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S chwann cell involvement in the peripheral neuropathy of spinocerebellar ataxia type 3
Author(s) -
Suga Noriaki,
Katsuno Masahisa,
Koike Haruki,
Banno Haruhiko,
Suzuki Keisuke,
Hashizume Atsushi,
Mano Tomoo,
Iijima Masahiro,
Kawagashira Yuichi,
Hirayama Masaaki,
Nakamura Tomohiko,
Watanabe Hirohisa,
Tanaka Fumiaki,
Sobue Gen
Publication year - 2014
Publication title -
neuropathology and applied neurobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.538
H-Index - 95
eISSN - 1365-2990
pISSN - 0305-1846
DOI - 10.1111/nan.12055
Subject(s) - spinocerebellar ataxia , pathology , dorsal root ganglion , peripheral neuropathy , medicine , ataxia , spinal cord , anatomy , disease , endocrinology , psychiatry , diabetes mellitus
Aims Spinocerebellar ataxia type 3 ( SCA 3) is an inherited spinocerebellar ataxia caused by the expansion of trinucleotide CAG repeats in the gene encoding ataxin‐3. The clinical manifestations of SCA 3 include peripheral neuropathy, which is an important cause of disability in a subset of patients. Although the loss of neurones in the dorsal root ganglion ( DRG ) has been postulated to be the cause of this neuropathy, the precise mechanism remains to be elucidated. Methods To clarify the clinicopathological characteristics of SCA 3‐associated peripheral neuropathy, we performed nerve conduction studies and histopathological analyses. Nerve conduction studies were carried out in 18 SCA 3 patients. Immunohistochemical analyses of the anterior and posterior roots of the spinal cord and peripheral nerves were performed in five SCA 3 patients. We also employed immunohistochemistry and immunoelectron microscopy analyses with an anti‐polyglutamine antibody. Results The mean sensory nerve action potentials of the SCA 3 patients were half of the normal values. The motor conduction velocities were decreased, and the distal latencies were also significantly prolonged in the nerves studied relative to the those in normal controls. Histopathological analyses detected axonal sprouting and myelin thinning in all cases. Ataxin‐3 aggregates were found in the cytoplasm of S chwann cells in all of the SCA 3 patients examined but not in control subjects. Conclusions I n addition to the previously reported neuronopathy, the results of the present study indicate that S chwann cells are involved in the formation of the pathogenic intracytoplasmic ataxin‐3 protein aggregates in patients with SCA 3‐associated neuropathy.