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Sumi-Akamaru H, Eto M, Yamauchi A, Uehara T, Kakuda K, Obayashi K, Kato S, Naka T, Mochizuki H. Evidence that glial cells attenuate G47R transthyretin accumulation in the central nervous system. Neuropathology 2017; 38:11-21. [PMID: 28960480 DOI: 10.1111/neup.12412] [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: 06/07/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 11/29/2022]
Abstract
Amyloidogenic protein forms amyloid aggregations at membranes leading to dysfunction of amyloid clearance and amyloidosis. Glial cells function in the clearance and degradation of amyloid β (Aβ) in the brain. This study aimed to clarify the reason why amyloid transthyretin (ATTR) rarely accumulates in the CNS. We pathologically analyzed the relationship between amyloid deposition with basement membranes or glial cells in a rare case of ATTR leptomeningeal amyloidosis. In addition, we compared the cytotoxicity of ATTR G47R, the amyloidosis-causing mutation in the case studied (n = 1), and Aβ in brains from patients with cerebral amyloid angiopathy (n = 6). In the subarachnoid space of the ATTR G47R case, most amyloids accumulated at the components of basement membranes. On the CNS surface, ATTR accumulations were retained by astrocytic end feet. In areas where glial end feet enveloped ATTR, ubiquitination and micro-vacuolation of ATTR was evident. The colocalization of GFAP and ubiquitin was also evident. The accumulation of ATTR G47R in the CNS was negatively correlated with the prevalence of astrocytes. Quantitatively, amyloid deposits along the vessels were mostly partial in cerebral Aβ angiopathy cases and nearly complete along the basement membrane in the ATTR G47R case. The vascular expressions of type IV collagen and smooth muscle actin were severely reduced in areas with ATTR G47R deposition, but not in areas with Aβ deposition. The vascular protein level recovered in the ATTR G47R case when vessels entered into areas of parenchyma that were rich in astrocytes. In addition, the strong interactions between the transthyretin variant and basement membranes may have led to dysfunction of transthyretin clearance and leptomeningeal amyloidosis. The present study was the first to show that glial cells may attenuate G47R transthyretin accumulation in the CNS.
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Affiliation(s)
- Hisae Sumi-Akamaru
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Masaki Eto
- Department of Neurology, Higashiosaka City Medical Center, Higashi-Osaka, Japan
| | - Amane Yamauchi
- Department of Diagnostic Pathology, Higashiosaka City Medical Center, Higashi-Osaka, Japan
| | - Takuya Uehara
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Neurology, Higashiosaka City Medical Center, Higashi-Osaka, Japan
| | - Keita Kakuda
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Neurology, Higashiosaka City Medical Center, Higashi-Osaka, Japan
| | - Konen Obayashi
- Department of Morphological and Physiological Sciences, Graduate School of Health Sciences, Kumamoto University, Kumamoto, Japan
| | - Shinsuke Kato
- Division of Neuropathology, Department of Pathology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Takashi Naka
- Department of Neurology, Higashiosaka City Medical Center, Higashi-Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Graduate School of Medicine, Osaka University, Suita, Japan
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Malmos KG, Stenvang M, Sahin C, Christiansen G, Otzen DE. The Changing Face of Aging: Highly Sulfated Glycosaminoglycans Induce Amyloid Formation in a Lattice Corneal Dystrophy Model Protein. J Mol Biol 2017; 429:2755-2764. [PMID: 28739480 DOI: 10.1016/j.jmb.2017.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/16/2017] [Accepted: 07/17/2017] [Indexed: 11/27/2022]
Abstract
Glycosaminoglycans (GAGs) are related to multiple biological functions and diseases. There is growing evidence that GAG concentration and sulfate content increase with age. The destabilizing mutation A546T in the corneal protein TGFBIp leads to lattice-type corneal dystrophy, but symptoms only appear in the fourth decade of life. We hypothesize that this delayed phenotype can be explained by increased GAG sulfation over time. Using in vitro assays with the C-terminal TGFIBIp domain Fas1-4, previously shown to recapitulate many properties of full-length TGFBIp, we find that only long GAGs with multiple sulfate groups on each repeating unit increase the amount of worm-like aggregates and induce long, straight fibrils in A546T. In contrast, GAGs did not induce aggregation of wildtype Fas1-4, suggesting that the finding might be specific for lattice corneal dystrophy mutants. Our results highlight a possible role of changing GAG sulfation in the accumulation of amyloid, which also may have implications for the development of neurodegenerative diseases.
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Affiliation(s)
- Kirsten G Malmos
- Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
| | - Marcel Stenvang
- Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Cagla Sahin
- Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
| | - Gunna Christiansen
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000 Aarhus, Denmark
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
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