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2.
NPJ Precis Oncol ; 2: 26, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30480095

RESUMO

Secretome of primary cultures is an accessible source of biological markers compared to more complex and less decipherable mixtures such as serum or plasma. The protonation state (PS) of secretome reflects the metabolism of cells and can be used for cancer early detection. Here, we demonstrate a superhydrophobic organic electrochemical device that measures PS in a drop of secretome derived from liquid biopsies. Using data from the sensor and principal component analysis (PCA), we developed algorithms able to efficiently discriminate tumour patients from non-tumour patients. We then validated the results using mass spectrometry and biochemical analysis of samples. For the 36 patients across three independent cohorts, the method identified tumour patients with high sensitivity and identification as high as 100% (no false positives) with declared subjects at-risk, for sporadic cancer onset, by intermediate values of PS. This assay could impact on cancer risk management, individual's diagnosis and/or help clarify risk in healthy populations.

3.
J Biol Regul Homeost Agents ; 31(4): 1087-1093, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29254319

RESUMO

Bergamot polyphenolic fraction (BPF) has been shown to positively modulate several mechanisms involved in metabolic syndrome, suggesting its use in therapy. In particular, it is able to induce a significant amelioration of serum lipid profile in hyperlipemic patients at different levels. The purpose of our study was to investigate the effect of BPF on cholesterol absorption physiologically mediated by pancreatic cholesterol ester hydrolase (pCEH). An in vitro activity assay was performed to study the effect of BPF on pCEH, whereas the rate of cholesterol absorption was evaluated through in vivo studies. In particular, male, Sprague-Dawley rats (200–225 g) were fed either normal chow or chow supplemented with 0.5% cholic acid, 5.5% peanut oil, and varying amounts of cholesterol (0 to 1.5%). BPF (10 mg/Kg) was daily administrated by means of a gastric gavage to animals fed with lipid supplemented diet for 4 weeks and, at the end of the study, plasma lipids and liver cholesteryl esters were measured in all experimental groups. Our results show that BPF was able to inhibit pCEH activity and this effect was confirmed, in vivo, via detection of lymphatic cholesteryl ester in rats fed with a cholesterol-rich diet. This evidence clarifies a further mechanism responsible for the hypolipemic properties of BPF previously observed in humans, confirming its beneficial effect in the therapy of hypercholesterolemia and in the treatment of metabolic syndrome.


Assuntos
Suplementos Nutricionais , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/farmacologia , Óleos de Plantas/farmacologia , Esterol Esterase/antagonistas & inibidores , Animais , Colesterol/administração & dosagem , Colesterol/sangue , Ésteres do Colesterol/sangue , Ácido Cólico/administração & dosagem , Ácido Cólico/sangue , Absorção Gastrointestinal/fisiologia , Humanos , Hiperlipidemias/metabolismo , Hiperlipidemias/patologia , Hipolipemiantes/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Óleos de Plantas/metabolismo , Ratos , Ratos Sprague-Dawley , Esterol Esterase/metabolismo , Triglicerídeos/sangue
4.
BMC Neurol ; 16: 127, 2016 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-27502239

RESUMO

BACKGROUND: Circulating Tumor Cells (CTCs) are promising biomarkers for monitoring solid cancer and were used to monitor brain tumors. Here we report two cases in which, for the first time, CTCs were used in cytological diagnostic evaluation to discriminate a space-occupying lesion of the brain. CASE PRESENTATION: Two cases of focal intracranial lesions, unclassified for diagnosis, untreated and apparently symptomatic, were examined after high-contrast resolution Magnetic Resonance Imaging and/or Computed Tomography scans. CTCs were seeded on chamber slides and short-time expanded under the optimized conditions as we previously reported. The first case was a focal lesion localized in the parietal-occipital area in a 67-year-old woman. The second case was a 31-year-old man with an expansive intracerebral lesion localized in the left peri-trigonal area. Both patients underwent excisional biopsy. Histopathological evaluation of the biopsy confirmed the previous cytological diagnoses, and the analysis of the clinical outcomes retrospectively validated both diagnoses. CONCLUSIONS: The cases here reported illustrate the potential for using expanded CTCs as non-invasive, real-time biopsy. Moreover, non-invasive real-time biopsy can represent an alternative diagnostic tool to be used when a functional area of the brain is at risk of injury from excisional biopsy procedures.


Assuntos
Neoplasias Encefálicas/patologia , Citodiagnóstico/métodos , Células Neoplásicas Circulantes/patologia , Adulto , Idoso , Astrocitoma/diagnóstico por imagem , Astrocitoma/patologia , Biópsia/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Células Cultivadas , Meios de Contraste , Feminino , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Segunda Neoplasia Primária/diagnóstico por imagem , Segunda Neoplasia Primária/patologia , Tomografia por Emissão de Pósitrons/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
5.
J Biol Regul Homeost Agents ; 29(3): 723-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26403416

RESUMO

Photoageing represents the addition of extrinsic chronic ultraviolet radiation-induced damage on intrinsic ageing and accounts for most age-associated changes in skin appearance. In this study, we evaluated the effect of 38% BPF, a highly concentrated extract of the bergamot fruit (Citrus bergamia) on UVB-induced photoageing by examining inflammatory cytokine expression, telomere length/telomerase alterations and cellular viability in human immortalized HaCaT keratinocytes. Our results suggest that 38% BPF protects HaCaT cells against UVB-induced oxidative stress and markers of photoageing in a dose-dependent manner and could be a useful supplement in skin care products. Together with antioxidant properties, BPF, a highly concentrated extract of the bergamot fruit, appears to modulate basic cellular signal transduction pathways leading to anti-proliferative, anti-aging and immune modulating responses.


Assuntos
Citrus/química , Queratinócitos/metabolismo , Polifenóis/farmacologia , Envelhecimento da Pele , Telomerase/metabolismo , Telômero/metabolismo , Raios Ultravioleta/efeitos adversos , Linhagem Celular Transformada , Humanos , Queratinócitos/patologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Polifenóis/química , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos da radiação
6.
Int J Cardiol Heart Vasc ; 6: 48-53, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28785626

RESUMO

AIM: Consistent expansion of primary human endothelial cells in vitro is critical in the development of engineered tissue. A variety of complex culture media and techniques developed from different basal media have been reported with alternate success. Incongruous results are further confounded by donor-to-donor variability and cellular source of derivation. Our results demonstrate how to overcome these limitations using soluble CD54 (sCD54) as additive to conventional culture medium. METHODS AND RESULTS: Isolated primary fragment of different vessel types was expanded in Ham's F12 DMEM, enriched with growth factors, Fetal Calf Serum and conditioned medium of Human Umbilical Vein Endothelial Cells (HUVEC) collected at different passages. Cytokine content of culture media was analyzed in order to identify the soluble factors correlating with better proliferation profile. sCD54 was found to induce the in vitro expansion of human endothelial cells (HECs) independently from the vessels source and even in the absence of HUVEC-conditioned medium. The HECs cultivated in the presence of sCD54 (50 ng/ml), resulted positive for the expression of CD146 and negative for CD45, and lower fibroblast contamination. Cells were capable to proliferate with an S phase of 25%, to produce vascular endothelial growth factor, VEGF, (10 ng/ml) and to give origin to vessel-like tubule in vitro. CONCLUSION: Our results demonstrate that sCD54 is an essential factor for the in-vitro expansion of HECs without donor and vessel-source variability. Resulting primary cultures can be useful, for tissue engineering in regenerative medicine (e.g. artificial micro tissue generation, coating artificial heart valve etc.) and bio-nanotechnology applications.

7.
J Biol Regul Homeost Agents ; 28(1): 105-16, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24750796

RESUMO

Morphine and related opioid drugs are currently the major drugs for severe pain. Their clinical utility is limited in the management of severe cancer pain due to the rapid development of tolerance. Restoring opioid efficacy is therefore of great clinical importance. A great body of evidence suggests the key role of free radicals and posttranslational modulation in the development of tolerance to the analgesic activity of morphine. Epidemiological studies have shown a relationship between the Mediterranean diet and a reduced incidence of pathologies such as coronary heart disease and cancer. A central hallmark of this diet is the high consumption of virgin olive oil as the main source of fat which contains antioxidant components in the non-saponifiable fraction, including phenolic compounds absent in seed oils. Here, we show that in a rodent model of opiate tolerance, removal of the free radicals with phenolic compounds of olive oil such as hydroxytyrosol and oleuropein reinstates the analgesic action of morphine. Chronic injection of morphine in mice led to the development of tolerance and this was associated with increased nitrotyrosin and malondialdehyde (MDA) formation together with nitration and deactivation of MnSOD in the spinal cord. Removal of free radicals by hydroxytyrosol and oleuropein blocked morphine tolerance by inhibiting nitration and MDA formation and replacing the MnSOD activity. The phenolic fraction of virgin olive oil exerts antioxidant activities in vivo and free radicals generation occurring during chronic morphine administration play a crucial role in the development of opioid tolerance. Our data suggest novel therapeutic approach in the management of chronic cancer pain, in particular for those patients who require long-term opioid treatment for pain relief without development of tolerance.


Assuntos
Analgésicos Opioides/farmacologia , Antioxidantes/uso terapêutico , Morfina/farmacologia , Neoplasias/fisiopatologia , Olea/química , Dor Intratável/tratamento farmacológico , Álcool Feniletílico/análogos & derivados , Piranos/uso terapêutico , Animais , Tolerância a Medicamentos , Glucosídeos Iridoides , Iridoides , Peroxidação de Lipídeos , Masculino , Camundongos , Estresse Oxidativo , Álcool Feniletílico/uso terapêutico , Superóxido Dismutase/metabolismo
8.
J Biol Regul Homeost Agents ; 28(4): 717-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25620181

RESUMO

The clinical development of locally and advanced non-small cell lung cancer (NSCLC) suffers from a lack of biomarkers as a guide in the selection of optimal prognostic prediction. Circulating Tumour Cells (CTCs) are correlated to prognosis and show efficacy in cancer monitoring in patients. However, their enumeration alone might be inadequate; it might also be critical to understand the viability, the apoptotic state and the kinetics of these cells. Here, we report what we believe to be a new and selective approach to visually detect tumour specific CTCs. Firstly, using labelled human lung cancer cells, we detected a specific density interval in which NSCL-CTCs were concentrated. Secondly, to better characterize CTCs in respect to their heterogeneous composition and tumour reference, blood and tumour biopsy were performed on specimens taken from the same patient. The approach consisted in comparing phenotype profile of CTCs, and their progenitor Tumour Stem Cells, (TSCs). Moreover, NSCL-CTCs were cultivated in short-time human cultures to provide response to drug sensitivity. Our bimodal approach allowed to reveal two items. Firstly, that one part of a tumour, proximal to the bronchial structure, displays a predominance of CD133+. Secondly, specific NSCL-CTCs Epithelial Cell Adhesion Molecule (EpCAM)+CD29+ can be used as a negative prognostic factor as well the high expression of CTCs EpCAM+. These data were confirmed by drug-sensitivity tests, in vitro, and by the survival curves, in vivo.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Células Neoplásicas Circulantes , Idoso , Idoso de 80 Anos ou mais , Biópsia , Carcinoma Pulmonar de Células não Pequenas/terapia , Ciclo Celular , Humanos , Neoplasias Pulmonares/terapia , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Medicina de Precisão
9.
J Biol Regul Homeost Agents ; 27(3): 781-90, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24152829

RESUMO

Superoxide, a reactive form of oxygen, can be produced in vivo either in normal and under pathophysiologic conditions or by photosensitizing chemicals, as during photodynamic treatment. Photodynamic therapies (PDT), widely adopted in Dermatology and Oncology, are known to generate reactive oxygen species (ROS) and may contribute to structural alterations and oxidatively generated modifications of cellular antioxidants. We hypothesized that over-production of free radicals would decrease the enzymatic activities of endogenous cellular antioxidants. To test this hypothesis, keratinocytes were treated with the photosensitizer Photofrin plus visible light to produce free radicals and CuZnSOD and MnSOD activities were measured. Photodynamic treatment of keratinocytes increases malonylaldehyde production, nitrotyrosine staining and superoxide production. The enzymatic activities of CuZnSOD and MnSOD were significantly decreased after Photofrin plus visible light treatment. Our results suggest that the main cellular antioxidant system can be inactivated by photodynamically generated ROS. Pretreatment of keratinocytes with free radicals scavenger such as Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP) was able to restore the endogenous antioxidant system activities, inhibiting the MDA formation, nitrotyrosine staining and superoxide formation. Antioxidant therapy could therefore be a useful tool in protecting healthy epidermal cells against common side effects induced by antitumor targeted therapies.


Assuntos
Queratinócitos/efeitos dos fármacos , Manganês/farmacologia , Metaloporfirinas/farmacologia , Fotoquimioterapia , Superóxido Dismutase/metabolismo , Células Cultivadas , Radicais Livres , Humanos , Queratinócitos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo
10.
Small ; 9(12): 2152-61, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23401360

RESUMO

Advances in carbohydrate sequencing technologies reveal the tremendous complexity of the glycome and the role that glycomics might have to bring insight into the biological functions. Carbohydrate-protein interactions, in particular, are known to be crucial to most mammalian physiological processes as mediators of cell adhesion and metastasis, signal transducers, and organizers of protein interactions. An assay is developed here to mimic the multivalency of biological complexes that selectively and sensitively detect carbohydrate-protein interactions. The binding of ß-galactosides and galectin-3--a protein that is correlated to the progress of tumor and metastasis--is examined. The efficiency of the assay is related to the expression of the receptor while anchoring to the interaction's strength. Comparative binding experiments reveal molecular binding preferences. This study establishes that the assay is robust to isolate metastatic cells from colon affected patients and paves the way to personalized medicine.


Assuntos
Carboidratos , Microfluídica/métodos , Proteínas/metabolismo , Adesão Celular/fisiologia , Linhagem Celular , Galactosídeos/química , Galectina 3/química , Células HCT116 , Humanos , Ligação Proteica
11.
Neurosci Lett ; 314(1-2): 53-6, 2001 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-11698145

RESUMO

The effect of IL-1 beta and TNF alpha infused into nucleus tractus solitari (NTS), nucleus parabrachialis medialis (NPBmed) and third cerebral ventricle of normotensive rats on blood pressure (BP) and heart rate (HR) was investigated. Microinfusion of IL-1 beta and TNF alpha into the third cerebral ventricle and NPBmed of normotensive rats produced a dose-dependent hypotensive and bradycardic response. A similar cardiovascular response was produced by infusion of IL1 beta into NTS but not by TNF alpha. When rats were pre-treated with Escherichia coli lipopolisaccharide (LPS), an enhancement of cardiovascular response elicited by IL-1 beta and TNF alpha was found. Thus, IL-1 beta and TNF alpha produce cardiovascular responses when infused into specific areas of the CNS. This effect is potentiated by LPS and this may explain the alteration in cardiovascular regulation which can be observed in diseases in which an excess of circulating endotoxins and cytokines may occur.


Assuntos
Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Interleucina-1/farmacologia , Ponte/efeitos dos fármacos , Núcleo Solitário/efeitos dos fármacos , Terceiro Ventrículo/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Infecções Bacterianas/complicações , Infecções Bacterianas/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Endotoxinas/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Lipopolissacarídeos/farmacologia , Masculino , Ponte/fisiologia , Ratos , Ratos Wistar , Núcleo Solitário/fisiologia , Terceiro Ventrículo/fisiologia
12.
Trends Neurosci ; 24(7): 411-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11410272

RESUMO

Neurological disorders represent one of the most common disturbances accompanying HIV infection. In the past few years, highly antiretroviral active therapy has significantly reduced the incidence of HIV-related diseases. However, neurological dysfunction in AIDS patients still remains an unresolved problem. Oxidative stress, which occurs in brain tissues of patients undergoing HIV infection and is implicated in cell death of both astroglia and neurones, has recently been suggested to play a role in the pathogenesis of neuroAIDS. Thus, a better understanding of the processes that trigger and modulate free radical formation in brain tissues of AIDS patients might help in a successful therapeutic approach to the neuropathogenesis of HIV infection.


Assuntos
Complexo AIDS Demência/metabolismo , Antioxidantes/metabolismo , Barreira Hematoencefálica/fisiologia , Radicais Livres/metabolismo , Estresse Oxidativo/fisiologia , Complexo AIDS Demência/tratamento farmacológico , Complexo AIDS Demência/fisiopatologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Catalase/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Produtos do Gene tat/metabolismo , Glutationa/metabolismo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/metabolismo , Infecções por HIV/fisiopatologia , Humanos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Compostos Organometálicos/farmacologia , Compostos Organometálicos/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana
13.
J Leukoc Biol ; 68(3): 429-35, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10985261

RESUMO

Infection of macrophages (M/M) by human immunodeficiency virus (HIV) is a main pathogenetic event leading to neuronal dysfunction and death in patients with AIDS dementia complex. Alteration of viability of neurons and astrocytes occurs in vivo even without their infection, thus it is conceivable that HIV-infected M/M may affect viability of such cells even without direct infection. To assess this hypothesis, we studied the effects of HIV-infected M/M on an astrocytic cell-line lacking CD4-receptor expression. Exposure to supernatants of HIV-infected M/M triggers complete disruption and apoptotic death of astrocytic cells. This effect is not related to HIV transmission from infected M/M, because HIV-DNA and p24 production in astrocytic cells remained negative. Apoptotic death of astrocytes is mainly mediated by Fas ligand released in supernatants of HIV-infected M/M (as demonstrated by complete reversal of such phenomenon by adding neutralizing antibodies against CD95 receptor). Treatment of astrocytic cells with recombinant (biologically active) Tat induces < 10% apoptosis, and gp120 was totally ineffective. Treatment of HIV-infected M/M with AZT completely reverses the proapoptotic effect of their supernatants on astrocytes, thus demonstrating that productive virus replication within M/M is required for the induction of astrocytic cell death. Taken together, data suggest that homeostasis of astrocytes may be affected by HIV-infected M/M in the absence of productive infection of target cells. This phenomenon may help to explain the cellular damage found in HIV-infected patients also in areas of the brain not strictly adjacent to HIV-infected M/M.


Assuntos
Apoptose/fisiologia , Astrócitos/patologia , Comunicação Celular/fisiologia , HIV , Macrófagos/virologia , Receptor fas/fisiologia , Fármacos Anti-HIV/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Proteína Ligante Fas , Produtos do Gene tat/fisiologia , Proteína gp120 do Envelope de HIV/fisiologia , Homeostase , Humanos , Macrófagos/patologia , Masculino , Glicoproteínas de Membrana/fisiologia , Pessoa de Meia-Idade , Necrose , Zidovudina/farmacologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana
14.
Br J Pharmacol ; 124(4): 742-6, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9690866

RESUMO

1. The role of the L-arginine-nitric oxide (NO) pathway on the formation of prostaglandin E2 (PGE2) by human cultured astroglial cells incubated with interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) was investigated. 2. Incubation of T 67 astroglial cell line with IL-beta (10 ng ml(-1)) and TNF-alpha (500 u ml(-1)) produced a significant (P<0.05) increase of both nitrite (the breakdown product of NO), cyclic GMP and PGE2 levels in cell supernatants. N omega-nitro-L-arginine methyl ester (L-NAME; 20-300 microM), an inhibitor of NO synthase (NOS), inhibited the increase of cyclic GMP and nitrite levels found in supernatants of cytokine-treated astroglial cells and reduced the release of PGE2. The latter effect showed that the enhanced arachidonic acid (AA) metabolism subsequent to stimulation of astroglial cells with IL-1beta and TNF-alpha was, at least in part, induced by NO. This occurred also when sodium nitroprusside (SNP; 120 microM), an NO donor, was incubated with astroglial cells, an effect antagonized by oxyhaemoglobin (OxyHb; 10 microM). 3. The inhibition elicited by L-NAME on PGE2-release by cytokine-treated astroglial cells was reversed by adding AA (40 microM), showing that the effect of NO on cytokine-dependent PGE2 release occurred at the cyclo-oxygenase (COX) level. Furthermore, the release of PGE2 in cytokine-treated astroglial cells was inhibited by indomethacin (10 microM), a COX inhibitor as well as by preincubating cells with dexamethasone (20 microM), an inhibitor of inducible enzymes, showing that the inducible isoform of COX (COX-2) was involved. 4. On the other hand, pretreating astroglial cells with methylene blue (MB; 10 microM), an inhibitor of NO biological activity acting at the guanylate cyclase level, failed to affect PGE2 release in cytokine-treated astroglial cells, leading to the conclusion that cyclic GMP changes related to NO formation are not involved in the generation of AA metabolites. 5. The present experiments demonstrated that the release of PGE2 by astroglial cells pretreated with IL-1beta and TNF-alpha is due to enhanced COX-2 activity via activation of the L-arginine-NO pathway, and this may be relevant to the understanding of the pathophysiological mechanisms underlying neuroimmune disorders.


Assuntos
Astrócitos/metabolismo , Dinoprostona/metabolismo , Interleucina-1/metabolismo , Isoenzimas/biossíntese , Óxido Nítrico/metabolismo , Prostaglandina-Endoperóxido Sintases/biossíntese , Fator de Necrose Tumoral alfa/metabolismo , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Astrócitos/enzimologia , Linhagem Celular , GMP Cíclico/metabolismo , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase/farmacologia , Dexametasona/farmacologia , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Humanos , Proteínas de Membrana , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Nitritos/metabolismo , Nitroprussiato/farmacologia
15.
Biochem Biophys Res Commun ; 238(3): 916-9, 1997 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-9325192

RESUMO

The effect of 0, 30, 60, 120, 240, 360 min hypoxia on the release of NO and PGE2 was investigated in human cultured astroglial cells. Exposure of astroglial cells to hypoxic injury produced a dose-dependent increase of the nitrite (the breakdown product of NO) level in the cell supernatant. In addition, a significant activation of the inducible isoform of NO synthase was seen, demonstrating that the enhancement on NO release produced by hypoxic injury was related to an increased biosynthesis of NO-generating enzyme(s). This effect was strongly antagonised by pretreating cells with dexamethasone (20 microM). The increase in NO release by hypoxic astroglial cells was accompanied by sustained release of PGE2, which was antagonised by the cyclooxygenase inhibitor indomethacin (10 microM), and partially attenuated by L-NAME (100 microM), a nitric oxide synthase inhibitor, showing that the release of PGE2 was driven by NO. Finally, inducible NOS activity elicited by hypoxic injury, was antagonised by incubating astroglial cells with antibodies directed against type 2 receptor for IL1 beta. In conclusion, hypoxia stimulates cytokine network in astroglial cells leading to enhanced release of NO and prostanoids and this may represent a key mechanism in cerebral blood flow disturbances.


Assuntos
Astrócitos/metabolismo , Astrócitos/fisiologia , Dinoprostona/metabolismo , Interleucina-1/fisiologia , Óxido Nítrico/metabolismo , Animais , Astrócitos/enzimologia , Astrocitoma , Hipóxia Celular/efeitos dos fármacos , Sistema Livre de Células , Humanos , Indometacina/farmacologia , Óxido Nítrico Sintase/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Células Tumorais Cultivadas
17.
J Biol Chem ; 272(12): 7582-5, 1997 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-9065411

RESUMO

Previous results indicate that induction of inducible nitric-oxide synthase (iNOS) expression may be kept suppressed by the endogenous NO level as produced by a constitutive NOS (cNOS) enzyme. In cell types possessing both cNOS and iNOS, this may represent an evident paradox. Here, we report that lipopolysaccharide and interferon-gamma, which are able to strongly induce iNOS in astrocytoma cells, can rapidly inhibit the NO production generated by the constitutive NOS isoform, thus obtaining the best conditions for iNOS induction and resolving the apparent paradox. In fact, a 30-min treatment of T67 cells with the combination of lipopolysaccharide plus interferon-gamma (MIX) strongly inhibits the cNOS activity, as determined by measuring [3H]citrulline production. In addition, the effect of MIX is also observed by measuring nitrite, the stable breakdown product of NO: a 30-min pretreatment of T67 cells with MIX is able to reduce significantly the N-methyl-D-aspartate-induced nitrite production. Finally, using reverse transcriptase-polymerase chain reaction, we have observed that a 30-min treatment of T67 cells with MIX does not affect expression of mRNA coding for the neuronal NOS-I isoform. These results suggest the novel concept of a possible role of a cNOS isoform in astrocytes as a control function on iNOS induction.


Assuntos
Astrócitos/enzimologia , Cálcio/metabolismo , Escherichia coli/metabolismo , Interferon gama/farmacologia , Lipopolissacarídeos/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Astrocitoma , Inibidores Enzimáticos/farmacologia , Humanos , N-Metilaspartato/farmacologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas
18.
J Clin Invest ; 97(11): 2562-8, 1996 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-8647949

RESUMO

We have evaluated the contributions of nitric oxide (NO) and prostacyclin (PGI2) in the in vivo antiplatelet effects of clinically useful nitrovasodilators. In rats, intravenous infusion of three NO donors, glyceryl trinitrate, sodium nitroprusside, or 3'-morpholinosydnonimine, the stable metabolite of molsidomine, released 6-keto PGF1alpha (the stable metabolite of PGI2) and inhibited ex vivo human platelet aggregation to adenosine diphosphate by at least 80%. In in vitro studies, glyceryl trinitrate, sodium nitroprusside, and 3'-morpholinosydnonimine, at clinically attainable concentrations, increased cyclooxygenase activity in endothelial cells (EC), which resulted in a four- to sixfold release of 6-keto PGF1alpha. Pretreatment of the EC with hemoglobin which binds to and inactivates the biological actions of NO, but not by methylene blue (MelB), attenuated the NO-mediated PGI2 from the EC by at least 70%. Release of 6-keto PGF1alpha by the NO donors increased the ability of these compounds to inhibit thrombin-induced human platelet aggregation by at least 10 times; this potentiation was inhibited by hemoglobin but not by MeB. MeB blocked the direct anti-platelet effect of the NO donors in the absence of EC. In summary, we have demonstrated that NO, directly as well as together with an NO-driven cyclooxygenase activation (and hence PGI2), release contributes to the marked anti-platelet effects observed after the in vivo administration of clinically used nitrovasodilators.


Assuntos
Endotélio Vascular/enzimologia , Epoprostenol/fisiologia , Óxido Nítrico/fisiologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/metabolismo , Vasodilatadores/farmacologia , 6-Cetoprostaglandina F1 alfa/sangue , Difosfato de Adenosina/farmacologia , Animais , Aorta , Bovinos , Células Cultivadas , Endotélio Vascular/efeitos dos fármacos , Ativação Enzimática , Hemoglobinas/metabolismo , Hemoglobinas/farmacologia , Humanos , Cinética , Masculino , Azul de Metileno/farmacologia , Modelos Cardiovasculares , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Óxido Nítrico/farmacologia , Nitroglicerina/farmacologia , Nitroprussiato/farmacologia , Penicilamina/análogos & derivados , Penicilamina/farmacologia , Ratos , Ratos Sprague-Dawley , S-Nitroso-N-Acetilpenicilamina , Vasodilatação , Verapamil/farmacologia
19.
Biochem Biophys Res Commun ; 215(3): 793-9, 1995 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-7488043

RESUMO

The role of the L-arginine-NO pathway on the formation of PGE2 by human cultured astroglial cells incubated with NMDA has been investigated. Preincubation of T 67 astroglial cell line with NMDA (10-600 microM) produced a significant dose-dependent increase of both nitrite (the breakdown product of NO), PGE2 and cGMP levels in cell supernatant. This effect was inhibited by coincubation of cells with L-NAME (20-300 microM), an inhibitor of NO synthase showing that the release of PGE2 subsequent to NMDA receptor stimulation was driven by NO. The release of PGE2 but not elevation of nitrite and cGMP levels was affected by indomethacin (10 microM), an inhibitor of cyclooxygenase. The inhibitory effect of L-NAME on PGE2 release by NMDA-pretreated astroglial cells was reverted by arachidonic acid, showing that the effect of NO on PGE2 release occurred at the cyclo-oxygenase level. Thus, the present experiments demonstrate that the release of PGE2 by astroglial cells pretreated with NMDA is driven by activation of the L-arginine-NO pathway, and this may be relevant in the pathophysiological mechanisms where glutamatergic neurotransmission is involved.


Assuntos
Astrócitos/metabolismo , Dinoprostona/metabolismo , N-Metilaspartato/farmacologia , Óxido Nítrico/fisiologia , Ácido Araquidônico/farmacologia , Arginina/análogos & derivados , Arginina/farmacologia , Astrócitos/efeitos dos fármacos , Astrocitoma , Linhagem Celular , GMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Humanos , Cinética , NG-Nitroarginina Metil Éster , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Nitritos/metabolismo , Nitroprussiato/farmacologia , Oxiemoglobinas/farmacologia , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia , Células Tumorais Cultivadas
20.
Biochem Biophys Res Commun ; 215(3): 822-7, 1995 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-7488047

RESUMO

We report that NO synthase activity, as expressed by citrulline and nitrite formation in brain homogenates, is decreased in 24-month old in comparison to 3-month old rats. In particular, a Ca(++)-dependent NO synthase activity was detected in homogenates obtained from cortical, hippocampal, cerebellar and lower brain stem slices from both 3- and 24 month-old rats. The amount of citrulline generated from L-arginine was significantly decreased in the hippocampus and lower brain stem by 40 and 48%, respectively. No changes were observed in NO synthase activity in cortical and cerebellar homogenates. Thus, the L-arginine-NO pathway seems to be impaired in selected areas of rat brain and this may contribute to the understanding of pathophysiological mechanisms underlying age-related cerebral disorders.


Assuntos
Envelhecimento/metabolismo , Encéfalo/enzimologia , Óxido Nítrico Sintase/metabolismo , Animais , Encéfalo/crescimento & desenvolvimento , Tronco Encefálico/enzimologia , Cálcio/farmacologia , Cerebelo/enzimologia , Citrulina/metabolismo , Lobo Frontal/enzimologia , Hipocampo/enzimologia , Técnicas In Vitro , Masculino , Nitritos/metabolismo , Especificidade de Órgãos , Lobo Parietal/enzimologia , Ratos , Ratos Wistar
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