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Olson RJ, Hopp K, Wells H, Smith JM, Furtado J, Constans MM, Escobar DL, Geurts AM, Torres VE, Harris PC. Synergistic Genetic Interactions between Pkhd1 and Pkd1 Result in an ARPKD-Like Phenotype in Murine Models. J Am Soc Nephrol 2019; 30:2113-2127. [PMID: 31427367 PMCID: PMC6830782 DOI: 10.1681/asn.2019020150] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/12/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD) are genetically distinct, with ADPKD usually caused by the genes PKD1 or PKD2 (encoding polycystin-1 and polycystin-2, respectively) and ARPKD caused by PKHD1 (encoding fibrocystin/polyductin [FPC]). Primary cilia have been considered central to PKD pathogenesis due to protein localization and common cystic phenotypes in syndromic ciliopathies, but their relevance is questioned in the simple PKDs. ARPKD's mild phenotype in murine models versus in humans has hampered investigating its pathogenesis. METHODS To study the interaction between Pkhd1 and Pkd1, including dosage effects on the phenotype, we generated digenic mouse and rat models and characterized and compared digenic, monogenic, and wild-type phenotypes. RESULTS The genetic interaction was synergistic in both species, with digenic animals exhibiting phenotypes of rapidly progressive PKD and early lethality resembling classic ARPKD. Genetic interaction between Pkhd1 and Pkd1 depended on dosage in the digenic murine models, with no significant enhancement of the monogenic phenotype until a threshold of reduced expression at the second locus was breached. Pkhd1 loss did not alter expression, maturation, or localization of the ADPKD polycystin proteins, with no interaction detected between the ARPKD FPC protein and polycystins. RNA-seq analysis in the digenic and monogenic mouse models highlighted the ciliary compartment as a common dysregulated target, with enhanced ciliary expression and length changes in the digenic models. CONCLUSIONS These data indicate that FPC and the polycystins work independently, with separate disease-causing thresholds; however, a combined protein threshold triggers the synergistic, cystogenic response because of enhanced dysregulation of primary cilia. These insights into pathogenesis highlight possible common therapeutic targets.
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Affiliation(s)
- Rory J Olson
- Department of Biochemistry and Molecular Biology, Mayo Graduate School of Biomedical Sciences, Rochester, Minnesota
| | - Katharina Hopp
- Division of Renal Diseases and Hypertension, University of Colorado, Denver, Colorado
| | - Harrison Wells
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jessica M Smith
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Jessica Furtado
- Department of Biochemistry and Molecular Biology, Mayo Graduate School of Biomedical Sciences, Rochester, Minnesota
- Biological and Biomedical Sciences Program, Yale University School of Medicine, New Haven, Connecticut; and
| | - Megan M Constans
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Diana L Escobar
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aron M Geurts
- Gene Editing Rat Resource Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Peter C Harris
- Department of Biochemistry and Molecular Biology, Mayo Graduate School of Biomedical Sciences, Rochester, Minnesota;
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
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Hartung EA, Dell KM, Matheson M, Warady BA, Furth SL. Growth in Children with Autosomal Recessive Polycystic Kidney Disease in the CKiD Cohort Study. Front Pediatr 2016; 4:82. [PMID: 27559537 PMCID: PMC4978942 DOI: 10.3389/fped.2016.00082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/27/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Previous studies have suggested that some children with autosomal recessive polycystic kidney disease (ARPKD) have growth impairment out of proportion to their degree of chronic kidney disease (CKD). The objective of this study was to systematically compare growth parameters in children with ARPKD to those with other congenital causes of CKD in the chronic kidney disease in Children (CKiD) prospective cohort study. METHODS Height SD scores (z-scores), proportion of children with severe short stature (z-score < -1.88), rates of growth hormone use, and annual change in height z-score were analyzed in children with ARPKD (n = 22) compared with two matched control groups: children with aplastic/hypoplastic/dysplastic kidneys (n = 44) and obstructive uropathy (OU) (n = 44). Differences in baseline characteristics were tested by Wilcoxon rank-sum test or Fisher's exact test. Matched differences in annual change in height z-score were tested by Wilcoxon signed-rank test. RESULTS Median height z-score in children with ARPKD was -1.1 [interquartile range -1.5, -0.2]; 14% of the ARPKD group had height z-score < -1.88, and 18% were using growth hormone. There were no significant differences in median height z-score, proportion with height z-score < -1.88, growth hormone use, or annual change in height z-score between the ARPKD and control groups. CONCLUSION Children with ARPKD and mild-to-moderate CKD in the CKiD cohort have a high prevalence of growth abnormalities, but these are similar to children with other congenital causes of CKD. This study does not support a disease-specific effect of ARPKD on growth, at least in the subset of children with mild-to-moderate CKD.
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Affiliation(s)
- Erum A Hartung
- Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Katherine M Dell
- Department of Pediatrics, Center for Pediatric Nephrology, Cleveland Clinic Children's, Case Western Reserve University , Cleveland, OH , USA
| | - Matthew Matheson
- Department of Epidemiology, Johns Hopkins University , Baltimore, MD , USA
| | - Bradley A Warady
- Division of Pediatric Nephrology, Children's Mercy Hospital , Kansas City, MO , USA
| | - Susan L Furth
- Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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Hartung EA, Guay-Woodford LM. Autosomal recessive polycystic kidney disease: a hepatorenal fibrocystic disorder with pleiotropic effects. Pediatrics 2014; 134:e833-45. [PMID: 25113295 PMCID: PMC4143997 DOI: 10.1542/peds.2013-3646] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/07/2014] [Indexed: 12/31/2022] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is an important cause of chronic kidney disease in children. The care of ARPKD patients has traditionally been the realm of pediatric nephrologists; however, the disease has multisystem effects, and a comprehensive care strategy often requires a multidisciplinary team. Most notably, ARPKD patients have congenital hepatic fibrosis, which can lead to portal hypertension, requiring close follow-up by pediatric gastroenterologists. In severely affected infants, the diagnosis is often first suspected by obstetricians detecting enlarged, echogenic kidneys and oligohydramnios on prenatal ultrasounds. Neonatologists are central to the care of these infants, who may have respiratory compromise due to pulmonary hypoplasia and massively enlarged kidneys. Surgical considerations can include the possibility of nephrectomy to relieve mass effect, placement of dialysis access, and kidney and/or liver transplantation. Families of patients with ARPKD also face decisions regarding genetic testing of affected children, testing of asymptomatic siblings, or consideration of preimplantation genetic diagnosis for future pregnancies. They may therefore interface with genetic counselors, geneticists, and reproductive endocrinologists. Children with ARPKD may also be at risk for neurocognitive dysfunction and may require neuropsychological referral. The care of patients and families affected by ARPKD is therefore a multidisciplinary effort, and the general pediatrician can play a central role in this complex web of care. In this review, we outline the spectrum of clinical manifestations of ARPKD and review genetics of the disease, clinical and genetic diagnosis, perinatal management, management of organ-specific complications, and future directions for disease monitoring and potential therapies.
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Affiliation(s)
- Erum A Hartung
- Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and
| | - Lisa M Guay-Woodford
- Center for Translational Science, Children's National Health System, Washington, District of Columbia
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Garcia-Gonzalez MA, Menezes LF, Piontek KB, Kaimori J, Huso DL, Watnick T, Onuchic LF, Guay-Woodford LM, Germino GG. Genetic interaction studies link autosomal dominant and recessive polycystic kidney disease in a common pathway. Hum Mol Genet 2007; 16:1940-50. [PMID: 17575307 PMCID: PMC2085232 DOI: 10.1093/hmg/ddm141] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Polycystic kidney disease (PKD) describes a heterogeneous collection of disorders that differ significantly with respect to their etiology and clinical presentation. They share, however, abnormal tubular morphology as a common feature, leading to the hypothesis that their respective gene products may function cooperatively in a common pathway to maintain tubular integrity. To study the pathobiology of one major form of human PKD, we generated a mouse line with a floxed allele of Pkhd1, the orthologue of the gene mutated in human autosomal recessive PKD. Cre-mediated excision of exons 3-4 results in a probable hypomorphic allele. Pkhd1(del3-4/del3-4) developed a range of phenotypes that recapitulate key features of the human disease. Like in humans, abnormalities of the biliary tract were an invariant finding. Most mice 6 months or older also developed renal cysts. Subsets of animals presented with either perinatal respiratory failure or exhibited growth retardation that was not due to the renal disease. We then tested for genetic interaction between Pkhd1 and Pkd1, the mouse orthologue of the gene most commonly linked to human autosomal dominant PKD. Pkd1(+/-); Pkhd1(del3-4/del3-4) mice had markedly more severe disease than Pkd1(+/+); Pkhd1(del3-4/del3-4) littermates. These studies are the first to show genetic interaction between the major loci responsible for human renal cystic disease in a common PKD pathway.
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Affiliation(s)
- Miguel A. Garcia-Gonzalez
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
| | - Luis F. Menezes
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
| | - Klaus B. Piontek
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
| | - Junya Kaimori
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
| | - David L. Huso
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Terry Watnick
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
| | - Luiz F. Onuchic
- Department of Medicine, University of São Paulo School of Medicine, São Paulo, Brazil
| | | | - Gregory G. Germino
- Department of Medicine, Division of Nephrology and ² Department of Molecular Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, MD, USA
- Corresponding author: Gregory Germino, Johns Hopkins University School of Medicine, Ross 958, 720 Rutland Avenue, Baltimore, MD 21205, Telephone: 410-614-1650, Telefax: 410-614-5129, E-mail:
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Abstract
A retrospective analysis was conducted on 10 consecutive cases of neonatal ARPKD, 9 of whom received kidney transplants (KT). All were diagnosed antenatally (n = 6) or at birth. In the first month of life 70% required ventilatory support. Pre-emptive bilateral nephrectomy and peritoneal dialysis (PD) catheter placement were performed in 9 at a mean age of 7.8 +/- 11.9 months. The indications for nephrectomy were massive kidneys, resulting in suboptimal nutrition and respiratory compromise. All patients received assisted enteral nutrition, with significant increase in mean tolerated feeds following nephrectomy (p < 0.05), with increase in mean normalized weight and height (0.92 and 1.2 delta SDS respectively), by one year post-transplantation. KT was performed at a mean age and weight of 2.5 +/- 1.4 years and 13.3 +/- 6.1 kg. The mean creatinine clearance at one year post-KT was 91.3 +/- 38.1 mls/min/1.73 m(2), with a projected graft life expectancy of 18.4 years. Patient survival was 89% and death censored graft survival was 100%, at a mean follow-up of 6.1 +/- 4.5 years post-transplant. Six patients demonstrated evidence of hepatic fibrosis, one of which required liver transplantation. In patients with massive kidneys from ARPKD, pre-emptive bilateral nephrectomy, supportive PD and early aggressive nutrition, can minimize early infant mortality, so that subsequent KT can be performed with excellent patient and graft survival.
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Affiliation(s)
- Mona Beaunoyer
- Department of Transplant Surgery, Stanford University, Stanford, CA 94304, USA
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Guay-Woodford LM, Desmond RA. Autosomal recessive polycystic kidney disease: the clinical experience in North America. Pediatrics 2003; 111:1072-80. [PMID: 12728091 DOI: 10.1542/peds.111.5.1072] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE We designed a longitudinal clinical database for autosomal recessive polycystic kidney disease (ARPKD), recruited patients from pediatric nephrology centers in the United States and Canada, and examined their clinical morbidities and survival characteristics. We initially targeted enrollment to children who were born and diagnosed after January 1, 1990, so as to capture a cohort that is representative of ARPKD patients born in the last decade. When a significant number of older ARPKD patients were also referred, we extended our database to include all patients who met our inclusion criteria, thereby allowing direct comparisons between a long-term survivor subset and a cohort that included both neonatal survivors and nonsurvivors. DESIGN Patient entry into our database required either compatible histopathology or ultrasonographic evidence of enlarged, echogenic kidneys and the presence of at least 1 of the following additional criteria: a) biopsy-proven ARPKD in a sibling; b) biliary fibrosis based on either clinical or histopathologic evidence; c) no sonographic evidence of renal cysts in the parents (parents must be >30 years of age); or d) parental consanguinity, eg, first-cousin marriage. Clinical questionnaires (primary data form and follow-up data form) were developed to collect initial patient data and follow-up data at yearly intervals. RESULTS Thirty-four centers provided clinical information for 254 patients and of these, 209 had sufficient data for analyses. When stratified by date of birth, 166 (79.4%) were born on or after January 1, 1990 (younger cohort) and 43 children (20.6%) were born before 1990 (older cohort). The gender distribution was equal in both cohorts. The median age at diagnosis was significantly later in the older cohort and no deaths were reported among these patients, suggesting that this group is biased toward long-term survivors. In the younger cohort, 74.7% of the patients are alive, with a median age of 5.4 years. In this group, 40.5% of patients required ventilation and 11.6% developed chronic lung disease. Hypertension was a common, but not universal finding in both cohorts. The relative risk for developing hypertension was higher in the older cohort, but the median age at diagnosis was significantly earlier in the younger cohort. Chronic renal insufficiency (CRI) was reported in approximately 40% of patients with no significant difference in the relative risk between age groups. However, in the younger cohort, the median age at diagnosis was significantly earlier and the age of diagnosis of CRI and hypertension were significantly correlated. Clinically significant morbidities related to periportal fibrosis were more common in the older cohort. There was a trend toward increasing frequency of portal hypertension with age in both cohorts. Portal hypertension was not significantly correlated with either systemic hypertension or CRI. CONCLUSIONS The ARPKD Clinical Database represents the largest single cohort of ARPKD patients collected to date. Our initial data analysis provides several new clinical insights. First, in our subset of long-term survivors, ARPKD has a slower rate of disease progression, as assessed by age of ARPKD diagnosis, as well as age of diagnosis of clinical morbidities. Second, neonatal ventilation was strongly predictive of mortality as well as an earlier age of diagnosis in those who developed hypertension or chronic renal insufficiency. However, for infants who survive the perinatal period, the long-term prognosis for patient survival is much better than generally perceived. Third, although systemic hypertension and CRI were significantly correlated with respect to age of diagnosis, similar relationships with portal hypertension were not evident, suggesting that disease progression may have organ-specific patterns. Fourth, only a subset of patients may be at risk for developing clinically significant manifestations of periportal fibrosis. Based on these observations, the next challenges will be to determine how various factors, such as specific mutations in the ARPKD gene, PKHD1(polycystic kidney and hepatic disease 1), variations in modifying gene loci, modulation by as yet unspecified environmental factors, and/or gene-environment interactions contribute to the marked variability in survival and disease expression observed among ARPKD patients.
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Affiliation(s)
- Lisa M Guay-Woodford
- Division of Genetic and Translational Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
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Lilova M, Kaplan BS, Meyers KEC. Recombinant human growth hormone therapy in autosomal recessive polycystic kidney disease. Pediatr Nephrol 2003; 18:57-61. [PMID: 12488992 DOI: 10.1007/s00467-002-0986-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2002] [Revised: 07/26/2002] [Accepted: 07/29/2002] [Indexed: 10/27/2022]
Abstract
Patients with autosomal recessive polycystic kidney disease (ARPKD) may have growth retardation that is disproportionate to the degree of renal dysfunction. We treated growth-retarded ARPKD patients with recombinant growth hormone (rhGH) and document the response to therapy and effect of rhGH on the rate of progression of renal failure. The diagnosis of ARPKD and congenital hepatic fibrosis was made on the basis of clinical findings and by abdominal ultrasound examinations. Seventeen patients (6 girls/11 boys) aged 0.3-18.3 years were studied. Diagnosis was made prenatally in 6, after birth in 3, and in 8 between 0.33 and 10 years. Follow-up was 2 months to 14.3 years (median 6.9 years). Growth, growth velocity, weight, and bone age were measured before and after treatment with rhGH. Insulin-like growth factor-1 and IGF binding protein 3 were measured prior to rhGH therapy. Five children (1 girl/4 boys) with height Z-scores < or =1.2 (5/17) aged 4.5-11.9 years received rhGH therapy. Duration of rhGH therapy was 0.3-5.4 years. All responded to rhGH (Z-score before -2.8 vs. -1.26 after treatment, P=0.03). An increase in height Z-score was noted 0.5-1.5 years after starting rhGH therapy. There were no side effects from rhGH therapy. The initial Z-score in the untreated group was -0.35 and the final score was -0.64. Initial glomerular filtration rate (GFR) in the treated group was 77 versus 104 ml/min per 1.73 m(2) in the non-treated group. GFR in 3 of 6 growth-retarded patients (<5th percentile) was 38, 65, and 30 ml/min per 1.73 m(2). GFR in 2 of 11 non-growth-retarded patients was 30 and 26 ml/min per 1.73 m(2). The change from initial GFR and final GFR in treated patients was 77 versus 76 ml/min per 1.73 m(2), and non-treated patients 104 versus 89 ml/min per 1.73 m(2) ( P>0.05). Growth failure in ARPKD may be attributable to factors other than chronic renal insufficiency alone. Use of rhGH therapy in ARPKD is safe, effective, and has the potential to improve the physical and psychological well-being of these children.
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Affiliation(s)
- Marusia Lilova
- Division of Nephrology and Department of Pediatrics, The Children's Hospital of Philadelphia, PA 19104, USA
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