34 research outputs found

    Critical Residues in the CC′ Ridge of the Human Nectin1 Receptor V Domain Enable Herpes Simplex Virus Entry into the Cell and Act Synergistically with the Downstream Region

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    AbstractThe site on nectin1 receptor required for herpes simplex virus (HSV) entry into the cell was previously mapped to the 64–94 region, encompassing the predicted CC′C" region of the immunoglobulin V domain. Within it lies a minimal HSV entry site (residues 77–94). Here we transferred the 65–76 region (C strand and CC′ loop) and portions, or single amino acids, thereof to nectin2, a homolog nonfunctional for wt HSV-1 entry. Replacement of the seven- or of three-amino-acid-long stretches from nectin1 to nectin2 (amino acids 69–75, 69–71, or 72–75) transferred wt HSV-1 and BHV-1 entry activity and enhanced HSV-2, PrV, and HSV-HSV(U21) entry to levels observed with nectin1. Thus, the CC′ ridge is sufficient to mediate wt HSV entry at a reduced level and responsible for the wide virus range of the receptor. Altogether the HSV entry site appears to be composed of contiguous synergistic regions, 64–76 and 77–94, each independently capable of mediating virus entry at reduced efficiency

    A novel mtDNA point mutation in tRNAVal is associated with hypertrophic cardiomyopathy and MELAS

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    Background. Pathological mutations of mitochondrial (mt) DNA may cause specific diseases such as cardiomyopathies or hearing loss, or syndromes such as mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome. We describe a novel mtDNA mutation in a patient with severe hypertrophic cardiomyopathy associated with MELAS. The familial phenotype included 1) hypertrophic cardiomyopathy and MELAS, 2) clinically mild cardiac hypertrophy, and 3) deafness. Methods. The proband and her first degree relatives underwent echo and electrocardiograms, and biochemical tests. Magnetic resonance imaging of the brain was performed in the proband. mtDNA was fully analyzed by sequencing. DNA purification, polymerase chain reaction and direct automated sequencing were performed following standard procedures. Heteroplasmy of the novel mutation was quantified by densitometric analysis. Results. A novel G1644A transition affecting the tRNAVal was identified in the proband and maternal relatives. The mutation has been interpreted as pathological because the G at the 1644 position is a highly conserved base, is heteroplasmic with higher levels of mutant DNA in the proband than in the relatives, is located in the unique tRNAVal, is very close to a mutation described as causative of MELAS, and finally has not been found in 100 healthy controls. Conclusions. Although it is rare for patients with MELAS to be referred to cardiological evaluation because of coexisting cardiomyopathy, cardiologists should be aware of this association as well as of the non cardiac signs that may address the diagnosis to mtDNA defect-related disease in families with a variable phenotype. © 2004 CEPI Srl

    Prominent role of the Ig-like V domain in trans-interactions of nectins. Nectin3 and nectin 4 bind to the predicted C-C'-C"-D beta-strands of the nectin1 V domain.

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    Nectins form a family of integral molecules that belong to the immunoglobulin superfamily. Their ectodomain is made of three Ig-like domains (V, C, C). This family comprises at least five members, namely nectin1, -2, -3, -4, and poliovirus receptor (PVR), that are involved in different physiological and pathological processes. (i) Nectins are adhesion molecules localized at adherens junctions in epithelial cells. (ii) Some nectins act as poliovirus or alpha-herpesvirus receptors (nectin1). (iii) Nectin1 mutations are involved in orofacial developmental abnormalities in humans. Adhesion properties of nectins are mediated by Ca(2+)-independent homophilic and heterophilic processes through ectodomain trans-interactions. We have described a nectin trans-hetero-interaction network: nectin3 binds to nectin1, nectin2, and PVR; nectin1 also binds to nectin4. In the present study we compared the affinities of the different trans-interactions mediated by nectin1. We found that the K(D) of nectin1/nectin3 and nectin1/nectin4 interactions is 1 and 100 nm, respectively, whereas the K(D) of the nectin1-mediated homophilic interaction is 1 microm. We show that nectin1/nectin3 and nectin1/nectin4 trans-hetero-interactions were mediated through trans V to V domain interactions, whereas C domains contributed to increase the affinity of the interaction. Nectin3 and nectin4 share a common binding region in the nectin1 V domain: (i) nectin3 strongly competed with nectin4 binding, (ii) nectin3 and nectin4 binding to nectin1 was reduced by a number of monoclonal antibodies directed against the nectin1 V domain, and (iii) the glycoprotein D of herpes simplex virus-1 that binds to the V domain of nectin1 reduced nectin3 and nectin4 binding. Finally, using chimeric nectin1/PVR receptors where PVR V domain beta-strands were substituted with the corresponding regions of nectin1, the nectin3 and nectin4 minimal binding region on nectin1 V domain was mapped to the C-C'-C"-D beta-strands

    Chronic administration of saturated fats and fructose differently affect SREBP activity resulting in different modulation of Nrf2 and Nlrp3 inflammasome pathways in mice liver

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    The overconsumption of both saturated fats and fructose in the modern society has been related to the development of nonalcoholic fatty liver disease (NAFLD). However, the specific contribution of individual dietary components on the progression of NAFLD to nonalcoholic steatohepatitis (NASH) has been poorly investigated.Therefore, the aim of our study was to investigate the dissimilar effects of these two dietary components on selected proinflammatory and antioxidant pathways in the liver of C57BL/6 mice fed a standard (SD), a 45% saturated fat (HFAT) or a 60% fructose (HFRT) diet for 12 weeks. HFAT diet evoked systemic metabolic alterations and overweight, not observed in HFRT mice. However, HFRT mice had a greater hepatic triglyceride deposition with increased ratio of triacylglycerols containing the palmitic acid compared to HFAT, as assessed by liquid chromatography-mass spectrometry analysis. This effect is due to the higher activation of the SCAP/SREBP1c lipogenic pathway by HFRT feeding. In addition, we found inhibition of Keap1/Nrf2 antioxidant signaling and more robust stimulation of the Nlrp3 inflammasome pathway in the livers of HFRT-fed mice when compared with HFAT-fed mice, which is consistent with the recent finding that palmitate and SREBP1c are implicated in hepatic oxidative stress and inflammation. These effects were associated with increased hepatic inflammation, as confirmed by high expression of markers of leukocyte infiltration in the HFRT group. Thus, we hypothesize an amplifying loop among lipogenesis, palmitate, Nrf2 and Nlrp3 that leads to a higher risk of NAFLD progression to NASH in a high-fructose diet compared to a high-saturated fat intake. (C) 2017 Elsevier Inc. All rights reserved

    Safety and efficacy of ketorolac continuous infusion for multimodal analgesia of vaso-occlusive crisis in patients with sickle cell disease

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    Pain is an hallmark of sickle-cell-related acute clinical manifestations as part of acute vaso-occlusive crisis (VOC). In SCD pain has different origins such as vascular or neuropathic pain, which requires multimodal analgesia. This is based on the administration of drugs with different pharmacological mechanisms of action, maximizing analgesia and minimizing their adverse events and the risk of drug-addition in patients experiencing acute-recurrent pain events as in SCD. Ketorolac is a potent non-narcotic analgesic, being relatively safe and effective during pain-management in children and adults. Up to now, there is a lack of safety information on continuous infusion ketorolac as used to control acute pain in patients with SCD, and the benefits/risks ratio needs to be investigated. Here, we report for the first time the safety profile of ketorolac in the special population of patients with SCD. We confirmed that ketorolac in combination with tramadol, an opioid like molecule, is effective in pain control of adult patients with SCD experiencing acute severe VOCs defined by pain visual analog scale. Our study shows that short term (72 h) continuous infusion of ketorolac plus tramadol is not associated with adverse events such as liver or kidney acute disfunction or abnormalities in coagulation parameters during patients' hospitalization and within 30 days after patients discharge. This is extremely important for patients with SCD, who should have access to multimodal therapy to control recurrent acute pain crisis in order to limit central sensitization a fearsome issue of undertreated recurrent acute pain and of chronic pain

    Molecular spectroscopy for ground-state transfer of ultracold RbCs molecules

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    We perform one- and two-photon high resolution spectroscopy on ultracold samples of RbCs Feshbach molecules with the aim to identify a suitable route for efficient ground-state transfer in the quantum-gas regime to produce quantum gases of dipolar RbCs ground-state molecules. One-photon loss spectroscopy allows us to probe deeply bound rovibrational levels of the mixed excited (A1{\Sigma}+ - b3{\Pi}0) 0+ molecular states. Two-photon dark state spectroscopy connects the initial Feshbach state to the rovibronic ground state. We determine the binding energy of the lowest rovibrational level |v"=0,J"=0> of the X1{\Sigma}+ ground state to be DX 0 = 3811.5755(16) 1/cm, a 300-fold improvement in accuracy with respect to previous data. We are now in the position to perform stimulated two-photon Raman transfer to the rovibronic ground state.Comment: Submitted to PCCP themed issue: Physics and Chemistry of Cold Molecule

    Targeting of PED/PEA-15 Molecular Interaction with Phospholipase D1 Enhances Insulin Sensitivity in Skeletal Muscle Cells

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    Phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15) is overexpressed in several tissues of individuals affected by type 2 diabetes. In intact cells and in transgenic animal models, PED/PEA-15 overexpression impairs insulin regulation of glucose transport, and this is mediated by its interaction with the C-terminal D4 domain of phospholipase D1 (PLD1) and the consequent increase of protein kinase C-alpha activity. Here we show that interfering with the interaction of PED/PEA-15 with PLD1 in L6 skeletal muscle cells overexpressing PED/PEA-15 (L6(PED/PEA-15)) restores insulin sensitivity. Surface plasmon resonance and ELISA-like assays show that PED/PEA-15 binds in vitro the D4 domain with high affinity (K(D) = 0.37 +/- 0.13 mum), and a PED/PEA-15 peptide, spanning residues 1-24, PED-(1-24), is able to compete with the PED/PEA-15-D4 recognition. When loaded into L6(PED/PEA-15) cells and in myocytes derived from PED/PEA-15-overexpressing transgenic mice, PED-(1-24) abrogates the PED/PEA-15-PLD1 interaction and reduces protein kinase C-alpha activity to levels similar to controls. Importantly, the peptide restores insulin-stimulated glucose uptake by approximately 70%. Similar results are obtained by expression of D4 in L6(PED/PEA-15). All these findings suggest that disruption of the PED/PEA-15-PLD1 molecular interaction enhances insulin sensitivity in skeletal muscle cells and indicate that PED/PEA-15 as an important target for type 2 diabetes

    Artificial Neural Networks Versus Multiple Logistic Regression to Predict 30-Day Mortality After Operations For Type A Ascending Aortic Dissection§

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    There are few comparative reports on the overall accuracy of neural networks (NN), assessed only versus multiple logistic regression (LR), to predict events in cardiovascular surgery studies and none has been performed among acute aortic dissection (AAD) Type A patients. OBJECTIVES: We aimed at investigating the predictive potential of 30-day mortality by a large series of risk factors in AAD Type A patients comparing the overall performance of NN versus LR. METHODS: We investigated 121 plus 87 AAD Type A patients consecutively operated during 7 years in two Centres. Forced and stepwise NN and LR solutions were obtained and compared, using receiver operating characteristic area under the curve (AUC) and their 95% confidence intervals (CI) and Gini's coefficients. Both NN and LR models were re-applied to data from the second Centre to adhere to a methodological imperative with NN. RESULTS: Forced LR solutions provided AUC 87.9+/-4.1% (CI: 80.7 to 93.2%) and 85.7+/-5.2% (CI: 78.5 to 91.1%) in the first and second Centre, respectively. Stepwise NN solution of the first Centre had AUC 90.5+/-3.7% (CI: 83.8 to 95.1%). The Gini's coefficients for LR and NN stepwise solutions of the first Centre were 0.712 and 0.816, respectively. When the LR and NN stepwise solutions were re-applied to the second Centre data, Gini's coefficients were, respectively, 0.761 and 0.850. Few predictors were selected in common by LR and NN models: the presence of pre-operative shock, intubation and neurological symptoms, immediate post-operative presence of dialysis in continuous and the quantity of post-operative bleeding in the first 24 h. The length of extracorporeal circulation, post-operative chronic renal failure and the year of surgery were specifically detected by NN. CONCLUSIONS: Different from the International Registry of AAD, operative and immediate post-operative factors were seen as potential predictors of short-term mortality. We report a higher overall predictive accuracy with NN than with LR. However, the list of potential risk factors to predict 30-day mortality after AAD Type A by NN model is not enlarged significantly

    Common genetic variants on chromosome 9p21 are associated with myocardial infarction and type 2 diabetes in an Italian population

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    <p>Abstract</p> <p>Background</p> <p>A genomic region on chromosome 9p21 has been identified as closely associated with increased susceptibility to coronary artery disease (CAD) and to type 2 diabetes (T2D) although the evidence suggests that the genetic variants within chromosome 9p21 that contribute to CAD are different from those that contribute to T2D.</p> <p>We carried out an association case-control study in an Italian population to test the association between two single nucleotide polymorphisms (SNPs) on the 9p21 locus, rs2891168 and rs10811661, previously reported by the PROCARDIS study, and respectively myocardial infarction (MI) and T2D. Our aim was to confirm the previous findings on a larger sample and to verify the independence of their susceptibility effects: rs2891168 associated with MI but not with T2D and rs10811661 associated with T2D but not with MI.</p> <p>Methods</p> <p>Genomic DNA samples of 2407 Italians with T2D (602 patients), who had had a recent MI (600), or had both diseases (600) and healthy controls (605) were genotyped for the two SNPs. The genotypes were determined by allelic discrimination using a fluorescent-based TaqMan assay.</p> <p>Results</p> <p>SNP rs2891168 was associated with MI, but not with T2D and the G-allele odds ratio (OR) was 1.20 (95% CI 1.02-1.41); SNP rs10811661 was associated with T2D, but not with MI, and the T-allele OR was 1.27 (95% CI 1.04-1.55). ORs estimates from the present study and the PROCARDIS study were pooled and confirmed the previous findings, with greater precision.</p> <p>Conclusions</p> <p>Our replication study showed that rs2891168 and rs10811661 are independently associated respectively with MI and T2D in an Italian population. Pooling our results with those reported by the PROCARDIS group, we also obtained a significant result of association with diabetes for rs10811661 in the European population.</p
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