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Florentin J, Zhao J, Tai YY, Sun W, Ohayon LL, O'Neil SP, Arunkumar A, Zhang X, Zhu J, Al Aaraj Y, Watson A, Sembrat J, Rojas M, Chan SY, Dutta P. Loss of Amphiregulin drives inflammation and endothelial apoptosis in pulmonary hypertension. Life Sci Alliance 2022; 5:5/11/e202101264. [PMID: 35732465 PMCID: PMC9218345 DOI: 10.26508/lsa.202101264] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 06/09/2022] [Accepted: 06/09/2022] [Indexed: 12/15/2022] Open
Abstract
Pulmonary hypertension (PH) is a vascular disease characterized by elevated pulmonary arterial pressure, leading to right ventricular failure and death. Pathogenic features of PH include endothelial apoptosis and vascular inflammation, which drive vascular remodeling and increased pulmonary arterial pressure. Re-analysis of the whole transcriptome sequencing comparing human pulmonary arterial endothelial cells (PAECs) isolated from PH and control patients identified AREG, which encodes Amphiregulin, as a key endothelial survival factor. PAECs from PH patients and mice exhibited down-regulation of AREG and its receptor epidermal growth factor receptor (EGFR). Moreover, the deficiency of AREG and EGFR in ECs in vivo and in vitro heightened inflammatory leukocyte recruitment, cytokine production, and endothelial apoptosis, as well as diminished angiogenesis. Correspondingly, hypoxic mice lacking Egfr in ECs (cdh5 cre/+ Egfr fl/fl) displayed elevated RVSP and pulmonary remodeling. Computational analysis identified NCOA6, PHB2, and RRP1B as putative genes regulating AREG in endothelial cells. The master transcription factor of hypoxia HIF-1⍺ binds to the promoter regions of these genes and up-regulates their expression in hypoxia. Silencing of these genes in cultured PAECs decreased inflammation and apoptosis, and increased angiogenesis in hypoxic conditions. Our pathway analysis and gene silencing experiments revealed that BCL2-associated agonist of cell death (BAD) is a downstream mediator of AREG BAD silencing in ECs lacking AREG mitigated inflammation and apoptosis, and suppressed tube formation. In conclusion, loss of Amphiregulin and its receptor EGFR in PH is a crucial step in the pathogenesis of PH, promoting pulmonary endothelial cell death, influx of inflammatory myeloid cells, and vascular remodeling.
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Affiliation(s)
- Jonathan Florentin
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jingsi Zhao
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Yi-Yin Tai
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Wei Sun
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lee L Ohayon
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Scott P O'Neil
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Anagha Arunkumar
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Xinyi Zhang
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jianhui Zhu
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yassmin Al Aaraj
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Annie Watson
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - John Sembrat
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mauricio Rojas
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen Y Chan
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Partha Dutta
- Division of Cardiology, Department of Medicine, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA .,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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2
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Liu D, Song M, Jing F, Liu B, Yi Q. Diagnostic Value of Immune-Related Genes in Kawasaki Disease. Front Genet 2021; 12:763496. [PMID: 34956318 PMCID: PMC8709561 DOI: 10.3389/fgene.2021.763496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/11/2021] [Indexed: 12/19/2022] Open
Abstract
Kawasaki disease (KD) is a systemic vasculitis that predominantly damages medium- and small-sized vessels, and mainly causes coronary artery lesions (CALs). The diagnostic criterion of KD mainly depends on clinical features, so children could be easily misdiagnosed and could suffer from CALs. Through analysis, a total of 14 immune-related DEGs were obtained, of which IL1B, ADM, PDGFC, and TGFA were identified as diagnostic markers of KD. Compared with the non-KD group, KD patients contained a higher proportion of naive B cells, activated memory CD4 T cells, gamma delta T cells, and neutrophils, while the proportions of memory B cells, CD8 T cells, activated memory CD4 T cells, and activated NK cells were relatively lower. In conclusion, immune-related genes can be used as diagnostic markers of KD, and the difference in immune cells between KD and non-KD might provide new insight into understanding the pathogenesis of KD.
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Affiliation(s)
- Dong Liu
- Department of Cardiovascular Medicine, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Department of Pediatrics, Sichuan Clinical Research Center for Birth Defects, The Affliated Hospital of Southwest Medical University, Luzhou, China.,Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Meixuan Song
- Department of Gastrointestinal Surgery, The Affliated Hospital of Southwest Medical University, Luzhou, China
| | - Fengchuan Jing
- Department of Cardiovascular Medicine, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Bin Liu
- Department of Pediatrics, Sichuan Clinical Research Center for Birth Defects, The Affliated Hospital of Southwest Medical University, Luzhou, China
| | - Qijian Yi
- Department of Cardiovascular Medicine, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Pediatrics, Chongqing, China
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Norton CE, Sheak JR, Yan S, Weise-Cross L, Jernigan NL, Walker BR, Resta TC. Augmented Pulmonary Vasoconstrictor Reactivity after Chronic Hypoxia Requires Src Kinase and Epidermal Growth Factor Receptor Signaling. Am J Respir Cell Mol Biol 2020; 62:61-73. [PMID: 31264901 PMCID: PMC6938133 DOI: 10.1165/rcmb.2018-0106oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/28/2019] [Indexed: 12/20/2022] Open
Abstract
Chronic hypoxia augments pressure- and agonist-induced pulmonary vasoconstriction through myofilament calcium sensitization. NADPH oxidases contribute to the development of pulmonary hypertension, and both epidermal growth factor receptor and Src kinases can regulate NADPH oxidase. We tested the hypothesis that Src-epidermal growth factor receptor (EGFR) signaling mediates enhanced vasoconstrictor sensitivity after chronic hypoxia through NADPH oxidase-derived superoxide generation. Protocols employed pharmacological inhibitors in isolated, pressurized rat pulmonary arteries to examine the contribution of a variety of signaling moieties to enhanced vascular tone after chronic hypoxia. Superoxide generation in pulmonary arterial smooth muscle cells was assessed using the fluorescent indicator dihydroethidium. Indices of pulmonary hypertension were measured in rats treated with the EGFR inhibitor gefitinib. Inhibition of NADPH oxidase, Rac1 (Ras-related C3 botulinum toxin substrate 1), and EGFR abolished pressure-induced pulmonary arterial tone and endothelin-1 (ET-1)-dependent calcium sensitization and vasoconstriction after chronic hypoxia. Consistently, chronic hypoxia augmented ET-1-induced superoxide production through EGFR signaling, and rats treated chronically with gefitinib displayed reduced right ventricular pressure and diminished arterial remodeling. Src kinases were also activated by ET-1 after chronic hypoxia and contributed to enhanced basal arterial tone and vasoconstriction in response to ET-1. A role for matrix metalloproteinase 2 to mediate Src-dependent EGFR activation is further supported by our findings. Our studies support a novel role for an Src kinase-EGFR-NADPH oxidase signaling axis to mediate enhanced pulmonary vascular smooth muscle Ca2+ sensitization, vasoconstriction, and pulmonary hypertension after chronic hypoxia.
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Affiliation(s)
- Charles E Norton
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Joshua R Sheak
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Simin Yan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Benjimen R Walker
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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Säleby J, Bouzina H, Ahmed S, Lundgren J, Rådegran G. Plasma receptor tyrosine kinase RET in pulmonary arterial hypertension diagnosis and differentiation. ERJ Open Res 2019; 5:00037-2019. [PMID: 31754623 PMCID: PMC6856495 DOI: 10.1183/23120541.00037-2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 09/14/2019] [Indexed: 12/16/2022] Open
Abstract
Background Pulmonary arterial hypertension (PAH) is a serious disease exhibiting unspecific symptoms, as a result of which diagnosis is often delayed and prognosis is poor. The underlying pathophysiology includes vasoconstriction and remodelling of small pulmonary arteries. As receptor tyrosine kinases (RTKs) and their ligands have been shown to promote PAH remodelling, our aim was to evaluate if their plasma levels may be utilised to differentiate between various causes of pulmonary hypertension. Methods 28 biomarkers involved in RTK signalling were measured using proximity extension assays in venous plasma from patients with PAH (n=48), chronic thromboembolic pulmonary hypertension (CTEPH) (n=20), pulmonary hypertension due to diastolic (n=33) or systolic (n=36) heart failure and heart failure patients without pulmonary hypertension (n=15), as well as healthy controls (n=20). Results Plasma proto-oncogene tyrosine-protein kinase receptor Ret (RET) was decreased (p<0.04) in PAH compared with all disease groups and controls. RET generated a sensitivity of 64.6% and a specificity of 81.6% for detecting PAH from other disease groups. PAH and the other pulmonary hypertension groups showed elevated plasma tyrosine-protein kinase MER (p<0.01), vascular endothelial growth factor (VEGF)-A (p<0.02), VEGF-D (p<0.01), placental growth factor (p<0.01), amphiregulin (p<0.02), hepatocyte growth factor (p<0.01) and transforming growth factor-α (p<0.05) and decreased VEGF receptor-2 (p<0.04) and epidermal growth factor receptor (p<0.01) levels compared with controls. Conclusion Plasma RET differentiates patients with PAH from those with CTEPH, systolic or diastolic heart failure with or without pulmonary hypertension as well as healthy controls. Future studies would be of value to determine the clinical usefulness of RET as a biomarker and its link to PAH pathophysiology. Receptor tyrosine kinases have been shown to promote PAH remodelling. Plasma RET differentiates PAH from other causes of PH. RET could have the potential to be used as a future diagnostic biomarker.http://bit.ly/2LChPUS
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Affiliation(s)
- Joanna Säleby
- Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund University, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
| | - Habib Bouzina
- Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund University, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
| | - Salaheldin Ahmed
- Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund University, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
| | - Jakob Lundgren
- Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund University, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
| | - Göran Rådegran
- Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund University, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
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Weise-Cross L, Resta TC, Jernigan NL. Redox Regulation of Ion Channels and Receptors in Pulmonary Hypertension. Antioxid Redox Signal 2019; 31:898-915. [PMID: 30569735 PMCID: PMC7061297 DOI: 10.1089/ars.2018.7699] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/11/2018] [Indexed: 02/06/2023]
Abstract
Significance: Pulmonary hypertension (PH) is characterized by elevated vascular resistance due to vasoconstriction and remodeling of the normally low-pressure pulmonary vasculature. Redox stress contributes to the pathophysiology of this disease by altering the regulation and activity of membrane receptors, K+ channels, and intracellular Ca2+ homeostasis. Recent Advances: Antioxidant therapies have had limited success in treating PH, leading to a growing appreciation that reductive stress, in addition to oxidative stress, plays a role in metabolic and cell signaling dysfunction in pulmonary vascular cells. Reactive oxygen species generation from mitochondria and NADPH oxidases has substantial effects on K+ conductance and membrane potential, and both receptor-operated and store-operated Ca2+ entry. Critical Issues: Some specific redox changes resulting from oxidation, S-nitrosylation, and S-glutathionylation are known to modulate membrane receptor and ion channel activity in PH. However, many sites of regulation that have been elucidated in nonpulmonary cell types have not been tested in the pulmonary vasculature, and context-specific molecular mechanisms are lacking. Future Directions: Here, we review what is known about redox regulation of membrane receptors and ion channels in PH. Further investigation of the mechanisms involved is needed to better understand the etiology of PH and develop better targeted treatment strategies.
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Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C. Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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Bouzina H, Rådegran G. Low plasma stem cell factor combined with high transforming growth factor-α identifies high-risk patients in pulmonary arterial hypertension. ERJ Open Res 2018; 4:00035-2018. [PMID: 30443557 PMCID: PMC6230818 DOI: 10.1183/23120541.00035-2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/17/2018] [Indexed: 12/29/2022] Open
Abstract
In pulmonary arterial hypertension (PAH), severe vasoconstriction and remodelling of small pulmonary arteries result in high mortality. Receptor tyrosine kinases and their ligands, such as transforming growth factor (TGF)-α, modulate proliferation in PAH. Although the receptor tyrosine kinase c-Kit has been shown to be overexpressed in PAH, the expression and role of its ligand stem cell factor (SCF) remain unknown. However, low plasma SCF levels are known to be linked to higher cardiovascular mortality risk. Using proximity extension assays, we measured SCF and TGF-α in venous plasma from treatment-naïve PAH patients and healthy controls. Patients were stratified into risk classes based on PAH guidelines. Plasma SCF was decreased (p=0.013) and TGF-α was increased (p<0.0001) in PAH patients compared to controls. SCF correlated to pulmonary vascular resistance (r=−0.66, p<0.0001), cardiac index (r=0.66, p<0.0001), venous oxygen saturation (r=0.47, p<0.0008), mean right atrial pressure (r=−0.44, p<0.002) and N-terminal pro-brain natriuretic protein (r=−0.39, p<0.006). SCF was lower in “high-risk” compared to “intermediate-risk” (p=0.0015) or “low-risk” (p=0.0009) PAH patients. SCF and TGF-α levels combined (SCF/TGF-α) resulted in 85.7% sensitivity and 81.5% specificity for detecting high-risk patients (p<0.0001). Finally, REVEAL (Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management) risk scores in PAH patients correlated to SCF/TGF-α levels (r=−0.50, p=0.0003). In conclusion, low plasma SCF combined with high TGF-α identifies high-risk PAH patients at baseline. Lower circulating SCF levels, which are associated with worse haemodynamics, may be related to the c-Kit accumulation previously observed in PAH. Plasma stem cell factor and transforming growth factor-α are related to pulmonary arterial hypertension severity and risk assessmenthttp://ow.ly/s5O330lDjN9
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Affiliation(s)
- Habib Bouzina
- Lund University, Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
| | - Göran Rådegran
- Lund University, Dept of Clinical Sciences Lund, Cardiology, Faculty of Medicine, Lund, Sweden.,The Hemodynamic Lab, The Section for Heart Failure and Valvular Disease, VO Heart and Lung Medicine, Skåne University Hospital, Lund, Sweden
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7
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Pool CM, Jin Y, Chen B, Liu Y, Nelin LD. Hypoxic-induction of arginase II requires EGF-mediated EGFR activation in human pulmonary microvascular endothelial cells. Physiol Rep 2018; 6:e13693. [PMID: 29845760 PMCID: PMC5974731 DOI: 10.14814/phy2.13693] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 03/31/2018] [Accepted: 04/03/2018] [Indexed: 12/22/2022] Open
Abstract
We have previously shown that hypoxia-induced proliferation of human pulmonary microvascular endothelial cells (hPMVEC) depends on arginase II, and that epidermal growth factor receptor (EGFR) is necessary for hypoxic-induction of arginase II. However, it remains unclear how hypoxia activates EGFR-mediated signaling in hPMVEC. We hypothesized that hypoxia results in epidermal growth factor (EGF) production and that EGF binds to EGFR to activate the signaling cascade leading to arginase II induction and proliferation in hPMVEC. We found that hypoxia significantly increased the mRNA levels of EGF, EGFR, and arginase in hPMVEC. Hypoxia significantly increased pEGFR(Tyr845) protein levels and an EGF neutralizing antibody prevented the hypoxic induction of pEGFR. Inhibiting EGFR activation prevented hypoxia-induced arginase II mRNA and protein induction. Treatment of hPMVEC with exogenous EGF resulted in greater levels of arginase II protein both in normoxia and hypoxia. An EGF neutralizing antibody diminished hypoxic induction of arginase II and resulted in fewer viable cells in hPMVEC. Similarly, siRNA against EGF prevented hypoxic induction of arginase II and resulted in fewer viable cells. Finally, conditioned media from hypoxic hPMVEC induced proliferation in human pulmonary artery smooth muscle cells (hPASMC), however, conditioned media from a group of hypoxic hPMVEC in which EGF were knocked down did not promote hPASMC proliferation. These findings demonstrate that hypoxia-induced arginase II expression and cellular proliferation depend on autocrine EGF production leading to EGFR activation in hPMVEC. We speculate that EGF-EGFR signaling may be a novel therapeutic target for pulmonary hypertensive disorders associated with hypoxia.
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Affiliation(s)
- Caitlyn M. Pool
- Pulmonary Hypertension GroupCenter for Perinatal ResearchResearch Institute at Nationwide Children's HospitalColumbusOhio
- Department of PediatricsThe Ohio State UniversityColumbusOhio
| | - Yi Jin
- Pulmonary Hypertension GroupCenter for Perinatal ResearchResearch Institute at Nationwide Children's HospitalColumbusOhio
- Department of PediatricsThe Ohio State UniversityColumbusOhio
| | - Bernadette Chen
- Pulmonary Hypertension GroupCenter for Perinatal ResearchResearch Institute at Nationwide Children's HospitalColumbusOhio
- Department of PediatricsThe Ohio State UniversityColumbusOhio
| | - Yusen Liu
- Pulmonary Hypertension GroupCenter for Perinatal ResearchResearch Institute at Nationwide Children's HospitalColumbusOhio
- Department of PediatricsThe Ohio State UniversityColumbusOhio
| | - Leif D. Nelin
- Pulmonary Hypertension GroupCenter for Perinatal ResearchResearch Institute at Nationwide Children's HospitalColumbusOhio
- Department of PediatricsThe Ohio State UniversityColumbusOhio
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Oak P, Hilgendorff A. The BPD trio? Interaction of dysregulated PDGF, VEGF, and TGF signaling in neonatal chronic lung disease. Mol Cell Pediatr 2017; 4:11. [PMID: 29116547 PMCID: PMC5676585 DOI: 10.1186/s40348-017-0076-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 10/17/2017] [Indexed: 12/26/2022] Open
Abstract
The development of neonatal chronic lung disease (nCLD), i.e., bronchopulmonary dysplasia (BPD) in preterm infants, significantly determines long-term outcome in this patient population. Risk factors include mechanical ventilation and oxygen toxicity impacting on the immature lung resulting in impaired alveolarization and vascularization. Disease development is characterized by inflammation, extracellular matrix remodeling, and apoptosis, closely intertwined with the dysregulation of growth factor signaling. This review focuses on the causes and consequences of altered signaling in central pathways like transforming growth factor (TGF), platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF) driving these above indicated processes, i.e., inflammation, matrix remodeling, and vascular development. We emphasize the shared and distinct role of these pathways as well as their interconnection in disease initiation and progression, generating important knowledge for the development of future treatment strategies.
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Affiliation(s)
- Prajakta Oak
- Comprehensive Pneumology Center, University Hospital of the University of Munich and Helmholtz Zentrum Muenchen, Munich, Germany
| | - Anne Hilgendorff
- Comprehensive Pneumology Center, University Hospital of the University of Munich and Helmholtz Zentrum Muenchen, Munich, Germany.
- Department of Neonatology, Perinatal Center Grosshadern, Ludwig-Maximilians University, Munich, Germany.
- Center for Comprehensive Developmental Care, Dr. von Haunersches Children's Hospital University, Hospital Ludwig-Maximilians University, Munich, Germany.
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9
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Jernigan NL, Resta TC, Gonzalez Bosc LV. Altered Redox Balance in the Development of Chronic Hypoxia-induced Pulmonary Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 967:83-103. [PMID: 29047083 DOI: 10.1007/978-3-319-63245-2_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Normally, the pulmonary circulation is maintained in a low-pressure, low-resistance state with little resting tone. Pulmonary arteries are thin-walled and rely heavily on pulmonary arterial distension and recruitment for reducing pulmonary vascular resistance when cardiac output is elevated. Under pathophysiological conditions, however, active vasoconstriction and vascular remodeling lead to enhanced pulmonary vascular resistance and subsequent pulmonary hypertension (PH). Chronic hypoxia is a critical pathological factor associated with the development of PH resulting from airway obstruction (COPD, sleep apnea), diffusion impairment (interstitial lung disease), developmental lung abnormalities, or high altitude exposure (World Health Organization [WHO]; Group III). The rise in pulmonary vascular resistance increases right heart afterload causing right ventricular hypertrophy that can ultimately lead to right heart failure in patients with chronic lung disease. PH is typically characterized by diminished paracrine release of vasodilators, antimitogenic factors, and antithrombotic factors (e.g., nitric oxide and protacyclin) and enhanced production of vasoconstrictors and mitogenic factors (e.g., reactive oxygen species and endothelin-1) from the endothelium and lung parenchyma. In addition, phenotypic changes to pulmonary arterial smooth muscle cells (PASMC), including alterations in Ca2+ homeostasis, Ca2+ sensitivity, and activation of transcription factors are thought to play prominent roles in the development of both vasoconstrictor and arterial remodeling components of hypoxia-associated PH. These changes in PASMC function are briefly reviewed in Sect. 1 and the influence of altered reactive oxygen species homeostasis on PASMC function discussed in Sects. 2-4.
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Affiliation(s)
- Nikki L Jernigan
- Department Cell Biology and Physiology, Vascular Physiology Group, University of New Mexico Health Sciences Center, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Thomas C Resta
- Department Cell Biology and Physiology, Vascular Physiology Group, University of New Mexico Health Sciences Center, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Laura V Gonzalez Bosc
- Department Cell Biology and Physiology, Vascular Physiology Group, University of New Mexico Health Sciences Center, University of New Mexico, Albuquerque, NM, 87131, USA.
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10
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Mangla A, Agarwal N, Carmel C, Lad T. Erlotinib Induced Fatal Interstitial Lung Disease in a Patient with Metastatic Non-Small Cell Lung Cancer: Case Report and Review of Literature. Rare Tumors 2016; 8:6410. [PMID: 27746884 PMCID: PMC5064300 DOI: 10.4081/rt.2016.6410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/16/2016] [Accepted: 05/13/2016] [Indexed: 11/23/2022] Open
Abstract
Erlotinib is one of the most widely used tyrosine kinase inhibitor targeting human epidermal growth factor receptor. Since its introduction, it has revolutionized the treatment of advanced non-small cell lung cancer. Skin rashes and diarrhea are the most often reported side effects of erlotinib however it is also associated with interstitial pneumonitis or interstitial lung disease, which often turns out to be fatal complication of using this medicine. Though reported scarcely in the western world, the association of interstitial lung disease with epidermal growth factor receptor has attracted a lot of attention in the recent times. Various researches working with murine models of bleomycin-induced pulmonary fibrosis have found a pro and con role of the receptor in development of the interstitial lung disease. We present the case of a patient diagnosed with stage IV adenocarcinoma of the lung with metastasis to brain. He was found to be positive for the human epidermal growth factor mutation and was hence started on erlotinib. Within a few weeks of starting the medicine the patient was admitted with diarrhea. During the course of this admission he developed acute shortness of breath diagnosed as interstitial pneumonitis. The purpose of this case report is to review the literature associated with erlotinib induced interstitial pneumonitis and make the practicing oncologists aware of this rare yet fatal complication of erlotinib. Here we will also review literature, pertaining to the role of epidermal growth factor receptor in development of interstitial lung disease.
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Affiliation(s)
- Ankit Mangla
- Department of Internal Medicine, John H. Stroger, Jr. Hospital of Cook County, Chicago, IL, USA; Division of Hematology/Oncology, John H. Stroger, Jr. Hospital of Cook County, Chicago, IL, USA
| | - Nikki Agarwal
- Division of Hematology/Oncology, John H. Stroger, Jr. Hospital of Cook County , Chicago, IL, USA
| | - Chou Carmel
- Division of Hematology/Oncology, John H. Stroger, Jr. Hospital of Cook County , Chicago, IL, USA
| | - Thomas Lad
- Division of Hematology/Oncology, John H. Stroger, Jr. Hospital of Cook County , Chicago, IL, USA
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11
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Li J, Li Y, He H, Liu C, Li W, Xie L, Zhang Y. Csk/Src/EGFR signaling regulates migration of myofibroblasts and alveolarization. Am J Physiol Lung Cell Mol Physiol 2016; 310:L562-71. [PMID: 26773066 DOI: 10.1152/ajplung.00162.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 01/05/2016] [Indexed: 12/21/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is characterized by premature alveolar developmental arrest. Antenatal exposure to inflammation inhibits lung morphogenesis, thus increasing the risk of developing BPD. Alveolar myofibroblasts are thought to migrate into the septal tips and elongate secondary septa during alveolarization. Here we found lipopolysaccharide (LPS) disrupted the directional migration of myofibroblasts and increased actin stress fiber expression and focal adhesion formation. In addition, COOH-terminal Src kinase (Csk) activity was downregulated in myofibroblasts treated with LPS, while activation of Src or epidermal growth factor receptor (EGFR) was upregulated by LPS treatment. Specifically, decreased Csk activity and increased activation of Src or EGFR was also observed in primary myofibroblasts isolated from newborn rat lungs with intra-amniotic LPS exposure, a model for BPD. Further investigation revealed that EGFR was involved in cell migration impairment induced by LPS, and Src inhibition blocked LPS-induced activation of EGFR or cell migration impairment. Csk silencing also resulted in EGFR activation and cell migration impairment. Besides, we found the effect of EGFR on myofibroblast migration was mediated through RhoA activation. EGFR inhibition alleviated the abnormal localization of myofibroblasts and improved alveolar development in antenatal LPS-treated rats. Taken together, our data suggest that the Csk/Src/EGFR signaling pathway is critically involved in regulating directional migration of myofibroblasts and may contribute to arrested alveolar development in BPD.
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Affiliation(s)
- Jianhui Li
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Yahui Li
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Hua He
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Chengbo Liu
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Wen Li
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Lijuan Xie
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and
| | - Yongjun Zhang
- Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; and MOE and Shanghai Key Laboratory of Children's Environmental Health, Shanghai, China
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12
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Jobe AH. Animal Models, Learning Lessons to Prevent and Treat Neonatal Chronic Lung Disease. Front Med (Lausanne) 2015; 2:49. [PMID: 26301222 PMCID: PMC4528292 DOI: 10.3389/fmed.2015.00049] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/14/2015] [Indexed: 11/23/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) is a unique injury syndrome caused by prolonged injury and repair imposed on an immature and developing lung. The decreased septation and decreased microvascular development phenotype of BPD can be reproduced in newborn rodents with increased chronic oxygen exposure and in premature primates and sheep with oxygen and/or mechanical ventilation. The inflammation caused by oxidants, inflammatory agonists, and/or stretch injury from mechanical ventilation seems to promote the anatomic abnormalities. Multiple interventions targeted to specific inflammatory cells or pathways or targeted to decreasing ventilation-mediated injury can substantially prevent the anatomic changes associated with BPD in term rodents and in preterm sheep or primate models. Most of the anti-inflammatory therapies with benefit in animal models have not been tested clinically. None of the interventions that have been tested clinically are as effective as anticipated from the animal models. These inconsistencies in responses likely are explained by the antenatal differences in lung exposures of the developing animals relative to very preterm humans. The animals generally have normal lungs while the lungs of preterm infants are exposed variably to intrauterine inflammation, growth abnormalities, antenatal corticosteroids, and poorly understood effects from the causes of preterm delivery. The animal models have been essential for the definition of the mediators that can cause a BPD phenotype. These models will be necessary to develop and test future-targeted interventions to prevent and treat BPD.
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Affiliation(s)
- Alan H Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati , Cincinnati, OH , USA
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13
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Li C, Wei R, Jones-Hall YL, Vittal R, Zhang M, Liu W. Epidermal growth factor receptor (EGFR) pathway genes and interstitial lung disease: an association study. Sci Rep 2014; 4:4893. [PMID: 24819665 PMCID: PMC4018612 DOI: 10.1038/srep04893] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 04/17/2014] [Indexed: 12/28/2022] Open
Abstract
The etiology and pathogenesis of idiopathic interstitial lung disease (ILD) remain incompletely understood. Genetic susceptibility to ILD has been demonstrated in previous studies. It is well known that EGFR inhibitors can induce ILD in human lung cancer patient with ethnic differences, which prompted us to hypothesize that genetic variation in EGFR pathway genes confer susceptibility to ILD. We aimed in this study to investigate whether functional polymorphisms of EGFR and its ligands genes (EGF and TGFA) were associated with ILD. Three EGFR [-216G/T (rs712830), -191A/C (rs712829), 497R > K(A/G) (rs2227983)], one EGF [61A/G, (rs4444903)] and one TGFA (rs3821262C/T) polymorphisms previously demonstrated to alter gene functions were genotyped in 229 sporadic idiopathic ILD patients and 693 normal healthy individuals. Allelic and genotypic association tests between these polymorphisms and ILD were performed. The EGF 61A/G polymorphism was significantly associated with elevated risk of ILD, with the frequency of G allele significantly increased in the ILD patient population (OR = 1.33, 95%CI = 1.07-1.66, P = 0.0099). None of the other polymorphisms were associated with risk of ILD. Our study suggested that the EGF 61A/G polymorphism may be associated with sporadic ILD. While a false positive finding cannot be excluded, independent studies are warranted to further validate this result.
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Affiliation(s)
- Chong Li
- 1] Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy,Purdue University, West Lafayette, Indiana [2] Department of Respiratory Medicine, the Third Affiliated Hospital of Suzhou University, Changzhou, Jiangsu, China
| | - Rongrong Wei
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy,Purdue University, West Lafayette, Indiana
| | - Yava L Jones-Hall
- Department of Comparative Pathobiology, College of Veterinary Medicine; Purdue University, West Lafayette, Indiana
| | - Ragini Vittal
- Center for Immunobiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Min Zhang
- Department of Statistics, Purdue University, West Lafayette, Indiana
| | - Wanqing Liu
- 1] Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy,Purdue University, West Lafayette, Indiana [2] Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana
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14
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Vallath S, Hynds RE, Succony L, Janes SM, Giangreco A. Targeting EGFR signalling in chronic lung disease: therapeutic challenges and opportunities. Eur Respir J 2014; 44:513-22. [PMID: 24435005 DOI: 10.1183/09031936.00146413] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Chronic respiratory diseases, including pulmonary fibrosis, chronic obstructive pulmonary disease (COPD) and lung cancer, are the second leading cause of death among Europeans. Despite this, there have been only a few therapeutic advances in these conditions over the past 20 years. In this review we provide evidence that targeting the epidermal growth factor receptor (EGFR) signalling pathway may represent a novel therapeutic panacea for treating chronic lung disease. Using evidence from human patient samples, transgenic animal models, and cell and molecular biology studies we highlight the roles of this signalling pathway in lung development, homeostasis, repair, and disease ontogeny. We identify mechanisms underlying lung EGFR pathway regulation and suggest how targeting these mechanisms using new and existing therapies has the potential to improve future lung cancer, COPD and pulmonary fibrosis patient outcomes.
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Affiliation(s)
- Sabari Vallath
- Lungs for Living Research Centre, Division of Medicine, University College London, UK
| | - Robert E Hynds
- Lungs for Living Research Centre, Division of Medicine, University College London, UK
| | - Laura Succony
- Lungs for Living Research Centre, Division of Medicine, University College London, UK
| | - Sam M Janes
- Lungs for Living Research Centre, Division of Medicine, University College London, UK
| | - Adam Giangreco
- Lungs for Living Research Centre, Division of Medicine, University College London, UK
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15
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Norton CE, Broughton BRS, Jernigan NL, Walker BR, Resta TC. Enhanced depolarization-induced pulmonary vasoconstriction following chronic hypoxia requires EGFR-dependent activation of NAD(P)H oxidase 2. Antioxid Redox Signal 2013; 18:1777-88. [PMID: 22966991 PMCID: PMC3619151 DOI: 10.1089/ars.2012.4836] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
AIMS Chronic hypoxia (CH) enhances depolarization-induced myofilament Ca(2+) sensitization and resultant pulmonary arterial constriction through superoxide (O(2)(-))-dependent stimulation of RhoA. Because NAD(P)H oxidase (NOX) has been implicated in the development of pulmonary hypertension, we hypothesized that vascular smooth muscle (VSM) depolarization increases NOX-derived O(2)(-) production leading to myofilament Ca(2+) sensitization and augmented vasoconstrictor reactivity following CH. As epidermal growth factor receptor (EGFR) mediates Rac1-dependent NOX activation in renal mesangial cells, we further sought to examine the role EGFR plays in this response. RESULTS Vasoconstrictor responses to depolarizing concentrations of KCl were greater in lungs isolated from CH (4 wk, 0.5 atm) rats compared to normoxic controls, and this effect of CH was abolished by the general NOX inhibitor, apocynin. CH similarly augmented KCl-induced vasoconstriction and O(2)(-) generation (assessed using the fluorescent indicator, dihydroethidium) in Ca(2+)-permeabilized, pressurized small pulmonary arteries. These latter responses to CH were prevented by general inhibition of NOX isoforms (apocynin, diphenylene iodonium), and by selective inhibition of NOX 2 (gp91ds-tat), Rac1 (NSC 23766), and EGFR (AG 1478). Consistent with these observations, CH increased KCl-induced EGFR phosphorylation, and augmented depolarization-induced Rac1 activation in an EGFR-dependent manner. INNOVATION This study establishes a novel signaling axis in VSM linking membrane depolarization to contraction that is independent of Ca(2+) influx, and which mediates myofilament Ca(2+) sensitization in the hypertensive pulmonary circulation. CONCLUSION CH augments membrane depolarization-induced pulmonary VSM Ca(2+) sensitization and vasoconstriction through EGFR-dependent stimulation of Rac1 and NOX 2.
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Affiliation(s)
- Charles E Norton
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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16
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Diminished Pulmonary Expression of Hypoxia-Inducible Factor 2- α, Vascular Endothelial Growth Factor and Hepatocyte Growth Factor in Chickens Exposed to Chronic Hypobaric Hypoxia. J Poult Sci 2012. [DOI: 10.2141/jpsa.011036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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17
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Ahlfeld SK, Conway SJ. Aberrant signaling pathways of the lung mesenchyme and their contributions to the pathogenesis of bronchopulmonary dysplasia. ACTA ACUST UNITED AC 2011; 94:3-15. [PMID: 22125178 DOI: 10.1002/bdra.22869] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 09/09/2011] [Accepted: 09/12/2011] [Indexed: 01/12/2023]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease in infants born extremely preterm, typically before 28 weeks' gestation, characterized by a prolonged need for supplemental oxygen or positive pressure ventilation beyond 36 weeks postmenstrual age. The limited number of autopsy samples available from infants with BPD in the postsurfactant era has revealed a reduced capacity for gas exchange resulting from simplification of the distal lung structure with fewer, larger alveoli because of a failure of normal lung alveolar septation and pulmonary microvascular development. The mechanisms responsible for alveolar simplification in BPD have not been fully elucidated, but mounting evidence suggests that aberrations in the cross-talk between growth factors of the lung mesenchyme and distal airspace epithelium have a key role. Animal models that recapitulate the human condition have expanded our knowledge of the pathology of BPD and have identified candidate matrix components and growth factors in the developing lung that are disrupted by conditions that predispose infants to BPD and interfere with normal vascular and alveolar morphogenesis. This review focuses on the deviations from normal lung development that define the pathophysiology of BPD and summarizes the various candidate mesenchyme-associated proteins and growth factors that have been identified as being disrupted in animal models of BPD. Finally, future areas of research to identify novel targets affected in arrested lung development and recovery are discussed.
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Affiliation(s)
- Shawn K Ahlfeld
- Developmental Biology and Neonatal Medicine Program, H.B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
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18
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Kramer EL, Hardie WD, Mushaben EM, Acciani TH, Pastura PA, Korfhagen TR, Hershey GK, Whitsett JA, Le Cras TD. Rapamycin decreases airway remodeling and hyperreactivity in a transgenic model of noninflammatory lung disease. J Appl Physiol (1985) 2011; 111:1760-7. [PMID: 21903885 DOI: 10.1152/japplphysiol.00737.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Airway hyperreactivity (AHR) and remodeling are cardinal features of asthma and chronic obstructive pulmonary disease. New therapeutic targets are needed as some patients are refractory to current therapies and develop progressive airway remodeling and worsening AHR. The mammalian target of rapamycin (mTOR) is a key regulator of cellular proliferation and survival. Treatment with the mTOR inhibitor rapamycin inhibits inflammation and AHR in allergic asthma models, but it is unclear if rapamycin can directly inhibit airway remodeling and AHR, or whether its therapeutic effects are entirely mediated through immunosuppression. To address this question, we utilized transforming growth factor-α (TGF-α) transgenic mice null for the transcription factor early growth response-1 (Egr-1) (TGF-α Tg/Egr-1(ko/ko) mice). These mice develop airway smooth muscle thickening and AHR in the absence of altered lung inflammation, as previously reported. In this study, TGF-α Tg/Egr-1(ko/ko) mice lost body weight and developed severe AHR after 3 wk of lung-specific TGF-α induction. Rapamycin treatment prevented body weight loss, airway wall thickening, abnormal lung mechanics, and increases in airway resistance to methacholine after 3 wk of TGF-α induction. Increases in tissue damping and airway elastance were also attenuated in transgenic mice treated with rapamycin. TGF-α/Egr-1(ko/ko) mice on doxycycline for 8 wk developed severe airway remodeling. Immunostaining for α-smooth muscle actin and morphometric analysis showed that rapamycin treatment prevented airway smooth muscle thickening around small airways. Pentachrome staining, assessments of lung collagen and fibronectin mRNA levels, indicated that rapamycin also attenuated fibrotic pathways induced by TGF-α expression for 8 wk. Thus rapamycin reduced airway remodeling and AHR, demonstrating an important role for mTOR signaling in TGF-α-induced/EGF receptor-mediated reactive airway disease.
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Affiliation(s)
- Elizabeth L Kramer
- Section of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
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19
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Abstract
Our understanding of, and approach to, pulmonary arterial hypertension has undergone a paradigm shift in the past decade. Once a condition thought to be dominated by increased vasoconstrictor tone and thrombosis, pulmonary arterial hypertension is now seen as a vasculopathy in which structural changes driven by excessive vascular cell growth and inflammation, with recruitment and infiltration of circulating cells, play a major role. Perturbations of a number of molecular mechanisms have been described, including pathways involving growth factors, cytokines, metabolic signaling, elastases, and proteases, that may underlie the pathogenesis of the disease. Elucidating their contribution to the pathophysiology of pulmonary arterial hypertension could offer new drug targets. The role of progenitor cells in vascular repair is also under active investigation. The right ventricular response to increased pressure load is recognized as critical to survival and the molecular mechanisms involved are attracting increasing interest. The challenge now is to integrate this new knowledge and explore how it can be used to categorize patients by molecular phenotype and tailor treatment more effectively.
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Affiliation(s)
- Ralph T. Schermuly
- Max-Planck-Institute for Heart and Lung Research, Parkstrasse 1, Bad Nauheim, 61231 Germany
| | - Hossein A. Ghofrani
- University Hospital Giessen and Marburg, University of Giessen Lung Center, Klinikstrasse 36, Giessen, 35392 Germany
| | - Martin R. Wilkins
- Division of Experimental Medicine, Centre for Pharmacology and Therapeutics, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN UK
| | - Friedrich Grimminger
- University Hospital Giessen and Marburg, University of Giessen Lung Center, Klinikstrasse 36, Giessen, 35392 Germany
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20
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The role of transforming growth factors beta1 and beta3 in pre- and post-natal pulmonary surfactant development. Cell Biol Int 2011; 35:287-92. [DOI: 10.1042/cbi20090486] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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A Quantitative Study of the Pulmonary Vascular Bed and Pulmonary Weight: Body Weight Ratio in Chickens Exposed to Relative Normoxia and Chronic Hypobaric Hypoxia. J Poult Sci 2011. [DOI: 10.2141/jpsa.011030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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A role for epidermal growth factor receptor in idiopathic pulmonary fibrosis onset. Mol Biol Rep 2010; 38:4613-7. [DOI: 10.1007/s11033-010-0594-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 11/20/2010] [Indexed: 10/18/2022]
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23
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Dahal BK, Cornitescu T, Tretyn A, Pullamsetti SS, Kosanovic D, Dumitrascu R, Ghofrani HA, Weissmann N, Voswinckel R, Banat GA, Seeger W, Grimminger F, Schermuly RT. Role of Epidermal Growth Factor Inhibition in Experimental Pulmonary Hypertension. Am J Respir Crit Care Med 2010; 181:158-67. [DOI: 10.1164/rccm.200811-1682oc] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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24
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Warburton D, El-Hashash A, Carraro G, Tiozzo C, Sala F, Rogers O, De Langhe S, Kemp PJ, Riccardi D, Torday J, Bellusci S, Shi W, Lubkin SR, Jesudason E. Lung organogenesis. Curr Top Dev Biol 2010; 90:73-158. [PMID: 20691848 DOI: 10.1016/s0070-2153(10)90003-3] [Citation(s) in RCA: 297] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Developmental lung biology is a field that has the potential for significant human impact: lung disease at the extremes of age continues to cause major morbidity and mortality worldwide. Understanding how the lung develops holds the promise that investigators can use this knowledge to aid lung repair and regeneration. In the decade since the "molecular embryology" of the lung was first comprehensively reviewed, new challenges have emerged-and it is on these that we focus the current review. Firstly, there is a critical need to understand the progenitor cell biology of the lung in order to exploit the potential of stem cells for the treatment of lung disease. Secondly, the current familiar descriptions of lung morphogenesis governed by growth and transcription factors need to be elaborated upon with the reinclusion and reconsideration of other factors, such as mechanics, in lung growth. Thirdly, efforts to parse the finer detail of lung bud signaling may need to be combined with broader consideration of overarching mechanisms that may be therapeutically easier to target: in this arena, we advance the proposal that looking at the lung in general (and branching in particular) in terms of clocks may yield unexpected benefits.
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Affiliation(s)
- David Warburton
- The Saban Research Institute, Childrens Hospital Los Angeles, Los Angeles, California, USA
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25
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Le Cras TD, Korfhagen TR, Davidson C, Schmidt S, Fenchel M, Ikegami M, Whitsett JA, Hardie WD. Inhibition of PI3K by PX-866 prevents transforming growth factor-alpha-induced pulmonary fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 176:679-86. [PMID: 20042669 DOI: 10.2353/ajpath.2010.090123] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Transforming growth factor-alpha (TGFalpha) is a ligand for the epidermal growth factor receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. EGFR signaling activates several intracellular signaling pathways including phosphatidylinositol 3'-kinase (PI3K). We previously showed that induction of lung-specific TGFalpha expression in transgenic mice caused progressive pulmonary fibrosis over a 4-week period. The increase in levels of phosphorylated Akt, detected after 1 day of doxycycline-induced TGFalpha expression, was blocked by treatment with the PI3K inhibitor, PX-866. Daily administration of PX-866 during TGFalpha induction prevented increases in lung collagen and airway resistance as well as decreases in lung compliance. Treatment of mice with oral PX-866 4 weeks after the induction of TGFalpha prevented additional weight loss and further increases in total collagen, and attenuated changes in pulmonary mechanics. These data show that PI3K is activated in TGFalpha/EGFR-mediated pulmonary fibrosis and support further studies to determine the role of PI3K activation in human lung fibrotic disease, which could be amenable to targeted therapy.
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Affiliation(s)
- Timothy D Le Cras
- Divisions of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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26
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Le Merrer J, Becker JAJ, Befort K, Kieffer BL. Reward processing by the opioid system in the brain. Physiol Rev 2009; 89:1379-412. [PMID: 19789384 DOI: 10.1152/physrev.00005.2009] [Citation(s) in RCA: 674] [Impact Index Per Article: 44.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The opioid system consists of three receptors, mu, delta, and kappa, which are activated by endogenous opioid peptides processed from three protein precursors, proopiomelanocortin, proenkephalin, and prodynorphin. Opioid receptors are recruited in response to natural rewarding stimuli and drugs of abuse, and both endogenous opioids and their receptors are modified as addiction develops. Mechanisms whereby aberrant activation and modifications of the opioid system contribute to drug craving and relapse remain to be clarified. This review summarizes our present knowledge on brain sites where the endogenous opioid system controls hedonic responses and is modified in response to drugs of abuse in the rodent brain. We review 1) the latest data on the anatomy of the opioid system, 2) the consequences of local intracerebral pharmacological manipulation of the opioid system on reinforced behaviors, 3) the consequences of gene knockout on reinforced behaviors and drug dependence, and 4) the consequences of chronic exposure to drugs of abuse on expression levels of opioid system genes. Future studies will establish key molecular actors of the system and neural sites where opioid peptides and receptors contribute to the onset of addictive disorders. Combined with data from human and nonhuman primate (not reviewed here), research in this extremely active field has implications both for our understanding of the biology of addiction and for therapeutic interventions to treat the disorder.
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Affiliation(s)
- Julie Le Merrer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Département Neurobiologie et Génétique, Illkirch, France
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27
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Jin N, Cho SN, Raso MG, Wistuba I, Smith Y, Yang Y, Kurie JM, Yen R, Evans CM, Ludwig T, Jeong JW, DeMayo FJ. Mig-6 is required for appropriate lung development and to ensure normal adult lung homeostasis. Development 2009; 136:3347-56. [PMID: 19710174 DOI: 10.1242/dev.032979] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitogen-inducible gene 6 [Mig-6; Errfi1 (ErbB receptor feedback inhibitor 1); RALT (receptor-associated late transducer); gene 33] is a ubiquitously expressed adaptor protein containing CRIB, SH3 and 14-3-3 interacting domains and has been shown to negatively regulate EGF signaling. Ablation of Mig-6 results in a partial lethal phenotype in which surviving mice acquire degenerative joint diseases and tumors in multiple organs. We have determined that the early lethality in Mig-6(-/-) mice occurs in the perinatal period, with mice displaying abnormal lung development. Histological examination of Mig-6(-/-) lungs (E15.5-P3) revealed reduced septation, airway over-branching, alveolar type II cell hyperplasia, and disturbed vascular formation. In neonatal Mig-6(-/-) lungs, cell proliferation increased in the airway epithelium but apoptosis increased in the blood vessels. Adult Mig-6(-/-) mice developed features of chronic obstructive pulmonary disease (COPD); however, when Mig-6 was inducibly ablated in adult mice (Mig-6(d/d)), the lungs were normal. Knockdown of MIG-6 in H441 human bronchiolar epithelial cells increased phospho-EGFR and phospho-AKT levels as well as cell proliferation, whereas knockdown of MIG-6 in human lung microvascular endothelial (HMVEC-L) cells promoted their apoptosis. These results demonstrate that Mig-6 is required for prenatal and perinatal lung development, in part through the regulation of EGF signaling, as well as for maintaining proper pulmonary vascularization.
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Affiliation(s)
- Nili Jin
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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28
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Kramer EL, Mushaben EM, Pastura PA, Acciani TH, Deutsch GH, Khurana Hershey GK, Korfhagen TR, Hardie WD, Whitsett JA, Le Cras TD. Early growth response-1 suppresses epidermal growth factor receptor-mediated airway hyperresponsiveness and lung remodeling in mice. Am J Respir Cell Mol Biol 2009; 41:415-25. [PMID: 19188657 DOI: 10.1165/rcmb.2008-0470oc] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Transforming growth factor (TGF)-alpha and its receptor, the epidermal growth factor receptor, are induced after lung injury and are associated with remodeling in chronic pulmonary diseases, such as pulmonary fibrosis and asthma. Expression of TGF-alpha in the lungs of adult mice causes fibrosis, pleural thickening, and pulmonary hypertension, in addition to increased expression of a transcription factor, early growth response-1 (Egr-1). Egr-1 was increased in airway smooth muscle (ASM) and the vascular adventitia in the lungs of mice conditionally expressing TGF-alpha in airway epithelium (Clara cell secretory protein-rtTA(+/-)/[tetO](7)-TGF-alpha(+/-)). The goal of this study was to determine the role of Egr-1 in TGF-alpha-induced lung disease. To accomplish this, TGF-alpha-transgenic mice were crossed to Egr-1 knockout (Egr-1(ko/ko)) mice. The lack of Egr-1 markedly increased the severity of TGF-alpha-induced pulmonary disease, dramatically enhancing airway muscularization, increasing pulmonary fibrosis, and causing greater airway hyperresponsiveness to methacholine. Smooth muscle hyperplasia, not hypertrophy, caused the ASM thickening in the absence of Egr-1. No detectable increases in pulmonary inflammation were found. In addition to the airway remodeling disease, vascular remodeling and pulmonary hypertension were also more severe in Egr-1(ko/ko) mice. Thus, Egr-1 acts to suppress epidermal growth factor receptor-mediated airway and vascular muscularization, fibrosis, and airway hyperresponsiveness in the absence of inflammation. This provides a unique model to study the processes causing pulmonary fibrosis and ASM thickening without the complicating effects of inflammation.
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Affiliation(s)
- Elizabeth L Kramer
- Section of Neonatology, Perinatal & Pulmonary Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA
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Zhu M, Cho YK, Li CS. Activation of delta-opioid receptors reduces excitatory input to putative gustatory cells within the nucleus of the solitary tract. J Neurophysiol 2008; 101:258-68. [PMID: 19019978 DOI: 10.1152/jn.90648.2008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The rostral nucleus of the solitary tract (NST) is the first central relay in the gustatory pathway and plays a key role in processing and modulation of gustatory information. Here, we investigated the effects of opioid receptor agonists and antagonists on synaptic responses of the gustatory parabrachial nuclei (PbN)-projecting neurons in the rostral NST to electrical stimulation of the solitary tract (ST) using whole cell recordings in the hamster brain stem slices. ST-evoked excitatory postsynaptic currents (EPSCs) were significantly reduced by met-enkephalin (MetE) in a concentration-dependent fashion and this effect was eliminated by naltrexone hydrochloride, a nonselective opioid receptor antagonist. Bath application of naltrindole hydrochloride, a selective delta-opioid receptor antagonist, eliminated MetE-induced reduction of EPSCs, whereas CTOP, a selective mu-opioid receptor antagonist had no effect, indicating that delta-opioid receptors are involved in the reduction of ST-evoked EPSCs induced by MetE. SNC80, a selective delta-opioid receptor agonist, mimicked the effect of MetE. The SNC80-induced reduction of ST-evoked EPSCs was eliminated by 7-benzylidenenaltrexone, a selective delta1-opioid receptor antagonist but not by naltriben mesylate, a selective delta2-opioid receptor antagonist, indicating that delta1-opioid receptors mediate the reduction of ST-evoked EPSCs induced by SNC80. Single-cell reverse transcriptase-polymerase chain reaction analysis revealed the presence of delta1-opioid receptor mRNA in cells that responded to SNC80 with a reduction in ST-evoked EPSCs. Moreover, Western blot analysis demonstrated the presence of 40-kDa delta-opioid receptor proteins in the rostral NST tissue. These results suggest that postsynaptic delta1-opioid receptors are involved in opioid-induced reduction of ST-evoked EPSCs of PbN-projecting rostral NST cells.
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Affiliation(s)
- Mingyan Zhu
- Department of Anatomy, Southern Illinois University School of Medicine, Life Science III Room 2073, 1135 Lincoln Dr., Carbondale, IL 62901, USA
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30
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Abstract
Inflammation is important in the development of bronchopulmonary dysplasia (BPD). Polymorphonuclear cells and macrophages and proinflammatory cytokines/chemokines denote early inflammation in clinical scenarios such as in utero inflammation with chorioamnionitis or initial lung injury associated with respiratory distress syndrome or ventilator-induced lung injury. The persistence and non-resolution of lung inflammation contributes greatly to BPD, including altering the lung's ability to repair, contributing to fibrosis, and inhibiting secondary septation, alveolarization, and normal vascular development. Further understanding of the role of inflammation in the pathogenesis of BPD, in particular, during the chronic inflammatory period, offers us the opportunity to develop inflammation-related prevention and treatment strategies of this disease that has long-standing consequences for very premature infants.
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Hardie WD, Davidson C, Ikegami M, Leikauf GD, Le Cras TD, Prestridge A, Whitsett JA, Korfhagen TR. EGF receptor tyrosine kinase inhibitors diminish transforming growth factor-α-induced pulmonary fibrosis. Am J Physiol Lung Cell Mol Physiol 2008; 294:L1217-25. [DOI: 10.1152/ajplung.00020.2008] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Transforming growth factor-α (TGF-α) is a ligand for the EGF receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. We determined the effects of EGFR tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) on the development and progression of TGF-α-induced pulmonary fibrosis. Using a doxycycline-regulatable transgenic mouse model of lung-specific TGF-α expression, we determined effects of treatment with gefitinib and erlotinib on changes in lung histology, total lung collagen, pulmonary mechanics, pulmonary hypertension, and expression of genes associated with synthesis of ECM and vascular remodeling. Induction in the lung of TGF-α caused progressive pulmonary fibrosis over an 8-wk period. Daily administration of gefitinib or erlotinib prevented development of fibrosis, reduced accumulation of total lung collagen, prevented weight loss, and prevented changes in pulmonary mechanics. Treatment of mice with gefitinib 4 wk after the induction of TGF-α prevented further increases in and partially reversed total collagen levels and changes in pulmonary mechanics and pulmonary hypertension. Increases in expression of genes associated with synthesis of ECM as well as decreases of genes associated with vascular remodeling were also prevented or partially reversed. Administration of gefitinib or erlotinib did not cause interstitial fibrosis or increases in lavage cell counts. Administration of small molecule EGFR tyrosine kinase inhibitors prevented further increases in and partially reversed pulmonary fibrosis induced directly by EGFR activation without inducing inflammatory cell influx or additional lung injury.
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Xu M, Platoshyn O, Makino A, Dillmann WH, Akassoglou K, Remillard CV, Yuan JXJ. Characterization of agonist-induced vasoconstriction in mouse pulmonary artery. Am J Physiol Heart Circ Physiol 2007; 294:H220-8. [PMID: 17982012 DOI: 10.1152/ajpheart.00968.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In recent years, transgenic mouse models have been developed to examine the underlying cellular and molecular mechanisms of lung disease and pulmonary vascular disease, such as asthma, pulmonary thromboembolic disease, and pulmonary hypertension. However, there has not been systematic characterization of the basic physiological pulmonary vascular reactivity in normal and transgenic mice. This represents an intellectual "gap", since it is important to characterize basic murine pulmonary vascular reactivity in response to various contractile and relaxant factors to which the pulmonary vasculature is exposed under physiological conditions. The present study evaluates excitation- and pharmacomechanical-contraction coupling in pulmonary arteries (PA) isolated from wild-type BALB/c mice. We demonstrate that both pharmaco- and electromechanical coupling mechanisms exist in mice PA. These arteries are also reactive to stimulation by alpha(1)-adrenergic agonists, serotonin, endothelin-1, vasopressin, and U-46619 (a thromboxane A(2) analog). We conclude that the basic vascular responsiveness of mouse PA is similar to those observed in PA of other species, including rat, pig, and human, albeit on a different scale and to varying amplitudes.
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Affiliation(s)
- Minlin Xu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0725, USA
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Kramer EL, Deutsch GH, Sartor MA, Hardie WD, Ikegami M, Korfhagen TR, Le Cras TD. Perinatal increases in TGF-α disrupt the saccular phase of lung morphogenesis and cause remodeling: microarray analysis. Am J Physiol Lung Cell Mol Physiol 2007; 293:L314-27. [PMID: 17468132 DOI: 10.1152/ajplung.00354.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Transforming growth factor-α (TGF-α) and its receptor, the epithelial growth factor receptor (EGFR), have been associated with lung remodeling in premature infants with bronchopulmonary dysplasia (BPD). The goal of this study was to target TGF-α overexpression to the saccular phase of lung morphogenesis and determine early alterations in gene expression. Conditional lung-specific TGF-α bitransgenic mice and single-transgene control mice were generated. TGF-α overexpression was induced by doxycycline (Dox) treatment from embryonic day 16.5 (E16.5) to E18.5. After birth, all bitransgenic pups died by postnatal day 7 (P7). Lung histology at E18.5 and P1 showed abnormal lung morphogenesis in bitransgenic mice, characterized by mesenchymal thickening, vascular remodeling, and poor apposition of capillaries to distal air spaces. Surfactant levels (saturated phosphatidylcholine) were not reduced in bitransgenic mice. Microarray analysis was performed after 1 or 2 days of Dox treatment during the saccular (E17.5, E18.5) and alveolar phases (P4, P5) to identify genes induced by EGFR signaling that were shared or unique to each phase. We found 196 genes to be altered (>1.5-fold change; P < 0.01 for at least 2 time points), with only 32% similarly altered in both saccular and alveolar phases. Western blot analysis and immunostaining showed that five genes selected from the microarrays (egr-1, SP-B, SP-D, S100A4, and pleiotrophin) were also increased at the protein level. Pathological changes in TGF-α-overexpressing mice bore similarities to premature infants born in the saccular phase who develop BPD, including remodeling of the distal lung septae and arteries.
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Affiliation(s)
- Elizabeth L Kramer
- Section of Neonatology, Perinatal and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Abstract
AIM This is the first systematic study using quantitative real-time PCR to analyze and compare the expression profiles for critical members of the epidermal growth factor (EGF), transforming growth factor beta (TGFbeta), and vascular endothelial growth factor (VEGF) families in developing rat lungs. METHODS mRNA expression was quantified at embryonic (E) day 15, 17, 19, 21, and postnatal age 1 day, 2 weeks, 12 weeks. RESULTS EGF and EGFR increased during gestation and development, then decreased in adulthood, whereas TGFalpha was highest at birth and remained unchanged afterwards. All TGFbeta isoforms increased slightly during pregnancy, reached highest expression during development, and returned to neonatal levels in adulthood. TGFbetaRI and TGFbetaRII patterns were similar to TGFbeta2 and TGFbeta1 respectively, whereas TGFbetaRIII expression was lowest at the postnatal time points. VEGF(164) and VEGF(120) showed a steady increase up to 2 weeks and declined at 12 weeks, whereas highest VEGF(188) expression occurred at 12 weeks. VEGF-A receptors expression paralleled the summation of all three isoforms, increasing steadily with age. CONCLUSION Expression of growth factors in the developing lung is characterized by highly regulated distinctive patterns that may be critical to understand the early origin and progression of pulmonary diseases in childhood as well as in adulthood. Quantitative real-time PCR analysis revealed several differences compared to previously reported expression patterns defined with older methodologies.
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Affiliation(s)
- Edward M Mager
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
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35
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Ko EA, Burg ED, Platoshyn O, Msefya J, Firth AL, Yuan JXJ. Functional characterization of voltage-gated K+ channels in mouse pulmonary artery smooth muscle cells. Am J Physiol Cell Physiol 2007; 293:C928-37. [PMID: 17581857 DOI: 10.1152/ajpcell.00101.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mice are useful animal models to study pathogenic mechanisms involved in pulmonary vascular disease. Altered expression and function of voltage-gated K(+) (K(V)) channels in pulmonary artery smooth muscle cells (PASMCs) have been implicated in the development of pulmonary arterial hypertension. K(V) currents (I(K(V))) in mouse PASMCs have not been comprehensively characterized. The main focus of this study was to determine the biophysical and pharmacological properties of I(K(V)) in freshly dissociated mouse PASMCs with the patch-clamp technique. Three distinct whole cell I(K(V)) were identified based on the kinetics of activation and inactivation: rapidly activating and noninactivating currents (in 58% of the cells tested), rapidly activating and slowly inactivating currents (23%), and slowly activating and noninactivating currents (17%). Of the cells that demonstrated the rapidly activating noninactivating current, 69% showed I(K(V)) inhibition with 4-aminopyridine (4-AP), while 31% were unaffected. Whole cell I(K(V)) were very sensitive to tetraethylammonium (TEA), as 1 mM TEA decreased the current amplitude by 32% while it took 10 mM 4-AP to decrease I(K(V)) by a similar amount (37%). Contribution of Ca(2+)-activated K(+) (K(Ca)) channels to whole cell I(K(V)) was minimal, as neither pharmacological inhibition with charybdotoxin or iberiotoxin nor perfusion with Ca(2+)-free solution had an effect on the whole cell I(K(V)). Steady-state activation and inactivation curves revealed a window K(+) current between -40 and -10 mV with a peak at -31.5 mV. Single-channel recordings revealed large-, intermediate-, and small-amplitude currents, with an averaged slope conductance of 119.4 +/- 2.7, 79.8 +/- 2.8, 46.0 +/- 2.2, and 23.6 +/- 0.6 pS, respectively. These studies provide detailed electrophysiological and pharmacological profiles of the native K(V) currents in mouse PASMCs.
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Affiliation(s)
- Eun A Ko
- Div. of Pulmonary and Critical Care Medicine, Dept. of Medicine, Univ. of California, San Diego, 9500 Gilman Dr., MC 0725, La Jolla, CA 92093-0725, USA
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36
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Hardie WD, Korfhagen TR, Sartor MA, Prestridge A, Medvedovic M, Le Cras TD, Ikegami M, Wesselkamper SC, Davidson C, Dietsch M, Nichols W, Whitsett JA, Leikauf GD. Genomic profile of matrix and vasculature remodeling in TGF-alpha induced pulmonary fibrosis. Am J Respir Cell Mol Biol 2007; 37:309-21. [PMID: 17496152 PMCID: PMC1994231 DOI: 10.1165/rcmb.2006-0455oc] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Expression of transforming growth factor alpha (TGF-alpha) in the respiratory epithelium of transgenic mice caused pulmonary fibrosis, cachexia, pulmonary hypertension, and altered lung function. To identify genes and molecular pathways mediating lung remodeling, mRNA microarray analysis was performed at multiple times after TGF-alpha expression and revealed changes consistent with a role for TGF-alpha in the regulation of extracellular matrix and vasculogenesis. Transcripts for extracellular matrix proteins were augmented along with transcripts for genes previously identified to have roles in pulmonary fibrosis, including tenascin C, osteopontin, and serine (or cysteine) peptidase inhibitor, clade F, member 1. Transcripts regulating vascular processes including endothelin receptor type B, endothelial-specific receptor tyrosine kinase, and caveolin, caveolae protein 1 were decreased. When TGF-alpha expression was no longer induced, lung remodeling partially reversed and lung function and pulmonary hypertension normalized. Transcripts increased during resolution included midkine, matrix metalloproteinase 2, and hemolytic complement. Hierarchical clustering revealed that genes regulated by TGF-alpha were similar to those altered in the lungs of patients with idiopathic pulmonary fibrosis. These studies support a role for epithelial cell-derived TGF-alpha in the regulation of processes that alter the airway and vascular architecture and function.
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MESH Headings
- Animals
- Blood Pressure
- Doxycycline/pharmacology
- Extracellular Matrix/genetics
- Female
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Humans
- Hypertension, Pulmonary/genetics
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/physiopathology
- Hypertrophy, Right Ventricular/genetics
- Hypertrophy, Right Ventricular/pathology
- Hypertrophy, Right Ventricular/physiopathology
- Lung/blood supply
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Oligonucleotide Array Sequence Analysis
- Pulmonary Fibrosis/etiology
- Pulmonary Fibrosis/genetics
- Pulmonary Fibrosis/pathology
- Pulmonary Fibrosis/physiopathology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Respiratory Mechanics
- Transforming Growth Factor alpha/genetics
- Transforming Growth Factor alpha/physiology
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Affiliation(s)
- William D Hardie
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, Ohio 45229, USA.
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37
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Abstract
Advances in genetic engineering have allowed the creation of animals with additional or deleted genes. New genes may be inserted in mice, specific genes inactivated or "knocked out," and more complex animals created in which genes can be turned on or off at different times in development or in different tissues. These animal models allow for more detailed studies of the proteins encoded by the manipulated gene, an improved understanding of the pathophysiology of diseases resulting from the genetic alterations, and model organisms in which to study potential new therapies. Multiple mouse models involving genes important in surfactant production and regulation relevant to lung disease observed in human newborns have been created. This review will discuss the creation of such animals and illustrate their utility in understanding human disease.
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Affiliation(s)
- Stephan W Glasser
- Division of Pulmonary Biology, Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
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38
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Fantozzi I, Platoshyn O, Wong AH, Zhang S, Remillard CV, Furtado MR, Petrauskene OV, Yuan JXJ. Bone morphogenetic protein-2 upregulates expression and function of voltage-gated K+ channels in human pulmonary artery smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2006; 291:L993-1004. [PMID: 16815889 DOI: 10.1152/ajplung.00191.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activity of voltage-gated K(+) (K(V)) channels in pulmonary artery smooth muscle cells (PASMC) plays an important role in control of apoptosis and proliferation in addition to regulating membrane potential and pulmonary vascular tone. Bone morphogenetic proteins (BMPs) inhibit proliferation and induce apoptosis in normal human PASMC, whereas dysfunctional BMP signaling and downregulated K(V) channels are involved in pulmonary vascular medial hypertrophy associated with pulmonary hypertension. This study evaluated the effect of BMP-2 on K(V) channel function and expression in normal human PASMC. BMP-2 (100 nM for 18-24 h) significantly (>2-fold) upregulated mRNA expression of KCNA5, KCNA7, KCNA10, KCNC3, KCNC4, KCNF1, KCNG3, KCNS1, and KCNS3 but downregulated (at least 2-fold) KCNAB1, KCNA2, KCNG2, and KCNV2. The most dramatic change was the >10-fold downregulation of KCNG2 and KCNV2, two electrically silent gamma-subunits that form heterotetramers with functional K(V) channel alpha-subunits (e.g., KCNB1-2). Furthermore, the amplitude and current density of whole cell K(V) currents were significantly increased in PASMC treated with BMP-2. It has been demonstrated that K(+) currents generated by KCNB1 and KCNG1 (or KCNG2) or KCNB1 and KCNV2 heterotetramers are smaller than those generated by KCNB1 homotetramers, indicating that KCNG2 and KCNV2 (2 subunits that were markedly downregulated by BMP-2) are inhibitors of functional K(V) channels. These results suggest that BMP-2 divergently regulates mRNA expression of various K(V) channel alpha-, beta-, and gamma-subunits and significantly increases whole cell K(V) currents in human PASMC. Finally, we present evidence that attenuation of c-Myc expression by BMP-2 may be involved in BMP-2-mediated increase in K(V) channel activity and regulation of K(V) channel expression. The increased K(V) channel activity may be involved in the proapoptotic and/or antiproliferative effects of BMP-2 on PASMC.
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MESH Headings
- Apoptosis/physiology
- Bone Morphogenetic Protein 2
- Bone Morphogenetic Proteins/metabolism
- Bone Morphogenetic Proteins/pharmacology
- Cells, Cultured
- Gene Expression/drug effects
- Gene Expression/physiology
- Humans
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Patch-Clamp Techniques
- Potassium/metabolism
- Potassium Channels, Voltage-Gated/genetics
- Potassium Channels, Voltage-Gated/metabolism
- Protein Subunits/genetics
- Protein Subunits/metabolism
- Proto-Oncogene Proteins c-myc/genetics
- Proto-Oncogene Proteins c-myc/metabolism
- Pulmonary Artery/cytology
- Pulmonary Artery/drug effects
- Pulmonary Artery/physiology
- RNA, Messenger/metabolism
- Transforming Growth Factor beta/metabolism
- Transforming Growth Factor beta/pharmacology
- Up-Regulation/physiology
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Affiliation(s)
- Ivana Fantozzi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of California San Diego, 9500 Gilman Drive, MC 0725, La Jolla, 92093-0725, USA
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39
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Sanderson MP, Dempsey PJ, Dunbar AJ. Control of ErbB signaling through metalloprotease mediated ectodomain shedding of EGF-like factors. Growth Factors 2006; 24:121-36. [PMID: 16801132 DOI: 10.1080/08977190600634373] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Epidermal growth factor (EGF)-like proteins comprise a group of structurally similar growth factors, which contain a conserved six-cysteine residue motif called the EGF-domain. EGF-like factors are synthesized as transmembrane precursors, which can undergo proteolytic cleavage at the cell surface to release a mature soluble ectodomain; a process often referred to as "ectodomain shedding". Ectodomain shedding of EGF-like factors has been linked to multiple zinc-binding metalloproteases of the matrix metalloprotease (MMP) and a disintegrin and metalloprotease (ADAM) families. Shedding can be activated by a variety of pharmacological and physiological stimuli and these activation events have been linked to the enhancement of metalloprotease activity, possibly via the action of intracellular signaling modules. Once shed from the cell surface, EGF-like factors bind to a family of four cell surface receptors named ErbB-1, -2, -3 and -4. Heterodimerization or homodimerization of these receptors following ligand binding drives intracellular signal transduction cascades, which eventuate in diverse cell fates including proliferation, differentiation, migration and inhibition of apoptosis. In addition to its role in driving normal developmental processes, a wealth of evidence now exists showing that de-regulated ErbB signaling is associated with the formation of tumors in a variety of tissues and that ectodomain shedding of EGF-like factors plays a critical event in this process. Thus, knowledge of the molecular mechanisms by which EGF-like factors are shed from the cell surface and the nature of the proteases and cellular signals that govern this process is crucial to understanding ErbB receptor signaling and potentially also in the development of novel cancer therapeutics targeting the ErbB pathway. This review focuses on the structure and function of EGF-like factors, and the mechanisms that govern the shedding of these transmembrane molecules from the cell surface.
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Affiliation(s)
- Michael P Sanderson
- Tumor Immunology Programme, German Cancer Research Centre, Heidelberg, Germany
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40
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Abstract
Organized and coordinated lung development follows transcriptional regulation of a complex set of cell-cell and cell-matrix interactions resulting in a blood-gas interface ready for physiologic gas exchange at birth. Transcription factors, growth factors, and various other signaling molecules regulate epithelial-mesenchymal interactions by paracrine and autocrine mechanisms. Transcriptional control at the earliest stages of lung development results in cell differentiation and cell commitment in the primitive lung bud, in essence setting up a framework for pattern formation and branching morphogenesis. Branching morphogenesis results in the formation of the conductive airway system, which is critical for alveolization. Lung development is influenced at all stages by spatial and temporal distribution of various signaling molecules and their receptors and also by the positive and negative control of signaling by paracrine, autocrine, and endocrine mechanisms. Lung bud formation, cell differentiation, and its interaction with the splanchnic mesoderm are regulated by HNF-3beta, Shh, Nkx2.1, HNF-3/Forkhead homolog-8 (HFH-8), Gli, and GATA transcription factors. HNF-3beta regulates Nkx2.1, a transcription factor critical to the formation of distal pulmonary structures. Nkx2.1 regulates surfactant protein genes that are important for the development of alveolar stability at birth. Shh, produced by the foregut endoderm, regulates lung morphogenesis signaling through Gli genes expressed in the mesenchyme. FGF10, produced by the mesoderm, regulates branching morphogenesis via its receptors on the lung epithelium. Alveolization and formation of the capillary network are influenced by various factors that include PDGF, vascular endothelial growth factor (VEGF), and retinoic acid. Epithelial-endothelial interactions during lung development are important in establishing a functional blood-gas interface. The effects of various growth factors on lung development have been demonstrated by gain- or loss-of-function studies in null mutant and transgenic mice models. Understanding the role of growth factors and various other signaling molecules and their cellular interactions in lung development will provide us with new insights into the pathogenesis of bronchopulmonary dysplasia and disorders of lung morphogenesis.
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Affiliation(s)
- Vasanth H Kumar
- Department of Pediatrics (Neonatology), State University of New York, The Women & Children's Hospital of Buffalo, Buffalo, New York, USA
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41
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Schneider MR, Dahlhoff M, Herbach N, Renner-Mueller I, Dalke C, Puk O, Graw J, Wanke R, Wolf E. Betacellulin overexpression in transgenic mice causes disproportionate growth, pulmonary hemorrhage syndrome, and complex eye pathology. Endocrinology 2005; 146:5237-46. [PMID: 16179416 DOI: 10.1210/en.2005-0418] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The EGF family comprises a network of ligands and receptors that regulate proper development and elicit diverse functions in physiology and pathology. Betacellulin (BTC) is a rather poorly characterized member of the EGF family whose in vivo effects have been linked mainly to endocrine pancreas, intestine, and mammary gland function. In vitro studies revealed that this growth factor is a potent mitogen for diverse cell types and suggested unique receptor-binding properties. Genetic ablation of BTC in mice yielded a mild phenotype, probably because of opportunistic compensation by other EGF receptor ligands. To study the biological capabilities of BTC in vivo, we generated transgenic mice overexpressing BTC ubiquitously, with highest expression levels in heart, lung, brain, and pancreas. Mice overexpressing BTC exhibit high early postnatal mortality, reduced body weight gain, and impaired longitudinal growth. In addition, a variety of pathological alterations were observed. Cataract and abnormally shaped retinal layers as well as bone alterations leading to a dome-shaped, round head form were hallmarks of BTC transgenic mice. The most important finding and the cause of reduced life expectancy of BTC transgenic mice were severe alterations of the lung. Pulmonary pathology was primarily characterized by alveolar hemorrhage, thickening of the alveolar septa, intraalveolar accumulation of hemosiderin-containing macrophages, and nodular pulmonary remodeling. Thus, our model uncovers multiple consequences of BTC overexpression in vivo. These transgenic mice provide a useful model for examining the effects of BTC excess on different organs.
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Affiliation(s)
- Marlon R Schneider
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, University of Munich, Germany.
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42
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Yong C, Bridenbaugh EA, Zawieja DC, Swartz MA. Microarray Analysis of VEGF-C Responsive Genes in Human Lymphatic Endothelial Cells. Lymphat Res Biol 2005; 3:183-207. [PMID: 16379588 DOI: 10.1089/lrb.2005.3.183] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Vascular endothelial growth factor-C (VEGF-C) is considered one of the most important factors influencing lymphatic endothelial cell biology. The goal of this work was to characterize the gene expression response by lymphatic endothelial cells (LECs) to VEGF-C. Primary cultures of human microvascular LECs were exposed to 100 ng/mL VEGF-C for 30 minutes and 6 hours, and their lysates were evaluated by microarray analysis to determine changes in mRNA expression induced by VEGF-C. Characteristic of a response to a growth factor stimulus, the largest number of differentially expressed genes were transcription factors and cell cycle related. A number of genes known to be important in angiogenesis, tumorigenesis and tumor invasion, and the transport of proteins, solutes, and lipids were also affected. Interestingly, a number of genes related to lipid metabolism as well as neurogenesis and neurodegeneration were also responsive to VEGF-C stimulation. Further analysis of these genes may not only provide insight into the molecular mechanisms underlying lymphangiogenesis and associated pathogenesis, but may also identify other important roles of VEGF-C.
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MESH Headings
- Cells, Cultured
- Cytokines/biosynthesis
- Cytokines/genetics
- Down-Regulation
- Endothelium, Lymphatic/cytology
- Endothelium, Lymphatic/metabolism
- Endothelium, Lymphatic/physiology
- Gene Expression Profiling
- Growth Substances/biosynthesis
- Growth Substances/genetics
- Humans
- Lipid Metabolism/genetics
- Male
- Morphogenesis/genetics
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neovascularization, Pathologic/genetics
- Neovascularization, Physiologic/genetics
- Nervous System/chemistry
- Nervous System/metabolism
- Oligonucleotide Array Sequence Analysis
- Protein Transport/genetics
- Receptors, Cytokine/biosynthesis
- Receptors, Cytokine/genetics
- Receptors, Growth Factor/biosynthesis
- Receptors, Growth Factor/genetics
- Up-Regulation
- Vascular Endothelial Growth Factor C/physiology
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Affiliation(s)
- Carolyn Yong
- Integrative Biosciences Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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43
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Affiliation(s)
- W A Cupples
- Centre for Biomedical Research, Department of Biology, University of Victoria, PO Box 3020, STN CSC Victoria, British Columbia, Canada V8W 3N5.
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Ikegami M, Le Cras TD, Hardie WD, Stahlman MT, Whitsett JA, Korfhagen TR. TGF-alpha perturbs surfactant homeostasis in vivo. Am J Physiol Lung Cell Mol Physiol 2005; 289:L34-43. [PMID: 15764643 DOI: 10.1152/ajplung.00407.2004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To determine potential relationships between transforming growth factor (TGF)-alpha and surfactant homeostasis, the metabolism, function, and composition of surfactant phospholipid and proteins were assessed in transgenic mice in which TGF-alpha was expressed in respiratory epithelial cells. Secretion of saturated phosphatidylcholine was decreased 40-60% by expression of TGF-alpha. Although SP-A, SP-B, and SP-C mRNA levels were unchanged by expression of TGF-alpha, SP-A and SP-B content in bronchoalveolar lavage fluid was decreased. The minimum surface tension of surfactant isolated from the transgenic mice was significantly increased. Incubation of cultured normal mice type II cells with TGF-alpha in vitro did not change secretion of surfactant phosphatidylcholine and SP-B, indicating that TGF-alpha does not directly influence surfactant secretion. Expression of a dominant negative (mutant) EGF receptor in the respiratory epithelium blocked the TGF-alpha-induced changes in lung morphology and surfactant secretion, indicating that EGF receptor signaling in distal epithelial cells was required for TGF-alpha effects on surfactant homeostasis. Because many epithelial cells were embedded in fibrotic lesions caused by TGF-alpha, changes in surfactant homeostasis may at least in part be influenced by tissue remodeling that results in decreased surfactant secretion. The number of nonembedded type II cells was decreased 30% when TGF-alpha was expressed during development and was increased threefold by TGF-alpha expression in adulthood, suggesting possible alteration of type II cells on surfactant metabolism in the adult lung. Abnormalities in surfactant function and decreased surfactant level in the airways may contribute to the pathophysiology induced by TGF-alpha in both the developing and adult lung.
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Affiliation(s)
- Machiko Ikegami
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, OH 45229-3039, USA.
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Le Cras TD, Fernandez LG, Pastura PA, Laubach VE. Vascular growth and remodeling in compensatory lung growth following right lobectomy. J Appl Physiol (1985) 2004; 98:1140-8. [PMID: 15516366 DOI: 10.1152/japplphysiol.00479.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies in animal models have shown that, following lobectomy (LBX), there is compensatory growth in the remaining lung. The vascular growth response following right LBX (R-LBX) is poorly understood. To test the hypothesis that arterial growth and remodeling occur in response to LBX, in proportion to the amount of right lung tissue removed, two (24% of lung mass; R-LBX2 group) or three right lobes (52% of lung mass; R-LBX3 group) were removed via thoracotomy from adult rats. Sham control animals underwent thoracotomy only. Arteriograms were generated 3 wk after surgery. The areas of the left lung arteriogram, arterial branching, length of arterial branches, arterial density, and arterial-to-alveolar ratios were measured. To determine whether R-LBX causes vascular remodeling and pulmonary hypertension, muscularization of arterioles and right ventricular hypertrophy were assessed. Lung weight and volume indexes were greater in R-LBX3. Arterial area of the left lung increased 26% in R-LBX2 and 47% in R-LBX3. The length of large arteries increased in R-LBX3 and to a lesser extent in R-LBX2. The ratio of distal pulmonary arteries to alveoli was similar after R-LBX2 compared with sham but was 30% lower in R-LBX3. Muscularization of arterioles increased after R-LBX3, but not in R-LBX2. Right ventricular hypertrophy increased 50-70% in R-LBX3, but not in R-LBX2. Whereas removal of three right lung lobes induced arterial growth in the left lungs of adult rats, which was proportionate to the number of lobes removed, the ratio of distal pulmonary arteries to alveoli was not normal, and vascular remodeling and pulmonary hypertension developed.
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Affiliation(s)
- Timothy D Le Cras
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039, USA.
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Le Cras TD, Hardie WD, Deutsch GH, Albertine KH, Ikegami M, Whitsett JA, Korfhagen TR. Transient induction of TGF-α disrupts lung morphogenesis, causing pulmonary disease in adulthood. Am J Physiol Lung Cell Mol Physiol 2004; 287:L718-29. [PMID: 15090366 DOI: 10.1152/ajplung.00084.2004] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Clinical studies have associated increased transforming growth factor (TGF)-α and EGF receptor with lung remodeling in diseases including bronchopulmonary dysplasia (BPD). BPD is characterized by disrupted alveolar and vascular morphogenesis, inflammation, and remodeling. To determine whether transient increases in TGF-α are sufficient to disrupt postnatal lung morphogenesis, we utilized neonatal transgenic mice conditionally expressing TGF-α. Expression of TGF-α from postnatal days 3 to 5 disrupted postnatal alveologenesis, causing permanent enlargement of distal air spaces in neonatal and adult mice. Lung volume-to-body weight ratios and lung compliance were increased in adult TGF-α transgenic mice, whereas tissue and airway elastance were reduced. Elastin fibers in the alveolar septae were fragmented and disorganized. Pulmonary vascular morphogenesis was abnormal in TGF-α mice, with attenuated and occasionally tortuous arterial branching. The ratios of right ventricle weight to left ventricle plus septal weight were increased in TGF-α mice, indicating pulmonary hypertension. Electron microscopy showed gaps in the capillary endothelium and extravasation of erythrocytes into the alveolar space of TGF-α mice. Hemorrhage and inflammatory cells were seen in distal air spaces at 1 mo of age. In adult TGF-α mice, alveolar remodeling, nodules, proteinaceous deposits, and inflammatory cells were seen. Immunostaining for pro-surfactant protein C showed that type II cells were abundant in the nodules, as well as neutrophils and macrophages. Trichrome staining showed that pulmonary fibrosis was minimal, apart from areas of nodular remodeling in adult TGF-α mice. Transient induction of TGF-α during early alveologenesis permanently disrupted lung structure and function and caused chronic lung disease.
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Affiliation(s)
- T D Le Cras
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio 45229, USA.
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Le Cras TD, Spitzmiller RE, Albertine KH, Greenberg JM, Whitsett JA, Akeson AL. VEGF causes pulmonary hemorrhage, hemosiderosis, and air space enlargement in neonatal mice. Am J Physiol Lung Cell Mol Physiol 2004; 287:L134-42. [PMID: 15033636 DOI: 10.1152/ajplung.00050.2004] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To determine whether increased levels of VEGF disrupt postnatal lung formation or function, conditional transgenic mice in which VEGF 164 expression was enhanced in respiratory epithelial cells were produced. VEGF expression was induced in the lungs of VEGF transgenic pups with doxycycline from postnatal day 1 through 2 and 6 wk of age. VEGF levels were higher in bronchoalveolar lavage fluid (BALF) and lung homogenates of VEGF transgenic mice compared with endogenous VEGF levels in controls. Neonatal mortality was increased by 50% in VEGF transgenic mice. Total protein content in BALF was elevated in VEGF transgenic mice. Surfactant protein B protein expression was unaltered in VEGF transgenic mice. Although postnatal alveolar and vascular development were not disrupted by VEGF expression, VEGF transgenic mice developed pulmonary hemorrhage, alveolar remodeling, and macrophage accumulation as early as 2 wk of age. Electron microscopy demonstrated abnormal alveolar capillary endothelium in the VEGF transgenic mice. In many locations, the endothelium was discontinuous with segments of attenuated endothelial cells. Large numbers of hemosiderin-laden macrophages and varying degrees of emphysema were observed in adult VEGF transgenic mice. Overexpression of VEGF in the neonatal lung increased infant mortality and caused pulmonary hemorrhage, hemosiderosis, alveolar remodeling, and inflammation.
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Affiliation(s)
- T D Le Cras
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, OH 45229-3039, USA.
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Wilson JD, Nicklous DM, Aloyo VJ, Simansky KJ. An orexigenic role for mu-opioid receptors in the lateral parabrachial nucleus. Am J Physiol Regul Integr Comp Physiol 2003; 285:R1055-65. [PMID: 14557237 DOI: 10.1152/ajpregu.00108.2003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The pontine parabrachial nucleus (PBN) has been implicated in regulating ingestion and contains opioids that promote feeding elsewhere in the brain. We tested the actions of the selective mu-opioid receptor (mu-OR) agonist [d-Ala2,N-Me-Phe4,Gly5-ol]enkephalin (DAMGO) in the PBN on feeding in male rats with free access to food. Infusing DAMGO (0.5-4.0 nmol/0.5 microl) into the lateral parabrachial region (LPBN) increased food intake. The hyperphagic effect was anatomically specific to infusions within the LPBN, dose and time related, and selective for ingestion of chow compared with (nonnutritive) kaolin. The nonselective opioid antagonist naloxone (0.1-10.0 nmol intra-PBN) antagonized DAMGO-induced feeding, with complete blockade by 1.0 nmol and no effect on baseline. The highly selective mu-opioid antagonist d-Phe-Cys-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP; 1.0 nmol) also prevented this action of DAMGO, but the kappa-antagonist nor-binaltorphimine did not. Naloxone and CTAP (10.0 nmol) decreased intake during scheduled feeding. Thus stimulating mu-ORs in the LPBN increases feeding, whereas antagonizing these sites inhibits feeding. Together, our results implicate mu-ORs in the LPBN in the normal regulation of food intake.
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Affiliation(s)
- John D Wilson
- Dept. of Pharmacology and Physiology, Drexel Univ. College of Medicine, Mailstop 488, 245 N. 15th St., Philadelphia, PA 19102-1192, USA
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