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1.
Clin Exp Allergy ; 47(9): 1170-1184, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28456994

RESUMO

BACKGROUND: Increasing evidence has shown the close link between energy metabolism and the differentiation, function, and longevity of immune cells. Chronic inflammatory conditions such as parasitic infections and cancer trigger a metabolic reprogramming from the preferential use of glucose to the up-regulation of fatty acid oxidation (FAO) in myeloid cells, including macrophages and granulocytic and monocytic myeloid-derived suppressor cells. Asthma is a chronic inflammatory condition where macrophages, eosinophils, and polymorphonuclear cells play an important role in its pathophysiology. OBJECTIVE: We tested whether FAO might play a role in the development of asthma-like traits and whether the inhibition of this metabolic pathway could represent a novel therapeutic approach. METHODS: OVA- and house dust mite (HDM)-induced murine asthma models were used in this study. RESULTS: Key FAO enzymes were significantly increased in the bronchial epithelium and inflammatory immune cells infiltrating the respiratory epithelium of mice exposed to OVA or HDM. Pharmacologic inhibition of FAO significantly decreased allergen-induced airway hyperresponsiveness, decreased the number of inflammatory cells, and reduced the production of cytokines and chemokines associated with asthma. CONCLUSIONS AND CLINICAL RELEVANCE: These novel observations suggest that allergic airway inflammation increases FAO in inflammatory cells to support the production of cytokines, chemokines, and other factors important in the development of asthma. Inhibition of FAO by re-purposing existing drugs approved for the treatment of heart disease may provide a novel therapeutic approach for the treatment of asthma.


Assuntos
Asma/etiologia , Asma/metabolismo , Ácidos Graxos/metabolismo , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Oxirredução , Alérgenos , Animais , Asma/tratamento farmacológico , Asma/patologia , Biomarcadores , Quimiocinas/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Sistema Imunitário/efeitos dos fármacos , Imunidade Inata/imunologia , Imunoglobulina E/imunologia , Masculino , Camundongos , Terapia de Alvo Molecular , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/patologia
2.
Vet Pathol ; 51(4): 832-45, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24045888

RESUMO

Reports of primary nervous system tumors in wild raccoons are extremely rare. Olfactory tumors were diagnosed postmortem in 9 free-ranging raccoons from 4 contiguous counties in California and 1 raccoon from Oregon within a 26-month period between 2010 and 2012. We describe the geographic and temporal features of these 10 cases, including the laboratory diagnostic investigations and the neuropathologic, immunohistochemical, and ultrastructural characteristics of these tumors in the affected animals. All 9 raccoons from California were found within a localized geographic region of the San Francisco Bay Area (within a 44.13-km radius). The tight temporal and geographic clustering and consistent anatomic location in the olfactory system of tumor types not previously described in raccoons (malignant peripheral nerve sheath tumors and undifferentiated sarcomas) strongly suggest either a common cause or a precipitating factor leading to induction or potentiation of neuro-oncogenesis and so prompted an extensive diagnostic investigation to explore possible oncogenic infectious and/or toxic causes. By a consensus polymerase chain reaction strategy, a novel, recently reported polyomavirus called raccoon polyomavirus was identified in all 10 tumors but not in the normal brain tissue from the affected animals, suggesting that the virus might play a role in neuro-oncogenesis. In addition, expression of the viral protein T antigen was detected in all tumors containing the viral sequences. We discuss the potential role of raccoon polyomavirus as an oncogenic virus.


Assuntos
Surtos de Doenças/veterinária , Neurilemoma/epidemiologia , Neurilemoma/veterinária , Neurilemoma/virologia , Polyomavirus/genética , Guaxinins , Animais , California/epidemiologia , Análise por Conglomerados , Imuno-Histoquímica/veterinária , Microdissecção e Captura a Laser/veterinária , Microscopia Eletrônica/veterinária , Neurilemoma/patologia , Oregon/epidemiologia , Reação em Cadeia da Polimerase/veterinária
3.
Transl Oncol ; 12(7): 895-907, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078963

RESUMO

Anticancer effects of a common lipid-lowering drug, fenofibrate, have been described in the literature for a quite some time; however, fenofibrate has not been used as a direct anticancer therapy. We have previously reported that fenofibrate in its unprocessed form (ester) accumulates in the mitochondria, inhibits mitochondrial respiration, and triggers a severe energy deficit and extensive glioblastoma cell death. However, fenofibrate does not cross the blood brain barrier and is quickly processed by blood and tissue esterases to form the PPARα agonist fenofibric acid, which is practically ineffective effective in triggering cancer cell death. To address these issues, we have made several chemical modifications in fenofibrate structure to increase its stability, water solubility, tissue penetration, and ultimately anticancer potential. Our data show that, in comparison to fenofibrate, four new compounds designated here as PP1, PP2, PP3, and PP4 have improved anticancer activity in vitro. Like fenofibrate, the compounds block mitochondrial respiration and trigger massive glioblastoma cell death in vitro. In addition, one of the lead compounds, PP1, has improved water solubility and is significantly more stable when exposed to human blood in comparison to fenofibrate. Importantly, mice bearing large intracranial glioblastoma tumors demonstrated extensive areas of tumor cell death within the tumor mass following oral administration of PP1, and the treated mice did not show any major signs of distress, and accumulated PP1 at therapeutically relevant concentrations in several tissues, including brain and intracranial tumors.

4.
Oncogene ; 26(16): 2308-17, 2007 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-17016438

RESUMO

We have previously reported that insulin-like growth factor-I (IGF-I) supports growth and survival of mouse and human medulloblastoma cell lines, and that IGF-I receptor (IGF-IR) is constitutively phosphorylated in human medulloblastoma clinical samples. Here, we demonstrate that a specific inhibitor of insulin-like growth factor-I receptor (IGF-IR), NVP-AEW541, attenuated growth and survival of mouse (BsB8) and human (D384, Daoy) medulloblastoma cell lines. Cell cycle analysis demonstrated that G1 arrest and apoptosis contributed to the action of NVP-AEW54. Interestingly, very aggressive BsB8 cells, which derive from cerebellar tumors of transgenic mice expressing viral oncoprotein (large T-antigen from human polyomavirus JC) became much more sensitive to NVP-AEW541 when exposed to anchorage-independent culture conditions. This high sensitivity to NVP-AEW54 in suspension was accompanied by the loss of GSK-3beta constitutive phosphorylation and was independent from T-antigen-mediated cellular events (Supplementary Materials). BsB8 cells were partially rescued from NVP-AEW541 by GSK3beta inhibitor, lithium chloride and were sensitized by GSK3beta activator, sodium nitroprusside (SNP). Importantly, human medulloblastoma cells, D384, which demonstrated partial resistance to NVP-AEW541 in suspension cultures, become much more sensitive following SNP-mediated GSK3beta dephosphorylation (activation). Our results indicate that hypersensitivity of medulloblastoma cells in anchorage-independence is linked to GSK-3beta activity and suggest that pharmacological intervention against IGF-IR with simultaneous activation of GSK3beta could be highly effective against medulloblastomas, which have intrinsic ability of disseminating the CNS via cerebrospinal fluid.


Assuntos
Neoplasias Cerebelares/patologia , Quinase 3 da Glicogênio Sintase/metabolismo , Meduloblastoma/patologia , Receptor IGF Tipo 1/antagonistas & inibidores , Animais , Divisão Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Glicogênio Sintase Quinase 3 beta , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Fosforilação
5.
Int J Oncol ; 33(2): 287-95, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18636149

RESUMO

The A3 adenosine receptor (A(3)AR) is highly expressed in tumors and was suggested as a target for cancer treatment. In this study, we show that A(3)AR is highly expressed in tumor tissues and in peripheral blood mononuclear cells (PBMCs) derived from patients with HCC, as well as from HCC tumor-bearing rats. The high expression level of the receptor was directly correlated to overexpression of NF-kappaB, known as a transcription factor of A(3)AR. CF102, a synthetic highly selective agonist to A(3)AR induced a marked dose response inhibition of tumor growth in N1S1 HCC tumor rats, via de-regulation of the NF-kappaB and the Wnt signal transduction pathways, resulting in apoptosis of tumor cells. Taken together, A(3)AR is highly expressed in tumors and PBMCs of HCC patients and tumor-bearing rats. CF102 induced apoptosis and tumor growth inhibition. These data suggest A(3)AR as a novel targeted therapy to treat HCC.


Assuntos
Adenosina/análogos & derivados , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , NF-kappa B/efeitos dos fármacos , Proteínas Wnt/efeitos dos fármacos , Adenosina/farmacologia , Agonistas do Receptor A3 de Adenosina , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Western Blotting , Carcinoma Hepatocelular/metabolismo , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Neoplasias Hepáticas/metabolismo , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor A3 de Adenosina/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Proteínas Wnt/metabolismo
6.
Environ Sci Pollut Res Int ; 24(7): 6241-6251, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27640057

RESUMO

Degradation of bisphenol A (BPA, 0.5 L, 30 mg L-1) was studied by photo-Fenton treatment, while Fenton reagents were variables. The efficiency of the degradation process was evaluated by the reduction of total organic carbon (TOC), the biochemical oxygen demand (BOD), and toxicity. For toxicity analysis, bacterial methods were found infeasible, but the in vitro assay of VERO cells culture was successfully applied. Experiments according to a 22 design of experiments (DOE) with star points and three center points for statistical validity allowed selecting those process conditions (Fe(II) and H2O2 load) that maximized the process performance. Photo-Fenton process effectively eliminated BPA and partly degraded its by-products (residual TOC <15 %) under substoichiometric H2O2 dose (100.62 mg L-1) and at least 4 mg L-1 Fe(II), after a 90-min treatment. All treated samples were at least partially biodegradable. The cytotoxic concentration (LD50) of BPA for VERO cells was 7 mg L-1. With small H2O2 amount (15.24 mg L-1), only low BPA mineralization (TOC = 92 %) was attained. Toxicity was also detected to 50 % of cellular mortality even at long reaction times. However, 40.25 mg L-1 of H2O2 decreased residual TOC to 70 % while cell mortality decreased down to 25 %. With more H2O2, the residual TOC decreased down to 15 % but cell mortality remained within the 20-25 % level. Photo-Fenton increased the biodegradability and reduced the toxicity of the studied sample.


Assuntos
Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Análise da Demanda Biológica de Oxigênio , Carbono/análise , Peróxido de Hidrogênio/química , Ferro/química , Fenóis/química , Fenóis/toxicidade , Fotólise , Animais , Chlorocebus aethiops , Oxirredução , Células Vero , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
7.
O.F.I.L ; 32(1)enero 2022. tab, graf
Artigo em Espanhol | IBECS (Espanha) | ID: ibc-205734

RESUMO

Introducción: El estado de alarma decretado por la pandemia del virus SARS COV-2 del 14 de marzo hasta el 21 de junio, ha supuesto un desafío para el área de pacientes externos de los Servicios de Farmacia. Nos centramos en los pacientes con hemofilia que se administran factores de la coagulación de forma crónica para prevenir hemorragias.Objetivos: Analizar durante este periodo el porcentaje de pacientes que han recogido su medicación, han mantenido la adherencia al tratamiento y las barreras encontradas para ello. Cuantificar el número y gravedad de episodios hemorrágicos (EH) sufridos y su relación con la pandemia. Analizar la prevalencia y gravedad de COVID en hemofílicos.Métodos: Uno objetivo, utilizando los registros del hospital y otro subjetivo, mediante encuesta oral durante la consulta de atención farmacéutica presencial o telemática.Resultados: El 80% de los pacientes retiraron medicación durante el periodo de estudio, un 30% en domicilio. El último mes las dispensaciones a domicilio se acompañaron de consulta telemática.Un 24% de pacientes disminuyó su adherencia respecto al 2019. Las principales causas fueron dificultad para acudir al hospital, y percepción de no necesitar tratamiento ante la inactividad.No se registraron más EH o ingresos por causas imputables a la pandemia.No hubo ningún enfermo COVID-19 grave y la incidencia de pacientes con síntomas leves fue similar a la población general.Conclusión: La mayoría de los pacientes con hemofilia pudieron acceder a su medicación. La adherencia se redujo. Los EH no aumentaron por causas atribuibles a la pandemia. La incidencia de COVID-19 fue similar a la población. (AU)


Introduction: The state of alarm decreed by the SARS COV-2 virus pandemic from March 14th to June 21st, has meant a challenge for the outpatient area of the pharmacy services. We focus on hemophilia patients who are chronically administered clotting factors to prevent bleeding.Objectives: To analyse during this period the percentage of patients who have collected their medication, maintained adherence to treatment and the barriers encountered in doing so. To quantify the number and severity of haemorrhagic episodes (HD) suffered and their relationship with the pandemic. Analyse the prevalence and severity of COVID in haemophiliacs.Methods: One objective, using hospital records, and one subjective, using an oral survey during the face-to-face or telematic pharmaceutical care consultation.Results: 80% of patients withdrew medication during the study period, 30% at home. In the last month, home deliveries were accompanied by telematic consultation.24% of patients decreased their adherence with respect to 2019. The main causes were difficulty in going to hospital, and perception of not needing treatment in the face of inactivity.There were no more HD or admissions for reasons attributable to the pandemic.There were no serious COVID-19 patients and the incidence of patients with mild symptoms was similar to the general population.Conclusion: Most haemophilia patients were able to access their medication. Adherence was reduced. HD did not increase due to causes attributable to the pandemic. The incidence of COVID-19 was similar to the population. (AU)


Assuntos
Humanos , Coronavirus , Hemofilia A , Pandemias , Terapêutica , Pacientes , Espanha
8.
Leukemia ; 31(3): 614-624, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27538487

RESUMO

Primary effusion lymphoma (PEL) is an incurable malignancy that develops in immunodeficient patients as a consequence of latent infection of B-cells with Kaposi's sarcoma-associated herpes virus (KSHV). Malignant growth of KSHV-infected B cells requires the activity of the transcription factor nuclear factor (NF)-κB, which controls maintenance of viral latency and suppression of the viral lytic program. Here we show that the KSHV proteins K13 and K15 promote NF-κB activation via the protease mucosa-associated lymphoid tissue lymphoma translocation protein-1 (MALT1), a key driver of NF-κB activation in lymphocytes. Inhibition of the MALT1 protease activity induced a switch from the latent to the lytic stage of viral infection, and led to reduced growth and survival of PEL cell lines in vitro and in a xenograft model. These results demonstrate a key role for the proteolytic activity of MALT1 in PEL, and provide a rationale for the pharmacological targeting of MALT1 in PEL therapy.


Assuntos
Caspases/metabolismo , Infecções por Herpesviridae/complicações , Infecções por Herpesviridae/virologia , Herpesvirus Humano 8/fisiologia , Linfoma de Efusão Primária/etiologia , Linfoma de Efusão Primária/patologia , Proteínas de Neoplasias/metabolismo , Latência Viral , Animais , Biomarcadores , Caspases/genética , Linhagem Celular , Sobrevivência Celular/genética , Modelos Animais de Doenças , Ativação Enzimática , Citometria de Fluxo , Inativação Gênica , Interações Hospedeiro-Patógeno , Humanos , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa , NF-kappa B/metabolismo , Proteínas de Neoplasias/genética , Ligação Proteica , Proteínas Virais/metabolismo , Ativação Viral , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Biocell ; 30(3): 423-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17375462

RESUMO

Parathion is an organophosphorate pesticide amply used in agriculture. Many alterations induced by organophosphorate pesticides have been described, such as: cytogenetic alterations in germinal cells, oligozoospermia and teratozoospermia in the mouse. The effect of Parathion, both pure (PP) and commercial (PC), on mouse interstitial cell testosterone production was evaluated in vivo and in vitro. Male mice were intraperitoneally injected with a single dose of 1/3 LD50 of Parathion, both PP and PC. The animals were sacrificed at 1, 8 and 40 days post injection to evaluate the impact of disrupting testosterone production on spermatogonia, spermatocytes and elongated spermatids. The plasma testosterone was assayed by standard radioimmunoanalysis. The same method was used to assay testosterone in the culture medium of interstitial cells obtained from the control and Parathion treated animals at the same time intervals. Sperm count, sperm teratozoospermia and tubular blockage were analyzed for an appraisal of spermatogenesis. Increase in the teratozoospermia and tubular blockage was detected in the PP and PC group at 8 and 40 days post injection. Plasma testosterone levels drop significantly at 8 days and recovered slowly at 40 days only in PP animals as detected in vivo, implying interference of testicular steroidogenesis due to the toxicant. Recuperation of normality occurs at long time intervals. In conclusion, Parathion disturbs the synthesis of testosterone in mice affecting qualitatively the spermatogenesis


Assuntos
Inseticidas/toxicidade , Paration/toxicidade , Espermatogênese/efeitos dos fármacos , Testosterona/biossíntese , Acetilcolinesterase/sangue , Animais , Masculino , Camundongos , Camundongos Endogâmicos , Contagem de Espermatozoides , Espermatozoides/anormalidades , Testosterona/sangue
10.
Cancer Res ; 61(10): 4287-93, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11358858

RESUMO

JC virus (JCV) is a neurotropic polyomavirus infecting greater than 70% of the human population worldwide during early childhood. Replication of JCV in brains of individuals with impaired immune systems results in the fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Furthermore, JCV possesses an oncogenic potential and induces development of various neuroectodermal origin tumors including medulloblastomas and glioblastomas in experimental animals. The oncogenecity of JCV is attributed to the viral early gene product, T-antigen, which has the ability to associate with and functionally inactivate well-studied tumor suppressor proteins including p53 and pRB: The observations from laboratory animal experiments have provided a rationale for examining the presence of the JCV DNA sequence and expression of the viral oncogenic protein in human brain tumors. We have examined 85 clinical specimens from the United Kingdom, Greece, and the United States, representing various human brain tumors including oligodendroglioma, astrocytoma, pilocytic astrocytoma, oligoastrocytoma, anaplastic astrocytoma, anaplastic oligodendroglioma, glioblastoma multiforme, gliomatosis cerebri, gliosarcoma, ependymoma, and subependymoma, for their possible association with JCV. We performed gene amplification techniques using a pair of primers that recognize the JCV DNA sequence, and we demonstrated the presence of the viral early sequence in 49 (69%) of 71 samples. More importantly, our results from immunohistochemistry analysis revealed expression of JCV T-antigen in the nuclei of tumor cells in 28 (32.9%) of 85 tested samples. These observations, along with earlier in vitro and in vivo data on the transforming ability of this human neurotropic virus invite additional studies to re-evaluate the role of JCV in the pathogenesis of human brain tumors.


Assuntos
Antígenos Transformantes de Poliomavirus/genética , Neoplasias Encefálicas/virologia , DNA Viral/genética , Vírus JC/genética , Animais , Antígenos Transformantes de Poliomavirus/biossíntese , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Cricetinae , Expressão Gênica , Humanos , Imuno-Histoquímica , Vírus JC/imunologia , Mesocricetus , Proteína Supressora de Tumor p53/biossíntese
13.
Oncogenesis ; 5(8): e257, 2016 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-27548814

RESUMO

Neuroendocrine tumors (NETs), which can have survival rates as low as 4%, currently have limited therapeutic interventions available highlighting the dire need for the identification of novel biological targets for use as new potential drug targets. One such potential target is retinoblastoma-binding protein 2 (RBP2), an H3K4 demethylase whose overexpression has been linked to cancer formation and metastasis in non-endocrine tumor types. We measured RBP2 mRNA and protein levels in enteropancreatic NETs by measuring RBP2 in matched human normal and NET tissue samples. Further, proliferation, migration, invasion and colony formation assays were performed in the physiologically relevant NET cell lines ßlox5, H727 and QGP-1 to understand the role of RBP2 and its demethylase activity on end points of tumorigenesis. Our data indicate a strong correlation between RBP2 mRNA and protein expression in NET specimens. RBP2 was overexpressed relative to tissue-matched normal controls in 80% of the human tumors measured. In vitro studies showed RBP2 overexpression significantly increased proliferation, migration, invasion and colony formation, whereas knockdown significantly decreases the same parameters in a demethylase-independent manner. The cell cycle inhibitors p21 and p57 decreased with RBP2 overexpression and increased upon its depletion, suggesting a regulatory role for RBP2 in cellular proliferation. Taken together, our results support the hypothesis that the aberrant overexpression of RBP2 is a frequent contributing factor to tumor formation and metastasis in enteropancreatic NETs.

14.
Oncogene ; 19(42): 4840-6, 2000 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-11039901

RESUMO

In recent years, there has been mounting evidence pointing to the association of polyomaviruses with a wide range of human cancers. The human neurotropic polyomavirus, JCV, infecting greater than 75% of the human population produces a regulatory protein named T-antigen which is expressed at the early phase of viral lytic infection and plays a critical role in completion of the viral life cycle. Furthermore, this protein has the ability to transform neural cells in vitro and its expression has been detected in several human neural-origin tumors. To further investigate the oncogenic potential of the JCV early protein in vivo, transgenic mice expressing JCV T-antigen under the control of its own promoter were generated. Nearly 50% of the animals developed large, solid masses within the base of the skull by 1 year of age. Evaluation of the location as well as histological and immunohistochemical data suggest that the tumors arise from the pituitary gland. As T-antigen is known to interact with several cell cycle regulators, the neoplasms were analysed for the presence of the tumor suppressor protein, p53. Immunoprecipitation/Western blot analysis demonstrated overexpression of wild-type, but not mutant p53 within tumor tissue. In addition, co-immunoprecipitation established an interaction between p53 and T-antigen and overexpression of p53 downstream target protein, p21/WAF1. This report describes the analysis of inheritable pituitary adenomas induced by expression of the human polyomavirus, JCV T-antigen in transgenic mice where T-antigen disrupts the p53 pathway by binding to and sequestering wild-type p53. This animal model may serve as a useful tool to further evaluate mechanisms of tumorigenesis by JCV T-antigen.


Assuntos
Adenoma/virologia , Antígenos Transformantes de Poliomavirus/fisiologia , Transformação Celular Viral/genética , Genoma Viral , Vírus JC/patogenicidade , Neoplasias Hipofisárias/virologia , Adenoma/química , Adenoma/genética , Adenoma/patologia , Animais , Animais não Endogâmicos , Antígenos Transformantes de Poliomavirus/análise , Antígenos Transformantes de Poliomavirus/genética , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/genética , Feminino , Regulação Viral da Expressão Gênica , Genes p53 , Neoplasias Intestinais/genética , Neoplasias Intestinais/virologia , Vírus JC/genética , Vírus JC/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Neoplasias Hipofisárias/química , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/patologia , Regiões Promotoras Genéticas , Proteínas Recombinantes/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo
15.
Oncogene ; 20(29): 3857-68, 2001 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-11439349

RESUMO

Insulin-like growth factor I receptor (IGF-IR) has been implicated in the normal and malignant growth of many cell types including cells from the central nervous system. In the cerebellar cortex IGF-IR mRNA is found in granular cells and IGF-I stimulation is mitogenic and protects cells from low-potassium-induced apoptosis. Since primitive neuroectodermal tumors/medulloblastomas (PNETs/medulloblastomas) are suspected to originate from the external cerebellar granular layer, it is reasonable to postulate that IGF-IR and/or its signaling molecules may contribute to the transformation of these poorly differentiated cells. To study activation of the IGF-IR system in medulloblastomas, we have utilized an antibody (anti-pY1316) that specifically recognizes the phosphorylated (active) form of the IGF-IR. Medulloblastoma biopsy specimens were positive when examined immunohistochemically with anti-Y1316 antibody. Further analysis of the IGF-IR system was performed in three human (Daoy, TE-671, D283 Med) and four mouse (BsB8, BsB13, Bs-1b, Bs-1c) medulloblastoma cell lines. All the murine cell lines examined express IGF-IR and PI3-kinase at relatively normal levels, and grossly overexpress IRS-1, when compared with normal mouse cerebellum. Within 15 min following IGF-I stimulation both mouse and human cell lines phosphorylate the beta subunit of the IGF-IR, IRS-1, Akt, and MAP kinases. They respond with cell proliferation when stimulated solely with IGF-I and are strongly inhibited when challenged with a dominant negative mutant of the IGF-IR (486/STOP), or with antisense oligonucleotides against the IGF-IR mRNA.


Assuntos
Neoplasias Cerebelares/metabolismo , Meduloblastoma/metabolismo , Receptor IGF Tipo 1/metabolismo , Animais , Divisão Celular , Neoplasias Cerebelares/patologia , Humanos , Proteínas Substratos do Receptor de Insulina , Meduloblastoma/patologia , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/fisiologia , Transdução de Sinais , Células Tumorais Cultivadas
16.
Oncogene ; 20(35): 4864-70, 2001 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-11521197

RESUMO

By using the early genome of the human neurotropic polyomavirus, JCV, we have created transgenic animals that develop cerebellar primitive neuroectodermal tumors which model human medulloblastoma. Expression of T-antigen was found in some, but not all, tumor cells, and examination of the clonal cell lines derived from the tumor population showed enhanced tumorigenicity of cells expressing T-antigen in comparison to T-antigen negative cells. Considering the earlier notion on the potential involvement of beta-catenin with human medulloblastoma, we investigated various components of the Wnt signaling pathway including beta-catenin, its partner transcription factor, LEF-1, and their downstream target gene c-myc in these two cell populations. Immunohistochemical staining of the cells revealed enhanced nuclear appearance of beta-catenin in T-antigen positive cells. Results from Western blot showed higher levels of beta-catenin and LEF-1 in T-antigen positive cells in comparison to those in T-antigen negative cells. The enhanced level of LEF-1 expression correlated with the increase in DNA binding activity of this protein in nuclear extracts of T-antigen positive cells. Results from Northern and Western blot analyses revealed that the level of c-myc expression is augmented both at the RNA and protein levels in T-antigen positive cells. These observations corroborated results from transfection studies indicating the ability of JCV T-antigen to stimulate c-myc promoter activity. Further, co-transfection experiments revealed that the amount of c-myc and T-antigen protein in tumor cells may dictate the activity of JCV early promoter in these cells. These observations are interesting in light of recent discoveries on the association of JCV with human medulloblastoma and suggest that communication between JCV and the Wnt pathway may be an important event in the genesis of these tumors.


Assuntos
Neoplasias Cerebelares/etiologia , Vírus JC , Meduloblastoma/etiologia , Proteínas Proto-Oncogênicas/fisiologia , Transativadores , Proteínas de Peixe-Zebra , Animais , Antígenos Virais de Tumores/análise , Sítios de Ligação , Proteínas do Citoesqueleto/análise , Proteínas de Ligação a DNA/metabolismo , Genes myc , Humanos , Fator 1 de Ligação ao Facilitador Linfoide , Camundongos , Fatores de Transcrição/metabolismo , Proteínas Wnt , beta Catenina
17.
J Leukoc Biol ; 65(4): 458-65, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10204574

RESUMO

The broad range of histological lesions associated with HIV-1 are somewhat subtle relative to the clinical manifestations that occur as a result of HIV infection. Although it is clear that HIV has a causative role in CNS disease, dementia appears to be a consequence of the infiltration of inflammatory cells and cytokine dysregulation rather than the amount of virus in CNS. The HIV transregulatory protein Tat plays an important intracellular as well as extracellular role in the dysregulation of cytokines. The cytokines and possibly chemokines that are induced by Tat modify the action of astrocytes such that the survival of neurons is compromised. Pathogenetic alteration induced by Tat involves a series of interactions between circulating monocyte/macrophages, endothelial cells, and astrocytes. Cytokine dysregulation induced by viral infection and extracellular Tat leads to alterations in expression of adhesion molecules and promotes migration of non-infected inflammatory cells into the CNS compartment. We demonstrate here that recombinant HIV-1 Tat protein introduced by stereotaxic injection into mouse brain can induce pathologically relevant alterations including macrophage invasion as well as astrocytosis. The mechanism of destruction of the CNS by Tat appears to involve autocrine and paracrine pathways that depend not only on Tat, but cytokine and chemokine signaling pathways that are altered by viral infection. In this review, we discuss various pathogenic effects of Tat in brain cells and provide experimental evidence for an increased TNF-alpha level in CSF in mice injected intracerebrally with Tat protein.


Assuntos
Doenças do Sistema Nervoso Central/patologia , Doenças do Sistema Nervoso Central/virologia , Produtos do Gene tat/fisiologia , Infecções por HIV/virologia , HIV-1/patogenicidade , Animais , Doenças do Sistema Nervoso Central/imunologia , Infecções por HIV/imunologia , Infecções por HIV/patologia , HIV-1/imunologia , HIV-1/metabolismo , Humanos , Modelos Biológicos , Proteínas Virais/fisiologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana
18.
Fitoterapia ; 76(2): 204-9, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15752631

RESUMO

The aqueous extract of Viscum album leaves showed a significant coronary vasodilator activity on the Langendorff's isolated and perfused heart model. The data obtained suggest that the aqueous extract of V. album contains some biologically active principles that may act as inducers of the nitric oxide/soluble guanylate cyclase pathway.


Assuntos
Vasos Coronários/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Vasodilatadores/farmacologia , Viscum album , Animais , Circulação Coronária/efeitos dos fármacos , Circulação Coronária/fisiologia , Vasos Coronários/fisiologia , Guanilato Ciclase/metabolismo , Cobaias , Coração/efeitos dos fármacos , Coração/fisiologia , Masculino , Óxido Nítrico/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Vasodilatadores/administração & dosagem , Vasodilatadores/uso terapêutico
19.
Mater Sci Eng C Mater Biol Appl ; 49: 472-484, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25686974

RESUMO

Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core-shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds.


Assuntos
Materiais Biocompatíveis , Butileno Glicóis/química , Polietilenoglicóis/química , Polímeros/química , Alicerces Teciduais , Animais , Células Cultivadas , Chlorocebus aethiops , Humanos
20.
Neurology ; 58(6): 895-900, 2002 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-11914404

RESUMO

OBJECTIVE: To investigate the presence of human polyomavirus JC virus genome and the expression of the viral oncoprotein T-antigen in neoplastic cells of a patient with MS and a glioblastoma multiforme. BACKGROUND: The postmortem examination of an immunocompetent patient with a neurologic disorder revealed the concurrence of MS plaques in the white matter of the brain and a glioblastoma multiforme in the region of the thalamus. METHODS AND RESULTS: PCR analysis of DNA from demyelinated plaques and the tumor area using primers derived from specific regions of the JC virus genome revealed the presence of viral DNA corresponding to the viral early and late genes. Further examination of the samples for the JC virus regulatory region identified the presence of sequences identical to JC virus Mad-4 and JC virus W1 viral isolates in the tumor and the demyelinated regions. Results from immunohistochemistry showed the detection of the viral early protein, T-antigen, and the cellular tumor suppressor protein, p53, in the nuclei of neoplastic cells. Interestingly, expression of T-antigen, but not p53, was observed in neurofilament-positive cells with neuronal morphology and in glial fibrillary acidic protein-positive astrocytes in the cortex juxtaposed to the MS plaques. Examination of viral late gene expression by immunohistochemistry showed no evidence for viral capsid proteins, thus ruling out productive replication of JC virus in the tumor and MS demyelinated plaques. CONCLUSIONS: These observations provide molecular and clinical evidence of the association of JC virus in the brain of a patient with concurrent glioblastoma multiforme and MS.


Assuntos
Antígenos Transformantes de Poliomavirus/biossíntese , Neoplasias Encefálicas/virologia , Glioblastoma/virologia , Vírus JC/imunologia , Esclerose Múltipla/virologia , Tálamo/virologia , Idoso , Sequência de Aminoácidos , Antígenos Transformantes de Poliomavirus/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Vírus JC/genética , Vírus JC/isolamento & purificação , Dados de Sequência Molecular , Esclerose Múltipla/genética , Esclerose Múltipla/patologia , Tálamo/metabolismo , Tálamo/patologia
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