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Koster KP, Fyke Z, Nguyen TTA, Niqula A, Noriega-González LY, Woolfrey KM, Dell’Acqua ML, Cologna SM, Yoshii A. Akap5 links synaptic dysfunction to neuroinflammatory signaling in a mouse model of infantile neuronal ceroid lipofuscinosis. Front Synaptic Neurosci 2024; 16:1384625. [PMID: 38798824 PMCID: PMC11116793 DOI: 10.3389/fnsyn.2024.1384625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 04/23/2024] [Indexed: 05/29/2024] Open
Abstract
Palmitoylation and depalmitoylation represent dichotomic processes by which a labile posttranslational lipid modification regulates protein trafficking and degradation. The depalmitoylating enzyme, palmitoyl-protein thioesterase 1 (PPT1), is associated with the devastating pediatric neurodegenerative condition, infantile neuronal ceroid lipofuscinosis (CLN1). CLN1 is characterized by the accumulation of autofluorescent lysosomal storage material (AFSM) in neurons and robust neuroinflammation. Converging lines of evidence suggest that in addition to cellular waste accumulation, the symptomology of CLN1 corresponds with disruption of synaptic processes. Indeed, loss of Ppt1 function in cortical neurons dysregulates the synaptic incorporation of the GluA1 AMPA receptor (AMPAR) subunit during a type of synaptic plasticity called synaptic scaling. However, the mechanisms causing this aberration are unknown. Here, we used the Ppt1-/- mouse model (both sexes) to further investigate how Ppt1 regulates synaptic plasticity and how its disruption affects downstream signaling pathways. To this end, we performed a palmitoyl-proteomic screen, which provoked the discovery that Akap5 is excessively palmitoylated at Ppt1-/- synapses. Extending our previous data, in vivo induction of synaptic scaling, which is regulated by Akap5, caused an excessive upregulation of GluA1 in Ppt1-/- mice. This synaptic change was associated with exacerbated disease pathology. Furthermore, the Akap5- and inflammation-associated transcriptional regulator, nuclear factor of activated T cells (NFAT), was sensitized in Ppt1-/- cortical neurons. Suppressing the upstream regulator of NFAT activation, calcineurin, with the FDA-approved therapeutic FK506 (Tacrolimus) modestly improved neuroinflammation in Ppt1-/- mice. These findings indicate that the absence of depalmitoylation stifles synaptic protein trafficking and contributes to neuroinflammation via an Akap5-associated mechanism.
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Affiliation(s)
- Kevin P. Koster
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Zach Fyke
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | - Thu T. A. Nguyen
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Amanda Niqula
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
| | | | - Kevin M. Woolfrey
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Stephanie M. Cologna
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Akira Yoshii
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL, United States
- Department of Neurology, University of Illinois at Chicago, Chicago, IL, United States
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Puhl AC, Raman R, Havener TM, Minerali E, Hickey AJ, Ekins S. Identification of New Modulators and Inhibitors of Palmitoyl-Protein Thioesterase 1 for CLN1 Batten Disease and Cancer. ACS OMEGA 2024; 9:11870-11882. [PMID: 38496939 PMCID: PMC10938339 DOI: 10.1021/acsomega.3c09607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/02/2024] [Accepted: 02/13/2024] [Indexed: 03/19/2024]
Abstract
Palmitoyl-protein thioesterase 1 (PPT1) is an understudied enzyme that is gaining attention due to its role in the depalmitoylation of several proteins involved in neurodegenerative diseases and cancer. PPT1 is overexpressed in several cancers, specifically cholangiocarcinoma and esophageal cancers. Inhibitors of PPT1 lead to cell death and have been shown to enhance the killing of tumor cells alongside known chemotherapeutics. PPT1 is hence a viable target for anticancer drug development. Furthermore, mutations in PPT1 cause a lysosomal storage disorder called infantile neuronal ceroid lipofuscinosis (CLN1 disease). Molecules that can inhibit, stabilize, or modulate the activity of this target are needed to address these diseases. We used PPT1 enzymatic assays to identify molecules that were subsequently tested by using differential scanning fluorimetry and microscale thermophoresis. Selected compounds were also tested in neuroblastoma cell lines. The resulting PPT1 screening data was used for building machine learning models to help select additional compounds for testing. We discovered two of the most potent PPT1 inhibitors reported to date, orlistat (IC50 178.8 nM) and palmostatin B (IC50 11.8 nM). When tested in HepG2 cells, it was found that these molecules had decreased activity, indicating that they were likely not penetrating the cells. The combination of in vitro enzymatic and biophysical assays enabled the identification of several molecules that can bind or inhibit PPT1 and may aid in the discovery of modulators or chaperones. The molecules identified could be used as a starting point for further optimization as treatments for other potential therapeutic applications outside CLN1 disease, such as cancer and neurological diseases.
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Affiliation(s)
- Ana C. Puhl
- Collaborations
Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Renuka Raman
- Collaborations
Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Tammy M. Havener
- UNC
Catalyst for Rare Diseases, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Eni Minerali
- Collaborations
Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
| | - Anthony J. Hickey
- UNC
Catalyst for Rare Diseases, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- RTI
International, Research Triangle
Park, North Carolina 27709, United States
| | - Sean Ekins
- Collaborations
Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, North Carolina 27606, United States
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Boya P, Kaarniranta K, Handa JT, Sinha D. Lysosomes in retinal health and disease. Trends Neurosci 2023; 46:1067-1082. [PMID: 37848361 PMCID: PMC10842632 DOI: 10.1016/j.tins.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 09/06/2023] [Accepted: 09/24/2023] [Indexed: 10/19/2023]
Abstract
Lysosomes play crucial roles in various cellular processes - including endocytosis, phagocytosis, and autophagy - which are vital for maintaining retinal health. Moreover, these organelles serve as environmental sensors and act as central hubs for multiple signaling pathways. Through communication with other cellular components, such as mitochondria, lysosomes orchestrate the cytoprotective response essential for preserving cellular homeostasis. This coordination is particularly critical in the retina, given its high metabolic rate and susceptibility to photo-oxidative stress. Consequently, impaired lysosomal function and dysregulated communication between lysosomes and other organelles contribute significantly to the pathobiology of major retinal degenerative diseases. This review explores the pivotal role of lysosomes in retinal cells and their involvement in retinal degenerative diseases.
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Affiliation(s)
- Patricia Boya
- Department of Neuroscience, University of Fribourg, Fribourg, Switzerland
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland; Department of Molecular Genetics, University of Lodz, Lodz, Poland
| | - James T Handa
- The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Debasish Sinha
- The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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4
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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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5
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Jana M, Dutta D, Poddar J, Pahan K. Activation of PPARα Exhibits Therapeutic Efficacy in a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis. J Neurosci 2023; 43:1814-1829. [PMID: 36697260 PMCID: PMC10010460 DOI: 10.1523/jneurosci.2447-21.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal inherited neurodegenerative disease of children that occurs because of defective function of the lysosomal membrane glycoprotein CLN3. JNCL features glial activation and accumulation of autofluorescent storage material containing subunit c of mitochondrial ATP synthase (SCMAS), ultimately resulting into neuronal loss. Until now, no effective therapy is available for JNCL. This study underlines the possible therapeutic importance of gemfibrozil, an activator of peroxisome proliferator-activated receptor α (PPARα) and a lipid-lowering drug approved by the Food and Drug Administration in an animal model of JNCL. Oral gemfibrozil treatment reduced microglial and astroglial activation, attenuated neuroinflammation, restored the level of transcription factor EB (TFEB; the master regulator of lysosomal biogenesis), and decreased the accumulation of storage material SCMAS in somatosensory barrel field (SBF) cortex of Cln3Δex7/8 (Cln3ΔJNCL) mice of both sexes. Accordingly, gemfibrozil treatment also improved locomotor activities of Cln3ΔJNCL mice. While investigating the mechanism, we found marked loss of PPARα in the SBF cortex of Cln3ΔJNCL mice, which increased after gemfibrozil treatment. Oral gemfibrozil also stimulated the recruitment of PPARα to the Tfeb gene promoter in vivo in the SBF cortex of Cln3ΔJNCL mice, indicating increased transcription of Tfeb in the CNS by gemfibrozil treatment via PPARα. Moreover, disease pathologies aggravated in Cln3ΔJNCL mice lacking PPARα (Cln3ΔJNCLΔPPARα) and gemfibrozil remained unable to decrease SCMAS accumulation, reduce glial activation, and improve locomotor performance of Cln3ΔJNCLΔPPARα mice. These results suggest that activation of PPARα may be beneficial for JNCL and that gemfibrozil may be repurposed for the treatment of this incurable disease.SIGNIFICANCE STATEMENT Despite intense investigations, no effective therapy is available for JNCL, an incurable inherited lysosomal storage disorder. Here, we delineate that oral administration of gemfibrozil, a lipid-lowering drug, decreases glial inflammation, normalizes and/or upregulates TFEB, and reduces accumulation of autofluorescent storage material in SBF cortex to improve locomotor activities in Cln3Δex7/8 (Cln3ΔJNCL) mice. Aggravation of disease pathology in Cln3ΔJNCL mice lacking PPARα (Cln3ΔJNCLΔPPARα) and inability of gemfibrozil to decrease SCMAS accumulation, reduce glial activation, and improve locomotor performance of Cln3ΔJNCLΔPPARα mice delineates an important role of PPARα in this process. These studies highlight a new property of gemfibrozil and indicate its possible therapeutic use in JNCL patients.
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Affiliation(s)
- Malabendu Jana
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612
| | - Debashis Dutta
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612
| | - Jit Poddar
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612
| | - Kalipada Pahan
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612
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Murray SJ, Mitchell NL. Natural history of retinal degeneration in ovine models of CLN5 and CLN6 neuronal ceroid lipofuscinoses. Sci Rep 2022; 12:3670. [PMID: 35256654 PMCID: PMC8901734 DOI: 10.1038/s41598-022-07612-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/14/2022] [Indexed: 11/08/2022] Open
Abstract
Neuronal ceroid lipofuscinoses (NCL; Batten disease) are a group of inherited neurodegenerative diseases with a common set of symptoms including cognitive and motor decline and vision loss. Naturally occurring sheep models of CLN5 and CLN6 disease display the key clinical features of NCL, including a progressive loss of vision. We assessed retinal histology, astrogliosis, and lysosomal storage accumulation in CLN5 affected (CLN5-/-) and CLN6 affected (CLN6-/-) sheep eyes and age-matched controls at 3, 6, 12, and 18 months of age to determine the onset and progression of retinal pathology in NCL sheep. The retina of CLN5-/- sheep shows progressive atrophy of the outer retinal layers, widespread gliosis, and accumulation of lysosomal storage in retinal ganglion cells late in disease. In contrast, CLN6-/- retina shows significant atrophy of all retinal layers, progressive gliosis, and earlier accumulation of lysosomal storage. This study has highlighted the differential vulnerability of retinal layers and the time course of retinal atrophy in two distinct models of NCL disease. This data will be valuable in determining potential targets for ocular therapies and the optimal timing of these therapies for protection from retinal dysfunction and degeneration in NCL.
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Affiliation(s)
- S J Murray
- Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 85084, Lincoln, Canterbury, 7647, New Zealand
| | - N L Mitchell
- Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 85084, Lincoln, Canterbury, 7647, New Zealand.
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7
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Kim WD, Wilson-Smillie MLDM, Thanabalasingam A, Lefrancois S, Cotman SL, Huber RJ. Autophagy in the Neuronal Ceroid Lipofuscinoses (Batten Disease). Front Cell Dev Biol 2022; 10:812728. [PMID: 35252181 PMCID: PMC8888908 DOI: 10.3389/fcell.2022.812728] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), also referred to as Batten disease, are a family of neurodegenerative diseases that affect all age groups and ethnicities around the globe. At least a dozen NCL subtypes have been identified that are each linked to a mutation in a distinct ceroid lipofuscinosis neuronal (CLN) gene. Mutations in CLN genes cause the accumulation of autofluorescent lipoprotein aggregates, called ceroid lipofuscin, in neurons and other cell types outside the central nervous system. The mechanisms regulating the accumulation of this material are not entirely known. The CLN genes encode cytosolic, lysosomal, and integral membrane proteins that are associated with a variety of cellular processes, and accumulated evidence suggests they participate in shared or convergent biological pathways. Research across a variety of non-mammalian and mammalian model systems clearly supports an effect of CLN gene mutations on autophagy, suggesting that autophagy plays an essential role in the development and progression of the NCLs. In this review, we summarize research linking the autophagy pathway to the NCLs to guide future work that further elucidates the contribution of altered autophagy to NCL pathology.
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Affiliation(s)
- William D. Kim
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | | | - Aruban Thanabalasingam
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | - Stephane Lefrancois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de La Recherche Scientifique, Laval, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Centre D'Excellence en Recherche sur Les Maladies Orphelines–Fondation Courtois (CERMO-FC), Université Du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Susan L. Cotman
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA, United States
| | - Robert J. Huber
- Department of Biology, Trent University, Peterborough, ON, Canada
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8
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Liu J, Bassal M, Schlichting S, Braren I, Di Spiezio A, Saftig P, Bartsch U. Intravitreal gene therapy restores the autophagy-lysosomal pathway and attenuates retinal degeneration in cathepsin D-deficient mice. Neurobiol Dis 2022; 164:105628. [PMID: 35033660 DOI: 10.1016/j.nbd.2022.105628] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 11/16/2022] Open
Abstract
Loss of vision due to progressive retinal degeneration is a hallmark of neuronal ceroid lipofuscinoses (NCL), a group of fatal neurodegenerative lysosomal storage diseases. Enzyme substitution therapies represent promising treatment options for NCLs caused by dysfunctions of soluble lysosomal enzymes. Here, we compared the efficacy of a cell-based enzyme substitution strategy and a gene therapy approach to attenuate the retinal pathology in cathepsin D- (CTSD) deficient mice, an animal model of CLN10 disease. Levels of enzymatically active CTSD in mutant retinas were significantly higher after an adeno-associated virus vector-mediated CTSD transfer to retinal glial cells and retinal pigment epithelial cells than after intravitreal transplantations of a CTSD overexpressing clonal neural stem cell line. In line with this finding, the gene therapy treatment restored the disrupted autophagy-lysosomal pathway more effectively than the cell-based approach, as indicated by a complete clearance of storage, significant attenuation of lysosomal hypertrophy, and normalized levels of the autophagy marker sequestosome 1/p62 and microtubule-associated protein 1 light chain 3-II. While the cell-based treatment did not prevent the rapidly progressing loss of various retinal cell types, the gene therapy approach markedly attenuated retinal degeneration as demonstrated by a pronounced rescue of photoreceptor cells and rod bipolar cells.
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Affiliation(s)
- Junling Liu
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Mahmoud Bassal
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Stefanie Schlichting
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Ingke Braren
- Vector Facility, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | | | - Paul Saftig
- Institute of Biochemistry, Christian-Albrechts-University Kiel, 24118 Kiel, Germany
| | - Udo Bartsch
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
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9
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Targeting lysosomes in human disease: from basic research to clinical applications. Signal Transduct Target Ther 2021; 6:379. [PMID: 34744168 PMCID: PMC8572923 DOI: 10.1038/s41392-021-00778-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/26/2021] [Indexed: 01/18/2023] Open
Abstract
In recent years, accumulating evidence has elucidated the role of lysosomes in dynamically regulating cellular and organismal homeostasis. Lysosomal changes and dysfunction have been correlated with the development of numerous diseases. In this review, we interpreted the key biological functions of lysosomes in four areas: cellular metabolism, cell proliferation and differentiation, immunity, and cell death. More importantly, we actively sought to determine the characteristic changes and dysfunction of lysosomes in cells affected by these diseases, the causes of these changes and dysfunction, and their significance to the development and treatment of human disease. Furthermore, we outlined currently available targeting strategies: (1) targeting lysosomal acidification; (2) targeting lysosomal cathepsins; (3) targeting lysosomal membrane permeability and integrity; (4) targeting lysosomal calcium signaling; (5) targeting mTOR signaling; and (6) emerging potential targeting strategies. Moreover, we systematically summarized the corresponding drugs and their application in clinical trials. By integrating basic research with clinical findings, we discussed the current opportunities and challenges of targeting lysosomes in human disease.
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10
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Retinal Degeneration and Microglial Dynamics in Mature Progranulin-Deficient Mice. Int J Mol Sci 2021; 22:ijms222111557. [PMID: 34768987 PMCID: PMC8584076 DOI: 10.3390/ijms222111557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/22/2021] [Accepted: 10/23/2021] [Indexed: 11/16/2022] Open
Abstract
Progranulin (PGRN) is a secreted glycoprotein that regulates numerous cellular processes. The role of PGRN as a regulator of lysosomes has recently received attention. The purpose of this study was to characterize the retinal phenotype in mature PGRN knockout (Grn−/−) mice. The a-wave amplitude of scotopic electroretinogram and outer nuclear thickness were significantly reduced at 6 months of age in Grn−/− mice compared to wild-type (Grn+/+) mice. In Grn−/− mice, retinal microglial cells accumulated on the retinal pigment epithelium (RPE) apical layer, and the number of infiltrated microglia and white fundus lesions between 2 and 6 months of age showed a close affinity. In Grn+/+ mice, PGRN was located in the retina, while the strongest PGRN signals were detected in the RPE-choroid. The different effects of PGRN deficiency on the expression of lysosomal proteins between the retina and RPE-choroid were demonstrated. Our data suggest that the subretinal translocation of microglia is a characteristic phenotype in the retina of mature PGRN knockout mice. The different effects of PGRN deficiency on the expression of lysosomal proteins between the retina and RPE-choroid might modulate microglial dynamics in PGRN knockout mice.
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11
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Bartsch U, Liu J, Bassal M, Jankowiak W, Spitzer MS, Bartsch S. [Preclinical developments of treatment options for retinal dystrophy in neuronal ceroid lipofuscinosis]. Ophthalmologe 2021; 118:769-770. [PMID: 34086071 DOI: 10.1007/s00347-021-01419-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Udo Bartsch
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland.
| | - Junling Liu
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland
| | - Mahmoud Bassal
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland
| | - Wanda Jankowiak
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland
| | - Martin S Spitzer
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland
| | - Susanne Bartsch
- Klinik und Poliklinik für Augenheilkunde, Experimentelle Ophthalmologie, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Deutschland
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Groh J, Berve K, Martini R. Immune modulation attenuates infantile neuronal ceroid lipofuscinosis in mice before and after disease onset. Brain Commun 2021; 3:fcab047. [PMID: 33977263 PMCID: PMC8098642 DOI: 10.1093/braincomms/fcab047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/27/2020] [Accepted: 01/26/2021] [Indexed: 12/26/2022] Open
Abstract
Targeting neuroinflammation in models for infantile and juvenile forms of neuronal ceroid lipofuscinosis (NCL, CLN disease) with the clinically established immunomodulators fingolimod and teriflunomide significantly attenuates the neurodegenerative phenotype when applied preventively, i.e. before the development of substantial neural damage and clinical symptoms. Here, we show that in a mouse model for the early onset and rapidly progressing CLN1 form, more complex clinical phenotypes like disturbed motor coordination and impaired visual acuity are also ameliorated by immunomodulation. Moreover, we show that the disease outcome can be attenuated even when fingolimod and teriflunomide treatment starts after disease onset, i.e. when neurodegeneration is ongoing and clinical symptoms are detectable. In detail, treatment with either drug led to a reduction in T-cell numbers and microgliosis in the CNS, although not to the same extent as upon preventive treatment. Pharmacological immunomodulation was accompanied by a reduction of axonal damage, neuron loss and astrogliosis in the retinotectal system and by reduced brain atrophy. Accordingly, the frequency of myoclonic jerks and disturbed motor coordination were attenuated. Overall, disease alleviation was remarkably substantial upon therapeutic treatment with both drugs, although less robust than upon preventive treatment. To test the relevance of putative immune-independent mechanisms of action in this model, we treated CLN1 mice lacking mature T- and B-lymphocytes. Immunodeficient CLN1 mice showed, as previously reported, an improved neurological phenotype in comparison with genuine CLN1 mice which could not be further alleviated by either of the drugs, reflecting a predominantly immune-related therapeutic mechanism of action. The present study supports and strengthens our previous view that repurposing clinically approved immunomodulators may alleviate the course of CLN1 disease in human patients, even though diagnosis usually occurs when symptoms have already emerged.
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Affiliation(s)
- Janos Groh
- Section of Developmental Neurobiology, Department of Neurology, University Hospital Würzburg, 97080 Würzburg, Germany
| | - Kristina Berve
- Section of Developmental Neurobiology, Department of Neurology, University Hospital Würzburg, 97080 Würzburg, Germany
| | - Rudolf Martini
- Section of Developmental Neurobiology, Department of Neurology, University Hospital Würzburg, 97080 Würzburg, Germany
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Bassal M, Liu J, Jankowiak W, Saftig P, Bartsch U. Rapid and Progressive Loss of Multiple Retinal Cell Types in Cathepsin D-Deficient Mice-An Animal Model of CLN10 Disease. Cells 2021; 10:696. [PMID: 33800998 PMCID: PMC8003850 DOI: 10.3390/cells10030696] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/11/2021] [Accepted: 03/19/2021] [Indexed: 12/18/2022] Open
Abstract
Vision loss is among the characteristic symptoms of neuronal ceroid lipofuscinosis (NCL), a fatal neurodegenerative lysosomal storage disorder. Here, we performed an in-depth analysis of retinal degeneration at the molecular and cellular levels in mice lacking the lysosomal aspartyl protease cathepsin D, an animal model of congenital CLN10 disease. We observed an early-onset accumulation of storage material as indicated by elevated levels of saposin D and subunit C of the mitochondrial ATP synthase. The accumulation of storage material was accompanied by reactive astrogliosis and microgliosis, elevated expression of the autophagy marker sequestosome 1/p62 and a dysregulated expression of several lysosomal proteins. The number of cone photoreceptor cells was reduced as early as at postnatal day 5. At the end stage of the disease, the outer nuclear layer was almost atrophied, and all cones were lost. A significant loss of rod and cone bipolar cells, amacrine cells and ganglion cells was found at advanced stages of the disease. Results demonstrate that cathepsin D deficiency results in an early-onset and rapidly progressing retinal dystrophy that involves all retinal cell types. Data of the present study will serve as a reference for studies aimed at developing treatments for retinal degeneration in CLN10 disease.
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Affiliation(s)
- Mahmoud Bassal
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.B.); (J.L.); (W.J.)
| | - Junling Liu
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.B.); (J.L.); (W.J.)
| | - Wanda Jankowiak
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.B.); (J.L.); (W.J.)
| | - Paul Saftig
- Institute of Biochemistry, Christian-Albrechts-University Kiel, 24118 Kiel, Germany;
| | - Udo Bartsch
- Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (M.B.); (J.L.); (W.J.)
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[Experimental therapeutic approaches for the treatment of retinal dystrophy in neuronal ceroid lipofuscinosis]. Ophthalmologe 2021; 118:106-112. [PMID: 33030566 DOI: 10.1007/s00347-020-01237-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Neuronal ceroid lipofuscinosis (NCL) is a group of rare and fatal neurodegenerative lysosomal storage diseases. Progressive retinal degeneration and loss of vision are among the characteristic symptoms of affected patients. A brain-directed enzyme replacement therapy has been shown to significantly attenuate the neurological symptoms in CLN2 patients and is currently the only approved therapy for NCL; however, there is presently no treatment option for retinal dystrophy in NCL. OBJECTIVE This short review aims to give an overview of preclinical studies that have developed and evaluated therapeutic strategies for the treatment of retinal dystrophy in animal models of different NCL forms. MATERIAL AND METHODS The key findings of preclinical studies that have achieved positive therapeutic effects on retinal structure and/or function using different treatment strategies are summarized and discussed. RESULTS AND CONCLUSION The published data on preclinical studies demonstrate the efficacy of different therapeutic strategies to attenuate retinal degeneration and vision loss in animal models for different NCL forms. It remains to be seen whether these promising results can be confirmed in future clinical studies.
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Behnke V, Langmann T. [Neuroinflammation in neuronal ceroid lipofuscinosis]. Ophthalmologe 2021; 118:98-105. [PMID: 33411040 DOI: 10.1007/s00347-020-01301-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND Retinal degeneration and neuroinflammation are often early hallmarks of different subtypes of neuronal ceroid lipofuscinosis (NCL) in patients and genetic animal models. OBJECTIVE This article gives a summary of recently published research articles and novel concepts in the field of NCL-related neuroinflammation. MATERIAL AND METHODS A search was carried out in PubMed for relevant publications and the results as well as own NCL-related research are discussed. RESULTS Microglia and other glial cells are chronically activated and show various dysfunctions in the central nervous system (CNS) and retina of NCL patients and animal models. This is accompanied by significant changes in the transcriptome and proteome. In NCL there is also involvement of the adaptive immune response, as demonstrated by the influx of autoantibodies and activated T cells. CONCLUSION A deeper understanding of the molecular processes that contribute to neuroinflammation and ultimately lead to neuronal cell death is an important basis for the discovery of possible biomarkers and the development of immunotherapies in NCL.
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Affiliation(s)
- V Behnke
- Lehrstuhl für Experimentelle Immunologie des Auges, Zentrum für Augenheilkunde, Medizinische Fakultät und Uniklinik Köln, Joseph-Stelzmann-Str. 9, 50931, Köln, Deutschland
| | - T Langmann
- Lehrstuhl für Experimentelle Immunologie des Auges, Zentrum für Augenheilkunde, Medizinische Fakultät und Uniklinik Köln, Joseph-Stelzmann-Str. 9, 50931, Köln, Deutschland. .,Zentrum für Molekulare Medizin, Köln, Deutschland.
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Ramachandra Rao S, Skelton LA, Wu F, Onysk A, Spolnik G, Danikiewicz W, Butler MC, Stacks DA, Surmacz L, Mu X, Swiezewska E, Pittler SJ, Fliesler SJ. Retinal Degeneration Caused by Rod-Specific Dhdds Ablation Occurs without Concomitant Inhibition of Protein N-Glycosylation. iScience 2020; 23:101198. [PMID: 32526701 PMCID: PMC7287266 DOI: 10.1016/j.isci.2020.101198] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/10/2020] [Accepted: 05/20/2020] [Indexed: 12/16/2022] Open
Abstract
Dehydrodolichyl diphosphate synthase (DHDDS) catalyzes the committed step in dolichol synthesis. Recessive mutations in DHDDS cause retinitis pigmentosa (RP59), resulting in blindness. We hypothesized that rod photoreceptor-specific ablation of Dhdds would cause retinal degeneration due to diminished dolichol-dependent protein N-glycosylation. Dhddsflx/flx mice were crossed with rod-specific Cre recombinase-expressing (Rho-iCre75) mice to generate rod-specific Dhdds knockout mice (Dhddsflx/flx iCre+). In vivo morphological and electrophysiological evaluation of Dhddsflx/flx iCre+ retinas revealed mild retinal dysfunction at postnatal (PN) 4 weeks, compared with age-matched controls; however, rapid photoreceptor degeneration ensued, resulting in almost complete loss of rods and cones by PN 6 weeks. Retina dolichol levels were markedly decreased by PN 4 weeks in Dhddsflx/flx iCre+ mice, relative to controls; despite this, N-glycosylation of retinal proteins, including opsin (the dominant rod-specific glycoprotein), persisted in Dhddsflx/flx iCre+ mice. These findings challenge the conventional mechanistic view of RP59 as a congenital disorder of glycosylation. Deletion of Dhdds in rod cells caused rapid retinal degeneration in mice Retinal dolichol levels markedly decreased before onset of degeneration Protein N-glycosylation was uncompromised despite Dhdds deletion Degeneration also involved gliosis, microglial activation, and phagoptosis
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY 142015, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA
| | - Lara A Skelton
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY 142015, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA
| | - Fuguo Wu
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA; New York State Center of Excellence in Bioinformatics and Life Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA
| | - Agnieszka Onysk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Grzegorz Spolnik
- Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw 02106, Poland
| | - Witold Danikiewicz
- Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw 02106, Poland
| | - Mark C Butler
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY 142015, USA
| | - Delores A Stacks
- Department of Optometry and Vision Science, Vision Science Research Center, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Liliana Surmacz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Xiuqian Mu
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA; New York State Center of Excellence in Bioinformatics and Life Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA
| | - Ewa Swiezewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Steven J Pittler
- Department of Optometry and Vision Science, Vision Science Research Center, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Steven J Fliesler
- Department of Ophthalmology/Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14209, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY 142015, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY 14203, USA.
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