979 resultados para Intermediate-filament Proteins


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3-Deoxyglucosone (3-DG) is a reactive dicarbonyl sugar thought to be a key intermediate in the nonenzymatic polymerization and browning of proteins by glucose. 3-DG may be formed in vivo from fructose, fructose 3-phosphate, or Amadori adducts to protein, such as N epsilon-fructoselysine (FL), all of which are known to be elevated in body fluids or tissues in diabetes. Modification of proteins by 3-DG formed in vivo is thought to be limited by enzymatic reduction of 3-DG to less reactive species, such as 3-deoxyfructose (3-DF). In this study, we have measured 3-DF, as a metabolic fingerprint of 3-DG, in plasma and urine from a group of diabetic patients and control subjects. Plasma and urinary 3-DF concentrations were significantly increased in the diabetic compared with the control population (0.853 +/- 0.189 vs. 0.494 +/- 0.072 microM, P <0.001, and 69.9 +/- 44.2 vs. 38.7 +/- 16.1 nmol/mg creatinine, P <0.001, respectively). Plasma and urinary 3-DF concentrations correlated strongly with one another, with HbA1c (P <0.005 in all cases), and with urinary FL (P <0.02 and P = 0.005, respectively). The overall increase in 3-DF concentrations in plasma and urine in diabetes and their correlation with other indexes of glycemic control suggest that increased amounts of 3-DG are formed in the body during hyperglycemia in diabetes and then metabolized to 3-DF. These observations are consistent with a role for increased formation of the dicarbonyl sugar 3-DG in the accelerated browning of tissue proteins in diabetes.

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Modifications of extant plasma proteins, structural proteins,and other macromolecules are enhanced in diabetes because of increased glycation (secondary to increased glucose concentrations) and perhaps because of increased oxidative stress, Increased glycation is present from the time of onset of diabetes, but the relation between diabetes and oxidative stress is less clear: increased oxidative stress may occur later in the course of disease, as vascular damage becomes established, or it may be a feature of uncomplicated diabetes, The combined effects of protein modification by glycation and oxidation may contribute to the development of accelerated atherosclerosis in diabetes and to the development of microvascular complications, Thus, even if not increased by diabetes, variations in oxidative stress may modulate the consequences of hyperglycemia in individual diabetic patients, In this review, the close interaction between glycation and oxidative processes is discussed, and the theme is developed that the most significant modifications of proteins are the result of interactions with reactive carbonyl groups, While glucose itself contains a carbonyl group that is involved in the initial glycation reaction, the most important and reactive carbonyls are formed by free radical-oxidation reactions damaging either carbohydrates (including glucose itself) or lipids, The resulting carbonyl-containing intermediate products then modify proteins, yielding "glycoxidation" and "lipoxidation" products, respectively, This common pathway for glucose and lipid-mediated stress, which may contribute to diabetic complications, is the basis for the carbonyl stress hypothesis for the development of diabetic complications.

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The common liver fluke, Fasciola hepatica, is a parasite of mammals. In the western world its effects are largely felt on agriculture where infection of cows, sheep and other farm animals is estimated to cause millions of dollars ofif financial losses. In the developing world, the problem is even more serious with an estimated 7 million infected people and many millions more at risk of infection. Calcium signalling is of key importance in all eukaryotic species and recent discoveries of novel types of calcium binding proteins in liver flukes (and related trematodes) suggest that there may be calcium signalling processes which are unique to this group of organisms. If so, these pathways may provide potential targets for the design of novel anthelmintic drugs. Here, we review three main groups of F. hepatica calcium binding proteins: the FH8 family, the calmodulin family (FhCaM1, FhCaM2 and FhCaM3) and the EF-hand/dynein light chain family (FH22, FhCaBP3, FhCaBP4). Considerable information has been gathered on the sequences, predicted structures and biochemical properties of these molecules. The challenge now is to understand their functions in the organism.

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UDP-galactose 4-epimerase (GALE; EC 5.1.3.2; UniProt: Q14376) catalyses the interconversion of UDP-galactose and UDP-glucose (figure 1a). In the majority of eukaryotes studied to date, the enzyme is also able to interconvert UDP-N-acetylgalactosamine (UDP-GalNAc) and UDP-N-acetylglucosamine (UDP-GlcNAc) (figure 1b). The first of these reactions occurs as part of the Leloir pathway, which converts galactose into the glycolytic intermediate glucose 6-phosphate. Both reactions are important in the maintenance of UDP-monosaccharide pools and, consequently, in supplying raw materials for the glycosylation of proteins and lipids. The enzyme has attracted considerable research interest because mutations in the corresponding gene are associated with the genetic disease type III galactosemia (OMIN #230350). There is also some interest in using the enzyme as a biocatalyst to interconvert its substrates and related UDP-monosaccharides.

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Seepage flow under hydraulic structures provided with intermediate filters has been investigated. The flow through the banks of the canal has been included in the model. Different combinations of intermediate filter and canal width were studied. Different lengths of the floor, differential heads, and depths of the sheet pile driven beneath the floor were also investigated. The introduction of an intermediate filter to the floor of hydraulic structures reduced the uplift force acting on the downstream floor by up to 72%. The maximum uplift reduction occurred when the ratio of the distance of filter location downstream from the cutoff to the differential head was 1. Introducing a second filter in the downstream side resulted in a further reduction in the exit hydraulic gradient and in the uplift force, which reached 90%. The optimum locations of the two filters occurred when the first filter was placed just downstream of the cutoff wall and the second filter was placed nearly at the middistance between the cutoff and the end toe of the floor. The results showed significant differences between the three-dimensional (3D) and the two-dimensional (2D) analyses.

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The genetic variation existing in a set of barley (Hordeum vulgare L.) landrace samples recently collected in Morocco was estimated. Two kinds of genetic markers, seed storage proteins (hordeins) and random amplified polymorphic DNA (RAPD), were used. Only six out of 31 landraces were subjected to RAPD analysis. Both kinds of markers, RAPD and storage proteins, yielded similar results, showing that the level of variation observed in Moroccan barley was high: all landraces showed variability; 808 different storage protein patterns (multilocus associations) were observed among 1897 individuals (2.32 seeds per association, on average) with an average of 43 multilocus associations per accession. In general, genetic variation within accessions was higher than between accessions. The 100 polymorphic RAPD bands generated by 21 effective primers were able to generate enough patterns to differentiate between uniform cultivars and even between individuals in variable accessions. One of the aims of this work was to compare the effectiveness of RAPD versus storage protein techniques in assessing the variability of genetic resource collections. On average hordeins were more polymorphic than RAPDs: they showed more alternatives per band on gels and a higher percentage of polymorphic bands, although RAPDs supply a higher number of bands. Although RAPD is an easy and standard technique, storage protein analysis is technically easier, cheaper and needs less sophisticated equipment. Thus, when resources are a limiting factor and considering the cost of consumables and work time, seed storage proteins must be the technique of choice for a first estimation of genetic variation in plant genetic resource collections.

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Emergent multiple predator effects (MPEs) might radically alter predictions of predatory impact that are based solely on the impact of individuals. In the context of biological invasions, determining if and how the individual-level impacts of invasive predators relates to their impacts in multiple-individual situations will inform understanding of how such impacts might propagate through recipient communities. Here, we use functional responses (the relationship between prey consumption rate and prey density) to compare the impacts of the invasive freshwater mysid crustacean Hemimysis anomala with a native counterpart Mysis salemaai when feeding on basal cladoceran prey (i) as individuals, (ii) in conspecific groups and (iii) in conspecific groups in the presence of a higher fish predator, Gasterosteus aculeatus. In the absence of the higher predator, the invader consumed significantly more basal prey than the native, and consumption was additive for both mysid species - that is, group consumption was predictable from individual-level consumption. Invaders and natives were themselves equally susceptible to predation when feeding with the higher fish predator, but an MPE occurred only between the natives and higher predator, where consumption of basal prey was significantly reduced. In contrast, consumption by the invaders and higher predator remained additive. The presence of a higher predator serves to exacerbate the existing difference in individual-level consumption between invasive and native mysids. We attribute the mechanism responsible for the MPE associated with the native to a trait-mediated indirect interaction, and further suggest that the relative indifference to predator threat on the part of the invader contributes to its success and impacts within invaded communities.

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Multiple lines of evidence suggest that schizophrenia results from aberrant neurodevelopment. The neurogenin1 gene (neurog1) consists of a single 1,666 bp exon that encodes a basic helix-loop-helix (bHLH) transcription factor that causes neuronal differentiation and induces cortical and glutamatergic differentiation programs. Because of its function and its location in 5q31.1, which has been linked to schizophrenia in multiple samples, we tested it for association with the disorder. We sequenced neurog1 in 25 affected subjects from the Irish Study of High-Density Schizophrenia Families. We observed a 5'-UTR SNP at position -60, already present in databases as rs8192558, and tested it along with rs2344485, rs8192559, and rs2344484. Narrow, intermediate, and broad diagnostic definitions were used. The major alleles of rs8192558 and rs2344484 were over-transmitted to affected subjects using both Pedigree Disequilibrium Test (PDT) (0.01 <or = P <or = 0.06) and FBAT (0.02 <or = P <or = 0.07). A haplotype consisting of the major alleles of all four SNPs was significantly over-transmitted in FBAT to the broad definition (P = 0.049), with trend significance to the narrow and intermediate definitions, and with trend significance in PDT. In confirmatory tests using 657 cases and 411 controls, this haplotype was slightly but not significantly over-represented in cases (81% vs. 77%, P = 0.21). These results, along with a priori evidence for the involvement of neurog1 in neurodevelopment, suggest that variants in neurog1 might have a small effect on susceptibility to schizophrenia. This gene should be tested in additional and larger samples.

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Adaptor proteins play an important role in signal transduction by regulating the establishment and maintenance of functionally important protein complexes. A recently described member of this group of proteins is p130cas (CAS), which contains numerous sequence motifs predicted to be involved in mediating protein-protein interactions. We propose that adaptor molecules like CAS may help determine the response of a cell to a particular signal by interacting with specific subsets of cellular proteins. To test this hypothesis, we have identified potential binding partners of CAS that may play a rote in cellular transformation by the oncoproteins v-SRC and/or v-CRK. We show that individual domains of CAS associate with specific subsets of proteins in vitro, and that many of these interactions are dependent on the state of tyrosine-phosphorylation of CAS. Sequences necessary for interacting with the focal adhesion kinase pp125FAK (FAK), v-SRC and v-CRK have been mapped to distinct regions of CAS. In addition, the identification of a number of putative CAS-binding partners that are present in crk-transformed cell extracts but undetectable in normal and src-transformed cell extracts supports a model in which unique protein complexes are formed in response to different signals.

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Healthcare systems worldwide are facing an unprecedented demographic change as globally, the number of older people will triple to 2 billion by the year 2050. The resulting pressures on acute services have been instrumental in the development of intermediate care (IC) as a new healthcare model, which has its origins in the National Health Service in the UK. IC is an umbrella term for patient services that do not require the resources of a general hospital but are beyond the scope of a traditional primary care team. IC aims to promote timely discharge from hospital, prevent unnecessary hospital admissions and reduce the need for long-term residential care by optimizing functional independence. Various healthcare providers around the world have adopted similar models of care to manage changing healthcare needs. Polypharmacy, along with age-related changes, places older people at an increased risk of adverse drug events, including inappropriate prescribing, which has been shown to be prevalent in this population in other healthcare settings. Medicines management (the practice of maximizing health through optimal use of medicines) of older people has been discussed in the literature in a variety of settings; however, its place within IC is largely unknown. Despite IC being a multidisciplinary healthcare model, there is a lack of evidence to suggest that enhanced pharmaceutical involvement is core to the service provided within IC. This review article highlights the gap in the literature surrounding medicines management within IC and identifies potential solutions aimed at improving patient outcomes in this setting.

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Infections with helminth parasites prevent/attenuate auto-inflammatory disease. Here we show that molecules secreted by a helminth parasite could prevent Type 1 Diabetes (T1D) in nonobese diabetic (NOD) mice. When delivered at 4 weeks of age (coincident with the initiation of autoimmunity), the excretory/secretory products of Fasciola hepatica (FhES) prevented the onset of T1D, with 84% of mice remaining normoglycaemic and insulitis-free at 30 weeks of age. Disease protection was associated with suppression of IFN-γ secretion from autoreactive T cells and a switch to the production of a regulatory isotype (from IgG2a to IgG1) of autoantibody. Following FhES injection, peritoneal macrophages converted to a regulatory M2 phenotype, characterised by increased expression levels of Ym1, Arg-1, TGFβ and PD-L1. Expression of these M2 genetic markers increased in the pancreatic lymph nodes and the pancreas of FhES-treated mice. In vitro, FhES-stimulated M2 macrophages induced the differentiation of Tregs from splenocytes isolated from naïve NOD mice. Collectively, our data shows that FhES contains immune-modulatory molecules that mediate protection from autoimmune diabetes via the induction and maintenance of a regulatory immune environment.

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Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily of secreted cysteine knot proteins that includes TGFβ1, nodal, activins and inhibins. BMPs were first discovered by Urist in the 1960s when he showed that implantation of demineralized bone into intramuscular tissue of rabbits induced bone and cartilage formation. Since this seminal discovery, BMPs have also been shown to play key roles in several other biological processes, including limb, kidney, skin, hair and neuronal development, as well as maintaining vascular homeostasis. The multifunctional effects of BMPs make them attractive targets for the treatment of several pathologies, including bone disorders, kidney and lung fibrosis, and cancer. This review will summarize current knowledge on the BMP signalling pathway and critically evaluate the potential of recombinant BMPs as pharmacological agents for the treatment of bone repair and tissue fibrosis in patients.

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Aims. We study the formation and evolution of a failed filament eruption observed in NOAA active region 11121 near the southeast
limb on November 6, 2010.
Methods. We used a time series of SDO/AIA 304, 171, 131, 193, 335, and 94 Å images, SDO/HMI magnetograms, as well as ROSA
and ISOON Hα images to study the erupting active region.
Results. We identify coronal loop arcades associated with a quadrupolar magnetic configuration, and show that the expansion and
cancellation of the central loop arcade system over the filament is followed by the eruption of the filament. The erupting filament
reveals a clear helical twist and develops the same sign of writhe in the form of inverse γ-shape.
Conclusions. The observations support the “magnetic breakout” process in which the eruption is triggered by quadrupolar reconnection
in the corona. We propose that the formation mechanism of the inverse γ-shape flux rope is the magnetohydrodynamic helical
kink instability. The eruption has failed because of the large-scale, closed, overlying magnetic loop arcade that encloses the active
region