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Liu XY, Song X, Czosnyka M, Robba C, Czosnyka Z, Summers JL, Yu HJ, Gao GY, Smielewski P, Guo F, Pang MJ, Ming D. Congenital hydrocephalus: a review of recent advances in genetic etiology and molecular mechanisms. Mil Med Res 2024; 11:54. [PMID: 39135208 PMCID: PMC11318184 DOI: 10.1186/s40779-024-00560-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 07/28/2024] [Indexed: 08/15/2024] Open
Abstract
The global prevalence rate for congenital hydrocephalus (CH) is approximately one out of every five hundred births with multifaceted predisposing factors at play. Genetic influences stand as a major contributor to CH pathogenesis, and epidemiological evidence suggests their involvement in up to 40% of all cases observed globally. Knowledge about an individual's genetic susceptibility can significantly improve prognostic precision while aiding clinical decision-making processes. However, the precise genetic etiology has only been pinpointed in fewer than 5% of human instances. More occurrences of CH cases are required for comprehensive gene sequencing aimed at uncovering additional potential genetic loci. A deeper comprehension of its underlying genetics may offer invaluable insights into the molecular and cellular basis of this brain disorder. This review provides a summary of pertinent genes identified through gene sequencing technologies in humans, in addition to the 4 genes currently associated with CH (two X-linked genes L1CAM and AP1S2, two autosomal recessive MPDZ and CCDC88C). Others predominantly participate in aqueduct abnormalities, ciliary movement, and nervous system development. The prospective CH-related genes revealed through animal model gene-editing techniques are further outlined, focusing mainly on 4 pathways, namely cilia synthesis and movement, ion channels and transportation, Reissner's fiber (RF) synthesis, cell apoptosis, and neurogenesis. Notably, the proper functioning of motile cilia provides significant impulsion for cerebrospinal fluid (CSF) circulation within the brain ventricles while mutations in cilia-related genes constitute a primary cause underlying this condition. So far, only a limited number of CH-associated genes have been identified in humans. The integration of genotype and phenotype for disease diagnosis represents a new trend in the medical field. Animal models provide insights into the pathogenesis of CH and contribute to our understanding of its association with related complications, such as renal cysts, scoliosis, and cardiomyopathy, as these genes may also play a role in the development of these diseases. Genes discovered in animals present potential targets for new treatments but require further validation through future human studies.
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Affiliation(s)
- Xiu-Yun Liu
- Medical School, Tianjin University, Tianjin, 300072, China
- State Key Laboratory of Advanced Medical Materials and Devices, Tianjin University, Tianjin, 300072, China
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, 300380, China
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Xin Song
- Medical School, Tianjin University, Tianjin, 300072, China
| | - Marek Czosnyka
- Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Chiara Robba
- San Martino Policlinico Hospital, IRCCS for Oncology and Neuroscience, 16132, Genoa, Italy
| | - Zofia Czosnyka
- Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Jennifer Lee Summers
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Hui-Jie Yu
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Guo-Yi Gao
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Peter Smielewski
- Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Fang Guo
- Department of Neurosurgery, Tianjin Huanhu Hospital, Tianjin, 300350, China
| | - Mei-Jun Pang
- Medical School, Tianjin University, Tianjin, 300072, China.
| | - Dong Ming
- Medical School, Tianjin University, Tianjin, 300072, China.
- State Key Laboratory of Advanced Medical Materials and Devices, Tianjin University, Tianjin, 300072, China.
- Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin, 300380, China.
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Wolf MTF, Bonsib SM, Larsen CP, Hildebrandt F. Nephronophthisis: a pathological and genetic perspective. Pediatr Nephrol 2024; 39:1977-2000. [PMID: 37930417 DOI: 10.1007/s00467-023-06174-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 11/07/2023]
Abstract
Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is one of the most frequent genetic causes for kidney failure (KF) in children and adolescents. Over 20 genes cause NPHP and over 90 genes contribute to renal ciliopathies often involving multiple organs. About 15-20% of NPHP patients have additional extrarenal symptoms affecting other organs than the kidneys. The involvement of additional organ systems in syndromic forms of NPHP is explained by shared expression of most NPHP gene products in centrosomes and primary cilia, a sensory organelle present in most mammalian cells. This finding resulted in the classification of NPHP as a ciliopathy. If extrarenal symptoms are present in addition to NPHP, these disorders are defined as NPHP-related ciliopathies (NPHP-RC) and can involve the retina (e.g., with Senior-Løken syndrome), CNS (central nervous system) (e.g., with Joubert syndrome), liver (e.g., Boichis and Arima syndromes), or bone (e.g., Mainzer-Saldino and Sensenbrenner syndromes). This review focuses on the pathological findings and the recent genetic advances in NPHP and NPHP-RC. Different mechanisms and signaling pathways are involved in NPHP ranging from planar cell polarity, sonic hedgehog signaling (Shh), DNA damage response pathway, Hippo, mTOR, and cAMP signaling. A number of therapeutic interventions appear to be promising, ranging from vasopressin receptor 2 antagonists such as tolvaptan, cyclin-dependent kinase inhibitors such as roscovitine, Hh agonists such as purmorphamine, and mTOR inhibitors such as rapamycin.
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Affiliation(s)
- Matthias T F Wolf
- Division of Pediatric Nephrology, University of Texas, Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
- Division of Pediatric Nephrology, C.S. Mott Children's Hospital, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI, 48109, USA.
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Garcia-Nieto VM, Claverie-Martin F, Moraleda-Mesa T, Perdomo-Ramírez A, Fraga-Rodríguez GM, Luis-Yanes MI, Ramos-Trujillo E. Renal diseases that course with hypomagnesemia. Comments on a new hereditary hypomagnesemic tubulopathy. Nefrologia 2024; 44:23-31. [PMID: 38350738 DOI: 10.1016/j.nefroe.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/15/2023] [Indexed: 02/15/2024] Open
Abstract
Renal diseases associated with hypomagnesemia are a complex and diverse group of tubulopathies caused by mutations in genes encoding proteins that are expressed in the thick ascending limb of the loop of Henle and in the distal convoluted tubule. In this paper, we review the initial description, the clinical expressiveness and etiology of four of the first hypomagnesemic tubulopathies described: type 3 Bartter and Gitelman diseases, Autosomal recessive hypomagnesemia with secondary hypocalcemia and Familial hypomagnesemia with hypercalciuria and nephrocalcinosis. The basic biochemical patterns observed in renal tubular hypomagnesemias and the modalities of transport and interaction that occur between the transporters involved in the reabsorption of magnesium in the distal convoluted tubule are described below. Finally, the recent report of a new renal disease with hypomagnesemia, type 2 hypomagnesemia with secondary hypocalcemia caused by reduced TRPM7 channel activity is described.
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Affiliation(s)
- Víctor M Garcia-Nieto
- Unidad de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain.
| | - Félix Claverie-Martin
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Teresa Moraleda-Mesa
- Unidad de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Ana Perdomo-Ramírez
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Gloria Mª Fraga-Rodríguez
- Nefrologia Pediàtrica, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - María Isabel Luis-Yanes
- Unidad de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain; Departamento de Medicina Física y Farmacología, Facultad de Medicina, Universidad de la Laguna, Santa Cruz de Tenerife, Spain
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Leggatt GP, Seaby EG, Veighey K, Gast C, Gilbert RD, Ennis S. A Role for Genetic Modifiers in Tubulointerstitial Kidney Diseases. Genes (Basel) 2023; 14:1582. [PMID: 37628633 PMCID: PMC10454709 DOI: 10.3390/genes14081582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
With the increased availability of genomic sequencing technologies, the molecular bases for kidney diseases such as nephronophthisis and mitochondrially inherited and autosomal-dominant tubulointerstitial kidney diseases (ADTKD) has become increasingly apparent. These tubulointerstitial kidney diseases (TKD) are monogenic diseases of the tubulointerstitium and result in interstitial fibrosis and tubular atrophy (IF/TA). However, monogenic inheritance alone does not adequately explain the highly variable onset of kidney failure and extra-renal manifestations. Phenotypes vary considerably between individuals harbouring the same pathogenic variant in the same putative monogenic gene, even within families sharing common environmental factors. While the extreme end of the disease spectrum may have dramatic syndromic manifestations typically diagnosed in childhood, many patients present a more subtle phenotype with little to differentiate them from many other common forms of non-proteinuric chronic kidney disease (CKD). This review summarises the expanding repertoire of genes underpinning TKD and their known phenotypic manifestations. Furthermore, we collate the growing evidence for a role of modifier genes and discuss the extent to which these data bridge the historical gap between apparently rare monogenic TKD and polygenic non-proteinuric CKD (excluding polycystic kidney disease).
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Affiliation(s)
- Gary P. Leggatt
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
- Wessex Kidney Centre, Queen Alexandra Hospital, Portsmouth Hospitals NHS Trust, Portsmouth PO6 3LY, UK
- Renal Department, University Hospital Southampton, Southampton SO16 6YD, UK
| | - Eleanor G. Seaby
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
| | - Kristin Veighey
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
- Renal Department, University Hospital Southampton, Southampton SO16 6YD, UK
| | - Christine Gast
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
- Wessex Kidney Centre, Queen Alexandra Hospital, Portsmouth Hospitals NHS Trust, Portsmouth PO6 3LY, UK
| | - Rodney D. Gilbert
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
- Department of Paediatric Nephrology, Southampton Children’s Hospital, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Sarah Ennis
- Human Genetics & Genomic Medicine, University of Southampton, Southampton SO16 6YD, UK; (E.G.S.); (K.V.); (C.G.); (R.D.G.); (S.E.)
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Morrison AR. Magnesium Homeostasis: Lessons from Human Genetics. Clin J Am Soc Nephrol 2023; 18:969-978. [PMID: 36723340 PMCID: PMC10356123 DOI: 10.2215/cjn.0000000000000103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 02/02/2023]
Abstract
Mg 2+ , the fourth most abundant cation in the body, serves as a cofactor for about 600 cellular enzymes. One third of ingested Mg 2+ is absorbed from the gut through a saturable transcellular process and a concentration-dependent paracellular process. Absorbed Mg 2+ is excreted by the kidney and maintains serum Mg 2+ within a narrow range of 0.7-1.25 mmol/L. The reabsorption of Mg 2+ by the nephron is characterized by paracellular transport in the proximal tubule and thick ascending limb. The nature of the transport pathways in the gut epithelia and thick ascending limb has emerged from an understanding of the molecular mechanisms responsible for rare monogenetic disorders presenting with clinical hypomagnesemia. These human disorders due to loss-of-function mutations, in concert with mouse models, have led to a deeper understanding of Mg 2+ transport in the gut and renal tubule. This review focuses on the nature of the transporters and channels revealed by human and mouse genetics and how they are integrated into an understanding of human Mg 2+ physiology.
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Affiliation(s)
- Aubrey R Morrison
- Division of Nephrology, Department of Medicine and Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
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Functional characteristics and therapeutic potential of SLC41 transporters. J Pharmacol Sci 2023; 151:88-92. [PMID: 36707183 DOI: 10.1016/j.jphs.2022.12.003] [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: 11/17/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Magnesium (Mg2+) plays an important role in various cellular functions such as protein synthesis, DNA stability, energy metabolism, enzyme and channel activities, and muscle contractility. Therefore, intracellular Mg2+ concentration is tightly regulated by multiple Mg2+ transporters and channels. So far, various candidate genes of Mg2+ transporters have been identified, and the research on their structure and function is currently in progress. The Solute Carrier 41 (SLC41) family, which is related to the bacterial Mg2+ transporter/channel MgtE, comprises three isoforms of SLC41A1, SLC41A2, and SLC41A3. Based on recent studies, SLC41A1 is thought to mediate Mg2+ influx or Na+-dependent Mg2+ efflux across the plasma membrane, whereas SLC41A2 and SLC41A3 may mediate Mg2+ fluxes across either the plasma membrane or organellar membranes. Intriguingly, SLC41A1 variants have been identified in patients with Parkinson's disease (PD) and nephronophthisis-related ciliopathies. Further genetic analyses reveal the association of SLC41A1 polymorphisms with PD risks. This review highlights the recent advances in the understanding of the molecular and functional characteristics of SLC41 family towards its therapeutic and diagnostic applications.
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Ilenwabor BP, Franken GAC, Sponder G, Bos C, Racay P, Kolisek M, Hoenderop JGJ, de Baaij JHF. SLC41A1 knockout mice display normal magnesium homeostasis. Am J Physiol Renal Physiol 2022; 323:F553-F563. [PMID: 36049064 DOI: 10.1152/ajprenal.00101.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transcellular Mg2+ reabsorption in the distal convoluted tubule (DCT) of the kidneys plays an important role in maintaining systemic Mg2+ homeostasis. SLC41A1 is a Na+/Mg2+ exchanger that mediates Mg2+ efflux from cells and is hypothesized to facilitate basolateral extrusion of Mg2+ in the DCT. In this study, we generated a SLC41A1 knockout mouse model to examine the role of SLC41A1 in Mg2+ homeostasis. Slc41a1-/- mice exhibited similar serum and urine Mg2+ levels as their wild-type littermates. Dietary restriction of Mg2+ resulted in reduced serum Mg2+ concentration and urinary Mg2+ excretion, which was similar in the wild-type and knockout groups. Expression of genes encoding Mg2+ channels and transporters such as transient receptor potential melastatin 6 (Trpm6), transient receptor potential melastatin 7 (Trpm7), cyclin and CBS domain divalent metal cation transport mediator 2 (Cnnm2), and Slc41a3 were unchanged based on genotype. We investigated the potential redundancy of SLC41A1 and its homolog SLC41A3 by generating a double knockout mouse. Although Slc41a3-/- knockout mice showed significantly reduced serum Mg2+ compared with wild-type and Slc41a1-/- knockout groups, double knockout mice displayed similar serum Mg2+ levels as Slc41a3-/- knockout mice. In conclusion, our data show that SLC41A1 is not involved in the regulation of systemic Mg2+ homeostasis in mice. Our data also demonstrate that SLC41A1 does not compensate for the loss of SLC41A3, suggesting different functions of these SLC41 proteins in vivo.NEW & NOTEWORTHY SLC41A1 has been hypothesized to mediate Mg2+ extrusion in the distal convoluted tubule and thus regulate Mg2+ homeostasis. This study investigated the role of SLC41A1 in Mg2+ homeostasis in vivo using a transgenic mouse model. Our results demonstrate that SLC41A1 is not required to maintain normal Mg2+ balance in mice. We also show that SLC41A3 is more important than SLC41A1 in regulating systemic Mg2+ levels.
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Affiliation(s)
- Barnabas P Ilenwabor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gijs A C Franken
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Freie Universität Berlin, Berlin, Germany
| | - Caro Bos
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Peter Racay
- Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University in Bratislava, Martin, Slovakia.,Biomedical Center Martin, Jessenius Faculty of Medicine, Comenius University in Bratislava, Martin, Slovakia
| | - Martin Kolisek
- Biomedical Center Martin, Jessenius Faculty of Medicine, Comenius University in Bratislava, Martin, Slovakia
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Wang D, Chen X, Wen Q, Li Z, Chen W, Chen W, Wang X. A single heterozygous nonsense mutation in the TTC21B gene causes adult-onset nephronophthisis 12: A case report and review of literature. Mol Genet Genomic Med 2022; 10:e2076. [PMID: 36263627 PMCID: PMC9747551 DOI: 10.1002/mgg3.2076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/25/2022] [Accepted: 09/30/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Nephronophthisis type 12 (NPHP 12) is a rare cilia-related cystic kidney disease, caused by TTC21B mutation, mainly involving the kidneys, which generally occurs in children. Our study aimed to illustrate its clinical, pathological and genetic characteristics by reporting an adult-onset case of NPHP 12 caused by a single heterozygous nonsense mutation of TTC21B confirmed by renal histology and whole exome sequencing and reviewing related literature with a comparative analysis of the clinical features of each case. It will further increase the recognition of this rare kidney genetic disease, which sometimes can manifest as an adult disease. RESULTS A 33-years-old man showed a chronic disease course, and he exhibited slight renal dysfunction (CKD stage 3, eGFR = 49 ml/[min* 1.73 m2]) with renal tubular proteinuria, without any extrarenal manifestations, congenital malformation history of kidney disease, or family hereditary disease. Renal histological findings showed substantial interstitial fibrosis with some irregular and tortuous tubules with complex branches and segmental thickening and splitting of the tubular basement membrane. The patient was diagnosed with chronic interstitial nephritis for an unknown reason clinically. Further genetic analysis revealed a single heterozygous nonsense mutation in the TTC21B gene and NPHP 12 was diagnosed finally. CONCLUSION A single heterozygous mutation in the TTC21B gene may cause atypical NPHP12, which had a relatively later onset and milder clinical symptoms without developmental abnormalities. Therefore, for unexplained adult-onset chronic interstitial nephritis with unusual changes of renal tubules and interstitial fibrosis, even without a clear history of hereditary kidney disease, genetic testing is still recommended. The correct diagnosis of this rare adult-onset hereditary nephropathy can avoid unnecessary treatment.
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Affiliation(s)
- Dan Wang
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
| | - Xionghui Chen
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
| | - Qiong Wen
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
| | - Zhijian Li
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
| | - Wei Chen
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
| | - Wenfang Chen
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,Department of PathologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina
| | - Xin Wang
- Department of NephrologyThe First Affiliated Hospital, Sun Yat‐sen UniversityGuangzhouChina,NHC Key Laboratory of Clinical Nephrology (Sun Yat‐sen University) and Guangdong Provincial Key Laboratory of NephrologySun Yat‐sen UniversityGuangzhouChina
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Jin F, Huang Y, Hattori M. Recent Advances in the Structural Biology of Mg 2+ Channels and Transporters. J Mol Biol 2022; 434:167729. [PMID: 35841930 DOI: 10.1016/j.jmb.2022.167729] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022]
Abstract
Magnesium ions (Mg2+) are the most abundant divalent cations in living organisms and are essential for various physiological processes, including ATP utilization and the catalytic activity of numerous enzymes. Therefore, the homeostatic mechanisms associated with cellular Mg2+ are crucial for both eukaryotic and prokaryotic organisms and are thus strictly controlled by Mg2+ channels and transporters. Technological advances in structural biology, such as the expression screening of membrane proteins, in meso phase crystallization, and recent cryo-EM techniques, have enabled the structure determination of numerous Mg2+ channels and transporters. In this review article, we provide an overview of the families of Mg2+ channels and transporters (MgtE/SLC41, TRPM6/7, CorA/Mrs2, CorC/CNNM), and discuss the structural biology prospects based on the known structures of MgtE, TRPM7, CorA and CorC.
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Affiliation(s)
- Fei Jin
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yichen Huang
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai 200438, China.
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10
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Berghaus C, Groh AC, Breljak D, Ciarimboli G, Sabolić I, Pavenstädt H, Weide T. Impact of Pals1 on Expression and Localization of Transporters Belonging to the Solute Carrier Family. Front Mol Biosci 2022; 9:792829. [PMID: 35252349 PMCID: PMC8888964 DOI: 10.3389/fmolb.2022.792829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Pals1 is part of the evolutionary conserved Crumbs polarity complex and plays a key role in two processes, the formation of apicobasal polarity and the establishment of cell-cell contacts. In the human kidney, up to 1.5 million nephrons control blood filtration, as well as resorption and recycling of inorganic and organic ions, sugars, amino acids, peptides, vitamins, water and further metabolites of endogenous and exogenous origin. All nephron segments consist of polarized cells and express high levels of Pals1. Mice that are functionally haploid for Pals1 develop a lethal phenotype, accompanied by heavy proteinuria and the formation of renal cysts. However, on a cellular level, it is still unclear if reduced cell polarization, incomplete cell-cell contact formation, or an altered Pals1-dependent gene expression accounts for the renal phenotype. To address this, we analyzed the transcriptomes of Pals1-haploinsufficient kidneys and the littermate controls by gene set enrichment analysis. Our data elucidated a direct correlation between TGFβ pathway activation and the downregulation of more than 100 members of the solute carrier (SLC) gene family. Surprisingly, Pals1-depleted nephrons keep the SLC's segment-specific expression and subcellular distribution, demonstrating that the phenotype is not mainly due to dysfunctional apicobasal cell polarization of renal epithelia. Our data may provide first hints that SLCs may act as modulating factors for renal cyst formation.
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Affiliation(s)
- Carmen Berghaus
- University Hospital of Münster (UKM), Internal Medicine D (MedD), Münster, Germany
| | - Ann-Christin Groh
- University Hospital of Münster (UKM), Internal Medicine D (MedD), Münster, Germany
| | - Davorka Breljak
- Molecular Toxicology, Institute for Medical Research and Occupational Health, Zagreb, Croatia
| | - Giuliano Ciarimboli
- University Hospital of Münster (UKM), Internal Medicine D (MedD), Münster, Germany
| | - Ivan Sabolić
- Molecular Toxicology, Institute for Medical Research and Occupational Health, Zagreb, Croatia
| | - Hermann Pavenstädt
- University Hospital of Münster (UKM), Internal Medicine D (MedD), Münster, Germany
| | - Thomas Weide
- University Hospital of Münster (UKM), Internal Medicine D (MedD), Münster, Germany
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Gupta S, Ozimek-Kulik JE, Phillips JK. Nephronophthisis-Pathobiology and Molecular Pathogenesis of a Rare Kidney Genetic Disease. Genes (Basel) 2021; 12:genes12111762. [PMID: 34828368 PMCID: PMC8623546 DOI: 10.3390/genes12111762] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 12/17/2022] Open
Abstract
The exponential rise in our understanding of the aetiology and pathophysiology of genetic cystic kidney diseases can be attributed to the identification of cystogenic genes over the last three decades. The foundation of this was laid by positional cloning strategies which gradually shifted towards next-generation sequencing (NGS) based screenings. This shift has enabled the discovery of novel cystogenic genes at an accelerated pace unlike ever before and, most notably, the past decade has seen the largest increase in identification of the genes which cause nephronophthisis (NPHP). NPHP is a monogenic autosomal recessive cystic kidney disease caused by mutations in a diverse clade of over 26 identified genes and is the most common genetic cause of renal failure in children. NPHP gene types present with some common pathophysiological features alongside a diverse range of extra-renal phenotypes associated with specific syndromic presentations. This review provides a timely update on our knowledge of this disease, including epidemiology, pathophysiology, anatomical and molecular features. We delve into the diversity of the NPHP causing genes and discuss known molecular mechanisms and biochemical pathways that may have possible points of intersection with polycystic kidney disease (the most studied renal cystic pathology). We delineate the pathologies arising from extra-renal complications and co-morbidities and their impact on quality of life. Finally, we discuss the current diagnostic and therapeutic modalities available for disease management, outlining possible avenues of research to improve the prognosis for NPHP patients.
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Affiliation(s)
- Shabarni Gupta
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (J.E.O.-K.); (J.K.P.)
- Correspondence:
| | - Justyna E. Ozimek-Kulik
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (J.E.O.-K.); (J.K.P.)
- School of Women’s and Children’s Health, University of New South Wales, Sydney, NSW 2031, Australia
- Department of Paediatric Nephrology, Sydney Children’s Hospital Network, Children’s Hospital at Westmead, Sydney, NSW 2145, Australia
| | - Jacqueline Kathleen Phillips
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (J.E.O.-K.); (J.K.P.)
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12
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Ellison DH, Maeoka Y, McCormick JA. Molecular Mechanisms of Renal Magnesium Reabsorption. J Am Soc Nephrol 2021; 32:2125-2136. [PMID: 34045316 PMCID: PMC8729834 DOI: 10.1681/asn.2021010042] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/28/2021] [Accepted: 05/01/2021] [Indexed: 02/04/2023] Open
Abstract
Magnesium is an essential cofactor in many cellular processes, and aberrations in magnesium homeostasis can have life-threatening consequences. The kidney plays a central role in maintaining serum magnesium within a narrow range (0.70-1.10 mmol/L). Along the proximal tubule and thick ascending limb, magnesium reabsorption occurs via paracellular pathways. Members of the claudin family form the magnesium pores in these segments, and also regulate magnesium reabsorption by adjusting the transepithelial voltage that drives it. Along the distal convoluted tubule transcellular reabsorption via heteromeric TRPM6/7 channels predominates, although paracellular reabsorption may also occur. In this segment, the NaCl cotransporter plays a critical role in determining transcellular magnesium reabsorption. Although the general machinery involved in renal magnesium reabsorption has been identified by studying genetic forms of magnesium imbalance, the mechanisms regulating it are poorly understood. This review discusses pathways of renal magnesium reabsorption by different segments of the nephron, emphasizing newer findings that provide insight into regulatory process, and outlining critical unanswered questions.
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Affiliation(s)
- David H. Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon,Veterans Affairs Portland Healthcare System, Portland, Oregon
| | - Yujiro Maeoka
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - James A. McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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13
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Stokman MF, Saunier S, Benmerah A. Renal Ciliopathies: Sorting Out Therapeutic Approaches for Nephronophthisis. Front Cell Dev Biol 2021; 9:653138. [PMID: 34055783 PMCID: PMC8155538 DOI: 10.3389/fcell.2021.653138] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/19/2021] [Indexed: 12/13/2022] Open
Abstract
Nephronophthisis (NPH) is an autosomal recessive ciliopathy and a major cause of end-stage renal disease in children. The main forms, juvenile and adult NPH, are characterized by tubulointerstitial fibrosis whereas the infantile form is more severe and characterized by cysts. NPH is caused by mutations in over 20 different genes, most of which encode components of the primary cilium, an organelle in which important cellular signaling pathways converge. Ciliary signal transduction plays a critical role in kidney development and tissue homeostasis, and disruption of ciliary signaling has been associated with cyst formation, epithelial cell dedifferentiation and kidney function decline. Drugs have been identified that target specific signaling pathways (for example cAMP/PKA, Hedgehog, and mTOR pathways) and rescue NPH phenotypes in in vitro and/or in vivo models. Despite identification of numerous candidate drugs in rodent models, there has been a lack of clinical trials and there is currently no therapy that halts disease progression in NPH patients. This review covers the most important findings of therapeutic approaches in NPH model systems to date, including hypothesis-driven therapies and untargeted drug screens, approached from the pathophysiology of NPH. Importantly, most animal models used in these studies represent the cystic infantile form of NPH, which is less prevalent than the juvenile form. It appears therefore important to develop new models relevant for juvenile/adult NPH. Alternative non-orthologous animal models and developments in patient-based in vitro model systems are discussed, as well as future directions in personalized therapy for NPH.
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Affiliation(s)
- Marijn F Stokman
- Department of Genetics, University Medical Center Utrecht, Utrecht, Netherlands
- Université de Paris, Imagine Institute, Laboratory of Inherited Kidney Diseases, INSERM UMR 1163, Paris, France
| | - Sophie Saunier
- Université de Paris, Imagine Institute, Laboratory of Inherited Kidney Diseases, INSERM UMR 1163, Paris, France
| | - Alexandre Benmerah
- Université de Paris, Imagine Institute, Laboratory of Inherited Kidney Diseases, INSERM UMR 1163, Paris, France
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14
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Molecular genetics of renal ciliopathies. Biochem Soc Trans 2021; 49:1205-1220. [PMID: 33960378 DOI: 10.1042/bst20200791] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/25/2022]
Abstract
Renal ciliopathies are a heterogenous group of inherited disorders leading to an array of phenotypes that include cystic kidney disease and renal interstitial fibrosis leading to progressive chronic kidney disease and end-stage kidney disease. The renal tubules are lined with epithelial cells that possess primary cilia that project into the lumen and act as sensory and signalling organelles. Mutations in genes encoding ciliary proteins involved in the structure and function of primary cilia cause ciliopathy syndromes and affect many organ systems including the kidney. Recognised disease phenotypes associated with primary ciliopathies that have a strong renal component include autosomal dominant and recessive polycystic kidney disease and their various mimics, including atypical polycystic kidney disease and nephronophthisis. The molecular investigation of inherited renal ciliopathies often allows a precise diagnosis to be reached where renal histology and other investigations have been unhelpful and can help in determining kidney prognosis. With increasing molecular insights, it is now apparent that renal ciliopathies form a continuum of clinical phenotypes with disease entities that have been classically described as dominant or recessive at both extremes of the spectrum. Gene-dosage effects, hypomorphic alleles, modifier genes and digenic inheritance further contribute to the genetic complexity of these disorders. This review will focus on recent molecular genetic advances in the renal ciliopathy field with a focus on cystic kidney disease phenotypes and the genotypes that lead to them. We discuss recent novel insights into underlying disease mechanisms of renal ciliopathies that might be amenable to therapeutic intervention.
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15
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Jin F, Sun M, Fujii T, Yamada Y, Wang J, Maturana AD, Wada M, Su S, Ma J, Takeda H, Kusakizako T, Tomita A, Nakada-Nakura Y, Liu K, Uemura T, Nomura Y, Nomura N, Ito K, Nureki O, Namba K, Iwata S, Yu Y, Hattori M. The structure of MgtE in the absence of magnesium provides new insights into channel gating. PLoS Biol 2021; 19:e3001231. [PMID: 33905418 PMCID: PMC8104411 DOI: 10.1371/journal.pbio.3001231] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 05/07/2021] [Accepted: 04/12/2021] [Indexed: 12/15/2022] Open
Abstract
MgtE is a Mg2+ channel conserved in organisms ranging from prokaryotes to eukaryotes, including humans, and plays an important role in Mg2+ homeostasis. The previously determined MgtE structures in the Mg2+-bound, closed-state, and structure-based functional analyses of MgtE revealed that the binding of Mg2+ ions to the MgtE cytoplasmic domain induces channel inactivation to maintain Mg2+ homeostasis. There are no structures of the transmembrane (TM) domain for MgtE in Mg2+-free conditions, and the pore-opening mechanism has thus remained unclear. Here, we determined the cryo-electron microscopy (cryo-EM) structure of the MgtE-Fab complex in the absence of Mg2+ ions. The Mg2+-free MgtE TM domain structure and its comparison with the Mg2+-bound, closed-state structure, together with functional analyses, showed the Mg2+-dependent pore opening of MgtE on the cytoplasmic side and revealed the kink motions of the TM2 and TM5 helices at the glycine residues, which are important for channel activity. Overall, our work provides structure-based mechanistic insights into the channel gating of MgtE.
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Affiliation(s)
- Fei Jin
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
| | - Minxuan Sun
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
| | - Takashi Fujii
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
- Riken Quantitative Biology Center, Osaka, Japan
| | - Yurika Yamada
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Andrés D. Maturana
- Department of Bioengineering Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Miki Wada
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Shichen Su
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute for Complex Systems, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Multiscale Research Institute for Complex Systems, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Hironori Takeda
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Tsukasa Kusakizako
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Atsuhiro Tomita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yoshiko Nakada-Nakura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kehong Liu
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Tomoko Uemura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yayoi Nomura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Norimichi Nomura
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Koichi Ito
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
- Riken Quantitative Biology Center, Osaka, Japan
| | - So Iwata
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- RIKEN SPring-8 Center, Kouto, Hyogo, Japan
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
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16
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Olde Hanhof CJA, Yousef Yengej FA, Rookmaaker MB, Verhaar MC, van der Wijst J, Hoenderop JG. Modeling Distal Convoluted Tubule (Patho)Physiology: An Overview of Past Developments and an Outlook Toward the Future. Tissue Eng Part C Methods 2021; 27:200-212. [PMID: 33544049 DOI: 10.1089/ten.tec.2020.0345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The kidneys are essential for maintaining electrolyte homeostasis. Blood electrolyte composition is controlled by active reabsorption and secretion processes in dedicated segments of the kidney tubule. Specifically, the distal convoluted tubule (DCT) and connecting tubule are important for regulating the final excretion of sodium, magnesium, and calcium. Studies unravelling the specific function of these segments have greatly improved our understanding of DCT (patho)physiology. Over the years, experimental models used to study the DCT have changed and the field has advanced from early dissection studies with rats and rabbits to the use of various transgenic mouse models. Developments in dissection techniques and cell culture methods have resulted in immortalized mouse DCT cell lines and made it possible to specifically obtain DCT fragments for ex vivo studies. However, we still do not fully understand the complex (patho)physiology of this segment and there is need for advanced human DCT models. Recently, kidney organoids and tubuloids have emerged as new complex cell models that provide excellent opportunities for physiological studies, disease modeling, drug discovery, and even personalized medicine in the future. This review presents an overview of cell models used to study the DCT and provides an outlook on kidney organoids and tubuloids as model for DCT (patho)physiology. Impact statement This study provides a detailed overview of past and future developments on cell models used to study kidney (patho)physiology and specifically the distal convoluted tubule (DCT) segment. Hereby, we highlight the need for an advanced human cell model of this segment and summarize recent advances in the field of kidney organoids and tubuloids with a focus on DCT properties. The findings reported in this review are significant for future developments toward an advanced human model of the DCT that will help to increase our understanding of DCT (patho)physiology.
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Affiliation(s)
- Charlotte J A Olde Hanhof
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Fjodor A Yousef Yengej
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, Utrecht, The Netherlands.,Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten B Rookmaaker
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marianne C Verhaar
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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17
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Franken GAC, Adella A, Bindels RJM, de Baaij JHF. Mechanisms coupling sodium and magnesium reabsorption in the distal convoluted tubule of the kidney. Acta Physiol (Oxf) 2021; 231:e13528. [PMID: 32603001 PMCID: PMC7816272 DOI: 10.1111/apha.13528] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023]
Abstract
Hypomagnesaemia is a common feature of renal Na+ wasting disorders such as Gitelman and EAST/SeSAME syndrome. These genetic defects specifically affect Na+ reabsorption in the distal convoluted tubule, where Mg2+ reabsorption is tightly regulated. Apical uptake via TRPM6 Mg2+ channels and basolateral Mg2+ extrusion via a putative Na+ -Mg2+ exchanger determines Mg2+ reabsorption in the distal convoluted tubule. However, the mechanisms that explain the high incidence of hypomagnesaemia in patients with Na+ wasting disorders of the distal convoluted tubule are largely unknown. In this review, we describe three potential mechanisms by which Mg2+ reabsorption in the distal convoluted tubule is linked to Na+ reabsorption. First, decreased activity of the thiazide-sensitive Na+ /Cl- cotransporter (NCC) results in shortening of the segment, reducing the Mg2+ reabsorption capacity. Second, the activity of TRPM6 and NCC are determined by common regulatory pathways. Secondary effects of NCC dysregulation such as hormonal imbalance, therefore, might disturb TRPM6 expression. Third, the basolateral membrane potential, maintained by the K+ permeability and Na+ -K+ -ATPase activity, provides the driving force for Na+ and Mg2+ extrusion. Depolarisation of the basolateral membrane potential in Na+ wasting disorders of the distal convoluted tubule may therefore lead to reduced activity of the putative Na+ -Mg2+ exchanger SLC41A1. Elucidating the interconnections between Mg2+ and Na+ transport in the distal convoluted tubule is hampered by the currently available models. Our analysis indicates that the coupling of Na+ and Mg2+ reabsorption may be multifactorial and that advanced experimental models are required to study the molecular mechanisms.
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Affiliation(s)
- Gijs A. C. Franken
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - Anastasia Adella
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - René J. M. Bindels
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
| | - Jeroen H. F. de Baaij
- Department of PhysiologyRadboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands
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18
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Maeoka Y, McCormick JA. NaCl cotransporter activity and Mg 2+ handling by the distal convoluted tubule. Am J Physiol Renal Physiol 2020; 319:F1043-F1053. [PMID: 33135481 DOI: 10.1152/ajprenal.00463.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The genetic disease Gitelman syndrome, knockout mice, and pharmacological blockade with thiazide diuretics have revealed that reduced activity of the NaCl cotransporter (NCC) promotes renal Mg2+ wasting. NCC is expressed along the distal convoluted tubule (DCT), and its activity determines Mg2+ entry into DCT cells through transient receptor potential channel subfamily M member 6 (TRPM6). Several other genetic forms of hypomagnesemia lower the drive for Mg2+ entry by inhibiting activity of basolateral Na+-K+-ATPase, and reduced NCC activity may do the same. Lower intracellular Mg2+ may promote further Mg2+ loss by directly decreasing activity of Na+-K+-ATPase. Lower intracellular Mg2+ may also lower Na+-K+-ATPase indirectly by downregulating NCC. Lower NCC activity also induces atrophy of DCT cells, decreasing the available number of TRPM6 channels. Conversely, a mouse model with increased NCC activity was recently shown to display normal Mg2+ handling. Moreover, recent studies have identified calcineurin and uromodulin (UMOD) as regulators of both NCC and Mg2+ handling by the DCT. Calcineurin inhibitors paradoxically cause hypomagnesemia in a state of NCC activation, but this may be related to direct effects on TRPM6 gene expression. In Umod-/- mice, the cause of hypomagnesemia may be partly due to both decreased NCC expression and lower TRPM6 expression on the cell surface. This mini-review discusses these new findings and the possible role of altered Na+ flux through NCC and ultimately Na+-K+-ATPase in Mg2+ reabsorption by the DCT.
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Affiliation(s)
- Yujiro Maeoka
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
| | - James A McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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19
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Mellott A, Rockwood J, Zhelay T, Luu CT, Kaitsuka T, Kozak JA. TRPM7 channel activity in Jurkat T lymphocytes during magnesium depletion and loading: implications for divalent metal entry and cytotoxicity. Pflugers Arch 2020; 472:1589-1606. [PMID: 32964285 DOI: 10.1007/s00424-020-02457-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/14/2022]
Abstract
TRPM7 is a cation channel-protein kinase highly expressed in T lymphocytes and other immune cells. It has been proposed to constitute a cellular entry pathway for Mg2+ and divalent metal cations such as Ca2+, Zn2+, Cd2+, Mn2+, and Ni2+. TRPM7 channels are inhibited by cytosolic Mg2+, rendering them largely inactive in intact cells. The dependence of channel activity on extracellular Mg2+ is less well studied. Here, we measured native TRPM7 channel activity in Jurkat T cells maintained in external Mg2+ concentrations varying between 400 nM and 1.4 mM for 1-3 days, obtaining an IC50 value of 54 μM. Maintaining the cells in 400 nM or 8 μM [Mg2+]o resulted in almost complete activation of TRPM7 in intact cells, due to cytosolic Mg2+ depletion. A total of 1.4 mM [Mg2+]o was sufficient to fully eliminate the basal current. Submillimolar concentrations of amiloride prevented cellular Mg2+ depletion but not loading. We investigated whether the cytotoxicity of TRPM7 permeant metal ions Ni2+, Zn2+, Cd2+, Co2+, Mn2+, Sr2+, and Ba2+ requires TRPM7 channel activity. Mg2+ loading modestly reduced cytotoxicity of Zn2+, Co2+, Ni2+, and Mn2+ but not of Cd2+. Channel blocker NS8593 reduced Co2+ and Mn2+ but not Cd2+ or Zn2+ cytotoxicity and interfered with Mg2+ loading as evaluated by TRPM7 channel basal activity. Ba2+ and Sr2+ were neither detectably toxic nor permeant through the plasma membrane. These results indicate that in Jurkat T cells, entry of toxic divalent metal cations primarily occurs through pathways distinct from TRPM7. By contrast, we found evidence that Mg2+ entry requires TRPM7 channels.
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Affiliation(s)
- Alayna Mellott
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Jananie Rockwood
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Charles Tuan Luu
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Taku Kaitsuka
- School of Pharmacy in Fukuoka, International University of Health and Welfare, Enokizu 137-1, Okawa, Fukuoka, Japan
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA.
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20
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Xie J, Cheng CS, Zhu XY, Shen YH, Song LB, Chen H, Chen Z, Liu LM, Meng ZQ. Magnesium transporter protein solute carrier family 41 member 1 suppresses human pancreatic ductal adenocarcinoma through magnesium-dependent Akt/mTOR inhibition and bax-associated mitochondrial apoptosis. Aging (Albany NY) 2020; 11:2681-2698. [PMID: 31076559 PMCID: PMC6535063 DOI: 10.18632/aging.101940] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/24/2019] [Indexed: 01/26/2023]
Abstract
The aim of this study was to identify the function of the Mg2+ transporter protein solute carrier family 41 member 1 SLC41A1 in pancreatic ductal adenocarcinoma and the underlying mechanisms. A total of 27 solute carrier proteins were differentially expressed in pancreatic ductal adenocarcinoma. Three of these proteins were correlated with clinical outcomes in patients, among which SLC41A1 was downregulated in tumour. Overexpression of SLC41A1 suppressed orthotopic tumour growth in a mouse model and reduced the cell proliferation, colony formation, and invasiveness of KP3 and Panc-1 cells, which may have been associated with the increased population of apoptotic-prone cells. Overexpression of SLC41A1 reduced the mitochondrial membrane potential, induced Bax while suppressed Bcl-2 expression. Suppression of Bax abrogated the tumour-suppressive effects of SLC41A1. Furthermore, overexpression of SLC41A1 promoted Mg2+ efflux and suppressed Akt/mTOR activity, which is the upstream regulator of Bax and Bcl-2. An increase in Akt activity and supplementation with Mg2+ abolished SLC41A1-induced tumour suppression. The results of this study suggest that SLC41A1 may be a potential target for the treatment of pancreatic ductal adenocarcinoma.
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Affiliation(s)
- Jing Xie
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Chien-Shan Cheng
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Xiao Yan Zhu
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Ye Hua Shen
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Li Bin Song
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Hao Chen
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Zhen Chen
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Lu Ming Liu
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
| | - Zhi Qiang Meng
- Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, P. R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P. R. China
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21
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Sanchez-Mut JV, Glauser L, Monk D, Gräff J. Comprehensive analysis of PM20D1 QTL in Alzheimer's disease. Clin Epigenetics 2020; 12:20. [PMID: 32014019 PMCID: PMC6998837 DOI: 10.1186/s13148-020-0814-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 01/15/2020] [Indexed: 12/21/2022] Open
Abstract
Background Alzheimer’s disease (AD) is a complex disorder caused by a combination of genetic and non-genetic risk factors. In addition, an increasing evidence suggests that epigenetic mechanisms also accompany AD. Genetic and epigenetic factors are not independent, but multiple loci show genetic-epigenetic interactions, the so-called quantitative trait loci (QTLs). Recently, we identified the first QTL association with AD, namely Peptidase M20 Domain Containing 1 (PM20D1). We observed that PM20D1 DNA methylation, RNA expression, and genetic background are correlated and, in turn, associated with AD. We provided mechanistic insights for these correlations and had shown that by genetically increasing and decreasing PM20D1 levels, AD-related pathologies were decreased and accelerated, respectively. However, since the PM20D1 QTL region encompasses also other genes, namely Nuclear Casein Kinase and Cyclin Dependent Kinase Substrate 1 (NUCKS1); RAB7, member RAS oncogene family-like 1 (RAB7L1); and Solute Carrier Family 41 Member 1 (SLC41A1), we investigated whether these genes might also contribute to the described AD association. Results Here, we report a comprehensive analysis of these QTL genes using a repertoire of in silico methods as well as in vivo and in vitro experimental approaches. First, we analyzed publicly available databases to pinpoint the major QTL correlations. Then, we validated these correlations using a well-characterized set of samples and locus-specific approaches—i.e., Sanger sequencing for the genotype, cloning/sequencing and pyrosequencing for the DNA methylation, and allele-specific and real-time PCR for the RNA expression. Finally, we defined the functional relevance of the observed alterations in the context of AD in vitro. Using this approach, we show that only PM20D1 DNA methylation and expression are significantly correlated with the AD-risk associated background. We find that the expression of SLC41A1 and PM20D1—but not NUCKS1 and RAB7L1—is increased in mouse models and human samples of AD, respectively. However, SLC41A1 and PM20D1 are differentially regulated by AD-related stressors, with only PM20D1 being upregulated by amyloid-β and reactive oxygen species, and with only PM20D1 being neuroprotective when overexpressed in cell and primary cultures. Conclusions Our findings reinforce PM20D1 as the most likely gene responsible of the previously reported PM20D1 QTL association with AD.
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Affiliation(s)
- Jose Vicente Sanchez-Mut
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
| | - Liliane Glauser
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - David Monk
- Genomic Imprinting Cancer Group, Institut d'Investigació Biomedica de Bellvitge, E-08908, Barcelona, Spain.,Biomedical Research Centre, School of Biological Sciences, University of East Anglia, NR4 7TJ, Norwich, UK
| | - Johannes Gräff
- Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
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22
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Swimming with the fishes: delineating tubular transport pathways for magnesium. Pflugers Arch 2019; 471:817-818. [DOI: 10.1007/s00424-019-02286-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 05/16/2019] [Indexed: 10/26/2022]
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23
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Arjona FJ, Latta F, Mohammed SG, Thomassen M, van Wijk E, Bindels RJM, Hoenderop JGJ, de Baaij JHF. SLC41A1 is essential for magnesium homeostasis in vivo. Pflugers Arch 2019; 471:845-860. [PMID: 30417250 PMCID: PMC6533229 DOI: 10.1007/s00424-018-2234-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/01/2018] [Accepted: 11/04/2018] [Indexed: 01/19/2023]
Abstract
Solute carrier family 41 member A1 (SLC41A1) has been suggested to mediate magnesium (Mg2+) transport by several in vitro studies. However, the physiological function of SLC41A1 remains to be elucidated. In this study, cellular Mg2+ transport assays combined with zebrafish slc41a1 knockdown experiments were performed to disclose SLC41A1 function and its physiological relevance. The gene slc41a1 is ubiquitously expressed in zebrafish tissues and is regulated by water and dietary Mg2+ availability. Knockdown of slc41a1 in zebrafish larvae grown in a Mg2+-free medium resulted in a unique phenotype characterized by a decrease in zebrafish Mg content. This decrease shows that SLC41A1 is required to maintain Mg2+ balance and its dysfunction results in renal Mg2+ wasting in zebrafish larvae. Importantly, the Mg content of the larvae is rescued when mouse SLC41A1 is expressed in slc41a1-knockdown zebrafish. Conversely, expression of mammalian SLC41A1-p.Asp262Ala, harboring a mutation in the ion-conducting SLC41A1 pore, did not reverse the renal Mg2+ wasting. 25Mg2+ transport assays in human embryonic kidney 293 (HEK293) cells overexpressing SLC41A1 demonstrated that SLC41A1 mediates cellular Mg2+ extrusion independently of sodium (Na+). In contrast, SLC41A1-p.Asp262Ala expressing HEK293 cells displayed similar Mg2+ extrusion activities than control (mock) cells. In polarized Madin-Darby canine kidney cells, SLC41A1 localized to the basolateral cell membrane. Our results demonstrate that SLC41A1 facilitates renal Mg2+ reabsorption in the zebrafish model. Furthermore, our data suggest that SLC41A1 mediates both Mg2+ uptake and extrusion.
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Affiliation(s)
- Francisco J Arjona
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Femke Latta
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sami G Mohammed
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michael Thomassen
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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24
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Treadwell R, de Moliner F, Subiros-Funosas R, Hurd T, Knox K, Vendrell M. A fluorescent activatable probe for imaging intracellular Mg 2+ . Org Biomol Chem 2019; 16:239-244. [PMID: 29256562 PMCID: PMC5789582 DOI: 10.1039/c7ob02965a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An BODIPY probe for detection and imaging of Mg2+ without interference from Ca2+ is described.
An activatable BODIPY probe for in vitro detection and fluorescence cell imaging of free Mg2+ without interference from Ca2+ is described. Fluorescence amplification of the probe is observed upon detection of physiological concentrations of Mg2+ due to reduced rotation of the fluorophore and effective chelation by a quinolizine-based core.
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Affiliation(s)
- Ryan Treadwell
- Medical Research Council Centre for Inflammation Research, The University of Edinburgh, EH16 4TJ Edinburgh, UK.
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25
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Luo F, Tao YH. Nephronophthisis: A review of genotype-phenotype correlation. Nephrology (Carlton) 2018; 23:904-911. [PMID: 29717526 PMCID: PMC6175366 DOI: 10.1111/nep.13393] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2018] [Indexed: 12/13/2022]
Abstract
Nephronophthisis is an autosomal recessive cystic kidney disease and one of the most common genetic disorders causing end‐stage renal disease in children. Nephronophthisis is a genetically heterogenous disorder with more than 25 identified genes. In 10%–20% of cases, there are additional features of a ciliopathy syndrome, such as retinal defects, liver fibrosis, skeletal abnormalities, and brain developmental disorders. This review provides an update of the recent advances in the clinical features and related gene mutations of nephronophthisis, and novel approaches for therapy in nephronophthisis patients may be needed. Nephronophthisis (NPHP) is a renal ciliopathy affecting children and young adults. This review gives an update on the recent advances in the clinical features and related gene mutations of NPHP.
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Affiliation(s)
- Fenglan Luo
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Sichuan, Chengdu, China.,Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry Education, West China Second University Hospital, Sichuan University, Sichuan, Chengdu, China
| | - Yu-Hong Tao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Sichuan, Chengdu, China
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26
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Schäffers OJM, Hoenderop JGJ, Bindels RJM, de Baaij JHF. The rise and fall of novel renal magnesium transporters. Am J Physiol Renal Physiol 2018; 314:F1027-F1033. [DOI: 10.1152/ajprenal.00634.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Body Mg2+ balance is finely regulated in the distal convoluted tubule (DCT), where a tight interplay among transcellular reabsorption, mitochondrial exchange, and basolateral extrusion takes place. In the last decades, several research groups have aimed to identify the molecular players in these processes. A multitude of proteins have been proposed to function as Mg2+ transporter in eukaryotes based on phylogenetic analysis, differential gene expression, and overexpression studies. However, functional evidence for many of these proteins is lacking. The aim of this review is, therefore, to critically reconsider all putative Mg2+ transporters and put their presumed function in context of the renal handling of Mg2+. Sufficient experimental evidence exists to acknowledge transient receptor potential melastatin (TRPM) 6 and TRPM7, solute carrier family 41 (SLC41) A1 and SLC41A3, and mitochondrial RNA splicing 2 (MRS2) as Mg2+ transporters. TRPM6/7 facilitate Mg2+ influx, SLC41A1 mediates Mg2+ extrusion, and MRS2 and SLC41A3 are implicated in mitochondrial Mg2+ homeostasis. These proteins are highly expressed in the DCT. The function of cyclin M (CNNM) proteins is still under debate. For the other proposed Mg2+ transporters including Mg2+ transporter subtype 1 (MagT1), nonimprinted in Prader-Willi/Angelman syndrome (NIPA), membrane Mg2+ transport (MMgT), Huntingtin-interacting protein 14 (HIP14), and ATP13A4, functional evidence is limited, or functions alternative to Mg2+ transport have been suggested. Additional characterization of their Mg2+ transport proficiency should be provided before further claims about their role as Mg2+ transporter can be made.
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Affiliation(s)
- Olivier J. M. Schäffers
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G. J. Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J. M. Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen H. F. de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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27
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Gulati A, Somlo S. Whole exome sequencing: a state-of-the-art approach for defining (and exploring!) genetic landscapes in pediatric nephrology. Pediatr Nephrol 2018; 33:745-761. [PMID: 28660367 DOI: 10.1007/s00467-017-3698-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/04/2017] [Accepted: 05/09/2017] [Indexed: 12/30/2022]
Abstract
The genesis of whole exome sequencing as a powerful tool for detailing the protein coding sequence of the human genome was conceptualized based on the availability of next-generation sequencing technology and knowledge of the human reference genome. The field of pediatric nephrology enriched with molecularly unsolved phenotypes is allowing the clinical and research application of whole exome sequencing to enable novel gene discovery and provide amendment of phenotypic misclassification. Recent studies in the field have informed us that newer high-throughput sequencing techniques are likely to be of high yield when applied in conjunction with conventional genomic approaches such as linkage analysis and other strategies used to focus subsequent analysis. They have also emphasized the need for the validation of novel genetic findings in large collaborative cohorts and the production of robust corroborative biological data. The well-structured application of comprehensive genomic testing in clinical and research arenas will hopefully continue to advance patient care and precision medicine, but does call for attention to be paid to its integrated challenges.
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Affiliation(s)
- Ashima Gulati
- Division of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA.
| | - Stefan Somlo
- Departments of Internal Medicine and Genetics, Yale University School of Medicine, New Haven, CT, USA
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28
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Tutakhel OAZ, Bianchi F, Smits DA, Bindels RJM, Hoenderop JGJ, van der Wijst J. Dominant functional role of the novel phosphorylation site S811 in the human renal NaCl cotransporter. FASEB J 2018; 32:4482-4493. [PMID: 29547703 DOI: 10.1096/fj.201701047r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The NaCl cotransporter (NCC) is essential for electrolyte homeostasis and control of blood pressure. The human SLC12A3 gene, which encodes NCC, gives rise to 3 isoforms, of which only the shortest isoform [NaCl cotransporter isoform 3 (NCC3)] has been studied extensively. All NCC isoforms share key phosphorylation sites at T55 and T60 that are essential mediators of NCC function. Recently, a novel phosphorylation site at S811 was identified in isoforms 1 and 2 [NaCl cotransporter splice variant (NCCSV)], which are only present in humans and higher primates. The aim of the current study, therefore, is to investigate the role of S811 phosphorylation in the regulation of NCC by a combination of biochemical and fluorescent microscopy analyses. We demonstrate that hypotonic low-chloride buffer increases S811 phosphorylation, whereas phosphorylation-deficient S811A mutant hinders phosphorylation at T55 and T60 in NCCSV and NCC3. NCCSV S811A impairs NCC3 activity in a dominant-negative fashion, although it does not affect plasma membrane abundance. This effect may be explained by the heterodimerization of NCCSV with NCC3. Taken together, our study highlights the dominant-negative effect of NCCSV on T55 and T60 phosphorylation and NCC activity. Here, we reveal a new function of NCCSV in humans that broadens the understanding on NCC regulation in blood pressure control.-Tutakhel, O. A. Z., Bianchi, F., Smits, D. A., Bindels, R. J. M., Hoenderop, J. G. J., van der Wijst, J. Dominant functional role of the novel phosphorylation site S811 in the human renal NaCl cotransporter.
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Affiliation(s)
- Omar A Z Tutakhel
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans Bianchi
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Daniël A Smits
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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29
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Giménez-Mascarell P, Schirrmacher CE, Martínez-Cruz LA, Müller D. Novel Aspects of Renal Magnesium Homeostasis. Front Pediatr 2018; 6:77. [PMID: 29686978 PMCID: PMC5900390 DOI: 10.3389/fped.2018.00077] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/13/2018] [Indexed: 12/29/2022] Open
Abstract
Magnesium (Mg2+) is indispensable for several vital functions, such as neurotransmission, cardiac conductance, blood glucose, blood pressure regulation, and proper function of more than 300 enzymes. Thus, Mg2+ homeostasis is subject to tight regulation. Besides the fast and immediate regulation of plasma Mg2+, a major part of Mg2+ homeostasis is realized by a concerted action of epithelial molecular structures that tightly control intestinal uptake and renal absorption. This mechanism is provided by a combination of para- and transcellular pathways. Whereas the first pathway provides the organism with a maximal amount of vital substances by a minimal energy expenditure, the latter enables controlling and fine-tuning by means of local and regional regulatory systems and also, hormonal control. The paracellular pathway is driven by an electrochemical gradient and realized in principal by the tight junction (TJ), a supramolecular organization of membrane-bound proteins and their adaptor and scaffolding proteins. TJ determinants are claudins (CLDN), a family of membrane spanning proteins that generate a barrier or a pore between two adjacent epithelial cells. Many insights into molecular mechanisms of Mg2+ handling have been achieved by the identification of alterations and mutations in human genes which cause disorders of paracellular Mg2+ pathways (CLDN10, CLDN14, CLDN16, CLDN19). Also, in the distal convoluted tubule, a basolateral protein, CNNM2, causes if mutated, familial dominant and also recessive renal Mg2+ wasting, albeit its true function has not been clarified yet, but is assumed to play a key role in the transcellular pathway. Moreover, mutations in human genes that are involved in regulating these proteins directly or indirectly cause, if mutated human diseases, mostly in combination with comorbidities as diabetes, cystic renal disease, or metabolic abnormalities. Generation and characterization of animal models harboring the corresponding mutations have further contributed to the elucidation of physiology and pathophysiology of Mg2+ disorders. Finally, high-end crystallization techniques allow understanding of Mg2+ handling in more detail. As this field is rapidly growing, we describe here the principles of physiology and pathophysiology of epithelial transport of renal Mg2+ homeostasis with emphasis on recently identified mechanisms involved.
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Affiliation(s)
| | - Carlotta Else Schirrmacher
- Department of Pediatric Gastroenterology, Nephrology and Metabolism, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Dominik Müller
- Department of Pediatric Gastroenterology, Nephrology and Metabolism, Charité - Universitätsmedizin Berlin, Berlin, Germany
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30
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Magnesium Extravaganza: A Critical Compendium of Current Research into Cellular Mg 2+ Transporters Other than TRPM6/7. Rev Physiol Biochem Pharmacol 2018; 176:65-105. [PMID: 30406297 DOI: 10.1007/112_2018_15] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Magnesium research has boomed within the last 20 years. The real breakthrough came at the start of the new millennium with the discovery of a plethora of possible Mg homeostatic factors that, in particular, included putative Mg2+ transporters. Until that point, Mg research was limited to biochemical and physiological work, as no target molecular entities were known that could be used to explore the molecular biology of Mg homeostasis at the level of the cell, tissue, organ, or organism and to translate such knowledge into the field of clinical medicine and pharmacology. Because of the aforementioned, Mg2+ and Mg homeostasis, both of which had been heavily marginalized within the biomedical field in the twentieth century, have become overnight a focal point of many studies ranging from primary biomedical research to translational medicine.The amount of literature concerning cellular Mg2+ transport and cellular Mg homeostasis is increasing, together with a certain amount of confusion, especially about the function(s) of the newly discovered and, in the majority of instances, still only putative Mg2+ transporters/Mg2+ homeostatic factors. Newcomers to the field of Mg research will thus find it particularly difficult to orient themselves.Here, we briefly but critically summarize the status quo of the current understanding of the molecular entities behind cellular Mg2+ homeostasis in mammalian/human cells other than TRPM6/7 chanzymes, which have been universally accepted as being unspecific cation channel kinases allowing the flux of Mg2+ while constituting the major gateway for Mg2+ to enter the cell.
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31
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Tomita A, Zhang M, Jin F, Zhuang W, Takeda H, Maruyama T, Osawa M, Hashimoto KI, Kawasaki H, Ito K, Dohmae N, Ishitani R, Shimada I, Yan Z, Hattori M, Nureki O. ATP-dependent modulation of MgtE in Mg 2+ homeostasis. Nat Commun 2017; 8:148. [PMID: 28747715 PMCID: PMC5529423 DOI: 10.1038/s41467-017-00082-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 05/26/2017] [Indexed: 11/09/2022] Open
Abstract
Magnesium is an essential ion for numerous physiological processes. MgtE is a Mg2+ selective channel involved in the maintenance of intracellular Mg2+ homeostasis, whose gating is regulated by intracellular Mg2+ levels. Here, we report that ATP binds to MgtE, regulating its Mg2+-dependent gating. Crystal structures of MgtE–ATP complex show that ATP binds to the intracellular CBS domain of MgtE. Functional studies support that ATP binding to MgtE enhances the intracellular domain affinity for Mg2+ within physiological concentrations of this divalent cation, enabling MgtE to function as an in vivo Mg2+ sensor. ATP dissociation from MgtE upregulates Mg2+ influx at both high and low intracellular Mg2+ concentrations. Using site-directed mutagenesis and structure based-electrophysiological and biochemical analyses, we identify key residues and main structural changes involved in the process. This work provides the molecular basis of ATP-dependent modulation of MgtE in Mg2+ homeostasis. MgtE is an Mg2+ transporter involved in Mg2+ homeostasis. Here, the authors report that ATP regulates the Mg+2-dependent gating of MgtE and use X-ray crystallography combined with functional studies to propose the molecular mechanisms involved in this process.
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Affiliation(s)
- Atsuhiro Tomita
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Mingfeng Zhang
- State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, 2005 Songhu Road, Yangpu District, Shanghai, 200438, China
| | - Fei Jin
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, 2005 Songhu Road, Yangpu District, Shanghai, 200438, China
| | - Wenhui Zhuang
- State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, 2005 Songhu Road, Yangpu District, Shanghai, 200438, China
| | - Hironori Takeda
- Faculty of Life Science, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Tatsuro Maruyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masanori Osawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Ken-Ichi Hashimoto
- Department of Green and Sustainable Chemistry, Tokyo Denki University, 5 Asahi-cho, Senju, Adachi-ku, Tokyo, 120-8551, Japan
| | - Hisashi Kawasaki
- Department of Green and Sustainable Chemistry, Tokyo Denki University, 5 Asahi-cho, Senju, Adachi-ku, Tokyo, 120-8551, Japan
| | - Koichi Ito
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Ichio Shimada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Zhiqiang Yan
- State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, 2005 Songhu Road, Yangpu District, Shanghai, 200438, China. .,Department of Human Anatomy, School of Basic Medicine Sciences, Southwest Medical University, Luzhou, Sichuan, 646000, China.
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, 2005 Songhu Road, Yangpu District, Shanghai, 200438, China.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan.
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32
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Amiri FS, Kariminejad A. Juvenile nephronophthisis and dysthyroidism: a rare association. CEN Case Rep 2017; 6:98-104. [PMID: 28509138 DOI: 10.1007/s13730-017-0252-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/07/2017] [Indexed: 11/28/2022] Open
Abstract
Nephronophthisis, an autosomal recessive kidney disease, represents the most frequent genetic cause of end-stage kidney disease in the first three decades of life. A 27-year-old male was presented with gait imbalance, sever pruritus since 10 days prior time of admission. In past medical history, he had bilateral cataract, torsional nystagmus, and bilateral optic nerve atrophy since 2 years of age. He was also mentioned history of multinodular goiter with dysfunctional thyroid state since 2 years before admission. At admission bilateral blindness, torsional nystagmus, asymmetric thyromegaly with nodularity was found in physical examination. Laboratory tests showed elevated urea and creatinine (200, 10.7 mg/dl), hypomagnesemia (1.1 mEq/l), decreased thyroid stimulating hormone (<0.004 mIU/l). Ophthalmologist consultation confirmed retinitis pigmentosa. Renal sonography showed small-sized kidneys. Brain magnetic resonance imaging did not reveal molar tooth sign. Genetic testing performed and a large homozygous deletion at the NPHP1 gene locus was found. The patient was diagnosed with juvenile nephronophthisis and consideration of dysthyroidism as extrarenal manifestation of nephronophthisis is suggested in this case. Furthermore, loss of function mutation in SLC41A1 gene that leads to magnesium depletion must be noted in patients with suspected to nephronophthisis.
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Affiliation(s)
- Fateme Shamekhi Amiri
- Division of Nephrology, Imam khomeini hospital, Faculty of medicine, National University of Tehran Medical Sciences, Tehran, Iran.
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33
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Srivastava S, Molinari E, Raman S, Sayer JA. Many Genes-One Disease? Genetics of Nephronophthisis (NPHP) and NPHP-Associated Disorders. Front Pediatr 2017; 5:287. [PMID: 29379777 PMCID: PMC5770800 DOI: 10.3389/fped.2017.00287] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/14/2017] [Indexed: 12/13/2022] Open
Abstract
Nephronophthisis (NPHP) is a renal ciliopathy and an autosomal recessive cause of cystic kidney disease, renal fibrosis, and end-stage renal failure, affecting children and young adults. Molecular genetic studies have identified more than 20 genes underlying this disorder, whose protein products are all related to cilia, centrosome, or mitotic spindle function. In around 15% of cases, there are additional features of a ciliopathy syndrome, including retinal defects, liver fibrosis, skeletal abnormalities, and brain developmental disorders. Alongside, gene identification has arisen molecular mechanistic insights into the disease pathogenesis. The genetic causes of NPHP are discussed in terms of how they help us to define treatable disease pathways including the cyclic adenosine monophosphate pathway, the mTOR pathway, Hedgehog signaling pathways, and DNA damage response pathways. While the underlying pathology of the many types of NPHP remains similar, the defined disease mechanisms are diverse, and a personalized medicine approach for therapy in NPHP patients is likely to be required.
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Affiliation(s)
- Shalabh Srivastava
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Renal Unit, City Hospitals Sunderland and South Tyneside NHS Foundation Trust, Sunderland, United Kingdom
| | - Elisa Molinari
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Shreya Raman
- Department of Histopathology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Renal Services, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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de Baaij JHF, Arjona FJ, van den Brand M, Lavrijsen M, Lameris ALL, Bindels RJM, Hoenderop JGJ. Identification of SLC41A3 as a novel player in magnesium homeostasis. Sci Rep 2016; 6:28565. [PMID: 27349617 PMCID: PMC4923877 DOI: 10.1038/srep28565] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 06/02/2016] [Indexed: 01/08/2023] Open
Abstract
Regulation of the body Mg(2+) balance takes place in the distal convoluted tubule (DCT), where transcellular reabsorption determines the final urinary Mg(2+) excretion. The basolateral Mg(2+) extrusion mechanism in the DCT is still unknown, but recent findings suggest that SLC41 proteins contribute to Mg(2+) extrusion. The aim of this study was, therefore, to characterize the functional role of SLC41A3 in Mg(2+) homeostasis using the Slc41a3 knockout (Slc41a3(-/-)) mouse. By quantitative PCR analysis it was shown that Slc41a3 is the only SLC41 isoform with enriched expression in the DCT. Interestingly, serum and urine electrolyte determinations demonstrated that Slc41a3(-/-) mice suffer from hypomagnesemia. The intestinal Mg(2+) absorption capacity was measured using the stable (25)Mg(2+) isotope in mice fed a low Mg(2+) diet. (25)Mg(2+) uptake was similar in wildtype (Slc41a3(+/+)) and Slc41a3(-/-) mice, although Slc41a3(-/-) animals exhibited increased intestinal mRNA expression of Mg(2+) transporters Trpm6 and Slc41a1. Remarkably, some of the Slc41a3(-/-) mice developed severe unilateral hydronephrosis. In conclusion, SLC41A3 was established as a new factor for Mg(2+) handling.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Francisco J Arjona
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Michiel van den Brand
- Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Marla Lavrijsen
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Anke L L Lameris
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
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Abstract
Over the past decades, hypomagnesemia (serum Mg(2+) <0.7 mmol/L) has been strongly associated with type 2 diabetes mellitus (T2DM). Patients with hypomagnesemia show a more rapid disease progression and have an increased risk for diabetes complications. Clinical studies demonstrate that T2DM patients with hypomagnesemia have reduced pancreatic β-cell activity and are more insulin resistant. Moreover, dietary Mg(2+) supplementation for patients with T2DM improves glucose metabolism and insulin sensitivity. Intracellular Mg(2+) regulates glucokinase, KATP channels, and L-type Ca(2+) channels in pancreatic β-cells, preceding insulin secretion. Moreover, insulin receptor autophosphorylation is dependent on intracellular Mg(2+) concentrations, making Mg(2+) a direct factor in the development of insulin resistance. Conversely, insulin is an important regulator of Mg(2+) homeostasis. In the kidney, insulin activates the renal Mg(2+) channel transient receptor potential melastatin type 6 that determines the final urinary Mg(2+) excretion. Consequently, patients with T2DM and hypomagnesemia enter a vicious circle in which hypomagnesemia causes insulin resistance and insulin resistance reduces serum Mg(2+) concentrations. This Perspective provides a systematic overview of the molecular mechanisms underlying the effects of Mg(2+) on insulin secretion and insulin signaling. In addition to providing a review of current knowledge, we provide novel directions for future research and identify previously neglected contributors to hypomagnesemia in T2DM.
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Affiliation(s)
- Lisanne M M Gommers
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K.
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Mastrototaro L, Tietjen U, Sponder G, Vormann J, Aschenbach JR, Kolisek M. Insulin Modulates the Na+/Mg2+ Exchanger SLC41A1 and Influences Mg2+ Efflux from Intracellular Stores in Transgenic HEK293 Cells. J Nutr 2015; 145:2440-7. [PMID: 26355001 DOI: 10.3945/jn.115.213918] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/07/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Magnesium deficiency is a common complication of diabetes with an unclear molecular background. OBJECTIVE We investigated the effect of the insulin (INS)-signaling pathway (ISP) on the regulation of Mg(2+) efflux (Mg(2+)E) conducted by solute carrier family 41, member A1 (SLC41A1; activated by protein kinase A) in transgenic human embryonic kidney (HEK) 293 cells. METHODS HEK293 cells overexpressing SLC41A1 were loaded with the Mg(2+) fluorescent indicator mag-fura-2 and Mg(2+). Measurements of Mg(2+)E were conducted in Mg(2+)-free buffer by using fast-filter fluorescence spectrometry. We examined the effects of INS, inhibitors of ISP or p38 mitogen-activated protein kinase (p38 MAPK), an activator of adenylate cyclase (ADC), and their combinations on SLC41A1-attributed Mg(2+)E. RESULTS The application of 400 μU/mL INS inhibited SLC41A1-mediated Mg(2+)E by up to 50.6% compared with INS-untreated cells (P < 0.001). Moreover, INS evoked the early onset of Mg(2+) release from intracellular stores. The application of 0.1 μM wortmannin or 10 μM zardaverine (both ISP inhibitors) restored SLC41A1 Mg(2+)E capacity in the presence of INS to the same levels in INS-untreated cells. The simultaneous application of 10 μM forskolin, an ADC activator, and INS resulted in a reduction of Mg(2+)E of up to 59% compared with untreated cells (P < 0.001), which was comparable to that in cells treated with INS alone. Inhibition of p38 MAPK with 10 μM SB 202190 (SB) in the absence of INS resulted in a decrease (P < 0.001) of SLC41A1-dependent Mg(2+)E (by up to 49%) compared with Mg(2+)E measured in untreated cells. Simultaneous exposure of cells to SB and INS had a stronger inhibitory effect on SLC41A1 activity than INS alone (P < 0.05). CONCLUSIONS INS affects intracellular Mg(2+) concentration in transgenic HEK293 cells by regulating SLC41A1 activity (via ISP) and by influencing the compartmentalization and cellular distribution of Mg(2+). In addition, p38 MAPK activates SLC41A1 independently of INS action.
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Affiliation(s)
- Lucia Mastrototaro
- Institute of Veterinary Physiology, Freie Universität, Berlin, Germany; and
| | - Uwe Tietjen
- Institute of Veterinary Physiology, Freie Universität, Berlin, Germany; and
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Freie Universität, Berlin, Germany; and
| | - Jürgen Vormann
- Institute for Prevention and Nutrition, Ismaning/Munich, Germany
| | - Jörg R Aschenbach
- Institute of Veterinary Physiology, Freie Universität, Berlin, Germany; and
| | - Martin Kolisek
- Institute of Veterinary Physiology, Freie Universität, Berlin, Germany; and
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Abstract
PURPOSE OF REVIEW Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is one of the most common genetic disorders causing end-stage renal disease (ESRD) in children and adolescents. NPHP is a genetically heterogenous disorder with 20 identified genes. NPHP occurs as an isolated kidney disease, but approximately 15% of NPHP patients have additional extrarenal symptoms affecting other organs [e.g. eyes, liver, bones and central nervous system (CNS)]. The pleiotropy in NPHP is explained by the finding that almost all NPHP gene products share expression in primary cilia, a sensory organelle present in most mammalian cells. If extrarenal symptoms are present in addition to NPHP, these disorders are classified as NPHP-related ciliopathies (NPHP-RC). This review provides an update about recent advances in the field of NPHP-RC. RECENT FINDINGS The identification of novel disease-causing genes has improved our understanding of the pathomechanisms contributing to NPHP-RC. Multiple interactions between different NPHP-RC gene products have been published and outline the interconnectivity of the affected proteins and shared pathways. SUMMARY The significance of recently identified genes for NPHP-RC is discussed and the complex role and interaction of NPHP proteins in ciliary function and cellular signalling pathways is highlighted.
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MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Adolescent
- Child
- Cilia/pathology
- Cilia/physiology
- Cytoskeletal Proteins
- Genes, Recessive
- Humans
- Kidney/pathology
- Kidney Diseases, Cystic/complications
- Kidney Diseases, Cystic/congenital
- Kidney Diseases, Cystic/pathology
- Kidney Diseases, Cystic/physiopathology
- Kidney Failure, Chronic/etiology
- Kidney Failure, Chronic/genetics
- Kidney Failure, Chronic/pathology
- Kidney Failure, Chronic/physiopathology
- Membrane Proteins/metabolism
- Mutation/genetics
- Phenotype
- Signal Transduction
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Affiliation(s)
- Matthias T F Wolf
- Division of Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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de Baaij JHF, Hoenderop JGJ, Bindels RJM. Magnesium in man: implications for health and disease. Physiol Rev 2015; 95:1-46. [PMID: 25540137 DOI: 10.1152/physrev.00012.2014] [Citation(s) in RCA: 886] [Impact Index Per Article: 98.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Magnesium (Mg(2+)) is an essential ion to the human body, playing an instrumental role in supporting and sustaining health and life. As the second most abundant intracellular cation after potassium, it is involved in over 600 enzymatic reactions including energy metabolism and protein synthesis. Although Mg(2+) availability has been proven to be disturbed during several clinical situations, serum Mg(2+) values are not generally determined in patients. This review aims to provide an overview of the function of Mg(2+) in human health and disease. In short, Mg(2+) plays an important physiological role particularly in the brain, heart, and skeletal muscles. Moreover, Mg(2+) supplementation has been shown to be beneficial in treatment of, among others, preeclampsia, migraine, depression, coronary artery disease, and asthma. Over the last decade, several hereditary forms of hypomagnesemia have been deciphered, including mutations in transient receptor potential melastatin type 6 (TRPM6), claudin 16, and cyclin M2 (CNNM2). Recently, mutations in Mg(2+) transporter 1 (MagT1) were linked to T-cell deficiency underlining the important role of Mg(2+) in cell viability. Moreover, hypomagnesemia can be the consequence of the use of certain types of drugs, such as diuretics, epidermal growth factor receptor inhibitors, calcineurin inhibitors, and proton pump inhibitors. This review provides an extensive and comprehensive overview of Mg(2+) research over the last few decades, focusing on the regulation of Mg(2+) homeostasis in the intestine, kidney, and bone and disturbances which may result in hypomagnesemia.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Abstract
PURPOSE OF REVIEW The tight control of blood magnesium (Mg) levels is of central importance for numerous physiological processes. A persistent low Mg status (hypomagnesemia) is associated with severe health risks and is involved in the pathogenesis of type 2 diabetes mellitus, osteoporosis, asthma, and heart and vascular diseases. The current view has expanded significantly as a result of the identification of novel genes and regulatory pathways involved in hypomagnesemic disorders. This review aims to give an up-to-date overview of transient receptor potential melastatin 6 (TRPM6) regulation and its role in the maintenance of Mg homeostasis. RECENT FINDINGS The epithelial Mg channel TRPM6 is considered to be the Mg entry pathway in the distal convoluted tubule of the kidney, where it functions as gatekeeper for controlling the body's Mg balance. Various factors and hormones contribute not only to the function, but also to the dysregulation of TRPM6, which has a substantial impact on renal Mg handling. Recent genetic and molecular studies have further elucidated the signaling processes of epithelial Mg transport, including their effect on the expression and function of TRPM6. SUMMARY Knowledge of TRPM6 functioning is of vital importance to decipher its role in Mg handling and will, in particular, provide a molecular basis for achieving a better understanding of Mg mal(re)absorption and hence systemic Mg balance.
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40
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Abstract
Magnesium, the fourth most abundant cation in the human body, is involved in several essential physiological, biochemical, and cellular processes regulating cardiovascular function. It plays a critical role in modulating vascular smooth muscle tone, endothelial cell function, and myocardial excitability and is thus central to the pathogenesis of several cardiovascular disorders such as hypertension, atherosclerosis, coronary artery disease, congestive heart failure, and cardiac arrhythmias. This review discusses the vasodilatory, anti-inflammatory, anti-ischemic, and antiarrhythmic properties of magnesium and its current role in the prevention and treatment of cardiovascular disorders.
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Blaine J, Chonchol M, Levi M. Renal control of calcium, phosphate, and magnesium homeostasis. Clin J Am Soc Nephrol 2014; 10:1257-72. [PMID: 25287933 DOI: 10.2215/cjn.09750913] [Citation(s) in RCA: 408] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.
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Affiliation(s)
- Judith Blaine
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Michel Chonchol
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Moshe Levi
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
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Kurschat CE, Müller RU, Franke M, Maintz D, Schermer B, Benzing T. An approach to cystic kidney diseases: the clinician's view. Nat Rev Nephrol 2014; 10:687-99. [DOI: 10.1038/nrneph.2014.173] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Abstract
The distal convoluted tubule is the nephron segment that lies immediately downstream of the macula densa. Although short in length, the distal convoluted tubule plays a critical role in sodium, potassium, and divalent cation homeostasis. Recent genetic and physiologic studies have greatly expanded our understanding of how the distal convoluted tubule regulates these processes at the molecular level. This article provides an update on the distal convoluted tubule, highlighting concepts and pathophysiology relevant to clinical practice.
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Affiliation(s)
- Arohan R Subramanya
- Departments of Medicine and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania;
| | - David H Ellison
- Departments of Medicine and Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon; and Portland Veterans Affairs Medical Center, Portland, Oregon
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Taskiran EZ, Korkmaz E, Gucer S, Kosukcu C, Kaymaz F, Koyunlar C, Bryda EC, Chaki M, Lu D, Vadnagara K, Candan C, Topaloglu R, Schaefer F, Attanasio M, Bergmann C, Ozaltin F. Mutations in ANKS6 cause a nephronophthisis-like phenotype with ESRD. J Am Soc Nephrol 2014; 25:1653-61. [PMID: 24610927 DOI: 10.1681/asn.2013060646] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Nephronophthisis (NPHP) is one of the most common genetic causes of CKD; however, the underlying genetic abnormalities have been established in <50% of patients. We performed genome-wide analysis followed by targeted resequencing in a Turkish consanguineous multiplex family and identified a canonic splice site mutation in ANKS6 associated with an NPHP-like phenotype. Furthermore, we identified four additional ANKS6 variants in a cohort of 56 unrelated patients diagnosed with CKD due to nephronophthisis, chronic GN, interstitial nephritis, or unknown etiology. Immunohistochemistry in human embryonic kidney tissue demonstrated that the expression patterns of ANKS6 change substantially during development. Furthermore, we detected increased levels of both total and active β-catenin in precystic tubuli in Han:SPRD Cy/+ rats. Overall, these data indicate the importance of ANKS6 in human kidney development and suggest a mechanism by which mutations in ANKS6 may contribute to an NPHP-like phenotype in humans.
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Affiliation(s)
- Ekim Z Taskiran
- Nephrogenetics Laboratory, andDepartments of Medical Genetics
| | | | | | | | | | | | - Elizabeth C Bryda
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | | | | | | | - Cengiz Candan
- **Department of Pediatric Nephrology, Istanbul Medeniyet University, Istanbul, Turkey
| | - Rezan Topaloglu
- Pediatric Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Franz Schaefer
- Pediatric Nephrology Division, Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany
| | - Massimo Attanasio
- Department of Internal Medicine, andEugene McDermott Center for Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany; Department of Nephrology and Center for Clinical Research, University Hospital, Freiburg, Germany; and
| | - Fatih Ozaltin
- Nephrogenetics Laboratory, andPediatric Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey; Hacettepe University Center for Biobanking and Genomics, Ankara, Turkey
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Schweigel-Röntgen M, Kolisek M. SLC41 transporters--molecular identification and functional role. CURRENT TOPICS IN MEMBRANES 2014; 73:383-410. [PMID: 24745990 DOI: 10.1016/b978-0-12-800223-0.00011-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The solute carrier family 41 (SLC41) encompasses three members A1, A2, and A3. Based on their distant homology to the bacterial Mg²⁺ channel MgtE, all have been linked to Mg²⁺ transport. There is only very limited knowledge on the molecular biology and exact functions of SLC41A2 and SLC41A3. SLC41A1 is ubiquitously expressed and data on its functional and molecular properties, regulation, complex-forming ability, and spectrum of binding partners are available. SLC41A1 was recently identified as being the Na⁺/Mg²⁺ exchanger (NME)-a predominant Mg²⁺ efflux system. Mg²⁺-dependent and hormonal regulation of NME activity is now known to depend on the intracellular N terminus of SLC41A1 that is involved in Mg²⁺ sensing and contains phosphorylation sites for protein kinase (PK) A and PKC. Data showing a link between SLC41A1 and human disorders such as Parkinson's disease, nephronophthisis (induced by the null mutation c.698G>T in renal SLC41A1), and preeclampsia make the protein a candidate therapeutic target.
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Affiliation(s)
- Monika Schweigel-Röntgen
- Institute for Muscle Biology & Growth, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.
| | - Martin Kolisek
- Institute of Veterinary Physiology, Free University Berlin, Berlin, Germany
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Basolateral Mg2+ extrusion via CNNM4 mediates transcellular Mg2+ transport across epithelia: a mouse model. PLoS Genet 2013; 9:e1003983. [PMID: 24339795 PMCID: PMC3854942 DOI: 10.1371/journal.pgen.1003983] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 10/15/2013] [Indexed: 12/24/2022] Open
Abstract
Transcellular Mg2+ transport across epithelia, involving both apical entry and basolateral extrusion, is essential for magnesium homeostasis, but molecules involved in basolateral extrusion have not yet been identified. Here, we show that CNNM4 is the basolaterally located Mg2+ extrusion molecule. CNNM4 is strongly expressed in intestinal epithelia and localizes to their basolateral membrane. CNNM4-knockout mice showed hypomagnesemia due to the intestinal malabsorption of magnesium, suggesting its role in Mg2+ extrusion to the inner parts of body. Imaging analyses revealed that CNNM4 can extrude Mg2+ by exchanging intracellular Mg2+ with extracellular Na+. Furthermore, CNNM4 mutations cause Jalili syndrome, characterized by recessive amelogenesis imperfecta with cone-rod dystrophy. CNNM4-knockout mice showed defective amelogenesis, and CNNM4 again localizes to the basolateral membrane of ameloblasts, the enamel-forming epithelial cells. Missense point mutations associated with the disease abolish the Mg2+ extrusion activity. These results demonstrate the crucial importance of Mg2+ extrusion by CNNM4 in organismal and topical regulation of magnesium. Magnesium is an essential element for living organisms. Its absorption occurs at the intestine through the barrier comprised of epithelial cells. In this process, transcellular Mg2+ transport across epithelia, involving both entry from one side and extrusion from the other side, is important. Previous studies have revealed the role of Mg2+-permeable channel protein in Mg2+ entry into the epithelial cells. However, the identity of proteins involved in Mg2+ extrusion to the inner parts of body has remained unknown. Mice genetically engineered not to express CNNM4, which localizes to the epithelial membrane facing to the inner parts of body, show hypomagnesemia due to the defect in magnesium absorption. Functional analyses using culture cells directly reveal that CNNM4 can extrude intracellular Mg2+ to the outside of cells. These results indicate that CNNM4 mediates transcellular Mg2+ transport across the intestinal epithelia. Furthermore, we also show that these CNNM4-lacking mice also have a defect in amelogenesis, which is consistent with the disease symptoms of Jalili syndrome that is known to be caused by mutations in the CNNM4 gene.
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Fleig A, Schweigel-Röntgen M, Kolisek M. Solute Carrier Family SLC41, what do we really know about it? ACTA ACUST UNITED AC 2013; 2. [PMID: 24340240 DOI: 10.1002/wmts.95] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The 41st family of solute carriers (SLC41) comprises three members A1, A2 and A3, which are distantly homologous to bacterial Mg2+ channel MgtE. SLC41A1 was recently characterized as being an Na+/Mg2+ exchanger (NME; a predominant cellular Mg2+ efflux system). Little is known about the exact function of SLC41A2 and SLC41A3, although, these proteins have also been linked to Mg2+ transport in human (animal) cells. The molecular biology (including membrane topology, cellular localization, transcriptomics and proteomics) of SLC41A2 and SLC41A3 compared with SLC41A1 has only been poorly explored. Significantly more data with regard to function, functional regulation, involvement in cellular signalling, complex-forming ability, spectrum of binding partners and involvement in the pathophysiology of human diseases are available for SLC41A1. Three recent observations namely the identification of the null mutation, c.698G>T, in SLC41A1 underlying the nephronophthisis-like phenotype, the recognition of a putative link between SLC41A1 and Parkinson's disease, and the observation that nearly 55% of preeclamptic placental samples overexpress SLC41A1, marks the protein as a possible therapeutic target of these diseases. A potential role of the SLC41 family of Mg2+ transporters in the pathophysiology of human diseases is further substantiated by the finding that SLC41A3 knockout mice develop abnormal locomotor coordination.
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Affiliation(s)
- Andrea Fleig
- Laboratory of Cell and Molecular Signalling, Center for Biomedical Research at The Queen's Medical Center, Honolulu, HI USA
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Kolisek M, Sponder G, Mastrototaro L, Smorodchenko A, Launay P, Vormann J, Schweigel-Röntgen M. Substitution p.A350V in Na⁺/Mg²⁺ exchanger SLC41A1, potentially associated with Parkinson's disease, is a gain-of-function mutation. PLoS One 2013; 8:e71096. [PMID: 23976986 PMCID: PMC3744568 DOI: 10.1371/journal.pone.0071096] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 06/24/2013] [Indexed: 12/31/2022] Open
Abstract
Parkinson's disease (PD) is a complex multifactorial ailment predetermined by the interplay of various environmental and genetic factors. Systemic and intracellular magnesium (Mg) deficiency has long been suspected to contribute to the development and progress of PD and other neurodegenerative diseases. However, the molecular background is unknown. Interestingly, gene SLC41A1 located in the novel PD locus PARK16 has recently been identified as being a Na+/Mg2+ exchanger (NME, Mg2+ efflux system), a key component of cellular magnesium homeostasis. Here, we demonstrate that the substitution p.A350V potentially associated with PD is a gain-of-function mutation that enhances a core function of SLC41A1, namely Na+-dependent Mg2+ efflux by 69±10% under our experimental conditions (10-minute incubation in high-Na+ (145 mM) and completely Mg2+-free medium). The increased efflux capacity is accompanied by an insensitivity of mutant NME to cAMP stimulation suggesting disturbed hormonal regulation and leads to a reduced proliferation rate in p.A350V compared with wt cells. We hypothesize that enhanced Mg2+-efflux conducted by SLC41A1 variant p.A350V might result, in the long-term, in chronic intracellular Mg2+-deficiency, a condition that is found in various brain regions of PD patients and that exacerbates processes triggering neuronal damage.
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Affiliation(s)
- Martin Kolisek
- Institute of Veterinary-Physiology, Free University Berlin, Berlin, Germany
- * E-mail: (MK); (MSR)
| | - Gerhard Sponder
- Institute of Veterinary-Physiology, Free University Berlin, Berlin, Germany
| | - Lucia Mastrototaro
- Institute of Veterinary-Physiology, Free University Berlin, Berlin, Germany
| | - Alina Smorodchenko
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | | | | | - Monika Schweigel-Röntgen
- Institute for Nutritional Physiology “Oskar Kellner”, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany
- * E-mail: (MK); (MSR)
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Caliskan Y, Gharavi AG. Working out nephronophthisis genetics one family at a time. J Am Soc Nephrol 2013; 24:865-8. [PMID: 23687355 DOI: 10.1681/asn.2013040427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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