Navegando por Palavras-chave "Signaling pathways"
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- ItemAcesso aberto (Open Access)Avaliação da imunoexpressão de proteínas da via de sinalização Wnt canônica e não canônica no adenocarcinoma gástrico(Universidade Federal de São Paulo (UNIFESP), 2017-08-31) Oliveira, Levindo Alves de [UNIFESP]; Waisberg, Jaques [UNIFESP]; Oshima, Celina Tizuko Fujiyama [UNIFESP]; http://lattes.cnpq.br/8007052437699905; http://lattes.cnpq.br/8316985163665041; http://lattes.cnpq.br/0021377306376898; Universidade Federal de São Paulo (UNIFESP)Objectives: The aim was to analyze the expression of proteins in canonical and non-canonical Wnt signaling pathways in gastric adenocarcinoma tissue. To correlate the expression of such proteins with the patients’ biodemographical characteristics and morphological and anatomopathological characteristics of the tumor. Method: The expression of proteins in Wnt signaling pathways (Wnt-5a, FZD5, GSK3B, axin, CK1, ubiquitin, D1 cyclin and C-MYC) was evaluated in 72 patients who underwent gastric adenocarcinoma surgery. Forty-five (64.3%) were male and the age average was 64.6±11.8 years. The protein level was determined by immunohistochemistry using monoclonal antibodies in gastric tissue samples in tissue microarray. Results: The expression of CK1 protein was positive in cell cytoplasm and significant in tumors without compromised surgical margins (p= 0.031). The ubiquitin protein presented strong expression in both cell nucleus and cytoplasm and was significantly more intense in both nucleus and cytoplasm of cells of moderately and well-differentiated tumors (p= 0.037) and in intestinal tumors (p = 0.031). The D1cyclin protein was expressed only in cell nucleus and was significantly more intense in male patients’ tumors (p= 0.039). The C-MYC protein was expressed in both cell cytoplasm and nucleus and the absence of its cytoplasmic expression was significantly higher in intestinal tumors (p= 0.028) and significant odds ratio (p= 0.021). The immunoexpressions of the Wnt-5a and Frizzled-5 proteins did not present significant differences (p≤0.05) regarding the epidemiological characteristics of the patients and anatomopathological aspects of the tumor. Conclusions:The strong expression of the protein of Wnt signaling pathway suggests the relevance and involvement of the canonical pathway in the occurrence of gastric adenocarcinoma. The significant absence of expression of Wnt-5a and FZD5 proteins suggests that the non-canonical pathway is not activated in gastric adenocarcinoma tissue.
- ItemSomente MetadadadosEfeito do uso de glicocorticóides na função e morfologia cardíaca de ratos(Universidade Federal de São Paulo (UNIFESP), 2016-06-09) Guimaraes, Fabiana de Salvi [UNIFESP]; Medeiros, Alessandra [UNIFESP]; http://lattes.cnpq.br/0071198026371230; Universidade Federal de São Paulo (UNIFESP)Introduction Glucocorticoids are drugs widely used in the clinic for their anti-inflammatory and immunosuppressive properties, but high doses and/or prolonged treatment are associated with cardiac remodeling. Objective To study the effect of using GCs (dexamethasone) in cardiac morphology and function, in signaling pathways that regulate the flow of Ca2+ as well as the possible signaling pathways for pathological cardiac hypertrophy in the rat heart. Methods Male Wistar rats, adult (400 - 415g) were randomized into two groups: treated with dexamethasone (DEX) and feed Pair Control (Cont- PF). The animals in the treated group received 35 ug/ g body weight/day of dexamethasone in drinking water for 15 days. Was evaluated by echocardiography fractional shortening and the ratio E/A waves, as parameters of systolic and diastolic function, respectively. The isometric tension developed and the rate of voltage change per unit time carried by functional analysis contractility in vitro, the positive peak derived from (+ dT/dt) and negative (-dT/dt) were obtained, which inform the temporal variation cardiac inotropic, which were also analyzed by the method of cardiac contractility. After sacrificing the animals, the cardiac chambers were weighed separately and corrected for tibia length. By histological analysis evaluated the diameter of cardiomyocytes and collagen percentage of these tissues. The method of the comet assay was used to evaluate apoptosis of cardiac tissue. And finally, intracellular signaling proteins related to Ca2+ homeostasis and calcineurin. Data were analyzed by Student's t - test or one-way ANOVA with repeated measures, with post hoc Student - Newman Keuls. Results We observed that there were some important cardiovascular abnormalities such as elevated blood pressure, impaired relaxation in heart muscle and therefore diastolic function, increased percentage of collagen and apoptosis of cardiomyocytes treated animals GC. Regarding the analysis of myocardial contractility assessed by the papillary muscle, an increase in its size as well as its thickness. However, it was accompanied by a reduction of its maximum length (Lmax), tension development (TD), the relaxation time (TR) and its temporal variables: + dT/dt and -dT/dt. The study of hemodynamic parameters in anesthetized animals was not sensitive enough to show cardiac dysfunction in the DEXA group. Regarding the expression of proteins involved in calcium homeostasis, we observed an increase in expression of phospholamban phosphorylated at threonine 17, reduction in the expression of NCX and no change in the expression of Serca 2a protein. Since the expression of members of the protein calcineurin, we observed an increase in cytoplasmic and nuclear expression of NFAT c3 and GATA-4, and increase in nuclear calcineurin expression. Conclusion The findings of this study demonstrate that there is an increase in blood pressure in animal of DEXA group, as well as an increase in the size of these hearts, accompanied by a reduction of diastolic function, increased fibrosis assessed by the percentage of collagen, increased myocardial apoptosis and significant hemodynamic changes for the proper functioning of the heart muscle, with consequent alteration of protein expression related to Ca2+ homeostasis and calcineurin.
- ItemAcesso aberto (Open Access)Estudo comparativo do efeito da Echinácea purpúrea e sorafenibe em células de adenocarcinoma renal humano em cultura(Universidade Federal de São Paulo (UNIFESP), 2010-09-29) Tassetano, Renata Cristina Tornelli [UNIFESP]; Schor, Nestor [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: The renal cell carcinoma (CR) is relatively rare compared to other cancers. One of the most potent tumor mitogen, vascular endothelial growth factor, VEGF is regulated by numerous pathways, especially Ras and Akt, which are targets of many therapeutic agents, among them sorafenib. These signaling pathways play an important role in the development and maintenance of the multidrug resistance (MDR). Echinacea purpurea is used as an alternative treatment for some cancers, and promising for the treatment of CR. Aim: Analyze the effect of Ech purpurea (Ech) on the cellular viability, apoptosis, Ras and Akt signaling pathway as well as tumor angiogenesis throughout VGEF and potential proteins alteration in the cellular resistance to drugs. Methods: Herbal echinacea were added to cell culture Caki-1 for subsequent analysis of cell viability (Crystal Violet), apoptosis (flow cytometry), release of the enzyme lactate dehydrogenase - LDH (Bio 200), protein expression of VEGF, Ras and Akt (Western blot ) and gene expression MDR, MRP, LRP (RT-PCR). The experiments were performed after 24, 48 and 72 hours of treatment. The results were analyzed by One Way ANOVA, p <0.001 vs CT (X ± SE vs CT). Results: Group treated with Ech demonstrated decrease in cell viability dose and time dependent compared to the control (IC50, 150mg/mL) from 0 to 300ug/mL (p<0.001). We observed a statistically significant increase of apoptotic cells for group 72 hours comparing with control group: 4.7±0.4 vs. 7.6±0.7 (p<0.001), respectively. Also, a decrease in protein expression (p<0.05) of the Akt (0.301±0.02 vs. 0.193±0.009) and VEGF (0.729±0.01 vs. 0.439±0.01) in 48 hours, as well as Ras in 24 hours (0.484±0.05 vs. 0.289±0.02) were obtained. By analyzing the genic expression of the proteins resistance to multiple drugs, Ech caused a substantial decrease of 100% for MDR and MRP with 25% decreases in LRP, suggesting an important effect in blunt the resistance protein to drugs. Conclusion: To our knowledge, the Ech has anti-oncogenic properties since it showed activity on the viability and apoptosis. Likewise, Ech has its role on the signaling pathways Akt and Ras, which are important mediators of cell cycle progression and apoptosis. These blunted pathways demonstrated an important role on VEGF inhibition, as well as in the regulation of multidrug resistance.
- ItemSomente MetadadadosEstudos in vitro da participação da leptina em células endoteliais pulmonares de ratos nutridos e desnutridos intrauterinamente(Universidade Federal de São Paulo, 2014-03-02) Santos, Leila Aparecida dos [UNIFESP]; Landgraf, Richardt Gama [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Studies suggest that intrauterine malnutrition can "program" the fetal tissues making them more prone to disorders associated with food, such as type 2 diabetes, metabolic syndrome and other chronic diseases in adulthood , and induce changes in the immune response and inflammatory. Leptin, the main hormone secreted by adipose tissue, has a pleiotropic action, working in various systems such as the regulation of energy balance, reproduction, hematopoiesis, lymphopoiesis and has a modulating action of the immune system. Pulmonary endothelial cells were obtained from Wistar rats, male or intrauterine undernourished fed rats at 12 weeks of age. These cells were stimulated with leptin or LPS or leptin plus LPS, furthermore, cells with no stimulus were used as controls. Two hours after stimulation, production of inflammatory mediators PGE2, LTB4, IL1?, TNF? and the expression of ERK ½, and leptin receptors were analyzed. We observed that expression of the leptin receptor is 63 % lower in primary cultures of endothelial cells derived from intrauterine undernourished rats. Leptin alone did not induce any change in levels of inflammatory mediators evaluated, whereas LPS increased levels of PGE2 (250 %) and LTB4 (29%). Only endothelial cells of rats fed LPS administration + leptin production increased lipid mediators compared to LPS group (PGE 2 - and LTB4 28 % - 18%). The assay for IL1? showed that only cells from the control animals showed expression of IL1?. The expression of TNF and activation of ERK ½ showed a contradictory result because only the endothelial cells from the malnourished animals showed higher expression and activation, respectively. This result may suggest an expression of TNFa stimulation via LPS via another receptor with activation of ERK. These results suggest that the lower expression of the leptin receptor in lung endothelial cells in intrauterine undernourished rats could negatively modulate lipid mediator production in these cells.