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1.
bioRxiv ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38712097

RESUMO

Upon antigenic stimulation, CD4 + T-cells undergo clonal expansion, elevating their bioenergetic demands and utilization of nutrients like glucose and glutamine. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a well-known regulator of oxidative stress, but its involvement in modulating the metabolism of CD4 + T-cells remains unexplored. Here, we elucidate the role of Nrf2 beyond the traditional antioxidation, in modulating activation-driven expansion of CD4 + T-cells by influencing their nutrient metabolism. T-cell-specific activation of Nrf2 enhances early activation and IL-2 secretion, upregulates TCR-signaling, and increases activation-driven proliferation of CD4 + T-cells. Mechanistically, high Nrf2 inhibits glucose metabolism through glycolysis but promotes glutamine metabolism via glutaminolysis to support increased T-cell proliferation. Further, Nrf2 expression is temporally regulated in activated CD4 + T-cells with elevated expression during the early activation, but decreased expression thereafter. Overall, our findings uncover a novel role of Nrf2 as a metabolic modulator of CD4 + T-cells, thus providing a framework for improving Nrf2-targeting therapies and T-cell immunotherapies.

2.
Antiviral Res ; 216: 105651, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37270160

RESUMO

Many poxviruses are significant human and animal pathogens, including viruses that cause smallpox and mpox (formerly monkeypox). Identifying novel and potent antiviral compounds is critical to successful drug development targeting poxviruses. Here we tested two compounds, nucleoside trifluridine, and nucleotide adefovir dipivoxil, for antiviral activities against vaccinia virus (VACV), mpox virus (MPXV), and cowpox virus (CPXV) in physiologically relevant primary human fibroblasts. Both compounds potently inhibited the replication of VACV, CPXV, and MPXV (MA001 2022 isolate) in plaque assays. In our recently developed assay based on a recombinant VACV expressing secreted Gaussia luciferase, they both exhibited high potency in inhibiting VACV replication with EC50s in the low nanomolar range. In addition, both trifluridine and adefovir dipivoxil inhibited VACV DNA replication and downstream viral gene expression. Our results characterized trifluridine and adefovir dipivoxil as strong poxvirus antiviral compounds and further validate the VACV Gaussia luciferase assay as a highly efficient and reliable reporter tool for identifying poxvirus inhibitors. Given that both compounds are FDA-approved drugs, and trifluridine is already used to treat ocular vaccinia, further development of trifluridine and adefovir dipivoxil holds great promise in treating poxvirus infections, including mpox.


Assuntos
Mpox , Poxviridae , Vacínia , Animais , Humanos , Vaccinia virus/fisiologia , Vacínia/tratamento farmacológico , Vírus da Varíola Bovina , Antivirais/farmacologia , Antivirais/metabolismo , Trifluridina/metabolismo , Linhagem Celular , Poxviridae/metabolismo
3.
Immunohorizons ; 7(4): 288-298, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37099275

RESUMO

Ubiquitously expressed in mammalian cells, the Kelch-like ECH-associated protein 1 (Keap1)-NF erythroid 2-related factor 2 (Nrf2) complex forms the evolutionarily conserved antioxidation system to tackle oxidative stress caused by reactive oxygen species. Reactive oxygen species, generated as byproducts of cellular metabolism, were identified as essential second messengers for T cell signaling, activation, and effector responses. Apart from its traditional role as an antioxidant, a growing body of evidence indicates that Nrf2, tightly regulated by Keap1, modulates immune responses and regulates cellular metabolism. Newer functions of Keap1 and Nrf2 in immune cell activation and function, as well as their role in inflammatory diseases such as sepsis, inflammatory bowel disease, and multiple sclerosis, are emerging. In this review, we highlight recent findings about the influence of Keap1 and Nrf2 in the development and effector functions of adaptive immune cells, that is, T cells and B cells, and discuss the knowledge gaps in our understanding. We also summarize the research potential and targetability of Nrf2 for treating immune pathologies.


Assuntos
Antioxidantes , Fator 2 Relacionado a NF-E2 , Animais , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Mamíferos/metabolismo
4.
bioRxiv ; 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36993701

RESUMO

Many poxviruses are significant human and animal pathogens, including viruses that cause smallpox and mpox. Identification of inhibitors of poxvirus replication is critical for drug development to manage poxvirus threats. Here we tested two compounds, nucleoside trifluridine and nucleotide adefovir dipivoxil, for antiviral activities against vaccinia virus (VACV) and mpox virus (MPXV) in physiologically relevant primary human fibroblasts. Both trifluridine and adefovir dipivoxil potently inhibited replication of VACV and MPXV (MA001 2022 isolate) in a plaque assay. Upon further characterization, they both conferred high potency in inhibiting VACV replication with half maximal effective concentrations (EC 50 ) at low nanomolar levels in our recently developed assay based on a recombinant VACV secreted Gaussia luciferase. Our results further validated that the recombinant VACV with Gaussia luciferase secretion is a highly reliable, rapid, non-disruptive, and simple reporter tool for identification and chracterization of poxvirus inhibitors. Both compounds inhibited VACV DNA replication and downstream viral gene expression. Given that both compounds are FDA-approved drugs, and trifluridine is used to treat ocular vaccinia in medical practice due to its antiviral activity, our results suggest that it holds great promise to further test trifluridine and adefovir dipivoxil for countering poxvirus infection, including mpox.

5.
Microbiol Spectr ; 11(1): e0194322, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36537798

RESUMO

We utilized a high-throughput cell-based assay to screen several chemical libraries for inhibitors of herpes simplex virus 1 (HSV-1) gene expression. From this screen, four aurora kinase inhibitors were identified that potently reduced gene expression during HSV-1 lytic infection. HSV-1 is known to interact with cellular kinases to regulate gene expression by modulating the phosphorylation and/or activities of viral and cellular proteins. To date, the role of aurora kinases in HSV-1 lytic infection has not been reported. We demonstrated that three aurora kinase inhibitors strongly reduced the transcript levels of immediate-early (IE) genes ICP0, ICP4, and ICP27 and impaired HSV-1 protein expression from all classes of HSV-1, including ICP0, ICP4, ICP8, and gC. These restrictions caused by the aurora kinase inhibitors led to potent reductions in HSV-1 viral replication. The compounds TAK 901, JNJ 7706621, and PF 03814735 decreased HSV-1 titers by 4,500-, 13,200-, and 8,400-fold, respectively, when present in a low micromolar range. The antiviral activity of these compounds correlated with an apparent decrease in histone H3 phosphorylation at serine 10 (H3S10ph) during viral infection, suggesting that the phosphorylation status of H3 influences HSV-1 gene expression. Furthermore, we demonstrated that the aurora kinase inhibitors also impaired the replication of other RNA and DNA viruses. These inhibitors significantly reduced yields of vaccinia virus (a poxvirus, double-stranded DNA, cytoplasmic replication) and mouse hepatitis virus (a coronavirus, positive-sense single-strand RNA [ssRNA]), whereas vesicular stomatitis virus (rhabdovirus, negative-sense ssRNA) yields were unaffected. These results indicated that the activities of aurora kinases play pivotal roles in the life cycles of diverse viruses. IMPORTANCE We have demonstrated that aurora kinases play a role during HSV-1 lytic infection. Three aurora kinase inhibitors significantly impaired HSV-1 immediate-early gene expression. This led to a potent reduction in HSV-1 protein expression and viral replication. Together, our results illustrate a novel role for aurora kinases in the HSV-1 lytic cycle and demonstrate that aurora kinase inhibitors can restrict HSV-1 replication. Furthermore, these aurora kinase inhibitors also reduced the replication of murine coronavirus and vaccinia virus, suggesting that multiple viral families utilize the aurora kinases for their own replication.


Assuntos
Herpes Simples , Herpesvirus Humano 1 , Proteínas Imediatamente Precoces , Vírus de RNA , Animais , Camundongos , Herpesvirus Humano 1/genética , Proteínas Imediatamente Precoces/genética , Proteínas Virais/genética , Proteínas Virais/metabolismo , Linhagem Celular , Herpes Simples/genética , DNA/metabolismo , RNA/metabolismo , Estágios do Ciclo de Vida
6.
PLoS One ; 17(10): e0276172, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36301960

RESUMO

BACKGROUND: Glomerular diseases are important causes of morbidity and mortality among children in developing countries. Renal biopsy is the gold standard for determining histological diagnosis, prognosis, and therapy options. This study aimed to investigate the clinical, histopathological, and direct immunofluorescence findings of renal biopsy results in Nepalese children under 18 years old. METHODS: In this retrospective cross-sectional study, the available data from children who had undergone kidney biopsy between 2016 and the end of 2020 were evaluated. Demographic data, indications of biopsy, histopathologic findings, and direct immunofluorescence findings were collected and presented. RESULTS: The mean age of the patients was 12.14 ± 4.07 years. Male/female ratio was 1:1. The majority of biopsy cases were aged between 11-15 years of age. The most common indication for biopsy in children was nephrotic syndrome (68.25%). Lupus nephritis with 28 cases (22.22%) had the highest frequency in overall renal biopsies. Minimal change disease (MCD) with 22 cases (17.46%) followed by Ig A nephropathy with 16 cases (12.69%) were the most frequent primary glomerulonephritis. Lupus nephritis showed full house positivity, and MCD showed full house negativity in all Direct immunofluorescence (DIF) parameters, whereas immunoglobulin A nephropathy showed 100% positivity in Ig A in DIF. CONCLUSIONS: Nephrotic syndrome was the most common indication for renal biopsy. The most common primary glomerulonephritis was MCD, while secondary glomerulonephritis was lupus nephritis. Clinical data, light microscopy, and direct DIF played an integral role in the overall final diagnosis.


Assuntos
Glomerulonefrite por IGA , Glomerulonefrite , Nefropatias , Nefrite Lúpica , Nefrose Lipoide , Síndrome Nefrótica , Criança , Humanos , Feminino , Masculino , Adolescente , Síndrome Nefrótica/patologia , Rim/patologia , Nefrite Lúpica/patologia , Estudos Retrospectivos , Estudos Transversais , Nepal , Nefropatias/diagnóstico , Nefropatias/patologia , Nefrose Lipoide/patologia , Glomerulonefrite/patologia , Biópsia/métodos , Glomerulonefrite por IGA/patologia
7.
Egypt Heart J ; 74(1): 39, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35575838

RESUMO

BACKGROUND: Pericardial cysts are rare, with the most common etiology being congenital. Ventricular septal defect is the most common congenital heart disease in children. However, the combination of pericardial cyst, ventricular septal defect, and patent ductus arteriosus is extremely rare. CASE PRESENTATION: A one-year-old boy with ventricular septal defect and patent ductus arteriosus was planned for surgical correction. Intraoperatively, we made an additional diagnosis of a large pericardial cyst; and the cyst was excised along with ventricular septal defect closure and patent ductus arteriosus ligation. CONCLUSIONS: Pericardial cysts can sometimes be missed with transthoracic echocardiography. Excision of the cyst can safely be done during concomitant cardiac surgery.

8.
Braz. J. Pharm. Sci. (Online) ; 58: e201209, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1420457

RESUMO

Abstract The present study describes chemical composition, phytochemicals, antifungal activities, antioxidant assays and total phenolic content of essential oil and varied polarity solvent extract from flowers of Alpinia malaccensis (Burm.f.). Total 27 components were identified in essential oil by GC-MS with terpinen-4-ol (28.6%) and α- terpineol (12.8%) as the main constituent. The essential oil was found to have maximal levels of phenolic content (64.60 µg/mL) as compared to the other extracts. The antioxidant assay evaluated in extracts and essential oil by different methods revealed good-to-moderate antioxidant potential with different IC50 values viz. (188.02 -250.25 µg/mL) in Fe3+ reducing power, (153.15-201.59 µg/mL) in Fe2+ metal-chelating ability, (130.39-181.12 µg/mL) in DPPH, (88.29-187.32 µg/mL) in OH radical, (79.04-156.79 µg/mL), in NO radical and (138.72-233.00 µg/mL) in superoxide anion scavenging activities, respectively. The methanolic extract display remarkable fungicidal activity against the tested pathogens followed by dichloromethane extract, essential oil, hexane extract and petroleum ether extract respectively, with MIC values ranging from 31.25 to 500 µg/mL. Based on results, it can be inferred that the flower of A. malaccensis if explored further for its medicinal properties, might be a good source to develop a safe and sustainable natural food preservative


Assuntos
Óleos Voláteis/análise , Extratos Vegetais/análise , Flores/classificação , Alpinia/efeitos adversos , Antifúngicos/farmacologia , Antioxidantes/farmacologia
9.
Braz. J. Pharm. Sci. (Online) ; 58: e201031, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1420397

RESUMO

Abstract This study was aimed to explore the chemical composition and biological activities of essential oil from aerial part of Mosla dianthera along with its major isolated compound, carvone. The hydro-distilled essential oil was analysed by GC-MS and biological activities were investigated in terms of antioxidant, anti-inflammatory, herbicidal, antibacterial, anti-fungal and anti-feedant properties. GC-MS analysis led to the identification of forty-nine components contributing 96.2% of essential oil with carvone (41.9%) as the most abundant constituent. The oil and carvone showed good to moderate antioxidant potentials determined by radical scavenging, reducing power and metal chelating activities. Carvone showed good anti-inflammatory activity (78.0%) compared to essential oil (74.2%). Both essential oil and carvone exhibited excellent herbicidal activity against Raphanus raphanistrum subsp. sativus seeds. The essential oil and carvone showed significant anti-bacterial efficacy against Bacillus cereus and Escherichia coli. It was observed that essential oil showed strong antifungal property than carvone against Alternaria alternata and Curvularia lunata. Both the samples exhibited anti-feedant activity in a dose dependent manner against third instar larvae of Spilosoma obliqua. Results obtained revealed the possible applications of essential oil and carvone as a bioactive source of natural antioxidants, excellent herbicide and an effective substance for antifungal and antifeedant activities.

10.
mBio ; 12(5): e0063521, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34517756

RESUMO

Cellular activities are finely regulated by numerous signaling pathways to support specific functions of complex life processes. Viruses are obligate intracellular parasites. Each step of viral replication is ultimately governed by the interaction of a virus with its host cells. Because of the demands of viral replication, the nutritional needs of virus-infected cells differ from those of uninfected cells. To improve their chances of survival and replication, viruses have evolved to commandeer cellular processes, including cell metabolism, augmenting these processes to support their needs. This article summarizes recent findings regarding virus-induced alterations to major cellular metabolic pathways focusing on how viruses modulate various signaling cascades to induce these changes. We begin with a general introduction describing the role played by signaling pathways in cellular metabolism. We then discuss how different viruses target these signaling pathways to reprogram host metabolism to favor the viral needs. We highlight the gaps in understanding metabolism-related virus-host interactions and discuss how studying these changes will enhance our understanding of fundamental processes involved in metabolic regulation. Finally, we discuss the potential to harness these processes to combat viral diseases, as well as other diseases, including metabolic disorders and cancers.


Assuntos
Interações entre Hospedeiro e Microrganismos , Interações Hospedeiro-Patógeno/fisiologia , Viroses/virologia , Vírus/metabolismo , Animais , Humanos , Redes e Vias Metabólicas , Camundongos , Transdução de Sinais , Replicação Viral
11.
PLoS Pathog ; 17(2): e1009303, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33529218

RESUMO

Metabolism is a crucial frontier of host-virus interaction as viruses rely on their host cells to provide nutrients and energy for propagation. Vaccinia virus (VACV) is the prototype poxvirus. It makes intensive demands for energy and macromolecules in order to build hundreds and thousands of viral particles in a single cell within hours of infection. Our comprehensive metabolic profiling reveals profound reprogramming of cellular metabolism by VACV infection, including increased levels of the intermediates of the tri-carboxylic acid (TCA) cycle independent of glutaminolysis. By investigating the level of citrate, the first metabolite of the TCA cycle, we demonstrate that the elevation of citrate depends on VACV-encoded viral growth factor (VGF), a viral homolog of cellular epidermal growth factor. Further, the upregulation of citrate is dependent on STAT3 signaling, which is activated non-canonically at the serine727 upon VACV infection. The STAT3 activation is dependent on VGF, and VGF-dependent EGFR and MAPK signaling. Together, our study reveals a novel mechanism by which VACV manipulates cellular metabolism through a specific viral factor and by selectively activating a series of cellular signaling pathways.


Assuntos
Citratos/metabolismo , Ciclo do Ácido Cítrico , Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fator de Transcrição STAT3/metabolismo , Vaccinia virus/fisiologia , Vacínia/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Fibroblastos/virologia , Interações Hospedeiro-Patógeno , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Sistema de Sinalização das MAP Quinases , Metaboloma , Fosforilação , Fator de Transcrição STAT3/genética , Transdução de Sinais , Vacínia/virologia
12.
Viral Immunol ; 34(1): 41-48, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33074779

RESUMO

Nucleocytoplasmic large DNA viruses (NCLDVs) are a group of large viruses that infect a wide range of hosts, from animals to protists. These viruses are grouped together in NCLDV based on genomic sequence analyses. They share a set of essential genes for virion morphogenesis and replication. Most NCLDVs generally have large physical sizes while their morphologies vary in different families, such as icosahedral, brick, or oval shape, raising the question of the possible regulatory factor on their morphogenesis. The capsids of icosahedral NCLDVs are assembled from small building blocks, named capsomers, which are the trimeric form of the major capsid proteins. Note that the capsids of immature poxvirus are spherical even though they are assembled from capsomers that share high structural conservation with those icosahedral NCLDVs. The recently published high resolution structure of NCLDVs, Paramecium bursaria Chlorella virus 1 and African swine fever virus, described the intensive network of minor capsid proteins that are located underneath the capsomers. Among these minor proteins is the elongated tape measure protein (TmP) that spans from one icosahedral fivefold vertex to another. In this study, we focused on the critical roles that TmP plays in the assembly of icosahedral NCLDV capsids, answering a question raised in a previously proposed spiral mechanism. Interestingly, basic local alignment search on the TmPs showed no significant hits in poxviruses, which might be the factor that differentiates poxviruses and icosahedral NCLDVs in their morphogenesis.


Assuntos
Proteínas do Capsídeo/metabolismo , Capsídeo/química , Capsídeo/metabolismo , Vírus de DNA/química , Vírus de DNA/metabolismo , Montagem de Vírus , Vírus da Febre Suína Africana/química , Vírus da Febre Suína Africana/metabolismo , Animais , Chlorella/virologia , Suínos
13.
Braz. arch. biol. technol ; 64: e21210186, 2021. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1355819

RESUMO

Abstract The essential oils from the fresh leaves of three Melalecua spp. viz; Melaleuca leucadendron (L.) Melaleuca linariifolia Sm. and Melaleuca bracteata F. Muell. growing in Tarai region of North India were analyzed by a combination of gas chromatography/mass spectrometry. The analysis revealed the presence of several constituents of industrial and pharmacological importance. M. leucadendron essential oil was found to be dominated by E-nerolidol (85.7%) rich chemotype. 1,8-cineole (61.1%) along with significant presence of α-terpineol (12.3%), α-pinene (4.0%), β-myrcene (3.8%), and E-caryophyllene (1.7%) were identified in the essential oil from M. linariifolia Similarly M. bracteata was dominated by the presence of phenylpropanoids viz; methyl eugenol (74.8%) and methyl cinnamate (8.0%). The essential oils were studied for their in-vitro antioxidant, anti-inflammatory and antimicrobial potential. All the oils revealed potential antioxidant activity with maximum in M. bracteata essential oil. All the oils exhibited significant antibacterial activity against Bacillus megaterium, Staphylococcus aureus, Escherichia coli,Salmonella typhimurium and anti-fungal activity against phytopathogenic fungi Fusarium oxysporum, Sclerotinia sclerotiorum, Exserohilum turcicum and Curvularia lunata. The observations from present study suggest further cultivation of Melaleucas and its commercialization as industrial crops.

14.
ACS Infect Dis ; 6(9): 2301-2303, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32786295

RESUMO

Asparagine biosynthesis and breakdown are tightly regulated in mammalian cells. Recent studies indicate that asparagine supply could be a limiting factor for the replication of some viruses such as vaccinia virus and human cytomegalovirus. In this Viewpoint, we highlight the importance of asparagine metabolism during virus replication and rationalize that asparagine metabolism could be a viable target for broad-spectrum antiviral development. To achieve this goal, more studies into asparagine metabolism during viral infections are demanded. These efforts would benefit beyond viral diseases, as asparagine supply is also a limiting factor in various stages of cancer development.


Assuntos
Asparagina , Vírus , Animais , Antivirais , Citomegalovirus , Humanos , Replicação Viral
15.
Vaccines (Basel) ; 8(3)2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708182

RESUMO

Four decades after the eradication of smallpox, poxviruses continue to threaten the health of humans and other animals. Vaccinia virus (VACV) was used as the vaccine that successfully eradicated smallpox and is a prototypic member of the poxvirus family. Many cellular pathways play critical roles in productive poxvirus replication. These pathways provide opportunities to expand the arsenal of poxvirus antiviral development by targeting the cellular functions required for efficient poxvirus replication. In this study, we developed and optimized a secreted Gaussia luciferase-based, simplified assay procedure suitable for high throughput screening. Using this procedure, we screened a customized compound library that contained over 3200 bioactives and FDA (Food and Drug Administration)-approved chemicals, most having known cellular targets, for their inhibitory effects on VACV replication. We identified over 140 compounds that suppressed VACV replication. Many of these hits target cellular pathways previously reported to be required for efficient VACV replication, validating the effectiveness of our screening. Importantly, we also identified hits that target cellular functions with previously unknown roles in the VACV replication cycle. Among those in the latter category, we verified the antiviral role of several compounds targeting the janus kinase/signal transducer and activator of transcription-3 (JAK/STAT3) signaling pathway by showing that STAT3 inhibitors reduced VACV replication. Our findings identify pathways that are candidates for use in the prevention and treatment of poxvirus infections and additionally provide a foundation to investigate diverse cellular pathways for their roles in poxvirus replications.

16.
Case Rep Crit Care ; 2020: 8857058, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33425398

RESUMO

BACKGROUND: Severe complications of acute appendicitis (AA) hitherto well described are less common in clinical practice nowadays. When a septic child is encountered with a short history of abdominal symptoms and disproportionate signs of peritonitis further complicated by radiological findings causing a diagnostic conundrum, management becomes exceedingly demanding. Case Presentation. A 10-year-old previously healthy boy presented to the emergency room with generalized abdominal pain associated with fever and jaundice for a day. Blood workup revealed leucopenia, hyperbilirubinemia, hyponatremia, and elevated CRP. Initial radiological evaluation suggested hollow viscous perforation. He was diagnosed to have hollow viscous perforation peritonitis in severe sepsis. At laparotomy, generalized peritoneal contamination was found, the source of which could be traced down to the gangrenous perforated appendix. CONCLUSION: Complicated appendicitis, in children, can present with baffling findings. Timely identification of an ill child, adequate workup, prompt resuscitation, and source control are imperative for a successful outcome.

17.
J Virol ; 93(13)2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30996100

RESUMO

Viruses actively interact with host metabolism because viral replication relies on host cells to provide nutrients and energy. Vaccinia virus (VACV; the prototype poxvirus) prefers glutamine to glucose for efficient replication to the extent that VACV replication is hindered in glutamine-free medium. Remarkably, our data show that VACV replication can be fully rescued from glutamine depletion by asparagine supplementation. By global metabolic profiling, as well as genetic and chemical manipulation of the asparagine supply, we provide evidence demonstrating that the production of asparagine, which exclusively requires glutamine for biosynthesis, accounts for VACV's preference of glutamine to glucose rather than glutamine's superiority over glucose in feeding the tricarboxylic acid (TCA) cycle. Furthermore, we show that sufficient asparagine supply is required for efficient VACV protein synthesis. Our study highlights that the asparagine supply, the regulation of which has been evolutionarily tailored in mammalian cells, presents a critical barrier to VACV replication due to a high asparagine content of viral proteins and a rapid demand of viral protein synthesis. The identification of asparagine availability as a critical limiting factor for efficient VACV replication suggests a new direction of antiviral strategy development.IMPORTANCE Viruses rely on their infected host cells to provide nutrients and energy for replication. Vaccinia virus, the prototypic member of the poxviruses, which comprise many significant human and animal pathogens, prefers glutamine to glucose for efficient replication. Here, we show that the preference is not because glutamine is superior to glucose as the carbon source to fuel the tricarboxylic acid cycle for vaccinia virus replication. Rather interestingly, the preference is because the asparagine supply for efficient viral protein synthesis becomes limited in the absence of glutamine, which is necessary for asparagine biosynthesis. We provide further genetic and chemical evidence to demonstrate that asparagine availability plays a critical role in efficient vaccinia virus replication. This discovery identifies a weakness of vaccinia virus and suggests a possible direction to intervene in poxvirus infection.


Assuntos
Asparagina/metabolismo , Glutamina/metabolismo , Vaccinia virus/metabolismo , Vacínia/virologia , Animais , Antivirais , Linhagem Celular , Humanos , Metaboloma , Poxviridae , Biossíntese de Proteínas , Proteínas Virais/metabolismo , Replicação Viral
18.
Front Microbiol ; 8: 2196, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29204136

RESUMO

Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV), the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression.

19.
Medicines (Basel) ; 4(4)2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-29117116

RESUMO

Background:Acorus calamus (Sweet flag) is a known herbal drug commonly used in traditional medicine. Our aim was to perform seasonal and altitudinal phytochemical screening to assess the antioxidant activity of the essential oils in the rhizome and leaves of A. calamus from three different altitudes. Methods: Phytochemical screening was performed using GC/MS analysis and in vitro antioxidant assay was done by different methods. Results: The essential oils mainly contained α-asarone, ß-asarone (35.3-90.6%), and Z-isoelemicin (1.7-7.3%) as the major constituents, besides linalool, Z-methyl isoeugenol, shyobunone, kessane, etc. All the oils exhibited vast molecular diversity in terms of quantitative ingredients. All essential oils were studied for their antioxidant activity by different methods, including their effect on the DPPH radical-scavenging activity, reducing power, and chelating properties of Fe2+. The oils isolated in all the different seasons exhibited antioxidant activity as a function of concentration, with IC50 values ranging from 475.48 ± 0.08 to 11.72 ± 0.03 compared to standards. Conclusion : From the results obtained it can be inferred that the herb may be a good source of bioactive compounds and can work as an antioxidant to prevent oxidative deterioration in food. The data provide a basis for its in-situ investigation for judicious exploitation.

20.
Medicines (Basel) ; 4(3)2017 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-28930267

RESUMO

Background:Callicarpa macrophylla (Varbenaceae) is a medicinal shrub and is traditionally used in India, China, and South Asia. Methods: The plant material was collected from lower Himalayan region of Uttarakhand in India. The essential oils from three different aerial parts were analyzed by GC-MS. Antioxidant activity, phenolic assay, and various pharmacological activities were determined by using existing methods which are generally practiced widely. Results: Over 51, 53, and 40 compounds were identified in C. macrophylla leaves essential oil (CMLEO), C. macrophylla pre mature seeds and fruits essential oil (CMEO-I) and C.macrophylla mature seeds and fruits essential oil (CMEO-II), respectively. These oils differ in relative contents of major compounds viz; ß-selinene (37.51% in CMLEO, 44.66% in CMEO-I and 57.01% in CMEO-II), phyllocladene (9.76% in CMLEO, 5.80% in CMEO-I and 12.38% in CMEO-II), caryophelline oxide (7.34% in CMLEO, 8.74% in CMEO-I and 5.0% in CMEO-II), 9E-epi-caryophelline (6.23% in CMLEO, 1.27% in CMEO-I and 3.43% in CMEO-II), longipinocarvone (4.96% in CMLEO, 1.17% in CMEO-I and 2.0% in CMEO-II), and 1,8-cineole (2.23% in CMLEO, 3.10% in CMEO-I and 1.62% in CMEO-II). The oils exhibited good in vitro antioxidant activity. The maximum activity was found in CMEO-II with IC50 values 7.37 ± 0.11, 11.49 ± 0.87, 14.59 ± 0.18, 15.66 ± 0.03, and 17.49 ± 0.13 µl/mL. The essential oils showed qualitative and quantitative diversity in the makeup of essential oils constituents. The oils were found to exhibit anti-inflammatory, analgesic, and antipyretic activity on swiss albino mice compared to the standard drugs, viz; ibuprofen, paracetamol and indomethacin. Conclusion: It is inferred from the study that the plant parts can be used scientifically in traditional systems as folk herbal medicine. Furthermore, we have generated a database for future reference and judicious exploitation of these oils from their natural setting.

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