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Casas-Deza D, Martínez-Sapiña A, Espina S, Garcia-Rodriguez B, Fernandez-Bonilla EM, Sanz-Paris A, Gonzalez-Irazabal Y, Bernal-Monterde V, Arbones-Mainar JM. Evaluation of Cardiovascular Risk Factors after Hepatitis C Virus Eradication with Direct-Acting Antivirals in a Cohort of Treatment-Naïve Patients without History of Cardiovascular Disease. J Clin Med 2022; 11:jcm11144049. [PMID: 35887813 PMCID: PMC9315656 DOI: 10.3390/jcm11144049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 12/04/2022] Open
Abstract
Background: Hepatitis C virus (HCV) produces changes at multiple levels in host metabolism, especially in lipid profile and cardio-metabolic risk. It is unclear how HCV eradication by direct-acting antivirals (DAAs) modifies those changes. Objective: To evaluate the impact of DAA treatment on different risk factors associated with cardiovascular disease. Methods: Prospective study with two-year follow-up. All patients treated with DAAs in the Liver Clinic of a tertiary hospital were included. Patients co-infected with HBV or HIV, with other causes of liver disease, on lipid-lowering treatment, pregnant, or with previous HCV treatment were excluded. The results were analyzed using linear mixed models. Results: 167 patients (53% female, 9.6% cirrhosis) were included. Low plasma lipid levels were observed before initiating HCV eradication. During the first year after treatment with DAA, we observed a sustained increase in cholesterol, triglycerides, HDL cholesterol (only in men), and LDL-cholesterol levels. An ameliorated glycemic control was also observed with a decrease in fasting insulin and reduced HOMA. Iron metabolism and coagulation function also improved with lower levels of serum ferritin and prothrombin activity; these biochemical changes resulted in a new diagnosis of hypercholesterolaemia in 17.4% of patients, requiring initiation of statins in 15%. Two non-fatal cardiovascular events were observed during the first 2 years of follow-up. Conclusions: DAA treatments returned plasma lipids to the normal range without increasing either the occurrence of cardiovascular events or the consumption of lipid-lowering medication beyond what is normal in a sex- and age-matched population.
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Affiliation(s)
- Diego Casas-Deza
- Gastroenterology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (D.C.-D.); (S.E.); (E.M.F.-B.)
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
| | - Ana Martínez-Sapiña
- Clinical Microbiology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain;
| | - Silvia Espina
- Gastroenterology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (D.C.-D.); (S.E.); (E.M.F.-B.)
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
| | - Beatriz Garcia-Rodriguez
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
- Clinical Biochemistry Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain
| | - Eva M. Fernandez-Bonilla
- Gastroenterology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (D.C.-D.); (S.E.); (E.M.F.-B.)
| | - Alejandro Sanz-Paris
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
- Nutrition Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain
| | - Yolanda Gonzalez-Irazabal
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
- Clinical Biochemistry Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain
| | - Vanesa Bernal-Monterde
- Gastroenterology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (D.C.-D.); (S.E.); (E.M.F.-B.)
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
- Correspondence: (V.B.-M.); (J.M.A.-M.)
| | - Jose M. Arbones-Mainar
- Instituto de Investigación Sanitaria (IIS) Aragon, 50009 Zaragoza, Spain; (B.G.-R.); (A.S.-P.); (Y.G.-I.)
- Translational Research Unit, Miguel Servet University Hospital, Instituto Aragonés de Ciencias de la Salud (IACS), 50009 Zaragoza, Spain
- Centro de Investigación Biomédica en Red Fisiopatología Obesidad y Nutrición (CIBERObn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Correspondence: (V.B.-M.); (J.M.A.-M.)
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Mussarat S, Ali R, Ali S, Mothana RA, Ullah R, Adnan M. Medicinal Animals and Plants as Alternative and Complementary Medicine in Southern Regions of Khyber Pakhtunkhwa, Pakistan. Front Pharmacol 2021; 12:649046. [PMID: 34504421 PMCID: PMC8422074 DOI: 10.3389/fphar.2021.649046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 06/29/2021] [Indexed: 12/05/2022] Open
Abstract
Background: Local communities use animals and plants as common traditional therapies for various diseases. The study aimed to document animals and animal-plant mixture recipes that are used as alternative and complementary medicine in southern regions of Khyber Pakhtunkhwa, Pakistan. Methods: The data were collected (2017–2018) in three remote areas (Dera Ismail Khan, Bannu, and Lakki Marwat) through questionnaires and face-to-face interviews with local inhabitants. Data on ethnomedicinal uses and cultural values of animal products or parts and their mixture with plants were analyzed using various indices such as frequency of citation (FC), informant consensus (FIC), and fidelity level (FL) to find the highly preferred species in the area. Results: A total of 185 informants (117 females and 68 males) were interviewed. The study documented 32 animal species, vertebrates (n = 24) and invertebrates (n = 8), for curing 37 types of diseases. Mammals (n = 13) were among the most commonly utilized species followed by birds (n = 8), arthropods (n = 7), reptiles (n = 2), and fishes and annelids (n = 1 each). Among the reported animals, Herpestes edwardsi (mongoose), Macaca mulatta (monkey), Labeo rohita (rohu), Oryctolagus cuniculus (rabbit), and Streptopelia decaocto (dove) were the newly reported species used as alternative medicine. The meat of Capra hircus (goat), monkey, and rabbit was used to treat chronic diseases such as hepatitis C, cancer, epilepsy, and asthma. A total of 17 plants belonging to 15 botanical families were used in combination with animal parts/products. The commonly used families were Piperaceae (31%) followed by Apiaceae (27%). The notable plant species in combination with animal products were Curcuma longa, Piper nigrum, Coriandrum sativum, Brassica rapa, and Phoenix dactylifera. Seeds were the highest used part in animal-plant mixture recipes. Gallus gallus (chicken) and Columba livia (pigeon) secured the highest (FC = 28) and (FL = 80%), respectively. FIC results had shown the highest degree of consensus for general body weakness (FIC = 0.88) and pyrexia (FIC = 0.86). Conclusion: Our findings suggest that local communities in the southern regions of Khyber Pakhtunkhwa have substantial knowledge about the formulation of ethnomedicines from both flora and fauna that need urgent documentation to avoid eroding and for conservational purposes. The newly reported phytozootherapeutic recipes and animal species can potentially be a source of pharmacologically active constituents and should be checked experimentally for further confirmation.
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Affiliation(s)
- Sakina Mussarat
- Department of Botanical and Environmental Sciences, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Rehman Ali
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Shandana Ali
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Ramzi A Mothana
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Riaz Ullah
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Muhammad Adnan
- Department of Botanical and Environmental Sciences, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
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Zhang J, Tang K, Zhang Y, Ma Y, Zhang C, Hu H, Jia X, Zhuang R, Jin B, Wang M, Zhang X, Liu D, Zhang Y. The Presence of Circulating Nucleated Red Blood Cells Is Associated With Disease Severity in Patients of Hemorrhagic Fever With Renal Syndrome. Front Med (Lausanne) 2021; 8:665410. [PMID: 34113638 PMCID: PMC8186265 DOI: 10.3389/fmed.2021.665410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/19/2021] [Indexed: 12/31/2022] Open
Abstract
Hemorrhagic fever with renal syndrome (HFRS) is a regional infectious disease of epidemic potential caused by the Hantaan virus (HTNV). Red blood cells (RBCs) are the major components of peripheral blood. However, pathological changes in RBCs and the underlying mechanisms during HTNV infection remain largely unclear. Therefore, this study sought to explore changes in RBCs in the peripheral blood of HFRS patients. We isolated PBMCs from HFRS patients and performed single-cell RNA sequencing. The results showed that clusters of RBCs in the peripheral blood of HFRS could be classified as nucleated red blood cells (NRBC) based on their cellular components, gene expression profiles and cell surface markers. In addition, it was shown that the higher the count of NRBC in peripheral blood, the more severe the disease status was. Moreover, hematological indices related to RBCs were analyzed and the results showed that impairment in the folate pathway might be the possible reason behind the presence of NRBCs. This study, for the first time showed that the presence of NRBCs in the peripheral blood of HFRS patients was associated with disease severity. This was also the first study to show that infection with the HTNV virus hindered the maturation of RBCs. Therefore, this work provides further insights on the role of and pathological changes in RBCs during HTNV infection.
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Affiliation(s)
- Jingang Zhang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China.,Brigade of Cadet, Air Force Medical University, Xi'an, China
| | - Kang Tang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Yun Zhang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Ying Ma
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Chunmei Zhang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Haifeng Hu
- Center for Infectious Diseases, Second Affiliated Hospital of Air Force Medical University, Xi'an, China
| | - Xiaozhou Jia
- Department of Infectious Disease, Xi'an Eighth Hospital, Xi'an, China
| | - Ran Zhuang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Boquan Jin
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Meng Wang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Xiyue Zhang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
| | - Dalu Liu
- Department of Radiation Medicine and Protection, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, China
| | - Yusi Zhang
- Department of Immunology, Basic Medicine School, Air Force Medical University, Xi'an, China
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Wee AKH. COVID-19's toll on the elderly and those with diabetes mellitus - Is vitamin B12 deficiency an accomplice? Med Hypotheses 2021; 146:110374. [PMID: 33257090 PMCID: PMC7659645 DOI: 10.1016/j.mehy.2020.110374] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 08/20/2020] [Accepted: 10/22/2020] [Indexed: 02/08/2023]
Abstract
COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically damaging restrictions that keep this group of people safe. Without a vaccine, there is thus an urgent need to identify potential modifiable risk factors which can help manage overall fatality or recovery rates. Case fatality rates are highly variable between (and even within) nations; nutritional differences have been proposed to account significantly for this disparity. Indeed, vitamin B12 deficiency is a common denominator between the elderly and those with diabetes. The question on hand thus lies on whether managing B12 deficiencies will impact COVID-19 fatality outcome or recovery rates. Herein, we review the latest evidence that shows that B12 deficiency associates in multiple areas very similar to where COVID-19 exerts its damaging effects: immunologically; microbiologically; haematologically; and through endothelial cell signalling-supporting the hypothesis that B12 deficiency is a potential modifiable risk factor in our fight against COVID-19.
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Affiliation(s)
- Andrew Kien Han Wee
- SingHealth Polyclinics, Marine Parade Polyclinic, Blk 80 Marine Parade Central, #01-792, Singapore 440080, Singapore; SingHealth Duke-NUS Medical School, Family Medicine Academic Clinical Programme ("FM ACP"), Office of Academic & Clinical Development, 8 College Road, Singapore 169857, Singapore.
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5
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Valdés JJ, Miller AD. New opportunities for designing effective small interfering RNAs. Sci Rep 2019; 9:16146. [PMID: 31695077 PMCID: PMC6834666 DOI: 10.1038/s41598-019-52303-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/10/2019] [Indexed: 12/13/2022] Open
Abstract
Small interfering RNAs (siRNAs) that silence genes of infectious diseases are potentially potent drugs. A continuing obstacle for siRNA-based drugs is how to improve their efficacy for adequate dosage. To overcome this obstacle, the interactions of antiviral siRNAs, tested in vivo, were computationally examined within the RNA-induced silencing complex (RISC). Thermodynamics data show that a persistent RISC cofactor is significantly more exothermic for effective antiviral siRNAs than their ineffective counterparts. Detailed inspection of viral RNA secondary structures reveals that effective antiviral siRNAs target hairpin or pseudoknot loops. These structures are critical for initial RISC interactions since they partially lack intramolecular complementary base pairing. Importing two temporary RISC cofactors from magnesium-rich hairpins and/or pseudoknots then kickstarts full RNA hybridization and hydrolysis. Current siRNA design guidelines are based on RNA primary sequence data. Herein, the thermodynamics of RISC cofactors and targeting magnesium-rich RNA secondary structures provide additional guidelines for improving siRNA design.
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MESH Headings
- Argonaute Proteins/chemistry
- Argonaute Proteins/metabolism
- Base Pairing
- Crystallography, X-Ray
- Drug Design
- Humans
- Hydrolysis
- Magnesium
- Molecular Docking Simulation
- Monte Carlo Method
- Nucleic Acid Conformation
- Nucleic Acid Hybridization
- RNA Interference
- RNA, Messenger/chemistry
- RNA, Messenger/metabolism
- RNA, Small Interfering/chemistry
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Viral/antagonists & inhibitors
- RNA, Viral/chemistry
- RNA-Induced Silencing Complex
- Structure-Activity Relationship
- Thermodynamics
- RNA, Guide, CRISPR-Cas Systems
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Affiliation(s)
- James J Valdés
- Veterinary Research Institute, Hudcova 70, CZ-62100, Brno, Czech Republic.
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovska 1160/31, CZ-37005, České Budějovice, Czech Republic.
| | - Andrew D Miller
- Veterinary Research Institute, Hudcova 70, CZ-62100, Brno, Czech Republic.
- KP Therapeutics Ltd, 86 Deansgate, Manchester, M3 2ER, UK.
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The Role of Micronutrients in the Infection and Subsequent Response to Hepatitis C Virus. Cells 2019; 8:cells8060603. [PMID: 31212984 PMCID: PMC6627053 DOI: 10.3390/cells8060603] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
Micronutrient deficiencies develop for a variety of reasons, whether geographic, socioeconomic, nutritional, or as a result of disease pathologies such as chronic viral infection. As micronutrients are essential for a strong immune response, deficiencies can significantly dampen both the innate and the adaptive arms of antiviral immunity. The innate immune response in particular is crucial to protect against hepatitis C virus (HCV), a hepatotropic virus that maintains chronic infection in up to 80% of individuals if left untreated. While many micronutrients are required for HCV replication, an overlapping group of micronutrients are also necessary to enact a potent immune response. As the liver is responsible for the storage and metabolism of many micronutrients, HCV persistence can influence the micronutrients’ steady state to benefit viral persistence both directly and by weakening the antiviral response. This review will focus on common micronutrients such as zinc, iron, copper, selenium, vitamin A, vitamin B12, vitamin D and vitamin E. We will explore their role in the pathogenesis of HCV infection and in the response to antiviral therapy. While chronic hepatitis C virus infection drives deficiencies in micronutrients such as zinc, selenium, vitamin A and B12, it also stimulates copper and iron excess; these micronutrients influence antioxidant, inflammatory and immune responses to HCV.
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Baruah V, Bose S. Computational identification of hepatitis E virus-encoded microRNAs and their targets in human. J Med Virol 2019; 91:1545-1552. [PMID: 30919453 DOI: 10.1002/jmv.25471] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 02/13/2019] [Accepted: 03/12/2019] [Indexed: 12/26/2022]
Abstract
microRNAs (miRNAs) are small, noncoding RNAs which regulate eukaryotic gene expression via RNA interference pathway. Recently, miRNAs have been identified in a number of viruses with current evidence suggesting that they regulate gene expression in both virus and host. This makes viral miRNAs potential targets of clinical intervention, with the possibility of inhibiting aberrant host gene expression associated with the disease. In this study, computational approaches were taken to scan the hepatitis E virus (HEV) genome for putative pre-miRNA molecules, which were then analyzed for the presence of mature miRNAs. The 3'-untranslated region (3'-UTR) and 5'-UTR sequences targeted by these miRNAs were identified using Miranda computational tool, followed by the functional annotation of the associated messenger RNAs (mRNAs) using Gene Ontology terms and Kyoto Encyclopaedia of Genes and Genomes pathway analysis. We identified a total of nine viral encoded miRNAs in HEV. After functional annotation, the majority of the viral miRNA targets were found to be associated with cell cycle, cell differentiation, nitrogen compound metabolism, transmembrane transport, and chromosome organization. This in-silico study identified putative viral miRNAs encoded by HEV and their potential human mRNAs targets. These viral miRNAs have the potential to affect host gene expression as well as viral life cycle and pathogenesis and can, therefore, serve as potential therapeutic targets during HEV infection.
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Affiliation(s)
- Vargab Baruah
- Department of Biotechnology, Gauhati University, Guwahati, Assam, India
| | - Sujoy Bose
- Department of Biotechnology, Gauhati University, Guwahati, Assam, India
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Mechie NC, Goralzcyk AD, Reinhardt L, Mihm S, Amanzada A. Association of serum vitamin B12 levels with stage of liver fibrosis and treatment outcome in patients with chronic hepatitis C virus genotype 1 infection: a retrospective study. BMC Res Notes 2015; 8:260. [PMID: 26109044 PMCID: PMC4479221 DOI: 10.1186/s13104-015-1248-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/17/2015] [Indexed: 12/18/2022] Open
Abstract
Background Chronic hepatitis C (CHC) is a global health challenge. New therapeutic agents with excellent sustained virological response (SVR) rates are available mainly in developed countries, while the majority of CHC patients live in countries with low health budget. Predictors of therapeutic response are therefore necessary. Vitamin B12 appears to be involved in hepatitis C virus replication. Methods We therefore studied retrospectively the relationship between baseline serum vitamin B12 levels and clinical features in 116 CHC genotype 1 infected patients. Logistic regression models with univariate and multivariate analysis were used in the statistical analysis. Results Baseline serum vitamin B12 levels were found to be positively associated with serum transaminase activities (AST, p = 0.002, ALT, p = 0.04), baseline viral load (p < 0.0001), stage of fibrosis (p = 0.0001) and favorable interferon-λ3/4 (IFNL3/IFNL4) rs12979860 genotypes (p = 0.04), and inversely with SVR (p < 0.001) as well as with rapid virological response (p = 0.001). Patients with baseline serum vitamin B12 levels below a cut-off value of 570 ng/L achieved a SVR rate of 59% with an odds ratio (OR) of 13.4 [confidence interval (CI) 4.3–41.9, p < 0.0001] compared to patients above the cut-off value. By combining serum vitamin B12 levels and IFNL3/IFNL4 rs12979860 genotypes, patients with baseline serum vitamin B12 levels below the cut-off value of 570 ng/L and IFNL3/IFNL4 rs12979860 CC genotype achieved a SVR rate of even 80% with an OR of 54 (CI 9.9–293, p < 0.0001) compared to patients above the cut-off value and non-CC-genotypes. Conclusion Our data suggest baseline serum vitamin B12 levels as useful noninvasive marker for characterizing CHC patients. They might further help to identify responders to a standard treatment.
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Affiliation(s)
- Nicolae-Catalin Mechie
- Department of Gastroenterology and Endocrinology, University Medical Center Goettingen, Georg-August University Goettingen, Robert Koch Strasse 40, 37075, Göttingen, Germany.
| | - Armin D Goralzcyk
- Division of Internal Medicine, Clinic of Herzberg and Osterode, Dr Froessel Allee, 37412, Herzberg am Harz, Germany.
| | - Lars Reinhardt
- Department of Gastroenterology and Endocrinology, University Medical Center Goettingen, Georg-August University Goettingen, Robert Koch Strasse 40, 37075, Göttingen, Germany.
| | - Sabine Mihm
- Department of Gastroenterology and Endocrinology, University Medical Center Goettingen, Georg-August University Goettingen, Robert Koch Strasse 40, 37075, Göttingen, Germany.
| | - Ahmad Amanzada
- Department of Gastroenterology and Endocrinology, University Medical Center Goettingen, Georg-August University Goettingen, Robert Koch Strasse 40, 37075, Göttingen, Germany.
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Lee TH, Tillmann HL, Patel K. Individualized therapy for hepatitis C infection: focus on the interleukin-28B polymorphism in directing therapy. Mol Diagn Ther 2014; 18:25-38. [PMID: 24022240 DOI: 10.1007/s40291-013-0053-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatitis C virus—a major global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma—affects millions of people worldwide. Pegylated interferon (Peg-IFN) and ribavirin (RBV) had been the standard treatment for a decade until availability of the protease inhibitors in 2011. However, current antiviral therapy is still IFN-based and is associated with significant side effects and variable treatment response. Thus, various host and viral factors have been evaluated before and during treatment for the prediction of sustained virologic response to antiviral therapy. In 2009, genome-wide association studies found the single-nucleotide polymorphisms, located near the host interleukin-28B (IL28B) gene that encodes IFN-λ3, to be the best pretreatment predictor of virologic response to Peg-IFN and RBV therapy in chronic hepatitis C genotype 1 patients. Additionally, inosine triphosphatase (ITPA) gene variants were found to be associated with RBV-induced hemolytic anemia, which could affect treatment dose for selected patients. IL28B, ITPA, and other treatment predictors allowed for a potential individualized approach to treat hepatitis C. In the era of increased overall virologic response rates and good tolerability of the rapidly developing non-IFN oral direct-acting antiviral therapy regimens, the need for individualized treatment is likely to diminish. Various predictors of response, including IL28B will likely be of reduced importance in the near future.
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Abstract
The lack of small animal models for hepatitis C virus has impeded the discovery and development of anti-HCV drugs. HCV-IRES plays an important role in HCV gene expression, and is an attractive target for antiviral therapy. In this study, we report a zebrafish model with a biscistron expression construct that can co-transcribe GFP and HCV-core genes by human hepatic lipase promoter and zebrafish liver fatty acid binding protein enhancer. HCV core translation was designed mediated by HCV-IRES sequence and gfp was by a canonical cap-dependent mechanism. Results of fluorescence image and in situ hybridization indicate that expression of HCV core and GFP is liver-specific; RT-PCR and Western blotting show that both core and gfp expression are elevated in a time-dependent manner for both transcription and translation. It means that the HCV-IRES exerted its role in this zebrafish model. Furthermore, the liver-pathological impact associated with HCV-infection was detected by examination of gene markers and some of them were elevated, such as adiponectin receptor, heparanase, TGF-β, PDGF-α, etc. The model was used to evaluate three clinical drugs, ribavirin, IFNα-2b and vitamin B12. The results show that vitamin B12 inhibited core expression in mRNA and protein levels in dose-dependent manner, but failed to impact gfp expression. Also VB12 down-regulated some gene transcriptions involved in fat liver, liver fibrosis and HCV-associated pathological process in the larvae. It reveals that HCV-IRES responds to vitamin B12 sensitively in the zebrafish model. Ribavirin did not disturb core expression, hinting that HCV-IRES is not a target site of ribavirin. IFNα-2b was not active, which maybe resulted from its degradation in vivo for the long time. These findings demonstrate the feasibility of the zebrafish model for screening of anti-HCV drugs targeting to HCV-IRES. The zebrafish system provides a novel evidence of using zebrafish as a HCV model organism.
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Molecular and cellular effects of vitamin B12 in brain, myocardium and liver through its role as co-factor of methionine synthase. Biochimie 2013; 95:1033-40. [PMID: 23415654 DOI: 10.1016/j.biochi.2013.01.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/30/2013] [Indexed: 12/16/2022]
Abstract
Vitamin B12 (cobalamin, cbl) is a cofactor of methionine synthase (MTR) in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAM), which is involved in epigenomic regulatory mechanisms. We have established a neuronal cell model with stable expression of a transcobalamin-oleosin chimer and subsequent decreased cellular availability of vitamin B12, which produces reduced proliferation, increased apoptosis and accelerated differentiation through PP2A, NGF and TACE pathways. Anti-transcobalamin antibody or impaired transcobalamin receptor expression produce also impaired proliferation in other cells. Consistently, the transcription, protein expression and activity of MTR are increased in proliferating cells of skin and intestinal epitheliums, in rat intestine crypts and in proliferating CaCo2 cells, while MTR activity correlates with DNA methylation in rat intestine villi. Exposure to nitrous oxide in animal models identified impairment of MTR reaction as the most important metabolic cause of neurological manifestations of B12 deficiency. Early vitamin B12 and folate deprivation during gestation and lactation of a 'dam-progeny' rat model developed in our laboratory is associated with long-lasting disabilities of behavior and memory capacities, with persisting hallmarks related to increased apoptosis, impaired neurogenesis and altered plasticity. We found also an epigenomic deregulation of energy metabolism and fatty acids beta-oxidation in myocardium and liver, through imbalanced methylation/acetylation of PGC-1alpha and decreased expression of SIRT1. These nutrigenomic effects display similarities with the molecular mechanisms of fetal programming. Beside deficiency, B12 loading increases the expression of MTR through internal ribosome entry sites (IRES) and down-regulates MDR-1 gene expression. In conclusion, vitamin B12 influences cell proliferation, differentiation and apoptosis in brain. Vitamin B12 and folate combined deficiency impairs fatty acid oxidation and energy metabolism in liver and heart through epigenomic mechanisms related to imbalanced acetylation/methylation. Some but not all of these effects reflect the upstream role of vitamin B12 in SAM synthesis.
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12
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Villaflores OB, Chen YJ, Chen CP, Yeh JM, Wu TY. Effects of curcumin and demethoxycurcumin on amyloid-β precursor and tau proteins through the internal ribosome entry sites: A potential therapeutic for Alzheimer's disease. Taiwan J Obstet Gynecol 2012; 51:554-64. [DOI: 10.1016/j.tjog.2012.09.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2012] [Indexed: 12/11/2022] Open
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13
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Tillmann HL. Vitamins? The magic bullet against hepatitis C. Expert Rev Anti Infect Ther 2012; 10:1273-1277. [DOI: 10.1586/eri.12.127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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14
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Abu-Mouch S, Fireman Z, Jarchovsky J, Zeina AR, Assy N. Vitamin D supplementation improves sustained virologic response in chronic hepatitis C (genotype 1)-naïve patients. World J Gastroenterol 2011; 17:5184-90. [PMID: 22215943 PMCID: PMC3243885 DOI: 10.3748/wjg.v17.i47.5184] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 03/27/2011] [Accepted: 04/03/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine whether adding vitamin D, a potent immunomodulator, improves the hepatitis C virus (HCV) response to antiviral therapy.
METHODS: Seventy-two consecutive patients with chronic HCV genotype 1 were randomized into two groups: the treatment group (n = 36, 50% male, mean age 47 ± 11 years) received Peg-α-2b interferon (1.5 μg/kg per week) plus ribavirin (1000-1200 mg/d) together with vitamin D3 (2000 IU/d, target serum level > 32 ng/mL), and the control group (n = 36, 60% male, mean age 49 ± 7 years) received identical therapy without vitamin D. HCV-RNA was assessed by real-time polymerase chain reaction (sensitivity, 10 IU/mL). The sustained virologic response (SVR) was defined as undetectable HCV-RNA at 24 wk post-treatment.
RESULTS: Clinical characteristics were similar in both groups. The treatment group had a higher mean body mass index (27 ± 4 kg/m2vs 24 ± 3 kg/m2; P < 0.01), viral load (50% vs 42%, P < 0.01), and fibrosis score (> F2: 42% vs 19%, P < 0.001) than the controls. At week 4, 16 (44%) treated patients and 6 (17%) controls were HCV-RNA negative (P < 0.001). At week 12, 34 (94%) treated patients and 17 (48%) controls were HCV-RNA negative (P < 0.001). At 24 wk post-treatment (SVR), 31 (86%) treated patients and 15 (42%) controls were HCV-RNA negative (P < 0.001). Viral load, advanced fibrosis and vitamin D supplementation were strongly and independently associated with SVR (multivariate analysis). Adverse events were mild and typical of Peg-α-2b/ribavirin.
CONCLUSION: Adding vitamin D to conventional Peg-α-2b/ribavirin therapy for treatment-naïve patients with chronic HCV genotype 1 infection significantly improves the viral response.
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15
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Rosenberg P, Hagen K. Serum B12 levels predict response to treatment with interferon and ribavirin in patients with chronic HCV infection. J Viral Hepat 2011; 18:129-34. [PMID: 20196801 DOI: 10.1111/j.1365-2893.2010.01288.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Vitamin B12 is stored in hepatocytes and inhibits hepatitis C virus (HCV) RNA translation. The implication of B12 in the setting of antiviral treatment is unknown. This study aims to retrospectively evaluate the discriminative efficacy of pretreatment B12 serum levels (s-B12) on end-of-treatment response (ETR) in patients with chronic HCV. Ninety-nine treatment naïve HCV patients, treated with interferon and ribavirin were studied. Serum B12 (s-B12) was analysed in samples collected before treatment start. Pretreatment s-B12 levels were correlated to ETR using univariate analysis. S-B12 and clinical data were evaluated in a multivariate logistic regression model. Mean pretreatment s-B12 was 331 pm in ETR and 260 pm in nonresponders (NR) (P = 0.012). In patients with s-B12 levels ≤ 360 pm, 23 (31.5%) were NR and 50 (68.5%) had ETR. In patients with s-B12 > 360 pm, one (3.8%) was NR and 25 (96.2%) had ETR (P = 0.0034). The results of the multivariate analysis were as follows: Pretreatment s-B12 > 360 vs ≤ 360 pm: OR 28.6 CI 2.31-354, P = 0.008. Fibrosis stage 3-4 vs 0-2: OR 0.29 CI 0.074-1.12, P = 0.068. Genotype 2/3 vs 1/4/5: OR 15.5 CI 2.87-83.9, P = 0.0012. Dose reduction vs no dose reduction: OR 0.21, CI 0.048-0.91 P = 0.034. Standard interferon vs pegylated-interferon: OR 0.079, CI 0.0091-0.68 P = 0.019. Age and gender were not correlated to ETR. S-B12 > 360 pm is independently correlated to ETR in HCV patients treated with interferon and ribavirin. This suggests that B12 is involved in suppression of viral replication during anti-HCV treatment.
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Affiliation(s)
- P Rosenberg
- Department of Medicine, Karolinska Institute, Stockholm, Sweden.
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16
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Abstract
The mechanisms of hepatitis C virus (HCV) replication remain poorly understood, and the cellular factors required for HCV replication are yet to be completely defined. CD81 is known to mediate HCV entry. Our study uncovered an unexpected novel function of CD81 in the HCV life cycle that is important for HCV RNA replication. HCV replication occurred efficiently in infected cells with high levels of CD81 expression. In HCV-infected or RNA-transfected cells with low levels of CD81 expression, initial viral protein synthesis occurred normally, but efficient replication failed to proceed. The aborted replication could be restored by the transient transfection of a CD81 expression plasmid. CD81-dependent replication was demonstrated with both an HCV infectious cell culture and HCV replicon cells of genotypes 1b and 2a. We also showed that CD81 expression is positively correlated with the kinetics of HCV RNA synthesis but inversely related to the kinetics of viral protein production, suggesting that CD81 may control viral replication by directing viral RNA template function to RNA replication. Thus, CD81 may be necessary for the efficient replication of the HCV genome in addition to its role in viral entry.
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17
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Scalabrino G, Veber D, Mutti E. Experimental and clinical evidence of the role of cytokines and growth factors in the pathogenesis of acquired cobalamin-deficient leukoneuropathy. ACTA ACUST UNITED AC 2008; 59:42-54. [DOI: 10.1016/j.brainresrev.2008.05.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 04/30/2008] [Accepted: 05/01/2008] [Indexed: 01/08/2023]
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18
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Solomon LR. Disorders of cobalamin (Vitamin B12) metabolism: Emerging concepts in pathophysiology, diagnosis and treatment. Blood Rev 2007; 21:113-30. [DOI: 10.1016/j.blre.2006.05.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Yano M, Ikeda M, Abe KI, Dansako H, Ohkoshi S, Aoyagi Y, Kato N. Comprehensive analysis of the effects of ordinary nutrients on hepatitis C virus RNA replication in cell culture. Antimicrob Agents Chemother 2007; 51:2016-27. [PMID: 17420205 PMCID: PMC1891399 DOI: 10.1128/aac.01426-06] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
To date, only a limited number of studies have reported finding an influence of ordinary nutrients on hepatitis C virus (HCV) RNA replication. However, the effects of other nutrients on HCV RNA replication remain largely unknown. We recently developed a reporter assay system for genome-length HCV RNA replication in hepatoma-derived HuH-7 cells (OR6). Here, using this OR6 assay system, we comprehensively examined 46 nutrients from four nutrient groups: vitamins, amino acids, fatty acids, and salts. We found that three nutrients-beta-carotene, vitamin D(2), and linoleic acid-inhibited HCV RNA replication and that their combination caused additive and/or synergistic effects on HCV RNA replication. In addition, combined treatment with each of the three nutrients and interferon alpha or beta or fluvastatin inhibited HCV RNA replication in an additive manner, while combined treatment with cyclosporine synergistically inhibited HCV RNA replication. In contrast, we found that vitamin E enhanced HCV RNA replication and negated the effects of the three anti-HCV nutrients and cyclosporine but not those of interferon or fluvastatin. These results will provide useful information for the treatment of chronic hepatitis C patients who also take anti-HCV nutrients as an adjunctive therapy in combination with interferon. In conclusion, among the ordinary nutrients tested, beta-carotene, vitamin D(2), and linoleic acid possessed anti-HCV activity in a cell culture system, and these nutrients are therefore considered to be potential candidates for enhancing the effects of interferon therapy.
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Affiliation(s)
- Masahiko Yano
- Department of Molecular Biology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
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20
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Jang SK. Internal initiation: IRES elements of picornaviruses and hepatitis c virus. Virus Res 2005; 119:2-15. [PMID: 16377015 DOI: 10.1016/j.virusres.2005.11.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 08/29/2005] [Accepted: 11/02/2005] [Indexed: 02/08/2023]
Abstract
The scanning hypothesis provides an explanation for events preceding the first peptide bond formation during the translation of the vast majority of eukaryotic mRNAs. However, this hypothesis does not explain the translation of eukaryotic mRNAs lacking the cap structure required for scanning. The existence of a group of positive sense RNA viruses lacking cap structures (e.g. picornaviruses) indicates that host cells also contain a 5' cap-independent translation mechanism. This review discusses the translation mechanisms of atypical viral mRNAs such as picornaviruses and hepatitis c virus, and uses these mechanisms to propose a general theme for all translation, including that of both eukaryotic and prokaryotic mRNAs.
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Affiliation(s)
- Sung Key Jang
- NRL, PBC, Department of Life Science, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea.
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21
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Murata T, Hijikata M, Shimotohno K. Enhancement of internal ribosome entry site-mediated translation and replication of hepatitis C virus by PD98059. Virology 2005; 340:105-15. [PMID: 16005928 DOI: 10.1016/j.virol.2005.06.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 05/11/2005] [Accepted: 06/08/2005] [Indexed: 12/22/2022]
Abstract
Translation initiation of hepatitis C virus (HCV) occurs in an internal ribosome entry site (IRES)-dependent manner. We found that HCV IRES-dependent protein synthesis is enhanced by PD98059, an inhibitor of the extracellular signal-regulated kinase (ERK) signaling pathway, while cellular cap-dependent translation was relatively unaffected by the compound. Treatment of cells with PD98059 allowed for robust HCV replication following cellular incubation with HCV-positive serum. Though the molecular mechanism underlying IRES enhancement remains elusive, PD98059 is a potent accelerator of HCV RNA replication.
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Affiliation(s)
- Takayuki Murata
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
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22
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Oltean S, Banerjee R. A B12-responsive internal ribosome entry site (IRES) element in human methionine synthase. J Biol Chem 2005; 280:32662-8. [PMID: 16051610 DOI: 10.1074/jbc.m501964200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Regulation of homocysteine, a sulfur-containing amino acid that is a risk factor for cardiovascular diseases, is poorly understood. Methionine synthase (MS) is a key enzyme that clears intracellular homocysteine, and its activity is induced by its cofactor, vitamin B12, at a translational level. In this study, we demonstrate that translation of MS, which has a long and highly structured 5'-untranslated region, is initiated from an internal ribosome entry site (IRES), which is modulated by B12. The minimal IRES element spans 71 bases immediately upstream of the initiation codon. Electrophoretic mobility shift analysis reveals the presence of a B12 -dependent protein-RNA complex and suggests the possibility that B12-dependent increase of IRES efficiency is mediated via a protein. Modulation of the IRES-dependent translation of an essential gene by the cofactor of the encoded enzyme represents a novel example of a gene-nutrient interaction.
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Affiliation(s)
- Sebastian Oltean
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA
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23
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Nava-Ocampo AA, Pastrak A, Cruz T, Koren G. Pharmacokinetics of high doses of cyanocobalamin administered by intravenous injection for 26 weeks in rats. Clin Exp Pharmacol Physiol 2005; 32:13-8. [PMID: 15730428 DOI: 10.1111/j.1440-1681.2005.04145.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
1. High doses of vitamin B12 (cyanocobalamin) may be therapeutically effective to treat neurological alterations secondary to a wide range of disease states. The aim of the present study was to evaluate the effect of dose and repeated administration on the pharmacokinetics of cyanocobalamin in rats. 2. Forty-eight rats were randomly assigned to receive 1, 5, 25 or 100 mg/kg cyanocobalamin for 182 days (26 weeks). Cyanocobalamin plasma levels were quantified by HPLC on days 1, 85 and 182 of treatment and were analysed by means of non-compartment pharmacokinetic (PK) analysis. In addition, population PK analysis was used to fit cyanocobalamin plasma concentrations to time by means of a two-compartment model for intravascular administration. 3. The half-life of cyanocobalamin ranged from approximately 20 to 50 min, clearance ranged from 4.5 to 9 mL/min and the volume of distribution at steady state ranged from 140 to 470 mL. A statistically significant negative relationship existed between the dose of cyanocobalamin and the normalized area under the plasma concentration-time curve (AUC). This non-linearity was not exhibited in population PK analysis. No evidence of toxicity was observed. 4. At very high and prolonged doses (up to 100 mg/kg for 26 weeks), intravascular administration of cyanocobalamin in rats follows a two-compartment kinetic model and cyanocobalamin undergoes extensive extravascular distribution. The negative relationship between dose and normalized AUC is compatible with possible saturation of tubular reabsorption, thus increasing renal clearance at higher doses.
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Affiliation(s)
- Alejandro A Nava-Ocampo
- Division of Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, Canada.
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24
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Li D, Lott WB, Martyn J, Haqshenas G, Gowans EJ. Differential effects on the hepatitis C virus (HCV) internal ribosome entry site by vitamin B12 and the HCV core protein. J Virol 2004; 78:12075-81. [PMID: 15479850 PMCID: PMC523236 DOI: 10.1128/jvi.78.21.12075-12081.2004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To investigate the role of the hepatitis C virus internal ribosome entry site (HCV IRES) domain IV in translation initiation and regulation, two chimeric IRES elements were constructed to contain the reciprocal domain IV in the otherwise HCV and classical swine fever virus IRES elements. This permitted an examination of the role of domain IV in the control of HCV translation. A specific inhibitor of the HCV IRES, vitamin B(12), was shown to inhibit translation directed by all IRES elements which contained domain IV from the HCV and the GB virus B IRES elements, whereas the HCV core protein could only suppress translation from the wild-type HCV IRES. Thus, the mechanisms of translation inhibition by vitamin B(12) and the core protein differ, and they target different regions of the IRES.
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Affiliation(s)
- Dongsheng Li
- Macfarlane Burnet Institute for Medical Research and Public Health, GPO Box 2284, Melbourne, VIC 3001, Australia
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25
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Ray PS, Das S. Inhibition of hepatitis C virus IRES-mediated translation by small RNAs analogous to stem-loop structures of the 5'-untranslated region. Nucleic Acids Res 2004; 32:1678-87. [PMID: 15020704 PMCID: PMC390326 DOI: 10.1093/nar/gkh328] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Translation of the hepatitis C virus (HCV) RNA is mediated by the interaction of ribosomes and cellular proteins with an internal ribosome entry site (IRES) located within the 5'-untranslated region (5'-UTR). We have investigated whether small RNA molecules corresponding to the different stem-loop (SL) domains of the HCV IRES, when introduced in trans, can bind to the cellular proteins and antagonize their binding to the viral IRES, thereby inhibiting HCV IRES-mediated translation. We have found that a RNA molecule corresponding to SL III could efficiently inhibit HCV IRES-mediated translation in a dose-dependent manner without affecting cap-dependent translation. The SL III RNA was found to bind to most of the cellular proteins which interacted with the HCV 5'-UTR. A smaller RNA corresponding to SL e+f of domain III also strongly and selectively inhibited HCV IRES-mediated translation. This RNA molecule interacted with the ribosomal S5 protein and prevented the recruitment of the 40S ribosomal subunit. This study reveals valuable insights into the role of the SL structures of the HCV IRES in mediating ribosome entry. Finally, these results provide a basis for developing anti-HCV therapy using small RNA molecules mimicking the SL structures of the 5'-UTR to specifically block viral RNA translation.
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Affiliation(s)
- Partho Sarothi Ray
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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26
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Abstract
Functional RNAs such as ribosomal RNA and structured domains of mRNA are targets for small molecule ligands that can act as modulators of the RNA biological activity. Natural ligands for RNA display a bewildering structural and chemical complexity that has yet to be matched by synthetic RNA binders. Comparison of natural and artificial ligands for RNA may help to direct future approaches to design and synthesize potent novel scaffolds for specific recognition of RNA targets.
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Affiliation(s)
- Thomas Hermann
- Department of Computational Chemistry & Structure, Anadys Parmaceuticals, Inc., 9050 Camino Santa Fe, San Diego, CA 92121, USA.
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27
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N/A. N/A. Shijie Huaren Xiaohua Zazhi 2003; 11:810-814. [DOI: 10.11569/wcjd.v11.i6.810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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28
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Oltean S, Banerjee R. Nutritional modulation of gene expression and homocysteine utilization by vitamin B12. J Biol Chem 2003; 278:20778-84. [PMID: 12670934 DOI: 10.1074/jbc.m300845200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Vitamins B12, B6, and folic acid converge at the homocysteine metabolic junction where they support the activities of two key enzymes involved in intracellular homocysteine management, methionine synthase (MS) and cystathionine beta-synthase. The molecular mechanism for the regulation of homocysteine metabolism by B12 supplementation has been investigated in this study. B12 supplementation does not alter mRNA or protein turnover rates but induces translational up-regulation of MS by shifting the mRNA from the ribonucleoprotein to the polysome pool. The B12-responsive element has been localized by deletion analysis using a reporter gene assay to a 70-bp region located at the 3' end of the 5'-untranslated region of the MS mRNA. The cellular consequence of the B12 response is a 2- and 3.5-fold increase in the flux of homocysteine through the MS-dependent transmethylation pathway in HepG2 and 293 cells, respectively. It is speculated that B12-induced up-regulation of MS may have evolved as an adaptive strategy for rapidly sequestering an essential and rare nutrient whose availability may have been limited in the evolutionary history of mammals, a problem that is exacerbated by the absence of this vitamin from the plant kingdom.
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Affiliation(s)
- Sebastian Oltean
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA
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29
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Li D, Takyar ST, Lott WB, Gowans EJ. Amino acids 1-20 of the hepatitis C virus (HCV) core protein specifically inhibit HCV IRES-dependent translation in HepG2 cells, and inhibit both HCV IRES- and cap-dependent translation in HuH7 and CV-1 cells. J Gen Virol 2003; 84:815-825. [PMID: 12655082 DOI: 10.1099/vir.0.18697-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A self-modulating mechanism by the hepatitis C virus (HCV) core protein has been suggested to influence the level of HCV replication, but current data on this subject are contradictory. We examined the effect of wild-type and mutated core protein on HCV IRES- and cap-dependent translation. The wild-type core protein was shown to inhibit both IRES- and cap-dependent translation in an in vitro system. This effect was duplicated in a dose-dependent manner with a synthetic peptide representing amino acids 1-20 of the HCV core protein. This peptide was able to bind to the HCV IRES as shown by a mobility shift assay. In contrast, a peptide derived from the hepatitis B virus (HBV) core protein that contained a similar proportion of basic residues was unable to inhibit translation or bind the HCV IRES. A recombinant vaccinia-HCV core virus was used to examine the effect of the HCV core protein on HCV IRES-dependent translation in cells and this was compared with the effects of an HBV core-recombinant vaccinia virus. In CV-1 and HuH7 cells, the HCV core protein inhibited translation directed by the IRES elements of HCV, encephalomyocarditis virus and classical swine fever virus as well as cap-dependent translation, whereas in HepG2 cells, only HCV IRES-dependent translation was affected. Thus, the ability of the HCV core protein to selectively inhibit HCV IRES-dependent translation is cell-specific. N-terminal truncated (aa 1-20) HCV core protein that was expressed from a novel recombinant vaccinia virus in cells abrogated the inhibitory phenotype of the core protein in vivo, consistent with the above in vitro data.
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Affiliation(s)
- Dongsheng Li
- Clinical Medical Virology Research Centre, University of Queensland, St Lucia, QLD 4067, Australia
- Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Brisbane, QLD 4029, Australia
| | - Seyed Taghi Takyar
- Clinical Medical Virology Research Centre, University of Queensland, St Lucia, QLD 4067, Australia
- Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Brisbane, QLD 4029, Australia
| | - William B Lott
- Clinical Medical Virology Research Centre, University of Queensland, St Lucia, QLD 4067, Australia
- Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Brisbane, QLD 4029, Australia
| | - Eric J Gowans
- Clinical Medical Virology Research Centre, University of Queensland, St Lucia, QLD 4067, Australia
- Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Brisbane, QLD 4029, Australia
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30
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Abstract
The base of knowledge concerning RNA structure and function has been expanding rapidly in recent years. Simultaneously, an increasing awareness of the pivotal role RNA plays in viral diseases has prompted many researchers to apply new technologies in high-throughput screening and molecular modelling to the design of antiviral drugs that target RNA. While the two RNA viruses with the greatest unmet medical need, HIV and HCV, have been most actively pursued, the approaches discussed in this review are relevant to all virus infections. Both traditional small-molecule and large-molecule therapeutics, such as antisense, ribozymes and interfering dsRNAs have been described, and several molecules are under development for commercialization. The purpose of this review is to summarize the current state of the art in this field and to postulate new directions in the future.
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MESH Headings
- Antiviral Agents/therapeutic use
- Base Sequence
- Drug Design
- Humans
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation
- Oligonucleotides, Antisense/genetics
- Oligonucleotides, Antisense/therapeutic use
- RNA, Antisense/genetics
- RNA, Antisense/therapeutic use
- RNA, Catalytic/genetics
- RNA, Catalytic/therapeutic use
- RNA, Viral/chemistry
- RNA, Viral/drug effects
- RNA, Viral/genetics
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Affiliation(s)
- Kevin L McKnight
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Ind., USA.
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31
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Takyar SS, Gowans EJ, Lott WB. Vitamin B12 stalls the 80 S ribosomal complex on the hepatitis C internal ribosome entry site. J Mol Biol 2002; 319:1-8. [PMID: 12051931 DOI: 10.1016/s0022-2836(02)00300-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of cyanocobalamin (CNCbl, vitamin B12) on hepatitis C virus internal ribosome entry site (HCV IRES)-dependent initiation of translation was studied by ribosomal toeprinting and sucrose gradient centrifugation analysis. These results suggested that CNCbl did not inhibit HCV IRES-dependent translation by a competitive binding mechanism. CNCbl allowed 80 S elongation complex formation on the mRNA, but stalled the initiation at that point, effectively trapping the 80 S ribosomal complexes on the HCV IRES. CNCbl had no effect on cap-dependent mRNA, consistent with the known mRNA specificity of this translational inhibitor. To help elucidate the mechanism, comparative data were collected for the well-characterised translation inhibitors cycloheximide and 5'-guanylyl-imidophosphate. Although CNCbl stalled HCV IRES-dependent translation at approximately the same step in initiation as cycloheximide, the mechanisms of these two inhibitors are distinct.
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Affiliation(s)
- Seyedtaghi S Takyar
- Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Herston, Qld 4029, Australia
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32
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Harvey I, Garneau P, Pelletier J. Inhibition of translation by RNA-small molecule interactions. RNA (NEW YORK, N.Y.) 2002; 8:452-63. [PMID: 11991640 PMCID: PMC1370268 DOI: 10.1017/s135583820202633x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Small molecule ligand-RNA interactions have the potential to influence gene expression at a variety of steps and in a number of ways. Here, we demonstrate that such interactions are sufficiently stable to inhibit translation of eukaryotic mRNAs in vitro and in vivo. Inhibition is only observed when the 5' UTR of the mRNA is targeted, and the response is proportional to the number of binding sites within this region. We find that small molecule ligand-RNA interactions can be sufficiently stable to prevent 80S ribosome assembly on an mRNA template. The ability to specifically ablate expression of a defined mRNA with a small molecule ligand demonstrates proof of principle for pharmacological targeting aimed at controlling translation of specific mRNAs.
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Affiliation(s)
- Isabelle Harvey
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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