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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [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: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Ames JB. Structural basis of retinal membrane guanylate cyclase regulation by GCAP1 and RD3. Front Mol Neurosci 2022; 15:988142. [PMID: 36157073 PMCID: PMC9493048 DOI: 10.3389/fnmol.2022.988142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Retinal membrane guanylate cyclases (RetGC1 and RetGC2) are expressed in photoreceptor rod and cone cells, where they promote the onset of visual recovery during phototransduction. The catalytic activity of RetGCs is regulated by their binding to regulatory proteins, guanylate cyclase activating proteins (GCAP1-5) and the retinal degeneration 3 protein (RD3). RetGC1 is activated by its binding to Ca2+-free/Mg2+-bound GCAP1 at low cytosolic Ca2+ levels in light-activated photoreceptors. By contrast, RetGC1 is inactivated by its binding to Ca2+-bound GCAP1 and/or RD3 at elevated Ca2+ levels in dark-adapted photoreceptors. The Ca2+ sensitive cyclase activation helps to replenish the cytosolic cGMP levels in photoreceptors during visual recovery. Mutations in RetGC1, GCAP1 or RD3 that disable the Ca2+-dependent regulation of cyclase activity are genetically linked to rod/cone dystrophies and other inherited forms of blindness. Here I review the structural interaction of RetGC1 with GCAP1 and RD3. I propose a two-state concerted model in which the dimeric RetGC1 allosterically switches between active and inactive conformational states with distinct quaternary structures that are oppositely stabilized by the binding of GCAP1 and RD3. The binding of Ca2+-free/Mg2+-bound GCAP1 is proposed to activate the cyclase by stabilizing RetGC1 in an active conformation (R-state), whereas Ca2+-bound GCAP1 and/or RD3 inhibit the cyclase by locking RetGC1 in an inactive conformation (T-state). Exposed hydrophobic residues in GCAP1 (residues H19, Y22, M26, F73, V77, W94) are essential for cyclase activation and could be targeted by rational drug design for the possible treatment of rod/cone dystrophies.
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The Clinical Spectrum and Disease Course of DRAM2 Retinopathy. Int J Mol Sci 2022; 23:ijms23137398. [PMID: 35806404 PMCID: PMC9266529 DOI: 10.3390/ijms23137398] [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: 05/31/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 11/26/2022] Open
Abstract
Pathogenic variants in DNA-damage regulated autophagy modulator 2 gene (DRAM2) cause a rare autosomal recessive retinal dystrophy and its disease course is not well understood. We present two Slovenian patients harboring a novel DRAM2 variant and a detailed review of all 23 other patients described to date. Whole exome and whole genome sequencing were performed in the two patients, and both underwent ophthalmological examination with a 2-year follow-up. PubMed was searched for papers with clinical descriptions of DRAM2 retinopathy. Patient 1 was homozygous for a novel variant, p.Met1?, and presented with the acute onset of photopsia and retina-wide retinopathy at the age of 35 years. The patient was first thought to have an autoimmune retinopathy and was treated with mycophenolate mofetil, which provided some symptomatic relief. Patient 2 was compound heterozygous for p.Met1? and p.Leu246Pro and presented with late-onset maculopathy at the age of 59 years. On review, patients with DRAM2 retinopathy usually present in the third decade with central visual loss, outer retinal layer loss on optical coherence tomography and a hyperautofluorescent ring on fundus autofluorescence. Either cone–rod or rod–cone dystrophy phenotype is observed on electroretinography, reflecting the importance of DRAM2 in both photoreceptor types. Non-null variants can result in milder disease.
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Zhang J, Wu J, Lu D, To CH, Lam TC, Lin B. Retinal Proteomic Analysis in a Mouse Model of Endotoxin-Induced Uveitis Using Data-Independent Acquisition-Based Mass Spectrometry. Int J Mol Sci 2022; 23:ijms23126464. [PMID: 35742911 PMCID: PMC9223489 DOI: 10.3390/ijms23126464] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/24/2022] [Accepted: 06/07/2022] [Indexed: 02/04/2023] Open
Abstract
Uveitis is a group of sight-threatening ocular inflammatory diseases, potentially leading to permanent vision loss in patients. However, it remains largely unknown how uveitis causes retinal malfunction and vision loss. Endotoxin-induced uveitis (EIU) in rodents is a good animal model to study uveitis and associated acute retinal inflammation. To understand the pathogenic mechanism of uveitis and screen potential targets for treatment, we analyzed the retinal proteomic profile of the EIU mouse model using a data-independent acquisition-based mass spectrometry (SWATH-MS). After systemic LPS administration, we observed activation of microglial cells accompanied with the elevation of pro-inflammatory mediators and visual function declines. In total, we observed 79 upregulated and 90 downregulated differentially expressed proteins (DEPs). Among the DEPs, we found that histone family members (histone H1, H2A, H2B) and blood proteins including haptoglobin (HP), hemopexin (HPX), and fibrinogen gamma chain (FGG) were dramatically increased in EIU groups relative to those in control groups. We identified phototransduction and synaptic vesicle cycle as the top two significant KEGG pathways. Moreover, canonical pathway analysis on DEPs using Ingenuity Pathway Analysis revealed top three most significant enriched pathways related to acute phase response signaling, synaptogenesis signaling, and eif2 signaling. We further confirmed upregulation of several DEPs associated with the acute phase response signaling including HP, HPX, and FGG in LPS-treated retinas by qPCR and Western blot. In summary, this study serves as the first report to detect retinal proteome changes in the EIU model. The study provides several potential candidates for exploring the mechanism and novel therapeutic targets for uveitis and other retinal inflammatory diseases.
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Affiliation(s)
- Jing Zhang
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
| | - Jiangmei Wu
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
| | - Daqian Lu
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
| | - Chi-Ho To
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
- Centre for Eye and Vision Research (CEVR), Hong Kong SAR, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Thomas Chuen Lam
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
- Centre for Eye and Vision Research (CEVR), Hong Kong SAR, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong SAR, China
- Correspondence: (T.C.L.); (B.L.)
| | - Bin Lin
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China; (J.Z.); (J.W.); (D.L.); (C.-H.T.)
- Centre for Eye and Vision Research (CEVR), Hong Kong SAR, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong SAR, China
- Correspondence: (T.C.L.); (B.L.)
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Avesani A, Bielefeld L, Weisschuh N, Marino V, Mazzola P, Stingl K, Haack TB, Koch KW, Dell’Orco D. Molecular Properties of Human Guanylate Cyclase-Activating Protein 3 (GCAP3) and Its Possible Association with Retinitis Pigmentosa. Int J Mol Sci 2022; 23:ijms23063240. [PMID: 35328663 PMCID: PMC8948881 DOI: 10.3390/ijms23063240] [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: 02/21/2022] [Revised: 03/12/2022] [Accepted: 03/15/2022] [Indexed: 11/17/2022] Open
Abstract
The cone-specific guanylate cyclase-activating protein 3 (GCAP3), encoded by the GUCA1C gene, has been shown to regulate the enzymatic activity of membrane-bound guanylate cyclases (GCs) in bovine and teleost fish photoreceptors, to an extent comparable to that of the paralog protein GCAP1. To date, the molecular mechanisms underlying GCAP3 function remain largely unexplored. In this work, we report a thorough characterization of the biochemical and biophysical properties of human GCAP3, moreover, we identified an isolated case of retinitis pigmentosa, in which a patient carried the c.301G>C mutation in GUCA1C, resulting in the substitution of a highly conserved aspartate residue by a histidine (p.(D101H)). We found that myristoylated GCAP3 can activate GC1 with a similar Ca2+-dependent profile, but significantly less efficiently than GCAP1. The non-myristoylated form did not induce appreciable regulation of GC1, nor did the p.D101H variant. GCAP3 forms dimers under physiological conditions, but at odds with its paralogs, it tends to form temperature-dependent aggregates driven by hydrophobic interactions. The peculiar properties of GCAP3 were confirmed by 2 ms molecular dynamics simulations, which for the p.D101H variant highlighted a very high structural flexibility and a clear tendency to lose the binding of a Ca2+ ion to EF3. Overall, our data show that GCAP3 has unusual biochemical properties, which make the protein significantly different from GCAP1 and GCAP2. Moreover, the newly identified point mutation resulting in a substantially unfunctional protein could trigger retinitis pigmentosa through a currently unknown mechanism.
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Affiliation(s)
- Anna Avesani
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (A.A.); (V.M.)
| | - Laura Bielefeld
- Division of Biochemistry, Department of Neuroscience, University of Oldenburg, 26111 Oldenburg, Germany; (L.B.); (K.-W.K.)
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany;
| | - Valerio Marino
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (A.A.); (V.M.)
| | - Pascale Mazzola
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany; (P.M.); (T.B.H.)
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany;
| | - Tobias B. Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany; (P.M.); (T.B.H.)
- Centre for Rare Diseases, University of Tübingen, 72076 Tübingen, Germany
| | - Karl-Wilhelm Koch
- Division of Biochemistry, Department of Neuroscience, University of Oldenburg, 26111 Oldenburg, Germany; (L.B.); (K.-W.K.)
| | - Daniele Dell’Orco
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (A.A.); (V.M.)
- Correspondence: ; Tel.: +39-045-802-7637
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Structural Insights into Retinal Guanylate Cyclase Activator Proteins (GCAPs). Int J Mol Sci 2021; 22:ijms22168731. [PMID: 34445435 PMCID: PMC8395740 DOI: 10.3390/ijms22168731] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Retinal guanylate cyclases (RetGCs) promote the Ca2+-dependent synthesis of cGMP that coordinates the recovery phase of visual phototransduction in retinal rods and cones. The Ca2+-sensitive activation of RetGCs is controlled by a family of photoreceptor Ca2+ binding proteins known as guanylate cyclase activator proteins (GCAPs). The Mg2+-bound/Ca2+-free GCAPs bind to RetGCs and activate cGMP synthesis (cyclase activity) at low cytosolic Ca2+ levels in light-activated photoreceptors. By contrast, Ca2+-bound GCAPs bind to RetGCs and inactivate cyclase activity at high cytosolic Ca2+ levels found in dark-adapted photoreceptors. Mutations in both RetGCs and GCAPs that disrupt the Ca2+-dependent cyclase activity are genetically linked to various retinal diseases known as cone-rod dystrophies. In this review, I will provide an overview of the known atomic-level structures of various GCAP proteins to understand how protein dimerization and Ca2+-dependent conformational changes in GCAPs control the cyclase activity of RetGCs. This review will also summarize recent structural studies on a GCAP homolog from zebrafish (GCAP5) that binds to Fe2+ and may serve as a Fe2+ sensor in photoreceptors. The GCAP structures reveal an exposed hydrophobic surface that controls both GCAP1 dimerization and RetGC binding. This exposed site could be targeted by therapeutics designed to inhibit the GCAP1 disease mutants, which may serve to mitigate the onset of retinal cone-rod dystrophies.
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Avesani A, Marino V, Zanzoni S, Koch KW, Dell'Orco D. Molecular properties of human guanylate cyclase-activating protein 2 (GCAP2) and its retinal dystrophy-associated variant G157R. J Biol Chem 2021; 296:100619. [PMID: 33812995 PMCID: PMC8113879 DOI: 10.1016/j.jbc.2021.100619] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 12/31/2022] Open
Abstract
In murine and bovine photoreceptors, guanylate cyclase-activating protein 2 (GCAP2) activates retinal guanylate cyclases (GCs) at low Ca2+ levels, thus contributing to the Ca2+/cGMP negative feedback on the cyclase together with its paralog guanylate cyclase-activating protein 1, which has the same function but different Ca2+ sensitivity. In humans, a GCAP2 missense mutation (G157R) has been associated with inherited retinal degeneration (IRD) via an unknown molecular mechanism. Here, we characterized the biochemical properties of human GCAP2 and the G157R variant, focusing on its dimerization and the Ca2+/Mg2+-binding processes in the presence or absence of N-terminal myristoylation. We found that human GCAP2 and its bovine/murine orthologs significantly differ in terms of oligomeric properties, cation binding, and GC regulation. Myristoylated GCAP2 endothermically binds up to 3 Mg2+ with high affinity and forms a compact dimer that may reversibly dissociate in the presence of Ca2+. Conversely, nonmyristoylated GCAP2 does not bind Mg2+ over the physiological range and remains as a monomer in the absence of Ca2+. Both myristoylated and nonmyristoylated GCAP2 bind Ca2+ with high affinity. At odds with guanylate cyclase-activating protein 1 and independently of myristoylation, human GCAP2 does not significantly activate retinal GC1 in a Ca2+-dependent fashion. The IRD-associated G157R variant is characterized by a partly misfolded, molten globule-like conformation with reduced affinity for cations and prone to form aggregates, likely mediated by hydrophobic interactions. Our findings suggest that GCAP2 might be mostly implicated in processes other than phototransduction in human photoreceptors and suggest a possible molecular mechanism for G157R-associated IRD.
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Affiliation(s)
- Anna Avesani
- Department of Neurosciences, Biomedicine and Movement Sciences, Biological Chemistry Section, University of Verona, Verona, Italy
| | - Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Biological Chemistry Section, University of Verona, Verona, Italy
| | - Serena Zanzoni
- Centro Piattaforme Tecnologiche, University of Verona, Verona, Italy
| | - Karl-Wilhelm Koch
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, Oldenburg, Germany
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Biological Chemistry Section, University of Verona, Verona, Italy.
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Dal Cortivo G, Marino V, Bonì F, Milani M, Dell'Orco D. Missense mutations affecting Ca 2+-coordination in GCAP1 lead to cone-rod dystrophies by altering protein structural and functional properties. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118794. [PMID: 32650103 DOI: 10.1016/j.bbamcr.2020.118794] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023]
Abstract
Guanylate cyclase activating protein 1 (GCAP1) is a neuronal calcium sensor (NCS) involved in the early biochemical steps underlying the phototransduction cascade. By switching from a Ca2+-bound form in the dark to a Mg2+-bound state following light activation of the cascade, GCAP1 triggers the activation of the retinal guanylate cyclase (GC), thus replenishing the levels of 3',5'-cyclic monophosphate (cGMP) necessary to re-open CNG channels. Here, we investigated the structural and functional effects of three missense mutations in GCAP1 associated with cone-rod dystrophy, which severely perturb the homeostasis of cGMP and Ca2+. Substitutions affect residues directly involved in Ca2+ coordination in either EF3 (D100G) or EF4 (E155A and E155G) Ca2+ binding motifs. We found that all GCAP1 variants form relatively stable dimers showing decreased apparent affinity for Ca2+ and blocking the enzyme in a constitutively active state at physiological levels of Ca2+. Interestingly, by corroborating spectroscopic experiments with molecular dynamics simulations we show that beside local structural effects, mutation of the bidentate glutamate in an EF-hand calcium binding motif can profoundly perturb the flexibility of the adjacent EF-hand as well, ultimately destabilizing the whole domain. Therefore, while Ca2+-binding to GCAP1 per se occurs sequentially, allosteric effects may connect EF hand motifs, which appear to be essential for the integrity of the structural switch mechanism in GCAP1, and perhaps in other NCS proteins.
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Affiliation(s)
- Giuditta Dal Cortivo
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, I-37134 Verona, Italy
| | - Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, I-37134 Verona, Italy
| | - Francesco Bonì
- CNR-IBF, Istituto di Biofisica, Via Celoria 26, I-20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, Via Celoria 26, I-20133 Milano, Italy
| | - Mario Milani
- CNR-IBF, Istituto di Biofisica, Via Celoria 26, I-20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, Via Celoria 26, I-20133 Milano, Italy
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, I-37134 Verona, Italy.
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Nabil-Adam A, Shreadah MA, El Moneam NMA, El-Assar SA. Various In Vitro Bioactivities of Secondary Metabolites Isolated from the Sponge Hyrtios aff. Erectus from the Red Sea Coast of Egypt. Turk J Pharm Sci 2020; 17:127-135. [PMID: 32454771 DOI: 10.4274/tjps.galenos.2018.72677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/13/2018] [Indexed: 02/07/2023]
Abstract
Objectives The present study revealed the presence of bioactive constituents in Hyrtios aff. erectus sponge (HES) extract collected from the Red Sea using skin and scuba diving. Materials and Methods Cytotoxicity was tested against hepatocellular carcinoma cell lines as a prescreening test. Results The HES extract had high contents of total phenolic compounds (0.061 mg/g), flavonoids (0.2839 mg/g), and carotenoids (1.976 mg/g). Moreover, the HES extract showed high antioxidant capacity with 93.0% and 99% at 1 mg using 2.2'-Diphenyl-α-picrylhydrazyl and 2.2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), respectively. Cytotoxic activity against cancerous cell lines showed that the HES extract could inhibit cell growth effectively with IC50=47.5 μg/mL. Furthermore, anticancer activity using protein tyrosine kinase and sphingosine kinase 1 inhibitor screening assays resulted in 71.66% and 85.21% inhibition activity, respectively. The anti-inflammatory assays showed that the inhibition activity against cyclooxygenase (COX1), COX2, interleukin-6, and tumor necrosis factor-α was 71.82%, 81.13%, 80.89%, and 59.74%, respectively. At the same time, the anti-Alzheimer results using acetylcholine inhibition assay showed high activity at 1 mg with 83.51%. Additionally, the antiviral activity using the reverse transcriptase inhibition assay was 91.70%. Conclusion This marine sponge isolated from the Red Sea showed tremendous activity against many diseases and it is considered an excellent source for bioactive pharmaceutical compounds.
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Affiliation(s)
- Asmaa Nabil-Adam
- Marine Biotechnology and Natural Products Lab (MBNP), National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
| | - Mohamed A Shreadah
- Marine Biotechnology and Natural Products Lab (MBNP), National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt
| | - Nehad M Abd El Moneam
- Alexandria University, Faculty of Science, Department of Biochemistry, Alexandria, Egypt
| | - Samy A El-Assar
- Alexandria University, Faculty of Science, Department of Botany and Microbiology, Alexandria, Egypt
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Constitutive Activation of Guanylate Cyclase by the G86R GCAP1 Variant Is Due to "Locking" Cation-π Interactions that Impair the Activator-to-Inhibitor Structural Transition. Int J Mol Sci 2020; 21:ijms21030752. [PMID: 31979372 PMCID: PMC7037459 DOI: 10.3390/ijms21030752] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 02/06/2023] Open
Abstract
Guanylate Cyclase activating protein 1 (GCAP1) mediates the Ca2+-dependent regulation of the retinal Guanylate Cyclase (GC) in photoreceptors, acting as a target inhibitor at high [Ca2+] and as an activator at low [Ca2+]. Recently, a novel missense mutation (G86R) was found in GUCA1A, the gene encoding for GCAP1, in patients diagnosed with cone-rod dystrophy. The G86R substitution was found to affect the flexibility of the hinge region connecting the N- and C-domains of GCAP1, resulting in decreased Ca2+-sensitivity and abnormally enhanced affinity for GC. Based on a structural model of GCAP1, here, we tested the hypothesis of a cation-π interaction between the positively charged R86 and the aromatic W94 as the main mechanism underlying the impaired activator-to-inhibitor conformational change. W94 was mutated to F or L, thus, resulting in the double mutants G86R+W94L/F. The double mutants showed minor structural and stability changes with respect to the single G86R mutant, as well as lower affinity for both Mg2+ and Ca2+, moreover, substitutions of W94 abolished "phase II" in Ca2+-titrations followed by intrinsic fluorescence. Interestingly, the presence of an aromatic residue in position 94 significantly increased the aggregation propensity of Ca2+-loaded GCAP1 variants. Finally, atomistic simulations of all GCAP1 variants in the presence of Ca2+ supported the presence of two cation-π interactions involving R86, which was found to act as a bridge between W94 and W21, thus, locking the hinge region in an activator-like conformation and resulting in the constitutive activation of the target under physiological conditions.
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Tang S, Xia Y, Dai Y, Liu Y, Li J, Pan X, Chen P. Functional characterization of a novel GUCA1A missense mutation (D144G) in autosomal dominant cone dystrophy: A novel pathogenic GUCA1A variant in COD. Mol Vis 2019; 25:921-xxx. [PMID: 32025184 PMCID: PMC6982429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 12/30/2019] [Indexed: 10/26/2022] Open
Abstract
Purpose To elucidate the clinical phenotypes and pathogenesis of a novel missense mutation in guanylate cyclase activator A1A (GUCA1A) associated with autosomal dominant cone dystrophy (adCOD). Methods The members of a family with adCOD were clinically evaluated. Relevant genes were captured before being sequenced with targeted next-generation sequencing and confirmed with Sanger sequencing. Sequence analysis was made of the conservativeness of mutant residues. An enzyme-linked immunosorbent assay (ELISA) was implemented to detect the cyclic guanosine monophosphate (cGMP) concentration. Then limited protein hydrolysis and an electrophoresis shift were used to assess possible changes in the structure. Coimmunoprecipitation was employed to analyze the interaction between GCAP1 and retGC1. Immunofluorescence staining was performed to observe the colocalization of GCAP1 and retGC1 in human embryonic kidney (HEK)-293 cells. Results A pathogenic mutation in GUCA1A (c.431A>G, p.D144G, exon 5) was revealed in four generations of a family with adCOD. GUCA1A encodes guanylate cyclase activating protein 1 (GCAP1). D144, located in the EF4 loop involving calcium binding, was highly conserved in the species. GCAP1-D144G was more susceptible to hydrolysis, and the mobility of the D144G band became slower in the presence of Ca2+. At high Ca2+ concentrations, GCAP1-D144G stimulated retGC1 in the HEK-293 membrane to significantly increase intracellular cGMP protein concentrations. Compared with wild-type (WT) GCAP1, GCAP1-D144G had an increased interaction with retGC1, as detected in the coimmunoprecipitation assay. Conclusions The newly discovered missense mutation in GUCA1A (p.D144G) might lead to an imbalance of Ca2+ and cGMP homeostasis and eventually, cause a significant variation in adCOD.
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Affiliation(s)
- Suzhen Tang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao266071, Shandong Province, China
| | - Yujun Xia
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao266071, Shandong Province, China
| | - Yunhai Dai
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Yaning Liu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao266071, Shandong Province, China
| | - Jingshuo Li
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao266071, Shandong Province, China
| | - Xiaojing Pan
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Peng Chen
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao266071, Shandong Province, China
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12
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Nabil-Adam A, Shreadah MA, Abd El Moneam NM, El-Assar SA. Pesudomance sp. Bacteria Associated with Marine Sponge as a Promising and Sustainable Source of Bioactive Molecules. Curr Pharm Biotechnol 2019; 20:964-984. [PMID: 31258072 DOI: 10.2174/1389201020666190619092502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 01/04/2019] [Accepted: 05/13/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND The study was conducted to identify the bacterial strain associated with marine sponge Hyrtiosaff. erectus collected from the Red Sea coastal water and to assess the utilization of their secondary metabolites for human benefit as antioxidant, anti-Alzheimer, anti-viral, anticancer and anti-inflammatory agent. METHODS After biochemical identification of Pesudomance sp. bacterial strain, the total polyphenol contents, cytotoxic, antioxidant, anti-Alzheimer, anti-viral, anticancer and anti-inflammatory activity of the Pesudomance sp. ethyl acetate extract were investigated by applying different biochemical assays. Polyphenol contents were investigated using spectrophotometric techniques. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and 2,2/-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical scavenging activity assays. The cytotoxic effects were investigated by using the human cancerous cell lines. RESULTS The anti-Alzheimer, anti-viral, anticancer and anti-inflammatory activities were determined using ELISA. Qualitative phytochemical analysis of the Pesudomance sp. extract demonstrated the presence of a large and diverse group of substances such as alkaloids, carbohydrates, flavonoids, phenols, terpenoids, saponins, and tannins. The strong antioxidant activity of the Pesudomance sp. extract was mainly attributed to the protective role of polyphenols against reactive oxygen. It was also observed that Pesudomance sp. extract possessed significant anti-Alzheimer activity with 94% at 1 mg. The extract showed also high antiviral activity (90%) using reverse transcriptase enzymes inhibition assay. The examination of the anticancer activity by applying two experimental models, i.e., PTK and SHKI cleared out high significant percentages of 76.19 and 83.09 %; respectively. CONCLUSION The anti-inflammatory profiling using TNF, COX1, COX2, IL6 also revealed high antiinflammatory activity with different metabolic pathway of 62.70, 75.444, 79.27 and 54.15 %; respectively. The present study concluded that ethyl acetate extract of Pesudomance sp. possessed strong antioxidant, anti-Alzheimer, and anti-viral, anticancer and anti-inflammatory activities. Further studies are required to purify the bioactive compounds.
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Affiliation(s)
- Asmaa Nabil-Adam
- Marine Biotechnology and Natural products Lab (MBNP), National Institute of Oceanography & Fisheries (NIOF), Alexandria, Egypt
| | - Mohamed A Shreadah
- Marine Biotechnology and Natural products Lab (MBNP), National Institute of Oceanography & Fisheries (NIOF), Alexandria, Egypt
| | - Nehad M Abd El Moneam
- Biochemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Samy A El-Assar
- Botany and Microbiology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
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13
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Mizobuchi K, Hayashi T, Katagiri S, Yoshitake K, Fujinami K, Yang L, Kuniyoshi K, Shinoda K, Machida S, Kondo M, Ueno S, Terasaki H, Matsuura T, Tsunoda K, Iwata T, Nakano T. Characterization of GUCA1A-associated dominant cone/cone-rod dystrophy: low prevalence among Japanese patients with inherited retinal dystrophies. Sci Rep 2019; 9:16851. [PMID: 31728034 PMCID: PMC6856191 DOI: 10.1038/s41598-019-52660-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/21/2019] [Indexed: 12/14/2022] Open
Abstract
GUCA1A gene variants are associated with autosomal dominant (AD) cone dystrophy (COD) and cone-rod dystrophy (CORD). GUCA1A-associated AD-COD/CORD has never been reported in the Japanese population. The purpose of this study was to investigate clinical and genetic features of GUCA1A-associated AD-COD/CORD from a large Japanese cohort. We identified 8 variants [c.C50_80del (p.E17VfsX22), c.T124A (p.F42I), c.C204G (p.D68E), c.C238A (p.L80I), c.T295A (p.Y99N), c.A296C (p.Y99S), c.C451T (p.L151F), and c.A551G (p.Q184R)] in 14 families from our whole exome sequencing database composed of 1385 patients with inherited retinal diseases (IRDs) from 1192 families. Three variants (p.Y99N, p.Y99S, and p.L151F), which are located on/around EF-hand domains 3 and 4, were confirmed as "pathogenic", whereas the other five variants, which did not co-segregate with IRDs, were considered "non-pathogenic". Ophthalmic findings of 9 patients from 3 families with the pathogenic variants showed central visual impairment from early to middle-age onset and progressive macular atrophy. Electroretinography revealed severely decreased or non-recordable cone responses, whereas rod responses were highly variable, ranging from nearly normal to non-recordable. Our results indicate that the three pathogenic variants, two of which were novel, underlie AD-COD/CORD with progressive retinal atrophy, and the prevalence (0.25%, 3/1192 families) of GUCA1A-associated IRDs may be low among Japanese patients.
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Affiliation(s)
- Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan. .,Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, Tokyo, Japan.
| | - Satoshi Katagiri
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan
| | - Kaoru Fujinami
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.,UCL Institute of Ophthalmology associated with Moorfields Eye Hospital, London, UK
| | - Lizhu Yang
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuki Kuniyoshi
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Kei Shinoda
- Department of Ophthalmology, Teikyo University School of Medicine, Tokyo, Japan
| | - Shigeki Machida
- Department of Ophthalmology, Dokkyo Medical University Saitama Medical Center, Saitama, Japan.,Department of Ophthalmology, Iwate Medical University School of Medicine, Iwate, Japan
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Mie, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Tomokazu Matsuura
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazushige Tsunoda
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
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14
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Collison FT, Fishman GA, Nagasaki T, Zernant J, McAnany JJ, Park JC, Allikmets R. Characteristic Ocular Features in Cases of Autosomal Recessive PROM1 Cone-Rod Dystrophy. Invest Ophthalmol Vis Sci 2019; 60:2347-2356. [PMID: 31136651 PMCID: PMC6538366 DOI: 10.1167/iovs.19-26993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose To define characteristic ocular features in a group of patients with autosomal recessive (AR) PROM1 cone-rod dystrophy (CRD). Methods Three males and one female from three unrelated families were first seen at the ages of 15 to 22 years and diagnosed with CRD. Clinical testing available for review included full-field electroretinogram (ERG) in three patients, as well as near-infrared autofluorescence (NIR-AF), spectral-domain optical coherence tomography (SD-OCT), and color fundus photography in all four patients. Whole exome sequencing (WES) was performed on all cases, and whole genome sequencing (WGS) was performed in two families. Results WES found compound heterozygous PROM1 variants in one isolated male, plus heterozygous variants in the remaining patients. WGS uncovered deleterious PROM1 variants in these two families. ERG showed markedly reduced cone-isolated amplitudes and variably reduced rod-isolated amplitudes. The dark-adapted combined rod and cone responses demonstrated notably reduced a-wave amplitudes and moderately reduced b-waves, and the resultant waveform resembled the normal rod-isolated response. On fundus examination, oval-shaped macular lesions were observed, as were several small, circular hypoautofluorescent lesions within the posterior pole on NIR-AF. Three patients showed extramacular circular atrophic lesions. Conclusions The autofluorescence changes, peripheral retinal abnormalities, and ERG findings have not been emphasized in previous reports of AR PROM1, but they became a recognizable phenotype in this cohort of patients. A similar constellation of findings may be observed in CRD due to CDHR1, a functionally related gene. The pattern of abnormalities reported herein may help to focus genetic screening in patients with these findings.
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Affiliation(s)
- Frederick T Collison
- The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States
| | - Gerald A Fishman
- The Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States.,Department of Ophthalmology and Visual Sciences, The University of Illinois at Chicago, Chicago, Illinois, United States
| | - Takayuki Nagasaki
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - Jana Zernant
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, The University of Illinois at Chicago, Chicago, Illinois, United States
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, The University of Illinois at Chicago, Chicago, Illinois, United States
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, New York, United States.,Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
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15
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Boulanger-Scemama E, Mohand-Saïd S, El Shamieh S, Démontant V, Condroyer C, Antonio A, Michiels C, Boyard F, Saraiva JP, Letexier M, Sahel JA, Zeitz C, Audo I. Phenotype Analysis of Retinal Dystrophies in Light of the Underlying Genetic Defects: Application to Cone and Cone-Rod Dystrophies. Int J Mol Sci 2019; 20:ijms20194854. [PMID: 31574917 PMCID: PMC6801687 DOI: 10.3390/ijms20194854] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/20/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022] Open
Abstract
Phenotypes observed in a large cohort of patients with cone and cone-rod dystrophies (COD/CORDs) are described based on multimodal retinal imaging features in order to help in analyzing massive next-generation sequencing data. Structural abnormalities of 58 subjects with molecular diagnosis of COD/CORDs were analyzed through specific retinal imaging including spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (BAF/IRAF). Findings were analyzed with the underlying genetic defects. A ring of increased autofluorescence was mainly observed in patients with CRX and GUCY2D mutations (33% and 22% of cases respectively). “Speckled” autofluorescence was observed with mutations in three different genes (ABCA4 64%; C2Orf71 and PRPH2, 18% each). Peripapillary sparing was only found in association with mutations in ABCA4, although only present in 40% of such genotypes. Regarding SD-OCT, specific outer retinal abnormalities were more commonly observed in particular genotypes: focal retrofoveal interruption and GUCY2D mutations (50%), foveal sparing and CRX mutations (50%), and outer retinal atrophy associated with hyperreflective dots and ABCA4 mutations (69%). This study outlines the phenotypic heterogeneity of COD/CORDs hampering statistical correlations. A larger study correlating retinal imaging with genetic results is necessary to identify specific clinical features that may help in selecting pathogenic variants generated by high-throughput sequencing.
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Affiliation(s)
- Elise Boulanger-Scemama
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Fondation Ophtalmologique Adolphe de Rothschild, 75012 Paris, France.
| | - Saddek Mohand-Saïd
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
| | - Said El Shamieh
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon.
| | - Vanessa Démontant
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Christel Condroyer
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Aline Antonio
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
| | - Christelle Michiels
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Fiona Boyard
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | | | | | - José-Alain Sahel
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- Fondation Ophtalmologique Adolphe de Rothschild, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
- Académie des Sciences-Institut de France, 75006 Paris, France.
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburg, PA 15213, USA.
| | - Christina Zeitz
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, 17 rue Moreau, 75012 Paris, France.
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, 28 rue de Charenton, 75012 Paris, France.
- University College London Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK.
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16
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Marino V, Dal Cortivo G, Oppici E, Maltese PE, D'Esposito F, Manara E, Ziccardi L, Falsini B, Magli A, Bertelli M, Dell'Orco D. A novel p.(Glu111Val) missense mutation in GUCA1A associated with cone-rod dystrophy leads to impaired calcium sensing and perturbed second messenger homeostasis in photoreceptors. Hum Mol Genet 2019; 27:4204-4217. [PMID: 30184081 DOI: 10.1093/hmg/ddy311] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/24/2018] [Indexed: 01/09/2023] Open
Abstract
Guanylate Cyclase-Activating Protein 1 (GCAP1) regulates the enzymatic activity of the photoreceptor guanylate cyclases (GC), leading to inhibition or activation of the cyclic guanosine monophosphate (cGMP) synthesis depending on its Ca2+- or Mg2+-loaded state. By genetically screening a family of patients diagnosed with cone-rod dystrophy, we identified a novel missense mutation with autosomal dominant inheritance pattern (c.332A>T; p.(Glu111Val); E111V from now on) in the GUCA1A gene coding for GCAP1. We performed a thorough biochemical and biophysical investigation of wild type (WT) and E111V human GCAP1 by heterologous expression and purification of the recombinant proteins. The E111V substitution disrupts the coordination of the Ca2+ ion in the high-affinity site (EF-hand 3, EF3), thus significantly decreasing the ability of GCAP1 to sense Ca2+ (∼80-fold higher Kdapp compared to WT). Both WT and E111V GCAP1 form dimers independently on the presence of cations, but the E111V Mg2+-bound form is prone to severe aggregation over time. Molecular dynamics simulations suggest a significantly increased flexibility of both the EF3 and EF4 cation binding loops for the Ca2+-bound form of E111V GCAP1, in line with the decreased affinity for Ca2+. In contrast, a more rigid backbone conformation is observed in the Mg2+-bound state compared to the WT, which results in higher thermal stability. Functional assays confirm that E111V GCAP1 interacts with the target GC with a similar apparent affinity (EC50); however, the mutant shifts the GC inhibition out of the physiological [Ca2+] (IC50E111V ∼10 μM), thereby leading to the aberrant constitutive synthesis of cGMP under conditions of dark-adapted photoreceptors.
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Affiliation(s)
- Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy.,Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Giuditta Dal Cortivo
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Elisa Oppici
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | | | - Fabiana D'Esposito
- Imperial College Ophthalmic Research Unit, Western Eye Hospital, Imperial College Healthcare NHS Trust, London, UK.,MAGI Euregio, Bolzano, Italy.,Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, Federico II University, Naples, Italy
| | | | | | - Benedetto Falsini
- Institute of Ophthalmology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario "A. Gemelli", IRCCS, Rome, Italy
| | - Adriano Magli
- Department of Pediatric Ophthalmology, University of Salerno, Fisciano (SA), Italy
| | - Matteo Bertelli
- MAGI'S Lab s.r.l., Rovereto, Italy.,MAGI Euregio, Bolzano, Italy
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
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17
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Marino V, Dell'Orco D. Evolutionary-Conserved Allosteric Properties of Three Neuronal Calcium Sensor Proteins. Front Mol Neurosci 2019; 12:50. [PMID: 30899213 PMCID: PMC6417375 DOI: 10.3389/fnmol.2019.00050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/11/2019] [Indexed: 12/21/2022] Open
Abstract
Neuronal Calcium Sensors (NCS) are highly conserved proteins specifically expressed in neurons. Calcium (Ca2+)-binding to their EF-hand motifs results in a conformational change, which is crucial for the recognition of a specific target and the downstream biological process. Here we present a comprehensive analysis of the allosteric communication between Ca2+-binding sites and the target interfaces of three NCS, namely NCS1, recoverin (Rec), and GCAP1. In particular, Rec was investigated in different Ca2+-loading states and in complex with a peptide from the Rhodopsin Kinase (GRK1) while NCS1 was studied in a Ca2+-loaded state in complex with either the same GRK1 target or a peptide from the D2 Dopamine receptor. A Protein Structure Network (PSN) accounting for persistent non-covalent interactions between amino acids was built for each protein state based on exhaustive Molecular Dynamics simulations. Structural network analysis helped unveiling the role of key amino acids in allosteric mechanisms and their evolutionary conservation among homologous proteins. Results for NCS1 highlighted allosteric inter-domain interactions between Ca2+-binding motifs and residues involved in target recognition. Robust long range, allosteric protein-target interactions were found also in Rec, in particular originating from the EF3 motif. Interestingly, Tyr 86, involved the hydrophobic packing of the N-terminal domain, was found to be a key residue for both intra- and inter-molecular communication with EF3, regardless of the presence of target or Ca2+ ions. Finally, based on a comprehensive topological PSN analysis for Rec, NCS1, and GCAP1 and multiple sequence alignments with homolog proteins, we propose that an evolution-driven correlation may exist between the amino acids mediating the highest number of persistent interactions (high-degree hubs) and their conservation. Such conservation is apparently fundamental for the specific structural dynamics required in signaling events.
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Affiliation(s)
- Valerio Marino
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy.,Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Daniele Dell'Orco
- Section of Biological Chemistry, Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy
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18
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Gill JS, Georgiou M, Kalitzeos A, Moore AT, Michaelides M. Progressive cone and cone-rod dystrophies: clinical features, molecular genetics and prospects for therapy. Br J Ophthalmol 2019; 103:bjophthalmol-2018-313278. [PMID: 30679166 PMCID: PMC6709772 DOI: 10.1136/bjophthalmol-2018-313278] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/23/2018] [Accepted: 11/29/2018] [Indexed: 12/16/2022]
Abstract
Progressive cone and cone-rod dystrophies are a clinically and genetically heterogeneous group of inherited retinal diseases characterised by cone photoreceptor degeneration, which may be followed by subsequent rod photoreceptor loss. These disorders typically present with progressive loss of central vision, colour vision disturbance and photophobia. Considerable progress has been made in elucidating the molecular genetics and genotype-phenotype correlations associated with these dystrophies, with mutations in at least 30 genes implicated in this group of disorders. We discuss the genetics, and clinical, psychophysical, electrophysiological and retinal imaging characteristics of cone and cone-rod dystrophies, focusing particularly on four of the most common disease-associated genes: GUCA1A, PRPH2, ABCA4 and RPGR Additionally, we briefly review the current management of these disorders and the prospects for novel therapies.
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Affiliation(s)
- Jasdeep S Gill
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London, UK
- Ophthalmology Department, University of California San Francisco School of Medicine, San Francisco, California, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
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19
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Peshenko IV, Cideciyan AV, Sumaroka A, Olshevskaya EV, Scholten A, Abbas S, Koch KW, Jacobson SG, Dizhoor AM. A G86R mutation in the calcium-sensor protein GCAP1 alters regulation of retinal guanylyl cyclase and causes dominant cone-rod degeneration. J Biol Chem 2019; 294:3476-3488. [PMID: 30622141 DOI: 10.1074/jbc.ra118.006180] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 01/04/2019] [Indexed: 11/06/2022] Open
Abstract
The guanylyl cyclase-activating protein, GCAP1, activates photoreceptor membrane guanylyl cyclase (RetGC) in the light, when free Ca2+ concentrations decline, and decelerates the cyclase in the dark, when Ca2+ concentrations rise. Here, we report a novel mutation, G86R, in the GCAP1 (GUCA1A) gene in a family with a dominant retinopathy. The G86R substitution in a "hinge" region connecting EF-hand domains 2 and 3 in GCAP1 strongly interfered with its Ca2+-dependent activator-to-inhibitor conformational transition. The G86R-GCAP1 variant activated RetGC at low Ca2+ concentrations with higher affinity than did the WT GCAP1, but failed to decelerate the cyclase at the Ca2+ concentrations characteristic of dark-adapted photoreceptors. Ca2+-dependent increase in Trp94 fluorescence, indicative of the GCAP1 transition to its RetGC inhibiting state, was suppressed and shifted to a higher Ca2+ range. Conformational changes in G86R GCAP1 detectable by isothermal titration calorimetry (ITC) also became less sensitive to Ca2+, and the dose dependence of the G86R GCAP1-RetGC1 complex inhibition by retinal degeneration 3 (RD3) protein was shifted toward higher than normal concentrations. Our results indicate that the flexibility of the hinge region between EF-hands 2 and 3 is required for placing GCAP1-regulated Ca2+ sensitivity of the cyclase within the physiological range of intracellular Ca2+ at the expense of reducing GCAP1 affinity for the target enzyme. The disease-linked mutation of the hinge Gly86, leading to abnormally high affinity for the target enzyme and reduced Ca2+ sensitivity of GCAP1, is predicted to abnormally elevate cGMP production and Ca2+ influx in photoreceptors in the dark.
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Affiliation(s)
- Igor V Peshenko
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027
| | - Artur V Cideciyan
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Alexander Sumaroka
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Elena V Olshevskaya
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027
| | - Alexander Scholten
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Seher Abbas
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Karl-Wilhelm Koch
- the Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Samuel G Jacobson
- the Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and
| | - Alexander M Dizhoor
- From the Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania 19027,
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20
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Tsokolas G, Almuhtaseb H, Griffiths H, Shawkat F, Pengelly RJ, Sarah E, Lotery A. Long term follow-up of a family with GUCY2D dominant cone dystrophy. Int J Ophthalmol 2018; 11:1945-1950. [PMID: 30588428 DOI: 10.18240/ijo.2018.12.12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/06/2018] [Indexed: 12/20/2022] Open
Abstract
AIM To describe long term follow-up in a family with GUCY2D dominant cone dystrophy. METHODS Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms (ERGs) and occipital pattern reversal visual evoked potentials were recorded. RESULTS Two members of the same family (father and son) were identified to have the heterozygous R838C mutation in the GUCY2D gene. The father presented at the age of 45 with bilateral bull's eye maculopathy and temporal disc pallor. Over 13y of serial follow up visits, the bull's eye maculopathy progressed gradually into macular atrophy. Electrophysiological tests were significantly degraded suggesting poor macular function. Spectral-domain optical coherence tomography (SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. His son presented at the age of 16 with bilateral granular retinal pigment epithelial changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer. CONCLUSION Both family members exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene.
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Affiliation(s)
- Georgios Tsokolas
- Clinical and Experimental Sciences, University of Southampton, Southampton, Hampshire SO16 6YD, UK.,Eye Unit, University Hospital Southampton, Southampton, Hampshire SO16 6YD, UK
| | - Hussein Almuhtaseb
- Clinical and Experimental Sciences, University of Southampton, Southampton, Hampshire SO16 6YD, UK.,Eye Unit, University Hospital Southampton, Southampton, Hampshire SO16 6YD, UK
| | - Helen Griffiths
- Clinical and Experimental Sciences, University of Southampton, Southampton, Hampshire SO16 6YD, UK
| | - Fatima Shawkat
- Eye Unit, University Hospital Southampton, Southampton, Hampshire SO16 6YD, UK
| | - Reuben J Pengelly
- Human Genetics & Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton, Hamphsire, SO16 6YD, UK
| | - Ennis Sarah
- Human Genetics & Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton, Hamphsire, SO16 6YD, UK
| | - Andrew Lotery
- Clinical and Experimental Sciences, University of Southampton, Southampton, Hampshire SO16 6YD, UK.,Eye Unit, University Hospital Southampton, Southampton, Hampshire SO16 6YD, UK
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21
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Lima LH, Zett C, Kniggendorf V, Marianelli B, de Carvalho RAP, Farah ME, Sallum JMF. Progressive expansion of the hyperautofluorescent ring in cone-rod dystrophy patients. Ophthalmic Genet 2018; 39:492-499. [PMID: 29671671 DOI: 10.1080/13816810.2018.1461911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE To evaluate the expansion of the hyperautofluorescent ring and the retinal structure changes over time in cone-rod dystrophy (CRD) patients, using fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT). METHODS Retrospective case series study. Six eyes of three CRD patients with a parafoveal hyperautofluorescent ring were studied. The diagnosis of CRD was established by the presence of the implicit time shift at 30-Hz flicker and prevalent decrease of photopic over scotopic responses on electroretinography. External and internal ring expansion was evaluated by measurements of its area at baseline and at 24-month follow-up using FAF. SD-OCT analyzed the retinal structure of the ring and the length of devoid ellipsoid zone (EZ) was measured over time. RESULTS The mean age of study patients was 21 years old and the mean baseline visual acuity was 20/200. The external and internal FAF rings involving the fovea were identified in all study eyes. SD-OCT showed a normal retinal structure outside the ring. At the transitional zone of the ring, disorganization of both EZ and external limiting membrane (ELM) was observed. Inside the hyperautofluorescent ring, EZ and ELM were not identified. At 24-month follow-up examination, the mean % area increase of external and internal rings were 18.32% and 20.42%, respectively, and was concordant with the EZ band defect length enlargement. CONCLUSION Progressive expansion of hyperautofluorescent macular ring with a correspondent EZ band defect enlargement was observed over time in CRD patients.
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Affiliation(s)
- Luiz H Lima
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
| | - Claudio Zett
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil.,b Department of Ophthalmology , Pontificia Universidad Católica de Valparaíso , Valparaíso , Chile
| | - Vinícius Kniggendorf
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
| | - Bruna Marianelli
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
| | - Ricardo A P de Carvalho
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
| | - Michel E Farah
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
| | - Juliana M F Sallum
- a Department of Ophthalmology , Federal University of Sao Paulo (UNIFESP) , São Paulo , Brazil
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22
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López-Begines S, Plana-Bonamaisó A, Méndez A. Molecular determinants of Guanylate Cyclase Activating Protein subcellular distribution in photoreceptor cells of the retina. Sci Rep 2018; 8:2903. [PMID: 29440717 PMCID: PMC5811540 DOI: 10.1038/s41598-018-20893-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/26/2018] [Indexed: 11/10/2022] Open
Abstract
Retinal guanylate cyclase (RetGC) and guanylate cyclase activating proteins (GCAPs) play an important role during the light response in photoreceptor cells. Mutations in these proteins are linked to distinct forms of blindness. RetGC and GCAPs exert their role at the ciliary outer segment where phototransduction takes place. We investigated the mechanisms governing GCAP1 and GCAP2 distribution to rod outer segments by expressing selected GCAP1 and GCAP2 mutants as transient transgenes in the rods of GCAP1/2 double knockout mice. We show that precluding GCAP1 direct binding to RetGC (K23D/GCAP1) prevented its distribution to rod outer segments, while preventing GCAP1 activation of RetGC post-binding (W94A/GCAP1) did not. We infer that GCAP1 translocation to the outer segment strongly depends on GCAP1 binding affinity for RetGC, which points to GCAP1 requirement to bind to RetGC to be transported. We gain further insight into the distinctive regulatory steps of GCAP2 distribution, by showing that a phosphomimic at position 201 is sufficient to retain GCAP2 at proximal compartments; and that the bovine equivalent to blindness-causative mutation G157R/GCAP2 results in enhanced phosphorylation in vitro and significant retention at the inner segment in vivo, as likely contributing factors to the pathophysiology.
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Affiliation(s)
- Santiago López-Begines
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.,Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain
| | - Anna Plana-Bonamaisó
- Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain
| | - Ana Méndez
- Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain. .,Department of Physiology, University of Barcelona School of Medicine-Bellvitge Health Science Campus, Barcelona, Spain.
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23
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Sengillo JD, Cabral T, Schuerch K, Duong J, Lee W, Boudreault K, Xu Y, Justus S, Sparrow JR, Mahajan VB, Tsang SH. Electroretinography Reveals Difference in Cone Function between Syndromic and Nonsyndromic USH2A Patients. Sci Rep 2017; 7:11170. [PMID: 28894305 PMCID: PMC5593892 DOI: 10.1038/s41598-017-11679-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 08/15/2017] [Indexed: 11/23/2022] Open
Abstract
Usher syndrome is an inherited and irreversible disease that manifests as retinitis pigmentosa (RP) and bilateral neurosensory hearing loss. Mutations in Usherin 2A (USH2A) are not only a frequent cause of Usher syndrome, but also nonsyndromic RP. Although gene- and cell-based therapies are on the horizon for RP and Usher syndrome, studies characterizing natural disease are lacking. In this retrospective analysis, retinal function of USH2A patients was quantified with electroretinography. Both groups had markedly reduced rod and cone responses, but nonsyndromic USH2A patients had 30 Hz-flicker electroretinogram amplitudes that were significantly higher than syndromic patients, suggesting superior residual cone function. There was a tendency for Usher syndrome patients to have a higher distribution of severe mutations, and alleles in this group had a higher odds of containing nonsense or frame-shift mutations. These data suggest that the previously reported severe visual phenotype seen in syndromic USH2A patients could relate to a greater extent of cone dysfunction. Additionally, a genetic threshold may exist where mutation burden relates to visual phenotype and the presence of hearing deficits. The auditory phenotype and allelic hierarchy observed among patients should be considered in prospective studies of disease progression and during enrollment for future clinical trials.
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Affiliation(s)
- Jesse D Sengillo
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Thiago Cabral
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Department of Ophthalmology, Federal University of Espírito Santo, Vitoria, Brazil.,Department of Ophthalmology, Federal University of São Paulo, Sao Paulo, Brazil
| | - Kaspar Schuerch
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Jimmy Duong
- Department of Biostatistics, Columbia University, New York, NY, USA
| | - Winston Lee
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Katherine Boudreault
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Department of Ophthalmology, University of Montreal, Montreal, Canada
| | - Yu Xu
- Department of Ophthalmology, Xin Hua Hospital affiliate of Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sally Justus
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Janet R Sparrow
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA. .,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA. .,Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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24
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Manes G, Mamouni S, Hérald E, Richard AC, Sénéchal A, Aouad K, Bocquet B, Meunier I, Hamel CP. Cone dystrophy or macular dystrophy associated with novel autosomal dominant GUCA1A mutations. Mol Vis 2017; 23:198-209. [PMID: 28442884 PMCID: PMC5389339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/31/2017] [Indexed: 10/27/2022] Open
Abstract
PURPOSE Sixteen different mutations in the guanylate cyclase activator 1A gene (GUCA1A), have been previously identified to cause autosomal dominant cone dystrophy (adCOD), cone-rod dystrophy (adCORD), macular dystrophy (adMD), and in an isolated patient, retinitis pigmentosa (RP). The purpose of this study is to report on two novel mutations and the patients' clinical features. METHODS Clinical investigations included visual acuity and visual field testing, fundus examination, high-resolution spectral-domain optical coherence tomography (OCT), fundus autofluorescence imaging, and full-field and multifocal electroretinogram (ERG) recordings. GUCA1A was screened by Sanger sequencing in a cohort of 12 French families with adCOD, adCORD, and adMD. RESULTS We found two novel GUCA1A mutations-one amino acid deletion, c.302_304delTAG (p.Val101del), and one missense mutation, c.444T>A (p.Asp148Glu)-each of which was found in one family. The p.Asp148Glu mutation affected one of the Ca2+-binding amino acids of the EF4 hand, while the p.Val101del mutation resulted in the in-frame deletion of Valine-101, localized between two Ca2+-binding aspartic acid residues at positions 100 and 102 of the EF3 hand. Both families complained of visual acuity loss worsening with age. However, the p.Asp148Glu mutation was present in one family with adCOD involving abnormal cone function and an absence of macular atrophy, whereas p.Val101del mutation was encountered in another family with adMD without a generalized cone defect. CONCLUSIONS The two novel mutations described in this study are associated with distinct phenotypes, MD for p.Val101del and COD for p.Asp148Glu, with no intrafamilial phenotypic heterogeneity.
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Affiliation(s)
- Gaël Manes
- Institut National de la Santé et de la Recherche Médicale, U1051, Institute for Neurosciences of Montpellier, Montpellier, France,University of Montpellier, Montpellier, France
| | - Sonia Mamouni
- CHRU, Genetics of Sensory Diseases, Montpellier, France
| | | | | | - Audrey Sénéchal
- Institut National de la Santé et de la Recherche Médicale, U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Karim Aouad
- Aravis Medical Center, Ophthalmology Department, Argonay, France
| | - Béatrice Bocquet
- University of Montpellier, Montpellier, France,CHRU, Genetics of Sensory Diseases, Montpellier, France
| | - Isabelle Meunier
- Institut National de la Santé et de la Recherche Médicale, U1051, Institute for Neurosciences of Montpellier, Montpellier, France,University of Montpellier, Montpellier, France,CHRU, Genetics of Sensory Diseases, Montpellier, France
| | - Christian P. Hamel
- Institut National de la Santé et de la Recherche Médicale, U1051, Institute for Neurosciences of Montpellier, Montpellier, France,University of Montpellier, Montpellier, France,CHRU, Genetics of Sensory Diseases, Montpellier, France
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25
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Marino V, Dell'Orco D. Allosteric communication pathways routed by Ca 2+/Mg 2+ exchange in GCAP1 selectively switch target regulation modes. Sci Rep 2016; 6:34277. [PMID: 27739433 PMCID: PMC5064319 DOI: 10.1038/srep34277] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/09/2016] [Indexed: 12/11/2022] Open
Abstract
GCAP1 is a neuronal calcium sensor protein that regulates the phototransduction cascade in vertebrates by switching between activator and inhibitor of the target guanylate cyclase (GC) in a Ca2+-dependent manner. We carried out exhaustive molecular dynamics simulations of GCAP1 and determined the intramolecular communication pathways involved in the specific GC activator/inhibitor switch. The switch was found to depend on the Mg2+/Ca2+ loading states of the three EF hands and on the way the information is transferred from each EF hand to specific residues at the GCAP1/GC interface. Post-translational myristoylation is fundamental to mediate long range allosteric interactions including the EF2-EF4 coupling and the communication between EF4 and the GC binding interface. Some hubs in the identified protein network are the target of retinal dystrophy mutations, suggesting that the lack of complete inhibition of GC observed in many cases is likely due to the perturbation of intra/intermolecular communication routes.
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Affiliation(s)
- Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, strada le Grazie 8, I-37134 Verona, Italy
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, strada le Grazie 8, I-37134 Verona, Italy.,Centre for BioMedical Computing (CBMC), University of Verona, strada le Grazie 8, I-37134 Verona, Italy
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26
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Jiang L, Frederick JM, Baehr W. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations. Front Mol Neurosci 2014; 7:25. [PMID: 24778606 PMCID: PMC3985072 DOI: 10.3389/fnmol.2014.00025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/19/2014] [Indexed: 12/26/2022] Open
Abstract
RNA interference (RNAi) knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc) AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C) establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F) producing a slowly progressing cone-rod dystrophy (CORD). The late onset GCAP1(L151F)-CORD mimics the dystrophy observed in human GCAP1-CORD patients. Subretinal injection of scAAV2/8 carrying shRNA expression cassettes specific for bovine or mouse guanylate cyclase-activating protein 1 (GCAP1) showed strong expression at 1 week post-injection. In both allele-specific [GCAP1(Y99C)-RP] and nonallele-specific [GCAP1(L151F)-CORD] models of dominant retinal dystrophy, RNAi-mediated gene silencing enhanced photoreceptor survival, delayed onset of degeneration and improved visual function. Such results provide a "proof of concept" toward effective RNAi-based gene therapy mediated by scAAV2/8 for dominant retinal disease based on GCAP1 mutation. Further, nonallele-specific RNAi knockdown of GCAP1 may prove generally applicable toward the rescue of any human GCAP1-based dominant cone-rod dystrophy.
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Affiliation(s)
- Li Jiang
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA
| | - Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Science Center Salt Lake City, UT, USA ; Department of Biology, University of Utah Salt Lake City, UT, USA ; Department of Neurobiology and Anatomy, University of Utah Health Science Center Salt Lake City, UT, USA
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