libbrecht L, Roskams T, Fevery J, Nevens F. A stable model of cirrhotic portal hypertension in the rat: thioacetamide revisited. Eur J Clin Invest 2006; 36:242-9. [PMID: 16620286 DOI: 10.1111/j.1365-2362.2006.01620.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Cirrhotic animal models are vital to investigate complications of chronic liver disease. We chronologically characterized the effect of thioacetamide, administrated orally and adapted weekly to weight changes, focusing on the optimal moment to obtain all typical features of portal hypertension and cirrhosis. MATERIALS AND METHODS Male Wistar rats, 200-250 g, were intoxicated for 6, 12 or 18 weeks (n = 8 per group), respectively, and compared with age-matched controls (n = 4 per group). An in-situ perfusion model was used to evaluate intrahepatic resistance and endothelial function. Splanchnic blood flow and portosystemic shunting were assessed by a perivascular flow probe. RESULTS Rats intoxicated for 6 or 12 weeks had no mortality and histologically showed hepatitis and advanced fibrosis, respectively. At 18 weeks, mortality was 16% (on a total of 56 animals) and only at that moment all animals showed homogenous macronodular cirrhosis with signs of high-grade hepatocellular dysplasia. Portal hypertension was present at 12 weeks (11 +/- 0.4 vs. 5.9 +/- 0.4 mmHg, P < 0.001), but was not associated with the hyperdynamic state until 18 weeks (12.1 +/- 0.8 vs. 5.6 +/- 0.5 mmHg, P < 0.001). At this latter time-point, we also observed increased intrahepatic resistance associated with endothelial dysfunction, hyperresponsiveness to vasoconstrictors, splanchnic hyperaemia and portosystemic shunting. These alterations were associated with increased systemic levels of nitrate/nitrite and thromboxane A(2). CONCLUSION Thioacetamide, adapted to weekly weight changes, leads to a homogenous, reproducible model of cirrhosis in the rat in 18 weeks, which is associated with all the typical characteristics of portal hypertension, including endothelial dysfunction.
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Affiliation(s)
- W Laleman
- Department pf Hepatology, University Hospital Gasthuisberg, Leuven, Belgium
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Váli L, Taba G, Szentmihályi K, Fébel H, Kurucz T, Pallai Z, Kupcsulik P, Blázovics A. Reduced antioxidant level and increased oxidative damage in intact liver lobes during ischaemia-reperfusion. World J Gastroenterol 2006; 12:1086-91. [PMID: 16534850 PMCID: PMC4087901 DOI: 10.3748/wjg.v12.i7.1086] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat model.
METHODS: In nembutal narcosis, the left lateral and the medial lobes of the liver were clipped for 45 min to make the total blood supply flow through the other lobes. Total antioxidant status, glutathione peroxidase and superoxide dysmutase activity, as well as the concentrations of diene conjugates and free sulphydril groups, H-donating ability and reducing power of the liver samples were determined. Chemiluminescent intensity of the liver was also measured. Metal ions (Al, Ca, Cu, Fe, Mg, Mn, Zn) and P and S concentrations of the liver were determined with an inductively coupled plasma optical emission spectrometer and Se content was measured by cathodic stripping voltammetry.
RESULTS: Glutathione peroxidase and superoxide dysmutase activities of the liver decreased significantly in the hyperemia group compared to those observed in the sham operated group. The level of total antioxidant status was also significantly lower in the hyperemia group. H-donating ability, reducing power and free sulphydril group concentration showed the same tendency. A significant correlation (P<0.05) was found between the changes in non-specific antioxidant activities. This pointed to simultaneous activity of the antioxidant defence system. Al, Cu, Mn, Zn, and S were lower in the hyperemia group than in the sham operated group when the levels of Ca, Fe, Mg, Se and P ions were higher during hyperemia.
CONCLUSION: Oxidative stress is one of the main factors for the injury of intact liver lobes during ischaemia-reperfusion.
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Affiliation(s)
- László Váli
- Department of Medicine, Semmelweis University, H-1088 Budapest, Szentkirályiu. 46., Hungary
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Yang YY, Lin HC, Huang YT, Lee TY, Hou MC, Wang YW, Lee FY, Lee SD. Roles of anandamide in the hepatic microcirculation in cirrhotic rats. Am J Physiol Gastrointest Liver Physiol 2006; 290:G328-34. [PMID: 16407591 DOI: 10.1152/ajpgi.00367.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cannabinoids have been reported to participate in the pathogenesis of peripheral vasodilatation in cirrhosis. However, their roles in increased intrahepatic resistance (IHR) in cirrhotic livers are unknown. We aimed to investigate the effects of cannabinoids in the hepatic microcirculation of cirrhotic rats produced by bile duct ligation. In isolated liver perfusion, portal perfusion pressure (PPP) and the production of eicosanoids in the perfusate were measured. In addition, various hepatic protein levels [cyclooxygenase (COX) isoform and 5-lipoxygenase (5-LOX)] were also determined. Finally, concentration-response curves for PPP and the corresponding production of eicosanoids in response to anandamide (1.44 x 10(-10)-1.44 x 10(-3) M) after indomethacin (COX inhibitor), piriprost (5-LOX inhibitor), or furegrelate (thromboxane A(2) synthase inhibitor) preincubation were obtained. The study showed that cirrhotic livers had significantly higher levels of PPP, COX-2 and 5-LOX protein expression, and production of thromboxane B(2) (TXB(2)) and cysteinyl leukotrienes (Cys-LTs) than normal livers. Anandamide induced a dose-dependent increase in PPP in both normal and cirrhotic livers. The anandamide-induced increase in PPP was found concomitantly with a significant increase in TXB(2) and Cys-LT production in the perfusate. In response to anandamide administration, cirrhotic livers exhibited a significantly greater increase in IHR and production of TXB(2) and Cys-LTs than normal livers. Indomethacin and furegrelate, but not piriprost, significantly ameliorated the anandamide-induced increase in IHR in cirrhotic livers. In conclusion, anandamide plays, in part, an important role in increased IHR of cirrhotic livers. The anandamide-induced increase in IHR in cirrhotic livers may be mediated by increased COX-derived eicosanoid (mainly thromboxane A(2)) production.
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Affiliation(s)
- Ying-Ying Yang
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
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Abraldes JG, García-Pagán JC. Modelos animales en el estudio de la hipertensión portal. GASTROENTEROLOGIA Y HEPATOLOGIA 2006; 29:51-9. [PMID: 16393631 DOI: 10.1157/13083254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Animal models allow detailed study of the hemodynamic alterations in portal hypertension syndrome and of the molecular mechanisms involved in the abnormalities in splenic and systemic circulation associated with this syndrome. Models of prehepatic portal hypertension can be used to study alterations in the splenic circulation and the physiopathology of hyperdynamic circulation. Moreover, models of cirrhosis allow the alterations in intrahepatic microcirculation that lead to increased resistance to portal flow to be studied. The present review summarizes currently available animal models of portal hypertension and analyzes their relative utility in investigating the distinct disorders associated with this entity. The criteria for the choice of a particular model, depending on the specific objectives of the study, are also discussed.
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Affiliation(s)
- J G Abraldes
- Servicio de Hepatología, ICMDiM, Hospital Clínic, IDIBAPS, Universidad de Barcelona, Barcelona, Spain
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50
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Laleman W, Omasta A, Van de Casteele M, Zeegers M, Vander Elst I, Van Landeghem L, Severi T, van Pelt J, Roskams T, Fevery J, Nevens F. A role for asymmetric dimethylarginine in the pathophysiology of portal hypertension in rats with biliary cirrhosis. Hepatology 2005; 42:1382-90. [PMID: 16317694 DOI: 10.1002/hep.20968] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reduced intrahepatic endothelial nitric oxide synthase (eNOS) activity contributes to the pathogenesis of portal hypertension (PHT) associated with cirrhosis. We evaluated whether asymmetric dimethylarginine (ADMA), a putative endogenous NOS inhibitor, may be involved in PHT associated with cirrhosis. Two rat models of cirrhosis (thioacetamide [TAA]-induced and bile duct excision [BDE]-induced, n = 10 each), one rat model of PHT without cirrhosis (partial portal vein-ligated [PPVL], n = 10), and sham-operated control rats (n = 10) were studied. We assessed hepatic NOS activity, eNOS protein expression, plasma ADMA levels, and intrahepatic endothelial function. To evaluate intrahepatic endothelial function, concentration-effect curves of acetylcholine were determined in situ in perfused normal rat livers and livers of rats with TAA- or BDE-induced cirrhosis (n = 10) that had been preincubated with either vehicle or ADMA; in addition, measurements of nitrite/nitrate (NOx) and ADMA were made in perfusates. Both models of cirrhosis exhibited decreased hepatic NOS activity. In rats with TAA-induced cirrhosis, this decrease was associated with reduced hepatic eNOS protein levels and immunoreactivity. Rats with BDE-induced cirrhosis had eNOS protein levels comparable to those in control rats but exhibited significantly higher plasma ADMA levels than those in all other groups. In normal perfused liver, ADMA induced impaired endothelium-dependent vasorelaxation and reduced NOx perfusate levels, phenomena that were mimicked by N(G)-nitro-L-arginine-methyl ester. In contrast to perfused livers with cirrhosis induced by TAA, impaired endothelial cell-mediated relaxation in perfused livers with cirrhosis induced by BDE was exacerbated by ADMA and was associated with a decreased rate of removal of ADMA (34.3% +/- 6.0% vs. 70.9% +/- 3.2%). In conclusion, in rats with TAA-induced cirrhosis, decreased eNOS enzyme levels seem to be responsible for impaired NOS activity; in rats with biliary cirrhosis, an endogenous NOS inhibitor, ADMA, may mediate decreased NOS activity.
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Affiliation(s)
- Wim Laleman
- Laboratories of Hepatology, University Hospital Gasthuisberg, Leuven, Belgium
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