Toshihiro Hokonohara

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (4)17.35 Total impact

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    ABSTRACT: Basophilic inclusions (BIs), which are characterized by their staining properties of being weakly argyrophilic, reactive with Nissl staining, and immunohistochemically negative for tau and transactive response (TAR) DNA-binding protein 43 (TDP-43), have been identified in patients with juvenile-onset amyotrophic lateral sclerosis (ALS) and adult-onset atypical ALS with ophthalmoplegia, autonomic dysfunction, cerebellar ataxia, or a frontal lobe syndrome. Mutations in the fused in sarcoma gene (FUS) have been reported in cases of familial and sporadic ALS, and FUS immunoreactivity has been demonstrated in basophilic inclusion body disease (BIBD), neuronal intermediate filament inclusion disease (NIFID), and atypical frontotemporal lobar degeneration with ubiquitin-positive and tau-negative inclusions (aFTLD-U). In the present study, we immunohistochemically and ultrastructurally studied an autopsy case of sporadic adult-onset ALS with numerous BIs. The patient presented with the classical clinical course of ALS since 75 years of age and died at age 79. Postmortem examination revealed that both Betz cells in the motor cortex and motor neurons in the spinal cord were affected. The substantia nigra was spared. Notably, BIs were frequently observed in the motor neurons of the anterior horns, the inferior olivary nuclei, and the basal nuclei of Meynert. BIs were immunopositive for p62, LC3, and FUS, but immunonegative for tau, TDP-43, and neurofilament. Ultrastructurally, BIs consisted of filamentous or granular structures associated with degenerated organelles with no limiting membrane. There were no Bunina bodies, skein-like inclusions, or Lewy-like inclusions. All exons and exon/intron boundaries of the FUS gene were sequenced but no mutations were identified.
    No preview · Article · Feb 2011 · Neuropathology
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    ABSTRACT: Mutations in the fused in sarcoma (FUS, also known as translated in liposarcoma) gene have been recently discovered to be associated with familial amyotrophic lateral sclerosis (FALS) in African, European and American populations. In a Japanese family with FALS, we found the R521C FUS mutation, which has been reported to be found in various ethnic backgrounds. The family history revealed 23 patients with FALS among 46 family members, suggesting a 100% penetrance rate. They developed muscle weakness at an average age of 35.3 years, followed by dysarthria, dysphagia, spasticity and muscle atrophy. The average age of death was 37.2 years. Neuropathological examination of the index case revealed remarkable atrophy of the brainstem tegmentum characterized by cytoplasmic basophilic inclusion bodies in the neurons of the brainstem. We screened 40 FALS families in Japan and found 4 mutations (S513P, K510E, R514S, H517P) in exon 14 and 15 of FUS. Even in Asian races, FALS with FUS mutations may have the common characteristics of early onset, rapid progress and high penetrance rate, although in patients with the S513P mutation it was late-onset. Degeneration in multiple systems and cytoplasmic basophilic inclusion bodies were found in the autopsied cases.
    No preview · Article · Mar 2010 · Journal of Human Genetics
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    ABSTRACT: Mutations in the fused in sarcoma gene (FUS) were recently found in patients with familial amyotrophic lateral sclerosis (ALS). The present study aimed to clarify unique features of familial ALS caused by FUS mutation in the Japanese population. We carried out clinical, neuropathological, and genetic studies on a large Japanese pedigree with familial ALS. In six successive generations of this family, 16 individuals of both sexes were affected by progressive muscle atrophy and weakness, indicating an autosomal dominant trait. Neurological examination of six patients revealed an age at onset of 48.2+/-8.1 years in fourth generation patients, while it was 31 and 20 years in fifth and sixth generation patients, respectively. Motor paralysis progressed rapidly in these patients, culminating in respiratory failure within 1 year. The missense mutation c.1561 C>T (p.R521C) was found in exon 15 of FUS in the four patients examined. Neuropathological study of one autopsied case with the FUS mutation revealed multiple system degeneration in addition to upper and lower motor neuron involvement: the globus pallidus, thalamus, substantia nigra, cerebellum, inferior olivary nucleus, solitary nucleus, intermediolateral horn, Clarke's column, Onuf's nucleus, central tegmental tract, medial lemniscus, medial longitudinal fasciculus, superior cerebellar peduncle, posterior column, and spinocerebellar tract were all degenerated. Argyrophilic and basophilic neuronal or glial cytoplasmic inclusions immunoreactive for FUS, GRP78/BiP, p62, and ubiquitin were detected in affected lesions. The FUS R521C mutation in this Japanese family caused familial ALS with pathological features of multiple system degeneration and neuronal basophilic inclusions.
    No preview · Article · Dec 2009 · Acta Neuropathologica
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    ABSTRACT: We report the first non-Caucasian case of facial onset sensory and motor neuronopathy (FOSMN) syndrome partially responding to various immunotherapies. A 55-year-old man had first felt paresthesia on his right cheek at age 45. This gradually extended to the scalp. Paresthesia of bilateral fingers and dysphagia appeared 6 years later. On admission, facial sensory impairment and bulbar palsy were found. There were no sensory or motor deficits evident in any limb, except for decreased deep tendon reflex and vibratory sensation. Videofluorography (VF) revealed decreased pharyngeal clearance. The sensory nerve action potential (SNAP) amplitudes of median and ulnar nerves were decreased. Intravenous immunoglobulin therapy and plasma exchange ameliorated his dysesthesia and dysphagia after several weeks, and resulted in improvements in VF and SNAP abnormalities. These observations suggest that FOSMN syndrome maybe, in part, immune-mediated.
    No preview · Article · Sep 2008 · Journal of the Neurological Sciences