33 research outputs found

    A multi-ethnic meta-analysis identifies novel genes, including ACSL5, associated with amyotrophic lateral sclerosis

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    Amyotrophic lateral sclerosis (ALS) is a devastating progressive motor neuron disease that affects people of all ethnicities. Approximately 90% of ALS cases are sporadic and thought to have multifactorial pathogenesis. To understand the genetics of sporadic ALS, we conducted a genome-wide association study using 1,173 sporadic ALS cases and 8,925 controls in a Japanese population. A combined meta-analysis of our Japanese cohort with individuals of European ancestry revealed a significant association at the ACSL5 locus (top SNP p = 2.97 × 10−8). We validated the association with ACSL5 in a replication study with a Chinese population and an independent Japanese population (1941 ALS cases, 3821 controls; top SNP p = 1.82 × 10−4). In the combined meta-analysis, the intronic ACSL5 SNP rs3736947 showed the strongest association (p = 7.81 × 10−11). Using a gene-based analysis of the full multi-ethnic dataset, we uncovered additional genes significantly associated with ALS: ERGIC1, RAPGEF5, FNBP1, and ATXN3. These results advance our understanding of the genetic basis of sporadic ALS

    Combinatorial Measurement of CDKN1A/p21 and KIF20A Expression for Discrimination of DNA Damage-Induced Clastogenicity

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    In vitro mammalian cytogenetic tests detect chromosomal aberrations and are used for testing the genotoxicity of compounds. This study aimed to identify a supportive genomic biomarker could minimize the risk of misjudgments and aid appropriate decision making in genotoxicity testing. Human lymphoblastoid TK6 cells were treated with each of six DNA damage-inducing genotoxins (clastogens) or two genotoxins that do not cause DNA damage. Cells were exposed to each compound for 4 h, and gene expression was comprehensively examined using Affymetrix U133A microarrays. Toxicogenomic analysis revealed characteristic alterations in the expression of genes included in cyclin-dependent kinase inhibitor 1A (CDKN1A/p21)-centered network. The majority of genes included in this network were upregulated on treatment with DNA damage-inducing clastogens. The network, however, also included kinesin family member 20A (KIF20A) downregulated by treatment with all the DNA damage-inducing clastogens. Downregulation of KIF20A expression was successfully confirmed using additional DNA damage-inducing clastogens. Our analysis also demonstrated that nucleic acid constituents falsely downregulated the expression of KIF20A, possibly via p16 activation, independently of the CDKN1A signaling pathway. Our results indicate the potential of KIF20A as a supportive biomarker for clastogenicity judgment and possible mechanisms involved in KIF20A downregulation in DNA damage and non-DNA damage signaling networks

    Modafinil alleviates levodopa-induced excessive nighttime sleepiness and restores monoaminergic systems in a nocturnal animal model of Parkinson's disease

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    Treatment with dopaminergic agents result excessive daytime sleepiness (EDS) and some studies have shown the benefit of using modafinil for treating excessive daytime sleepiness of Parkinson's disease (PD) patient. We investigated whether modafinil have ameliorative properties against levodopa induced excessive nighttime sleepiness (ENS) in MPTP-treated murine nocturnal PD model. Our EEG analyses of whole day recordings revealed that modafinil reduce ENS of this nocturnal PD models with levodopa medications. Therefore, we investigated whether, modafinil post-treatment followed by MPTP shows any effect on monoamine contents of brain and found to robustly increased noradrenaline (NA) concentration of MPTP treated mice. Modafinil post-treatment, in neurorestorative context (5 days post-lesion) led to increased striatal dopamine (DA) concentrations of MPTP-treated mice. Here, we first confirmed that modafinil ameliorates levodopa induced excessive sleepiness and restores monoaminergic systems. The arousal and anti-parkinsonian effects displayed by modafinil indicate that in combination with dopaminergic agents, modafinil co-administration may be worthwhile in trying to suppress the excessive daytime sleepiness and progressive dopaminergic neuron loss in PD. Keywords: Parkinson's disease, Excessive day time sleepiness, Monoamines, MPTP, Modafinil, Neurorestoration, Nocturna

    Chloride Intracellular Channel Protein 2 Promotes Microglial Invasion: A Link to Microgliosis in the Parkinson’s Disease Brain

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    Activated microglia potentially cause neurodegeneration in Parkinson’s disease (PD). Matrix metalloproteinase (MMP)-9 plays a crucial role in the pathogenesis of PD, but the modulator of microglial release of MMP-9 remains obscure. Given the modulatory effect of chloride intracellular channel protein 2 (CLIC2) on MMPs, we aimed to determine the role of CLIC2 in regulating microglial MMP expression and activation. We found that CLIC2 is expressed in microglia and neurons in rat brain tissue and focused on the function of CLIC2 in primary cultured microglia. Exposure to recombinant CLIC2 protein enhanced microglial invasion activity, and its knockdown abolished this activity. Moreover, increased activation of MMP-9 was confirmed by the addition of the CLIC2 protein, and CLIC2 knockdown eliminated this activation. Additionally, increased expression of CLIC2 was observed in PD-modeled tissue. In conclusion, CLIC2 increases MMP-9 activity in the microglia, which are involved in PD pathogenesis

    Evaluation of Constituents of <i>Piper retrofractum</i> Fruits on Neurotrophic Activity

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    Three new compounds, <b>1</b>–<b>3</b>, together with 22 known compounds, were isolated from the fruits of <i>Piper retrofractum</i>. The structures of the new compounds were elucidated on the basis of spectroscopic data analysis and comparison with literature values. Compound <b>1</b> was found to enhance the neurite outgrowth of NGF-mediated PC12 cells at concentrations ranging from 0.1 to 10 μM

    Loss of activating EGFR mutant gene contributes to acquired resistance to EGFR tyrosine kinase inhibitors in lung cancer cells.

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    Non-small-cell lung cancer harboring epidermal growth factor receptor (EGFR) mutations attains a meaningful response to EGFR-tyrosine kinase inhibitors (TKIs). However, acquired resistance to EGFR-TKIs could affect long-term outcome in almost all patients. To identify the potential mechanisms of resistance, we established cell lines resistant to EGFR-TKIs from the human lung cancer cell lines PC9 and11-18, which harbored activating EGFR mutations. One erlotinib-resistant cell line from PC9 and two erlotinib-resistant cell lines and two gefitinib-resistant cell lines from 11-18 were independently established. Almost complete loss of mutant delE746-A750 EGFR gene was observed in the erlotinib-resistant cells isolated from PC9, and partial loss of the mutant L858R EGFR gene copy was specifically observed in the erlotinib- and gefitinib-resistant cells from 11-18. However, constitutive activation of EGFR downstream signaling, PI3K/Akt, was observed even after loss of the mutated EGFR gene in all resistant cell lines even in the presence of the drug. In the erlotinib-resistant cells from PC9, constitutive PI3K/Akt activation was effectively inhibited by lapatinib (a dual TKI of EGFR and HER2) or BIBW2992 (pan-TKI of EGFR family proteins). Furthermore, erlotinib with either HER2 or HER3 knockdown by their cognate siRNAs also inhibited PI3K/Akt activation. Transfection of activating mutant EGFR complementary DNA restored drug sensitivity in the erlotinib-resistant cell line. Our study indicates that loss of addiction to mutant EGFR resulted in gain of addiction to both HER2/HER3 and PI3K/Akt signaling to acquire EGFR-TKI resistance

    The effect of erlotinib, lapatinib and BIBW2992 on phosphorylation of Akt and EGFR family proteins in PC9/ER1 cells.

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    <p>A, PC9/ER1 cells were treated with or without 1 µM erlotinib, and 5 µM lapatinib for 5 hrs, and followed Western blot analysis. B, PC9/ER1 cells were treated with 10 nM of siRNAs of scrumble and EGFR family genes, and exposed to erlotinib (1 µM) or BIBW2992 (1 µM) for 5 hrs, and followed Western blot analysis.</p

    Summary of EGFR mutation status in cell samples of refractory cancer patients<sup>a)</sup>.

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    a)<p>EGFR mutation status including wild-type (WT), E746-A750 del (del), L858R and T790M was determined by both IHC and RNA-LNA PCR clamp assays with 11 clinical samples of cancer patients refractory to gefitinib treatment.</p>b)<p>EGFR mutation status determined by IHC analysis is presented by scoring (0, 1+, 2+, 3+) (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041017#pone-0041017-g008" target="_blank">Figure 8</a>) of immunostaining intensity in cancer cells in primary tumor and disseminated samples of 11 patients (Primary tumor sample/Disseminated and/or metastatic sample). nd, not determined.</p
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