THAIS MARTINS DE LIMA
Projetos de Pesquisa
Unidades Organizacionais
LIM/51 - Laboratório de Emergências Clínicas, Hospital das Clínicas, Faculdade de Medicina
LIM/02 - Laboratório de Anatomia Médico-Cirúrgica, Hospital das Clínicas, Faculdade de Medicina
LIM/02 - Laboratório de Anatomia Médico-Cirúrgica, Hospital das Clínicas, Faculdade de Medicina
5 resultados
Resultados de Busca
Agora exibindo 1 - 5 de 5
- Molecular Mechanisms by Which Saturated Fatty Acids Modulate TNF-alpha Expression in Mouse Macrophage Lineage(2011) LIMA-SALGADO, Thais Martins de; ALBA-LOUREIRO, Tatiana C.; NASCIMENTO, Caroline S. do; NUNES, Maria T.; CURI, RuiMany macrophage functions are modulated by fatty acids (FAs), including cytokine release, such as tumor necrosis factor-alpha (TNF-alpha). TNF-alpha is of great interest due to its role in the inflammation process observed in several diseases such as rheumatoid arthritis, atherosclerosis, and obesity. However, the mechanisms by which FA effects occur have not been completely elucidated yet. In this study, we used a mouse monocyte lineage (J774 cells) to evaluate the effect of 50 and 100 mu M of saturated (palmitic and stearic acids), monounsaturated (oleic acid) and polyunsaturated (linoleic acid) FAs on TNF-alpha production. Alterations in gene expression, poly(A) tail length and activation of transcription factors were evaluated. Oleic and linoleic acids, usually known as neutral or pro-inflammatory FA, inhibited LPS-induced TNF-alpha secretion by the cells. Saturated FAs were potent inducers of TNF-alpha expression and secretion under basal and inflammatory conditions (in the presence of LPS). Although the effect of the saturated FA was similar, the mechanism involved in each case seem to be distinct, as palmitic acid increased EGR-1 and CREB binding activity and stearic acid increased mRNA poly(A) tail. These results may contribute to the understanding of the molecular mechanisms by which saturated FAs modulate the inflammatory response and may lead to design of associations of dietary and pharmacological strategies to counteract the pathological effects of TNF-alpha.
- Effect of medium/omega-6 long chain triglyceride-based emulsion on leucocyte death and inflammatory gene expression(2011) CURY-BOAVENTURA, M. F.; GORJAO, R.; LIMA, T. Martins de; FIAMONCINI, J.; GODOY, A. B. P.; DESCHAMPHS, F. C.; SORIANO, F. G.; CURI, R.Lipid emulsion (LE) containing medium/omega-6 long chain triglyceride-based emulsion (MCT/omega-6 LCT LE) has been recommended in the place of omega-6 LCT-based emulsion to prevent impairment of immune function. The impact of MCT/omega-6 LCT LE on lymphocyte and neutrophil death and expression of genes related to inflammation was investigated. Seven volunteers were recruited and infusion of MCT/omega-6 LCT LE was performed for 6 h. Four volunteers received saline and no change was found. Blood samples were collected before, immediately afterwards and 18 h after LE infusion. Lymphocytes and neutrophils were studied immediately after isolation and after 24 and 48 h in culture. The following determinations were carried out: plasma-free fatty acids, triacylglycerol and cholesterol concentrations, plasma fatty acid composition, neutral lipid accumulation in lymphocytes and neutrophils, signs of lymphocyte and neutrophil death and lymphocyte expression of genes related to inflammation. MCT/omega-6 LCT LE induced lymphocyte and neutrophil death. The mechanism for MCT/omega-6 LCT LE-dependent induction of leucocyte death may involve changes in neutral lipid content and modulation of expression of genes related to cell death, proteolysis, cell signalling, inflammatory response, oxidative stress and transcription.
- Modulatory effect of fatty acids on fungicidal activity, respiratory burst and TNF-alpha and IL-6 production in J774 murine macrophages(2011) LIMA-SALGADO, Thais Martins de; SAMPAIO, Sandra Coccuzzo; CURY-BOAVENTURA, Maria Fernanda; CURI, RuiThe reported effects of different families of fatty acids (FA; SFA, MUFA, n-3 and n-6 PUFA) on human health and the importance of macrophage respiratory burst and cytokine release to immune defence led us to examine the influence of palmitic acid (PA), oleic acid (OA), linoleic acid, arachidonic acid, EPA and DHA on macrophage function. We determined fungicidal activity, reactive oxygen species (ROS) and cytokine production after the treatment of J774 cells with non-toxic concentrations of the FA. PA had a late and discrete stimulating effect on ROS production, which may be associated with the reduced fungicidal activity of the cells after treatment with this FA. OA presented a sustained stimulatory effect on ROS production and increased fungicidal activity of the cells, suggesting that enrichment of diets with OA may be beneficial for pathogen elimination. The effects of PUFA on ROS production were time-and dose-dependently regulated, with no evident differences between n-3 and n-6 PUFA. It was worth noting that most changes induced after stimulation of the cells with lipopolysaccharide were suppressed by the FA. The present results suggest that supplementation of the diet with specific FA, not classes of FA, might enable an improvement in host defence mechanisms or a reduction in adverse immunological reactions.
- Toxicity of fatty acids on ECV-304 endothelial cells(2011) MASI, Laureane Nunes; PORTIOLI-SANCHES, Erica Paula; LIMA-SALGADO, Thais Martins; CURI, RuiThe effects of stearic (saturated) or oleic (monounsaturated) acids and their combination with omega-3 and omega-6 polyunsaturated fatty acids (PUFA) on death of endothelial cells (ECV-304 cell line) were investigated. We examined: loss of plasma membrane integrity, DNA fragmentation, accumulation of neutral lipids (NL) and release of reactive oxygen species (ROS). The fatty acids studied were: stearic (SA), oleic (OA), docosahexaenoic (DHA), eicosapentaenoic (EPA), linoleic (LA) and gamma-linolenic (gamma A) acids. SA at 150 mu M induced cell death, did not lead to accumulation of NL and raised the release of ROS. omega-3 PUFA decreased ROS production, increased NL content but did not protect against ECV-304 cell death induced by SA. omega-6 PUFA inhibited SA-induced cell death, increased NL content and decreased ROS production. OA caused cell death but did not increase NL content and ROS production even at 300 mu M. omega-3 and omega-6 FA associated with OA further increased cell death with no change in ROS production and NL content. Concluding, omega-6 PUFA had a greater protective effect than omega-3 PUFA on the deleterious effects caused by SA whereas OA had low cytotoxicity but, when associated with PUFA, presented marked toxic effects on ECV-304 endothelial cells.
- PPAR gamma expression is increased in systemic lupus erythematosus patients and represses CD40/CD40L signaling pathway(2011) OXER, D. S.; GODOY, L. C.; BORBA, E.; LIMA-SALGADO, T.; PASSOS, L. A.; LAURINDO, I.; KUBO, S.; BARBEIRO, D. F.; FERNANDES, D.; LAURINDO, F. R.; VELASCO, I. T.; CURI, R.; BONFA, E.; SOUZA, H. P.Systemic lupus erythematosus (SLE) is a heterogeneous disease involving several immune cell types and pro-inflammatory signals, including the one triggered by binding of CD40L to the receptor CD40. Peroxisome-proliferator activated receptor gamma (PPAR gamma) is a transcription factor with anti-inflammatory properties. Here we investigated whether CD40 and PPAR gamma could exert opposite effects in the immune response and the possible implications for SLE. Increased PPAR gamma mRNA levels were detected by real-time PCR in patients with active SLE, compared to patients with inactive SLE PPAR gamma/GAPDH mRNA = 2.21 +/- 0.49 vs. 0.57 +/- 0.14, respectively (p < 0.05) or patients with infectious diseases and healthy subjects (p < 0.05). This finding was independent of the corticosteroid therapy. We further explored these observations in human THP1 and in SLE patient-derived macrophages, where activation of CD40 by CD40L promoted augmented PPAR gamma gene transcription compared to non-stimulated cells (PPAR gamma/GAPDH mRNA = 1.14 +/- 0.38 vs. 0.14 +/- 0.01, respectively; p < 0.05). This phenomenon occurred specifically upon CD40 activation, since lipopolysaccharide treatment did not induce a similar response. In addition, increased activity of PPAR gamma was also detected after CD40 activation, since higher PPAR gamma-dependent transcription of CD36 transcription was observed. Furthermore, CD40L-stimulated transcription of CD80 gene was elevated in cells treated with PPAR gamma-specific small interfering RNA (small interfering RNA, siRNA) compared to cells treated with CD40L alone (CD80/GAPDH mRNA = 0.11 +/- 0.04 vs. 0.05 +/- 0.02, respectively; p < 0.05), suggesting a regulatory role for PPAR gamma on the CD40/CD40L pathway. Altogether, our findings outline a novel mechanism through which PPAR gamma regulates the inflammatory signal initiated by activation of CD40, with important implications for the understanding of immunological mechanisms underlying SLE and the development of new treatment strategies. Lupus (2011) 20, 575-587.