Publications by authors named "Hironori Takamura"

The formation of hypertrophic scars and keloids is strongly associated with mechanical stimulation, and myofibroblasts are known to play a major role in abnormal scar formation. Wounds in patients with neurofibromatosis type 1 (NF1) become inconspicuous and lack the tendency to form abnormal scars. We hypothesized that there would be a unique response to mechanical stimulation and subsequent scar formation in NF1.

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Article Synopsis
  • - SUMO1 plays a role in neurodegenerative diseases by promoting tau protein aggregation and altering its phosphorylation, which is significant in Alzheimer's and related conditions.
  • - In patients with progressive supranuclear palsy (PSP), SUMO1 was found to co-localize with altered tau inclusions, particularly associated with truncated versions of tau.
  • - The study suggests that the modification of truncated tau by SUMO1 may exacerbate tau aggregation and hinder the cell's ability to clear protein deposits, potentially contributing to the progression of PSP.
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Arginine methylation is a common posttranslational modification that modulates protein function. SCY1-like pseudokinase 1 (SCYL1) is crucial for neuronal functions and interacts with γ-COP to form coat protein complex I (COPI) vesicles that regulate Golgi morphology. However, the molecular mechanism by which SCYL1 is regulated remains unclear.

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Small ubiquitin-related modifiers (SUMOs) conjugated or bound to target proteins can affect protein trafficking, processing and solubility. SUMOylation has been suggested to play a role in the amyloid plaque and neurofibrillary tangle pathology of Alzheimer disease (AD) and related neurodegenerative diseases. The current study examines the impact of SUMO1 on processing of the amyloid precursor protein (APP) leading to the production and deposition of the amyloid-β (Aβ) peptide.

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Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined.

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Recently, accumulating reports have suggested the importance of endoplasmic reticulum (ER) stress signaling in the differentiation of several tissues and cells, including myoblasts and osteoblasts. Secretory cells are easily subjected to ER stress during maturation of their secreted proteins. Skin fibroblasts produce and release several proteins, such as collagens, matrix metalloproteinases (MMPs), the tissue inhibitors of metalloproteinases (TIMPs) and glycosaminoglycans (GAGs), and the production of these proteins is increased at wound sites.

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Background: The dysbindin-1 gene (DTNBP1: dystrobrevin binding protein 1) is a promising schizophrenia susceptibility gene, known to localize almost exclusively to neurons in the brain, and participates in the regulation of neurotransmitter release, membrane-surface receptor expression, and synaptic plasticity. Sandy mice, with spontaneous Dtnbp1 deletion, display behavioral abnormalities relevant to symptoms of schizophrenia. However, it remains unknown if dysbindin-1 gain-of-function is beneficial or detrimental.

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Background: Changes in serotonin transporter (SERT) function have been implicated in autism. SERT function is influenced by the number of transporter molecules present at the cell surface, which is regulated by various cellular mechanisms including interactions with other proteins. Thus, we searched for novel SERT-binding proteins and investigated whether the expression of one such protein was affected in subjects with autism.

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Disrupted-in-schizophrenia 1 (DISC1) is a gene disrupted by a translocation, t(1;11) (q42.1;q14.3), that segregates with major psychiatric disorders, including schizophrenia, recurrent major depression and bipolar affective disorder, in a Scottish family.

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Alzheimer's disease (AD) is characterized by the accumulation of amyloid-β (Aβ). The genes that govern this process, however, have remained elusive. To this end, we combined distinct mouse strains with transcriptomics to directly identify disease-relevant genes.

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X-linked mental retardation (XLMR) is a common cause of moderate to severe intellectual disability in males. XLMR protein related to neurite extension (Xpn, also known as KIAA2022) has been implicated as a gene responsible for XLMR in humans. Although Xpn is highly expressed in the developing brain and is involved in neurite outgrowth in PC12 cells and neurons, little is known about the functional role of Xpn.

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Disrupted-in-schizophrenia 1 (DISC1)-binding zinc finger protein (DBZ) is a DISC1-interacting molecule and the interaction between DBZ and DISC1 is involved in neurite outgrowth in vitro. DBZ is highly expressed in brain, especially in the cortex. However, the physiological roles of DBZ in vivo have not been clarified.

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Mitochondria are dynamic organelles that change in response to extracellular stimuli. These changes are essential for normal mitochondrial/cellular function and are controlled by a tight balance between two antagonistic pathways that promote fusion and fission. Although some molecules have been identified to mediate the mitochondrial fusion and fission process, the underlying mechanisms remain unclear.

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Stress in mitochondria or the endoplasmic reticulum (ER) independently causes cell death. Recently, it was reported that ER stress causes mitochondrial dysfunction via p53-upregulated modulator of apoptosis (PUMA). However, little is known regarding the mitochondria molecules that mediate ER dysfunction.

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Objectives: Papassotiropoulos et al. (Science 314: p 475) discovered that a single nucleotide polymorphism (SNP) of the KIBRA gene (rs17070145) was associated with delayed recall performance in Caucasians. KIBRA is highly expressed in the brain and kidneys, and is reported to be involved in synaptic plasticity.

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The chitinase 3-like 1 (CHI3L1) gene acts as a cellular survival factor in response to several environmental and psychosocial stresses. The expression level of CHI3L1 was increased in the hippocampus and prefrontal cortex regions of patients with schizophrenia. Genetic variants of the CHI3L1 gene have been significantly associated with schizophrenia in two distinct ethnic groups, the Chinese and Irish populations.

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G72 is one of the most widely tested genes for association with schizophrenia. As G72 activates the D-amino acid oxidase (DAO), G72 is termed D-amino acid oxidase activator (DAOA). The aim of this study is to investigate the association between G72 and schizophrenia in a Japanese population, using the largest sample size to date (1774 patients with schizophrenia and 2092 healthy controls).

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A number of reports have provided genetic evidence for an association between the DTNBP1 gene (coding dysbindin) and schizophrenia. In addition, sandy mice, which harbor a deletion in the DTNBP1 gene and lack dysbindin, display behavioral abnormalities suggestive of an association with schizophrenia. However, the mechanism by which the loss of dysbindin induces schizophrenia-like behaviors remains unclear.

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Background: Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1) gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline.

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During attempts to examine the phosphorylation status of extracellular signal-regulated kinase (ERK) in cerebral cortex immunohistochemically, we determined whether deep anesthesia for euthanasia disturbs the phosphorylation status of ERK, because the anesthesia might influence activity-dependent phosphorylation of ERK. We compared effects of short (2 and 5 min) and long (>10 min) anesthesia by pentobarbital on the immunoreactivity for phosphorylated ERK in the visual and entorhinal cortices of rat. The long anesthesia drastically reduced the density of phosphorylated ERK immunopositive cells to about 15% of the short anesthesia condition.

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Monocular deprivation (MD) of vision leads to a loss of cortical response to the deprived eye in the early postnatal period (ocular dominance plasticity). The activity of several signal molecules, including extracellular signal-regulated kinase (ERK), has been reported as playing a crucial role in the ocular dominance plasticity. Although pharmacological inhibition of ERK disturbed the ocular dominance plasticity, it remains to be elucidated how the ERK activity is modulated by MD.

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