1
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Dada LA, Welch LC, Magnani ND, Ren Z, Han H, Brazee PL, Celli D, Flozak AS, Weng A, Herrerias MM, Kryvenko V, Vadász I, Runyan CE, Abdala-Valencia H, Shigemura M, Casalino-Matsuda SM, Misharin AV, Budinger GS, Gottardi CJ, Sznajder JI. Hypercapnia alters stroma-derived Wnt production to limit β-catenin signaling and proliferation in AT2 cells. JCI Insight 2023; 8:e159331. [PMID: 36626234 PMCID: PMC9977495 DOI: 10.1172/jci.insight.159331] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Persistent symptoms and radiographic abnormalities suggestive of failed lung repair are among the most common symptoms in patients with COVID-19 after hospital discharge. In mechanically ventilated patients with acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2 pneumonia, low tidal volumes to reduce ventilator-induced lung injury necessarily elevate blood CO2 levels, often leading to hypercapnia. The role of hypercapnia on lung repair after injury is not completely understood. Here - using a mouse model of hypercapnia exposure, cell lineage tracing, spatial transcriptomics, and 3D cultures - we show that hypercapnia limits β-catenin signaling in alveolar type II (AT2) cells, leading to their reduced proliferative capacity. Hypercapnia alters expression of major Wnts in PDGFRα+ fibroblasts from those maintaining AT2 progenitor activity toward those that antagonize β-catenin signaling, thereby limiting progenitor function. Constitutive activation of β-catenin signaling in AT2 cells or treatment of organoid cultures with recombinant WNT3A protein bypasses the inhibitory effects of hypercapnia. Inhibition of AT2 proliferation in patients with hypercapnia may contribute to impaired lung repair after injury, preventing sealing of the epithelial barrier and increasing lung flooding, ventilator dependency, and mortality.
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Affiliation(s)
- Laura A. Dada
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Lynn C. Welch
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Natalia D. Magnani
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ziyou Ren
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hyebin Han
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Patricia L. Brazee
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Diego Celli
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Annette S. Flozak
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Anthea Weng
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mariana Maciel Herrerias
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Vitalii Kryvenko
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
- The Cardio-Pulmonary Institute, Giessen, Germany
| | - István Vadász
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
- The Cardio-Pulmonary Institute, Giessen, Germany
| | - Constance E. Runyan
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hiam Abdala-Valencia
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Masahiko Shigemura
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | | | - Alexander V. Misharin
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - G.R. Scott Budinger
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Cara J. Gottardi
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Jacob I. Sznajder
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
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2
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Watanabe S, Markov NS, Lu Z, Piseaux Aillon R, Soberanes S, Runyan CE, Ren Z, Grant RA, Maciel M, Abdala-Valencia H, Politanska Y, Nam K, Sichizya L, Kihshen HG, Joshi N, McQuattie-Pimentel AC, Gruner KA, Jain M, Sznajder JI, Morimoto RI, Reyfman PA, Gottardi CJ, Budinger GRS, Misharin AV. Resetting proteostasis with ISRIB promotes epithelial differentiation to attenuate pulmonary fibrosis. Proc Natl Acad Sci U S A 2021; 118:e2101100118. [PMID: 33972447 PMCID: PMC8157939 DOI: 10.1073/pnas.2101100118] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Pulmonary fibrosis is a relentlessly progressive and often fatal disease with a paucity of available therapies. Genetic evidence implicates disordered epithelial repair, which is normally achieved by the differentiation of small cuboidal alveolar type 2 (AT2) cells into large, flattened alveolar type 1 (AT1) cells as an initiating event in pulmonary fibrosis pathogenesis. Using models of pulmonary fibrosis in young adult and old mice and a model of adult alveologenesis after pneumonectomy, we show that administration of ISRIB, a small molecule that restores protein translation by EIF2B during activation of the integrated stress response (ISR), accelerated the differentiation of AT2 into AT1 cells. Accelerated epithelial repair reduced the recruitment of profibrotic monocyte-derived alveolar macrophages and ameliorated lung fibrosis. These findings suggest a dysfunctional role for the ISR in regeneration of the alveolar epithelium after injury with implications for therapy.
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Affiliation(s)
- Satoshi Watanabe
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
- Department of Respiratory Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa 920-8641, Japan
| | - Nikolay S Markov
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Ziyan Lu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Raul Piseaux Aillon
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Saul Soberanes
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Constance E Runyan
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Ziyou Ren
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Rogan A Grant
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Mariana Maciel
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Hiam Abdala-Valencia
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Yuliya Politanska
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Kiwon Nam
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Lango Sichizya
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Hermon G Kihshen
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Nikita Joshi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Alexandra C McQuattie-Pimentel
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Katherine A Gruner
- Mouse Histology and Phenotyping Laboratory, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611
| | - Manu Jain
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Jacob I Sznajder
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Richard I Morimoto
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Paul A Reyfman
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Cara J Gottardi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - G R Scott Budinger
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611;
| | - Alexander V Misharin
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611;
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3
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McQuattie-Pimentel AC, Ren Z, Joshi N, Watanabe S, Stoeger T, Chi M, Lu Z, Sichizya L, Aillon RP, Chen CI, Soberanes S, Chen Z, Reyfman PA, Walter JM, Anekalla KR, Davis JM, Helmin KA, Runyan CE, Abdala-Valencia H, Nam K, Meliton AY, Winter DR, Morimoto RI, Mutlu GM, Bharat A, Perlman H, Gottardi CJ, Ridge KM, Chandel NS, Sznajder JI, Balch WE, Singer BD, Misharin AV, Budinger GS. The lung microenvironment shapes a dysfunctional response of alveolar macrophages in aging. J Clin Invest 2021; 131:140299. [PMID: 33586677 PMCID: PMC7919859 DOI: 10.1172/jci140299] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022] Open
Abstract
Alveolar macrophages orchestrate the response to viral infections. Age-related changes in these cells may underlie the differential severity of pneumonia in older patients. We performed an integrated analysis of single-cell RNA-Seq data that revealed homogenous age-related changes in the alveolar macrophage transcriptome in humans and mice. Using genetic lineage tracing with sequential injury, heterochronic adoptive transfer, and parabiosis, we found that the lung microenvironment drove an age-related resistance of alveolar macrophages to proliferation that persisted during influenza A viral infection. Ligand-receptor pair analysis localized these changes to the extracellular matrix, where hyaluronan was increased in aged animals and altered the proliferative response of bone marrow-derived macrophages to granulocyte macrophage colony-stimulating factor (GM-CSF). Our findings suggest that strategies targeting the aging lung microenvironment will be necessary to restore alveolar macrophage function in aging.
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Affiliation(s)
| | - Ziyou Ren
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Nikita Joshi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Satoshi Watanabe
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Thomas Stoeger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
| | - Monica Chi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ziyan Lu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Lango Sichizya
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Raul Piseaux Aillon
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ching-I Chen
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Saul Soberanes
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Zhangying Chen
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Paul A. Reyfman
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - James M. Walter
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Kishore R. Anekalla
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Jennifer M. Davis
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Kathryn A. Helmin
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Constance E. Runyan
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Hiam Abdala-Valencia
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Kiwon Nam
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Angelo Y. Meliton
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Chicago Hospitals, Chicago, Illinois, USA
| | - Deborah R. Winter
- Department of Medicine, Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | - Richard I. Morimoto
- Department of Biochemistry and Molecular Genetics, Northwestern University, Evanston, Illinois, USA
| | - Gökhan M. Mutlu
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Chicago Hospitals, Chicago, Illinois, USA
| | - Ankit Bharat
- Department of Surgery, Division of Thoracic Surgery, Northwestern University, Chicago, Illinois, USA
| | - Harris Perlman
- Department of Medicine, Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | - Cara J. Gottardi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Karen M. Ridge
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Navdeep S. Chandel
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - Jacob I. Sznajder
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - William E. Balch
- The Scripps Research Institute Department of Chemical Physiology, La Jolla, California, USA
| | - Benjamin D. Singer
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
- Department of Biochemistry and Molecular Genetics, Northwestern University, Evanston, Illinois, USA
| | - Alexander V. Misharin
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
| | - G.R. Scott Budinger
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois, USA
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4
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Runyan CE, Welch LC, Lecuona E, Shigemura M, Amarelle L, Abdala‐Valencia H, Joshi N, Lu Z, Nam K, Markov NS, McQuattie‐Pimentel AC, Piseaux‐Aillon R, Politanska Y, Sichizya L, Watanabe S, Williams KJ, Budinger GRS, Sznajder JI, Misharin AV. Impaired phagocytic function in CX3CR1 + tissue-resident skeletal muscle macrophages prevents muscle recovery after influenza A virus-induced pneumonia in old mice. Aging Cell 2020; 19:e13180. [PMID: 32720752 PMCID: PMC7587460 DOI: 10.1111/acel.13180] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/14/2020] [Accepted: 05/30/2020] [Indexed: 12/23/2022] Open
Abstract
Skeletal muscle dysfunction in survivors of pneumonia disproportionately affects older individuals in whom it causes substantial morbidity. We found that skeletal muscle recovery was impaired in old compared with young mice after influenza A virus-induced pneumonia. In young mice, recovery of muscle loss was associated with expansion of tissue-resident skeletal muscle macrophages and downregulation of MHC II expression, followed by a proliferation of muscle satellite cells. These findings were absent in old mice and in mice deficient in Cx3cr1. Transcriptomic profiling of tissue-resident skeletal muscle macrophages from old compared with young mice showed downregulation of pathways associated with phagocytosis and proteostasis, and persistent upregulation of inflammatory pathways. Consistently, skeletal muscle macrophages from old mice failed to downregulate MHCII expression during recovery from influenza A virus-induced pneumonia and showed impaired phagocytic function in vitro. Like old animals, mice deficient in the phagocytic receptor Mertk showed no macrophage expansion, MHCII downregulation, or satellite cell proliferation and failed to recover skeletal muscle function after influenza A pneumonia. Our data suggest that a loss of phagocytic function in a CX3CR1+ tissue-resident skeletal muscle macrophage population in old mice precludes satellite cell proliferation and recovery of skeletal muscle function after influenza A pneumonia.
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Affiliation(s)
- Constance E. Runyan
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Lynn C. Welch
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Emilia Lecuona
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Masahiko Shigemura
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Luciano Amarelle
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Hiam Abdala‐Valencia
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Nikita Joshi
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Ziyan Lu
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Kiwon Nam
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Nikolay S. Markov
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | | | - Raul Piseaux‐Aillon
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Yuliya Politanska
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Lango Sichizya
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Satoshi Watanabe
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Kinola J.N. Williams
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - G. R. Scott Budinger
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Jacob I. Sznajder
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Alexander V. Misharin
- Division of Pulmonary and Critical Care MedicineFeinberg School of MedicineNorthwestern UniversityChicagoILUSA
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5
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Radigan KA, Nicholson TT, Welch LC, Chi M, Amarelle L, Angulo M, Shigemura M, Shigemura A, Runyan CE, Morales-Nebreda L, Perlman H, Ceco E, Lecuona E, Dada LA, Misharin AV, Mutlu GM, Sznajder JI, Budinger GRS. Influenza A Virus Infection Induces Muscle Wasting via IL-6 Regulation of the E3 Ubiquitin Ligase Atrogin-1. J Immunol 2018; 202:484-493. [PMID: 30530483 DOI: 10.4049/jimmunol.1701433] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/05/2018] [Indexed: 12/26/2022]
Abstract
Muscle dysfunction is common in patients with adult respiratory distress syndrome and is associated with morbidity that can persist for years after discharge. In a mouse model of severe influenza A pneumonia, we found the proinflammatory cytokine IL-6 was necessary for the development of muscle dysfunction. Treatment with a Food and Drug Administration-approved Ab antagonist to the IL-6R (tocilizumab) attenuated the severity of influenza A-induced muscle dysfunction. In cultured myotubes, IL-6 promoted muscle degradation via JAK/STAT, FOXO3a, and atrogin-1 upregulation. Consistent with these findings, atrogin-1+/- and atrogin-1-/- mice had attenuated muscle dysfunction following influenza infection. Our data suggest that inflammatory endocrine signals originating from the injured lung activate signaling pathways in the muscle that induce dysfunction. Inhibiting these pathways may limit morbidity in patients with influenza A pneumonia and adult respiratory distress syndrome.
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Affiliation(s)
- Kathryn A Radigan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Trevor T Nicholson
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Lynn C Welch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Monica Chi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Luciano Amarelle
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.,Departamento de Fisiopatología, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; and
| | - Martín Angulo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.,Departamento de Fisiopatología, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay; and
| | - Masahiko Shigemura
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Atsuko Shigemura
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Constance E Runyan
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Luisa Morales-Nebreda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Harris Perlman
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Ermelinda Ceco
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Emilia Lecuona
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Laura A Dada
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Alexander V Misharin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Gokhan M Mutlu
- Section of Pulmonary and Critical Care Medicine, University of Chicago, Chicago, IL 60637
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611;
| | - G R Scott Budinger
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611;
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6
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Runyan CE, Liu Z, Schnaper HW. Phosphatidylinositol 3-kinase and Rab5 GTPase inversely regulate the Smad anchor for receptor activation (SARA) protein independently of transforming growth factor-β1. J Biol Chem 2012; 287:35815-24. [PMID: 22942286 DOI: 10.1074/jbc.m112.380493] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
SARA has been shown to be a regulator of epithelial cell phenotype, with reduced expression during TGF-β1-mediated epithelial-to-mesenchymal transition. Examination of the pathways that might play a role in regulating SARA expression identified phosphatidylinositol 3-kinase (PI3K) pathway inhibition as sufficient to reduce SARA expression. The mechanism of PI3K inhibition-mediated SARA down-regulation differs from that induced by TGF-β1 in that, unlike TGF-β1, PI3K-dependent depletion of SARA was apparent within 6 h and did not occur at the mRNA or promoter level but was blocked by inhibition of proteasome-mediated degradation. This effect was independent of Akt activity because neither reducing nor enhancing Akt activity modulated the expression of SARA. Therefore, this is likely a direct effect of p85α action, and co-immunoprecipitation of SARA and p85α confirmed that these proteins interact. Both SARA and PI3K have been shown to be associated with endosomes, and either LY294002 or p85α knockdown enlarged SARA-containing endocytic vesicles. Inhibition of clathrin-mediated endocytosis blocked SARA down-regulation, and a localization-deficient mutant SARA was protected against down-regulation. As inhibiting PI3K can activate the endosomal fusion-regulatory small GTPase Rab5, we expressed GTPase-deficient Rab5 and observed endosomal enlargement and reduced SARA protein expression, similar to that seen with PI3K inhibition. Importantly, either interference with PI3K via LY294002 or p85α knockdown, or constitutive activity of the Rab5 pathway, enhanced the expression of smooth muscle α-actin. Together, these data suggest that although TGF-β1 can induce epithelial-to-mesenchymal transition through reduction in SARA expression, SARA is also basally regulated by its interaction with PI3K.
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Affiliation(s)
- Constance E Runyan
- Department of Pediatrics, Northwestern University, Chicago, Illinois 60611, USA.
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7
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Basu RK, Hubchak S, Hayashida T, Runyan CE, Schumacker PT, Schnaper HW. Interdependence of HIF-1α and TGF-β/Smad3 signaling in normoxic and hypoxic renal epithelial cell collagen expression. Am J Physiol Renal Physiol 2011; 300:F898-905. [PMID: 21209004 DOI: 10.1152/ajprenal.00335.2010] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Increasing evidence suggests that chronic kidney disease may develop following acute kidney injury and that this may be due, in part, to hypoxia-related phenomena. Hypoxia-inducible factor (HIF) is stabilized in hypoxic conditions and regulates multiple signaling pathways that could contribute to renal fibrosis. As transforming growth factor (TGF)-β is known to mediate renal fibrosis, we proposed a profibrotic role for cross talk between the TGF-β1 and HIF-1α signaling pathways in kidney cells. Hypoxic incubation increased HIF-1α protein expression in cultured human renal tubular epithelial cells and mouse embryonic fibroblasts. TGF-β1 treatment further increased HIF-1α expression in cells treated with hypoxia and also increased HIF-1α in normoxic conditions. TGF-β1 did not increase HIF-1α mRNA levels nor decrease the rate of protein degradation, suggesting that it enhances normoxic HIF-1α translation. TGF-β receptor (ALK5) kinase activity was required for increased HIF-1α expression in response to TGF-β1, but not to hypoxia. A dominant negative Smad3 decreased the TGF-β-stimulated reporter activity of a HIF-1α-sensitive hypoxia response element. Conversely, a dominant negative HIF-1α construct decreased Smad-binding element promoter activity in response to TGF-β. Finally, blocking HIF-1α transcription with a biochemical inhibitor, a dominant negative construct, or gene-specific knockdown decreased basal and TGF-β1-stimulated type I collagen expression, while HIF-1α overexpression increased both. Taken together, our data demonstrate cooperation in signaling between Smad3 and HIF-1α and suggest a new paradigm in which HIF-1α is necessary for normoxic, TGF-β1-stimulated renal cell fibrogenesis.
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Affiliation(s)
- Rajit K Basu
- Divisions of Critical Care, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Runyan CE, Hayashida T, Hubchak S, Curley JF, Schnaper HW. Role of SARA (SMAD anchor for receptor activation) in maintenance of epithelial cell phenotype. J Biol Chem 2009; 284:25181-9. [PMID: 19620243 DOI: 10.1074/jbc.m109.032847] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By inducing epithelial-to-mesenchymal transition (EMT), transforming growth factor-beta (TGF-beta) promotes cancer progression and fibrosis. Here we show that expression of the TGF-beta receptor-associated protein, SARA (Smad anchor for receptor activation), decreases within 72 h of exposure to TGF-beta and that this decline is both required and sufficient for the induction of several markers of EMT. It has been suggested recently that expression of the TGF-beta signaling mediators, Smad2 and Smad3, may have different functional effects, with Smad2 loss being more permissive for EMT progression. We find that the loss of SARA expression leads to a concomitant decrease in Smad2 expression and a disruption of Smad2-specific transcriptional activity, with no effect on Smad3 signaling or expression. Further, the effects of inducing the loss of Smad2 mimic those of the loss of SARA, enhancing expression of the EMT marker, smooth muscle alpha-actin. Smad2 mRNA levels are not affected by the loss of SARA. However, the ubiquitination of Smad2 is increased in SARA-deficient cells. We therefore examined the E3 ubiquitin ligase Smurf2 and found that although Smurf2 expression was unaltered in SARA-deficient cells, the interaction of Smad2 and Smurf2 was enhanced. These results describe a significant role for SARA in regulating cell phenotype and suggest that its effects are mediated through modification of the balance between Smad2 and Smad3 signaling. In part, this is achieved by enhancing the association of Smad2 with Smurf2, leading to Smad2 degradation.
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Affiliation(s)
- Constance E Runyan
- Department of Pediatrics, Northwestern University, Chicago, Illinois 60611, USA.
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Schnaper HW, Jandeska S, Runyan CE, Hubchak SC, Basu RK, Curley JF, Smith RD, Hayashida T. TGF-beta signal transduction in chronic kidney disease. Front Biosci (Landmark Ed) 2009; 14:2448-65. [PMID: 19273211 DOI: 10.2741/3389] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Transforming growth factor (TGF)-beta is a central stimulus of the events leading to chronic progressive kidney disease, having been implicated in the regulation of cell proliferation, hypertrophy, apoptosis and fibrogenesis. The fact that it mediates these varied events suggests that multiple mechanisms play a role in determining the outcome of TGF-beta signaling. Regulation begins with the availability and activation of TGF-beta and continues through receptor expression and localization, control of the TGF-beta family-specific Smad signaling proteins, and interaction of the Smads with multiple signaling pathways extending into the nucleus. Studies of these mechanisms in kidney cells and in whole-animal experimental models, reviewed here, are beginning to provide insight into the role of TGF-beta in the pathogenesis of renal dysfunction and its potential treatment.
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Affiliation(s)
- H William Schnaper
- Division of Kidney Diseases, Department of Pediatrics, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave.; Chicago, IL 60611-3008, USA.
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Poncelet AC, Schnaper HW, Tan R, Liu Y, Runyan CE. Cell phenotype-specific down-regulation of Smad3 involves decreased gene activation as well as protein degradation. J Biol Chem 2007; 282:15534-40. [PMID: 17400544 DOI: 10.1074/jbc.m701991200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Signaling by transforming growth factor-beta (TGF-beta), a regulator of several biological processes, including renal fibrosis, is mediated, in part, by the Smad proteins. Tight control of Smad level and activity is critical for proper TGF-beta biological functions. Here, we have investigated the mechanisms involved in regulating Smad3 expression. In human glomerular mesangial cells, Smad3 protein levels were specifically reduced by 24 h of TGF-beta1 treatment, whereas Smad2 and Smad4 levels were not. TGF-beta1 increased endogenous Smad3 ubiquitination, and proteasome inhibitor treatment blocked TGF-beta1-mediated Smad3 down-regulation resulting in accumulation of ubiquitinated Smad3. These data support the concept that Smad3 down-regulation occurs via degradation by the ubiquitin/proteasome machinery. However, changes in Smad3 protein levels were also paralleled by changes in Smad3 mRNA expression. TGF-beta1 did not decrease Smad3 mRNA stability, but it significantly inhibited Smad3 promoter activity. In renal tubular epithelial cells, decreased Smad3 levels were observed only after exposure to TGF-beta1 for longer time periods (5-7 days) that paralleled epithelial-to-mesenchymal transition, as determined by increased expression of smooth muscle alpha-actin and decreased expression of E-cadherin. Decline in Smad3 expression also occurred in kidneys after unilateral ureteral obstruction, a model of tubulointerstitial fibrosis associated with TGF-beta up-regulation and epithelial-to-mesenchymal transition. Our data show for the first time that TGF-beta1 modulates the expression of a receptor-activated Smad at both the protein and transcriptional level. Smad3 down-regulation could represent a feedback loop controlling TGF-beta signaling in a cell phenotype-specific manner.
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Affiliation(s)
- Anne-Christine Poncelet
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98109, USA.
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Abstract
Members of the Smad protein family are fundamental downstream mediators of TGF-beta signals. However, the basic, linear Smad signaling pathway is unlikely to be the sole contributor to the plethora of cell type-specific TGF-beta responses. Investigators have identified a number of molecules that interact with the TGF-beta receptors (TbetaRs) and may explain, at least in part, the tight regulation of TGF-beta effects. Understanding these TbetaR-interacting molecules is thus a matter of great potential significance for elucidating TGF-beta-family signal transduction. The present article reviews our current understanding of the roles and mechanisms of action of this relatively understudied group of molecules.
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Affiliation(s)
- Constance E Runyan
- Department of Pediatrics, Feinberg School of Medicine, Chicago, IL, USA.
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Runyan CE, Schnaper HW, Poncelet AC. The Role of Internalization in Transforming Growth Factor β1-induced Smad2 Association with Smad Anchor for Receptor Activation (SARA) and Smad2-dependent Signaling in Human Mesangial Cells. J Biol Chem 2005; 280:8300-8. [PMID: 15613484 DOI: 10.1074/jbc.m407939200] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent data investigating the role of the Smad anchor for receptor activation (SARA) in TGF-beta signaling have suggested that it has a crucial function in both aiding the recruitment of Smad to the TGF-beta receptor, and ensuring appropriate subcellular localization of the activated receptor-bound complex. The FYVE domain in SARA directs its localization to early endosomal compartments where it can interact with both the TGF-beta receptors and Smads. However, the necessity of endocytosis in the TGF-beta response remains controversial. We sought to examine the role of internalization in TGF-beta/Smad signaling in human kidney mesangial cells. Using co-immunoprecipitation studies, we show that endogenous Smad2 interacts with SARA after TGF-beta1 stimulation. Inhibition of clathrin-mediated internalization only slightly affects TGF-beta1-stimulated association between SARA and Smad2, Smad2 phosphorylation, or Smad2 interaction with Smad4. However, endocytosis inhibition decreases TGF-beta1-induced Smad2 nuclear translocation and thus abrogates Smad2-dependent transcriptional responses. The TGF-beta1-stimulated association between SARA and Smad2 peaks at 30 min followed by separation of the complex components. However, under conditions of inhibited endocytosis, Smad2 remains bound to SARA for at least 6 h without a significant decline in associated levels. This lack of complex dissociation correlates with a lack of Smad2 nuclear accumulation and reduction of Smad2-dependent ARE-Luc reporter activity. Our data therefore suggest that endocytosis plays a critical role in TGF-beta signaling in mesangial cells, and that internalization enhances the dissociation of Smad2 from the TGF-beta receptor-SARA complex, allowing Smad2 to accumulate in the nucleus and modulate target gene transcription.
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Affiliation(s)
- Constance E Runyan
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
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Runyan CE, Schnaper HW, Poncelet AC. The phosphatidylinositol 3-kinase/Akt pathway enhances Smad3-stimulated mesangial cell collagen I expression in response to transforming growth factor-beta1. J Biol Chem 2003; 279:2632-9. [PMID: 14610066 DOI: 10.1074/jbc.m310412200] [Citation(s) in RCA: 182] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Transforming growth factor (TGF)-beta has been associated with renal glomerular matrix accumulation. We previously showed that Smad3 promotes COL1A2 gene activation by TGF-beta1 in human glomerular mesangial cells. Here, we report that the PI3K/Akt pathway also plays a role in TGF-beta1-increased collagen I expression. TGF-beta1 stimulates the activity of phosphoinositide-dependent kinase (PDK)-1, a downstream target of PI3K, starting at 1 min. Akt, a kinase downstream of PDK-1, is phosphorylated and concentrates in the membrane fraction within 5 min of TGF-beta1 treatment. The PI3K inhibitor LY294002 decreases TGF-beta1-stimulated alpha1(I) and alpha2(I) collagen mRNA expression. Similarly, LY294002 or an Akt dominant negative construct blocks TGF-beta1 induction of COL1A2 promoter activity. However, PI3K stimulation alone is not sufficient to increase collagen I expression, since neither a constitutively active p110 PI3K construct nor PDGF, which induces Akt phosphorylation, is able to stimulate COL1A2 promoter activity or mRNA expression, respectively. LY294002 inhibits stimulation of COL1A2 promoter activity by Smad3. In a Gal4-LUC assay system, blockade of the PI3K pathway significantly decreases TGF-beta1-induced transcriptional activity of Gal4-Smad3. Activity of SBE-LUC, a Smad3/4-responsive construct, is stimulated by over-expression of Smad3 or Smad3D, in which the three C-terminal serine phospho-acceptor residues are mutated. This induction is blocked by LY294002, suggesting that inhibition of the PI3K pathway decreases Smad3 transcriptional activity independently of C-terminal serine phosphorylation. However, TGF-beta1-induced total serine phosphorylation of Smad3 is decreased by LY294002, suggesting that Smad3 is phosphorylated by the PI3K pathway at serine residues other than the direct TGF-beta receptor I target site. Thus, although the PI3K-PDK1-Akt pathway alone is insufficient to stimulate COL1A2 gene transcription, its activation by TGF-beta1 enhances Smad3 transcriptional activity leading to increased collagen I expression in human mesangial cells. This cross-talk between the Smad and PI3K pathways likely contributes to TGF-beta1 induction of glomerular scarring.
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Affiliation(s)
- Constance E Runyan
- Department of Pediatrics, Northwestern University, Chicago, Illinois 60611, USA
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Abstract
Transforming growth factor (TGF)-beta has been associated with fibrogenesis in clinical studies and animal models. We previously showed that Smad3 promotes COL1A2 gene activation by TGF-beta1 in human mesangial cells. In addition to the Smad pathway, it has been suggested that TGF-beta1 could also activate more classical growth factor signaling. Here, we report that protein kinase C (PKC)delta plays a role in TGF-beta1-stimulated collagen I production. In an in vitro kinase assay, TGF-beta1 treatment specifically increased mesangial cell PKCdelta activity in a time-dependent manner. Translocation to the membrane was detected by immunocytochemistry and immunoblot, suggesting activation of PKCdelta by TGF-beta1. Inhibition of PKCdelta by rottlerin decreased basal and TGF-beta1-stimulated collagen I production, mRNA expression, and COL1A2 promoter activity, whereas blockade of conventional PKCs by Gö 6976 had little or no effect. In a Gal4-LUC assay system, inhibition of PKCdelta abolished TGF-beta1-induced transcriptional activity of Gal4-Smad3 and Gal4-Smad4(266-552). Overexpression of Smad3 or Smad3D, in which the three COOH-terminal serine phosphoacceptor residues have been mutated, increased activity of the SBE-LUC construct, containing four DNA binding sites for Smad3 and Smad4. This induction was blocked by PKCdelta inhibition, suggesting that rottlerin decreased Smad3 transcriptional activity independently of COOH-terminal serine phosphorylation. Blockade of PKCdelta abolished ligand-independent and ligand-dependent stimulation of COL1A2 promoter activity by Smad3. These data indicate that PKCdelta is activated by TGF-beta1 in human mesangial cells. TGF-beta1-stimulated PKCdelta activity positively regulates Smad transcriptional activity and is required for COL1A2 gene transcription. Thus cross talk among multiple signaling pathways likely contributes to the pathogenesis of glomerular matrix accumulation.
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Hubchak SC, Runyan CE, Kreisberg JI, Schnaper HW. Cytoskeletal rearrangement and signal transduction in TGF-beta1-stimulated mesangial cell collagen accumulation. J Am Soc Nephrol 2003; 14:1969-80. [PMID: 12874450 DOI: 10.1097/01.asn.0000076079.02452.92] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
TGF-beta1 has been implicated in glomerular extracellular matrix accumulation, although the precise cellular mechanism(s) by which this occurs is not fully understood. The authors have previously shown that the Smad signaling pathway is present and functional in human glomerular mesangial cells and plays a role in activating type I collagen gene expression. It also was determined that TGF-beta1 activates ERK mitogen-activated protein kinase in mesangial cells to enhance Smad activation and collagen expression. Here, it was shown that TGF-beta1 rapidly induces cytoskeletal rearrangement in human mesangial cells, stimulating smooth muscle alpha-actin detection in stress fibers and promoting focal adhesion complex assembly and redistribution. Disrupting the actin cytoskeleton with cytochalasin D (Cyto D) selectively decreased basal and TGF-beta1-induced cell-layer collagen I and IV accumulation. The balance of matrix metalloproteinases (MMP) and inhibitors was altered by Cyto D or TGF-beta1 alone, increasing MMP activity, increasing MMP-1 expression, and decreasing tissue inhibitor of matrix metalloproteinase-2 expression. Cyto D also decreased basal and TGF-beta1-stimulated alpha1(I) collagen mRNA but did not inhibit TGF-beta-stimulated alpha1(IV) mRNA expression. A similar decrease in alpha1(I) mRNA expression caused by the actin polymerization inhibitor latrunculin B was partially blocked by the addition of jasplakinolide, which promotes actin assembly. The Rho-family GTPase inhibitor C. difficile toxin B or the Rho-associated kinase inhibitor Y-27632 also blocked TGF-beta1-stimulated alpha1(I) mRNA expression. Cytoskeletal disruption reduced Smad2 phosphorylation but had little effect on mRNA stability, TGF-beta receptor number, or receptor affinity. Thus, TGF-beta1-mediated collagen I accumulation is associated with cytoskeletal rearrangement and Rho-GTPase signaling.
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Affiliation(s)
- Susan C Hubchak
- Department of Pediatrics, Northwestern University Medical School, Chicago, Illinois, USA.
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Shpeizer B, Poojary DM, Ahn K, Runyan CE, Clearfield A. Nickel Oxide Interstratified α-Zirconium Phosphate, a Composite Exhibiting Ferromagnetic Behavior. Science 1994; 266:1357-9. [PMID: 17772842 DOI: 10.1126/science.266.5189.1357] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
As part of an ongoing research program to synthesize novel pillared layered materials, nickel and cobalt hydroxyacetates were inserted between the layers of amine intercalates of alpha-zirconium phosphate. The structure of the resultant nickel composite, derived from x-ray powder data, was found to consist of a three-tiered layer of nickel atoms bridged by hydroxo and acetato groups. Heating to 420 degrees C converted the hydroxyacetate layers to oxide and imparted ordered magnetic domains to the composite. The phosphate layers appear to act as a template directing the growth of the inserted layers in this class of composite materials.
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