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Tesla R, Guhl C, Werthmann GC, Dixon D, Cenik B, Addepalli Y, Liang J, Fass DM, Rosenthal Z, Haggarty SJ, Williams NS, Posner BA, Ready JM, Herz J. Benzoxazole-derivatives enhance progranulin expression and reverse the aberrant lysosomal proteome caused by GRN haploinsufficiency. Nat Commun 2024; 15:6125. [PMID: 39033178 PMCID: PMC11271458 DOI: 10.1038/s41467-024-50076-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 07/01/2024] [Indexed: 07/23/2024] Open
Abstract
Heterozygous loss-of-function mutations in the GRN gene are a major cause of hereditary frontotemporal dementia. The mechanisms linking frontotemporal dementia pathogenesis to progranulin deficiency are not well understood, and there is currently no treatment. Our strategy to prevent the onset and progression of frontotemporal dementia in patients with GRN mutations is to utilize small molecule positive regulators of GRN expression to boost progranulin levels from the remaining functional GRN allele, thus restoring progranulin levels back to normal within the brain. This work describes a series of blood-brain-barrier-penetrant small molecules which significantly increase progranulin protein levels in human cellular models, correct progranulin protein deficiency in Grn+/- mouse brains, and reverse lysosomal proteome aberrations, a phenotypic hallmark of frontotemporal dementia, more efficiently than the previously described small molecule suberoylanilide hydroxamic acid. These molecules will allow further elucidation of the cellular functions of progranulin and its role in frontotemporal dementia and will also serve as lead structures for further drug development.
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Affiliation(s)
- Rachel Tesla
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Charlotte Guhl
- Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Gordon C Werthmann
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Danielle Dixon
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Basar Cenik
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Yesu Addepalli
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jue Liang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Daniel M Fass
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Zachary Rosenthal
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Stephen J Haggarty
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Departments of Neurology and Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Noelle S Williams
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bruce A Posner
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joseph M Ready
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Center for Translational Neurodegeneration Research, Dallas, TX, USA.
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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2
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Riordan R, Saxton A, McMillan PJ, Kow RL, Liachko NF, Kraemer BC. TMEM106B C-terminal fragments aggregate and drive neurodegenerative proteinopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598478. [PMID: 38915598 PMCID: PMC11195232 DOI: 10.1101/2024.06.11.598478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Genetic variation in the lysosomal and transmembrane protein 106B (TMEM106B) modifies risk for a diverse range of neurodegenerative disorders, especially frontotemporal lobar degeneration (FTLD) with progranulin (PGRN) haplo-insufficiency, although the molecular mechanisms involved are not yet understood. Through advances in cryo-electron microscopy (cryo-EM), homotypic aggregates of the C-Terminal domain of TMEM106B (TMEM CT) were discovered as a previously unidentified cytosolic proteinopathy in the brains of FTLD, Alzheimer's disease, progressive supranuclear palsy (PSP), and dementia with Lewy bodies (DLB) patients. While it remains unknown what role TMEM CT aggregation plays in neuronal loss, its presence across a range of aging related dementia disorders indicates involvement in multi-proteinopathy driven neurodegeneration. To determine the TMEM CT aggregation propensity and neurodegenerative potential, we characterized a novel transgenic C. elegans model expressing the human TMEM CT fragment constituting the fibrillar core seen in FTLD cases. We found that pan-neuronal expression of human TMEM CT in C. elegans causes neuronal dysfunction as evidenced by behavioral analysis. Cytosolic aggregation of TMEM CT proteins accompanied the behavioral dysfunction driving neurodegeneration, as illustrated by loss of GABAergic neurons. To investigate the molecular mechanisms driving TMEM106B proteinopathy, we explored the impact of PGRN loss on the neurodegenerative effect of TMEM CT expression. To this end, we generated TMEM CT expressing C. elegans with loss of pgrn-1, the C. elegans ortholog of human PGRN. Neither full nor partial loss of pgrn-1 altered the motor phenotype of our TMEM CT model suggesting TMEM CT aggregation occurs downstream of PGRN loss of function. We also tested the ability of genetic suppressors of tauopathy to rescue TMEM CT pathology. We found that genetic knockout of spop-1, sut-2, and sut-6 resulted in weak to no rescue of proteinopathy phenotypes, indicating that the mechanistic drivers of TMEM106B proteinopathy may be distinct from tauopathy. Taken together, our data demonstrate that TMEM CT aggregation can kill neurons. Further, expression of TMEM CT in C. elegans neurons provides a useful model for the functional characterization of TMEM106B proteinopathy in neurodegenerative disease.
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Affiliation(s)
- Ruben Riordan
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Aleen Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Pamela J. McMillan
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Rebecca L Kow
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Nicole F. Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Brian C. Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington 98195, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington 98195, USA
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3
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Bowhay CR, Hanington PC. Animal granulins: In the GRN scheme of things. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 152:105115. [PMID: 38101714 DOI: 10.1016/j.dci.2023.105115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/06/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
Granulins are conserved in nearly all metazoans, with an intriguing loss in insects. These pleiotropic peptides are involved in numerous physiological and pathological processes yet have been overwhelmingly examined in mammalian systems. While work in other animal models has been informative, a richer understanding of the proteins should be obtained by integrating knowledge from all available contexts. The main bodies of work described here include 1) the structure-function relationships of progranulin and its cleavage products, 2) the role of expanded granulin gene families and different isoforms in fish immunology, 3) the release of granulin peptides to promote host angiogenesis by parasitic worms, 4) a diversity of molluscan uses for granulins, including immune activation in intermediate hosts to trematodes, 5) knowledge gained on lysosomal functions from C. elegans and the stress-related activities of granulins. We provide an overview of functional reports across the Metazoa to inform much-needed future research.
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Affiliation(s)
- Christina R Bowhay
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Patrick C Hanington
- School of Public Health, University of Alberta, Edmonton, AB, T6G 2R3, Canada.
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Sung W, Noh MY, Nahm M, Kim YS, Ki CS, Kim YE, Kim HJ, Kim SH. Progranulin haploinsufficiency mediates cytoplasmic TDP-43 aggregation with lysosomal abnormalities in human microglia. J Neuroinflammation 2024; 21:47. [PMID: 38347588 PMCID: PMC10863104 DOI: 10.1186/s12974-024-03039-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/07/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Progranulin (PGRN) haploinsufficiency due to progranulin gene (GRN) variants can cause frontotemporal dementia (FTD) with aberrant TAR DNA-binding protein 43 (TDP-43) accumulation. Despite microglial burden with TDP-43-related pathophysiology, direct microglial TDP-43 pathology has not been clarified yet, only emphasized in neuronal pathology. Thus, the objective of this study was to investigate TDP-43 pathology in microglia of patients with PGRN haploinsufficiency. METHODS To design a human microglial cell model with PGRN haploinsufficiency, monocyte-derived microglia (iMGs) were generated from FTD-GRN patients carrying pathogenic or likely pathogenic variants (p.M1? and p.W147*) and three healthy controls. RESULTS iMGs from FTD-GRN patients with PGRN deficiency exhibited severe neuroinflammation phenotype and failure to maintain their homeostatic molecular signatures, along with impaired phagocytosis. In FTD-GRN patients-derived iMGs, significant cytoplasmic TDP-43 aggregation and accumulation of lipid droplets with profound lysosomal abnormalities were observed. These pathomechanisms were mediated by complement C1q activation and upregulation of pro-inflammatory cytokines. CONCLUSIONS Our study provides considerable cellular and molecular evidence that loss-of-function variants of GRN in human microglia can cause microglial dysfunction with abnormal TDP-43 aggregation induced by inflammatory milieu as well as the impaired lysosome. Elucidating the role of microglial TDP-43 pathology in intensifying neuroinflammation in individuals with FTD due to PGRN deficiency and examining consequential effects on microglial dysfunction might yield novel insights into the mechanisms underlying FTD and neurodegenerative disorders.
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Affiliation(s)
- Wonjae Sung
- Department of Neurology, College of Medicine, Hanyang University, 222, Wangsimni-Ro, Seongdong-Gu, Seoul, 04763, Republic of Korea
| | - Min-Young Noh
- Department of Neurology, College of Medicine, Hanyang University, 222, Wangsimni-Ro, Seongdong-Gu, Seoul, 04763, Republic of Korea
| | - Minyeop Nahm
- Dementia Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Yong Sung Kim
- Department of Neurology, College of Medicine, Hanyang University, 222, Wangsimni-Ro, Seongdong-Gu, Seoul, 04763, Republic of Korea
| | | | - Young-Eun Kim
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Hee-Jin Kim
- Department of Neurology, College of Medicine, Hanyang University, 222, Wangsimni-Ro, Seongdong-Gu, Seoul, 04763, Republic of Korea
| | - Seung Hyun Kim
- Department of Neurology, College of Medicine, Hanyang University, 222, Wangsimni-Ro, Seongdong-Gu, Seoul, 04763, Republic of Korea.
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5
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Wang AL, Mambou EA, Kao AW. The progranulin cleavage product granulin 3 exerts a dominant negative effect on animal fitness. Hum Mol Genet 2024; 33:245-253. [PMID: 37903062 PMCID: PMC10800025 DOI: 10.1093/hmg/ddad184] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/01/2023] Open
Abstract
Progranulin is an evolutionarily conserved protein that has been implicated in human neurodevelopmental and neurodegenerative diseases. Human progranulin is comprised of multiple cysteine-rich, biologically active granulin peptides. Granulin peptides accumulate with age and stress, however their functional contributions relative to full-length progranulin remain unclear. To address this, we generated C. elegans strains that produced quantifiable levels of both full-length progranulin/PGRN-1 protein and cleaved granulin peptide. Using these strains, we demonstrated that even in the presence of intact PGRN-1, granulin peptides suppressed the activity of the lysosomal aspartyl protease activity, ASP-3/CTSD. Granulin peptides were also dominant over PGRN-1 in compromising animal fitness as measured by progress through development and stress response. Finally, the degradation of human TDP-43 was impaired when the granulin to PGRN-1 ratio was increased, representing a disease-relevant downstream impact of impaired lysosomal function. In summary, these studies suggest that not only absolute progranulin levels, but also the balance between full-length progranulin and its cleavage products, is important in regulating lysosomal biology. Given its relevance in human disease, this suggests that the processing of progranulin into granulins should be considered as part of disease pathobiology and may represent a site of therapeutic intervention.
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Affiliation(s)
- Austin L Wang
- Memory and Aging Center, Weill Institute for Neuroscience, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Edwina A Mambou
- Memory and Aging Center, Weill Institute for Neuroscience, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Aimee W Kao
- Memory and Aging Center, Weill Institute for Neuroscience, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Bakar Aging Research Institute, University of California, San Francisco, San Francisco, CA, United States
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6
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Eck RJ, Stair JG, Kraemer BC, Liachko NF. Simple models to understand complex disease: 10 years of progress from Caenorhabditis elegans models of amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Front Neurosci 2024; 17:1300705. [PMID: 38239833 PMCID: PMC10794587 DOI: 10.3389/fnins.2023.1300705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 11/28/2023] [Indexed: 01/22/2024] Open
Abstract
The nematode Caenorhabditis elegans are a powerful model system to study human disease, with numerous experimental advantages including significant genetic and cellular homology to vertebrate animals, a short lifespan, and tractable behavioral, molecular biology and imaging assays. Beginning with the identification of SOD1 as a genetic cause of amyotrophic lateral sclerosis (ALS), C. elegans have contributed to a deeper understanding of the mechanistic underpinnings of this devastating neurodegenerative disease. More recently this work has expanded to encompass models of other types of ALS and the related disease frontotemporal lobar degeneration (FTLD-TDP), including those characterized by mutation or accumulation of the proteins TDP-43, C9orf72, FUS, HnRNPA2B1, ALS2, DCTN1, CHCHD10, ELP3, TUBA4A, CAV1, UBQLN2, ATXN3, TIA1, KIF5A, VAPB, GRN, and RAB38. In this review we summarize these models and the progress and insights from the last ten years of using C. elegans to study the neurodegenerative diseases ALS and FTLD-TDP.
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Affiliation(s)
- Randall J. Eck
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Jade G. Stair
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
| | - Brian C. Kraemer
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
| | - Nicole F. Liachko
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
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7
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Doyle JJ, Parker JA. Genetic Interactions of Progranulin Across the ALS-FTD Spectrum and Beyond. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000304. [PMID: 38188422 PMCID: PMC10767572 DOI: 10.17912/micropub.biology.000304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 08/08/2021] [Accepted: 12/19/2023] [Indexed: 01/09/2024]
Abstract
Progranulin (PGRN) is a growth factor in which mutations are one of the leading causes of frontotemporal dementia (FTD), and has been implicated in an assortment of neurodegenerative diseases. Conversely, higher levels of the protein have shown potential as a general neuronal protective factor. While examining its neuroprotective applications on a broader scale would be unfeasible in mammalian models, we turned to the nematode C. elegans to map the interactions of PGRN across multiple genetic models of neurodegenerative diseases. Our results indicate that while the overexpression of PGRN appears to be protective across all models tested, the loss of PGRN exacerbated the disease phenotypes of all but three of the models tested. Given the ease of genetic analysis in nematodes, we propose this model organism as an efficient tool to build a comprehensive map of PGRN's genetic interactions.
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Affiliation(s)
- James J. Doyle
- Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- Metabolic Disorders and Complications, RI-MUHC, Montreal, McGill, Canada
| | - J Alex Parker
- CRCHUM and Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada
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8
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Ortiz GG, Ramírez-Jirano J, Arizaga RL, Delgado-Lara DLC, Torres-Sánchez ED. Frontotemporal-TDP and LATE Neurocognitive Disorders: A Pathophysiological and Genetic Approach. Brain Sci 2023; 13:1474. [PMID: 37891841 PMCID: PMC10605418 DOI: 10.3390/brainsci13101474] [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: 09/15/2023] [Revised: 10/07/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Frontotemporal lobar degeneration (FTLD) belongs to a heterogeneous group of highly complex neurodegenerative diseases and represents the second cause of presenile dementia in individuals under 65. Frontotemporal-TDP is a subgroup of frontotemporal dementia characterized by the aggregation of abnormal protein deposits, predominantly transactive response DNA-binding protein 43 (TDP-43), in the frontal and temporal brain regions. These deposits lead to progressive degeneration of neurons resulting in cognitive and behavioral impairments. Limbic age-related encephalopathy (LATE) pertains to age-related cognitive decline primarily affecting the limbic system, which is crucial for memory, emotions, and learning. However, distinct, emerging research suggests a potential overlap in pathogenic processes, with some cases of limbic encephalopathy displaying TDP-43 pathology. Genetic factors play a pivotal role in both disorders. Mutations in various genes, such as progranulin (GRN) and chromosome 9 open reading frame 72 (C9orf72), have been identified as causative in frontotemporal-TDP. Similarly, specific genetic variants have been associated with an increased risk of developing LATE. Understanding these genetic links provides crucial insights into disease mechanisms and the potential for targeted therapies.
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Affiliation(s)
- Genaro Gabriel Ortiz
- Department of Philosophical and Methodological Disciplines, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico;
- Postgraduate Gerontology Program, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico
| | - Javier Ramírez-Jirano
- Neurosciences Division, Western Biomedical Research Center, Mexican Social Security Institute, IMSS, Guadalajara 44340, Jalisco, Mexico;
| | - Raul L. Arizaga
- Public Health Department, School of Medicine, University of Buenos Aires, Buenos Aires C1121ABG, Argentina;
| | - Daniela L. C. Delgado-Lara
- Department of Philosophical and Methodological Disciplines, University Health Sciences Center, University of Guadalajara, Guadalajara 44340, Jalisco, Mexico;
- Departamento Académico de Formación Universitaria, Ciencias de la Salud, Universidad Autónoma de Guadalajara, Zapopan 45129, Jalisco, Mexico
| | - Erandis D. Torres-Sánchez
- Department of Medical and Life Sciences, University Center of la Cienega, University of Guadalajara, Ocotlan 47820, Jalisco, Mexico
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9
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Davis SE, Cook AK, Hall JA, Voskobiynyk Y, Carullo NV, Boyle NR, Hakim AR, Anderson KM, Hobdy KP, Pugh DA, Murchison CF, McMeekin LJ, Simmons M, Margolies KA, Cowell RM, Nana AL, Spina S, Grinberg LT, Miller BL, Seeley WW, Arrant AE. Patients with sporadic FTLD exhibit similar increases in lysosomal proteins and storage material as patients with FTD due to GRN mutations. Acta Neuropathol Commun 2023; 11:70. [PMID: 37118844 PMCID: PMC10148425 DOI: 10.1186/s40478-023-01571-4] [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: 04/20/2023] [Accepted: 04/24/2023] [Indexed: 04/30/2023] Open
Abstract
Loss of function progranulin (GRN) mutations are a major autosomal dominant cause of frontotemporal dementia (FTD). Patients with FTD due to GRN mutations (FTD-GRN) develop frontotemporal lobar degeneration with TDP-43 pathology type A (FTLD-TDP type A) and exhibit elevated levels of lysosomal proteins and storage material in frontal cortex, perhaps indicating lysosomal dysfunction as a mechanism of disease. To investigate whether patients with sporadic FTLD exhibit similar signs of lysosomal dysfunction, we compared lysosomal protein levels, transcript levels, and storage material in patients with FTD-GRN or sporadic FTLD-TDP type A. We analyzed samples from frontal cortex, a degenerated brain region, and occipital cortex, a relatively spared brain region. In frontal cortex, patients with sporadic FTLD-TDP type A exhibited similar increases in lysosomal protein levels, transcript levels, and storage material as patients with FTD-GRN. In occipital cortex of both patient groups, most lysosomal measures did not differ from controls. Frontal cortex from a transgenic mouse model of TDP-opathy had similar increases in cathepsin D and lysosomal storage material, showing that TDP-opathy and neurodegeneration can drive these changes independently of progranulin. To investigate these changes in additional FTLD subtypes, we analyzed frontal cortical samples from patients with sporadic FTLD-TDP type C or Pick's disease, an FTLD-tau subtype. All sporadic FTLD groups had similar increases in cathepsin D activity, lysosomal membrane proteins, and storage material as FTD-GRN patients. However, patients with FTLD-TDP type C or Pick's disease did not have similar increases in lysosomal transcripts as patients with FTD-GRN or sporadic FTLD-TDP type A. Based on these data, accumulation of lysosomal proteins and storage material may be a common aspect of end-stage FTLD. However, the unique changes in gene expression in patients with FTD-GRN or sporadic FTLD-TDP type A may indicate distinct underlying lysosomal changes among FTLD subtypes.
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Affiliation(s)
- Skylar E Davis
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anna K Cook
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Justin A Hall
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yuliya Voskobiynyk
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nancy V Carullo
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicholas R Boyle
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ahmad R Hakim
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kristian M Anderson
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kierra P Hobdy
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Derian A Pugh
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Charles F Murchison
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Laura J McMeekin
- Department of Neuroscience, Southern Research, Birmingham, AL, USA
| | - Micah Simmons
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neuroscience, Southern Research, Birmingham, AL, USA
| | | | - Rita M Cowell
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neuroscience, Southern Research, Birmingham, AL, USA
| | - Alissa L Nana
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Salvatore Spina
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Lea T Grinberg
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William W Seeley
- Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Andrew E Arrant
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA.
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA.
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10
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TDP-43 condensates and lipid droplets regulate the reactivity of microglia and regeneration after traumatic brain injury. Nat Neurosci 2022; 25:1608-1625. [PMID: 36424432 DOI: 10.1038/s41593-022-01199-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/11/2022] [Indexed: 11/27/2022]
Abstract
Decreasing the activation of pathology-activated microglia is crucial to prevent chronic inflammation and tissue scarring. In this study, we used a stab wound injury model in zebrafish and identified an injury-induced microglial state characterized by the accumulation of lipid droplets and TAR DNA-binding protein of 43 kDa (TDP-43)+ condensates. Granulin-mediated clearance of both lipid droplets and TDP-43+ condensates was necessary and sufficient to promote the return of microglia back to the basal state and achieve scarless regeneration. Moreover, in postmortem cortical brain tissues from patients with traumatic brain injury, the extent of microglial activation correlated with the accumulation of lipid droplets and TDP-43+ condensates. Together, our results reveal a mechanism required for restoring microglia to a nonactivated state after injury, which has potential for new therapeutic applications in humans.
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11
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Bhopatkar AA, Dhakal S, Abernathy HG, Morgan SE, Rangachari V. Charge and Redox States Modulate Granulin-TDP-43 Coacervation Toward Phase Separation or Aggregation. Biophys J 2022; 121:2107-2126. [PMID: 35490297 DOI: 10.1016/j.bpj.2022.04.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 04/05/2022] [Accepted: 04/27/2022] [Indexed: 11/26/2022] Open
Abstract
Cytoplasmic inclusions containing aberrant proteolytic fragments of TDP-43 are associated with frontotemporal lobar degeneration (FTLD) and other related pathologies. In FTLD, TDP-43 is translocated into the cytoplasm and proteolytically cleaved to generate a prion-like domain (PrLD) containing C-terminal fragments (C25 and C35) that form toxic inclusions. Under stress, TDP-43 partitions into membraneless organelles called stress granules (SGs) by coacervating with RNA and other proteins. To glean into the factors that influence the dynamics between these cytoplasmic foci, we investigated the effects of cysteine-rich granulins (GRNs 1-7), which are the proteolytic products of progranulin, a protein implicated in FTLD, on TDP-43. We show that extracellular GRNs, typically generated during inflammation, internalize and colocalize with PrLD as puncta in the cytoplasm of neuroblastoma cells but show less likelihood of their presence in SGs. In addition, we show GRNs and PrLD coacervate to undergo liquid-liquid phase separation (LLPS) or form gel- or solid-like aggregates. Using charge patterning and conserved cysteines among the wild-type GRNs as guides, along with specifically engineered mutants, we discover that the negative charges on GRNs drive LLPS while the positive charges and the redox state of cysteines modulate these phase transitions. Furthermore, RNA and GRNs compete and expel one another from PrLD condensates, providing a basis for GRN's absence in SGs. Together, the results help uncover potential modulatory mechanisms by which extracellular GRNs, formed during chronic inflammatory conditions, could internalize, and modulate cytoplasmic TDP-43 inclusions in proteinopathies.
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Affiliation(s)
- Anukool A Bhopatkar
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg MS 39406
| | - Shailendra Dhakal
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg MS 39406
| | - Hannah G Abernathy
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg MS 39406
| | - Sarah E Morgan
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg MS 39406
| | - Vijay Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg MS 39406;; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg MS 39406;.
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12
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Chitramuthu BP, Campos-García VR, Bateman A. Multiple Molecular Pathways Are Influenced by Progranulin in a Neuronal Cell Model-A Parallel Omics Approach. Front Neurosci 2022; 15:775391. [PMID: 35095393 PMCID: PMC8791029 DOI: 10.3389/fnins.2021.775391] [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: 09/13/2021] [Accepted: 12/13/2021] [Indexed: 11/13/2022] Open
Abstract
Progranulin (PGRN) is critical in supporting a healthy CNS. Its haploinsufficiency results in frontotemporal dementia, while in experimental models of age-related neurodegenerative diseases, the targeted expression of PGRN greatly slows the onset of disease phenotypes. Nevertheless, much remains unclear about how PGRN affects its target cells. In previous studies we found that PGRN showed a remarkable ability to support the survival of NSC-34 motor neuron cells under conditions that would otherwise lead to their apoptosis. Here we used the same model to investigate other phenotypes of PGRN expression in NSC-34 cells. PGRN significantly influenced morphological differentiation, resulting in cells with enlarged cell bodies and extended projections. At a molecular level this correlated with pathways associated with the cytoskeleton and synaptic differentiation. Depletion of PGRN led to increased expression of several neurotrophic receptors, which may represent a homeostatic mechanism to compensate for loss of neurotrophic support from PGRN. The exception was RET, a neurotrophic tyrosine receptor kinase, which, when PGRN levels are high, shows increased expression and enhanced tyrosine phosphorylation. Other receptor tyrosine kinases also showed higher tyrosine phosphorylation when PGRN was elevated, suggesting a generalized enhancement of receptor activity. PGRN was found to bind to multiple plasma membrane proteins, including RET, as well as proteins in the ER/Golgi apparatus/lysosome pathway. Understanding how these various pathways contribute to PGRN action may provide routes toward improving neuroprotective therapies.
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Affiliation(s)
- Babykumari P Chitramuthu
- Division of Experimental Medicine, Faculty of Medicine and Health Sciences, McGill University, and Centre for Translational Biology, Metabolic Disorders and Complications, McGill University Health Centre Research Institute, Montréal, QC, Canada
| | - Víctor R Campos-García
- Division of Experimental Medicine, Faculty of Medicine and Health Sciences, McGill University, and Centre for Translational Biology, Metabolic Disorders and Complications, McGill University Health Centre Research Institute, Montréal, QC, Canada
| | - Andrew Bateman
- Division of Experimental Medicine, Faculty of Medicine and Health Sciences, McGill University, and Centre for Translational Biology, Metabolic Disorders and Complications, McGill University Health Centre Research Institute, Montréal, QC, Canada
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13
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Rhinn H, Tatton N, McCaughey S, Kurnellas M, Rosenthal A. Progranulin as a therapeutic target in neurodegenerative diseases. Trends Pharmacol Sci 2022; 43:641-652. [PMID: 35039149 DOI: 10.1016/j.tips.2021.11.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/12/2021] [Accepted: 11/18/2021] [Indexed: 01/02/2023]
Abstract
Progranulin (PGRN, encoded by the GRN gene) plays a key role in the development, survival, function, and maintenance of neurons and microglia in the mammalian brain. It regulates lysosomal biogenesis, inflammation, repair, stress response, and aging. GRN loss-of-function mutations cause neuronal ceroid lipofuscinosis or frontotemporal dementia-GRN (FTD-GRN) in a gene dosage-dependent manner. Mutations that reduce PGRN levels increase the risk for developing Alzheimer's disease, Parkinson's disease, and limbic-predominant age-related transactivation response DNA-binding protein 43 encephalopathy, as well as exacerbate the progression of amyotrophic lateral sclerosis (ALS) and FTD caused by the hexanucleotide repeat expansion in the C9orf72 gene. Elevating and/or restoring PGRN levels is an attractive therapeutic strategy and is being investigated for neurodegenerative diseases through multiple mechanisms of action.
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Affiliation(s)
- Herve Rhinn
- Alector, Inc., South San Francisco, CA 94080, USA
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14
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Mohan S, Sampognaro PJ, Argouarch AR, Maynard JC, Welch M, Patwardhan A, Courtney EC, Zhang J, Mason A, Li KH, Huang EJ, Seeley WW, Miller BL, Burlingame A, Jacobson MP, Kao AW. Processing of progranulin into granulins involves multiple lysosomal proteases and is affected in frontotemporal lobar degeneration. Mol Neurodegener 2021; 16:51. [PMID: 34344440 PMCID: PMC8330050 DOI: 10.1186/s13024-021-00472-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 07/13/2021] [Indexed: 11/24/2022] Open
Abstract
Background Progranulin loss-of-function mutations are linked to frontotemporal lobar degeneration with TDP-43 positive inclusions (FTLD-TDP-Pgrn). Progranulin (PGRN) is an intracellular and secreted pro-protein that is proteolytically cleaved into individual granulin peptides, which are increasingly thought to contribute to FTLD-TDP-Pgrn disease pathophysiology. Intracellular PGRN is processed into granulins in the endo-lysosomal compartments. Therefore, to better understand the conversion of intracellular PGRN into granulins, we systematically tested the ability of different classes of endo-lysosomal proteases to process PGRN at a range of pH setpoints. Results In vitro cleavage assays identified multiple enzymes that can process human PGRN into multi- and single-granulin fragments in a pH-dependent manner. We confirmed the role of cathepsin B and cathepsin L in PGRN processing and showed that these and several previously unidentified lysosomal proteases (cathepsins E, G, K, S and V) are able to process PGRN in distinctive, pH-dependent manners. In addition, we have demonstrated a new role for asparagine endopeptidase (AEP) in processing PGRN, with AEP having the unique ability to liberate granulin F from the pro-protein. Brain tissue from individuals with FTLD-TDP-Pgrn showed increased PGRN processing to granulin F and increased AEP activity in degenerating brain regions but not in regions unaffected by disease. Conclusions This study demonstrates that multiple lysosomal proteases may work in concert to liberate multi-granulin fragments and granulins. It also implicates both AEP and granulin F in the neurobiology of FTLD-TDP-Pgrn. Modulating progranulin cleavage and granulin production may represent therapeutic strategies for FTLD-Pgrn and other progranulin-related diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s13024-021-00472-1.
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Affiliation(s)
- Swetha Mohan
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Paul J Sampognaro
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Andrea R Argouarch
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Jason C Maynard
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Mackenzie Welch
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Anand Patwardhan
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Emma C Courtney
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Jiasheng Zhang
- Department of Pathology, University of California, San Francisco, California, 94143, USA
| | - Amanda Mason
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, California, 94143, USA
| | - William W Seeley
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Alma Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Mathew P Jacobson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Aimee W Kao
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA.
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15
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Chien HM, Lee CC, Huang JJT. The Different Faces of the TDP-43 Low-Complexity Domain: The Formation of Liquid Droplets and Amyloid Fibrils. Int J Mol Sci 2021; 22:ijms22158213. [PMID: 34360978 PMCID: PMC8348237 DOI: 10.3390/ijms22158213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
Transactive response DNA-binding protein 43 (TDP-43) is a nucleic acid-binding protein that is involved in transcription and translation regulation, non-coding RNA processing, and stress granule assembly. Aside from its multiple functions, it is also known as the signature protein in the hallmark inclusions of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) patients. TDP-43 is built of four domains, but its low-complexity domain (LCD) has become an intense research focus that brings to light its possible role in TDP-43 functions and involvement in the pathogenesis of these neurodegenerative diseases. Recent endeavors have further uncovered the distinct biophysical properties of TDP-43 under various circumstances. In this review, we summarize the multiple structural and biochemical properties of LCD in either promoting the liquid droplets or inducing fibrillar aggregates. We also revisit the roles of the LCD in paraspeckles, stress granules, and cytoplasmic inclusions to date.
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Affiliation(s)
- Hung-Ming Chien
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
- Department of Chemistry, National Taiwan University, Taipei City 115, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei City 115, Taiwan
| | - Chi-Chang Lee
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
| | - Joseph Jen-Tse Huang
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
- Department of Applied Chemistry, National Chiayi University, Chiayi City 600, Taiwan
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei City 115, Taiwan
- Correspondence: ; Tel.: +886-2-5572-8652
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16
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Davis SE, Roth JR, Aljabi Q, Hakim AR, Savell KE, Day JJ, Arrant AE. Delivering progranulin to neuronal lysosomes protects against excitotoxicity. J Biol Chem 2021; 297:100993. [PMID: 34298019 PMCID: PMC8379502 DOI: 10.1016/j.jbc.2021.100993] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/08/2021] [Accepted: 07/19/2021] [Indexed: 01/18/2023] Open
Abstract
Loss-of-function mutations in progranulin (GRN) are a major genetic cause of frontotemporal dementia (FTD), possibly due to loss of progranulin’s neurotrophic and anti-inflammatory effects. Progranulin promotes neuronal growth and protects against excitotoxicity and other forms of injury. It is unclear if these neurotrophic effects are mediated through cellular signaling or through promotion of lysosomal function. Progranulin is a secreted proprotein that may activate neurotrophic signaling through cell-surface receptors. However, progranulin is efficiently trafficked to lysosomes and is necessary for maintaining lysosomal function. To determine which of these mechanisms mediates progranulin’s protection against excitotoxicity, we generated lentiviral vectors expressing progranulin (PGRN) or lysosome-targeted progranulin (L-PGRN). L-PGRN was generated by fusing the LAMP-1 transmembrane and cytosolic domains to the C-terminus of progranulin. L-PGRN exhibited no detectable secretion, but was delivered to lysosomes and processed into granulins. PGRN and L-PGRN protected against NMDA excitotoxicity in rat primary cortical neurons, but L-PGRN had more consistent protective effects than PGRN. L-PGRN’s protective effects were likely mediated through the autophagy-lysosomal pathway. In control neurons, an excitotoxic dose of NMDA stimulated autophagy, and inhibiting autophagy with 3-methyladenine reduced excitotoxic cell death. L-PGRN blunted the autophagic response to NMDA and occluded the protective effect of 3-methyladenine. This was not due to a general impairment of autophagy, as L-PGRN increased basal autophagy and did not alter autophagy after nutrient starvation. These data show that progranulin’s protection against excitotoxicity does not require extracellular progranulin, but is mediated through lysosomes, providing a mechanistic link between progranulin’s lysosomal and neurotrophic effects.
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Affiliation(s)
- Skylar E Davis
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama, USA; Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jonathan R Roth
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama, USA; Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Qays Aljabi
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama, USA; Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ahmad R Hakim
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama, USA; Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Katherine E Savell
- Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeremy J Day
- Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Andrew E Arrant
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, Alabama, USA; Alzheimer's Disease Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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17
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Chemical and genetic rescue of in vivo progranulin-deficient lysosomal and autophagic defects. Proc Natl Acad Sci U S A 2021; 118:2022115118. [PMID: 34140407 DOI: 10.1073/pnas.2022115118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In 2006, GRN mutations were first linked to frontotemporal dementia (FTD), the leading cause of non-Alzheimer dementias. While much research has been dedicated to understanding the genetic causes of the disease, our understanding of the mechanistic impacts of GRN deficiency has only recently begun to take shape. With no known cure or treatment available for GRN-related FTD, there is a growing need to rapidly advance genetic and/or small-molecule therapeutics for this disease. This issue is complicated by the fact that, while lysosomal dysfunction seems to be a key driver of pathology, the mechanisms linking a loss of GRN to a pathogenic state remain unclear. In our attempt to address these key issues, we have turned to the nematode, Caenorhabditis elegans, to model, study, and find potential therapies for GRN-deficient FTD. First, we show that the loss of the nematode GRN ortholog, pgrn-1, results in several behavioral and molecular defects, including lysosomal dysfunction and defects in autophagic flux. Our investigations implicate the sphingolipid metabolic pathway in the regulation of many of the in vivo defects associated with pgrn-1 loss. Finally, we utilized these nematodes as an in vivo tool for high-throughput drug screening and identified two small molecules with potential therapeutic applications against GRN/pgrn-1 deficiency. These compounds reverse the biochemical, cellular, and functional phenotypes of GRN deficiency. Together, our results open avenues for mechanistic and therapeutic research into the outcomes of GRN-related neurodegeneration, both genetic and molecular.
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18
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Wang XM, Zeng P, Fang YY, Zhang T, Tian Q. Progranulin in neurodegenerative dementia. J Neurochem 2021; 158:119-137. [PMID: 33930186 DOI: 10.1111/jnc.15378] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 03/28/2021] [Accepted: 04/16/2021] [Indexed: 01/21/2023]
Abstract
Long-term or severe lack of protective factors is important in the pathogenesis of neurodegenerative dementia. Progranulin (PGRN), a neurotrophic factor expressed mainly in neurons and microglia, has various neuroprotective effects such as anti-inflammatory effects, promoting neuron survival and neurite growth, and participating in normal lysosomal function. Mutations in the PGRN gene (GRN) have been found in several neurodegenerative dementias, including frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD). Herein, PGRN deficiency and PGRN hydrolytic products (GRNs) in the pathological changes related to dementia, including aggregation of tau and TAR DNA-binding protein 43 (TDP-43), amyloid-β (Aβ) overproduction, neuroinflammation, lysosomal dysfunction, neuronal death, and synaptic deficit have been summarized. Furthermore, as some therapeutic strategies targeting PGRN have been developed in various models, we highlighted PGRN as a potential anti-neurodegeneration target in dementia.
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Affiliation(s)
- Xiao-Ming Wang
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Key Laboratory of Neurological Disease of National Education Ministry, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Zeng
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Key Laboratory of Neurological Disease of National Education Ministry, Huazhong University of Science and Technology, Wuhan, China
| | - Ying-Yan Fang
- Hubei Key Laboratory for Kidney Disease Pathogenesis and Intervention, Hubei Polytechnic University School of Medicine, Huangshi, China
| | - Teng Zhang
- Department of Neurology, Shanxian Central Hospital, The Affiliated Huxi Hospital of Jining Medical College, Heze, China
| | - Qing Tian
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Key Laboratory of Neurological Disease of National Education Ministry, Huazhong University of Science and Technology, Wuhan, China
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19
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Hummel R, Lang M, Walderbach S, Wang Y, Tegeder I, Gölz C, Schäfer MKE. Single intracerebroventricular progranulin injection adversely affects the blood-brain barrier in experimental traumatic brain injury. J Neurochem 2021; 158:342-357. [PMID: 33899947 DOI: 10.1111/jnc.15375] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 04/17/2021] [Accepted: 04/18/2021] [Indexed: 12/23/2022]
Abstract
Progranulin (PGRN) is a neurotrophic and anti-inflammatory factor with protective effects in animal models of ischemic stroke, subarachnoid hemorrhage, and traumatic brain injury (TBI). Administration of recombinant (r) PGRN prevents exaggerated brain pathology after TBI in Grn-deficient mice, suggesting that local injection of recombinant progranulin (rPGRN) provides therapeutic benefit in the acute phase of TBI. To test this hypothesis, we subjected adult male C57Bl/6N mice to the controlled cortical impact model of TBI, administered a single dose of rPGRN intracerebroventricularly (ICV) shortly before the injury, and examined behavioral and biological effects up to 5 days post injury (dpi). The anti-inflammatory bioactivity of rPGRN was confirmed by its capability to inhibit the inflammation-induced hypertrophy of murine primary microglia and astrocytes in vitro. In C57Bl/6N mice, however, ICV administration of rPGRN failed to attenuate behavioral deficits over the 5-day observation period. (Immuno)histological gene and protein expression analyses at 5 dpi did not reveal a therapeutic benefit in terms of brain injury size, brain inflammation, glia activation, cell numbers in neurogenic niches, and neuronal damage. Instead, we observed a failure of TBI-induced mRNA upregulation of the tight junction protein occludin and increased extravasation of serum immunoglobulin G into the brain parenchyma at 5 dpi. In conclusion, single ICV administration of rPGRN had not the expected protective effects in the acute phase of murine TBI, but appeared to cause an aggravation of blood-brain barrier disruption. The data raise questions about putative PGRN-boosting approaches in other types of brain injuries and disease.
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Affiliation(s)
- Regina Hummel
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Manuel Lang
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Simona Walderbach
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Yong Wang
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Medical Faculty, Goethe-University Frankfurt, Frankfurt, Germany
| | - Christina Gölz
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.,Focus Program Translational Neurosciences (FTN) of the Johannes Gutenberg-University Mainz, Mainz, Germany.,Research Center for Immunotherapy (FZI) of the Johannes Gutenberg-University Mainz, Mainz, Germany
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20
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Giunta M, Solje E, Gardoni F, Borroni B, Benussi A. Experimental Disease-Modifying Agents for Frontotemporal Lobar Degeneration. J Exp Pharmacol 2021; 13:359-376. [PMID: 33790662 PMCID: PMC8005747 DOI: 10.2147/jep.s262352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Frontotemporal dementia is a clinically, genetically and pathologically heterogeneous neurodegenerative disorder, enclosing a wide range of different pathological entities, associated with the accumulation of proteins such as tau and TPD-43. Characterized by a high hereditability, mutations in three main genes, MAPT, GRN and C9orf72, can drive the neurodegenerative process. The connection between different genes and proteinopathies through specific mechanisms has shed light on the pathophysiology of the disease, leading to the identification of potential pharmacological targets. New experimental strategies are emerging, in both preclinical and clinical settings, which focus on small molecules rather than gene therapy. In this review, we provide an insight into the aberrant mechanisms leading to FTLD-related proteinopathies and discuss recent therapies with the potential to ameliorate neurodegeneration and disease progression.
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Affiliation(s)
- Marcello Giunta
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Eino Solje
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Barbara Borroni
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Alberto Benussi
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
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21
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Zbinden A, Pérez-Berlanga M, De Rossi P, Polymenidou M. Phase Separation and Neurodegenerative Diseases: A Disturbance in the Force. Dev Cell 2021; 55:45-68. [PMID: 33049211 DOI: 10.1016/j.devcel.2020.09.014] [Citation(s) in RCA: 213] [Impact Index Per Article: 71.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/09/2020] [Accepted: 09/13/2020] [Indexed: 12/12/2022]
Abstract
Protein aggregation is the main hallmark of neurodegenerative diseases. Many proteins found in pathological inclusions are known to undergo liquid-liquid phase separation, a reversible process of molecular self-assembly. Emerging evidence supports the hypothesis that aberrant phase separation behavior may serve as a trigger of protein aggregation in neurodegeneration, and efforts to understand and control the underlying mechanisms are underway. Here, we review similarities and differences among four main proteins, α-synuclein, FUS, tau, and TDP-43, which are found aggregated in different diseases and were independently shown to phase separate. We discuss future directions in the field that will help shed light on the molecular mechanisms of aggregation and neurodegeneration.
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Affiliation(s)
- Aurélie Zbinden
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Manuela Pérez-Berlanga
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pierre De Rossi
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Magdalini Polymenidou
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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22
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Gururaj S, Sampognaro PJ, Argouarch AR, Kao AW. Progranulin Adsorbs to Polypropylene Tubes and Disrupts Functional Assays: Implications for Research, Biomarker Studies, and Therapeutics. Front Neurosci 2021; 14:602235. [PMID: 33381010 PMCID: PMC7768044 DOI: 10.3389/fnins.2020.602235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 11/16/2020] [Indexed: 11/19/2022] Open
Abstract
Progranulin (PGRN) is a tightly regulated, secreted glycoprotein involved in a wide range of biological processes that is of tremendous interest to the scientific community due to its involvement in neoplastic, neurodevelopmental, and neurodegenerative diseases. In particular, progranulin haploinsufficiency leads to frontotemporal dementia. While performing experiments with a HIS-tagged recombinant human (rh) PGRN protein, we observed a measurable depletion of protein from solution due to its adsorption onto polypropylene (PPE) microcentrifuge tubes. In this study, we have quantified the extent of rhPGRN adsorption to PPE tubes while varying experimental conditions, including incubation time and temperature. We found that ∼25–35% of rhPGRN becomes adsorbed to the surface of PPE tubes even after a short incubation period. We then directly showed the deleterious impact of PGRN adsorption in functional assays and have recommended alternative labware to minimize these effects. Although the risk of adsorption of some purified proteins and peptides to polymer plastics has been characterized previously, this is the first report of rhPGRN adsorption. Moreover, since PGRN is currently being studied and utilized in both basic science laboratories to perform in vitro studies and translational laboratories to survey PGRN as a quantitative dementia biomarker and potential replacement therapy, the reported observations here are broadly impactful and will likely significantly affect the design and interpretation of future experiments centered on progranulin biology.
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Affiliation(s)
- Sushmitha Gururaj
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Paul J Sampognaro
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Andrea R Argouarch
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
| | - Aimee W Kao
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
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23
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Chaplot K, Jarvela TS, Lindberg I. Secreted Chaperones in Neurodegeneration. Front Aging Neurosci 2020; 12:268. [PMID: 33192447 PMCID: PMC7481362 DOI: 10.3389/fnagi.2020.00268] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/03/2020] [Indexed: 12/11/2022] Open
Abstract
Protein homeostasis, or proteostasis, is a combination of cellular processes that govern protein quality control, namely, protein translation, folding, processing, and degradation. Disruptions in these processes can lead to protein misfolding and aggregation. Proteostatic disruption can lead to cellular changes such as endoplasmic reticulum or oxidative stress; organelle dysfunction; and, if continued, to cell death. A majority of neurodegenerative diseases involve the pathologic aggregation of proteins that subverts normal neuronal function. While prior reviews of neuronal proteostasis in neurodegenerative processes have focused on cytoplasmic chaperones, there is increasing evidence that chaperones secreted both by neurons and other brain cells in the extracellular - including transsynaptic - space play important roles in neuronal proteostasis. In this review, we will introduce various secreted chaperones involved in neurodegeneration. We begin with clusterin and discuss its identification in various protein aggregates, and the use of increased cerebrospinal fluid (CSF) clusterin as a potential biomarker and as a potential therapeutic. Our next secreted chaperone is progranulin; polymorphisms in this gene represent a known genetic risk factor for frontotemporal lobar degeneration, and progranulin overexpression has been found to be effective in reducing Alzheimer's- and Parkinson's-like neurodegenerative phenotypes in mouse models. We move on to BRICHOS domain-containing proteins, a family of proteins containing highly potent anti-amyloidogenic activity; we summarize studies describing the biochemical mechanisms by which recombinant BRICHOS protein might serve as a therapeutic agent. The next section of the review is devoted to the secreted chaperones 7B2 and proSAAS, small neuronal proteins which are packaged together with neuropeptides and released during synaptic activity. Since proteins can be secreted by both classical secretory and non-classical mechanisms, we also review the small heat shock proteins (sHsps) that can be secreted from the cytoplasm to the extracellular environment and provide evidence for their involvement in extracellular proteostasis and neuroprotection. Our goal in this review focusing on extracellular chaperones in neurodegenerative disease is to summarize the most recent literature relating to neurodegeneration for each secreted chaperone; to identify any common mechanisms; and to point out areas of similarity as well as differences between the secreted chaperones identified to date.
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Affiliation(s)
| | | | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
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24
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Solomon DA, Mitchell JC, Salcher-Konrad MT, Vance CA, Mizielinska S. Review: Modelling the pathology and behaviour of frontotemporal dementia. Neuropathol Appl Neurobiol 2020; 45:58-80. [PMID: 30582188 DOI: 10.1111/nan.12536] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/16/2018] [Indexed: 12/11/2022]
Abstract
Frontotemporal dementia (FTD) encompasses a collection of clinically and pathologically diverse neurological disorders. Clinical features of behavioural and language dysfunction are associated with neurodegeneration, predominantly of frontal and temporal cortices. Over the past decade, there have been significant advances in the understanding of the genetic aetiology and neuropathology of FTD which have led to the creation of various disease models to investigate the molecular pathways that contribute to disease pathogenesis. The generation of in vivo models of FTD involves either targeting genes with known disease-causative mutations such as GRN and C9orf72 or genes encoding proteins that form the inclusions that characterize the disease pathologically, such as TDP-43 and FUS. This review provides a comprehensive summary of the different in vivo model systems used to understand pathomechanisms in FTD, with a focus on disease models which reproduce aspects of the wide-ranging behavioural phenotypes seen in people with FTD. We discuss the emerging disease pathways that have emerged from these in vivo models and how this has shaped our understanding of disease mechanisms underpinning FTD. We also discuss the challenges of modelling the complex clinical symptoms shown by people with FTD, the confounding overlap with features of motor neuron disease, and the drive to make models more disease-relevant. In summary, in vivo models can replicate many pathological and behavioural aspects of clinical FTD, but robust and thorough investigations utilizing shared features and variability between disease models will improve the disease-relevance of findings and thus better inform therapeutic development.
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Affiliation(s)
- D A Solomon
- UK Dementia Research Institute, King's College London, London, Camberwell, UK.,Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - J C Mitchell
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - M-T Salcher-Konrad
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - C A Vance
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - S Mizielinska
- UK Dementia Research Institute, King's College London, London, Camberwell, UK.,Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
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James J, Valuparampil Varghese M, Vasilyev M, Langlais PR, Tofovic SP, Rafikova O, Rafikov R. Complex III Inhibition-Induced Pulmonary Hypertension Affects the Mitochondrial Proteomic Landscape. Int J Mol Sci 2020; 21:ijms21165683. [PMID: 32784406 PMCID: PMC7461049 DOI: 10.3390/ijms21165683] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023] Open
Abstract
The mitochondria play a vital role in controlling cell metabolism and regulating crucial cellular outcomes. We previously demonstrated that chronic inhibition of the mitochondrial complex III in rats by Antimycin A (AA) induced sustained pulmonary vasoconstriction. On the metabolic level, AA-induced mitochondrial dysfunction resulted in a glycolytic shift that was reported as the primary contributor to pulmonary hypertension pathogenesis. However, the regulatory proteins driving this metabolic shift with complex III inhibition are yet to be explored. Therefore, to delineate the mechanisms, we followed changes in the rat lung mitochondrial proteome throughout AA treatment. Rats treated with AA for up to 24 days showed a disturbed mitochondrial proteome with significant changes in 28 proteins (p < 0.05). We observed a time-dependent decrease in the expression of key proteins that regulate fatty acid oxidation, the tricarboxylic acid cycle, the electron transport chain, and amino acid metabolism, indicating a correlation with diminished mitochondrial function. We also found a significant dysregulation in proteins that controls the protein import machinery and the clearance and detoxification of oxidatively damaged peptides via proteolysis and mitophagy. This could potentially lead to the onset of mitochondrial toxicity due to misfolded protein stress. We propose that chronic inhibition of mitochondrial complex III attenuates mitochondrial function by disruption of the global mitochondrial metabolism. This potentially aggravates cellular proliferation by initiating a glycolytic switch and thereby leads to pulmonary hypertension.
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Affiliation(s)
- Joel James
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
| | - Mathews Valuparampil Varghese
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
| | - Mikhail Vasilyev
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
| | - Paul R. Langlais
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
| | - Stevan P. Tofovic
- Vascular Medicine Institute, Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213; USA;
| | - Olga Rafikova
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
| | - Ruslan Rafikov
- Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, AZ 85721, USA; (J.J.); (M.V.V.); (M.V.); (P.R.L.); (O.R.)
- Correspondence:
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Bhopatkar AA, Uversky VN, Rangachari V. Granulins modulate liquid-liquid phase separation and aggregation of the prion-like C-terminal domain of the neurodegeneration-associated protein TDP-43. J Biol Chem 2020; 295:2506-2519. [PMID: 31911437 DOI: 10.1074/jbc.ra119.011501] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
TAR DNA-binding protein 43 (TDP-43) has emerged as a key player in many neurodegenerative pathologies, including frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Hallmarks of both FTLD and ALS are the toxic cytoplasmic inclusions of the prion-like C-terminal fragments of TDP-43 CTD (TDP-43 C-terminal domain), formed upon proteolytic cleavage of full-length TDP-43 in the nucleus and subsequent transport to the cytoplasm. Both full-length TDP-43 and its CTD are also known to form stress granules by coacervating with RNA in the cytoplasm during stress and may be involved in these pathologies. Furthermore, mutations in the PGRN gene, leading to haploinsufficiency and diminished function of progranulin (PGRN) protein, are strongly linked to FTLD and ALS. Recent reports have indicated that proteolytic processing of PGRN to smaller protein modules called granulins (GRNs) contributes to FTLD and ALS progression, with specific GRNs exacerbating TDP-43-induced cytotoxicity. Here we investigated the interactions between the proteolytic products of both TDP-43 and PGRN. Based on structural disorder and charge distributions, we hypothesized that GRN-3 and GRN-5 could interact with the TDP-43 CTD. We show that, under both reducing and oxidizing conditions, GRN-3 and GRN-5 interact with and differentially modulate TDP-43 CTD aggregation and/or liquid-liquid phase separation in vitro GRN-3 promoted insoluble aggregates of the TDP-43 CTD while GRN-5 mediated liquid-liquid phase separation. These results constitute the first observation of an interaction between GRNs and TDP-43, suggesting a mechanism by which attenuated PGRN function could lead to familial FTLD or ALS.
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Affiliation(s)
- Anukool A Bhopatkar
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi 39406
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida 33620; Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi 39406.
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27
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Tanaka M, Kuse Y, Nakamura S, Hara H, Shimazawa M. Potential effects of progranulin and granulins against retinal photoreceptor cell degeneration. Mol Vis 2019; 25:902-911. [PMID: 32025182 PMCID: PMC6982430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 12/30/2019] [Indexed: 11/16/2022] Open
Abstract
Purpose The authors previously reported that progranulin attenuated retinal degeneration. The present study focused on the role of progranulin and its cleavage products, granulins, in the pathogenesis of photoreceptor degeneration. Methods Photoreceptor degeneration was induced with excessive exposure of murine photoreceptor cells and the retinas of albino mice to white fluorescent light. Damaged photoreceptor cells and retinas were examined using a cell death assay, western blotting, and immunostaining. Results Even after proteolytic cleavage, treatment with progranulin or its cleavage products or both exerted protective effects on photoreceptors against light exposure. In the murine retina, the expression levels of granulins and the macrophage and microglia marker Iba-1 were increased at 48 h after light exposure. Additionally, progranulin+ and Iba-1+ double-positive cells had accumulated in the outer nuclear layer, the primary location of photoreceptor cells. Conclusions These results suggest that progranulin or its cleavage products, granulins, or both may be therapeutic targets for age-related macular degeneration and other neurodegenerative diseases.
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28
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Huber RJ, Hughes SM, Liu W, Morgan A, Tuxworth RI, Russell C. The contribution of multicellular model organisms to neuronal ceroid lipofuscinosis research. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165614. [PMID: 31783156 DOI: 10.1016/j.bbadis.2019.165614] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 02/07/2023]
Abstract
The NCLs (neuronal ceroid lipofuscinosis) are forms of neurodegenerative disease that affect people of all ages and ethnicities but are most prevalent in children. Commonly known as Batten disease, this debilitating neurological disorder is comprised of 13 different subtypes that are categorized based on the particular gene that is mutated (CLN1-8, CLN10-14). The pathological mechanisms underlying the NCLs are not well understood due to our poor understanding of the functions of NCL proteins. Only one specific treatment (enzyme replacement therapy) is approved, which is for the treating the brain in CLN2 disease. Hence there remains a desperate need for further research into disease-modifying treatments. In this review, we present and evaluate the genes, proteins and studies performed in the social amoeba, nematode, fruit fly, zebrafish, mouse and large animals pertinent to NCL. In particular, we highlight the use of multicellular model organisms to study NCL protein function, pathology and pathomechanisms. Their use in testing novel therapeutic approaches is also presented. With this information, we highlight how future research in these systems may be able to provide new insight into NCL protein functions in human cells and aid in the development of new therapies.
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Affiliation(s)
- Robert J Huber
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Stephanie M Hughes
- Department of Biochemistry, School of Biomedical Sciences, Brain Health Research Centre and Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Wenfei Liu
- School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Alan Morgan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St., Liverpool L69 3BX, UK
| | - Richard I Tuxworth
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Claire Russell
- Dept. Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
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Wallings RL, Humble SW, Ward ME, Wade-Martins R. Lysosomal Dysfunction at the Centre of Parkinson's Disease and Frontotemporal Dementia/Amyotrophic Lateral Sclerosis. Trends Neurosci 2019; 42:899-912. [PMID: 31704179 DOI: 10.1016/j.tins.2019.10.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/25/2019] [Accepted: 10/04/2019] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) and frontotemporal dementia/amyotrophic lateral sclerosis (FTD/ALS) are insidious and incurable neurodegenerative diseases that represent a significant burden to affected individuals, caregivers, and an ageing population. Both PD and FTD/ALS are defined at post mortem by the presence of protein aggregates and the loss of specific subsets of neurons. We examine here the crucial role of lysosome dysfunction in these diseases and discuss recent evidence for converging mechanisms. This review draws upon multiple lines of evidence from genetic studies, human tissue, induced pluripotent stem cells (iPSCs), and animal models to argue that lysosomal failure is a primary mechanism of disease, rather than merely reflecting association with protein aggregate end-points. This review provides compelling rationale for targeting lysosomes in future therapeutics for both PD and FTD/ALS.
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Affiliation(s)
- Rebecca L Wallings
- Department of Physiology, Emory University, Decatur, GA, USA; Current address: Department of Neuroscience, Center for Translational Research and Neurodegenerative Disease, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Stewart W Humble
- Oxford Parkinson's Disease Centre, Department of Physiology Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK; National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Michael E Ward
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
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Nagy D, Martens LH, Leventhal L, Chen A, Kelley C, Stoiljkovic M, Hajós M. Age-dependent emergence of neurophysiological and behavioral abnormalities in progranulin-deficient mice. ALZHEIMERS RESEARCH & THERAPY 2019; 11:88. [PMID: 31639062 PMCID: PMC6805349 DOI: 10.1186/s13195-019-0540-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/21/2019] [Indexed: 11/10/2022]
Abstract
Background Loss-of-function mutations in the progranulin gene cause frontotemporal dementia, a genetic, heterogeneous neurodegenerative disorder. Progranulin deficiency leads to extensive neuronal loss in the frontal and temporal lobes, altered synaptic connectivity, and behavioral alterations. Methods The chronological emergence of neurophysiological and behavioral phenotypes of Grn heterozygous and homozygous mice in the dorsomedial thalamic—medial prefrontal cortical pathway were evaluated by in vivo electrophysiology and reward-seeking/processing behavior, tested between ages 3 and 12.5 months. Results Electrophysiological recordings identified a clear age-dependent deficit in the thalamocortical circuit. Both heterozygous and homozygous mice exhibited impaired input-output relationships and paired-pulse depression, but evoked response latencies were only prolonged in heterozygotes. Furthermore, we demonstrate firstly an abnormal reward-seeking/processing behavior in the homozygous mice which correlates with previously reported neuroinflammation. Conclusion Our findings indicate that murine progranulin deficiency causes age-dependent neurophysiological and behavioral abnormalities thereby indicating their validity in modeling aspects of human frontotemporal dementia.
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Affiliation(s)
- Dávid Nagy
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., New Haven, CT, 06520, USA
| | | | | | - Angela Chen
- FORUM Pharmaceuticals, Inc., Waltham, MA, 02451, USA
| | - Craig Kelley
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., New Haven, CT, 06520, USA
| | - Milan Stoiljkovic
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., New Haven, CT, 06520, USA
| | - Mihály Hajós
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., New Haven, CT, 06520, USA.
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Butler VJ, Gao F, Corrales CI, Cortopassi WA, Caballero B, Vohra M, Ashrafi K, Cuervo AM, Jacobson MP, Coppola G, Kao AW. Age- and stress-associated C. elegans granulins impair lysosomal function and induce a compensatory HLH-30/TFEB transcriptional response. PLoS Genet 2019; 15:e1008295. [PMID: 31398187 PMCID: PMC6703691 DOI: 10.1371/journal.pgen.1008295] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/21/2019] [Accepted: 07/07/2019] [Indexed: 12/11/2022] Open
Abstract
The progressive failure of protein homeostasis is a hallmark of aging and a common feature in neurodegenerative disease. As the enzymes executing the final stages of autophagy, lysosomal proteases are key contributors to the maintenance of protein homeostasis with age. We previously reported that expression of granulin peptides, the cleavage products of the neurodegenerative disease protein progranulin, enhance the accumulation and toxicity of TAR DNA binding protein 43 (TDP-43) in Caenorhabditis elegans (C. elegans). In this study we show that C. elegans granulins are produced in an age- and stress-dependent manner. Granulins localize to the endolysosomal compartment where they impair lysosomal protease expression and activity. Consequently, protein homeostasis is disrupted, promoting the nuclear translocation of the lysosomal transcription factor HLH-30/TFEB, and prompting cells to activate a compensatory transcriptional program. The three C. elegans granulin peptides exhibited distinct but overlapping functional effects in our assays, which may be due to amino acid composition that results in distinct electrostatic and hydrophobicity profiles. Our results support a model in which granulin production modulates a critical transition between the normal, physiological regulation of protease activity and the impairment of lysosomal function that can occur with age and disease.
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Affiliation(s)
- Victoria J. Butler
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, California, United States of America
| | - Fuying Gao
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Biobehavioral Sciences and Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Christian I. Corrales
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, California, United States of America
| | - Wilian A. Cortopassi
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, United States of America
| | - Benjamin Caballero
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Mihir Vohra
- Department of Physiology, University of California, San Francisco, California, United States of America
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, California, United States of America
| | - Ana Maria Cuervo
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Matthew P. Jacobson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, United States of America
| | - Giovanni Coppola
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Biobehavioral Sciences and Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Aimee W. Kao
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, California, United States of America
- * E-mail:
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Butler VJ, Cortopassi WA, Gururaj S, Wang AL, Pierce OM, Jacobson MP, Kao AW. Multi-Granulin Domain Peptides Bind to Pro-Cathepsin D and Stimulate Its Enzymatic Activity More Effectively Than Progranulin in Vitro. Biochemistry 2019; 58:2670-2674. [PMID: 31099551 DOI: 10.1021/acs.biochem.9b00275] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Progranulin (PGRN) is an evolutionarily conserved glycoprotein associated with several disease states, including neurodegeneration, cancer, and autoimmune disorders. This protein has recently been implicated in the regulation of lysosome function, whereby PGRN may bind to and promote the maturation and activity of the aspartyl protease cathepsin D (proCTSD, inactive precursor; matCTSD, mature, enzymatically active form). As the full-length PGRN protein can be cleaved into smaller peptides, called granulins, we assessed the function of these granulin peptides in binding to proCTSD and stimulating matCTSD enzyme activity in vitro. Here, we report that full-length PGRN and multi-granulin domain peptides bound to proCTSD with low to submicromolar binding affinities. This binding promoted proCTSD destabilization, the magnitude of which was greater for multi-granulin domain peptides than for full-length PGRN. Such destabilization correlated with enhanced matCTSD activity at acidic pH. The presence and function of multi-granulin domain peptides have typically been overlooked in previous studies. This work provides the first in vitro quantification of their binding and activity on proCTSD. Our study highlights the significance of multi-granulin domain peptides in the regulation of proCTSD maturation and enzymatic activity and suggests that attention to PGRN processing will be essential for the future understanding of the molecular mechanisms leading to neurodegenerative disease states with loss-of-function mutations in PGRN.
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Affiliation(s)
- Victoria J Butler
- Department of Neurology , University of California , San Francisco , California 94143 , United States
| | - Wilian A Cortopassi
- Department of Pharmaceutical Chemistry , University of California , San Francisco , California 94143 , United States
| | - Sushmitha Gururaj
- Department of Neurology , University of California , San Francisco , California 94143 , United States
| | - Austin L Wang
- Department of Neurology , University of California , San Francisco , California 94143 , United States
| | - Olivia M Pierce
- Department of Pharmaceutical Chemistry , University of California , San Francisco , California 94143 , United States
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry , University of California , San Francisco , California 94143 , United States
| | - Aimee W Kao
- Department of Neurology , University of California , San Francisco , California 94143 , United States
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Microglial Progranulin: Involvement in Alzheimer's Disease and Neurodegenerative Diseases. Cells 2019; 8:cells8030230. [PMID: 30862089 PMCID: PMC6468562 DOI: 10.3390/cells8030230] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases such as Alzheimer’s disease have proven resistant to new treatments. The complexity of neurodegenerative disease mechanisms can be highlighted by accumulating evidence for a role for a growth factor, progranulin (PGRN). PGRN is a glycoprotein encoded by the GRN/Grn gene with multiple cellular functions, including neurotrophic, anti-inflammatory and lysosome regulatory properties. Mutations in the GRN gene can lead to frontotemporal lobar degeneration (FTLD), a cause of dementia, and neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Both diseases are associated with loss of PGRN function resulting, amongst other features, in enhanced microglial neuroinflammation and lysosomal dysfunction. PGRN has also been implicated in Alzheimer’s disease (AD). Unlike FTLD, increased expression of PGRN occurs in brains of human AD cases and AD model mice, particularly in activated microglia. How microglial PGRN might be involved in AD and other neurodegenerative diseases will be discussed. A unifying feature of PGRN in diseases might be its modulation of lysosomal function in neurons and microglia. Many experimental models have focused on consequences of PGRN gene deletion: however, possible outcomes of increasing PGRN on microglial inflammation and neurodegeneration will be discussed. We will also suggest directions for future studies on PGRN and microglia in relation to neurodegenerative diseases.
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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: 11] [Impact Index Per Article: 1.8] [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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Hofmann JW, Seeley WW, Huang EJ. RNA Binding Proteins and the Pathogenesis of Frontotemporal Lobar Degeneration. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2018; 14:469-495. [PMID: 30355151 DOI: 10.1146/annurev-pathmechdis-012418-012955] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Frontotemporal dementia is a group of early onset dementia syndromes linked to underlying frontotemporal lobar degeneration (FTLD) pathology that can be classified based on the formation of abnormal protein aggregates involving tau and two RNA binding proteins, TDP-43 and FUS. Although elucidation of the mechanisms leading to FTLD pathology is in progress, recent advances in genetics and neuropathology indicate that a majority of FTLD cases with proteinopathy involving RNA binding proteins show highly congruent genotype-phenotype correlations. Specifically, recent studies have uncovered the unique properties of the low-complexity domains in RNA binding proteins that can facilitate liquid-liquid phase separation in the formation of membraneless organelles. Furthermore, there is compelling evidence that mutations in FTLD genes lead to dysfunction in diverse cellular pathways that converge on the endolysosomal pathway, autophagy, and neuroinflammation. Together, these results provide key mechanistic insights into the pathogenesis and potential therapeutic targets of FTLD.
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Affiliation(s)
- Jeffrey W Hofmann
- Department of Pathology, University of California, San Francisco, California 94143, USA;
| | - William W Seeley
- Department of Pathology, University of California, San Francisco, California 94143, USA; .,Department of Neurology, University of California, San Francisco, California 94148, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, California 94143, USA; .,Pathology Service 113B, Veterans Affairs Medical Center, San Francisco, California 94121, USA
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Rudich P, Snoznik C, Watkins SC, Monaghan J, Pandey UB, Lamitina ST. Nuclear localized C9orf72-associated arginine-containing dipeptides exhibit age-dependent toxicity in C. elegans. Hum Mol Genet 2018; 26:4916-4928. [PMID: 29036691 PMCID: PMC5886095 DOI: 10.1093/hmg/ddx372] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/21/2017] [Indexed: 01/07/2023] Open
Abstract
A hexanucleotide repeat expansion mutation in the C9orf72 gene represents a prevalent genetic cause of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Non-canonical translation of this repeat gives rise to several distinct dipeptide protein species that could play pathological roles in disease. Here, we show in the model system Caenorhabditis elegans that expression of the arginine-containing dipeptides, but not alanine-containing dipeptides, produces toxic phenotypes in multiple cellular contexts, including motor neurons. Expression of either (PR)50 or (GR)50 during development caused a highly penetrant developmental arrest, while post-developmental expression caused age-onset paralysis. Both (PR)50- and (GR)50-green fluorescent protein tagged dipeptides were present in the nucleus and nuclear localization was necessary and sufficient for their toxicity. Using an inducible expression system, we discovered that age-onset phenotypes caused by (PR)50 required both continual (PR)50 expression and an aged cellular environment. The toxicity of (PR)50 was modified by genetic mutations that uncouple physiological aging from chronological aging. However, these same mutations failed to modify the toxicity of (GR)50, suggesting that (PR)50 and (GR)50 exert their toxicity through partially distinct mechanism(s). Changing the rate of physiological aging also mitigates toxicity in other C. elegans models of ALS, suggesting that the (PR)50 dipeptide might engage similar toxicity mechanisms as other ALS disease-causing proteins.
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Affiliation(s)
- Paige Rudich
- Graduate Program in Cell Biology and Molecular Physiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Carley Snoznik
- Division of Child Neurology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Simon C Watkins
- Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - John Monaghan
- Division of Child Neurology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Udai Bhan Pandey
- Division of Child Neurology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA.,Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15261, USA.,Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - S Todd Lamitina
- Graduate Program in Cell Biology and Molecular Physiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA.,Division of Child Neurology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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The lysosomal function of progranulin, a guardian against neurodegeneration. Acta Neuropathol 2018; 136:1-17. [PMID: 29744576 DOI: 10.1007/s00401-018-1861-8] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 04/25/2018] [Accepted: 05/01/2018] [Indexed: 12/12/2022]
Abstract
Progranulin (PGRN), encoded by the GRN gene in humans, is a secreted growth factor implicated in a multitude of processes ranging from regulation of inflammation to wound healing and tumorigenesis. The clinical importance of PGRN became especially evident in 2006, when heterozygous mutations in the GRN gene, resulting in haploinsufficiency, were found to be one of the main causes of frontotemporal lobar degeneration (FTLD). FTLD is a clinically heterogenous disease that results in the progressive atrophy of the frontal and temporal lobes of the brain. Despite significant research, the exact function of PGRN and its mechanistic relationship to FTLD remain unclear. However, growing evidence suggests a role for PGRN in the lysosome-most striking being that homozygous GRN mutation leads to neuronal ceroid lipofuscinosis, a lysosomal storage disease. Since this discovery, several links between PGRN and the lysosome have been established, including the existence of two independent lysosomal trafficking pathways, intralysosomal processing of PGRN into discrete functional peptides, and direct and indirect regulation of lysosomal hydrolases. Here, we summarize the cellular functions of PGRN, its roles in the nervous system, and its link to multiple neurodegenerative diseases, with a particular focus dedicated to recent lysosome-related mechanistic developments.
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Fricker M, Tolkovsky AM, Borutaite V, Coleman M, Brown GC. Neuronal Cell Death. Physiol Rev 2018; 98:813-880. [PMID: 29488822 PMCID: PMC5966715 DOI: 10.1152/physrev.00011.2017] [Citation(s) in RCA: 674] [Impact Index Per Article: 112.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/23/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023] Open
Abstract
Neuronal cell death occurs extensively during development and pathology, where it is especially important because of the limited capacity of adult neurons to proliferate or be replaced. The concept of cell death used to be simple as there were just two or three types, so we just had to work out which type was involved in our particular pathology and then block it. However, we now know that there are at least a dozen ways for neurons to die, that blocking a particular mechanism of cell death may not prevent the cell from dying, and that non-neuronal cells also contribute to neuronal death. We review here the mechanisms of neuronal death by intrinsic and extrinsic apoptosis, oncosis, necroptosis, parthanatos, ferroptosis, sarmoptosis, autophagic cell death, autosis, autolysis, paraptosis, pyroptosis, phagoptosis, and mitochondrial permeability transition. We next explore the mechanisms of neuronal death during development, and those induced by axotomy, aberrant cell-cycle reentry, glutamate (excitoxicity and oxytosis), loss of connected neurons, aggregated proteins and the unfolded protein response, oxidants, inflammation, and microglia. We then reassess which forms of cell death occur in stroke and Alzheimer's disease, two of the most important pathologies involving neuronal cell death. We also discuss why it has been so difficult to pinpoint the type of neuronal death involved, if and why the mechanism of neuronal death matters, the molecular overlap and interplay between death subroutines, and the therapeutic implications of these multiple overlapping forms of neuronal death.
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Affiliation(s)
- Michael Fricker
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Aviva M Tolkovsky
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Vilmante Borutaite
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Michael Coleman
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
| | - Guy C Brown
- Hunter Medical Research Institute, University of Newcastle, Callaghan, New South Wales , Australia ; Department of Clinical Neurosciences, University of Cambridge , Cambridge , United Kingdom ; Neuroscience Institute, Lithuanian University of Health Sciences , Kaunas , Lithuania ; and Department of Biochemistry, University of Cambridge , Cambridge , United Kingdom
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Townley RA, Boeve BF, Benarroch EE. Progranulin: Functions and neurologic correlations. Neurology 2017; 90:118-125. [PMID: 29263224 DOI: 10.1212/wnl.0000000000004840] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Ryan A Townley
- From the Department of Neurology, Mayo Clinic, Rochester, MN
| | - Bradley F Boeve
- From the Department of Neurology, Mayo Clinic, Rochester, MN
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40
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Chitramuthu BP, Bennett HPJ, Bateman A. Progranulin: a new avenue towards the understanding and treatment of neurodegenerative disease. Brain 2017; 140:3081-3104. [PMID: 29053785 DOI: 10.1093/brain/awx198] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 06/26/2017] [Indexed: 12/14/2022] Open
Abstract
Progranulin, a secreted glycoprotein, is encoded in humans by the single GRN gene. Progranulin consists of seven and a half, tandemly repeated, non-identical copies of the 12 cysteine granulin motif. Many cellular processes and diseases are associated with this unique pleiotropic factor that include, but are not limited to, embryogenesis, tumorigenesis, inflammation, wound repair, neurodegeneration and lysosome function. Haploinsufficiency caused by autosomal dominant mutations within the GRN gene leads to frontotemporal lobar degeneration, a progressive neuronal atrophy that presents in patients as frontotemporal dementia. Frontotemporal dementia is an early onset form of dementia, distinct from Alzheimer's disease. The GRN-related form of frontotemporal lobar dementia is a proteinopathy characterized by the appearance of neuronal inclusions containing ubiquitinated and fragmented TDP-43 (encoded by TARDBP). The neurotrophic and neuro-immunomodulatory properties of progranulin have recently been reported but are still not well understood. Gene delivery of GRN in experimental models of Alzheimer's- and Parkinson's-like diseases inhibits phenotype progression. Here we review what is currently known concerning the molecular function and mechanism of action of progranulin in normal physiological and pathophysiological conditions in both in vitro and in vivo models. The potential therapeutic applications of progranulin in treating neurodegenerative diseases are highlighted.
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Affiliation(s)
- Babykumari P Chitramuthu
- Endocrine Research Laboratory, Royal Victoria Hospital, and McGill University Health Centre Research Institute, Centre for Translational Biology, Platform in Metabolic Disorders and Complications, 1001 Decarie Boulevard, QC, Canada, H4A 3J1
| | - Hugh P J Bennett
- Endocrine Research Laboratory, Royal Victoria Hospital, and McGill University Health Centre Research Institute, Centre for Translational Biology, Platform in Metabolic Disorders and Complications, 1001 Decarie Boulevard, QC, Canada, H4A 3J1
| | - Andrew Bateman
- Endocrine Research Laboratory, Royal Victoria Hospital, and McGill University Health Centre Research Institute, Centre for Translational Biology, Platform in Metabolic Disorders and Complications, 1001 Decarie Boulevard, QC, Canada, H4A 3J1
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Abstract
Cancer cells have defects in regulatory mechanisms that usually control cell proliferation and homeostasis. Different cancer cells share crucial alterations in cell physiology, which lead to malignant growth. Tumorigenesis or tumor growth requires a series of events that include constant cell proliferation, promotion of metastasis and invasion, stimulation of angiogenesis, evasion of tumor suppressor factors, and avoidance of cell death pathways. All these events in tumor progression may be regulated by growth factors produced by normal or malignant cells. The growth factor progranulin has significant biological effects in different types of cancer. This protein is a regulator of tumorigenesis because it stimulates cell proliferation, migration, invasion, angiogenesis, malignant transformation, resistance to anticancer drugs, and immune evasion. This review focuses on the biological effects of progranulin in several cancer models and provides evidence that this growth factor should be considered as a potential biomarker and target in cancer treatment.
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Mao Q, Wang D, Li Y, Kohler M, Wilson J, Parton Z, Shmaltsuyeva B, Gursel D, Rademakers R, Weintraub S, Mesulam MM, Xia H, Bigio EH. Disease and Region Specificity of Granulin Immunopositivities in Alzheimer Disease and Frontotemporal Lobar Degeneration. J Neuropathol Exp Neurol 2017; 76:957-968. [PMID: 29044416 DOI: 10.1093/jnen/nlx085] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Heterozygous loss-of-function mutations in GRN, the progranulin gene, which result in progranulin (PGRN) protein haploinsufficiency, are a major cause of frontotemporal lobar degeneration with TDP-43 proteinopathy (FTLD-TDP). PGRN is composed of seven and a half repeats of a highly conserved granulin motif that is cleaved to produce the granulin peptides A-G and paragranulin. To better understand the role of PGRN and granulin (Grn) peptides in the pathogenesis of neurodegeneration, we evaluated PGRN/Grn in brains of patients with Alzheimer disease, FTLD-TDP type A with or without GRN mutations, and normal individuals, using a panel of monoclonal antibodies against Grn peptides A-G. In the neocortex, Grn peptide-specific immunostains were observed, for example, membranous Grn E immunopositivity in pyramidal neurons, and Grn C immunopositivity in ramified microglia. In the hippocampus, Grn immunopositivity in the CA1 and CA2 regions showed disease-specific changes in both neurons and microglia. Most interestingly, in FTLD-TDP type A with GRN mutations, there is a 60% decrease in the density of Grn-positive microglia in the hippocampal CA1, suggesting that haploinsufficiency of the GRN mutations also extends to PGRN expression in microglia. This study provides important insights into future studies of the pathogenesis and treatment of FTLD-TDP.
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Affiliation(s)
- Qinwen Mao
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Dongyang Wang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Yanqing Li
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Missia Kohler
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Jayson Wilson
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Zachary Parton
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Bella Shmaltsuyeva
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Demirkan Gursel
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Rosa Rademakers
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Sandra Weintraub
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Marek-Marsel Mesulam
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
| | - Haibin Xia
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Laboratory of Gene Therapy, Department of Biochemistry, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, P.R. China; The Cognitive Neurology and Alzheimer Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Pathology Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida
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Tang SS, Li J, Tan L, Yu JT. Genetics of Frontotemporal Lobar Degeneration: From the Bench to the Clinic. J Alzheimers Dis 2017; 52:1157-76. [PMID: 27104909 DOI: 10.3233/jad-160236] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Frontotemporal lobar degeneration (FTLD) is a clinically heterogeneous neurodegenerative disease with a strong genetic component. In this review, we summarize most common mutations in MAPT, GRN, and C90RF72, as well as less common mutations in VCP, CHMP2B, TARDBP, FUS gene and so on. Several guidelines have been developed to help gene testing based on genotype-phenotype correlation, the underlying histopathological subtypes, and the neuroanatomic associations. Furthermore, we also summarize molecular pathways implicated by genes and novel targets for FTLD prevention and management in recent years.
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Ghag G, Holler CJ, Taylor G, Kukar TL, Uversky VN, Rangachari V. Disulfide bonds and disorder in granulin-3: An unusual handshake between structural stability and plasticity. Protein Sci 2017; 26:1759-1772. [PMID: 28608407 PMCID: PMC5563133 DOI: 10.1002/pro.3212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/06/2017] [Accepted: 06/06/2017] [Indexed: 11/09/2022]
Abstract
Granulins (GRNs) are a family of small (∼6 kDa) proteins generated by the proteolytic processing of their precursor, progranulin (PGRN), in many cell types. Both PGRN and GRNs are implicated in a plethora of biological functions, often in opposing roles to each other. Lately, GRNs have generated significant attention due to their implicated roles in neurodegenerative disorders. Despite their physiological and pathological significance, the structure-function relationships of GRNs are poorly defined. GRNs contain 12 conserved cysteines forming six intramolecular disulfide bonds, making them rather exceptional, even among a few proteins with high disulfide bond density. Solution NMR investigations in the past have revealed a unique structure containing putative interdigitated disulfide bonds for several GRNs, but GRN-3 was unsolvable due to its heterogeneity and disorder. In our previous report, we showed that abrogation of disulfide bonds in GRN-3 renders the protein completely disordered (Ghag et al., Prot Eng Des Sel 2016). In this study, we report the cellular expression and biophysical analysis of fully oxidized, native GRN-3. Our results indicate that both E. coli and human embryonic kidney (HEK) cells do not exclusively make GRN-3 with homogenous disulfide bonds, likely due to the high cysteine density within the protein. Biophysical analysis suggests that GRN-3 structure is dominated by irregular loops held together only by disulfide bonds, which induced remarkable thermal stability to the protein despite the lack of regular secondary structure. This unusual handshake between disulfide bonds and disorder within GRN-3 could suggest a unique adaptation of intrinsically disordered proteins towards structural stability.
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Affiliation(s)
- Gaurav Ghag
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi, 39406
| | - Christopher J Holler
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, 30322
| | - Georgia Taylor
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, 30322
| | - Thomas L Kukar
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, 30322
| | - Vladimir N Uversky
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, 33612
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi, 39406
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Intracellular Proteolysis of Progranulin Generates Stable, Lysosomal Granulins that Are Haploinsufficient in Patients with Frontotemporal Dementia Caused by GRN Mutations. eNeuro 2017; 4:eN-NWR-0100-17. [PMID: 28828399 PMCID: PMC5562298 DOI: 10.1523/eneuro.0100-17.2017] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/19/2017] [Accepted: 08/01/2017] [Indexed: 01/17/2023] Open
Abstract
Homozygous or heterozygous mutations in the GRN gene, encoding progranulin (PGRN), cause neuronal ceroid lipofuscinosis (NCL) or frontotemporal dementia (FTD), respectively. NCL and FTD are characterized by lysosome dysfunction and neurodegeneration, indicating PGRN is important for lysosome homeostasis in the brain. PGRN is trafficked to the lysosome where its functional role is unknown. PGRN can be cleaved into seven 6-kDa proteins called granulins (GRNs); however, little is known about how GRNs are produced or if levels of GRNs are altered in FTD-GRN mutation carriers. Here, we report the identification and characterization of antibodies that reliably detect several human GRNs by immunoblot and immunocytochemistry. Using these tools, we find that endogenous GRNs are present within multiple cell lines and are constitutively produced. Further, extracellular PGRN is endocytosed and rapidly processed into stable GRNs within lysosomes. Processing of PGRN into GRNs is conserved between humans and mice and is modulated by sortilin expression and mediated by cysteine proteases (i.e. cathpesin L). Induced lysosome dysfunction caused by alkalizing agents or increased expression of transmembrane protein 106B (TMEM106B) inhibit processing of PGRN into GRNs. Finally, we find that multiple GRNs are haploinsufficient in primary fibroblasts and cortical brain tissue from FTD-GRN patients. Taken together, our findings raise the interesting possibility that GRNs carry out critical lysosomal functions and that loss of GRNs should be explored as an initiating factor in lysosomal dysfunction and neurodegeneration caused by GRN mutations.
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Lee CW, Stankowski JN, Chew J, Cook CN, Lam YW, Almeida S, Carlomagno Y, Lau KF, Prudencio M, Gao FB, Bogyo M, Dickson DW, Petrucelli L. The lysosomal protein cathepsin L is a progranulin protease. Mol Neurodegener 2017; 12:55. [PMID: 28743268 PMCID: PMC5526245 DOI: 10.1186/s13024-017-0196-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 07/18/2017] [Indexed: 11/25/2022] Open
Abstract
Haploinsufficiency of GRN, the gene encoding progranulin (PGRN), causes frontotemporal lobar degeneration (FTLD), the second most common cause of early-onset dementia. Receptor-mediated lysosomal targeting has been shown to regulate brain PGRN levels, and complete deficiency of PGRN is a direct cause of neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Here we show that the lysosomal cysteine protease cathepsin L (Cat L) can mediate the proteolytic cleavage of intracellular PGRN into poly-granulin and granulin fragments. Further, PGRN and Cat L co-localize in lysosomes of HEK293 cells, iPSC-derived neurons and human cortical neurons from human postmortem tissue. These data identify Cat L as a key intracellular lysosomal PGRN protease, and provides an intriguing new link between lysosomal dysfunction and FTLD.
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Affiliation(s)
- Chris W Lee
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA. .,Present Address: Atlantic Health System, Morristown, NJ, USA. .,Present Address: Biomedical Research Institute of New Jersey, Cedar Knolls, NJ, USA.
| | | | - Jeannie Chew
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA
| | - Casey N Cook
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA
| | - Ying-Wai Lam
- Vermont Genetics Network Proteomics Facility, University of Vermont, Burlington, VT, USA.,Department of Biology, University of Vermont, Burlington, VT, USA
| | - Sandra Almeida
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Yari Carlomagno
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA
| | - Kwok-Fai Lau
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA
| | - Fen-Biao Gao
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Matthew Bogyo
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, 32224, USA.
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Abstract
The discovery that heterozygous and homozygous mutations in the gene encoding progranulin are causally linked to frontotemporal dementia and lysosomal storage disease, respectively, reveals previously unrecognized roles of the progranulin protein in regulating lysosome biogenesis and function. Given the importance of lysosomes in cellular homeostasis, it is not surprising that progranulin deficiency has pleiotropic effects on neural circuit development and maintenance, stress response, innate immunity and ageing. This Progress article reviews recent advances in progranulin biology emphasizing its roles in lysosomal function and brain innate immunity, and outlines future avenues of investigation that may lead to new therapeutic approaches for neurodegeneration.
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Willemse EAJ, Durieux-Lu S, van der Flier WM, Pijnenburg YAL, de Jonge R, Teunissen CE. Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid. J Alzheimers Dis 2017; 53:107-16. [PMID: 27104901 DOI: 10.3233/jad-160061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Progranulin (PGRN) levels in blood and cerebrospinal fluid (CSF) are increasingly studied as potential markers for neurodegenerative disorders. We aimed to 1) characterize two commercially available PGRN ELISAs on several assay validation parameters, 2) assess the stability of PGRN in serum and CSF under pre-analytical conditions, and 3) compare stability in the two assays. Intra- and inter-assay variation, inter-lot variation, linearity, lower limit of detection, and kit correlations were assessed for the Adipogen and R&D PGRN ELISA kits. Blood and serum samples were experimentally exposed to ≤9 freeze/thaw cycles, delayed processing for ≤24 h at room temperature and 4°C, and to temperature stability tests for ≤3 weeks at -20°C, 4°C, room temperature, and 37°C. Both commercial PGRN ELISA kits showed acceptable ranges for intra- and inter-assay variation, where the R&D kit performed more accurate than the Adipogen kit, especially for inter-assay variation (intra-assay serum: 6.7 and 8.3%, respectively; inter-assay serum: 9.2 and 21.0%; intra-assay CSF: 3.6 and 12.0%; inter-assay CSF: 16.0 and 44.5%). Absolute serum PGRN concentrations were 1.9-fold higher in Adipogen than R&D (p < 0.001) and strongly correlated between both kits (ρ= 0.86, p < 0.0001) and CSF PGRN levels were on the borderline of detection in both kits. PGRN was typically stable under all pre-analytical conditions addressed, although two weeks at 37°C resulted in decreased PGRN concentrations in CSF, only when using the Adipogen kit. These results support further examination of PGRN as a potential marker in neurodegenerative diseases, since PGRN is stable in serum and CSF and can be measured using ELISA kits from several providers.
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Affiliation(s)
- Eline A J Willemse
- Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands.,Neurology and Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - Sisi Durieux-Lu
- Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - Wiesje M van der Flier
- Neurology and Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands.,Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | - Yolande A L Pijnenburg
- Neurology and Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - Robert de Jonge
- Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - Charlotte E Teunissen
- Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
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Papegaey A, Eddarkaoui S, Deramecourt V, Fernandez-Gomez FJ, Pantano P, Obriot H, Machala C, Anquetil V, Camuzat A, Brice A, Maurage CA, Le Ber I, Duyckaerts C, Buée L, Sergeant N, Buée-Scherrer V. Reduced Tau protein expression is associated with frontotemporal degeneration with progranulin mutation. Acta Neuropathol Commun 2016; 4:74. [PMID: 27435172 PMCID: PMC4952067 DOI: 10.1186/s40478-016-0345-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/10/2016] [Indexed: 12/12/2022] Open
Abstract
Reduction of Tau protein expression was described in 2003 by Zhukareva et al. in a variant of frontotemporal lobar degeneration (FTLD) referred to as diagnosis of dementia lacking distinctive histopathology, then re-classified as FTLD with ubiquitin inclusions. However, the analysis of Tau expression in FTLD has not been reconsidered since then. Knowledge of the molecular basis of protein aggregates and genes that are mutated in the FTLD spectrum would enable to determine whether the “Tau-less” is a separate pathological entity or if it belongs to an existing subclass of FTLD. To address this question, we have analyzed Tau expression in the frontal brain areas from control, Alzheimer’s disease and FTLD cases, including FTLD- Tau (MAPT), FTLD-TDP (sporadic, FTLD-TDP-GRN, FTLD-TDP-C9ORF72) and sporadic FTLD-FUS, using western blot and 2D-DIGE (Two-Dimensional fluorescence Difference Gel Electrophoresis) approaches. Surprisingly, we found that most of the FTLD-TDP-GRN brains are characterized by a huge reduction of Tau protein expression without any decrease in Tau mRNA levels. Interestingly, only cases affected by point mutations, rather than cases with total deletion of one GRN allele, seem to be affected by this reduction of Tau protein expression. Moreover, proteomic analysis highlighted correlations between reduced Tau protein level, synaptic impairment and massive reactive astrogliosis in these FTLD-GRN cases. Consistent with a recent study, our data also bring new insights regarding the role of progranulin in neurodegeneration by suggesting its involvement in lysosome and synaptic regulation. Together, our results demonstrate a strong association between progranulin deficiency and reduction of Tau protein expression that could lead to severe neuronal and glial dysfunctions. Our study also indicates that this FTLD-TDP-GRN subgroup could be part as a distinct entity of FTLD classification.
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Rollinson S, Young K, Bennion-Callister J, Pickering-Brown SM. Identification of biological pathways regulated by PGRN and GRN peptide treatments using transcriptome analysis. Eur J Neurosci 2016; 44:2214-25. [PMID: 27307215 DOI: 10.1111/ejn.13297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/14/2016] [Indexed: 01/06/2023]
Abstract
Mutations in progranulin (PGRN) have been linked to two neurodegenerative disorders, heterozygote mutations with frontotemporal lobar degeneration (FTLD) and homozygote mutations with neuronal ceroid lipofuscinosis (NCL). Human PGRN is 593aa secreted growth factor, made up of seven and a half repeats of a highly conserved granulin motif that is cleaved to produce the granulin peptides A-G and paragranulin. While it is thought that PGRN protects against neurodegeneration through its role in inflammation and tissue repair, the role of PGRN and granulins in the nervous system is currently unclear. To better understand this, we prepared recombinant PGRN, granulin A-F and paragranulin, and used these to treat differentiated neuronal SH-SY5Y cells. Using RNA sequencing and bioinformatics techniques we investigated the functional effects of PGRN and the individual granulins upon the transcriptome. For PGRN treatment we show that the main effect of short-duration treatments is the down-regulation of transcripts, supporting that signalling pathway induction appears to be dominant effect. Gene ontology analysis, however, also supports the regulation of biological processes such as the spliceosome and proteasome in response to PGRN treatment, as well as the lysosomal pathway constituents such as CHMP1A, further supporting the role of PGRN in lysosomal function. We also show that the response to granulin treatments involves the regulation of numerous non-coding RNA's, and the granulins cluster into groups of similar activity on the basis of expression profile with paragranulin and PGRN having similar expression profiles, while granulins B, D, E and G appear more similar.
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Affiliation(s)
- Sara Rollinson
- Institute of Brain Behaviour and Mental Health, University of Manchester, AV Hill Building, Ackers Street, Manchester, M13 9PT, UK
| | - Kate Young
- Institute of Brain Behaviour and Mental Health, University of Manchester, AV Hill Building, Ackers Street, Manchester, M13 9PT, UK
| | - Janis Bennion-Callister
- Institute of Brain Behaviour and Mental Health, University of Manchester, AV Hill Building, Ackers Street, Manchester, M13 9PT, UK
| | - Stuart M Pickering-Brown
- Institute of Brain Behaviour and Mental Health, University of Manchester, AV Hill Building, Ackers Street, Manchester, M13 9PT, UK
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