Publications by authors named "Masataka Hoshino"

BACKGROUND Cerebral venous thrombosis (CVT) is a rare but fatal complication of hyperthyroidism that is induced by the hypercoagulable state of thyrotoxicosis. Although it is frequently difficult to diagnose CVT promptly, it is important to consider it in the differential diagnosis when a hyperthyroid patient presents with atypical neurologic symptoms. CASE REPORT A 49-year-old Japanese female with unremarkable medical history came in with thyroid storm and multiple progressive ischemic stroke identified at another hospital.

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A 51-year-old male who showed severe ataxia, dysarthria, bilateral blepharoptosis, diplopia and nystagmus with the subacute onset was reported. The chest roentgenogram and CT scan revealed mass lesions at the hilus of the left lung. The tumor markers, NSE and ProGRP, were elevated; 12.

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Transcriptional disturbance is implicated in the pathology of polyglutamine diseases, including Huntington's disease (HD). However, it is unknown whether transcriptional repression leads to neuronal death or what forms that death might take. We found transcriptional repression-induced atypical death (TRIAD) of neurons to be distinct from apoptosis, necrosis, or autophagy.

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Mutations of PQBP-1 (polyglutamine binding protein-1) have been shown recently to cause human mental retardation accompanied by microcephaly at a high frequency. As a first step towards understanding the molecular basis of this developmental anomaly, we analysed developmental expression of PQBP-1 by in situ hybridization, immunohistochemistry and Western blot analysis. Although it had been shown by Northern blot analysis that PQBP-1 mRNA is expressed in multiple organs in adult mice, our present results revealed that PQBP-1 mRNA and protein are dominantly expressed in the central nervous system (CNS) in embryos and in newborn mice.

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Polyglutamine tract-binding protein-1 (PQBP-1) is a nuclear protein that interacts and colocalizes with mutant polyglutamine proteins. We previously reported that PQBP-1 transgenic mice show a late-onset motor neuron disease-like phenotype and cell death of motor neurons analogous to human neurodegeneration. To investigate the molecular mechanisms underlying the motor neuron death, we performed microarray analyses using the anterior horn tissues of the spinal cord and compared gene expression profiles between pre-symptomatic transgenic and age-matched control mice.

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Aggregation of disease proteins is believed to be a central event in the pathology of polyglutamine diseases, whereas the relationship between aggregation and neuronal death remains controversial. We investigated this question by expressing mutant huntingtin (htt) with a defective adenovirus in different types of neurons prepared from rat cerebral cortex, striatum or cerebellum. The distribution pattern of inclusions is not identical among different types of primary neurons.

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By using direct immunocytochemistry of BrU incorporated to RNA in the nuclei, we evaluated the effect of mutant huntingtin and ataxin-1 on general transcription in primary cortical and cerebellar neurons. Our quantitative analyses clearly showed that these mutant polyglutamine disease proteins repress general transcription. In addition, we found that general transcription level was almost similar in inclusion body-positive and -negative neurons.

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The amyloid precursor protein (APP) can be catabolized mainly via either an amyloidogenic or non-amyloidogenic pathway, leading to the production of amyloid beta (Abeta) or the secreted form of APP (sAPP), respectively. Abeta is a major component of deposits found in Alzheimer's disease brains and plays an important role in the pathogenesis of this disease, whereas sAPP (though it might have some neurotropic function) has a largely unknown function and metabolism. In this study, a novel 11-kDa APP amino-terminal fragment from Neuro2a cells (but also present in primary cultured neurons, glias, and mouse cerebral cortex) was characterized using mass spectrometric and amino acid sequence analyzes.

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Perturbation of histone acetyl-transferase (HAT) activity is implicated in the pathology of polyglutamine diseases, and suppression of the counteracting histone deacetylase (HDAC) proteins has been proposed as a therapeutic candidate for these intractable disorders. Meanwhile, it is not known whether mutant polyglutamine disease protein affects the HDAC activity in declining neurons, though the answer is essential for application of anti-HDAC drugs for polyglutamine diseases. Here, we show the effect of mutant huntingtin (htt) protein on the expression and activity of HDAC proteins in rat primary cortical neurons as well as in human Huntington's disease (HD) brains.

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