961 resultados para INCREASED EXPRESSION
Resumo:
Congenital muscular dystrophy with laminin α2 chain deficiency (MDC1A) is one of the most severe forms of muscular disease and is characterized by severe muscle weakness and delayed motor milestones. The genetic basis of MDC1A is well known, yet the secondary mechanisms ultimately leading to muscle degeneration and subsequent connective tissue infiltration are not fully understood. In order to obtain new insights into the molecular mechanisms underlying MDC1A, we performed a comparative proteomic analysis of affected muscles (diaphragm and gastrocnemius) from laminin α2 chain-deficient dy(3K)/dy(3K) mice, using multidimensional protein identification technology combined with tandem mass tags. Out of the approximately 700 identified proteins, 113 and 101 proteins, respectively, were differentially expressed in the diseased gastrocnemius and diaphragm muscles compared with normal muscles. A large portion of these proteins are involved in different metabolic processes, bind calcium, or are expressed in the extracellular matrix. Our findings suggest that metabolic alterations and calcium dysregulation could be novel mechanisms that underlie MDC1A and might be targets that should be explored for therapy. Also, detailed knowledge of the composition of fibrotic tissue, rich in extracellular matrix proteins, in laminin α2 chain-deficient muscle might help in the design of future anti-fibrotic treatments. All MS data have been deposited in the ProteomeXchange with identifier PXD000978 (http://proteomecentral.proteomexchange.org/dataset/PXD000978).
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Maternal high-fat diet (HFD) impairs hippocampal development of offspring promoting decreased proliferation of neural progenitors, in neuronal differentiation, in dendritic spine density and synaptic plasticity reducing neurogenic capacity. Notch signaling pathway participates in molecular mechanisms of the neurogenesis. The activation of Notch signaling leads to the upregulation of Hes5, which inhibits the proliferation and differentiation of neural progenitors. This study aimed to investigate the Notch/Hes pathway activation in the hippocampus of the offspring of dams fed an HFD. Female Swiss mice were fed a control diet (CD) and an HFD from pre-mating until suckling. The bodyweight and mass of adipose tissue in the mothers and pups were also measured. The mRNA and protein expression of Notch1, Hes5, Mash1, and Delta1 in the hippocampus was assessed by RT-PCR and western blotting, respectively. Dams fed the HFD and their pups had an increased bodyweight and amount of adipose tissue. Furthermore, the offspring of mothers fed the HFD exhibited an increased Hes5 expression in the hippocampus compared with CD offspring. In addition, HFD offspring also expressed increased amounts of Notch1 and Hes5 mRNA, whereas Mash1 expression was decreased. However, the expression of Delta1 did not change significantly. We propose that the overexpression of Hes5, a Notch effector, downregulates the expression of the proneural gene Mash1 in the offspring of obese mothers, delaying cellular differentiation. These results provide further evidence that an offspring's hippocampus is molecularly susceptible to maternal HFD and suggest that Notch1 signaling in this brain region is important for neuronal differentiation.
Resumo:
Rhizophores of Vernonia herbacea, an Asteraceae found in the Brazilian Cerrado, store high amounts of fructans that vary in composition over the phenological cycle. Fructan 1-exohydrolase (1-FEH) activity is detectable during the sprouting phase, mainly in the proximal regions of rhizophores, of plants induced to sprout by defoliation and/or cold storage. We found an increase in 1-FEH gene expression during natural and induced sprouting and further enhancement through low-temperature treatment. Furthermore, a comparative analysis of 1-FEH gene expression in different regions of the rhizophores during the transition from dormancy to sprouting is presented. Transcripts were detected mainly in the proximal region, coinciding with high 1-FEH activity and a high concentration of free fructose. Low temperature promoted the accumulation of fructans of a low degree of polymerization (DP) and enhanced 1-FEH activity and gene expression. It is hypothesized that a set of 1-FEH proteins acts in two different ways during fructan mobilization: (1) by hydrolyzing fructo-oligosaccharides and -polysaccharides in sprouting plants (naturally or induced) for carbon supply and (2) by hydrolyzing preferably fructo-polysaccharides under low temperature to maintain the oligosaccharide pool for plant cold acclimation. (C) 2010 Elsevier GmbH. All rights reserved.
Resumo:
Protease-activated receptor 1 (PAR-1) is a G-protein-coupled receptor that is overexpressed in solid tumors, being associated with several pro-tumoral responses including primary growth, invasion, metastasis and angiogenesis. Expression of PAR-1 in human leukemic cell lines is reported but the status of its expression in human leukemic patients is currently unknown. In this study we evaluated the expression pattern of PAR-1 in patients with the four main types of leukemia - chronic lymphocytic leukemia subtype B (B-CLL), acute lymphoblastic leukemia subtype B (B-ALL), acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). Flow cytometry analyses show that lymphocytes from B-CLL patients express this receptor at similar levels to healthy individuals. On the other hand, it was observed a significant increase in PAR-1 expression in B-ALL lymphocytes as compared to B-CLL and healthy donors. Flow cytometric and real-time PCR demonstrated a significant increase in PAR-1 expression in granulocytes from CML patients in blast phase (CML-BP) but not in chronic phase (CML-CP) as compared to healthy donors. Finally, a significant increase in PAR-1 expression has been also observed in blasts from AML (subtypes M4 and M5) patients, as compared to monocytes or granulocytes from healthy donors. We conclude that PAR-1 might play an important biological role in aggressive leukemias and might offer additional strategies for the development of new therapies. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
Polymerase chain reaction (PCR)-based differential display was used to screen for alterations in gene expression in the mesolimbic system of the human alcoholic brain. Total RNA was extracted from the nucleus accumbens of five alcoholic and five control brains. A selected subpopulation of mRNA was reverse-transcribed to cDNA and amplified by PCR. A differentially expressed cDNA fragment was recovered, cloned, and sequenced. Full sequence analysis of this 467 bp fragment revealed 98.2% homology with the human mitochondrial 12S rRNA gene. Dot-blot analysis showed increased expression of this gem in nucleus accumbens and hippocampus, but not in the superior frontal cortex, primary motor cortex, caudate, and pallidus/putamen In a total of eight human alcoholic brains, compared with seven control brains. A similar increased expression was observed by dot-blot analysis, using RNA from the cerebral cortex of rats chronically treated with alcohol vapor. Hybridization of a 16S rRNA oligonucleotide probe indicated that the expression of both rRNAs genes was significantly increased in nucleus accumbens. These results indicate that chronic alcohol consumption induces alteration in expression of mitochondrial genes in selected brain regions. The altered gene expression may reflect mitochondrial dysfunction In the alcohol-affected brain.
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Tumour cells are known to be highly glycolytic, thus producing high amounts of lactic acid. Monocarboxylate transporters (MCTs), by promoting the efflux of the accumulating acids, constitute one of the most important mechanisms in the maintenance of tumour intracellular pH. Since data concerning MCT expression in colorectal carcinomas (CRC) are scarce and controversial, the present study aimed to assess the expressions of MCT1, 2, and 4 in a well characterized series of CRC and assess their role in CRC carcinogenesis. CRC samples (126 cases) were analyzed for MCT1, MCT2, and MCT4 immunoexpression and findings correlated with clinico-pathological parameters. Expression of all MCT isoforms in tumour cells was significantly increased when compared to adjacent normal epithelium. Remarkably, there was a significant gain of membrane expression for MCT1 and MCT4 and loss of plasma membrane expression for MCT2 in tumour cells. Plasma membrane expression of MCT1 was directly related to the presence of vascular invasion. This is the larger study on MCT expression in CRC and evaluates for the first time its clinico-pathological significance. The increased expression of these transporters suggests an important role in CRC, which might justify their use, especially MCT1 and MCT4, as targets in CRC drug therapy.
Resumo:
To identify novel genes involved in the molecular pathogenesis of chronic lymphocytic leukemia (CLL) we performed a serial analysis of gene expression (SAGE) in CLL cells, and compared this with healthy B cells (nCD19(+)). We found a high level of similarity among CLL subtypes, but a comparison of CLL versus nCD19(+) libraries revealed 55 genes that were over-represented and 49 genes that were down-regulated in CLL. A gene ontology analysis revealed that TOSO, which plays a functional role upstream of Fas extrinsic apoptosis pathway, was over-expressed in CLL cells. This finding was confirmed by real-time reverse transcription-polymerase chain reaction in 78 CLL and 12 nCD19(+) cases (P <.001). We validated expression using flow cytometry and tissue microarray and demonstrated a 5.6-fold increase of TOSO protein in circulating CLL cells (P =.013) and lymph nodes (P =.006). Our SAGE results have demonstrated that TOSO is a novel overexpressed antiapoptotic gene in CLL.
Resumo:
Fatty acids inhibit insulin-mediated glucose metabolism in skeletal muscle, an effect largely attributed to defects in insulin-mediated glucose transport. Insulin-resistant mice transgenic for the overexpression of lipoprotein lipase (LPL) in skeletal muscle were used to examine the molecular mechanism(s) in more detail. Using DNA gene chip array technology, and confirmation by RT-PCR and Western analysis, increases in the yeast Sec1p homolog Munc18c mRNA and protein were found in the gastrocnemius muscle of transgenic mice, but not other tissues. Munc18c has been previously demonstrated to impair insulin-mediated glucose transport in mammalian cells in vitro. Of interest, stably transfected C2C12 cells overexpressing LPL not only demonstrated increases in Munc18c mRNA and protein but also in transcription rates of the Munc18c gene. jlr To confirm the relevance of fatty acid metabolism and insulin resistance to the expression of Munc18c in vivo, a 2-fold increase in Munc18c protein was demonstrated in mice fed a high-fat diet for 4 weeks. Together, these data are the first to implicate in vivo increases in Munc18c as a potential contributing mechanism to fatty acid-induced insulin resistance.
Resumo:
Tumour cells are known to be highly glycolytic, thus producing high amounts of lactic acid. Monocarboxylate transporters (MCTs), by promoting the efflux of the accumulating acids, constitute one of the most important mechanisms in the maintenance of tumour intracellular pH. Since data concerning MCT expression in colorectal carcinomas (CRC) are scarce and controversial, the present study aimed to assess the expressions of MCT1, 2, and 4 in a well characterized series of CRC and assess their role in CRC carcinogenesis. CRC samples (126 cases) were analyzed for MCT1, MCT2, and MCT4 immunoexpression and findings correlated with clinico-pathological parameters. Expression of all MCT isoforms in tumour cells was significantly increased when compared to adjacent normal epithelium. Remarkably, there was a significant gain of membrane expression for MCT1 and MCT4 and loss of plasma membrane expression for MCT2 in tumour cells. Plasma membrane expression of MCT1 was directly related to the presence of vascular invasion. This is the larger study on MCT expression in CRC and evaluates for the first time its clinico-pathological significance. The increased expression of these transporters suggests an important role in CRC, which might justify their use, especially MCT1 and MCT4, as targets in CRC drug therapy.
Resumo:
The immune mechanisms involved in dengue fever and dengue hemorrhagic/dengue shock syndrome are not well understood. The ex vivo activation status of immune cells during the dengue disease in patients was examined. CD4and CD8 T cells were reduced during the acute phase. Interestingly, CD8 T cells co-expressing activation marker HLA-DR, Q, P, and cytolytic granule protein-Tia-1 were significantly higher in dengue patients than in controls. Detection of adhesion molecules indicated that in dengue patients the majority of T cells (CD4 and CD8) express the activation/memory phenotype, characterized as CD44HIGH and lack the expression of the naïve cell marker, CD62L LOW. Also, the levels of T cells co-expressing ICAM-1 (CD54), VLA-4, and LFA-1 (CD11a) were significantly increased. CD8 T lymphocytes expressed predominantly low levels of anti-apoptotic molecule Bcl-2 in the acute phase, possibly leading to the exhibition of a phenotype of activated/effector cells. Circulating levels of IL-18, TGF-b1 and sICAM-1 were significantly elevated in dengue patients. Early activation events occur during acute dengue infection which might contribute to viral clearance. Differences in expression of adhesion molecules among CD4 and CD8 T cells might underlie the selective extravasation of these subsets from blood circulation into lymphoid organs and/or tissues. In addition, activated CD8 T cells would be more susceptible to apoptosis as shown by the alteration in Bcl-2 expression. Cytokines such as IL-18, TGF-b1, and sICAM-1 may be contributing by either stimulating or suppressing the adaptative immune response, during dengue infection, thereby perhaps establishing a relationship with disease severity.
Resumo:
PURPOSE: To evaluate and validate mRNA expression markers capable of identifying patients with ErbB2-positive breast cancer associated with distant metastasis and reduced survival. PATIENTS AND METHODS: Expression of 60 genes involved in breast cancer biology was assessed by quantitative real-time PCR (qrt-PCR) in 317 primary breast cancer patients and correlated with clinical outcome data. Results were validated subsequently using two previously published and publicly available microarray data sets with different patient populations comprising 295 and 286 breast cancer samples, respectively. RESULTS: Of the 60 genes measured by qrt-PCR, urokinase-type plasminogen activator (uPA or PLAU) mRNA expression was the most significant marker associated with distant metastasis-free survival (MFS) by univariate Cox analysis in patients with ErbB2-positive tumors and an independent factor in multivariate analysis. Subsequent validation in two microarray data sets confirmed the prognostic value of uPA in ErbB2-positive tumors by both univariate and multivariate analysis. uPA mRNA expression was not significantly associated with MFS in ErbB2-negative tumors. Kaplan-Meier analysis showed in all three study populations that patients with ErbB2-positive/uPA-positive tumors exhibited significantly reduced MFS (hazard ratios [HR], 4.3; 95% CI, 1.6 to 11.8; HR, 2.7; 95% CI, 1.2 to 6.2; and, HR, 2.8; 95% CI, 1.1 to 7.1; all P < .02) as compared with the group with ErbB2-positive/uPA-negative tumors who exhibited similar outcome to those with ErbB2-negative tumors, irrespective of uPA status. CONCLUSION: After evaluation of 898 breast cancer patients, uPA mRNA expression emerged as a powerful prognostic indicator in ErbB2-positive tumors. These results were consistent among three independent study populations assayed by different techniques, including qrt-PCR and two microarray platforms.
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Previous studies showed a fetal sheep liver extract (FSLE), in association with LPS, injected into aged (>20 months) mice reversed the altered polarization (increased IL-4 and IL-10 with decreased IL-2 and IFN-gamma) in cytokine production seen from ConA stimulated lymphoid cells of those mice. Aged mice show a >60% decline in numbers and suppressive function of both CD4(+)CD25(+)Foxp3(+)Treg and so-called Tr3 (CD4(+)TGFbeta(+)). Their number/function is restored to levels seen in control (8-week-old) mice by FSLE. We have reported at length on the ability of a novel pair of immunoregulatory molecules, members of the TREM family, namely CD200:CD200R, to control development of dendritic cells (DCs) which themselves regulate production of Foxp3(+) Treg. The latter express a distinct subset of TLRs which control their function. We report that a feature of the altered Treg expression following combined treatment with FSLE and monophosphoryl lipid A, MPLA (a bioactive component of lipid A of LPS) is the altered gene expression both of distinct subsets of TLRs and of CD200Rs. We speculate that this may represent one of the mechanisms by which FSLE and MPLA alter immunity in aged mice.
Resumo:
Cx40-deficient mice (Cx40-/-) are hypertensive due to increased renin secretion. We evaluated the renal expression of neuronal nitric oxide synthase (nNOS) and cyclooxygenases COX-1 and COX-2, three macula densa enzymes. The levels of nNOS were increased in kidneys of Cx40-/- mice, as well as in those of wild-type (WT) mice subjected to the two-kidney one-clip model of hypertension. In contrast, the levels of COX-2 expression were only increased in the hypoperfused kidney of Cx40-/- mice. Treatment with indomethacin lowered blood pressure and renin mRNA in Cx40-/- mice without affecting renin levels, indicating that changes in COX-2 do not cause the altered secretion of renin. Suppression of NOS activity by N(G)-nitro-L-arginine methyl ester (L-NAME) decreased renin levels in Cx40-/- animals, indicating that NO regulates renin expression in the absence of Cx40. Treatment with candesartan normalized blood pressure in Cx40-/- mice, and decreased the levels of both COX-2 and nNOS. After a treatment combining candesartan and L-NAME, the blood pressure of Cx40-/- mice was higher than that of WT mice, showing that NO may counterbalance the vasoconstrictor effects of angiotensin II in Cx40-/- mice. These data document that renal COX-2 and nNOS are differentially regulated due to the elevation of renin-dependent blood pressure in mice lacking Cx40.
Resumo:
Composts are the products obtained after the aerobic degradation of different types of organic matter waste and can be used as substrates or substrate/soil amendments for plant cultivation. There is a small but increasing number of reports that suggest that foliar diseases may be reduced when using compost, rather than standard substrates, as growing medium. The purpose of this study was to examine the gene expression alteration produced by the compost to gain knowledge of the mechanisms involved in compost-induced systemic resistance. A compost from olive marc and olive tree leaves was able to induce resistance against Botrytis cinerea in Arabidopsis, unlike the standard substrate, perlite. Microarray analyses revealed that 178 genes were differently expressed, with a fold change cut-off of 1, of which 155 were up-regulated and 23 were down-regulated in compost-grown, as against perlite-grown plants. A functional enrichment study of up-regulated genes revealed that 38 Gene Ontology terms were significantly enriched. Response to stress, biotic stimulus, other organism, bacterium, fungus, chemical and abiotic stimulus, SA and ABA stimulus, oxidative stress, water, temperature and cold were significantly enriched, as were immune and defense responses, systemic acquired resistance, secondary metabolic process and oxireductase activity. Interestingly, PR1 expression, which was equally enhanced by growing the plants in compost and by B. cinerea inoculation, was further boosted in compost-grown pathogen-inoculated plants. Compost triggered a plant response that shares similarities with both systemic acquired resistance and ABA-dependent/independent abiotic stress responses.
Resumo:
Interactions of neurons with microglia may play a dominant role in sleep regulation. TNF may exert its somnogeneic effects by promoting attraction of microglia and their processes to the vicinity of dendrites and synapses. We found TNF to stimulate neurons (i) to produce CCL2, CCL7 and CXCL10, chemokines acting on mononuclear phagocytes and (ii) to stimulate the expression of the macrophage colony stimulating factor (M-CSF/Csf1), which leads to elongation of microglia processes. TNF may also act on neurons by affecting the expression of genes essential in sleep-wake behavior. The neuronal expression of Homer1a mRNA, increases during spontaneous and enforced periods of wakefulness. Mice with a deletion of Homer1a show a reduced wakefulness with increased non-rapid eye movement (NREM) sleep during the dark period. Recently the TNF-dependent increase of NREM sleep in the dark period of mice with CD40-induced immune activation was found to be associated with decreased expression of Homer1a. In the present study we investigated the effects of TNF and IL-1β on gene expression in cultures of the neuronal cell line HT22 and cortical neurons. TNF slightly increased the expression of Homer1a and IL-1β profoundly enhanced the expression of Early growth response 2 (Egr2). The data presented here indicate that the decreased expression of Homer1a, which was found in the dark period of mice with CD40-induced increase of NREM sleep is not due to inhibitory effects of TNF and IL-1β on the expression of Homer1a in neurons.