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Shimada H, Powell TL, Jansson T. Regulation of placental amino acid transport in health and disease. Acta Physiol (Oxf) 2024; 240:e14157. [PMID: 38711335 PMCID: PMC11162343 DOI: 10.1111/apha.14157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/19/2024] [Accepted: 04/23/2024] [Indexed: 05/08/2024]
Abstract
Abnormal fetal growth, i.e., intrauterine growth restriction (IUGR) or fetal growth restriction (FGR) and fetal overgrowth, is associated with increased perinatal morbidity and mortality and is strongly linked to the development of metabolic and cardiovascular disease in childhood and later in life. Emerging evidence suggests that changes in placental amino acid transport may contribute to abnormal fetal growth. This review is focused on amino acid transport in the human placenta, however, relevant animal models will be discussed to add mechanistic insights. At least 25 distinct amino acid transporters with different characteristics and substrate preferences have been identified in the human placenta. Of these, System A, transporting neutral nonessential amino acids, and System L, mediating the transport of essential amino acids, have been studied in some detail. Importantly, decreased placental Systems A and L transporter activity is strongly associated with IUGR and increased placental activity of these two amino acid transporters has been linked to fetal overgrowth in human pregnancy. An array of factors in the maternal circulation, including insulin, IGF-1, and adiponectin, and placental signaling pathways such as mTOR, have been identified as key regulators of placental Systems A and L. Studies using trophoblast-specific gene targeting in mice have provided compelling evidence that changes in placental Systems A and L are mechanistically linked to altered fetal growth. It is possible that targeting specific placental amino acid transporters or their upstream regulators represents a novel intervention to alleviate the short- and long-term consequences of abnormal fetal growth in the future.
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Affiliation(s)
- Hiroshi Shimada
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
- Departments of Obstetrics & Gynecology, Sapporo Medical University, Sapporo, Japan
| | - Theresa L Powell
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
- Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, CO, US
| | - Thomas Jansson
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
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2
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Li Y, Guo Y, Bröer A, Dai L, Brӧer S, Yan R. Cryo-EM structure of the human Asc-1 transporter complex. Nat Commun 2024; 15:3036. [PMID: 38589439 PMCID: PMC11001984 DOI: 10.1038/s41467-024-47468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 04/02/2024] [Indexed: 04/10/2024] Open
Abstract
The Alanine-Serine-Cysteine transporter 1 (Asc-1 or SLC7A10) forms a crucial heterodimeric transporter complex with 4F2hc (SLC3A2) through a covalent disulfide bridge. This complex enables the sodium-independent transport of small neutral amino acids, including L-Alanine (L-Ala), Glycine (Gly), and D-Serine (D-Ser), within the central nervous system (CNS). D-Ser and Gly are two key endogenous glutamate co-agonists that activate N-methyl-d-aspartate (NMDA) receptors by binding to the allosteric site. Mice deficient in Asc-1 display severe symptoms such as tremors, ataxia, and seizures, leading to early postnatal death. Despite its physiological importance, the functional mechanism of the Asc-1-4F2hc complex has remained elusive. Here, we present cryo-electron microscopy (cryo-EM) structures of the human Asc-1-4F2hc complex in its apo state, D-Ser bound state, and L-Ala bound state, resolved at 3.6 Å, 3.5 Å, and 3.4 Å, respectively. Through detailed structural analysis and transport assays, we uncover a comprehensive alternating access mechanism that underlies conformational changes in the complex. In summary, our findings reveal the architecture of the Asc-1 and 4F2hc complex and provide valuable insights into substrate recognition and the functional cycle of this essential transporter complex.
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Affiliation(s)
- Yaning Li
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
- Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yingying Guo
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Angelika Bröer
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Lu Dai
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
| | - Renhong Yan
- Department of Biochemistry, Key University Laboratory of Metabolism and Health of Guangdong, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China.
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3
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Koo KC, Halawani A, Wong VK, Lange D, Chew BH. Monogenic features of urolithiasis: A comprehensive review. Asian J Urol 2024; 11:169-179. [PMID: 38680588 PMCID: PMC11053333 DOI: 10.1016/j.ajur.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 03/28/2023] [Indexed: 05/01/2024] Open
Abstract
Objective Urolithiasis formation has been attributed to environmental and dietary factors. However, evidence is accumulating that genetic background can contribute to urolithiasis formation. Advancements in the identification of monogenic causes using high-throughput sequencing technologies have shown that urolithiasis has a strong heritable component. Methods This review describes monogenic factors implicated in a genetic predisposition to urolithiasis. Peer-reviewed journals were evaluated by a PubMed search until July 2023 to summarize disorders associated with monogenic traits, and discuss clinical implications of identification of patients genetically susceptible to urolithiasis formation. Results Given that more than 80% of urolithiases cases are associated with calcium accumulation, studies have focused mainly on monogenetic contributors to hypercalciuric urolithiases, leading to the identification of receptors, channels, and transporters involved in the regulation of calcium renal tubular reabsorption. Nevertheless, available candidate genes and linkage methods have a low resolution for evaluation of the effects of genetic components versus those of environmental, dietary, and hormonal factors, and genotypes remain undetermined in the majority of urolithiasis formers. Conclusion The pathophysiology underlying urolithiasis formation is complex and multifactorial, but evidence strongly suggests the existence of numerous monogenic causes of urolithiasis in humans.
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Affiliation(s)
- Kyo Chul Koo
- Department of Urology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Victor K.F. Wong
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Dirk Lange
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Ben H. Chew
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
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Abad Baucells C, Schönauer R, Halbritter J. The genetics of cystinuria - an update and critical reevaluation. Curr Opin Nephrol Hypertens 2024; 33:231-237. [PMID: 38240263 DOI: 10.1097/mnh.0000000000000949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
PURPOSE OF REVIEW We aimed to critically evaluate how the establishment of genotype-based treatment for cystinuria has been hampered due to the large number of variants of unknown significance (VUS) within the disease causing genes as well as challenges in accessing a large enough sample size for systematic analysis of endpoint parameters that truly reflect disease severity. This review further discusses how to overcome these hurdles with the establishment of a cystinuria-specific refinement of the current American College of Medical Genetics and Genomics (ACMG)-criteria of variant interpretation. RECENT FINDINGS Novel tools such as AlphaMissense combined with the establishment of a refined ACMG criterion will play a significant role in classifying VUS within the responsible disease genes SLC3A1 (rBAT) and SLC7A9 (BAT1). This will also be essential in elucidating the role of promising candidate genes, such as SLC7A13 (AGT1), which have been derived from murine model systems and still need further research to determine if they are involved in human cystinuria. SUMMARY Cystinuria was one of the first disorders to receive a gene-based classification, nonetheless, the clinically actionable implications of genetic diagnostics is still minor. This is due to poorly characterized genotype-phenotype correlations which results in a lack of individualized (genotype-) based management and metaphylaxis.
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Affiliation(s)
- Clàudia Abad Baucells
- Department of Nephrology and Medical Intensive Care, Charité Universitätsmedizin Berlin, Berlin, Germany
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Prot-Bertoye C, Jung V, Tostivint I, Roger K, Benoist JF, Jannot AS, Van Straaten A, Knebelmann B, Guerrera IC, Courbebaisse M. Effect of urine alkalization on urinary inflammatory markers in cystinuric patients. Clin Kidney J 2024; 17:sfae040. [PMID: 38510798 PMCID: PMC10953617 DOI: 10.1093/ckj/sfae040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Indexed: 03/22/2024] Open
Abstract
Background Cystinuria is associated with a high prevalence of chronic kidney disease (CKD). We previously described a urinary inflammatory-protein signature (UIS), including 38 upregulated proteins, in cystinuric patients (Cys-patients), compared with healthy controls (HC). This UIS was higher in Cys-patients with CKD. In the present observational study, we aimed to investigate the UIS in Cys-patients without CKD and patients with calcium nephrolithiasis (Lith-patients), versus HC and the effect of urine alkalization on the UIS of Cys-patients. Methods UIS was evaluated by nano-liquid chromatography coupled to high-resolution mass spectrometry in adult HC, Lith-patients and non-treated Cys-patients with an estimated glomerular filtration rate >60 mL/min/1.73 m2, and after a 3-month conventional alkalizing treatment in Cys-patients. Results Twenty-one Cys-patients [12 men, median age (interquartile range) 30.0 (25.0-44.0) years], 12 Lith-patients [8 men, 46.2 (39.5-54.2) years] and 7 HC [2 men, 43.1 (31.0-53.9) years] were included. Among the 38 proteins upregulated in our previous work, 11 proteins were also upregulated in Cys-patients compared with HC in this study (5 circulating inflammatory proteins and 6 neutrophil-derived proteins). This UIS was also found in some Lith-patients. Using this UIS, we identified two subclusters of Cys-patients (5 with a very high/high UIS and 16 with a moderate/low UIS). In the Cys-patients with very high/high UIS, urine alkalization induced a significant decrease in urinary neutrophil-derived proteins. Conclusion A high UIS is present in some Cys-patients without CKD and decreases under alkalizing treatment. This UIS could be a prognostic marker to predict the evolution towards CKD in cystinuria.
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Affiliation(s)
- Caroline Prot-Bertoye
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Physiologie – Explorations fonctionnelles, Paris, France
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France
- CNRS ERL 8228 – Laboratoire de Physiologie Rénale et Tubulopathies, Paris, France
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Paris, France
- Association LUNNE Lithiases UriNaires Network, Paris, France
| | - Vincent Jung
- Proteomics Platform Necker, Université Paris Cité – Structure Fédérative de Recherche Necker, INSERM US24/CNRS UAR3633, Paris, France
| | - Isabelle Tostivint
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Association LUNNE Lithiases UriNaires Network, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital de la Pitié Salpêtrière, Service de Néphrologie, Paris, France
- GRC 20 ARDELURO groupe de recherche clinique Analyse, Recherche, Développement et Evaluation en Endourologie et Lithiase Urinaire, Médecine Sorbonne Université, Paris, France
| | - Kevin Roger
- Proteomics Platform Necker, Université Paris Cité – Structure Fédérative de Recherche Necker, INSERM US24/CNRS UAR3633, Paris, France
| | - Jean-François Benoist
- Faculté de pharmacie, Université Paris Saclay, Orsay, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Necker, Service de Biochimie métabolique, Paris, France
| | - Anne-Sophie Jannot
- Assistance Publique-Hôpitaux de Paris – Centre, Université Paris Cité, Hôpital Européen Georges Pompidou, Service d'informatique Médicale, Santé Publique et Biostatistiques, Paris, France. HeKA, Centre de recherche des Cordeliers, INSERM, INRIA, Paris, France
| | - Alexis Van Straaten
- Assistance Publique-Hôpitaux de Paris – Centre, Université Paris Cité, Hôpital Européen Georges Pompidou, Service d'informatique Médicale, Santé Publique et Biostatistiques, Paris, France. HeKA, Centre de recherche des Cordeliers, INSERM, INRIA, Paris, France
| | - Bertrand Knebelmann
- Faculté de médecine, Université Paris Cité, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Necker, Service de Néphrologie, Paris, France
- INEM Unité Inserm U1151, Paris, France
| | - Ida Chiara Guerrera
- Proteomics Platform Necker, Université Paris Cité – Structure Fédérative de Recherche Necker, INSERM US24/CNRS UAR3633, Paris, France
| | - Marie Courbebaisse
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Physiologie – Explorations fonctionnelles, Paris, France
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Paris, France
- Association LUNNE Lithiases UriNaires Network, Paris, France
- Faculté de médecine, Université Paris Cité, Paris, France
- INEM Unité Inserm U1151, Paris, France
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Bhatt NP, Deshpande AV, Starkey MR. Pharmacological interventions for the management of cystinuria: a systematic review. J Nephrol 2024; 37:293-308. [PMID: 37957454 PMCID: PMC11043141 DOI: 10.1007/s40620-023-01795-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/26/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND Cystinuria is a rare genetic kidney stone disease, with no cure. Current treatments involve lowering urinary cystine levels and increasing cystine solubility. This systematic review evaluates the available literature regarding non-surgical interventions for cystinuria. METHODS Key electronic databases were searched for studies that described the clinical management of cystinuria with high diuresis, alkalinizing agents and thiol-based drugs that were published between 2000 and 2022. Observational studies were included if they contained clinical investigation with at least one previous or current episode of cystine stones, urine cystine levels > 250 mg/L and patients being managed with urinary dilution, alkalinizing agents or other pharmacological agents. All included studies were assessed for study design, patient characteristics and outcomes. A qualitative and critical analysis was performed whereby study quality was assessed using Methodological Index for Non-Randomized Studies (MINORS). Two authors performed the quality assessment and excluded the studies with a low MINORS score. RESULTS Fourteen studies met the review inclusion and quality criteria. Of the fourteen studies, two reported treatment using alkalinizing agents, six reported treatment using thiol-based drugs, and six reported combination treatment using alkalinizing agents and thiol-based drugs. These studies indicated that first-line therapies, including high fluid intake and urinary alkalinization, increased urine volume to > 3 L/day and urinary pH > 7.0, and were associated with reduced urinary cystine levels and cystine stone formation. Second-line therapy with cystine-binding thiol drugs, such as tiopronin and D-penicillamine, reduced urinary cystine levels, cystine crystal volume and increased cystine solubility, resulting in decreased cystine stone formation and stone recurrence rate. Further, combined intervention with alkalinizing agents and thiol-based drugs synergistically reduced stone recurrence. CONCLUSION Cystinuria treatment may require a combined approach of high diuresis, alkalinization and pharmacological interventions with regular monitoring of urinary pH, cystine levels, cystine crystal volume and solubility. However, poor adherence to treatment is relatively frequent, hence the pressing urgency for improved therapies and treatments.
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Affiliation(s)
- Nirmal Prasad Bhatt
- Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Bladder and Kidney Health Discovery Program, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Aniruddh Vijay Deshpande
- Bladder and Kidney Health Discovery Program, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Centre for Kidney Research, Children's Hospital at Westmead, New South Wales, Australia
- Department of Surgery, Urology Unit, Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Malcolm Ronald Starkey
- Department of Immunology, Central Clinical School, Monash University, Melbourne, VIC, Australia.
- Bladder and Kidney Health Discovery Program, Central Clinical School, Monash University, Melbourne, VIC, Australia.
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Mayayo-Vallverdú C, Prat E, Vecino-Pérez M, González L, Gràcia-Garcia S, San Miguel L, Lopera N, Arias A, Artuch R, López de Heredia M, Torrecilla C, Rousaud-Barón F, Angerri O, Errasti-Murugarren E, Nunes V. Exploring the Contribution of the Transporter AGT1/rBAT in Cystinuria Progression: Insights from Mouse Models and a Retrospective Cohort Study. Int J Mol Sci 2023; 24:17140. [PMID: 38138969 PMCID: PMC10743100 DOI: 10.3390/ijms242417140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/25/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023] Open
Abstract
More than 20 years have passed since the identification of SLC3A1 and SLC7A9 as causative genes for cystinuria. However, cystinuria patients exhibit significant variability in the age of lithiasis onset, recurrence, and response to treatment, suggesting the presence of modulatory factors influencing cystinuria severity. In 2016, a second renal cystine transporter, AGT1, encoded by the SLC7A13 gene, was discovered. Although it was discarded as a causative gene for cystinuria, its possible effect as a modulatory gene remains unexplored. Thus, we analyzed its function in mouse models of cystinuria, screened the SLC7A13 gene in 34 patients with different lithiasic phenotypes, and functionally characterized the identified variants. Mice results showed that AGT1/rBAT may have a protective role against cystine lithiasis. In addition, among the four missense variants detected in patients, two exhibited a 25% impairment in AGT1/rBAT transport. However, no correlation between SLC7A13 genotypes and lithiasis phenotypes was observed in patients, probably because these variants were found in heterozygous states. In conclusion, our results, consistent with a previous study, suggest that AGT1/rBAT does not have a relevant effect on cystinuria patients, although an impact in patients carrying homozygous pathogenic variants cannot be discarded.
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Affiliation(s)
- Clara Mayayo-Vallverdú
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
- Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, 08907 L’Hospitalet de Llobregat, Spain
| | - Esther Prat
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
- Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, 08907 L’Hospitalet de Llobregat, Spain
| | - Marta Vecino-Pérez
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
| | - Laura González
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain (R.A.)
| | - Silvia Gràcia-Garcia
- Urinary Lithiasis Laboratory, Fundació Puigvert, 08025 Barcelona, Spain; (S.G.-G.); (N.L.)
| | - Luz San Miguel
- Urology Service, Fundació Puigvert, 08025 Barcelona, Spain; (L.S.M.); (F.R.-B.); (O.A.)
| | - Noelia Lopera
- Urinary Lithiasis Laboratory, Fundació Puigvert, 08025 Barcelona, Spain; (S.G.-G.); (N.L.)
| | - Angela Arias
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain (R.A.)
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
| | - Rafael Artuch
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain (R.A.)
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
| | - Miguel López de Heredia
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain (R.A.)
| | - Carlos Torrecilla
- Urology Service, Hospital Universitari de Bellvitge, 08908 L’Hospitalet de Llobregat, Spain;
| | - Ferran Rousaud-Barón
- Urology Service, Fundació Puigvert, 08025 Barcelona, Spain; (L.S.M.); (F.R.-B.); (O.A.)
| | - Oriol Angerri
- Urology Service, Fundació Puigvert, 08025 Barcelona, Spain; (L.S.M.); (F.R.-B.); (O.A.)
| | - Ekaitz Errasti-Murugarren
- Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, 08907 L’Hospitalet de Llobregat, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain (R.A.)
| | - Virginia Nunes
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), 08908 L’Hospitalet de Llobregat, Spain; (C.M.-V.); (E.P.); (M.V.-P.); (L.G.); (M.L.d.H.)
- Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, 08907 L’Hospitalet de Llobregat, Spain
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Wu CHW, Badreddine J, Chang J, Huang YRM, Kim FJ, Wild T, Tsai ACH, Meeks N, Donalisio Da Silva R, Molina WR, Schumacher FR. Population genetics analysis of SLC3A1 and SLC7A9 revealed the etiology of cystine stone may be more than what our current genetic knowledge can explain. Urolithiasis 2023; 51:101. [PMID: 37561200 DOI: 10.1007/s00240-023-01473-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
BACKGROUND Cystine stone is a Mendelian genetic disease caused by SLC3A1 or SLC7A9. In this study, we aimed to estimate the genetic prevalence of cystine stones and compare it with the clinical prevalence to better understand the disease etiology. METHODS We analyzed genetic variants in the general population using the 1000 Genomes project and the Human Gene Mutation Database to extract all SLC3A1 and SLC7A9 pathogenic variants. All variants procured from both databases were intersected. Pathogenic allele frequency, carrier rate, and affected rate were calculated and estimated based on Hardy-Weinberg equilibrium. RESULTS We found that 9 unique SLC3A1 pathogenic variants were carried by 26 people and 5 unique SLC7A9 pathogenic variants were carried by 12 people, all of whom were heterozygote carriers. No homozygote, compoun d heterozygote, or double heterozygote was identified in the 1000 Genome database. Based on the Hardy-Weinberg equilibrium, the calculated genetic prevalence of cystine stone disease is 1 in 30,585. CONCLUSION The clinical prevalence of cystine stone has been previously reported as 1 in 7,000, a notably higher figure than the genetic prevalence of 1 in 30,585 calculated in this study. This suggests that the etiology of cystine stone is more complex than what our current genetic knowledge can explain. Possible factors that may contribute to this difference include novel causal genes, undiscovered pathogenic variants, alternative inheritance models, founder effects, epigenetic modifications, environmental factors, or other modifying factors. Further investigation is needed to fully understand the etiology of cystine stone.
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Affiliation(s)
- Chen-Han Wilfred Wu
- Department of Genetics and Genome Sciences, Department of Urology, Case Western Reserve University School of Medicine and University Hospitals, Cleveland, OH, USA.
| | - Jad Badreddine
- Department of Genetics and Genome Sciences, Department of Urology, Case Western Reserve University School of Medicine and University Hospitals, Cleveland, OH, USA
| | - Joshua Chang
- Department of Genetics and Genome Sciences, Department of Urology, Case Western Reserve University School of Medicine and University Hospitals, Cleveland, OH, USA
| | - Yu-Ren Mike Huang
- Department of Genetics and Genome Sciences, Department of Urology, Case Western Reserve University School of Medicine and University Hospitals, Cleveland, OH, USA
| | - Fernando J Kim
- Division of Urology, Department of Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Trevor Wild
- Division of Urology, Department of Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anne Chun-Hui Tsai
- Section of Genetics, Department of Pediatrics, University of Illinois Chicago, Chicago, IL, USA
| | - Naomi Meeks
- Division of Clinical Genetics and Metabolism, Department of Pediatrics, Children's Hospital Colorado, University of Colorado, Aurora, CO, USA
| | | | - Wilson R Molina
- Department of Urology, School of Medicine, University of Kansas, Kansas City, KS, USA
| | - Fredrick R Schumacher
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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Mayayo-Vallverdú C, López de Heredia M, Prat E, González L, Espino Guarch M, Vilches C, Muñoz L, Asensi MA, Serra C, Llebaria A, Casado M, Artuch R, Garrabou G, Garcia-Roves PM, Pallardó FV, Nunes V. The antioxidant l-Ergothioneine prevents cystine lithiasis in the Slc7a9 -/- mouse model of cystinuria. Redox Biol 2023; 64:102801. [PMID: 37418888 PMCID: PMC10359938 DOI: 10.1016/j.redox.2023.102801] [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: 05/31/2023] [Revised: 06/21/2023] [Accepted: 06/24/2023] [Indexed: 07/09/2023] Open
Abstract
The high recurrence rate of cystine lithiasis observed in cystinuria patients highlights the need for new therapeutic options to address this chronic disease. There is growing evidence of an antioxidant defect in cystinuria, which has led to test antioxidant molecules as new therapeutic approaches. In this study, the antioxidant l-Ergothioneine was evaluated, at two different doses, as a preventive and long-term treatment for cystinuria in the Slc7a9-/- mouse model. l-Ergothioneine treatments decreased the rate of stone formation by more than 60% and delayed its onset in those mice that still developed calculi. Although there were no differences in metabolic parameters or urinary cystine concentration between control and treated mice, cystine solubility was increased by 50% in the urines of treated mice. We also demonstrate that l-Ergothioneine needs to be internalized by its transporter OCTN1 (Slc22a4) to be effective, as when administrated to the double mutant Slc7a9-/-Slc22a4-/- mouse model, no effect on the lithiasis phenotype was observed. In kidneys, we detected a decrease in GSH levels and an impairment of maximal mitochondrial respiratory capacity in cystinuric mice that l-Ergothioneine treatment was able to restore. Thus, l-Ergothioneine administration prevented cystine lithiasis in the Slc7a9-/- mouse model by increasing urinary cystine solubility and recovered renal GSH metabolism and mitochondrial function. These results support the need for clinical trials to test l-Ergothioneine as a new treatment for cystinuria.
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Affiliation(s)
- Clara Mayayo-Vallverdú
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, Barcelona, Spain.
| | - Miguel López de Heredia
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain
| | - Esther Prat
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, Barcelona, Spain
| | - Laura González
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain
| | - Meritxell Espino Guarch
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Immunology Department, Sidra Medicine, Doha, Qatar
| | - Clara Vilches
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, 08860, Castelldefels, Barcelona, Spain
| | - Lourdes Muñoz
- SIMChem, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Miguel A Asensi
- Departamento de Fisiología. Universidad de Valencia-INCLIVA, Valencia, Spain
| | - Carmen Serra
- SIMChem, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Amadeu Llebaria
- SIMChem, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain; MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Mercedes Casado
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain; Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Rafael Artuch
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain; Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Gloria Garrabou
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain; Muscle Research and Mitochondrial Function Laboratory, Cellex-Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Internal Medicine Department-Hospital Clínic of Barcelona, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Pablo M Garcia-Roves
- Department of Physiological Sciences, School of Medicine and Health Sciences, Nutrition, Metabolism and Gene therapy Group Diabetes and Metabolism Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), University of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28029, Madrid, Spain
| | - Federico V Pallardó
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) -CB06/07/0069 - CB06/07/0061 - CB06/07/0073 - CB06/07/1002 - Instituto de Salud Carlos III, Madrid, Spain; Departamento de Fisiología. Universidad de Valencia-INCLIVA, Valencia, Spain
| | - Virginia Nunes
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Spain; Genetics Section, Physiological Sciences Department, Health Sciences and Medicine Faculty, University of Barcelona, Barcelona, Spain.
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10
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Bai P, Zhang W, Lai L, Huang H, Qin J, Duan B, Wang H, Chen Y, Jia Y, Xing J, Wang T, Chen B. Declaration: Novel SLC3A1 mutation in a cystinuria patient with xanthine stones: a case report. BMC Urol 2023; 23:130. [PMID: 37525149 PMCID: PMC10391995 DOI: 10.1186/s12894-023-01300-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 07/21/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Cystinuria and xanthinuria are both rare genetic diseases involving urinary calculi. However, cases combining these two disorders have not yet been reported. CASE PRESENTATION In this study, we report a case of cystinuria with xanthine stones and hyperuricemia. The 23-year-old male patient was diagnosed with kidney and ureteral stones, solitary functioning kidney and hyperuricemia after admission to the hospital. The stones were removed by surgery and found to be composed of xanthine. CONCLUSION Genetic testing by next-generation sequencing technology showed that the patient carried the homozygous nonsense mutation c.1113 C> A (p.Tyr371*) in the SLC3A1 gene, which was judged to be a functionally pathogenic variant. Sanger sequencing revealed that the patient's parents carried this heterozygous mutation, which is a pathogenic variant that can cause cystinuria. The 24-h urine metabolism analysis showed that the cystine content was 644 mg (<320 mg/24 h), indicating that the patient had cystinuria, consistent with the genetic test results. This case shows that cystinuria and xanthine stones can occur simultaneously, and provides evidence of a possible connection between the two conditions. Furthermore, our findings demonstrate the potential value of genetic testing using next-generation sequencing to effectively assist in the clinical diagnosis and treatment of patients with urinary calculi.
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Affiliation(s)
- Peide Bai
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - WenZhao Zhang
- Department of Pediatric Surgery, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Longhui Lai
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Haichao Huang
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Jiaxuan Qin
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Bo Duan
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Huiqiang Wang
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Yuedong Chen
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Yuanyuan Jia
- GloriousMed Clinical Laboratory (Shanghai) Co., Ltd, Shanghai, China
| | - Jinchun Xing
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Tao Wang
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China.
- Department of Pediatric Surgery, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China.
| | - Bin Chen
- Department of Urology, The First Affiliated Hospital of Xiamen University, Xiamen, China.
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11
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Jersin RÅ, Jonassen LR, Dankel SN. The neutral amino acid transporter SLC7A10 in adipose tissue, obesity and insulin resistance. Front Cell Dev Biol 2022; 10:974338. [PMID: 36172277 PMCID: PMC9512047 DOI: 10.3389/fcell.2022.974338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022] Open
Abstract
Obesity, insulin resistance and type 2 diabetes represent major global health challenges, and a better mechanistic understanding of the altered metabolism in these conditions may give improved treatment strategies. SLC7A10, a member of the SLC7 subfamily of solute carriers, also named ASC-1 (alanine, serine, cysteine transporter-1), has recently been implicated as an important modulator of core processes in energy- and lipid metabolism, through its particularly high expression in adipocytes. In human cohorts, adipose SLC7A10 mRNA shows strong inverse correlations with insulin resistance, adipocyte size and components of the metabolic syndrome, strong heritability, and an association with type 2 diabetes risk alleles. SLC7A10 has been proposed as a marker of white as opposed to thermogenic beige and brown adipocytes, supported by increased formation of thermogenic beige adipocytes upon loss of Slc7a10 in mouse white preadipocytes. Overexpression of SLC7A10 in mature white adipocytes was found to lower the generation of reactive oxygen species (ROS) and stimulate mitochondrial respiratory capacity, while SLC7A10 inhibition had the opposite effect, indicating that SLC7A10 supports a beneficial increase in mitochondrial activity in white adipocytes. Consistent with these beneficial effects, inhibition of SLC7A10 was in mouse and human white adipocyte cultures found to increase lipid accumulation, likely explained by lowered serine uptake and glutathione production. Additionally, zebrafish with partial global Slc7a10b loss-of-function were found to have greater diet-induced body weight and larger visceral adipocytes compared to controls. However, challenging that SLC7A10 exerts metabolic benefits only in white adipocytes, suppression of SLC7A10 has been reported to decrease mitochondrial respiration and expression of thermogenic genes also in some beige and brown adipocyte cultures. Taken together, the data point to an important but complex role of SLC7A10 in metabolic regulation across different adipose tissue depots and adipocyte subtypes. Further research into SLC7A10 functions in specific adipocyte subtypes may lead to new precision therapeutics for mitigating the risk of insulin resistance and type 2 diabetes.
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Affiliation(s)
- Regine Åsen Jersin
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Laura Roxana Jonassen
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Simon Nitter Dankel
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
- *Correspondence: Simon Nitter Dankel,
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12
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Ma Z, Wang W, Zhang D, Zhang Y, Zhao Y, Li X, Zhao L, Lin C, Wang J, Zhou B, Cheng J, Xu D, Li W, Yang X, Huang Y, Cui P, Liu J, Zeng X, Zhai R, Zhang X. Ovine RAP1GAP and rBAT gene polymorphisms and their association with tail fat deposition in Hu sheep. Front Vet Sci 2022; 9:974513. [PMID: 36090178 PMCID: PMC9453205 DOI: 10.3389/fvets.2022.974513] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Excessive fat deposition in the tail of sheep will affect its feed efficiency, which will increase the feeding cost. The purpose of this study was to identify the single nucleotide polymorphisms (SNPs) of RAP1GAP and rBAT genes by PCR amplification and Sanger sequencing, the SNPs were genotyped by KASP genotyping assays to evaluate their association with tail fat deposition traits. The results showed that two intronic mutations of g.13561 G > A and g.1460 T > C were found in RAP1GAP and rBAT, respectively. There were three genotypes of GG, AG, AA and CC, CT and TT at these two loci, respectively. Association analysis showed that g.13561 G > A of RAP1GAP was associated with tail width, tail fat weight and relative tail fat weight (P < 0.05). The g.1460 T > C of rBAT was associated with tail width and tail fat weight (P < 0.05). Different combinations of genotypes also differed significantly with tail fat deposition traits. In the tail fat tissue, the expression levels of RAP1GAP gene was significantly higher in small-tailed sheep than in big-tailed sheep, and the expression levels of rBAT gene was significantly higher in big-tailed sheep than in small-tailed sheep. In the liver, the expression levels of RAP1GAP and rBAT gene was significantly higher at 6 months than at 0 and 3 months. In conclusion, RAP1GAP and rBAT polymorphisms can be used as a candidate molecular marker to reduce tail fat deposition in sheep.
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Affiliation(s)
- Zongwu Ma
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Weimin Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
- The State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Deyin Zhang
- The State Key Laboratory of Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Yukun Zhang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Yuan Zhao
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiaolong Li
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Liming Zhao
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Changchun Lin
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Jianghui Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Bubo Zhou
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Jiangbo Cheng
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Dan Xu
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Wenxin Li
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiaobin Yang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Yongliang Huang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Panpan Cui
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Jia Liu
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiwen Zeng
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Rui Zhai
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiaoxue Zhang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
- *Correspondence: Xiaoxue Zhang
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13
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del Alamo D, DeSousa L, Nair RM, Rahman S, Meiler J, Mchaourab HS. Integrated AlphaFold2 and DEER investigation of the conformational dynamics of a pH-dependent APC antiporter. Proc Natl Acad Sci U S A 2022; 119:e2206129119. [PMID: 35969794 PMCID: PMC9407458 DOI: 10.1073/pnas.2206129119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/08/2022] [Indexed: 11/18/2022] Open
Abstract
The Amino Acid-Polyamine-Organocation (APC) transporter GadC contributes to the survival of pathogenic bacteria under extreme acid stress by exchanging extracellular glutamate for intracellular γ-aminobutyric acid (GABA). Its structure, determined in an inward-facing conformation at alkaline pH, consists of the canonical LeuT-fold with a conserved five-helix inverted repeat, thereby resembling functionally divergent transporters such as the serotonin transporter SERT and the glucose-sodium symporter SGLT1. However, despite this structural similarity, it is unclear if the conformational dynamics of antiporters such as GadC follow the blueprint of these or other LeuT-fold transporters. Here, we used double electron-electron resonance (DEER) spectroscopy to monitor the conformational dynamics of GadC in lipid bilayers in response to acidification and substrate binding. To guide experimental design and facilitate the interpretation of the DEER data, we generated an ensemble of structural models in multiple conformations using a recently introduced modification of AlphaFold2 . Our experimental results reveal acid-induced conformational changes that dislodge the Cterminus from the permeation pathway coupled with rearrangement of helices that enables isomerization between inward- and outward-facing states. The substrate glutamate, but not GABA, modulates the dynamics of an extracellular thin gate without shifting the equilibrium between inward- and outward-facing conformations. In addition to introducing an integrated methodology for probing transporter conformational dynamics, the congruence of the DEER data with patterns of structural rearrangements deduced from ensembles of AlphaFold2 models illuminates the conformational cycle of GadC underpinning transport and exposes yet another example of the divergence between the dynamics of different families in the LeuT-fold.
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Affiliation(s)
- Diego del Alamo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212
- Department of Chemistry, Vanderbilt University, Nashville, TN 37212
| | - Lillian DeSousa
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212
| | - Rahul M. Nair
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212
| | - Suhaila Rahman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN 37212
- Institute for Drug Discovery, Leipzig University, Leipzig, Germany 04109
| | - Hassane S. Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212
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14
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D'Ambrosio V, Capolongo G, Goldfarb D, Gambaro G, Ferraro PM. Cystinuria: an update on pathophysiology, genetics, and clinical management. Pediatr Nephrol 2022; 37:1705-1711. [PMID: 34812923 DOI: 10.1007/s00467-021-05342-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 09/22/2021] [Accepted: 10/12/2021] [Indexed: 11/25/2022]
Abstract
Cystinuria is the most common genetic cause of nephrolithiasis in children. It is considered a heritable aminoaciduria as the genetic defect affects the reabsorption of cystine and three other amino acids (ornithine, lysine, and arginine) in the renal proximal tubule. Patients affected by this condition have elevated excretion of cystine in the urine, and because of this amino acid's low solubility at normal urine pH, patients tend to form cystine calculi. To date, two genes have been identified as disease-causative: SLC3A1 and SLC7A9, encoding for the two subunits of the heterodimeric transporter. The clinical features of this condition are solely related to nephrolithiasis. The diagnosis is usually made during infancy or adolescence, but cases of late diagnosis are common. The goal of therapy is to reduce excretion and increase the solubility of cystine, through both modifications of dietary habits and pharmacological treatment. However, therapeutic interventions are not always sufficient, and patients often have to undergo several surgical procedures during their lives to treat recurrent nephrolithiasis. The goal of this literature review is to synthesize the available evidence on diagnosis and management of patients affected by cystinuria in order to provide physicians with a practical tool that can be used in daily clinical practice. This review also aims to shed some light on new therapy directions with the aim of ameliorating kidney outcomes while improving adherence to treatment and quality of life of cystinuric patients.
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Affiliation(s)
- Viola D'Ambrosio
- Dipartimento Di Scienze Mediche E Chirurgiche, U.O.S. Terapia Conservativa Della Malattia Renale Cronica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Agostino Gemelli 8, U.O.C. Nefrologia, 00168, Rome, Italy
- Dipartimento Universitario Di Medicina E Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Giovanna Capolongo
- Department of Translational Medical Sciences, Unit of Nephrology, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - David Goldfarb
- Nephrology Section, VA, New York Harbor Healthcare System, New York, NY, USA
- Division of Nephrology, New York University Langone Medical Center, New York, NY, USA
| | - Giovanni Gambaro
- Department of Medicine, Division of Nephrology and Dialysis, Renal Unit, University of Verona, Verona, Italy
| | - Pietro Manuel Ferraro
- Dipartimento Di Scienze Mediche E Chirurgiche, U.O.S. Terapia Conservativa Della Malattia Renale Cronica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Agostino Gemelli 8, U.O.C. Nefrologia, 00168, Rome, Italy.
- Dipartimento Universitario Di Medicina E Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, Rome, Italy.
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15
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Rullo-Tubau J, Bartoccioni P, Llorca O, Errasti-Murugarren E, Palacín M. HATs meet structural biology. Curr Opin Struct Biol 2022; 74:102389. [DOI: 10.1016/j.sbi.2022.102389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/31/2022] [Accepted: 04/10/2022] [Indexed: 11/26/2022]
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16
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Ca 2+-mediated higher-order assembly of heterodimers in amino acid transport system b 0,+ biogenesis and cystinuria. Nat Commun 2022; 13:2708. [PMID: 35577790 PMCID: PMC9110406 DOI: 10.1038/s41467-022-30293-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 04/22/2022] [Indexed: 02/06/2023] Open
Abstract
Cystinuria is a genetic disorder characterized by overexcretion of dibasic amino acids and cystine, causing recurrent kidney stones and kidney failure. Mutations of the regulatory glycoprotein rBAT and the amino acid transporter b0,+AT, which constitute system b0,+, are linked to type I and non-type I cystinuria respectively and they exhibit distinct phenotypes due to protein trafficking defects or catalytic inactivation. Here, using electron cryo-microscopy and biochemistry, we discover that Ca2+ mediates higher-order assembly of system b0,+. Ca2+ stabilizes the interface between two rBAT molecules, leading to super-dimerization of b0,+AT-rBAT, which in turn facilitates N-glycan maturation and protein trafficking. A cystinuria mutant T216M and mutations of the Ca2+ site of rBAT cause the loss of higher-order assemblies, resulting in protein trapping at the ER and the loss of function. These results provide the molecular basis of system b0,+ biogenesis and type I cystinuria and serve as a guide to develop new therapeutic strategies against it. More broadly, our findings reveal an unprecedented link between transporter oligomeric assembly and protein-trafficking diseases.
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17
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Differences in renal cortex transcriptional profiling of wild-type and novel type B cystinuria model rats. Urolithiasis 2022; 50:279-291. [PMID: 35416493 PMCID: PMC9110498 DOI: 10.1007/s00240-022-01321-6] [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: 09/05/2021] [Accepted: 03/03/2022] [Indexed: 11/20/2022]
Abstract
Cystinuria is a genetic disorder of cystine transport that accounts for 1–2% of all cases of renal lithiasis. It is characterized by hyperexcretion of cystine in urine and recurrent cystine lithiasis. Defective transport of cystine into epithelial cells of renal tubules occurs because of mutations of the transport heterodimer, including protein b0,+AT (encoded by SLC7A9) and rBAT (encoded by SLC3A1) linked through a covalent disulfide bond. Study generated a novel type B cystinuria rat model by artificially deleting 7 bp of Slc7a9 gene exon 3 using the CRISPR-Cas9 system, and those Slc7a9-deficient rats were proved to be similar with cystinuria in terms of genome, transcriptome, translation, and biologic phenotypes with no off-target editing. Subsequent comparisons of renal histopathology indicated model rats gained typical secondary changes as medullary fibrosis with no stone formation. A total of 689 DEGs (383 upregulated and 306 downregulated) were differentially expressed in the renal cortex of cystinuria rats. In accordance with the functional annotation of DEGs, the potential role of glutathione metabolism processes in the kidney of cystinuria rat model was proposed, and KEGG analysis results showed that knock-out of Slc7a9 gene triggered more biological changes which has not been studied. In short, for the first time, a rat model and its transcriptional database that mimics the pathogenesis and clinical consequences of human type B cystinuria were generated.
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18
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Singh P, Harris PC, Sas DJ, Lieske JC. The genetics of kidney stone disease and nephrocalcinosis. Nat Rev Nephrol 2022; 18:224-240. [PMID: 34907378 DOI: 10.1038/s41581-021-00513-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2021] [Indexed: 12/15/2022]
Abstract
Kidney stones (also known as urinary stones or nephrolithiasis) are highly prevalent, affecting approximately 10% of adults worldwide, and the incidence of stone disease is increasing. Kidney stone formation results from an imbalance of inhibitors and promoters of crystallization, and calcium-containing calculi account for over 80% of stones. In most patients, the underlying aetiology is thought to be multifactorial, with environmental, dietary, hormonal and genetic components. The advent of high-throughput sequencing techniques has enabled a monogenic cause of kidney stones to be identified in up to 30% of children and 10% of adults who form stones, with ~35 different genes implicated. In addition, genome-wide association studies have implicated a series of genes involved in renal tubular handling of lithogenic substrates and of inhibitors of crystallization in stone disease in the general population. Such findings will likely lead to the identification of additional treatment targets involving underlying enzymatic or protein defects, including but not limited to those that alter urinary biochemistry.
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Affiliation(s)
- Prince Singh
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Division of Molecular Biology and Biochemistry, Mayo Clinic, Rochester, MN, USA
| | - David J Sas
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA. .,Division of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
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19
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Karahoda R, Zaugg J, Fuenzalida B, Kallol S, Moser-Haessig R, Staud F, Albrecht C. Trophoblast Differentiation Affects Crucial Nutritive Functions of Placental Membrane Transporters. Front Cell Dev Biol 2022; 10:820286. [PMID: 35273963 PMCID: PMC8901483 DOI: 10.3389/fcell.2022.820286] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/25/2022] [Indexed: 12/17/2022] Open
Abstract
Cytotrophoblasts are progenitor cells that proliferate and fuse to form the multinucleated syncytiotrophoblast layer, implicated in placental endocrine and transport functions. While membrane transporters play a critical role in the distribution of nutrients, hormones, and xenobiotics at the maternal-fetal interface, their selectivity to the syncytiotrophoblast layer is poorly characterized. We aimed to evaluate the regulation of placental transporters in response to trophoblast differentiation in vitro. Experiments were carried out in isolated primary human trophoblast cells before and after syncytialization. Gene expression of six molecular markers and thirty membrane transporters was investigated by qPCR analysis. Subsequently, functional expression was evaluated for proteins involved in the transplacental transfer of essential nutrients i.e., cholesterol (ABCA1, ABCG1), glucose (SLC2A1), leucine (SLC3A2, SLC7A5), and iron (transferrin receptor, TfR1). We identified that human chorionic gonadotropin, placental lactogen, endoglin, and cadherin-11 serve as optimal gene markers for the syncytialization process. We showed that trophoblast differentiation was associated with differential gene expression (mostly up-regulation) of several nutrient and drug transporters. Further, we revealed enhanced protein expression and activity of ABCG1, SLC3A2, SLC7A5, and TfR1 in syncytialized cells, with ABCA1 and GLUT1 displaying no change. Taken together, these results indicate that the syncytiotrophoblast has a dominant role in transporting essential nutrients cholesterol, leucine, and iron. Nonetheless, we present evidence that the cytotrophoblast cells may also be linked to transport functions that could be critical for the cell fusion processes. Our findings collectively yield new insights into the cellular functions associated with or altered by the trophoblast fusion. Importantly, defective syncytialization could lead to nutrient transfer imbalance, ultimately compromising fetal development and programming.
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Affiliation(s)
- Rona Karahoda
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - Jonas Zaugg
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.,Swiss National Centre of Competence in Research, NCCR TransCure, University of Bern, Bern, Switzerland
| | - Barbara Fuenzalida
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Sampada Kallol
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.,Swiss National Centre of Competence in Research, NCCR TransCure, University of Bern, Bern, Switzerland
| | | | - Frantisek Staud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - Christiane Albrecht
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.,Swiss National Centre of Competence in Research, NCCR TransCure, University of Bern, Bern, Switzerland
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20
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Correia MJ, Pimpão AB, Fernandes DGF, Morello J, Sequeira CO, Calado J, Antunes AMM, Almeida MS, Branco P, Monteiro EC, Vicente JB, Serpa J, Pereira SA. Cysteine as a Multifaceted Player in Kidney, the Cysteine-Related Thiolome and Its Implications for Precision Medicine. Molecules 2022; 27:1416. [PMID: 35209204 PMCID: PMC8874463 DOI: 10.3390/molecules27041416] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 11/16/2022] Open
Abstract
In this review encouraged by original data, we first provided in vivo evidence that the kidney, comparative to the liver or brain, is an organ particularly rich in cysteine. In the kidney, the total availability of cysteine was higher in cortex tissue than in the medulla and distributed in free reduced, free oxidized and protein-bound fractions (in descending order). Next, we provided a comprehensive integrated review on the evidence that supports the reliance on cysteine of the kidney beyond cysteine antioxidant properties, highlighting the relevance of cysteine and its renal metabolism in the control of cysteine excess in the body as a pivotal source of metabolites to kidney biomass and bioenergetics and a promoter of adaptive responses to stressors. This view might translate into novel perspectives on the mechanisms of kidney function and blood pressure regulation and on clinical implications of the cysteine-related thiolome as a tool in precision medicine.
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Affiliation(s)
- Maria João Correia
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
| | - António B. Pimpão
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
| | - Dalila G. F. Fernandes
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), 2780-157 Oeiras, Portugal; (D.G.F.F.); (J.B.V.)
| | - Judit Morello
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
| | - Catarina O. Sequeira
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
| | - Joaquim Calado
- Centre for Toxicogenomics and Human Health (ToxOmics), Genetics, Oncology and Human Toxicology, Nova Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal;
- Nephrology Department, Centro Hospitalar Universitário de Lisboa Central, 1069-166 Lisboa, Portugal
| | - Alexandra M. M. Antunes
- Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, 1049-001 Lisboa, Portugal;
| | - Manuel S. Almeida
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
- Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, 2790-134 Carnaxide, Portugal
| | - Patrícia Branco
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
- Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, 2790-134 Carnaxide, Portugal
| | - Emília C. Monteiro
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
| | - João B. Vicente
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), 2780-157 Oeiras, Portugal; (D.G.F.F.); (J.B.V.)
| | - Jacinta Serpa
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
- Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG), 1099-023 Lisboa, Portugal
| | - Sofia A. Pereira
- CEDOC, NOVA Medical School, Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal; (M.J.C.); (A.B.P.); (J.M.); (C.O.S.); (M.S.A.); (P.B.); (E.C.M.); (J.S.)
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21
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Structural basis for substrate specificity of heteromeric transporters of neutral amino acids. Proc Natl Acad Sci U S A 2021; 118:2113573118. [PMID: 34848541 DOI: 10.1073/pnas.2113573118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2021] [Indexed: 11/18/2022] Open
Abstract
Despite having similar structures, each member of the heteromeric amino acid transporter (HAT) family shows exquisite preference for the exchange of certain amino acids. Substrate specificity determines the physiological function of each HAT and their role in human diseases. However, HAT transport preference for some amino acids over others is not yet fully understood. Using cryo-electron microscopy of apo human LAT2/CD98hc and a multidisciplinary approach, we elucidate key molecular determinants governing neutral amino acid specificity in HATs. A few residues in the substrate-binding pocket determine substrate preference. Here, we describe mutations that interconvert the substrate profiles of LAT2/CD98hc, LAT1/CD98hc, and Asc1/CD98hc. In addition, a region far from the substrate-binding pocket critically influences the conformation of the substrate-binding site and substrate preference. This region accumulates mutations that alter substrate specificity and cause hearing loss and cataracts. Here, we uncover molecular mechanisms governing substrate specificity within the HAT family of neutral amino acid transporters and provide the structural bases for mutations in LAT2/CD98hc that alter substrate specificity and that are associated with several pathologies.
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22
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Cogal AG, Arroyo J, Shah RJ, Reese KJ, Walton BN, Reynolds LM, Kennedy GN, Seide BM, Senum SR, Baum M, Erickson SB, Jagadeesh S, Soliman NA, Goldfarb DS, Beara-Lasic L, Edvardsson VO, Palsson R, Milliner DS, Sas DJ, Lieske JC, Harris PC. Comprehensive Genetic Analysis Reveals Complexity of Monogenic Urinary Stone Disease. Kidney Int Rep 2021; 6:2862-2884. [PMID: 34805638 PMCID: PMC8589729 DOI: 10.1016/j.ekir.2021.08.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/24/2021] [Accepted: 08/30/2021] [Indexed: 01/06/2023] Open
Abstract
Introduction Because of phenotypic overlap between monogenic urinary stone diseases (USD), gene-specific analyses can result in missed diagnoses. We used targeted next generation sequencing (tNGS), including known and candidate monogenic USD genes, to analyze suspected primary hyperoxaluria (PH) or Dent disease (DD) patients genetically unresolved (negative; N) after Sanger analysis of the known genes. Cohorts consisted of 285 PH (PHN) and 59 DD (DDN) families. Methods Variants were assessed using disease-specific and population databases plus variant assessment tools and categorized using the American College of Medical Genetics (ACMG) guidelines. Prior Sanger analysis identified 47 novel PH or DD gene pathogenic variants. Results Screening by tNGS revealed pathogenic variants in 14 known monogenic USD genes, accounting for 45 families (13.1%), 27 biallelic and 18 monoallelic, including 1 family with a copy number variant (CNV). Recurrent genes included the following: SLC34A3 (n = 13), CLDN16 (n = 8), CYP24A1 (n = 4), SLC34A1 (n = 3), SLC4A1 (n = 3), APRT (n = 2), CLDN19 (n = 2), HNF4A1 (n = 2), and KCNJ1 (n = 2), whereas ATP6V1B1, CASR, and SLC12A1 and missed CNVs in the PH genes AGXT and GRHPR accounted for 1 pedigree each. Of the 48 defined pathogenic variants, 27.1% were truncating and 39.6% were novel. Most patients were diagnosed before 18 years of age (76.1%), and 70.3% of biallelic patients were homozygous, mainly from consanguineous families. Conclusion Overall, in patients suspected of DD or PH, 23.9% and 7.3% of cases, respectively, were caused by pathogenic variants in other genes. This study shows the value of a tNGS screening approach to increase the diagnosis of monogenic USD, which can optimize therapies and facilitate enrollment in clinical trials.
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Affiliation(s)
- Andrea G Cogal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Jennifer Arroyo
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Ronak Jagdeep Shah
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Kalina J Reese
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Brenna N Walton
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Laura M Reynolds
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gabrielle N Kennedy
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Barbara M Seide
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Sarah R Senum
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Stephen B Erickson
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Neveen A Soliman
- Department of Pediatrics, Center of Pediatric Nephrology and Transplantation, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - David S Goldfarb
- Nephrology Division, New York University Langone Health and New York University School of Medicine, New York, New York, USA
| | - Lada Beara-Lasic
- Nephrology Division, New York University Langone Health and New York University School of Medicine, New York, New York, USA
| | - Vidar O Edvardsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Children's Medical Center, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
| | - Runolfur Palsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Division of Nephrology, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
| | - Dawn S Milliner
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - David J Sas
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
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23
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Bröer S, Gauthier-Coles G. Amino Acid Homeostasis in Mammalian Cells with a Focus on Amino Acid Transport. J Nutr 2021; 152:16-28. [PMID: 34718668 PMCID: PMC8754572 DOI: 10.1093/jn/nxab342] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/02/2021] [Accepted: 09/17/2021] [Indexed: 12/12/2022] Open
Abstract
Amino acid homeostasis is maintained by import, export, oxidation, and synthesis of nonessential amino acids, and by the synthesis and breakdown of protein. These processes work in conjunction with regulatory elements that sense amino acids or their metabolites. During and after nutrient intake, amino acid homeostasis is dominated by autoregulatory processes such as transport and oxidation of excess amino acids. Amino acid deprivation triggers processes such as autophagy and the execution of broader transcriptional programs to maintain plasma amino acid concentrations. Amino acid transport plays a crucial role in the absorption of amino acids in the intestine, the distribution of amino acids across cells and organs, the recycling of amino acids in the kidney, and the recycling of amino acids after protein breakdown.
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24
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A case of early onset cystinuria in a 4-month-old girl. CEN Case Rep 2021; 11:216-219. [PMID: 34669168 DOI: 10.1007/s13730-021-00655-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 10/12/2021] [Indexed: 10/20/2022] Open
Abstract
Cystinuria is an autosomal recessive disorder characterized by a decrease in the reabsorption of cystine and dibasic amino acids (lysine, ornithine, and arginine) in the renal proximal tubule. It presents with recurrent urolithiasis. Cystinuria accounts for 6-8% of all pediatric urolithiasis. The age of onset is typically 10-30 years. Here, we report a case of early-onset cystinuria. A 4-month-old girl presented with hematuria. We noticed multiple renal calculi in ultrasonography and abdominal computerized tomography scans. The diagnosis was cystinuria with urinary calculus analysis and urinary amino acid analysis. The patient was treated with urine alkalinization and cystine chelating drugs. Gene analysis showed a P482L heterozygous mutation from her mother, and an A70V heterozygous mutation from her father, in the SLC7A9 gene. This gene encodes a putative subunit of the neutral and basic amino acid transport protein, BAT1. Although cystinuria is an autosomal recessive disease, there have been previous reports of P482L heterozygous mutations greatly suppressing cystine reabsorption and causing cystinuria symptoms. Therefore, the highly influential P482L mutation of the SLC7A9 gene may have contributed to the onset of this autosomal recessive disease at an extremely young age.
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25
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Lenherr-Taube N, Young EJ, Furman M, Elia Y, Assor E, Chitayat D, Uster T, Kirwin S, Robbins K, Vinette KMB, Daneman A, Marshall CR, Collins C, Thummel K, Sochett E, Levine MA. Mild Idiopathic Infantile Hypercalcemia-Part 1: Biochemical and Genetic Findings. J Clin Endocrinol Metab 2021; 106:2915-2937. [PMID: 34125233 PMCID: PMC8475208 DOI: 10.1210/clinem/dgab431] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Indexed: 11/19/2022]
Abstract
CONTEXT Idiopathic infantile hypercalcemia (IIH), an uncommon disorder characterized by elevated serum concentrations of 1,25 dihydroxyvitamin D (1,25(OH)2D) and low parathyroid hormone (PTH) levels, may present with mild to severe hypercalcemia during the first months of life. Biallelic variants in the CYP24A1 or SLC34A1 genes are associated with severe IIH. Little is known about milder forms. OBJECTIVE This work aims to characterize the genetic associations and biochemical profile of mild IIH. METHODS This is a cross-sectional study including children between age 6 months and 17 years with IIH who were followed in the Calcium Clinic at the Hospital for Sick Children (SickKids), Toronto, Canada. Twenty children with mild IIH on calcium-restricted diets were evaluated. We performed a dietary assessment and analyzed biochemical measures including vitamin D metabolites and performed a stepwise molecular genetic analysis. Complementary biochemical assessments and renal ultrasounds were offered to first-degree family members of positive probands. RESULTS The median age was 16 months. Median serum levels of calcium (2.69 mmol/L), urinary calcium:creatinine ratio (0.72 mmol/mmol), and 1,25(OH)2D (209 pmol/L) were elevated, whereas intact PTH was low normal (22.5 ng/L). Mean 1,25(OH)2D/PTH and 1,25(OH)2D/25(OH)D ratios were increased by comparison to healthy controls. Eleven individuals (55%) had renal calcification. Genetic variants were common (65%), with the majority being heterozygous variants in SLC34A1 and SLC34A3, while a minority showed variants of CYP24A1 and other genes related to hypercalciuria. CONCLUSION The milder form of IIH has a distinctive vitamin D metabolite profile and is primarily associated with heterozygous SLC34A1 and SLC34A3 variants.
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Affiliation(s)
- Nina Lenherr-Taube
- Department of Pediatrics, Division of Endocrinology, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Edwin J Young
- Genome Diagnostics, Department of Paediatric Medicine, The Hospital for Sick Children, M5G 1X8 Toronto, Ontario, Canada
| | - Michelle Furman
- Department of Pediatrics, Division of Endocrinology, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Yesmino Elia
- Department of Pediatrics, Division of Endocrinology, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Esther Assor
- Department of Pediatrics, Division of Endocrinology, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - David Chitayat
- Department of Obstetrics and Gynecology, The Prenatal Diagnosis and Medical Genetics Program, Mount Sinai Hospital, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
- Department of Pediatrics, Division of Clinical Genetics and Metabolism, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Tami Uster
- Department of Obstetrics and Gynecology, The Prenatal Diagnosis and Medical Genetics Program, Mount Sinai Hospital, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Susan Kirwin
- Nemours Molecular Diagnostics Laboratory, Nemours Children’s Health System, Wilmington, Delaware 19802, USA
| | - Katherine Robbins
- Nemours Molecular Diagnostics Laboratory, Nemours Children’s Health System, Wilmington, Delaware 19802, USA
| | - Kathleen M B Vinette
- Nemours Molecular Diagnostics Laboratory, Nemours Children’s Health System, Wilmington, Delaware 19802, USA
| | - Alan Daneman
- Department of Diagnostic Imaging, Division of General Radiology and Body Imaging, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Christian R Marshall
- Genome Diagnostics, Department of Paediatric Medicine, The Hospital for Sick Children, M5G 1X8 Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, M5S 1A8 Toronto, Ontario, Canada
| | - Carol Collins
- Department of Pharmaceutics, University of Washington, Seattle, Washington 98195, USA
| | - Kenneth Thummel
- Department of Pharmaceutics, University of Washington, Seattle, Washington 98195, USA
| | - Etienne Sochett
- Department of Pediatrics, Division of Endocrinology, The Hospital for Sick Children, University of Toronto, M5G 1X8 Toronto, Ontario, Canada
| | - Michael A Levine
- Division of Endocrinology and Diabetes and Center for Bone Health, Children’s Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
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26
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Nicolàs-Aragó A, Fort J, Palacín M, Errasti-Murugarren E. Rush Hour of LATs towards Their Transport Cycle. MEMBRANES 2021; 11:602. [PMID: 34436365 PMCID: PMC8399266 DOI: 10.3390/membranes11080602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 12/29/2022]
Abstract
The mammalian SLC7 family comprises the L-amino acid transporters (LATs) and the cationic amino acid transporters (CATs). The relevance of these transporters is highlighted by their involvement in several human pathologies, including inherited rare diseases and acquired diseases, such as cancer. In the last four years, several crystal or cryo-EM structures of LATs and CATs have been solved. These structures have started to fill our knowledge gap that previously was based on the structural biology of remote homologs of the amino acid-polyamine-organocation (APC) transporters. This review recovers this structural and functional information to start generating the molecular bases of the transport cycle of LATs. Special attention is given to the known transporter conformations within the transport cycle and the molecular bases for substrate interaction and translocation, including the asymmetric interaction of substrates at both sides of the plasma membrane.
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Affiliation(s)
- Adrià Nicolàs-Aragó
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (J.F.)
| | - Joana Fort
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (J.F.)
- CIBERER (Centro Español en Red de Biomedicina de Enfermedades Raras), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Manuel Palacín
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (J.F.)
- CIBERER (Centro Español en Red de Biomedicina de Enfermedades Raras), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Ekaitz Errasti-Murugarren
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (J.F.)
- CIBERER (Centro Español en Red de Biomedicina de Enfermedades Raras), 08028 Barcelona, Spain
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Mansilla MA, Sompallae RR, Nishimura CJ, Kwitek AE, Kimble MJ, Freese ME, Campbell CA, Smith RJ, Thomas CP. Targeted broad-based genetic testing by next-generation sequencing informs diagnosis and facilitates management in patients with kidney diseases. Nephrol Dial Transplant 2021; 36:295-305. [PMID: 31738409 PMCID: PMC7834596 DOI: 10.1093/ndt/gfz173] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/23/2019] [Indexed: 12/15/2022] Open
Abstract
Background The clinical diagnosis of genetic renal diseases may be limited by the overlapping spectrum of manifestations between diseases or by the advancement of disease where clues to the original process are absent. The objective of this study was to determine whether genetic testing informs diagnosis and facilitates management of kidney disease patients. Methods We developed a comprehensive genetic testing panel (KidneySeq) to evaluate patients with various phenotypes including cystic diseases, congenital anomalies of the kidney and urinary tract (CAKUT), tubulointerstitial diseases, transport disorders and glomerular diseases. We evaluated this panel in 127 consecutive patients ranging in age from newborns to 81 years who had samples sent in for genetic testing. Results The performance of the sequencing pipeline for single-nucleotide variants was validated using CEPH (Centre de’Etude du Polymorphism) controls and for indels using Genome-in-a-Bottle. To test the reliability of the copy number variant (CNV) analysis, positive samples were re-sequenced and analyzed. For patient samples, a multidisciplinary review board interpreted genetic results in the context of clinical data. A genetic diagnosis was made in 54 (43%) patients and ranged from 54% for CAKUT, 53% for ciliopathies/tubulointerstitial diseases, 45% for transport disorders to 33% for glomerulopathies. Pathogenic and likely pathogenic variants included 46% missense, 11% nonsense, 6% splice site variants, 23% insertion–deletions and 14% CNVs. In 13 cases, the genetic result changed the clinical diagnosis. Conclusion Broad genetic testing should be considered in the evaluation of renal patients as it complements other tests and provides insight into the underlying disease and its management.
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Affiliation(s)
- M Adela Mansilla
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA, USA
| | | | - Carla J Nishimura
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA, USA
| | - Anne E Kwitek
- Physiology, Medical College of Wisconsin, Iowa City, IA, USA
| | - Mycah J Kimble
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA, USA
| | | | - Colleen A Campbell
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA, USA
| | - Richard J Smith
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA, USA.,Internal Medicine, University of Iowa, Iowa City, IA, USA.,Pediatrics, University of Iowa, Iowa City, IA, USA
| | - Christie P Thomas
- Internal Medicine, University of Iowa, Iowa City, IA, USA.,Pediatrics, University of Iowa, Iowa City, IA, USA.,Veterans Affairs Medical Center, Iowa City, IA, USA
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Halbritter J. Genetics of kidney stone disease-Polygenic meets monogenic. Nephrol Ther 2021; 17S:S88-S94. [PMID: 33910705 DOI: 10.1016/j.nephro.2020.02.003] [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] [Received: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 11/16/2022]
Abstract
Kidney stone disease comprising nephrolithiasis and nephrocalcinosis is a clinical syndrome of increasing prevalence with remarkable heterogeneity. Stone composition, age of manifestation, rate of recurrence, and impairment of kidney function varies with underlying etiologies. While calcium-based kidney stones account for the vast majority their etiology is still poorly understood. Recent studies underline the notion that genetic susceptibility together with dietary habits constitutes the major driver of kidney stone formation. In addition to single gene (Mendelian) disorders, which are most likely underestimated in the adult population, common risk alleles explain part of the observed heritability. Interestingly, identified GWAS loci often match those of Mendelian disease genes and vice versa (CASR, SLC34A1, CYP24A1). These findings provide mechanistic links related to renal calcium homeostasis, vitamin D metabolism, and CaSR-signaling regulated by the CaSR-CLDN14-CLDN16/19 axis (paracellular Ca2+ reabsorption) and TRPV5 (transcellular Ca2+ reabsorption). Recent identification of new single gene disorders of calcium-oxalate-nephrolithiasis (SLC26A1, CLDN2) and distal renal tubular acidosis with nephrocalcinosis (FOXI1, WDR72, ATP6V1C2) enabled additional insights into the kidney-gut axis and molecular prerequisites of proper urinary acidification. Implementation of centralized patient registries on hereditary kidney stone diseases are necessary to build up well characterized cohorts for urgently needed clinical studies.
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Affiliation(s)
- Jan Halbritter
- Medical Department III, Endocrinology, Nephrology and Rheumatology, Division of Nephrology, University of Leipzig Medical Center, Leipzig, Germany.
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29
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Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
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Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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30
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Halalsheh OM, Al-Shehabat MA, Al-Ghazo M, Al-Ghalayini IF, Altal YA, Al-Okour R, Altal O. Analysis of SLC7A9 gene mutations among Jordanian patients with cystinuria. Ann Med Surg (Lond) 2021; 63:102182. [PMID: 33680451 PMCID: PMC7930589 DOI: 10.1016/j.amsu.2021.102182] [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: 12/25/2020] [Revised: 02/08/2021] [Accepted: 02/12/2021] [Indexed: 11/29/2022] Open
Abstract
Background Cystinuria is known as a heritable disorder affecting the cysteine reabsorption by renal system as well as the reabsorption of dibasic amino acids. The main objectives of the present study were to identify genetic mutations in SLC7A9 gene associated with cystinuria. Methods A cross sectional study design was conducted. A total of 28 patients diagnosed with cystinuria were included. Molecular techniques were applied to identify genetic mutations in SLC7A9 gene. Results The mean age of study participants was 31.57 ± 2.88 years, and slightly more than two thirds of participants were males. Mutations of SLC 7A9 gene showed that the majority of cases (57.1%) were homogeneous, (7.1%) heterogeneous, and slightly more than one third of patients had no mutations. There was no statistically significant relationship between mutations for the SLC7A9 gene and gender (p = 0.249). Conclusion Mutations in the SLC7A9 gene are prevalent and can be used as molecular tools to diagnose cystinuria. Cystinuria is an inherited disorder of dibasic amino acid as cystine transport in kidney. SLC7A9 Cystinuria gene was recently isolated in many cystinuria patient from different racial populations. Mutations in the SLC7A9 gene are prevalent in Jordanian (Arab) populations.
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Affiliation(s)
- Omar M. Halalsheh
- Department of General Surgery and Urology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
- Corresponding author. Department of Urology, Faculty of Medicine Jordan University of Science and Technology, King Abdullah University Hospital, P. O. Box: 3030, Irbid, 22110, Jordan.
| | - Mustafa A. Al-Shehabat
- Department of Physiology and Biochemistry, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Moh''D.A. Al-Ghazo
- Department of General Surgery and Urology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Ibrahim F. Al-Ghalayini
- Department of General Surgery and Urology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Yaman A. Altal
- Department of General Surgery and Urology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Radwan Al-Okour
- Department of General Surgery and Urology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Omar Altal
- Department of Obstetrics and Gynecology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
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31
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Errasti-Murugarren E, Palacín M. Heteromeric Amino Acid Transporters in Brain: from Physiology to Pathology. Neurochem Res 2021; 47:23-36. [PMID: 33606172 DOI: 10.1007/s11064-021-03261-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 12/12/2022]
Abstract
In humans, more than 50 transporters are responsible for the traffic and balance of amino acids within and between cells and tissues, and half of them have been associated with disease [1]. Covering all common amino acids, Heteromeric Amino acid Transporters (HATs) are one class of such transporters. This review first highlights structural and functional studies that solved the atomic structure of HATs and revealed molecular clues on substrate interaction. Moreover, this review focuses on HATs that have a role in the central nervous system (CNS) and that are related to neurological diseases, including: (i) LAT1/CD98hc and its role in the uptake of branched chain amino acids trough the blood brain barrier and autism. (ii) LAT2/CD98hc and its potential role in the transport of glutamine between plasma and cerebrospinal fluid. (iii) y+LAT2/CD98hc that is emerging as a key player in hepatic encephalopathy. xCT/CD98hc as a potential therapeutic target in glioblastoma, and (iv) Asc-1/CD98hc as a potential therapeutic target in pathologies with alterations in NMDA glutamate receptors.
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Affiliation(s)
- Ekaitz Errasti-Murugarren
- Institute for Research in Biomedicine. Institute of Science and Technology (BIST), 08028, Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 08028, Barcelona, Spain.
| | - Manuel Palacín
- Institute for Research in Biomedicine. Institute of Science and Technology (BIST), 08028, Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 08028, Barcelona, Spain. .,Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain.
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To VPTH, Masagounder K, Loewen ME. Critical transporters of methionine and methionine hydroxyl analogue supplements across the intestine: What we know so far and what can be learned to advance animal nutrition. Comp Biochem Physiol A Mol Integr Physiol 2021; 255:110908. [PMID: 33482339 DOI: 10.1016/j.cbpa.2021.110908] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/15/2020] [Accepted: 01/11/2021] [Indexed: 11/19/2022]
Abstract
DL-methionine (DL-Met) and its analogue DL-2-hydroxy-4-(methylthio) butanoic acid (DL-methionine hydroxyl analogue or DL-MHA) have been used as nutritional supplements in the diets of farmed raised animals. Knowledge of the intestinal transport mechanisms involved in these products is important for developing dietary strategies. This review provides updated information of the expression, function, and transport kinetics in the intestine of known Met-linked transporters along with putative MHA-linked transporters. As a neutral amino acid (AA), the transport of DL-Met is facilitated by multiple apical sodium-dependent/-independent high-/low-affinity transporters such as ASCT2, B0AT1 and rBAT/b0,+AT. The basolateral transport largely relies on the rate-limiting uniporter LAT4, while the presence of the basolateral antiporter y+LAT1 is probably necessary for exchanging intracellular cationic AAs and Met in the blood. In contrast, the intestinal transport kinetics of DL-MHA have been scarcely studied. DL-MHA transport is generally accepted to be mediated simply by the proton-dependent monocarboxylate transporter MCT1. However, in-depth mechanistic studies have indicated that DL-MHA transport is also achieved through apical sodium monocarboxylate transporters (SMCTs). In any case, reliance on either a proton or sodium gradient would thus require energy input for both Met and MHA transport. This expanding knowledge of the specific transporters involved now allows us to assess the effect of dietary ingredients on the expression and function of these transporters. Potentially, the resulting information could be furthered with selective breeding to reduce overall feed costs.
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Affiliation(s)
- Van Pham Thi Ha To
- Veterinary Biomedical Science, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Matthew E Loewen
- Veterinary Biomedical Science, University of Saskatchewan, Saskatoon, SK, Canada.
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Transport of L-Arginine Related Cardiovascular Risk Markers. J Clin Med 2020; 9:jcm9123975. [PMID: 33302555 PMCID: PMC7764698 DOI: 10.3390/jcm9123975] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
L-arginine and its derivatives, asymmetric and symmetric dimethylarginine (ADMA and SDMA) and L-homoarginine, have emerged as cardiovascular biomarkers linked to cardiovascular outcomes and various metabolic and functional pathways such as NO-mediated endothelial function. Cellular uptake and efflux of L-arginine and its derivatives are facilitated by transport proteins. In this respect the cationic amino acid transporters CAT1 and CAT2 (SLC7A1 and SLC7A2) and the system y+L amino acid transporters (SLC7A6 and SLC7A7) have been most extensively investigated, so far, but the number of transporters shown to mediate the transport of L-arginine and its derivatives is constantly increasing. In the present review we assess the growing body of evidence regarding the function, expression, and clinical relevance of these transporters and their possible relation to cardiovascular diseases.
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34
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Facilitated Diffusion of Proline across Membranes of Liposomes and Living Cells by a Calix[4]pyrrole Cavitand. Chem 2020. [DOI: 10.1016/j.chempr.2020.08.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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35
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Zhao Y, Fang X, Fan Y, Sun Y, He L, Xu M, Xu G, Li Y, Huang Y, Yu Y, Geng H. Integration of exome sequencing and metabolic evaluation for the diagnosis of children with urolithiasis. World J Urol 2020; 39:2759-2765. [PMID: 32936332 DOI: 10.1007/s00345-020-03449-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 09/07/2020] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To investigate the prevalence of inherited causes in an early onset urolithiasis cohort and each metabolic subgroup. METHODS A retrospective analysis of both metabolic and genomic data was performed for the first 105 pediatric urolithiasis patients who underwent exome sequencing at our hospital from February 2016 to October 2018. Measurements included the diagnostic yield of exome sequencing in the entire cohort and each metabolic subgroup (hyperoxaluria, hypocitraturia, hypercalciuria, hyperuricosuria and cystine stone subgroups). The conformity between molecular diagnoses and metabolic evaluation was also evaluated. RESULTS The present study involved a cohort of 105 pediatric patients with urolithiasis, from which diagnostic variants were identified in 38 patients (36%), including 27 primary hyperoxaluria and 11 cystinuria. In the metabolic subgroup analyses, 41% hyperoxaluria cases were primary hyperoxaluria caused by monogenic defects, and 100% of the causes of cystine stones could be explained by monogenic defects. However, no appropriate inherited causes were identified for hypocitraturia, hypercalciuria, or hyperuricosuria in the cohort. A high conformity (100%) was obtained between the molecular diagnoses and metabolic evaluation. CONCLUSION Exome sequencing in a cohort of 105 pediatric patients with urolithiasis yielded a genetic diagnosis in 36% of cases and the molecular diagnostic yield varies substantially across different metabolic abnormalities.
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Affiliation(s)
- Yining Zhao
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Xiaoliang Fang
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Yanjie Fan
- Department of Pediatric Endocrinology/Genetics, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu Sun
- Department of Pediatric Endocrinology/Genetics, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Lei He
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Maosheng Xu
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Guofeng Xu
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Yufeng Li
- Department of Pediatric Nephrology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yunteng Huang
- Department of Urology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yongguo Yu
- Department of Pediatric Endocrinology/Genetics, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hongquan Geng
- Department of Pediatric Urology, Children's Urolithiasis Treatment Center of National Health Commission of China, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China.
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Servais A, Thomas K, Dello Strologo L, Sayer JA, Bekri S, Bertholet-Thomas A, Bultitude M, Capolongo G, Cerkauskiene R, Daudon M, Doizi S, Gillion V, Gràcia-Garcia S, Halbritter J, Heidet L, van den Heijkant M, Lemoine S, Knebelmann B, Emma F, Levtchenko E. Cystinuria: clinical practice recommendation. Kidney Int 2020; 99:48-58. [PMID: 32918941 DOI: 10.1016/j.kint.2020.06.035] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023]
Abstract
Cystinuria (OMIM 220100) is an autosomal recessive hereditary disorder in which high urinary cystine excretion leads to the formation of cystine stones because of the low solubility of cystine at normal urinary pH. We developed clinical practice recommendation for diagnosis, surgical and medical treatment, and follow-up of patients with cystinuria. Elaboration of these clinical practice recommendations spanned from June 2018 to December 2019 with a consensus conference in January 2019. Selected topic areas were chosen by the co-chairs of the conference. Working groups focusing on specific topics were formed. Group members performed systematic literature review using MEDLINE, drafted the statements, and discussed them. They included geneticists, medical biochemists, pediatric and adult nephrologists, pediatric and adult urologists experts in cystinuria, and the Metabolic Nephropathy Joint Working Group of the European Reference Network for Rare Kidney Diseases (ERKNet) and eUROGEN members. Overall 20 statements were produced to provide guidance on diagnosis, genetic analysis, imaging techniques, surgical treatment (indication and modalities), conservative treatment (hydration, dietetic, alkalinization, and cystine-binding drugs), follow-up, self-monitoring, complications (renal failure and hypertension), and impact on quality of life. Because of the rarity of the disease and the poor level of evidence in the literature, these statements could not be graded. This clinical practice recommendation provides guidance on all aspects of the management of both adults and children with cystinuria, including diagnosis, surgery, and medical treatment.
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Affiliation(s)
- Aude Servais
- Nephrology and Transplantation Department, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, APHP, Université de Paris, Paris, France.
| | - Kay Thomas
- Stone Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Luca Dello Strologo
- Renal Transplant Clinic, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, UK; The Newcastle upon Tyne NHS Hospitals Foundation Trust, Newcastle upon Tyne, UK; NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK
| | - Soumeya Bekri
- Department of Metabolic Biochemistry, Rouen University Hospital, Rouen, France
| | - Aurelia Bertholet-Thomas
- Centre de Référence des Maladies Rénales Rares, Filière ORKID, Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, Lyon, France
| | | | - Giovanna Capolongo
- Unit of Nephrology, Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | | | - Michel Daudon
- UMR S 1155 and Physiology Unit, AP-HP, Hôpital Tenon, Sorbonne Université and INSERM, Paris, France
| | - Steeve Doizi
- Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Service d'Urologie, Hôpital Tenon, AP-HP, Paris, France
| | - Valentine Gillion
- Département de Néphrologie adulte, Cliniques universitaires Saint Luc, Bruxelles, Belgium
| | - Silvia Gràcia-Garcia
- Laboratory of Renal Lithiasis, Clinical Laboratories, Fundació Puigvert, Barcelona, Spain
| | - Jan Halbritter
- Division of Nephrology, Department of Endocrinology, Nephrology, and Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Laurence Heidet
- Néphrologie Pédiatrique, Centre de Référence MARHEA, Hôpital universitaire Necker-Enfants Malades, Paris, France
| | - Marleen van den Heijkant
- Pediatric Renal Center, University Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sandrine Lemoine
- Nephrology and Renal Function Unit, Edouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France; University of Lyon, Lyon, France
| | - Bertrand Knebelmann
- Nephrology and Transplantation Department, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, APHP, Université de Paris, Paris, France
| | - Francesco Emma
- Division of Nephrology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - Elena Levtchenko
- Division of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium; Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium
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Structural basis for amino acid exchange by a human heteromeric amino acid transporter. Proc Natl Acad Sci U S A 2020; 117:21281-21287. [PMID: 32817565 DOI: 10.1073/pnas.2008111117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Heteromeric amino acid transporters (HATs) comprise a group of membrane proteins that belong to the solute carrier (SLC) superfamily. They are formed by two different protein components: a light chain subunit from an SLC7 family member and a heavy chain subunit from the SLC3 family. The light chain constitutes the transport subunit whereas the heavy chain mediates trafficking to the plasma membrane and maturation of the functional complex. Mutation, malfunction, and dysregulation of HATs are associated with a wide range of pathologies or represent the direct cause of inherited and acquired disorders. Here we report the cryogenic electron microscopy structure of the neutral and basic amino acid transport complex (b[0,+]AT1-rBAT) which reveals a heterotetrameric protein assembly composed of two heavy and light chain subunits, respectively. The previously uncharacterized interaction between two HAT units is mediated via dimerization of the heavy chain subunits and does not include participation of the light chain subunits. The b(0,+)AT1 transporter adopts a LeuT fold and is captured in an inward-facing conformation. We identify an amino-acid-binding pocket that is formed by transmembrane helices 1, 6, and 10 and conserved among SLC7 transporters.
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Identification, Expression, and Roles of the Cystine/Glutamate Antiporter in Ocular Tissues. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4594606. [PMID: 32655769 PMCID: PMC7320271 DOI: 10.1155/2020/4594606] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/21/2020] [Indexed: 01/21/2023]
Abstract
The cystine/glutamate antiporter (system x c -) is composed of a heavy chain subunit 4F2hc linked by a disulphide bond to a light chain xCT, which exchanges extracellular cystine, the disulphide form of the amino acid cysteine, for intracellular glutamate. In vitro research in the brain, kidney, and liver have shown this antiporter to play a role in minimising oxidative stress by providing a source of intracellular cysteine for the synthesis of the antioxidant glutathione. In vivo studies using the xCT knockout mouse revealed that the plasma cystine/cysteine redox couple was tilted to a more oxidative state demonstrating system xc - to also play a role in maintaining extracellular redox balance by driving a cystine/cysteine redox cycle. In addition, through import of cystine, system xc - also serves to export glutamate into the extracellular space which may influence neurotransmission and glutamate signalling in neural tissues. While changes to system xc - function has been linked to cancer and neurodegenerative disease, there is limited research on the roles of system xc - in the different tissues of the eye, and links between the antiporter, aging, and ocular disease. Hence, this review seeks to consolidate research on system xc - in the cornea, lens, retina, and ocular humours conducted across several species to shed light on the in vitro and in vivo roles of xCT in the eye and highlight the utility of the xCT knockout mouse as a tool to investigate the contribution of xCT to age-related ocular diseases.
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Yan R, Li Y, Shi Y, Zhou J, Lei J, Huang J, Zhou Q. Cryo-EM structure of the human heteromeric amino acid transporter b 0,+AT-rBAT. SCIENCE ADVANCES 2020; 6:eaay6379. [PMID: 32494597 PMCID: PMC7159911 DOI: 10.1126/sciadv.aay6379] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/22/2020] [Indexed: 05/16/2023]
Abstract
Heteromeric amino acid transporters (HATs) catalyze the transmembrane movement of amino acids, comprising two subunits, a heavy chain and a light chain, linked by a disulfide bridge. The b0,+AT (SLC7A9) is a representative light chain of HATs, forming heterodimer with rBAT, a heavy chain which mediates the membrane trafficking of b0,+AT. The b0,+AT-rBAT complex is an obligatory exchanger, which mediates the influx of cystine and cationic amino acids and the efflux of neutral amino acids in kidney and small intestine. Here, we report the cryo-EM structure of the human b0,+AT-rBAT complex alone and in complex with arginine substrate at resolution of 2.7 and 2.3 Å, respectively. The overall structure of b0,+AT-rBAT exists as a dimer of heterodimer consistent with the previous study. A ligand molecule is bound to the substrate binding pocket, near which an occluded pocket is identified, to which we found that it is important for substrate transport.
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Affiliation(s)
- Renhong Yan
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yaning Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yi Shi
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Jiayao Zhou
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Corresponding author. (Q.Z.); (J.H.)
| | - Qiang Zhou
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
- Corresponding author. (Q.Z.); (J.H.)
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40
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Li C, Yang Y, Zheng Y, Shen F, Liu L, Li Y, Li L, Zhao Y. Genetic and Clinical Analyses of 13 Chinese Families With Cystine Urolithiasis and Identification of 15 Novel Pathogenic Variants in SLC3A1 and SLC7A9. Front Genet 2020; 11:74. [PMID: 32133030 PMCID: PMC7040229 DOI: 10.3389/fgene.2020.00074] [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: 10/09/2019] [Accepted: 01/22/2020] [Indexed: 11/13/2022] Open
Abstract
Background Cystinuria is a rare genetic disorder characterized by defective renal reabsorption of cystine, ornithine, arginine, and lysine. The increased urinary excretion of cystine results in the development of cystine urolithiasis (CU). The mutated SLC3A1 and SLC7A9 genes are the cause of CU, a global disorder. Its frequency and mutation spectrum vary between different populations. In Asia, the data for CU are limited. Method Urinary stones were collected from patients of a single center over a five-year period and analyzed via Fourier transform infrared spectroscopy. Genomic DNA was isolated from 13 patients with CU and their parents and from 26 controls affected by calcium oxalate dihydrate stones. The coding regions and the exon-intron boundaries of SLC3A1 and SLC7A9 were subjected to PCR amplification and then sequenced via traditional Sanger sequencing. Genetic variants were functionally annotated using the InterVar, ClinVar, gnom AD, and HGMD databases. Results From the 232 samples of urinary stones, we identified 13 patients with CU (10 males and 3 females). The onset age was from 7 months to 9 years. The CU stones varied from 0.26 cm3 to 18.67 cm3. Sanger sequencing detected a total of 14 SLC3A1 (nine were novel) and 10 SLC7A9 (six were novel) rare variants from the 13 CU families. All variants, including 15 novel variants, were pathogenic, disease-causing, or damaging. Conclusion All 13 pediatric CU families harbored SLC3A1 or/and SLC7A9 rare variants. A total of 15 novel pathogenic variants in SLC3A1 and SLC7A9 were identified. This study expanded the known mutational spectrum of CU in the Chinese population.
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Affiliation(s)
- Chuangye Li
- Department of Urology, Hunan Children's Hospital, Changsha, China
| | - Yongjia Yang
- The Laboratory of Genetics and Metabolism, Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, University of South China, Changsha, China
| | - Yu Zheng
- The Laboratory of Genetics and Metabolism, Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, University of South China, Changsha, China
| | - Fang Shen
- The Laboratory of Genetics and Metabolism, Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, University of South China, Changsha, China
| | - Li Liu
- Department of Urology, Hunan Children's Hospital, Changsha, China
| | - Yanfang Li
- Department of Urology, Hunan Children's Hospital, Changsha, China
| | - Liping Li
- The Laboratory of Genetics and Metabolism, Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, University of South China, Changsha, China
| | - Yaowang Zhao
- Department of Urology, Hunan Children's Hospital, Changsha, China
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Yahyaoui R, Pérez-Frías J. Amino Acid Transport Defects in Human Inherited Metabolic Disorders. Int J Mol Sci 2019; 21:ijms21010119. [PMID: 31878022 PMCID: PMC6981491 DOI: 10.3390/ijms21010119] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023] Open
Abstract
Amino acid transporters play very important roles in nutrient uptake, neurotransmitter recycling, protein synthesis, gene expression, cell redox balance, cell signaling, and regulation of cell volume. With regard to transporters that are closely connected to metabolism, amino acid transporter-associated diseases are linked to metabolic disorders, particularly when they involve different organs, cell types, or cell compartments. To date, 65 different human solute carrier (SLC) families and more than 400 transporter genes have been identified, including 11 that are known to include amino acid transporters. This review intends to summarize and update all the conditions in which a strong association has been found between an amino acid transporter and an inherited metabolic disorder. Many of these inherited disorders have been identified in recent years. In this work, the physiological functions of amino acid transporters will be described by the inherited diseases that arise from transporter impairment. The pathogenesis, clinical phenotype, laboratory findings, diagnosis, genetics, and treatment of these disorders are also briefly described. Appropriate clinical and diagnostic characterization of the underlying molecular defect may give patients the opportunity to avail themselves of appropriate therapeutic options in the future.
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Affiliation(s)
- Raquel Yahyaoui
- Laboratory of Metabolic Disorders and Newborn Screening Center of Eastern Andalusia, Málaga Regional University Hospital, 29011 Málaga, Spain
- Grupo Endocrinología y Nutrición, Diabetes y Obesidad, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain
- Correspondence:
| | - Javier Pérez-Frías
- Grupo Multidisciplinar de Investigación Pediátrica, Instituto de Investigación Biomédica de Málaga-IBIMA, 29010 Málaga, Spain;
- Departamento de Farmacología y Pediatría, Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
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Krammer EM, Prévost M. Function and Regulation of Acid Resistance Antiporters. J Membr Biol 2019; 252:465-481. [DOI: 10.1007/s00232-019-00073-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/08/2019] [Indexed: 01/07/2023]
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Abstract
Background Cystinuria is an inherited disorder of renal amino acid transport that causes recurrent nephrolithiasis and significant morbidity in humans. It has an incidence of 1 in 7000 worldwide making it one of the most common genetic disorders in man. We phenotypically characterized a mouse model of cystinuria type A resultant from knockout of Slc3a1. Methods Knockout of Slc3a1 at RNA and protein levels was evaluated using real-time quantitative PCR and immunofluorescence. Slc3a1 knockout mice were placed on normal or breeder chow diets and evaluated for cystine stone formation over time suing x-ray analysis, and the development of kidney injury by measuring injury biomarkers. Kidney injury was also evaluated via histologic analysis. Amino acid levels were measured in the blood of mice using high performance liquid chromatography. Liver glutathione levels were measured using a luminescent-based assay. Results We confirmed knockout of Slc3a1 at the RNA level, while Slc7a9 RNA representing the co-transporter was preserved. As expected, we observed bladder stone formation in Slc3a1−/− mice. Male Slc3a1−/− mice exhibited lower weights compared to Slc3a1+/+. Slc3a1−/− mice on a regular diet demonstrated elevated blood urea nitrogen (BUN) without elevation of serum creatinine. However, placing the knockout animals on a breeder chow diet, containing a higher cystine concentration, resulted in the development of elevation of both BUN and creatinine indicative of more severe chronic kidney disease. Histological examination revealed that these dietary effects resulted in worsened kidney tubular obstruction and interstitial inflammation as well as worsened bladder inflammation. Cystine is a precursor for the antioxidant molecule glutathione, so we evaluated glutathione levels in the livers of Slc3a1−/− mice. We found significantly lowered levels of both reduced and total glutathione in the knockout animals. Conclusions Our results suggest that that diet can affect the development and progression of chronic kidney disease in an animal model of cystinuria, which may have important implications for patients with this disease. Additionally, reduced glutathione may predispose those with cystinuria to injury caused by oxidative stress. Word count: 327. Electronic supplementary material The online version of this article (10.1186/s12882-019-1417-8) contains supplementary material, which is available to authorized users.
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Cryo-EM structure of the human L-type amino acid transporter 1 in complex with glycoprotein CD98hc. Nat Struct Mol Biol 2019; 26:510-517. [DOI: 10.1038/s41594-019-0237-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023]
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45
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L amino acid transporter structure and molecular bases for the asymmetry of substrate interaction. Nat Commun 2019; 10:1807. [PMID: 31000719 PMCID: PMC6472337 DOI: 10.1038/s41467-019-09837-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 04/02/2019] [Indexed: 11/26/2022] Open
Abstract
L-amino acid transporters (LATs) play key roles in human physiology and are implicated in several human pathologies. LATs are asymmetric amino acid exchangers where the low apparent affinity cytoplasmic side controls the exchange of substrates with high apparent affinity on the extracellular side. Here, we report the crystal structures of an LAT, the bacterial alanine-serine-cysteine exchanger (BasC), in a non-occluded inward-facing conformation in both apo and substrate-bound states. We crystallized BasC in complex with a nanobody, which blocks the transporter from the intracellular side, thus unveiling the sidedness of the substrate interaction of BasC. Two conserved residues in human LATs, Tyr 236 and Lys 154, are located in equivalent positions to the Na1 and Na2 sites of sodium-dependent APC superfamily transporters. Functional studies and molecular dynamics (MD) calculations reveal that these residues are key for the asymmetric substrate interaction of BasC and in the homologous human transporter Asc-1. L-Amino acid Transporters (LATs) are asymmetric amino acid exchangers. Here the authors determine the crystal structure of a prokaryotic LAT, the alanine-serine-cysteine exchanger (BasC) and identify key residues for asymmetric substrate interaction in both BasC and the homologous human transporter Asc-1 through functional studies.
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46
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Bartoccioni P, Fort J, Zorzano A, Errasti-Murugarren E, Palacín M. Functional characterization of the alanine-serine-cysteine exchanger of Carnobacterium sp AT7. J Gen Physiol 2019; 151:505-517. [PMID: 30696726 PMCID: PMC6445583 DOI: 10.1085/jgp.201812195] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/16/2018] [Accepted: 01/03/2019] [Indexed: 01/18/2023] Open
Abstract
Proteins of the L-type amino acid transporter (LAT) subfamily take up amino acids from the environment for use in the cell. Bartoccioni et al. show that the bacterial amino acid exchanger BasC is functionally similar to the human LAT Asc1, making BasC a useful model for this class of transporters. Many key cell processes require prior cell uptake of amino acids from the environment, which is facilitated by cell membrane amino acid transporters such as those of the L-type amino acid transporter (LAT) subfamily. Alterations in LAT subfamily amino acid transport are associated with several human diseases, including cancer, aminoacidurias, and neurodegenerative conditions. Therefore, from the perspective of human health, there is considerable interest in obtaining structural information about these transporter proteins. We recently solved the crystal structure of the first LAT transporter, the bacterial alanine-serine-cysteine exchanger of Carnobacterium sp AT7 (BasC). Here, we provide a complete functional characterization of detergent-purified, liposome-reconstituted BasC transporter to allow the extension of the structural insights into mechanistic understanding. BasC is a sodium- and proton-independent small neutral amino acid exchanger whose substrate and inhibitor selectivity are almost identical to those previously described for the human LAT subfamily member Asc-1. Additionally, we show that, like its human counterparts, this transporter has apparent affinity asymmetry for the intra- and extracellular substrate binding sites—a key feature in the physiological role played by these proteins. BasC is an excellent paradigm of human LAT transporters and will contribute to our understanding of the molecular mechanisms underlying substrate recognition and translocation at both sides of the plasma membrane.
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Affiliation(s)
- Paola Bartoccioni
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras, Barcelona, Spain
| | - Joana Fort
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras, Barcelona, Spain.,Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Antonio Zorzano
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain.,Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, Spain
| | - Ekaitz Errasti-Murugarren
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Manuel Palacín
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain .,Centro de Investigación Biomédica en Red de Enfermedades Raras, Barcelona, Spain.,Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain
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47
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Oliveira B, Unwin R, Walsh SB. Inherited proximal tubular disorders and nephrolithiasis. Urolithiasis 2019; 47:35-42. [PMID: 30673801 DOI: 10.1007/s00240-018-01103-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/08/2018] [Indexed: 12/20/2022]
Abstract
The proximal tubule is responsible for reclaiming water, phosphates and amino acids from the tubular filtrate. There are genetic defects in both phosphate and amino acid transporters leading to nephrolithiasis. This review also explores genetic defects in regulators of phosphate and calcium transport in this nephron segment that lead to stone formation.
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Affiliation(s)
- Ben Oliveira
- Royal Free Hospital/Medical School, Centre for Nephrology, University College London, London, NW3 2PF, UK
| | - Robert Unwin
- Royal Free Hospital/Medical School, Centre for Nephrology, University College London, London, NW3 2PF, UK.,AstraZeneca IMED ECD CVRM R&D, Gothenburg, Sweden
| | - Stephen B Walsh
- Royal Free Hospital/Medical School, Centre for Nephrology, University College London, London, NW3 2PF, UK.
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Abstract
The small intestine mediates the absorption of amino acids after ingestion of protein and sustains the supply of amino acids to all tissues. The small intestine is an important contributor to plasma amino acid homeostasis, while amino acid transport in the large intestine is more relevant for bacterial metabolites and fluid secretion. A number of rare inherited disorders have contributed to the identification of amino acid transporters in epithelial cells of the small intestine, in particular cystinuria, lysinuric protein intolerance, Hartnup disorder, iminoglycinuria, and dicarboxylic aminoaciduria. These are most readily detected by analysis of urine amino acids, but typically also affect intestinal transport. The genes underlying these disorders have all been identified. The remaining transporters were identified through molecular cloning techniques to the extent that a comprehensive portrait of functional cooperation among transporters of intestinal epithelial cells is now available for both the basolateral and apical membranes. Mouse models of most intestinal transporters illustrate their contribution to amino acid homeostasis and systemic physiology. Intestinal amino acid transport activities can vary between species, but these can now be explained as differences of amino acid transporter distribution along the intestine. © 2019 American Physiological Society. Compr Physiol 9:343-373, 2019.
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Affiliation(s)
- Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Stephen J Fairweather
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
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Sumayao R, Newsholme P, McMorrow T. The Role of Cystinosin in the Intermediary Thiol Metabolism and Redox Homeostasis in Kidney Proximal Tubular Cells. Antioxidants (Basel) 2018; 7:antiox7120179. [PMID: 30513914 PMCID: PMC6315507 DOI: 10.3390/antiox7120179] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/22/2018] [Accepted: 11/24/2018] [Indexed: 01/26/2023] Open
Abstract
Cystinosin is a lysosomal transmembrane protein which facilitates transport of the disulphide amino acid cystine (CySS) from the lysosomes of the cell. This protein is encoded by the CTNS gene which is defective in the lysosomal storage disorder, cystinosis. Because of the apparent involvement of cystinosin in the intermediary thiol metabolism, its discovery has fuelled investigations into its role in modulating cellular redox homeostasis. The kidney proximal tubular cells (PTCs) have become the focus of various studies on cystinosin since the protein is highly expressed in these cells and kidney proximal tubular transport dysfunction is the foremost clinical manifestation of cystinosis. The lysosomal CySS pool is a major source of cytosolic cysteine (Cys), the limiting amino acid for the synthesis of an important antioxidant glutathione (GSH) via the γ-glutamyl cycle. Therefore, loss of cystinosin function is presumed to lead to cytosolic deficit of Cys which may impair GSH synthesis. However, studies using in vitro models lacking cystinosin yielded inconsistent results and failed to establish the mechanistic role of cystinosin in modulating GSH synthesis and redox homeostasis. Because of the complexity of the metabolic micro- and macro-environment in vivo, using in vitro models alone may not be able to capture the complete sequence of biochemical and physiological events that occur as a consequence of loss of cystinosin function. The coexistence of pathways for the overall handling and disposition of GSH, the modulation of CTNS gene by intracellular redox status and the existence of a non-canonical isoform of cystinosin may constitute possible rescue mechanisms in vivo to remediate redox perturbations in renal PTCs. Importantly, the mitochondria seem to play a critical role in orchestrating redox imbalances initiated by cystinosin dysfunction. Non-invasive techniques such as in vivo magnetic resonance imaging with the aid of systems biology approaches may provide invaluable mechanistic insights into the role of cystinosin in the essential intermediary thiol metabolism and in the overall regulation cellular redox homeostasis.
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Affiliation(s)
- Rodolfo Sumayao
- Chemistry Department, De La Salle University, Manila 1004, Philippines.
| | - Philip Newsholme
- School of Pharmacy and Biomedical Sciences and Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth 6845, Australia.
| | - Tara McMorrow
- Conway Institute, School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland.
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50
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Olschok K, Vester U, Lahme S, Kurth I, Eggermann T. No evidence for point mutations in the novel renal cystine transporter AGT1/SLC7A13 contributing to the etiology of cystinuria. BMC Nephrol 2018; 19:278. [PMID: 30342472 PMCID: PMC6196009 DOI: 10.1186/s12882-018-1080-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 10/08/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Cystinuria is caused by the defective renal reabsorption of cystine and dibasic amino acids, and results in cystine stone formation. So far, mutations in two genes have been identified as causative. The SLC3A1/rBAT gene encodes the heavy subunit of the heterodimeric rBAT-b0,+AT transporter, whereas the light chain is encoded by the SLC7A9/ b0,+AT gene. In nearly 85% of patients mutations in both genes are detectable, but a significant number of patients currently remains without a molecular diagnosis. Thus, the existence of a further cystinuria gene had been suggested, and the recently identified AGT1/SLC7A13 represents the long-postulated partner of rBAT and third cystinuria candidate gene. METHODS We screened a cohort of 17 cystinuria patients for SLC7A13 variants which were negative for SLC3A1 and SLC7A9 mutations. RESULTS Despite strong evidences for an involvement of SLC7A13 mutations in cystinuria, we could not confirm a relevant role of SLC7A13 for the disease. CONCLUSION With the exclusion of SLC7A13/AGT1 as the third cystinuria gene accounting for the SLC3A1 and SLC7A9 mutation negative cases, it becomes obvious that other genetic factors should be responsible for the cystinuria phenotype in nearly 15% of patients.
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Affiliation(s)
- Kathrin Olschok
- Institute of Human Genetics, University Hospital, Technical University RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany
| | - Udo Vester
- Pediatric Hospital, University Hospital, University of Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Sven Lahme
- Department of Urology, St. Trudpert Hospital, Wilferdinger Str. 67, 75179 Pforzheim, Germany
| | - Ingo Kurth
- Institute of Human Genetics, University Hospital, Technical University RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany
| | - Thomas Eggermann
- Institute of Human Genetics, University Hospital, Technical University RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany
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