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Sakti DH, Cornish EE, Fraser CL, Nash BM, Sandercoe TM, Jones MM, Rowe NA, Jamieson RV, Johnson AM, Grigg JR. Early recognition of CLN3 disease facilitated by visual electrophysiology and multimodal imaging. Doc Ophthalmol 2023:10.1007/s10633-023-09930-1. [PMID: 36964447 DOI: 10.1007/s10633-023-09930-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 03/07/2023] [Indexed: 03/26/2023]
Abstract
BACKGROUND Neuronal ceroid lipofuscinosis is a group of neurodegenerative disorders with varying visual dysfunction. CLN3 is a subtype which commonly presents with visual decline. Visual symptomatology can be indistinct making early diagnosis difficult. This study reports ocular biomarkers of CLN3 patients to assist clinicians in early diagnosis, disease monitoring, and future therapy. METHODS Retrospective review of 5 confirmed CLN3 patients in our eye clinic. Best corrected visual acuity (BCVA), electroretinogram (ERG), ultra-widefield (UWF) fundus photography and fundus autofluorescence (FAF), and optical coherence tomography (OCT) studies were undertaken. RESULTS Five unrelated children, 4 females and 1 male, with median age of 6.2 years (4.6-11.7) at first assessment were investigated at the clinic from 2016 to 2021. Four homozygous and one heterozygous pathogenic CLN3 variants were found. Best corrected visual acuities (BCVAs) ranged from 0.18 to 0.88 logMAR at first presentation. Electronegative ERGs were identified in all patients. Bull's eye maculopathies found in all patients. Hyper-autofluorescence ring surrounding hypo-autofluorescence fovea on FAF was found. Foveal ellipsoid zone (EZ) disruptions were found in all patients with additional inner and outer retinal microcystic changes in one patient. Neurological problems noted included autism, anxiety, motor dyspraxia, behavioural issue, and psychomotor regression. CONCLUSIONS CLN3 patients presented at median age 6.2 years with visual decline. Early onset maculopathy with an electronegative ERG and variable cognitive and motor decline should prompt further investigations including neuropaediatric evaluation and genetic assessment for CLN3 disease. The structural parameters such as EZ and FAF will facilitate ocular monitoring.
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Affiliation(s)
- Dhimas H Sakti
- Save Sight Institute, Speciality of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney Eye Hospital Campus, 8 Macquarie St, Sydney, NSW, 2001, Australia
- Department of Ophthalmology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Elisa E Cornish
- Save Sight Institute, Speciality of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney Eye Hospital Campus, 8 Macquarie St, Sydney, NSW, 2001, Australia
- Eye Genetics Research Unit, The Children's Hospital at Westmead, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Clare L Fraser
- Save Sight Institute, Speciality of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney Eye Hospital Campus, 8 Macquarie St, Sydney, NSW, 2001, Australia
| | - Benjamin M Nash
- Eye Genetics Research Unit, The Children's Hospital at Westmead, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
- Sydney Genome Diagnostics, Sydney Children's Hospital Network (Westmead), Sydney, Australia
| | - Trent M Sandercoe
- Department of Ophthalmology, Sydney Children's Hospital Network (Westmead), Sydney, Australia
| | - Michael M Jones
- Department of Ophthalmology, Sydney Children's Hospital Network (Westmead), Sydney, Australia
| | - Neil A Rowe
- Department of Ophthalmology, Sydney Children's Hospital Network (Westmead), Sydney, Australia
| | - Robyn V Jamieson
- Save Sight Institute, Speciality of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney Eye Hospital Campus, 8 Macquarie St, Sydney, NSW, 2001, Australia
- Eye Genetics Research Unit, The Children's Hospital at Westmead, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Alexandra M Johnson
- Department of Neurology, Sydney Children's Hospital, University of New South Wales, Sydney, Australia
| | - John R Grigg
- Save Sight Institute, Speciality of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney Eye Hospital Campus, 8 Macquarie St, Sydney, NSW, 2001, Australia.
- Eye Genetics Research Unit, The Children's Hospital at Westmead, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia.
- Department of Ophthalmology, Sydney Children's Hospital Network (Westmead), Sydney, Australia.
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2
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Remtulla AAN, Huber RJ. The conserved cellular roles of CLN proteins: Novel insights from Dictyostelium discoideum. Eur J Cell Biol 2023; 102:151305. [PMID: 36917916 DOI: 10.1016/j.ejcb.2023.151305] [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: 01/13/2023] [Revised: 02/15/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), collectively referred to as Batten disease, are a group of fatal neurodegenerative disorders that primarily affect children. The etiology of Batten disease is linked to mutations in 13 genes that encode distinct CLN proteins, whose functions have yet to be fully elucidated. The social amoeba Dictyostelium discoideum has been adopted as an efficient and powerful model system for studying the diverse cellular roles of CLN proteins. The genome of D. discoideum encodes several homologs of human CLN proteins, and a growing body of literature supports the conserved roles and networking of CLN proteins in D. discoideum and humans. In humans, CLN proteins have diverse cellular roles related to autophagy, signal transduction, lipid homeostasis, lysosomal ion homeostasis, and intracellular trafficking. Recent work also indicates that CLN proteins play an important role in protein secretion. Remarkably, many of these findings have found parallels in studies with D. discoideum. Accordingly, this review will highlight the translatable value of novel work with D. discoideum in the field of NCL research and propose further avenues of research using this biomedical model organism for studying the NCLs.
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Affiliation(s)
- Adam A N Remtulla
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada
| | - Robert J Huber
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada; Department of Biology, Trent University, Peterborough, Ontario, Canada.
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3
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Crespi B, Alcock J. Conflicts over calcium and the treatment of COVID-19. EVOLUTION MEDICINE AND PUBLIC HEALTH 2020; 9:149-156. [PMID: 33732462 PMCID: PMC7717197 DOI: 10.1093/emph/eoaa046] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022]
Abstract
Several recent studies have provided evidence that use of calcium channel blockers (CCBs), especially amlodipine and nifedipine, can reduce mortality from coronavirus disease 2019 (COVID-19). Moreover, hypocalcemia (a reduced level of serum ionized calcium) has been shown to be strongly positively associated with COVID-19 severity. Both effectiveness of CCBs as antiviral therapy, and positive associations of hypocalcemia with mortality, have been demonstrated for many other viruses as well. We evaluate these findings in the contexts of virus–host evolutionary conflicts over calcium metabolism, and hypocalcemia as either pathology, viral manipulation or host defence against pathogens. Considerable evidence supports the hypothesis that hypocalcemia represents a host defence. Indeed, hypocalcemia may exert antiviral effects in a similar manner as do CCBs, through interference with calcium metabolism in virus-infected cells. Prospective clinical studies that address the efficacy of CCBs and hypocalcemia should provide novel insights into the pathogenicity and treatment of COVID-19 and other viruses.
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Affiliation(s)
- Bernard Crespi
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Joe Alcock
- Department of Emergency Medicine, University of New Mexico, Albuquerque, NM, USA
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4
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Egunlusi AO, Malan SF, Omoruyi SI, Ekpo OE, Joubert J. 4-Oxatricyclo[5.2.1.0 2,6]dec-8-ene-3,5-dione Derivatives as NMDA Receptor- and VGCC Blockers with Neuroprotective Potential. Molecules 2020; 25:E4552. [PMID: 33027964 PMCID: PMC7582567 DOI: 10.3390/molecules25194552] [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: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
The impact of excitotoxicity mediated by N-methyl-D-aspartate (NMDA) receptor overactivation and voltage gated calcium channel (VGCC) depolarization is prominent among the postulated processes involved in the development of neurodegenerative disorders. NGP1-01, a polycyclic amine, has been shown to be neuroprotective through modulation of the NMDA receptor and VGCC, and attenuation of MPP+-induced neurotoxicity. Recently, we reported on the calcium modulating effects of tricycloundecene derivatives, structurally similar to NGP1-01, on the NMDA receptor and VGCC of synaptoneurosomes. In the present study, we investigated novel 4-oxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives for their cytotoxicity, neuroprotective effects via attenuation of MPP+-induced neurotoxicity and calcium influx inhibition abilities through the NMDA receptor and VGCC using neuroblastoma SH-SY5Y cells. All compounds, in general, showed low or no toxicity against neuroblastoma cells at 10-50 µM concentrations. At 10 µM, all compounds significantly attenuated MPP+-induced neurotoxicity as evident by the enhancement in cell viability between 23.05 ± 3.45% to 53.56 ± 9.29%. In comparison to known active compounds, the derivatives demonstrated mono or dual calcium modulating effect on the NMDA receptor and/or VGCC. Molecular docking studies using the NMDA receptor protein structure indicated that the compounds are able to bind in a comparable manner to the crystallographic pose of MK-801 inside the NMDA ion channel. The biological characteristics, together with results from in silico studies, suggest that these compounds could act as neuroprotective agents for the purpose of halting or slowing down the degenerative processes in neuronal cells.
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Affiliation(s)
- Ayodeji O. Egunlusi
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sylvester I. Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
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Open and rearranged norbornane derived polycyclic cage molecules as potential neuroprotective agents through attenuation of MPP +- and calcium overload-induced excitotoxicity in neuroblastoma SH-SY5Y cells. Eur J Med Chem 2020; 204:112617. [PMID: 32717484 DOI: 10.1016/j.ejmech.2020.112617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 02/07/2023]
Abstract
The neuroprotective effects of closed polycyclic cage molecules such as NGP1-01, memantine and amantadine have been extensively explored. These effects are mostly linked to the antagonism of the N-methyl-d-aspartate (NMDA) receptor- and the blockage of voltage gated calcium channels (VGCC). The synthesis of structurally related open and rearranged cage derivatives has been studied in depth. However, very little is known on their neuroprotective effects. In this study, a series of open and rearranged polycyclic cage molecules containing a norbornane derived scaffold were synthesised and evaluated for cytotoxicity, neuroprotection and calcium blocking effects via the NMDA receptor and VGCC on neuroblastoma cells at a 10 μM concentration. All compounds showed negligible cytotoxicity and were able to significantly attenuate MPP+-induced neurotoxicity between 26.07 ± 12.50% to 48.42 ± 0.76%, with compound 14 showing the best neuroprotective effect. In comparison to known NMDA receptor antagonists, all compounds demonstrated moderate to excellent calcium blocking effects of 26.50 ± 2.28 to 72.95 ± 3.38%. Docking studies suggest that these compounds are able to show significant NMDA receptor channel blocking ability since they bind in a comparable manner to the crystallographic pose of MK-801 inside the NMDAR ion channel. Some compounds were also able to attenuate calcium influx through VGCC channels between 21.28 ± 3.69% to 50.34 ± 7.67%. Compound 4 and 15 showed the highest inhibition of calcium influx at the VGCC and NMDA receptor, respectively. The compounds exhibiting good cytotoxicity-, neuroprotective- and calcium blocking profiles could potentially act as neuroprotective agents to clinically benefit people suffering from neurodegenerative disorders.
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Lloyd-Evans E, Waller-Evans H. Lysosomal Ca 2+ Homeostasis and Signaling in Health and Disease. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035311. [PMID: 31653642 DOI: 10.1101/cshperspect.a035311] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Calcium (Ca2+) signaling is an essential process in all cells that is maintained by a plethora of channels, pumps, transporters, receptors, and intracellular Ca2+ sequestering stores. Changes in cytosolic Ca2+ concentration govern processes as far reaching as fertilization, cell growth, and motility through to cell death. In recent years, lysosomes have emerged as a major intracellular Ca2+ storage organelle with an increasing involvement in triggering or regulating cellular functions such as endocytosis, autophagy, and Ca2+ release from the endoplasmic reticulum. This review will summarize recent work in the area of lysosomal Ca2+ signaling and homeostasis, including newly identified functions, and the involvement of lysosome-derived Ca2+ signals in human disease. In addition, we explore recent controversies in the techniques used for measurement of lysosomal Ca2+ content.
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Affiliation(s)
- Emyr Lloyd-Evans
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Helen Waller-Evans
- Medicines Discovery Institute, Cardiff University, Cardiff CF10 3AT, United Kingdom
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7
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Petcherski A, Chandrachud U, Butz ES, Klein MC, Zhao WN, Reis SA, Haggarty SJ, Ruonala MO, Cotman SL. An Autophagy Modifier Screen Identifies Small Molecules Capable of Reducing Autophagosome Accumulation in a Model of CLN3-Mediated Neurodegeneration. Cells 2019; 8:cells8121531. [PMID: 31783699 PMCID: PMC6953052 DOI: 10.3390/cells8121531] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/23/2019] [Accepted: 11/24/2019] [Indexed: 12/17/2022] Open
Abstract
Alterations in the autophagosomal–lysosomal pathway are a major pathophysiological feature of CLN3 disease, which is the most common form of childhood-onset neurodegeneration. Accumulating autofluorescent lysosomal storage material in CLN3 disease, consisting of dolichols, lipids, biometals, and a protein that normally resides in the mitochondria, subunit c of the mitochondrial ATPase, provides evidence that autophagosomal–lysosomal turnover of cellular components is disrupted upon loss of CLN3 protein function. Using a murine neuronal cell model of the disease, which accurately mimics the major gene defect and the hallmark features of CLN3 disease, we conducted an unbiased search for modifiers of autophagy, extending previous work by further optimizing a GFP-LC3 based assay and performing a high-content screen on a library of ~2000 bioactive compounds. Here we corroborate our earlier screening results and identify expanded, independent sets of autophagy modifiers that increase or decrease the accumulation of autophagosomes in the CLN3 disease cells, highlighting several pathways of interest, including the regulation of calcium signaling, microtubule dynamics, and the mevalonate pathway. Follow-up analysis on fluspirilene, nicardipine, and verapamil, in particular, confirmed activity in reducing GFP-LC3 vesicle burden, while also demonstrating activity in normalizing lysosomal positioning and, for verapamil, in promoting storage material clearance in CLN3 disease neuronal cells. This study demonstrates the potential for cell-based screening studies to identify candidate molecules and pathways for further work to understand CLN3 disease pathogenesis and in drug development efforts.
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Affiliation(s)
- Anton Petcherski
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
- Center for Membrane Proteomics, Goethe University of Frankfurt, 60438 Frankfurt am Main, Germany;
| | - Uma Chandrachud
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Elisabeth S. Butz
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Madeleine C. Klein
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Wen-Ning Zhao
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Surya A. Reis
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Stephen J. Haggarty
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
| | - Mika O. Ruonala
- Center for Membrane Proteomics, Goethe University of Frankfurt, 60438 Frankfurt am Main, Germany;
| | - Susan L. Cotman
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA; (A.P.); (U.C.); (E.S.B.); (M.C.K.); (W.-N.Z.); (S.A.R.); (S.J.H.)
- Correspondence: ; Tel.: +1-617-726-9180
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Mathavarajah S, O'Day DH, Huber RJ. Neuronal Ceroid Lipofuscinoses: Connecting Calcium Signalling through Calmodulin. Cells 2018; 7:cells7110188. [PMID: 30380624 PMCID: PMC6262527 DOI: 10.3390/cells7110188] [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] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/24/2018] [Accepted: 10/27/2018] [Indexed: 02/06/2023] Open
Abstract
Despite the increased focus on the role of calcium in the neuronal ceroid lipofuscinoses (NCLs, also known as Batten disease), links between calcium signalling and the proteins associated with the disease remain to be identified. A central protein in calcium signalling is calmodulin (CaM), which regulates many of the same cellular processes affected in the NCLs. In this study, we show that 11 of the 13 NCL proteins contain putative CaM-binding domains (CaMBDs). Many of the missense mutations documented from NCL patients overlap with the predicted CaMBDs and are often key residues of those domains. The two NCL proteins lacking such domains, CLN7 and CLN11, share a commonality in undergoing proteolytic processing by cathepsin L, which contains a putative CaMBD. Since CaM appears to have both direct and indirect roles in the NCLs, targeting it may be a valid therapeutic approach for treating the disease.
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Affiliation(s)
| | - Danton H O'Day
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada.
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
| | - Robert J Huber
- Department of Biology, Trent University, Peterborough, ON K9L 0G2, Canada.
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Studniarczyk D, Needham EL, Mitchison HM, Farrant M, Cull-Candy SG. Altered Cerebellar Short-Term Plasticity but No Change in Postsynaptic AMPA-Type Glutamate Receptors in a Mouse Model of Juvenile Batten Disease. eNeuro 2018; 5:ENEURO.0387-17.2018. [PMID: 29780879 PMCID: PMC5956745 DOI: 10.1523/eneuro.0387-17.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/22/2018] [Accepted: 03/27/2018] [Indexed: 12/28/2022] Open
Abstract
Juvenile Batten disease is the most common progressive neurodegenerative disorder of childhood. It is associated with mutations in the CLN3 gene, causing loss of function of CLN3 protein and degeneration of cerebellar and retinal neurons. It has been proposed that changes in granule cell AMPA-type glutamate receptors (AMPARs) contribute to the cerebellar dysfunction. In this study, we compared AMPAR properties and synaptic transmission in cerebellar granule cells from wild-type and Cln3 knock-out mice. In Cln3Δex1-6 cells, the amplitude of AMPA-evoked whole-cell currents was unchanged. Similarly, we found no change in the amplitude, kinetics, or rectification of synaptic currents evoked by individual quanta, or in their underlying single-channel conductance. We found no change in cerebellar expression of GluA2 or GluA4 protein. By contrast, we observed a reduced number of quantal events following mossy-fiber stimulation in Sr2+, altered short-term plasticity in conditions of reduced extracellular Ca2+, and reduced mossy fiber vesicle number. Thus, while our results suggest early presynaptic changes in the Cln3Δex1-6 mouse model of juvenile Batten disease, they reveal no evidence for altered postsynaptic AMPARs.
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Affiliation(s)
- Dorota Studniarczyk
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Elizabeth L. Needham
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Hannah M. Mitchison
- UCL Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, United Kingdom
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Stuart G. Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
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10
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Loss of Cln3 impacts protein secretion in the social amoeba Dictyostelium. Cell Signal 2017; 35:61-72. [DOI: 10.1016/j.cellsig.2017.03.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/12/2017] [Accepted: 03/27/2017] [Indexed: 12/30/2022]
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11
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Kwon YJ, Falk MJ, Bennett MJ. Flunarizine rescues reduced lifespan in CLN3 triple knock-out Caenorhabditis elegans model of batten disease. J Inherit Metab Dis 2017; 40:291-296. [PMID: 27766444 PMCID: PMC5309197 DOI: 10.1007/s10545-016-9986-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/20/2016] [Accepted: 09/25/2016] [Indexed: 01/22/2023]
Abstract
CLN3 disease (Spielmeyer-Vogt-Sjogren-Batten disease, previously known as classic juvenile neuronal ceroid lipofuscinosis, NCL) is a pediatric-onset progressive neurodegenerative disease characterized by progressive vision loss, seizures, loss of cognitive and motor function, and early death. While no precise biochemical mechanism or therapies are known, the pathogenesis of CLN3 disease involves intracellular calcium accumulation that may trigger apoptosis. Our prior work in in vitro cell models of CLN3 deficiency suggested that FDA-approved calcium channel antagonists may have therapeutic value. To further evaluate the potential efficacy of this approach in an otherwise untreatable disorder, we sought to compare the therapeutic effects and underlying mechanisms in an animal model of CLN3 disease. Here, we used the well-characterized XT7 complete cln-3 knockout strain of C. elegans to evaluate the therapeutic efficacy of calcium channel antagonist therapy in a living animal model of Batten disease. Therapeutic effects of five calcium channel antagonists were evaluated on XT7 animal lifespan and in vivo mitochondrial physiology. Remarkably, maximal therapeutic efficacy in this model animal was observed with 1 μM flunarizine, the identical concentration previously identified in cell-based neuronal models of CLN3 disease. Specifically, flunarizine rescued the short lifespan of XT7 worms and prevented their pathophysiologic mitochondrial accumulation. These results confirm the treatment efficacy and dosing of flunarizine in cln-3 disease in a translational model organism. Clinical treatment trials in CLN3 human patients are now needed to test the dosing regimen and efficacy of flunarizine in individuals suffering with this otherwise untreatable and ultimately lethal neurologic disease.
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Affiliation(s)
- Young Joon Kwon
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, ARC 1002C, 3615 Civic Center Boulevard, Philadelphia, PA, 19104, USA
| | - Marni J Falk
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, ARC 1002C, 3615 Civic Center Boulevard, Philadelphia, PA, 19104, USA.
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Michael J Bennett
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, 34th and Civic Center Blvd, 5NW58, Philadelphia, PA, 19104, USA.
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12
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Huber RJ. Using the social amoeba Dictyostelium to study the functions of proteins linked to neuronal ceroid lipofuscinosis. J Biomed Sci 2016; 23:83. [PMID: 27881166 PMCID: PMC5122030 DOI: 10.1186/s12929-016-0301-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/15/2016] [Indexed: 12/12/2022] Open
Abstract
Neuronal ceroid lipofuscinosis (NCL), also known as Batten disease, is a debilitating neurological disorder that affects both children and adults. Thirteen genetically distinct genes have been identified that when mutated, result in abnormal lysosomal function and an excessive accumulation of ceroid lipofuscin in neurons, as well as other cell types outside of the central nervous system. The NCL family of proteins is comprised of lysosomal enzymes (PPT1/CLN1, TPP1/CLN2, CTSD/CLN10, CTSF/CLN13), proteins that peripherally associate with membranes (DNAJC5/CLN4, KCTD7/CLN14), a soluble lysosomal protein (CLN5), a protein present in the secretory pathway (PGRN/CLN11), and several proteins that display different subcellular localizations (CLN3, CLN6, MFSD8/CLN7, CLN8, ATP13A2/CLN12). Unfortunately, the precise functions of many of the NCL proteins are still unclear, which has made targeted therapy development challenging. The social amoeba Dictyostelium discoideum has emerged as an excellent model system for studying the normal functions of proteins linked to human neurological disorders. Intriguingly, the genome of this eukaryotic soil microbe encodes homologs of 11 of the 13 known genes linked to NCL. The genetic tractability of the organism, combined with its unique life cycle, makes Dictyostelium an attractive model system for studying the functions of NCL proteins. Moreover, the ability of human NCL proteins to rescue gene-deficiency phenotypes in Dictyostelium suggests that the biological pathways regulating NCL protein function are likely conserved from Dictyostelium to human. In this review, I will discuss each of the NCL homologs in Dictyostelium in turn and describe how future studies can exploit the advantages of the system by testing new hypotheses that may ultimately lead to effective therapy options for this devastating and currently untreatable neurological disorder.
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Affiliation(s)
- Robert J Huber
- Department of Biology, Trent University, 2140 East Bank Drive, Peterborough, ON, K9J 7B8, Canada.
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Huber RJ, Myre MA, Cotman SL. Aberrant adhesion impacts early development in a Dictyostelium model for juvenile neuronal ceroid lipofuscinosis. Cell Adh Migr 2016; 11:399-418. [PMID: 27669405 DOI: 10.1080/19336918.2016.1236179] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Neuronal ceroid lipofuscinosis (NCL), also known as Batten disease, refers to a group of severe neurodegenerative disorders that primarily affect children. The most common subtype of the disease is caused by loss-of-function mutations in CLN3, which is conserved across model species from yeast to human. The precise function of the CLN3 protein is not known, which has made targeted therapy development challenging. In the social amoeba Dictyostelium discoideum, loss of Cln3 causes aberrant mid-to-late stage multicellular development. In this study, we show that Cln3-deficiency causes aberrant adhesion and aggregation during the early stages of Dictyostelium development. cln3- cells form ∼30% more multicellular aggregates that are comparatively smaller than those formed by wild-type cells. Loss of Cln3 delays aggregation, but has no significant effect on cell speed or cAMP-mediated chemotaxis. The aberrant aggregation of cln3- cells cannot be corrected by manually pulsing cells with cAMP. Moreover, there are no significant differences between wild-type and cln3- cells in the expression of genes linked to cAMP chemotaxis (e.g., adenylyl cyclase, acaA; the cAMP receptor, carA; cAMP phosphodiesterase, pdsA; g-protein α 9 subunit, gpaI). However, during this time in development, cln3- cells show reduced cell-substrate and cell-cell adhesion, which correlate with changes in the levels of the cell adhesion proteins CadA and CsaA. Specifically, loss of Cln3 decreases the intracellular level of CsaA and increases the amount of soluble CadA in conditioned media. Together, these results suggest that the aberrant aggregation of cln3- cells is due to reduced adhesion during the early stages of development. Revealing the molecular basis underlying this phenotype may provide fresh new insight into CLN3 function.
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Affiliation(s)
- Robert J Huber
- a Department of Biology , Trent University , Peterborough , Ontario , Canada
| | - Michael A Myre
- b Department of Biological Sciences , University of Massachusetts Lowell , Lowell , Massachusetts , USA
| | - Susan L Cotman
- c Center for Human Genetic Research, Massachusetts General Hospital , Harvard Medical School , Boston , Massachusetts , USA
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Oetjen S, Kuhl D, Hermey G. Revisiting the neuronal localization and trafficking of CLN3 in juvenile neuronal ceroid lipofuscinosis. J Neurochem 2016; 139:456-470. [DOI: 10.1111/jnc.13744] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/14/2016] [Accepted: 07/16/2016] [Indexed: 01/17/2023]
Affiliation(s)
- Sandra Oetjen
- Institute for Molecular and Cellular Cognition; Center for Molecular Neurobiology Hamburg; University Medical Center Hamburg-Eppendorf; Hamburg Germany
| | - Dietmar Kuhl
- Institute for Molecular and Cellular Cognition; Center for Molecular Neurobiology Hamburg; University Medical Center Hamburg-Eppendorf; Hamburg Germany
| | - Guido Hermey
- Institute for Molecular and Cellular Cognition; Center for Molecular Neurobiology Hamburg; University Medical Center Hamburg-Eppendorf; Hamburg Germany
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Carneiro MFH, Morais C, Small DM, Vesey DA, Barbosa F, Gobe GC. Thimerosal induces apoptotic and fibrotic changes to kidney epithelial cells in vitro. ENVIRONMENTAL TOXICOLOGY 2015; 30:1423-1433. [PMID: 24942245 DOI: 10.1002/tox.22012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
Thimerosal is an ethyl mercury-containing compound used mainly in vaccines as a bactericide. Although the kidney is a key target for mercury toxicity, thimerosal nephrotoxicity has not received the same attention as other mercury species. The aim of this study was to determine the potential cytotoxic mechanisms of thimerosal on human kidney cells. Human kidney proximal tubular epithelial (HK2) cells were exposed for 24 h to thimerosal (0-2 µM), and assessed for cell viability, apoptosis, and cell proliferation; expression of proteins Bax, nuclear factor-κB subunits, and transforming growth factor-β1 (TGFβ1); mitochondrial health (JC-1, MitoTracker Red CMXRos); and fibronectin levels (enzyme-linked immunosorbent assay). Thimerosal diminished HK2 cell viability and mitosis, promoted apoptosis, impaired the mitochondrial permeability transition, enhanced Bax and TGFβ1 expression, and augmented fibronectin secretion. This is the first report about kidney cell death and pro-fibrotic mechanisms promoted by thimerosal. Collectively, these in vitro results demonstrate that (1) thimerosal induces kidney epithelial cell apoptosis via upregulating Bax and the mitochondrial apoptotic pathway, and (2) thimerosal is a potential pro-fibrotic agent in human kidney cells. We suggest that new evidence on toxicity as well as continuous surveillance in terms of fibrogenesis is required concerning thimerosal use.
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Affiliation(s)
- Maria Fernanda Hornos Carneiro
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Do Café, s/n, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Christudas Morais
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - David M Small
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - David A Vesey
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
| | - Fernando Barbosa
- Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Do Café, s/n, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Glenda C Gobe
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Kent Street, Woolloongabba, Brisbane, Queensland, Australia
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Kinarivala N, Trippier PC. Progress in the Development of Small Molecule Therapeutics for the Treatment of Neuronal Ceroid Lipofuscinoses (NCLs). J Med Chem 2015; 59:4415-27. [PMID: 26565590 DOI: 10.1021/acs.jmedchem.5b01020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited and incurable neurodegenerative disorders primarily afflicting the pediatric population. Current treatment regimens offer only symptomatic relief and do not target the underlying cause of the disease. Although the underlying pathophysiology that drives disease progression is unknown, several small molecules have been identified with diverse mechanisms of action that provide promise for the treatment of this devastating disease. This review aims to summarize the current cellular and animal models available for the identification of potential therapeutics and presents the current state of knowledge on small molecule compounds that demonstrate in vitro and/or in vivo efficacy across the NCLs with an emphasis on targets of action.
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Affiliation(s)
- Nihar Kinarivala
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States
| | - Paul C Trippier
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States.,Center for Chemical Biology, Department of Chemistry and Biochemistry, Texas Tech University , Lubbock, Texas 79409, United States
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Lim JA, Kakhlon O, Li L, Myerowitz R, Raben N. Pompe disease: Shared and unshared features of lysosomal storage disorders. Rare Dis 2015; 3:e1068978. [PMID: 26619007 PMCID: PMC4620984 DOI: 10.1080/21675511.2015.1068978] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 01/29/2023] Open
Abstract
Pompe disease, an inherited deficiency of lysosomal acid α-glucosidase (GAA), is a severe metabolic myopathy with a wide range of clinical manifestations. It is the first recognized lysosomal storage disorder and the first neuromuscular disorder for which a therapy (enzyme replacement) has been approved. As GAA is the only enzyme that hydrolyses glycogen to glucose in the acidic environment of the lysosome, its deficiency leads to glycogen accumulation within and concomitant enlargement of this organelle. Since the introduction of the therapy, the overall understanding of the disease has progressed significantly, but the pathophysiology of muscle damage is still not fully understood. The emerging complex picture of the pathological cascade involves disturbance of calcium homeostasis, mitochondrial abnormalities, dysfunctional autophagy, accumulation of toxic undegradable materials, and accelerated production of lipofuscin deposits that are unrelated to aging. The relationship of Pompe disease to other lysosomal storage disorders and potential therapeutic interventions for Pompe disease are discussed.
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Affiliation(s)
- Jeong-A Lim
- Laboratory of Muscle Stem Cells and Gene Regulation; National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institutes of Health ; Bethesda, MD USA
| | - Or Kakhlon
- Department of Neurology; Hadassah-Hebrew University Medical Center ; Ein Kerem, Jerusalem, Israel
| | - Lishu Li
- Laboratory of Muscle Stem Cells and Gene Regulation; National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institutes of Health ; Bethesda, MD USA
| | - Rachel Myerowitz
- Laboratory of Muscle Stem Cells and Gene Regulation; National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institutes of Health ; Bethesda, MD USA ; St. Mary's College of Maryland ; St. Mary's City, MD USA
| | - Nina Raben
- Laboratory of Muscle Stem Cells and Gene Regulation; National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institutes of Health ; Bethesda, MD USA
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Chandrachud U, Walker MW, Simas AM, Heetveld S, Petcherski A, Klein M, Oh H, Wolf P, Zhao WN, Norton S, Haggarty SJ, Lloyd-Evans E, Cotman SL. Unbiased Cell-based Screening in a Neuronal Cell Model of Batten Disease Highlights an Interaction between Ca2+ Homeostasis, Autophagy, and CLN3 Protein Function. J Biol Chem 2015; 290:14361-80. [PMID: 25878248 DOI: 10.1074/jbc.m114.621706] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Indexed: 11/06/2022] Open
Abstract
Abnormal accumulation of undigested macromolecules, often disease-specific, is a major feature of lysosomal and neurodegenerative disease and is frequently attributed to defective autophagy. The mechanistic underpinnings of the autophagy defects are the subject of intense research, which is aided by genetic disease models. To gain an improved understanding of the pathways regulating defective autophagy specifically in juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), a neurodegenerative disease of childhood, we developed and piloted a GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) screening assay to identify, in an unbiased fashion, genotype-sensitive small molecule autophagy modifiers, employing a JNCL neuronal cell model bearing the most common disease mutation in CLN3. Thapsigargin, a sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) Ca(2+) pump inhibitor, reproducibly displayed significantly more activity in the mouse JNCL cells, an effect that was also observed in human-induced pluripotent stem cell-derived JNCL neural progenitor cells. The mechanism of thapsigargin sensitivity was Ca(2+)-mediated, and autophagosome accumulation in JNCL cells could be reversed by Ca(2+) chelation. Interrogation of intracellular Ca(2+) handling highlighted alterations in endoplasmic reticulum, mitochondrial, and lysosomal Ca(2+) pools and in store-operated Ca(2+) uptake in JNCL cells. These results further support an important role for the CLN3 protein in intracellular Ca(2+) handling and in autophagic pathway flux and establish a powerful new platform for therapeutic screening.
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Affiliation(s)
- Uma Chandrachud
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Mathew W Walker
- the Sir Martin Evans Building, School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Alexandra M Simas
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Sasja Heetveld
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Anton Petcherski
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Madeleine Klein
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Hyejin Oh
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Pavlina Wolf
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Wen-Ning Zhao
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Stephanie Norton
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Stephen J Haggarty
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
| | - Emyr Lloyd-Evans
- the Sir Martin Evans Building, School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Susan L Cotman
- From the Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 and
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Huber RJ, Myre MA, Cotman SL. Loss of Cln3 function in the social amoeba Dictyostelium discoideum causes pleiotropic effects that are rescued by human CLN3. PLoS One 2014; 9:e110544. [PMID: 25330233 PMCID: PMC4201555 DOI: 10.1371/journal.pone.0110544] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/15/2014] [Indexed: 12/15/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCL) are a group of inherited, severe neurodegenerative disorders also known as Batten disease. Juvenile NCL (JNCL) is caused by recessive loss-of-function mutations in CLN3, which encodes a transmembrane protein that regulates endocytic pathway trafficking, though its primary function is not yet known. The social amoeba Dictyostelium discoideum is increasingly utilized for neurological disease research and is particularly suited for investigation of protein function in trafficking. Therefore, here we establish new overexpression and knockout Dictyostelium cell lines for JNCL research. Dictyostelium Cln3 fused to GFP localized to the contractile vacuole system and to compartments of the endocytic pathway. cln3− cells displayed increased rates of proliferation and an associated reduction in the extracellular levels and cleavage of the autocrine proliferation repressor, AprA. Mid- and late development of cln3− cells was precocious and cln3− slugs displayed increased migration. Expression of either Dictyostelium Cln3 or human CLN3 in cln3− cells suppressed the precocious development and aberrant slug migration, which were also suppressed by calcium chelation. Taken together, our results show that Cln3 is a pleiotropic protein that negatively regulates proliferation and development in Dictyostelium. This new model system, which allows for the study of Cln3 function in both single cells and a multicellular organism, together with the observation that expression of human CLN3 restores abnormalities in Dictyostelium cln3− cells, strongly supports the use of this new model for JNCL research.
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Affiliation(s)
- Robert J. Huber
- Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Michael A. Myre
- Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Susan L. Cotman
- Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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