122 research outputs found

    Hepatitis C virus attenuates mitochondrial lipid β-oxidation by downregulating mitochondrial trifunctional-protein expression

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    The course of hepatitis C virus (HCV) infection and disease progression involves alterations in lipid metabolism, leading to symptoms such as hypocholesterolemia and steatosis. Steatosis can be induced by multiple mechanisms, including increases in lipid biosynthesis and uptake, impaired lipoprotein secretion, and/or attenuation of lipid β-oxidation. However, little is known about the effects of HCV on lipid β-oxidation. A previous proteomics study revealed that HCV interacted with both the α- and β-subunits of the mitochondrial trifunctional protein (MTP), an enzyme complex which catalyzes the last 3 steps of mitochondrial lipid β-oxidation for cellular energy production. Here we show that in HCV-infected Huh7.5 cells, lipid β-oxidation was significantly attenuated. Consistently with this, MTP protein and mRNA levels were suppressed by HCV infection. A loss-offunction study showed that MTP depletion rendered cells less responsive to alpha interferon (IFN-α) treatment by impairing IFN-stimulated gene expression. These aspects of host-virus interaction explain how HCV alters host energy homeostasis and how it may also contribute to the establishment of persistent infection in the liver

    Recombinant IFN-α2a-NGR exhibits higher inhibitory function on tumor neovessels formation compared with IFN-α2a in vivo and in vitro

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    Purpose We compared the efficacy of ofatumumab (O) versus rituximab (R) in combination with cisplatin, cytarabine, and dexamethasone (DHAP) salvage treatment, followed by autologous stem-cell transplantation (ASCT) in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). Patients and Methods Patients with CD201 DLBCL age >= 18 years who had experienced their first relapse or who were refractory to first-line R-CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)-like treatment were randomly assigned between three cycles of R-DHAP or O-DHAP. Either O 1,000 mg or R 375 mg/m2 was administered for a total of four infusions (days 1 and 8 of cycle 1; day 1 of cycles 2 and 3 of DHAP). Patients who experienced a response after two cycles of treatment received the third cycle, followed by high-dose therapy and ASCT. Primary end point was progression-free survival (PFS), with failure to achieve a response after cycle 2 included as an event. Results Between March 2010 and December 2013, 447 patients were randomly assigned. Median age was 57 years (range, 18 to 83 years); 17% were age >= 65 years; 63% had stage III and IV disease; 71% did not achieve complete response (CR) or experience response for, 1 year on first-line R-CHOP. Response rate for O-DHAP was 38% (CR, 15%) versus 42% (CR, 22%) for R-DHAP. ASCT on protocol was completed by 74 patients (33%) in the O arm and 83 patients (37%) in the R arm. PFS, event-free survival, and overall survival were not significantly different between O-DHAP versus R-DHAP: PFS at 2 years was 24% versus 26% (hazard ratio [HR], 1.12; 95% CI, 0.89 to 1.42; P = .33); event-free survival at 2 years was 16% versus 18% (HR, 1.10; P=.35); and overall survival at 2 years was 41% versus 38% (HR, 0.90; P=.38). Positron emission tomography negativity before ASCT was highly predictive for superior outcome. Conclusion No difference in efficacy was found between O-DHAP and R-DHAP as salvage treatment of relapsed or refractory DLBCL. (C) 2016 by American Society of Clinical Oncolog

    Establishment of infectious HCV virion-producing cells with newly designed full-genome replicon RNA

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    Hepatitis C virus (HCV) replicon systems enable in-depth analysis of the life cycle of HCV. However, the previously reported full-genome replicon system is unable to produce authentic virions. On the basis of these results, we constructed newly designed full-genomic replicon RNA, which is composed of the intact 5′-terminal-half RNA extending to the NS2 region flanked by an extra selection marker gene. Huh-7 cells harboring this full-genomic RNA proliferated well under G418 selection and secreted virion-like particles into the supernatant. These particles, which were round and 50 nm in diameter when analyzed by electron microscopy, had a buoyant density of 1.08 g/mL that shifted to 1.19 g/mL after NP-40 treatment; these figures match the putative densities of intact virions and nucleocapsids without envelope. The particles also showed infectivity in a colony-forming assay. This system may offer another option for investigating the life cycle of HCV

    Role of Dlg5/lp-dlg, a Membrane-Associated Guanylate Kinase Family Protein, in Epithelial-Mesenchymal Transition in LLc-PK1 Renal Epithelial Cells

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    Discs large homolog 5 (Dlg5) is a member of the membrane-associated guanylate kinase adaptor family of proteins, some of which are involved in the regulation of epithelial-to-mesenchymal transition (EMT). Dlg5 has been described as a susceptibility gene for Crohn's disease; however, the physiological function of Dlg5 is unknown. We show here that transforming growth factor-β (TGF-β)-induced EMT suppresses Dlg5 expression in LLc-PK1 cells. Depletion of Dlg5 expression by knockdown promoted the expression of the mesenchymal marker proteins, fibronectin and α-smooth muscle actin, and suppressed the expression of E-cadherin. In addition, activation of JNK and p38, which are stimulated by TGF-β, was enhanced by Dlg5 depletion. Furthermore, inhibition of the TGF-β receptor suppressed the effects of Dlg5 depletion. These observations suggest that Dlg5 is involved in the regulation of TGF-βreceptor-dependent signals and EMT

    An Inducer of VGF Protects Cells against ER Stress-Induced Cell Death and Prolongs Survival in the Mutant SOD1 Animal Models of Familial ALS

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    Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disease, and recent evidence has suggested that endoplasmic reticulum (ER) stress signaling is involved in the pathogenesis of ALS. Here we identified a small molecule, SUN N8075, which has a marked protective effect on ER stress-induced cell death, in an in vitro cell-based screening, and its protective mechanism was mediated by an induction of VGF nerve growth factor inducible (VGF): VGF knockdown with siRNA completely abolished the protective effect of SUN N8075 against ER-induced cell death, and overexpression of VGF inhibited ER-stress-induced cell death. VGF level was lower in the spinal cords of sporadic ALS patients than in the control patients. Furthermore, SUN N8075 slowed disease progression and prolonged survival in mutant SOD1 transgenic mouse and rat models of ALS, preventing the decrease of VGF expression in the spinal cords of ALS mice. These data suggest that VGF plays a critical role in motor neuron survival and may be a potential new therapeutic target for ALS, and SUN N8075 may become a potential therapeutic candidate for treatment of ALS
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