1
|
Mungara P, Waiss M, Hartwig S, Burger D, Cordat E. Unraveling the molecular landscape of kAE1: a narrative review. Can J Physiol Pharmacol 2024; 102:396-407. [PMID: 38669699 DOI: 10.1139/cjpp-2023-0482] [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] [Indexed: 04/28/2024]
Abstract
Kidney anion exchanger 1 (kAE1) is an isoform of the AE1 protein encoded by the SLC4A1 gene. It is a basolateral membrane protein expressed by α-intercalated cells in the connecting tubules and collecting duct of the kidney. Its main function is to exchange bicarbonate and chloride ions between the blood and urine to maintain blood pH at physiological threshold. The kAE1 protein undergoes multiple post-translational modifications such as phosphorylation and ubiquitination and interacts with many different proteins such as claudin-4 and carbonic anhydrase II. Mutations in the gene may lead to the development of distal renal tubular acidosis, characterized by the failure to acidify the urine, which may result in nephrocalcinosis and in more severe cases, renal failure. In this review, we discuss the structure and function of kAE1, its post-translational modifications, and protein-protein interactions. Finally, we discuss insights gained from the study of kAE1 mutations in humans and in mice.
Collapse
Affiliation(s)
- Priyanka Mungara
- Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine, College of Health Sciences, University of Alberta, Edmonton, AB, Canada
| | - Moubarak Waiss
- School of Pharmaceutical Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Sunny Hartwig
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Dylan Burger
- School of Pharmaceutical Sciences, University of Ottawa, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, Kidney Research Centre, Ottawa, ON, Canada
| | - Emmanuelle Cordat
- Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine, College of Health Sciences, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
2
|
Guo W, Ji P, Xie Y. Genetic Diagnosis and Treatment of Inherited Renal Tubular Acidosis. KIDNEY DISEASES (BASEL, SWITZERLAND) 2023; 9:371-383. [PMID: 37901710 PMCID: PMC10601937 DOI: 10.1159/000531556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/12/2023] [Indexed: 10/31/2023]
Abstract
Background Renal tubular acidosis (RTA) is caused by various disruptions to the secretion of H+ by distal renal tubules and/or dysfunctional reabsorption of HCO3- by proximal renal tubules, which causes renal acidification dysfunction, ultimately leading to a clinical syndrome characterized by hyperchloremic metabolic acidosis with a normal anion gap. With the development of molecular genetics and gene sequencing technology, inherited RTA has also attracted attention, and an increasing number of RTA-related pathogenic genes have been discovered and reported. Summary This paper focuses on the latest progress in the research of inherited RTA and systematically reviews the pathogenic genes, protein functions, clinical manifestations, internal relationship between genotypes and clinical phenotypes, diagnostic clues, differential diagnosis, and treatment strategies associated with inherited RTA. This paper aims to deepen the understanding of inherited RTA and reduce the missed diagnosis and misdiagnosis of RTA. Key Messages This review systematically summarizes the pathogenic genes, pathophysiological mechanisms, differential diagnosis, and treatment of different types of inherited RTA, which has good clinical value for guiding the diagnosis and treatment of inherited RTA.
Collapse
Affiliation(s)
- Wenkai Guo
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, China
- School of Medicine, Nankai University, Tianjin, China
| | - Pengcheng Ji
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, China
| | - Yuansheng Xie
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, China
- School of Medicine, Nankai University, Tianjin, China
| |
Collapse
|
3
|
Thongchot S, Aksonnam K, Thuwajit P, Yenchitsomanus PT, Thuwajit C. Nucleolin‑based targeting strategies in cancer treatment: Focus on cancer immunotherapy (Review). Int J Mol Med 2023; 52:81. [PMID: 37477132 PMCID: PMC10555485 DOI: 10.3892/ijmm.2023.5284] [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: 03/27/2023] [Accepted: 06/15/2023] [Indexed: 07/22/2023] Open
Abstract
The benefits of treating several types of cancers using immunotherapy have recently been established. The overexpression of nucleolin (NCL) in a number of types of cancer provides an attractive antigen target for the development of novel anticancer immunotherapeutic treatments. NCL is a multifunctional protein abundantly distributed in the nucleus, cytoplasm and cell membrane. It influences carcinogenesis, and the proliferation, survival and metastasis of cancer cells, leading to cancer progression. Additionally, the meta‑analysis of total and cytoplasmic NCL overexpression indicates a poor prognosis of patients with breast cancer. The AS1411 aptamers currently appear to have therapeutic action in the phase II clinical trial. The authors' research group has recently explored the anticancer function of NCL through the activation of T cells by dendritic cell‑based immunotherapy. The present review describes and discusses the mechanisms through which the multiple functions of NCL can participate in the progression of cancer. In addition, the studies that define the utility of NCL‑dependent anticancer therapies are summarized, with specific focus being paid to cancer immunotherapeutic approaches.
Collapse
Affiliation(s)
- Suyanee Thongchot
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
- Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Krittaya Aksonnam
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Peti Thuwajit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
| | - Pa-Thai Yenchitsomanus
- Siriraj Center of Research Excellence for Cancer Immunotherapy (SiCORE-CIT), Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University
- Division of Molecular Medicine, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Chanitra Thuwajit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University
| |
Collapse
|
4
|
Guerra Hernández NE, Gómez Tenorio C, Méndez Silva LP, Moraleda Mesa T, Escobar LI, Salvador C, Vargas Poussou R, García Nieto VM. Autosomal dominant distal renal tubular acidosis in two pediatric patients with mutations in the SLC4A1 gene. Can the maximum urinary pCO 2 test be normal? Nefrologia 2023; 43:484-490. [PMID: 37775346 DOI: 10.1016/j.nefroe.2023.08.006] [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: 05/12/2021] [Accepted: 09/06/2021] [Indexed: 10/01/2023] Open
Abstract
Primary distal renal tubular acidosis (dRTA) is a rare tubulopathy characterised by the presence of hyperchloremic metabolic acidosis. It is caused by the existence of a defect in the function of the H+ -ATPase located on the luminal side of the α-intercalated cells or the Cl - HCO3- (AE1) anion exchanger located on the basolateral side. Patients do not acidify the urine after acid overload (NH4Cl) or after stimulating H+ secretion by obtaining a high intratubular concentration of an anion such as chlorine (pH is measured) or HCO3- (urinary pCO2 is measured). We present a family with autosomal dominant dRTA produced by a heterozygous mutation in the SLC4A1 gene in which the two paediatric members showed a test of normal maximum urinary pCO2. Our hypothesis is that since the H + -ATPase is intact, at least initially, the stimulation induced by intratubular electronegativity to secrete H + could be effective, which would allow the maximum urinary pCO2 to be paradoxically normal, which could explain the onset, moderate presentation of symptoms and late diagnosis in patients with this mutation. This is the first documented case of a dominant dRTA in Mexico.
Collapse
Affiliation(s)
- Norma E Guerra Hernández
- Servicio de Nefrología Pediátrica, Hospital General del Centro Médico Nacional «La Raza», Instituto Mexicano del Seguro Social, Ciudad de México, Mexico.
| | - Circe Gómez Tenorio
- Servicio de Nefrología Pediátrica, Hospital General del Centro Médico Nacional «La Raza», Instituto Mexicano del Seguro Social, Ciudad de México, Mexico; Servicio de Nefrología Pediátrica, Hospital Hospital de Ginecología No. 48, Instituto Mexicano del Seguro Social, León, Guanajuato, Mexico
| | - Laura Paloma Méndez Silva
- Servicio de Nefrología Pediátrica, Hospital Hospital de Ginecología No. 48, Instituto Mexicano del Seguro Social, León, Guanajuato, Mexico
| | - Teresa Moraleda Mesa
- Servicio de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Tenerife, Spain
| | - Laura I Escobar
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Carolina Salvador
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | | | - Víctor M García Nieto
- Servicio de Nefrología Pediátrica, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Tenerife, Spain
| |
Collapse
|
5
|
Yang M, Sheng Q, Ge S, Song X, Dong J, Guo C, Liao L. Mutations and clinical characteristics of dRTA caused by SLC4A1 mutations: Analysis based on published patients. Front Pediatr 2023; 11:1077120. [PMID: 36776909 PMCID: PMC9910804 DOI: 10.3389/fped.2023.1077120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/06/2023] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND AND AIMS The genetic and clinical characteristics of patients with distal renal tubular acidosis (dRTA) caused by SLC4A1 mutations have not been systematically recorded before. Here, we summarized the SLC4A1 mutations and clinical characteristics associated with dRTA. METHODS Database was searched, and the mutations and clinical manifestations of patients were summarized from the relevant articles. RESULTS Fifty-three eligible articles involving 169 patients were included and 41 mutations were identified totally. Fifteen mutations involving 100 patients were autosomal dominant inheritance, 21 mutations involving 61 patients were autosomal recessive inheritance. Nephrocalcinosis or kidney stones were found in 72.27%, impairment in renal function in 14.29%, developmental disorders in 61.16%, hematological abnormalities in 33.88%, and muscle weakness in 13.45% of patients. The age of onset was younger (P < 0.01), urine pH was higher (P < 0.01), and serum potassium was lower (P < 0.001) in recessive patients than patients with dominant SLC4A1 mutations. Autosomal recessive inheritance was more often found in Asian patients (P < 0.05). CONCLUSIONS The children present with metabolic acidosis with high urinary pH, accompanying hypokalemia, hyperchloremia, nephrocalcinosis, growth retardation and hematological abnormalities should be suspected as dRTA and suggested a genetic testing. The patients with recessive dRTA are generally more severely affected than that with dominant SLC4A1 mutations. Autosomal recessive inheritance was more often found in Asian patients, and more attentions should be paid to the Asian patients.
Collapse
Affiliation(s)
- Mengge Yang
- Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Ji-nan, China.,Cheeloo College of Medicine, Shandong University, Department of Endocrinology and Metabology, Shandong Provincial Qianfoshan Hospital, Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Shandong Institute of Nephrology, Ji-nan, China
| | - Qiqi Sheng
- Division of Endocrinology, Department of Internal Medicine, Qilu Hospital of Shandong University, Ji-nan, China
| | - Shenghui Ge
- Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Ji-nan, China
| | - Xinxin Song
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Ji-nan, China
| | - Jianjun Dong
- Division of Endocrinology, Department of Internal Medicine, Qilu Hospital of Shandong University, Ji-nan, China
| | - Congcong Guo
- Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Ji-nan, China.,College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Ji-nan, China
| | - Lin Liao
- Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Ji-nan, China.,Cheeloo College of Medicine, Shandong University, Department of Endocrinology and Metabology, Shandong Provincial Qianfoshan Hospital, Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Shandong Institute of Nephrology, Ji-nan, China.,College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Ji-nan, China
| |
Collapse
|
6
|
Guerra Hernández NE, Gómez Tenorio C, Méndez Silva LP, Moraleda Mesa T, Escobar LI, Salvador C, Vargas Poussou R, García Nieto VM. Acidosis tubular renal distal autosómica dominante en dos pacientes pediátricos con mutaciones en el gen SLC4A1. ¿La prueba de la pCO2 urinaria máxima puede ser normal? Nefrologia 2021. [DOI: 10.1016/j.nefro.2021.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
|
7
|
Watanabe T. Improving outcomes for patients with distal renal tubular acidosis: recent advances and challenges ahead. PEDIATRIC HEALTH MEDICINE AND THERAPEUTICS 2018; 9:181-190. [PMID: 30588151 PMCID: PMC6296208 DOI: 10.2147/phmt.s174459] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Primary distal renal tubular acidosis (dRTA) is a rare genetic disorder caused by impaired distal acidification due to a failure of type A intercalated cells (A-ICs) in the collecting tubule. dRTA is characterized by persistent hyperchloremia, a normal plasma anion gap, and the inability to maximally lower urinary pH in the presence of systemic metabolic acidosis. Common clinical features of dRTA include vomiting, failure to thrive, polyuria, hypercalciuria, hypocitraturia, nephrocalcinosis, nephrolithiasis, growth delay, and rickets. Mutations in genes encoding three distinct transport proteins in A-ICs have been identified as causes of dRTA, including the B1/ATP6V1B1 and a4/ATP6V0A4 subunits of the vacuolar-type H+-ATPase (H+-ATPase) and the chloride–bicarbonate exchanger AE1/SLC4A1. Homozygous or compound heterozygous mutations in ATP6V1B1 and ATP6V0A4 lead to autosomal recessive (AR) dRTA. dRTA caused by SLC4A1 mutations can occur with either autosomal dominant or AR transmission. Red blood cell abnormalities have been associated with AR dRTA due to SLC4A1 mutations, including hereditary spherocytosis, Southeast Asia ovalocytosis, and others. Some patients with dRTA exhibit atypical clinical features, including transient and reversible proximal tubular dysfunction and hyperammonemia. Incomplete dRTA presents with inadequate urinary acidification, but without spontaneous metabolic acidosis and recurrent urinary stones. Heterozygous mutations in the AE1 or H+-ATPase genes have recently been reported in patients with incomplete dRTA. Early and sufficient doses of alkali treatment are needed for patients with dRTA. Normalized serum bicarbonate, urinary calcium excretion, urinary low-molecular-weight protein levels, and growth rate are good markers of adherence to and/or efficacy of treatment. The prognosis of dRTA is generally good in patients with appropriate treatment. However, recent studies showed an increased frequency of chronic kidney disease (CKD) in patients with dRTA during long-term follow-up. The precise pathogenic mechanisms of CKD in patients with dRTA are unknown.
Collapse
Affiliation(s)
- Toru Watanabe
- Department of Pediatrics, Niigata City General Hospital, Niigata City 950-1197, Japan,
| |
Collapse
|
8
|
Deejai N, Wisanuyotin S, Nettuwakul C, Khositseth S, Sawasdee N, Saetai K, Yenchitsomanus PT, Rungroj N. Molecular Diagnosis of Solute Carrier Family 4 Member 1 (SLC4A1) Mutation–Related Autosomal Recessive Distal Renal Tubular Acidosis. Lab Med 2018; 50:78-86. [DOI: 10.1093/labmed/lmy051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Nipaporn Deejai
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Suwannee Wisanuyotin
- Division of Nephrology, Department of Pediatrics, Faculty of Medicine, Khon Kaen University, Thailand
| | - Choochai Nettuwakul
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sookkasem Khositseth
- Division of Nephrology, Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
| | - Nunghathai Sawasdee
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kiattichai Saetai
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pa-thai Yenchitsomanus
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nanyawan Rungroj
- Division of Molecular Genetics, Department of Research and Development, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| |
Collapse
|
9
|
Rungroj N, Nettuwakul C, Sawasdee N, Sangnual S, Deejai N, Misgar RA, Pasena A, Khositseth S, Kirdpon S, Sritippayawan S, Vasuvattakul S, Yenchitsomanus PT. Distal renal tubular acidosis caused by tryptophan-aspartate repeat domain 72 (WDR72) mutations. Clin Genet 2018; 94:409-418. [PMID: 30028003 DOI: 10.1111/cge.13418] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/21/2018] [Accepted: 07/17/2018] [Indexed: 12/18/2022]
Abstract
Hereditary distal renal tubular acidosis (dRTA) is a rare genetic disease that is caused by mutations in SLC4A1, ATP6V1B1, or ATP6V0A4. However, there are many families with hereditary dRTA in whom the disease-causing genes are unknown. Accordingly, we performed whole exome sequencing and genetic studies of the members of a family with autosomal recessive dRTA of an unknown genetic etiology. Here, we report compound heterozygous pathogenic variations in tryptophan-aspartate repeat domain 72 (WDR72) (c.1777A>G [p.R593G] and c.2522T>A [p.L841Q]) in three affected siblings of a family with dRTA. Both variants segregated with dRTA in the family and were not observed in normal control subjects. Homologous modeling and in silico mutagenesis indicated that R593G and L841Q alter the H-bond formations in the nearby residues, affecting the WDR72 protein structure. All these evidences indicate that the identified WDR72 variations were probably to have caused hereditary dRTA in the reported family. In addition, homozygous nonsense mutation (c.2686C>T [p.R896X]) was identified in another family, strongly supporting the causal role of WDR72 in dRTA. Based on our literature review, WDR72 mutations associated with dRTA have not been previously described. This is the first identification of pathogenic variations in WDR72 as a cause of hereditary dRTA.
Collapse
Affiliation(s)
- N Rungroj
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Division of Molecular Genetics, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - C Nettuwakul
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - N Sawasdee
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - S Sangnual
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - N Deejai
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - R A Misgar
- Department of Endocrinology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, India
| | - A Pasena
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Department of Immunology and Immunology Graduate Program, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - S Khositseth
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathumthani, Thailand
| | - S Kirdpon
- Department of Pediatrics, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - S Sritippayawan
- Division of Nephrology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - S Vasuvattakul
- Division of Nephrology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - P T Yenchitsomanus
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| |
Collapse
|
10
|
Park E, Phaymany V, Yi ES, Phangmanixay S, Cheong HI, Choi Y. Primary Autosomal Recessive Distal Renal Tubular Acidosis Caused by a Common Homozygous SLC4A1 Mutation in Two Lao Families. J Korean Med Sci 2018; 33:e95. [PMID: 29573245 PMCID: PMC5865059 DOI: 10.3346/jkms.2018.33.e95] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/17/2017] [Indexed: 11/20/2022] Open
Abstract
Primary distal renal tubular acidosis (dRTA) caused by mutations of the SLC4A1 gene, which encodes for erythroid and kidney isoforms of anion exchanger, shows marked difference in inheritance patterns and clinical features in different parts of the world. While the disease shows autosomal dominant inheritance without any red cell morphological abnormalities in the temperate countries, it is almost invariably recessive, and often accompanies red cell morphological abnormalities or hemolytic anemia in the tropics, especially in Southeast Asia. Here, we report three patients with autosomal recessive (AR) dRTA, presenting with typical findings of failure to thrive and rickets, from two unrelated Lao families. The mutational analyses revealed that all three patients harbored the same homozygous SLC4A1 mutation, p.Gly701Asp. Adequate supplementation of alkali and potassium resulted in remarkable improvement of growth retardation and skeletal deformities of the patients. This is the first case report of Lao patients with AR dRTA caused by SLC4A1 mutations.
Collapse
Affiliation(s)
- Eujin Park
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Vilaphone Phaymany
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
- Department of Pediatrics, Children's Hospital, Vientiane, Lao PRD
| | - Eun Sang Yi
- Department of Pediatrics, Children's Hospital, Vientiane, Lao PRD
- Department of Pediatrics, Korea University Guro Hospital, Seoul, Korea
| | | | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
- Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
- Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
| | - Yong Choi
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| |
Collapse
|
11
|
γ-COPI mediates the retention of kAE1 G701D protein in Golgi apparatus – a mechanistic explanation of distal renal tubular acidosis associated with the G701D mutation. Biochem J 2017. [DOI: 10.1042/bcj20170088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mutations of the solute carrier family 4 member 1 (SLC4A1) gene encoding kidney anion (chloride/bicarbonate ion) exchanger 1 (kAE1) can cause genetic distal renal tubular acidosis (dRTA). Different SLC4A1 mutations give rise to mutant kAE1 proteins with distinct defects in protein trafficking. The mutant kAE1 protein may be retained in endoplasmic reticulum (ER) or Golgi apparatus, or mis-targeted to the apical membrane, failing to display its function at the baso-lateral membrane. The ER-retained mutant kAE1 interacts with calnexin chaperone protein; disruption of this interaction permits the mutant kAE1 to reach the cell surface and display anion exchange activity. However, the mechanism of Golgi retention of mutant kAE1 G701D protein, which is otherwise functional, is still unclear. In the present study, we show that Golgi retention of kAE1 G701D is due to a stable interaction with the Golgi-resident protein, coat protein complex I (COPI), that plays a role in retrograde vesicular trafficking and Golgi-based quality control. The interaction and co-localization of kAE1 G701D with the γ-COPI subunit were demonstrated in human embryonic kidney (HEK-293T) cells by co-immunoprecipitation and immunofluorescence staining. Small interference RNA (siRNA) silencing of COPI expression in the transfected HEK-293T cells increased the cell surface expression of transgenic kAE1 G701D, as shown by immunofluorescence staining. Our data unveil the molecular mechanism of Golgi retention of kAE1 G701D and suggest that disruption of the COPI-kAE1 G701D interaction could be a therapeutic strategy to treat dRTA caused by this mutant.
Collapse
|
12
|
Reithmeier RAF, Casey JR, Kalli AC, Sansom MSP, Alguel Y, Iwata S. Band 3, the human red cell chloride/bicarbonate anion exchanger (AE1, SLC4A1), in a structural context. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1507-32. [PMID: 27058983 DOI: 10.1016/j.bbamem.2016.03.030] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/21/2016] [Accepted: 03/29/2016] [Indexed: 02/03/2023]
Abstract
The crystal structure of the dimeric membrane domain of human Band 3(1), the red cell chloride/bicarbonate anion exchanger 1 (AE1, SLC4A1), provides a structural context for over four decades of studies into this historic and important membrane glycoprotein. In this review, we highlight the key structural features responsible for anion binding and translocation and have integrated the following topological markers within the Band 3 structure: blood group antigens, N-glycosylation site, protease cleavage sites, inhibitor and chemical labeling sites, and the results of scanning cysteine and N-glycosylation mutagenesis. Locations of mutations linked to human disease, including those responsible for Southeast Asian ovalocytosis, hereditary stomatocytosis, hereditary spherocytosis, and distal renal tubular acidosis, provide molecular insights into their effect on Band 3 folding. Finally, molecular dynamics simulations of phosphatidylcholine self-assembled around Band 3 provide a view of this membrane protein within a lipid bilayer.
Collapse
Affiliation(s)
- Reinhart A F Reithmeier
- Department of Biochemistry, 1 King's College Circle, University of Toronto, Toronto M5S 1A8, Canada.
| | - Joseph R Casey
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Antreas C Kalli
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Yilmaz Alguel
- Division of Molecular Biosciences, Imperial College London, London, SW7 2AZ, UK
| | - So Iwata
- Division of Molecular Biosciences, Imperial College London, London, SW7 2AZ, UK
| |
Collapse
|
13
|
Khositseth S, Bruce LJ, Walsh SB, Bawazir WM, Ogle GD, Unwin RJ, Thong MK, Sinha R, Choo KE, Chartapisak W, Kingwatanakul P, Sumboonnanonda A, Vasuvattakul S, Yenchitsomanus P, Wrong O. Tropical distal renal tubular acidosis: clinical and epidemiological studies in 78 patients. QJM 2012; 105:861-77. [PMID: 22919024 DOI: 10.1093/qjmed/hcs139] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Distal renal tubular acidosis (dRTA) caused by mutations of the SLC4A1 gene encoding the erythroid and kidney isoforms of anion exchanger 1 (AE1 or band 3) has a high prevalence in some tropical countries, particularly Thailand, Malaysia, the Philippines and Papua New Guinea (PNG). Here the disease is almost invariably recessive and can result from either homozygous or compound heterozygous SLC4A1 mutations. METHODS We have collected and reviewed our own and published data on tropical dRTA to provide a comprehensive series of clinical and epidemiological studies in 78 patients. RESULTS Eight responsible SLC4A1 mutations have been described so far, four of them affecting multiple unrelated families. With the exception of the mutation causing South-East Asian ovalocytosis (SAO), none of these mutations has been reported outside the tropics, where dRTA caused by SLC4A1 mutations is much rarer and almost always dominant, resulting from mutations that are quite different from those found in the tropics. SLC4A1 mutations, including those causing dRTA, may cause morphological red cell changes, often with excess haemolysis. In dRTA, these red cell changes are usually clinically recessive and not present in heterozygotes. The high tropical prevalence of dRTA caused by SLC4A1 mutations is currently unexplained. CONCLUSION A hypothesis suggesting that changes in red cell metabolism caused by these mutations might protect against malaria is put forward to explain the phenomenon, and a possible mechanism for this effect is proposed.
Collapse
Affiliation(s)
- S Khositseth
- University College Medical School, Royal Free Campus and Hospital, London NW3 2PF, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Zhang Z, Liu KX, He JW, Fu WZ, Yue H, Zhang H, Zhang CQ, Zhang ZL. Identification of Two Novel Mutations in the SLC4A1 Gene in Two Unrelated Chinese Families with Distal Renal Tubular Acidosis. Arch Med Res 2012; 43:298-304. [DOI: 10.1016/j.arcmed.2012.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/25/2012] [Indexed: 10/28/2022]
|
15
|
Vasuvattakul S. Molecular Approach for Distal Renal Tubular Acidosis Associated AE1 Mutations. Electrolyte Blood Press 2010; 8:25-31. [PMID: 21468194 PMCID: PMC3041492 DOI: 10.5049/ebp.2010.8.1.25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 05/19/2010] [Indexed: 11/05/2022] Open
Abstract
The molecular approaches to distal renal tubular acidosis (dRTA) associated AE1 mutations lead us to understand the genetic and pathophysiological aspects of the acidification defects. An unanticipated high value of the urine-blood (U-B) PCO(2) after NaHCO(3) loading observed in a case of dRTA and southeast Asian ovalocytosis (SAO) might be from a mistarget of the AE1 to the luminal membrane of type A intercalated cells. The mutations of the AE1 gene resulted in SAO and also affected renal acidification function. Notwithstanding, after the NH4Cl loading in 20 individuals with SAO, the acidification in the distal nephron was normal. The presence of both SAO and G701D mutations of AE1 gene would explain the abnormal urinary acidification in the patients with the compound heterozogosity. In terms of the effect of the mutations on trafficking of AE1, truncated kidney isoform (kAE1) of wild-type showed a 'dominant-positive effect' in rescuing the recessive mutant kAE1 (S773P or G701D) trafficking to the plasma membrane, in contrast with the dominant mutant kAE1 (R589H) resulting in a 'dominant-negative effect' when heterodimerized with the wild-type kAE1. It is notable that the dominant mutants kAE1 (R901X or G609R) expression in MDCK cells clearly results in aberrant surface expression with some mutant protein appearing at the apical membrane. These might result in net bicarbonate secretion and increasing U-B PCO(2) in the distal nephron. The molecular physiological and genetic approaches have permitted identification of the molecular defects, predominantly in transporter proteins, and should in turn prompt development of novel therapeutic strategies.
Collapse
Affiliation(s)
- Somkiat Vasuvattakul
- Renal Division, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| |
Collapse
|
16
|
Shao L, Xu Y, Dong Q, Lang Y, Yue S, Miao Z. A novel SLC4A1 variant in an autosomal dominant distal renal tubular acidosis family with a severe phenotype. Endocrine 2010; 37:473-8. [PMID: 20960171 DOI: 10.1007/s12020-010-9340-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 03/26/2010] [Indexed: 10/19/2022]
Abstract
Mutations in SLC4A1, encoding the chloride-bicarbonate exchanger AE1, cause distal renal tubular acidosis (dRTA), a disease of defective urinary acidification by the distal nephron. We searched for SLC4A1 gene mutations in six patients from a Chinese family with a severe phenotype of dRTA (growth impairment, severe metabolic acidosis, with/or without gross nephrocalcinosis and renal impairment). All coding regions of kidney isoform of AE1, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. A novel 1-bp duplication at nucleotide 2713 (c.2713dupG, band 3 Qingdao) in exon 20 of SLC4A1 in this family was identified by direct sequencing analysis. This duplication alters the encoded protein through codon 905, and results in a reading frame for 15 extra condons (instead of 8) before the new stop condon at position 919 (p.Asp905Glyfs15). We suggest that RTA should be considered as a diagnostic possibility in adult subjects with nephrocalcinosis and chronic renal insufficiency, and family survey should be carefully performed.
Collapse
Affiliation(s)
- Leping Shao
- Department of Nephrology, Affilated Hospital of Qingdao University School of Medicine, #16, Jiangsu Road, Qingdao 266003, People's Republic of China.
| | | | | | | | | | | |
Collapse
|
17
|
Band 3 Edmonton I, a novel mutant of the anion exchanger 1 causing spherocytosis and distal renal tubular acidosis. Biochem J 2010; 426:379-88. [DOI: 10.1042/bj20091525] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
dRTA (distal renal tubular acidosis) and HS (hereditary spherocytosis) are two diseases that can be caused by mutations in the gene encoding the AE1 (anion exchanger 1; Band 3). dRTA is characterized by defective urinary acidification, leading to metabolic acidosis, renal stones and failure to thrive. HS results in anaemia, which may require regular blood transfusions and splenectomy. Mutations in the gene encoding AE1 rarely cause both HS and dRTA. In the present paper, we describe a novel AE1 mutation, Band 3 Edmonton I, which causes dominant HS and recessive dRTA. The patient is a compound heterozygote with the new mutation C479W and the previously described mutation G701D. Red blood cells from the patient presented a reduced amount of AE1. Expression in a kidney cell line showed that kAE1 (kidney AE1) C479W is retained intracellularly. As kAE1 is a dimer, we performed co-expression studies and found that, in kidney cells, kAE1 C479W and G701D proteins traffic independently from each other despite their ability to form heterodimers. Therefore the patient carries one kAE1 mutant that is retained in the Golgi (G701D) and another kAE1 mutant (C479W) located in the endoplasmic reticulum of kidney cells, and is thus probably unable to reabsorb bicarbonate into the blood. We conclude that the C479W mutant is a novel trafficking mutant of AE1, which causes HS due to a decreased cell-surface AE1 protein and results in dRTA due to its intracellular retention in kidney.
Collapse
|
18
|
Ungsupravate D, Sawasdee N, Khositseth S, Udomchaiprasertkul W, Khoprasert S, Li J, Reithmeier RAF, Yenchitsomanus PT. Impaired trafficking and intracellular retention of mutant kidney anion exchanger 1 proteins (G701D and A858D) associated with distal renal tubular acidosis. Mol Membr Biol 2010; 27:92-103. [DOI: 10.3109/09687681003588020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
19
|
Chang YH, Shaw CF, Jian SH, Hsieh KH, Chiou YH, Lu PJ. Compound mutations in human anion exchanger 1 are associated with complete distal renal tubular acidosis and hereditary spherocytosis. Kidney Int 2009; 76:774-83. [DOI: 10.1038/ki.2009.258] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
20
|
Khositseth S, Sirikanaerat A, Khoprasert S, Opastirakul S, Kingwatanakul P, Thongnoppakhun W, Yenchitsomanus PT. Hematological abnormalities in patients with distal renal tubular acidosis and hemoglobinopathies. Am J Hematol 2008; 83:465-71. [PMID: 18266205 DOI: 10.1002/ajh.21151] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mutations of the human SLC4A1 gene encoding erythroid and kidney isoforms of anion exchanger 1 (AE1, band 3) result in erythrocyte abnormalities or distal renal tubular acidosis (dRTA) and such mutations are observed in Southeast Asia, where hemoglobinopathies are prevalent. Genetic and hematological studies in 18 Thai patients with dRTA have shown that 12 of them (67%) carried SLC4A1 mutations (7 G701D/G701D, 3 SAO/G701D, and 2 G701D/A858D). Of these 12 patients, three had homozygous G701D/G701D and heterozygous Hb E; one compound heterozygous SAO/G701D and heterozygous alpha(+)-thalassemia; and one compound heterozygous G701D/A858D and heterozygous Hb E. Of 6 patients without SLC4A1 mutation, two each carried heterozygous or homozygous Hb E and one of the latter also had Hb H disease (--(SEA)/-alpha(4.2)). The blood smears of patients with homozygous G701D/G701D showed approximately 25% ovalocytes. Strikingly, the patients with coexistence of homozygous G701D/G701D and heterozygous Hb E had 58% ovalocytes. Similarly, the patients who had compound heterozygous SAO/G701D showed 49% ovalocytes, but the patient with coexistence of compound heterozygous SAO/G701D and heterozygous alpha(+)-thalassemia had 70% ovalocytes. Our previous study has shown that under metabolic acidosis, the patients with homozygous G701D/G701D or compound heterozygous SAO/G701D had reticulocytosis, indicating compensated hemolysis. A patient with compound heterozygous SAO/G701D and heterozygous alpha(+)-thalassemia presented with hemolytic anemia and hepatosplenomegaly which was alleviated by alkaline therapy. Taken together, the coexistence of both homozygous or compound heterozygous SLC4A1 mutations and hemoglobinopathy has a combined effect on red cell morphology and degree of hemolytic anemia, which is aggravated by acidosis.
Collapse
|
21
|
Dominant-negative effect of Southeast Asian ovalocytosis anion exchanger 1 in compound heterozygous distal renal tubular acidosis. Biochem J 2008; 410:271-81. [PMID: 17941824 DOI: 10.1042/bj20070615] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 10/15/2007] [Accepted: 10/17/2007] [Indexed: 11/17/2022]
Abstract
The human chloride/bicarbonate AE1 (anion exchanger) is a dimeric glycoprotein expressed in the red blood cell membrane,and expressed as an N-terminal (Delta1-65) truncated form, kAE1(kidney AE1), in the basolateral membrane of alpha-intercalated cells in the distal nephron. Mutations in AE1 can cause SAO (Southeast Asian ovalocytosis) or dRTA (distal renal tubular acidosis), an inherited kidney disease resulting in impaired acid secretion. The dominant SAO mutation (Delta400-408) that results in an inactive transporter and altered erythrocyte shape occurs in manydRTA families, but does not itself result in dRTA. Compound heterozygotes of four dRTA mutations (R602H, G701D, DeltaV850 and A858D) with SAO exhibit dRTA and abnormal red blood cell properties. Co-expression of kAE1 and kAE1 SAO with the dRTAmutantswas studied in polarized epithelial MDCK(Madin-Darbycanine kidney) cells. Like SAO, the G701D and DeltaV850 mutants were predominantly retained intracellularly, whereas the R602H and A858D mutants could traffic to the basolateral membrane. When co-expressed in transfected cells, kAE1 WT (wild-type)and kAE1 SAO could interact with the dRTA mutants. MDCK cells co-expressing kAE1 SAO with kAE1 WT, kAE1 R602Hor kAE1 A858D showed a decrease in cell-surface expression of the co-expressed proteins. When co-expressed, kAE1 WT colocalized with the kAE1 R602H, kAE1 G701D, kAE1 DeltaV850 and kAE1 A858D mutants at the basolateral membrane, whereaskAE1 SAO co-localized with kAE1 WT, kAE1 R602H, kAE1 G701D, kAE1 DeltaV850 and kAE1 A858D in MDCK cells. The decrease in cell-surface expression of the dRTAmutants as a result of the interaction with kAE1 SAO would account for the impaired expression of functional kAE1 at the basolateral membrane of alpha-intercalated cells, resulting in dRTA in compound heterozygous patients.
Collapse
|
22
|
Williamson RC, Toye AM. Glycophorin A: Band 3 aid. Blood Cells Mol Dis 2008; 41:35-43. [PMID: 18304844 DOI: 10.1016/j.bcmd.2008.01.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 01/04/2008] [Indexed: 11/24/2022]
Abstract
Band 3 (B3) is a major site of cytoskeletal attachment to the erythrocyte membrane and is important for gas exchange. A truncated isoform of B3 (kB3) is expressed in the alpha-intercalated cells of the kidney and its functional activity and basolateral localization are essential for acid secretion. B3 mutations generally lead to red blood cell (RBC) specific disease (hereditary spherocytosis (HS), Southeast Asian Ovalocytosis or hereditary stomatocytosis) or kidney disease (distal Renal Tubular Acidosis--dRTA). It is rare for both the RBC and kidney disease phenotypes to co-exist, but this does occur in knockout mice, and also in humans (B3 Coimbra and B3 Courcouronne) or cattle with homozygous HS mutations. This is because RBCs express a B3 chaperone-like molecule in the form of Glycophorin A that can rescue the majority of B3 mutations that cause dRTA but probably not the majority of HS mutations. The study of naturally occurring B3 variant blood and expression of B3 or kB3 mutants in heterologous expression systems has provided valuable information concerning B3 trafficking and interactions in the RBC and kidney. This article will review these studies and comment on our current understanding of the interaction between GPA with B3 and also on the proposed B3 centred macrocomplex.
Collapse
Affiliation(s)
- Rosalind C Williamson
- University of Bristol, Department of Biochemistry, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
| | | |
Collapse
|
23
|
Abstract
Inherited acidosis may result from a primary renal defect in acid-base handling, emphasizing the central role of the kidney in control of body pH; as a secondary phenomenon resulting from abnormal renal electrolyte handling; or from excess production of acid elsewhere in the body. Here, we review our current understanding of the inherited renal acidoses at a genetic and molecular level.
Collapse
Affiliation(s)
- Andrew C Fry
- Department of Medical Genetics and Division of Renal Medicine, University of Cambridge, Cambridge Institute for Medical Research, UK
| | | |
Collapse
|
24
|
Khositseth S, Sirikanerat A, Wongbenjarat K, Opastirakul S, Khoprasert S, Peuksungnern R, Wattanasirichaigoon D, Thongnoppakhun W, Viprakasit V, Yenchitsomanus PT. Distal renal tubular acidosis associated with anion exchanger 1 mutations in children in Thailand. Am J Kidney Dis 2007; 49:841-850.e1. [PMID: 17533027 DOI: 10.1053/j.ajkd.2007.03.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Accepted: 03/05/2007] [Indexed: 11/11/2022]
Abstract
BACKGROUND Mutations in the anion exchanger 1 (AE1) gene encoding the erythroid and kidney anion (chloride-bicarbonate) exchanger 1 may result in hereditary distal renal tubular acidosis (dRTA). Hemoglobinopathies are common in Thailand. We analyzed AE1 and hemoglobin mutations in children in Thailand with dRTA to evaluate their association with clinical manifestations. STUDY DESIGN Case series. SETTING & PARTICIPANTS 17 patients were recruited from 6 referral hospitals in 4 regions of Thailand. PREDICTORS AE1 mutations were detected by means of nucleotide sequence alterations. Hemoglobin E (HbE) was detected by means of hemoglobin typing, and thalassemia, by means of analysis of globin genes. Hemolytic anemia was indicated by decreased hemoglobin and hematocrit values in the presence of reticulocytosis. OUTCOMES & MEASUREMENTS Leading clinical manifestations in patients were failure to thrive and muscle weakness. Compensated or overt anemia was identified in some cases. Coexistence of AE1 mutations with HbE or alpha(+)-thalassemia was present in a number of patients. RESULTS 12 of 17 patients (70%) carried AE1 mutations, 7 patients (41%) had HbE, and 1 patient (6%) had alpha(+)-thalassemia. Patients with AE1 mutations presented with compensated hemolysis when they had metabolic acidosis. A patient with compound heterozygous Southeast Asian ovalocytosis/G701D and heterozygous alpha(+)-thalassemia showed severe hemolytic anemia. LIMITATIONS 5 patients (30%) without detectable AE1 mutation also were unknown for other genetic abnormalities. CONCLUSIONS Most of the patients with dRTA studied carried autosomal recessive AE1 mutations. Metabolic acidosis, which could be alleviated by adequate alkaline therapy, induced variable degrees of hemolysis in patients with dRTA associated with autosomal recessive AE1 mutations, especially in the presence of thalassemia.
Collapse
Affiliation(s)
- Sookkasem Khositseth
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Bangkok, Thailand
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Cordat E. Unraveling trafficking of the kidney anion exchanger 1 in polarized MDCK epithelial cells. Biochem Cell Biol 2007; 84:949-59. [PMID: 17215882 DOI: 10.1139/o06-200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kidney anion exchanger 1 (kAE1) is a membrane glycoprotein expressed at the basolateral membrane of type A intercalated cells in the kidney collecting tubule. Mutations occurring in the gene encoding this protein can give rise to distal renal tubular acidosis (dRTA), a disease characterized by an impaired urine acidification, nephrocalcinosis, and renal failure. Here we review how the study of dRTA mutants in polarized epithelial cells has shed light on the cellular mechanisms resulting in this renal disease.
Collapse
Affiliation(s)
- Emmanuelle Cordat
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
26
|
Yang Q, Li G, Singh SK, Alexander EA, Schwartz JH. Vacuolar H+-ATPase B1 Subunit Mutations that Cause Inherited Distal Renal Tubular Acidosis Affect Proton Pump Assembly and Trafficking in Inner Medullary Collecting Duct Cells. J Am Soc Nephrol 2006; 17:1858-66. [PMID: 16769747 DOI: 10.1681/asn.2005121277] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Point mutations in the B1 subunit of vacuolar H+ -ATPase are associated with impaired ability of the distal nephron to secrete acid (distal renal tubular acidosis). For testing of the hypothesis that these mutations interfere with assembly and trafficking of the H+ -ATPase, constructs that mimic seven known point mutations in inherited distal renal tubular acidosis (M) or wild-type (WT) B1 were transfected into a rat inner medullary collecting duct cell line to express green fluorescence protein (GFP)-B1WT or GFP-B1M fusion proteins. In co-immunoprecipitation studies, GFP-B1WT formed complexes with other H+ -ATPase subunits (c, H, and E), whereas GFP-B1M did not. Proteins that were immunoprecipitated with anti-GFP antibody from GFP-B1WT cells had ATPase activity, whereas proteins from GFP-B1M cells did not. Proton pump-mediated intracellular pH transport was inhibited in GFP-B1M-transfected cells but not in GFP-B1WT cells. GFP-B1WT and GFP-B1M are present in the apical membrane and increased with cellular acidification. In GFP-B1WT cells, the apical membrane fraction of GFP-B1, endogenous B1, and the 31-kD subunits of the H+ -ATPase increased with cell acidification. In GFP-B1M cells, the endogenous B1 and 31-kD subunits did not increase with acidification. B1 point mutations prevent normal assembly of the H+ -ATPase and also may act as an inhibitor of H+ -ATPase function by competing with endogenous intact H+ -ATPase for trafficking in inner medullary collecting duct cells.
Collapse
Affiliation(s)
- Qiongqiong Yang
- Renal Section, 1st Affiliated Hospital of Zhongshan University, Guangzhou, China
| | | | | | | | | |
Collapse
|
27
|
Pushkin A, Kurtz I. SLC4 base (HCO3 -, CO3 2-) transporters: classification, function, structure, genetic diseases, and knockout models. Am J Physiol Renal Physiol 2006; 290:F580-99. [PMID: 16461757 DOI: 10.1152/ajprenal.00252.2005] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In prokaryotic and eukaryotic organisms, biochemical and physiological processes are sensitive to changes in H(+) activity. For these processes to function optimally, a variety of proteins have evolved that transport H(+)/base equivalents across cell and organelle membranes, thereby maintaining the pH of various intracellular and extracellular compartments within specific limits. The SLC4 family of base (HCO(3)(-), CO(3)(2(-))) transport proteins plays an essential role in mediating Na(+)- and/or Cl(-)-dependent base transport in various tissues and cell types in mammals. In addition to pH regulation, specific members of this family also contribute to vectorial transepithelial base transport in several organ systems including the kidney, pancreas, and eye. The importance of these transporters in mammalian cell biology is highlighted by the phenotypic abnormalities resulting from spontaneous SLC4 mutations in humans and targeted deletions in murine knockout models. This review focuses on recent advances in our understanding of the molecular organization and functional properties of SLC4 transporters and their role in disease.
Collapse
Affiliation(s)
- Alexander Pushkin
- Division of Nephrology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, 10833 Le Conte Avenue, Rm. 7-155 Factor Bldg., Los Angeles, CA 90095, USA
| | | |
Collapse
|
28
|
Choo KE, Nicoli TK, Bruce LJ, Tanner MJA, Ruiz-Linares A, Wrong OM. Recessive distal renal tubular acidosis in Sarawak caused by AE1 mutations. Pediatr Nephrol 2006; 21:212-7. [PMID: 16252102 DOI: 10.1007/s00467-005-2061-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 07/08/2005] [Accepted: 07/13/2005] [Indexed: 01/06/2023]
Abstract
Mutations of the AE1 (SLC4A1, Anion-Exchanger 1) gene that codes for band 3, the renal and red cell anion exchanger, are responsible for many cases of familial distal renal tubular acidosis (dRTA). In Southeast Asia this disease is usually recessive, caused either by homozygosity of a single AE1 mutation or by compound heterozygosity of two different AE1 mutations. We describe two unrelated boys in Sarawak with dRTA associated with compound heterozygosity of AE1 mutations. Both had Southeast Asian ovalocytosis (SAO), a morphological abnormality of red cells caused by a deletion of band 3 residues 400-408. In addition, one boy had a DNA sequence abnormality of band 3 residue (G701D), which has been reported from elsewhere in Southeast Asia. The other boy had the novel sequence abnormality of band 3 (Q759H) and profound hemolytic anemia.
Collapse
Affiliation(s)
- Keng E Choo
- Department of Paediatrics and Child Health, Universiti Malaysia Sarawak, Kuching, Sarawak, Malaysia
| | | | | | | | | | | |
Collapse
|
29
|
Wongthida P, Akkarapatumwong V, Limjindaporn T, Kittanakom S, Keskanokwong T, Eurwilaichitr L, Yenchitsomanus PT. Analysis of the interaction between human kidney anion exchanger 1 and kanadaptin using yeast two-hybrid systems. Genet Mol Biol 2006. [DOI: 10.1590/s1415-47572006000100003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
30
|
Yenchitsomanus PT, Kittanakom S, Rungroj N, Cordat E, Reithmeier RAF. Molecular mechanisms of autosomal dominant and recessive distal renal tubular acidosis caused by SLC4A1 (AE1) mutations. J Mol Genet Med 2005; 1:49-62. [PMID: 19565014 PMCID: PMC2702069 DOI: 10.4172/1747-0862.1000013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 09/06/2005] [Accepted: 09/13/2005] [Indexed: 12/22/2022] Open
Abstract
Mutations of SLC4A1 (AE1) encoding the kidney anion (Cl−/HCO3−) exchanger 1 (kAE1 or band 3) can result in either autosomal dominant (AD) or autosomal recessive (AR) distal renal tubular acidosis (dRTA). The molecular mechanisms associated with SLC4A1 mutations resulting in these different modes of inheritance are now being unveiled using transfected cell systems. The dominant mutants kAE1 R589H, R901X and S613F, which have normal or insignificant changes in anion transport function, exhibit intracellular retention with endoplasmic reticulum (ER) localization in cultured non-polarized and polarized cells, while the dominant mutants kAE1 R901X and G609R are mis-targeted to apical membrane in addition to the basolateral membrane in cultured polarized cells. A dominant-negative effect is likely responsible for the dominant disease because heterodimers of kAE1 mutants and the wild-type protein are intracellularly retained. The recessive mutants kAE1 G701D and S773P however exhibit distinct trafficking defects. The kAE1 G701D mutant is retained in the Golgi apparatus, while the misfolded kAE1 S773P, which is impaired in ER exit and is degraded by proteosome, can only partially be delivered to the basolateral membrane of the polarized cells. In contrast to the dominant mutant kAE1, heterodimers of the recessive mutant kAE1 and wild-type kAE1 are able to traffic to the plasma membrane. The wild-type kAE1 thus exhibits a ‘dominant-positive effect’ relative to the recessive mutant kAE1 because it can rescue the mutant proteins from intracellular retention to be expressed at the cell surface. Consequently, homozygous or compound heterozygous recessive mutations are required for presentation of the disease phenotype. Future work using animal models of dRTA will provide additional insight into the pathophysiology of this disease.
Collapse
Affiliation(s)
- Pa-Thai Yenchitsomanus
- Division of Medical Molecular Biology and BIOTEC-Medical Biotechnology Unit, Division of Molecular Genetics, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | | | | | | | | |
Collapse
|
31
|
Laing CM, Toye AM, Capasso G, Unwin RJ. Renal tubular acidosis: developments in our understanding of the molecular basis. Int J Biochem Cell Biol 2005; 37:1151-61. [PMID: 15778079 DOI: 10.1016/j.biocel.2005.01.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 12/31/2004] [Accepted: 01/07/2005] [Indexed: 11/17/2022]
Abstract
Renal tubular acidosis is a metabolic acidosis due to impaired acid excretion by the kidney. Hyperchloraemic acidosis with a normal anion gap and normal (or near normal) glomerular filtration rate, and in the absence of diarrhoea, defines this disorder. However, systemic acidosis is not always evident and renal tubular acidosis can present with hypokalaemia, medullary nephrocalcinosis and recurrent calcium phosphate stone disease, as well as growth retardation and rickets in children, or short stature and osteomalacia in adults. Renal dysfunction in renal tubular acidosis is not always confined to acid excretion and can be part of a more generalised renal tubule defect, as in the renal Fanconi syndrome. Isolated renal tubular acidosis is more usually acquired, due to drugs, autoimmune disease, post-obstructive uropathy or any cause of medullary nephrocalcinosis. Less commonly, it is inherited and may be associated with deafness, osteopetrosis or ocular abnormalities. The clinical classification of renal tubular acidosis has been correlated with our current physiological model of how the nephron excretes acid, and this has facilitated genetic studies that have identified mutations in several genes encoding acid and base ion transporters. In vitro functional studies of these mutant proteins in cell expression systems have helped to elucidate the molecular mechanisms underlying renal tubular acidosis, which ultimately may lead to new therapeutic options in what is still treatment only by giving an oral alkali.
Collapse
Affiliation(s)
- Christopher M Laing
- Centre for Nephrology, Royal Free and University College Medical School, London NW3, UK
| | | | | | | |
Collapse
|
32
|
Kittanakom S, Cordat E, Akkarapatumwong V, Yenchitsomanus PT, Reithmeier RAF. Trafficking defects of a novel autosomal recessive distal renal tubular acidosis mutant (S773P) of the human kidney anion exchanger (kAE1). J Biol Chem 2004; 279:40960-71. [PMID: 15252044 DOI: 10.1074/jbc.m405356200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Autosomal dominant and recessive distal renal tubular acidosis (dRTA) can be caused by mutations in the anion exchanger 1 (AE1 or SLC4A1) gene, which encodes the erythroid chloride/bicarbonate anion exchanger membrane glycoprotein (eAE1) and a truncated kidney isoform (kAE1). The biosynthesis and trafficking of kAE1 containing a novel recessive missense dRTA mutation (kAE1 S773P) was studied in transiently transfected HEK-293 cells, expressing the mutant alone or in combination with wild-type kAE1 or another recessive mutant, kAE1 G701D. The kAE1 S773P mutant was expressed at a three times lower level than wild-type, had a 2-fold decrease in its half-life, and was targeted for degradation by the proteasome. It could not be detected at the plasma membrane in human embryonic kidney cells and showed predominant endoplasmic reticulum immunolocalization in both human embryonic kidney and LLC-PK1 cells. The oligosaccharide on a kAE1 S773P N-glycosylation mutant (N555) was not processed to the complex form indicating impaired exit from the endoplasmic reticulum. The kAE1 S773P mutant showed decreased binding to an inhibitor affinity resin and increased sensitivity to proteases, suggesting that it was not properly folded. The other recessive dRTA mutant, kAE1 G701D, also exhibited defective trafficking to the plasma membrane. The recessive kAE1 mutants formed dimers like wild-type AE1 and could hetero-oligomerize with wild-type kAE1 or with each other. Hetero-oligomers of wild-type kAE1 with recessive kAE1 S773P or G701D, in contrast to the dominant kAE1 R589H mutant, were delivered to the plasma membrane.
Collapse
MESH Headings
- Acidosis, Renal Tubular/metabolism
- Anion Exchange Protein 1, Erythrocyte/chemistry
- Anion Exchange Protein 1, Erythrocyte/genetics
- Anions
- Biological Transport
- Biotinylation
- Blotting, Western
- Cell Line
- Cell Membrane/metabolism
- Cell Separation
- DNA, Complementary/metabolism
- Electrophoresis, Polyacrylamide Gel
- Endoplasmic Reticulum/metabolism
- Flow Cytometry
- Genes, Dominant
- Heterozygote
- Homozygote
- Humans
- Microscopy, Fluorescence
- Models, Biological
- Mutation
- Oligosaccharides/chemistry
- Plasmids/metabolism
- Polymorphism, Single-Stranded Conformational
- Precipitin Tests
- Protein Binding
- Protein Folding
- Protein Structure, Tertiary
- Time Factors
- Transfection
Collapse
Affiliation(s)
- Saranya Kittanakom
- Canadian Institutes of Health Research Group in Membrane Biology, Departments of Biochemistry and Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | | | | | | |
Collapse
|
33
|
Sritippayawan S, Sumboonnanonda A, Vasuvattakul S, Keskanokwong T, Sawasdee N, Paemanee A, Thuwajit P, Wilairat P, Nimmannit S, Malasit P, Yenchitsomanus PT. Novel compound heterozygous SLC4A1 mutations in Thai patients with autosomal recessive distal renal tubular acidosis. Am J Kidney Dis 2004; 44:64-70. [PMID: 15211439 DOI: 10.1053/j.ajkd.2004.03.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Mutations in the SLC4A1 gene have been found to cause either autosomal dominant (AD) or autosomal recessive (AR) distal renal tubular acidosis (dRTA). The SLC4A1 mutations causing AD dRTA were reported in white patients, whereas those associated with AR dRTA were often found in Southeast Asia. Here, the authors report additional novel SLC4A1 mutations in 3 patients with AR dRTA from 2 unrelated Thai families. METHODS The patients and members of their families were clinically studied. Red cell morphology and sulfate influx were examined. The SLC4A1 gene was screened, analyzed, and confirmed for mutations by molecular genetic techniques. RESULTS In the first family, the patient had dRTA, rickets, failure to thrive, nephrocalcinosis, and hypokalemic-hyperchloremic metabolic acidosis with a urine pH level of 7.00. He had novel compound heterozygous SLC4A1 G701D/S773P mutations, inherited from clinically normal heterozygous mother and father. In the second family, the patient and his sister had dRTA and Southeast Asian ovalocytosis (SAO) with different clinical severity. The patient had proximal muscle weakness, rickets, nephrocalcinosis, hypokalemia, normal anion gap metabolic acidosis, and urine pH level of 6.80. His sister was asymptomatic but the urine pH level could not be lowered to below 5.50 after a short acid load. Both siblings had compound heterozygous SLC4A1 SAO/R602H mutations. CONCLUSION Two novel compound heterozygous SLC4A1 G701D/S773P and SAO/R602H mutations were identified in Thai patients with AR dRTA.
Collapse
Affiliation(s)
- Suchai Sritippayawan
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Rungroj N, Devonald MAJ, Cuthbert AW, Reimann F, Akkarapatumwong V, Yenchitsomanus PT, Bennett WM, Karet FE. A Novel Missense Mutation in AE1 Causing Autosomal Dominant Distal Renal Tubular Acidosis Retains Normal Transport Function but Is Mistargeted in Polarized Epithelial Cells. J Biol Chem 2004; 279:13833-8. [PMID: 14734552 DOI: 10.1074/jbc.m400188200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in SLC4A1, encoding the chloride-bicarbonate exchanger AE1, cause distal renal tubular acidosis (dRTA), a disease of defective urinary acidification by the distal nephron. In this study we report a novel missense mutation, G609R, causing dominant dRTA in affected members of a large Caucasian pedigree who all exhibited metabolic acidosis with alkaline urine, prominent nephrocalcinosis, and progressive renal impairment. To investigate the potential disease mechanism, the consequent effects of this mutation were determined. We first assessed anion transport function of G609R by expression in Xenopus oocytes. Western blotting and immunofluorescence demonstrated that the mutant protein was expressed at the oocyte cell surface. Measuring chloride and bicarbonate fluxes revealed normal 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-inhibitable anion exchange, suggesting that loss-of-function of kAE1 cannot explain the severe disease phenotype in this kindred. We next expressed epitope-tagged wild-type or mutant kAE1 in Madin-Darby canine kidney cells. In monolayers grown to polarity, mutant kAE1 was detected subapically and at the apical membrane, as well as at the basolateral membrane, in contrast to the normal basolateral appearance of wild-type kAE1. These findings suggest that the seventh transmembrane domain that contains Gly-609 plays an important role in targeting kAE1 to the correct cell surface compartment. They confirm that dominant dRTA is associated with non-polarized trafficking of the protein, with no significant effect on anion transport function in vitro, which remains an unusual mechanism of human disease.
Collapse
Affiliation(s)
- Nanyawan Rungroj
- Departments of Medical Genetics,University of Cambridge, Cambridge CB2 2XY, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
PURPOSE OF REVIEW Research in the past several years has led to the understanding of numerous genetic mutations that lead to inheritable forms of distal renal tubular acidosis (dRTA). Most of these mutations affect the physiology of the A-intercalated cells of the renal cortical collecting duct. These include mutations of genes encoding carbonic anhydrase II, kidney anion exchanger 1, and different subunits of the H+-ATPase proton pump. Genetic defects in any one of these components may impair renal acidification and thereby result in persistent acidosis, failure to thrive, and nephrocalcinosis. RECENT FINDINGS The present review provides a summary of the most recently identified genetic mutations resulting in a dRTA phenotype and, when possible, describes a mechanism. Most causes of dRTA are due to loss of function or inappropriate targeting of transporters. SUMMARY The collaboration of clinicians, geneticists, and renal physiologists has enabled us to better understand at the cellular level the different mechanisms leading to dRTA. Such information should lead to earlier diagnosis and treatment, thereby minimizing the irreversible complications affecting patients with this or similar diseases.
Collapse
Affiliation(s)
- Julie A Nicoletta
- Department of Pediatrics, University of Rochester School of Medicine, Box 777, 601 Elmwood Avenue, Rochester, New York 14642, USA
| | | |
Collapse
|
36
|
Yenchitsomanus PT, Sawasdee N, Paemanee A, Keskanokwong T, Vasuvattakul S, Bejrachandra S, Kunachiwa W, Fucharoen S, Jittphakdee P, Yindee W, Promwong C. Anion exchanger 1 mutations associated with distal renal tubular acidosis in the Thai population. J Hum Genet 2003; 48:451-456. [PMID: 12938018 DOI: 10.1007/s10038-003-0059-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Accepted: 07/03/2003] [Indexed: 11/26/2022]
Abstract
We have previously demonstrated that compound heterozygous (SAO/G701D) and homozygous (G701D/G701D) mutations of the anion exchanger 1 (AE1) gene, encoding erythroid and kidney AE1 proteins, cause autosomal recessive distal renal tubular acidosis (AR dRTA) in Thai patients. It is thus of interest to examine the prevalence of these mutations in the Thai population. The SAO and G701D mutations were examined in 844 individuals from north, northeast, central, and south Thailand. Other reported mutations including R602H, DeltaV850, and A858D were also examined in some groups of subjects. The SAO mutation was common in the southern Thai population; its heterozygote frequency was 7/206 and estimated allele frequency 1.70%. However, this mutation was not observed in populations of three other regions of Thailand. In contrast, the G701D mutation was not found in the southern population but was observed in the northern, northeastern, and central populations, with heterozygote frequencies of 1/216, 3/205, and 1/217, and estimated allele frequencies of 0.23%, 0.73%, and 0.23%, respectively. The higher allele frequency of the G701D mutation in the northeastern Thai population corresponds to our previous finding that all Thai patients with AR dRTA attributable to homozygous G701D mutation originate from this population. This suggests that the G701D allele that is observed in this region might arise in northeastern Thailand. The presence of patients with compound heterozygous SAO/G701D in southern Thailand and Malaysia and their apparently absence in northeastern Thailand indicate that the G701D allele may have migrated to the southern peninsular region where SAO is common, resulting in pathogenic allelic interaction.
Collapse
Affiliation(s)
- Pa-Thai Yenchitsomanus
- Division of Medical Molecular Biology, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
- Medical Biotechnology Unit, National Center for Biotechnology and Genetic Engineering (BIOTEC), National Science and Technology Development Agency (NSTDA), Bangkok, Thailand.
| | - Nunghathai Sawasdee
- Division of Medical Molecular Biology, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Atchara Paemanee
- Division of Medical Molecular Biology, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Medical Biotechnology Unit, National Center for Biotechnology and Genetic Engineering (BIOTEC), National Science and Technology Development Agency (NSTDA), Bangkok, Thailand
| | - Thitima Keskanokwong
- Division of Medical Molecular Biology, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Somkiat Vasuvattakul
- Division of Nephrology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sasitorn Bejrachandra
- Department of Transfusion Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Warunee Kunachiwa
- Department of Clinical Immunology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Supan Fucharoen
- Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Prapaporn Jittphakdee
- Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand
| | - Wanwimon Yindee
- Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand
| | - Charupon Promwong
- Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand
| |
Collapse
|
37
|
Yusoff NM, Van Rostenberghe H, Shirakawa T, Nishiyama K, Amin N, Darus Z, Zainal N, Isa N, Nozu H, Matsuo M. High prevalence of Southeast Asian ovalocytosis in Malays with distal renal tubular acidosis. J Hum Genet 2003; 48:650-653. [PMID: 14618420 DOI: 10.1007/s10038-003-0095-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2003] [Accepted: 09/26/2003] [Indexed: 11/26/2022]
Abstract
Southeast Asian ovalocytosis (SAO) is a red blood cell abnormality common in malaria-endemic regions and caused by a 27 nt deletion of the band 3 protein gene. Since band 3 protein, also known as anion exchanger 1, is expressed in renal distal tubules, the incidence of SAO was examined in distal renal tubular acidosis (dRTA) in Malays in Kelantan, Malaysia. Twenty-two patients with dRTA and 50 healthy volunteers were examined for complication of SAO by both morphological and genetic analyses. SAO was identified in 18 of the 22 dRTA patients (81.8%), but only two of the 50 controls (4%). The incidence of SAO was significantly high in those with dRTA (p<0.001), indicating a dysfunctional role for band 3 protein/anion exchanger 1 in the development of dRTA.
Collapse
Affiliation(s)
- Narazah Mohd Yusoff
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Hans Van Rostenberghe
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Taku Shirakawa
- Faculty of Health Science, Kobe University School of Medicine, Kobe, Japan
| | - Kaoru Nishiyama
- Faculty of Health Science, Kobe University School of Medicine, Kobe, Japan
| | - Noryati Amin
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Zainal Darus
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Nik Zainal
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Nizam Isa
- Human Genome Center, School of Medical Science, Health Campus, University Sains Malaysia, Kelantan, Malaysia
| | - Hiroyuki Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunokicho, Chuo, Kobe 650-0017, Japan
| | - Masafumi Matsuo
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunokicho, Chuo, Kobe 650-0017, Japan.
| |
Collapse
|
38
|
Sritippayawan S, Kirdpon S, Vasuvattakul S, Wasanawatana S, Susaengrat W, Waiyawuth W, Nimmannit S, Malasit P, Yenchitsomanus PT. A de novo R589C mutation of anion exchanger 1 causing distal renal tubular acidosis. Pediatr Nephrol 2003; 18:644-8. [PMID: 12750988 DOI: 10.1007/s00467-003-1112-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2002] [Revised: 12/11/2002] [Accepted: 12/17/2002] [Indexed: 10/25/2022]
Abstract
Anion exchanger 1 (AE1 or SLC4A1) mutations have been reported to cause distal renal tubular acidosis (dRTA), a disease characterized by impaired acid excretion in the distal nephron. We have recently demonstrated homozygous AE1 G701D mutation as a common molecular defect of autosomal recessive (AR) dRTA in a group of Thai pediatric patients. In the present work, we discovered a de novo heterozygous AE1 R589C mutation, previously documented in inherited autosomal dominant (AD) dRTA. Arginine at this position is conserved in all vertebrate AE proteins indicating its functional importance. Three different mutations at this position (R589C, R589H, and R589S) were all found in AD dRTA and a de novo R589H mutation has previously been recorded. Our report is the second de novo mutation but with a different substituted amino acid. A high prevalence of AE1 R589 mutations and the presence of at least two de novo mutations at this position lead us to propose that codon 589 (CGC) is a "mutational hotspot" of AE1. The mechanism of recurrent mutations probably involves methylation and deamination altering cytosine (C) to thymine (T) in the CpG dinucleotides.
Collapse
Affiliation(s)
- Suchai Sritippayawan
- Renal Division, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | | | | | | | | | | | | | | | | |
Collapse
|