1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Fuentealba LM, Pizarro H, Marzolo MP. OCRL1 Deficiency Affects the Intracellular Traffic of ApoER2 and Impairs Reelin-Induced Responses. Biomolecules 2024; 14:799. [PMID: 39062513 PMCID: PMC11274606 DOI: 10.3390/biom14070799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
Abstract
Lowe Syndrome (LS) is a rare X-linked disorder characterized by renal dysfunction, cataracts, and several central nervous system (CNS) anomalies. The mechanisms underlying the neurological dysfunction in LS remain unclear, albeit they share some phenotypic characteristics similar to the deficiency or dysfunction of the Reelin signaling, a relevant pathway with roles in CNS development and neuronal functions. In this study, we investigated the role of OCRL1, an inositol polyphosphate 5-phosphatase encoded by the OCRL gene, mutated in LS, focusing on its impact on endosomal trafficking and receptor recycling in human neuronal cells. Specifically, we tested the effects of OCRL1 deficiency in the trafficking and signaling of ApoER2/LRP8, a receptor for the ligand Reelin. We found that loss of OCRL1 impairs ApoER2 intracellular trafficking, leading to reduced receptor expression and decreased levels at the plasma membrane. Additionally, human neurons deficient in OCRL1 showed impairments in ApoER2/Reelin-induced responses. Our findings highlight the critical role of OCRL1 in regulating ApoER2 endosomal recycling and its impact on the ApoER2/Reelin signaling pathway, providing insights into potential mechanisms underlying the neurological manifestations of LS.
Collapse
Affiliation(s)
| | | | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 7810128, Chile; (L.M.F.); (H.P.)
| |
Collapse
|
3
|
Chen S, Lo CH, Liu Z, Wang Q, Ning K, Li T, Sun Y. Base editing correction of OCRL in Lowe syndrome: ABE-mediated functional rescue in patient-derived fibroblasts. Hum Mol Genet 2024; 33:1142-1151. [PMID: 38557732 DOI: 10.1093/hmg/ddae045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/27/2024] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Lowe syndrome, a rare X-linked multisystem disorder presenting with major abnormalities in the eyes, kidneys, and central nervous system, is caused by mutations in OCRL gene (NG_008638.1). Encoding an inositol polyphosphate 5-phosphatase, OCRL catalyzes the hydrolysis of PI(4,5)P2 into PI4P. There are no effective targeted treatments for Lowe syndrome. Here, we demonstrate a novel gene therapy for Lowe syndrome in patient fibroblasts using an adenine base editor (ABE) that can efficiently correct pathogenic point mutations. We show that ABE8e-NG-based correction of a disease-causing mutation in a Lowe patient-derived fibroblast line containing R844X mutation in OCRL gene, restores OCRL expression at mRNA and protein levels. It also restores cellular abnormalities that are hallmarks of OCRL dysfunction, including defects in ciliogenesis, microtubule anchoring, α-actinin distribution, and F-actin network. The study indicates that ABE-mediated gene therapy is a feasible treatment for Lowe syndrome, laying the foundation for therapeutic application of ABE in the currently incurable disease.
Collapse
Affiliation(s)
- Siyu Chen
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
| | - Chien-Hui Lo
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
| | - Zhiquan Liu
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
| | - Qing Wang
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
| | - Ke Ning
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
| | - Tingting Li
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
- Department of Ophthalmology, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Road, Pudong district, Shanghai 200120, China
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, 1651 Page Mill Road, Rm 2220, Palo Alto, CA 94304, United States
- Palo Alto Veterans Administration, 3801 Miranda Avenue, Palo Alto, CA 94304, United States
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Koo KC, Halawani A, Wong VK, Lange D, Chew BH. Monogenic features of urolithiasis: A comprehensive review. Asian J Urol 2024; 11:169-179. [PMID: 38680588 PMCID: PMC11053333 DOI: 10.1016/j.ajur.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 03/28/2023] [Indexed: 05/01/2024] Open
Abstract
Objective Urolithiasis formation has been attributed to environmental and dietary factors. However, evidence is accumulating that genetic background can contribute to urolithiasis formation. Advancements in the identification of monogenic causes using high-throughput sequencing technologies have shown that urolithiasis has a strong heritable component. Methods This review describes monogenic factors implicated in a genetic predisposition to urolithiasis. Peer-reviewed journals were evaluated by a PubMed search until July 2023 to summarize disorders associated with monogenic traits, and discuss clinical implications of identification of patients genetically susceptible to urolithiasis formation. Results Given that more than 80% of urolithiases cases are associated with calcium accumulation, studies have focused mainly on monogenetic contributors to hypercalciuric urolithiases, leading to the identification of receptors, channels, and transporters involved in the regulation of calcium renal tubular reabsorption. Nevertheless, available candidate genes and linkage methods have a low resolution for evaluation of the effects of genetic components versus those of environmental, dietary, and hormonal factors, and genotypes remain undetermined in the majority of urolithiasis formers. Conclusion The pathophysiology underlying urolithiasis formation is complex and multifactorial, but evidence strongly suggests the existence of numerous monogenic causes of urolithiasis in humans.
Collapse
Affiliation(s)
- Kyo Chul Koo
- Department of Urology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Victor K.F. Wong
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Dirk Lange
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Ben H. Chew
- Department of Urological Sciences, University of British Columbia, Stone Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Kalot R, Sentell Z, Kitzler TM, Torban E. Primary cilia and actin regulatory pathways in renal ciliopathies. FRONTIERS IN NEPHROLOGY 2024; 3:1331847. [PMID: 38292052 PMCID: PMC10824913 DOI: 10.3389/fneph.2023.1331847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024]
Abstract
Ciliopathies are a group of rare genetic disorders caused by defects to the structure or function of the primary cilium. They often affect multiple organs, leading to brain malformations, congenital heart defects, and anomalies of the retina or skeletal system. Kidney abnormalities are among the most frequent ciliopathic phenotypes manifesting as smaller, dysplastic, and cystic kidneys that are often accompanied by renal fibrosis. Many renal ciliopathies cause chronic kidney disease and often progress to end-stage renal disease, necessitating replacing therapies. There are more than 35 known ciliopathies; each is a rare hereditary condition, yet collectively they account for a significant proportion of chronic kidney disease worldwide. The primary cilium is a tiny microtubule-based organelle at the apex of almost all vertebrate cells. It serves as a "cellular antenna" surveying environment outside the cell and transducing this information inside the cell to trigger multiple signaling responses crucial for tissue morphogenesis and homeostasis. Hundreds of proteins and unique cellular mechanisms are involved in cilia formation. Recent evidence suggests that actin remodeling and regulation at the base of the primary cilium strongly impacts ciliogenesis. In this review, we provide an overview of the structure and function of the primary cilium, focusing on the role of actin cytoskeleton and its regulators in ciliogenesis. We then describe the key clinical, genetic, and molecular aspects of renal ciliopathies. We highlight what is known about actin regulation in the pathogenesis of these diseases with the aim to consider these recent molecular findings as potential therapeutic targets for renal ciliopathies.
Collapse
Affiliation(s)
- Rita Kalot
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Zachary Sentell
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Thomas M. Kitzler
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- McGill University Health Center, Montreal, QC, Canada
| | - Elena Torban
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| |
Collapse
|
9
|
Huang L, Zhang Y, Fu H, Gu W, Mao J. A missense mutant of ocrl1 promotes apoptosis of tubular epithelial cells and disrupts endocytosis and the cell cycle of podocytes in Dent-2 Disease. Cell Commun Signal 2023; 21:256. [PMID: 38049819 PMCID: PMC10696739 DOI: 10.1186/s12964-023-01272-4] [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: 04/03/2023] [Accepted: 08/13/2023] [Indexed: 12/06/2023] Open
Abstract
BACKGROUND This study aimed to identify an orcl1 mutation in a patient with Dent-2 Disease and investigate the underlying mechanisms. METHODS The ocrl1 mutation was identified through exome sequencing. Knockdown of orcl1 and overexpression of the orcl1 mutant were performed in HK-2 and MPC5 cells to study its function, while flow cytometry measured reactive oxygen species (ROS), phosphatidylserine levels, and cell apoptosis. Scanning electron microscopy observed crystal adhesion, while transmission electron microscopy examined kidney tissue pathology. Laser scanning confocal microscopy was used to examine endocytosis, and immunohistochemical and immunofluorescence assays detected protein expression. Additionally, podocyte-specific orcl1 knockout mice were generated to investigate the role of orcl1 in vivo. RESULTS We identified a mutation resulting in the replacement of Histidine with Arginine at position 318 (R318H) in ocrl1 in the proband. orcl1 was widely expressed in the kidney. In vitro experiments showed that knockdown of orcl1 and overexpression of ocrl1 mutant increased ROS, phosphatidylserine exocytosis, crystal adhesion, and cell apoptosis in HK-2 cells. Knockdown of orcl1 in podocytes reduced endocytosis and disrupted the cell cycle while increasing cell migration. In vivo studies in mice showed that conditional deletion of orcl1 in podocytes caused glomerular dysfunction, including proteinuria and fibrosis. CONCLUSION This study identified an R318H mutation in orcl1 in a patient with Dent-2 Disease. This mutation may contribute to renal injury by promoting ROS production and inducing cell apoptosis in tubular cells, while disrupting endocytosis and the cell cycle, and promoting cell migration of podocytes. Video Abstract.
Collapse
Affiliation(s)
- Limin Huang
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine. National Clinical Research Center for Child Health, Hangzhou, China
| | - Yingying Zhang
- Department of Pediatrics, Clinical Center of Pediatric Nephrology of Henan Province, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Haidong Fu
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine. National Clinical Research Center for Child Health, Hangzhou, China
| | - Weizhong Gu
- Department of Pathologyology, Children's Hospital, Zhejiang University School of Medicine. National Clinical Research Center for Child Health, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine. National Clinical Research Center for Child Health, Hangzhou, China.
| |
Collapse
|
10
|
Lee JH, Lee J, Suh DH. A Case of Hidradenitis Suppurativa in a Genetically Confirmed Lowe Syndrome Patient. Ann Dermatol 2023; 35:S314-S316. [PMID: 38061729 PMCID: PMC10727890 DOI: 10.5021/ad.22.131] [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: 06/12/2022] [Revised: 08/12/2022] [Accepted: 01/12/2023] [Indexed: 12/20/2023] Open
Abstract
Lowe syndrome (LS), also known as oculocerebrorenal syndrome, is an X-linked multisystemic disorder caused by mutations in OCRL1, which encodes a member of the inositol-5-phosphatase family. As implied by its name, congenital cataracts, defects in the central nervous system, and renal manifestations are the main symptoms. Early hidradenitis suppurativa (HS) occurrence in Dent disease 2 (DD2), which is a mild variant of LS and shares the OCRL1 gene mutation, has been reported, although not in LS patients. Here, we report a case of HS in a 17-year-old boy with genetically confirmed LS, which suggests that defects in the OCRL1 gene may contribute to HS pathogenesis.
Collapse
Affiliation(s)
- Jun Hyo Lee
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
- Acne, Rosacea, Seborrheic Dermatitis and Hidradenitis Suppurativa Research Laboratory, Seoul National University Hospital, Seoul, Korea
| | - Jiwon Lee
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
| | - Dae Hun Suh
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
- Acne, Rosacea, Seborrheic Dermatitis and Hidradenitis Suppurativa Research Laboratory, Seoul National University Hospital, Seoul, Korea.
| |
Collapse
|
11
|
Derkaczew M, Martyniuk P, Hofman R, Rutkowski K, Osowski A, Wojtkiewicz J. The Genetic Background of Abnormalities in Metabolic Pathways of Phosphoinositides and Their Linkage with the Myotubular Myopathies, Neurodegenerative Disorders, and Carcinogenesis. Biomolecules 2023; 13:1550. [PMID: 37892232 PMCID: PMC10605126 DOI: 10.3390/biom13101550] [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: 08/27/2023] [Revised: 09/16/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Myo-inositol belongs to one of the sugar alcohol groups known as cyclitols. Phosphatidylinositols are one of the derivatives of Myo-inositol, and constitute important mediators in many intracellular processes such as cell growth, cell differentiation, receptor recycling, cytoskeletal organization, and membrane fusion. They also have even more functions that are essential for cell survival. Mutations in genes encoding phosphatidylinositols and their derivatives can lead to many disorders. This review aims to perform an in-depth analysis of these connections. Many authors emphasize the significant influence of phosphatidylinositols and phosphatidylinositols' phosphates in the pathogenesis of myotubular myopathies, neurodegenerative disorders, carcinogenesis, and other less frequently observed diseases. In our review, we have focused on three of the most often mentioned groups of disorders. Inositols are the topic of many studies, and yet, there are no clear results of successful clinical trials. Analysis of the available literature gives promising results and shows that further research is still needed.
Collapse
Affiliation(s)
- Maria Derkaczew
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland
- Students’ Scientific Club of Pathophysiologists, Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, 10-082 Olsztyn, Poland
| | - Piotr Martyniuk
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland
- Students’ Scientific Club of Pathophysiologists, Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, 10-082 Olsztyn, Poland
| | - Robert Hofman
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland
- Students’ Scientific Club of Pathophysiologists, Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, 10-082 Olsztyn, Poland
| | - Krzysztof Rutkowski
- Students’ Scientific Club of Pathophysiologists, Department of Human Physiology and Pathophysiology, School of Medicine, University of Warmia and Mazury, 10-082 Olsztyn, Poland
- The Nicolaus Copernicus Municipal Polyclinical Hospital in Olsztyn, 10-045 Olsztyn, Poland
| | - Adam Osowski
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland
| | - Joanna Wojtkiewicz
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland
| |
Collapse
|
12
|
Morleo M, Venditti R, Theodorou E, Briere LC, Rosello M, Tirozzi A, Tammaro R, Al-Badri N, High FA, Shi J, Putti E, Ferrante L, Cetrangolo V, Torella A, Walker MA, Tenconi R, Iascone M, Mei D, Guerrini R, van der Smagt J, Kroes HY, van Gassen KLI, Bilal M, Umair M, Pingault V, Attie-Bitach T, Amiel J, Ejaz R, Rodan L, Zollino M, Agrawal PB, Del Bene F, Nigro V, Sweetser DA, Franco B. De novo missense variants in phosphatidylinositol kinase PIP5KIγ underlie a neurodevelopmental syndrome associated with altered phosphoinositide signaling. Am J Hum Genet 2023; 110:1377-1393. [PMID: 37451268 PMCID: PMC10432144 DOI: 10.1016/j.ajhg.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 07/18/2023] Open
Abstract
Phosphoinositides (PIs) are membrane phospholipids produced through the local activity of PI kinases and phosphatases that selectively add or remove phosphate groups from the inositol head group. PIs control membrane composition and play key roles in many cellular processes including actin dynamics, endosomal trafficking, autophagy, and nuclear functions. Mutations in phosphatidylinositol 4,5 bisphosphate [PI(4,5)P2] phosphatases cause a broad spectrum of neurodevelopmental disorders such as Lowe and Joubert syndromes and congenital muscular dystrophy with cataracts and intellectual disability, which are thus associated with increased levels of PI(4,5)P2. Here, we describe a neurodevelopmental disorder associated with an increase in the production of PI(4,5)P2 and with PI-signaling dysfunction. We identified three de novo heterozygous missense variants in PIP5K1C, which encodes an isoform of the phosphatidylinositol 4-phosphate 5-kinase (PIP5KIγ), in nine unrelated children exhibiting intellectual disability, developmental delay, acquired microcephaly, seizures, visual abnormalities, and dysmorphic features. We provide evidence that the PIP5K1C variants result in an increase of the endosomal PI(4,5)P2 pool, giving rise to ectopic recruitment of filamentous actin at early endosomes (EEs) that in turn causes dysfunction in EE trafficking. In addition, we generated an in vivo zebrafish model that recapitulates the disorder we describe with developmental defects affecting the forebrain, including the eyes, as well as craniofacial abnormalities, further demonstrating the pathogenic effect of the PIP5K1C variants.
Collapse
Affiliation(s)
- Manuela Morleo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples, Italy.
| | - Rossella Venditti
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II," Medical School, Naples, Italy
| | - Evangelos Theodorou
- Center for Genomic Medicine, Divisions of Pediatric Hematology/Oncology and Medical Genetics and Metabolism, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lauren C Briere
- Center for Genomic Medicine, Divisions of Pediatric Hematology/Oncology and Medical Genetics and Metabolism, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marion Rosello
- Sorbonne Université, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Alfonsina Tirozzi
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples, Italy; Department of Epidemiology and Prevention, IRCCS NEUROMED, Pozzilli, Italy
| | - Roberta Tammaro
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy
| | - Nour Al-Badri
- Sorbonne Université, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Frances A High
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Jiahai Shi
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Elena Putti
- Sorbonne Université, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Luigi Ferrante
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy
| | - Viviana Cetrangolo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy
| | - Annalaura Torella
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Melissa A Walker
- Department of Neurology, Division of Neurogenetics, Child Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Romano Tenconi
- Clinical Genetics Unit, Department of Women and Children's Health, University of Padova, Padova, Italy
| | - Maria Iascone
- Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy
| | - Davide Mei
- Meyer Children's Hospital IRCCS, Neuroscience Department, Florence, Italy
| | - Renzo Guerrini
- Meyer Children's Hospital IRCCS, Neuroscience Department, Florence, Italy
| | - Jasper van der Smagt
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Hester Y Kroes
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Koen L I van Gassen
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Muhammad Bilal
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center & King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Veronica Pingault
- Service de Médecine Génomique des Maladies Rares, et Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
| | - Tania Attie-Bitach
- Service de Médecine Génomique des Maladies Rares, et Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
| | - Jeannine Amiel
- Service de Médecine Génomique des Maladies Rares, et Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
| | - Resham Ejaz
- Division of Genetics, Department of Pediatrics, McMaster Children's Hospital, Hamilton, ON, Canada
| | - Lance Rodan
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA; Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Marcella Zollino
- Institute of Medical Genetics, A. Gemelli School of Medicine, Catholic University of the Sacred Heart, Rome, Italy
| | - Pankaj B Agrawal
- Divisions of Newborn Medicine, Boston Children's Hospital, Boston, MA, USA; Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Filippo Del Bene
- Sorbonne Université, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - David A Sweetser
- Center for Genomic Medicine, Divisions of Pediatric Hematology/Oncology and Medical Genetics and Metabolism, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy; Scuola Superiore Meridionale (SSM, School of Advanced Studies), Genomics and Experimental Medicine Program, Naples, Italy; Medical Genetics, Department of Translational Medicine, University of Naples "Federico II," Via Sergio Pansini, 80131 Naples, Italy
| |
Collapse
|
13
|
Chen H, Lu C, Tan Y, Weber-Boyvat M, Zheng J, Xu M, Xiao J, Liu S, Tang Z, Lai C, Li M, Olkkonen VM, Yan D, Zhong W. Oculocerebrorenal syndrome of Lowe (OCRL) controls leukemic T-cell survival by preventing excessive PI(4,5)P 2 hydrolysis in the plasma membrane. J Biol Chem 2023:104812. [PMID: 37172724 DOI: 10.1016/j.jbc.2023.104812] [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: 03/28/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
T-cell acute lymphoblastic leukemia (T-ALL) is one of the deadliest and most aggressive hematological malignancies, but its pathological mechanism in controlling cell survival is not fully understood. Oculocerebrorenal syndrome (also called Lowe syndrome) is a rare X-linked recessive disorder characterized by cataracts, intellectual disability, and proteinuria. This disease has been shown to be caused by mutation of Oculocerebrorenal syndrome of Lowe 1 (OCRL1; OCRL), encoding a phosphatidylinositol 4,5-diphosphate [PI(4,5)P2] 5-phosphatase involved in regulating membrane trafficking, however, its function in cancer cells is unclear. Here, we uncovered that OCRL1 is overexpressed in T-ALL cells and knockdown of OCRL1 results in cell death, indicating the essential role of OCRL in controlling T-ALL cell survival. We show OCRL is primarily localized in the Golgi, and can translocate to plasma membrane (PM) upon ligand stimulation. We found OCRL interacts with OSBP-related protein 4L (ORP4L), which facilitates OCRL translocation from the Golgi to the PM upon cluster of differentiation 3 (CD3) stimulation. Thus, OCRL represses the activity of ORP4L to prevent excessive PI(4,5)P2 hydrolysis by phosphoinositide phospholipase C β3 (PLCβ3) and uncontrolled Ca2+ release from the endoplasmic reticulum (ER). We propose OCRL1 deletion leads to accumulation of PI(4,5)P2 in the PM, disrupting the normal Ca2+ oscillation pattern in the cytosol and leading to mitochondrial Ca2+ overloading, ultimately causing T-ALL cell mitochondrial dysfunction and cell death. These results highlight a critical role for OCRL in maintaining moderate PI(4,5)P2 availability in T-ALL cells. Our findings also raise the possibility of targeting OCRL1 to treat T-ALL disease.
Collapse
Affiliation(s)
- Huanzhao Chen
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Chen Lu
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Yuhui Tan
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Marion Weber-Boyvat
- Minerva Foundation Institute for Medical Research, Biomedicum 2U, FI-00290 Helsinki, Finland. Department of Anatomy, Faculty of Medicine, FI-00014 University of Helsinki, Finland; Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Jie Zheng
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Mengyang Xu
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Jie Xiao
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Shuang Liu
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Zhiquan Tang
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Chaofeng Lai
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China
| | - Mingchuan Li
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China; Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China
| | - Vesa M Olkkonen
- Minerva Foundation Institute for Medical Research, Biomedicum 2U, FI-00290 Helsinki, Finland. Department of Anatomy, Faculty of Medicine, FI-00014 University of Helsinki, Finland
| | - Daoguang Yan
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China; Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China.
| | - Wenbin Zhong
- MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou, 510632, China; Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China.
| |
Collapse
|
14
|
Lee JJ, Ramadesikan S, Black AF, Christoffer C, Pacheco AFP, Subramanian S, Hanna CB, Barth G, Stauffacher CV, Kihara D, Aguilar RC. Heterogeneity in Lowe Syndrome: Mutations Affecting the Phosphatase Domain of OCRL1 Differ in Impact on Enzymatic Activity and Severity of Cellular Phenotypes. Biomolecules 2023; 13:615. [PMID: 37189363 PMCID: PMC10135975 DOI: 10.3390/biom13040615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/23/2023] [Accepted: 03/25/2023] [Indexed: 04/01/2023] Open
Abstract
Lowe Syndrome (LS) is a condition due to mutations in the OCRL1 gene, characterized by congenital cataracts, intellectual disability, and kidney malfunction. Unfortunately, patients succumb to renal failure after adolescence. This study is centered in investigating the biochemical and phenotypic impact of patient's OCRL1 variants (OCRL1VAR). Specifically, we tested the hypothesis that some OCRL1VAR are stabilized in a non-functional conformation by focusing on missense mutations affecting the phosphatase domain, but not changing residues involved in binding/catalysis. The pathogenic and conformational characteristics of the selected variants were evaluated in silico and our results revealed some OCRL1VAR to be benign, while others are pathogenic. Then we proceeded to monitor the enzymatic activity and function in kidney cells of the different OCRL1VAR. Based on their enzymatic activity and presence/absence of phenotypes, the variants segregated into two categories that also correlated with the severity of the condition they induce. Overall, these two groups mapped to opposite sides of the phosphatase domain. In summary, our findings highlight that not every mutation affecting the catalytic domain impairs OCRL1's enzymatic activity. Importantly, data support the inactive-conformation hypothesis. Finally, our results contribute to establishing the molecular and structural basis for the observed heterogeneity in severity/symptomatology displayed by patients.
Collapse
Affiliation(s)
- Jennifer J. Lee
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Swetha Ramadesikan
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Adrianna F. Black
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Charles Christoffer
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Andres F. Pacheco Pacheco
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Sneha Subramanian
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Claudia B. Hanna
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Gillian Barth
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Cynthia V. Stauffacher
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Daisuke Kihara
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Ruben Claudio Aguilar
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; (J.J.L.); (A.F.B.); (A.F.P.P.); (S.S.); (C.B.H.); (G.B.); (C.V.S.); (D.K.)
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
15
|
Bura A, de Matteis MA, Bender M, Swinkels M, Versluis J, Jansen AJG, Jurak Begonja A. Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading. Br J Haematol 2023; 200:87-99. [PMID: 36176266 DOI: 10.1111/bjh.18478] [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: 05/10/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/28/2022]
Abstract
Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.
Collapse
Affiliation(s)
- Ana Bura
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Maria Antonietta de Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital Wuerzburg, Rudolf Virchow Center, Wuerzburg, Germany
| | - Maurice Swinkels
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jurjen Versluis
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | | | | |
Collapse
|
16
|
Chen C, Hu J, Ling K. The Role of Primary Cilia-Associated Phosphoinositide Signaling in Development. J Dev Biol 2022; 10:51. [PMID: 36547473 PMCID: PMC9785882 DOI: 10.3390/jdb10040051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/07/2022] Open
Abstract
Primary cilia are microtube-based organelles that extend from the cell surface and function as biochemical and mechanical extracellular signal sensors. Primary cilia coordinate a series of signaling pathways during development. Cilia dysfunction leads to a pleiotropic group of developmental disorders, termed ciliopathy. Phosphoinositides (PIs), a group of signaling phospholipids, play a crucial role in development and tissue homeostasis by regulating membrane trafficking, cytoskeleton reorganization, and organelle identity. Accumulating evidence implicates the involvement of PI species in ciliary defects and ciliopathies. The abundance and localization of PIs in the cell are tightly regulated by the opposing actions of kinases and phosphatases, some of which are recently discovered in the context of primary cilia. Here, we review several cilium-associated PI kinases and phosphatases, including their localization along cilia, function in regulating the ciliary biology under normal conditions, as well as the connection of their disease-associated mutations with ciliopathies.
Collapse
Affiliation(s)
- Chuan Chen
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | - Jinghua Hu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | - Kun Ling
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| |
Collapse
|
17
|
Sena C, Iannello G, Skowronski AA, Dannheim K, Cheung L, Agrawal PB, Hirschhorn JN, Zeitler P, LeDuc CA, Stratigopoulos G, Thaker VV. Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms. J Med Genet 2022; 59:1171-1178. [PMID: 35803701 PMCID: PMC10186212 DOI: 10.1136/jmedgenet-2022-108490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/11/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the OCRL gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy. METHODS This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association. Frequency of non-ocular clinical feature(s) of LS and their age of onset was summarised. An LS-specific therapy effectiveness scale was used to assess the response to the administered treatment. Expression of OCRL and relevant neuropeptides was measured in postmortem human brain by qPCR. Gene expression in the mouse brain was determined by reanalysis of publicly available bulk and single cell RNA sequencing. RESULTS A total of 137 individuals (1 female, 89.1% white, median age 14 years (range 0.8-56)) were included in the study. Short stature (height <3rd percentile) was noted in 81% (n=111) individuals, and 15% (n=20) received growth hormone therapy. Undescended testis was reported in 47% (n=64), and median age of onset of puberty was 15 years. Additional features were dental problems (n=77, 56%), bone fractures (n=63, 46%), hypophosphataemia (n=60, 44%), developmental delay and behavioural issues. OCRL is expressed in human and mouse hypothalami, and in hypothalamic cell clusters expressing Ghrh, Sst, Oxt, Pomc and pituitary cells expressing Gh and Prl. CONCLUSIONS There is a wide spectrum of the clinical phenotype of LS. Some of the features may be partly driven by the loss of function of OCRL in the hypothalamus and the pituitary.
Collapse
Affiliation(s)
- Cecilia Sena
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Grazia Iannello
- Columbia Stem Cell Initiative, Stem Cell Core, Columbia University Irving Medical Center, New York, New York, USA
| | - Alicja A Skowronski
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Katelyn Dannheim
- Department of Pathology and Laboratory Medicine, Rhode Island and Hasbro Children's Hospitals and the Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Leonard Cheung
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Pankaj B Agrawal
- Division of Neonatology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Joel N Hirschhorn
- Division of Endocrinology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Phillip Zeitler
- Department of Endocrinology, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Charles A LeDuc
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - George Stratigopoulos
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| | - Vidhu V Thaker
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, USA
- Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, New York, USA
| |
Collapse
|
18
|
Iida T, Hosojima M, Kabasawa H, Yamamoto-Kabasawa K, Goto S, Tanaka T, Kitamura N, Nakada M, Itoh S, Ogasawara S, Kaseda R, Suzuki Y, Narita I, Saito A. Urinary A- and C-megalin predict progression of diabetic kidney disease: an exploratory retrospective cohort study. J Diabetes Complications 2022; 36:108312. [PMID: 36228564 DOI: 10.1016/j.jdiacomp.2022.108312] [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: 04/28/2022] [Revised: 08/17/2022] [Accepted: 09/17/2022] [Indexed: 11/25/2022]
Abstract
AIMS Megalin, a proximal tubular endocytosis receptor, is excreted in urine in two forms: ectodomain (A-megalin) and full-length (C-megalin). We explored whether urinary megalin levels can be used as independent prognostic biomarkers in the progression of diabetic kidney disease (DKD). METHODS The associations between baseline urinary A-megalin/creatinine (Cr) and/or C-megalin/Cr levels and the subsequent estimated glomerular filtration rate (eGFR) slope were analyzed using a generalized estimating equation. Patients were categorized into higher or lower groups based on the optimal cutoff values, obtained from a receiver operating characteristic curve, of the two forms of urinary megalin. RESULTS We retrospectively analyzed 188 patients with type 2 diabetes. The eGFR slopes of the higher A-megalin/Cr and higher C-megalin/Cr groups were - 0.904 and -0.749 ml/min/1.73 m2/year steeper than those of the lower groups, respectively. Moreover, the eGFR slope was -1.888 ml/min/1.73 m2/year steeper in the group with both higher A- and higher C-megalin/Cr than in the other group. These results remained significant when adjusted for known urinary biomarkers (albumin, α1-microglobulin, β2-microglobulin, and N-acetyl-β-d-glucosaminidase). CONCLUSIONS Urinary A- and C-megalin/Cr levels are likely to be prognostic biomarkers in the progression of DKD independent of other urinary biomarkers.
Collapse
Affiliation(s)
- Tomomichi Iida
- Department of Applied Molecular Medicine, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan; Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Michihiro Hosojima
- Department of Clinical Nutrition Science, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan.
| | - Hideyuki Kabasawa
- Department of Clinical Nutrition Science, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Keiko Yamamoto-Kabasawa
- Department of Health Promotion Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Sawako Goto
- Department of Applied Molecular Medicine, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Takahiro Tanaka
- Clinical and Translational Research Center, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan
| | - Nobutaka Kitamura
- Clinical and Translational Research Center, Niigata University Medical and Dental Hospital, 1-754 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8520, Japan
| | - Mitsutaka Nakada
- Diagnostics Research Department, Life Innovation Research Institute, DENKA Innovation Center, Denka Co., Ltd., 3-5-1 Asahimachi, Machida, Tokyo 194-8560, Japan
| | - Shino Itoh
- Diagnostics Research Department, Life Innovation Research Institute, DENKA Innovation Center, Denka Co., Ltd., 3-5-1 Asahimachi, Machida, Tokyo 194-8560, Japan
| | - Shinya Ogasawara
- Diagnostics Research Department, Life Innovation Research Institute, DENKA Innovation Center, Denka Co., Ltd., 3-5-1 Asahimachi, Machida, Tokyo 194-8560, Japan
| | - Ryohei Kaseda
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Yoshiki Suzuki
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Ichiei Narita
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Akihiko Saito
- Department of Applied Molecular Medicine, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan.
| |
Collapse
|
19
|
Droubi A, Wallis C, Anderson KE, Rahman S, de Sa A, Rahman T, Stephens LR, Hawkins PT, Lowe M. The inositol 5-phosphatase INPP5B regulates B cell receptor clustering and signaling. J Cell Biol 2022; 221:e202112018. [PMID: 35878408 PMCID: PMC9351708 DOI: 10.1083/jcb.202112018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/27/2022] [Accepted: 07/05/2022] [Indexed: 11/22/2022] Open
Abstract
Upon antigen binding, the B cell receptor (BCR) undergoes clustering to form a signalosome that propagates downstream signaling required for normal B cell development and physiology. BCR clustering is dependent on remodeling of the cortical actin network, but the mechanisms that regulate actin remodeling in this context remain poorly defined. In this study, we identify the inositol 5-phosphatase INPP5B as a key regulator of actin remodeling, BCR clustering, and downstream signaling in antigen-stimulated B cells. INPP5B acts via dephosphorylation of the inositol lipid PI(4,5)P2 that in turn is necessary for actin disassembly, BCR mobilization, and cell spreading on immobilized surface antigen. These effects can be explained by increased actin severing by cofilin and loss of actin linking to the plasma membrane by ezrin, both of which are sensitive to INPP5B-dependent PI(4,5)P2 hydrolysis. INPP5B is therefore a new player in BCR signaling and may represent an attractive target for treatment of B cell malignancies caused by aberrant BCR signaling.
Collapse
Affiliation(s)
- Alaa Droubi
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Connor Wallis
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Saifur Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Aloka de Sa
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | | | | - Martin Lowe
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| |
Collapse
|
20
|
Williams DM, Gungordu L, Jackson-Crawford A, Lowe M. Assessment of endocytic traffic and Ocrl function in the developing zebrafish neuroepithelium. J Cell Sci 2022; 135:276669. [PMID: 35979861 PMCID: PMC9592051 DOI: 10.1242/jcs.260339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/11/2022] [Indexed: 12/05/2022] Open
Abstract
Endocytosis allows cells to internalise a wide range of molecules from their environment and to maintain their plasma membrane composition. It is vital during development and for maintenance of tissue homeostasis. The ability to visualise endocytosis in vivo requires suitable assays to monitor the process. Here, we describe imaging-based assays to visualise endocytosis in the neuroepithelium of living zebrafish embryos. Injection of fluorescent tracers into the brain ventricles followed by live imaging was used to study fluid-phase or receptor-mediated endocytosis, for which we used receptor-associated protein (RAP, encoded by Lrpap1) as a ligand for low-density lipoprotein receptor-related protein (LRP) receptors. Using dual-colour imaging combined with expression of endocytic markers, it is possible to track the progression of endocytosed tracers and to monitor trafficking dynamics. Using these assays, we reveal a role for the Lowe syndrome protein Ocrl in endocytic trafficking within the neuroepithelium. We also found that the RAP-binding receptor Lrp2 (encoded by lrp2a) appears to contribute only partially to neuroepithelial RAP endocytosis. Altogether, our results provide a basis to track endocytosis within the neuroepithelium in vivo and support a role for Ocrl in this process. This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Daniel M Williams
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Lale Gungordu
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - 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
| | - 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
| |
Collapse
|
21
|
Wang C, Zhang W, Wang L, Liu W, Guo H. Case Report: Combined Cataract Surgery and Minimally Invasive Glaucoma Surgery Provide an Alternative Treatment Approach for Lowe Syndrome. Front Med (Lausanne) 2022; 9:913229. [PMID: 35847784 PMCID: PMC9283680 DOI: 10.3389/fmed.2022.913229] [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: 04/05/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
We describe the case of a 4-month-old boy who presented with bilateral congenital cataract and high intraocular pressure (IOP) in the left eye, followed by mental retardation and delayed motor development. Genetic investigation revealed the boy had a splicing variant (c.940-11G>A) of the oculocerebrorenal syndrome of Lowe (OCRL) gene. The boy underwent a lensectomy for congenital cataract in his right eye, and lensectomy combined with a 360° suture trabeculotomy to remove the clouded lens and to control IOP of the left eye. During postoperative one-and-a-half-year follow-up, the boy exhibited an improved visual acuity and a well-controlled IOP without the use of topical IOP-lowering medications. Lowe syndrome is a rare multisystemic disorder that is diagnosed through clinical manifestation and genetic testing. The possibility of Lowe syndrome should be considered in patients presenting with typical triad, and genetic analysis should be performed in time to confirm the diagnosis. We recommend combined cataract surgery and minimally invasive glaucoma surgery (MIGS) as a safe, feasible, and efficient method to treat congenital cataract and glaucoma in Lowe syndrome patients.
Collapse
|
22
|
Akhtar BM, Bhatia P, Acharya S, Sharma S, Sharma Y, Aswathy BS, Ganapathy K, Vasudevan A, Raghu P. A human stem cell resource to decipher the biochemical and cellular basis of neurodevelopmental defects in Lowe Syndrome. Biol Open 2022; 11:274000. [PMID: 35023542 PMCID: PMC8822356 DOI: 10.1242/bio.059066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 12/14/2021] [Indexed: 11/20/2022] Open
Abstract
Human brain development is a complex process where multiple cellular and developmental events are coordinated to generate normal structure and function. Alteration in any of these events can impact brain development, manifesting clinically as neurodevelopmental disorders. Human genetic disorders of lipid metabolism often present with features of altered brain function. Lowe syndrome (LS) is an X-linked recessive disease with features of altered brain function. LS results from mutations in OCRL1, which encodes a phosphoinositide 5-phosphatase enzyme. However, the cellular mechanisms by which loss of OCRL1 leads to brain defects remain unknown. Human brain development involves several cellular and developmental features not conserved in other species and understanding such mechanisms remains a challenge. Rodent models of LS have been generated but failed to recapitulate features of the human disease. Here we describe the generation of human stem cell lines from LS patients. Further, we present biochemical characterization of lipid metabolism in patient cell lines and demonstrate their use as a ‘disease-in-a-dish’ model for understanding the mechanism by which loss of OCRL1 leads to altered cellular and physiological brain development. This article has an associated First Person interview with the first author of the paper. Summary: A human iPSC resource to study the cellular basis of neurodevelopmental defects in Lowe syndrome.
Collapse
Affiliation(s)
- Bilal M Akhtar
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru-560065, India
| | - Priyanka Bhatia
- Brain Development and Disease Mechanisms, Institute for Stem Cell Science and Regenerative Medicine, Bengaluru-560065, India
| | - Shubhra Acharya
- Brain Development and Disease Mechanisms, Institute for Stem Cell Science and Regenerative Medicine, Bengaluru-560065, India
| | - Sanjeev Sharma
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru-560065, India
| | - Yojet Sharma
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru-560065, India
| | - B S Aswathy
- Brain Development and Disease Mechanisms, Institute for Stem Cell Science and Regenerative Medicine, Bengaluru-560065, India
| | - Kavina Ganapathy
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru-560065, India.,Department of Biotechnology, Center for Post Graduate Studies, School of Sciences, Jain University, Bangalore-560027, India
| | - Anil Vasudevan
- Department of Pediatric Nephrology, St. John's Medical College Hospital, Bengaluru-560034, India
| | - Padinjat Raghu
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru-560065, India.,Brain Development and Disease Mechanisms, Institute for Stem Cell Science and Regenerative Medicine, Bengaluru-560065, India
| |
Collapse
|
23
|
Perazella MA, Herlitz LC. The Crystalline Nephropathies. Kidney Int Rep 2021; 6:2942-2957. [PMID: 34901567 PMCID: PMC8640557 DOI: 10.1016/j.ekir.2021.09.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/12/2021] [Accepted: 09/07/2021] [Indexed: 12/14/2022] Open
Abstract
Crystalline nephropathies are a unique form of kidney disease characterized by the histologic finding of intrarenal crystal deposition. The intrinsic nature of some molecules and ions combined with a favorable tubular fluid physiology leads to crystal precipitation and deposition within the tubular lumens. Crystal deposition promotes kidney injury through tubular obstruction and both direct and indirect cytotoxicities. Further kidney injury develops from inflammation triggered by these crystals. From a clinical standpoint, the crystalline nephropathies are associated with abnormal urinalysis and urinary sediment findings, tubulopathies, acute kidney injury (AKI), and/or chronic kidney disease (CKD). Urine sediment examination is often helpful in alerting clinicians to the possibility of crystal-related kidney injury. The identification of crystals within the kidneys on biopsy by pathologists prompts clinicians to evaluate patients for medication-related kidney injury, dysproteinemia-related malignancies, and certain inherited disorders. This review will focus on the clinical and pathologic aspects of these 3 categories of crystalline nephropathies.
Collapse
Affiliation(s)
- Mark A Perazella
- Section of Nephrology, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.,Section of Nephrology, Department of Medicine, VA Medical Center, West Haven, Connecticut, USA
| | - Leal C Herlitz
- Department of Anatomic Pathology, Cleveland Clinic, Cleveland, Ohio, USA
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Zhang Y, Deng L, Chen X, Hu Y, Chen Y, Chen K, Zhou J. Novel pathogenic OCRL mutations and genotype-phenotype analysis of Chinese children affected by oculocerebrorenal syndrome: two cases and a literature review. BMC Med Genomics 2021; 14:219. [PMID: 34488756 PMCID: PMC8422650 DOI: 10.1186/s12920-021-01069-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Oculocerebrorenal syndrome of Lowe is a rare X-linked disorder characterized by congenital cataracts, mental retardation, and proximal tubulopathy. This condition is caused by a mutation of OCRL gene (located at chromosome Xq26.1), which encodes an inositol polyphosphate 5-phosphatase. CASE PRESENTATION We identified two novel OCRL mutations in two unrelated Chinese boys, each with a severe phenotype of Lowe syndrome. A novel de novo deletion (hemizygous c.659_662delAGGG, p.E220Vfs*29) was present in patient 1 and a novel splicing mutation (hemizygous c.2257-2A > T) that was maternally inherited was present in patient 2. A renal biopsy in patient 2 indicated mild mesangial proliferative glomerulonephritis, mild focal mononuclear cells infiltration, and interstitial focal fibrosis. Moreover, renal expression of OCRL-1 protein in patient 2 was significantly reduced compared to a control patient with thin basement membrane disease. CONCLUSIONS This study reports two novel OCRL variants associated with severe ocular and neurologic deficiency, despite only mild renal dysfunction. Based on our two patients and a literature review, the genotype-phenotype correlation of OCRL mutations with this severe phenotype of Lowe syndrome suggest a possible clustering of missense, deletion, and nonsense mutations in the 5-phosphatase domain and Rho-GAP domain in the Chinese population.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Linxia Deng
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Xiaohong Chen
- Department of Endocrinology and Metabolism, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingjie Hu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Yaxian Chen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Kang Chen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China
| | - Jianhua Zhou
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095, Jiefang Ave., Wuhan, 430030, People's Republic of China.
| |
Collapse
|
26
|
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.
Collapse
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
| |
Collapse
|
27
|
Kowal TJ, Prosseda PP, Ning K, Wang B, Alvarado J, Sendayen BE, Jabbehdari S, Stamer WD, Hu Y, Sun Y. Optogenetic Modulation of Intraocular Pressure in a Glucocorticoid-Induced Ocular Hypertension Mouse Model. Transl Vis Sci Technol 2021; 10:10. [PMID: 34111256 PMCID: PMC8107493 DOI: 10.1167/tvst.10.6.10] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/22/2021] [Indexed: 01/03/2023] Open
Abstract
Purpose Steroid-induced glaucoma is a common form of secondary open angle glaucoma characterized by ocular hypertension (elevated intraocular pressure [IOP]) in response to prolonged glucocorticoid exposure. Elevated IOP occurs with increased outflow resistance and altered trabecular meshwork (TM) function. Recently, we used an optogenetic approach in TM to regulate the 5-phosphatase, OCRL, which contributes to regulating PI(4,5)P2 levels. Here, we applied this system with the aim of reversing compromised outflow function in a steroid-induced ocular hypertension mouse model. Methods Elevated IOP was induced by chronic subconjunctival dexamethasone injections in wild-type C57Bl/6j mice. AAV2 viruses containing optogenetic modules of cryptochrome 2 (Cry2)-OCRL-5ptase and CIBN-GFP were injected into the anterior chamber. Four weeks after viral expression and dexamethasone exposure, IOP was measured by tonometer and outflow facility was measured by perfusion apparatus. Human TM cells were treated with dexamethasone, stimulated by light and treated with rhodamine-phalloidin to analyze actin structure. Results Dexamethasone treatment elevated IOP and decreased outflow facility in wild-type mice. Optogenetic constructs were expressed in the TM of mouse eyes. Light stimulation caused CRY2-OCRL-5ptase to translocate to plasma membrane (CIBN-CAAX-GFP) and cilia (CIBN-SSTR3-GFP) in TM cells, which rescued the IOP and outflow facility. In addition, aberrant actin structures formed by dexamethasone treatment were reduced by optogenetic stimulation in human TM cells in culture. Conclusions Subcellular targeting of inositol phosphatases to remove PIP2 represents a promising strategy to reverse defective TM function in steroid-induced ocular hypertension. Translational Relevance Targeted modulation of OCRL may be used to decrease steroid-induced elevated IOP.
Collapse
Affiliation(s)
- Tia J. Kowal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Philipp P. Prosseda
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Ke Ning
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Biao Wang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Jorge Alvarado
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Brent E. Sendayen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Sayena Jabbehdari
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - W. Daniel Stamer
- Duke Eye Center, Department of Ophthalmology, Duke University, Durham, NC, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA
- Palo Alto Veterans Administration, Palo Alto, CA, USA
| |
Collapse
|
28
|
Role of protons in calcium signaling. Biochem J 2021; 478:895-910. [PMID: 33635336 DOI: 10.1042/bcj20200971] [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: 12/15/2020] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 02/03/2023]
Abstract
Thirty-six years after the publication of the important article by Busa and Nuccitelli on the variability of intracellular pH (pHi) and the interdependence of pHi and intracellular Ca2+ concentration ([Ca2+]i), little research has been carried out on pHi and calcium signaling. Moreover, the results appear to be contradictory. Some authors claim that the increase in [Ca2+]i is due to a reduction in pHi, others that it is caused by an increase in pHi. The reasons for these conflicting results have not yet been discussed and clarified in an exhaustive manner. The idea that variations in pHi are insignificant, because cellular buffers quickly stabilize the pHi, may be a limiting and fundamentally wrong concept. In fact, it has been shown that protons can move and react in the cell before they are neutralized. Variations in pHi have a remarkable impact on [Ca2+]i and hence on some of the basic biochemical mechanisms of calcium signaling. This paper focuses on the possible triggering role of protons during their short cellular cycle and it suggests a new hypothesis for an IP3 proton dependent mechanism of action.
Collapse
|
29
|
Montaño-Rendón F, Grinstein S, Walpole GFW. Monitoring Phosphoinositide Fluxes and Effectors During Leukocyte Chemotaxis and Phagocytosis. Front Cell Dev Biol 2021; 9:626136. [PMID: 33614656 PMCID: PMC7890364 DOI: 10.3389/fcell.2021.626136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/22/2023] Open
Abstract
The dynamic re-organization of cellular membranes in response to extracellular stimuli is fundamental to the cell physiology of myeloid and lymphoid cells of the immune system. In addition to maintaining cellular homeostatic functions, remodeling of the plasmalemma and endomembranes endow leukocytes with the potential to relay extracellular signals across their biological membranes to promote rolling adhesion and diapedesis, migration into the tissue parenchyma, and to ingest foreign particles and effete cells. Phosphoinositides, signaling lipids that control the interface of biological membranes with the external environment, are pivotal to this wealth of functions. Here, we highlight the complex metabolic transitions that occur to phosphoinositides during several stages of the leukocyte lifecycle, namely diapedesis, migration, and phagocytosis. We describe classical and recently developed tools that have aided our understanding of these complex lipids. Finally, major downstream effectors of inositides are highlighted including the cytoskeleton, emphasizing the importance of these rare lipids in immunity and disease.
Collapse
Affiliation(s)
- Fernando Montaño-Rendón
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada
| | - Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
30
|
Egot M, Lasne D, Poirault-Chassac S, Mirault T, Pidard D, Dreano E, Elie C, Gandrille S, Marchelli A, Baruch D, Rendu J, Fauré J, Flaujac C, Gratacap MP, Sié P, Gaussem P, Salomon R, Baujat G, Bachelot-Loza C. Role of oculocerebrorenal syndrome of Lowe (OCRL) protein in megakaryocyte maturation, platelet production and functions: a study in patients with Lowe syndrome. Br J Haematol 2021; 192:909-921. [PMID: 33528045 DOI: 10.1111/bjh.17346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/16/2020] [Accepted: 01/03/2021] [Indexed: 11/29/2022]
Abstract
Lowe syndrome (LS) is an oculocerebrorenal syndrome of Lowe (OCRL1) genetic disorder resulting in a defect of the OCRL protein, a phosphatidylinositol-4,5-bisphosphate 5-phosphatase containing various domains including a Rho GTPase-activating protein (RhoGAP) homology domain catalytically inactive. We previously reported surgery-associated bleeding in patients with LS, suggestive of platelet dysfunction, accompanied with a mild thrombocytopenia in several patients. To decipher the role of OCRL in platelet functions and in megakaryocyte (MK) maturation, we conducted a case-control study on 15 patients with LS (NCT01314560). While all had a drastically reduced expression of OCRL, this deficiency did not affect platelet aggregability, but resulted in delayed thrombus formation on collagen under flow conditions, defective platelet spreading on fibrinogen and impaired clot retraction. We evidenced alterations of the myosin light chain phosphorylation (P-MLC), with defective Rac1 activity and, inversely, elevated active RhoA. Altered cytoskeleton dynamics was also observed in cultured patient MKs showing deficient proplatelet extension with increased P-MLC that was confirmed using control MKs transfected with OCRL-specific small interfering(si)RNA (siOCRL). Patients with LS also had an increased proportion of circulating barbell-shaped proplatelets. Our present study establishes that a deficiency of the OCRL protein results in a defective actomyosin cytoskeleton reorganisation in both MKs and platelets, altering both thrombopoiesis and some platelet responses to activation necessary to ensure haemostasis.
Collapse
Affiliation(s)
- Marion Egot
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Dominique Lasne
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France.,AP-HP, Laboratoire d'Hématologie, Hôpital Necker-Enfants Malades, Paris, France
| | - Sonia Poirault-Chassac
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Tristan Mirault
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France.,AP-HP, Service de Médecine Vasculaire, Hôpital Européen Georges-Pompidou, Paris, France
| | - Dominique Pidard
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Elise Dreano
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Caroline Elie
- AP-HP, Unité de Recherche Clinique, Hôpital Necker-Enfants Malades, Paris, France
| | - Sophie Gandrille
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Aurore Marchelli
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - Dominique Baruch
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France
| | - John Rendu
- University Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, Grenoble, France
| | - Julien Fauré
- University Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences, Grenoble, France
| | - Claire Flaujac
- Centre hospitalier de Versailles, André Mignot, Service de Biologie Médicale, Secteur Hémostase, Le Chesnay, France
| | - Marie-Pierre Gratacap
- INSERM U1048 and Université Toulouse 3, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU-Rangueil, Toulouse, France
| | - Pierre Sié
- INSERM U1048 and Université Toulouse 3, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), CHU-Rangueil, Toulouse, France.,CHU de Toulouse, Laboratoire d'Hématologie, Toulouse, France
| | - Pascale Gaussem
- Université de Paris, Innovations Thérapeutiques en Hémostase, Paris, INSERM U1140, France.,AP-HP, Service d'Hématologie Biologique, Hôpital Européen Georges Pompidou, Paris, France
| | - Rémi Salomon
- AP-HP, Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, INSERM U983, Paris, France
| | - Geneviève Baujat
- AP-HP, Service de Génétique, Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
| | | |
Collapse
|
31
|
Jin YY, Huang LM, Quan XF, Mao JH. Dent disease: classification, heterogeneity and diagnosis. World J Pediatr 2021; 17:52-57. [PMID: 32248351 DOI: 10.1007/s12519-020-00357-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 03/05/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Dent disease is a rare tubulopathy characterized by manifestations of proximal tubular dysfunction, which occurs almost exclusively in males. It mainly presents symptoms in early childhood and may progress to end-stage renal failure between the 3rd and 5th decades of human life. According to its various genetic basis and to clinical signs and symptoms, researchers define two forms of Dent disease (Dent diseases 1 and 2) and suggest that these forms are produced by mutations in the CLCN5 and OCRL genes, respectively. Dent diseases 1 and 2 account for 60% and 15% of all Dent disease cases, and their genetic cause is generally understood. However, the genetic cause of the remaining 25% of Dent disease cases remains unidentified. DATA SOURCES All relevant peer-reviewed original articles published thus far have been screened out from PubMed and have been referenced. RESULTS Genetic testing has been used greatly to identify mutation types of CLCN5 and OCRL gene, and next-generation sequencing also has been used to identify an increasing number of unknown genotypes. Gene therapy may bring new hope to the treatment of Dent disease. The abuse of hormones and immunosuppressive agents for the treatment of Dent disease should be avoided to prevent unnecessary harm to children. CONCLUSIONS The current research progress in classification, genetic heterogeneity, diagnosis, and treatment of Dent disease reviewed in this paper enables doctors and researchers to better understand Dent disease and provides a basis for improved prevention and treatment.
Collapse
Affiliation(s)
- Yan-Yan Jin
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China
| | - Li-Min Huang
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China
| | - Xiao-Fang Quan
- Chigene (Beijing) Translational Medical Research Center Co. Ltd, E2 Biomedical Park, No. 88 Kechuang Sixth Ave, Yizhuang, Beijing, China
| | - Jian-Hua Mao
- Department of Nephrology, National Clinical Research Center for Child Health, The Children's Hospital, Zhejiang University School of Medicine, #57 Zhugan Lane, Hangzhou, 310006, China.
| |
Collapse
|
32
|
Berquez M, Gadsby JR, Festa BP, Butler R, Jackson SP, Berno V, Luciani A, Devuyst O, Gallop JL. The phosphoinositide 3-kinase inhibitor alpelisib restores actin organization and improves proximal tubule dysfunction in vitro and in a mouse model of Lowe syndrome and Dent disease. Kidney Int 2020; 98:883-896. [PMID: 32919786 PMCID: PMC7550850 DOI: 10.1016/j.kint.2020.05.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 05/01/2020] [Accepted: 05/15/2020] [Indexed: 12/19/2022]
Abstract
Loss-of-function mutations in the OCRL gene, which encodes the phosphatidylinositol [PI] 4,5-bisphosphate [PI(4,5)P2] 5-phosphatase OCRL, cause defective endocytosis and proximal tubule dysfunction in Lowe syndrome and Dent disease 2. The defect is due to increased levels of PI(4,5)P2 and aberrant actin polymerization, blocking endosomal trafficking. PI 3-phosphate [PI(3)P] has been recently identified as a coactivator with PI(4,5)P2 in the actin pathway. Here, we tested the hypothesis that phosphoinositide 3-kinase (PI3K) inhibitors may rescue the endocytic defect imparted by OCRL loss, by rebalancing phosphoinositide signals to the actin machinery. The broad-range PI3K inhibitor copanlisib and class IA p110α PI3K inhibitor alpelisib reduced aberrant actin polymerization in OCRL-deficient human kidney cells in vitro. Levels of PI 3,4,5-trisphosphate, PI(4,5)P2 and PI(3)P were all reduced with alpelisib treatment, and siRNA knockdown of the PI3K catalytic subunit p110α phenocopied the actin phenotype. In a humanized OcrlY/- mouse model, alpelisib reduced endosomal actin staining while restoring stress fiber architecture and levels of megalin at the plasma membrane of proximal tubule cells, reflected by improved endocytic uptake of low molecular weight proteins in vivo. Thus, our findings support the link between phosphoinositide lipids, actin polymerization and endocytic trafficking in the proximal tubule and represent a proof-of-concept for repurposing alpelisib in Lowe syndrome/Dent disease 2.
Collapse
Affiliation(s)
- Marine Berquez
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Jonathan R Gadsby
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - Richard Butler
- Gurdon Institute, University of Cambridge, Cambridge, UK
| | - Stephen P Jackson
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Valeria Berno
- Experimental Imaging Center, ALEMBIC, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Olivier Devuyst
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
| | - Jennifer L Gallop
- Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK.
| |
Collapse
|
33
|
Bhowmick SS, Lang AE. Movement Disorders and Renal Diseases. Mov Disord Clin Pract 2020; 7:763-779. [PMID: 33043074 DOI: 10.1002/mdc3.13005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023] Open
Abstract
Movement disorders often emerge from the interplay of complex pathophysiological processes involving the kidneys and the nervous system. Tremor, myoclonus, ataxia, chorea, and parkinsonism can occur in the context of renal dysfunction (azotemia and electrolyte abnormalities) or they can be part of complications of its management (dialysis and renal transplantation). On the other hand, myoglobinuria from rhabdomyolysis in status dystonicus and certain drugs used in the management of movement disorders can cause nephrotoxicity. Distinct from these well-recognized associations, it is important to appreciate that there are several inherited and acquired disorders in which movement abnormalities do not occur as a consequence of renal dysfunction or vice versa but are manifestations of common pathophysiological processes affecting the nervous system and the kidneys. These disorders are the emphasis of this review. Increasing awareness of these conditions among neurologists may help them to identify renal involvement earlier, take timely intervention by anticipating complications and focus on therapies targeting common mechanisms in addition to symptomatic management of movement disorders. Recognition of renal impairment in a patient with complex neurological presentation may narrow down the differentials and aid in reaching a definite diagnosis.
Collapse
Affiliation(s)
- Suvorit S Bhowmick
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
| | - Anthony E Lang
- Division of Neurology, Department of Medicine, Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital University Health Network Toronto Ontario Canada
| |
Collapse
|
34
|
Dumic KK, Anticevic D, Petrinovic-Doresic J, Zigman T, Zarković K, Rokic F, Vugrek O. Lowe syndrome - Old and new evidence of secondary mitochondrial dysfunction. Eur J Med Genet 2020; 63:104022. [PMID: 32712215 DOI: 10.1016/j.ejmg.2020.104022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 05/05/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022]
Abstract
The oculocerebrorenal syndrome of Lowe (LS) is a rare, progressive, multisystemic X-linked disorder caused by mutations in OCRL gene. Patients classically present with ocular abnormalities including bilateral congenital cataracts and glaucoma, intellectual delay, severe generalized hypotonia with absent tendon reflexes, and proximal renal tubular dysfunction. Congenital bilateral cataracts and hypotonia are present at birth in almost all patients, while other classical symptoms develop gradually with variable severity. Consequently, differential diagnosis in infant period in these patients can be broad including other rare metabolic and neurologic disorders. Herein we present a 4.5 year old boy with Lowe syndrome caused by mutation of OCRL gene, NM_000276.4:c.643C > T; p.(Gln215*), initially diagnosed as having mitochondriopathy due to alteration of mitochondria on electron microscopic examination in different tissues and decreased values of mitochondrial energy metabolism measurements in muscle. No pathogenic mutations in mitochondrial DNA were found on whole exome sequencing. This patient recall historical hypothesis of secondary mitochondrial dysfunction in Lowe syndrome, that may be caused/intensified by some of disease symptoms.
Collapse
Affiliation(s)
- Katja K Dumic
- Department of Pediatrics, Division for Pediatric Endocrinology and Diabetes, University Hospital Centre Zagreb, University of Zagreb Medical School, Croatia.
| | - Darko Anticevic
- Division of Orthopedic Surgery, Specialty Hospital 'St. Catherine', Zabok, Croatia
| | | | - Tamara Zigman
- Department of Pediatrics, Division for Genetics and Inherited Metabolic Diseases, University Hospital Centre Zagreb, Croatia
| | - Kamelija Zarković
- Department of Pathology, University Hospital Centre Zagreb, University of Zagreb Medical School, Croatia
| | - Filip Rokic
- Laboratory for Advanced Genomics, Ruđer Bošković Institute, Zagreb, Croatia
| | - Oliver Vugrek
- Laboratory for Advanced Genomics, Ruđer Bošković Institute, Zagreb, Croatia
| |
Collapse
|
35
|
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.
Collapse
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.
| |
Collapse
|
36
|
Finkelstein S, Gospe SM, Schuhmann K, Shevchenko A, Arshavsky VY, Lobanova ES. Phosphoinositide Profile of the Mouse Retina. Cells 2020; 9:cells9061417. [PMID: 32517352 PMCID: PMC7349851 DOI: 10.3390/cells9061417] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/18/2020] [Accepted: 06/04/2020] [Indexed: 12/24/2022] Open
Abstract
Phosphoinositides are known to play multiple roles in eukaryotic cells. Although dysregulation of phosphoinositide metabolism in the retina has been reported to cause visual dysfunction in animal models and human patients, our understanding of the phosphoinositide composition of the retina is limited. Here, we report a characterization of the phosphoinositide profile of the mouse retina and an analysis of the subcellular localization of major phosphorylated phosphoinositide forms in light-sensitive photoreceptor neurons. Using chromatography of deacylated phosphatidylinositol headgroups, we established PI(4,5)P2 and PI(4)P as two major phosphorylated phosphoinositides in the retina. Using high-resolution mass spectrometry, we revealed 18:0/20:4 and 16:0/20:4 as major fatty-acyl chains of retinal phosphoinositides. Finally, analysis of fluorescent phosphoinositide sensors in rod photoreceptors demonstrated distinct subcellular distribution patterns of major phosphoinositides. The PI(4,5)P2 reporter was enriched in the inner segments and synapses, but was barely detected in the light-sensitive outer segments. The PI(4)P reporter was mostly found in the outer and inner segments and the areas around nuclei, but to a lesser degree in the synaptic region. These findings provide support for future mechanistic studies defining the biological significance of major mono- (PI(4)P) and bisphosphate (PI(4,5)P2) phosphatidylinositols in photoreceptor biology and retinal health.
Collapse
Affiliation(s)
- Stella Finkelstein
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; (S.F.); (S.M.G.III); (V.Y.A.)
| | - Sidney M. Gospe
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; (S.F.); (S.M.G.III); (V.Y.A.)
| | - Kai Schuhmann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany; (K.S.); (A.S.)
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany; (K.S.); (A.S.)
| | - Vadim Y. Arshavsky
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; (S.F.); (S.M.G.III); (V.Y.A.)
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
| | - Ekaterina S. Lobanova
- Department of Ophthalmology, University of Florida, Gainesville, FL 32610, USA
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
- Correspondence:
| |
Collapse
|
37
|
Ates KM, Wang T, Moreland T, Veeranan-Karmegam R, Ma M, Jeter C, Anand P, Wenzel W, Kim HG, Wolfe LA, Stephen J, Adams DR, Markello T, Tifft CJ, Settlage R, Gahl WA, Gonsalvez GB, Malicdan MC, Flanagan-Steet H, Pan YA. Deficiency in the endocytic adaptor proteins PHETA1/2 impairs renal and craniofacial development. Dis Model Mech 2020; 13:dmm041913. [PMID: 32152089 PMCID: PMC7272357 DOI: 10.1242/dmm.041913] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/27/2020] [Indexed: 12/20/2022] Open
Abstract
A critical barrier in the treatment of endosomal and lysosomal diseases is the lack of understanding of the in vivo functions of the putative causative genes. We addressed this by investigating a key pair of endocytic adaptor proteins, PH domain-containing endocytic trafficking adaptor 1 and 2 (PHETA1/2; also known as FAM109A/B, Ses1/2, IPIP27A/B), which interact with the protein product of OCRL, the causative gene for Lowe syndrome. Here, we conducted the first study of PHETA1/2 in vivo, utilizing the zebrafish system. We found that impairment of both zebrafish orthologs, pheta1 and pheta2, disrupted endocytosis and ciliogenesis in renal tissues. In addition, pheta1/2 mutant animals exhibited reduced jaw size and delayed chondrocyte differentiation, indicating a role in craniofacial development. Deficiency of pheta1/2 resulted in dysregulation of cathepsin K, which led to an increased abundance of type II collagen in craniofacial cartilages, a marker of immature cartilage extracellular matrix. Cathepsin K inhibition rescued the craniofacial phenotypes in the pheta1/2 double mutants. The abnormal renal and craniofacial phenotypes in the pheta1/2 mutant animals were consistent with the clinical presentation of a patient with a de novo arginine (R) to cysteine (C) variant (R6C) of PHETA1. Expressing the patient-specific variant in zebrafish exacerbated craniofacial deficits, suggesting that the R6C allele acts in a dominant-negative manner. Together, these results provide insights into the in vivo roles of PHETA1/2 and suggest that the R6C variant is contributory to the pathogenesis of disease in the patient.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Kristin M Ates
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA 24016, USA
| | - Tong Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- JC Self Research Institute, Greenwood Genetic Center, Greenwood, SC 29646, USA
| | - Trevor Moreland
- JC Self Research Institute, Greenwood Genetic Center, Greenwood, SC 29646, USA
| | | | - Manxiu Ma
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA 24016, USA
| | - Chelsi Jeter
- JC Self Research Institute, Greenwood Genetic Center, Greenwood, SC 29646, USA
| | - Priya Anand
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - Wolfgang Wenzel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - Hyung-Goo Kim
- Neurological Disorder Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Lynne A Wolfe
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshi Stephen
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David R Adams
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas Markello
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cynthia J Tifft
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert Settlage
- Advanced Research Computing Unit, Division of Information Technology, Virginia Tech, Blacksburg, VA 24060, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
- National Institutes of Health Undiagnosed Diseases Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Graydon B Gonsalvez
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - May Christine Malicdan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
- National Institutes of Health Undiagnosed Diseases Program, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Y Albert Pan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA 24016, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24060, USA
- Department of Psychiatry and Behavioral Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA
| |
Collapse
|
38
|
Waschbüsch D, Purlyte E, Pal P, McGrath E, Alessi DR, Khan AR. Structural Basis for Rab8a Recruitment of RILPL2 via LRRK2 Phosphorylation of Switch 2. Structure 2020; 28:406-417.e6. [PMID: 32017888 PMCID: PMC7139218 DOI: 10.1016/j.str.2020.01.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/27/2019] [Accepted: 01/13/2020] [Indexed: 12/18/2022]
Abstract
Rab8a is associated with the dynamic regulation of membrane protrusions in polarized cells. Rab8a is one of several Rab GTPases that are substrates of leucine-rich repeat kinase 2 (LRRK2), a serine/threonine kinase that is linked to Parkinson's disease. Rab8a is phosphorylated at T72 (pT72) in its switch 2 helix and recruits the phospho-specific effector RILPL2, which subsequently regulates ciliogenesis. Here, we report the crystal structure of phospho-Rab8a (pRab8a) in complex with the RH2 (RILP homology) domain of RILPL2. The complex is a heterotetramer with RILPL2 forming a central α-helical dimer that bridges two pRab8a molecules. The N termini of the α helices cross over, forming an X-shaped cap (X-cap) that orients Arg residues from RILPL2 toward pT72. X-cap residues critical for pRab8a binding are conserved in JIP3 and JIP4, which also interact with LRRK2-phosphorylated Rab10. We propose a general mode of recognition for phosphorylated Rab GTPases by this family of phospho-specific effectors.
Collapse
Affiliation(s)
- Dieter Waschbüsch
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland
| | - Elena Purlyte
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Prosenjit Pal
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Emma McGrath
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland
| | - Dario R Alessi
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Amir R Khan
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland; Division of Newborn Medicine, Boston Children's Hospital, Boston, USA.
| |
Collapse
|
39
|
Much More Than a Scaffold: Cytoskeletal Proteins in Neurological Disorders. Cells 2020; 9:cells9020358. [PMID: 32033020 PMCID: PMC7072452 DOI: 10.3390/cells9020358] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 02/08/2023] Open
Abstract
Recent observations related to the structure of the cytoskeleton in neurons and novel cytoskeletal abnormalities involved in the pathophysiology of some neurological diseases are changing our view on the function of the cytoskeletal proteins in the nervous system. These efforts allow a better understanding of the molecular mechanisms underlying neurological diseases and allow us to see beyond our current knowledge for the development of new treatments. The neuronal cytoskeleton can be described as an organelle formed by the three-dimensional lattice of the three main families of filaments: actin filaments, microtubules, and neurofilaments. This organelle organizes well-defined structures within neurons (cell bodies and axons), which allow their proper development and function through life. Here, we will provide an overview of both the basic and novel concepts related to those cytoskeletal proteins, which are emerging as potential targets in the study of the pathophysiological mechanisms underlying neurological disorders.
Collapse
|
40
|
Doodnauth SA, Grinstein S, Maxson ME. Constitutive and stimulated macropinocytosis in macrophages: roles in immunity and in the pathogenesis of atherosclerosis. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180147. [PMID: 30967001 DOI: 10.1098/rstb.2018.0147] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Macrophages respond to several stimuli by forming florid membrane ruffles that lead to fluid uptake by macropinocytosis. This type of induced macropinocytosis, executed by a variety of non-malignant and malignant cells, is initiated by transmembrane receptors and is involved in nutrient acquisition and mTOR signalling. However, macrophages also perform a unique type of constitutive ruffling and macropinocytosis that is dependent on the presence of extracellular calcium. Calcium-sensing receptors are responsible for this activity. This distinct form of macropinocytosis enables macrophages to continuously sample their microenvironment for antigenic molecules and for pathogen- and danger-associated molecular patterns, as part of their immune surveillance functions. Interestingly, even within the monocyte lineage, there are differences in macropinocytic ability that reflect the polarized functional roles of distinct macrophage subsets. This review discusses the shared and distinct features of both induced and constitutive macropinocytosis displayed by the macrophage lineage and their roles in physiology, immunity and pathophysiology. In particular, we analyse the role of macropinocytosis in the uptake of modified low-density lipoprotein (LDL) and its contribution to foam cell and atherosclerotic plaque formation. We propose a combined role of scavenger receptors and constitutive macropinocytosis in oxidized LDL uptake, a process we have termed 'receptor-assisted macropinocytosis'. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'.
Collapse
Affiliation(s)
- Sasha A Doodnauth
- 1 Princess Margaret Cancer Center, University Health Network , Toronto, ON , Canada M5G 1L7.,2 Department of Medical Biophysics, University of Toronto , Toronto, ON , Canada M5G 1L7
| | - Sergio Grinstein
- 3 Program in Cell Biology, Hospital for Sick Children , 686 Bay Street, Toronto, ON , Canada M5G 0A4.,4 Department of Biochemistry, University of Toronto , 1 King's Circle, Toronto, ON , Canada M5S 1A8.,5 Keenan Research Centre of the Li Ka Shing Knowledge Institute , St. Michael's Hospital, 290 Victoria Street, Toronto, ON , Canada M5C 1N8
| | - Michelle E Maxson
- 3 Program in Cell Biology, Hospital for Sick Children , 686 Bay Street, Toronto, ON , Canada M5G 0A4
| |
Collapse
|
41
|
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.
Collapse
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,
| |
Collapse
|
42
|
van der Wijst J, Belge H, Bindels RJM, Devuyst O. Learning Physiology From Inherited Kidney Disorders. Physiol Rev 2019; 99:1575-1653. [PMID: 31215303 DOI: 10.1152/physrev.00008.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The identification of genes causing inherited kidney diseases yielded crucial insights in the molecular basis of disease and improved our understanding of physiological processes that operate in the kidney. Monogenic kidney disorders are caused by mutations in genes coding for a large variety of proteins including receptors, channels and transporters, enzymes, transcription factors, and structural components, operating in specialized cell types that perform highly regulated homeostatic functions. Common variants in some of these genes are also associated with complex traits, as evidenced by genome-wide association studies in the general population. In this review, we discuss how the molecular genetics of inherited disorders affecting different tubular segments of the nephron improved our understanding of various transport processes and of their involvement in homeostasis, while providing novel therapeutic targets. These include inherited disorders causing a dysfunction of the proximal tubule (renal Fanconi syndrome), with emphasis on epithelial differentiation and receptor-mediated endocytosis, or affecting the reabsorption of glucose, the handling of uric acid, and the reabsorption of sodium, calcium, and magnesium along the kidney tubule.
Collapse
Affiliation(s)
- Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Hendrica Belge
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Olivier Devuyst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| |
Collapse
|
43
|
Raghu P, Joseph A, Krishnan H, Singh P, Saha S. Phosphoinositides: Regulators of Nervous System Function in Health and Disease. Front Mol Neurosci 2019; 12:208. [PMID: 31507376 PMCID: PMC6716428 DOI: 10.3389/fnmol.2019.00208] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 08/07/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphoinositides, the seven phosphorylated derivatives of phosphatidylinositol have emerged as regulators of key sub-cellular processes such as membrane transport, cytoskeletal function and plasma membrane signaling in eukaryotic cells. All of these processes are also present in the cells that constitute the nervous system of animals and in this setting too, these are likely to tune key aspects of cell biology in relation to the unique structure and function of neurons. Phosphoinositides metabolism and function are mediated by enzymes and proteins that are conserved in evolution, and analysis of knockouts of these in animal models implicate this signaling system in neural function. Most recently, with the advent of human genome analysis, mutations in genes encoding components of the phosphoinositide signaling pathway have been implicated in human diseases although the cell biological basis of disease phenotypes in many cases remains unclear. In this review we evaluate existing evidence for the involvement of phosphoinositide signaling in human nervous system diseases and discuss ways of enhancing our understanding of the role of this pathway in the human nervous system's function in health and disease.
Collapse
Affiliation(s)
- Padinjat Raghu
- National Centre for Biological Sciences-TIFR, Bengaluru, India
| | | | | | | | | |
Collapse
|
44
|
Del Signore SJ, Rodal AA. The enemy of my enemy: PTEN and PLCXD collude to fight endosomal PtdIns(4,5)P 2. J Cell Biol 2019; 218:2082-2083. [PMID: 31189610 PMCID: PMC6605809 DOI: 10.1083/jcb.201906022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Loss of the phosphoinositide 5-phosphatase OCRL causes accumulation of PtdIns(4,5)P2 on membranes and, ultimately, Lowe syndrome. In this issue, Mondin et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201805155) discover that a surprising partnership between PTEN and the phospholipase PLCXD can compensate for OCRL to suppress endosomal PtdIns(4,5)P2 accumulation.
Collapse
Affiliation(s)
- Steven J Del Signore
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA
| | - Avital A Rodal
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA
| |
Collapse
|
45
|
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.
Collapse
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
| |
Collapse
|
46
|
Hilbi H, Nagai H, Kubori T, Roy CR. Subversion of Host Membrane Dynamics by the Legionella Dot/Icm Type IV Secretion System. Curr Top Microbiol Immunol 2019. [PMID: 29536361 DOI: 10.1007/978-3-319-75241-9_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Legionella species are Gram-negative ubiquitous environmental bacteria, which thrive in biofilms and parasitize protozoa. Employing an evolutionarily conserved mechanism, the opportunistic pathogens also replicate intracellularly in mammalian macrophages. This feature is a prerequisite for the pathogenicity of Legionella pneumophila, which causes the vast majority of clinical cases of a severe pneumonia, termed "Legionnaires' disease." In macrophages as well as in amoeba, L. pneumophila grows in a distinct membrane-bound compartment, the Legionella-containing vacuole (LCV). Formation of this replication-permissive pathogen compartment requires the bacterial Dot/Icm type IV secretion system (T4SS). Through the T4SS as many as 300 different "effector" proteins are injected into host cells, where they presumably subvert pivotal processes. Less than 40 Dot/Icm substrates have been characterized in detail to date, a number of which show unprecedented biological activities. Some of these effector proteins target host cell small GTPases, phosphoinositide lipids, the chelator phytate, the ubiquitination machinery, the retromer complex, the actin cytoskeleton, or the autophagy pathway. A recently discovered class of L. pneumophila effectors modulates the activity of other effectors and is termed "metaeffectors." Here, we summarize recent insight into the cellular functions and biochemical activities of L. pneumophila effectors and metaeffectors targeting the host's endocytic, retrograde, or autophagic pathways.
Collapse
Affiliation(s)
- Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zurich, Switzerland.
| | - Hiroki Nagai
- School of Medicine, Gifu University, Yanagido 1-1, Gifu, 501-1194, Japan.
| | - Tomoko Kubori
- School of Medicine, Gifu University, Yanagido 1-1, Gifu, 501-1194, Japan.
| | - Craig R Roy
- Department of Microbial Pathogenesis, Yale University, 295 Congress Avenue, BCMM 354B, New Haven, CT, 06536-0812, USA.
| |
Collapse
|
47
|
Tiosano D, Baris HN, Chen A, Hitzert MM, Schueler M, Gulluni F, Wiesener A, Bergua A, Mory A, Copeland B, Gleeson JG, Rump P, van Meer H, Sival DA, Haucke V, Kriwinsky J, Knaup KX, Reis A, Hauer NN, Hirsch E, Roepman R, Pfundt R, Thiel CT, Wiesener MS, Aslanyan MG, Buchner DA. Mutations in PIK3C2A cause syndromic short stature, skeletal abnormalities, and cataracts associated with ciliary dysfunction. PLoS Genet 2019; 15:e1008088. [PMID: 31034465 PMCID: PMC6508738 DOI: 10.1371/journal.pgen.1008088] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/09/2019] [Accepted: 03/12/2019] [Indexed: 02/07/2023] Open
Abstract
PIK3C2A is a class II member of the phosphoinositide 3-kinase (PI3K) family that catalyzes the phosphorylation of phosphatidylinositol (PI) into PI(3)P and the phosphorylation of PI(4)P into PI(3,4)P2. At the cellular level, PIK3C2A is critical for the formation of cilia and for receptor mediated endocytosis, among other biological functions. We identified homozygous loss-of-function mutations in PIK3C2A in children from three independent consanguineous families with short stature, coarse facial features, cataracts with secondary glaucoma, multiple skeletal abnormalities, neurological manifestations, among other findings. Cellular studies of patient-derived fibroblasts found that they lacked PIK3C2A protein, had impaired cilia formation and function, and demonstrated reduced proliferative capacity. Collectively, the genetic and molecular data implicate mutations in PIK3C2A in a new Mendelian disorder of PI metabolism, thereby shedding light on the critical role of a class II PI3K in growth, vision, skeletal formation and neurological development. In particular, the considerable phenotypic overlap, yet distinct features, between this syndrome and Lowe’s syndrome, which is caused by mutations in the PI-5-phosphatase OCRL, highlight the key role of PI metabolizing enzymes in specific developmental processes and demonstrate the unique non-redundant functions of each enzyme. This discovery expands what is known about disorders of PI metabolism and helps unravel the role of PIK3C2A and class II PI3Ks in health and disease. Identifying the genetic basis of rare disorders can provide insight into gene function, susceptibility to disease, guide the development of new therapeutics, improve opportunities for genetic counseling, and help clinicians evaluate and potentially treat complicated clinical presentations. However, it is estimated that the genetic basis of approximately one-half of all rare genetic disorders remains unknown. We describe one such rare disorder based on genetic and clinical evaluations of individuals from 3 unrelated consanguineous families with a similar constellation of features including short stature, coarse facial features, cataracts with secondary glaucoma, multiple skeletal abnormalities, neurological manifestations including stroke, among other findings. We discovered that these features were due to deficiency of the PIK3C2A enzyme. PIK3C2A is a class II member of the phosphoinositide 3-kinase (PI3K) family that catalyzes the phosphorylation of the lipids phosphatidylinositol (PI) into PI(3)P and the phosphorylation of PI(4)P into PI(3,4)P2 that are essential for a variety of cellular processes including cilia formation and vesicle trafficking. This syndrome is the first monogenic disorder caused by mutations in a class II PI3K family member and thus sheds new light on their role in human development.
Collapse
Affiliation(s)
- Dov Tiosano
- Division of Pediatric Endocrinology, Ruth Children's Hospital, Rambam Medical Center, Haifa, Israel
- Rappaport Family Faculty of Medicine, Technion—Israel Institute of Technology, Haifa, Israel
| | - Hagit N. Baris
- Rappaport Family Faculty of Medicine, Technion—Israel Institute of Technology, Haifa, Israel
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel
| | - Anlu Chen
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Marrit M. Hitzert
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Markus Schueler
- Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Federico Gulluni
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, Torino, Italy
| | - Antje Wiesener
- Institute of Human Genetics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Antonio Bergua
- Department of Ophthalmology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel
| | - Brett Copeland
- Laboratory of Pediatric Brain Diseases, Rockefeller University, New York, New York, United States of America
| | - Joseph G. Gleeson
- Laboratory of Pediatric Brain Diseases, Rockefeller University, New York, New York, United States of America
- Department of Neurosciences, University of California, San Diego, La Jolla, California, United States of America
| | - Patrick Rump
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hester van Meer
- Department of Pediatrics, Beatrix Children’s Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Deborah A. Sival
- Department of Pediatrics, Beatrix Children’s Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Volker Haucke
- Leibniz-Institut für Molekulare Pharmakologie, Berlin Faculty of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Josh Kriwinsky
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Karl X. Knaup
- Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Nadine N. Hauer
- Institute of Human Genetics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, Torino, Italy
| | - Ronald Roepman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christian T. Thiel
- Institute of Human Genetics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Michael S. Wiesener
- Department of Nephrology and Hypertension, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Mariam G. Aslanyan
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - David A. Buchner
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, United States of America
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
- Research Institute for Children’s Health, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
48
|
IPIP27 Coordinates PtdIns(4,5)P 2 Homeostasis for Successful Cytokinesis. Curr Biol 2019; 29:775-789.e7. [PMID: 30799246 PMCID: PMC6408333 DOI: 10.1016/j.cub.2019.01.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 12/03/2018] [Accepted: 01/15/2019] [Indexed: 12/12/2022]
Abstract
During cytokinesis, an actomyosin contractile ring drives the separation of the two daughter cells. A key molecule in this process is the inositol lipid PtdIns(4,5)P2, which recruits numerous factors to the equatorial region for contractile ring assembly. Despite the importance of PtdIns(4,5)P2 in cytokinesis, the regulation of this lipid in cell division remains poorly understood. Here, we identify a role for IPIP27 in mediating cellular PtdIns(4,5)P2 homeostasis. IPIP27 scaffolds the inositol phosphatase oculocerebrorenal syndrome of Lowe (OCRL) by coupling it to endocytic BAR domain proteins. Loss of IPIP27 causes accumulation of PtdIns(4,5)P2 on aberrant endomembrane vacuoles, mislocalization of the cytokinetic machinery, and extensive cortical membrane blebbing. This phenotype is observed in Drosophila and human cells and can result in cytokinesis failure. We have therefore identified IPIP27 as a key modulator of cellular PtdIns(4,5)P2 homeostasis required for normal cytokinesis. The results indicate that scaffolding of inositol phosphatase activity is critical for maintaining PtdIns(4,5)P2 homeostasis and highlight a critical role for this process in cell division. IPIP27 scaffolds the inositol phosphatase OCRL via coupling to BAR domain proteins IPIP27 scaffolding of OCRL is critical for cellular PtdIns(4,5)P2 homeostasis IPIP27 is required for cortical actin and membrane stability during cytokinesis IPIP27 function is conserved from flies to humans
Collapse
|
49
|
Abstract
Legionella pneumophila is the causative agent of a pneumonia termed Legionnaires' disease. The facultative intracellular bacterium employs the Icm/Dot type IV secretion system (T4SS) and a plethora of translocated "effector" proteins to interfere with host vesicle trafficking pathways and establish a replicative niche, the Legionella-containing vacuole (LCV). Internalization of the pathogen and the events immediately ensuing are accompanied by host cell-mediated phosphoinositide (PI) lipid changes and the Icm/Dot-controlled conversion of the LCV from a PtdIns(3)P-positive vacuole into a PtdIns(4)P-positive replication-permissive compartment, which tightly associates with the endoplasmic reticulum. The source and formation of PtdIns(4)P are ill-defined. Using dually labeled Dictyostelium discoideum amoebae and real-time high-resolution confocal laser scanning microscopy (CLSM), we show here that nascent LCVs continuously capture and accumulate PtdIns(4)P-positive vesicles from the host cell. Trafficking of these PtdIns(4)P-positive vesicles to LCVs occurs independently of the Icm/Dot system, but their sustained association requires a functional T4SS. During the infection, PtdIns(3)P-positive membranes become compacted and segregated from the LCV, and PtdIns(3)P-positive vesicles traffic to the LCV but do not fuse. Moreover, using eukaryotic and prokaryotic PtdIns(4)P probes (2×PHFAPP-green fluorescent protein [2×PHFAPP-GFP] and P4CSidC-GFP, respectively) along with Arf1-GFP, we show that PtdIns(4)P-rich membranes of the trans-Golgi network associate with the LCV. Intriguingly, the interaction dynamics of 2×PHFAPP-GFP and P4CSidC-GFP are spatially separable and reveal the specific PtdIns(4)P pool from which the LCV PI originates. These findings provide high-resolution real-time insights into how L. pneumophila exploits the cellular dynamics of membrane-bound PtdIns(4)P for LCV formation.IMPORTANCE The environmental bacterium Legionella pneumophila causes a life-threatening pneumonia termed Legionnaires' disease. The bacteria grow intracellularly in free-living amoebae as well as in respiratory tract macrophages. To this end, L. pneumophila forms a distinct membrane-bound compartment called the Legionella-containing vacuole (LCV). Phosphoinositide (PI) lipids are crucial regulators of the identity and dynamics of host cell organelles. The PI lipid PtdIns(4)P is a hallmark of the host cell secretory pathway, and decoration of LCVs with this PI is required for pathogen vacuole maturation. The source, dynamics, and mode of accumulation of PtdIns(4)P on LCVs are largely unknown. Using Dictyostelium amoebae producing different fluorescent probes as host cells, we show here that LCVs rapidly acquire PtdIns(4)P through the continuous interaction with PtdIns(4)P-positive host vesicles derived from the Golgi apparatus. Thus, the PI lipid pattern of the secretory pathway contributes to the formation of the replication-permissive pathogen compartment.
Collapse
|
50
|
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.
Collapse
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
| |
Collapse
|