160 research outputs found

    The Involvement of Neuron-Specific Factors in Dendritic Spinogenesis: Molecular Regulation and Association with Neurological Disorders

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    Dendritic spines are the location of excitatory synapses in the mammalian nervous system and are neuron-specific subcellular structures essential for neural circuitry and function. Dendritic spine morphology is determined by the F-actin cytoskeleton. Factin remodeling must coordinate with different stages of dendritic spinogenesis, starting from dendritic filopodia formation to the filopodia-spines transition and dendritic spine maturation and maintenance. Hundreds of genes, including F-actin cytoskeleton regulators, membrane proteins, adaptor proteins, and signaling molecules, are known to be involved in regulating synapse formation. Many of these genes are not neuron-specific, but how they specifically control dendritic spine formation in neurons is an intriguing question. Here, we summarize how ubiquitously expressed genes, including syndecan-2, NF1 (encoding neurofibromin protein), VCP, and CASK, and the neuron-specific gene CTTNBP2 coordinate with neurotransmission, transsynaptic signaling, and cytoskeleton rearrangement to control dendritic filopodia formation, filopodia-spines transition, and dendritic spine maturation and maintenance. The aforementioned genes have been associated with neurological disorders, such as autism spectrum disorders (ASDs), mental retardation, learning difficulty, and frontotemporal dementia. We also summarize the corresponding disorders in this report

    Tanshinone IIA Inhibits High Glucose-Induced Collagen Synthesis via Nuclear Factor Erythroid 2-Related Factor 2 in Cardiac Fibroblasts

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    Background/Aims: Diabetes is associated with increased incidence of myocardial dysfunction, which is partly characterized by interstitial and perivascular fibrosis. Cardiac fibroblasts have been identified as an important participant in the development of cardiac fibrosis. Exposure of cultured cardiac fibroblasts to high glucose resulted in increased collagen synthesis. Tanshinone IIA can alleviate the ventricular fibrosis that develops in a number of different experimental conditions. However, whether tanshinone IIA can prevent high glucose-induced collagen synthesis in cardiac fibroblasts remains unknown. The aim of this study was to evaluate the effects of tanshinone IIA on high glucose-induced collagen synthesis in cardiac fibroblasts. Methods: Rat cardiac fibroblasts were cultured in high glucose (25 mM) media in the absence or presence of tanshinone IIA and the changes in collagen synthesis, transforming growth factor-β1 (TGF-β1) production and related signaling molecules were assessed by 3H-proline incorporation, quantitative polymerase chain reaction, enzyme linked immunosorbent assay, and Western blotting. Results: The results indicate cardiac fibroblasts exposed to high glucose condition show increased cell proliferation and collagen synthesis and these effects were abolished by tanshinone IIA treatment. Furthermore, the inhibitory effect of tanshinone IIA on high glucose induced cell proliferation and collagen synthesis may be associated with its activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the inhibition of TGF-β1 production and Smad2/3 phosphorylation. Conclusion: In summary, our results highlights the critical role tanshinone IIA plays as an antioxidant in attenuating high glucose-mediated collagen synthesis through inhibiting TGF-β1/Smad signaling in cardiac fibroblasts which provide a mechanistic basis for the clinical application of tanshinone IIA in the treating diabetic-related cardiac fibrosis

    Intensify the application of ZnO-based nanodevices in humid environment: O2/H2 plasma suppressed the spontaneous reaction of amorphous ZnO nanowires

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    [[abstract]]In this work, we have demonstrated that amorphous ZnO nanobranches (a-ZnO NBs) could spontaneously react from the crystalline ZnO NWs (c-ZnO NWs) at specific humid environment. The spontaneous reaction mechanism and result can be analyzed by humidity controlling and optical microscope (OM)/scanning electron microscope (SEM)/Kelvin probe force microscopy (KPFM)/transmission electron microscopy (TEM) system. We can make the c-ZnO NWs spontaneous reaction happen at different humid environments and suppress the a-ZnO NBs spontaneous reaction by oxygen/hydrogen plasma surface passivation. The hydrogen plasma surface treatment also can improve the UV sensing sensitivity more than twofold. This work provides the mechanism and methods of the a-ZnO NBs spontaneous growth and offers the passivation treatment for strengthening and enhancing ZnO-based nanodevice application in humid environment and UV light detection, respectively.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[booktype]]紙本[[countrycodes]]DE

    Molecular signature of clinical severity in recovering patients with severe acute respiratory syndrome coronavirus (SARS-CoV)

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    BACKGROUND: Severe acute respiratory syndrome (SARS), a recent epidemic human disease, is caused by a novel coronavirus (SARS-CoV). First reported in Asia, SARS quickly spread worldwide through international travelling. As of July 2003, the World Health Organization reported a total of 8,437 people afflicted with SARS with a 9.6% mortality rate. Although immunopathological damages may account for the severity of respiratory distress, little is known about how the genome-wide gene expression of the host changes under the attack of SARS-CoV. RESULTS: Based on changes in gene expression of peripheral blood, we identified 52 signature genes that accurately discriminated acute SARS patients from non-SARS controls. While a general suppression of gene expression predominated in SARS-infected blood, several genes including those involved in innate immunity, such as defensins and eosinophil-derived neurotoxin, were upregulated. Instead of employing clustering methods, we ranked the severity of recovering SARS patients by generalized associate plots (GAP) according to the expression profiles of 52 signature genes. Through this method, we discovered a smooth transition pattern of severity from normal controls to acute SARS patients. The rank of SARS severity was significantly correlated with the recovery period (in days) and with the clinical pulmonary infection score. CONCLUSION: The use of the GAP approach has proved useful in analyzing the complexity and continuity of biological systems. The severity rank derived from the global expression profile of significantly regulated genes in patients may be useful for further elucidating the pathophysiology of their disease

    Single nucleotide polymorphisms of the APC gene and colorectal cancer risk: a case-control study in Taiwan

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    BACKGROUND: Colorectal cancer (CRC), which has become especially prevalent in developed countries, is currently the third highest cause of cancer mortality in Taiwan. Mutation of the adenomatous polyposis coli (APC) gene, a tumour suppressor, is thought to be an early event in colorectal tumourigenesis. To date, however, no large-scale screening for APC gene variants in Chinese subjects has been performed. The present study was undertaken to identify APC gene variants that are significantly associated with the occurrence of CRC in Taiwanese subjects. METHODS: In order to compare the genotype distribution of variant sites, the full-length APC genes of 74 healthy individuals and 80 CRC patients were sequenced. RESULTS: Among the 154 Taiwanese subjects examined in this study, three new mutations, but no previously reported mutations, were found. One deletion at codon 460 leading to a frameshift and two missense mutations resulting in p.V1125A and p.S1126R substitutions were identified. Additionally, three high risk genotypes associated with three single nucleotide polymorphisms and one low risk genotype at codon 1822 were identified. CONCLUSION: The findings of this case-control study are consistent with the proposal that Taiwanese subjects differ from other subjects with respect to phenotypic presentation of APC and CRC risk

    Impact of Ancestral Differences and Reassessment of the Classification of Previously Reported Pathogenic Variants in Patients With Brugada Syndrome in the Genomic Era: A SADS-TW BrS Registry

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    Brugada syndrome (BrS) is a heritable disease that results in sudden cardiac death. In the exome/genomic era, certain reported pathogenic variants in some genetic diseases have been reclassified as benign owing to their high frequency in some ancestries. In the present study, we comprehensively reassessed all previously reported pathogenic variants of BrS. We collected all pathogenic variants of BrS reported in the Human Gene Mutation Database and ClinVar throughout April 2017. We compared the minor allele frequency (MAF) of each variant among different ancestries by searching public whole-genome and exome databases. After considering the maximum credible allele frequency, variants with a MAF ≥ 0.001 were considered to be of questionable pathogenicity. We also investigated the percentage of SCN5A variants with a MAF ≥ 0.001 in 124 BrS patients from the Han Chinese population. We collected a total of 440 BrS variants, of which 18 had a MAF ≥ 0.001. There was a greater percentage of non-SCN5A variants with a MAF ≥ 0.001 than of SCN5A variants (21.8 versus 1.6%, p < 0.0001). There were fewer frameshift and nonsense mutations than missense mutations (0.9 versus 5.6%, p = 0.032). Of the 18 variants, 14 (77.8%) were present only in the reference Asian population. In our cohort, we identified two SCN5A variants (p.A226V and p.V1340I) with MAFs ≥ 0.001 (0.45%). In conclusion, ancestral differences are important when considering the pathogenicity of BrS variants, especially in the case of missense variants and non-SCN5A variants, which may be pathogenic in some ancestries but only disease-predisposing in others

    Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population.

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    Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

    Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

    Get PDF
    Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P interaction  = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

    The involvement of endoplasmic reticulum formation and protein synthesis efficiency in VCP- and ATL1-related neurological disorders

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    Abstract The endoplasmic reticulum (ER) is the biggest organelle in cells and is involved in versatile cellular processes. Formation and maintenance of ER morphology are regulated by a series of proteins controlling membrane fusion and curvature. At least six different ER morphology regulators have been demonstrated to be involved in neurological disorders—including Valosin-containing protein (VCP), Atlastin-1 (ATL1), Spastin (SPAST), Reticulon 2 (RTN2), Receptor expression enhancing protein 1 (REEP1) and RAB10—suggesting a critical role of ER formation in neuronal activity and function. Among these genes, mutations in VCP gene involve in inclusion body myopathy with Paget disease of bone and frontotemporal dementia (IBMPFD), familial amyotrophic lateral sclerosis (ALS), autism spectrum disorders (ASD), and hereditary spastic paraplegia (HSP). ATL1 is also one of causative genes of HSP. RAB10 is associated with Parkinson’s disease (PD). A recent study showed that VCP and ATL1 work together to regulate dendritic spine formation by controlling ER formation and consequent protein synthesis efficiency. RAB10 shares the same function with VCP and ATL1 to control ER formation and protein synthesis efficiency but acts independently. Increased protein synthesis by adding extra leucine to cultured neurons ameliorated dendritic spine deficits caused by VCP and ATL1 deficiencies, strengthening the significance of protein synthesis in VCP- and ATL1-regulated dendritic spine formation. These findings provide new insight into the roles of ER and protein synthesis in controlling dendritic spine formation and suggest a potential etiology of neurodegenerative disorders caused by mutations in VCP, ATL1 and other genes encoding proteins regulating ER formation and morphogenesis
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