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1.
J Family Med Prim Care ; 11(8): 4635-4643, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36352929

RESUMO

Introduction: Brucellosis is one of the most common zoonosis diseases in developing and undeveloped countries, with adverse socio-economic status and animal and human health. The essential element for effective prevention and control of brucellosis is to improve the community's Knowledge, Attitude, and Practice (KAP) through Health Education Intervention (HEI). Aim: To assess health education intervention's effect on promoting knowledge, beliefs, and preventive behaviors on brucellosis among rural populations in Nagpur district, Maharashtra, India. Methods and Materials: 382 subjects over 18 years with a history of animal contact or consuming animal products were randomly selected. Data were collected through questionnaires and checklists. The pre-test was implemented and followed by HEI. The post-test was conducted after 45 to 60 days. For the attitude five-point Likert scale and knowledge and practice, a two-point assessment scale [yes, no] was applied. SPSS was used to analyze paired t-test, and P < 0.05 was considered significant. Result: Of 382 subjects, 300 (78.5%) were male, and the mean age of 42.15 ± 13.72. Before HEI, 18 (5%) subjects heard about brucellosis. After HEI, reduction in the risk behaviors practices like raw milk consumption (P < 0.0001), assisted animal delivery without gown (P = 0.002), throwing animal birth products in the dustbin (P < 0.0001) were statistically significant. After implementing HEI, subjects were more aware of animal and human brucellosis signs/symptoms (P < 0.0001). Awareness of disease transmission route (P < 0.0001) and up-gradation in knowledge (P < 0.0001) were statistically significant among subjects after HEI. Conclusions: HEI substantially affects KAP and changes community behaviors to prevent brucellosis transmission. The authors recommend implementing HEI in the community to prevent brucellosis.

2.
J Family Med Prim Care ; 10(2): 1028-1033, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34041116

RESUMO

INTRODUCTION: Brucellosis is a recognised occupational threat among animal handler and raw animal product consumers. In India, there is a likelihood of missed diagnoses and under-reporting cases by physicians causing an extended debilitating illness. We steered research to conclude the seroprevalence and risk factors allied with Human Brucellosis (HB) among the rural population in Nagpur District, Maharashtra, India. METHODS: Closed-ended questionnaires used for a cross-sectional study to collect data for demographics and risk exposure variables. 382 subjects' serum-samples were tested by using Rose-Bengal (RBPT) and ELISA technique. An odd ratio calculated for risk factors for HB reported positive or negative. Data were analysed by using SPSS. RESULTS: The brucellosis seroprevalence in rural Nagpur was 1.83%. The mean age was 42.32 years, 78.5% were male, and 21.5% were female. Prevalence was higher among males [85.7%] than females [14.3%]. The risk for brucellosis among males (OR = 1.65, 95% CI = 0.19-13.92, P = 0.64) was more than females. Handling raw meat had more risk (OR = 3.14, 95% CI = 0.40 - 28.6, P = 0.23) than those not handling raw meat. Milking animal was protective (OR = 0.88, 95% CI = 0.80 - 0.96, P < 0.001) for brucellosis than those not milking animal. Subjects reported more likely to be a seropositive to human brucellosis those involved in assisted animal delivery (P = 0.001), drinking unpasteurised milk (P<0.001), consuming milk products made from raw milk (P<0.001) and eating raw meat (P = 0.001). CONCLUSION: Health education program is essential to generate awareness for brucellosis in the rural community to prevent animal to human disease transmission.

3.
Nanoscale ; 10(39): 18451-18456, 2018 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-30270375

RESUMO

A liquid can be heated up above its boiling point, known as superheating. In this metastable state, the liquid temperature keeps increasing as the liquid is being heated. In contrast, we experimentally demonstrate that the temperature of superheated water can be kept constant even at elevated heating power. Water heating is done by the photothermal conversion of plasmonic titanium nitride nanostructures on a sapphire substrate under the illumination of continuous wave laser irradiation. The temperature-constant superheating is also observed for ethylene glycol and 2-acetoxy-1-methoxypropane, and is attributed to the high thermal conductivity of the substrate. This unique superheating yet achieved by a simple method can be useful in optical trapping and various optical heating applications.

4.
J Cell Physiol ; 232(3): 517-525, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27249540

RESUMO

Identification of cellular proteins, in addition to already known transcription factors such as NF-κB, Sp1, C-EBPß, NFAT, ATF/CREB, and LEF-1, which interact with the HIV-1 LTR, is critical in understanding the mechanism of HIV-1 replication in monocytes/macrophages. Our studies demonstrate upregulation of pyruvate kinase isoform M2 (PKM2) expression during HIV-1SF162 infection of monocyte/macrophages and reactivation of HIV-1 in U1 cells, a macrophage model of latency. We observed that HIV-1SF162 infection of monocyte/macrophages and reactivation of HIV-1 in U1 cells by PMA resulted in increased levels of nuclear PKM2 compared to PMA-induced U937 cells. Furthermore, there was a significant increase in the nuclear dimeric form of PKM2 in the PMA-induced U1 cells in comparison to PMA-induced U937 cells. We focused on understanding the potential role of PKM2 in HIV-1 LTR transactivation. Chromatin immunoprecipitation (ChIP) analysis in PMA-activated U1 and TZM-bl cells demonstrated the interaction of PKM2 with the HIV-1 LTR. Our studies show that overexpression of PKM2 results in transactivation of HIV-1 LTR-luciferase reporter in U937, U-87 MG, and TZM-bl cells. Using various truncated constructs of the HIV-1 LTR, we mapped the region spanning -120 bp to -80 bp to be essential for PKM2-mediated transactivation. This region contains the NF-κB binding site and deletion of this site attenuated PKM2-mediated activation of HIV-1 LTR. Immunoprecipitation experiments using U1 cell lysates demonstrated a physical interaction between PKM2 and the p65 subunit of NF-κB. These observations demonstrate for the first time that PKM2 is a transcriptional co-activator of HIV-1 LTR. J. Cell. Physiol. 232: 517-525, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteínas de Transporte/metabolismo , Repetição Terminal Longa de HIV/genética , HIV-1/genética , Proteínas de Membrana/metabolismo , Hormônios Tireóideos/metabolismo , Sítios de Ligação , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , HIV-1/efeitos dos fármacos , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Modelos Biológicos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Subunidades Proteicas/metabolismo , Transporte Proteico/efeitos dos fármacos , Deleção de Sequência , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição RelA/metabolismo , Células U937 , Replicação Viral/efeitos dos fármacos , Proteínas de Ligação a Hormônio da Tireoide
5.
Infect Dis Poverty ; 5(1): 112, 2016 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-27955687

RESUMO

BACKGROUND: Intestinal schistosomiasis due to Schistosoma mansoni was first reported in Oman in 1979. We describe the trend in parasitological and serological prevalence of human infection with S. mansoni in the endemic area over the period 1982-2014, and the compliance of data generated by the national monitoring and evaluation system with schistosomiasis elimination criteria set by the Ministry of Health of Oman. METHODS: Parasitological and serological assessments were carried out on population (mainly children) living in the area at risk for schistosomiasis in Dhofar, the country's only endemic Governorate, for a period of over 30 years. Kato-Katz thick smear and Indirect Haemagglutination Assay were the techniques employed. RESULTS: Data indicate a progressive decline in prevalence of S. mansoni throughout the 1980s and the 1990s, a recrudescence in the early 2000s, and a more marked decrease following the implementation of six rounds of mass treatment with praziquantel from 2007 to 2013. Latest parasitological prevalence (2011) was 0%, while latest serological prevalence (2014) was 0.11%. CONCLUSION: Transmission of schistosomiasis has reached very low levels in Oman. Elimination criteria established by the Ministry of Health of Oman (parasitological prevalence ≤ 1% and serological prevalence ≤ 5%) have been met since 2008. Further investigations are required to assess whether interruption of transmission has been achieved in some or all foci, in view of the establishment of a formal verification process under the auspices of WHO.


Assuntos
Praziquantel/uso terapêutico , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Adolescente , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Criança , Humanos , Omã/epidemiologia , Praziquantel/farmacologia , Prevalência , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/transmissão , Estudos Soroepidemiológicos
6.
Proc Natl Acad Sci U S A ; 111(46): 16436-41, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25368146

RESUMO

Carbonic anhydrase (CA) is one of nature's fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme's sensitivity to the harsh process conditions. Using directed evolution, the properties of a ß-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 °C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability and alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. At pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction.

7.
Virol J ; 8: 477, 2011 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-22023789

RESUMO

We previously demonstrated the ability of HIV-1 Vpr protein to activate the oxidative stress pathway, thus leading to the induction of the hypoxia inducible factor 1 alpha (HIF-1α). Therefore, we sought to examine the interplay between the two proteins and the impact of HIF-1α activation on HIV-1 transcription. Using transient transfection assays, we identified the optimal concentration of HIF-1α necessary for the activation of the HIV-1 promoter as well as the domain within HIF-1α responsible for this activation. Our findings indicated that activation of the HIV-1 LTR by Vpr is HIF-1α dependent. Furthermore, we showed that both Vpr and HIF-1α activate the HIV-1 promoter through the GC-rich binding domain within the LTR. Taken together, these data shed more light on the mechanisms used by Vpr to activate the HIV-1 promoter and placed HIF-1α as a major participant in this activation.


Assuntos
Regulação Viral da Expressão Gênica , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Regiões Promotoras Genéticas , Replicação Viral , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo , Repetição Terminal Longa de HIV , HIV-1/genética , HIV-1/crescimento & desenvolvimento , Humanos , Ligação Proteica
8.
PLoS One ; 6(1): e16148, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21249135

RESUMO

The HIV-1 protein, Tat has been implicated in AIDS pathogenesis however, the amount of circulating Tat is believed to be very low and its quantification has been difficult. We performed the quantification of Tat released from infected cells and taken up by neurons using high performance capillary electrophoresis. This is the first report to successfully measure the amount of Tat in neurons and places Tat as a key player involved in HIV-associated neurocognitive disorders.


Assuntos
Eletroforese Capilar/métodos , Produtos do Gene tat/análise , HIV-1/química , Neurônios/virologia , Complexo AIDS Demência/etiologia , Comunicação Celular , Linhagem Celular , Produtos do Gene tat/sangue , Humanos , Neurônios/química
9.
Proc Natl Acad Sci U S A ; 107(16): 7497-502, 2010 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-20368414

RESUMO

BAG3, a member of the BAG family of heat shock protein (HSP) 70 cochaperones, is expressed in response to stressful stimuli in a number of normal cell types and constitutively in a variety of tumors, including pancreas carcinomas, lymphocytic and myeloblastic leukemias, and thyroid carcinomas. Down-regulation of BAG3 results in cell death, but the underlying molecular mechanisms are still elusive. Here, we investigated the molecular mechanism of BAG3-dependent survival in human osteosarcoma (SAOS-2) and melanoma (M14) cells. We show that bag3 overexpression in tumors promotes survival through the NF-kappaB pathway. Indeed, we demonstrate that BAG3 alters the interaction between HSP70 and IKKgamma, increasing availability of IKKgamma and protecting it from proteasome-dependent degradation; this, in turn, results in increased NF-kappaB activity and survival. These results identify bag3 as a potential target for anticancer therapies in those tumors in which this gene is constitutively expressed. As a proof of principle, we show that treatment of a mouse xenograft tumor model with bag3siRNA-adenovirus that down-regulates bag3 results in reduced tumor growth and increased animal survival.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Regulação Neoplásica da Expressão Gênica , Quinase I-kappa B/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Feminino , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Biológicos , NF-kappa B/metabolismo , RNA Interferente Pequeno/metabolismo
10.
Virus Res ; 146(1-2): 97-106, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19747512

RESUMO

The polyomavirus JC (JCV) causes the demyelinating disease progressive multifocal leukoencephalopathy (PML). Infection by JCV is very common in childhood after which the virus enters a latent state, which is poorly understood. Under conditions of severe immunosuppression, especially AIDS, JCV may reactivate to cause PML. Expression of JC viral proteins is regulated by the JCV non-coding control region (NCCR), which contains an NF-kappaB binding site previously shown to activate transcription. We now report that C/EBPbeta inhibits basal and NF-kappaB-stimulated JCV transcription via the same site. Gel shift analysis showed C/EBPbeta bound to this region in vitro and ChIP assays confirmed this binding in vivo. Further, a ternary complex of NF-kappaB/p65, C/EBPbeta-LIP and JCV DNA could be detected in co-immunoprecipitation experiments. Mutagenesis analysis of the JCV NCCR indicated p65 and C/EBPbeta-LIP bound to adjacent but distinct sites and that both sites regulate basal and p65-stimulated transcription. Thus C/EBPbeta negatively regulates JCV, which together with NF-kappaB activation, may control the balance between JCV latency and activation leading to PML. This balance may be regulated by proinflammatory cytokines in the brain.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Vírus JC/fisiologia , Transcrição Gênica , Sítios de Ligação , Linhagem Celular , Imunoprecipitação da Cromatina , DNA Viral/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , NF-kappa B/metabolismo , Neuroglia/virologia , Ligação Proteica
11.
J Interferon Cytokine Res ; 29(6): 313-26, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19441883

RESUMO

Chemokines constitute a family of chemoattractant cytokines and are subdivided into four families on the basis of the number and spacing of the conserved cysteine residues in the N-terminus of the protein. Chemokines play a major role in selectively recruiting monocytes, neutrophils, and lymphocytes, as well as in inducing chemotaxis through the activation of G-protein-coupled receptors. Monocyte chemoattractant protein-1 (MCP-1/CCL2) is one of the key chemokines that regulate migration and infiltration of monocytes/macrophages. Both CCL2 and its receptor CCR2 have been demonstrated to be induced and involved in various diseases. Migration of monocytes from the blood stream across the vascular endothelium is required for routine immunological surveillance of tissues, as well as in response to inflammation. This review will discuss these biological processes and the structure and function of CCL2.


Assuntos
Quimiocina CCL2/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Imunoterapia , Monócitos/metabolismo , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Quimiocina CCL2/química , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Quimiotaxia/imunologia , Regulação da Expressão Gênica , Predisposição Genética para Doença , Infecções por HIV/metabolismo , HIV-1/patogenicidade , Humanos , Monócitos/imunologia , Monócitos/patologia , Polimorfismo Genético , Receptores CCR2/genética , Receptores CCR2/imunologia , Receptores CCR2/metabolismo , Doenças Vasculares/imunologia , Doenças Vasculares/metabolismo , Virulência
12.
Brain Res ; 1275: 81-6, 2009 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-19328187

RESUMO

The lack of productive infection of neurons by HIV-1 suggests that the neuronal damage seen in AIDS patients with cognitive disorders is caused indirectly via viral and cellular proteins with neurotoxic activity. Among HIV-1 proteins, Vpr has been shown to deregulate expression of various important cytokines and inflammatory proteins in infected and uninfected cells. However, the mechanisms underlying these changes remain unclear. Here, we demonstrate that neurons can take up Vpr that is released into the supernatant of HIV-infected microglia. We also found that administration of recombinant Vpr (rVpr) to human neurons resulted in a slow but sustained elevation of intracellular calcium [Ca(2+)]i. Interestingly, our data also show that [Ca(2+)]i elevation by Vpr leads to ROS production and impairs glutamate signaling in neuronal cells. Vpr disturbs calcium homeostasis through downregulation of endogenous PMCA. Finally, we found that the permeability of the plasma membrane increases in neurons treated with Vpr. Therefore, we conclude that soluble Vpr is a major viral factor that causes a disturbance in neuronal communication leading to neuronal dysfunction. The outcome of these studies will advance the understanding of HIV-1 pathogenesis and will help in the development of new therapeutic approaches.


Assuntos
Cálcio/fisiologia , HIV-1 , Neurônios/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/fisiologia , Cálcio/antagonistas & inibidores , Comunicação Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Regulação para Baixo/fisiologia , Humanos , Microglia/metabolismo , Microglia/virologia , Neurônios/virologia , Células U937 , Regulação para Cima/fisiologia
13.
J Biol Chem ; 284(17): 11364-73, 2009 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-19204000

RESUMO

The detection of biomarkers of oxidative stress in brain tissue and cerebrospinal fluid of patients with human immunodeficiency virus, type 1 (HIV)-associated dementia indicates the involvement of stress pathways in the neuropathogenesis of AIDS. Although the biological importance of oxidative stress on events involved in AIDS neuropathogenesis and the HIV-1 proteins responsible for oxidative stress remain to be elucidated, our results point to the activation of hypoxia-inducible factor 1 (HIF-1) upon HIV-1 infection and its elevation in brain cells of AIDS patients with dementia. HIF-1 is a transcription factor that is responsive to oxygen. Under hypoxic conditions, HIF-1alpha becomes stable and translocates to the nucleus where it dimerizes with aryl hydrocarbon receptor nuclear translocator and modulates gene transcription. Activation of HIF-1 can also be mediated by the HIV-1 accessory protein Vpr. In addition, cellular components, including reactive oxygen species, contribute to the induction of HIF-1alpha. Our results show that Vpr induces reactive oxygen species by increasing H(2)O(2) production, which can contribute to HIF-1alpha accumulation. Interestingly, increased levels of HIF-1alpha stimulated HIV-1 gene transcription through HIF-1 association with HIV-1 long terminal repeat. These observations point to the existence of a positive feedback interplay between HIF-1alpha and Vpr and that, by inducing oxidative stress via activation of HIF-1, Vpr can induce HIV-1 gene expression and dysregulate multiple host cellular pathways.


Assuntos
Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo , Encéfalo/metabolismo , Linhagem Celular , Dimerização , Células HeLa , Humanos , Peróxido de Hidrogênio/metabolismo , Microglia/metabolismo , Modelos Biológicos , Estresse Oxidativo , Regiões Promotoras Genéticas , Interferência de RNA , Espécies Reativas de Oxigênio
14.
J Cell Physiol ; 218(2): 264-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18821563

RESUMO

BAG3, a member of the BAG co-chaperones family, is expressed in several cell types subjected to stressful conditions, such as exposure to high temperature, heavy metals, drugs. Furthermore, it is constitutively expressed in some tumors. Among the biological activities of the protein, there is apoptosis downmodulation; this appears to be exerted through BAG3 interaction with the heat shock protein (Hsp) 70, that influences cell apoptosis at several levels. We recently reported that BAG3 protein was detectable in the cytoplasm of reactive astrocytes in HIV-1-associated encephalopathy biopsies. Here we report that downmodulation of BAG3 protein levels allows caspase-3 activation by HIV-1 infection in human primary microglial cells. This is the first reported evidence of a role for BAG3 in the balance of death versus survival during viral infection.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Caspase 3/metabolismo , HIV-1/fisiologia , Microglia/enzimologia , Microglia/virologia , Proteínas Reguladoras de Apoptose , Encéfalo/citologia , Encéfalo/metabolismo , Células Cultivadas , Ativação Enzimática , Humanos
15.
J Neuroimmune Pharmacol ; 4(1): 140-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19023660

RESUMO

The cytokine tumor necrosis factor alpha (TNFalpha) is a key factor in several inflammatory diseases and its levels increase in response to a variety of internal or external stimuli. The regulation of the TNFalpha promoter is mediated by several transcription factors including the nuclear factor kappa B protein (NF-kappaB). This study examines the role of NF-kappaB in the regulation of TNFalpha production by morphine in microglia. Using reverse transcriptase polymerase chain reaction, we demonstrated the presence of morphine receptors in these cells. We next demonstrated the ability of morphine to promote TNFalpha production and secretion by these cells using a cytokine array assay. Transient transfection experiments led to the identification of the region located between nucleotides -751 and -615 within the TNFalpha promoter as being responsive to morphine treatment. The DNA sequence of this region contains a motif indicative of a potential NF-kappaB binding site. The use of a small interfering RNA directed against p65, a subunit of NF-kappaB, demonstrated that TNFalpha induction by morphine is NF-kappaB-dependent. All of the effects of morphine were reversed by the morphine inhibitor, naloxone. These data provide important insights into the effects of morphine on microglia.


Assuntos
Analgésicos Opioides/farmacologia , Morfina/farmacologia , NF-kappa B/fisiologia , Neuroglia/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Analgésicos Opioides/antagonistas & inibidores , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Western Blotting , Células Cultivadas , Infecções por HIV/virologia , HIV-1 , Humanos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Morfina/antagonistas & inibidores , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Neuroglia/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Células U937
16.
Cancer Biol Ther ; 7(12): 1926-35, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18927497

RESUMO

BACKGROUND: The nucleic acid-binding protein Puralpha is involved at stalled DNA replication forks, in double-strand break (DSB) DNA repair and the cellular response to DNA replication stress. Puralpha also regulates homologous recombination-directed DNA repair (HRR). RESULTS: Cells lacking Puralpha showed enhanced sensitivity to cisplatin as evaluated by assays for cell viability and cell clonogenicity. This was seen both in Puralpha-negative MEFs and in human glioblastoma cells treated with siRNA directed against Puralpha. MEFs lacking Puralpha also showed enhanced H2AX phosphorylation in response to cisplatin. Repair of a reporter plasmid that had been treated with cisplatin was decreased in a reactivation assay using Puralpha-negative MEFs and the capacity of nuclear extracts from Puralpha-negative MEFs to perform non-homologous end-joining in vitro was also impaired. METHODS: We investigated the effects of the DNA damage-inducing cancer chemotherapeutic agent cisplatin on mouse embryo fibroblasts (MEFs) from PURA(-/-) knockout mice that lack Puralpha. CONCLUSIONS: Puralpha has a role in the cellular response to cisplatin-induced DNA damage and may provide new therapeutic modalities for cisplatin-resistant tumors.


Assuntos
Cisplatino/uso terapêutico , Dano ao DNA , Reparo do DNA/fisiologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/fisiologia , Neoplasias/tratamento farmacológico , Fatores de Transcrição/fisiologia , Animais , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/efeitos adversos , Cisplatino/farmacologia , Ensaio de Unidades Formadoras de Colônias , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/uso terapêutico , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Neoplasias/genética , Neoplasias/patologia , Fatores de Transcrição/deficiência , Fatores de Transcrição/uso terapêutico
17.
Cell Cycle ; 7(17): 2682-90, 2008 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18719392

RESUMO

HIV-associated dementia (HAD) is the most common AIDS-associated neurological disorder and is characterized by the development of synaptodendritic injury to neurons. To advance HAD therapy, it is crucial to identify the mechanisms and factors involved. The viral protein HIV-1 Tat is among those factors and is released by HIV-1-infected cells and can be taken up by adjacent neuronal cells leading to neurotoxic effects. Multiple cellular host proteins have been identified as Tat cofactors in causing neuronal injury. Interestingly, most of these factors function through activation of the p53 pathway. We have now examined the ability of Tat to activate the p53 pathway leading to the induction of endogenous p53 and p73 in neuronal cells. We found that Tat induced p53 and p73 levels in SH-SY5Y cells and that this induction caused retraction of neurites. In the absence of either p53 or p73, Tat failed to induce dendritic retraction or to activate the proapoptotic proteins, such as Bax. Further, we found that p53-accumulation in Tat-treated cells depends on the presence of p73. Therefore, we conclude that Tat contributes to neuronal degeneration through activation of a pathway involving p53 and p73. This information will be valuable for the development of therapeutic agents that affect these pathways to protect CNS neurons and prevent HAD.


Assuntos
Complexo AIDS Demência/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Complexo AIDS Demência/patologia , Apoptose , Proteínas Reguladoras de Apoptose , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Linhagem Celular Tumoral , HIV-1/fisiologia , Humanos , Modelos Biológicos , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Neurônios/metabolismo , Neurônios/patologia , Fosforilação , Fosfosserina/metabolismo , Transporte Proteico , Frações Subcelulares/metabolismo , Proteína Supressora de Tumor p53/deficiência , Regulação para Cima , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo
18.
Mol Immunol ; 45(15): 4028-35, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18649942

RESUMO

St. John's Wort is commonly known for its antiviral, antidepressant, and cytotoxic properties, but traditionally St. John's Wort has also been used to treat inflammation. In this study, we sought to characterize the mechanisms used by St. John's Wort to treat inflammation by examining the effect of the recently isolated protein from St. John's Wort, p27SJ on the expression of MCP-1. By employing an adenovirus expression vector, we demonstrate that a low concentration of p27SJ upregulates the MCP-1 promoter through the transcription factor C/EBPbeta. In addition, we found that C/EBPbeta-homologous protein (CHOP) or siRNA-C/EBPbeta significantly reduced the ability of p27SJ to activate MCP-1 gene expression. Results from protein-protein interaction studies illustrate the existence of a physical interaction between p27SJ and C/EBPbeta in microglial cells. The use of chromatin immunoprecipitation assay (ChIP) led to the identification of a new cis-element that is responsive to C/EBPbeta within the MCP-1 promoter. Association of C/EBPbeta with MCP-1 DNA was not affected by the presence of p27SJ. The biological activity of MCP-1 produced by cultures of adenovirus-p27SJ transduced cells was increased relative to controls as measured by the transmigration of human Jurkat cells. Thus, we conclude that at high concentration, p27SJ is a potential agent that may be developed as a modulator of MCP-1 leading to the inhibition of the cytokine-mediated inflammatory responses.


Assuntos
Quimiocina CCL2/biossíntese , Hypericum/química , Proteínas de Plantas/farmacologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Quimiocina CCL2/genética , Regulação da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Ligação Proteica
19.
J Virol ; 82(3): 1558-69, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17989177

RESUMO

Productive infection of oligodendrocytes, which are responsible for the formation of myelin sheath in the central nervous system, with the human neurotropic virus JC virus (JCV) causes the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). In addition to encoding T antigen and the capsid proteins, which are produced at the early and late phases of the infection cycle, respectively, JCV encodes a small regulatory protein named agnoprotein that is important for successful completion of the virus life cycle. Here we used bipotential CG-4 cells to examine the impact of agnoprotein on oligodendrocyte differentiation and survival in the absence of JCV lytic infection. We demonstrate that the expression of agnoprotein delayed the formation of complex outgrowth networks of the cells during oligodendrocyte differentiation. These alterations were accompanied by high levels of DNA damage, induction of proapoptotic proteins, and suppression of prosurvival signaling. Accordingly, apoptosis was significantly increased upon the induction of CG-4 cells toward differentiation in cells expressing agnoprotein. These observations provide the first evidence for the possible involvement of agnoprotein, independent from its role in viral replication, in a series of biological events that may contribute to the pathological features seen in PML lesions.


Assuntos
Apoptose , Vírus JC/fisiologia , Oligodendroglia/virologia , Proteínas Virais Reguladoras e Acessórias/fisiologia , Diferenciação Celular/fisiologia , Linhagem Celular , Humanos
20.
J Med Chem ; 50(24): 5938-50, 2007 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-17973469

RESUMO

Secretory phospholipase A2 (sPLA2) and matrix metallopreoteinases (MMPs) are key enzymes involved in rheumatoid arthritis (RA), and their modulation thus represents a potential therapeutic option. On the basis of Escherichia coli radioassay, synthetic peptides were designed and screened for sPLA2 inhibition. The linear peptide, 10f (PIP-18), inhibited the recombinant human synovial sPLA2 activity with an IC50 of 1.19 microM. Not only did the peptide interfere with the function of sPLA2, but it also appeared to inhibit mRNA expression of sPLA2 and various MMPs in IL-1beta-stimulated RA synovial fibroblast (RASF) cultures and thereby the production of the corresponding proteins (>80% inhibition). Nuclear magnetic resonance (NMR), modeling, and docking studies indicate that in solution the peptide exhibits a beta-turn at residues Trp-Asp-Gly-Val and possibly binds to the hydrophobic channel of sPLA2. The results strongly suggest that the modulatory action of peptide 10f may play a major role in counteracting the development of RA.


Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Modelos Moleculares , Peptídeos/síntese química , Fosfolipases A2 Secretórias/antagonistas & inibidores , Fosfolipases A2 Secretórias/química , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Artrite Reumatoide/enzimologia , Células Cultivadas , Dicroísmo Circular , Fibroblastos/efeitos dos fármacos , Fibroblastos/enzimologia , Expressão Gênica/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Metaloproteinases da Matriz/biossíntese , Oligopeptídeos/síntese química , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Fosfolipases A2 Secretórias/biossíntese , Ligação Proteica , Conformação Proteica , Coelhos , Soluções , Relação Estrutura-Atividade , Líquido Sinovial/citologia
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