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Howard-Anderson JR, Gewin L, Rockey DC, Krousel-Wood M, Roman J. Strategies for developing a successful career in academic medicine. Am J Med Sci 2024; 367:215-227. [PMID: 38160710 DOI: 10.1016/j.amjms.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
Academic medicine provides physicians an opportunity for long-term career satisfaction and fulfillment. However, despite the potential for great reward, academic careers can be challenging. To better define approaches to successfully navigate academic medicine, the Southern Society for Clinical Investigation sponsored a workshop titled 'Successful Careers in Academic Medicine' during the 2023 Southern Regional Meeting held in New Orleans; the critical elements of which are highlighted in the following summary. Participants discussed the benefits of an academic career, summarized strategies for negotiating a job, listed critical tools for career development, and discussed key concepts about planning and navigating the academic medicine promotion process. The information provides a roadmap for physicians to develop successful careers in academic medicine.
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Affiliation(s)
- Jessica R Howard-Anderson
- Department of Medicine, Division of Infectious Diseases, Emory University, Atlanta, GA, United States
| | - Leslie Gewin
- Department of Medicine, Division of Nephrology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Don C Rockey
- Digestive Disease Research Center, Medical University of South Carolina, Charleston, SC, United States
| | - Marie Krousel-Wood
- Departments of Medicine and Epidemiology, Center for Health Outcomes, Implementation and Community-Engaged Science, Tulane University, New Orleans, LA, United States
| | - Jesse Roman
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Thomas Jefferson University, Philadelphia, PA, United States.
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2
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Neyra JA, Gewin L, Ng JH, Barreto EF, Freshly B, Willett J, Abdel-Rahman EM, McCoy I, Kwong YD, Silver SA, Cerda J, Vijayan A. Challenges in the Care of Patients with AKI Receiving Outpatient Dialysis: AKINow Recovery Workgroup Report. Kidney360 2024; 5:274-284. [PMID: 38055734 PMCID: PMC10914193 DOI: 10.34067/kid.0000000000000332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 11/29/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Up to one third of survivors of AKI that required dialysis (AKI-D) during hospitalization remain dialysis dependent at hospital discharge. Of these, 20%-60%, depending on the clinical setting, eventually recover enough kidney function to stop dialysis, and the remainder progress to ESKD. METHODS To describe the challenges facing those still receiving dialysis on discharge, the AKINow Committee conducted a group discussion comprising 59 participants, including physicians, advanced practitioners, nurses, pharmacists, and patients. The discussion was framed by a patient who described gaps in care delivery at different transition points and miscommunication between care team members and the patient. RESULTS Group discussions collected patient perspectives of ( 1 ) being often scared and uncertain about what is happening to and around them and ( 2 ) the importance of effective and timely communication, a comfortable physical setting, and attentive and caring health care providers for a quality health care experience. Provider perspectives included ( 1 ) the recognition of the lack of evidence-based practices and quality indicators, the significant variability in current care models, and the uncertain reimbursement incentives focused on kidney recovery and ( 2 ) the urgency to address communication barriers among hospital providers and outpatient facilities. CONCLUSIONS The workgroup identified key areas for future research and policy change to ( 1 ) improve communication among hospital providers, dialysis units, and patients/care partners; ( 2 ) develop tools for risk classification, subphenotyping, and augmented clinical decision support; ( 3 ) improve education to providers, staff, and patients/care partners; ( 4 ) identify best practices to improve relevant outcomes; ( 5 ) validate quality indicators; and ( 6 ) assess the effect of social determinants of health on outcomes. We urge all stakeholders involved in the process of AKI-D care to align goals and work together to fill knowledge gaps and optimize the care to this highly vulnerable patient population.
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Affiliation(s)
- Javier A. Neyra
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Leslie Gewin
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Jia H. Ng
- Division of Kidney Diseases and Hypertension, Department of Medicine, Donald and Barbara Zucker School of Medicine, Hempstead, New York
| | | | | | - Jeff Willett
- ASN: American Society of Nephrology, Washington, DC
| | - Emaad M. Abdel-Rahman
- Division of Nephrology, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Ian McCoy
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Yuenting D. Kwong
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Samuel A. Silver
- Division of Nephrology, Kingston Health Sciences Center, Queen's University, Kingston, Ontario, Canada
| | - Jorge Cerda
- Division of Nephrology, Department of Medicine, Albany Medical College, Albany, New York
| | - Anitha Vijayan
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri
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3
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Barreto EF, Cerda J, Freshly B, Gewin L, Kwong YD, McCoy IE, Neyra JA, Ng JH, Silver SA, Vijayan A, Abdel-Rahman EM. Optimum Care of AKI Survivors Not Requiring Dialysis after Discharge: An AKINow Recovery Workgroup Report. Kidney360 2024; 5:124-132. [PMID: 37986185 PMCID: PMC10833609 DOI: 10.34067/kid.0000000000000309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023]
Abstract
AKI survivors experience gaps in care that contribute to worse outcomes, experience, and cost.Challenges to optimal care include issues with information transfer, education, collaborative care, and use of digital health tools.Research is needed to study these challenges and inform optimal use of diagnostic and therapeutic interventions to promote recovery AKI affects one in five hospitalized patients and is associated with poor short-term and long-term clinical and patient-centered outcomes. Among those who survive to discharge, significant gaps in documentation, education, communication, and follow-up have been observed. The American Society of Nephrology established the AKINow taskforce to address these gaps and improve AKI care. The AKINow Recovery workgroup convened two focus groups, one each focused on dialysis-independent and dialysis-requiring AKI, to summarize the key considerations, challenges, and opportunities in the care of AKI survivors. This article highlights the discussion surrounding care of AKI survivors discharged without the need for dialysis. On May 3, 2022, 48 patients and multidisciplinary clinicians from diverse settings were gathered virtually. The agenda included a patient testimonial, plenary sessions, facilitated small group discussions, and debriefing. Core challenges and opportunities for AKI care identified were in the domains of transitions of care, education, collaborative care delivery, diagnostic and therapeutic interventions, and digital health applications. Integrated multispecialty care delivery was identified as one of the greatest challenges to AKI survivor care. Adequate templates for communication and documentation; education of patients, care partners, and clinicians about AKI; and a well-coordinated multidisciplinary posthospital follow-up plan form the basis for a successful care transition at hospital discharge. The AKINow Recovery workgroup concluded that advancements in evidence-based, patient-centered care of AKI survivors are needed to improve health outcomes, care quality, and patient and provider experience. Tools are being developed by the AKINow Recovery workgroup for use at the hospital discharge to facilitate care continuity.
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Affiliation(s)
| | - Jorge Cerda
- Division of Nephrology, Department of Medicine, Albany Medical College, Albany, New York
| | | | - Leslie Gewin
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Y. Diana Kwong
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Ian E. McCoy
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Javier A. Neyra
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jia H. Ng
- Division of Kidney Diseases and Hypertension, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Great Neck, New York
| | - Samuel A. Silver
- Division of Nephrology, Kingston Health Sciences Center, Queen's University, Kingston, Ontario, Canada
| | - Anitha Vijayan
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Emaad M. Abdel-Rahman
- Division of Nephrology, Department of Medicine, University of Virginia, Charlottesville, VA
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4
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Yang M, Lopez LN, Brewer M, Delgado R, Menshikh A, Clouthier K, Zhu Y, Vanichapol T, Yang H, Harris RC, Gewin L, Brooks CR, Davidson AJ, de Caestecker M. Inhibition of retinoic acid signaling in proximal tubular epithelial cells protects against acute kidney injury. JCI Insight 2023; 8:e173144. [PMID: 37698919 PMCID: PMC10619506 DOI: 10.1172/jci.insight.173144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/15/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023] Open
Abstract
Retinoic acid receptor (RAR) signaling is essential for mammalian kidney development but, in the adult kidney, is restricted to occasional collecting duct epithelial cells. We now show that there is widespread reactivation of RAR signaling in proximal tubular epithelial cells (PTECs) in human sepsis-associated acute kidney injury (AKI) and in mouse models of AKI. Genetic inhibition of RAR signaling in PTECs protected against experimental AKI but was unexpectedly associated with increased expression of the PTEC injury marker Kim1. However, the protective effects of inhibiting PTEC RAR signaling were associated with increased Kim1-dependent apoptotic cell clearance, or efferocytosis, and this was associated with dedifferentiation, proliferation, and metabolic reprogramming of PTECs. These data demonstrate the functional role that reactivation of RAR signaling plays in regulating PTEC differentiation and function in human and experimental AKI.
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Affiliation(s)
- Min Yang
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lauren N. Lopez
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Maya Brewer
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Rachel Delgado
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Anna Menshikh
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kelly Clouthier
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yuantee Zhu
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Thitinee Vanichapol
- Department of Molecular Medicine & Pathology, The University of Auckland, Auckland, New Zealand
| | - Haichun Yang
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Raymond C. Harris
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Leslie Gewin
- Washington University in St. Louis School of Medicine and the St. Louis Veterans Affairs Hospital, St. Louis, Missouri, USA
| | - Craig R. Brooks
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alan J. Davidson
- Department of Molecular Medicine & Pathology, The University of Auckland, Auckland, New Zealand
| | - Mark de Caestecker
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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5
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Yang M, Lopez LN, Brewer M, Delgado R, Menshikh A, Clouthier K, Zhu Y, Vanichapol T, Yang H, Harris R, Gewin L, Brooks C, Davidson A, de Caestecker MP. Inhibition of Retinoic Acid Signaling in Proximal Tubular Epithelial cells Protects against Acute Kidney Injury by Enhancing Kim-1-dependent Efferocytosis. bioRxiv 2023:2023.06.15.545113. [PMID: 37398101 PMCID: PMC10312711 DOI: 10.1101/2023.06.15.545113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Retinoic acid receptor (RAR) signaling is essential for mammalian kidney development, but in the adult kidney is restricted to occasional collecting duct epithelial cells. We now show there is widespread reactivation of RAR signaling in proximal tubular epithelial cells (PTECs) in human sepsis-associated acute kidney injury (AKI), and in mouse models of AKI. Genetic inhibition of RAR signaling in PTECs protects against experimental AKI but is associated with increased expression of the PTEC injury marker, Kim-1. However, Kim-1 is also expressed by de-differentiated, proliferating PTECs, and protects against injury by increasing apoptotic cell clearance, or efferocytosis. We show that the protective effect of inhibiting PTEC RAR signaling is mediated by increased Kim-1 dependent efferocytosis, and that this is associated with de-differentiation, proliferation, and metabolic reprogramming of PTECs. These data demonstrate a novel functional role that reactivation of RAR signaling plays in regulating PTEC differentiation and function in human and experimental AKI. Graphical abstract
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6
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Kayhan M, Vouillamoz J, Rodriguez DG, Bugarski M, Mitamura Y, Gschwend J, Schneider C, Hall A, Legouis D, Akdis CA, Peter L, Rehrauer H, Gewin L, Wenger RH, Khodo SN. Intrinsic TGF-β signaling attenuates proximal tubule mitochondrial injury and inflammation in chronic kidney disease. Nat Commun 2023; 14:3236. [PMID: 37270534 PMCID: PMC10239443 DOI: 10.1038/s41467-023-39050-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 10/03/2022] [Accepted: 05/26/2023] [Indexed: 06/05/2023] Open
Abstract
Excessive TGF-β signaling and mitochondrial dysfunction fuel chronic kidney disease (CKD) progression. However, inhibiting TGF-β failed to impede CKD in humans. The proximal tubule (PT), the most vulnerable renal segment, is packed with giant mitochondria and injured PT is pivotal in CKD progression. How TGF-β signaling affects PT mitochondria in CKD remained unknown. Here, we combine spatial transcriptomics and bulk RNAseq with biochemical analyses to depict the role of TGF-β signaling on PT mitochondrial homeostasis and tubulo-interstitial interactions in CKD. Male mice carrying specific deletion of Tgfbr2 in the PT have increased mitochondrial injury and exacerbated Th1 immune response in the aristolochic acid model of CKD, partly, through impaired complex I expression and mitochondrial quality control associated with a metabolic rewiring toward aerobic glycolysis in the PT cells. Injured S3T2 PT cells are identified as the main mediators of the maladaptive macrophage/dendritic cell activation in the absence of Tgfbr2. snRNAseq database analyses confirm decreased TGF-β receptors and a metabolic deregulation in the PT of CKD patients. This study describes the role of TGF-β signaling in PT mitochondrial homeostasis and inflammation in CKD, suggesting potential therapeutic targets that might be used to mitigate CKD progression.
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Affiliation(s)
- Merve Kayhan
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | | | - Milica Bugarski
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Yasutaka Mitamura
- Swiss Institute of Allergy and Asthma Research, University of Zurich, Zurich, Switzerland
| | - Julia Gschwend
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | | | - Andrew Hall
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - David Legouis
- Laboratory of Nephrology, Department of Medicine and Cell Physiology, Hospital and University of Geneva, Geneva, Switzerland
| | - Cezmi A Akdis
- Swiss Institute of Allergy and Asthma Research, University of Zurich, Zurich, Switzerland
| | - Leary Peter
- Functional Genomics Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Hubert Rehrauer
- Functional Genomics Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Leslie Gewin
- Department of Internal Medicine, Division of Nephrology, Washington University, St. Louis, USA
- Department of Medicine, St. Louis Veterans Affairs, St. Louis, USA
| | - Roland H Wenger
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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7
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Cole HA, Moore-Lotridge SN, Hawley GD, Jacobson R, Yuasa M, Gewin L, Nyman JS, Flick MJ, Schoenecker JG. The Deleterious Effects of Impaired Fibrinolysis on Skeletal Development Are Dependent on Fibrin(ogen), but Independent of Interlukin-6. Front Cardiovasc Med 2021; 8:768338. [PMID: 34938785 PMCID: PMC8685342 DOI: 10.3389/fcvm.2021.768338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Chronic diseases in growing children, such as autoimmune disorders, obesity, and cancer, are hallmarked by musculoskeletal growth disturbances and osteoporosis. Many of the skeletal changes in these children are thought to be secondary to chronic inflammation. Recent studies have likewise suggested that changes in coagulation and fibrinolysis may contribute to musculoskeletal growth disturbances. In prior work, we demonstrated that mice deficient in plasminogen, the principal protease of degrading and clearing fibrin matrices, suffer from inflammation-driven systemic osteoporosis and that elimination of fibrinogen resulted in normalization of IL-6 levels and complete rescue of the skeletal phenotype. Given the intimate link between coagulation, fibrinolysis, and inflammation, here we determined if persistent fibrin deposition, elevated IL-6, or both contribute to early skeletal aging and physeal disruption in chronic inflammatory conditions. Skeletal growth as well as bone quality, physeal development, and vascularity were analyzed in C57BL6/J mice with plasminogen deficiency with and without deficiencies of either fibrinogen or IL-6. Elimination of fibrinogen, but not IL-6, rescued the skeletal phenotype and growth disturbances in this model of chronic disease. Furthermore, the skeletal phenotypes directly correlated with both systemic and local vascular changes in the skeletal environment. In conclusion, these results suggest that fibrinolysis through plasmin is essential for skeletal growth and maintenance, and is multifactorial by limiting inflammation and preserving vasculature.
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Affiliation(s)
- Heather A Cole
- Departments of Nuclear Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Stephanie N Moore-Lotridge
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States.,Center of Bone Biology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Gregory D Hawley
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Richard Jacobson
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Masato Yuasa
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Orthopaedic and Spinal Surgery, Tokyo Medical and Dental University, Tokyo, Japan
| | - Leslie Gewin
- Departments of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Research, Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, United States
| | - Jeffry S Nyman
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States.,Center of Bone Biology, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Research, Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, United States.,Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Matthew J Flick
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, United States.,University of North Carolina Blood Research Center, University of North Carolina, Chapel Hill, NC, United States.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
| | - Jonathan G Schoenecker
- Departments of Orthopaedics, Vanderbilt University Medical Center, Nashville, TN, United States.,Center of Bone Biology, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Pharmacology, Vanderbilt University, Nashville, TN, United States.,Departments of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Departments of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States.,Departments of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
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Borza CM, Bolas G, Bock F, Zhang X, Akabogu FC, Zhang MZ, de Caestecker M, Yang M, Yang H, Lee E, Gewin L, Fogo AB, McDonald WH, Zent R, Pozzi A. DDR1 contributes to kidney inflammation and fibrosis by promoting the phosphorylation of BCR and STAT3. JCI Insight 2021; 7:150887. [PMID: 34941574 PMCID: PMC8855801 DOI: 10.1172/jci.insight.150887] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 12/21/2021] [Indexed: 11/25/2022] Open
Abstract
Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase activated by collagen, contributes to chronic kidney disease. However, its role in acute kidney injury and subsequent development of kidney fibrosis is not clear. Thus, we performed a model of severe ischemia/reperfusion-induced acute kidney injury that progressed to kidney fibrosis in WT and Ddr1-null mice. We showed that Ddr1-null mice had reduced acute tubular injury, inflammation, and tubulointerstitial fibrosis with overall decreased renal monocyte chemoattractant protein (MCP-1) levels and STAT3 activation. We identified breakpoint cluster region (BCR) protein as a phosphorylated target of DDR1 that controls MCP-1 production in renal proximal tubule epithelial cells. DDR1-induced BCR phosphorylation or BCR downregulation increased MCP-1 secretion, suggesting that BCR negatively regulates the levels of MCP-1. Mechanistically, phosphorylation or downregulation of BCR increased β-catenin activity and in turn MCP-1 production. Finally, we showed that DDR1-mediated STAT3 activation was required to stimulate the secretion of TGF-β. Thus, DDR1 contributes to acute and chronic kidney injury by regulating BCR and STAT3 phosphorylation and in turn the production of MCP-1 and TGF-β. These findings identify DDR1 an attractive therapeutic target for ameliorating both proinflammatory and profibrotic signaling in kidney disease.
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Affiliation(s)
- Corina M. Borza
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Gema Bolas
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Fabian Bock
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Xiuqi Zhang
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Favour C. Akabogu
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Ming-Zhi Zhang
- Department of Medicine, Division of Nephrology and Hypertension, and
| | | | - Min Yang
- Department of Medicine, Division of Nephrology and Hypertension, and
| | - Haichun Yang
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Leslie Gewin
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Agnes B. Fogo
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - W. Hayes McDonald
- Proteomics Laboratory, Mass Spectrometry Research Center, Vanderbilt University, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Roy Zent
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Veterans Affairs, Nashville, Nashville, Tennessee, USA
| | - Ambra Pozzi
- Department of Medicine, Division of Nephrology and Hypertension, and
- Department of Veterans Affairs, Nashville, Nashville, Tennessee, USA
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Yao L, Wright MF, Farmer BC, Peterson LS, Khan AM, Zhong J, Gewin L, Hao CM, Yang HC, Fogo AB. Fibroblast-specific plasminogen activator inhibitor-1 depletion ameliorates renal interstitial fibrosis after unilateral ureteral obstruction. Nephrol Dial Transplant 2020; 34:2042-2050. [PMID: 31071225 DOI: 10.1093/ndt/gfz050] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 02/20/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Plasminogen activator inhibitor-1 (PAI-1) expression increases extracellular matrix deposition and contributes to interstitial fibrosis in the kidney after injury. While PAI-1 is ubiquitously expressed in the kidney, we hypothesized that interstitial fibrosis is strongly dependent on fibroblast-specific PAI-1 (fbPAI-1). METHODS Tenascin C Cre (TNC Cre) and fbPAI-1 knockdown (KD) mice with green fluorescent protein (GFP) expressed within the TNC construct underwent unilateral ureteral obstruction and were sacrificed 10 days later. RESULTS GFP+ cells in fbPAI-1 KD mice showed significantly reduced PAI-1 expression. Interstitial fibrosis, measured by Sirius red staining and collagen I western blot, was significantly decreased in fbPAI-1 KD compared with TNC Cre mice. There was no significant difference in transforming growth factor β (TGF-β) expression or its activation between the two groups. However, GFP+ cells from fbPAI-1 KD mice had lower TGF β and connective tissue growth factor (CTGF) expression. The number of fibroblasts was decreased in fbPAI-1 KD compared with TNC Cre mice, correlating with decreased alpha smooth muscle actin (α-SMA) expression and less fibroblast cell proliferation. TNC Cre mice had decreased E-cadherin, a marker of differentiated tubular epithelium, in contrast to preserved expression in fbPAI-1 KD. F4/80-expressing cells, mostly CD11c+/F4/80+ cells, were increased while M1 macrophage markers were decreased in fbPAI-1 KD compared with TNC Cre mice. CONCLUSION These findings indicate that fbPAI-1 depletion ameliorates interstitial fibrosis by decreasing fibroblast proliferation in the renal interstitium, with resulting decreased collagen I. This is linked to decreased M1 macrophages and preserved tubular epithelium.
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Affiliation(s)
- Lan Yao
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Medical Healthcare Center, Beijing Friendship Hospital of Capital Medical University, Beijing, China
| | - M Frances Wright
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Brandon C Farmer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Biology, Western Kentucky University, Bowling Green, KY, USA
| | - Laura S Peterson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Amir M Khan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Jianyong Zhong
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Leslie Gewin
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Chuan-Ming Hao
- Division of Nephrology, Huashan Hospital, Fudan University, Shanghai, China
| | - Hai-Chun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Agnes B Fogo
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN, USA
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10
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Kishi S, Brooks CR, Taguchi K, Ichimura T, Mori Y, Akinfolarin A, Gupta N, Galichon P, Elias BC, Suzuki T, Wang Q, Gewin L, Morizane R, Bonventre JV. Proximal tubule ATR regulates DNA repair to prevent maladaptive renal injury responses. J Clin Invest 2019; 129:4797-4816. [PMID: 31589169 PMCID: PMC6819104 DOI: 10.1172/jci122313] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [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: 06/06/2018] [Accepted: 07/23/2019] [Indexed: 12/11/2022] Open
Abstract
Maladaptive proximal tubule (PT) repair has been implicated in kidney fibrosis through induction of cell-cycle arrest at G2/M. We explored the relative importance of the PT DNA damage response (DDR) in kidney fibrosis by genetically inactivating ataxia telangiectasia and Rad3-related (ATR), which is a sensor and upstream initiator of the DDR. In human chronic kidney disease, ATR expression inversely correlates with DNA damage. ATR was upregulated in approximately 70% of Lotus tetragonolobus lectin-positive (LTL+) PT cells in cisplatin-exposed human kidney organoids. Inhibition of ATR resulted in greater PT cell injury in organoids and cultured PT cells. PT-specific Atr-knockout (ATRRPTC-/-) mice exhibited greater kidney function impairment, DNA damage, and fibrosis than did WT mice in response to kidney injury induced by either cisplatin, bilateral ischemia-reperfusion, or unilateral ureteral obstruction. ATRRPTC-/- mice had more cells in the G2/M phase after injury than did WT mice after similar treatments. In conclusion, PT ATR activation is a key component of the DDR, which confers a protective effect mitigating the maladaptive repair and consequent fibrosis that follow kidney injury.
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Affiliation(s)
- Seiji Kishi
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Department of Nephrology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
- Department of General Medicine, Kawasaki Medical School, Kurashiki, Japan
| | - Craig R. Brooks
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kensei Taguchi
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Takaharu Ichimura
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Yutaro Mori
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Akinwande Akinfolarin
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Navin Gupta
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Pierre Galichon
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Sorbonne Université, INSERM UMR S1155, AP-HP, Hôpital Tenon, Paris, France
| | - Bertha C. Elias
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Tomohisa Suzuki
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Qian Wang
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Leslie Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ryuji Morizane
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Joseph V. Bonventre
- Renal Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
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11
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Love HD, Ao M, Jorgensen S, Swearingen L, Ferrell N, Evans R, Gewin L, Harris RC, Zent R, Roy S, Fissell WH. Substrate Elasticity Governs Differentiation of Renal Tubule Cells in Prolonged Culture. Tissue Eng Part A 2019; 25:1013-1022. [PMID: 30484388 DOI: 10.1089/ten.tea.2018.0182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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] [Indexed: 11/12/2022] Open
Abstract
IMPACT STATEMENT Successful clinical tissue engineering requires functional fidelity of the cultured cell to its in vivo counterpart, but this has been elusive in renal tissue engineering. Typically, renal proximal tubule cells in culture have a flattened morphology and do not express key transporters essential to their function. In this article, we show for the first time that in vitro substrate mechanical properties dictate differentiation of cultured renal proximal tubule cells. Remarkably, this effect was only discernable after 4 weeks in culture, longer than usually reported for this cell type. These results demonstrate a new tunable parameter to optimize cell differentiation in renal tissue engineering.
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Affiliation(s)
- Harold D Love
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Mingfang Ao
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Seiver Jorgensen
- 2College of Arts and Science, Vanderbilt University, Nashville, Tennessee
| | - Lindsey Swearingen
- 2College of Arts and Science, Vanderbilt University, Nashville, Tennessee
| | - Nicholas Ferrell
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rachel Evans
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Leslie Gewin
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Raymond C Harris
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Roy Zent
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Shuvo Roy
- 3Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California
| | - William H Fissell
- 1Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
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12
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Colon S, Luan H, Liu Y, Meyer C, Gewin L, Bhave G. Peroxidasin and eosinophil peroxidase, but not myeloperoxidase, contribute to renal fibrosis in the murine unilateral ureteral obstruction model. Am J Physiol Renal Physiol 2019; 316:F360-F371. [PMID: 30565999 PMCID: PMC6397377 DOI: 10.1152/ajprenal.00291.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 06/13/2018] [Revised: 12/05/2018] [Accepted: 12/15/2018] [Indexed: 01/21/2023] Open
Abstract
Renal fibrosis is the pathological hallmark of chronic kidney disease (CKD) and manifests as glomerulosclerosis and tubulointerstitial fibrosis. Reactive oxygen species contribute significantly to renal inflammation and fibrosis, but most research has focused on superoxide and hydrogen peroxide (H2O2). The animal heme peroxidases myeloperoxidase (MPO), eosinophil peroxidase (EPX), and peroxidasin (PXDN) uniquely metabolize H2O2 into highly reactive and destructive hypohalous acids, such as hypobromous and hypochlorous acid. However, the role of these peroxidases and their downstream hypohalous acids in the pathogenesis of renal fibrosis is unclear. Our study defines the contribution of MPO, EPX, and PXDN to renal inflammation and tubulointerstitial fibrosis in the murine unilateral ureteral obstruction (UUO) model. Using a nonspecific inhibitor of animal heme peroxidases and peroxidase-specific knockout mice, we find that loss of EPX or PXDN, but not MPO, reduces renal fibrosis. Furthermore, we demonstrate that eosinophils, the source of EPX, accumulate in the renal interstitium after UUO. These findings point to EPX and PXDN as potential therapeutic targets for renal fibrosis and CKD and suggest that eosinophils modulate the response to renal injury.
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Affiliation(s)
- Selene Colon
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Haiyan Luan
- Department of Basic Medical Sciences, Jiamusi University, Jiamusi, China
| | - Yan Liu
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine , Nashville, Tennessee
- Department of Veterans Affairs, Tennessee Valley Health Care System, Nashville, Tennessee
| | - Cameron Meyer
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
| | - Gautam Bhave
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
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13
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Chung S, Overstreet JM, Li Y, Wang Y, Niu A, Wang S, Fan X, Sasaki K, Jin GN, Khodo SN, Gewin L, Zhang MZ, Harris RC. TGF-β promotes fibrosis after severe acute kidney injury by enhancing renal macrophage infiltration. JCI Insight 2018; 3:123563. [PMID: 30385721 DOI: 10.1172/jci.insight.123563] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/19/2018] [Indexed: 12/28/2022] Open
Abstract
TGF-β signals through a receptor complex composed of 2 type I and 2 type II (TGF-βRII) subunits. We investigated the role of macrophage TGF-β signaling in fibrosis after AKI in mice with selective monocyte/macrophage TGF-βRII deletion (macrophage TGF-βRII-/- mice). Four weeks after injury, renal TGF-β1 expression and fibrosis were higher in WT mice than macrophage TGF-βRII-/- mice, which had decreased renal macrophages. The in vitro chemotactic response to f-Met-Leu-Phe was comparable between bone marrow-derived monocytes (BMMs) from WT and macrophage TGF-βRII-/- mice, but TGF-βRII-/- BMMs did not respond to TGF-β. We then implanted Matrigel plugs suffused with either f-Met-Leu-Phe or TGF-β1 into WT or macrophage TGF-βRII-/- mice. After 6 days, f-Met-Leu-Phe induced similar macrophage infiltration into the Matrigel plugs of WT and macrophage TGF-βRII-/- mice, but TGF-β induced infiltration only in WT mice. We further determined the number of labeled WT or TGF-βRII-/- BMMs infiltrating into WT kidneys 20 days after ischemic injury. There were more labeled WT BMMs than TGF-βRII-/- BMMs. Therefore, macrophage TGF-βRII deletion protects against the development of tubulointerstitial fibrosis following severe ischemic renal injury. Chemoattraction of macrophages to the injured kidney through a TGF-β/TGF-βRII axis is a heretofore undescribed mechanism by which TGF-β can mediate renal fibrosis during progressive renal injury.
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Affiliation(s)
- Sungjin Chung
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jessica M Overstreet
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Yan Li
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Yinqiu Wang
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Aolei Niu
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Suwan Wang
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Xiaofeng Fan
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Kensuke Sasaki
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Guan-Nan Jin
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Stellor Nlandu Khodo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Leslie Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ming-Zhi Zhang
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Department of Veterans Affairs, Nashville, Tennessee, USA
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14
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Chang Y, Lau WL, Jo H, Tsujino K, Gewin L, Reed NI, Atakilit A, Nunes ACF, DeGrado WF, Sheppard D. Pharmacologic Blockade of αv β1 Integrin Ameliorates Renal Failure and Fibrosis In Vivo. J Am Soc Nephrol 2017; 28:1998-2005. [PMID: 28220032 DOI: 10.1681/asn.2015050585] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 01/11/2017] [Indexed: 12/12/2022] Open
Abstract
Activated fibroblasts are deemed the main executors of organ fibrosis. However, regulation of the pathologic functions of these cells in vivo is poorly understood. PDGF receptor β (PDGFRβ) is highly expressed in activated pericytes, a main source of fibroblasts. Studies using a PDGFRβ promoter-driven Cre system to delete αv integrins in activated fibroblasts identified these integrins as core regulators of fibroblast activity across solid organs, including the kidneys. Here, we used the same PDGFRβ-Cre line to isolate and study renal fibroblasts ex vivo We found that renal fibroblasts express three αv integrins, namely αvβ1, αvβ3, and αvβ5. Blockade of αvβ1 prevented direct binding of fibroblasts to the latency-associated peptide of TGF-β1 and prevented activation of the latent TGF-β complex. Continuous administration of a recently described potent small molecule inhibitor of αvβ1, compound 8, starting the day of unilateral ureteral obstruction operation, inhibited collagen deposition in the kidneys of mice 14 days later. Compound 8 also effectively attenuated renal failure, as measured by BUN levels in mice fed an adenine diet known to cause renal injury followed by fibrosis. Inhibition of αvβ1 integrin could thus hold promise as a therapeutic intervention in CKD characterized by renal fibrosis.
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Affiliation(s)
- Yongen Chang
- Division of Nephrology, Department of Medicine, University of California Irvine, Irvine, California;
| | - Wei Ling Lau
- Division of Nephrology, Department of Medicine, University of California Irvine, Irvine, California
| | - Hyunil Jo
- Department of Pharmaceutical Chemistry and
| | - Kazuyuki Tsujino
- Division of Pulmonary and Critical Care, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Nilgun Isik Reed
- Division of Pulmonary and Critical Care, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Amha Atakilit
- Division of Pulmonary and Critical Care, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | | | | | - Dean Sheppard
- Division of Pulmonary and Critical Care, Department of Medicine, University of California San Francisco, San Francisco, California; and
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15
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Gewin L, Zent R, Pozzi A. Progression of chronic kidney disease: too much cellular talk causes damage. Kidney Int 2016; 91:552-560. [PMID: 27773427 DOI: 10.1016/j.kint.2016.08.025] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/31/2016] [Accepted: 08/16/2016] [Indexed: 01/10/2023]
Abstract
Tubulointerstitial fibrosis, tubular atrophy, and peritubular capillary rarefaction are major hallmarks of chronic kidney disease. The tubulointerstitium consists of multiple cell components including tubular epithelial, mesenchymal (fibroblasts and pericytes), endothelial, and inflammatory cells. Crosstalk among these cell components is a key component in the pathogenesis of this complex disease. After severe or recurrent injury, the renal tubular epithelial cells undergo changes in structure and cell cycle that are accompanied by altered expression and production of cytokines. These cytokines contribute to the initiation of the fibrotic response by favoring activation of fibroblasts, recruitment of inflammatory cells, and loss of endothelial cells. This review focuses on how augmented growth factor and cytokine production induces epithelial crosstalk with cells in the interstitium to promote progressive tubulointerstitial fibrosis after renal injury.
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Affiliation(s)
- Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA.
| | - Ambra Pozzi
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee, USA; Veterans Affairs Medical Center, Nashville, Tennessee, USA; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee, USA; Department of Molecular Physiology and Biophysics, Vanderbilt Medical Center, Nashville, Tennessee, USA
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16
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17
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Nlandu Khodo S, Neelisetty S, Woodbury L, Green E, Harris RC, Zent R, Gewin L. Deleting the TGF-β receptor in proximal tubules impairs HGF signaling. Am J Physiol Renal Physiol 2016; 310:F499-510. [PMID: 26739889 DOI: 10.1152/ajprenal.00446.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/30/2015] [Indexed: 01/26/2023] Open
Abstract
Transforming growth factor-β (TGF-β) and hepatocyte growth factor (HGF) play key roles in regulating the response to renal injury but are thought to mediate divergent effects on cell behavior. However, how TGF-β signaling alters the response to HGF in epithelia, the key site of HGF signaling in the injured kidney, is not well studied. Contrary to our expectation, we showed that deletion of the TGF-β type II receptor in conditionally immortalized proximal tubule (PT) cells impaired HGF-dependent signaling. This reduced signaling was due to decreased transcription of c-Met, the HGF receptor, and the TGF-β-dependent c-Met transcription and increased response to HGF in PT cells were mediated by the Notch pathway. The interactions of TGF-β, HGF, and Notch pathways had biologically significant effects on branching morphogenesis, cell morphology, migration, and proliferation. In conclusion, epithelial TGF-β signaling promotes HGF signaling in a Notch-dependent pathway. These findings suggest that TGF-β modulates PT responses not only by direct effects, but also by affecting other growth factor signaling pathways.
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Affiliation(s)
- Stellor Nlandu Khodo
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Surekha Neelisetty
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Luke Woodbury
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Elizabeth Green
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee
| | - Raymond C Harris
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Molecular Physiology and Biophysics, Vanderbilt Medical Center, Nashville, Tennessee; Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Roy Zent
- Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cancer Biology, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee; Department of Medicine, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Leslie Gewin
- Department of Research, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee; and Division of Nephrology, Department of Medicine, Vanderbilt Medical Center, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee;
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18
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Chen X, Wang H, Liao HJ, Hu W, Gewin L, Mernaugh G, Zhang S, Zhang ZY, Vega-Montoto L, Vanacore RM, Fässler R, Zent R, Pozzi A. Integrin-mediated type II TGF-β receptor tyrosine dephosphorylation controls SMAD-dependent profibrotic signaling. J Clin Invest 2014; 124:3295-310. [PMID: 24983314 DOI: 10.1172/jci71668] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 05/21/2014] [Indexed: 12/20/2022] Open
Abstract
Tubulointerstitial fibrosis underlies all forms of end-stage kidney disease. TGF-β mediates both the development and the progression of kidney fibrosis through binding and activation of the serine/threonine kinase type II TGF-β receptor (TβRII), which in turn promotes a TβRI-mediated SMAD-dependent fibrotic signaling cascade. Autophosphorylation of serine residues within TβRII is considered the principal regulatory mechanism of TβRII-induced signaling; however, there are 5 tyrosine residues within the cytoplasmic tail that could potentially mediate TβRII-dependent SMAD activation. Here, we determined that phosphorylation of tyrosines within the TβRII tail was essential for SMAD-dependent fibrotic signaling within cells of the kidney collecting duct. Conversely, the T cell protein tyrosine phosphatase (TCPTP) dephosphorylated TβRII tail tyrosine residues, resulting in inhibition of TβR-dependent fibrotic signaling. The collagen-binding receptor integrin α1β1 was required for recruitment of TCPTP to the TβRII tail, as mice lacking this integrin exhibited impaired TCPTP-mediated tyrosine dephosphorylation of TβRII that led to severe fibrosis in a unilateral ureteral obstruction model of renal fibrosis. Together, these findings uncover a crosstalk between integrin α1β1 and TβRII that is essential for TβRII-mediated SMAD activation and fibrotic signaling pathways.
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19
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Zhang MZ, Wang Y, Yao B, Gewin L, Wei S, Capdevila JH, Harris RC. Role of epoxyeicosatrienoic acids (EETs) in mediation of dopamine's effects in the kidney. Am J Physiol Renal Physiol 2013; 305:F1680-6. [PMID: 24154693 DOI: 10.1152/ajprenal.00409.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We have recently demonstrated that intrarenal dopamine plays an important role in preventing the development of systemic hypertension. Similarly, renal cytochrome P-450 (CYP)-epoxygenase-derived arachidonic acid metabolites, epoxyeicosatrienoic acids (EETs), also are antihypertensive through inhibiting sodium reabsorption and vasodilation. The potential interaction between renal dopamine and epoxygenase systems was investigated. Catechol-O-methyl-transferase (COMT)(-/-) mice with increased intrarenal dopamine levels and proximal tubule deletion of aromatic amino acid decarboxylase (ptAADC(-/-)) mice with renal dopamine deficiency were treated with a low-salt diet or high-salt diet for 2 wk. Wild-type or Cyp2c44(-/-) mice were treated with gludopa, which selectively increased renal dopamine levels. In low salt-treated mice, urinary EET levels were related to renal dopamine levels, being highest in COMT(-/-) mice and lowest in ptAADC(-/-) mice. In high salt-treated mice, total EET and individual EET levels in both the kidney and urine were also highest in COMT(-/-) mice and lowest in ptAADC(-/-) mice. Selective increases in renal dopamine in response to gludopa administration led to marked increases in both total and all individual EET levels in the kidney without any changes in blood levels. qRT-PCR and immunoblotting indicated that gludopa increased renal Cyp2c44 mRNA and protein levels. Gludopa induced marked increases in urine volume and urinary sodium excretion in wild-type mice. In contrast, gludopa did not induce significant increases in urine volume or urinary sodium excretion in Cyp2c44(-/-) mice. These studies demonstrate that renal EET levels are maintained by intrarenal dopamine, and Cyp2c44-derived EETs play an important role in intrarenal dopamine-induced natriuresis and diuresis.
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Affiliation(s)
- Ming-Zhi Zhang
- Div. of Nephrology, C3121 MCN, Vanderbilt Univ. School of Medicine and Nashville Veterans Affairs Hospital, Nashville, TN 37232.
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21
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Gewin L, Vadivelu S, Neelisetty S, Srichai MB, Paueksakon P, Pozzi A, Harris RC, Zent R. Deleting the TGF-β receptor attenuates acute proximal tubule injury. J Am Soc Nephrol 2012; 23:2001-11. [PMID: 23160515 DOI: 10.1681/asn.2012020139] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
TGF-β is a profibrotic growth factor in CKD, but its role in modulating the kidney's response to AKI is not well understood. The proximal tubule epithelial cell, which is the main cellular target of AKI, expresses high levels of both TGF-β and its receptors. To determine how TGF-β signaling in this tubular segment affects the response to AKI, we selectively deleted the TGF-β type II receptor in the proximal tubules of mice. This deletion attenuated renal impairment and reduced tubular apoptosis in mercuric chloride-induced injury. In vitro, deficiency of the TGF-β type II receptor protected proximal tubule epithelial cells from hydrogen peroxide-induced apoptosis, which was mediated in part by Smad-dependent signaling. Taken together, these results suggest that TGF-β signaling in the proximal tubule has a detrimental effect on the response to AKI as a result of its proapoptotic effects.
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Affiliation(s)
- Leslie Gewin
- Department of Research, Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
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Srichai MB, Colleta H, Gewin L, Matrisian L, Abel TW, Koshikawa N, Seiki M, Pozzi A, Harris RC, Zent R. Membrane-type 4 matrix metalloproteinase (MT4-MMP) modulates water homeostasis in mice. PLoS One 2011; 6:e17099. [PMID: 21347258 PMCID: PMC3037967 DOI: 10.1371/journal.pone.0017099] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 01/19/2011] [Indexed: 12/11/2022] Open
Abstract
MT4-MMP is a membrane-type metalloproteinase (MMP) anchored to the membrane by a glycosyl-phosphatidylinositol (GPI) motif. GPI-type MT-MMPs (MT4- and MT6-MMP) are related to other MT-MMPs, but their physiological substrates and functions in vivo have yet to be identified. In this manuscript we show that MT4-MMP is expressed early in kidney development, as well as in the adult kidney, where the highest levels of expression are found in the papilla. MT4-MMP null mice had minimal renal developmental abnormalities, with a minor branching morphogenesis defect in early embryonic kidney development and slightly dysmorphic collecting ducts in adult mice. Interestingly, MT4-MMP null mice had higher baseline urine osmolarities relative to wild type controls, but these animals were able to concentrate and dilute their urines normally. However, MT4-MMP-null mice had decreased daily water intake and daily urine output, consistent with primary hypodipsia. MT4-MMP was shown to be expressed in areas of the hypothalamus considered important for regulating thirst. Thus, our results show that although MT4-MMP is expressed in the kidney, this metalloproteinase does not play a major role in renal development or function; however it does appear to modify the neural stimuli that modulate thirst.
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Affiliation(s)
- Manakan B. Srichai
- Department of Medicine, Veterans Administration Hospital, Nashville, Tennessee, United States of America
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Heloisa Colleta
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Linsey Matrisian
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Ty W. Abel
- Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Naohiko Koshikawa
- Division of Cancer Cell Research, Institute of Medical Science, University of Tokyo, Minato ku, Tokyo, Japan
| | - Motoharu Seiki
- Division of Cancer Cell Research, Institute of Medical Science, University of Tokyo, Minato ku, Tokyo, Japan
| | - Ambra Pozzi
- Department of Medicine, Veterans Administration Hospital, Nashville, Tennessee, United States of America
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Raymond C. Harris
- Department of Medicine, Veterans Administration Hospital, Nashville, Tennessee, United States of America
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Roy Zent
- Department of Medicine, Veterans Administration Hospital, Nashville, Tennessee, United States of America
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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23
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Gewin L, Bulus N, Mernaugh G, Moeckel G, Harris RC, Moses HL, Pozzi A, Zent R. TGF-beta receptor deletion in the renal collecting system exacerbates fibrosis. J Am Soc Nephrol 2010; 21:1334-43. [PMID: 20576806 DOI: 10.1681/asn.2010020147] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
TGF-beta plays a key role in upregulating matrix production in injury-induced renal fibrosis, but how TGF-beta signaling in distinct compartments of the kidney, such as specific segments of the nephron, affects the response to injury is unknown. In this study, we determined the role of TGF-beta signaling both in development of the renal collecting system and in response to injury by selectively deleting the TGF-beta type II receptor in mice at the initiation of ureteric bud development. These mice developed normally but demonstrated a paradoxic increase in fibrosis associated with enhanced levels of active TGF-beta after unilateral ureteral obstruction. Consistent with this observation, TGF-beta type II receptor deletion in cultured collecting duct cells resulted in excessive integrin alphavbeta6-dependent TGF-beta activation that increased collagen synthesis in co-cultured renal interstitial fibroblasts. These results suggest that inhibiting TGF-beta receptor-mediated function in collecting ducts may exacerbate renal fibrosis by enhancing paracrine TGF-beta signaling between epithelial and interstitial cells.
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Affiliation(s)
- Leslie Gewin
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Zhang X, Mernaugh G, Yang DH, Gewin L, Srichai MB, Harris RC, Iturregui JM, Nelson RD, Kohan DE, Abrahamson D, Fässler R, Yurchenco P, Pozzi A, Zent R. beta1 integrin is necessary for ureteric bud branching morphogenesis and maintenance of collecting duct structural integrity. Development 2009; 136:3357-66. [PMID: 19710172 DOI: 10.1242/dev.036269] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The kidney collecting system develops from branching morphogenesis of the ureteric bud (UB). This process requires signaling by growth factors such as glial cell line derived neurotrophic factor (GDNF) and fibroblast growth factors (FGFs) as well as cell extracellular matrix interactions mediated by integrins. The importance of integrin signaling in UB development was investigated by deleting integrin beta1 at initiation (E10.5) and late (E18.5) stages of development. Deletion at E10.5 resulted in a severe branching morphogenesis phenotype. Deletion at E18.5 did not alter renal development but predisposed the collecting system to severe injury following ureteric obstruction. beta1 integrin was required for renal tubular epithelial cells to mediate GDNF- and FGF-dependent signaling despite normal receptor localization and activation in vitro. Aberrations in the same signaling molecules were present in the beta1-null UBs in vivo. Thus beta1 integrins can regulate organ branching morphogenesis during development by mediating growth-factor-dependent signaling in addition to their well-defined role as adhesion receptors.
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Affiliation(s)
- Xi Zhang
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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25
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Abstract
Human papillomavirus type 16 (HPV-16) E6 activates telomerase specifically in epithelial cells. The oncogene c-myc has also been shown to activate telomerase in several cell types. Here we show that while both HPV-16 E6 and c-myc require intact E boxes to transactivate the hTERT promoter, E6 does not induce hTERT transcription simply by inducing expression of c-myc. Moreover, hTERT transactivation by HPV-16 E6 correlates with its ability to bind the cellular E6-associated protein (E6AP), suggesting that E6 and E6AP may target a regulator of hTERT expression.
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Affiliation(s)
- L Gewin
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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26
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Abstract
Deinococcus radiodurans is a highly radiation-resistant bacterium that is classed in a major subbranch of the bacterial domain. Since very little is known about gene expression in this bacterium, an initial study of promoters was undertaken. In order to isolate promoters and study promoter function, a series of integrative vectors for stable chromosomal insertion in D. radiodurans were developed. These vectors are based on Escherichia coli replicons that are unable to replicate autonomously in D. radiodurans and carry homologous sequences for replacement recombination in the D. radiodurans chromosome. The resulting integration vectors were used to study expression of reporter genes fused to a number of putative promoters that were amplified from the D. radiodurans R1 genome. Further analysis of these and other putative promoters was performed by Northern hybridization and primer extension experiments. In contrast to previous reports, the -10 and -35 regions of these promoters resembled the sigma(70) consensus sequence of E. coli.
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Affiliation(s)
- R Meima
- Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA
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27
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Abstract
While p53 activity is critical for a DNA damage-induced G(1) checkpoint, its role in the G(2) checkpoint has not been compelling because cells lacking p53 retain the ability to arrest in G(2) following DNA damage. Comparison between normal human foreskin fibroblasts (HFFs) and HFFs in which p53 was eliminated by transduction with human papillomavirus type 16 E6 showed that treatment with adriamycin initiated arrest in G(2) with active cyclin B/CDC2 kinase, regardless of p53 status. Both E6-transduced HFFs and control (LXSN)-transduced cells maintained a prolonged arrest in G(2); however cells with functional p53 extinguished cyclin B-associated kinase activity. Down regulation was mediated by p53-dependent transcriptional repression of the CDC2 and cyclin B promoters. In contrast, cells lacking p53 showed a prolonged G(2) arrest despite high levels of cyclin B/CDC2 kinase activity, at least some of which translocated into the nucleus. Furthermore, the G(2) checkpoint became attenuated as p53-deficient cells aged in culture. Thus, at late passage, E6-transduced HFFs entered mitosis following DNA damage, whereas the age-matched parental HFFs sustained a G(2) arrest. These results indicate that normal cells have p53-independent pathways to maintain DNA damage-induced G(2) arrest, which may be augmented by p53-dependent functions, and that cells lacking p53 are at greater risk of losing the pathway that protects against aneuploidy.
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Affiliation(s)
- T M Passalaris
- Program in Cancer Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA
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