title: Severely exacerbated neuromyelitis optica rat model with extensive astrocytopathy by high affinity anti-aquaporin-4 monoclonal antibody.
abstract: BACKGROUND
  Neuromyelitis optica (NMO), an autoimmune astrocytopathic disease associated with anti-aquaporin-4 (AQP4) antibody, is characterized by extensive necrotic lesions preferentially involving the optic nerves and spinal cord. However, previous in-vivo experimental models injecting human anti-AQP4 antibodies only resulted in mild spinal cord lesions compared to NMO autopsied cases. Here, we investigated whether the formation of severe NMO-like lesions occurs in Lewis rats in the context of experimental autoimmune encephalomyelitis (EAE), intraperitoneally injecting incremental doses of purified human immunoglobulin-G from a NMO patient (hIgGNMO) or a high affinity anti-AQP4 monoclonal antibody (E5415A), recognizing extracellular domain of AQP4 made by baculovirus display method.
  
  
  RESULTS
  NMO-like lesions were observed in the spinal cord, brainstem, and optic chiasm of EAE-rats with injection of pathogenic IgG (hIgGNMO and E5415A), but not in control EAE. Only in higher dose E5415A rats, there were acute and significantly severer clinical exacerbations (tetraparesis or moribund) compared with controls, within half day after the injection of pathogenic IgG. Loss of AQP4 was observed both in EAE rats receiving hIgGNMO and E5415A in a dose dependent manner, but the ratio of AQP4 loss in spinal sections became significantly larger in those receiving high dose E5415A up to about 50 % than those receiving low-dose E5415A or hIgGNMO less than 3 %. These lesions were also characterized by extensive loss of glial fibrillary acidic protein but relatively preserved myelin sheaths with perivascular deposition of IgG and C5b-9, which is compatible with post mortem NMO pathology. In high dose E5415A rats, massive neutrophil infiltration was observed especially at the lesion edge, and such lesions were highly vacuolated with partial demyelination and axonal damage. In contrast, such changes were absent in EAE rats receiving low-dose E5415A and hIgGNMO.
  
  
  CONCLUSIONS
  In the present study, we established a severe experimental NMO rat model with highly clinical exacerbation and extensive tissue destructive lesions typically observed in NMO patients, which has not adequately been realized in in-vivo rodent models. Our data suggest that the pathogenic antibodies could induce immune mediated astrocytopathy with mobilized neutrophils, resulted in early lesion expansion of NMO lesion with vacuolation and other tissue damages. (350/350).
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kurosawa
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan. misu@med.tohoku.ac.jp.|Department of Multiple Sclerosis Therapeutics, Tohoku University Graduate School of Medicine, Sendai, Japan. misu@med.tohoku.ac.jp.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Misu
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Department of Multiple Sclerosis Therapeutics, Tohoku University Graduate School of Medicine, Sendai, Japan.|Department of Neurology, Faculty of Medicine, University of Sao Paulo, Sao Paulo, Brazil.|Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
authors.forename: Douglas Kazutoshi
authors.initials: DK
authors.lastname: Sato
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.|Department of Neurology, Yonezawa National Hospital, Yamagata, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Keio Advanced Research Center for Water Biology and Medicine, Keio University, Tokyo, Japan.|Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Iwanari
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ogawa
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakashima
authors.affiliation: Department of Multiple Sclerosis Therapeutics, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fujihara
authors.affiliation: Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Hamakubo
authors.affiliation: Keio Advanced Research Center for Water Biology and Medicine, Keio University, Tokyo, Japan.|Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Yasui
authors.affiliation: Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Aoki
mesh_terms: D000368:Aged; D000818:Animals; D000915:Antibody Affinity / Q000187:drug effects; D051401:Aquaporin 4 / Q000276:immunology*; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D003186:Complement C9 / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000009:adverse effects*; D008840:Microfilament Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009471:Neuromyelitis Optica / Q000139:chemically induced* / Q000473:pathology*; D020556:Neutrophil Infiltration / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D013997:Time Factors; D014617:Vacuoles / Q000473:pathology
chemical_list: C491049:Aif1 protein, mouse; D051401:Aquaporin 4; D002135:Calcium-Binding Proteins; D003186:Complement C9; D007074:Immunoglobulin G; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; C040352:complement C9 polymer