17 research outputs found

    Hepatic Fgf21 Expression Is Repressed after Simvastatin Treatment in Mice.

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    Fibroblast growth factor 21 (Fgf21) is a hormone with emerging beneficial roles in glucose and lipid homeostasis. The interest in Fgf21 as a potential antidiabetic drug and the factors that regulate its production and secretion is growing. Statins are the most widely prescribed drug for the treatment of dyslipidemia. However, the function of statins is not limited to the lowering of cholesterol as they are associated with pleiotropic actions such as antioxidant, anti-inflammatory and cytoprotective effects. The recently described effect of statins on mitochondrial function and the induction of Fgf21 by mitochondrial stress prompted us to investigate the effect of statin treatment on Fgf21 expression in the liver. To this end, C57BL6J male mice and primary mouse hepatocytes were treated with simvastatin, and Fgf21 expression was subsequently assessed by immunoblotting and quantitative real-time PCR. Hepatic Fgf21 protein and mRNA and circulating levels of FGF21significantly decreased in mice that had received simvastatin in their food (0.1% w/w) for 1 week. This effect was also observed with simvastatin doses as low as 0.01% w/w for 1 week or following 2 intraperitoneal injections within a single day. The reduction in Fgf21 mRNA levels was further verified in primary mouse hepatocytes, indicating that the effect of simvastatin is cell autonomous. In conclusion, simvastatin treatment reduced the circulating and hepatic Fgf21 levels and this effect warrants further investigation with reference to its role in metabolism

    ETHNOS: A versatile electronic tool for the development and curation of national genetic databases

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    National and ethnic mutation databases (NEMDBs) are emerging online repositories, recording extensive information about the described genetic heterogeneity of an ethnic group or population. These resources facilitate the provision of genetic services and provide a comprehensive list of genomic variations among different populations. As such, they enhance awareness of the various genetic disorders. Here, we describe the features of the ETHNOS software, a simple but versatile tool based on a flat-file database that is specifically designed for the development and curation of NEMDBs. ETHNOS is a freely available softw

    ETHNOS : A versatile electronic tool for the development and curation of national genetic databases.

    Get PDF
    National and ethnic mutation databases (NEMDBs) are emerging online repositories, recording extensive information about the described genetic heterogeneity of an ethnic group or population. These resources facilitate the provision of genetic services and provide a comprehensive list of genomic variations among different populations. As such, they enhance awareness of the various genetic disorders. Here, we describe the features of the ETHNOS software, a simple but versatile tool based on a flat-file database that is specifically designed for the development and curation of NEMDBs. ETHNOS is a freely available software which runs more than half of the NEMDBs currently available. Given the emerging need for NEMDB in genetic testing services and the fact that ETHNOS is the only off-the-shelf software available for NEMDB development and curation, its adoption in subsequent NEMDB development would contribute towards data content uniformity, unlike the diverse contents and quality of the available gene (locus)-specific databases. Finally, we allude to the potential applications of NEMDBs, not only as worldwide central allele frequency repositories, but also, and most importantly, as data warehouses of individual-level genomic data, hence allowing for a comprehensive ethnicity-specific documentation of genomic variation

    Evidence for association of STAT4 and IL12RB2 variants with Myasthenia gravis susceptibility: What is the effect on gene expression in thymus?

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    Myasthenia gravis (MG) is an autoimmune disease mediated by the presence of autoantibodies that bind mainly to the acetylcholine receptor (AChR) in the neuromuscular junction. In our case-control association study, we analyzed common variants located in genes of the IL12/STAT4 and IL10/STAT3 signaling pathways. A total of 175 sporadic MG patients of Greek descent, positively detected with anti-AChR autoantibodies and 84 ethnically-matched, healthy volunteers were enrolled in the study. Thymus samples were obtained from 16 non-MG individuals for relative gene expression analysis. The strongest signals of association were observed in the cases of rs6679356 between the late-onset MG patients and controls and rs7574865 between early-onset MG and controls. Our investigation of the correlation between the MG-associated variants and the expression levels of each gene in thymus did not result in significant differences

    Nicotinic cholinergic system and COVID-19: In silico identification of interactions between α7 nicotinic acetylcholine receptor and the cryptic epitopes of SARS-Co-V and SARS-CoV-2 Spike glycoproteins

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    SARS-CoV-2 is the coronavirus that originated in Wuhan in December 2019 and has spread globally. Studies have shown that smokers are less likely to be diagnosed with or be hospitalized for COVID-19 but, once hospitalized, have higher odds for an adverse outcome. We have previously presented the potential interaction between SARS-CoV-2 Spike glycoprotein and nicotinic acetylcholine receptors (nAChRs), due to a “toxin-like” epitope on the Spike glycoprotein, with homology to a sequence of a snake venom toxin. This epitope coincides with the well-described cryptic epitope for the human anti-SARS-CoV antibody CR3022. In this study, we present the molecular complexes of both SARS-CoV and SARS-CoV-2 Spike glycoproteins, at their open or closed conformations, with the model of the human α7 nAChR. We found that all studied protein complexes' interface involves a large part of the “toxin-like” sequences of SARS-CoV and SARS-CoV-2 Spike glycoproteins and toxin binding site of human α7 nAChR. Our findings provide further support to the hypothesis about the protective role of nicotine and other cholinergic agonists. The potential therapeutic role of CR3022 and other similar monoclonal antibodies with increased affinity for SARS-CoV-2 Spike glycoprotein against the clinical effects originating from the dysregulated cholinergic pathway should be further explored. © 2021 Elsevier Lt

    Non-contact Current Transfer Induces the Formation and Improves the X-ray Diffraction Quality of Protein Crystals

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    The effect of non-contact current transfer on the crystallization of three model proteins (hen egg white lysozyme, bovine pancreatic ribonuclease A, and human recombinant insulin) was investigated using a prototype ion-generator device. The device can produce an equivalent of microcurrent that can be transmitted in a contactless manner by spraying negatively charged ions and using available air gases (O-2) as a transfer medium. From a crystallographic perspective, non-contact current transfer technology clearly enhanced the crystal formation process of these three proteins, as evidenced by the high crystallization speed and crystal quality. The quality and X-ray diffraction patterns of lysozyme crystals grown in the presence and absence of the device's microcurrent were analyzed. Our results indicate a significant positive effect on the quality of the X-ray diffraction pattern after non-contact current transfer, highlighting the value of this technique in protein crystallization

    Nicotinic cholinergic system and COVID-19: In silico evaluation of nicotinic acetylcholine receptor agonists as potential therapeutic interventions

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    SARS-CoV-2 infection was announced as a pandemic in March 2020. Since then, several scientists have focused on the low prevalence of smokers among hospitalized COVID-19 patients. These findings led to our hypothesis that the Nicotinic Cholinergic System (NCS) plays a crucial role in the manifestation of COVID-19 and its severe symptoms. Molecular modeling revealed that the SARS-CoV-2 Spike glycoprotein might bind to nicotinic acetylcholine receptors (nAChRs) through a cryptic epitope homologous to snake toxins, substrates well documented and known for their affinity to the nAChRs. This binding model could provide logical explanations for the acute inflammatory disorder in patients with COVID-19, which may be linked to severe dysregulation of NCS. In this study, we present a series of complexes with cholinergic agonists that can potentially prevent SARS-CoV-2 Spike glycoprotein from binding to nAChRs, avoiding dysregulation of the NCS and moderating the symptoms and clinical manifestations of COVID-19. If our hypothesis is verified by in vitro and in vivo studies, repurposing agents currently approved for smoking cessation and neurological conditions could provide the scientific community with a therapeutic option in severe COVID-19. © 202

    Tobacco-specific nitrosamines: A literature review

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    Cigarette smoke is a complex mixture of chemicals, including several tobacco-specific nitrosamines (TSNA). Most TSNA are formed in tobacco during the post-harvest period, while a number are produced when a cigarette is burned. Considerable evidence supports the role of TSNA important causative factors for cancers of the lung, pancreas, esophagus, and oral cavity in people who use tobacco products. Of the known TSNA, nicotine-derived nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN) are the most carcinogenic. Other TSNA include N′-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB). New tobacco products (e.g., e-cigarettes) designed to attract consumers who are concerned about the health effects of tobacco have been appearing on the market. Several studies have reported that certain TSNA have been detected in the replacement liquids and vapour of e-cigarettes, but the levels are generally considerably lower than in tobacco cigarettes. Additionally, the FDA recently announced its intention to regulate TSNA in e-cigarettes, cigar tobacco and pipe tobacco. With the rise of new technologies for reducing the use of tobacco products—such as e-cigarettes— to evaluate exposure levels to these harmful chemicals over time, researchers will be monitoring levels of TSNA in the body as a result of the use of these devices. © 201

    Expression of Fgf21 in liver and serum after simvastatin treatment in mice.

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    <p><b>A.</b> Immunoblotting analysis of Fgf21 in the livers of 3-month old male mice treated with simvastatin (0.1% w/w in chow) for 1 week. Immunoblots for Ampkα and elf2a and Coomassie blue staining of the gel were used as loading controls. <b>B.</b> Relative Fgf21 protein levels as assessed by immunoblotting after normalization to elf2a levels. Data are presented as the mean ± SEM. n = 5 per treatment. *P<0.05. <b>C, D, E, F, G, H</b>. mRNA levels of Fgf21(C), Hmgcr (D), Pcsk9 (E), Acox1 (F), Cyp4a10 (G), Cyp7a1 (H) in the livers of 3-month old male mice treated with simvastatin (0.1% w/w in chow) for 1 week. Relative mRNA levels were assessed by qRT-PCR. Data are presented as the mean ±SEM. n = 7–8 per treatment. *P<0.05. <b>I.</b> Assessment of serum Fgf21 levels by ELISA in 3-month old male mice treated with vehicle or simvastatin. Data are presented as the mean ±SEM. n = 7–8 per treatment. *P<0.05.</p
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