1
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Bannell TAK, Cockburn JJB. The molecular structure and function of fibrocystin, the key gene product implicated in autosomal recessive polycystic kidney disease (ARPKD). Ann Hum Genet 2024; 88:58-75. [PMID: 37905714 DOI: 10.1111/ahg.12535] [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: 07/11/2023] [Revised: 09/14/2023] [Accepted: 10/03/2023] [Indexed: 11/02/2023]
Abstract
Autosomal recessive polycystic kidney disease is an early onset inherited hepatorenal disorder affecting around 1 in 20,000 births with no approved specific therapies. The disease is almost always caused by variations in the polycystic kidney and hepatic disease 1 gene, which encodes fibrocystin (FC), a very large, single-pass transmembrane glycoprotein found in primary cilia, urine and urinary exosomes. By comparison to proteins involved in autosomal dominant PKD, our structural and molecular understanding of FC has lagged far behind such that there are no published experimentally determined structures of any part of the protein. Bioinformatics analyses predict that the ectodomain contains a long chain of immunoglobulin-like plexin-transcription factor domains, a protective antigen 14 domain, a tandem G8-TMEM2 homology region and a sperm protein, enterokinase and agrin domain. Here we review current knowledge on the molecular function of the protein from a structural perspective.
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Affiliation(s)
- Travis A K Bannell
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Joseph J B Cockburn
- Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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2
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Harafuji N, Yang C, Wu M, Thiruvengadam G, Gordish-Dressman H, Thompson RG, Bell PD, Rosenberg AZ, Dafinger C, Liebau MC, Bebok Z, Caldovic L, Guay-Woodford LM. Differential regulation of MYC expression by PKHD1/Pkhd1 in human and mouse kidneys: phenotypic implications for recessive polycystic kidney disease. Front Cell Dev Biol 2023; 11:1270980. [PMID: 38125876 PMCID: PMC10731465 DOI: 10.3389/fcell.2023.1270980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/30/2023] [Indexed: 12/23/2023] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD; MIM#263200) is a severe, hereditary, hepato-renal fibrocystic disorder that leads to early childhood morbidity and mortality. Typical forms of ARPKD are caused by pathogenic variants in the PKHD1 gene, which encodes the fibrocystin/polyductin (FPC) protein. MYC overexpression has been proposed as a driver of renal cystogenesis, but little is known about MYC expression in recessive PKD. In the current study, we provide the first evidence that MYC is overexpressed in kidneys from ARPKD patients and confirm that MYC is upregulated in cystic kidneys from cpk mutant mice. In contrast, renal MYC expression levels were not altered in several Pkhd1 mutant mice that lack a significant cystic kidney phenotype. We leveraged previous observations that the carboxy-terminus of mouse FPC (FPC-CTD) is proteolytically cleaved through Notch-like processing, translocates to the nucleus, and binds to double stranded DNA, to examine whether the FPC-CTD plays a role in regulating MYC/Myc transcription. Using immunofluorescence, reporter gene assays, and ChIP, we demonstrate that both human and mouse FPC-CTD can localize to the nucleus, bind to the MYC/Myc P1 promoter, and activate MYC/Myc expression. Interestingly, we observed species-specific differences in FPC-CTD intracellular trafficking. Furthermore, our informatic analyses revealed limited sequence identity of FPC-CTD across vertebrate phyla and database queries identified temporal differences in PKHD1/Pkhd1 and CYS1/Cys1 expression patterns in mouse and human kidneys. Given that cystin, the Cys1 gene product, is a negative regulator of Myc transcription, these temporal differences in gene expression could contribute to the relative renoprotection from cystogenesis in Pkhd1-deficient mice. Taken together, our findings provide new mechanistic insights into differential mFPC-CTD and hFPC-CTD regulation of MYC expression in renal epithelial cells, which may illuminate the basis for the phenotypic disparities between human patients with PKHD1 pathogenic variants and Pkhd1-mutant mice.
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Affiliation(s)
- Naoe Harafuji
- Center for Translational Research, Children’s National Hospital, Washington, DC, United States
| | - Chaozhe Yang
- Center for Translational Research, Children’s National Hospital, Washington, DC, United States
| | - Maoqing Wu
- Center for Translational Research, Children’s National Hospital, Washington, DC, United States
| | - Girija Thiruvengadam
- Center for Translational Research, Children’s National Hospital, Washington, DC, United States
| | | | - R. Griffin Thompson
- Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - P. Darwin Bell
- Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins University, Baltimore, MD, United States
| | - Claudia Dafinger
- Department of Pediatrics and Center for Molecular Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Max C. Liebau
- Department of Pediatrics, Center for Family Health, Center for Rare Diseases and Center for Molecular Medicine, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Zsuzsanna Bebok
- Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC, United States
- Department of Genomics and Precision Medicine, School of Medical and Health Sciences, The George Washington University, Washington, DC, United States
| | - Lisa M. Guay-Woodford
- Center for Translational Research, Children’s National Hospital, Washington, DC, United States
- Center for Genetic Medicine Research, Children’s National Hospital, Washington, DC, United States
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3
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Walker RV, Yao Q, Xu H, Maranto A, Swaney KF, Ramachandran S, Li R, Cassina L, Polster BM, Outeda P, Boletta A, Watnick T, Qian F. Fibrocystin/Polyductin releases a C-terminal fragment that translocates into mitochondria and suppresses cystogenesis. Nat Commun 2023; 14:6513. [PMID: 37845212 PMCID: PMC10579373 DOI: 10.1038/s41467-023-42196-4] [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: 08/31/2022] [Accepted: 10/03/2023] [Indexed: 10/18/2023] Open
Abstract
Fibrocystin/Polyductin (FPC), encoded by PKHD1, is associated with autosomal recessive polycystic kidney disease (ARPKD), yet its precise role in cystogenesis remains unclear. Here we show that FPC undergoes complex proteolytic processing in developing kidneys, generating three soluble C-terminal fragments (ICDs). Notably, ICD15, contains a novel mitochondrial targeting sequence at its N-terminus, facilitating its translocation into mitochondria. This enhances mitochondrial respiration in renal epithelial cells, partially restoring impaired mitochondrial function caused by FPC loss. FPC inactivation leads to abnormal ultrastructural morphology of mitochondria in kidney tubules without cyst formation. Moreover, FPC inactivation significantly exacerbates renal cystogenesis and triggers severe pancreatic cystogenesis in a Pkd1 mouse mutant Pkd1V/V in which cleavage of Pkd1-encoded Polycystin-1 at the GPCR Proteolysis Site is blocked. Deleting ICD15 enhances renal cystogenesis without inducing pancreatic cysts in Pkd1V/V mice. These findings reveal a direct link between FPC and a mitochondrial pathway through ICD15 cleavage, crucial for cystogenesis mechanisms.
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Affiliation(s)
- Rebecca V Walker
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Qin Yao
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Hangxue Xu
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anthony Maranto
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kristen F Swaney
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sreekumar Ramachandran
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rong Li
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, Singapore, 117411, Singapore
| | - Laura Cassina
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Brian M Polster
- Department of Anesthesiology and Center for Shock, Trauma, and Anesthesiology Research, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Patricia Outeda
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alessandra Boletta
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Terry Watnick
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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4
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Yang C, Harafuji N, Caldovic L, Yu W, Boddu R, Bhattacharya S, Barseghyan H, Gordish-Dressman H, Foreman O, Bebok Z, Eicher EM, Guay-Woodford LM. Pkhd1 cyli/cyli mice have altered renal Pkhd1 mRNA processing and hormonally sensitive liver disease. J Mol Med (Berl) 2023; 101:1141-1151. [PMID: 37584738 PMCID: PMC10482757 DOI: 10.1007/s00109-023-02351-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 06/30/2023] [Accepted: 07/12/2023] [Indexed: 08/17/2023]
Abstract
Autosomal-recessive polycystic kidney disease (ARPKD; MIM #263200) is a severe, hereditary, hepato-renal fibrocystic disorder that causes early childhood morbidity and mortality. Mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene, which encodes the protein fibrocystin/polyductin complex (FPC), cause all typical forms of ARPKD. Several mouse lines carrying diverse, genetically engineered disruptions in the orthologous Pkhd1 gene have been generated, but none expresses the classic ARPKD renal phenotype. In the current study, we characterized a spontaneous mouse Pkhd1 mutation that is transmitted as a recessive trait and causes cysticliver (cyli), similar to the hepato-biliary disease in ARPKD, but which is exacerbated by age, sex, and parity. We mapped the mutation to Chromosome 1 and determined that an insertion/deletion mutation causes a frameshift within Pkhd1 exon 48, which is predicted to result in a premature termination codon (UGA). Pkhd1cyli/cyli (cyli) mice exhibit a severe liver pathology but lack renal disease. Further analysis revealed that several alternatively spliced Pkhd1 mRNA, all containing exon 48, were expressed in cyli kidneys, but in lower abundance than in wild-type kidneys, suggesting that these transcripts escaped from nonsense-mediated decay (NMD). We identified an AAAAAT motif in exon 48 upstream of the cyli mutation which could enable ribosomal frameshifting, thus potentially allowing production of sufficient amounts of FPC for renoprotection. This mechanism, expressed in a species-specific fashion, may help explain the disparities in the renal phenotype observed between Pkhd1 mutant mice and patients with PKHD1-related disease. KEY MESSAGES: The Pkhd1cyli/cyli mouse expresses cystic liver disease, but no kidney phenotype. Pkhd1 mRNA expression is decreased in cyli liver and kidneys compared to wild-type. Ribosomal frameshifting may be responsible for Pkhd1 mRNA escape from NMD. Pkhd1 mRNA escape from NMD could contribute to the absent kidney phenotype.
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Affiliation(s)
- Chaozhe Yang
- Center for Translational Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Naoe Harafuji
- Center for Translational Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, DC, 20010, USA
- Department of Genomics and Precision Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Weiying Yu
- Center for Translational Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Ravindra Boddu
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Surajit Bhattacharya
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Hayk Barseghyan
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, DC, 20010, USA
- Department of Genomics and Precision Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Heather Gordish-Dressman
- Center for Translational Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Oded Foreman
- Genentech USA, Inc, South San Francisco, CA, 94080, USA
- Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Zsuzsa Bebok
- Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Eva M Eicher
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
| | - Lisa M Guay-Woodford
- Center for Translational Research, Children's National Research Institute, Washington, DC, 20010, USA.
- Center for Genetic Medicine Research, Children's National Research Institute, Washington, DC, 20010, USA.
- Children's Hospital of Philadelphia, Philadelphia, USA.
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5
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Adams DE, Heuer LS, Rojas M, Zhang W, Ridgway WM. Mutated Pkhd1 alone is sufficient to cause autoimmune biliary disease on the nonobese diabetic (NOD) genetic background. Immunogenetics 2023; 75:27-37. [PMID: 36097289 PMCID: PMC9468241 DOI: 10.1007/s00251-022-01276-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/27/2022] [Indexed: 01/21/2023]
Abstract
We previously reported that nonobese diabetic (NOD) congenic mice (NOD.c3c4 mice) developed an autoimmune biliary disease (ABD) with similarities to human primary biliary cholangitis (PBC), including anti-mitochondrial antibodies and organ-specific biliary lymphocytic infiltrates. We narrowed the possible contributory regions in a novel NOD.Abd3 congenic mouse to a B10 congenic region on chromosome 1 ("Abd3") and a mutated Pkhd1 gene (Pkhd1del36-67) upstream from Abd3, and we showed via backcrossing studies that the NOD genetic background was necessary for disease. Here, we show that NOD.Abd3 mice develop anti-PDC-E2 autoantibodies at high levels, and that placing the chromosome 1 interval onto a scid background eliminates disease, demonstrating the critical role of the adaptive immune system in pathogenesis. While the NOD genetic background is essential for disease, it was still unclear which of the two regions in the Abd3 locus were necessary and sufficient for disease. Here, using a classic recombinant breeding approach, we prove that the mutated Pkhd1del36-67 alone, on the NOD background, causes ABD. Further characterization of the mutant sequence demonstrated that the Pkhd1 gene is disrupted by an ETnII-beta retrotransposon inserted in intron 35 in an anti-sense orientation. Homozygous Pkhd1 mutations significantly affect viability, with the offspring skewed away from a Mendelian distribution towards NOD Pkhd1 homozygous or heterozygous genotypes. Cell-specific abnormalities, on a susceptible genetic background, can therefore induce an organ-specific autoimmunity directed to the affected cells. Future work will aim to characterize how mutant Pkhd1 can cause such an autoimmune response.
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Affiliation(s)
- David E Adams
- Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
- Department of Internal Medicine, Cincinnati VA Medical Center, Cincinnati, OH, 45267, USA
| | - Luke S Heuer
- Department of Internal Medicine, Sacramento VA Medical Center, VA Northern California Health Care System, Mather, CA, 95655, USA
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, 95616, USA
| | - Manuel Rojas
- School of Medicine and Health Sciences, Doctoral Program in Biological and Biomedical Sciences, Center for Autoimmune Diseases Research (CREA), Universidad del Rosario, Bogota, Colombia
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, 95616, USA
| | - Weici Zhang
- Department of Internal Medicine, Sacramento VA Medical Center, VA Northern California Health Care System, Mather, CA, 95655, USA
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, 95616, USA
| | - William M Ridgway
- Department of Internal Medicine, Sacramento VA Medical Center, VA Northern California Health Care System, Mather, CA, 95655, USA.
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, CA, 95616, USA.
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6
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Airik M, McCourt B, Ozturk TT, Huynh AB, Zhang X, Tometich JT, Topaloglu R, Ozen H, Orhan D, Nejak-Bowen K, Monga SP, Hand TW, Ozaltin F, Airik R. Mitigation of portal fibrosis and cholestatic liver disease in ANKS6-deficient livers by macrophage depletion. FASEB J 2022; 36:e22157. [PMID: 35032404 PMCID: PMC8852242 DOI: 10.1096/fj.202101387r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/19/2021] [Accepted: 12/27/2021] [Indexed: 02/03/2023]
Abstract
Congenital hepatic fibrosis (CHF) is a developmental liver disease that is caused by mutations in genes that encode ciliary proteins and is characterized by bile duct dysplasia and portal fibrosis. Recent work has demonstrated that mutations in ANKS6 can cause CHF due to its role in bile duct development. Here, we report a novel ANKS6 mutation, which was identified in an infant presenting with neonatal jaundice due to underlying biliary abnormalities and liver fibrosis. Molecular analysis revealed that ANKS6 liver pathology is associated with the infiltration of inflammatory macrophages to the periportal fibrotic tissue and ductal epithelium. To further investigate the role of macrophages in CHF pathophysiology, we generated a novel liver-specific Anks6 knockout mouse model. The mutant mice develop biliary abnormalities and rapidly progressing periportal fibrosis reminiscent of human CHF. The development of portal fibrosis in Anks6 KO mice coincided with the accumulation of inflammatory monocytes and macrophages in the mutant liver. Gene expression and flow cytometric analysis demonstrated the preponderance of M1- over M2-like macrophages at the onset of fibrosis. A critical role for macrophages in promoting peribiliary fibrosis was demonstrated by depleting the macrophages with clodronate liposomes which effectively reduced inflammatory gene expression and fibrosis, and ameliorated tissue histology and biliary function in Anks6 KO livers. Together, this study demonstrates that macrophages play an important role in the initiation of liver fibrosis in ANKS6-deficient livers and their therapeutic elimination may provide an avenue to mitigate CHF in patients.
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Affiliation(s)
- Merlin Airik
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Blake McCourt
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tugba Tastemel Ozturk
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Amy B Huynh
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoyi Zhang
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Justin T Tometich
- R.K. Mellon Institute for Pediatric Research, Department of Pediatrics, Division of Infectious Disease, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, 15224
| | - Rezan Topaloglu
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Hasan Ozen
- Division of Gastroenterology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Diclehan Orhan
- Pediatric Pathology Unit, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Kari Nejak-Bowen
- Department of Pathology and Pittsburgh Liver Research Center, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Satdarshan P Monga
- Department of Pathology and Pittsburgh Liver Research Center, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Timothy W Hand
- R.K. Mellon Institute for Pediatric Research, Department of Pediatrics, Division of Infectious Disease, UPMC Children’s Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, 15224
| | - Fatih Ozaltin
- Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey,Nephrogenetics Laboratory, Division of Pediatric Nephrology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Rannar Airik
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA,Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA,Corresponding Author: Name: Rannar Airik, PhD, Address: UPMC Children’s Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, USA, , Tel.: +1 (412) 692-6229, Fax.: +1 (412) 692-7816
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7
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Yu SS, Wang E, Chiang CY, Cheng PH, Yeh YS, Wu YY, Chiou YY, Jiang ST. Large deletion of Wdr19 in developing renal tubules disrupts primary ciliogenesis leading to polycystic kidney disease in mice. J Pathol 2022; 257:5-16. [PMID: 35007346 DOI: 10.1002/path.5863] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/03/2021] [Accepted: 01/06/2022] [Indexed: 11/11/2022]
Abstract
WD repeat domain 19 (Wdr19) is a major component of the intraflagellar transport (IFT) machinery, which is involved in the function of primary cilia. However, the effects of Wdr19 on primary cilia formation, cystogenesis, and polycystic kidney disease (PKD) progression remain unclear. To study these effects, we generated three lines of kidney-specific conditional knockout mice: Wdr19-knockout (Wdr19-KO, Wdr19f/- ::Cdh16-CreTg/0 ), Pkd1-knockout (Pkd1-KO, Pkd1f/- ::Cdh16-CreTg/0 ), and Wdr19/Pkd1-double knockout (Wdr19&Pkd1-dKO, Wdr19f/- ;Pkd1f/- ::Cdh16-CreTg/0 ) mice. Ultrastructural analysis using transmission electron microscopy (TEM) indicated that the primary cilia were almost absent at postnatal day 10 in Wdr19-KO mice compared with Pkd1-KO and wild-type (WT) mice. However, the primary cilia appeared structurally normal even if malfunctional in Pkd1-deficient cysts. The Pkd1-KO mice had the most severe PKD progression, including the shortest lifespan (14 days) and the largest renal cysts, among the three knockout lines. Thus, the molecular mechanism of renal cystogenesis in Wdr19-KO mice (primary cilia abrogation) was different from that in Pkd1-KO mice (primary cilia malfunction). In summary, Wdr19 deficiency leads to primary cilia abrogation and renal cyst formation. Wdr19 is primarily proposed to participate in retrograde IFT and to be crucial for the construction of primary cilia, which are critical organelles for tubulogenesis in the developing kidneys. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Shang-Shiuan Yu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 70457, Taiwan.,National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
| | - Ellian Wang
- Department of Physiology, National Cheng Kung University Medical College, Tainan, 70101, Taiwan
| | - Chih-Ying Chiang
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
| | - Po-Hao Cheng
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
| | - Yu-Shan Yeh
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
| | - Ying-Ying Wu
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
| | - Yuan-Yow Chiou
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan.,Division of Pediatric Nephrology, Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 70403, Taiwan
| | - Si-Tse Jiang
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, 74147, Taiwan
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8
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Yang C, Harafuji N, O'Connor AK, Kesterson RA, Watts JA, Majmundar AJ, Braun DA, Lek M, Laricchia KM, Fathy HM, Mane S, Shril S, Hildebrandt F, Guay-Woodford LM. Cystin genetic variants cause autosomal recessive polycystic kidney disease associated with altered Myc expression. Sci Rep 2021; 11:18274. [PMID: 34521872 PMCID: PMC8440558 DOI: 10.1038/s41598-021-97046-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/22/2021] [Indexed: 11/08/2022] Open
Abstract
Mutation of the Cys1 gene underlies the renal cystic disease in the Cys1cpk/cpk (cpk) mouse that phenocopies human autosomal recessive polycystic kidney disease (ARPKD). Cystin, the protein product of Cys1, is expressed in the primary apical cilia of renal ductal epithelial cells. In previous studies, we showed that cystin regulates Myc expression via interaction with the tumor suppressor, necdin. Here, we demonstrate rescue of the cpk renal phenotype by kidney-specific expression of a cystin-GFP fusion protein encoded by a transgene integrated into the Rosa26 locus. In addition, we show that expression of the cystin-GFP fusion protein in collecting duct cells down-regulates expression of Myc in cpk kidneys. Finally, we report the first human patient with an ARPKD phenotype due to homozygosity for a deleterious splicing variant in CYS1. These findings suggest that mutations in Cys1/CYS1 cause an ARPKD phenotype in mouse and human, respectively, and that the renal cystic phenotype in the mouse is driven by overexpression of the Myc proto-oncogene.
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Affiliation(s)
- Chaozhe Yang
- Center for Translational Research, Children's National Research Institute, 111 Michigan Ave NW, Washington, DC, 20010, USA
| | - Naoe Harafuji
- Center for Translational Research, Children's National Research Institute, 111 Michigan Ave NW, Washington, DC, 20010, USA
| | - Amber K O'Connor
- Center for Translational Research, Children's National Research Institute, 111 Michigan Ave NW, Washington, DC, 20010, USA
| | - Robert A Kesterson
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Jacob A Watts
- Center for Translational Research, Children's National Research Institute, 111 Michigan Ave NW, Washington, DC, 20010, USA
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Daniela A Braun
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Monkol Lek
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Kristen M Laricchia
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hanan M Fathy
- Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Shrikant Mane
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Yale Center for Mendelian Genomics, Yale University School of Medicine, New Haven, CT, USA
| | - Shirlee Shril
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Lisa M Guay-Woodford
- Center for Translational Research, Children's National Research Institute, 111 Michigan Ave NW, Washington, DC, 20010, USA.
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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9
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Cordido A, Vizoso-Gonzalez M, Garcia-Gonzalez MA. Molecular Pathophysiology of Autosomal Recessive Polycystic Kidney Disease. Int J Mol Sci 2021; 22:6523. [PMID: 34204582 PMCID: PMC8235086 DOI: 10.3390/ijms22126523] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/19/2022] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is a rare disorder and one of the most severe forms of polycystic kidney disease, leading to end-stage renal disease (ESRD) in childhood. PKHD1 is the gene that is responsible for the vast majority of ARPKD. However, some cases have been related to a new gene that was recently identified (DZIP1L gene), as well as several ciliary genes that can mimic a ARPKD-like phenotypic spectrum. In addition, a number of molecular pathways involved in the ARPKD pathogenesis and progression were elucidated using cellular and animal models. However, the function of the ARPKD proteins and the molecular mechanism of the disease currently remain incompletely understood. Here, we review the clinics, treatment, genetics, and molecular basis of ARPKD, highlighting the most recent findings in the field.
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Affiliation(s)
- Adrian Cordido
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (A.C.); (M.V.-G.)
- Grupo de Medicina Xenómica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
| | - Marta Vizoso-Gonzalez
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (A.C.); (M.V.-G.)
- Grupo de Medicina Xenómica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
| | - Miguel A. Garcia-Gonzalez
- Grupo de Xenética e Bioloxía do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxía (No. 11), Instituto de Investigación Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain; (A.C.); (M.V.-G.)
- Grupo de Medicina Xenómica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
- Fundación Publica Galega de Medicina Xenómica-SERGAS, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
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10
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Besse W, Roosendaal C, Tuccillo L, Roy SG, Gallagher AR, Somlo S. Adult Inactivation of the Recessive Polycystic Kidney Disease Gene Causes Polycystic Liver Disease. ACTA ACUST UNITED AC 2020; 1:1068-1076. [PMID: 33554127 DOI: 10.34067/kid.0002522020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background A major difference between autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD) lies in the pattern of inheritance, and the resultant timing and focality of cyst formation. In both diseases, cysts form in the kidney and liver as a consequence of the cellular recessive genotype of the respective disease gene, but this occurs by germline inheritance in ARPKD and somatic second hit mutations to the one normal allele in ADPKD. The fibrocystic liver phenotype in ARPKD is attributed to abnormal ductal plate formation because of the absence of PKHD1 expression during embryogenesis and organ development. The finding of polycystic liver disease in a subset of adult PKHD1 heterozygous carriers raises the question of whether somatic second hit mutations in PKHD1 in adults may also result in bile duct-derived cyst formation. Methods We used an adult-inducible Pkhd1 mouse model to examine whether Pkhd1 has a functional role in maintaining bile duct homeostasis after normal liver development. Results Inactivation of Pkhd1 beginning at 4 weeks of age resulted in a polycystic liver phenotype with minimal fibrosis at 17 weeks. Increased biliary epithelium, which lines these liver cysts, was most pronounced in female mice. We assessed genetic interaction of this phenotype with either reduced or increased copies of Pkd1, and found no significant effects on the Pkhd1 phenotype in the liver or kidney from altered Pkd1 expression. Conclusions Somatic adult inactivation of Pkhd1 results in a polycystic liver phenotype. Pkhd1 is a required gene in adulthood for biliary structural homeostasis independent of Pkd1. This suggests that PKHD1 heterozygous carrier patients can develop liver cysts after somatic mutations in their normal copy of PKHD1.
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Affiliation(s)
- Whitney Besse
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Charlotte Roosendaal
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Luigi Tuccillo
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Sounak Ghosh Roy
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Anna-Rachel Gallagher
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut
| | - Stefan Somlo
- Department of Internal Medicine, Section of Nephrology, Yale School of Medicine, New Haven, Connecticut.,Department of Genetics, Yale School of Medicine, New Haven, Connecticut
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11
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Haumann S, Müller RU, Liebau MC. Metabolic Changes in Polycystic Kidney Disease as a Potential Target for Systemic Treatment. Int J Mol Sci 2020; 21:ijms21176093. [PMID: 32847032 PMCID: PMC7503958 DOI: 10.3390/ijms21176093] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 12/16/2022] Open
Abstract
Autosomal recessive and autosomal dominant polycystic kidney disease (ARPKD, ADPKD) are systemic disorders with pronounced hepatorenal phenotypes. While the main underlying genetic causes of both ARPKD and ADPKD have been well-known for years, the exact molecular mechanisms resulting in the observed clinical phenotypes in the different organs, remain incompletely understood. Recent research has identified cellular metabolic changes in PKD. These findings are of major relevance as there may be an immediate translation into clinical trials and potentially clinical practice. Here, we review important results in the field regarding metabolic changes in PKD and their modulation as a potential target of systemic treatment.
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Affiliation(s)
- Sophie Haumann
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany;
| | - Roman-Ulrich Müller
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany;
- CECAD, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany
| | - Max C. Liebau
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany;
- Center for Molecular Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Correspondence: ; Tel.: +49-221-478-4359
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12
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Shan D, Rezonzew G, Mullen S, Roye R, Zhou J, Chumley P, Revell DZ, Challa A, Kim H, Lockhart ME, Schoeb TR, Croyle MJ, Kesterson RA, Yoder BK, Guay-Woodford LM, Mrug M. Heterozygous Pkhd1 C642* mice develop cystic liver disease and proximal tubule ectasia that mimics radiographic signs of medullary sponge kidney. Am J Physiol Renal Physiol 2019; 316:F463-F472. [PMID: 30600684 PMCID: PMC6442377 DOI: 10.1152/ajprenal.00181.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Heterozygosity for human polycystic kidney and hepatic disease 1 ( PKHD1) mutations was recently associated with cystic liver disease and radiographic findings resembling medullary sponge kidney (MSK). However, the relevance of these associations has been tempered by a lack of cystic liver or renal disease in heterozygous mice carrying Pkhd1 gene trap or exon deletions. To determine whether heterozygosity for a smaller Pkhd1 defect can trigger cystic renal disease in mice, we generated and characterized mice with the predicted truncating Pkhd1C642* mutation in a region corresponding to the middle of exon 20 cluster of five truncating human mutations (between PKHD1G617fs and PKHD1G644*). Mouse heterozygotes or homozygotes for the Pkhd1C642* mutation did not have noticeable liver or renal abnormalities on magnetic resonance images during their first weeks of life. However, when aged to ~1.5 yr, the Pkhd1C642* heterozygotes developed prominent cystic liver changes; tissue analyses revealed biliary cysts and increased number of bile ducts without signs of congenital hepatic fibrosis-like portal field inflammation and fibrosis that was seen in Pkhd1C642* homozygotes. Interestingly, aged female Pkhd1C642* heterozygotes, as well as homozygotes, developed radiographic changes resembling MSK. However, these changes correspond to proximal tubule ectasia, not an MSK-associated collecting duct ectasia. In summary, by demonstrating that cystic liver and kidney abnormalities are triggered by heterozygosity for the Pkhd1C642* mutation, we provide important validation for relevant human association studies. Together, these investigations indicate that PKHD1 mutation heterozygosity (predicted frequency 1 in 70 individuals) is an important underlying cause of cystic liver disorders and MSK-like manifestations in a human population.
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Affiliation(s)
- Dan Shan
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Gabriel Rezonzew
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Sean Mullen
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Ronald Roye
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Juling Zhou
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Phillip Chumley
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Dustin Z Revell
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Anil Challa
- Department of Genetics, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Harrison Kim
- Department of Radiology, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Mark E Lockhart
- Department of Radiology, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Trenton R Schoeb
- Department of Genetics, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Mandy J Croyle
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Robert A Kesterson
- Department of Genetics, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Bradley K Yoder
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham , Birmingham, Alabama
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System , Washington, District of Columbia
| | - Michal Mrug
- Department of Medicine, The University of Alabama at Birmingham , Birmingham, Alabama.,Department of Veterans Affairs Medical Center , Birmingham, Alabama
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13
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Abstract
Cystic kidneys are common causes of end-stage renal disease, both in children and in adults. Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are cilia-related disorders and the two main forms of monogenic cystic kidney diseases. ADPKD is a common disease that mostly presents in adults, whereas ARPKD is a rarer and often more severe form of polycystic kidney disease (PKD) that usually presents perinatally or in early childhood. Cell biological and clinical research approaches have expanded our knowledge of the pathogenesis of ADPKD and ARPKD and revealed some mechanistic overlap between them. A reduced 'dosage' of PKD proteins is thought to disturb cell homeostasis and converging signalling pathways, such as Ca2+, cAMP, mechanistic target of rapamycin, WNT, vascular endothelial growth factor and Hippo signalling, and could explain the more severe clinical course in some patients with PKD. Genetic diagnosis might benefit families and improve the clinical management of patients, which might be enhanced even further with emerging therapeutic options. However, many important questions about the pathogenesis of PKD remain. In this Primer, we provide an overview of the current knowledge of PKD and its treatment.
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Affiliation(s)
- Carsten Bergmann
- Department of Medicine, University Hospital Freiburg, Freiburg, Germany.
| | - Lisa M. Guay-Woodford
- Center for Translational Science, Children’s National Health System, Washington, DC, USA
| | - Peter C. Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Shigeo Horie
- Department of Urology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Dorien J. M. Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Vicente E. Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
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14
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Lin S, Shang TY, Wang MF, Lin J, Ye XJ, Zeng DW, Huang JF, Zhang NW, Wu YL, Zhu YY. Polycystic kidney and hepatic disease 1 gene mutations in von Meyenburg complexes: Case report. World J Clin Cases 2018; 6:296-300. [PMID: 30211211 PMCID: PMC6134282 DOI: 10.12998/wjcc.v6.i9.296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/04/2018] [Accepted: 06/08/2018] [Indexed: 02/05/2023] Open
Abstract
Von Meyenburg complexes (VMCs) are a rare type of ductal plate malformation. We herein report two Chinese families with VMCs, and the suspicious gene mutation of this disease. Proband A was a 62-year-old woman with abnormal echographic presentation of the liver. She received magnetic resonance imaging (MRI) examination and liver biopsy, and the results showed she had VMCs. Histologically proved hepatocellular carcinoma was found 1 year after the diagnosis of VMCs. Proband B was a 57-year-old woman with intrahepatic diffuse lesions displayed by abdominal ultrasonography. Her final diagnoses were VMCs, congenital hepatic fibrosis, and hepatitis B surface e antigen-negative chronic hepatitis B after a series of examinations. Then, all the family members of both proband A and proband B were screened for VMCs by MRI or ultrasonography. The results showed that four of the 11 family members from two families, including two males and two females, were diagnosed with VMCs. DNA samples were extracted from the peripheral blood of those 11 individuals of two VMCs pedigrees and subjected to polymerase chain reaction amplification of the polycystic kidney and hepatic disease 1 (PKHD1) gene. Two different mutation loci were identified. Heterozygous mutations located in exon 32 (c.4280delG, p.Gly1427ValfsX6) in family A and exon 28 (c.3118C>T, p.Arg1040Ter) in family B were detected. We speculate that PKHD1 gene mutations may be responsible for the development of VMCs.
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Affiliation(s)
- Su Lin
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Tian-Yu Shang
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Ming-Fang Wang
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Jian Lin
- Department of Hepato-Biliary-Pancreatic Surgery, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Xiao-Jian Ye
- Department of Ultrasound, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Da-Wu Zeng
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Jiao-Feng Huang
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Nan-Wen Zhang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Yi-Long Wu
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Yue-Yong Zhu
- Liver Research Center, the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China
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15
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Tam PKH, Yiu RS, Lendahl U, Andersson ER. Cholangiopathies - Towards a molecular understanding. EBioMedicine 2018; 35:381-393. [PMID: 30236451 PMCID: PMC6161480 DOI: 10.1016/j.ebiom.2018.08.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 12/14/2022] Open
Abstract
Liver diseases constitute an important medical problem, and a number of these diseases, termed cholangiopathies, affect the biliary system of the liver. In this review, we describe the current understanding of the causes of cholangiopathies, which can be genetic, viral or environmental, and the few treatment options that are currently available beyond liver transplantation. We then discuss recent rapid progress in a number of areas relevant for decoding the disease mechanisms for cholangiopathies. This includes novel data from analysis of transgenic mouse models and organoid systems, and we outline how this information can be used for disease modeling and potential development of novel therapy concepts. We also describe recent advances in genomic and transcriptomic analyses and the importance of such studies for improving diagnosis and determining whether certain cholangiopathies should be viewed as distinct or overlapping disease entities.
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Affiliation(s)
- Paul K H Tam
- Department of Surgery, Li Ka Shing Faculty of Medicine, and Dr. Li Dak-Sum Research Centre, The University of Hong Kong - Karolinska Institutet Collaboration in Regenerative Medicine, and The University of Hong Kong, Hong Kong.
| | - Rachel S Yiu
- Department of Surgery, Li Ka Shing Faculty of Medicine, and Dr. Li Dak-Sum Research Centre, The University of Hong Kong - Karolinska Institutet Collaboration in Regenerative Medicine, and The University of Hong Kong, Hong Kong
| | - Urban Lendahl
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Emma R Andersson
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden; Department of Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden.
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16
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Huang W, Rainbow DB, Wu Y, Adams D, Shivakumar P, Kottyan L, Karns R, Aronow B, Bezerra J, Gershwin ME, Peterson LB, Wicker LS, Ridgway WM. A Novel Pkhd1 Mutation Interacts with the Nonobese Diabetic Genetic Background To Cause Autoimmune Cholangitis. THE JOURNAL OF IMMUNOLOGY 2017; 200:147-162. [PMID: 29158418 DOI: 10.4049/jimmunol.1701087] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/19/2017] [Indexed: 12/13/2022]
Abstract
We previously reported that NOD.c3c4 mice develop spontaneous autoimmune biliary disease (ABD) with anti-mitochondrial Abs, histopathological lesions, and autoimmune T lymphocytes similar to human primary biliary cholangitis. In this article, we demonstrate that ABD in NOD.c3c4 and related NOD ABD strains is caused by a chromosome 1 region that includes a novel mutation in polycystic kidney and hepatic disease 1 (Pkhd1). We show that a long terminal repeat element inserted into intron 35 exposes an alternative polyadenylation site, resulting in a truncated Pkhd1 transcript. A novel NOD congenic mouse expressing aberrant Pkhd1, but lacking the c3 and c4 chromosomal regions (NOD.Abd3), reproduces the immunopathological features of NOD ABD. RNA sequencing of NOD.Abd3 common bile duct early in disease demonstrates upregulation of genes involved in cholangiocyte injury/morphology and downregulation of immunoregulatory genes. Consistent with this, bone marrow chimera studies show that aberrant Pkhd1 must be expressed in the target tissue (cholangiocytes) and the immune system (bone marrow). Mutations of Pkhd1 produce biliary abnormalities in mice but have not been previously associated with autoimmunity. In this study, we eliminate clinical biliary disease by backcrossing this Pkhd1 mutation onto the C57BL/6 genetic background; thus, the NOD genetic background (which promotes autoimmunity) is essential for disease. We propose that loss of functional Pkhd1 on the NOD background produces early bile duct abnormalities, initiating a break in tolerance that leads to autoimmune cholangitis in NOD.Abd3 congenic mice. This model is important for understanding loss of tolerance to cholangiocytes and is relevant to the pathogenesis of several human cholangiopathies.
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Affiliation(s)
- Wenting Huang
- Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Daniel B Rainbow
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Wellcome Trust Center for Human Genetics, Nuffield Department of Medicine, National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Yuehong Wu
- Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - David Adams
- Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Pranavkumar Shivakumar
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Leah Kottyan
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Rebekah Karns
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Bruce Aronow
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Jorge Bezerra
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - M Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA 95616; and
| | | | - Linda S Wicker
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Wellcome Trust Center for Human Genetics, Nuffield Department of Medicine, National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - William M Ridgway
- Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH 45267;
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17
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Abstract
INTRODUCTION Polycystic kidney disease (PKD) is clinically and genetically heterogeneous and constitutes the most common heritable kidney disease. Most patients are affected by the autosomal dominant form (ADPKD) which generally is an adult-onset multisystem disorder. By contrast, the rarer recessive form ARPKD usually already manifests perinatally or in childhood. In some patients, however, ADPKD and ARPKD can phenotypically overlap with early manifestation in ADPKD and only late onset in ARPKD. Progressive fibrocystic renal changes are often accompanied by severe hepatobiliary changes or other extrarenal abnormalities. Areas covered: A reduced dosage of disease proteins disturbs cell homeostasis and explains a more severe clinical course in some PKD patients. Cystic kidney disease is also a common feature of other ciliopathies and genetic syndromes. Genetic diagnosis may guide clinical management and helps to avoid invasive measures and to detect renal and extrarenal comorbidities early in the clinical course. Expert Commentary: The broad phenotypic and genetic heterogeneity of cystic and polycystic kidney diseases make NGS a particularly powerful approach. Interpretation of data becomes the challenge and bench and bedside benefit from digitized multidisciplinary interrelationships.
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Affiliation(s)
- Carsten Bergmann
- a Center for Human Genetics , Bioscientia , Ingelheim , Germany.,b Department of Medicine , University Hospital Freiburg , Freiburg , Germany
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18
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Outeda P, Menezes L, Hartung EA, Bridges S, Zhou F, Zhu X, Xu H, Huang Q, Yao Q, Qian F, Germino GG, Watnick T. A novel model of autosomal recessive polycystic kidney questions the role of the fibrocystin C-terminus in disease mechanism. Kidney Int 2017; 92:1130-1144. [PMID: 28729032 PMCID: PMC6005173 DOI: 10.1016/j.kint.2017.04.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/09/2017] [Accepted: 04/27/2017] [Indexed: 12/11/2022]
Abstract
Autosomal recessive polycystic kidney disease (OMIM 263200) is a serious condition of the kidney and liver caused by mutations in a single gene, PKHD1. This gene encodes fibrocystin/polyductin (FPC, PD1), a large protein shown by in vitro studies to undergo Notch-like processing. Its cytoplasmic tail, reported to include a ciliary targeting sequence, a nuclear localization signal, and a polycystin-2 binding domain, is thought to traffic to the nucleus after cleavage. We now report a novel mouse line with a triple HA-epitope "knocked-in" to the C-terminus along with lox P sites flanking exon 67, which encodes most of the C-terminus (Pkhd1Flox67HA). The triple HA-epitope has no functional effect as assayed by phenotype and allows in vivo tracking of Fibrocystin. We used the HA tag to identify previously predicted Fibrocystin cleavage products in tissue. In addition, we found that Polycystin-2 fails to co-precipitate with Fibrocystin in kidney samples. Immunofluorescence studies with anti-HA antibodies demonstrate that Fibrocystin is primarily present in a sub-apical location the in kidney, biliary duct, and pancreatic ducts, partially overlapping with the Golgi. In contrast to previous studies, the endogenous protein in the primary cilia was not detectable in mouse tissues. After Cre-mediated deletion, homozygous Pkhd1Δ67 mice are completely normal. Thus, Pkhd1Flox67HA is a valid model to track Pkhd1-derived products containing the C-terminus. Significantly, exon 67 containing the nuclear localization signal and the polycystin-2 binding domain is not essential for Fibrocystin function in our model.
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Affiliation(s)
- Patricia Outeda
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Luis Menezes
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Erum A Hartung
- Division of Nephrology, Children's Hospital of Philadelphia, Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stacey Bridges
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Fang Zhou
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Study, Sichuan Academy of Sciences and Sichuan Provincial People's Hospital Chengdue, Sichuan, China
| | - Hangxue Xu
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Qiong Huang
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Qin Yao
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gregory G Germino
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
| | - Terry Watnick
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.
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19
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NEDD4-family E3 ligase dysfunction due to PKHD1/Pkhd1 defects suggests a mechanistic model for ARPKD pathobiology. Sci Rep 2017; 7:7733. [PMID: 28798345 PMCID: PMC5552802 DOI: 10.1038/s41598-017-08284-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 07/04/2017] [Indexed: 01/17/2023] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is an important childhood nephropathy, occurring 1 in 20,000 live births. The major clinical phenotypes are expressed in the kidney with dilatation of the collecting ducts, systemic hypertension, and progressive renal insufficiency, and in the liver with biliary dysgenesis, portal tract fibrosis, and portal hypertension. The systemic hypertension has been attributed to enhanced distal sodium reabsorption in the kidney, the structural defects have been ascribed to altered cellular morphology, and fibrosis to increased TGF-β signaling in the kidney and biliary tract, respectively. The pathogenic mechanisms underlying these abnormalities have not been determined. In the current report, we find that disrupting PKHD1 results in altered sub-cellular localization and function of the C2-WWW-HECT domain E3 family of ligases regulating these processes. We also demonstrate altered activity of RhoA and increased TGF-β signaling and ENaC activity. Linking these phenomena, we found that vesicles containing the PKHD1/Pkhd1 gene product, FPC, also contain the NEDD4 ubiquitin ligase interacting protein, NDFIP2, which interacts with multiple members of the C2-WWW-HECT domain E3 family of ligases. Our results provide a mechanistic explanation for both the cellular effects and in vivo phenotypic abnormalities in mice and humans that result from Pkhd1/PKHD1 mutation.
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Hofmeister AF, Kömhoff M, Weber S, Grgic I. Disease modeling in genetic kidney diseases: mice. Cell Tissue Res 2017; 369:159-170. [PMID: 28601904 DOI: 10.1007/s00441-017-2639-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/04/2017] [Indexed: 12/27/2022]
Abstract
The mouse still represents arguably the most important mammal organism in research for modeling human genetic kidney diseases in vivo. Compared with many other mammal species, the breeding and maintenance of mice in the laboratory is relatively simple and cheap and reproduction cycles are short. In addition to classic gene knockout mouse lines, new molecular biological technologies have led to the development of a plethora of other, more sophisticated, mouse models, allowing the targeting of genes or gene function in a cell-specific, tissue-specific and time-dependent fashion. With the refinement of more recently developed genome-editing technologies, including the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system and other engineered nucleases such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), our "tool set" of mouse models is expected to rapidly expand. These technological advances hold great promise and should enable us to study and hence understand the biology of inherited kidney diseases in greater detail. By analogy, we may be able to answer questions regarding the impact of individual proteins on the development of human kidney disorders, the underlying mechanisms governing the evolution of the disease and the predicted responsiveness to therapeutic interventions. Moreover, knockout and transgenic mouse models can be highly informative with respect to the effects of genetic variations on renal phenotypes. This review focuses on mouse models that have been devised primarily to study monogenic human kidney diseases, which are typically caused by a single abnormal gene and passed on in a Mendelian pattern. Despite the large number of human hereditary kidney disorders and the multitude of mouse models described in the literature, we attempt to give a balanced overview of several well-known renal pathologies, a few of which are addressed in some detail.
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Affiliation(s)
- Andreas F Hofmeister
- Department of Internal Medicine and Nephrology, University Hospital Giessen and Marburg, Philipps-University Marburg, Baldingerstrasse 1, 35033, Marburg, Germany
| | - Martin Kömhoff
- University Children's Hospital, Philipps-University Marburg, Marburg, Germany
| | - Stefanie Weber
- University Children's Hospital, Philipps-University Marburg, Marburg, Germany
| | - Ivica Grgic
- Department of Internal Medicine and Nephrology, University Hospital Giessen and Marburg, Philipps-University Marburg, Baldingerstrasse 1, 35033, Marburg, Germany.
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Abstract
Primary cilia are small, antenna-like structures that detect mechanical and chemical cues and transduce extracellular signals. While mammalian primary cilia were first reported in the late 1800s, scientific interest in these sensory organelles has burgeoned since the beginning of the twenty-first century with recognition that primary cilia are essential to human health. Among the most common clinical manifestations of ciliary dysfunction are renal cysts. The molecular mechanisms underlying renal cystogenesis are complex, involving multiple aberrant cellular processes and signaling pathways, while initiating molecular events remain undefined. Autosomal Dominant Polycystic Kidney Disease is the most common renal cystic disease, caused by disruption of polycystin-1 and polycystin-2 transmembrane proteins, which evidence suggests must localize to primary cilia for proper function. To understand how the absence of these proteins in primary cilia may be remediated, we review intracellular trafficking of polycystins to the primary cilium. We also examine the controversial mechanisms by which primary cilia transduce flow-mediated mechanical stress into intracellular calcium. Further, to better understand ciliary function in the kidney, we highlight the LKB1/AMPK, Wnt, and Hedgehog developmental signaling pathways mediated by primary cilia and misregulated in renal cystic disease.
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Bergmann C. Genetics of Autosomal Recessive Polycystic Kidney Disease and Its Differential Diagnoses. Front Pediatr 2017; 5:221. [PMID: 29479522 PMCID: PMC5811498 DOI: 10.3389/fped.2017.00221] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 10/02/2017] [Indexed: 01/09/2023] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is a hepatorenal fibrocystic disorder that is characterized by enlarged kidneys with progressive loss of renal function and biliary duct dilatation and congenital hepatic fibrosis that leads to portal hypertension in some patients. Mutations in the PKHD1 gene are the primary cause of ARPKD; however, the disease is genetically not as homogeneous as long thought and mutations in several other cystogenes can phenocopy ARPKD. The family history usually is negative, both for recessive, but also often for dominant disease genes due to de novo arisen mutations or recessive inheritance of variants in genes that usually follow dominant patterns such as the main ADPKD genes PKD1 and PKD2. Considerable progress has been made in the understanding of polycystic kidney disease (PKD). A reduced dosage of disease proteins leads to the disruption of signaling pathways underlying key mechanisms involved in cellular homeostasis, which may help to explain the accelerated and severe clinical progression of disease course in some PKD patients. A comprehensive knowledge of disease-causing genes is essential for counseling and to avoid genetic misdiagnosis, which is particularly important in the prenatal setting (e.g., preimplantation genetic diagnosis/PGD). For ARPKD, there is a strong demand for early and reliable prenatal diagnosis, which is only feasible by molecular genetic analysis. A clear genetic diagnosis is helpful for many families and improves the clinical management of patients. Unnecessary and invasive measures can be avoided and renal and extrarenal comorbidities early be detected in the clinical course. The increasing number of genes that have to be considered benefit from the advances of next-generation sequencing (NGS) which allows simultaneous analysis of a large group of genes in a single test at relatively low cost and has become the mainstay for genetic diagnosis. The broad phenotypic and genetic heterogeneity of cystic and polycystic kidney diseases make NGS a particularly powerful approach for these indications. Interpretation of genetic data becomes the challenge and requires deep clinical understanding.
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Affiliation(s)
- Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany.,Department of Medicine, University Hospital Freiburg, Freiburg, Germany
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Evidence for a "Pathogenic Triumvirate" in Congenital Hepatic Fibrosis in Autosomal Recessive Polycystic Kidney Disease. BIOMED RESEARCH INTERNATIONAL 2016; 2016:4918798. [PMID: 27891514 PMCID: PMC5116503 DOI: 10.1155/2016/4918798] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/20/2016] [Accepted: 10/13/2016] [Indexed: 12/29/2022]
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is a severe monogenic disorder that occurs due to mutations in the PKHD1 gene. Congenital hepatic fibrosis (CHF) associated with ARPKD is characterized by the presence of hepatic cysts derived from dilated bile ducts and a robust, pericystic fibrosis. Cyst growth, due to cyst wall epithelial cell hyperproliferation and fluid secretion, is thought to be the driving force behind disease progression. Liver fibrosis is a wound healing response in which collagen accumulates in the liver due to an imbalance between extracellular matrix synthesis and degradation. Whereas both hyperproliferation and pericystic fibrosis are hallmarks of CHF/ARPKD, whether or not these two processes influence one another remains unclear. Additionally, recent studies demonstrate that inflammation is a common feature of CHF/ARPKD. Therefore, we propose a "pathogenic triumvirate" consisting of hyperproliferation of cyst wall growth, pericystic fibrosis, and inflammation which drives CHF/ARPKD progression. This review will summarize what is known regarding the mechanisms of cyst growth, fibrosis, and inflammation in CHF/ARPKD. Further, we will discuss the potential advantage of identifying a core pathogenic feature in CHF/ARPKD to aid in the development of novel therapeutic approaches. If a core pathogenic feature does not exist, then developing multimodality therapeutic approaches to target each member of the "pathogenic triumvirate" individually may be a better strategy to manage this debilitating disease.
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Imaging of Von Meyenburg complexes. Diagn Interv Imaging 2015; 97:401-9. [PMID: 26522945 DOI: 10.1016/j.diii.2015.05.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/18/2015] [Accepted: 05/18/2015] [Indexed: 12/18/2022]
Abstract
Von Meyenburg complexes, or biliary hamartomas, are frequently incidentally detected. They are usually easy to characterize with magnetic resonance imaging. However, in some occasions they are difficult to differentiate from other liver lesions, in particular from small liver metastases. Von Meyenburg complexes are developmental malformations of the ductal plate. They can be found in association with Caroli disease and Caroli syndrome. Like other ductal plate malformations, Von Meyenburg complexes associated with cholangiocarcinoma have been described and their relationship has been established. This review provides an update on the etiopathogenesis of Von Meyenburg complexes, illustrates the imaging features on ultrasound, CT and MRI of this condition and discusses the most common diagnostic pitfalls. The relationships between Von Meyenburg complexes and the various ductal plate malformations and the most recent literature data regarding the relationships between Von Meyenburg complexes and cholangiocarcinoma are presented.
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Courcet JB, Minello A, Prieur F, Morisse L, Phelip JM, Beurdeley A, Meynard D, Massenet D, Lacassin F, Duffourd Y, Gigot N, St-Onge J, Hillon P, Vanlemmens C, Mousson C, Cerceuil JP, Guiu B, Thevenon J, Thauvin-Robinet C, Jacquemin E, Rivière JB, Michel-Calemard L, Faivre L. Compound heterozygousPKHD1variants cause a wide spectrum of ductal plate malformations. Am J Med Genet A 2015; 167A:3046-53. [DOI: 10.1002/ajmg.a.37352] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 08/12/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Jean-Benoît Courcet
- Service de p; é; diatrie 1 et de génétique médicale; Centre Hospitalo-Universitaire; Dijon France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
| | - Anne Minello
- Service d'hépato-gastro-entérologie; Centre Hospitalo-Universitaire; Dijon France
| | - Fabienne Prieur
- Service De Génétique Clinique Chromosomique et Moléculaire; Pole De Biologie; Centre Hospitalo-Universitaire De Saint-Etienne - H; ô; pital Nord; Avenue Albert Raimond Saint-Priest-En-Jarez France
| | - Laurent Morisse
- Service de médecine polyvalente; Hôpital de SIA; Wallis et Futuna Uvea France
| | - Jean-Marc Phelip
- Service d'Hépato-gastro-entérologie; Centre Hospitalo-Universitaire; Sant-Etienne France
| | - Alain Beurdeley
- Service de chirurgie; Hôpital de SIA; Wallis et Futuna Uvea France
| | - Daniel Meynard
- Laboratoire de biologie médicale; Hôpital de SIA; Wallis et Futuna Uvea France
| | - Denis Massenet
- Laboratoire de biologie médicale; Hôpital de SIA; Wallis et Futuna Uvea France
| | - Flore Lacassin
- Service de Médecine Interne; Hôpital Magenta; Nouméa France
| | - Yannis Duffourd
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
- Laboratoire de biologie moléculaire; Centre Hospitalo-Universitaire; Dijon France
| | - Nadège Gigot
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
- Laboratoire de biologie moléculaire; Centre Hospitalo-Universitaire; Dijon France
| | - Judith St-Onge
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
- Laboratoire de biologie moléculaire; Centre Hospitalo-Universitaire; Dijon France
| | - Patrick Hillon
- Service d'hépato-gastro-entérologie; Centre Hospitalo-Universitaire; Dijon France
| | - Claire Vanlemmens
- Service de gastro-entérologie et hépatologie; Hôpital Jean Minjoz; Centre Hospitalo-Universitaire; Besançon France
| | | | | | - Boris Guiu
- Service de radiologie; Centre Hospitalo-Universitaire; Dijon France
| | - Julien Thevenon
- Service de p; é; diatrie 1 et de génétique médicale; Centre Hospitalo-Universitaire; Dijon France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
| | - Christel Thauvin-Robinet
- Service de p; é; diatrie 1 et de génétique médicale; Centre Hospitalo-Universitaire; Dijon France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
| | - Emmanuel Jacquemin
- Service d'hépatologie pédiatrique; Centre Hospitalo-Universitaire; Le Kremlin-Bic ê tre France
| | - Jean-Baptiste Rivière
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
- Laboratoire de biologie moléculaire; Centre Hospitalo-Universitaire; Dijon France
| | - Laurence Michel-Calemard
- Service d'endocrinologie moléculaire et maladies rares; Centre de Biologie et Pathologie Est CHU de Lyon-GH Est; Hospices Civils de Lyon; Bron France
| | - Laurence Faivre
- Service de p; é; diatrie 1 et de génétique médicale; Centre Hospitalo-Universitaire; Dijon France
- Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD); Centre Hospitalo-Universitaire; Dijon France
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Beaudry JB, Cordi S, Demarez C, Lepreux S, Pierreux CE, Lemaigre FP. Proliferation-Independent Initiation of Biliary Cysts in Polycystic Liver Diseases. PLoS One 2015; 10:e0132295. [PMID: 26125584 PMCID: PMC4488361 DOI: 10.1371/journal.pone.0132295] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 06/11/2015] [Indexed: 12/14/2022] Open
Abstract
Biliary cysts in adult patients affected by polycystic liver disease are lined by cholangiocytes that proliferate, suggesting that initiation of cyst formation depends on proliferation. Here, we challenge this view by analyzing cyst-lining cell proliferation and differentiation in Cpk mouse embryos and in livers from human fetuses affected by Autosomal Recessive Polycystic Kidney Disease (ARPKD), at early stages of cyst formation. Proliferation of fetal cholangiocyte precursors, measured by immunostaining in human and mouse livers, was low and did not differ between normal and ARPKD or Cpk livers, excluding excessive proliferation as an initiating cause of liver cysts. Instead, our analyses provide evidence that the polycystic livers exhibit increased and accelerated differentiation of hepatoblasts into cholangiocyte precursors, eventually coalescing into large biliary cysts. Lineage tracing experiments, performed in mouse embryos, indicated that the cholangiocyte precursors in Cpk mice generate cholangiocytes and periportal hepatocytes, like in wild-type animals. Therefore, contrary to current belief, cyst formation in polycystic liver disease does not necessarily depend on overproliferation. Combining our prenatal data with available data from adult livers, we propose that polycystic liver can be initiated by proliferation-independent mechanisms at a fetal stage, followed by postnatal proliferation-dependent cyst expansion.
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Affiliation(s)
| | - Sabine Cordi
- Université catholique de Louvain, de Duve Institute, Brussels, Belgium
| | - Céline Demarez
- Université catholique de Louvain, de Duve Institute, Brussels, Belgium
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ARPKD and early manifestations of ADPKD: the original polycystic kidney disease and phenocopies. Pediatr Nephrol 2015; 30:15-30. [PMID: 24584572 PMCID: PMC4240914 DOI: 10.1007/s00467-013-2706-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/11/2013] [Accepted: 11/12/2013] [Indexed: 12/11/2022]
Abstract
Renal cysts are clinically and genetically heterogeneous conditions. Polycystic kidney disease (PKD) is common and its characterization has paved the way for the identification of a growing number of cilia-related disorders (ciliopathies) of which most show cystic kidneys. While the recessive form of PKD (ARPKD) virtually always presents in childhood, early onset can, in some instances, also occur in the dominant form (ADPKD). Both ADPKD genes (PKD1 and PKD2) can also be inherited in a recessive way, making the story more complex with evidence for a dosage-sensitive network. Several phenocopies are known, and mutations in HNF1ß or genes that typically cause other ciliopathies, such as nephronophthisis, Bardet-Biedl, Joubert syndrome and related disorders, can mimic PKD. An accurate genetic diagnosis is crucial for genetic counseling, prenatal diagnostics, and the clinical management of patients and their families. The increasing number of genes that have to be considered in patients with cystic kidney disease is challenging to address by conventional techniques and largely benefits from next-generation sequencing-based approaches. The parallel analysis of targeted genes considerably increases the detection rate, allows for better interpretation of identified variants, and avoids genetic misdiagnoses.
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Hopp K, Wang X, Ye H, Irazabal MV, Harris PC, Torres VE. Effects of hydration in rats and mice with polycystic kidney disease. Am J Physiol Renal Physiol 2014; 308:F261-6. [PMID: 25503729 DOI: 10.1152/ajprenal.00345.2014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Vasopressin and V2 receptor signaling promote polycystic kidney disease (PKD) progression, raising the question whether suppression of vasopressin release through enhanced hydration can delay disease advancement. Enhanced hydration by adding 5% glucose to the drinking water has proven protective in a rat model orthologous to autosomal recessive PKD. We wanted to exclude a glucose effect and explore the influence of enhanced hydration in a mouse model orthologous to autosomal dominant PKD. PCK rats were assigned to normal water intake (NWI) or high water intake (HWI) groups achieved by feeding a hydrated agar diet (HWI-agar) or by adding 5% glucose to the drinking water (HWI-glucose), with the latter group used to recapitulate previously published results. Homozygous Pkd1 R3277C (Pkd1(RC/RC)) mice were assigned to NWI and HWI-agar groups. To evaluate the effectiveness of HWI, kidney weight and histomorphometry were assessed, and urine vasopressin, renal cAMP levels, and phosphodiesterase activities were measured. HWI-agar, like HWI-glucose, reduced urine vasopressin, renal cAMP levels, and PKD severity in PCK rats but not in Pkd1(RC/RC) mice. Compared with rat kidneys, mouse kidneys had higher phosphodiesterase activity and lower cAMP levels and were less sensitive to the cystogenic effect of 1-deamino-8-d-arginine vasopressin, as previously shown for Pkd1(RC/RC) mice and confirmed here in Pkd2(WS25/-) mice. We conclude that the effect of enhanced hydration in rat and mouse models of PKD differs. More powerful suppression of V2 receptor-mediated signaling than achievable by enhanced hydration alone may be necessary to affect the development of PKD in mouse models.
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Affiliation(s)
- Katharina Hopp
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Xiaofang Wang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Hong Ye
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - María V Irazabal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
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Drögemüller M, Jagannathan V, Welle MM, Graubner C, Straub R, Gerber V, Burger D, Signer-Hasler H, Poncet PA, Klopfenstein S, von Niederhäusern R, Tetens J, Thaller G, Rieder S, Drögemüller C, Leeb T. Congenital hepatic fibrosis in the Franches-Montagnes horse is associated with the polycystic kidney and hepatic disease 1 (PKHD1) gene. PLoS One 2014; 9:e110125. [PMID: 25295861 PMCID: PMC4190318 DOI: 10.1371/journal.pone.0110125] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/15/2014] [Indexed: 12/20/2022] Open
Abstract
Congenital hepatic fibrosis has been described as a lethal disease with monogenic autosomal recessive inheritance in the Swiss Franches-Montagnes horse breed. We performed a genome-wide association study with 5 cases and 12 controls and detected an association on chromosome 20. Subsequent homozygosity mapping defined a critical interval of 952 kb harboring 10 annotated genes and loci including the polycystic kidney and hepatic disease 1 (autosomal recessive) gene (PKHD1). PKHD1 represents an excellent functional candidate as variants in this gene were identified in human patients with autosomal recessive polycystic kidney and hepatic disease (ARPKD) as well as several mouse and rat mutants. Whereas most pathogenic PKHD1 variants lead to polycystic defects in kidney and liver, a small subset of the human ARPKD patients have only liver symptoms, similar to our horses with congenital hepatic fibrosis. The PKHD1 gene is one of the largest genes in the genome with multiple alternative transcripts that have not yet been fully characterized. We sequenced the genomes of an affected foal and 46 control horses to establish a comprehensive list of variants in the critical interval. We identified two missense variants in the PKHD1 gene which were strongly, but not perfectly associated with congenital hepatic fibrosis. We speculate that reduced penetrance and/or potential epistatic interactions with hypothetical modifier genes may explain the imperfect association of the detected PKHD1 variants. Our data thus indicate that horses with congenital hepatic fibrosis represent an interesting large animal model for the liver-restricted subtype of human ARPKD.
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Affiliation(s)
- Michaela Drögemüller
- Institute of Genetics, University of Bern, Bern, Switzerland
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
| | - Vidhya Jagannathan
- Institute of Genetics, University of Bern, Bern, Switzerland
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
| | - Monika M. Welle
- Institute of Animal Pathology, University of Bern, Bern, Switzerland
| | - Claudia Graubner
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Reto Straub
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Vinzenz Gerber
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Dominik Burger
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Bern, Switzerland
| | - Heidi Signer-Hasler
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
- Bern University of Applied Sciences HAFL, Zollikofen, Switzerland
| | | | | | - Ruedi von Niederhäusern
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
- Agroscope, Swiss National Stud Farm, Avenches, Switzerland
| | - Jens Tetens
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Kiel, Germany
| | - Georg Thaller
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Kiel, Germany
| | - Stefan Rieder
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
- Agroscope, Swiss National Stud Farm, Avenches, Switzerland
| | - Cord Drögemüller
- Institute of Genetics, University of Bern, Bern, Switzerland
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
| | - Tosso Leeb
- Institute of Genetics, University of Bern, Bern, Switzerland
- Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, Bern, Switzerland
- * E-mail:
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30
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Boddu R, Yang C, O’Connor AK, Hendrickson RC, Boone B, Cui X, Garcia-Gonzalez M, Igarashi P, Onuchic LF, Germino GG, Guay-Woodford LM. Intragenic motifs regulate the transcriptional complexity of Pkhd1/PKHD1. J Mol Med (Berl) 2014; 92:1045-56. [PMID: 24984783 PMCID: PMC4197071 DOI: 10.1007/s00109-014-1185-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/05/2014] [Accepted: 06/16/2014] [Indexed: 11/26/2022]
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) results from mutations in the human PKHD1 gene. Both this gene, and its mouse ortholog, Pkhd1, are primarily expressed in renal and biliary ductal structures. The mouse protein product, fibrocystin/polyductin complex (FPC), is a 445-kDa protein encoded by a 67-exon transcript that spans >500 kb of genomic DNA. In the current study, we observed multiple alternatively spliced Pkhd1 transcripts that varied in size and exon composition in embryonic mouse kidney, liver, and placenta samples, as well as among adult mouse pancreas, brain, heart, lung, testes, liver, and kidney. Using reverse transcription PCR and RNASeq, we identified 22 novel Pkhd1 kidney transcripts with unique exon junctions. Various mechanisms of alternative splicing were observed, including exon skipping, use of alternate acceptor/donor splice sites, and inclusion of novel exons. Bioinformatic analyses identified, and exon-trapping minigene experiments validated, consensus binding sites for serine/arginine-rich proteins that modulate alternative splicing. Using site-directed mutagenesis, we examined the functional importance of selected splice enhancers. In addition, we demonstrated that many of the novel transcripts were polysome bound, thus likely translated. Finally, we determined that the human PKHD1 R760H missense variant alters a splice enhancer motif that disrupts exon splicing in vitro and is predicted to truncate the protein. Taken together, these data provide evidence of the complex transcriptional regulation of Pkhd1/PKHD1 and identified motifs that regulate its splicing. Our studies indicate that Pkhd1/PKHD1 transcription is modulated, in part by intragenic factors, suggesting that aberrant PKHD1 splicing represents an unappreciated pathogenic mechanism in ARPKD. Key messages: Multiple mRNA transcripts are generated for Pkhd1 in renal tissues Pkhd1 transcription is modulated by standard splice elements and effectors Mutations in splice motifs may alter splicing to generate nonfunctional peptides.
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Affiliation(s)
- Ravindra Boddu
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chaozhe Yang
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | - Amber K. O’Connor
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
| | | | - Braden Boone
- Hudson Alpha Institute, Huntsville, AL 35806, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Miguel Garcia-Gonzalez
- Complexo Hospitalario de Santiago de Compostela, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
| | - Peter Igarashi
- Department of Medicine, University of Texas Southwestern School of Medicine, Dallas, TX 75235, USA
| | - Luiz F. Onuchic
- Department of Medicine, University of Sao Paulo, Sao Paulo, Brazil 01246-903
| | - Gregory G. Germino
- Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lisa M. Guay-Woodford
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center for Translational Science, Children’s National Medical Center, Washington, DC 20010, USA
- Children’s National Medical Center, 6th Floor Main Hospital, Center 6, 111 Michigan Ave NW, Washington, DC 20010, USA
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Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 or PKD2, which encode polycystin-1 and polycystin-2, respectively. Rodent models are available to study the pathogenesis of polycystic kidney disease (PKD) and for preclinical testing of potential therapies-either genetically engineered models carrying mutations in Pkd1 or Pkd2 or models of renal cystic disease that do not have mutations in these genes. The models are characterized by age at onset of disease, rate of disease progression, the affected nephron segment, the number of affected nephrons, synchronized or unsynchronized cyst formation and the extent of fibrosis and inflammation. Mouse models have provided valuable mechanistic insights into the pathogenesis of PKD; for example, mutated Pkd1 or Pkd2 cause renal cysts but additional factors are also required, and the rate of cyst formation is increased in the presence of renal injury. Animal studies have also revealed complex genetic and functional interactions among various genes and proteins associated with PKD. Here, we provide an update on the preclinical models commonly used to study the molecular pathogenesis of ADPKD and test potential therapeutic strategies. Progress made in understanding the pathophysiology of human ADPKD through these animal models is also discussed.
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Affiliation(s)
- Hester Happé
- Department of Human Genetics, Leiden University Medical Center, S4-P, PO Box 9600, Albinusdreef 2, Leiden, 2333 ZA Leiden, Netherlands
| | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, S4-P, PO Box 9600, Albinusdreef 2, Leiden, 2333 ZA Leiden, Netherlands
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32
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Williams SS, Cobo-Stark P, Hajarnis S, Aboudehen K, Shao X, Richardson JA, Patel V, Igarashi P. Tissue-specific regulation of the mouse Pkhd1 (ARPKD) gene promoter. Am J Physiol Renal Physiol 2014; 307:F356-68. [PMID: 24899057 DOI: 10.1152/ajprenal.00422.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Autosomal recessive polycystic kidney disease, an inherited disorder characterized by the formation of cysts in renal collecting ducts and biliary dysgenesis, is caused by mutations of the polycystic kidney and hepatic disease 1 (PKHD1) gene. Expression of PKHD1 is tissue specific and developmentally regulated. Here, we show that a 2.0-kb genomic fragment containing the proximal promoter of mouse Pkhd1 directs tissue-specific expression of a lacZ reporter gene in transgenic mice. LacZ is expressed in renal collecting ducts beginning during embryonic development but is not expressed in extrarenal tissues. The Pkhd1 promoter contains a binding site for the transcription factor hepatocyte nuclear factor (HNF)-1β, which is required for activity in transfected cells. Mutation of the HNF-1β-binding site abolishes the expression of the lacZ reporter gene in renal collecting ducts. Transgenes containing the 2.0-kb promoter and 2.7 kb of additional genomic sequence extending downstream to the second exon are expressed in the kidney, intrahepatic bile ducts, and male reproductive tract. This pattern overlaps with the endogenous expression of Pkhd1 and coincides with sites of expression of HNF-1β. We conclude that the proximal 2.0-kb promoter is sufficient for tissue-specific expression of Pkhd1 in renal collecting ducts in vivo and that HNF-1β is required for Pkhd1 promoter activity in collecting ducts. Additional genomic sequences located from exons 1-2 or elsewhere in the gene locus are required for expression in extrarenal tissues.
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Affiliation(s)
- Scott S Williams
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Patricia Cobo-Stark
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sachin Hajarnis
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Karam Aboudehen
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xinli Shao
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - James A Richardson
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas; and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Vishal Patel
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Peter Igarashi
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas;
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33
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Abstract
Polycystic diseases affect approximately 1/1000 and are important causes of kidney failure. No therapies presently are in clinical practice that can prevent disease progression. Multiple mouse models have been produced for the genetic forms of the disease that most commonly affect humans. In this report, we review recent progress in the field and describe some of the outstanding challenges.
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Affiliation(s)
- Luis Fernando Menezes
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10 Room 8D46, 10 Center Drive, Bethesda, MD 20892
| | - Gregory George Germino
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10 Room 8D46, 10 Center Drive, Bethesda, MD 20892
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34
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Abstract
OBJECTIVES Mutation in the Pkhd1 gene that encodes a ciliary protein, fibrocystin, causes multiple cysts in the kidneys and liver in the polycystic kidney (PCK) rat, a model for human autosomal recessive PCK disease. To clarify the role of primary cilia in the pancreatic duct, we examined the structure and function of the exocrine pancreas of PCK rats. METHODS Pancreatic juice and bile were collected from anesthetized rats. Pancreatic ductal structure was analyzed by microdissection and immunohist0chemistry. RESULTS Histologically pancreatic acini were apparently normal, and no cysts were detected in the pancreas. Larger pancreatic ducts were irregularly dilated with enhanced expression of AQP1 in epithelial cells. The pancreatic duct of PCK rats exhibited significantly (P < 0.05) higher distensibility than that of wild-type (WT) rat at a physiological luminal pressure (3 cm H2O). Pancreatic fluid secretion stimulated with a physiological dose of secretin (0.03 nmol/kg per hour) in PCK rats was significantly smaller than that in WT, but the differences were not significant at higher doses. The amylase responses to carbamylcholine were not different between PCK and WT rats. CONCLUSIONS These findings suggest that fibrocystin/primary cilia-dependent mechanisms may play a role in the regulation of pancreatic ductal structure and fluid secretion.
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35
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Abstract
Cilia are antenna-like organelles found on the surface of most cells. They transduce molecular signals and facilitate interactions between cells and their environment. Ciliary dysfunction has been shown to underlie a broad range of overlapping, clinically and genetically heterogeneous phenotypes, collectively termed ciliopathies. Literally, all organs can be affected. Frequent cilia-related manifestations are (poly)cystic kidney disease, retinal degeneration, situs inversus, cardiac defects, polydactyly, other skeletal abnormalities, and defects of the central and peripheral nervous system, occurring either isolated or as part of syndromes. Characterization of ciliopathies and the decisive role of primary cilia in signal transduction and cell division provides novel insights into tumorigenesis, mental retardation, and other common causes of morbidity and mortality, including diabetes mellitus and obesity. New technologies ("Next generation sequencing/NGS") have considerably improved genetic research and diagnostics by allowing simultaneous investigation of all disease genes at reduced costs and lower turn-around times. This is undoubtedly a result of the dynamic development in the field of human genetics and deserves increased attention in genetic counselling and the management of affected families.
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Affiliation(s)
- Carsten Bergmann
- Center for Human Genetics Bioscientia, Konrad-Adenauer-Str. 17, 55218 Ingelheim, Germany.
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36
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Caroli's Disease: Current Knowledge of Its Biliary Pathogenesis Obtained from an Orthologous Rat Model. Int J Hepatol 2012; 2012:107945. [PMID: 22007315 PMCID: PMC3168917 DOI: 10.1155/2012/107945] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 04/07/2011] [Indexed: 12/14/2022] Open
Abstract
Caroli's disease belongs to a group of hepatic fibropolycystic diseases and is a hepatic manifestation of autosomal recessive polycystic kidney disease (ARPKD). It is a congenital disorder characterized by segmental saccular dilatations of the large intrahepatic bile duct and is frequently associated with congenital hepatic fibrosis (CHF). The most viable theory explaining its pathogenesis suggests that it is related to ductal plate malformation. The development of the polycystic kidney (PCK) rat, an orthologous rodent model of Caroli's disease with CHF as well as ARPKD, has allowed the molecular pathogenesis of the disease and the therapeutic options for its treatment to be examined. The relevance of the findings of studies using PCK rats and/or the cholangiocyte cell line derived from them to the pathogenesis of human Caroli's disease is currently being analyzed. Fibrocystin/polyductin, the gene product responsible for ARPKD, is normally localized to primary cilia, and defects in the fibrocystin from primary cilia are observed in PCK cholangiocytes. Ciliopathies involving PCK cholangiocytes (cholangiociliopathies) appear to be associated with decreased intracellular calcium levels and increased cAMP concentrations, causing cholangiocyte hyperproliferation, abnormal cell matrix interactions, and altered fluid secretion, which ultimately result in bile duct dilatation. This article reviews the current knowledge about the pathogenesis of Caroli's disease with CHF, particularly focusing on studies of the mechanism responsible for the biliary dysgenesis observed in PCK rats.
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37
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Bakeberg JL, Tammachote R, Woollard JR, Hogan MC, Tuan HF, Li M, van Deursen JM, Wu Y, Huang BQ, Torres VE, Harris PC, Ward CJ. Epitope-tagged Pkhd1 tracks the processing, secretion, and localization of fibrocystin. J Am Soc Nephrol 2011; 22:2266-77. [PMID: 22021705 DOI: 10.1681/asn.2010111173] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Mutations in the PKHD1 gene, which encodes fibrocystin, cause autosomal recessive polycystic kidney disease (ARPKD). Unfortunately, the lack of specific antibodies to the mouse protein impairs the study of splicing, post-translational processing, shedding, and temporal and spatial expression of endogenous fibrocystin at the cellular and subcellular level. Here, we report using a knock-in strategy to generate a null Pkhd1 strain and a strain that expresses fibrocystin along with two SV5-Pk epitope tags engineered in-frame into the third exon, immediately C-terminal to the signal-peptide cleavage site in a poorly conserved region. By 6 mo of age, the Pkhd1-null mouse develops massive cystic hepatomegaly and proximal tubule dilation, whereas the mouse with epitope-tagged fibrocystin has histologically normal liver and kidneys at 14 mo. Although Pkhd1 was believed to generate many splice forms, our western analysis resolved fibrocystin as a 500 kD product without other forms in the 15-550 kD range. Western analysis also revealed that exosome-like vesicles (ELVs) secrete the bulk of fibrocystin in its mature cleaved form, and scanning electron microscopy identified that fibrocystin on ELVs attached to cilia. Furthermore, the addition of ELVs with epitope-tagged fibrocystin to wild-type cells showed that label transferred to primary cilia within 5 min. In summary, tagging of the endogenous Pkhd1 gene facilitates the study of the glycosylation, proteolytic cleavage, and shedding of fibrocystin.
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Affiliation(s)
- Jason L Bakeberg
- Division of Nephrology and Hypertension, Mayo Clinic, 703 Stabile Building, 200 First Street SW, Rochester, MN 55905, USA
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38
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Waters AM, Beales PL. Ciliopathies: an expanding disease spectrum. Pediatr Nephrol 2011; 26:1039-56. [PMID: 21210154 PMCID: PMC3098370 DOI: 10.1007/s00467-010-1731-7] [Citation(s) in RCA: 491] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Revised: 11/02/2010] [Accepted: 11/03/2010] [Indexed: 01/17/2023]
Abstract
Ciliopathies comprise a group of disorders associated with genetic mutations encoding defective proteins, which result in either abnormal formation or function of cilia. As cilia are a component of almost all vertebrate cells, cilia dysfunction can manifest as a constellation of features that include characteristically, retinal degeneration, renal disease and cerebral anomalies. Additional manifestations include congenital fibrocystic diseases of the liver, diabetes, obesity and skeletal dysplasias. Ciliopathic features have been associated with mutations in over 40 genes to date. However, with over 1,000 polypeptides currently identified within the ciliary proteome, several other disorders associated with this constellation of clinical features will likely be ascribed to mutations in other ciliary genes. The mechanisms underlying many of the disease phenotypes associated with ciliary dysfunction have yet to be fully elucidated. Several elegant studies have crucially demonstrated the dynamic ciliary localisation of components of the Hedgehog and Wnt signalling pathways during signal transduction. Given the critical role of the cilium in transducing "outside-in" signals, it is not surprising therefore, that the disease phenotypes consequent to ciliary dysfunction are a manifestation of aberrant signal transduction. Further investigation is now needed to explore the developmental and physiological roles of aberrant signal transduction in the manifestation of ciliopathy phenotypes. Utilisation of conditional and inducible murine models to delete or overexpress individual ciliary genes in a spatiotemporal and organ/cell-specific manner should help clarify some of the functional roles of ciliary proteins in the manifestation of phenotypic features.
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Affiliation(s)
- Aoife M. Waters
- Department of Nephro-Urology, Great Ormond Street Hospital, London, WC1N 3JH UK ,Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Philip L. Beales
- Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
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39
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Congenital fibrocystic liver diseases. Best Pract Res Clin Gastroenterol 2010; 24:573-84. [PMID: 20955960 DOI: 10.1016/j.bpg.2010.08.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 08/17/2010] [Accepted: 08/23/2010] [Indexed: 02/07/2023]
Abstract
Fibrocystic diseases affecting the liver and often also other organs like the kidneys are a clinically and genetically heterogeneous group of disorders that may present in utero or remain clinically silent into late adulthood. During recent years, substantial progress has been made in unravelling the aetiology with primary cilia playing a central pathogenic role in many if not all of these diseases. The fibrocystogenic process shares some common features including proliferation and dilatation of epithelial bile ducts with concomitant abnormal apoptosis, fluid secretion and extracellular matrix deposition. In this review, we summarise clinical and diagnostic aspects, mechanisms of hepatic cystogenesis, and recent knowledge on potential therapies for these conditions.
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40
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Hu B, He X, Li A, Qiu Q, Li C, Liang D, Zhao P, Ma J, Coffey RJ, Zhan Q, Wu G. Cystogenesis in ARPKD results from increased apoptosis in collecting duct epithelial cells of Pkhd1 mutant kidneys. Exp Cell Res 2010; 317:173-87. [PMID: 20875407 DOI: 10.1016/j.yexcr.2010.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 09/09/2010] [Accepted: 09/19/2010] [Indexed: 12/14/2022]
Abstract
Mutations in the PKHD1 gene result in autosomal recessive polycystic kidney disease (ARPKD) in humans. To determine the molecular mechanism of the cystogenesis in ARPKD, we recently generated a mouse model for ARPKD that carries a targeted mutation in the mouse orthologue of human PKHD1. The homozygous mutant mice display hepatorenal cysts whose phenotypes are similar to those of human ARPKD patients. By littermates of this mouse, we developed two immortalized renal collecting duct cell lines with Pkhd1 and two without. Under nonpermissive culture conditions, the Pkhd1(-/-) renal cells displayed aberrant cell-cell contacts and tubulomorphogenesis. The Pkhd1(-/-) cells also showed significantly reduced cell proliferation and elevated apoptosis. To validate this finding in vivo, we examined proliferation and apoptosis in the kidneys of Pkhd1(-/-) mice and their wildtype littermates. Using proliferation (PCNA and Histone-3) and apoptosis (TUNEL and caspase-3) markers, similar results were obtained in the Pkhd1(-/-) kidney tissues as in the cells. To identify the molecular basis of these findings, we analyzed the effect of Pkhd1 loss on multiple putative signaling regulators. We demonstrated that the loss of Pkhd1 disrupts multiple major phosphorylations of focal adhesion kinase (FAK), and these disruptions either inhibit the Ras/C-Raf pathways to suppress MEK/ERK activity and ultimately reduce cell proliferation, or suppress PDK1/AKT to upregulate Bax/caspase-9/caspase-3 and promote apoptosis. Our findings indicate that apoptosis may be a major player in the cyst formation in ARPKD, which may lead to new therapeutic strategies for human ARPKD.
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MESH Headings
- Animals
- Apoptosis/genetics
- Caspase 3/genetics
- Caspase 3/metabolism
- Caspase 9/genetics
- Caspase 9/metabolism
- Cell Line, Transformed
- Cell Proliferation
- Crosses, Genetic
- Cysts/genetics
- Disease Models, Animal
- Epithelial Cells/metabolism
- Genes, cdc
- Genotype
- Humans
- In Vitro Techniques
- Kidney/metabolism
- Kidney Tubules, Collecting/metabolism
- Mice
- Mice, Congenic
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation
- Phenotype
- Polycystic Kidney, Autosomal Recessive/genetics
- Polycystic Kidney, Autosomal Recessive/metabolism
- Polycystic Kidney, Autosomal Recessive/pathology
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Receptors, Cell Surface/genetics
- Signal Transduction/genetics
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Affiliation(s)
- Bo Hu
- Cancer Research Institute, University of South China, Hengyang, Hunan, 421001, China
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41
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Nishio S, Tian X, Gallagher AR, Yu Z, Patel V, Igarashi P, Somlo S. Loss of oriented cell division does not initiate cyst formation. J Am Soc Nephrol 2009; 21:295-302. [PMID: 19959710 DOI: 10.1681/asn.2009060603] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Polycystic kidney disease (PKD) can arise from either developmental or postdevelopmental processes. Recessive PKD, caused by mutations in PKHD1, is a developmental defect, whereas dominant PKD, caused by mutations in PKD1 or PKD2, occurs by a cellular recessive mechanism in mature kidneys. Oriented cell division is a feature of planar cell polarity that describes the orientation of the mitotic axes of dividing cells during development with respect to the luminal vector of the elongating nephron. In polycystic mutant mice, the loss of oriented cell division may also contribute to the pathogenesis of PKD. Here, we examined the role of oriented cell division in mouse models based on mutations in Pkd1, Pkd2, and Pkhd1. Precystic tubules after kidney-selective inactivation of either Pkd1 or Pkd2 did not lose oriented division before cystic dilation but lost oriented division after tubular dilation began. In contrast, Pkhd1(del4/del4) mice lost oriented cell division but did not develop kidney cysts. Increased intercalation of cells into the plane of the tubular epithelium maintained the normal tubular morphology in Pkhd1(del4/del4) mice, which had more cells present in transverse tubular profiles. In conclusion, loss of oriented cell division is a feature of Pkhd1 mutation and cyst formation, but it is neither sufficient to produce kidney cysts nor required to initiate cyst formation after mutation in Pkd1 or Pkd2.
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Affiliation(s)
- Saori Nishio
- Section of Nephrology, Yale University School of Medicine, P.O. Box 208029, 333 Cedar Street, New Haven, CT 06520-8029, USA
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42
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Molecular Characteristics and Functions of <I>PKHD1</I>*. PROG BIOCHEM BIOPHYS 2009. [DOI: 10.3724/sp.j.1206.2008.00657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Abstract
A number of inherited disorders result in renal cyst development. The most common form, autosomal dominant polycystic kidney disease (ADPKD), is a disorder most often diagnosed in adults and caused by mutation in PKD1 or PKD2. The PKD1 protein, polycystin-1, is a large receptor-like protein, whereas polycystin-2 is a transient receptor potential channel. The polycystin complex localizes to primary cilia and may act as a mechanosensor essential for maintaining the differentiated state of epithelia lining tubules in the kidney and biliary tract. Elucidation of defective cellular processes has highlighted potential therapies, some of which are now being tested in clinical trials. ARPKD is the neonatal form of PKD and is associated with enlarged kidneys and biliary dysgenesis. The disease phenotype is highly variable, ranging from neonatal death to later presentation with minimal kidney disease. ARPKD is caused by mutation in PKHD1, and two truncating mutations are associated with neonatal lethality. The ARPKD protein, fibrocystin, is localized to cilia/basal body and complexes with polycystin-2. Rare, syndromic forms of PKD also include defects of the eye, central nervous system, digits, and/or neural tube and highlight the role of cilia and pathways such as Wnt and Hh in their pathogenesis.
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Affiliation(s)
- Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota 55905, USA.
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44
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Wallace S, Blanchard T, Rabin L, Dick E, Allan J, Hubbard G. Ductal Plate Malformation in a Nonhuman Primate. Vet Pathol 2009; 46:84-7. [DOI: 10.1354/vp.46-1-84] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During necropsy of a 6-year-old, male African Green monkey ( Cercopithecus aethiops), multifocal pale, white to tan areas, 1–2 cm in diameter, were noted in the right lateral lobe, medial lobe, and capsular surface of the liver. Light microscopic examination of the liver revealed numerous spindle cells dispersed within interconnecting, broad bands of collagen, up to 200 μm in width, which often spanned and connected portal areas. A diagnosis of hepatic ductal plate malformation, most closely resembling congenital hepatic fibrosis with von Meyenburg complexes, was made. Few cases of ductal plate malformations in domestic animals are reported in the literature. To our knowledge, this is the first case reported in a nonhuman primate.
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Affiliation(s)
- S. Wallace
- Armed Forces Institute of Pathology, Washington, DC
| | - T. Blanchard
- Armed Forces Institute of Pathology, Washington, DC
| | - L. Rabin
- Armed Forces Institute of Pathology, Washington, DC
| | - E. Dick
- Southwest National Primate Research Center, San Antonio, TX
| | - J. Allan
- Southwest National Primate Research Center, San Antonio, TX
| | - G. Hubbard
- Southwest National Primate Research Center, San Antonio, TX
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45
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Flores J, Arnon R, Morotti RA, Guay-Woodford L, Emre S, Shneider BL. Rapid evolution of congenital hepatic fibrosis after liver transplantation for acute liver failure: the potential role of extrahepatic factors. Liver Transpl 2008; 14:660-4. [PMID: 18433070 DOI: 10.1002/lt.21415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A 9-year-old male underwent deceased donor liver transplantation for idiopathic fulminant hepatic failure. In the postoperative period, a review of perioperative biopsies of the donor liver revealed mild features of congenital hepatic fibrosis. Over the ensuing year, the recipient developed severe complications of congenital hepatic fibrosis including multiple episodes of cholangitis and progressive portal hypertension. After a second transplant, the patient had no further episodes of cholangitis and/or features of portal hypertension. Examination of the explanted liver revealed remarkable progression of the congenital hepatic fibrosis, suggesting that the phenotype of this disease may be dependent in part on extrahepatic factors.
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Affiliation(s)
- Judith Flores
- Department of Gastroenterology, Hospital de Pediatria, Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
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46
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Kidney cysts, pancreatic cysts, and biliary disease in a mouse model of autosomal recessive polycystic kidney disease. Pediatr Nephrol 2008; 23:733-41. [PMID: 18286309 DOI: 10.1007/s00467-007-0735-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 11/26/2007] [Accepted: 11/27/2007] [Indexed: 12/12/2022]
Abstract
Mutations in PKHD1 cause autosomal recessive polycystic kidney disease (ARPKD). We produced a mouse model of ARPKD by replacing exons 1-3 of Pkhd1 with a lacZ reporter gene utilizing homologous recombination. This approach yielded heterozygous Pkhd1 (lacZ/+) mice, that expressed beta-galactosidase in tissues where Pkhd1 is normally expressed, and homozygous Pkhd1 (lacZ/lacZ) knockout mice. Heterozygous Pkhd1 (lacZ/+) mice expressed beta-galactosidase in the kidney, liver, and pancreas. Homozygous Pkhd1 (lacZ/lacZ) mice lacked Pkhd1 expression and developed progressive renal cystic disease involving the proximal tubules, collecting ducts, and glomeruli. In the liver, inactivation of Pkhd1 resulted in dilatation of the bile ducts and periportal fibrosis. Dilatation of pancreatic exocrine ducts was uniformly seen in Pkhd1 (lacZ/lacZ ) mice, with pancreatic cysts arising less frequently. The expression of beta-galactosidase, Pkd1, and Pkd2 was reduced in the kidneys of Pkhd1 (lacZ/lacZ ) mice compared with wild-type littermates, but no changes in blood urea nitrogen (BUN) or liver function tests were observed. Collectively, these results indicate that deletion of exons 1-3 leads to loss of Pkhd1 expression and results in kidney cysts, pancreatic cysts, and biliary ductal plate malformations. The Pkhd1 (lacZ/lacZ ) mouse represents a new orthologous animal model for studying the pathogenesis of kidney cysts and biliary dysgenesis that characterize human ARPKD.
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47
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Kim I, Fu Y, Hui K, Moeckel G, Mai W, Li C, Liang D, Zhao P, Ma J, Chen XZ, George AL, Coffey RJ, Feng ZP, Wu G. Fibrocystin/polyductin modulates renal tubular formation by regulating polycystin-2 expression and function. J Am Soc Nephrol 2008; 19:455-68. [PMID: 18235088 DOI: 10.1681/asn.2007070770] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autosomal recessive polycystic kidney disease is caused by mutations in PKHD1, which encodes the membrane-associated receptor-like protein fibrocystin/polyductin (FPC). FPC associates with the primary cilia of epithelial cells and co-localizes with the Pkd2 gene product polycystin-2 (PC2), suggesting that these two proteins may function in a common molecular pathway. For investigation of this, a mouse model with a gene-targeted mutation in Pkhd1 that recapitulates phenotypic characteristics of human autosomal recessive polycystic kidney disease was produced. The absence of FPC is associated with aberrant ciliogenesis in the kidneys of Pkhd1-deficient mice. It was found that the COOH-terminus of FPC and the NH2-terminus of PC2 interact and that lack of FPC reduced PC2 expression but not vice versa, suggesting that PC2 may function immediately downstream of FPC in vivo. PC2-channel activities were dysregulated in cultured renal epithelial cells derived from Pkhd1 mutant mice, further supporting that both cystoproteins function in a common pathway. In addition, mice with mutations in both Pkhd1 and Pkd2 had a more severe renal cystic phenotype than mice with single mutations, suggesting that FPC acts as a genetic modifier for disease severity in autosomal dominant polycystic kidney disease that results from Pkd2 mutations. It is concluded that a functional and molecular interaction exists between FPC and PC2 in vivo.
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Affiliation(s)
- Ingyu Kim
- Division of Genetic Medicine, Department of Medicine and Cell and Developmental Biology, Vanderbilt University, 539 LH, 2215 Garland Avenue, Nashville, TN 37232, USA
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Gallagher AR, Esquivel EL, Briere TS, Tian X, Mitobe M, Menezes LF, Markowitz GS, Jain D, Onuchic LF, Somlo S. Biliary and pancreatic dysgenesis in mice harboring a mutation in Pkhd1. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 172:417-29. [PMID: 18202188 DOI: 10.2353/ajpath.2008.070381] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Autosomal recessive polycystic kidney disease is a hereditary fibrocystic disease that involves the kidneys and the biliary tract. Mutations in the PKHD1 gene are responsible for typical forms of autosomal recessive polycystic kidney disease. We have generated a mouse model with targeted mutation of Pkhd1 by disrupting exon 4, resulting in a mutant transcript with deletion of 66 codons and expression at approximately 30% of wild-type levels. Pkhd1(del4/del4) mice develop intrahepatic bile duct proliferation with progressive cyst formation and associated periportal fibrosis. In addition, these mice exhibit extrahepatic manifestations, including pancreatic cysts, splenomegaly, and common bile duct dilation. The kidneys are unaffected both histologically and functionally. Fibrocystin is expressed in the apical membranes and cilia of bile ducts and distal nephron segments but is absent from the proximal tubule. This pattern is unchanged in orthologous models of autosomal dominant polycystic kidney disease due to mutation in Pkd1 or Pkd2. Mutant fibrocystin in Pkhd1(del4/del4) mice also retains this expression pattern. The hypomorphic Pkhd1(del4/del4) mouse model provides evidence that reduced functional levels of fibrocystin are sufficient for cystogenesis and fibrosis in the liver and pancreas, but not the kidney, and supports the hypothesis of species-dependent differences in susceptibility of tissues to Pkhd1 mutations.
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Affiliation(s)
- Anna-Rachel Gallagher
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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49
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Abstract
Polycystic kidney disease (PKD) is a diverse group of human monogenic lethal conditions inherited as autosomal dominant (AD) or recessive (AR) traits. Recent development of genetically engineered mouse models of ADPKD, ARPKD, and nephronophthisis/medullary cystic disease (NPHP) are providing additional insights into the molecular mechanisms governing of these disease processes as well as the developmental differentiation of the normal kidney. Genotypic and phenotypic mouse models are discussed and provide evidence for the fundamental involvement of cell-matrix, cell-cell, and primary cilia-lumen interactions, as well as epithelial proliferation, apoptosis, and polarization. Structure/function relationships between the PKD1, PKD2, PKHD1, and NPHP genes and proteins support the notion of a regulatory multiprotein cystic complex with a mechanosensory function that integrates signals from the extracellular environment. The plethora of intracellular signaling cascades that can impact renal cystic development suggest an exquisitely sensitive requirement for integrated downstream transduction and provide potential targets for therapeutic intervention. Appropriate genocopy models that faithfully recapitulate the phenotypic characteristics of the disease will be invaluable tools to analyze the effects of modifier genes and small molecule inhibitor therapies.
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Sato Y, Harada K, Ozaki S, Furubo S, Kizawa K, Sanzen T, Yasoshima M, Ikeda H, Sasaki M, Nakanuma Y. Cholangiocytes with mesenchymal features contribute to progressive hepatic fibrosis of the polycystic kidney rat. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1859-71. [PMID: 18055542 DOI: 10.2353/ajpath.2007.070337] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The polycystic kidney (PCK) rat is an animal model of Caroli's disease with congenital hepatic fibrosis, in which the mechanism of progressive hepatic fibrosis remains unknown. This study aimed to clarify the mechanism of hepatic fibrosis of the PCK rat from the viewpoint of the contribution of pathological cholangiocytes. In liver sections of the PCK rats, intrahepatic bile ducts were constituted by two different phenotypes: bile ducts lined by cuboidal-shaped and flat-shaped cholangiocytes. The flat-shaped cholangiocytes showed reduced immunohistochemical expression of the biliary epithelial marker cytokeratin 19 and positive immunoreactivity for vimentin and fibronectin. When cultured cholangiocytes of the PCK rat were treated with transforming growth factor (TGF)-beta1, a potent inducer of epithelial-mesenchymal transition, induction of vimentin, fibronectin, and collagen expression occurred in the PCK cholangiocytes. Although the TGF-beta1 treatment reduced cytokeratin 19 expression, the epithelial cell features characterized by the expression of E-cadherin and zonula occludens-1 was maintained, and alpha-smooth muscle actin expression was not induced in the cholangiocytes. Cholangiocytes of the PCK rat may acquire mesenchymal features in response to TGF-beta1 and participate in progressive hepatic fibrosis by producing extracellular matrix molecules, which seems to be a different event from epithelial-mesenchymal transition.
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Affiliation(s)
- Yasunori Sato
- Department of Human Pathology, Kanazawa University, Graduate School of Medicine, Kanazawa 920-8640, Japan
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