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Culver SA, Hargett SR, Balugo JLLQ, Gildea JJ, Harris TE, Siragy HM. Nephron specific ATP6AP2 knockout increases urinary excretion of fatty acids and decreases renal cortical megalin expression. Sci Rep 2024; 14:18724. [PMID: 39134597 PMCID: PMC11319469 DOI: 10.1038/s41598-024-69749-x] [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: 03/20/2024] [Accepted: 08/08/2024] [Indexed: 08/15/2024] Open
Abstract
ATP6AP2 knockout in the renal nephron impairs receptor-mediated endocytosis, increasing urinary albumin and glucose excretion and impairing weight gain. Nonesterified fatty acids (NEFA) in urine are bound to albumin and reabsorbed in the proximal tubule through receptor-mediated endocytosis by the megalin-cubilin complex. We hypothesized that ATP6AP2 knockout increases urinary NEFA excretion through a reduction in megalin. Ten-week-old male C57BL/6 mice with nephron specific inducible ATP6AP2 knockout and noninduced controls were fed either normal diet (ND 12% fat) or high fat diet (HFD 45% fat) for 6 months. ATP6AP2 knockout significantly increased urine albumin:creatinine ratio in both ND and HFD fed mice while normalized urine NEFA concentration increased 489% and 259% in ND and HFD knockout mice compared to respective controls. Knockout decreased renal cortical megalin mRNA by 47% on ND and 49% on HFD while megalin protein expression decreased by 36% and 44% respectively. At the same time, markers of mTOR activity were increased while autophagy was impaired. Our results indicate that nephron specific ATP6AP2 knockout increases urinary NEFA excretion in the setting of impaired receptor-mediated endocytosis. Further investigation should determine whether ATP6AP2 contributes to obesity related ectopic lipid deposition in the proximal tubule.
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Affiliation(s)
- Silas A Culver
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22908-1409, USA.
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia Health System, Charlottesville, USA
| | - Jamie L L Q Balugo
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22908-1409, USA
| | - John J Gildea
- Department of Pathology, University of Virginia Health System, Charlottesville, USA
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia Health System, Charlottesville, USA
| | - Helmy M Siragy
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22908-1409, USA
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2
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Edwards A. Renal handling of albumin in rats with early stage diabetes: A theoretical analysis. J Physiol 2024; 602:3575-3592. [PMID: 38857419 PMCID: PMC11250707 DOI: 10.1113/jp286245] [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: 01/08/2024] [Accepted: 05/20/2024] [Indexed: 06/12/2024] Open
Abstract
In early diabetic nephropathy (DN), recent studies have shown that albuminuria stems mostly from alterations in tubular function rather than from glomerular damage. Several factors in DN, including hyperfiltration, hypertrophy and reduced abundance of the albumin receptors megalin and cubilin, affect albumin endocytosis in the proximal tubule (PT). To assess their respective contribution, we developed a model of albumin handling in the rat PT that couples the transport of albumin to that of water and solutes. Our simulations suggest that, under basal conditions, ∼75% of albumin is retrieved in the S1 segment. The model predicts negligible uptake in S3, as observed experimentally. It also accurately predicts the impact of acute hyperglycaemia on urinary albumin excretion. Simulations reproduce observed increases in albumin excretion in early DN by considering the combined effects of increased glomerular filtration rate (GFR), osmotic diuresis, hypertrophy, and megalin and cubilin downregulation, without stipulating changes in glomerular permselectivity. The results indicate that in isolation, glucose-elicited osmotic diuresis and glucose transporter upregulation raise albumin excretion only slightly. Enlargement of PT diameter not only augments uptake via surface area expansion, but also reduces fluid velocity and thus shear stress-induced stimulation of endocytosis. Overall, our model predicts that downregulation of megalin and cubilin and hyperfiltration both contribute significantly to increasing albumin excretion in rats with early-stage diabetes. The results also suggest that acute sodium-glucose cotransporter 2 inhibition lowers albumin excretion only if GFR decreases sufficiently, and that angiotensin II receptor blockers mitigate urinary albumin loss in early DN in large part by upregulating albumin receptor abundance. KEY POINTS: The urinary excretion of albumin is increased in early diabetic nephropathy (DN). It is difficult to experimentally disentangle the multiple factors that affect the renal handling of albumin in DN. We developed a mathematical model of albumin transport in the rat proximal tubule (PT) to examine the impact of elevated plasma glucose, hyperfiltration, PT hypertrophy and reduced abundance of albumin receptors on albumin uptake and excretion in DN. Our model predicts that glucose-elicited osmotic diuresis per se raises albumin excretion only slightly. Conversely, increases in PT diameter and length favour reduced albumin excretion. Our results suggest that downregulation of the receptors megalin and cubilin in PT cells and hyperfiltration both contribute significantly to increasing albumin excretion in DN. The model helps to better understand the mechanisms underlying urinary loss of albumin in early-stage diabetes, and the impact of specific treatments thereupon.
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Affiliation(s)
- Aurélie Edwards
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
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3
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Ralph DL, Ha D, Lei H, Priver TS, Smith SD, McFarlin BE, Schwindt S, Pandya D, Koepsell H, Pastor-Soler NM, Edwards A, McDonough AA. Potassium-Alkali-Enriched Diet, Hypertension, and Proteinuria following Uninephrectomy. J Am Soc Nephrol 2024:00001751-990000000-00357. [PMID: 38913441 DOI: 10.1681/asn.0000000000000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 06/10/2024] [Indexed: 06/26/2024] Open
Abstract
Key Points
A K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing Na+ reabsorption.Uninephrectomy-associated proteinuria could be attributed to elevated single-nephron GFR and downregulation of megalin, which reduced fractional protein endocytosis.
Background
Losing or donating a kidney is associated with risks of developing hypertension and albuminuria. Few studies address mechanisms or interventions. We investigate the potential benefits of a K+- alkali–enriched diet and the mechanisms underlying proteinuria.
Methods
Male Sprague Dawley rats were fed either a 2% NaCl+0.95% KCl diet (HNa-LK) or a 0.74% NaCl+3% K+-alkali diet (HK-alk) for 3 weeks before uninephrectomy and then maintained on respective diets for 12 weeks. BP (by tail-cuff), urine, blood, and kidney proteins were analyzed before and after uninephrectomy.
Results
Before uninephrectomy, HK-alk–fed versus HNa-LK–fed rats exhibited similar BPs and plasma [K+], [Na+], but lower proximal (NHE3, sodium bicarbonate cotransporter 1, NaPi2) and higher distal (NCC, ENaC, and pendrin) transporter abundance, a pattern facilitating K+ and HCO3
− secretion. After uninephrectomy, single-nephron GFR increased 50% and Li+ clearance doubled with both diets; in HK-alk versus HNa-LK, the increase in BP was less and ammoniagenesis was lower, abundance of proximal tubule transporters remained lower, ENaC-α fell, and NCCp increased, consistent with K+ conservation. After uninephrectomy, independent of diet, albuminuria increased eight-fold and abundance of endocytic receptors was reduced (megalin by 44%, disabled homolog 2 by 25%–35%) and kidney injury molecule-1 was increased.
Conclusions
The K-alkali–enriched diet blunted post-uninephrectomy hypertension and facilitated acid clearance by suppressing proximal Na+ transporters and increasing K+-alkali secretion. Furthermore, uninephrectomy-associated proteinuria could be attributed, at least in part, to elevated single-nephron GFR coupled with downregulation of megalin, which reduced fractional protein endocytosis and Vmax.
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Affiliation(s)
- Donna L Ralph
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Darren Ha
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hillmin Lei
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Taylor S Priver
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Scotti D Smith
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Brandon E McFarlin
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Seth Schwindt
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Drishti Pandya
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Hermann Koepsell
- Institute for Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Nuria M Pastor-Soler
- Division of Nephrology, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Aurelie Edwards
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
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Yang H, He L, Gong H, Wan C, Ding J, Liao P, Wang X. Identification of novel pathogenic variants of CUBN in patients with isolated proteinuria. Mol Genet Genomic Med 2024; 12:e2353. [PMID: 38488435 PMCID: PMC10941600 DOI: 10.1002/mgg3.2353] [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: 09/17/2023] [Revised: 11/29/2023] [Accepted: 12/11/2023] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Although proteinuria is long recognized as an independent risk factor for progressive chronic kidney diseases, not all forms of proteinuria are detrimental to kidney function, one of which is isolated proteinuria caused by cubilin (CUBN)-specific mutations. CUBN encodes an endocytic receptor, initially found to be responsible for the Imerslund-Gräsbeck syndrome (IGS; OMIM #261100) characterized by a combined phenotype of megaloblastic anemia and proteinuria. METHODS After analyzing their clinical and pathological characterizations, next-generation sequencing for renal disease genes or whole-exome sequencing (WES) was performed on four patients with non-progressive isolated proteinuria. CUBN biallelic pathogenic variants were identified and further analyzed by cDNA-PCR sequencing, immunohistochemistry, minigene assay, and multiple in silico prediction tools, including 3D protein modeling. RESULTS Here, we present four patients with isolated proteinuria caused by CUBN C-terminal biallelic pathogenic variants, all of which showed no typical IGS symptoms, such as anemia and vitamin B12 deficiency. Their urine protein levels fluctuated between +~++ and estimated glomerular filtration rate (eGFR) were normal or slightly higher. Mild mesangial hypercellularity was found in three children's renal biopsies. A homozygous splice-site variant of CUBN (c.6821+3 (IVS44) A>G) was proven to result in the exon 44 skipping and premature translation termination by cDNA sequencing and immunohistochemistry. Compound heterozygous mutations were identified among the other three children, including another novel splice-site variant (c.10764+1 (IVS66) G>A) causing the retention of first 4 nucleotides in intron 66 by minigene assay, two unreported missense mutations (c.4907G>A (p.R1636Q); c. 9095 A>G (p.Y3032C)), and two reported missense mutations in China (c.8938G>A (p.D2980N); c. 9287T>C (p.L3096P)), locating behind the vitamin B12-binding domain, affecting CUB11, CUB16, CUB22, CUB23, and CUB27 domains, respectively. CONCLUSION These results demonstrate that above CUBN mutations may cause non-progressive and isolated proteinuria, expanding the variant spectrum of CUBN and benefiting our understanding of proteinuria and renal function.
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Affiliation(s)
- Huihui Yang
- Department of Nephrology, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Lanfen He
- Department of Nephrology, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Hongjian Gong
- Clinical Research Center, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Chunhui Wan
- Precision Medical Center, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Juanjuan Ding
- Department of Nephrology, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Panli Liao
- Department of Nephrology, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
| | - Xiaowen Wang
- Department of Nephrology, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Center)Tongji Medical College, Huazhong University of Science & TechnologyWuhanChina
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Fujino M, Morito N, Hayashi T, Ojima M, Ishibashi S, Kuno A, Koshiba S, Yamagata K, Takahashi S. Transcription factor c-Maf deletion improves streptozotocin-induced diabetic nephropathy by directly regulating Sglt2 and Glut2. JCI Insight 2023; 8:163306. [PMID: 36787192 PMCID: PMC10070115 DOI: 10.1172/jci.insight.163306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
The transcription factor c-Maf has been widely studied and has been reported to play a critical role in embryonic kidney development; however, the postnatal functions of c-Maf in adult kidneys remain unknown as c-Maf-null C57BL/6J mice exhibit embryonic lethality. In this study, we investigated the role of c-Maf in adult mouse kidneys by comparing the phenotypes of tamoxifen-inducible (TAM-inducible) c-Maf-knockout mice (c-Maffl/fl; CAG-Cre-ERTM mice named "c-MafΔTAM") with those of c-Maffl/fl control mice, 10 days after TAM injection [TAM(10d)]. In addition, we examined the effects of c-Maf deletion on diabetic conditions by injecting the mice with streptozotocin, 4 weeks before TAM injection. c-MafΔTAM mice displayed primary glycosuria caused by sodium-glucose cotransporter 2 (Sglt2) and glucose transporter 2 (Glut2) downregulation in the kidneys without diabetes, as well as morphological changes and life-threatening injuries in the kidneys on TAM(10d). Under diabetic conditions, c-Maf deletion promoted recovery from hyperglycemia and suppressed albuminuria and diabetic nephropathy by causing similar effects as did Sglt2 knockout and SGLT2 inhibitors. In addition to demonstrating the potentially unique gene regulation of c-Maf, these findings highlight the renoprotective effects of c-Maf deficiency under diabetic conditions and suggest that c-Maf could be a novel therapeutic target gene for treating diabetic nephropathy.
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Affiliation(s)
- Mitsunori Fujino
- Department of Anatomy and Embryology, Faculty of Medicine
- PhD Program in Human Biology, School of Integrative and Global Majors
| | - Naoki Morito
- Department of Nephrology, Faculty of Medicine; and
| | - Takuto Hayashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Masami Ojima
- Department of Anatomy and Embryology, Faculty of Medicine
| | - Shun Ishibashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Akihiro Kuno
- Department of Anatomy and Embryology, Faculty of Medicine
| | - Seizo Koshiba
- Tohoku Medical Megabank Organization and
- Advanced Research Center for Innovations in Next-Generation Medicine (INGEM), Tohoku University, Sendai, Japan
| | | | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine
- Laboratory Animal Resource Center
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA)
- International Institute for Integrative Sleep Medicine (WPI-IIIS), and
- Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
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6
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Gan C, Zhou X, Chen D, Chi H, Qiu J, You H, Chen Y, Wang M, Yang H, Jiang W, Li Q. Novel pathogenic variants in CUBN uncouple proteinuria from renal function. J Transl Med 2022; 20:480. [PMID: 36266725 PMCID: PMC9583559 DOI: 10.1186/s12967-022-03706-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Proteinuria is an unfavorable clinical condition highly associated with a risk of renal and cardiovascular disease in chronic kidney disease (CKD). However, whether all proteinuria forms are linked to renal impairment are still unclear. Cubilin is an endocytic receptor highly expressed in renal proximal tubules mediating uptake of albumin, transferrin and α1-microglobulin. METHODS Exome sequencing method initially identified candidate genes. With the application of exome sequencing combined with Sanger sequencing, we further focused on CUBN through bioinformatics analysis. The pathogenic effects of the potentially causative variants were verified utilizing complementary analysis of clinical data and systematic characterization of the variants' expression and function with clinical samples and in vitro experiments in HEK293T cell lines along with in vivo experiments in mice. RESULTS In this study, we identified four novel variants locating after the vitamin B12 (vitB12)-binding domain of Cubilin (encoded by CUBN, NM_001081.3: c.4397G > A (p.C1466Y), c.6796C > T (p.R2266X), c.6821 + 3A > G and c.5153_5154delCT (p.S1718X)) in two families. Moreover, the variants severely affected the expression and function of Cubilin in renal proximal tubules and caused albuminuria, increasing levels in urine transferrin and α1-microglobulin, but without progressive glomerular filtration barrier (GFB) impairment, vitB12 deficiencies or abnormal blood levels of HDL and albumin. Further mechanistic insights showed that the variants after the vitB12-binding domain of CUBN merely disrupted the association with Amnionless (AMN) that exhibited aberrant localization in cell cytoplasm rather than membrane. CONCLUSIONS Here, our findings suggested that different mutation types after the vitB12-binding domain of CUBN uncouple proteinuria from glomerular filtration barrier, that may be an unexpectedly common benign condition in humans and may not require any proteinuria-lowering treatment or renal biopsy.
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Affiliation(s)
- Chun Gan
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Xindi Zhou
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Dan Chen
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Huan Chi
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Jiawen Qiu
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Hui You
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China
| | - Mo Wang
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Haiping Yang
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Wei Jiang
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
| | - Qiu Li
- Pediatric Research Institute, Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
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7
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Hall AM, Trepiccione F, Unwin RJ. Drug toxicity in the proximal tubule: new models, methods and mechanisms. Pediatr Nephrol 2022; 37:973-982. [PMID: 34050397 PMCID: PMC9023418 DOI: 10.1007/s00467-021-05121-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 03/23/2021] [Accepted: 05/05/2021] [Indexed: 10/28/2022]
Abstract
The proximal tubule (PT) reabsorbs most of the glomerular filtrate and plays an important role in the uptake, metabolism and excretion of xenobiotics. Some therapeutic drugs are harmful to the PT, and resulting nephrotoxicity is thought to be responsible for approximately 1 in 6 of cases of children hospitalized with acute kidney injury (AKI). Clinically, PT dysfunction leads to urinary wasting of important solutes normally reabsorbed by this nephron segment, leading to systemic complications such as bone demineralization and a clinical scenario known as the renal Fanconi syndrome (RFS). While PT defects can be diagnosed using a combination of blood and urine markers, including urinary excretion of low molecular weight proteins (LMWP), standardized definitions of what constitutes clinically significant toxicity are lacking, and identifying which patients will go on to develop progressive loss of kidney function remains a major challenge. In addition, much of our understanding of cellular mechanisms of drug toxicity is still limited, partly due to the constraints of available cell and animal models. However, advances in new and more sophisticated in vitro models of the PT, along with the application of high-content analytical methods that can provide readouts more relevant to the clinical manifestations of nephrotoxicity, are beginning to extend our knowledge. Such technical progress should help in discovering new biomarkers that can better detect nephrotoxicity earlier and predict its long-term consequences, and herald a new era of more personalized medicine.
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Affiliation(s)
- Andrew M. Hall
- grid.7400.30000 0004 1937 0650Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.412004.30000 0004 0478 9977Department of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Francesco Trepiccione
- grid.9841.40000 0001 2200 8888Department of Translational Medical Science, University of Campania ‘Luigi Vanvitelli’, Naples, Italy ,grid.428067.f0000 0004 4674 1402Biogem Research Institute, Ariano Irpino, Italy
| | - Robert J. Unwin
- grid.83440.3b0000000121901201Department of Renal Medicine, University College London, London, UK
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8
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Culver SA, Akhtar S, Rountree-Jablin C, Keller SR, Cathro HP, Gildea JJ, Siragy HM. Knockout of Nephron ATP6AP2 Impairs Proximal Tubule Function and Prevents High-Fat Diet-Induced Obesity in Male Mice. Endocrinology 2021; 162:bqab200. [PMID: 34534267 PMCID: PMC8489432 DOI: 10.1210/endocr/bqab200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Indexed: 12/24/2022]
Abstract
ATP6AP2 expression is increased in the nephron during high-fat diet (HFD) and its knockout (ATP6AP2 KO) reduces body weight (WT) in mice. We evaluated the contribution of ATP6AP2 to urinary glucose (UG) and albumin (Ualb) handling during HFD. We hypothesized that nephron ATP6AP2 KO increases UG and Ualb and minimizes HFD-induced obesity. Eight-week-old male C57BL/6J mice with inducible nephron-specific ATP6AP2 KO and noninduced controls were fed either normal diet (ND, 12% kcal fat) or HFD (45% kcal fat) for 6 months. ATP6AP2 KO mice on ND had 20% (P < 0.01) lower WT compared with controls. HFD-fed mice had 41% (P < 0.05) greater WT than ND-fed control mice. In contrast, ATP6AP2 KO abrogated the increase in WT induced by HFD by 40% (P < 0.05). Mice on HFD had less caloric intake compared with ND controls (P < 0.01). There were no significant differences in metabolic rate between all groups. UG and Ualb was significantly increased in ATP6AP2 KO mice on both ND and HFD. ATP6AP2 KO showed greater levels of proximal tubule apoptosis and histologic evidence of proximal tubule injury. In conclusion, our results demonstrate that nephron-specific ATP6AP2 KO is associated with glucosuria and albuminuria, most likely secondary to renal proximal tubule injury and/or dysfunction. Urinary loss of nutrients may have contributed to the reduced WT of knockout mice on ND and lack of WT gain in response to HFD. Future investigation should elucidate the mechanisms by which loss of renal ATP6AP2 causes proximal tubule injury and dysfunction.
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Affiliation(s)
- Silas A Culver
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Safia Akhtar
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Callie Rountree-Jablin
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Susanna R Keller
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Helen P Cathro
- Department of Pathology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - John J Gildea
- Department of Pathology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Helmy M Siragy
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA
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9
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Zhao L, Zhang J, Lei S, Ren H, Zou Y, Bai L, Zhang R, Xu H, Li L, Zhao Y, Cooper ME, Tong N, Zhang J, Liu F. Combining glomerular basement membrane and tubular basement membrane assessment improves the prediction of diabetic end-stage renal disease. J Diabetes 2021; 13:572-584. [PMID: 33352010 PMCID: PMC8246816 DOI: 10.1111/1753-0407.13150] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/17/2020] [Accepted: 12/20/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND To address the prognostic value of combining tubular basement membrane (TBM) and glomerular basement membrane (GBM) thickness in diabetic nephropathy (DN). METHODS This retrospective study enrolled 110 patients with type 2 diabetes and biopsy-proven DN from 2011 to 2018. The pathological findings were confirmed according to the Renal Pathology Society classifications. GBM and TBM thicknesses were determined using the Haas' direct measurement/arithmetic mean method and orthogonal intercept method, respectively. Cox proportional hazard models were used to investigate the hazard ratios (HRs) for the influence of combined GBM and TBM thickness for predicting end-stage renal disease (ESRD). RESULTS Patients were assigned to three groups according to the median GBM and TBM thickness: GBMlo TBMlo (GBM < 681 nm and TBM < 1200 nm), GBMhi TBMlo /GBMlo TBMhi (GBM ≥ 681 nm and TBM < 1200 nm, or GBM < 681 nm and TBM ≥ 1200 nm), and GBMhi TBMhi (GBM ≥ 681 nm and TBM ≥ 1200 nm). The GBMhi TBMlo /GBMlo TBMhi and GBMhi TBMhi groups displayed poorer renal function, a more severe glomerular classification and interstitial inflammation, and poorer renal survival rates than the GBMlo TBMlo group The GBMhi TBMlo /GBMlo TBMhi and GBMhi TBMhi groups had adjusted HRs of 1.49 (95% confidence interval [CI], 1.21-9.75) and 3.07 (95% CI, 2.87-12.78), respectively, compared with the GBMlo TBMlo group. CONCLUSIONS TBM thickness enhanced GBM thickness for renal prognosis in patients with type 2 diabetes.
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Affiliation(s)
- Lijun Zhao
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
- Division of General PracticeWest China Hospital of Sichuan UniversityChengduChina
| | - Junlin Zhang
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
| | - Song Lei
- Division of PathologyWest China Hospital of Sichuan UniversityChengduChina
| | - Honghong Ren
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
| | - Yutong Zou
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
| | - Lin Bai
- Histology and Imaging platform, Core Facility of West China HospitalChengduChina
| | - Rui Zhang
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
| | - Huan Xu
- Division of PathologyWest China Hospital of Sichuan UniversityChengduChina
| | - Lin Li
- Division of PathologyWest China Hospital of Sichuan UniversityChengduChina
| | - Yuancheng Zhao
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
| | - Mark E. Cooper
- Division of DiabetesCentral Clinical School, Monash UniversityMelbourneMelbourneAustralia
| | - Nanwei Tong
- Division of EndocrinologyWest China Hospital of Sichuan UniversityChengduChina
| | - Jie Zhang
- Histology and Imaging platform, Core Facility of West China HospitalChengduChina
| | - Fang Liu
- Division of NephrologyWest China Hospital of Sichuan UniversityChengduChina
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10
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Zhao L, Li L, Ren H, Zou Y, Zhang R, Wang S, Xu H, Zhang J, Liu F. Association between serum alkaline phosphatase and renal outcome in patients with type 2 diabetes mellitus. Ren Fail 2021; 42:818-828. [PMID: 32781868 PMCID: PMC7472471 DOI: 10.1080/0886022x.2020.1804402] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
This retrospective study included 299 patients with type 2 diabetes mellitus and biopsy-confirmed diabetic nephropathy (DN) to investigate the prognostic value of alkaline phosphatase (ALP) for renal outcome. Cox proportional hazards models were used to estimate the hazard ratios (HRs) for the serum ALP level on renal outcome, which was defined as end-stage renal disease (ESRD) or a 50% decline in estimated glomerular filtration rate (eGFR) from baseline. The median baseline ALP was 80 IU/L with an interquartile range of 64–97 IU/L. Serum ALP was negatively associated with eGFR but positively associated with proteinuria and renal interstitial fibrosis. During a median follow-up period of 23 months, ESRD or a 50% declined in the eGFR occurred in 156 (52.2%) patients. The highest quartile of ALP was significantly associated with poor renal outcome, as defined above (HR 2.38, 95% confidence interval [CI] 1.09–5.17), when adjusted for sociodemographics, baseline eGFR, proteinuria, liver function parameters, parathyroid hormone levels, and renal pathological findings. Each standard deviation higher in the natural log-transformed ALP was associated with a 25% increased risk for poor renal outcome. Additionally, there was a graded increase in the risk for poor renal outcome with higher ALP in patients with nephrotic-range proteinuria. However, no significant associations were observed between serum ALP levels and renal outcome in patients with non-nephrotic-range proteinuria. In conclusion, an elevated ALP level was independently associated with poor renal outcome in patients with type 2 diabetes mellitus and nephrotic-range proteinuria after multivariate adjustment.
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Affiliation(s)
- Lijun Zhao
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Lin Li
- Division of Pathology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Honghong Ren
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Yutong Zou
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Rui Zhang
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Shanshan Wang
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Huan Xu
- Division of Pathology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Jie Zhang
- Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, Regenerative Medicine Research Center, Chengdu, Sichuan, China
| | - Fang Liu
- Division of Nephrology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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11
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Bedin M, Boyer O, Servais A, Li Y, Villoing-Gaudé L, Tête MJ, Cambier A, Hogan J, Baudouin V, Krid S, Bensman A, Lammens F, Louillet F, Ranchin B, Vigneau C, Bouteau I, Isnard-Bagnis C, Mache CJ, Schäfer T, Pape L, Gödel M, Huber TB, Benz M, Klaus G, Hansen M, Latta K, Gribouval O, Morinière V, Tournant C, Grohmann M, Kuhn E, Wagner T, Bole-Feysot C, Jabot-Hanin F, Nitschké P, Ahluwalia TS, Köttgen A, Andersen CBF, Bergmann C, Antignac C, Simons M. Human C-terminal CUBN variants associate with chronic proteinuria and normal renal function. J Clin Invest 2020; 130:335-344. [PMID: 31613795 PMCID: PMC6934218 DOI: 10.1172/jci129937] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 10/02/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUNDProteinuria is considered an unfavorable clinical condition that accelerates renal and cardiovascular disease. However, it is not clear whether all forms of proteinuria are damaging. Mutations in CUBN cause Imerslund-Gräsbeck syndrome (IGS), which is characterized by intestinal malabsorption of vitamin B12 and in some cases proteinuria. CUBN encodes for cubilin, an intestinal and proximal tubular uptake receptor containing 27 CUB domains for ligand binding.METHODSWe used next-generation sequencing for renal disease genes to genotype cohorts of patients with suspected hereditary renal disease and chronic proteinuria. CUBN variants were analyzed using bioinformatics, structural modeling, and epidemiological methods.RESULTSWe identified 39 patients, in whom biallelic pathogenic variants in the CUBN gene were associated with chronic isolated proteinuria and early childhood onset. Since the proteinuria in these patients had a high proportion of albuminuria, glomerular diseases such as steroid-resistant nephrotic syndrome or Alport syndrome were often the primary clinical diagnosis, motivating renal biopsies and the use of proteinuria-lowering treatments. However, renal function was normal in all cases. By contrast, we did not found any biallelic CUBN variants in proteinuric patients with reduced renal function or focal segmental glomerulosclerosis. Unlike the more N-terminal IGS mutations, 37 of the 41 proteinuria-associated CUBN variants led to modifications or truncations after the vitamin B12-binding domain. Finally, we show that 4 C-terminal CUBN variants are associated with albuminuria and slightly increased GFR in meta-analyses of large population-based cohorts.CONCLUSIONCollectively, our data suggest an important role for the C-terminal half of cubilin in renal albumin reabsorption. Albuminuria due to reduced cubilin function could be an unexpectedly common benign condition in humans that may not require any proteinuria-lowering treatment or renal biopsy.FUNDINGATIP-Avenir program, Fondation Bettencourt-Schueller (Liliane Bettencourt Chair of Developmental Biology), Agence Nationale de la Recherche (ANR) Investissements d'avenir program (ANR-10-IAHU-01) and NEPHROFLY (ANR-14-ACHN-0013, to MS), Steno Collaborative Grant 2018 (NNF18OC0052457, to TSA and MS), Heisenberg Professorship of the German Research Foundation (KO 3598/5-1, to AK), Deutsche Forschungsgemeinschaft (DFG) Collaborative Research Centre (SFB) KIDGEM 1140 (project 246781735, to CB), and Federal Ministry of Education and Research (BMB) (01GM1515C, to CB).
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Affiliation(s)
| | - Olivia Boyer
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Pediatric Nephrology and
| | - Aude Servais
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Nephrology, Necker Hospital, Assistance Publique Hôpitaux de Paris (APHP), Paris, France
| | - Yong Li
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | | | - Marie-Josephe Tête
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
| | - Alexandra Cambier
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | - Julien Hogan
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | - Veronique Baudouin
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | | | | | - Florie Lammens
- Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | | | - Bruno Ranchin
- Department of Pediatric Nephrology, Hospices Civils de Lyon, Bron, France
| | - Cecile Vigneau
- Centre Hospitalier Universitaire de Rennes, INSERM U1085 IRSET-9, Rennes, France
| | - Iseline Bouteau
- Centre Hospitalier Universitaire de Poitiers, Poitiers, France
| | | | | | - Tobias Schäfer
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
| | - Lars Pape
- Department of Pediatric Kidney, Liver and Metabolic Disease, Hannover Medical School, Hannover, Germany
| | - Markus Gödel
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B. Huber
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Günter Klaus
- Department of Child and Adolescent Medicine, University Medical Center Marburg-Giessen, Marburg, Germany
| | - Matthias Hansen
- KfH-Nierenzentrum für Kinder und Jugendliche und Clementine-Kinderhospital, Frankfurt, Germany
| | - Kay Latta
- KfH-Nierenzentrum für Kinder und Jugendliche und Clementine-Kinderhospital, Frankfurt, Germany
| | - Olivier Gribouval
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
| | | | - Carole Tournant
- Department of Genetics, Necker Hospital, APHP, Paris, France
| | - Maik Grohmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
- Center for Human Genetics, Mainz, Germany
| | - Elisa Kuhn
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Timo Wagner
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Christine Bole-Feysot
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | - Fabienne Jabot-Hanin
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | - Patrick Nitschké
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | | | - Anna Köttgen
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | | | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
- Center for Human Genetics, Mainz, Germany
- Renal Division, Department of Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Corinne Antignac
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Genetics, Necker Hospital, APHP, Paris, France
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12
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Bedin M, Boyer O, Servais A, Li Y, Villoing-Gaudé L, Tête MJ, Cambier A, Hogan J, Baudouin V, Krid S, Bensman A, Lammens F, Louillet F, Ranchin B, Vigneau C, Bouteau I, Isnard-Bagnis C, Mache CJ, Schäfer T, Pape L, Gödel M, Huber TB, Benz M, Klaus G, Hansen M, Latta K, Gribouval O, Morinière V, Tournant C, Grohmann M, Kuhn E, Wagner T, Bole-Feysot C, Jabot-Hanin F, Nitschké P, Ahluwalia TS, Köttgen A, Andersen CBF, Bergmann C, Antignac C, Simons M. Human C-terminal CUBN variants associate with chronic proteinuria and normal renal function. J Clin Invest 2020. [PMID: 31613795 DOI: 10.1172/jci12937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023] Open
Abstract
BACKGROUNDProteinuria is considered an unfavorable clinical condition that accelerates renal and cardiovascular disease. However, it is not clear whether all forms of proteinuria are damaging. Mutations in CUBN cause Imerslund-Gräsbeck syndrome (IGS), which is characterized by intestinal malabsorption of vitamin B12 and in some cases proteinuria. CUBN encodes for cubilin, an intestinal and proximal tubular uptake receptor containing 27 CUB domains for ligand binding.METHODSWe used next-generation sequencing for renal disease genes to genotype cohorts of patients with suspected hereditary renal disease and chronic proteinuria. CUBN variants were analyzed using bioinformatics, structural modeling, and epidemiological methods.RESULTSWe identified 39 patients, in whom biallelic pathogenic variants in the CUBN gene were associated with chronic isolated proteinuria and early childhood onset. Since the proteinuria in these patients had a high proportion of albuminuria, glomerular diseases such as steroid-resistant nephrotic syndrome or Alport syndrome were often the primary clinical diagnosis, motivating renal biopsies and the use of proteinuria-lowering treatments. However, renal function was normal in all cases. By contrast, we did not found any biallelic CUBN variants in proteinuric patients with reduced renal function or focal segmental glomerulosclerosis. Unlike the more N-terminal IGS mutations, 37 of the 41 proteinuria-associated CUBN variants led to modifications or truncations after the vitamin B12-binding domain. Finally, we show that 4 C-terminal CUBN variants are associated with albuminuria and slightly increased GFR in meta-analyses of large population-based cohorts.CONCLUSIONCollectively, our data suggest an important role for the C-terminal half of cubilin in renal albumin reabsorption. Albuminuria due to reduced cubilin function could be an unexpectedly common benign condition in humans that may not require any proteinuria-lowering treatment or renal biopsy.FUNDINGATIP-Avenir program, Fondation Bettencourt-Schueller (Liliane Bettencourt Chair of Developmental Biology), Agence Nationale de la Recherche (ANR) Investissements d'avenir program (ANR-10-IAHU-01) and NEPHROFLY (ANR-14-ACHN-0013, to MS), Steno Collaborative Grant 2018 (NNF18OC0052457, to TSA and MS), Heisenberg Professorship of the German Research Foundation (KO 3598/5-1, to AK), Deutsche Forschungsgemeinschaft (DFG) Collaborative Research Centre (SFB) KIDGEM 1140 (project 246781735, to CB), and Federal Ministry of Education and Research (BMB) (01GM1515C, to CB).
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Affiliation(s)
| | - Olivia Boyer
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Pediatric Nephrology and
| | - Aude Servais
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Nephrology, Necker Hospital, Assistance Publique Hôpitaux de Paris (APHP), Paris, France
| | - Yong Li
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | | | - Marie-Josephe Tête
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
| | - Alexandra Cambier
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | - Julien Hogan
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | - Veronique Baudouin
- Department of Pediatric Nephrology and Transplantation, Robert-Debré Hospital, APHP, Paris, France
| | | | | | - Florie Lammens
- Centre Hospitalier Régional Universitaire de Lille, Lille, France
| | | | - Bruno Ranchin
- Department of Pediatric Nephrology, Hospices Civils de Lyon, Bron, France
| | - Cecile Vigneau
- Centre Hospitalier Universitaire de Rennes, INSERM U1085 IRSET-9, Rennes, France
| | - Iseline Bouteau
- Centre Hospitalier Universitaire de Poitiers, Poitiers, France
| | | | | | - Tobias Schäfer
- Renal Division, University Medical Center Freiburg, Freiburg, Germany
| | - Lars Pape
- Department of Pediatric Kidney, Liver and Metabolic Disease, Hannover Medical School, Hannover, Germany
| | - Markus Gödel
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Günter Klaus
- Department of Child and Adolescent Medicine, University Medical Center Marburg-Giessen, Marburg, Germany
| | - Matthias Hansen
- KfH-Nierenzentrum für Kinder und Jugendliche und Clementine-Kinderhospital, Frankfurt, Germany
| | - Kay Latta
- KfH-Nierenzentrum für Kinder und Jugendliche und Clementine-Kinderhospital, Frankfurt, Germany
| | - Olivier Gribouval
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
| | | | - Carole Tournant
- Department of Genetics, Necker Hospital, APHP, Paris, France
| | - Maik Grohmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
- Center for Human Genetics, Mainz, Germany
| | - Elisa Kuhn
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Timo Wagner
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Christine Bole-Feysot
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | - Fabienne Jabot-Hanin
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | - Patrick Nitschké
- Bioinformatic Platform, INSERM UMR 1163, Institut Imagine, Paris, France
- Bioinformatics Core Facility, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, Université de Paris, Paris, France
| | | | - Anna Köttgen
- Institute of Genetic Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | | | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
- Center for Human Genetics, Mainz, Germany
- Renal Division, Department of Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Corinne Antignac
- Laboratory of Hereditary Kidney Disease, Imagine Institute, INSERM U1163, Université de Paris, Paris, France
- Department of Genetics, Necker Hospital, APHP, Paris, France
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13
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CUBN variants uncouple proteinuria from kidney function. Nat Rev Nephrol 2019; 16:135-136. [PMID: 31836876 DOI: 10.1038/s41581-019-0242-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Ahluwalia TS, Schulz CA, Waage J, Skaaby T, Sandholm N, van Zuydam N, Charmet R, Bork-Jensen J, Almgren P, Thuesen BH, Bedin M, Brandslund I, Christensen CK, Linneberg A, Ahlqvist E, Groop PH, Hadjadj S, Tregouet DA, Jørgensen ME, Grarup N, Pedersen O, Simons M, Groop L, Orho-Melander M, McCarthy MI, Melander O, Rossing P, Kilpeläinen TO, Hansen T. A novel rare CUBN variant and three additional genes identified in Europeans with and without diabetes: results from an exome-wide association study of albuminuria. Diabetologia 2019; 62:292-305. [PMID: 30547231 PMCID: PMC6323095 DOI: 10.1007/s00125-018-4783-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/22/2018] [Indexed: 01/06/2023]
Abstract
AIMS/HYPOTHESIS Identifying rare coding variants associated with albuminuria may open new avenues for preventing chronic kidney disease and end-stage renal disease, which are highly prevalent in individuals with diabetes. Efforts to identify genetic susceptibility variants for albuminuria have so far been limited, with the majority of studies focusing on common variants. METHODS We performed an exome-wide association study to identify coding variants in a two-stage (discovery and replication) approach. Data from 33,985 individuals of European ancestry (15,872 with and 18,113 without diabetes) and 2605 Greenlanders were included. RESULTS We identified a rare (minor allele frequency [MAF]: 0.8%) missense (A1690V) variant in CUBN (rs141640975, β = 0.27, p = 1.3 × 10-11) associated with albuminuria as a continuous measure in the combined European meta-analysis. The presence of each rare allele of the variant was associated with a 6.4% increase in albuminuria. The rare CUBN variant had an effect that was three times stronger in individuals with type 2 diabetes compared with those without (pinteraction = 7.0 × 10-4, β with diabetes = 0.69, β without diabetes = 0.20) in the discovery meta-analysis. Gene-aggregate tests based on rare and common variants identified three additional genes associated with albuminuria (HES1, CDC73 and GRM5) after multiple testing correction (pBonferroni < 2.7 × 10-6). CONCLUSIONS/INTERPRETATION The current study identifies a rare coding variant in the CUBN locus and other potential genes associated with albuminuria in individuals with and without diabetes. These genes have been implicated in renal and cardiovascular dysfunction. The findings provide new insights into the genetic architecture of albuminuria and highlight target genes and pathways for the prevention of diabetes-related kidney disease.
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Affiliation(s)
- Tarunveer S Ahluwalia
- Steno Diabetes Center Copenhagen, Niels Steensens Vej 2, 2820, Gentofte, Denmark.
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Copenhagen Prospective Studies on Asthma in Childhood, Gentofte and Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
| | | | - Johannes Waage
- Copenhagen Prospective Studies on Asthma in Childhood, Gentofte and Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Tea Skaaby
- Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark
| | - Niina Sandholm
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
| | - Natalie van Zuydam
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Romain Charmet
- Inserm UMR-S 1166, Sorbonne Universités, UPMC Université Paris, Paris, France
| | - Jette Bork-Jensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Almgren
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Betina H Thuesen
- Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark
| | - Mathilda Bedin
- Paris Descartes University-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Ivan Brandslund
- Department of Clinical Immunology and Biochemistry, Lillebaelt Hospital, Vejle, Denmark
| | - Cramer K Christensen
- Department of Internal Medicine and Endocrinology, Lillebaelt Hospital, Vejle, Denmark
| | - Allan Linneberg
- Center for Clinical Research and Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark
| | - Emma Ahlqvist
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Per-Henrik Groop
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Samy Hadjadj
- L'institut du thorax, Department of Endocrinology, CIC 1413 INSERM, CHU Nantes, Nantes, France
| | | | - Marit E Jørgensen
- Steno Diabetes Center Copenhagen, Niels Steensens Vej 2, 2820, Gentofte, Denmark
- National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
| | - Niels Grarup
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matias Simons
- Paris Descartes University-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Leif Groop
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | | | - Mark I McCarthy
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Olle Melander
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Peter Rossing
- Steno Diabetes Center Copenhagen, Niels Steensens Vej 2, 2820, Gentofte, Denmark
- University of Copenhagen, Copenhagen, Denmark
| | - Tuomas O Kilpeläinen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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The Impact of the Nitric Oxide (NO)/Soluble Guanylyl Cyclase (sGC) Signaling Cascade on Kidney Health and Disease: A Preclinical Perspective. Int J Mol Sci 2018; 19:ijms19061712. [PMID: 29890734 PMCID: PMC6032334 DOI: 10.3390/ijms19061712] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/20/2022] Open
Abstract
Chronic Kidney Disease (CKD) is a highly prevalent disease with a substantial medical need for new and more efficacious treatments. The Nitric Oxide (NO), soluble guanylyl cyclase (sGC), cyclic guanosine monophosphate (cGMP) signaling cascade regulates various kidney functions. cGMP directly influences renal blood flow, renin secretion, glomerular function, and tubular exchange processes. Downregulation of NO/sGC/cGMP signaling results in severe kidney pathologies such as CKD. Therefore, treatment strategies aiming to maintain or increase cGMP might have beneficial effects for the treatment of progressive kidney diseases. Within this article, we review the NO/sGC/cGMP signaling cascade and its major pharmacological intervention sites. We specifically focus on the currently known effects of cGMP on kidney function parameters. Finally, we summarize the preclinical evidence for kidney protective effects of NO-donors, PDE inhibitors, sGC stimulators, and sGC activators.
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