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Du R, Zhou C, Chen S, Li T, Lin Y, Xu A, Huang Y, Mei H, Huang X, Tan D, Zheng R, Liang C, Cai Y, Shao Y, Zhang W, Liu L, Zeng C. Atypical phenotypes and novel OCRL variations in southern Chinese patients with Lowe syndrome. Pediatr Nephrol 2024; 39:2377-2391. [PMID: 38589698 DOI: 10.1007/s00467-024-06356-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Lowe syndrome is characterized by the presence of congenital cataracts, psychomotor retardation, and dysfunctional proximal renal tubules. This study presents a case of an atypical phenotype, investigates the genetic characteristics of eight children diagnosed with Lowe syndrome in southern China, and performs functional analysis of the novel variants. METHODS Whole-exome sequencing was conducted on eight individuals diagnosed with Lowe syndrome from three medical institutions in southern China. Retrospective collection and analysis of clinical and genetic data were performed, and functional analysis was conducted on the five novel variants. RESULTS In our cohort, the clinical symptoms of the eight Lowe syndrome individuals varied. One patient was diagnosed with Lowe syndrome but did not present with congenital cataracts. Common features among all patients included cognitive impairment, short stature, and low molecular weight proteinuria. Eight variations in the OCRL gene were identified, encompassing three previously reported and five novel variations. Among the novel variations, three nonsense mutations were determined to be pathogenic, and two patients harboring novel missense variations of uncertain significance exhibited severe typical phenotypes. Furthermore, all novel variants were associated with altered protein expression levels and impacted primary cilia formation. CONCLUSION This study describes the first case of an atypical Lowe syndrome patient without congenital cataracts in China and performs a functional analysis of novel variants in the OCRL gene, thereby expanding the understanding of the clinical manifestations and genetic diversity associated with Lowe syndrome.
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Affiliation(s)
- Rong Du
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Chengcheng Zhou
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Shehong Chen
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Pediatrics, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
| | - Tong Li
- Department of Pediatric Endocrinology, The First Affiliated Hospital of Shantou University Medical College, Shantou, 515041, China
| | - Yunting Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Aijing Xu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yonglan Huang
- Department of Guangzhou Newborn Screening Center, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Huifen Mei
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Xiaoli Huang
- Department of Pediatric Neurology, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Dongdong Tan
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Ruidan Zheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Cuili Liang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yanna Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yongxian Shao
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
| | - Wen Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China
| | - Chunhua Zeng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, National Children's Medical Center for South Central Region, Guangzhou Medical University, Guangzhou, 510623, China.
- Department of Endocrinology, Genetic, and Rare Diseases, Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, 545000, China.
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Coulter AM, Cortés V, Theodore CJ, Cianciolo RE, Korstanje R, Campellone KG. WHAMM functions in kidney reabsorption and polymerizes actin to promote autophagosomal membrane closure and cargo sequestration. Mol Biol Cell 2024; 35:ar80. [PMID: 38598293 PMCID: PMC11238085 DOI: 10.1091/mbc.e24-01-0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/01/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024] Open
Abstract
The actin cytoskeleton is essential for many functions of eukaryotic cells, but the factors that nucleate actin assembly are not well understood at the organismal level or in the context of disease. To explore the function of the actin nucleation factor WHAMM in mice, we examined how Whamm inactivation impacts kidney physiology and cellular proteostasis. We show that male WHAMM knockout mice excrete elevated levels of albumin, glucose, phosphate, and amino acids, and display structural abnormalities of the kidney proximal tubule, suggesting that WHAMM activity is important for nutrient reabsorption. In kidney tissue, the loss of WHAMM results in the accumulation of the lipidated autophagosomal membrane protein LC3, indicating an alteration in autophagy. In mouse fibroblasts and human proximal tubule cells, WHAMM and its binding partner the Arp2/3 complex control autophagic membrane closure and cargo receptor recruitment. These results reveal a role for WHAMM-mediated actin assembly in maintaining kidney function and promoting proper autophagosome membrane remodeling.
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Affiliation(s)
- Alyssa M. Coulter
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
| | | | - Corey J. Theodore
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
| | | | | | - Kenneth G. Campellone
- Department of Molecular & Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269
- Center on Aging, UConn Health, Farmington, CT 06030
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Lowenstein A, Swee G, Finkelman MD, Tesini D, Loo CY. Dental needs and conditions of individuals with Lowe syndrome: An observational study. SPECIAL CARE IN DENTISTRY 2024; 44:502-512. [PMID: 37128874 DOI: 10.1111/scd.12870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 05/03/2023]
Abstract
INTRODUCTION Lowe syndrome (LS) is an uncommon condition that affects the brain, kidneys, nervous system, and eyes, predominantly in males. The aim of this study was to examine dental conditions, dental treatments, and access and/or barriers to care for those with LS compared to healthy individuals. METHODS Surveys assessing dental conditions, dental treatments, and access and/or barriers to care were administered to families in the Lowe Syndrome Association and families with healthy children who had dental appointments at the Tufts University School of Dental Medicine (TUSDM) pediatric dental clinic. One parent or a guardian of pediatric patients with LS or not at TUSDM was asked to complete an online survey. RESULTS One hundred and eight surveys were obtained (n:58 from the LS group and n:50 from the healthy group). The LS group was significantly more likely (p < .05) to report "crooked/misaligned teeth," "difficult time chewing," "bad breath," and "mouth cysts" and was significantly less likely to report 6-month examination, "cleaning," and "filling." The LS group reported significantly greater difficulty locating a dentist. CONCLUSION The findings of this study indicate that individuals with LS are more vulnerable to developing severe dental conditions and experiencing difficulties in accessing dental care than healthy individuals. Additionally, those who present with this syndrome may be less likely to receive specific necessary dental treatments. As a result, it is essential to offer appropriate dental care and support to individuals with LS to guarantee they achieve optimal oral health.
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Affiliation(s)
- Adam Lowenstein
- Department of Pediatric Dentistry and Dental Research Administration, Tufts University School of Dental Medicine, Boston, Massachusetts, USA
| | - Gerald Swee
- Department of Pediatric Dentistry, Tufts University School of Dental Medicine, Boston, Massachusetts, USA
| | - Matthew D Finkelman
- Department of Public Health and Community Service, Tufts University School of Dental Medicine, Boston, Massachusetts, USA
| | - David Tesini
- Department of Pediatric Dentistry, Tufts University School of Dental Medicine, Boston, Massachusetts, USA
| | - Cheen Y Loo
- Department of Pediatric Dentistry, Tufts University School of Dental Medicine, Boston, Massachusetts, USA
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Ragate DC, Memon SS, Karlekar M, Lila AR, Sarathi V, Jamale T, Thakare S, Patil VA, Shah NS, Bandgar TR. Inherited Fanconi renotubular syndromes: unveiling the intricacies of hypophosphatemic rickets/osteomalacia. J Bone Miner Metab 2024; 42:155-165. [PMID: 38310177 DOI: 10.1007/s00774-023-01490-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 11/16/2023] [Indexed: 02/05/2024]
Abstract
INTRODUCTION Fanconi renotubular syndromes (FRTS) are a rare group of inherited phosphaturic disorders with limited Indian as well as global data on this condition. Here, we describe the experience of a single Endocrinology center from Western India on FRTS. MATERIALS AND METHODS Comprehensive clinical, biochemical, radiological, management, and genetic details of FRTS patients managed between 2010 and 2023 were collected and analyzed. RESULTS FRTS probands had mutations (eight novel) in six genes [CLCN5 (n = 4), SLC2A2 (n = 2), GATM, EHHADH, HNF4A, and OCRL (1 each)]. Among 15 FRTS patients (11 families), rickets/osteomalacia was the most common (n = 14) presentation with wide inter- and intra-familial phenotypic variability. Delayed diagnosis (median: 8.8 years), initial misdiagnosis (8/11 probands), and syndrome-specific discriminatory features (8/11 probands) were commonly seen. Hypophosphatemia, elevated alkaline phosphatase, normal parathyroid hormone (median: 36 pg/ml), high-normal/elevated 1,25(OH)2D (median: 152 pg/ml), hypercalciuria (median spot urinary calcium to creatinine ratio: 0.32), and variable proximal tubular dysfunction(s) were observed. Elevated C-terminal fibroblast growth factor 23 in two probands was misleading, till the genetic diagnosis was reached. Novel observations in our FRTS cohort were preserved renal function (till sixth decade) and enthesopathy in FRTS1 and FRTS3 families, respectively. CONCLUSION Our findings underscore frequent under- and misdiagnosis of FRTS; hence, a high index of suspicion for FRTS in phosphopenic rickets/osteomalacia, with early consideration of genetic testing is essential to ensure timely diagnosis of FRTS. The novel variants and phenotypic manifestations described here expand the disease spectrum of FRTS.
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Affiliation(s)
- Divya C Ragate
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
| | - Saba Samad Memon
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India.
| | - Manjiri Karlekar
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
| | - Anurag Ranjan Lila
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
| | - Vijaya Sarathi
- Department of Endocrinology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, Karnataka, India
| | - Tukaram Jamale
- Department of Nephrology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Sayali Thakare
- Department of Nephrology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Virendra A Patil
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
| | - Nalini S Shah
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
| | - Tushar R Bandgar
- Department of Endocrinology OPD, Seth G.S. Medical College and KEM Hospital, Parel, Mumbai, Maharashtra, 4000012, India
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Coulter AM, Cortés V, Theodore CJ, Cianciolo RE, Korstanje R, Campellone KG. WHAMM functions in kidney reabsorption and polymerizes actin to promote autophagosomal membrane closure and cargo sequestration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576497. [PMID: 38328079 PMCID: PMC10849548 DOI: 10.1101/2024.01.22.576497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The actin cytoskeleton is essential for many functions of eukaryotic cells, but the factors that nucleate actin assembly are not well understood at the organismal level or in the context of disease. To explore the function of the actin nucleation factor WHAMM in mice, we examined how Whamm inactivation impacts kidney physiology and cellular proteostasis. We show that male WHAMM knockout mice excrete elevated levels of albumin, glucose, phosphate, and amino acids, and display abnormalities of the kidney proximal tubule, suggesting that WHAMM activity is important for nutrient reabsorption. In kidney tissue, the loss of WHAMM results in the accumulation of the lipidated autophagosomal membrane protein LC3, indicating an alteration in autophagy. In mouse fibroblasts and human proximal tubule cells, WHAMM and its binding partner the Arp2/3 complex control autophagic membrane closure and cargo receptor recruitment. These results reveal a role for WHAMM-mediated actin assembly in maintaining kidney function and promoting proper autophagosome membrane remodeling.
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Affiliation(s)
- Alyssa M Coulter
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | | | - Corey J Theodore
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
| | | | | | - Kenneth G Campellone
- Department of Molecular & Cell Biology, Institute for Systems Genomics; University of Connecticut, Storrs CT, USA
- Center on Aging; UConn Health, Farmington CT, USA
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Singhania P, Dhar A, Deshpande A, Das D, Agrawal N, Chakraborty PP, Bhattacharjee R, Roy A. Rickets in proximal renal tubular acidosis: a case series of six distinct etiologies. J Pediatr Endocrinol Metab 2023; 36:879-885. [PMID: 37434360 DOI: 10.1515/jpem-2023-0155] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/23/2023] [Indexed: 07/13/2023]
Abstract
OBJECTIVES Proximal renal tubular acidosis (pRTA) is characterized by a defect in the ability of the proximal convoluted tubule to reabsorb bicarbonate. The biochemical hallmark of pRTA is hyperchloremic metabolic acidosis with a normal anion gap, accompanied by appropriate acidification of the urine (simultaneous urine pH <5.3). Isolated defects in bicarbonate transport are rare, and pRTA is more often associated with Fanconi syndrome (FS), which is characterized by urinary loss of phosphate, uric acid, glucose, amino acids, low-molecular-weight proteins, and bicarbonate. Children with pRTA may present with rickets, but pRTA is often overlooked as an underlying cause of this condition. CASE PRESENTATION We report six children with rickets and short stature due to pRTA. One case was idiopathic, while the remaining five had a specific underlying condition: Fanconi-Bickel syndrome, Dent's disease, nephropathic cystinosis, type 1 tyrosinemia, and sodium-bicarbonate cotransporter 1-A (NBC1-A) defect. CONCLUSIONS Five of these six children had features of FS, while the one with NBC1-A defect had isolated pRTA.
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Affiliation(s)
- Pankaj Singhania
- Department of Endocrinology and Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
| | - Abhranil Dhar
- Department of Endocrinology and Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
| | - Aditya Deshpande
- Department of Endocrinology and Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
| | - Debaditya Das
- Department of Endocrinology and Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
| | - Neeti Agrawal
- Department of Endocrinology, Medical College Kolkata, Kolkata, India
| | | | | | - Ajitesh Roy
- Department of Endocrinology, Vivekananda Institute of Medical Sciences, Kolkata, West Bengal, India
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Albuquerque ALB, Dos Santos Borges R, Conegundes AF, Dos Santos EE, Fu FMM, Araujo CT, Vaz de Castro PAS, Simões E Silva AC. Inherited Fanconi syndrome. World J Pediatr 2023; 19:619-634. [PMID: 36729281 DOI: 10.1007/s12519-023-00685-y] [Citation(s) in RCA: 6] [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: 10/04/2022] [Accepted: 01/08/2023] [Indexed: 02/03/2023]
Abstract
BACKGROUND Fanconi-Debré-de Toni syndrome (also known as Fanconi renotubular syndrome, or FRST) profoundly increased the understanding of the functions of the proximal convoluted tubule (PCT) and provided important insights into the pathophysiology of several kidney diseases and drug toxicities. DATA SOURCES We searched Pubmed and Scopus databases to find relevant articles about FRST. This review article focuses on the physiology of the PCT, as well as on the physiopathology of FRST in children, its diagnosis, and treatment. RESULTS FRST encompasses a wide variety of inherited and acquired PCT alterations that lead to impairment of PCT reabsorption. In children, FRST often presents as a secondary feature of systemic disorders that impair energy supply, such as Lowe's syndrome, Dent's disease, cystinosis, hereditary fructose intolerance, galactosemia, tyrosinemia, Alport syndrome, and Wilson's disease. Although rare, congenital causes of FRST greatly impact the morbidity and mortality of patients and impose diagnostic challenges. Furthermore, its treatment is diverse and considers the ability of the clinician to identify the correct etiology of the disease. CONCLUSION The early diagnosis and treatment of pediatric patients with FRST improve the prognosis and the quality of life.
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Affiliation(s)
- Anna Luiza Braga Albuquerque
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Rafael Dos Santos Borges
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Ana Flávia Conegundes
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Erika Emmylaine Dos Santos
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Frederico Moreira Man Fu
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Clara Tavares Araujo
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Pedro Alves Soares Vaz de Castro
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Ana Cristina Simões E Silva
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil.
- Department of Pediatrics, Faculty of Medicine, UFMG, Alfredo Balena Avenue, 190, 2Nd Floor, Room # 281, Belo Horizonte, MG, 30130-100, Brazil.
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Shen Y, Xu X, Chen J, Wang J, Dong G, Huang K, Fu J, Wu D, Wu W. De novo 11q13.3q13.4 deletion in a patient with Fanconi renotubular syndrome and intellectual disability: Case report and review of literature. Front Pediatr 2023; 11:1097062. [PMID: 37152320 PMCID: PMC10160663 DOI: 10.3389/fped.2023.1097062] [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: 11/16/2022] [Accepted: 03/27/2023] [Indexed: 05/09/2023] Open
Abstract
Objective To explore the genetic etiology of a child with facial dysmorphia, developmental delay, intellectual disability, Fanconi renotubular syndrome, and Chiari malformations. Materials and methods Whole exome sequencing (WES), Copy number variation sequencing (CNV-seq), and mitochondrial gene detection (Long-PCR + NGS) were applied to detect possible pathogenic mutations and chromosomal copy number variations (CNVs), together with databases and literature reviews to clarify the pathological significance of the candidate mutations. Results The WES revealed a 2.10 Mb interstitial deletion from 11q13.3 to 11q13.4, which was later confirmed by CNV-seq involving 11 OMIM genes, among which SHANK2, DHCR7, NADSYN1, FADD, NUMA1, IL18BP, ANO1, and FGF3 are disease-causing. The mitochondrial gene shows no variations. Conclusion The child has carried a de novo 11q13.3q13.4 microdeletion, in which SHANK2 genes may be the key gene responsible for the phenotype of intellectual disability. The renal manifestation of the child, which can be diagnosed as Fanconi renotubular syndrome, has an unknown cause but may result from the effect of the ANO1 gene. This case adds a new phenotype to the deletion of this region.
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Affiliation(s)
- Yingxiao Shen
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Xiaoqin Xu
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jiansong Chen
- Department of Orthopedics, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jingjing Wang
- Department of Nephrology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Guanping Dong
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ke Huang
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Junfen Fu
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Dingwen Wu
- Department of Genetics and Metabolism, Genetics and Metabolism, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
- Correspondence: Wei Wu Dingwen Wu
| | - Wei Wu
- Department of Endocrinology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
- Correspondence: Wei Wu Dingwen Wu
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Sandoval L, Fuentealba LM, Marzolo MP. Participation of OCRL1, and APPL1, in the expression, proteolysis, phosphorylation and endosomal trafficking of megalin: Implications for Lowe Syndrome. Front Cell Dev Biol 2022; 10:911664. [PMID: 36340038 PMCID: PMC9630597 DOI: 10.3389/fcell.2022.911664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Megalin/LRP2 is the primary multiligand receptor for the re-absorption of low molecular weight proteins in the proximal renal tubule. Its function is significantly dependent on its endosomal trafficking. Megalin recycling from endosomal compartments is altered in an X-linked disease called Lowe Syndrome (LS), caused by mutations in the gene encoding for the phosphatidylinositol 5-phosphatase OCRL1. LS patients show increased low-molecular-weight proteins with reduced levels of megalin ectodomain in the urine and accumulation of the receptor in endosomal compartments of the proximal tubule cells. To gain insight into the deregulation of megalin in the LS condition, we silenced OCRL1 in different cell lines to evaluate megalin expression finding that it is post-transcriptionally regulated. As an indication of megalin proteolysis, we detect the ectodomain of the receptor in the culture media. Remarkably, in OCRL1 silenced cells, megalin ectodomain secretion appeared significantly reduced, according to the observation in the urine of LS patients. Besides, the silencing of APPL1, a Rab5 effector associated with OCRL1 in endocytic vesicles, also reduced the presence of megalin’s ectodomain in the culture media. In both silencing conditions, megalin cell surface levels were significantly decreased. Considering that GSK3ß-mediated megalin phosphorylation reduces receptor recycling, we determined that the endosomal distribution of megalin depends on its phosphorylation status and OCRL1 function. As a physiologic regulator of GSK3ß, we focused on insulin signaling that reduces kinase activity. Accordingly, megalin phosphorylation was significantly reduced by insulin in wild-type cells. Moreover, even though in cells with low activity of OCRL1 the insulin response was reduced, the phosphorylation of megalin was significantly decreased and the receptor at the cell surface increased, suggesting a protective role of insulin in a LS cellular model.
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Affiliation(s)
- Lisette Sandoval
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Luz M. Fuentealba
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: María-Paz Marzolo,
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10
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Naylor RW, Lemarie E, Jackson-Crawford A, Davenport JB, Mironov A, Lowe M, Lennon R. A novel nanoluciferase transgenic reporter measures proteinuria in zebrafish. Kidney Int 2022; 102:815-827. [PMID: 35716957 DOI: 10.1101/2021.07.19.452884] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 05/28/2023]
Abstract
The zebrafish is an important animal system for modeling human diseases. This includes kidney dysfunction as the embryonic kidney (pronephros) shares considerable molecular and morphological homology with the human nephron. A key clinical indicator of kidney disease is proteinuria, but a high-throughput readout of proteinuria in the zebrafish is currently lacking. To remedy this, we used the Tol2 transposon system to generate a transgenic zebrafish line that uses the fabp10a liver-specific promoter to over-express a nanoluciferase molecule fused with the D3 domain of Receptor-Associated Protein (a type of molecular chaperone) which we term NL-D3. Using a luminometer, we quantified proteinuria in NL-D3 zebrafish larvae by measuring the intensity of luminescence in the embryo medium. In the healthy state, NL-D3 is not excreted, but when embryos were treated with chemicals that affected either proximal tubular reabsorption (cisplatin, gentamicin) or glomerular filtration (angiotensin II, Hanks Balanced Salt Solution, Bovine Serum Albumin), NL-D3 is detected in fish medium. Similarly, depletion of several gene products associated with kidney disease (nphs1, nphs2, lrp2a, ocrl, col4a3, and col4a4) also induced NL-D3 proteinuria. Treating col4a4 depleted zebrafish larvae (a model of Alport syndrome) with captopril reduced proteinuria in this system. Thus, our findings validate the use of the NL-D3 transgenic zebrafish as a robust and quantifiable proteinuria reporter. Hence, given the feasibility of high-throughput assays in zebrafish, this novel reporter will permit screening for drugs that ameliorate proteinuria, thereby prioritizing candidates for further translational studies.
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Affiliation(s)
- Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Emmanuel Lemarie
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | | | - J Bernard Davenport
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Aleksandr Mironov
- EM Core Facility (RRID: SCR_021147), Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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11
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Naylor RW, Lemarie E, Jackson-Crawford A, Davenport JB, Mironov A, Lowe M, Lennon R. A novel nanoluciferase transgenic reporter measures proteinuria in zebrafish. Kidney Int 2022; 102:815-827. [PMID: 35716957 PMCID: PMC7614274 DOI: 10.1016/j.kint.2022.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022]
Abstract
The zebrafish is an important animal system for modeling human diseases. This includes kidney dysfunction as the embryonic kidney (pronephros) shares considerable molecular and morphological homology with the human nephron. A key clinical indicator of kidney disease is proteinuria, but a high-throughput readout of proteinuria in the zebrafish is currently lacking. To remedy this, we used the Tol2 transposon system to generate a transgenic zebrafish line that uses the fabp10a liver-specific promoter to over-express a nanoluciferase molecule fused with the D3 domain of Receptor-Associated Protein (a type of molecular chaperone) which we term NL-D3. Using a luminometer, we quantified proteinuria in NL-D3 zebrafish larvae by measuring the intensity of luminescence in the embryo medium. In the healthy state, NL-D3 is not excreted, but when embryos were treated with chemicals that affected either proximal tubular reabsorption (cisplatin, gentamicin) or glomerular filtration (angiotensin II, Hanks Balanced Salt Solution, Bovine Serum Albumin), NL-D3 is detected in fish medium. Similarly, depletion of several gene products associated with kidney disease (nphs1, nphs2, lrp2a, ocrl, col4a3, and col4a4) also induced NL-D3 proteinuria. Treating col4a4 depleted zebrafish larvae (a model of Alport syndrome) with captopril reduced proteinuria in this system. Thus, our findings validate the use of the NL-D3 transgenic zebrafish as a robust and quantifiable proteinuria reporter. Hence, given the feasibility of high-throughput assays in zebrafish, this novel reporter will permit screening for drugs that ameliorate proteinuria, thereby prioritizing candidates for further translational studies.
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Affiliation(s)
- Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Emmanuel Lemarie
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | | | - J Bernard Davenport
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Aleksandr Mironov
- EM Core Facility (RRID: SCR_021147), Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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12
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Eibenberger K, Rezar-Dreindl S, Pusch F, Schmidt-Erfurth U, Stifter E. Management of cataract surgery in Lowe syndrome. Int J Ophthalmol 2022; 15:1198-1202. [PMID: 35919319 DOI: 10.18240/ijo.2022.07.22] [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: 07/29/2021] [Accepted: 04/27/2022] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the ophthalmic and anesthesiologic management of cataract surgery in children with Lowe syndrome receiving lens removal, the development and management of secondary glaucoma. METHODS This retrospective case series included 12 eyes of 6 children with genetically verified Lowe syndrome receiving cataract removal. Information regarding the type and duration of surgery and total anesthesia time were recorded. Additionally, intra- and postoperative complications were noted as well as clinical examinations such as visual acuity and funduscopy. RESULTS All children received simultaneous bilateral cataract surgery at the mean age of 8.98±3.58wk. Lensectomy combined with posterior capsulotomy and anterior vitrectomy was performed in all children. The mean time for cataract surgery per eye was 35.83±8.86min, whereas the total time of surgery was 153.33±22.11min. The mean extubation time and duration at recovery room was 42.33±22.60min and 130.00±64.37min, respectively. During surgery, a decrease of oxygen saturation below 93% was found in only one child. During the postoperative follow-up, nystagmus (6 children) and strabismus (5 children) was commonly found in contrast to no case of visual axis opacification. Secondary glaucoma developed in five eyes of three children, which was treated with topical eye drops in only one child. A trabeculectomy was performed in both eyes of one child, whereas removal of syechia and an iridectomy in one eye of one child. CONCLUSION Bilateral simultaneous cataract surgery under general anesthesia is a safe surgical procedure in Lowe syndrome children. The glaucoma screening with intraocular pressure measurements is crucial in the postoperative management of Lowe syndrome patients to avoid additional visual impairment.
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Affiliation(s)
- Katharina Eibenberger
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna 1090, Austria
| | - Sandra Rezar-Dreindl
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna 1090, Austria
| | - Franz Pusch
- Department of Anesthesiology, Medical University of Vienna, Vienna 1090, Austria
| | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna 1090, Austria
| | - Eva Stifter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna 1090, Austria
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13
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Alhasan K, D'Alessandri-Silva C, Mongia A, Topaloglu R, Tasic V, Filler G. Young Adults With Hereditary Tubular Diseases: Practical Aspects for Adult-Focused Colleagues. Adv Chronic Kidney Dis 2022; 29:292-307. [PMID: 36084976 DOI: 10.1053/j.ackd.2021.11.004] [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: 09/21/2021] [Revised: 11/07/2021] [Accepted: 11/15/2021] [Indexed: 11/11/2022]
Abstract
Recent advances in the management of kidney tubular diseases have resulted in a significant cohort of adolescents and young adults transitioning from pediatric- to adult-focused care. Most of the patients under adult-focused care have glomerular diseases, whereas rarer tubular diseases form a considerable proportion of pediatric patients. The purpose of this review is to highlight the clinical signs and symptoms of tubular disorders, as well as their diagnostic workup, including laboratory findings and imaging, during young adulthood. We will then discuss more common disorders such as cystinosis, cystinuria, distal kidney tubular acidosis, congenital nephrogenic diabetes insipidus, Dent disease, rickets, hypercalciuria, and syndromes such as Bartter, Fanconi, Gitelman, Liddle, and Lowe. This review is a practical guide on the diagnostic and therapeutic approach of tubular conditions affecting young adults who are transitioning to adult-focused care.
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Affiliation(s)
- Khalid Alhasan
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Cynthia D'Alessandri-Silva
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, and Nephrology, Connecticut Children's Medical Center, Hartford, CT
| | - Anil Mongia
- Department of Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY
| | - Rezan Topaloglu
- Department of Paediatrics, Division of Pediatric Nephrology, Hacettepe University School of Medicine, Ankara, Turkey
| | - Velibor Tasic
- University Children's Hospital, Medical School, Skopje, North Macedonia
| | - Guido Filler
- Department of Paediatrics, Division of Pediatric Nephrology, Western University, London, ON, Canada; Department of Medicine, Western University, London, ON, Canada; Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.
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14
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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: 53] [Impact Index Per Article: 26.5] [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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15
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Soares AD, Pereira JL, Cunha B, Esteves AM, Xavier MT, Costa AL. Oculocerebrorenal syndrome of lowe: Oral findings. PEDIATRIC DENTAL JOURNAL 2022. [DOI: 10.1016/j.pdj.2022.02.001] [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]
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16
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Guo Y, Zhou YH, Wu XP, Tang CY, Wang M, Mo ZH, Shepherd JA, Ng BK, Fan B, Zhou HD. Changes in Bone Mineral Density Following Conventional Oral Phosphonate Treatment of Hypophosphatemic Osteomalacia: A Non-Randomized Controlled Study. Int J Gen Med 2021; 14:7925-7931. [PMID: 34795510 PMCID: PMC8593346 DOI: 10.2147/ijgm.s332534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/20/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose There are limited clinical studies aimed at solving the problem of the efficiency of conventional treatment with oral phosphate and calcitriol in adults with hypophosphatemic osteomalacia (HO). In addition, there still had no good non-hazardous markers to evaluate the severity of bone loss of osteomalacia before and after treatment. Therefore, the purpose of this study was to assess the efficacy of conventional treatment with a self-blended phosphate supplementation and calcitriol on patients with HO and whether bone mineral density (BMD) can be helpful for monitoring the efficacy. Patients and Methods A total of 21 HO patients and 105 healthy controls were enrolled. All patients were tested for serum biomarkers and BMD of the lumbar spine (L1-L4), femoral neck, and total left hip. After three years of treatment, 11 of 21 HO patients were recalled for BMD measurement. According to the administration of drugs, HO patients with calcium and calcitriol were divided into three phosphate treatment groups: patients in group A (n = 3) received continuous phosphate supplementation, patients in group B (n = 5) received intermittent phosphate supplementation and patients in group C (n = 3) received no phosphate supplementation. Results The diagnoses of 21 HO patients were 5 cases of hereditary hypophosphatemic rickets, 4 cases of Fanconi syndrome with the features of renal tubular acidosis and vitamin D deficiency, and 12 cases of hereditary vitamin D abnormality. The average initial serum phosphorus level of the patient group was approximately 50% lower than that of the control group. Lower BMD was significantly observed in the HO group than the control group at the lumbar spine and total hip. Continuous treatment with the phosphate supplement could increase BMD in the lumbar spine and total hip by 33.4-52.3% and in the femoral neck increased by 43.2-79.3% compared with baseline, and the effect appears to be continued once treatment is discontinued. Conclusion These findings suggest that conventional therapy can improve bone mineral defects in patients with HO, especially in the femoral neck. Detection of BMD in HO patients is a good tool to assess the extent of bone defects and the therapeutic effect. Trial Registration Chinese Clinical Trial Registry, ChiCTR-OOC-16010095. Registered 7 December 2016. Retrospectively registered.
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Affiliation(s)
- Yue Guo
- National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China.,Department of Stomatology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Ying-Hui Zhou
- National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Xian-Ping Wu
- National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Chen-Yi Tang
- National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China
| | - Min Wang
- Department of Endocrinology, Xiangya Hospital of Central South University, Changsha, 410008, People's Republic of China
| | - Zhao-Hui Mo
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, 410013, People's Republic of China
| | - John A Shepherd
- Department of Radiology & Biomedical Imaging, University of California at San Francisco, San Francisco, CA, 94143, USA
| | - Bennett K Ng
- Department of Radiology & Biomedical Imaging, University of California at San Francisco, San Francisco, CA, 94143, USA
| | - Bo Fan
- Department of Radiology & Biomedical Imaging, University of California at San Francisco, San Francisco, CA, 94143, USA
| | - Hou-De Zhou
- National Clinical Research Center for Metabolic Diseases, Hunan Provincial Key Laboratory of Metabolic Bone Diseases, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People's Republic of China
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17
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Oltrabella F, Jackson-Crawford A, Yan G, Rixham S, Starborg T, Lowe M. IPIP27A cooperates with OCRL to support endocytic traffic in the zebrafish pronephric tubule. Hum Mol Genet 2021; 31:1183-1196. [PMID: 34673953 DOI: 10.1093/hmg/ddab307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 01/08/2023] Open
Abstract
Endocytosis is a fundamentally important process through which material is internalized into cells from the extracellular environment. In the renal proximal tubule, endocytosis of the abundant scavenger receptor megalin and its co-receptor cubilin play a vital role in retrieving low molecular weight proteins from the renal filtrate. Although we know much about megalin and its ligands, the machinery and mechanisms by which the receptor is trafficked through the endosomal system remain poorly defined. In this study, we show that Ipip27A, an interacting partner of the Lowe syndrome protein OCRL, is required for endocytic traffic of megalin within the proximal renal tubule of zebrafish larvae. Knockout of Ipip27A phenocopies the endocytic phenotype seen upon loss of OCRL, with a deficit in uptake of both fluid-phase and protein cargo, which is accompanied by a reduction in megalin abundance and altered endosome morphology. Rescue and co-depletion experiments indicate that Ipip27A functions together with OCRL to support proximal tubule endocytosis. The results therefore identify Ipip27A as a new player in endocytic traffic in the proximal tubule in vivo and support the view that defective endocytosis underlies the renal tubulopathy in Lowe syndrome and Dent-2 disease.
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Affiliation(s)
- Francesca Oltrabella
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.,Medical Scientific Liaison - Nephrology, Astellas Pharma, Via Dante, 20123 Milano, Italy
| | - Anthony Jackson-Crawford
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.,Department of Blood Sciences, Grange University Hospital, Llanyravon, Gwent, NP44 8YN
| | - Guanhua Yan
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Sarah Rixham
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Tobias Starborg
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.,Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0FA, UK
| | - Martin Lowe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
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18
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Madhivanan K, Ramadesikan S, Hsieh WC, Aguilar MC, Hanna CB, Bacallao RL, Aguilar RC. Lowe syndrome patient cells display mTOR- and RhoGTPase-dependent phenotypes alleviated by rapamycin and statins. Hum Mol Genet 2021; 29:1700-1715. [PMID: 32391547 DOI: 10.1093/hmg/ddaa086] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/20/2020] [Accepted: 05/04/2020] [Indexed: 12/25/2022] Open
Abstract
Lowe syndrome (LS) is an X-linked developmental disease characterized by cognitive deficiencies, bilateral congenital cataracts and renal dysfunction. Unfortunately, this disease leads to the early death of affected children often due to kidney failure. Although this condition was first described in the early 1950s and the affected gene (OCRL1) was identified in the early 1990s, its pathophysiological mechanism is not fully understood and there is no LS-specific cure available to patients. Here we report two important signaling pathways affected in LS patient cells. While RhoGTPase signaling abnormalities led to adhesion and spreading defects as compared to normal controls, PI3K/mTOR hyperactivation interfered with primary cilia assembly (scenario also observed in other ciliopathies with compromised kidney function). Importantly, we identified two FDA-approved drugs able to ameliorate these phenotypes. Specifically, statins mitigated adhesion and spreading abnormalities while rapamycin facilitated ciliogenesis in LS patient cells. However, no single drug was able to alleviate both phenotypes. Based on these and other observations, we speculate that Ocrl1 has dual, independent functions supporting proper RhoGTPase and PI3K/mTOR signaling. Therefore, this study suggest that Ocrl1-deficiency leads to signaling defects likely to require combinatorial drug treatment to suppress patient phenotypes and symptoms.
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Affiliation(s)
- Kayalvizhi Madhivanan
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Wen-Chieh Hsieh
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Mariana C Aguilar
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Claudia B Hanna
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
| | - Robert L Bacallao
- Division of Nephrology, Indiana University School of Medicine, 340 W 10th St #6200, Indianapolis, IN 46202, USA
| | - R Claudio Aguilar
- Department of Biological Sciences, Purdue University, Hansen Life Sciences Building, Room 321, 201 S. University street, West Lafayette, IN 47907, USA
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19
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Dao M, Arnoux JB, Bienaimé F, Brassier A, Brazier F, Benoist JF, Pontoizeau C, Ottolenghi C, Krug P, Boyer O, de Lonlay P, Servais A. Long-term renal outcome in methylmalonic acidemia in adolescents and adults. Orphanet J Rare Dis 2021; 16:220. [PMID: 33985557 PMCID: PMC8120835 DOI: 10.1186/s13023-021-01851-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 05/04/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Chronic kidney disease (CKD) is one of the main long-term prognosis factors in methylmalonic acidemia (MMA), a rare disease of propionate catabolism. Our objective was to precisely address the clinical and biological characteristics of long-term CKD in MMA adolescent and adult patients. PATIENTS AND METHODS In this retrospective study, we included MMA patients older than 13 years who had not received kidney and/or liver transplantation. We explored tubular functions, with special attention to proximal tubular function. We measured glomerular filtration rate (mGFR) by iohexol clearance and compared it to estimated glomerular filtration rate (eGFR) by Schwartz formula and CKD-EPI. RESULTS Thirteen patients were included (M/F = 5/8). Median age was 24 years (13 to 32). Median mGFR was 57 mL/min/1.73 m2 (23.3 to 105 mL/min/1.73 m2). Ten out of 13 patients had mGFR below 90 mL/min/1.73 m2. No patient had significant glomerular proteinuria. No patient had complete Fanconi syndrome. Only one patient had biological signs suggestive of incomplete proximal tubulopathy. Four out of 13 patients had isolated potassium loss, related to a non-reabsorbable anion effect of urinary methylmalonate. Both Schwartz formula and CKD-EPI significantly overestimated GFR. Bias were respectively 16 ± 15 mL/min/1.73 m2 and 37 ± 22 mL/min/1.73 m2. CONCLUSION CKD is a common complication of the MMA. Usual equations overestimate GFR. Therefore, mGFR should be performed to inform therapeutic decisions such as dialysis and/or transplantation. Mild evidence of proximal tubular dysfunction was found in only one patient, suggesting that other mechanisms are involved.
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Affiliation(s)
- Myriam Dao
- Adult Nephrology and Transplantation Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France.
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France.
| | - Jean-Baptiste Arnoux
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Frank Bienaimé
- Department of Physiology, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Anaïs Brassier
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - François Brazier
- Department of Physiology, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Jean-François Benoist
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
- Biochemistry Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Clément Pontoizeau
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
- Biochemistry Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Chris Ottolenghi
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
- Biochemistry Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Pauline Krug
- Pediatric Nephrology Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Olivia Boyer
- Pediatric Nephrology Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Pascale de Lonlay
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
| | - Aude Servais
- Adult Nephrology and Transplantation Department, Hôpital Necker Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
- Reference Center of Inherited Metabolic Diseases (MAMEA and MetabERN), Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015, Paris, France
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20
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Chakraborty PP, Bhattacharjee R, Patra S, Roy A, Gantait K, Chowdhury S. Clinical and Biochemical Characteristics of Patients with Renal Tubular Acidosis in Southern Part of West Bengal, India: A Retrospective Study. Indian J Endocrinol Metab 2021; 25:121-128. [PMID: 34660240 PMCID: PMC8477733 DOI: 10.4103/ijem.ijem_785_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/30/2021] [Accepted: 06/29/2021] [Indexed: 01/25/2023] Open
Abstract
PURPOSE OF THE STUDY Reversible proximal tubular dysfunction associated with distal renal tubular acidosis (dRTA) mimics type 3 RTA, a condition classically associated with features of both proximal RTA (pRTA) and dRTA. Proximal tubulopathy has been reported in children with primary dRTA, but the data in adults are lacking. STUDY DESIGN In this hospital record-based retrospective study, data from 66 consecutive cases of RTA, between January 2016 to December 2018, were retrieved and analyzed. RESULTS Mean age of the study population was 25.3 years (range: 3 months to 73 years). Six (9.1%) of them had pRTA, 58 (87.9%) had dRTA, 1 (1.5%) had type 3 RTA, and the remaining 1 (1.5%) had type 4 RTA. Ten patients (17.2%) with dRTA and 3 patients of pRTA (50%) had underlying secondary etiologies. Data on proximal tubular dysfunction were available for 30 patients with dRTA, of whom 1 had isolated dRTA, and the rest 29 patients had accompanying completely reversible proximal tubular dysfunction. Among the 10 cases of secondary dRTA, 6 were not evaluated for proximal tubular dysfunction. Of the remaining 4, 3 had reversible form of proximal tubular abnormality. Fifty-two patients with dRTA came from a population, indigenous to the "Rarh" region of India. CONCLUSIONS Proximal tubular dysfunction often accompanies dRTA; 75% of the children with primary dRTA, at least 29% of adults with primary dRTA, and at least 30% of adults with secondary dRTA manifest such completely reversible form of proximal tubulopathy. "Rarh' region of India probably is a hotspot for endemic dRTA.
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Affiliation(s)
- Partha Pratim Chakraborty
- Department of Medicine, Midnapore Medical College and Hospital, Midnapore, Kolkata, West Bengal, India
| | - Rana Bhattacharjee
- Department of Endocrinology and Metabolism, IPGME and R/SSKM Hospital, Kolkata, West Bengal, India
| | - Shinjan Patra
- Department of Medicine, Midnapore Medical College and Hospital, Midnapore, Kolkata, West Bengal, India
| | - Ajitesh Roy
- Department of Endocrinology and Metabolism, IPGME and R/SSKM Hospital, Kolkata, West Bengal, India
| | - Kripasindhu Gantait
- Department of Medicine, Midnapore Medical College and Hospital, Midnapore, Kolkata, West Bengal, India
| | - Subhankar Chowdhury
- Department of Endocrinology and Metabolism, IPGME and R/SSKM Hospital, Kolkata, West Bengal, India
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21
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McWilliam SJ, Wright RD, Welsh GI, Tuffin J, Budge KL, Swan L, Wilm T, Martinas IR, Littlewood J, Oni L. The complex interplay between kidney injury and inflammation. Clin Kidney J 2021; 14:780-788. [PMID: 33777361 PMCID: PMC7986351 DOI: 10.1093/ckj/sfaa164] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
Acute kidney injury (AKI) has gained significant attention following patient safety alerts about the increased risk of harm to patients, including increased mortality and hospitalization. Common causes of AKI include hypovolaemia, nephrotoxic medications, ischaemia and acute glomerulonephritis, although in reality it may be undetermined or multifactorial. A period of inflammation either as a contributor to the kidney injury or resulting from the injury is almost universally seen. This article was compiled following a workshop exploring the interplay between injury and inflammation. AKI is characterized by some degree of renal cell death through either apoptosis or necrosis, together with a strong inflammatory response. Studies interrogating the resolution of renal inflammation identify a whole range of molecules that are upregulated and confirm that the kidneys are able to intrinsically regenerate after an episode of AKI, provided the threshold of damage is not too high. Kidneys are unable to generate new nephrons, and dysfunctional or repeated episodes will lead to further nephron loss that is ultimately associated with the development of renal fibrosis and chronic kidney disease (CKD). The AKI to CKD transition is a complex process mainly facilitated by maladaptive repair mechanisms. Early biomarkers mapping out this process would allow a personalized approach to identifying patients with AKI who are at high risk of developing fibrosis and subsequent CKD. This review article highlights this process and explains how laboratory models of renal inflammation and injury assist with understanding the underlying disease process and allow interrogation of medications aimed at targeting the mechanistic interplay.
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Affiliation(s)
- Stephen J McWilliam
- Department of Paediatric Pharmacology, Alder Hey Children’s Hospital, Liverpool, UK
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Rachael D Wright
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Jack Tuffin
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kelly L Budge
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Laura Swan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Thomas Wilm
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Ioana-Roxana Martinas
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - James Littlewood
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Nephrology, Royal Liverpool University Hospital, Liverpool, UK
| | - Louise Oni
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Paediatric Nephrology, Alder Hey Children’s NHS Foundation Trust Hospital, Liverpool, UK
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22
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Sethi S, Sethi N, Mehta S, Kaur S, Makkar V, Sohal PM. Lowe syndrome - Case report with a novel mutation in the oculocerebrorenal gene. SAUDI JOURNAL OF KIDNEY DISEASES AND TRANSPLANTATION 2021; 31:285-288. [PMID: 32129227 DOI: 10.4103/1319-2442.279955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The oculocerebrorenal (OCRL) syndrome, also known as Lowe syndrome (LS), is an X-linked recessive disorder that predominantly affects males and is characterized by growth and mental retardation, congenital cataract and renal Fanconi syndrome. OCRL1 is the gene responsible for LS and encodes an inositol polyphosphate-5-phosphatase. We report a male child from North India, with LS with missense mutation in exon 14 of the OCRL gene.
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Affiliation(s)
- Suman Sethi
- Department of Nephrology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Nitin Sethi
- Department of Surgery, Fortis Hospital, Ludhiana, Punjab, India
| | - Sudhir Mehta
- Department of Nephrology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Simran Kaur
- Department of Nephrology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Vikas Makkar
- Department of Nephrology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - P M Sohal
- Department of Nephrology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
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23
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Lemaire M. Novel Fanconi renotubular syndromes provide insights in proximal tubule pathophysiology. Am J Physiol Renal Physiol 2020; 320:F145-F160. [PMID: 33283647 DOI: 10.1152/ajprenal.00214.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The various forms of Fanconi renotubular syndromes (FRTS) offer significant challenges for clinicians and present unique opportunities for scientists who study proximal tubule physiology. This review will describe the clinical characteristics, genetic underpinnings, and underlying pathophysiology of the major forms of FRST. Although the classic forms of FRTS will be presented (e.g., Dent disease or Lowe syndrome), particular attention will be paid to five of the most recently discovered FRTS subtypes caused by mutations in the genes encoding for L-arginine:glycine amidinotransferase (GATM), solute carrier family 34 (type Ii sodium/phosphate cotransporter), member 1 (SLC34A1), enoyl-CoAhydratase/3-hydroxyacyl CoA dehydrogenase (EHHADH), hepatocyte nuclear factor 4A (HNF4A), or NADH dehydrogenase complex I, assembly factor 6 (NDUFAF6). We will explore how mutations in these genes revealed unexpected mechanisms that led to compromised proximal tubule functions. We will also describe the inherent challenges associated with gene discovery studies based on findings derived from small, single-family studies by focusing the story of FRTS type 2 (SLC34A1). Finally, we will explain how extensive alternative splicing of HNF4A has resulted in confusion with mutation nomenclature for FRTS type 4.
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Affiliation(s)
- Mathieu Lemaire
- Division of Nephrology and Cell Biology Program, SickKids Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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24
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Hemolysis induced by Left Ventricular Assist Device is associated with proximal tubulopathy. PLoS One 2020; 15:e0242931. [PMID: 33253314 PMCID: PMC7703997 DOI: 10.1371/journal.pone.0242931] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/11/2020] [Indexed: 01/21/2023] Open
Abstract
Background Chronic subclinical hemolysis is frequent in patients implanted with Left Ventricular Assist Device (LVAD) and is associated with adverse outcomes. Consequences of LVADs-induced subclinical hemolysis on kidney structure and function is currently unknown. Methods Thirty-three patients implanted with a Heartmate II LVAD (Abbott, Inc, Chicago IL) were retrospectively studied. Hemolysis, Acute Kidney Injury (AKI) and the evolution of estimated Glomerular Filtration Rate were analyzed. Proximal Tubulopathy (PT) groups were defined according to proteinuria, normoglycemic glycosuria, and electrolytic disorders. The Receiver Operating Characteristic (ROC) curve was used to analyze threshold of LDH values associated with PT. Results Median LDH between PT groups were statistically different, 688 IU/L [642–703] and 356 IU/L [320–494] in the “PT” and “no PT” groups, respectively p = 0.006. To determine PT group, LDH threshold > 600 IU/L was associated with a sensitivity of 85.7% (95% CI, 42.1–99.6) and a specificity of 84.6% (95% CI, 65.1–95.6). The ROC's Area Under Curve was 0.83 (95% CI, 0.68–0.98). In the “PT” group, patients had 4.2 [2.5–5.0] AKI episodes per year of exposure, versus 1.6 [0.4–3.7] in the “no PT” group, p = 0.03. A higher occurrence of AKI was associated with subsequent development of Chronic Kidney Disease (CKD) (p = 0.02) and death (p = 0.05). Conclusions LVADs-induced subclinical hemolysis is associated with proximal tubular functional alterations, which in turn contribute to the occurrence of AKI and subsequent CKD. Owing to renal toxicity of hemolysis, measures to reduce subclinical hemolysis intensity as canula position or pump parameters should be systematically considered, as well as specific nephroprotective therapies.
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25
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Edwards A, Christensen EI, Unwin RJ, Norden AGW. Predicting the protein composition of human urine in normal and pathological states: Quantitative description based on Dent1 disease (
CLCN5
mutation). J Physiol 2020; 599:323-341. [DOI: 10.1113/jp280740] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 10/16/2020] [Indexed: 01/25/2023] Open
Affiliation(s)
- Aurélie Edwards
- Department of Biomedical Engineering Boston University Boston MA USA
| | | | - Robert J. Unwin
- Department of Renal Medicine Royal Free Campus University College London London UK
| | - Anthony G. W. Norden
- Department of Renal Medicine Royal Free Campus University College London London UK
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26
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Perdomo-Ramirez A, Antón-Gamero M, Rizzo DS, Trindade A, Ramos-Trujillo E, Claverie-Martin F. Two new missense mutations in the protein interaction ASH domain of OCRL1 identified in patients with Lowe syndrome. Intractable Rare Dis Res 2020; 9:222-228. [PMID: 33139981 PMCID: PMC7586875 DOI: 10.5582/irdr.2020.03092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The oculocerebrorenal syndrome of Lowe is a rare X-linked disease characterized by congenital cataracts, proximal renal tubulopathy, muscular hypotonia and mental impairment. This disease is caused by mutations in the OCRL gene encoding membrane bound inositol polyphosphate 5-phosphatase OCRL1. Here, we examined the OCRL gene of two Lowe syndrome patients and report two new missense mutations that affect the ASH domain involved in protein-protein interactions. Genomic DNA was extracted from peripheral blood of two non-related patients and their relatives. Exons and flanking intronic regions of OCRL were analyzed by direct sequencing. Several bioinformatics tools were used to assess the pathogenicity of the variants. The three-dimensional structure of wild-type and mutant ASH domains was modeled using the online server SWISS-MODEL. Clinical features suggesting the diagnosis of Lowe syndrome were observed in both patients. Genetic analysis revealed two novel missense variants, c.1907T>A (p.V636E) and c.1979A>C (p.H660P) in exon 18 of the OCRL gene confirming the clinical diagnosis in both cases. Variant c.1907T>A (p.V636E) was inherited from the patient's mother, while variant c.1979A>C (p.H660P) seems to have originated de novo. Analysis with bioinformatics tools indicated that both variants are pathogenic. Both amino acid changes affect the structure of the OCRL1 ASH domain. In conclusion, the identification of two novel missense mutations located in the OCRL1 ASH domain may shed more light on the functional importance of this domain. We suggest that p.V636E and p.H660P cause Lowe syndrome by disrupting the interaction of OCRL1 with other proteins or by impairing protein stability.
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Affiliation(s)
- Ana Perdomo-Ramirez
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | | | | | - Amelia Trindade
- Departamento de Medicina, Universidade Federal de Sao Carlos, Sao Paulo, Brazil
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Felix Claverie-Martin
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Address correspondence to:Félix Claverie-Martín, Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain. E-mail:
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27
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Abstract
Kidney stone disease (nephrolithiasis) is a common problem that can be associated with alterations in urinary solute composition including hypercalciuria. Studies suggest that the prevalence of monogenic kidney stone disorders, including renal tubular acidosis with deafness, Bartter syndrome, primary hyperoxaluria and cystinuria, in patients attending kidney stone clinics is ∼15%. However, for the majority of individuals, nephrolithiasis has a multifactorial aetiology involving genetic and environmental factors. Nonetheless, the genetic influence on stone formation in these idiopathic stone formers remains considerable and twin studies estimate a heritability of >45% for nephrolithiasis and >50% for hypercalciuria. The contribution of polygenic influences from multiple loci have been investigated by genome-wide association and candidate gene studies, which indicate that a number of genes and molecular pathways contribute to the risk of stone formation. Genetic approaches, studying both monogenic and polygenic factors in nephrolithiasis, have revealed that the following have important roles in the aetiology of kidney stones: transporters and channels; ions, protons and amino acids; the calcium-sensing receptor (a G protein-coupled receptor) signalling pathway; and the metabolic pathways for vitamin D, oxalate, cysteine, purines and uric acid. These advances, which have increased our understanding of the pathogenesis of nephrolithiasis, will hopefully facilitate the future development of targeted therapies for precision medicine approaches in patients with nephrolithiasis.
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Affiliation(s)
- Sarah A Howles
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK.,Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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28
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Incomplete cryptic splicing by an intronic mutation of OCRL in patients with partial phenotypes of Lowe syndrome. J Hum Genet 2020; 65:831-839. [PMID: 32427950 DOI: 10.1038/s10038-020-0773-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/01/2020] [Accepted: 05/01/2020] [Indexed: 01/03/2023]
Abstract
Mutations of OCRL cause Lowe syndrome, which is characterised by congenital cataracts, infantile hypotonia with mental retardation, and renal tubular dysfunction and Dent-2 disease, which only affects the kidney. While few patients with an intermediate phenotype between these diseases have been reported, the mechanism underlying variability in the phenotype is unclear. We identified an intronic mutation, c.2257-5G>A, in intron 20 of OCRL in an older brother with atypical Lowe syndrome without eye involvement and a younger brother with renal phenotype alone. This mutation created a splice acceptor motif that was accompanied by a cryptic premature termination codon at the junction of exons 20 and 21. The mutation caused incomplete alternative splicing, which created a small amount of wild-type transcript and a relatively large amount of alternatively spliced transcript with a premature termination codon. In the patients' cells, the alternatively spliced transcript was degraded by nonsense-mediated decay and the wild-type transcript was significantly decreased, but not completely depleted. These findings imply that an intronic mutation creating an incomplete alternative splicing acceptor site results in a relatively low level of wild-type OCRL mRNA expression, leading to partial phenotypes of Lowe syndrome.
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29
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Festa BP, Berquez M, Gassama A, Amrein I, Ismail HM, Samardzija M, Staiano L, Luciani A, Grimm C, Nussbaum RL, De Matteis MA, Dorchies OM, Scapozza L, Wolfer DP, Devuyst O. OCRL deficiency impairs endolysosomal function in a humanized mouse model for Lowe syndrome and Dent disease. Hum Mol Genet 2020; 28:1931-1946. [PMID: 30590522 PMCID: PMC6548226 DOI: 10.1093/hmg/ddy449] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/09/2018] [Accepted: 12/20/2018] [Indexed: 11/29/2022] Open
Abstract
Mutations in OCRL encoding the inositol polyphosphate 5-phosphatase OCRL (Lowe oculocerebrorenal syndrome protein) disrupt phosphoinositide homeostasis along the endolysosomal pathway causing dysfunction of the cells lining the kidney proximal tubule (PT). The dysfunction can be isolated (Dent disease 2) or associated with congenital cataracts, central hypotonia and intellectual disability (Lowe syndrome). The mechanistic understanding of Dent disease 2/Lowe syndrome remains scarce due to limitations of animal models of OCRL deficiency. Here, we investigate the role of OCRL in Dent disease 2/Lowe syndrome by using OcrlY/− mice, where the lethal deletion of the paralogue Inpp5b was rescued by human INPP5B insertion, and primary culture of proximal tubule cells (mPTCs) derived from OcrlY/− kidneys. The OcrlY/− mice show muscular defects with dysfunctional locomotricity and present massive urinary losses of low-molecular-weight proteins and albumin, caused by selective impairment of receptor-mediated endocytosis in PT cells. The latter was due to accumulation of phosphatidylinositol 4,5–bisphosphate PI(4,5)P2 in endolysosomes, driving local hyper-polymerization of F-actin and impairing trafficking of the endocytic LRP2 receptor, as evidenced in OcrlY/− mPTCs. The OCRL deficiency was also associated with a disruption of the lysosomal dynamic and proteolytic activity. Partial convergence of disease-pathways and renal phenotypes observed in OcrlY/− and Clcn5Y/− mice suggest shared mechanisms in Dent diseases 1 and 2. These studies substantiate the first mouse model of Lowe syndrome and give insights into the role of OCRL in cellular trafficking of multiligand receptors. These insights open new avenues for therapeutic interventions in Lowe syndrome and Dent disease.
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Affiliation(s)
| | - Marine Berquez
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Alkaly Gassama
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Irmgard Amrein
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, Institute of Human Movement Sciences and Sport, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Hesham M Ismail
- School of Pharmaceutical Sciences, University of Geneva, Rue Michel-Servet 1, Geneva, Switzerland
| | - Marijana Samardzija
- Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Leopoldo Staiano
- Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
| | | | - Christian Grimm
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland.,Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Robert L Nussbaum
- Department of Medicine and Institute of Human Genetics, University of California, San Francisco, CA, USA.,Invitae Corporation, San Francisco, CA, USA
| | | | - Olivier M Dorchies
- School of Pharmaceutical Sciences, University of Geneva, Rue Michel-Servet 1, Geneva, Switzerland
| | - Leonardo Scapozza
- School of Pharmaceutical Sciences, University of Geneva, Rue Michel-Servet 1, Geneva, Switzerland
| | - David Paul Wolfer
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich, Zurich, Switzerland.,Department of Health Sciences and Technology, ETH Zurich, Institute of Human Movement Sciences and Sport, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Olivier Devuyst
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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30
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Preston R, Naylor RW, Stewart G, Bierzynska A, Saleem MA, Lowe M, Lennon R. A role for OCRL in glomerular function and disease. Pediatr Nephrol 2020; 35:641-648. [PMID: 31811534 PMCID: PMC7056711 DOI: 10.1007/s00467-019-04317-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 07/15/2019] [Accepted: 07/23/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND Lowe syndrome and Dent-2 disease are caused by mutations in the OCRL gene, which encodes for an inositol 5-phosphatase. The renal phenotype associated with OCRL mutations typically comprises a selective proximal tubulopathy, which can manifest as Fanconi syndrome in the most extreme cases. METHODS Here, we report a 12-year-old male with nephrotic-range proteinuria and focal segmental glomerulosclerosis on renal biopsy. As a glomerular pathology was suspected, extensive investigation of tubular function was not performed. RESULTS Surprisingly, whole exome sequencing identified a genetic variant in OCRL (c1467-2A>G) that introduced a novel splice mutation leading to skipping of exon 15. In situ hybridisation of adult human kidney tissue and zebrafish larvae showed OCRL expression in the glomerulus, supporting a role for OCRL in glomerular function. In cultured podocytes, we found that OCRL associated with the linker protein IPIP27A and CD2AP, a protein that is important for maintenance of the podocyte slit diaphragm. CONCLUSION Taken together, this work suggests a previously under-appreciated role for OCRL in glomerular function and highlights the importance of investigating tubular function in patients with persistent proteinuria.
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Affiliation(s)
- Rebecca Preston
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Graham Stewart
- Renal Department, Ninewells Hospital, Dundee, DD1 9SY, UK
| | | | - Moin A Saleem
- Children's and Academic Renal Unit, University of Bristol, Bristol, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
- Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester Academic Health Science Centre, Manchester University Hospital NHS Foundation Trust, Manchester, UK.
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31
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Gliozzi ML, Espiritu EB, Shipman KE, Rbaibi Y, Long KR, Roy N, Duncan AW, Lazzara MJ, Hukriede NA, Baty CJ, Weisz OA. Effects of Proximal Tubule Shortening on Protein Excretion in a Lowe Syndrome Model. J Am Soc Nephrol 2019; 31:67-83. [PMID: 31676724 DOI: 10.1681/asn.2019020125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/24/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Lowe syndrome (LS) is an X-linked recessive disorder caused by mutations in OCRL, which encodes the enzyme OCRL. Symptoms of LS include proximal tubule (PT) dysfunction typically characterized by low molecular weight proteinuria, renal tubular acidosis (RTA), aminoaciduria, and hypercalciuria. How mutant OCRL causes these symptoms isn't clear. METHODS We examined the effect of deleting OCRL on endocytic traffic and cell division in newly created human PT CRISPR/Cas9 OCRL knockout cells, multiple PT cell lines treated with OCRL-targeting siRNA, and in orcl-mutant zebrafish. RESULTS OCRL-depleted human cells proliferated more slowly and about 10% of them were multinucleated compared with fewer than 2% of matched control cells. Heterologous expression of wild-type, but not phosphatase-deficient, OCRL prevented the accumulation of multinucleated cells after acute knockdown of OCRL but could not rescue the phenotype in stably edited knockout cell lines. Mathematic modeling confirmed that reduced PT length can account for the urinary excretion profile in LS. Both ocrl mutant zebrafish and zebrafish injected with ocrl morpholino showed truncated expression of megalin along the pronephric kidney, consistent with a shortened S1 segment. CONCLUSIONS Our data suggest a unifying model to explain how loss of OCRL results in tubular proteinuria as well as the other commonly observed renal manifestations of LS. We hypothesize that defective cell division during kidney development and/or repair compromises PT length and impairs kidney function in LS patients.
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Affiliation(s)
| | | | | | | | | | - Nairita Roy
- Department of Pathology, McGowan Institute for Regenerative Medicine, and Pittsburgh Liver Research Center, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, and Pittsburgh Liver Research Center, Pittsburgh, Pennsylvania
| | - Matthew J Lazzara
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia; and
| | - Neil A Hukriede
- Department of Developmental Biology, and.,Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Ora A Weisz
- Renal-Electrolyte Division, Department of Medicine,
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Dai C, Wang L, Li Y, Zheng Z, Qian J, Wang C, Liu Z, Shan X. Lowe syndrome with extremely short stature: growth hormone deficiency may be the pathogeny. Growth Factors 2019; 37:170-177. [PMID: 31576764 DOI: 10.1080/08977194.2019.1669589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lowe syndrome is an x-linked disorder characterized by congenital cataracts, nervous system abnormalities and renal tubular dysfunction. With the rising number of reported cases, more patients are found to suffer from endocrine abnormalities. Hereby, three Chinese patients with typical symptoms and extremely short stature were described. The OCRL gene was analyzed. A combination of blood biochemistry and radiological examinations were performed. Growth hormone provocation test was taken in one patient. Nucleotide sequence analysis revealed a de novo novel hemizygous mutation (c.2290_2291delinsCT) in exon 21 in an adolescent boy. As indicated by the growth hormone provocation test, the boy had growth hormone deficiency. The other two patients were brothers with extremely short stature, and manifested the same hemizygous mutation (c.2581G > A) in exon 23. It was speculated that the mutation of OCRL gene could lead to deficiency of growth hormone, for which an early growth hormone intervention may be beneficial.
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Affiliation(s)
- Chengjun Dai
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Liying Wang
- Beijing Tongren Hospital, Capital Medical University, Beijing, PR China
| | - Youli Li
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Zhichao Zheng
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Jieqi Qian
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Chaoban Wang
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Zishuo Liu
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xiaoou Shan
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
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Adalat S, Hayes WN, Bryant WA, Booth J, Woolf AS, Kleta R, Subtil S, Clissold R, Colclough K, Ellard S, Bockenhauer D. HNF1B Mutations Are Associated With a Gitelman-like Tubulopathy That Develops During Childhood. Kidney Int Rep 2019; 4:1304-1311. [PMID: 31517149 PMCID: PMC6732753 DOI: 10.1016/j.ekir.2019.05.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/29/2019] [Accepted: 05/20/2019] [Indexed: 12/20/2022] Open
Abstract
Background Mutations in the transcription factor hepatocyte nuclear factor 1B (HNF1B) are the most common inherited cause of renal malformations, yet also associated with renal tubular dysfunction, most prominently magnesium wasting with hypomagnesemia. The presence of hypomagnesemia has been proposed to help select appropriate patients for genetic testing. Yet, in a large cohort, hypomagnesemia was discriminatory only in adult, but not in pediatric patients. We therefore investigated whether hypomagnesemia and other biochemical changes develop with age. Methods We performed a retrospective analysis of clinical, biochemical, and genetic results of pediatric patients with renal malformations tested for HNF1B mutations, separated into 4 age groups. Values were excluded if concurrent estimated glomerular filtration rate (eGFR) was <30 ml/min per 1.73 m2, or after transplantation. Results A total of 199 patients underwent HNF1B genetic testing and mutations were identified in 52 (mut+). The eGFRs were comparable between mut+ and mut- in any age group. Although median plasma magnesium concentrations differed significantly between mut+ and mut- patients in all age groups, overt hypomagnesemia was not present until the second half of childhood in the mut+ group. There was also a significant difference in median potassium concentrations in late childhood with lower values in the mut+ cohort. Conclusions The abnormal tubular electrolyte handling associated with HNF1B mutations develops with age and is not restricted to magnesium, but consistent with a more generalized dysfunction of the distal convoluted tubule, reminiscent of Gitelman syndrome. The absence of these abnormalities in early childhood should not preclude HNF1B mutations from diagnostic considerations.
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Affiliation(s)
- Shazia Adalat
- Evelina Children’s Hospital, London, United Kingdom
- UCL Department of Renal Medicine, London, United Kingdom
| | - Wesley N. Hayes
- UCL Department of Renal Medicine, London, United Kingdom
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - William A. Bryant
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - John Booth
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Adrian S. Woolf
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, United Kingdom
- Royal Manchester Children’s Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Robert Kleta
- UCL Department of Renal Medicine, London, United Kingdom
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | | | - Rhian Clissold
- Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom
| | - Kevin Colclough
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, United Kingdom
| | - Sian Ellard
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Exeter, United Kingdom
- Institute of Biomedical and Clinical Science, College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Detlef Bockenhauer
- UCL Department of Renal Medicine, London, United Kingdom
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
- Correspondence: Detlef Bockenhauer, UCL Department of Renal Medicine, London WC1N 3JH, United Kingdom.
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Mondin VE, Ben El Kadhi K, Cauvin C, Jackson-Crawford A, Bélanger E, Decelle B, Salomon R, Lowe M, Echard A, Carréno S. PTEN reduces endosomal PtdIns(4,5)P 2 in a phosphatase-independent manner via a PLC pathway. J Cell Biol 2019; 218:2198-2214. [PMID: 31118240 PMCID: PMC6605811 DOI: 10.1083/jcb.201805155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 03/15/2019] [Accepted: 05/02/2019] [Indexed: 01/14/2023] Open
Abstract
This work reveals that the tumor suppressor PTEN acts through a PLC to reduce levels of endosomal PtdIns(4,5)P2, its own enzymatic product. This pathway can be chemically activated to rescue OCRL1 depletion in several disease models of the Lowe syndrome, a rare multisystemic genetic disease. The tumor suppressor PTEN dephosphorylates PtdIns(3,4,5)P3 into PtdIns(4,5)P2. Here, we make the unexpected discovery that in Drosophila melanogaster PTEN reduces PtdIns(4,5)P2 levels on endosomes, independently of its phosphatase activity. This new PTEN function requires the enzymatic action of dPLCXD, an atypical phospholipase C. Importantly, we discovered that this novel PTEN/dPLCXD pathway can compensate for depletion of dOCRL, a PtdIns(4,5)P2 phosphatase. Mutation of OCRL1, the human orthologue of dOCRL, causes oculocerebrorenal Lowe syndrome, a rare multisystemic genetic disease. Both OCRL1 and dOCRL loss have been shown to promote accumulation of PtdIns(4,5)P2 on endosomes and cytokinesis defects. Here, we show that PTEN or dPLCXD overexpression prevents these defects. In addition, we found that chemical activation of this pathway restores normal cytokinesis in human Lowe syndrome cells and rescues OCRL phenotypes in a zebrafish Lowe syndrome model. Our findings identify a novel PTEN/dPLCXD pathway that controls PtdIns(4,5)P2 levels on endosomes. They also point to a potential new strategy for the treatment of Lowe syndrome.
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Affiliation(s)
- Virginie E Mondin
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Canada
| | - Khaled Ben El Kadhi
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Canada
| | - Clothilde Cauvin
- Membrane Traffic and Cell Division Lab, Institut Pasteur, UMR3691, Centre National de la Recherche Scientifique, Paris, France.,Sorbonne Université, Collège Doctoral, Paris, France
| | | | - Emilie Bélanger
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Canada
| | - Barbara Decelle
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Canada
| | - Rémi Salomon
- Institut des Maladies Génétiques Imagine, Hôpital Necker-Enfants Malades, Université Paris Descartes, Paris, France
| | - Martin Lowe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Arnaud Echard
- Membrane Traffic and Cell Division Lab, Institut Pasteur, UMR3691, Centre National de la Recherche Scientifique, Paris, France
| | - Sébastien Carréno
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Canada .,Université de Montréal, Département de Pathologie et de Biologie Cellulaire, Montreal, Canada
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Shalaby AK, Emery-Billcliff P, Baralle D, Dabir T, Begum S, Waller S, Tabernero L, Lowe M, Self J. Identification and functional analysis of a novel oculocerebrorenal syndrome of Lowe ( OCRL) gene variant in two pedigrees with varying phenotypes including isolated congenital cataract. Mol Vis 2018; 24:847-852. [PMID: 30713423 PMCID: PMC6334980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/29/2018] [Indexed: 10/26/2022] Open
Abstract
Purpose To identify the genetic variation in two unrelated probands with congenital cataract and to perform functional analysis of the detected variants. Methods Clinical examination and phenotyping, segregation, and functional analysis were performed for the two studied pedigrees. Results A novel OCRL gene variant (c.1964A>T, p. (Asp655Val)) was identified. This variant causes defects in OCRL protein folding and mislocalization to the cytoplasm. In addition, the variant's location close to the Rab binding site is likely to be associated with membrane targeting abnormalities. Conclusions The results highlight the importance of early genetic diagnosis in infants with congenital cataract and show that mutations in the OCRL gene can present as apparently isolated congenital cataract.
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Affiliation(s)
- Ahmed K. Shalaby
- Ophthalmology Department, Princess of Wales Hospital, Manchester, UK
| | - Peter Emery-Billcliff
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Diana Baralle
- Human Development and Health, University of Southampton, UK
| | - Tabib Dabir
- Northern Regional Genetics Service Belfast City Hospital, Molecular Diagnostics and Microbiology, Belfast UK
| | | | - Sarah Waller
- Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Manchester, UK
| | - Lydia Tabernero
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Martin Lowe
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - James Self
- Clinical and Experimental Sciences, University of Southampton, UK
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Zaniew M, Bökenkamp A, Kolbuc M, La Scola C, Baronio F, Niemirska A, Szczepanska M, Bürger J, La Manna A, Miklaszewska M, Rogowska-Kalisz A, Gellermann J, Zampetoglou A, Wasilewska A, Roszak M, Moczko J, Krzemien A, Runowski D, Siten G, Zaluska-Lesniewska I, Fonduli P, Zurrida F, Paglialonga F, Gucev Z, Paripovic D, Rus R, Said-Conti V, Sartz L, Chung WY, Park SJ, Lee JW, Park YH, Ahn YH, Sikora P, Stefanidis CJ, Tasic V, Konrad M, Anglani F, Addis M, Cheong HI, Ludwig M, Bockenhauer D. Long-term renal outcome in children with OCRL mutations: retrospective analysis of a large international cohort. Nephrol Dial Transplant 2018; 33:85-94. [PMID: 27708066 DOI: 10.1093/ndt/gfw350] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022] Open
Abstract
Background Lowe syndrome (LS) and Dent-2 disease (DD2) are disorders associated with mutations in the OCRL gene and characterized by progressive chronic kidney disease (CKD). Here, we aimed to investigate the long-term renal outcome and identify potential determinants of CKD and its progression in children with these tubulopathies. Methods Retrospective analyses were conducted of clinical and genetic data in a cohort of 106 boys (LS: 88 and DD2: 18). For genotype-phenotype analysis, we grouped mutations according to their type and localization. To investigate progression of CKD we used survival analysis by Kaplan-Meier method using stage 3 CKD as the end-point. Results Median estimated glomerular filtration rate (eGFR) was lower in the LS group compared with DD2 (58.8 versus 87.4 mL/min/1.73 m2, P < 0.01). CKD stage II-V was found in 82% of patients, of these 58% and 28% had moderate-to-severe CKD in LS and DD2, respectively. Three patients (3%), all with LS, developed stage 5 of CKD. Survival analysis showed that LS was also associated with a faster CKD progression than DD2 (P < 0.01). On multivariate analysis, eGFR was dependent only on age (b = -0.46, P < 0.001). Localization, but not type of mutations, tended to correlate with eGFR. There was also no significant association between presence of nephrocalcinosis, hypercalciuria, proteinuria and number of adverse clinical events and CKD. Conclusions CKD is commonly found in children with OCRL mutations. CKD progression was strongly related to the underlying diagnosis but did not associate with clinical parameters, such as nephrocalcinosis or proteinuria.
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Affiliation(s)
- Marcin Zaniew
- Children's Hospital, Poznan, Poland.,Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poland
| | - Arend Bökenkamp
- Department of Pediatrics, VU Medical Center, Amsterdam, The Netherlands
| | | | - Claudio La Scola
- Nephrology and Dialysis Unit, Department of Woman, Child and Urological Diseases, Azienda Ospedaliero-Universitaria 'Sant'Orsola-Malpighi', Bologna, Italy
| | - Federico Baronio
- Endocrinology Unit, Department of Woman, Child and Urological Diseases, Azienda Ospedaliero-Universitaria 'Sant'Orsola-Malpighi', Bologna, Italy
| | - Anna Niemirska
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland
| | - Maria Szczepanska
- Chair and Clinical Department of Pediatrics, SMDZ in Zabrze, SUM in Katowice, Katowice, Poland
| | - Julia Bürger
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
| | - Angela La Manna
- Department of Pediatrics, II University of Naples, Naples, Italy
| | - Monika Miklaszewska
- Department of Pediatric Nephrology, Collegium Medicum of the Jagiellonian University, Cracow, Poland
| | - Anna Rogowska-Kalisz
- Department of Pediatrics, Immunology and Nephrology, Polish Mothers Memorial Hospital Research Institute, Lódz, Poland
| | - Jutta Gellermann
- Department of Pediatric Nephrology, Charité Universitätsmedizin Berlin, Charité Children's Hospital, Berlin, Germany
| | | | - Anna Wasilewska
- Department of Pediatrics and Nephrology, Medical University of Bialystok, Bialystok, Poland
| | - Magdalena Roszak
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland
| | - Jerzy Moczko
- Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Dariusz Runowski
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Warsaw, Poland
| | | | - Iga Zaluska-Lesniewska
- Department of Pediatrics, Medical University of Gdansk, Nephrology and Hypertension, Gdansk, Poland
| | | | - Franca Zurrida
- Pediatric Nephrology, Hospital G.Brotzu, Cagliari, Italy
| | - Fabio Paglialonga
- Pediatric Nephrology and Dialysis Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Zoran Gucev
- University Children's Hospital, Medical Faculty Skopje, Skopje, Macedonia
| | - Dusan Paripovic
- Nephrology Department, University Children's Hospital, Belgrade, Serbia
| | - Rina Rus
- Division of Nephrology, University Children's Hospital, Ljubljana, Slovenia
| | | | - Lisa Sartz
- Department of Pediatric and Adolescent Medicine, Skåne University Hospital, Lund, Sweden
| | - Woo Yeong Chung
- Department of Pediatrics, Inje University Busan Paik Hospital, Busan, Korea
| | - Se Jin Park
- Department of Pediatrics, Ajou University Daewoo Hospital, Geoje, Korea
| | - Jung Won Lee
- Department of Pediatrics, Ehwa University Mokdong Hospital, Seoul, Korea
| | - Yong Hoon Park
- Department of Pediatrics, Yeungnam University College of Medicine, Daegu, Korea
| | - Yo Han Ahn
- Department of Pediatrics, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
| | - Przemyslaw Sikora
- Polish Registry of Inherited Tubulopathies (POLtube), Polish Society of Pediatric Nephrology, Poland.,Department of Pediatric Nephrology, Medical University of Lublin, Lublin, Poland
| | | | - Velibor Tasic
- University Children's Hospital, Medical Faculty Skopje, Skopje, Macedonia
| | - Martin Konrad
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
| | - Franca Anglani
- Laboratory of Histomorphology and Molecular Biology of the Kidney, Department of Medicine, University of Padova, Padova, Italy
| | - Maria Addis
- Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Detlef Bockenhauer
- University College London, Institute of Child Health and Great Ormond Street Hospital for Children, National Health Service Trust, London, UK
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Abstract
Phosphoinositides (PIs) play pivotal roles in the regulation of many biological processes. The quality and quantity of PIs is regulated in time and space by the activity of PI kinases and PI phosphatases. The number of PI-metabolizing enzymes exceeds the number of PIs with, in many cases, more than one enzyme controlling the same biochemical step. This would suggest that the PI system has an intrinsic ability to buffer and compensate for the absence of a specific enzymatic activity. However, there are several examples of severe inherited human diseases caused by mutations in one of the PI enzymes, although other enzymes with the same activity are fully functional. The kidney depends strictly on PIs for physiological processes, such as cell polarization, filtration, solute reabsorption, and signal transduction. Indeed, alteration of the PI system in the kidney very often results in pathological conditions, both inherited and acquired. Most of the knowledge of the roles that PIs play in the kidney comes from the study of KO animal models for genes encoding PI enzymes and from the study of human genetic diseases, such as Lowe syndrome/Dent disease 2 and Joubert syndrome, caused by mutations in the genes encoding the PI phosphatases, OCRL and INPP5E, respectively.
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Affiliation(s)
- Leopoldo Staiano
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy .,University of Naples Federico II, 80131 Naples, Italy
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Ding W, Yousefi K, Shehadeh LA. Isolation, Characterization, And High Throughput Extracellular Flux Analysis of Mouse Primary Renal Tubular Epithelial Cells. J Vis Exp 2018. [PMID: 29985358 PMCID: PMC6101965 DOI: 10.3791/57718] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial dysfunction in the renal tubular epithelial cells (TECs) can lead to renal fibrosis, a major cause of chronic kidney disease (CKD). Therefore, assessing mitochondrial function in primary TECs may provide valuable insight into the bioenergetic status of the cells, providing insight into the pathophysiology of CKD. While there are a number of complex protocols available for the isolation and purification of proximal tubules in different species, the field lacks a cost-effective method optimized for tubular cell isolation without the need for purification. Here, we provide an isolation protocol that allows for studies focusing on both primary mouse proximal and distal renal TECs. In addition to cost-effective reagents and minimal animal procedures required in this protocol, the isolated cells maintain high energy levels after isolation and can be sub-cultured up to four passages, allowing for continuous studies. Furthermore, using a high throughput extracellular flux analyzer, we assess the mitochondrial respiration directly in the isolated TECs in a 96-well plate for which we provide recommendations for the optimization of cell density and compound concentration. These observations suggest that this protocol can be used for renal tubular ex vivo studies with a consistent, well-standardized production of renal TECs. This protocol may have broader future applications to study mitochondrial dysfunction associated with renal disorders for drug discovery or drug characterization purposes.
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Affiliation(s)
- Wen Ding
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine; Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine
| | - Keyvan Yousefi
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine; Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine
| | - Lina A Shehadeh
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine; Department of Medicine, Division of Cardiology, University of Miami Leonard M. Miller School of Medicine; Vascular Biology Institute, University of Miami Leonard M. Miller School of Medicine; Peggy and Harold Katz Family Drug Discovery Center, University of Miami Leonard M. Miller School of Medicine;
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39
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Hsieh WC, Ramadesikan S, Fekete D, Aguilar RC. Kidney-differentiated cells derived from Lowe Syndrome patient's iPSCs show ciliogenesis defects and Six2 retention at the Golgi complex. PLoS One 2018; 13:e0192635. [PMID: 29444177 PMCID: PMC5812626 DOI: 10.1371/journal.pone.0192635] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 01/26/2018] [Indexed: 12/11/2022] Open
Abstract
Lowe syndrome is an X-linked condition characterized by congenital cataracts, neurological abnormalities and kidney malfunction. This lethal disease is caused by mutations in the OCRL1 gene, which encodes for the phosphatidylinositol 5-phosphatase Ocrl1. While in the past decade we witnessed substantial progress in the identification and characterization of LS patient cellular phenotypes, many of these studies have been performed in knocked-down cell lines or patient's cells from accessible cell types such as skin fibroblasts, and not from the organs affected. This is partially due to the limited accessibility of patient cells from eyes, brain and kidneys. Here we report the preparation of induced pluripotent stem cells (iPSCs) from patient skin fibroblasts and their reprogramming into kidney cells. These reprogrammed kidney cells displayed primary cilia assembly defects similar to those described previously in cell lines. Additionally, the transcription factor and cap mesenchyme marker Six2 was substantially retained in the Golgi complex and the functional nuclear-localized fraction was reduced. These results were confirmed using different batches of differentiated cells from different iPSC colonies and by the use of the human proximal tubule kidney cell line HK2. Indeed, OCRL1 KO led to both ciliogenesis defects and Six2 retention in the Golgi complex. In agreement with Six2's role in the suppression of ductal kidney lineages, cells from this pedigree were over-represented among patient kidney-reprogrammed cells. We speculate that this diminished efficacy to produce cap mesenchyme cells would cause LS patients to have difficulties in replenishing senescent or damaged cells derived from this lineage, particularly proximal tubule cells, leading to pathological scenarios such as tubular atrophy.
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Affiliation(s)
- Wen-Chieh Hsieh
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
| | - Donna Fekete
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN United States of America
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN United States of America
| | - Ruben Claudio Aguilar
- Department of Biological Sciences, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN United States of America
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN United States of America
- Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN United States of America
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40
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Zhang H, Wang F, Xiao H, Yao Y. The ratio of urinary α1-microglobulin to microalbumin can be used as a diagnostic criterion for tubuloproteinuria. Intractable Rare Dis Res 2018; 7:46-50. [PMID: 29552446 PMCID: PMC5849625 DOI: 10.5582/irdr.2017.01079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Low-molecular-weight proteinuria is one of the characteristic clinical manifestations of renal tubular and interstitial diseases. Low-molecular-weight proteinuria is defined as excessive urinary loss of α1-microglobulin, β2-microglobulin, or other low-molecular-weight plasma proteins. The current study examined the ratio of urinary α1-microglobulin to microalbumin in 24 Chinese pediatric patients with renal tubular and interstitial diseases, including 10 patients with Dent disease, 2 patients with Lowe syndrome, 6 patients with acute tubulointerstitial nephritis (ATIN), 4 patients with acute tubulointerstitial nephritis with uveitis syndrome (TINU), and 2 patients with nephronophthisis (NPHP). Patients with steroid-sensitive nephrotic syndrome, IgA nephropathy, Henoch-Schonlein purpura nephritis, or lupus nephritis served as control groups. In all of the patients with tubular and interstitial disease, urinary α1-microglobin increased 10-300-fold above the upper limit of the normal range, the ratio of urinary α1-microglobulin to microalbumin was greater than 1, and the percentage of low-molecular-weight plasma proteins (LMWP) in urine was greater than 50% according to urine protein electrophoresis. There was close correlation between the ratio of urinary α1-microglobulin to microalbumin and the percentage of LMWP in urine according to urine protein electrophoresis (r = 0.797, p = 0.000). We suggested firstly that the ratio of urinary α1-microglobulin to microalbumin, greater than 1, can be used as a diagnostic criterion for tubuloproteinuria.
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Affiliation(s)
- Hongwen Zhang
- Department of Pediatric, Peking University First Hospital, Beijing, China
| | - Fang Wang
- Department of Pediatric, Peking University First Hospital, Beijing, China
| | - Huijie Xiao
- Department of Pediatric, Peking University First Hospital, Beijing, China
| | - Yong Yao
- Department of Pediatric, Peking University First Hospital, Beijing, China
- Address correspondence to: Dr. Yong Yao, Department of Pediatric, Peking University First Hospital, No.1 Xi An Men Da Jie, Beijing 100034, China. E-mail:
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Splicing Analysis of Exonic OCRL Mutations Causing Lowe Syndrome or Dent-2 Disease. Genes (Basel) 2018; 9:genes9010015. [PMID: 29300302 PMCID: PMC5793168 DOI: 10.3390/genes9010015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/11/2017] [Accepted: 12/27/2017] [Indexed: 01/12/2023] Open
Abstract
Mutations in the OCRL gene are associated with both Lowe syndrome and Dent-2 disease. Patients with Lowe syndrome present congenital cataracts, mental disabilities and a renal proximal tubulopathy, whereas patients with Dent-2 disease exhibit similar proximal tubule dysfunction but only mild, or no additional clinical defects. It is not yet understood why some OCRL mutations cause the phenotype of Lowe syndrome, while others develop the milder phenotype of Dent-2 disease. Our goal was to gain new insights into the consequences of OCRL exonic mutations on pre-mRNA splicing. Using predictive bioinformatics tools, we selected thirteen missense mutations and one synonymous mutation based on their potential effects on splicing regulatory elements or splice sites. These mutations were analyzed in a minigene splicing assay. Results of the RNA analysis showed that three presumed missense mutations caused alterations in pre-mRNA splicing. Mutation c.741G>T; p.(Trp247Cys) generated splicing silencer sequences and disrupted splicing enhancer motifs that resulted in skipping of exon 9, while mutations c.2581G>A; p.(Ala861Thr) and c.2581G>C; p.(Ala861Pro) abolished a 5′ splice site leading to skipping of exon 23. Mutation c.741G>T represents the first OCRL exonic variant outside the conserved splice site dinucleotides that results in alteration of pre-mRNA splicing. Our results highlight the importance of evaluating the effects of OCRL exonic mutations at the mRNA level.
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42
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Salihu S, Tosheska K, Cekovska S, Tasic V. Incidental Detection of Dent-2 Disease in an Infant with Febrile Proteinuria. Med Princ Pract 2018; 27:392-395. [PMID: 29772577 PMCID: PMC6167689 DOI: 10.1159/000490147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/17/2018] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE Febrile proteinuria is functional proteinuria and is seen as a transitory phenomenon during acute febrile illness, mainly viral infections. It is a benign phenomenon and clears promptly with resolution of the infection. CLINICAL PRESENTATION AND INTERVENTION In this report, we present a patient who was thought to have febrile proteinuria. Persistence of significant proteinuria after resolution of the infection prompted biochemical and genetic workup which led to the diagnosis of Dent-2 disease. CONCLUSION We recommend the use of SDS-PAGE (sodium dodecyl sulfate electropheresis) for the detection of low molecular weight proteinuria.
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Affiliation(s)
- Shpetim Salihu
- Department of Neonatology, University Clinical Center, Prishtina, Kosovo
| | - Katerina Tosheska
- Institute of Medical and Experimental Biochemistry, Medical School Skopje, Skopje, Macedonia
| | - Svetlana Cekovska
- Institute of Medical and Experimental Biochemistry, Medical School Skopje, Skopje, Macedonia
| | - Velibor Tasic
- University Children's Hospital, Medical School Skopje, Skopje, Macedonia
- *Prof. Dr. Velibor Tasic, University Children's Hospital, 17 Vodnjanska, MK-1000 Skopje (Macedonia), E-Mail
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43
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Abdalla E, El‐Beheiry A, Dieterich K, Thevenon J, Fauré J, Rendu J. “Lowe syndrome: A particularly severe phenotype without clinical kidney involvement”. Am J Med Genet A 2017; 176:460-464. [DOI: 10.1002/ajmg.a.38572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 11/02/2017] [Accepted: 11/13/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Ebtesam Abdalla
- Department of Human GeneticsMedical Research InstituteAlexandria UniversityAlexandriaEgypt
| | - Ahmed El‐Beheiry
- Department of RadiologyAlexandria Faculty of MedicineAlexandria UniversityAlexandriaEgypt
| | - Klaus Dieterich
- Département de Génétique et ProcréationCHU Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
| | - Julien Thevenon
- Département de Génétique et ProcréationCHU Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
| | - Julien Fauré
- Département de Biochimie Pharmacologie ToxicologieBiochimie et Génétique MoléculaireCentre Hospitalier Universitaire Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
- Grenoble Institut des NeurosciencesInserm U1216–Eq. 4 C‐MyPathLaTroncheFrance
| | - John Rendu
- Département de Biochimie Pharmacologie ToxicologieBiochimie et Génétique MoléculaireCentre Hospitalier Universitaire Grenoble AlpesUniversité Grenoble AlpesGrenobleFrance
- Grenoble Institut des NeurosciencesInserm U1216–Eq. 4 C‐MyPathLaTroncheFrance
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44
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Abstract
Lowe syndrome is an X-linked disease that is characterized by congenital cataracts, central hypotonia, intellectual disability and renal Fanconi syndrome. The disease is caused by mutations in OCRL, which encodes an inositol polyphosphate 5-phosphatase (OCRL) that acts on phosphoinositides - quantitatively minor constituents of cell membranes that are nonetheless pivotal regulators of intracellular trafficking. In this Review we summarize the considerable progress made over the past decade in understanding the cellular roles of OCRL in regulating phosphoinositide balance along the endolysosomal pathway, a fundamental system for the reabsorption of proteins and solutes by proximal tubular cells. We discuss how studies of OCRL have led to important discoveries about the basic mechanisms of membrane trafficking and describe the key features and limitations of the currently available animal models of Lowe syndrome. Mutations in OCRL can also give rise to a milder pathology, Dent disease 2, which is characterized by renal Fanconi syndrome in the absence of extrarenal pathologies. Understanding how mutations in OCRL give rise to two clinical entities with differing extrarenal manifestations represents an opportunity to identify molecular pathways that could be targeted to develop treatments for these conditions.
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45
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Besouw MTP, Bienias M, Walsh P, Kleta R, Van't Hoff WG, Ashton E, Jenkins L, Bockenhauer D. Clinical and molecular aspects of distal renal tubular acidosis in children. Pediatr Nephrol 2017; 32:987-996. [PMID: 28188436 DOI: 10.1007/s00467-016-3573-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/16/2016] [Accepted: 12/19/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Distal renal tubular acidosis (dRTA) is characterized by hyperchloraemic metabolic acidosis, hypokalaemia, hypercalciuria and nephrocalcinosis. It is due to reduced urinary acidification by the α-intercalated cells in the collecting duct and can be caused by mutations in genes that encode subunits of the vacuolar H+-ATPase (ATP6V1B1, ATP6V0A4) or the anion exchanger 1 (SLC4A1). Treatment with alkali is the mainstay of therapy. METHODS This study is an analysis of clinical data from a long-term follow-up of 24 children with dRTA in a single centre, including a genetic analysis. RESULTS Of the 24 children included in the study, genetic diagnosis was confirmed in 19 patients, with six children having mutations in ATP6V1B1, ten in ATP6V0A4 and three in SLC4A1; molecular diagnosis was not available for five children. Five novel mutations were detected (2 in ATP6V1B1 and 3 in ATP6V0A4). Two-thirds of patients presented with features of proximal tubular dysfunction leading to an erroneous diagnosis of renal Fanconi syndrome. The proximal tubulopathy disappeared after resolution of acidosis, indicating the importance of following proximal tubular function to establish the correct diagnosis. Growth retardation with a height below -2 standard deviation score was found in ten patients at presentation, but persisted in only three of these children once established on alkali treatment. Sensorineural hearing loss was found in five of the six patients with an ATP6V1B1 mutation. Only one patient with an ATP6V0A4 mutation had sensorineural hearing loss during childhood. Nine children developed medullary cysts, but without apparent clinical consequences. Cyst development in this cohort was not correlated with age at therapy onset, molecular diagnosis, growth parameters or renal function. CONCLUSION In general, the prognosis of dRTA is good in children treated with alkali.
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Affiliation(s)
- Martine T P Besouw
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, UK
| | - Marc Bienias
- Department of Pediatrics, Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden, Germany
| | - Patrick Walsh
- Great North Children's Hospital, Newcastle upon Tyne NHS Foundation Trust, Newcastle, UK
| | - Robert Kleta
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, UK.,Centre for Nephrology, University College London Institute of Child Health, London, UK
| | - William G Van't Hoff
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, UK
| | - Emma Ashton
- North East Thames Regional Genetics Service Laboratories, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Lucy Jenkins
- North East Thames Regional Genetics Service Laboratories, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Detlef Bockenhauer
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London, WC1N 3JH, UK. .,Centre for Nephrology, University College London Institute of Child Health, London, UK.
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46
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Ocular Pathology of Oculocerebrorenal Syndrome of Lowe: Novel Mutations and Genotype-Phenotype Analysis. Sci Rep 2017; 7:1442. [PMID: 28473699 PMCID: PMC5431454 DOI: 10.1038/s41598-017-01447-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/28/2017] [Indexed: 12/02/2022] Open
Abstract
Mutations in the OCRL1 gene result in the oculocerebrorenal syndrome of Lowe, with symptoms including congenital bilateral cataracts, glaucoma, renal failure, and neurological impairments. OCRL1 encodes an inositol polyphosphate 5-phosphatase which preferentially dephosphorylates phosphatidylinositide 4,5 bisphosphate (PI(4,5)P2). We have identified two novel mutations in two unrelated Lowe syndrome patients with congenital glaucoma. Novel deletion mutations are detected at c.739-742delAAAG in Lowe patient 1 and c.1595-1631del in Lowe patient 2. End stage glaucoma in patient 2 resulted in the enucleation of the eye, which on histology demonstrated corneal keloid, fibrous infiltration of the angle, ectropion uvea, retinal gliosis, and retinal ganglion cell loss. We measured OCRL protein levels in patient keratinocytes and found that Lowe 1 patient cells had significantly reduced OCRL protein as compared to the control keratinocytes. Genotype-phenotype correlation of OCRL1 mutations associated with congenital glaucoma revealed clustering of missense and deletion mutations in the 5-phosphatase domain and the RhoGAP-like domain. In conclusion, we report novel OCRL1 mutations in Lowe syndrome patients and the corresponding histopathologic analysis of one patient’s ocular pathology.
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47
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Oliveira B, Kleta R, Bockenhauer D, Walsh SB. Genetic, pathophysiological, and clinical aspects of nephrocalcinosis. Am J Physiol Renal Physiol 2016; 311:F1243-F1252. [DOI: 10.1152/ajprenal.00211.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 09/06/2016] [Indexed: 12/25/2022] Open
Abstract
Nephrocalcinosis describes the ectopic deposition of calcium salts in the kidney parenchyma. Nephrocalcinosis can result from a number of acquired causes but also an even greater number of genetic diseases, predominantly renal but also extrarenal. Here we provide a review of the genetic causes of nephrocalcinosis, along with putative mechanisms, illustrated by human and animal data.
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Affiliation(s)
- Ben Oliveira
- University College London, Centre for Nephrology, London, United Kingdom
| | - Robert Kleta
- University College London, Centre for Nephrology, London, United Kingdom
| | - Detlef Bockenhauer
- University College London, Centre for Nephrology, London, United Kingdom
| | - Stephen B. Walsh
- University College London, Centre for Nephrology, London, United Kingdom
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48
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Inoue K, Balkin DM, Liu L, Nandez R, Wu Y, Tian X, Wang T, Nussbaum R, De Camilli P, Ishibe S. Kidney Tubular Ablation of Ocrl/ Inpp5b Phenocopies Lowe Syndrome Tubulopathy. J Am Soc Nephrol 2016; 28:1399-1407. [PMID: 27895154 DOI: 10.1681/asn.2016080913] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 10/05/2016] [Indexed: 12/26/2022] Open
Abstract
Lowe syndrome and Dent disease are two conditions that result from mutations of the inositol 5-phosphatase oculocerebrorenal syndrome of Lowe (OCRL) and share the feature of impaired kidney proximal tubule function. Genetic ablation of Ocrl in mice failed to recapitulate the human phenotypes, possibly because of the redundant functions of OCRL and its paralog type 2 inositol polyphosphate-5-phosphatase (INPP5B). Germline knockout of both paralogs in mice results in early embryonic lethality. We report that kidney tubule-specific inactivation of Inpp5b on a global Ocrl-knockout mouse background resulted in low molecular weight proteinuria, phosphaturia, and acidemia. At the cellular level, we observed a striking impairment of clathrin-dependent and -independent endocytosis in proximal tubules, phenocopying what has been reported for Dent disease caused by mutations in the gene encoding endosomal proton-chloride exchange transporter 5. These results suggest that the functions of OCRL/INPP5B and proton-chloride exchange transporter 5 converge on shared mechanisms, the impairment of which has a dramatic effect on proximal tubule endocytosis.
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Affiliation(s)
| | - Daniel M Balkin
- Cell Biology.,Howard Hughes Medical Institute, and.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut
| | - Lijuan Liu
- Cell Biology.,Howard Hughes Medical Institute, and.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut.,Neuroscience, and
| | - Ramiro Nandez
- Cell Biology.,Howard Hughes Medical Institute, and.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut
| | - Yumei Wu
- Cell Biology.,Howard Hughes Medical Institute, and.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut.,Neuroscience, and
| | | | | | - Robert Nussbaum
- Department of Medicine and.,Institute of Human Genetics, University of California, San Francisco, California; and.,Howard Hughes Medical Institute, and
| | - Pietro De Camilli
- Cell Biology, .,Howard Hughes Medical Institute, and.,Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, Connecticut.,Neuroscience, and
| | - Shuta Ishibe
- Departments of Internal Medicine, .,Cellular and Molecular Physiology
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49
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Alexander RT, Cordat E, Chambrey R, Dimke H, Eladari D. Acidosis and Urinary Calcium Excretion: Insights from Genetic Disorders. J Am Soc Nephrol 2016; 27:3511-3520. [PMID: 27468975 DOI: 10.1681/asn.2016030305] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibition of calcium transport processes within the renal tubule. The mechanisms whereby acid alters the integrity and stability of bone have been examined extensively in the published literature. Here, after briefly reviewing this literature, we consider the effects of acid on calcium transport in the renal tubule and then discuss why not all gene defects that cause renal tubular acidosis are associated with hypercalciuria and nephrocalcinosis.
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Affiliation(s)
- R Todd Alexander
- Departments of Pediatrics and .,Physiology, University of Alberta, Edmonton, Canada
| | | | - Régine Chambrey
- Institut National de la Santé et de la Recherche Médicale U970, Paris Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Demark; and
| | - Dominique Eladari
- Institut National de la Santé et de la Recherche Médicale U970, Paris Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Department of Physiologie, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
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50
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Abstract
The oculocerebrorenal syndrome of Lowe is a rare X-linked multisystemic disorder characterized by the triad of congenital cataracts, intellectual disability, and proximal renal tubular dysfunction. Whereas the ocular manifestations and severe muscular hypotonia are the typical first diagnostic clues apparent at birth, the manifestations of incomplete renal Fanconi syndrome are often recognized only later in life. Other characteristic features are progressive severe growth retardation and behavioral problems, with tantrums. Many patients develop a debilitating arthropathy. Treatment is symptomatic, and the life span rarely exceeds 40 years. The causative oculocerebrorenal syndrome of Lowe gene (OCRL) encodes the inositol polyphosphate 5-phosphatase OCRL-1. OCRL variants have not only been found in classic Lowe syndrome, but also in patients with a predominantly renal phenotype classified as Dent disease type 2 (Dent-2). Recent data indicate that there is a phenotypic continuum between Dent-2 disease and Lowe syndrome, suggesting that there are individual differences in the ability to compensate for the loss of enzyme function. Extensive research has demonstrated that OCRL-1 is involved in multiple intracellular processes involving endocytic trafficking and actin skeleton dynamics. This explains the multi-organ manifestations of the disease. Still, the mechanisms underlying the wide phenotypic spectrum are poorly understood, and we are far from a causative therapy. In this review, we provide an update on clinical and molecular genetic findings in Lowe syndrome and the cellular and physiological functions of OCRL-1.
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