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Guignabert C, Tu L, Girerd B, Ricard N, Huertas A, Montani D, Humbert M. New Molecular Targets of Pulmonary Vascular Remodeling in Pulmonary Arterial Hypertension. Chest 2015; 147:529-537. [DOI: 10.1378/chest.14-0862] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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102
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Yang W, Hu B, Wu W, Batra S, Blackburn MR, Alcorn JL, Fallon MB, Zhang J. Alveolar type II epithelial cell dysfunction in rat experimental hepatopulmonary syndrome (HPS). PLoS One 2014; 9:e113451. [PMID: 25419825 PMCID: PMC4242631 DOI: 10.1371/journal.pone.0113451] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/24/2014] [Indexed: 12/18/2022] Open
Abstract
The hepatopulmonary syndrome (HPS) develops when pulmonary vasodilatation leads to abnormal gas exchange. However, in human HPS, restrictive ventilatory defects are also observed supporting that the alveolar epithelial compartment may also be affected. Alveolar type II epithelial cells (AT2) play a critical role in maintaining the alveolar compartment by producing four surfactant proteins (SPs, SP-A, SP-B, SP-C and SP-D) which also facilitate alveolar repair following injury. However, no studies have evaluated the alveolar epithelial compartment in experimental HPS. In this study, we evaluated the alveolar epithelial compartment and particularly AT2 cells in experimental HPS induced by common bile duct ligation (CBDL). We found a significant reduction in pulmonary SP production associated with increased apoptosis in AT2 cells after CBDL relative to controls. Lung morphology showed decreased mean alveolar chord length and lung volumes in CBDL animals that were not seen in control models supporting a selective reduction of alveolar airspace. Furthermore, we found that administration of TNF-α, the bile acid, chenodeoxycholic acid, and FXR nuclear receptor activation (GW4064) induced apoptosis and impaired SP-B and SP-C production in alveolar epithelial cells in vitro. These results imply that AT2 cell dysfunction occurs in experimental HPS and is associated with alterations in the alveolar epithelial compartment. Our findings support a novel contributing mechanism in experimental HPS that may be relevant to humans and a potential therapeutic target.
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Affiliation(s)
- Wenli Yang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Bingqian Hu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Wei Wu
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Sachin Batra
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Michael R. Blackburn
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Joseph L. Alcorn
- Division of Neonatology, Department of Pediatrics, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Michael B. Fallon
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
| | - Junlan Zhang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, United States of America
- * E-mail:
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103
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Localizations of Na(+)-D-glucose cotransporters SGLT1 and SGLT2 in human kidney and of SGLT1 in human small intestine, liver, lung, and heart. Pflugers Arch 2014; 467:1881-98. [PMID: 25304002 DOI: 10.1007/s00424-014-1619-7] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/16/2014] [Accepted: 09/23/2014] [Indexed: 02/08/2023]
Abstract
Novel affinity-purified antibodies against human SGLT1 (hSGLT1) and SGLT2 (hSGLT2) were used to localize hSGLT2 in human kidney and hSGLT1 in human kidney, small intestine, liver, lung, and heart. The renal locations of both transporters largely resembled those in rats and mice; hSGLT2 and SGLT1 were localized to the brush border membrane (BBM) of proximal tubule S1/S2 and S3 segments, respectively. Different to rodents, the renal expression of hSGLT1 was absent in thick ascending limb of Henle (TALH) and macula densa, and the expression of both hSGLTs was sex-independent. In small intestinal enterocytes, hSGLT1 was localized to the BBM and subapical vesicles. Performing double labeling with glucagon-like peptide 1 (GLP-1) or glucose-dependent insulinotropic peptide (GIP), hSGLT1 was localized to GLP-1-secreting L cells and GIP-secreting K cells as has been shown in mice. In liver, hSGLT1 was localized to biliary duct cells as has been shown in rats. In lung, hSGLT1 was localized to alveolar epithelial type 2 cells and to bronchiolar Clara cells. Expression of hSGLT1 in Clara cells was verified by double labeling with the Clara cell secretory protein CC10. Double labeling of human heart with aquaporin 1 immunolocalized the hSGLT1 protein in heart capillaries rather than in previously assumed myocyte sarcolemma. The newly identified locations of hSGLT1 implicate several extra renal functions of this transporter, such as fluid absorption in the lung, energy supply to Clara cells, regulation of enteroendocrine cells secretion, and release of glucose from heart capillaries. These functions may be blocked by reversible SGLT1 inhibitors which are under development.
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104
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Iyer VN. Liver transplantation for hepatopulmonary syndrome. Clin Liver Dis (Hoboken) 2014; 4:38-41. [PMID: 30992918 PMCID: PMC6448733 DOI: 10.1002/cld.412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/01/2014] [Accepted: 07/12/2014] [Indexed: 02/04/2023] Open
Affiliation(s)
- Vivek N. Iyer
- Division of Pulmonary and Critical Care MedicineMayo ClinicRochesterMN
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105
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Rabinovitch M, Guignabert C, Humbert M, Nicolls MR. Inflammation and immunity in the pathogenesis of pulmonary arterial hypertension. Circ Res 2014; 115:165-75. [PMID: 24951765 DOI: 10.1161/circresaha.113.301141] [Citation(s) in RCA: 661] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review summarizes an expanding body of knowledge indicating that failure to resolve inflammation and altered immune processes underlie the development of pulmonary arterial hypertension. The chemokines and cytokines implicated in pulmonary arterial hypertension that could form a biomarker platform are discussed. Pre-clinical studies that provide the basis for dysregulated immunity in animal models of the disease are reviewed. In addition, we present therapies that target inflammatory/immune mechanisms that are currently enrolling patients, and discuss others in development. We show how genetic and metabolic abnormalities are inextricably linked to dysregulated immunity and adverse remodeling in the pulmonary arteries.
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Affiliation(s)
- Marlene Rabinovitch
- From the Cardiovascular Institute and Department of Pediatrics (M.R.) and Department of Medicine (M.R.N.), Stanford University School of Medicine, CA; INSERM UMR_S 999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson and Université Paris-Sud, School of Medicine, Le Kremlin-Bicêtre (C.G., M.H.); and AP-HP, Service de Pneumologie, Centre de Référence de l'Hypertension Pulmonaire Sévère, DHU Thorax Innovation, Hôpital de Bicêtre, France (M.H.).
| | - Christophe Guignabert
- From the Cardiovascular Institute and Department of Pediatrics (M.R.) and Department of Medicine (M.R.N.), Stanford University School of Medicine, CA; INSERM UMR_S 999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson and Université Paris-Sud, School of Medicine, Le Kremlin-Bicêtre (C.G., M.H.); and AP-HP, Service de Pneumologie, Centre de Référence de l'Hypertension Pulmonaire Sévère, DHU Thorax Innovation, Hôpital de Bicêtre, France (M.H.)
| | - Marc Humbert
- From the Cardiovascular Institute and Department of Pediatrics (M.R.) and Department of Medicine (M.R.N.), Stanford University School of Medicine, CA; INSERM UMR_S 999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson and Université Paris-Sud, School of Medicine, Le Kremlin-Bicêtre (C.G., M.H.); and AP-HP, Service de Pneumologie, Centre de Référence de l'Hypertension Pulmonaire Sévère, DHU Thorax Innovation, Hôpital de Bicêtre, France (M.H.)
| | - Mark R Nicolls
- From the Cardiovascular Institute and Department of Pediatrics (M.R.) and Department of Medicine (M.R.N.), Stanford University School of Medicine, CA; INSERM UMR_S 999, LabEx LERMIT, Centre Chirurgical Marie Lannelongue, Le Plessis-Robinson and Université Paris-Sud, School of Medicine, Le Kremlin-Bicêtre (C.G., M.H.); and AP-HP, Service de Pneumologie, Centre de Référence de l'Hypertension Pulmonaire Sévère, DHU Thorax Innovation, Hôpital de Bicêtre, France (M.H.)
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106
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Abstract
Hepatopulmonary syndrome (HPS) is a pulmonary complication observed in patients with chronic liver disease and/or portal hypertension, attributable to an intrapulmonary vascular dilatation that induces severe hypoxaemia. Considering the favourable long-term survival of HPS patients as well as the reversal of the syndrome with a functional liver graft, HPS is now an indication for orthotopic liver transplantation (OLT). Consequently, blood gas analysis and imaging techniques should be performed when cirrhotic patients present with shortness of breath as well as when OLT candidates are placed on the transplant waiting list. If the arterial partial pressure of oxygen (PaO2) is more than 10.7 kPa when breathing room air, HPS can be excluded and no other investigation is needed. When the PaO2 when breathing room air is 10.7 kPa or less, contrast-enhanced echocardiography should be performed to exclude pulmonary vascular dilatation. Lung function tests may also help detect additional pulmonary diseases that can contribute to impaired oxygenation. When contrast-enhanced echocardiography is negative, HPS is excluded and no follow-up is needed. When contrast-enhanced echocardiography is positive and PaO2 less than 8 kPa, patients should obtain a severity score that provides them with a reasonable probability of being transplanted within 3 months. In mild-to-moderate HPS (PaO2 8 to 10.6 kPa), periodic follow-up is recommended every 3 months to detect any further deterioration in PaO2. Although no intraoperative deaths have been directly attributed to HPS, oxygenation may worsen immediately following OLT due to volume overload and postoperative infections. Mechanical ventilation is often prolonged with an extended stay in the ICU. A high postoperative mortality (mostly within 6 months) is observed in this group of patients in comparison to non-HPS patients. However, the recovery of an adequate PaO2 within 12 months after OLT explains the similar outcome of HPS and non-HPS patients following OLT over a longer time period.
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107
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Tian W, Jiang X, Tamosiuniene R, Sung YK, Qian J, Dhillon G, Gera L, Farkas L, Rabinovitch M, Zamanian RT, Inayathullah M, Fridlib M, Rajadas J, Peters-Golden M, Voelkel NF, Nicolls MR. Blocking macrophage leukotriene b4 prevents endothelial injury and reverses pulmonary hypertension. Sci Transl Med 2014; 5:200ra117. [PMID: 23986401 DOI: 10.1126/scitranslmed.3006674] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pulmonary hypertension (PH) is a serious condition that affects mainly young and middle-aged women, and its etiology is poorly understood. A prominent pathological feature of PH is accumulation of macrophages near the arterioles of the lung. In both clinical tissue and the SU5416 (SU)/athymic rat model of severe PH, we found that the accumulated macrophages expressed high levels of leukotriene A4 hydrolase (LTA4H), the biosynthetic enzyme for leukotriene B4 (LTB4). Moreover, macrophage-derived LTB4 directly induced apoptosis in pulmonary artery endothelial cells (PAECs). Further, LTB4 induced proliferation and hypertrophy of human pulmonary artery smooth muscle cells. We found that LTB4 acted through its receptor, BLT1, to induce PAEC apoptosis by inhibiting the protective endothelial sphingosine kinase 1 (Sphk1)-endothelial nitric oxide synthase (eNOS) pathway. Blocking LTA4H decreased in vivo LTB4 levels, prevented PAEC apoptosis, restored Sphk1-eNOS signaling, and reversed fulminant PH in the SU/athymic rat model of PH. Antagonizing BLT1 similarly reversed established PH. Inhibition of LTB4 biosynthesis or signal transduction in SU-treated athymic rats with established disease also improved cardiac function and reopened obstructed arterioles; this approach was also effective in the monocrotaline model of severe PH. Human plexiform lesions, one hallmark of PH, showed increased numbers of macrophages, which expressed LTA4H, and patients with connective tissue disease-associated pulmonary arterial hypertension exhibited significantly higher LTB4 concentrations in the systemic circulation than did healthy subjects. These results uncover a possible role for macrophage-derived LTB4 in PH pathogenesis and identify a pathway that may be amenable to therapeutic targeting.
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Affiliation(s)
- Wen Tian
- Veterans Affairs Palo Alto Health Care System/Stanford University, Palo Alto, CA 94304, USA
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108
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Abstract
The hepatopulmonary syndrome (HPS) is a pulmonary complication of cirrhosis and/or portal hypertension whereby patients develop hypoxemia as a result of alterations in pulmonary microvascular tone and architecture. HPS occurs in up to 30% of patients with cirrhosis. Although the degree of hypoxemia does not reliably correlate with the severity of liver disease, patients with HPS have a higher mortality than do patients with cirrhosis without the disorder. There has been progress into defining the mechanisms that lead to hypoxemia in HPS, but to date there are no therapeutic options for HPS aside from liver transplantation.
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109
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Shikata F, Sakaue T, Nakashiro KI, Okazaki M, Kurata M, Okamura T, Okura M, Ryugo M, Nakamura Y, Yasugi T, Higashiyama S, Izutani H. Pathophysiology of lung injury induced by common bile duct ligation in mice. PLoS One 2014; 9:e94550. [PMID: 24733017 PMCID: PMC3986091 DOI: 10.1371/journal.pone.0094550] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 03/17/2014] [Indexed: 12/13/2022] Open
Abstract
Background Liver dysfunction and cirrhosis affect vasculature in several organ systems and cause impairment of organ functions, thereby increasing morbidity and mortality. Establishment of a mouse model of hepatopulmonary syndrome (HPS) would provide greater insights into the genetic basis of the disease. Our objectives were to establish a mouse model of lung injury after common bile duct ligation (CBDL) and to investigate pulmonary pathogenesis for application in future therapeutic approaches. Methods Eight-week-old Balb/c mice were subjected to CBDL. Immunohistochemical analyses and real-time quantitative reverse transcriptional polymerase chain reaction were performed on pulmonary tissues. The presence of HPS markers was detected by western blot and microarray analyses. Results We observed extensive proliferation of CD31-positive pulmonary vascular endothelial cells at 2 weeks after CBDL and identified 10 upregulated and 9 down-regulated proteins that were associated with angiogenesis. TNF-α and MMP-9 were highly expressed at 3 weeks after CBDL and were less expressed in the lungs of the control group. Conclusions We constructed a mouse lung injury model by using CBDL. Contrary to our expectation, lung pathology in our mouse model exhibited differences from that of rat models, and the mechanisms responsible for these differences are unknown. This phenomenon may be explained by contrasting processes related to TNF induction of angiogenic signaling pathways in the inflammatory phase. Thus, we suggest that our mouse model can be applied to pulmonary pathological analyses in the inflammatory phase, i.e., to systemic inflammatory response syndrome, acute lung injury, and multiple organ dysfunction syndrome.
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Affiliation(s)
- Fumiaki Shikata
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Tomohisa Sakaue
- Department of Cell Growth and Tumor Regulation, Ehime University, Proteo-Science Center, Ehime University, Ehime, Japan
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Koh-ichi Nakashiro
- Department of Oral and Maxillofacial Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Mikio Okazaki
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Mie Kurata
- Department of Pathology, Division of Pathogenomics, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Toru Okamura
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Masahiro Okura
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Masahiro Ryugo
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Yuki Nakamura
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Takumi Yasugi
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Shigeki Higashiyama
- Department of Cell Growth and Tumor Regulation, Ehime University, Proteo-Science Center, Ehime University, Ehime, Japan
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Hironori Izutani
- Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan
- * E-mail:
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110
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Zhang J, Yang W, Hu B, Wu W, Fallon MB. Endothelin-1 activation of the endothelin B receptor modulates pulmonary endothelial CX3CL1 and contributes to pulmonary angiogenesis in experimental hepatopulmonary syndrome. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1706-14. [PMID: 24731444 DOI: 10.1016/j.ajpath.2014.02.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/29/2014] [Accepted: 02/11/2014] [Indexed: 02/06/2023]
Abstract
Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in HPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental HPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (±BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca(2+) and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1-induced ERK activation was Ca(2+) independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca(2+) and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.
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Affiliation(s)
- Junlan Zhang
- Division of Gastroenterology, Hepatology, and Nutrition, the Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Wenli Yang
- Division of Gastroenterology, Hepatology, and Nutrition, the Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Bingqian Hu
- Division of Gastroenterology, Hepatology, and Nutrition, the Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Wei Wu
- Division of Gastroenterology, Hepatology, and Nutrition, the Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Michael B Fallon
- Division of Gastroenterology, Hepatology, and Nutrition, the Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas.
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111
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Machicao VI, Balakrishnan M, Fallon MB. Pulmonary complications in chronic liver disease. Hepatology 2014; 59:1627-37. [PMID: 24089295 DOI: 10.1002/hep.26745] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 09/12/2013] [Indexed: 12/13/2022]
Abstract
The association of chronic liver disease with respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease have been characterized: hepatopulmonary syndrome (HPS), portopulmonary hypertension (POPH), and hepatic hydrothorax (HH). The development of portal hypertension is fundamental in the pathogenesis of each of these disorders. HPS is the most common condition, found in 5%-30% of cirrhosis patients, manifested by abnormal oxygenation due to the development of intrapulmonary vascular dilatations. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation (LT). POPH is characterized by development of pulmonary arterial hypertension in the setting of portal hypertension, and is present in 5%-10% of cirrhosis patients evaluated for LT. Screening for POPH in cirrhosis patients eligible for LT is critical since severe POPH is a relative contraindication for LT. Patients with moderate POPH, who respond adequately to medical therapy, may benefit from LT, although sufficient controlled data are lacking. HH is a transudative pleural effusion seen in 5%-10% of cirrhosis patients, in the absence of cardiopulmonary disease. Diagnosis of HH should prompt consideration for LT, which is the ultimate treatment for HH. Conservative management includes salt restriction and diuretics, with thoracentesis and transjugular intrahepatic portosystemic shunt (TIPS) as second-line therapeutic options.
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Affiliation(s)
- Victor I Machicao
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, TX
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112
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Chen Y, Yi B, Wang Z, Gu J, Li Y, Cui J, Lu K. Paxillin suppresses the proliferation of HPS rat serum treated PASMCs by up-regulating the expression of cytoskeletal proteins. MOLECULAR BIOSYSTEMS 2014; 10:759-66. [PMID: 24457422 DOI: 10.1039/c3mb70391f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hepatopulmonary syndrome (HPS) is a triad of advanced liver disease, intrapulmonary vasodilatation (IPVD), and arterial hypoxemia. The arterial hypoxemia induces pulmonary vascular remodelling (PVR). In recent studies, the role of the proliferation of pulmonary artery smooth muscle cells (PASMCs) in PVR associated with HPS has been established; the changes in cytoskeletal proteins play an essential role in the proliferation of PASMCs. Little is known about the relevance of cytoskeletal protein expression or the molecular mechanisms of PVR associated with HPS. In addition, it has been identified that paxillin could influence the cytoskeletal protein expression by some important signaling pathways in many diseases, including lung cancer and liver cancer. In this study, we found that HPS rat serum from a common bile duct ligation (CBDL) rat model decreased the expression of cytoskeletal proteins (α-actin, α-tubulin, and destrin) and enhanced the expression levels of paxillin mRNA and protein in PASMCs. After silencing paxillin with siRNA, we found that the down-regulation of cytoskeletal protein expression, induced by the HPS rat serum, was reversed. Additionally, we reported that HPS rat serum improved the proliferation of PASMCs and down-regulation of paxillin could significantly inhibit this variation. These findings suggest that the up-regulation of cytoskeletal protein expression, induced by the paxillin, may cause the dysregulation of PASMC proliferation as well as play a fundamental role in PVR associated with HPS. In conclusion, down-regulation of paxillin by siRNA results in the inhibition of the dysregulation of cytoskeletal proteins and proliferation of PASMCs, suggesting a potential therapeutic effect on PVR associated with HPS.
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Affiliation(s)
- Yang Chen
- Department of Anesthesia, Southwest Hospital, the Third Military Medical University, Chongqing 400038, China.
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113
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Sawada H, Saito T, Nickel NP, Alastalo TP, Glotzbach JP, Chan R, Haghighat L, Fuchs G, Januszyk M, Cao A, Lai YJ, Perez VDJ, Kim YM, Wang L, Chen PI, Spiekerkoetter E, Mitani Y, Gurtner GC, Sarnow P, Rabinovitch M. Reduced BMPR2 expression induces GM-CSF translation and macrophage recruitment in humans and mice to exacerbate pulmonary hypertension. ACTA ACUST UNITED AC 2014; 211:263-80. [PMID: 24446489 PMCID: PMC3920564 DOI: 10.1084/jem.20111741] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Idiopathic pulmonary arterial hypertension (PAH [IPAH]) is an insidious and potentially fatal disease linked to a mutation or reduced expression of bone morphogenetic protein receptor 2 (BMPR2). Because intravascular inflammatory cells are recruited in IPAH pathogenesis, we hypothesized that reduced BMPR2 enhances production of the potent chemokine granulocyte macrophage colony-stimulating factor (GM-CSF) in response to an inflammatory perturbation. When human pulmonary artery (PA) endothelial cells deficient in BMPR2 were stimulated with tumor necrosis factor (TNF), a twofold increase in GM-CSF was observed and related to enhanced messenger RNA (mRNA) translation. The mechanism was associated with disruption of stress granule formation. Specifically, loss of BMPR2 induced prolonged phospho-p38 mitogen-activated protein kinase (MAPK) in response to TNF, and this increased GADD34-PP1 phosphatase activity, dephosphorylating eukaryotic translation initiation factor (eIF2α), and derepressing GM-CSF mRNA translation. Lungs from IPAH patients versus unused donor controls revealed heightened PA expression of GM-CSF co-distributing with increased TNF and expanded populations of hematopoietic and endothelial GM-CSF receptor α (GM-CSFRα)-positive cells. Moreover, a 3-wk infusion of GM-CSF in mice increased hypoxia-induced PAH, in association with increased perivascular macrophages and muscularized distal arteries, whereas blockade of GM-CSF repressed these features. Thus, reduced BMPR2 can subvert a stress granule response, heighten GM-CSF mRNA translation, increase inflammatory cell recruitment, and exacerbate PAH.
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Affiliation(s)
- Hirofumi Sawada
- The Vera Moulton Wall Center for Pulmonary Vascular Disease, 2 Department of Pediatrics, 3 Department of Surgery, 4 Department of Microbiology and Immunology, 5 Department of Medicine, and 6 Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305
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114
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Yang W, Zhang J, Hu B, Wu W, Venter J, Alpini G, Fallon MB. The role of receptor tyrosine kinase activation in cholangiocytes and pulmonary vascular endothelium in experimental hepatopulmonary syndrome. Am J Physiol Gastrointest Liver Physiol 2014; 306:G72-80. [PMID: 24200956 PMCID: PMC3920086 DOI: 10.1152/ajpgi.00178.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pulmonary vascular dilation and angiogenesis underlie experimental hepatopulmonary syndrome (HPS) induced by common bile duct ligation (CBDL) and may respond to receptor tyrosine kinase (RTK) inhibition. Vascular endothelial growth factor-A (VEGF-A) expression occurs in proliferating cholangiocytes and pulmonary intravascular monocytes after CBDL, the latter contributing to angiogenesis. CBDL cholangiocytes also produce endothelin-1 (ET-1), which triggers lung vascular endothelin B receptor-mediated endothelial nitric oxide synthase (eNOS) activation and pulmonary intravascular monocyte accumulation. However, whether RTK pathway activation directly regulates cholangiocyte and pulmonary microvascular alterations in experimental HPS is not defined. We assessed RTK pathway activation in cholangiocytes and lung after CBDL and the effects of the type II RTK inhibitor sorafenib in experimental HPS. Cholangiocyte VEGF-A expression and ERK activation accompanied proliferation and increased hepatic and circulating ET-1 levels after CBDL. Sorafenib decreased each of these events and led to a reduction in lung eNOS activation and intravascular monocyte accumulation. Lung monocyte VEGF-A expression and microvascular Akt and ERK activation were also found in vivo after CBDL, and VEGF-A activated Akt and ERK and angiogenesis in rat pulmonary microvascular endothelial cells in vitro. Sorafenib inhibited VEGF-A-mediated signaling and angiogenesis in vivo and in vitro and improved arterial gas exchange and intrapulmonary shunting. RTK activation in experimental HPS upregulates cholangiocyte proliferation and ET-1 production, leading to pulmonary microvascular eNOS activation, intravascular monocyte accumulation, and VEGF-A-mediated angiogenic signaling pathways. These findings identify a novel mechanism in cholangiocytes through which RTK inhibition ameliorates experimental HPS.
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Affiliation(s)
- Wenli Yang
- Division of Gastroenterology, Hepatology and Nutrition, Dept. of Internal Medicine, The Univ. of Texas Health Science Center at Houston, 6431 Fannin St., MSB 4.234, Houston, TX 77030-1501.
| | - Junlan Zhang
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas;
| | - Bingqian Hu
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas;
| | - Wei Wu
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas;
| | - Julie Venter
- 2Department of Medicine, Texas A&M Health Science Center, Temple, Texas; and
| | - Gianfranco Alpini
- 3Research, Central Texas Veterans Health Care System, Scott & White Digestive Disease Research Center, Scott & White, Department of Medicine, Division of Gastroenterology, Texas A&M Health Science Center, College of Medicine, Temple, Texas
| | - Michael B. Fallon
- 1Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas;
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115
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Role of macrophages in bile acid-induced inflammatory response of fetal lung during maternal cholestasis. J Mol Med (Berl) 2013; 92:359-72. [DOI: 10.1007/s00109-013-1106-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 09/17/2013] [Accepted: 11/14/2013] [Indexed: 01/14/2023]
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Abstract
Severe cyanosis due to pulmonary arteriovenous fistulas occurs often after a bidirectional superior cavopulmonary anastomosis (Glenn operation) and also in some congenital anomalies in which hepatic venous blood bypasses the lungs in the first passage. Relocation of hepatic flow into the lungs usually causes these fistulas to disappear. Similar pulmonary arteriovenous fistulas are observed in hereditary haemorrhagic telangiectasia, and in liver disease (hepatopulmonary syndrome). There is no convincing identification yet of a responsible hepatic factor that produces these lesions. Candidates for such a factor are reviewed, and the possibility of angiotensin or bradykinin contributing to the fistulas is discussed.
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118
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Yu YRA, Mao L, Piantadosi CA, Gunn MD. CCR2 deficiency, dysregulation of Notch signaling, and spontaneous pulmonary arterial hypertension. Am J Respir Cell Mol Biol 2013; 48:647-54. [PMID: 23492191 DOI: 10.1165/rcmb.2012-0182oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In pulmonary arterial hypertension (PAH), there is overexpression of the chemokine, C-C chemokine ligand type 2 (CCL2), and infiltration of myeloid cells into the pulmonary vasculature. Inhibition of CCL2 in animals decreases PAH, suggesting that the CCL2 receptor (CCR2) plays a role in PAH development. To test this hypothesis, we exposed wild-type (WT) and CCR2-deficient (Ccr2(-/-)) mice to chronic hypobaric hypoxia to induce PAH. After hypoxic stress, Ccr2(-/-) mice displayed a more severe PAH phenotype, as demonstrated by increased right ventricular (RV) systolic pressures, RV hypertrophy, and tachycardia relative to WT mice. However, these mice also exhibited increased RV systolic pressures and increased pulmonary artery muscularization under normoxic conditions. Moreover, Ccr2(-/-) mice displayed decreased pulmonary vascular branching at 3 weeks of age and increased vascular muscularization at birth, suggesting that an abnormality in pulmonary vascular development leads to spontaneous PAH in these animals. No significant differences in cytokine responses were observed between WT and Ccr2(-/-) mice during either normoxia or hypoxia. However, Ccr2(-/-) mice displayed increased Notch-3 signaling and dysregulated Notch ligand expression, suggesting a possible cause for their abnormal pulmonary vascular development. Our findings imply that CCR2 does not directly contribute to the development of PAH, but does play a previously unrecognized role in pulmonary vasculature development and remodeling wherein the absence of CCR2 results in spontaneous PAH, most likely via dysregulation of Notch signaling. Our results demonstrate that CCR2 has impacts beyond leukocyte recruitment, and is required for the proper expression of Notch signaling molecules.
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Affiliation(s)
- Yen-Rei A Yu
- Division of Pulmonary and Critical Care, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
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119
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Sokollik C, Bandsma RHJ, Gana JC, van den Heuvel M, Ling SC. Congenital portosystemic shunt: characterization of a multisystem disease. J Pediatr Gastroenterol Nutr 2013; 56:675-81. [PMID: 23412540 DOI: 10.1097/mpg.0b013e31828b3750] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Congenital portosystemic shunts (CPSSs) are rare but increasingly recognized as a cause of important multisystem morbidity. We present new cases and a systematic literature review and propose an algorithm for the identification and care of affected patients. METHODS We reviewed the charts of consecutive patients seen in our pediatric liver clinic between 2003 and 2010 and systematically reviewed the literature of cases with CPSS. RESULTS We identified 316 published cases and 12 patients in our own clinic. Of the published cases (177 male), 185 had an extrahepatic and 131 an intrahepatic portosystemic shunt. Diagnosis was made at any age, from prenatal to late adulthood. Cardiac anomalies were found in 22% of patients. The main complications were hyperammonemia/neurological abnormalities (35%), liver tumors (26%), and pulmonary hypertension or hepatopulmonary syndrome (18%). The spectrum of neurological involvement ranged from changes in brain imaging, subtle abnormalities on neuropsychological testing, through learning disabilities to overt encephalopathy. Spontaneous shunt closure occurred mainly in infants with intrahepatic shunts. Therapeutic interventions included shunt closure by surgery or interventional radiology techniques (35%) and liver transplantation (10%) leading to an improvement of symptoms in the majority. These findings mirror the observations in our own patients. CONCLUSIONS In this largest review of the reported clinical experience, we identify that children with CPSS may present with otherwise unexplained developmental delay, encephalopathy, pulmonary hypertension, hypoxemia, or liver tumors. When CPSS is diagnosed, children should be screened for all of these complications. Spontaneous closure of intrahepatic shunts may occur in infancy. Closure of the shunt is indicated in symptomatic patients and is associated with a favorable outcome.
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Affiliation(s)
- Christiane Sokollik
- Department of Paediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Toronto, The Hospital for Sick Children, Ontario, Canada
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Moreira Silva H, Reis G, Guedes M, Cleto E, Vizcaíno JR, Kelly D, Gennery AR, Santos Silva E. A case of hepatopulmonary syndrome solved by mycophenolate mofetil (an inhibitor of angiogenesis and nitric oxide production). J Hepatol 2013; 58:630-3. [PMID: 23104163 DOI: 10.1016/j.jhep.2012.10.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/27/2012] [Accepted: 10/15/2012] [Indexed: 02/07/2023]
Affiliation(s)
- Helena Moreira Silva
- Pediatric Gastroenterology Unit, Department of Child and Adolescent, Centro Hospitalar do Porto, Portugal
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121
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Grace JA, Angus PW. Hepatopulmonary syndrome: update on recent advances in pathophysiology, investigation, and treatment. J Gastroenterol Hepatol 2013. [PMID: 23190201 DOI: 10.1111/jgh.12061] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatopulmonary syndrome (HPS) is an important cause of dyspnea and hypoxia in the setting of liver disease, occurring in 10-30% of patients with cirrhosis. It is due to vasodilation and angiogenesis in the pulmonary vascular bed, which leads to ventilation-perfusion mismatching, diffusion limitation to oxygen exchange, and arteriovenous shunting. There is evidence, primarily from animal studies, that vasodilation is mediated by a number of endogenous vasoactive molecules, including endothelin-1 and nitric oxide (NO). In experimental HPS, liver injury stimulates release of endothelin-1 and results in increased expression of ET(B) receptors on pulmonary endothelial cells, leading to upregulation of endothelial NO synthase (eNOS) and subsequent increased production of NO, which causes vasodilation. In addition, increased phagocytosis of bacterial endotoxin in the lung not only promotes stimulation of inducible NO synthase, which increases NO production, but also contributes to intrapulmonary accumulation of monocytes, which may stimulate angiogenesis via vascular endothelial growth factor pathway. Despite these insights into the pathogenesis of experimental HPS, there is no established medical therapy, and liver transplantation remains the main treatment for symptomatic HPS, although selected patients may benefit from other surgical or radiological interventions. In this review, we focus on recent advances in our understanding of the pathophysiology of HPS, and discuss current approaches to the investigation and treatment of this condition.
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Affiliation(s)
- Josephine A Grace
- Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria, Australia.
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Fallon MB, Zhang J. The lung in liver disease: old problem, new concepts. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2013; 124:250-262. [PMID: 23874031 PMCID: PMC3715896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Liver dysfunction has been recognized to influence the lung in many different clinical situations, although the mechanisms for these effects are not well understood. One increasingly recognized interaction, the hepatopulmonary syndrome (HPS) occurs in the context of cirrhosis and results when alveolar microvascular dilation causes arterial gas exchange abnormalities and hypoxemia. HPS occurs in up to 30% of patients with cirrhosis and significantly increases mortality in affected patients. Currently, liver transplantation is the only curative therapy. Experimental biliary cirrhosis induced by common bile duct ligation (CBDL) in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and has been contrasted with other experimental models of cirrhosis in which HPS does not develop. Microvascular dilation, intravascular monocyte infiltration, and angiogenesis in the lung have been identified as pathologic features that drive gas exchange abnormalities in experimental HPS. Our recent studies have identified biliary epithelium and activation and interaction between the endothelin-1 (ET-1)/endothelial endothelin B (ETB) receptor and CX3CL1/CX3CR1 pathways as important mechanisms for the observed pathologic events. These studies define novel interactions between the lung and liver in cirrhosis and may lead to effective medical therapies.
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Affiliation(s)
- Michael B Fallon
- Department of Internal Medicine, Division of Gastroenterology, Hepatology & Nutrition, The University of Texas Medical School at Houston, 6431 Fannin Street, MSB 4.234, Houston, Texas 77030, USA.
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Zeng J, Yi B, Wang Z, Ning J, Wang X, Lu K. Effect of annexin A2 on hepatopulmonary syndrome rat serum-induced proliferation of pulmonary arterial smooth muscle cells. Respir Physiol Neurobiol 2013; 185:332-8. [DOI: 10.1016/j.resp.2012.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 09/16/2012] [Accepted: 09/18/2012] [Indexed: 01/14/2023]
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Fritz JS, Fallon MB, Kawut SM. Pulmonary vascular complications of liver disease. Am J Respir Crit Care Med 2012; 187:133-43. [PMID: 23155142 DOI: 10.1164/rccm.201209-1583ci] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hepatopulmonary syndrome and portopulmonary hypertension are two pulmonary vascular complications of liver disease. The pathophysiology underlying each disorder is distinct, but patients with either condition may be limited by dyspnea. A careful evaluation of concomitant symptoms, the physical examination, pulmonary function testing and arterial blood gas analysis, and echocardiographic, imaging, and hemodynamic studies is crucial to establishing (and distinguishing) these diagnoses. Our understanding of the pathobiology, natural history, and treatment of these disorders has advanced considerably over the past decade; however, the presence of either still increases the risk of morbidity and mortality in patients with underlying liver disease. There is no effective medical treatment for hepatopulmonary syndrome. Although liver transplantation can resolve hepatopulmonary syndrome, there appears to be worse survival even with transplantation. Liver transplantation poses a very high risk of death in those with significant portopulmonary hypertension, where targeted medical therapies may improve functional status and allow successful transplantation in a small number of select patients.
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Affiliation(s)
- Jason S Fritz
- Department of Medicine, M.S., Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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125
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Enrichment of murine CD68+ CCR2+ and CD68+ CD206+ lung macrophages in acute pancreatitis-associated acute lung injury. PLoS One 2012; 7:e42654. [PMID: 23110041 PMCID: PMC3478261 DOI: 10.1371/journal.pone.0042654] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 07/09/2012] [Indexed: 01/12/2023] Open
Abstract
Acute lung injury (ALI) is an important cause of mortality in critically ill patients. Acute pancreatitis (AP) is one of the risk factors for developing this syndrome. Among the inflammatory cells, macrophages have a key role in determining the severity of the acute lung injury. In the lungs, macrophages constitute a heterogeneous cell population distributed in different compartments. Changes in not only the macrophage count, but also in their phenotype have been seen during the course of lung injury. A murine ductal ligation model of acute pancreatitis showed substantial morphological changes in the pancreas and lungs. Immunohistochemistry showed neutrophil recruitment into both organs after 9 hours and later on. F4/80(+) cells in the pancreas increased in the ligated animals, though there was not a significant difference in their number in the lungs as compared to sham operated animals. Flow cytometry analysis of lung macrophages demonstrated an enrichment of F4/80(-) CD68(+)CCR2(+) and F4/80(-) CD68(+)CD206(+) lung macrophages in ligated animals (AP) as compared to the sham operated group. The level of interleukin-6 in plasma increased 3 hours after ligation compared to the sham operated group, as a first indicator of a systemic inflammatory response.This study suggests a role for F4/80(-) CD68(+) macrophages in the pathogenesis of acute lung injury in acute pancreatitis. Studying lung macrophages for different phenotypic markers, their polarization, activation and recruitment, in the context of acute lung injury, is a novel area to potentially identify interventions which may improve the outcome of acute lung injury.
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126
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Zhang J, Yang W, Luo B, Hu B, Maheshwari A, Fallon MB. The role of CX₃CL1/CX₃CR1 in pulmonary angiogenesis and intravascular monocyte accumulation in rat experimental hepatopulmonary syndrome. J Hepatol 2012; 57:752-8. [PMID: 22659346 PMCID: PMC3667409 DOI: 10.1016/j.jhep.2012.05.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 05/14/2012] [Accepted: 05/17/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Hepatopulmonary syndrome (HPS), classically attributed to intrapulmonary vascular dilatation, occurs in 15-30% of cirrhotics and causes hypoxemia and increases mortality. In experimental HPS after common bile duct ligation (CBDL), monocytes adhere in the lung vasculature and produce vascular endothelial growth factor (VEGF)-A and angiogenesis ensues and contribute to abnormal gas exchange. However, the mechanisms for these events are unknown. The chemokine fractalkine (CX(3)CL1) can directly mediate monocyte adhesion and activate VEGF-A and angiogenesis via its receptor CX(3)CR1 on monocytes and endothelium during inflammatory angiogenesis. We explored whether pulmonary CX(3)CL1/CX(3)CR1 alterations occur after CBDL and influence pulmonary angiogenesis and HPS. METHODS Pulmonary CX(3)CL1/CX(3)CR1 expression and localization, CX(3)CL1 signaling pathway activation, monocyte accumulation, and development of angiogenesis and HPS were assessed in 2- and 4-week CBDL animals. The effects of a neutralizing antibody to CX(3)CR1 (anti-CX(3)CR1 Ab) on HPS after CBDL were evaluated. RESULTS Circulating CX(3)CL1 levels and lung expression of CX(3)CL1 and CX(3)CR1 in intravascular monocytes and microvascular endothelium increased in 2- and 4-week CBDL animals as HPS developed. These events were accompanied by pulmonary angiogenesis, monocyte accumulation, activation of CX(3)CL1 mediated signaling pathways (Akt, ERK) and increased VEGF-A expression and signaling. Anti-CX(3)CR1 Ab treatment reduced monocyte accumulation, decreased lung angiogenesis and improved HPS. These events were accompanied by inhibition of CX(3)CL1 signaling pathways and a reduction in VEGF-A expression and signaling. CONCLUSIONS Circulating CX(3)CL1 levels and pulmonary CX(3)CL1/CX(3)CR1 expression and signaling increase after CBDL and contribute to pulmonary intravascular monocyte accumulation, angiogenesis and development of experimental HPS.
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Affiliation(s)
- Junlan Zhang
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston
| | - Wenli Yang
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston
| | - Bao Luo
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston
| | - Bingqian Hu
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston
| | | | - Michael B. Fallon
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston
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Abstract
Hepatopulmonary syndrome (HPS) is a serious vascular complication of liver disease that occurs in 5-32% of patients with cirrhosis. The presence of HPS markedly increases mortality. No effective medical therapies are currently available and liver transplantation is the only established treatment option for HPS. The definition and diagnosis of HPS are established by the presence of a triad of liver disease with intrapulmonary vascular dilation that causes abnormal arterial gas exchange. Experimental biliary cirrhosis induced by common bile duct ligation in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and serves as a pertinent animal model. Pulmonary microvascular dilation and angiogenesis are two central pathogenic features that drive abnormal pulmonary gas exchange in experimental HPS, and thus might underlie HPS in humans. Defining the mechanisms involved in the microvascular alterations of HPS has the potential to lead to effective medical therapies. This Review focuses on the current understanding of the pathogenesis, clinical features and management of HPS.
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Affiliation(s)
- Junlan Zhang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 4.234, Houston, TX 77030-1501, USA
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128
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Hassoun PM, Adnot S. Update in pulmonary vascular diseases 2011. Am J Respir Crit Care Med 2012; 185:1177-82. [PMID: 22661524 DOI: 10.1164/rccm.201203-0377up] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Paul M Hassoun
- Division of Pulmonary and Critical Care Medicine, 1830 East Monument Street, Baltimore, MD 21287, USA.
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129
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Aharonson-Raz K, Lohmann KL, Townsend HG, Marques F, Singh B. Pulmonary intravascular macrophages as proinflammatory cells in heaves, an asthma-like equine disease. Am J Physiol Lung Cell Mol Physiol 2012; 303:L189-98. [PMID: 22659880 DOI: 10.1152/ajplung.00271.2011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Heaves, an obstructive neutrophilic airway inflammation of horses, is triggered by dust components such as endotoxin and has similarities to human asthma. Pulmonary intravascular macrophages (PIMs) increase horses' sensitivity to endotoxin-induced lung inflammation; however, their role in an airborne pathology remains unknown. Therefore, we investigated the role of PIMs in the development of heaves in horses. Clinical and inflammatory responses were evaluated following induction of heaves by moldy hay exposure and PIM depletion with gadolinium chloride (GC). Mares (N = 9) were exposed to four treatments: alfalfa cubes (Cb), alfalfa cubes + GC (Cb-GC), moldy hay (MH), and moldy hay + GC (MH-GC). Clinical scores and neutrophil concentrations in bronchoalveolar lavage (BAL) fluid were higher when mares received MH compared with MH-GC. BAL cells from MH-GC-treated mares had significantly lower IL-8 and TLR4 mRNA expression compared with MH-treated mares. In vitro LPS challenge significantly increased IL-8 but not TLR4 mRNA expression in BAL cells recovered from horses fed with MH, but not from the MH-GC treatment. In summary, PIM depletion attenuated clinical scores, reduced the alveolar migration of neutrophils, and decreased the expression of proinflammatory molecules in BAL cells of heaves horses, suggesting a proinflammatory role of PIMs in the development of airborne pathology.
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Affiliation(s)
- Karin Aharonson-Raz
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Canada
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130
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Sunahara KKS, Martins JO. Alveolar macrophages in diabetes: friends or foes? J Leukoc Biol 2012; 91:871-6. [DOI: 10.1189/jlb.0911488] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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131
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Abstract
As can be seen by the mounting literature, there has been immense progress in the field of pulmonary hypertension (PH) over the last three decades, illustrated by several important milestones including improved understanding of disease pathogenesis, new classifications of disease, advances in screening and diagnostic techniques, and new rules for staging and follow-up, which have subsequently led to improvements in patient outcomes. The objectives of this manuscript are to not only highlight these very recent advances but also point out areas of deficiencies or gaps in our knowledge that may serve a focal point for future discussion and investigation.
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Affiliation(s)
- Irene M Lang
- Division of Cardiology, Department of Internal Medicine II, Vienna General Hospital, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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132
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Schneberger D, Aharonson-Raz K, Singh B. Pulmonary intravascular macrophages and lung health: what are we missing? Am J Physiol Lung Cell Mol Physiol 2012; 302:L498-503. [PMID: 22227203 DOI: 10.1152/ajplung.00322.2011] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary intravascular macrophages (PIMs) are constitutively found in species such as cattle, horse, pig, sheep, goat, cats, and whales and can be induced in species such as rats, which normally lack them. It is believed that human lung lacks PIMs, but there are previous suggestions of their induction in patients suffering from liver dysfunction. Recent data show induction of PIMs in bile-duct ligated rats and humans suffering from hepato-pulmonary syndrome. Because constitutive and induced PIMs are pro-inflammatory in response to endotoxins and bacteria, there is a need to study their biology in inflammatory lung diseases such as sepsis, asthma, chronic obstructive pulmonary diseases, or hepato-pulmonary syndrome. We provide a review of PIM biology to make an argument for increased emphasis and better focus on the study of human PIMs to better understand their potential role in the pathophysiology and mechanisms of pulmonary diseases.
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Affiliation(s)
- David Schneberger
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Canada
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133
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Strait RT, Hicks W, Barasa N, Mahler A, Khodoun M, Köhl J, Stringer K, Witte D, Van Rooijen N, Susskind BM, Finkelman FD. MHC class I-specific antibody binding to nonhematopoietic cells drives complement activation to induce transfusion-related acute lung injury in mice. ACTA ACUST UNITED AC 2011; 208:2525-44. [PMID: 22025304 PMCID: PMC3256958 DOI: 10.1084/jem.20110159] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In a manner partially independent of activating Fcγ receptors, antibody-mediated production of complement component C5a and recruitment of macrophages elicit transfusion-related acute lung injury in mice. Transfusion-related acute lung injury (TRALI), a form of noncardiogenic pulmonary edema that develops during or within 6 h after a blood transfusion, is the most frequent cause of transfusion-associated death in the United States. Because development of TRALI is associated with donor antibodies (Abs) reactive with recipient major histocompatibility complex (MHC), a mouse model has been studied in which TRALI-like disease is caused by injecting mice with anti–MHC class I monoclonal Ab (mAb). Previous publications with this model have concluded that disease is caused by FcR-dependent activation of neutrophils and platelets, with production of reactive oxygen species that damage pulmonary vascular endothelium. In this study, we confirm the role of reactive oxygen species in the pathogenesis of this mouse model of TRALI and show ultrastructural evidence of pulmonary vascular injury within 5 min of anti–MHC class I mAb injection. However, we demonstrate that disease induction in this model involves macrophages rather than neutrophils or platelets, activation of complement and production of C5a rather than activation of FcγRI, FcγRIII, or FcγRIV, and binding of anti–MHC class I mAb to non-BM–derived cells such as pulmonary vascular endothelium. These observations have important implications for the prevention and treatment of TRALI.
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Affiliation(s)
- Richard T Strait
- Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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