1
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Hammoud S, Ivanova A, Osaki Y, Funk S, Yang H, Viquez O, Delgado R, Lu D, Phillips Mignemi M, Tonello J, Colon S, Lantier L, Wasserman DH, Humphreys BD, Koenitzer J, Kern J, de Caestecker M, Finkel T, Fogo A, Messias N, Lodhi IJ, Gewin LS. Tubular CPT1A deletion minimally affects aging and chronic kidney injury. JCI Insight 2024; 9:e181816. [PMID: 38716735 DOI: 10.1172/jci.insight.181816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024] Open
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2
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Hammoud S, Ivanova A, Osaki Y, Funk S, Yang H, Viquez O, Delgado R, Lu D, Phillips Mignemi M, Tonello J, Colon S, Lantier L, Wasserman DH, Humphreys BD, Koenitzer J, Kern J, de Caestecker M, Finkel T, Fogo A, Messias N, Lodhi IJ, Gewin LS. Tubular CPT1A deletion minimally affects aging and chronic kidney injury. JCI Insight 2024; 9:e171961. [PMID: 38516886 PMCID: PMC11063933 DOI: 10.1172/jci.insight.171961] [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: 05/02/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction. Surprisingly, Cpt1aCKO mice had no significant differences in kidney function or fibrosis compared with wild-type mice after aging or chronic injury. Primary tubule cells from aged Cpt1aCKO mice had a modest decrease in palmitate oxidation but retained the ability to metabolize long-chain fatty acids. Very-long-chain fatty acids, exclusively oxidized by peroxisomes, were reduced in kidneys lacking tubular CPT1A, consistent with increased peroxisomal activity. Single-nuclear RNA-Seq showed significantly increased expression of peroxisomal FAO enzymes in proximal tubules of mice lacking tubular CPT1A. These data suggest that peroxisomal FAO may compensate in the absence of CPT1A, and future genetic studies are needed to confirm the role of peroxisomal β-oxidation when mitochondrial FAO is impaired.
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Affiliation(s)
- Safaa Hammoud
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Alla Ivanova
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Yosuke Osaki
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Steven Funk
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Haichun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Olga Viquez
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Rachel Delgado
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Dongliang Lu
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Jane Tonello
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Selene Colon
- Division of Nephrology and Hypertension, Department of Medicine, and
| | - Louise Lantier
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - David H. Wasserman
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Benjamin D. Humphreys
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jeffrey Koenitzer
- Division of Pulmonary Critical Care Medicine, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Justin Kern
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Toren Finkel
- Aging Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Agnes Fogo
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Nidia Messias
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Leslie S. Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Nephrology and Hypertension, Department of Medicine, and
- Department of Medicine, Veterans Affairs Hospital, St. Louis, Missouri, USA
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3
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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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4
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Hyndman KA, Hukriede N, de Caestecker M. Introduction: The 2022 Acute Kidney Injury: Bench to Bedside Conference. Semin Nephrol 2022; 42:151275. [PMID: 36402655 DOI: 10.1016/j.semnephrol.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Kelly A Hyndman
- Division of Nephrology, The University of Alabama at Birmingham, Birmingham, AL
| | - Neil Hukriede
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA
| | - Mark de Caestecker
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN.
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5
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Long K, Vaughn Z, McDaniels MD, Joyasawal S, Przepiorski A, Parasky E, Sander V, Close D, Johnston PA, Davidson AJ, de Caestecker M, Hukriede NA, Huryn DM. Validation of HDAC8 Inhibitors as Drug Discovery Starting Points to Treat Acute Kidney Injury. ACS Pharmacol Transl Sci 2022; 5:207-215. [PMID: 35434532 PMCID: PMC9003639 DOI: 10.1021/acsptsci.1c00243] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Indexed: 12/25/2022]
Abstract
Acute kidney injury (AKI), a sudden loss of kidney function, is a common and serious condition for which there are no approved specific therapies. While there are multiple approaches to treat the underlying causes of AKI, no targets have been clinically validated. Here, we assessed a series of potent, selective competitive inhibitors of histone deacetylase 8 (HDAC8), a promising therapeutic target in an AKI setting. Using biochemical assays, zebrafish AKI phenotypic assays, and human kidney organoid assays, we show that selective HDAC8 inhibitors can lead to efficacy in increasingly stringent models. One of these, PCI-34051, was efficacious in a rodent model of AKI, further supporting the potential for HDAC8 inhibitors and, in particular, this scaffold as a therapeutic approach to AKI.
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Affiliation(s)
- Keith Long
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Zoe Vaughn
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Michael David McDaniels
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Sipak Joyasawal
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Aneta Przepiorski
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Emily Parasky
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Veronika Sander
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand 1010
| | - David Close
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Paul A Johnston
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Alan J Davidson
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand 1010
| | - Mark de Caestecker
- Department of Medicine, Division of Nephrology, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Neil A Hukriede
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Donna M Huryn
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Developmental Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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6
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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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7
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De La Cruz LK, Yang X, Menshikh A, Brewer M, Lu W, Wang M, Wang S, Ji X, Cachuela A, Yang H, Gallo D, Tan C, Otterbein L, de Caestecker M, Wang B. Adapting decarbonylation chemistry for the development of prodrugs capable of in vivo delivery of carbon monoxide utilizing sweeteners as carrier molecules. Chem Sci 2021; 12:10649-10654. [PMID: 34447558 PMCID: PMC8356820 DOI: 10.1039/d1sc02711e] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Carbon monoxide as an endogenous signaling molecule exhibits pharmacological efficacy in various animal models of organ injury. To address the difficulty in using CO gas as a therapeutic agent for widespread applications, we are interested in developing CO prodrugs through bioreversible caging of CO in an organic compound. Specifically, we have explored the decarboxylation-decarbonylation chemistry of 1,2-dicarbonyl compounds. Examination and optimization of factors favorable for maximal CO release under physiological conditions led to organic CO prodrugs using non-calorific sweeteners as leaving groups attached to the 1,2-dicarbonyl core. Attaching a leaving group with appropriate properties promotes the desired hydrolysis-decarboxylation-decarbonylation sequence of reactions that leads to CO generation. One such CO prodrug was selected to recapitulate the anti-inflammatory effects of CO against LPS-induced TNF-α production in cell culture studies. Oral administration in mice elevated COHb levels to the safe and efficacious levels established in various preclinical and clinical studies. Furthermore, its pharmacological efficacy was demonstrated in mouse models of acute kidney injury. These studies demonstrate the potential of these prodrugs with benign carriers as orally active CO-based therapeutics. This represents the very first example of orally active organic CO prodrugs with a benign carrier that is an FDA-approved sweetener with demonstrated safety profiles in vivo.
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Affiliation(s)
| | - Xiaoxiao Yang
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
| | - Anna Menshikh
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center Nashville TN 37232 USA
| | - Maya Brewer
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center Nashville TN 37232 USA
| | - Wen Lu
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
| | - Minjia Wang
- Department of Pharmaceutics and Drug Delivery, University of Mississippi MS 38677 USA
| | - Siming Wang
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
| | - Xingyue Ji
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
| | - Alyssa Cachuela
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
| | - Haichun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center Nashville TN 37232 USA
| | - David Gallo
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School Boston MA 02115 USA
| | - Chalet Tan
- Department of Pharmaceutics and Drug Delivery, University of Mississippi MS 38677 USA
| | - Leo Otterbein
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School Boston MA 02115 USA
| | - Mark de Caestecker
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center Nashville TN 37232 USA
| | - Binghe Wang
- Department of Chemistry, Georgia State University Atlanta GA 30303 USA
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8
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de Caestecker M. CDKL5: a promising new therapeutic target for acute kidney injury? Am J Physiol Renal Physiol 2020; 319:F865-F867. [PMID: 33073588 DOI: 10.1152/ajprenal.00535.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
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9
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Yang X, de Caestecker M, Otterbein LE, Wang B. Carbon monoxide: An emerging therapy for acute kidney injury. Med Res Rev 2020. [PMID: 31820474 DOI: 10.1012/med.21650] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.
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Affiliation(s)
- Xiaoxiao Yang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Leo E Otterbein
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Binghe Wang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
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10
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Terker AS, de Caestecker M. Modeling human disease: a mouse model of acute kidney injury to chronic kidney disease progression after cardiac arrest. Kidney Int 2020; 97:22-24. [PMID: 31901349 PMCID: PMC7197020 DOI: 10.1016/j.kint.2019.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 08/17/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 10/25/2022]
Abstract
Matsushita et al. describe a model of acute kidney injury to chronic kidney disease progression in mice surviving cardiac arrest: mice develop severe acute kidney injury that initially recovers but is followed by the onset of impaired renal function on longer-term follow-up. These findings suggest that distinct cardiorenal toxicities and/or injury dynamics are operative in this cardiac arrest model that do not occur in traditional models of acute kidney injury, providing new opportunities for therapeutic and biomarker discovery for an important clinical problem.
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Affiliation(s)
- Andrew Scott Terker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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11
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Yang X, de Caestecker M, Otterbein LE, Wang B. Carbon monoxide: An emerging therapy for acute kidney injury. Med Res Rev 2019; 40:1147-1177. [PMID: 31820474 DOI: 10.1002/med.21650] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [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: 07/28/2019] [Revised: 10/31/2019] [Accepted: 11/20/2019] [Indexed: 12/11/2022]
Abstract
Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.
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Affiliation(s)
- Xiaoxiao Yang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Leo E Otterbein
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Binghe Wang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
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12
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Scarfe L, Schock-Kusch D, Ressel L, Friedemann J, Shulhevich Y, Murray P, Wilm B, de Caestecker M. Transdermal Measurement of Glomerular Filtration Rate in Mice. J Vis Exp 2018. [PMID: 30394397 PMCID: PMC6235579 DOI: 10.3791/58520] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Transdermal analysis of glomerular filtration rate (GFR) is an established technique that is used to assess renal function in mouse and rat models of acute kidney injury and chronic kidney disease. The measurement system consists of a miniaturized fluorescence detector that is directly attached to the skin on the back of conscious, freely moving animals, and measures the excretion kinetics of the exogenous GFR tracer, fluorescein-isothiocyanate (FITC) conjugated sinistrin (an inulin analog). This system has been described in detail in rats. However, because of their smaller size, measurement of transcutaneous GFR in mice presents additional technical challenges. In this paper we therefore provide the first detailed practical guide to the use of transdermal GFR monitors in mice based on the combined experience of three different investigators who have been performing this assay in mice over a number of years.
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Affiliation(s)
- Lauren Scarfe
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center; Department of Cellular and Molecular Physiology, University of Liverpool
| | | | - Lorenzo Ressel
- Department of Veterinary Pathology and Public Health, Institute of Veterinary Science, University of Liverpool
| | | | | | - Patricia Murray
- Department of Cellular and Molecular Physiology, University of Liverpool
| | - Bettina Wilm
- Department of Cellular and Molecular Physiology, University of Liverpool;
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center;
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13
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Zuk A, Palevsky PM, Fried L, Harrell FE, Khan S, McKay DB, Devey L, Chawla L, de Caestecker M, Kaufman JS, Thompson BT, Agarwal A, Greene T, Okusa MD, Bonventre JV, Dember LM, Liu KD, Humphreys BD, Gossett D, Xie Y, Norton JM, Kimmel PL, Star RA. Overcoming Translational Barriers in Acute Kidney Injury: A Report from an NIDDK Workshop. Clin J Am Soc Nephrol 2018; 13:1113-1123. [PMID: 29523680 PMCID: PMC6032575 DOI: 10.2215/cjn.06820617] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [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] [Indexed: 12/14/2022]
Abstract
AKI is a complex clinical condition associated with high mortality, morbidity, and health care costs. Despite improvements in methodology and design of clinical trials, and advances in understanding the underlying pathophysiology of rodent AKI, no pharmacologic agent exists for the prevention or treatment of AKI in humans. To address the barriers that affect successful clinical translation of drug targets identified and validated in preclinical animal models of AKI in this patient population, the National Institute of Diabetes and Digestive and Kidney Diseases convened the "AKI Outcomes: Overcoming Barriers in AKI" workshop on February 10-12, 2015. The workshop used a reverse translational medicine approach to identify steps necessary to achieve clinical success. During the workshop, breakout groups were charged first to design feasible, phase 2, proof-of-concept clinical trials for delayed transplant graft function, prevention of AKI (primary prevention), and treatment of AKI (secondary prevention and recovery). Breakout groups then were responsible for identification of preclinical animal models that would replicate the pathophysiology of the phase 2 proof-of-concept patient population, including primary and secondary end points. Breakout groups identified considerable gaps in knowledge regarding human AKI, our understanding of the pathophysiology of AKI in preclinical animal models, and the fidelity of cellular and molecular targets that have been evaluated preclinically to provide information regarding human AKI of various etiologies. The workshop concluded with attendees defining a new path forward to a better understanding of the etiology, pathology, and pathophysiology of human AKI.
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Affiliation(s)
- Anna Zuk
- Akebia R&D, Akebia Therapeutics Inc., Cambridge, Massachusetts
| | - Paul M. Palevsky
- Department of Medicine, VA Pittsburgh Healthcare System/University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Linda Fried
- Department of Medicine, VA Pittsburgh Healthcare System/University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Frank E. Harrell
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Samina Khan
- Department of Clinical Development, Quark Pharmaceuticals, Fremont, California
| | - Dianne B. McKay
- Department of Medicine, University of California, San Diego, San Diego, California
| | - Luke Devey
- Heart Failure Discovery Performance Unit, GlaxoSmithKline, King of Prussia, Pennsylvania
| | - Lakhmir Chawla
- Department of Medicine, The George Washington University, Washington, DC
| | - Mark de Caestecker
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - James S. Kaufman
- Department of Medicine, VA New York Harbor Healthcare System, New York, New York
| | - B. Taylor Thompson
- Pulmonary and Critical Care Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Anupam Agarwal
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tom Greene
- Department of Epidemiology, University of Utah, Salt Lake City, Utah
| | - Mark Douglas Okusa
- Department of Medicine and Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - Joseph V. Bonventre
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Laura M. Dember
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kathleen D. Liu
- Department of Medicine and Nephrology, University of California San Francisco, San Francisco, California
| | - Benjamin D. Humphreys
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Daniel Gossett
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Yining Xie
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jenna M. Norton
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Paul L. Kimmel
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Robert A. Star
- Division of Kidney, Urologic and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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14
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Abstract
No therapies have been shown to improve outcomes in patients with acute kidney injury (AKI). Given the high morbidity and mortality associated with AKI this represents an important unmet medical need. A common feature of all of the therapeutic development efforts for AKI is that none were driven by target selection or preclinical modeling that was based primarily on human data. This is important when considering a heterogeneous and dynamic condition such as AKI, in which in the absence of more accurate molecular classifications, clinical cohorts are likely to include patients with different types of injury at different stages in the injury and repair continuum. The National Institutes of Health precision medicine initiative offers an opportunity to address this. By creating a molecular tissue atlas of AKI, defining patient subgroups, and identifying critical cells and pathways involved in human AKI, this initiative has the potential to transform our current approach to therapeutic discovery. In this review, we discuss the opportunities and challenges that this initiative presents, with a specific focus on AKI, what additional efforts will be needed to apply these discoveries to therapeutic development, and how we believe this effort might lead to the development of new therapeutics for subsets of patients with AKI.
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Affiliation(s)
- Mark de Caestecker
- Nephrology Division, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Raymond Harris
- Nephrology Division, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
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15
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Hukriede N, Vogt A, de Caestecker M. Drug Discovery to Halt the Progression of Acute Kidney Injury to Chronic Kidney Disease: A Case for Phenotypic Drug Discovery in Acute Kidney Injury. Nephron Clin Pract 2017; 137:268-272. [PMID: 28614822 DOI: 10.1159/000476079] [Citation(s) in RCA: 8] [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: 04/19/2017] [Accepted: 04/24/2017] [Indexed: 12/29/2022] Open
Abstract
The cellular responses that occur following acute kidney injury (AKI) are complex and dynamic, involving multiple cells types and molecular pathways. For this reason, early selection of defined molecular targets for therapeutic intervention is unlikely to be effective in complex in vivo models of AKI, let alone Phase 3 clinical trials in patients with even more complex AKI pathobiology. Phenotypic screening using zebrafish provides an attractive alternative that does not require prior knowledge of molecular targets and may identify compounds that modify multiple targets that might be missed in more traditional target-based screens. In this review, we discuss results of an academic drug discovery campaign that used zebrafish as a primary screening tool to discover compounds with favorable absorption, metabolism, and toxicity that enhance repair when given late after injury in multiple models of AKI. We discuss how this screening campaign is being integrated into a more comprehensive, phenotypic, and target-based screen for lead compound optimization.
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Affiliation(s)
- Neil Hukriede
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA, USA
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16
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West JD, Voss BM, Pavliv L, de Caestecker M, Hemnes AR, Carrier EJ. Antagonism of the thromboxane-prostanoid receptor is cardioprotective against right ventricular pressure overload. Pulm Circ 2016; 6:211-23. [PMID: 27252848 DOI: 10.1086/686140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH) and is a significant cause of morbidity and mortality in other forms of pulmonary hypertension. There are no approved therapies directed at preserving RV function. F-series and E-series isoprostanes are increased in heart failure and PAH, correlate to the severity of disease, and can signal through the thromboxane-prostanoid (TP) receptor, with effects from vasoconstriction to fibrosis. The goal of these studies was to determine whether blockade of the TP receptor with the antagonist CPI211 was beneficial therapeutically in PAH-induced RV dysfunction. Mice with RV dysfunction due to pressure overload by pulmonary artery banding (PAB) were given vehicle or CPI211. Two weeks after PAB, CPI211-treated mice were protected from fibrosis with pressure overload. Gene expression arrays and immunoblotting, quantitative histology and morphometry, and flow cytometric analysis were used to determine the mechanism of CPI211 protection. TP receptor inhibition caused a near normalization of fibrotic area, prevented cellular hypertrophy while allowing increased RV mass, increased expression of antifibrotic thrombospondin-4, and blocked induction of the profibrotic transforming growth factor β (TGF-β) pathway. A thromboxane synthase inhibitor or low-dose aspirin failed to replicate these results, which suggests that a ligand other than thromboxane mediates fibrosis through the TP receptor after pressure overload. This study suggests that TP receptor antagonism may improve RV adaptation in situations of pressure overload by decreasing fibrosis and TGF-β signaling.
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Affiliation(s)
- James D West
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Bryan M Voss
- Cumberland Pharmaceuticals, Nashville, Tennessee, USA
| | - Leo Pavliv
- Cumberland Pharmaceuticals, Nashville, Tennessee, USA
| | - Mark de Caestecker
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Anna R Hemnes
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Erica J Carrier
- Division of Allergy, Pulmonary, and Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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17
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Lowery J, King T, de Caestecker M. Reply to "Bone morphogenetic protein′s contribution to pulmonary artery hypertension". Surg Neurol Int 2016; 7:91. [PMID: 27857855 PMCID: PMC5093875 DOI: 10.4103/2152-7806.192635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 09/12/2016] [Indexed: 11/04/2022] Open
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18
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de Caestecker M, Humphreys BD, Liu KD, Fissell WH, Cerda J, Nolin TD, Askenazi D, Mour G, Harrell FE, Pullen N, Okusa MD, Faubel S. Bridging Translation by Improving Preclinical Study Design in AKI. J Am Soc Nephrol 2015; 26:2905-16. [PMID: 26538634 DOI: 10.1681/asn.2015070832] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [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: 12/22/2022] Open
Abstract
Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development.
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Affiliation(s)
- Mark de Caestecker
- Division of Nephology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Ben D Humphreys
- Division of Renal Diseases, Washington University School of Medicine, St. Louis, Missouri
| | - Kathleen D Liu
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - William H Fissell
- Division of Nephology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jorge Cerda
- Division of Nephrology and Hypertension, Albany Medical College, Albany, New York
| | - Thomas D Nolin
- Renal-Electrolyte Division, Department of Medicine and Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - David Askenazi
- Department of Pediatrics, Division of Nephrology, University of Alabama, Birmingham, Alabama
| | - Girish Mour
- Renal-Electrolyte Division, Department of Medicine and Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Frank E Harrell
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Nick Pullen
- Pfizer Global Research and Development, Inflammation & Immunology Research Unit, Cambridge, Massachusetts
| | - Mark D Okusa
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California; Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Sarah Faubel
- Renal Division, University of Colorado Denver and Denver Veterans Affairs Medical Center, Aurora, Colorado
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19
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Pierce J, Murphy AJ, Panzer A, de Caestecker C, Ayers GD, Neblett D, Saito-Diaz K, de Caestecker M, Lovvorn HN. SIX2 Effects on Wilms Tumor Biology. Transl Oncol 2014; 7:800-11. [PMID: 25500091 PMCID: PMC4311027 DOI: 10.1016/j.tranon.2014.09.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 09/17/2014] [Indexed: 11/25/2022] Open
Abstract
Wilms tumor (WT) blastema retains gene expression profiles characteristic of the multipotent nephron progenitor pool, or cap mesenchyme (CM), in the developing kidney. As a result, WT blastema and the CM are believed to represent contextual analogues of one another. Sine oculis homeobox 2 (SIX2) is a transcription factor expressed specifically in the CM, provides a critical mechanism for CM self-renewal, and remains persistently active in WT blastema, although its purpose in this childhood malignancy remains unclear. We hypothesized that SIX2, analogous to its function in development, confers a survival pathway to blastema, the putative WT stem cell. To test its functional significance in WT biology, wild-type SIX2 was overexpressed in the human WT cell line, WiT49. After validating this model, SIX2 effects on anchorage-independent growth, proliferation, invasiveness, canonical WNT pathway signaling, and gene expression of specific WNT pathway participants were evaluated. Relative to controls, WiT49 cells overexpressing SIX2 showed significantly enhanced anchorage-independent growth and early-passage proliferation representing surrogates of cell survival. Interestingly, overexpression of SIX2 generally repressed TCF/LEF-dependent canonical WNT signaling, which activates and coordinates both differentiation and stem pathways, but significantly heightened canonical WNT signaling through the survivin promoter, a mechanism that exclusively maintains the stem state. In summary, when overexpressed in a human WT cell line, SIX2 enhances cell survival and appears to shift the balance in WNT/β-catenin signaling away from a differentiation path and toward a stem cell survival path.
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Affiliation(s)
- Janene Pierce
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Andrew J Murphy
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Alexis Panzer
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Christian de Caestecker
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gregory D Ayers
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - David Neblett
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kenyi Saito-Diaz
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Mark de Caestecker
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Harold N Lovvorn
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA.
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20
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Murphy AJ, Pierce J, de Caestecker C, Libes J, Neblett D, de Caestecker M, Perantoni AO, Tanigawa S, Anderson JR, Dome JS, Das A, Carroll TJ, Lovvorn HN. Aberrant activation, nuclear localization, and phosphorylation of Yes-associated protein-1 in the embryonic kidney and Wilms tumor. Pediatr Blood Cancer 2014; 61:198-205. [PMID: 24115727 PMCID: PMC3955491 DOI: 10.1002/pbc.24788] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Accepted: 08/28/2013] [Indexed: 01/15/2023]
Abstract
BACKGROUND The Yes-associated-protein-1 (YAP1) is a novel, direct regulator of stem cell genes both in development and cancer. FAT4 is an upstream regulator that induces YAP1 cytosolic sequestering by phosphorylation (p-Ser 127) and therefore inhibits YAP1-dependent cellular proliferation. We hypothesized that loss of FAT4 signaling would result in expansion of the nephron progenitor population in kidney development and that YAP1 subcellular localization would be dysregulated in Wilms tumor (WT), an embryonal malignancy that retains gene expression profiles and histologic features reminiscent of the embryonic kidney. METHODS Fetal kidneys from Fat4(-/-) mice were harvested at e18.5 and markers of nephron progenitors were investigated using immunohistochemical analysis. To examine YAP1 subcellular localization in WT, a primary WT cell line (VUWT30) was analyzed by immunofluorescence. Forty WT specimens evenly distributed between favorable and unfavorable histology (n = 20 each), and treatment failure or success (n = 20 each) was analyzed for total and phosphorylated YAP1 using immunohistochemistry and Western blot. RESULTS Fat4(-/-) mouse fetal kidneys exhibit nuclear YAP1 with increased proliferation and expansion of nephron progenitor cells. In contrast to kidney development, subcellular localization of YAP1 is dysregulated in WT, with a preponderance of nuclear p-YAP1. By Western blot, median p-YAP1 quantity was 5.2-fold greater in unfavorable histology WT (P = 0.05). CONCLUSIONS Fetal kidneys in Fat4(-/-) mice exhibit a phenotype reminiscent of nephrogenic rests, a WT precursor lesion. In WT, YAP1 subcellular localization is dysregulated and p-YAP1 accumulation is a novel biomarker of unfavorable histology.
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Affiliation(s)
- Andrew J. Murphy
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee,Correspondence to: Andrew J. Murphy, Department of Pediatric Surgery, Vanderbilt University Medical Center, 2200 Children’s Way, Doctor’s Office Tower, Suite 7102, Monroe Carell Jr. Children’s Hospital at Vanderbilt, Nashville, TN 37232-9780.
| | - Janene Pierce
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Christian de Caestecker
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jaime Libes
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - David Neblett
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mark de Caestecker
- Department of Cell and Developmental Biology and Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alan O. Perantoni
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - Shunsuke Tanigawa
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland
| | - James R. Anderson
- Department of Biostatistics, Children’s Oncology Group and University of Nebraska Medical Center, Omaha, Nebraska
| | - Jeffrey S. Dome
- Division of Oncology, Children’s Oncology Group and Children’s National Medical Center, Washington, District of Columbia
| | - Amrita Das
- University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Harold N. Lovvorn
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
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21
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Frump AL, Lowery JW, Hamid R, Austin ED, de Caestecker M. Abnormal trafficking of endogenously expressed BMPR2 mutant allelic products in patients with heritable pulmonary arterial hypertension. PLoS One 2013; 8:e80319. [PMID: 24224048 PMCID: PMC3818254 DOI: 10.1371/journal.pone.0080319] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [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: 07/31/2013] [Accepted: 10/07/2013] [Indexed: 12/28/2022] Open
Abstract
More than 200 heterozygous mutations in the type 2 BMP receptor gene, BMPR2, have been identified in patients with Heritable Pulmonary Arterial Hypertension (HPAH). More severe clinical outcomes occur in patients with BMPR2 mutations by-passing nonsense-mediated mRNA decay (NMD negative mutations). These comprise 40% of HPAH mutations and are predicted to express BMPR2 mutant products. However expression of endogenous NMD negative BMPR2 mutant products and their effect on protein trafficking and signaling function have never been described. Here, we characterize the expression and trafficking of an HPAH-associated NMD negative BMPR2 mutation that results in an in-frame deletion of BMPR2 EXON2 (BMPR2ΔEx2) in HPAH patient-derived lymphocytes and in pulmonary endothelial cells (PECs) from mice carrying the same in-frame deletion of Exon 2 (Bmpr2 (ΔEx2/+) mice). The endogenous BMPR2ΔEx2 mutant product does not reach the cell surface and is retained in the endoplasmic reticulum. Moreover, chemical chaperones 4-PBA and TUDCA partially restore cell surface expression of Bmpr2ΔEx2 in PECs, suggesting that the mutant product is mis-folded. We also show that PECs from Bmpr2 (ΔEx2/+) mice have defects in the BMP-induced Smad1/5/8 and Id1 signaling axis, and that addition of chemical chaperones restores expression of the Smad1/5/8 target Id1. These data indicate that the endogenous NMD negative BMPRΔEx2 mutant product is expressed but has a folding defect resulting in ER retention. Partial correction of this folding defect and restoration of defective BMP signaling using chemical chaperones suggests that protein-folding agents could be used therapeutically in patients with these NMD negative BMPR2 mutations.
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Affiliation(s)
- Andrea L. Frump
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jonathan W. Lowery
- Department of Developmental Biology, Harvard University School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Rizwan Hamid
- Department of Pediatrics, Division of Molecular Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric D. Austin
- Department of Pediatrics, Division of Pediatric Pulmonary Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Mark de Caestecker
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- *E-mail:
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22
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Brown AC, Adams D, de Caestecker M, Yang X, Friesel R, Oxburgh L. FGF/EGF signaling regulates the renewal of early nephron progenitors during embryonic development. Development 2011; 138:5099-112. [PMID: 22031548 DOI: 10.1242/dev.065995] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Recent studies indicate that nephron progenitor cells of the embryonic kidney are arranged in a series of compartments of an increasing state of differentiation. The earliest progenitor compartment, distinguished by expression of CITED1, possesses greater capacity for renewal and differentiation than later compartments. Signaling events governing progression of nephron progenitor cells through stages of increasing differentiation are poorly understood, and their elucidation will provide key insights into normal and dysregulated nephrogenesis, as well as into regenerative processes that follow kidney injury. In this study, we found that the mouse CITED1(+) progenitor compartment is maintained in response to receptor tyrosine kinase (RTK) ligands that activate both FGF and EGF receptors. This RTK signaling function is dependent on RAS and PI3K signaling but not ERK. In vivo, RAS inactivation by expression of sprouty 1 (Spry1) in CITED1(+) nephron progenitors results in loss of characteristic molecular marker expression and in increased death of progenitor cells. Lineage tracing shows that surviving Spry1-expressing progenitor cells are impaired in their subsequent epithelial differentiation, infrequently contributing to epithelial structures. These findings demonstrate that the survival and developmental potential of cells in the earliest embryonic nephron progenitor cell compartment are dependent on FGF/EGF signaling through RAS.
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Affiliation(s)
- Aaron C Brown
- Center for Molecular Medicine, Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
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23
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Swanhart LM, Cosentino CC, Diep CQ, Davidson AJ, de Caestecker M, Hukriede NA. Zebrafish kidney development: basic science to translational research. ACTA ACUST UNITED AC 2011; 93:141-56. [PMID: 21671354 DOI: 10.1002/bdrc.20209] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The zebrafish has become a significant model system for studying renal organogenesis and disease, as well as for the quest for new therapeutics, because of the structural and functional simplicity of the embryonic kidney. Inroads to the nature and disease states of kidney-related ciliopathies and acute kidney injury (AKI) have been advanced by zebrafish studies. This model organism has been instrumental in the analysis of mutant gene function for human disease with respect to ciliopathies. Additionally, in the AKI field, recent work in the zebrafish has identified a bona fide adult zebrafish renal progenitor (stem) cell that is required for neo-nephrogenesis, both during the normal lifespan and in response to renal injury. Taken together, these studies solidify the zebrafish as a successful model system for studying the broad spectrum of ciliopathies and AKI that affect millions of humans worldwide, and point to a very promising future of zebrafish drug discovery. The emphasis of this review will be on the role of the zebrafish as a model for human kidney-related ciliopathies and AKI, and how our understanding of these complex pathologies is being furthered by this tiny teleost.
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Affiliation(s)
- Lisa M Swanhart
- Department of Developmental Biology, University of Pittsburgh, Pennsylvania 15213, USA
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24
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Clark PE, Polosukhina D, Love H, Correa H, Coffin C, Perlman EJ, de Caestecker M, Moses HL, Zent R. β-Catenin and K-RAS synergize to form primitive renal epithelial tumors with features of epithelial Wilms' tumors. Am J Pathol 2011; 179:3045-55. [PMID: 21983638 DOI: 10.1016/j.ajpath.2011.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/27/2011] [Accepted: 08/10/2011] [Indexed: 12/19/2022]
Abstract
Wilms' tumor (WT) is the most common childhood renal cancer. Although mutations in known tumor-associated genes (WT1, WTX, and CATNB) occur only in a third of tumors, many tumors show evidence of activated β-catenin-dependent Wnt signaling, but the molecular mechanism by which this occurs is unknown. A key obstacle to understanding the pathogenesis of WT is the paucity of mouse models that recapitulate its features in humans. Herein, we describe a transgenic mouse model of primitive renal epithelial neoplasms that have high penetrance and mimic the epithelial component of human WT. Introduction of a stabilizing β-catenin mutation restricted to the kidney is sufficient to induce primitive renal epithelial tumors; however, when compounded with activation of K-RAS, the mice develop large, bilateral, metastatic, multifocal primitive renal epithelial tumors that have the histologic and staining characteristics of the epithelial component of human WT. These highly malignant tumors have increased activation of the phosphatidylinositol 3-kinase-AKT and extracellular signal-regulated kinase pathways, increased expression of total and nuclear β-catenin, and increased downstream targets of this pathway, such as c-Myc and survivin. Thus, we developed a novel mouse model in which activated K-RAS synergizes with canonical Wnt/β-catenin signaling to form metastatic primitive renal epithelial tumors that mimic the epithelial component of human WT.
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Affiliation(s)
- Peter E Clark
- Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2765, USA.
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Langworthy M, Zhou B, de Caestecker M, Moeckel G, Baldwin HS. NFATc1 identifies a population of proximal tubule cell progenitors. J Am Soc Nephrol 2008; 20:311-21. [PMID: 19118153 DOI: 10.1681/asn.2008010094] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Recovery from acute kidney injury requires regeneration of tubule cells. Because calcineurin induces nuclear transport of NFATc proteins, whose expression pattern correlates with the nephron segments injured by calcineurin inhibitors, we hypothesized that NFATc1 plays a role in modifying epithelial regeneration after injury. To test this, we induced proximal tubular cell (PTC) injury in Balb/c mice and Nfatc1(+/-) mice with mercuric chloride; the PTCs of Nfatc1(+/-) mice demonstrated increased apoptosis, sustained injury, and delayed regeneration. To attenuate NFATc1 activity further, we injected cyclosporin A daily. Cyclosporin A-treated Nfatc1(+/-) mice demonstrated rapid and severe injury after administration of mercuric chloride, with increased serum creatinine, increased apoptosis, decreased PTC proliferation, and increased mortality compared with similarly treated wild-type mice. Using a novel NFATc1 transgenic line that reports activation of an NFATc1 enhancer domain critical for NFATc1 autoamplification, we demonstrated accentuated NFATc1 expression in a PTC subpopulation after mercuric chloride-induced injury. In addition, NFATc1-labeled, apoptosis-resistant PTCs proliferated to repair the damaged proximal tubule segment. These data provide evidence for a resident progenitor PTC population and suggest a role for NFATc1 in the regeneration of injured proximal tubules.
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Affiliation(s)
- Melissa Langworthy
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Frank DB, Lowery J, Anderson L, Brink M, Reese J, de Caestecker M. Increased susceptibility to hypoxic pulmonary hypertension in Bmpr2 mutant mice is associated with endothelial dysfunction in the pulmonary vasculature. Am J Physiol Lung Cell Mol Physiol 2007; 294:L98-109. [PMID: 18024717 DOI: 10.1152/ajplung.00034.2007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patients with familial pulmonary arterial hypertension inherit heterozygous mutations of the type 2 bone morphogenetic protein (BMP) receptor BMPR2. To explore the cellular mechanisms of this disease, we evaluated the pulmonary vascular responses to chronic hypoxia in mice carrying heterozygous hypomorphic Bmpr2 mutations (Bmpr2 delta Ex2/+). These mice develop more severe pulmonary hypertension after prolonged exposure to hypoxia without an associated increase in pulmonary vascular remodeling or proliferation compared with wild-type mice. This is associated with defective endothelial-dependent vasodilatation and enhanced vasoconstriction in isolated intrapulmonary artery preparations. In addition, there is a selective decrease in hypoxia-induced, BMP-dependent, endothelial nitric oxide synthase expression and Smad signaling in the intact lungs and in cultured pulmonary microvascular endothelial cells from Bmpr2 delta Ex2/+ mutant mice. These findings indicate that the pulmonary endothelium is a target of abnormal BMP signaling in Bmpr2 delta Ex2/+ mutant mice and suggest that endothelial dysfunction contributes to their increased susceptibility to hypoxic pulmonary hypertension.
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Affiliation(s)
- David B Frank
- Department of Cell and Developmental Biology, Vanderbilt Univ. School of Medicine, S3223 Medical Center North, 1161 21 St. South, Nashville, TN 37232-2372, USA
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Boyle S, Misfeldt A, Chandler KJ, Deal KK, Southard-Smith EM, Mortlock DP, Baldwin HS, de Caestecker M. Fate mapping using Cited1-CreERT2 mice demonstrates that the cap mesenchyme contains self-renewing progenitor cells and gives rise exclusively to nephronic epithelia. Dev Biol 2007; 313:234-45. [PMID: 18061157 DOI: 10.1016/j.ydbio.2007.10.014] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 10/15/2007] [Accepted: 10/16/2007] [Indexed: 12/20/2022]
Abstract
Classic tissue recombination and in vitro lineage tracing studies suggest that condensed metanephric mesenchyme (MM) gives rise to nephronic epithelium of the adult kidney. However, these studies do not distinguish between cap mesenchyme and pre-tubular aggregates comprising the condensed MM, nor do they establish whether these cells have self-renewing capacity. To address these questions, we generated Cited1-CreER(T2) BAC transgenic mice, which express tamoxifen-regulated Cre recombinase exclusively in the cap mesenchyme. Fate mapping was performed by crossing these mice with the Rosa26R(LacZ) reporter line and evaluating the location and cellular characteristics of LacZ positive cells at different time points following tamoxifen injection. These studies confirmed expected results from previous in vitro analysis of MM cell fate, and provide in vivo evidence that the cap mesenchyme does not contribute to collecting duct epithelium in the adult. Furthermore, by exploiting the temporally regulated Cre recombinase, these studies show that nephronic epithelium arising at different stages of nephrogenesis has distinct spatial distribution in the adult kidney, and demonstrate for the first time that the cap mesenchyme includes a population of self-renewing epithelial progenitor cells.
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Affiliation(s)
- Scott Boyle
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-2372, USA
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Lovvorn HN, Westrup J, Opperman S, Boyle S, Shi G, Anderson J, Perlman EJ, Perantoni AO, Wills M, de Caestecker M. CITED1 expression in Wilms' tumor and embryonic kidney. Neoplasia 2007; 9:589-600. [PMID: 17710162 PMCID: PMC1941694 DOI: 10.1593/neo.07358] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [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] [Received: 07/01/2004] [Accepted: 06/30/2005] [Indexed: 11/18/2022] Open
Abstract
Wilms' tumors, or nephroblastomas, are thought to arise from abnormal postnatal retention and dysregulated differentiation of nephrogenic progenitor cells that originate as a condensed metanephric mesenchyme within embryonic kidneys. We have previously shown that the transcriptional regulator CITED1 (CBP/p300-interacting transactivators with glutamic acid [E]/aspartic acid [D]-rich C-terminal domain) is expressed exclusively in these nephrogenic progenitor cells and is downregulated as they differentiate to form nephronic epithelia. In the current study, we show that CITED1 expression persists in blastemal cell populations of both experimental rat nephroblastomas and human Wilms' tumors, and that primary human Wilms' tumors presenting with disseminated disease show the highest level of CITED1 expression. Unlike the predominantly cytoplasmic subcellular localization of CITED1 in the normal developing kidney, CITED1 is clearly detectable in the nuclear compartment of Wilms' tumor blastema. These findings indicate that CITED1 is a marker of primitive blastema in Wilms' tumors and suggest that persistent expression and/or altered subcellular localization of CITED1 in the condensed metanephric mesenchyme could play a role in Wilms' tumor initiation and pathogenesis.
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Affiliation(s)
- Harold N Lovvorn
- The Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA.
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Smith JJ, Shiou SR, Dhawan P, Kis C, Kanies C, LaFleur B, de Caestecker M, Beauchamp DR. Restoration of Smad4 expression in colon cancer cells enables autocrine bone morphogenetic protein (BMP) tumor suppressor function. J Am Coll Surg 2007. [DOI: 10.1016/j.jamcollsurg.2007.06.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Boyle S, Shioda T, Perantoni AO, de Caestecker M. Cited1 and Cited2 are differentially expressed in the developing kidney but are not required for nephrogenesis. Dev Dyn 2007; 236:2321-30. [PMID: 17615577 DOI: 10.1002/dvdy.21242] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [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: 12/15/2022] Open
Abstract
Early kidney development in mammals is characterized by reciprocal tissue interaction between the ureteric bud and the metanephric mesenchyme. The coordinated response to this interaction is regulated largely at the transcriptional level. Here, we investigate the expression and function of Cited1, a transcriptional cofactor that we have previously implicated in kidney development. We show that Cited1 is expressed in the metanephric mesenchyme after invasion of the ureteric bud and that its expression is limited to the cap mesenchyme, those cells that aggregate most tightly around the tip of the ureteric bud and give rise to nephronic epithelium of the adult kidney. Cited1 is down-regulated during the initial stages of epithelial conversion and is not expressed past this progenitor stage. Despite its unique expression pattern, deletion of Cited1 does not disrupt kidney development. We hypothesized that this finding was due to functional redundancy with other members of this gene family. The expression pattern of Cited2 overlaps that of Cited1, but its deletion, either alone or in combination with Cited1, does not disrupt epithelial differentiation of the metanephric mesenchyme. From these studies, we conclude that Cited1 and 2 are dynamically expressed during kidney development, but are not required for nephrogenesis.
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Affiliation(s)
- Scott Boyle
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
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Abstract
PURPOSE Wilms' tumors arise from arrested differentiation of renal progenitor cells. CITED1 is a transcriptional regulator that blocks the metanephric mesenchymal-to-epithelial conversion and is expressed in the blastema of both the developing kidney and Wilms' tumors. We hypothesized that alterations of CITED1-dependent signaling promote persistence of blastema and thereby subject these pluripotent cells to future oncogenic events. METHODS We used a retroviral delivery system to overexpress the full-length CITED1 (F/L) protein and 2 deletion mutants lacking either of its known functional domains, deltaSID (Smad-4 Interacting Domain) and deltaCR2 (Conserved Region 2; the CITED1 transactivation domain), in a human Wilms' tumor cell line that endogenously expresses CITED1. In vitro effects on cellular proliferation and apoptosis were assayed. In vivo effects on tumorigenesis, growth, proliferation, and apoptosis were determined after heterotransplantation into immunodeficient mice (n = 15 per cell line). RESULTS In vitro, overexpression of CITED1-F/L significantly increased, whereas overexpression of the functionally inactivating mutant, CITED1-deltaCR2, significantly reduced cellular proliferation relative to the other lines (P < .0001). In vivo, Wilms' tumor incidence was significantly reduced in animals injected with cells overexpressing the mutant CITED1-deltaCR2 (7%) compared with CITED1-F/L (40%, P = .03) and CITED1-deltaSID (60%, P < .002). Similarly, mean tumor volume was least in the CITED1-deltaCR2 animals when compared with CITED1-F/L (P = .03) and CITED1-deltaSID animals (P < .005). Furthermore, the CITED1-deltaCR2 tumor showed the least cellular proliferation. Misexpression of CITED1 did not affect apoptosis either in vitro or in vivo. CONCLUSIONS Overexpression of CITED1 in a human Wilms' tumor cell line significantly increases proliferation in vitro, whereas mutation of its functionally critical transactivation domain (deltaCR2) significantly reduces proliferation. This mutation further perturbs tumorigenesis and tumor growth after heterotransplantation into immunodeficient mice. We speculate that overexpression of CITED1 promotes expansion of a rapidly proliferating population of blastema and thereby induces an unstable environment highly susceptible to future oncogenic events.
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Affiliation(s)
- Harold N Lovvorn
- Department of Pediatric Surgery, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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Abstract
Longstanding diabetes causes renal injury with early dropout of podocytes, albuminuria, glomerular and tubulointerstitial fibrosis, and progressive renal failure. The renal pathology seems to be driven, in part, by TGF-beta and is associated with a loss of renal bone morphogenic protein-7 (BMP-7) expression. Here, the hypothesis that maintenance of renal (especially podocyte) BMP-7 by transgenic expression reduces diabetic renal injury was tested. Diabetic mice that expressed the phosphoenolpyruvate carboxykinase promoter-driven BMP-7 transgene and nondiabetic, transgenic mice as well as diabetic and nondiabetic wild-type controls were studied for up to 1 yr. Transgenic expression of BMP-7 in glomerular podocytes and proximal tubules prevents podocyte dropout and reductions in nephrin levels in diabetic mice. Maintenance of BMP-7 also reduces glomerular fibrosis and interstitial collagen accumulation as well as collagen I and fibronectin expression. Diabetic wild-type mice develop progressive albuminuria, which is substantially reduced in transgenic mice. These effects of the BMP-7 transgene occur without changing renal TGF-beta levels. It is concluded that maintenance of renal BMP-7 during the evolution of diabetic nephropathy reduces diabetic renal injury, especially podocyte dropout. The findings also establish a role for endogenous glomerular BMP-7 as an autocrine regulator of podocyte integrity in vivo.
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Affiliation(s)
- Shinong Wang
- LABiomed, C-1-A, 1124 West Carson Street, Torrance, CA 90502, USA
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Abstract
Many of the signaling pathways that regulate tissue specification and coordinate cellular differentiation during embryogenesis have been identified over the last decade. These pathways are integrated at the transcriptional level, enabling activation of specific developmental programs in a temporally and spatially restricted fashion. Such developmental events are usually thought of in terms of hierarchical relationships, in which the expression of upstream factors leads to the sequential activation of a linear cascade of downstream genes. Whereas these models provide a simplistic approach to understand complex cellular events, genetic and biochemical studies in mice and other model organisms provide ample evidence that many of these factors interact at multiple levels in vivo and emphasize the importance of considering these linear events in context. The purpose of this review is to emphasize the complexity of these regulatory networks during the early phases of mammalian kidney development, outlining some of the limitations and alternative approaches that are being used to explore the complex nature of these networks in vivo. Before describing these networks in detail, we will provide a brief overview of the main structural changes and tissue interactions involved in mammalian kidney development, and go on to describe some of the limitations of our current approaches to evaluate the role of these developmental pathways in vivo.
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Affiliation(s)
- Scott Boyle
- Nephrology Division and Department of Cell and Developmental Biology, Vanderbilt University, 1161 21st St. South S3223, Medical Ctr. North, Nashville, TN 37232, USA
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Affiliation(s)
- David Frank
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Abstract
The transforming growth factor-beta (TGF-beta) superfamily of receptors comprises two groups of transmembrane serine-threonine kinase receptors, so called type I, and type II receptors, that are activated following engagement by members of the TGF-beta superfamily of ligands. These events specify diverse downstream responses that are differentially regulated by controlling access and activation of the ligands, their receptors and downstream substrates in different cell types. The purpose of this review is to describe the biochemical properties of these receptors, focusing specifically on the mechanisms regulating receptor/ligand interactions and activation in mammalian cells.
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Affiliation(s)
- Mark de Caestecker
- Division of Nephrology, S-3223 Medical Center North, 1161 21st Street S, Nashville, TN 37232-2372, USA.
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