RESUMO
The aims of the study were to compare the levels of tumor necrosis factor alpha (TNF-α) and its soluble type I (sTNF-R1) and type II (sTNF-R2) receptors detected in intracystic liquid and serum from benign and malignant ovarian neoplasms and to relate them to prognostic factors in epithelial ovarian cancer. The patients were divided into benign ovarian neoplasms (n = 46) and malignant ovarian neoplasms (n = 17). The serum and intracystic samples were collected before and during surgery for ovarian cyst, respectively. The levels of TNF-α, sTNF-R1, and sTNF-R2 were measured using ELISA. Results were compared with the Mann-Whitney test. Concentration of sTNF-R2 in the intracystic samples collected from the malignant neoplasia was significantly higher than that of the benign neoplasias (p = 0.02). Higher intracystic levels of sTNF-R2 exhibited a significant association with tumor differentiation grades 2 and 3 (p = 0.0087). There was no statistical significance in relation to serum levels. Tumor microenvironment levels of sTNF-R2 may represent a factor of poor prognosis in epithelial ovarian cancer.
Assuntos
Carcinoma Epitelial do Ovário/metabolismo , Neoplasias Ovarianas/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Microambiente Tumoral , Fator de Necrose Tumoral alfa/biossíntese , Carcinoma Epitelial do Ovário/diagnóstico , Feminino , Humanos , Neoplasias Ovarianas/diagnóstico , PrognósticoRESUMO
BACKGROUND: Reduction in the number of circulating blood lymphocytes (lymphocytopaenia) has been reported during clinical episodes of malaria and is normalized after treatment with anti-malaria drugs. While this phenomenon is well established in malaria infection, the underlying mechanisms are still not fully elucidated. In the present study, the occurrence of apoptosis and its pathways in CD4+ T cells was investigated in naturally Plasmodium vivax-infected individuals from a Brazilian endemic area (Porto Velho - RO). METHODS: Blood samples were collected from P. vivax-infected individuals and healthy donors. The apoptosis was characterized by cell staining with Annexin V/FITC and propidium iodide and the apoptosis-associated gene expression profile was carried out using RT2 Profiler PCR Array-Human Apoptosis. The plasma TNF level was determined by ELISA. The unpaired t-test or Mann-Whitney test was applied according to the data distribution. RESULTS: Plasmodium vivax-infected individuals present low number of leukocytes and lymphocytes with a higher percentage of CD4+ T cells in early and/or late apoptosis. Increased gene expression was observed for TNFRSF1B and Bid, associated with a reduction of Bcl-2, in individuals with P. vivax malaria. Furthermore, these individuals showed increased plasma levels of TNF compared to malaria-naive donors. CONCLUSIONS: The results of the present study suggest that P. vivax infection induces apoptosis of CD4+ T cells mediated by two types of signaling: by activation of the TNFR1 death receptor (extrinsic pathway), which is amplified by Bid, and by decreased expression of the anti-apoptotic protein Bcl-2 (intrinsic pathway). The T lymphocytes apoptosis could reflect a strategy of immune evasion triggered by the parasite, enabling their persistence but also limiting the occurrence of immunopathology.
Assuntos
Apoptose , Linfócitos T CD4-Positivos/fisiologia , Interações Hospedeiro-Patógeno , Malária Vivax/imunologia , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Adulto , Brasil , Técnicas Citológicas , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Transdução de Sinais , Adulto JovemRESUMO
The pineal gland, a circumventricular organ, plays an integrative role in defense responses. The injury-induced suppression of the pineal gland hormone, melatonin, which is triggered by darkness, allows the mounting of innate immune responses. We have previously shown that cultured pineal glands, which express toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1), produce TNF when challenged with lipopolysaccharide (LPS). Here our aim was to evaluate which cells present in the pineal gland, astrocytes, microglia or pinealocytes produced TNF, in order to understand the interaction between pineal activity, melatonin production and immune function. Cultured pineal glands or pinealocytes were stimulated with LPS. TNF content was measured using an enzyme-linked immunosorbent assay. TLR4 and TNFR1 expression were analyzed by confocal microscopy. Microglial morphology was analyzed by immunohistochemistry. In the present study, we show that although the main cell types of the pineal gland (pinealocytes, astrocytes and microglia) express TLR4, the production of TNF induced by LPS is mediated by microglia. This effect is due to activation of the nuclear factor kappa B (NF-kB) pathway. In addition, we observed that LPS activates microglia and modulates the expression of TNFR1 in pinealocytes. As TNF has been shown to amplify and prolong inflammatory responses, its production by pineal microglia suggests a glia-pinealocyte network that regulates melatonin output. The current study demonstrates the molecular and cellular basis for understanding how melatonin synthesis is regulated during an innate immune response, thus our results reinforce the role of the pineal gland as sensor of immune status.
Assuntos
Melatonina/biossíntese , Neuroglia/metabolismo , Comunicação Parácrina/fisiologia , Glândula Pineal/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Fatores de Necrose Tumoral/metabolismo , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Lipopolissacarídeos/farmacologia , Masculino , Melatonina/imunologia , Neuroglia/citologia , Neuroglia/imunologia , Comunicação Parácrina/efeitos dos fármacos , Glândula Pineal/citologia , Glândula Pineal/imunologia , Ratos , Ratos Wistar , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fatores de Necrose Tumoral/imunologiaRESUMO
BACKGROUND: Estrogens are recognized modulators of pituitary cell renewal, sensitizing cells to mitogenic and apoptotic signals. Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine that plays an important role in tissue homeostasis modulating cell proliferation, differentiation and death. We previously demonstrated that TNF-α-induced apoptosis of anterior pituitary cells from female rats is estrogen-dependent and predominant in cells from rats at proestrus when estradiol levels are the highest. AIMS: Considering that one of the mechanisms involved in the apoptotic action of estrogens can result from increased expression of cytokines and/or their receptors, the aim of the present study was to evaluate the effect of estrogens on the expression of TNF-α and its receptor, TNF receptor 1 (TNFR1), in anterior pituitary cells. METHODS/RESULTS: TNFR1 expression, determined by Western blot, was higher in anterior pituitary glands from rats at proestrus than at diestrus. Incubation of anterior pituitary cells from ovariectomized rats with 17ß-estradiol enhanced TNFR1 protein expression. As determined by double immunocytochemistry, the expression of TNF-α and TNFR1 was detected in prolactin-, GH-, LH- and ACTH-bearing cells. 17ß-estradiol increased the percentage of TNF-α and TNFR1-immunoreactive lactotropes but did not modify the number of GH-bearing cells expressing TNF-α or TNFR1. CONCLUSION: Our results demonstrate that estradiol increases the expression of TNF-α and TNFR1 in anterior pituitary cells, especially in lactotropes. The sensitizing action of estrogens to proapoptotic stimuli at proestrus in the anterior pituitary gland may involve changes in the expression of the TNF-α/TNFR1 system.
Assuntos
Estradiol/fisiologia , Regulação da Expressão Gênica/fisiologia , Lactotrofos/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Animais , Células Cultivadas , Estradiol/farmacologia , Ciclo Estral/fisiologia , Feminino , Lactotrofos/efeitos dos fármacos , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Ratos , Ratos WistarRESUMO
In a previous work we showed that the melanocortin alpha-melanocyte-stimulating hormone (α-MSH) exerts anti-inflammatory action through melanocortin 4 receptor (MC4R) in vivo in rat hypothalamus. In this work, we examined the effect of α-MSH on the expression of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) and their receptors in primary cultured rat hypothalamic neurons. We also investigated α-MSH's possible mechanism/s of action. α-MSH (5 µM) decreased TNF-α expression induced by 24h administration of a combination of bacterial lipopolysaccharide (LPS, 1 µg/ml) plus interferon-γ (IFN-γ, 50 ng/ml). Expression of TNF-α and IL-1ß receptors TNFR1, TNFR2 and IL-1RI, was up-regulated by LPS+IFN-γ whereas α-MSH did not modify basal or LPS+IFN-γ-induced-TNFRs or IL-1RI expression. Both α-MSH and LPS+IFN-γ treatments increased CREB activation. α-MSH did not modify NF-κB activation induced by LPS+IFN-γ in hypothalamic neurons. In conclusion, our data show that α-MSH reduces TNF-α expression in hypothalamic neurons by a mechanism which could be mediated by CREB. The regulation of inflammatory processes in the hypothalamus by α-MSH might help to prevent neurodegeneration resulting from inflammation.
Assuntos
Hipotálamo/imunologia , Hipotálamo/metabolismo , Interferon gama/antagonistas & inibidores , Lipopolissacarídeos/fisiologia , Receptores Tipo I de Fatores de Necrose Tumoral , Fator de Necrose Tumoral alfa/antagonistas & inibidores , alfa-MSH/fisiologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica/imunologia , Hipotálamo/citologia , Interferon gama/biossíntese , Interferon gama/genética , Lipopolissacarídeos/antagonistas & inibidores , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Neurônios/imunologia , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos Wistar , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genéticaRESUMO
AIM: Several lines of evidence suggest that major depressive disorder is associated with an inflammatory status. Tumor necrosis factor-alpha has been investigated as a potential molecular target in mood disorders. Tumor necrosis factor-alpha exerts its activity through binding to specific cell membrane receptors named as TNFR1 and TNFR2. The aim of the present study was to investigate soluble plasma TNFR1 (sTNFR1) and TNFR2 levels (sTNFR2) in major depressive disorder patients. METHODS: Female outpatients with major depressive disorder (n = 30) were compared with a healthy control group (n = 19). Severity of depressive symptoms was evaluated on Beck Depression Inventory; post-traumatic stress disorder (PTSD) symptoms were evaluated on PTSD Checklist-Civilian Version; and childhood abuse and neglect on the Childhood Trauma Questionnaire. Plasma tumor necrosis factor-alpha and its soluble receptors were measured by ELISA. RESULTS: Patients had no changes in tumor necrosis factor-alpha concentrations but did have increased sTNFR1 (P < 0.001) and sTNFR2 (P < 0.001) levels compared to controls. Plasma level of sTNFR1 was positively predicted by age (B = 0.25, P = 0.05) and PTSD-like symptoms (B = 0.41, P = 0.002) and plasma levels of sTNFR2 by depression severity (B = 0.67, P < 0.001). CONCLUSIONS: Soluble tumor necrosis factor-alpha receptors could be reliable markers of inflammatory activity in major depression.
Assuntos
Transtorno Depressivo Maior/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Adulto , Criança , Maus-Tratos Infantis/psicologia , Transtorno Depressivo Maior/psicologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral/genética , Inquéritos e Questionários , Fator de Necrose Tumoral alfa/sangue , Adulto JovemRESUMO
Chronic ethanol consumption leads to cell injury in virtually every tissue. Tumor necrosis factor-alpha (TNF-alpha) constitutes a major factor in the development of alcohol-induced liver injury. In alcohol-dependent subjects, elevated levels of plasma TNF-alpha are strongly predictive of mortality. Binding of TNF-alpha to TNF-alpha receptor-1 (TNF-R1) activates death domain pathways, leading to necrosis and apoptosis in most tissues, and it also increases the expression of intercellular adhesion molecules (i.e., ICAM-1), which promote inflammation. We determined whether ethanol exposure leads to increases in cellular TNF-R1. We incubated HepG2 human hepatoma cells and H4-II-E-C3 rat hepatoma cells with 25, 50, and 100 mM ethanol for various intervals of time up to 48 h. Human colonic adenocarcinoma cells (Caco-2 cells) and neonatal rat primary cardiomyocytes were also incubated with different concentrations of ethanol. Levels of TNF-R1 were measured either by a sandwich enzyme-linked immunosorbent assay (ELISA) method or by determining the extracellular transmembrane domain of TNF-R1 by an intact-cell ELISA method. Ethanol exposure for 48 h increased TNF-R1 levels in human hepatoma cells in a dose-dependent manner. Levels increased significantly by 164% at 50 mM and by 240% at 100 mM ethanol. Effects were time dependent and did not reach a plateau at 48 h. Similar increases in TNF-R1 were also observed in rat hepatoma cells (90% at 50 mM and 230% at 100 mM ethanol). Under similar conditions, Caco-2 cells showed a significant 80% increase in TNF-R1 levels at 200 mM ethanol, a concentration found in intestine. Neonatal rat primary cardiomyocytes showed TNF-R1 increases of 36% at 50 mM and 44% at 100 mM ethanol. These results indicate that exposure of different cell types to pharmacologic concentrations of ethanol increases TNF-R1 levels and may augment TNF-alpha-mediated cell injury in different tissues.