Publications by authors named "Chiyoko Uchida"

Here we show that Gas7 inhibits phosphorylated tau fibrillogenesis by binding to phosphorylated tau at its non-WW domain, presumably F-BAR domain. We revealed that Gas7 binds to the third repeat domain of tau, the core element of tau oligomerization and the C-terminal domain of tau and alters the conformation not to form fibrils. These results suggest that Gas7 may serve to protect against Alzheimer's disease and other tauopathies by preventing tau fibrillogenesis.

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Calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain and functions as a mediator of calcium signaling. We found that the relative activity of CaMKII was significantly lower in the WT mouse brains than in the Pin1 mouse brains. Pin1 binds to phosphorylated CaMKII and weakens its activity.

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Pin1, a peptidyl prolyl cis/trans isomerase (PPIase), regulates the activity and stability of various phosphorylated proteins. Pin1 consists of a PPIase domain and WW domain, both of which are required for the function of Pin1. However, how the behavior of these domains changes upon binding to phosphorylated proteins has not been analyzed.

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We searched for inhibitors against prolyl isomerase Pin1 in order to develop functional foods to prevent and cure various Pin1 related diseases such as cancer, diabetes, cardiovascular disease, Alzheimers's disease, and so on. We created a polyphenol library consisting of ingredients in healthy foods and beverages, since polyphenols like epigallocatechin gallate (EGCG) in green tea and 974B in brown algae had been identified as its Pin1 inhibitors. Several polyphenols such as EGCG derivatives, caffeic acid derivatives and tannic acid inhibited Pin1 activity.

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A prolyl isomerase Pin1 deficient (Pin1) male mice had severe testicular atrophy. We investigated the function of Pin1 in spermatogenesis by analyzing the Pin1 mice at reproductive age. Pin1 mice had lessαPLZF positive spermatogonia (undifferentiated spermatogonia) than wild type (WT).

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Here we show that Pin1, a peptidyl-prolyl cis/trans isomerase which catalyzes the isomerization of phosphorylated Ser/Thr-Pro, is a regulatory molecule of thrombopoiesis. We found that mice lacking the Pin1 gene (Pin1 mice) formed more megakaryocytes (MKs) than wild type mice (WT mice), and that the proplatelet formation of MKs was poorer in Pin1 mice than WT mice. Treatment of Meg-01 cells, a megakaryoblastic floating cell line, with shRNA against Pin1 suppressed the proplatelet formation.

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Objective: To examine the prevalence of and the factors contributing to leaves of absence and school discontinuation in Japanese college students over a 27-year period. Trends in these academic events over time were assessed, and students at elevated risk and psychosocial difficulties in need of supportive intervention were identified.

Methods: Surveys were collected from the majority of Japanese national universities between 1985 and 2012, yielding data on a total of 9.

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Medulloblastoma is the most common malignant brain tumor in children. Therapeutic approaches to medulloblastoma (combination of surgery, radiotherapy, and chemotherapy) have led to significant improvements, but these are achieved at a high cost to quality of life. Alternative therapeutic approaches are needed.

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Article Synopsis
  • Researchers discovered that a polyphenol from brown algae can inhibit the differentiation of fibroblasts into fat cells, known as adipocytes.
  • In an experiment, this compound was given to mice on a high-fat diet, which resulted in reduced fat accumulation, similar to that of mice on a normal diet.
  • The study concluded that the Pin1 protein is essential for the conversion of stem cells into adipocytes and suggested that the brown algae polyphenol may offer a potential treatment for obesity.
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It has been known that the phosphoSer/Thr-Pro-specific peptidyl prolyl cis/trans isomerase Pin1 regulates a variety of intracellular signaling pathways, including the response to the genotoxic drug doxorubicin. Pin1 binds phosphorylated p53 and stabilizes p53 to cause cell cycle arrest and apoptosis quickly in response to doxorubicin. Here we show another mechanism of Pin1 to maintain cell sensitivity to genotoxic stress, irrespective of whether p53 is present or not.

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The peptidyl prolyl cis/trans isomerase Pin1, the human ortholog of yeast Ess1 specifically isomerizes peptide bindings of pSer/pThr-Pro residues in various proteins, and regulates the expression levels and functions of phosphorylated proteins. Activation of Pin1 is associated with pathology of a variety of diseases, such as cancer, Alzheimer's disease, infectious diseases and so on. Therefore, regulatory compounds for Pin1 can be applied as a clinical medicine against these diseases.

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The peptidyl prolyl cis/trans isomerase Pin1 enhances the uptake of triglycerides and the differentiation of fibroblasts into adipose cells in response to insulin stimulation. Pin1 downregulation could be a potential approach to prevent and treat obesity-related disorders. In order to identify an inhibitor of Pin1 that exhibited minimal cytotoxicity, we established a high-throughput screen for Pin1 inhibitors and used this method to identify an inhibitor from 1,056 crude fractions of two natural product libraries.

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Mesenchymal stem cells (MSCs) can differentiate into a variety of cell types. MSCs exist in several tissues such as the bone marrow, adipose, muscle, cartilage, and tendon. This differentiation potential makes MSCs candidates for cell-based therapeutic strategies for mesenchymal tissue injuries.

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Background: A peptidyl prolyl cis/trans isomerase, Pin1, regulates insulin signal transduction. Pin1 reduces responses to insulin stimulation by binding CRTC2 (CREB-regulated transcriptional co-activator 2) and PPARγ (peroxisome prolifereator- activated receptor γ), but conversely enhances insulin signaling by binding IRS-1 (insulin receptor substrate-1), Akt kinase, and Smad3. Therefore, it is still unclear whether Pin1 inhibits or enhances adipose cell differentiation.

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Background: Prolyl isomerase Pin1 may be involved in innate immunity against microbial infection, but the mechanism how Pin1 controls the innate immunity is poorly understood.

Methodology/principal Findings: Injection of lipopolysaccharide (LPS) into the mice induces inflammatory pulmonary disorder and sometimes the serious damages lead to death. Comparing to the wild-type (WT) mice, the Pin1⁻/⁻ mice showed more serious damages in lung and the lower survival rate after the LPS injection.

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Unlabelled: In recent years, the increasing number of young people withdrawing from society, so called Hikikomori, has been a cause for concern in Japan. These are people who stay at home and do not work or attend school for more than 6 months. Most of them are not regarded as having any psychotic illness such as schizophrenia.

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Here, we report a novel role for hGas7b (human growth arrest specific protein 7b) in the regulation of microtubules. Using a bioinformatic approach, we studied the actin-binding protein hGas7b with a structural similarity to the WW domain of a peptidyl prolyl cis/trans isomerase, Pin1, that facilitates microtubule assembly. Thus, we have demonstrated that hGas7b binds Tau at the WW motif and that the hGas7b/Tau protein complex interacts with the microtubules, promoting tubulin polymerization.

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Background: Internet peer support groups for depression are becoming popular and could be affected by an increasing number of social network services (SNSs). However, little is known about participant characteristics, social relationships in SNSs, and the reasons for usage. In addition, the effects of SNS participation on people with depression are rather unknown.

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The process of microtubule elongation is thought to consist of two stages-formation of a tubulin sheet structure and its closure into a tube. However, real-time observation of this process has been difficult. Here, by utilizing phospho-tau binding protein Gas7 (growth-arrest-specific protein 7), we visualized the polymer transformation process by dark-field microscopy.

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Neurodegenerative tauopathies, including Alzheimer disease, are characterized by abnormal hyperphosphorylation of the microtubule-associated protein Tau. One group of tauopathies, known as frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), is directly associated with mutations of the gene tau. However, it is unknown why mutant Tau is highly phosphorylated in the patient brain.

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We investigated the enzyme activity of peptidyl prolyl cis/trans isomerases (PPIases) in brain, testis, lung, liver, and mouse embryonic fibroblasts (MEF) of Pin1+/+ and Pin1-/- mice. The aim of this study is to determine if other PPIases can substitute for the loss of Pin1 activity in Pin1-/- mice and what influence Pin1 depletion has on the activities of other PPIases members. The results show that high PPIase activities of Pin1 are found in organs that have the tendency to develop Pin1 knockout phenotypes and, therefore, provide for the first time an enzymological basis for these observations.

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Here we show that prolyl isomerase Pin1 is involved in the Abeta production central to the pathogenesis of Alzheimer's disease. Enzyme immunoassay of brains of the Pin1-deficient mice revealed that production of Abeta40 and Abeta42 was lower than that of the wild-type mice, indicating that Pin1 promotes Abeta production in the brain. GST-Pin1 pull-down and immunoprecipitation assay revealed that Pin1 binds phosphorylated Thr668-Pro of C99.

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