An In Vitro Model for Lewy Body-Like Hyaline Inclusion/Astrocytic Hyaline Inclusion: Induction by ER Stress with an ALS-Linked SOD1 Mutation

Satoru Yamagishi,Taiichi Katayama,Masaya Tohyama,Yoshihisa Koyama,Junichi Hitomi,Masaaki Kato,Manabu Taniguchi,Shinsuke Kato,Masashi Aoki,Yasuto Itoyama,Xiao-Jiang Li

doi:10.1371/journal.pone.0001030

Satoru Yamagishi, Taiichi Katayama + Show 9 more

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https://doi.org/10.1371/journal.pone.0001030

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Journal: PloS one	Publication Date: Oct 10, 2007
Citations: 80	License type: CC BY 4.0

Affiliation: Osaka University, Tohoku University, Tottori University

Abstract

Neuronal Lewy body-like hyaline inclusions (LBHI) and astrocytic hyaline inclusions (Ast-HI) containing mutant Cu/Zn superoxide dismutase 1 (SOD1) are morphological hallmarks of familial amyotrophic lateral sclerosis (FALS) associated with mutant SOD1. However, the mechanisms by which mutant SOD1 contributes to formation of LBHI/Ast-HI in FALS remain poorly defined. Here, we report induction of LBHI/Ast-HI-like hyaline inclusions (LHIs) in vitro by ER stress in neuroblastoma cells. These LHI closely resemble LBHI/Ast-HI in patients with SOD1-linked FALS. LHI and LBHI/Ast-HI share the following features: 1) eosinophilic staining with a pale core, 2) SOD1, ubiquitin and ER resident protein (KDEL) positivity and 3) the presence of approximately 15–25 nm granule-coated fibrils, which are morphological hallmark of mutant SOD1-linked FALS. Moreover, in spinal cord neurons of L84V SOD1 transgenic mice at presymptomatic stage, we observed aberrant aggregation of ER and numerous free ribosomes associated with abnormal inclusion-like structures, presumably early stage neuronal LBHI. We conclude that the LBHI/Ast-HI seen in human patients with mutant SOD1-linked FALS may arise from ER dysfunction.

Highlights

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder in which both upper and lower motor neurons begin to degenerate in middle-aged persons
We show that endoplasmic reticulum (ER) stress in a neuroblastoma line expressing mutant SOD1 can provoke SOD1 aggregation in ER and formation of Lewy bodylike hyaline inclusions (LBHI)/astrocytic hyaline inclusions (Ast-HI)-like hyaline inclusion bodies (LHIs), which show SOD1, ubiquitin, GRP78/BiP and ER resident protein (KDEL) immunopositivity similar to the shared cytopathological features of LBHI and Ast-HI
Ultrastructual analysis revealed that the LHIs in neuroblastoma cells were composed of granule-coated fibrils and granular materials, which are the typical morphological hallmarks of mutant SOD1-linked familial ALS (FALS), and were identical with the Ast-HI found in L84V SOD1 mice (Fig. 5C, F; [38]). These results suggest that LBHI/Ast-HI in FALS patients might be provoked by ER stress as we observed for LHIs

Summary

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder in which both upper and lower motor neurons begin to degenerate in middle-aged persons. Induced neuroblastoma LHI consisted of 15–25 nm granule-coated fibrils, a hallmark of mutant SOD1-linked FALS, raising the possibility that these acutely induced aggregations represent a precursor to LBHI/Ast-HI seen in advanced FALS In support of this possibility, we observe abnormal ER and numerous free ribosomes aggregated in the peri-nuclear region neuroblastoma cells expressing L84V SOD1 under ER stress condition and in spinal cord neurons in presymptomatic transgenic mice expressing L84V SOD1. Taken together, these findings suggest a model for early events in FALS cellular pathology, in which ER stress promotes the aggregation of mutant SOD1 and is involved in the development of LBHI/Ast-HI in patients with mutant SOD1 linked FALS

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MATERIALS AND METHODS