1
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Chakraborty P, Hasan G. ER-Ca 2+ stores and the regulation of store-operated Ca 2+ entry in neurons. J Physiol 2024; 602:1463-1474. [PMID: 36691983 DOI: 10.1113/jp283827] [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: 11/18/2022] [Accepted: 01/16/2023] [Indexed: 01/25/2023] Open
Abstract
Key components of endoplasmic reticulum (ER) Ca2+ release and store-operated Ca2+ entry (SOCE) are likely expressed in all metazoan cells. Due to the complexity of canonical Ca2+ entry mechanisms in neurons, the functional significance of ER-Ca2+ release and SOCE has been difficult to identify and establish. In this review we present evidence of how these two related mechanisms of Ca2+ signalling impact multiple aspects of neuronal physiology and discuss their interaction with the better understood classes of ion channels that are gated by either voltage changes or extracellular ligands in neurons. Given how a small imbalance in Ca2+ homeostasis can have strongly detrimental effects on neurons, leading to cell death, it is essential that neuronal SOCE is carefully regulated. We go on to discuss some mechanisms of SOCE regulation that have been identified in Drosophila and mammalian neurons. These include specific splice variants of stromal interaction molecules, different classes of membrane-interacting proteins and an ER-Ca2+ channel. So far these appear distinct from the mechanisms of SOCE regulation identified in non-excitable cells. Finally, we touch upon the significance of these studies in the context of certain human neurodegenerative diseases.
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Affiliation(s)
- Pragnya Chakraborty
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- SASTRA University, Thanjavur, Tamil Nadu, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
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2
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Yao J, Ni M, Tian S, Sun B, Wang R, Paul Estillore J, Back TG, Wayne Chen SR. A Gain-of-function Mutation in the Gating Domain of ITPR1 Impairs Motor Movement and Increases Thermal and Mechanical Sensitivity. Neuroscience 2023; 522:11-22. [PMID: 37164302 DOI: 10.1016/j.neuroscience.2023.04.031] [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: 12/10/2021] [Revised: 04/14/2023] [Accepted: 04/30/2023] [Indexed: 05/12/2023]
Abstract
Inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) is an intracellular Ca2+ release channel important for a number of fundamental cellular functions. Consistent with its critical physiological significance, mutations in ITPR1 are associated with disease. Surprisingly, nearly all the disease-associated ITPR1 mutations characterized to date are loss of function. Despite the paucity of ITPR1 gain-of-function (GOF) mutations, enhanced ITPR1 function as a result of dysregulation by ITPR1 interacting proteins is thought to be associated with ataxia, learning and memory impairments, Alzheimer's disease (AD) progression, and chronic pain. However, direct evidence for the role of ITPR1 GOF in disease is lacking. To determine whether GOF in ITPR1 itself has pathological ramifications, we employed a newly developed mouse model expressing an ITPR1 mutation in the gating domain of the channel, D2594K, that markedly increased the channel's sensitivity to activation by IP3. Behavioral studies showed that the ITPR1-D2594K+/- mutant mice displayed motor deficits and reduced muscle strength. However, the ITPR1-D2594K+/- mutation did not significantly alter hippocampal learning and memory and did not change learning and memory impairments when crossed with the 5xFAD AD model mice. On the other hand, ITPR1-D2594K+/- mice exhibited increased sensitivity to thermal and mechanical stimulation compared to WT. Interestingly, R-carvedilol treatment attenuated the enhanced thermal and mechanical nociception in ITPR1-D2594K+/- mice. Thus, the ITPR1-D2594K+/- mutation in the channel's gating domain has a marked impact on motor movements and pain perception, but little effect on hippocampal learning and memory.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada; Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Mingke Ni
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Shanshan Tian
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- Medical School, Kunming University of Science and Technology, Kunming, China
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada; Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada.
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3
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Terry LE, Arige V, Neumann J, Wahl AM, Knebel TR, Chaffer JW, Malik S, Liston A, Humblet-Baron S, Bultynck G, Yule DI. Missense mutations in inositol 1,4,5-trisphosphate receptor type 3 result in leaky Ca 2+ channels and activation of store-operated Ca 2+ entry. iScience 2022; 25:105523. [PMID: 36444295 PMCID: PMC9700043 DOI: 10.1016/j.isci.2022.105523] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/10/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Mutations in all subtypes of the inositol 1,4,5-trisphosphate receptor Ca2+ release channel are associated with human diseases. In this report, we investigated the functionality of three neuropathy-associated missense mutations in IP3R3 (V615M, T1424M, and R2524C). The mutants only exhibited function when highly over-expressed compared to endogenous hIP3R3. All variants resulted in elevated basal cytosolic Ca2+ levels, decreased endoplasmic reticulum Ca2+ store content, and constitutive store-operated Ca2+ entry in the absence of any stimuli, consistent with a leaky IP3R channel pore. These variants differed in channel function; when stably over-expressed the R2524C mutant was essentially dead, V615M was poorly functional, and T1424M exhibited activity greater than that of the corresponding wild-type following threshold stimulation. These results demonstrate that a common feature of these mutations is decreased IP3R3 function. In addition, these mutations exhibit a novel phenotype manifested as a constitutively open channel, which inappropriately gates SOCE in the absence of stimulation.
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Affiliation(s)
- Lara E. Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Vikas Arige
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Julika Neumann
- KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
| | - Amanda M. Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Taylor R. Knebel
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - James W. Chaffer
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
| | - Adrian Liston
- KU Leuven, Department of Microbiology and Immunology, Leuven, Belgium
| | | | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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4
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Superior Cerebellar Atrophy: An Imaging Clue to Diagnose ITPR1-Related Disorders. Int J Mol Sci 2022; 23:ijms23126723. [PMID: 35743164 PMCID: PMC9223788 DOI: 10.3390/ijms23126723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 02/04/2023] Open
Abstract
The inositol 1,4,5-triphosphate receptor type 1 (ITPR1) gene encodes an InsP3-gated calcium channel that modulates intracellular Ca2+ release and is particularly expressed in cerebellar Purkinje cells. Pathogenic variants in the ITPR1 gene are associated with different types of autosomal dominant spinocerebellar ataxia: SCA15 (adult onset), SCA29 (early-onset), and Gillespie syndrome. Cerebellar atrophy/hypoplasia is invariably detected, but a recognizable neuroradiological pattern has not been identified yet. With the aim of describing ITPR1-related neuroimaging findings, the brain MRI of 14 patients with ITPR1 variants (11 SCA29, 1 SCA15, and 2 Gillespie) were reviewed by expert neuroradiologists. To further evaluate the role of superior vermian and hemispheric cerebellar atrophy as a clue for the diagnosis of ITPR1-related conditions, the ITPR1 gene was sequenced in 5 patients with similar MRI pattern, detecting pathogenic variants in 4 of them. Considering the whole cohort, a distinctive neuroradiological pattern consisting in superior vermian and hemispheric cerebellar atrophy was identified in 83% patients with causative ITPR1 variants, suggesting this MRI finding could represent a hallmark for ITPR1-related disorders.
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5
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Lipid Dyshomeostasis and Inherited Cerebellar Ataxia. Mol Neurobiol 2022; 59:3800-3828. [PMID: 35420383 PMCID: PMC9148275 DOI: 10.1007/s12035-022-02826-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/01/2022] [Indexed: 12/04/2022]
Abstract
Cerebellar ataxia is a form of ataxia that originates from dysfunction of the cerebellum, but may involve additional neurological tissues. Its clinical symptoms are mainly characterized by the absence of voluntary muscle coordination and loss of control of movement with varying manifestations due to differences in severity, in the site of cerebellar damage and in the involvement of extracerebellar tissues. Cerebellar ataxia may be sporadic, acquired, and hereditary. Hereditary ataxia accounts for the majority of cases. Hereditary ataxia has been tentatively divided into several subtypes by scientists in the field, and nearly all of them remain incurable. This is mainly because the detailed mechanisms of these cerebellar disorders are incompletely understood. To precisely diagnose and treat these diseases, studies on their molecular mechanisms have been conducted extensively in the past. Accumulating evidence has demonstrated that some common pathogenic mechanisms exist within each subtype of inherited ataxia. However, no reports have indicated whether there is a common mechanism among the different subtypes of inherited cerebellar ataxia. In this review, we summarize the available references and databases on neurological disorders characterized by cerebellar ataxia and show that a subset of genes involved in lipid homeostasis form a new group that may cause ataxic disorders through a common mechanism. This common signaling pathway can provide a valuable reference for future diagnosis and treatment of ataxic disorders.
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6
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Schmitz EA, Takahashi H, Karakas E. Structural basis for activation and gating of IP 3 receptors. Nat Commun 2022; 13:1408. [PMID: 35301323 PMCID: PMC8930994 DOI: 10.1038/s41467-022-29073-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/24/2022] [Indexed: 12/29/2022] Open
Abstract
A pivotal component of the calcium (Ca2+) signaling toolbox in cells is the inositol 1,4,5-triphosphate (IP3) receptor (IP3R), which mediates Ca2+ release from the endoplasmic reticulum (ER), controlling cytoplasmic and organellar Ca2+ concentrations. IP3Rs are co-activated by IP3 and Ca2+, inhibited by Ca2+ at high concentrations, and potentiated by ATP. However, the underlying molecular mechanisms are unclear. Here we report cryo-electron microscopy (cryo-EM) structures of human type-3 IP3R obtained from a single dataset in multiple gating conformations: IP3-ATP bound pre-active states with closed channels, IP3-ATP-Ca2+ bound active state with an open channel, and IP3-ATP-Ca2+ bound inactive state with a closed channel. The structures demonstrate how IP3-induced conformational changes prime the receptor for activation by Ca2+, how Ca2+ binding leads to channel opening, and how ATP modulates the activity, providing insights into the long-sought questions regarding the molecular mechanism underpinning receptor activation and gating. IP3 receptors are intracellular calcium channels involved in numerous signaling pathways. Here, the authors present the cryo-EM structures of type-3 IP3 receptors in multiple gating conformations, including the active state revealing the molecular mechanism of the receptor activation.
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Affiliation(s)
- Emily A Schmitz
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA.,Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Hirohide Takahashi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA.,Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Erkan Karakas
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA. .,Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA.
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7
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Muñoz Cardona ML, López Mahecha JM. Gillespie’s Syndrome Phenotype in A Patient with a Homozygous Variant of Uncertain Significance in the ITPR1 Gene. Neuroophthalmology 2021; 46:186-189. [DOI: 10.1080/01658107.2021.1982991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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8
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Kinoshita A, Ohyama K, Tanimura S, Matsuda K, Kishino T, Negishi Y, Asahina N, Shiraishi H, Hosoki K, Tomiwa K, Ishihara N, Mishima H, Mori R, Nakashima M, Saitoh S, Yoshiura KI. Itpr1 regulates the formation of anterior eye segment tissues derived from neural crest cells. Development 2021; 148:271160. [PMID: 34338282 DOI: 10.1242/dev.188755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/19/2021] [Indexed: 01/23/2023]
Abstract
Mutations in ITPR1 cause ataxia and aniridia in individuals with Gillespie syndrome (GLSP). However, the pathogenic mechanisms underlying aniridia remain unclear. We identified a de novo GLSP mutation hotspot in the 3'-region of ITPR1 in five individuals with GLSP. Furthermore, RNA-sequencing and immunoblotting revealed an eye-specific transcript of Itpr1, encoding a 218amino acid isoform. This isoform is localized not only in the endoplasmic reticulum, but also in the nuclear and cytoplasmic membranes. Ocular-specific transcription was repressed by SOX9 and induced by MAF in the anterior eye segment (AES) tissues. Mice lacking seven base pairs of the last Itpr1 exon exhibited ataxia and aniridia, in which the iris lymphatic vessels, sphincter and dilator muscles, corneal endothelium and stroma were disrupted, but the neural crest cells persisted after completion of AES formation. Our analyses revealed that the 218-amino acid isoform regulated the directionality of actin fibers and the intensity of focal adhesion. The isoform might control the nuclear entry of transcriptional regulators, such as YAP. It is also possible that ITPR1 regulates both AES differentiation and muscle contraction in the iris.
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Affiliation(s)
- Akira Kinoshita
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
| | - Kaname Ohyama
- Department of Pharmacy Practice, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-3131, Japan
| | - Susumu Tanimura
- Department of Cell Regulation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-3131, Japan
| | - Katsuya Matsuda
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
| | - Tatsuya Kishino
- Gene Research Center, Center for Frontier Life Sciences, Nagasaki University, Nagasaki 852-8523, Japan
| | - Yutaka Negishi
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8602, Japan
| | - Naoko Asahina
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Kana Hosoki
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Osaka 594-1101, Japan
| | - Kiyotaka Tomiwa
- Department of Pediatrics, Todaiji Ryoiku Hospital for Children, Nara 630-8211, Japan
| | - Naoko Ishihara
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake 470-1192, Japan
| | - Hiroyuki Mishima
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
| | - Ryoichi Mori
- Department of Pathology, Nagasaki University School of Medicine and Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan
| | - Masahiro Nakashima
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8602, Japan
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki 852-8523, Japan
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9
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Woll KA, Van Petegem F. Calcium Release Channels: Structure and Function of IP3 Receptors and Ryanodine Receptors. Physiol Rev 2021; 102:209-268. [PMID: 34280054 DOI: 10.1152/physrev.00033.2020] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ca2+-release channels are giant membrane proteins that control the release of Ca2+ from the endoplasmic and sarcoplasmic reticulum. The two members, ryanodine receptors (RyRs) and inositol-1,4,5-trisphosphate Receptors (IP3Rs), are evolutionarily related and are both activated by cytosolic Ca2+. They share a common architecture, but RyRs have evolved additional modules in the cytosolic region. Their massive size allows for the regulation by tens of proteins and small molecules, which can affect the opening and closing of the channels. In addition to Ca2+, other major triggers include IP3 for the IP3Rs, and depolarization of the plasma membrane for a particular RyR subtype. Their size has made them popular targets for study via electron microscopic methods, with current structures culminating near 3Å. The available structures have provided many new mechanistic insights int the binding of auxiliary proteins and small molecules, how these can regulate channel opening, and the mechanisms of disease-associated mutations. They also help scrutinize previously proposed binding sites, as some of these are now incompatible with the structures. Many questions remain around the structural effects of post-translational modifications, additional binding partners, and the higher-order complexes these channels can make in situ. This review summarizes our current knowledge about the structures of Ca2+-release channels and how this informs on their function.
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Affiliation(s)
- Kellie A Woll
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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10
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Keehan L, Jiang MM, Li X, Marom R, Dai H, Murdock D, Liu P, Hunter JV, Heaney JD, Robak L, Emrick L, Lotze T, Blieden LS, Lewis RA, Levin AV, Capasso J, Craigen WJ, Rosenfeld JA, Lee B, Burrage LC. A novel de novo intronic variant in ITPR1 causes Gillespie syndrome. Am J Med Genet A 2021; 185:2315-2324. [PMID: 33949769 DOI: 10.1002/ajmg.a.62232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/01/2021] [Indexed: 11/07/2022]
Abstract
Gillespie syndrome (GLSP) is characterized by bilateral symmetric partial aplasia of the iris presenting as a fixed and large pupil, cerebellar hypoplasia with ataxia, congenital hypotonia, and varying levels of intellectual disability. GLSP is caused by either biallelic or heterozygous, dominant-negative, pathogenic variants in ITPR1. Here, we present a 5-year-old male with GLSP who was found to have a heterozygous, de novo intronic variant in ITPR1 (NM_001168272.1:c.5935-17G > A) through genome sequencing (GS). Sanger sequencing of cDNA from this individual's fibroblasts showed the retention of 15 nucleotides from intron 45, which is predicted to cause an in-frame insertion of five amino acids near the C-terminal transmembrane domain of ITPR1. In addition, qPCR and cDNA sequencing demonstrated reduced expression of both ITPR1 alleles in fibroblasts when compared to parental samples. Given the close proximity of the predicted in-frame amino acid insertion to the site of previously described heterozygous, de novo, dominant-negative, pathogenic variants in GLSP, we predict that this variant also has a dominant-negative effect on ITPR1 channel function. Overall, this is the first report of a de novo intronic variant causing GLSP, which emphasizes the utility of GS and cDNA studies for diagnosing patients with a clinical presentation of GLSP and negative clinical exome sequencing.
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Affiliation(s)
- Laura Keehan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Ming-Ming Jiang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Xiaohui Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - David Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Baylor Genetics, Houston, Texas, USA
| | - Jill V Hunter
- Texas Children's Hospital, Houston, Texas, USA.,Department of Radiology, Baylor College of Medicine, Houston, Texas, USA
| | - Jason D Heaney
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Laurie Robak
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Lisa Emrick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine (BCM), Houston, Texas, USA.,Division of Neurology and Developmental Neuroscience, Department of Pediatrics, BCM, Houston, Texas, USA
| | - Timothy Lotze
- Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine (BCM), Houston, Texas, USA.,Division of Neurology and Developmental Neuroscience, Department of Pediatrics, BCM, Houston, Texas, USA
| | - Lauren S Blieden
- Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Richard Alan Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
| | - Alex V Levin
- Flaum Eye Institute and Golisano Children's Hospital, Departments of Ophthalmology and Pediatrics, University of Rochester, Rochester, New York, USA
| | - Jenina Capasso
- Flaum Eye Institute and Golisano Children's Hospital, Departments of Ophthalmology and Pediatrics, University of Rochester, Rochester, New York, USA
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
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11
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Terry LE, Alzayady KJ, Wahl AM, Malik S, Yule DI. Disease-associated mutations in inositol 1,4,5-trisphosphate receptor subunits impair channel function. J Biol Chem 2020; 295:18160-18178. [PMID: 33093175 PMCID: PMC7939385 DOI: 10.1074/jbc.ra120.015683] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/21/2020] [Indexed: 01/27/2023] Open
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs), which form tetrameric channels, play pivotal roles in regulating the spatiotemporal patterns of intracellular calcium signals. Mutations in IP3Rs have been increasingly associated with many debilitating human diseases such as ataxia, Gillespie syndrome, and generalized anhidrosis. However, how these mutations affect IP3R function, and how the perturbation of as-sociated calcium signals contribute to the pathogenesis and severity of these diseases remains largely uncharacterized. Moreover, many of these diseases occur as the result of autosomal dominant inheritance, suggesting that WT and mutant subunits associate in heterotetrameric channels. How the in-corporation of different numbers of mutant subunits within the tetrameric channels affects its activities and results in different disease phenotypes is also unclear. In this report, we investigated representative disease-associated missense mutations to determine their effects on IP3R channel activity. Additionally, we designed concatenated IP3R constructs to create tetrameric channels with a predefined subunit composition to explore the functionality of heteromeric channels. Using calcium imaging techniques to assess IP3R channel function, we observed that all the mutations studied resulted in severely attenuated Ca2+ release when expressed as homotetramers. However, some heterotetramers retained varied degrees of function dependent on the composition of the tetramer. Our findings suggest that the effect of mutations depends on the location of the mutation in the IP3R structure, as well as on the stoichiometry of mutant subunits assembled within the tetrameric channel. These studies provide insight into the pathogenesis and penetrance of these devastating human diseases.
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Affiliation(s)
- Lara E Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Amanda M Wahl
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, USA.
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12
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Clinical and Genetic Overview of Paroxysmal Movement Disorders and Episodic Ataxias. Int J Mol Sci 2020; 21:ijms21103603. [PMID: 32443735 PMCID: PMC7279391 DOI: 10.3390/ijms21103603] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/15/2022] Open
Abstract
Paroxysmal movement disorders (PMDs) are rare neurological diseases typically manifesting with intermittent attacks of abnormal involuntary movements. Two main categories of PMDs are recognized based on the phenomenology: Paroxysmal dyskinesias (PxDs) are characterized by transient episodes hyperkinetic movement disorders, while attacks of cerebellar dysfunction are the hallmark of episodic ataxias (EAs). From an etiological point of view, both primary (genetic) and secondary (acquired) causes of PMDs are known. Recognition and diagnosis of PMDs is based on personal and familial medical history, physical examination, detailed reconstruction of ictal phenomenology, neuroimaging, and genetic analysis. Neurophysiological or laboratory tests are reserved for selected cases. Genetic knowledge of PMDs has been largely incremented by the advent of next generation sequencing (NGS) methodologies. The wide number of genes involved in the pathogenesis of PMDs reflects a high complexity of molecular bases of neurotransmission in cerebellar and basal ganglia circuits. In consideration of the broad genetic and phenotypic heterogeneity, a NGS approach by targeted panel for movement disorders, clinical or whole exome sequencing should be preferred, whenever possible, to a single gene approach, in order to increase diagnostic rate. This review is focused on clinical and genetic features of PMDs with the aim to (1) help clinicians to recognize, diagnose and treat patients with PMDs as well as to (2) provide an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.
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Inositol 1,4,5-Trisphosphate Receptors in Human Disease: A Comprehensive Update. J Clin Med 2020; 9:jcm9041096. [PMID: 32290556 PMCID: PMC7231134 DOI: 10.3390/jcm9041096] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/30/2020] [Accepted: 04/10/2020] [Indexed: 12/22/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (ITPRs) are intracellular calcium release channels located on the endoplasmic reticulum of virtually every cell. Herein, we are reporting an updated systematic summary of the current knowledge on the functional role of ITPRs in human disorders. Specifically, we are describing the involvement of its loss-of-function and gain-of-function mutations in the pathogenesis of neurological, immunological, cardiovascular, and neoplastic human disease. Recent results from genome-wide association studies are also discussed.
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Chen B, Qi CY, Chen L, Dai MJ, Miao YY, Chen R, Wei WE, Yang S, Wang HL, Duan XG, Gong MW, Wang Y, Xue ZF. A C1976Y missense mutation in the mouse Ip3r1 gene leads to short-term mydriasis and unfolded protein response in the iris constrictor muscles. Exp Anim 2019; 69:45-53. [PMID: 31391379 PMCID: PMC7004804 DOI: 10.1538/expanim.19-0007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ip3r1 encodes an inositol 1,4,5-trisphosphate-responsive calcium
channel. Mutations in the IP3R1 gene in humans may cause Gillespie
syndrome (GS) typically presents as fixed dilated pupils in affected infants, which was
referred to as iris hypoplasia. However, there is no report of mice with
Ip3r1 heterozygous mutations showing dilated pupils. Here, we report a
new Ip3r1 allele with short-term dilated pupil phenotype derived from an
N-ethyl-N-nitrosourea (ENU) mutagenesis screen. This allele carries a G5927A transition
mutation in Ip3r1 gene (NM_010585), which is predicted to result in a
C1976Y amino acid change in the open reading frame of IP3R1 (NP_034715). We named this
novel Ip3r1 allele Ip3r1C1976Y. Histology and
pharmacological tests show that the dilated pupil phenotype is a mydriasis caused by the
functional defect in the iris constrictor muscles in
Ip3r1C1976Y. The dilated pupil phenotype in
Ip3r1C1976Y was referred to as mydriasis and excluding
iris hypoplasia. IHC analysis revealed increased expression of BIP protein, the master
regulator of unfolded protein response (UPR) signaling, in
Ip3r1C1976Y mice that did not recover. This study is the
first report of an Ip3r1 mutation being associated with the mydriasis
phenotype. Ip3r1C1976Y mice represent a self-healing model
that may be used to study the therapeutic approach for Ip3r1-related
diseases.
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Affiliation(s)
- Bing Chen
- Institute of Comparative Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Chong-Yang Qi
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Li Chen
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Meng-Jun Dai
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Ya-You Miao
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Rui Chen
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Wan-E Wei
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Shun Yang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Hong-Ling Wang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Xiao-Ge Duan
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Min-Wei Gong
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Yi Wang
- College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
| | - Zheng-Feng Xue
- Institute of Comparative Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,College of Veterinary Medicine, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 12 Wenhui East Road, Yangzhou, Jiangsu Province 225009, P.R.China
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15
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Nicita F, Nardella M, Bellacchio E, Alfieri P, Terrone G, Piccini G, Graziola F, Pignata C, Capuano A, Bertini E, Zanni G. Heterozygous missense variants of SPTBN2 are a frequent cause of congenital cerebellar ataxia. Clin Genet 2019; 96:169-175. [PMID: 31066025 DOI: 10.1111/cge.13562] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/02/2019] [Accepted: 05/04/2019] [Indexed: 11/30/2022]
Abstract
Heterozygous missense variants in the SPTBN2 gene, encoding the non-erythrocytic beta spectrin 2 subunit (beta-III spectrin), have been identified in autosomal dominant spinocerebellar ataxia type 5 (SCA5), a rare adult-onset neurodegenerative disorder characterized by progressive cerebellar ataxia, whereas homozygous loss of function variants in SPTBN2 have been associated with early onset cerebellar ataxia and global developmental delay (SCAR14). Recently, heterozygous SPTBN2 missense variants have been identified in a few patients with an early-onset ataxic phenotype. We report five patients with non-progressive congenital ataxia and psychomotor delay, 4/5 harboring novel heterozygous missense variants in SPTBN2 and one patient with compound heterozygous SPTBN2 variants. With an overall prevalence of 5% in our cohort of unrelated patients screened by targeted next-generation sequencing (NGS) for congenital or early-onset cerebellar ataxia, this study indicates that both dominant and recessive mutations of SPTBN2 together with CACNA1A and ITPR1, are a frequent cause of early-onset/congenital non-progressive ataxia and that their screening should be implemented in this subgroup of disorders.
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Affiliation(s)
- Francesco Nicita
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Marta Nardella
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Emanuele Bellacchio
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, Rome, Italy
| | - Paolo Alfieri
- Unit of Child Neuropsychiatry, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Gaetano Terrone
- Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Giorgia Piccini
- Unit of Child Neuropsychiatry, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Federica Graziola
- Unit of Neurology, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Claudio Pignata
- Department of Translational Medical Sciences, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Alessandro Capuano
- Unit of Neurology, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Enrico Bertini
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
| | - Ginevra Zanni
- Unit of Muscular and Neurodegenerative Diseases, Department of Neurosciences, Bambino Gesù Children's Hospital, Rome, Italy
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Aberrant IP 3 receptor activities revealed by comprehensive analysis of pathological mutations causing spinocerebellar ataxia 29. Proc Natl Acad Sci U S A 2018; 115:12259-12264. [PMID: 30429331 DOI: 10.1073/pnas.1811129115] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Spinocerebellar ataxia type 29 (SCA29) is autosomal dominant congenital ataxia characterized by early-onset motor delay, hypotonia, and gait ataxia. Recently, heterozygous missense mutations in an intracellular Ca2+ channel, inositol 1,4,5-trisphosphate (IP3) receptor type 1 (IP3R1), were identified as a cause of SCA29. However, the functional impacts of these mutations remain largely unknown. Here, we determined the molecular mechanisms by which pathological mutations affect IP3R1 activity and Ca2+ dynamics. Ca2+ imaging using IP3R-null HeLa cells generated by genome editing revealed that all SCA29 mutations identified within or near the IP3-binding domain of IP3R1 completely abolished channel activity. Among these mutations, R241K, T267M, T267R, R269G, R269W, S277I, K279E, A280D, and E497K impaired IP3 binding to IP3R1, whereas the T579I and N587D mutations disrupted channel activity without affecting IP3 binding, suggesting that T579I and N587D compromise channel gating mechanisms. Carbonic anhydrase-related protein VIII (CA8) is an IP3R1-regulating protein abundantly expressed in cerebellar Purkinje cells and is a causative gene of congenital ataxia. The SCA29 mutation V1538M within the CA8-binding site of IP3R1 completely eliminated its interaction with CA8 and CA8-mediated IP3R1 inhibition. Furthermore, pathological mutations in CA8 decreased CA8-mediated suppression of IP3R1 by reducing protein stability and the interaction with IP3R1. These results demonstrated the mechanisms by which pathological mutations cause IP3R1 dysfunction, i.e., the disruption of IP3 binding, IP3-mediated gating, and regulation via the IP3R-modulatory protein. The resulting aberrant Ca2+ homeostasis may contribute to the pathogenesis of cerebellar ataxia.
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17
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De Silva D, Williamson KA, Dayasiri KC, Suraweera N, Quinters V, Abeysekara H, Wanigasinghe J, De Silva D, De Silva H. Gillespie syndrome in a South Asian child: a case report with confirmation of a heterozygous mutation of the ITPR1 gene and review of the clinical and molecular features. BMC Pediatr 2018; 18:308. [PMID: 30249237 PMCID: PMC6154888 DOI: 10.1186/s12887-018-1286-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 09/17/2018] [Indexed: 01/15/2023] Open
Abstract
Background Gillespie syndrome is a rare, congenital, neurological disorder characterized by the association of partial bilateral aniridia, non-progressive cerebellar ataxia and intellectual disability. Homozygous and heterozygous pathogenic variants of the ITPR1 gene encoding an inositol 1, 4, 5- triphosphate- responsive calcium channel have been identified in 13 patients recently. There have been 22 cases reported in the literature by 2016, mostly from the western hemisphere with none reported from Sri Lanka. Case presentation A 10-year-old girl born to healthy non-consanguineous parents with delayed development is described. She started walking unaided by 9 years with a significantly unsteady gait and her speech was similarly delayed. Physical examination revealed multiple cerebellar signs. Slit lamp examination of eyes revealed bilateral partial aniridia. Magnetic resonance imaging of brain at the age of 10 years revealed cerebellar (mainly vermian) hypoplasia. Genetic testing confirmed the clinical suspicion and demonstrated a heterozygous pathogenic variant c.7786_7788delAAG p.(Lys2596del) in the ITPR1 gene. Conclusion The report of this child with molecular confirmation of Gillespie syndrome highlights the need for careful evaluation of ophthalmological and neurological features in patients that enables correct clinical diagnosis. The availability of genetic testing enables more accurate counseling of the parents and patients regarding recurrence risks to other family members.
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Affiliation(s)
- Daham De Silva
- Department of Paediatrics, Faculty of Medicine, University of Colombo, Colombo, 8, Sri Lanka
| | - Kathleen A Williamson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | | | - Nayani Suraweera
- Professorial Paediatric Unit, Lady Ridgeway Hospital for Children, Colombo, 08, Sri Lanka
| | - Vinushiya Quinters
- Professorial Paediatric Unit, Lady Ridgeway Hospital for Children, Colombo, 08, Sri Lanka
| | - Hiranya Abeysekara
- Department of Ophthalmology, Lady Ridgeway Hospital for Children, Colombo, 08, Sri Lanka
| | - Jithangi Wanigasinghe
- Department of Paediatrics, Faculty of Medicine, University of Colombo, Colombo, 8, Sri Lanka
| | - Deepthi De Silva
- Department of Physiology, Faculty of Medicine, University of Kelaniya, Kelaniya, Sri Lanka.
| | - Harendra De Silva
- Department of Paediatrics, Faculty of Medicine, University of Colombo, Colombo, 8, Sri Lanka
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18
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The genetic architecture of aniridia and Gillespie syndrome. Hum Genet 2018; 138:881-898. [PMID: 30242502 PMCID: PMC6710220 DOI: 10.1007/s00439-018-1934-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 09/06/2018] [Indexed: 12/13/2022]
Abstract
Absence of part or all of the iris, aniridia, is a feature of several genetically distinct conditions. This review focuses on iris development and then the clinical features and molecular genetics of these iris malformations. Classical aniridia, a panocular eye malformation including foveal hypoplasia, is the archetypal phenotype associated with heterozygous PAX6 loss-of-function mutations. Since this was identified in 1991, many genetic mechanisms of PAX6 inactivation have been elucidated, the commonest alleles being intragenic mutations causing premature stop codons, followed by those causing C-terminal extensions. Rarely, aniridia cases are associated with FOXC1, PITX2 and/or their regulatory regions. Aniridia can also occur as a component of many severe global eye malformations. Gillespie syndrome—a triad of partial aniridia, non-progressive cerebellar ataxia and intellectual disability—is phenotypically and genotypically distinct from classical aniridia. The causative gene has recently been identified as ITPR1. The same characteristic Gillespie syndrome-like iris, with aplasia of the pupillary sphincter and a scalloped margin, is seen in ACTA2-related multisystemic smooth muscle dysfunction syndrome. WAGR syndrome (Wilms tumour, aniridia, genitourinary anomalies and mental retardation/intellectual disability), is caused by contiguous deletion of PAX6 and WT1 on chromosome 11p. Deletions encompassing BDNF have been causally implicated in the obesity and intellectual disability associated with the condition. Lastly, we outline a genetic investigation strategy for aniridia in light of recent developments, suggesting an approach based principally on chromosomal array and gene panel testing. This strategy aims to test all known aniridia loci—including the rarer, life-limiting causes—whilst remaining simple and practical.
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19
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Pathophysiological consequences of isoform-specific IP 3 receptor mutations. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1707-1717. [PMID: 29906486 DOI: 10.1016/j.bbamcr.2018.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 06/06/2018] [Accepted: 06/11/2018] [Indexed: 12/11/2022]
Abstract
Ca2+ signaling governs a diverse range of cellular processes and, as such, is subject to tight regulation. A main component of the complex intracellular Ca2+-signaling network is the inositol 1,4,5-trisphosphate (IP3) receptor (IP3R), a tetrameric channel that mediates Ca2+ release from the endoplasmic reticulum (ER) in response to IP3. IP3R function is controlled by a myriad of factors, such as Ca2+, ATP, kinases and phosphatases and a plethora of accessory and regulatory proteins. Further complexity in IP3R-mediated Ca2+ signaling is the result of the existence of three main isoforms (IP3R1, IP3R2 and IP3R3) that display distinct functional characteristics and properties. Despite their abundant and overlapping expression profiles, IP3R1 is highly expressed in neurons, IP3R2 in cardiomyocytes and hepatocytes and IP3R3 in rapidly proliferating cells as e.g. epithelial cells. As a consequence, dysfunction and/or dysregulation of IP3R isoforms will have distinct pathophysiological outcomes, ranging from neurological disorders for IP3R1 to dysfunctional exocrine tissues and autoimmune diseases for IP3R2 and -3. Over the past years, several IP3R mutations have surfaced in the sequence analysis of patient-derived samples. Here, we aimed to provide an integrative overview of the clinically most relevant mutations for each IP3R isoform and the subsequent molecular mechanisms underlying the etiology of the disease.
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20
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Terry LE, Alzayady KJ, Furati E, Yule DI. Inositol 1,4,5-trisphosphate Receptor Mutations associated with Human Disease. MESSENGER (LOS ANGELES, CALIF. : PRINT) 2018; 6:29-44. [PMID: 30197841 PMCID: PMC6128530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Calcium release into the cytosol via the inositol 1,4,5-trisphosphate receptor (IP3R) calcium channel is important for a variety of cellular processes. As a result, impairment or inhibition of this release can result in disease. Recently, mutations in all four domains of the IP3R have been suggested to cause diseases such as ataxia, cancer, and anhidrosis; however, most of these mutations have not been functionally characterized. In this review we summarize the reported mutations, as well as the associated symptoms. Additionally, we use clues from transgenic animals, receptor stoichiometry, and domain location of mutations to speculate on the effects of individual mutations on receptor structure and function and the overall mechanism of disease.
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Affiliation(s)
- Lara E Terry
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Esraa Furati
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - David I Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
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21
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Paganini L, Pesenti C, Milani D, Fontana L, Motta S, Sirchia SM, Scuvera G, Marchisio P, Esposito S, Cinnante CM, Tabano SM, Miozzo MR. A novel splice site variant in ITPR1
gene underlying recessive Gillespie syndrome. Am J Med Genet A 2018; 176:1427-1431. [DOI: 10.1002/ajmg.a.38704] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/06/2018] [Accepted: 03/15/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Leda Paganini
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Chiara Pesenti
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Donatella Milani
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Laura Fontana
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Silvia Motta
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Silvia Maria Sirchia
- Medical Genetics, Department of Health Sciences; Università degli Studi di Milano; Italy
| | - Giulietta Scuvera
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Paola Marchisio
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences; Università degli Studi di Perugia; Italy
| | - Claudia Maria Cinnante
- Neuroradiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
| | - Silvia Maria Tabano
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
| | - Monica Rosa Miozzo
- Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Milano Italy
- Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Italy
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22
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Egorova PA, Bezprozvanny IB. Inositol 1,4,5-trisphosphate receptors and neurodegenerative disorders. FEBS J 2018; 285:3547-3565. [PMID: 29253316 DOI: 10.1111/febs.14366] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/27/2017] [Accepted: 12/12/2017] [Indexed: 12/15/2022]
Abstract
The inositol 1,4,5-trisphosphate receptor (IP3 R) is an intracellular ion channel that mediates the release of calcium ions from the endoplasmic reticulum. It plays a role in basic biological functions, such as cell division, differentiation, fertilization and cell death, and is involved in developmental processes including learning, memory and behavior. Deregulation of neuronal calcium signaling results in disturbance of cell homeostasis, synaptic loss and dysfunction, eventually leading to cell death. Three IP3 R subtypes have been identified in mammalian cells and the predominant isoform in neurons is IP3 R type 1. Dysfunction of IP3 R type 1 may play a role in the pathogenesis of certain neurodegenerative diseases as enhanced activity of the IP3 R was observed in models of Huntington's disease, spinocerebellar ataxias and Alzheimer's disease. These results suggest that IP3 R-mediated signaling is a potential target for treatment of these disorders. In this review we discuss the structure, functions and regulation of the IP3 R in healthy neurons and in conditions of neurodegeneration.
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Affiliation(s)
- Polina A Egorova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St Petersburg, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St Petersburg, Russia.,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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23
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Bertini E, Zanni G, Boltshauser E. Nonprogressive congenital ataxias. HANDBOOK OF CLINICAL NEUROLOGY 2018; 155:91-103. [PMID: 29891079 DOI: 10.1016/b978-0-444-64189-2.00006-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The terminology of nonprogressive congenital ataxia (NPCA) refers to a clinically and genetically heterogeneous group of disorders characterized by congenital or early-onset ataxia, but no progression or even improvement on follow-up. Ataxia is preceded by muscular hypotonia and delayed motor (and usually language) milestones. We exclude children with prenatal, perinatal, and postnatal acquired diseases, malformations other than cerebellar hypoplasia, and defined syndromic disorders. Patients with NPCA have a high prevalence of cognitive and language impairments, in addition to increased occurrence of seizures, ocular signs (nystagmus, strabismus), behavior changes, and microcephaly. Neuroimaging is variable, ranging from normal cerebellar anatomy to reduced cerebellar volume (hypoplasia in the proper sense), and enlarged interfolial spaces, potentially mimicking atrophy. The latter appearance is often called "hypoplasia" as well, in view of the static clinical course. Some patients had progressive enlargement of cerebellar fissures, but a nonprogressive course. There is no imaging-clinical-genetic correlation. Dominant, recessive, and X-linked inheritance is documented for NPCA. Here, we focus on the still rather short list of dominant and recessive genes associated with NPCA, identified in the last few years. With future advances in genetics, we expect a rapid expansion of knowledge in this field.
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Affiliation(s)
- Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu' Children's Research Hospital, Rome, Italy.
| | - Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesu' Children's Research Hospital, Rome, Italy
| | - Eugen Boltshauser
- Department of Pediatric Neurology, University Children's Hospital, University of Zurich, Zurich, Switzerland
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