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Sachs W, Blume L, Loreth D, Schebsdat L, Hatje F, Koehler S, Wedekind U, Sachs M, Zieliniski S, Brand J, Conze C, Florea BI, Heppner F, Krüger E, Rinschen MM, Kretz O, Thünauer R, Meyer-Schwesinger C. The proteasome modulates endocytosis specifically in glomerular cells to promote kidney filtration. Nat Commun 2024; 15:1897. [PMID: 38429282 PMCID: PMC10907641 DOI: 10.1038/s41467-024-46273-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Kidney filtration is ensured by the interaction of podocytes, endothelial and mesangial cells. Immunoglobulin accumulation at the filtration barrier is pathognomonic for glomerular injury. The mechanisms that regulate filter permeability are unknown. Here, we identify a pivotal role for the proteasome in a specific cell type. Combining genetic and inhibitor-based human, pig, mouse, and Drosophila models we demonstrate that the proteasome maintains filtration barrier integrity, with podocytes requiring the constitutive and glomerular endothelial cells the immunoproteasomal activity. Endothelial immunoproteasome deficiency as well as proteasome inhibition disrupt the filtration barrier in mice, resulting in pathologic immunoglobulin deposition. Mechanistically, we observe reduced endocytic activity, which leads to altered membrane recycling and endocytic receptor turnover. This work expands the concept of the (immuno)proteasome as a control protease orchestrating protein degradation and antigen presentation and endocytosis, providing new therapeutic targets to treat disease-associated glomerular protein accumulations.
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Affiliation(s)
- Wiebke Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lukas Blume
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Desiree Loreth
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lisa Schebsdat
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Favian Hatje
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Sybille Koehler
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uta Wedekind
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Marlies Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Stephanie Zieliniski
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Johannes Brand
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | | | - Bogdan I Florea
- Bio-Organic Synthesis Group, Leiden University, Leiden, The Netherlands
| | - Frank Heppner
- Institute of Neuropathology, Charité, Berlin, Germany
| | - Elke Krüger
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, Greifswald, Germany
| | - Markus M Rinschen
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Roland Thünauer
- Leibniz Institute of Virology, Hamburg, Germany
- Technology Platform Light Microscopy (TPLM), University Hamburg, Hamburg, Germany
- Advanced Light and Fluorescence Microscopy (ALFM) Facility at the Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center of Kidney Health, Hamburg, Germany.
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2
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Sandholm N, Dahlström EH, Groop PH. Genetic and epigenetic background of diabetic kidney disease. Front Endocrinol (Lausanne) 2023; 14:1163001. [PMID: 37324271 PMCID: PMC10262849 DOI: 10.3389/fendo.2023.1163001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/10/2023] [Indexed: 06/17/2023] Open
Abstract
Diabetic kidney disease (DKD) is a severe diabetic complication that affects up to half of the individuals with diabetes. Elevated blood glucose levels are a key underlying cause of DKD, but DKD is a complex multifactorial disease, which takes years to develop. Family studies have shown that inherited factors also contribute to the risk of the disease. During the last decade, genome-wide association studies (GWASs) have emerged as a powerful tool to identify genetic risk factors for DKD. In recent years, the GWASs have acquired larger number of participants, leading to increased statistical power to detect more genetic risk factors. In addition, whole-exome and whole-genome sequencing studies are emerging, aiming to identify rare genetic risk factors for DKD, as well as epigenome-wide association studies, investigating DNA methylation in relation to DKD. This article aims to review the identified genetic and epigenetic risk factors for DKD.
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Affiliation(s)
- Niina Sandholm
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Emma H. Dahlström
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Per-Henrik Groop
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Department of Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC, Australia
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3
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Li J, Xu J, Jiang H, Zhang T, Ramakrishnan A, Shen L, Xu PX. Chromatin Remodelers Interact with Eya1 and Six2 to Target Enhancers to Control Nephron Progenitor Cell Maintenance. J Am Soc Nephrol 2021; 32:2815-2833. [PMID: 34716243 PMCID: PMC8806105 DOI: 10.1681/asn.2021040525] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/26/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Eya1 is a critical regulator of nephron progenitor cell specification and interacts with Six2 to promote NPC self-renewal. Haploinsufficiency of these genes causes kidney hypoplasia. However, how the Eya1-centered network operates remains unknown. METHODS We engineered a 2×HA-3×Flag-Eya1 knock-in mouse line and performed coimmunoprecipitation with anti-HA or -Flag to precipitate the multitagged-Eya1 and its associated proteins. Loss-of-function, transcriptome profiling, and genome-wide binding analyses for Eya1's interacting chromatin-remodeling ATPase Brg1 were carried out. We assayed the activity of the cis-regulatory elements co-occupied by Brg1/Six2 in vivo. RESULTS Eya1 and Six2 interact with the Brg1-based SWI/SNF complex during kidney development. Knockout of Brg1 results in failure of metanephric mesenchyme formation and depletion of nephron progenitors, which has been linked to loss of Eya1 expression. Transcriptional profiling shows conspicuous downregulation of important regulators for nephrogenesis in Brg1-deficient cells, including Lin28, Pbx1, and Dchs1-Fat4 signaling, but upregulation of podocyte lineage, oncogenic, and cell death-inducing genes, many of which Brg1 targets. Genome-wide binding analysis identifies Brg1 occupancy to a distal enhancer of Eya1 that drives nephron progenitor-specific expression. We demonstrate that Brg1 enrichment to two distal intronic enhancers of Pbx1 and a proximal promoter region of Mycn requires Six2 activity and that these Brg1/Six2-bound enhancers govern nephron progenitor-specific expression in response to Six2 activity. CONCLUSIONS Our results reveal an essential role for Brg1, its downstream pathways, and its interaction with Eya1-Six2 in mediating the fine balance among the self-renewal, differentiation, and survival of nephron progenitors.
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Affiliation(s)
- Jun Li
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jinshu Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Huihui Jiang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Ting Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Aarthi Ramakrishnan
- Department of Neurosciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Li Shen
- Department of Neurosciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York,Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York
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4
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Huang Z, Liu S, Tang A, Al-Rabadi L, Henkemeyer M, Mimche P, Huang Y. Key role for EphB2 receptor in kidney fibrosis. Clin Sci (Lond) 2021; 135:2127-2142. [PMID: 34462781 PMCID: PMC8433383 DOI: 10.1042/cs20210644] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 11/27/2022]
Abstract
Erythropoietin producing hepatocellular (Eph)-Eph receptor interacting (Ephrin) receptor-ligand signaling has been implicated in the development of tissue fibrosis, though it has not been well defined in the kidney. We detected substantial up-regulation of expression and phosphorylation of the EphB2 receptor tyrosine kinase in fibrotic kidney tissue obtained both from mice subjected to the unilateral renal ischemia-reperfusion (IR) model at 14 days and in patients suffering from chronic kidney disease (CKD). Knockout (KO) mice lacking EphB2 expression exhibited a normal renal structure and function, indicating no major role for this receptor in kidney development or action. Although IR injury is well-known to cause tissue damage, fibrosis, and renal dysfunction, we found that kidneys from EphB2KO mice showed much less renal tubular injury and retained a more preserved renal function. IR-injured kidneys from EphB2 KOs exhibited greatly reduced fibrosis and inflammation compared with injured wildtype (WT) littermates, and this correlated with a significant reduction in renal expression of profibrotic molecules, inflammatory cytokines, NADPH oxidases, and markers for cell proliferation, tubular epithelial-to-mesenchymal transition (EMT), myofibroblast activation, and apoptosis. A panel of 760 fibrosis-associated genes were further assessed, revealing that 506 genes in WT mouse kidney following IR injury changed their expression. However, 70.9% of those genes were back to or close to normal in expression when EphB2 was deleted. These data indicate that endogenous EphB2 expression and signaling are abnormally activated after kidney injury and subsequently contribute to the development of renal fibrosis via regulation of multiple profibrotic pathways.
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Affiliation(s)
- Zhimin Huang
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah Health Science, Salt Lake City, UT, U.S.A
- Department of Internal Medicine, Division of Nephrology, Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Simeng Liu
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah Health Science, Salt Lake City, UT, U.S.A
| | - Anna Tang
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah Health Science, Salt Lake City, UT, U.S.A
| | - Laith Al-Rabadi
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah Health Science, Salt Lake City, UT, U.S.A
| | - Mark Henkemeyer
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, U.S.A
| | - Patrice N. Mimche
- Department of Pathology, Division of Microbiology and Immunology, Molecular Medicine Program, University of Utah Health Science, Salt Lake City, UT, U.S.A
| | - Yufeng Huang
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah Health Science, Salt Lake City, UT, U.S.A
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5
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Lindström NO, Sealfon R, Chen X, Parvez RK, Ransick A, De Sena Brandine G, Guo J, Hill B, Tran T, Kim AD, Zhou J, Tadych A, Watters A, Wong A, Lovero E, Grubbs BH, Thornton ME, McMahon JA, Smith AD, Ruffins SW, Armit C, Troyanskaya OG, McMahon AP. Spatial transcriptional mapping of the human nephrogenic program. Dev Cell 2021; 56:2381-2398.e6. [PMID: 34428401 PMCID: PMC8396064 DOI: 10.1016/j.devcel.2021.07.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/06/2021] [Accepted: 07/27/2021] [Indexed: 12/11/2022]
Abstract
Congenital abnormalities of the kidney and urinary tract are among the most common birth defects, affecting 3% of newborns. The human kidney forms around a million nephrons from a pool of nephron progenitors over a 30-week period of development. To establish a framework for human nephrogenesis, we spatially resolved a stereotypical process by which equipotent nephron progenitors generate a nephron anlage, then applied data-driven approaches to construct three-dimensional protein maps on anatomical models of the nephrogenic program. Single-cell RNA sequencing identified progenitor states, which were spatially mapped to the nephron anatomy, enabling the generation of functional gene networks predicting interactions within and between nephron cell types. Network mining identified known developmental disease genes and predicted targets of interest. The spatially resolved nephrogenic program made available through the Human Nephrogenesis Atlas (https://sckidney.flatironinstitute.org/) will facilitate an understanding of kidney development and disease and enhance efforts to generate new kidney structures.
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Affiliation(s)
- Nils O Lindström
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Rachel Sealfon
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Xi Chen
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Riana K Parvez
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andrew Ransick
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Guilherme De Sena Brandine
- Molecular and Computational Biology, Division of Biological Sciences, University of Southern, Los Angeles, CA 90089, USA
| | - Jinjin Guo
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bill Hill
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Tracy Tran
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Albert D Kim
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jian Zhou
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Alicja Tadych
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Aaron Watters
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA
| | - Aaron Wong
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA
| | - Elizabeth Lovero
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA
| | - Brendan H Grubbs
- Maternal Fetal Medicine Division, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Matthew E Thornton
- Maternal Fetal Medicine Division, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jill A McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andrew D Smith
- Molecular and Computational Biology, Division of Biological Sciences, University of Southern, Los Angeles, CA 90089, USA
| | - Seth W Ruffins
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Chris Armit
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK; BGI Hong Kong, 26/F, Kings Wing Plaza 2, 1 On Kwan Street, Shek Mun, NT, Hong Kong
| | - Olga G Troyanskaya
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA; Department of Computer Science, Princeton University, Princeton, NJ, USA.
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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6
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Miao Z, Balzer MS, Ma Z, Liu H, Wu J, Shrestha R, Aranyi T, Kwan A, Kondo A, Pontoglio M, Kim J, Li M, Kaestner KH, Susztak K. Single cell regulatory landscape of the mouse kidney highlights cellular differentiation programs and disease targets. Nat Commun 2021; 12:2277. [PMID: 33859189 PMCID: PMC8050063 DOI: 10.1038/s41467-021-22266-1] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 02/28/2021] [Indexed: 12/19/2022] Open
Abstract
Determining the epigenetic program that generates unique cell types in the kidney is critical for understanding cell-type heterogeneity during tissue homeostasis and injury response. Here, we profile open chromatin and gene expression in developing and adult mouse kidneys at single cell resolution. We show critical reliance of gene expression on distal regulatory elements (enhancers). We reveal key cell type-specific transcription factors and major gene-regulatory circuits for kidney cells. Dynamic chromatin and expression changes during nephron progenitor differentiation demonstrates that podocyte commitment occurs early and is associated with sustained Foxl1 expression. Renal tubule cells follow a more complex differentiation, where Hfn4a is associated with proximal and Tfap2b with distal fate. Mapping single nucleotide variants associated with human kidney disease implicates critical cell types, developmental stages, genes, and regulatory mechanisms. The single cell multi-omics atlas reveals key chromatin remodeling events and gene expression dynamics associated with kidney development.
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Affiliation(s)
- Zhen Miao
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Graduate Group in Genomics and Computational Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Michael S Balzer
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Ziyuan Ma
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Hongbo Liu
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Junnan Wu
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Rojesh Shrestha
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Tamas Aranyi
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Amy Kwan
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Ayano Kondo
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Marco Pontoglio
- Epigenetics and Development Laboratory, Université de Paris Inserm U1151/CNRS UMR 8253, Institut Necker Enfants Malades, Paris, France
| | - Junhyong Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Mingyao Li
- Department of Epidemiology and Biostatistics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Katalin Susztak
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
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7
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Takahashi K, Kim RH, Pasic L, He L, Nagasaka S, Katagiri D, May T, Shimizu A, Harris RC, Mernaugh RL, Takahashi T. Agonistic anti-CD148 monoclonal antibody attenuates diabetic nephropathy in mice. Am J Physiol Renal Physiol 2020; 318:F647-F659. [PMID: 31984788 DOI: 10.1152/ajprenal.00288.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
CD148 is a transmembrane protein tyrosine phosphatase (PTP) that is expressed in the renal vasculature, including the glomerulus. Previous studies have shown that CD148 plays a role in the negative regulation of growth factor signals (including epidermal growth factor and vascular endothelial growth factor), suppressing cell proliferation and transformation. However, the role of CD148 in kidney disease remains unknown. Here, we generated an agonistic anti-CD148 antibody and evaluated its effects in murine diabetic nephropathy (DN). Monoclonal antibodies (mAbs) against the mouse CD148 ectodomain sequence were generated by immunizing CD148 knockout (CD148KO) mice. The mAbs that increased CD148 activity were selected by biological (proliferation) and biochemical (PTP activity) assays. The mAb (18E1) that showed strong agonistic activity was injected (10 mg/kg ip) in streptozotocin-induced wild-type and CD148KO diabetic mice for 6 wk, and the renal phenotype was then assessed. The effects of 18E1 mAb in podocyte growth factor signals were also assessed in culture. Compared with control IgG, 18E1 mAb significantly decreased albuminuria and mesangial expansion without altering hyperglycemia and blood pressure in wild-type diabetic mice. Immunohistochemical evaluation showed that 18E1 mAb significantly prevented the reduction of podocyte number and nephrin expression and decreased glomerular fibronectin expression and renal macrophage infiltration. The 18E1 mAb showed no effects in CD148KO diabetic mice. Furthermore, we demonstrated that 18E1 mAb reduces podocyte epidermal growth factor receptor signals in culture and in diabetic mice. These findings suggest that agonistic anti-CD148 mAb attenuates DN in mice, in part by reducing epidermal growth factor receptor signals in podocytes. This antibody may be used for the treatment of early DN.
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Affiliation(s)
- Keiko Takahashi
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rachel H Kim
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lejla Pasic
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee
| | - Lilly He
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Shinya Nagasaka
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Daisuke Katagiri
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Tracy May
- Vanderbilt University Antibody and Protein Resource, Nashville, Tennessee
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
| | | | - Takamune Takahashi
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, Tennessee
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8
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Guan M, Keaton JM, Dimitrov L, Hicks PJ, Xu J, Palmer ND, Ma L, Das SK, Chen YDI, Coresh J, Fornage M, Franceschini N, Kramer H, Langefeld CD, Mychaleckyj JC, Parekh RS, Post WS, Rasmussen-Torvik LJ, Rich SS, Rotter JI, Sedor JR, Thornley-Brown D, Tin A, Wilson JG, Freedman BI, Bowden DW, Ng MCY. Genome-wide association study identifies novel loci for type 2 diabetes-attributed end-stage kidney disease in African Americans. Hum Genomics 2019; 13:21. [PMID: 31092297 PMCID: PMC6521376 DOI: 10.1186/s40246-019-0205-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/11/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND End-stage kidney disease (ESKD) is a significant public health concern disproportionately affecting African Americans (AAs). Type 2 diabetes (T2D) is the leading cause of ESKD in the USA, and efforts to uncover genetic susceptibility to diabetic kidney disease (DKD) have had limited success. A prior genome-wide association study (GWAS) in AAs with T2D-ESKD was expanded with additional AA cases and controls and genotypes imputed to the higher density 1000 Genomes reference panel. The discovery analysis included 3432 T2D-ESKD cases and 6977 non-diabetic non-nephropathy controls (N = 10,409), followed by a discrimination analysis in 2756 T2D non-nephropathy controls to exclude T2D-associated variants. RESULTS Six independent variants located in or near RND3/RBM43, SLITRK3, ENPP7, GNG7, and APOL1 achieved genome-wide significant association (P < 5 × 10-8) with T2D-ESKD. Following extension analyses in 1910 non-diabetic ESKD cases and 908 non-diabetic non-nephropathy controls, a meta-analysis of 5342 AA all-cause ESKD cases and 6977 AA non-diabetic non-nephropathy controls revealed an additional novel all-cause ESKD locus at EFNB2 (rs77113398; P = 9.84 × 10-9; OR = 1.94). Exclusion of APOL1 renal-risk genotype carriers identified two additional genome-wide significant T2D-ESKD-associated loci at GRAMD3 and MGAT4C. A second variant at GNG7 (rs373971520; P = 2.17 × 10-8, OR = 1.46) remained associated with all-cause ESKD in the APOL1-negative analysis. CONCLUSIONS Findings provide further evidence for genetic factors associated with advanced kidney disease in AAs with T2D.
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Grants
- HHSN268201300026C NHLBI NIH HHS
- N01HC95160 NHLBI NIH HHS
- U01 DK057300 NIDDK NIH HHS
- N01HC95169 NHLBI NIH HHS
- R01 DK117445 NIDDK NIH HHS
- HHSN268201700001I NHLBI NIH HHS
- N01HC95159 NHLBI NIH HHS
- N01HC95167 NHLBI NIH HHS
- HHSC268200782096C, DK081350, DK066358, DK053591, DK087914, DK105556, HL56266, DK070941 NIH HHS
- UL1 TR001881 NCATS NIH HHS
- HHSN268201700003I NHLBI NIH HHS
- U01 DK070657 NIDDK NIH HHS
- HHSN268201500003C NHLBI NIH HHS
- U01 DK057304 NIDDK NIH HHS
- R01 DK070941 NIDDK NIH HHS
- UL1 TR002548 NCATS NIH HHS
- U01 DK057298 NIDDK NIH HHS
- UL1 RR025005 NCRR NIH HHS
- N01HC95163 NHLBI NIH HHS
- HHSN268201300025C, HHSN268201300026C, HHSN268201300027C, HHSN268201300028C, HHSN268201300029C, HHSN268200900041C, AG0005, N01-HC-65226 NIH HHS
- UL1 TR001079 NCATS NIH HHS
- U01 DK057295 NIDDK NIH HHS
- U01 DK105556 NIDDK NIH HHS
- R01 HL086694 NHLBI NIH HHS
- U01 DK057303 NIDDK NIH HHS
- P30 DK079626 NIDDK NIH HHS
- HHSN268201300048C NHLBI NIH HHS
- U01 HG004402 NHGRI NIH HHS
- N01HC95164 NHLBI NIH HHS
- HHSN268201300025C NHLBI NIH HHS
- N02HL64278 NHLBI NIH HHS
- N01HC95162 NHLBI NIH HHS
- N01HC95168 NHLBI NIH HHS
- R01 DK087914 NIDDK NIH HHS
- U01 DK057249 NIDDK NIH HHS
- P30 DK063491 NIDDK NIH HHS
- HHSN268201300027C NHLBI NIH HHS
- K99 DK081350 NIDDK NIH HHS
- HHSN268201300049C NHLBI NIH HHS
- R01 DK066358 NIDDK NIH HHS
- HHSN268200900041C NHLBI NIH HHS
- HHSN268201300028C NHLBI NIH HHS
- U01DK57292, U01DK57329, U01DK057300, U01DK057298, U01DK057249, U01DK57295, U01DK070657, U01DK057303, U01DK070657, U01DK57304, DK07024 NIH HHS
- HHSN268201700004I NHLBI NIH HHS
- N01HC95165 NHLBI NIH HHS
- N01HC95161 NHLBI NIH HHS
- HHSN268201300047C NHLBI NIH HHS
- UL1 TR001420 NCATS NIH HHS
- HHSN268201300050C NHLBI NIH HHS
- N01HC65226 NHLBI NIH HHS
- U01 DK057329 NIDDK NIH HHS
- M01 RR007122 NCRR NIH HHS
- R01 DK053591 NIDDK NIH HHS
- R01 MD012765 NIMHD NIH HHS
- UL1 TR000040 NCATS NIH HHS
- HHSN268201300046C NHLBI NIH HHS
- HHSN268201500003I, N01-HC-95159, N01-HC-95160, N01-HC-95161, N01-HC-95162, N01-HC-95163, N01-HC-95164, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, N01-HC-95169, UL1-TR-000040, UL1-TR-001079, UL1-TR-001420, UL1-TR-001881, DK063491, N02-HL-64278, UL1TR001881, DK063491 NIH HHS
- HHSN268201300049C, HHSN268201300050C, HHSN268201300048C, HHSN268201300046C, HHSN268201300047C NIH HHS
- HHSN268201700002I NHLBI NIH HHS
- HHSN268201700005I NHLBI NIH HHS
- U01 DK057292 NIDDK NIH HHS
- N01HC95166 NHLBI NIH HHS
- HHSN268201700001I, HHSN268201700002I, HHSN268201700003I, HHSN268201700004I, HHSN268201700005I, R01HL087641, R01HL086694, U01HG004402, HHSN268200625226C, UL1RR025005 NIH HHS
- HHSN268201300029C NHLBI NIH HHS
- R01 HL087641 NHLBI NIH HHS
- National Institutes of Health
- Wake Forest School of Medicine
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Affiliation(s)
- Meijian Guan
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jacob M Keaton
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Latchezar Dimitrov
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Pamela J Hicks
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jianzhao Xu
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Nicholette D Palmer
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Lijun Ma
- Department of Internal Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Swapan K Das
- Department of Internal Medicine, Section on Endocrinology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Yii-Der I Chen
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Josef Coresh
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Myriam Fornage
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Nora Franceschini
- Department of Epidemiology, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Holly Kramer
- Departments of Public Health Sciences and Medicine, Division of Nephrology and Hypertension, Loyola University Chicago, Maywood, IL, USA
- Department of Medicine, Hines Veteran's Affairs Medical Center, Hines, IL, USA
| | - Carl D Langefeld
- Center for Public Health Genomics, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Josyf C Mychaleckyj
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Rulan S Parekh
- Departments of Paediatrics and Medicine, Hospital for Sick Children, University Health Network and the University of Toronto, Toronto, ON, Canada
| | - Wendy S Post
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Laura J Rasmussen-Torvik
- Department of Preventive Medicine, Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Division of Genomic Outcomes, Departments of Pediatrics and Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - John R Sedor
- Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
- Glickman Urology and Kidney Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | | | - Adrienne Tin
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - James G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Barry I Freedman
- Department of Internal Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Donald W Bowden
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Maggie C Y Ng
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC, USA.
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA.
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
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9
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Kurtzeborn K, Cebrian C, Kuure S. Regulation of Renal Differentiation by Trophic Factors. Front Physiol 2018; 9:1588. [PMID: 30483151 PMCID: PMC6240607 DOI: 10.3389/fphys.2018.01588] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 10/23/2018] [Indexed: 12/11/2022] Open
Abstract
Classically, trophic factors are considered as proteins which support neurons in their growth, survival, and differentiation. However, most neurotrophic factors also have important functions outside of the nervous system. Especially essential renal growth and differentiation regulators are glial cell line-derived neurotrophic factor (GDNF), bone morphogenetic proteins (BMPs), and fibroblast growth factors (FGFs). Here we discuss how trophic factor-induced signaling contributes to the control of ureteric bud (UB) branching morphogenesis and to maintenance and differentiation of nephrogenic mesenchyme in embryonic kidney. The review includes recent advances in trophic factor functions during the guidance of branching morphogenesis and self-renewal versus differentiation decisions, both of which dictate the control of kidney size and nephron number. Creative utilization of current information may help better recapitulate renal differentiation in vitro, but it is obvious that significantly more basic knowledge is needed for development of regeneration-based renal therapies.
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Affiliation(s)
- Kristen Kurtzeborn
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Medicum, University of Helsinki, Helsinki, Finland
| | - Cristina Cebrian
- Developmental Biology Division, Cincinnati Children’s Hospital, Cincinnati, OH, United States
| | - Satu Kuure
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Medicum, University of Helsinki, Helsinki, Finland
- GM-Unit, Laboratory Animal Centre, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
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10
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Development of the renal vasculature. Semin Cell Dev Biol 2018; 91:132-146. [PMID: 29879472 DOI: 10.1016/j.semcdb.2018.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022]
Abstract
The kidney vasculature has a unique and complex architecture that is central for the kidney to exert its multiple and essential physiological functions with the ultimate goal of maintaining homeostasis. An appropriate development and coordinated assembly of the different vascular cell types and their association with the corresponding nephrons is crucial for the generation of a functioning kidney. In this review we provide an overview of the renal vascular anatomy, histology, and current knowledge of the embryological origin and molecular pathways involved in its development. Understanding the cellular and molecular mechanisms involved in renal vascular development is the first step to advance the field of regenerative medicine.
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11
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Basile DP, Yoder MC. Unique Gene Expression in Developing Ascending Vasa Recta: A Tale of Tie. J Am Soc Nephrol 2018. [PMID: 29531096 DOI: 10.1681/asn.2018020190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
| | - Mervin C Yoder
- Department of Pediatrics and the Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
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12
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Sun J, Wang X, Shi Y, Li J, Li C, Shi Z, Chen Y, Mao B. EphA7 regulates claudin6 and pronephros development in Xenopus. Biochem Biophys Res Commun 2017; 495:1580-1587. [PMID: 29223398 DOI: 10.1016/j.bbrc.2017.12.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/05/2017] [Indexed: 11/28/2022]
Abstract
Eph/ephrin molecules are widely expressed during embryonic development, and function in a variety of developmental processes. Here we studied the roles of the Eph receptor EphA7 and its soluble form in Xenopus pronephros development. EphA7 is specifically expressed in pronephric tubules at tadpole stages and knockdown of EphA7 by a translation blocking morpholino led to defects in tubule cell differentiation and morphogenesis. A soluble form of EphA7 (sEphA7) was also identified. Interestingly, the membrane level of claudin6 (CLDN6), a tetraspan transmembrane tight junction protein, was dramatically reduced in the translation blocking morpholino injected embryos, but not when a splicing morpholino was used, which blocks only the full length EphA7. In cultured cells, EphA7 binds and phosphorylates CLDN6, and reduces its distribution at the cell surface. Our work suggests a role of EphA7 in the regulation of cell adhesion during pronephros development, whereas sEphA7 works as an antagonist.
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Affiliation(s)
- Jian Sun
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Xiaolei Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yu Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; Department of Clinical Laboratory, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Jiejing Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Chaocui Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Zhaoying Shi
- Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yonglong Chen
- Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
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13
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Takahashi K, Kim R, Lauhan C, Park Y, Nguyen NG, Vestweber D, Dominguez MG, Valenzuela DM, Murphy AJ, Yancopoulos GD, Gale NW, Takahashi T. Expression of receptor-type protein tyrosine phosphatase in developing and adult renal vasculature. PLoS One 2017; 12:e0177192. [PMID: 28542220 PMCID: PMC5444631 DOI: 10.1371/journal.pone.0177192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 04/24/2017] [Indexed: 11/18/2022] Open
Abstract
Renal vascular development is a coordinated process that requires ordered endothelial cell proliferation, migration, intercellular adhesion, and morphogenesis. In recent decades, studies have defined the pivotal role of endothelial receptor tyrosine kinases (RPTKs) in the development and maintenance of renal vasculature. However, the expression and the role of receptor tyrosine phosphatases (RPTPs) in renal endothelium are poorly understood, though coupled and counterbalancing roles of RPTKs and RPTPs are well defined in other systems. In this study, we evaluated the promoter activity and immunolocalization of two endothelial RPTPs, VE-PTP and PTPμ, in developing and adult renal vasculature using the heterozygous LacZ knock-in mice and specific antibodies. In adult kidneys, both VE-PTP and PTPμ were expressed in the endothelium of arterial, glomerular, and medullary vessels, while their expression was highly limited in peritubular capillaries and venous endothelium. VE-PTP and PTPμ promoter activity was also observed in medullary tubular segments in adult kidneys. In embryonic (E12.5, E13.5, E15.5, E17.5) and postnatal (P0, P3, P7) kidneys, these RPTPs were expressed in ingrowing renal arteries, developing glomerular microvasculature (as early as the S-shaped stage), and medullary vessels. Their expression became more evident as the vasculatures matured. Peritubular capillary expression of VE-PTP was also noted in embryonic and postnatal kidneys. Compared to VE-PTP, PTPμ immunoreactivity was relatively limited in embryonic and neonatal renal vasculature and evident immunoreactivity was observed from the P3 stage. These findings indicate 1) VE-PTP and PTPμ are expressed in endothelium of arterial, glomerular, and medullary renal vasculature, 2) their expression increases as renal vascular development proceeds, suggesting that these RPTPs play a role in maturation and maintenance of these vasculatures, and 3) peritubular capillary VE-PTP expression is down-regulated in adult kidneys, suggesting a role of VE-PTP in the development of peritubular capillaries.
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Affiliation(s)
- Keiko Takahashi
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Rachel Kim
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Colette Lauhan
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Yuna Park
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Nghiep G. Nguyen
- University of Oklahoma College of Medicine, Oklahoma City, Oklahoma, United States of America
| | | | | | - David M. Valenzuela
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - Andrew J. Murphy
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - George D. Yancopoulos
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Nicholas W. Gale
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - Takamune Takahashi
- Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail:
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14
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Bidirectional signalling between EphA2 and ephrinA1 increases tubular cell attachment, laminin secretion and modulates erythropoietin expression after renal hypoxic injury. Pflugers Arch 2016; 468:1433-48. [PMID: 27228995 DOI: 10.1007/s00424-016-1838-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/01/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
Abstract
Acute kidney injury (AKI) is common in hospitalized patients and has a poor prognosis, the severity of AKI being linked to progression to chronic kidney disease. This stresses the need to search for protective mechanisms during the acute phase. We investigated kidney repair after hypoxic injury using a rat model of renal artery branch ligation, which led to an oxygen gradient vertical to the corticomedullary axis. Three distinct zones were observed: tubular necrosis, infarction border zone and preserved normal tissue. EphA2 is a receptor tyrosine kinase with pivotal roles in cell architecture, migration and survival, upon juxtacrine contact with its membrane-bound ligand EphrinA1. Following hypoxia, EphA2 was up-regulated in cortical and medullary tubular cells, while EphrinA1 was up-regulated in interstitial cells adjacent to peritubular capillaries. Moreover, erythropoietin (EPO) messenger RNA (mRNA) was strongly expressed in the border zone of infarcted kidney within the first 6 h. To gain more insight into the biological impact of EphA2 and EphrinA1 up-regulation, we activated the signalling pathways in vitro using recombinant EphrinA1/Fc or EphA2/Fc proteins. Stimulation of EphA2 forward signalling in the proximal tubular cell line HK2 increased cell attachment and laminin secretion at the baso-lateral side. Conversely, activation of reverse signalling through EphrinA1 expressed by Hep3B cells promoted EPO production at both the transcriptional and protein level. Strikingly, in co-culture experiments, juxtacrine contact between EphA2 expressing MDCK and EphrinA1 expressing Hep3B was sufficient to induce a significant up-regulation of EPO mRNA production in the latter cells, even in the absence of hypoxic conditions. The synergistic effects of EphA2 and hypoxia led to a 15-20-fold increase of EPO expression. Collectively, our results suggest an important role of EphA2/EphrinA1 signalling in kidney repair after hypoxic injury through stimulation of (i) tubular cell attachment, (ii) secretion of basal membrane proteins and (iii) EPO production. These findings could thus pave the way to new therapeutic approaches.
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15
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Eph/ephrin signaling in the kidney and lower urinary tract. Pediatr Nephrol 2016; 31:359-71. [PMID: 25903642 DOI: 10.1007/s00467-015-3112-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 02/06/2023]
Abstract
Development and homeostasis of the highly specialized cell types and tissues that constitute the organs of the urinary system, the kidneys and ureters, the bladder, and the urethra, require the tightly regulated exchange of signals in and between these tissues. Eph/ephrin signaling is a bidirectional signaling pathway that has been functionally implicated in many developmental and homeostatic contexts, most prominently in the vascular and neural system. Expression and knockout analyses have now provided evidence that Eph/ephrin signaling is of crucial relevance for cell and tissue interactions in the urinary system as well. A clear requirement has emerged in the formation of the vesicoureteric junction, in urorectal septation and glomerulogenesis during embryonic development, in maintenance of medullary tubular cells and podocytes in homeostasis, and in podocyte and glomerular injury responses. Deregulation of Eph/ephrin signaling may also contribute to the formation and progression of tumors in the urinary system, most prominently bladder and renal cell carcinoma. While in the embryonic contexts Eph/ephrin signaling regulates adhesion of epithelial cells, in the adult setting, cell-shape changes and cell survival seem to be the primary cellular processes mediated by this signaling module. With progression of the genetic analyses of mice conditionally mutant for compound alleles of Eph receptor and ephrin ligand genes, additional essential functions are likely to arise in the urinary system.
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16
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Pippin JW, Kaverina NV, Eng DG, Krofft RD, Glenn ST, Duffield JS, Gross KW, Shankland SJ. Cells of renin lineage are adult pluripotent progenitors in experimental glomerular disease. Am J Physiol Renal Physiol 2015; 309:F341-58. [PMID: 26062877 DOI: 10.1152/ajprenal.00438.2014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 06/04/2015] [Indexed: 12/31/2022] Open
Abstract
Modified vascular smooth muscle cells of the kidney afferent arterioles have recently been shown to serve as progenitors for glomerular epithelial cells in response to glomerular injury. To determine whether such cells of renin lineage (CoRL) serve as progenitors for other cells in kidney disease characterized by both glomerular and tubulointerstitial injury, permanent genetic cell fate mapping of adult CoRL using Ren1cCreER × Rs-tdTomato-R reporter mice was performed. TdTomato-labeled CoRL were almost completely restricted to the juxtaglomerular compartment in healthy kidneys. Following 2 wk of antibody-mediated focal segmental glomerulosclerosis (FSGS) or 16 wk of ⅚ nephrectomy-induced chronic kidney diseases, tdTomato-mapped CoRL were identified in both interstitial and glomerular compartments. In the interstitium, PDGFβ receptor (R)-expressing cells significantly increased, and a portion of these expressed tdTomato. This was accompanied by a decrease in native pericyte number, but an increase in the number of tdTomato cells that coexpressed the pericyte markers PDGFβ-R and NG2. These cells surrounded vessels and coexpressed the pericyte markers CD73 and CD146, but not the endothelial marker ERG. Within glomeruli of reporter mice with the ⅚ nephrectomy model, a subset of labeled CoRL migrated to the glomerular tuft and coexpressed podocin and synaptopodin. By contrast, labeled CoRL were not detected in glomerular or interstitial compartments following uninephrectomy. These observations indicate that in addition to supplying new adult podocytes to glomeruli, CoRL have the capacity to become new adult pericytes in the setting of interstitial disease. We conclude that CoRL have the potential to function as progenitors for multiple adult cell types in kidney disease.
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Affiliation(s)
- Jeffrey W Pippin
- Division of Nephrology, University of Washington, Seattle, Washington;
| | | | - Diana G Eng
- Division of Nephrology, University of Washington, Seattle, Washington
| | - Ronald D Krofft
- Division of Nephrology, University of Washington, Seattle, Washington
| | - Sean T Glenn
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York; and
| | - Jeremy S Duffield
- Division of Nephrology, University of Washington, Seattle, Washington; Biogen IDEC, Cambridge, Massachusetts
| | - Kenneth W Gross
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York; and
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17
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Abstract
Chronic progressive renal fibrosis leads to end-stage renal failure many patients with chronic kidney disease (CKD). Loss of the rich peritubular capillary network is a prominent feature, and seems independent of the specific underlying disease. The mechanisms that contribute to peritubular capillary regression include the loss of glomerular perfusion, as flow-dependent shear forces are required to provide the survival signal for endothelial cells. Also, reduced endothelial cell survival signals from sclerotic glomeruli and atrophic or injured tubule epithelial cells contribute to peritubular capillary regression. In response to direct tubular epithelial cell injury, and the inflammatory reaction that ensues, capillary pericytes dissociate from their blood vessels, also reducing endothelial cell survival. In addition, direct inflammatory injury of capillary endothelial cells, for instance in chronic allograft nephropathy, also contributes to capillary dropout. Chronic tissue hypoxia, which ensues from the rarefaction of the peritubular capillary network, can generate both an angiogenic and a fibrogenic response. However, in CKD, the balance is strongly tipped toward fibrogenesis. Understanding the underlying mechanisms for failed angiogenesis in CKD and harnessing endothelial-specific survival and pro-angiogenic mechanisms for therapy should be our goal if we are to reduce the disease burden from CKD.
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Affiliation(s)
| | - Marya Obeidat
- Department of Medicine, University of Alberta , Edmonton, Alberta, Canada
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Glomerular development--shaping the multi-cellular filtration unit. Semin Cell Dev Biol 2014; 36:39-49. [PMID: 25153928 DOI: 10.1016/j.semcdb.2014.07.016] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 01/09/2023]
Abstract
The glomerulus represents a highly structured filtration unit, composed of glomerular endothelial cells, mesangial cells, podocytes and parietal epithelial cells. During glomerulogenesis an intricate network of signaling pathways involving transcription factors, secreted factors and cell-cell communication is required to guarantee accurate evolvement of a functional, complex 3-dimensional glomerular architecture. Here, we want to provide an overview on the critical steps and relevant signaling cascades of glomerular development.
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Redefining the in vivo origin of metanephric nephron progenitors enables generation of complex kidney structures from pluripotent stem cells. Cell Stem Cell 2013; 14:53-67. [PMID: 24332837 DOI: 10.1016/j.stem.2013.11.010] [Citation(s) in RCA: 572] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/20/2013] [Accepted: 11/12/2013] [Indexed: 12/14/2022]
Abstract
Recapitulating three-dimensional (3D) structures of complex organs, such as the kidney, from pluripotent stem cells (PSCs) is a major challenge. Here, we define the developmental origins of the metanephric mesenchyme (MM), which generates most kidney components. Unexpectedly, we find that posteriorly located T(+) MM precursors are developmentally distinct from Osr1(+) ureteric bud progenitors during the postgastrulation stage, and we identify phasic Wnt stimulation and stage-specific growth factor addition as molecular cues that promote their development into the MM. We then use this information to derive MM from PSCs. These progenitors reconstitute the 3D structures of the kidney in vitro, including glomeruli with podocytes and renal tubules with proximal and distal regions and clear lumina. Furthermore, the glomeruli are efficiently vascularized upon transplantation. Thus, by reevaluating the developmental origins of metanephric progenitors, we have provided key insights into kidney specification in vivo and taken important steps toward kidney organogenesis in vitro.
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Grahammer F, Schell C, Huber TB. Molecular understanding of the slit diaphragm. Pediatr Nephrol 2013; 28:1957-62. [PMID: 23233041 DOI: 10.1007/s00467-012-2375-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 10/16/2012] [Accepted: 10/17/2012] [Indexed: 11/30/2022]
Abstract
Glomerular filtration has always attracted the interest of nephrologists and renal researchers alike. Although several key questions on the structure and function of the kidney filter may have been answered within the last 40 years of intense research, there still remain crucial questions to be solved. The following article attempts to give a brief overview of recent developments in glomerular research highlighting particular advances in our understanding of the slit diaphragm.
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Affiliation(s)
- Florian Grahammer
- Renal Division, University Hospital Freiburg, Hugstetter Strasse 55, Freiburg 79106, Germany
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21
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Basile DP, Yoder MC. Getting the “Inside” Scoop on EphrinB2 Signaling in Pericytes and the Effect on Peritubular Capillary Stability. J Am Soc Nephrol 2013; 24:521-3. [DOI: 10.1681/asn.2013020153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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22
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Shi W, Bugrim A, Nikolsky Y, Nikolskya T, Brennan RJ. Characteristics of genomic signatures derived using univariate methods and mechanistically anchored functional descriptors for predicting drug- and xenobiotic-induced nephrotoxicity. Toxicol Mech Methods 2012; 18:267-76. [PMID: 20020920 DOI: 10.1080/15376510701857072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
ABSTRACT The ideal toxicity biomarker is composed of the properties of prediction (is detected prior to traditional pathological signs of injury), accuracy (high sensitivity and specificity), and mechanistic relationships to the endpoint measured (biological relevance). Gene expression-based toxicity biomarkers ("signatures") have shown good predictive power and accuracy, but are difficult to interpret biologically. We have compared different statistical methods of feature selection with knowledge-based approaches, using GeneGo's database of canonical pathway maps, to generate gene sets for the classification of renal tubule toxicity. The gene set selection algorithms include four univariate analyses: t-statistics, fold-change, B-statistics, and RankProd, and their combination and overlap for the identification of differentially expressed probes. Enrichment analysis following the results of the four univariate analyses, Hotelling T-square test, and, finally out-of-bag selection, a variant of cross-validation, were used to identify canonical pathway maps-sets of genes coordinately involved in key biological processes-with classification power. Differentially expressed genes identified by the different statistical univariate analyses all generated reasonably performing classifiers of tubule toxicity. Maps identified by enrichment analysis or Hotelling T-square had lower classification power, but highlighted perturbed lipid homeostasis as a common discriminator of nephrotoxic treatments. The out-of-bag method yielded the best functionally integrated classifier. The map "ephrins signaling" performed comparably to a classifier derived using sparse linear programming, a machine learning algorithm, and represents a signaling network specifically involved in renal tubule development and integrity. Such functional descriptors of toxicity promise to better integrate predictive toxicogenomics with mechanistic analysis, facilitating the interpretation and risk assessment of predictive genomic investigations.
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Affiliation(s)
- Weiwei Shi
- GeneGo, Inc. 500 Renaissance Drive, #106, St. Joseph, MI, 49085
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23
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Obeidat M, Obeidat M, Ballermann BJ. Glomerular endothelium: A porous sieve and formidable barrier. Exp Cell Res 2012; 318:964-72. [DOI: 10.1016/j.yexcr.2012.02.032] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 02/24/2012] [Indexed: 12/20/2022]
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Wnuk M, Hlushchuk R, Janot M, Tuffin G, Martiny-Baron G, Holzer P, Imbach-Weese P, Djonov V, Huynh-Do U. Podocyte EphB4 signaling helps recovery from glomerular injury. Kidney Int 2012; 81:1212-25. [PMID: 22398409 DOI: 10.1038/ki.2012.17] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Eph receptor tyrosine kinases and their ligands (ephrins) have a pivotal role in the homeostasis of many adult organs and are widely expressed in the kidney. Glomerular diseases beginning with mesangiolysis can recover, with podocytes having a critical role in this healing process. We studied here the role of Eph signaling in glomerular disease recovery following mesangiolytic Thy1.1 nephritis in rats. EphB4 and ephrinBs were expressed in healthy glomerular podocytes and were upregulated during Thy1.1 nephritis, with EphB4 strongly phosphorylated around day 9. Treatment with NPV-BHG712, an inhibitor of EphB4 phosphorylation, did not cause glomerular changes in control animals. Nephritic animals treated with vehicle did not have morphological evidence of podocyte injury or loss; however, application of this inhibitor to nephritic rats induced glomerular microaneurysms, podocyte damage, and loss. Prolonged NPV-BHG712 treatment resulted in increased albuminuria and dysregulated mesangial recovery. Additionally, NPV-BHG712 inhibited capillary repair by intussusceptive angiogenesis (an alternative to sprouting angiogenesis), indicating a previously unrecognized role of podocytes in regulating intussusceptive vessel splitting. Thus, our results identify EphB4 signaling as a pathway allowing podocytes to survive transient capillary collapse during glomerular disease.
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Affiliation(s)
- Monika Wnuk
- Department of Nephrology and Hypertension, Inselspital, University of Bern Medical School, Bern, Switzerland
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25
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Maeshima Y, Makino H. Angiogenesis and chronic kidney disease. FIBROGENESIS & TISSUE REPAIR 2010; 3:13. [PMID: 20687922 PMCID: PMC2924264 DOI: 10.1186/1755-1536-3-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 08/05/2010] [Indexed: 01/13/2023]
Abstract
The number of patients requiring renal replacement therapy due to end-stage renal disease (ESRD) is increasing worldwide. The prevalence of chronic kidney disease (CKD), and the importance of CKD as a risk factor in development of ESRD and in complicating cardiovascular disease (CVD) have been confirmed. In recent years, the involvement of angiogenesis-related factors in the progression of CKD has been studied, and the potential therapeutic effects on CKD of modulating these factors have been identified. Vascular endothelial growth factor (VEGF)-A, a potent pro-angiogenic factor, is involved in the development of the kidney, in maintenance of the glomerular capillary structure and filtration barrier, and in the renal repair process after injury. VEGF-A is also involved in the development of early diabetic nephropathy, demonstrated by the therapeutic effects of anti-VEGF-A antibody. Angiopoietin (Ang)-1 induces the maturation of newly formed blood vessels, and the therapeutic effects of Ang-1 in diabetic nephropathy have been described. In experimental models of diabetic nephropathy, the therapeutic effects of angiogenesis inhibitors, including angiostatin, endostatin and tumstatin peptides, the isocoumarin NM-3, and vasohibin-1, have been reported. Further analysis of the involvement of angiogenesis-related factors in the development of CKD is required. Determining the disease stage at which therapy is most effective and developing an effective drug delivery system targeting the kidney will be essential for pro-or anti-angiogenic strategies for patients with CKD.
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Affiliation(s)
- Yohei Maeshima
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
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26
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Miao H, Wang B. Eph/ephrin signaling in epithelial development and homeostasis. Int J Biochem Cell Biol 2008; 41:762-70. [PMID: 18761422 DOI: 10.1016/j.biocel.2008.07.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 06/13/2008] [Accepted: 07/01/2008] [Indexed: 11/16/2022]
Abstract
Eph receptors and ephrin ligands are widely expressed during embryonic development with well-defined functions in directing neuronal and vascular network formation. Over the last decade, evidence has mounted that Ephs and ephrins are also actively involved in prenatal and postnatal development of epithelial tissues. Their functions beyond developmental settings are starting to be recognized as well. The diverse functions of Eph/ephrin are largely related to the complementary expression pattern of the Eph receptors and corresponding ephrin ligands that are expressed in adjacent compartments, although overlapping expression pattern also exists in epithelial tissue. The interconnection between Ephs or ephrins and classical cell junctional molecules suggests they may function coordinately in maintaining epithelial structural integrity and homeostasis. This review will highlight cellular and molecular evidence in current literature that support a role of Eph/ephrin systems in regulating epithelial cell development and physiology.
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Affiliation(s)
- Hui Miao
- Rammelkamp Center for Research, MetroHealth Campus, Case Western Reserve University School of Medicine, 2500 MetroHealth Drive, Cleveland, OH 44109, United States
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27
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Shin WS, Rockson SG. Animal models for the molecular and mechanistic study of lymphatic biology and disease. Ann N Y Acad Sci 2008; 1131:50-74. [PMID: 18519959 DOI: 10.1196/annals.1413.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The development of animal model systems for the study of the lymphatic system has resulted in an explosion of information regarding the mechanisms governing lymphatic development and the diseases associated with lymphatic dysfunction. Animal studies have led to a new molecular model of embryonic lymphatic vascular development, and have provided insight into the pathophysiology of both inherited and acquired lymphatic insufficiency. It has become apparent, however, that the importance of the lymphatic system to human disease extends, beyond its role in lymphedema, to many other diverse pathologic processes, including, very notably, inflammation and tumor lymphangiogenesis. Here, we have undertaken a systematic review of the models as they relate to molecular and functional characterization of the development, maturation, genetics, heritable and acquired diseases, and neoplastic implications of the lymphatic system. The translation of these advances into therapies for human diseases associated with lymphatic dysfunction will require the continued study of the lymphatic system through robust animal disease models that simulate their human counterparts.
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Affiliation(s)
- William S Shin
- Stanford Center for Lymphatic and Venous Disorders, Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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28
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Hicks PJ, Staten JL, Palmer ND, Langefeld CD, Ziegler JT, Keene KL, Sale MM, Bowden DW, Freedman BI. Association analysis of the ephrin-B2 gene in African-Americans with end-stage renal disease. Am J Nephrol 2008; 28:914-20. [PMID: 18580054 DOI: 10.1159/000141934] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Accepted: 05/12/2008] [Indexed: 01/13/2023]
Abstract
BACKGROUND Genome scans in African-Americans with end-stage renal disease (ESRD) identified linkage on chromosome 13q33 in the region containing the ephrin-B2 ligand (EFNB2) genes. Interactions between the ephrin-B2 receptor and ephrin-B2 ligand play essential roles in renal angiogenesis, blood vessel maturation, and kidney disease. METHODS The EFNB2 gene was evaluated as a positional candidate for non-diabetic and diabetic ESRD susceptibility in 1,071 unrelated African-American subjects; 316 with non-diabetic etiologies of ESRD, 394 with type 2 diabetes-associated ESRD and 361 healthy controls. Single nucleotide polymorphism (SNP) genotyping was performed on the Sequenom Mass Array System. Statistical analyses were computed using Dandelion version 1.26, Snpaddmix version 1.4 and Haploview version 3.32. RESULTS Twenty-eight HapMap tag SNPs were genotyped spanning the 39 kilobases (kb) of the EFNB2 coding region, with average spacing of 1.43 kb. Analysis of 710 ESRD patient samples and 361 controls provided no evidence of single SNP associations in either diabetic or non-diabetic ESRD; although nominal evidence of association with all-cause ESRD was observed with a two SNP (p = 0.022) and three SNP (p = 0.023) haplotype, both containing SNPs rs7490924 and rs2391335 in intron 1. CONCLUSIONS Although an attractive positional candidate gene, polymorphisms in the EFNB2 gene do not appear to contribute in a substantial way to non-diabetic, diabetic or all-cause ESRD susceptibility in African-Americans. Additional genes within the chromosome 13q33 linkage interval are likely contributors to African-American non-diabetic ESRD.
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Affiliation(s)
- Pamela J Hicks
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1053, USA
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Vaughan MR, Quaggin SE. How do mesangial and endothelial cells form the glomerular tuft? J Am Soc Nephrol 2008; 19:24-33. [PMID: 18178797 DOI: 10.1681/asn.2007040471] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The glomerular capillary tuft is a highly intricate and specialized microvascular bed that filters plasma water and solute to form urine. The mature glomerulus contains four cell types: Parietal epithelial cells that form Bowman's capsule, podocytes that cover the outermost layer of the glomerular filtration barrier, glycocalyx-coated fenestrated endothelial cells that are in direct contact with blood, and mesangial cells that sit between the capillary loops. Filtration begins only after the influx and organization of endothelial and mesangial cells in the developing glomerulus. Tightly coordinated movement and cross-talk between these cell types is required for the formation of a functional glomerular filtration barrier, and disruption of these processes has devastating consequences for early life. Current concepts of the role of mesangial and endothelial cells in formation of the capillary tuft are reviewed here.
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Affiliation(s)
- Michael R Vaughan
- Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, University of Toronto, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
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Quaggin SE, Kreidberg JA. Development of the renal glomerulus: good neighbors and good fences. Development 2008; 135:609-20. [PMID: 18184729 DOI: 10.1242/dev.001081] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The glomerulus of the mammalian kidney is an intricate structure that contains an unusual filtration barrier that retains higher molecular weight proteins and blood cells in the circulation. Recent studies have changed our conception of the glomerulus from a relatively static structure to a dynamic one, whose integrity depends on signaling between the three major cell lineages: podocytes, endothelial and mesangial cells. Research into the signaling pathways that control glomerular development and then maintain glomerular integrity and function has recently identified several genes, such as the nephrin and Wilms' tumor 1 genes, that are mutated in human kidney disease.
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Affiliation(s)
- Susan E Quaggin
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
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Sauter A, Machura K, Neubauer B, Kurtz A, Wagner C. Development of renin expression in the mouse kidney. Kidney Int 2008; 73:43-51. [PMID: 17898695 DOI: 10.1038/sj.ki.5002571] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
During metanephric kidney development, renin is expressed in the walls of larger intrarenal arteries, but is restricted to the terminal part of the preglomerular arterioles in the adult kidney. Our study describes the three-dimensional development of renin expression in mouse kidneys during fetal and postnatal life. Renin immunoreactivity first appeared at day 14 of development in the cells expressing alpha-smooth muscle actin (alphaSMA) in the arcuate arteries. Before adulthood, the branching of the arcuate arterial tree increased exponentially and renin expression shifted from proximal to distal parts of the tree. Renin expression at branching points or in the cones of growing vessels was not seen. Instead, renin expression appeared after vessel walls and branches were already established, disappeared a few days later, and remained only in the juxtaglomerular regions of afferent arterioles. In these arterioles, coexpression of renin and alphaSMA disappeared gradually, with the terminal cells expressing only renin. At all stages of kidney development, renin expression among comparable vessel segments was heterogeneous. Renin expression remained stable after it reached the terminal parts of afferent arterioles.
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Affiliation(s)
- A Sauter
- Institut für Physiologie der Universität Regensburg, D-93040 Regensburg, Germany
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Makino H, Suga SI. Alteration of glomerulogenesis- and podocyte structure-related gene expression in early diabetic nephropathy. Expert Rev Endocrinol Metab 2007; 2:615-622. [PMID: 30736124 DOI: 10.1586/17446651.2.5.615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diabetic nephropathy is a leading cause of end-stage renal disease. Several pathways, including the renin-angiotensin system, have been postulated as potential mechanisms of diabetic nephropathy. In addition, glomerulogenesis-related molecules are involved in the pathogenesis of diabetic nephropathy, especially at the early stage. They can be divided into three groups by function, that is, fibrosis-related, podocyte differentiation-related and angiogenesis-related molecules. Most of the molecules are expressed in the podocyte and upregulated, even during the normoalbuminuric stage. Expression of several podocyte structure-related molecules are also altered at the normoalbuminuric stage. They can contribute to the structural alteration of the podocyte in diabetic nephropathy. Thus, normalization of the expression of glomerulogenesis-related molecules could be a new target for preventing the initiation and progression of diabetic nephropathy.
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Affiliation(s)
- Hisashi Makino
- a National Cardiovascular Center, Department of Atherosclerosis and Diabetes Suita City, Osaka, Japan.
| | - Shin-Ichi Suga
- b Saiseikai Maebashi Hospital Department of Nephrology, 564-1 Kamishinden-machi, Maebashi, Gunma 371-0821, Japan.
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Hashimoto T, Karasawa T, Saito A, Miyauchi N, Han GD, Hayasaka K, Shimizu F, Kawachi H. Ephrin-B1 localizes at the slit diaphragm of the glomerular podocyte. Kidney Int 2007; 72:954-64. [PMID: 17667985 DOI: 10.1038/sj.ki.5002454] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ephs and ephrins are a family of membrane-bound proteins that function as receptor-ligand pairs. Members of the Eph-ephrin-B family have recently been reported to regulate the paracellular permeability of epithelial cells. In this study, we analyzed the expression and the function of ephrin-B1 in glomeruli. Using immunofluorescence (IF), we found that ephrin-B1 was expressed along the glomerular capillary loop. Immunoelectron microscopy revealed that ephrin-B1 expression was restricted at the slit diaphragm. Dual labeled IF showed ephrin-B1 colocalized with the slit diaphragm proteins nephrin and CD2-associated protein. Ephrin-B1 colocalized with nephrin at the late capillary loop stage of kidney development. Additionally, injection of rats with a nephritogenic anti-nephrin antibody (ANA) reduced ephrin-B1 expression. When podocytes were cultured in vitro, they extruded processes that co-stained for ephrin-B1 and for CD2-associated protein. When these podocytes were treated in culture with small interfering RNA for ephrin-B1, CD2-associated protein was reduced in the processes, with a remaining faint perinuclear staining. We suggest that ephrin-B1 has a role in maintaining barrier function at the slit diaphragm.
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Affiliation(s)
- T Hashimoto
- Department of Cell Biology, Institute of Nephrology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Ballermann BJ. Contribution of the endothelium to the glomerular permselectivity barrier in health and disease. Nephron Clin Pract 2007; 106:p19-25. [PMID: 17570944 DOI: 10.1159/000101796] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The endothelium that lines glomerular capillaries shares many properties with endothelial cells in general, but unlike most endothelial cells, it is extremely flat and densely perforated by transendothelial cell pores, the fenestrae. Until recently, it was believed that the fenestrae allow free passage of large proteins, and that the glomerular endothelium contributes little to the permselectivity of the glomerular capillary wall. METHODS Key studies addressing the nature of the glomerular capillary endothelium and its contribution to glomerular permselectivity were reviewed. RESULTS Glomerular endothelial cell flattening and fenestrae formation requires signals from differentiated podocytes, and from the glomerular basement membrane. Deletion of VEGF-A from podocytes prevents flattening and fenestration of glomerular endothelium. Application of VEGF-A to endothelial cells in vivo stimulates fenestrae formation, and neutralization of VEGF-A by soluble VEGF receptor 1 (sFlt-1) or anti-VEGF antibodies results in loss of glomerular fenestrae, and proteinuria. Neutralizing TGF-beta1 antibodies, deletion of laminin alpha3 in mice or laminin beta3 in humans cause similar defects. The glomerular endotheliosis lesion of pre-eclampsia is due to the placenta-derived inhibitors sFlt-1 and sEndoglin, which block the VEGF-A/VEGF receptor and TGF-beta/endoglin signaling, respectively, causing the loss of glomerular endothelial cell fenestrae, cell swelling and proteinuria. The glomerular endothelium is covered by a glycocalyx that extends into the fenestrae and by a more loosely associated endothelial cell surface layer of glycoproteins. Mathematical analyses of functional permselectivity studies have concluded that the glomerular endothelial cell glycocalyx and its associated surface layer account for the retention of up to 95% of proteins within the circulation. Furthermore, the fenestrae are critical for the maintenance of the high hydraulic conductivity of the glomerular capillary wall, and their loss results in a reduction in the glomerular filtration rate. CONCLUSIONS Loss of GFR and proteinuria can result from glomerular endothelial cell injury.
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Pabbisetty KB, Yue X, Li C, Himanen JP, Zhou R, Nikolov DB, Hu L. Kinetic analysis of the binding of monomeric and dimeric ephrins to Eph receptors: correlation to function in a growth cone collapse assay. Protein Sci 2007; 16:355-61. [PMID: 17322526 PMCID: PMC2203307 DOI: 10.1110/ps.062608807] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Eph receptors and ephrins play important roles in regulating cell migration and positioning during both normal and oncogenic tissue development. Using a surface plasma resonance (SPR) biosensor, we examined the binding kinetics of representative monomeric and dimeric ephrins to their corresponding Eph receptors and correlated the apparent binding affinity with their functional activity in a neuronal growth cone collapse assay. Our results indicate that the Eph receptor binding of dimeric ephrins, formed through fusion with disulfide-linked Fc fragments, is best described using a bivalent analyte model as a two-step process involving an initial monovalent 2:1 binding followed by a second bivalent 2:2 binding. The bivalent binding dramatically decreases the apparent dissociation rate constants with little effect on the initial association rate constants, resulting in a 30- to 6000-fold decrease in apparent equilibrium dissociation constants for the binding of dimeric ephrins to Eph receptors relative to their monomeric counterparts. Interestingly, the change was more prominent in the A-class ephrin/Eph interactions than in the B-class of ephrins to Eph receptors. The increase in apparent binding affinities correlated well with increased activation of Eph receptors and the resulting growth cone collapse. Our kinetic analysis and correlation of binding affinity with function helped us better understand the interactions between ephrins and Eph receptors and should be useful in the design of inhibitors that interfere with the interactions.
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Affiliation(s)
- Kumar B Pabbisetty
- Department of Pharmaceutical Chemistry, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
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Makino H, Miyamoto Y, Sawai K, Mori K, Mukoyama M, Nakao K, Yoshimasa Y, Suga SI. Altered gene expression related to glomerulogenesis and podocyte structure in early diabetic nephropathy of db/db mice and its restoration by pioglitazone. Diabetes 2006; 55:2747-56. [PMID: 17003339 DOI: 10.2337/db05-1683] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glomerular injury plays a pivotal role in the development of diabetic nephropathy. To elucidate molecular mechanisms underlying diabetic glomerulopathy, we compared glomerular gene expression profiles of db/db mice with those of db/m control mice at a normoalbuminuric stage characterized by hyperglycemia and at an early stage of diabetic nephropathy with elevated albuminuria, using cDNA microarray. In db/db mice at the normoalbuminuric stage, hypoxia-inducible factor-1alpha (HIF-1alpha), ephrin B2, glomerular epithelial protein 1, and Pod-1, which play key roles in glomerulogenesis, were already upregulated in parallel with an alteration of genes related to glucose metabolism, lipid metabolism, and oxidative stress. Podocyte structure-related genes, actinin 4alpha and dystroglycan 1 (DG1), were also significantly upregulated at an early stage. The alteration in the expression of these genes was confirmed by quantitative RT-PCR. Through pioglitazone treatment, gene expression of ephrin B2, Pod-1, actinin 4alpha, and DG1, as well as that of oxidative stress and lipid metabolism, was restored concomitant with attenuation of albuminuria. In addition, HIF-1alpha protein expression was partially attenuated by pioglitazone. These results suggest that not only metabolic alteration and oxidative stress, but also the alteration of gene expression related to glomerulogenesis and podocyte structure, may be involved in the pathogenesis of early diabetic glomerulopathy in type 2 diabetes.
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Affiliation(s)
- Hisashi Makino
- Department of Atherosclerosis and Diabetes, National Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita City, Osaka 565-8565, Japan
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Ogawa K, Wada H, Okada N, Harada I, Nakajima T, Pasquale EB, Tsuyama S. EphB2 and ephrin-B1 expressed in the adult kidney regulate the cytoarchitecture of medullary tubule cells through Rho family GTPases. J Cell Sci 2006; 119:559-70. [PMID: 16443753 DOI: 10.1242/jcs.02777] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Eph receptors and ephrin ligands are membrane-bound cell-cell communication molecules with well-defined functions in development, but their expression patterns and functions in many adult tissues are still largely unknown. We have detected substantial levels of the EphB2 and EphB6 receptors and the ephrin-B1 ligand in the adult mouse kidney by RT-PCR amplification. Immunolocalization experiments revealed that EphB2 is localized in the tubules of the inner and outer medulla and EphB6 is in the tubules of the outer medulla and cortex. By contrast, ephrin-B1 was detected in tubules throughout the whole nephron. Consistent with the overlapping expression of the EphB2 receptor and the ephrin-B1 ligand in the medulla, EphB2 is tyrosine-phosphorylated, and therefore activated, in the kidney. In the outer medulla, however, EphB2 signaling may be attenuated by the co-expressed kinase-inactive EphB6 receptor. Interestingly, we found that EphB signaling induces RhoA activation and Rac1 inactivation as well as cell retraction, enlargement of focal adhesions and prominent stress fibers in primary cultures of medullary tubule cells. These results suggest that EphB receptor signaling through Rho family GTPases regulates the cytoarchitecture and spatial organization of the tubule cells in the adult kidney medulla and, therefore, may affect the reabsorption ability of the kidney.
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Affiliation(s)
- Kazushige Ogawa
- Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
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Abstract
BACKGROUND Glomerular endothelial cells differ from most other endothelial cells in that they are extraordinarily flattened and highly fenestrated. In this differentiated form, they allow formation of glomerular ultrafiltrate at a prodigious rate. METHODS Molecular processes that dictate the development and differentiation of glomerular endothelium are reviewed. RESULTS During glomerular development, angioblasts already present in the metanephric blastema well before any organized angiogenic sprouts invade the capillary cleft of developing nephrons at the comma and S-shape stages in response to chemotactic and guiding cues from primitive podocytes. The angioblasts then undergo homotypic aggregation into precapillary cords as yet devoid of a lumen. Lumen development then proceeds through the loss of superfluous endothelial cells by apoptosis as well as flattening of the remaining viable endothelial cells. The final step, fenestration, is critically dependent on appropriate stimuli, most notably vascular endothelial growth factor A (VEGF-A), from differentiated podocytes. Current evidence suggests that the fenestrae of fully differentiated glomerular endothelium can be lost within hours if the VEGF-A stimulus is removed, and that the glomerular endotheliosis, loss of glomerular filtration rate (GFR) and proteinuria observed in preeclampsia are due to the circulating inhibitor of VEGF-A, soluble VEGF receptor 1 (VEGFR-1). CONCLUSION Differentiation of the glomerular endothelium is highly dependent on podocyte-derived stimuli and their loss leads to the derangements of glomerular function in preeclampsia.
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Affiliation(s)
- Barbara J Ballermann
- Division of Nephrology and Immunology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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Nozu K, Iijima K, Sakaeda T, Okumura K, Nakanishi K, Yoshikawa N, Honda M, Ikeda M, Matsuo M. Cyclosporin A absorption profiles in children with nephrotic syndrome. Pediatr Nephrol 2005; 20:910-3. [PMID: 15856324 DOI: 10.1007/s00467-005-1844-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 12/15/2004] [Accepted: 12/16/2004] [Indexed: 12/01/2022]
Abstract
A single blood concentration measurement of Neoral 2 h after administration (C2) is a new concept in therapeutic drug monitoring (TDM). In most adult patients, the concentration of cyclosporin A (CyA) peaks within 2 h after Neoral administration. Therefore, monitoring the area under the concentration-time curve over the first 4 h post-dose (AUC0-4) is considered to be the most reliable strategy for Neoral TDM. In addition, C2 is considered to be the most accurate predictor of AUC0-4, with which C2 correlates best. Thus, in adult patients, C2 monitoring is recommended as the best single-point TDM method for Neoral. However, in paediatric patients, the effectiveness of C2 monitoring is still unclear. We examined the trough concentration (C0), C1, C2, C3, and C4 of CyA in 60 patients (1 to 20 years old, mean age 7.42+/-0.67 years) who had nephrotic syndrome treated with Neoral. The peak concentration of C0-C4 was C1 or C2 in 38 patients (early peak group) and C3 or C4 in 22 patients (late peak group). C2 in the late peak group was significantly lower than that in the early peak group (422+/-50.1 vs. 665 +/-53.8 ng/ml, P =0.0008), although the administered doses of Neoral and C0 were similar between these groups. Therefore, TDM by C2 using the same standard as in the early peak group might result in an overdose of CyA in the late peak group. As the concentration peaked at 3 h or more after Neoral administration in the late peak group, AUC0-4 does not necessarily reflect the Neoral absorption profile. As more than 33% of the paediatric patients were in the late peak group, TDM by AUC0-4 or C2 should be used carefully in paediatric patients treated with Neoral.
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Affiliation(s)
- Kandai Nozu
- Department of Paediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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40
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Pitera JE, Woolf AS, Gale NW, Yancopoulos GD, Yuan HT. Dysmorphogenesis of kidney cortical peritubular capillaries in angiopoietin-2-deficient mice. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 165:1895-906. [PMID: 15579434 PMCID: PMC1618709 DOI: 10.1016/s0002-9440(10)63242-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Angiopoietin-2 (Ang-2) modulates Tie-2 receptor activation. In mouse kidney maturation, Ang-2 is expressed in arteries, with lower levels in tubules, whereas Tie-2 is expressed by endothelia. We hypothesized that Ang-2 deficiency disrupts kidney vessel patterning. The normal renal cortical peritubular space contains fenestrated capillaries, which have few pericytes; they receive water and solutes which proximal tubules reclaim from the glomerular filtrate. In wild-type neonates, alpha smooth muscle actin (alpha SMA), platelet-derived growth factor receptor beta (PDGFR beta), and desmin-expressing cells were not prominent in this compartment. In Ang-2 null mutants, alpha SMA, desmin, and PDGFR beta prominently immunolocalized in cortical peritubular locations. Some alpha SMA-positive cells were closely associated with CD31- and Tie-2-positive peritubular capillary endothelia, and some of the alpha SMA-positive cells expressed PDGFR beta, desmin, and neural/glial cell 2 (NG2), consistent with a pericyte-like identity. Immunoblotting suggested an increase of total and tyrosine-phosphorylated Tie-2 proteins in null mutant versus wild-type kidneys, and electron microscopy confirmed disorganized capillaries and adjacent cells in cortical peritubular spaces in mutant neonate kidneys. Hence, Ang-2 deficiency causes dysmorphogenesis of cortical peritubular capillaries, with adjacent cells expressing pericyte-like markers; we speculate the latter effect is caused by disturbed paracrine signaling between endothelial and surrounding mesenchymal precursor cells.
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Affiliation(s)
- Jolanta E Pitera
- Institute of Child Health, University College London, London, UK
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41
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Abstract
PURPOSE OF REVIEW Vascular endothelial growth factor is a major regulator of blood vessel biology and is highly expressed in presumptive and mature podocytes within the glomerulus. It has long been recognized that dysregulation of this factor occurs in a number of glomerular diseases; however, definitive proof that it plays a pathogenic or developmental role in glomerular biology has remained elusive. This review will summarize some of the recent advances in our understanding of the role(s) of VEGF in these processes. RECENT FINDINGS Gene targeting in the mouse has shown that tight regulation of vascular endothelial growth factor is required for development and maintenance of the glomerular filtration barrier. Podocyte-specific deletion of both alleles leads to congenital nephropathy and perinatal lethality. The glomeruli of mice that lack the 164 and 184 isoforms but express the 120 isoform, are smaller and have fewer capillary loops, whereas mice with podocyte-specific haploinsufficiency for all isoforms develop glomerular endotheliosis, the renal lesion seen in preeclampsia. Elevated levels of the soluble vascular endothelial growth factor receptor 1, which binds and inhibits circulating forms of VEGF were identified in patients with preeclampsia; rats injected with this soluble receptor develop hypertension, endotheliosis and proteinuria, similar to the lesion seen in podocyte-specific haploinsufficient VEGF mice. Conversely, podocyte-specific overexpression of the 164 isoform leads to collapsing glomerulopathy, the classic lesion seen in HIV-associated nephropathy. SUMMARY These results demonstrate that vascular endothelial growth factor plays a critical role in glomerular development and function, and provides the foundation to develop novel diagnostic or therapeutic tools for patients with glomerular disease.
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Affiliation(s)
- Vera Eremina
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Ontario, Canada
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42
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Andres AC, Munarini N, Djonov V, Bruneau S, Zuercher G, Loercher S, Rohrbach V, Ziemiecki A. EphB4 receptor tyrosine kinase transgenic mice develop glomerulopathies reminiscent of aglomerular vascular shunts. Mech Dev 2003; 120:511-6. [PMID: 12676328 DOI: 10.1016/s0925-4773(02)00461-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have established transgenic mice over-expressing the EphB4 receptor tyrosine kinase in the kidney. The EphB4 protein was localised to the developing tubular system of both control and transgenic newborn mice. In transgenic adults, transgene expression persisted in the proximal tubules and the Bowman's capsules, structures, which were not stained in control kidneys. The glomeruli of control animals consisted of regular, round vascular baskets with clearly discernable afferent and efferent arterioles. In contrast, approximately 40% of the transgenic glomeruli had an irregular shrivelled appearance and many exhibited fused, horse shoe-like afferent and efferent arterioles bypassing the glomerulus. These abnormal glomerular structures are very reminiscent of aglomerular vascular shunts, a human degenerative glomerulopathy of unknown aetiology.
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MESH Headings
- Animals
- DNA, Complementary/metabolism
- Disease Models, Animal
- Ephrin-B2/genetics
- Glomerulonephritis/genetics
- Immunohistochemistry
- Kidney/metabolism
- Kidney Diseases/genetics
- Kidney Diseases/pathology
- Kidney Glomerulus/pathology
- Mammary Tumor Virus, Mouse/genetics
- Mice
- Mice, Transgenic
- Microscopy, Electron, Scanning
- Neovascularization, Pathologic
- Peritoneovenous Shunt
- Phenotype
- Promoter Regions, Genetic
- RNA/metabolism
- Receptor, EphB4/genetics
- Receptor, EphB4/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
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Affiliation(s)
- Anne-Catherine Andres
- The Tiefenau Laboratory, Department of Clinical Research, University of Berne, Tiefenaustrasse 120, CH-3004 Berne, Switzerland
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Abstract
Glomerular podocytes are highly specialized cells with a complex cytoarchitecture. Their most prominent features are interdigitated foot processes with filtration slits in between. These are bridged by the slit diaphragm, which plays a major role in establishing the selective permeability of the glomerular filtration barrier. Injury to podocytes leads to proteinuria, a hallmark of most glomerular diseases. New technical approaches have led to a considerable increase in our understanding of podocyte biology including protein inventory, composition and arrangement of the cytoskeleton, receptor equipment, and signaling pathways involved in the control of ultrafiltration. Moreover, disturbances of podocyte architecture resulting in the retraction of foot processes and proteinuria appear to be a common theme in the progression of acquired glomerular disease. In hereditary nephrotic syndromes identified over the last 2 years, all mutated gene products were localized in podocytes. This review integrates our recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier.
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Affiliation(s)
- Hermann Pavenstädt
- Division of Nephrology, Department of Medicine, University Hospital Freiburg, Freiburg, Germany.
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44
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Abstract
Recent research has demonstrated that not only haemodynamic factors but also genetic programmes control arterial-venous cell fate and blood vessel identity. The identification of arteries and veins was previously based solely on morphological criteria and is now greatly facilitated by specific molecular markers. Moreover, signalling pathways controlling the arterial-venous decision during embryonic development have been outlined for the first time. This review gives an up-to-date overview of differentially expressed genes and the regulatory processes leading to the differentiation of arteries and veins.
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Affiliation(s)
- Ralf H Adams
- Cancer Research UK-London Research Institute, Vascular Development Laboratory, London, UK.
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45
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Liu Y, Hogan BLM. Differential gene expression in the distal tip endoderm of the embryonic mouse lung. Gene Expr Patterns 2002; 2:229-33. [PMID: 12617806 DOI: 10.1016/s1567-133x(02)00057-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the early development of the mouse lung a number of genes encoding signaling molecules are differentially expressed in the epithelium and mesenchyme of the distal buds. Evidence suggests they play a role in regulating the stereotypic processes of bud outgrowth and branching as well as proximal-distal patterning of both cell layers. To better understand the mechanisms underlying branching morphogenesis, a subtractive hybridization and differential screen was carried out for genes preferentially expressed in the epithelium at the tips of embryonic day 11.5 lung buds, versus more proximal regions. Twenty genes were identified, assigned to different categories based on sequence analysis, and their distal expression confirmed by whole-mount in situ hybridization.
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Affiliation(s)
- Yuru Liu
- Department of Cell and Developmental Biology, Howard Hughes Medical Institute, Vanderbilt University Medical Center, Nashville, TN 37232-2175, USA
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46
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Abstract
As organisms have evolved in size and complexity, tubular systems have developed to enable the efficient transport of substances into and out of tissues. These tubular systems are generated using strategies that are based on common elements of cell behaviour, including cell polarization, tube migration to target sites, cell-fate diversification and localization of specialized cells to different regions of the tube system. Using examples from both invertebrate and vertebrate systems, this review highlights progress in understanding these basic principles and briefly discusses the possible evolution of strategies to regulate the morphogenesis of tubular systems.
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Affiliation(s)
- Brigid L M Hogan
- Howard Hughes Medical Institute and Department of Cell and Developmental Biology, Vanderbilt Medical Center, Nashville, Tennessee 37232-2175, USA.
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