Browsing by Issue Date, starting with "2014-03-20"
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- Maize IgE binding proteins: each plant a different profile?Publication . Fonseca, Cátia; Planchon, Sébastien; Pinheiro, Carla; Renaut, Jenny; Ricardo, Cândido; Oliveira, M. Margarida; Batista, RitaBackground: Allergies are nearly always triggered by protein molecules and the majority of individuals with documented immunologic reactions to foods exhibit IgE hypersensitivity reactions. In this study we aimed to understand if natural differences, at proteomic level, between maize populations, may induce different IgE binding proteins profiles among maize-allergic individuals. We also intended to deepen our knowledge on maize IgE binding proteins. Results: In order to accomplish this goal we have used proteomic tools (SDS-PAGE and 2-D gel electrophoresis followed by western blot) and tested plasma IgE reactivity from four maize-allergic individuals against four different protein fractions (albumins, globulins, glutelins and prolamins) of three different maize cultivars. We have observed that maize cultivars have different proteomes that result in different IgE binding proteins profiles when tested against plasma from maize-allergic individuals. We could identify 19 different maize IgE binding proteins, 11 of which were unknown to date. Moreover, we found that most (89.5%) of the 19 identified potential maize allergens could be related to plant stress. Conclusions: These results lead us to conclude that, within each species, plant allergenic potential varies with genotype. Moreover, considering the stress-related IgE binding proteins identified, we hypothesise that the environment, particularly stress conditions, may alter IgE binding protein profiles of plant components.
- Alterations in lipid profile and enzymes paraoxonase and butyrylcholinesterase in CBS-deficient patientsPublication . Vanzin, Camila; Nogueira, Célia; Vilarinho, Laura; Wajner, Moacir; Wyse, Angela; Vargas, CarmenHomocystinuria is an inborn error of metabolism most frequently caused by cystathionine β-synthase (CBS) deficiency. Homocysteine (Hcy), methionine (Met) and other metabolites of Hcy accumulate in the body of affected patients, leading to clinical manifestations such as dislocation of the optic lents, osteoporosis, mental retardation, and thromboembolism. Despite the fact that thromboembolism represent the major cause of morbidity and the most frequent cause of death in CBS-deficient patients, the cause of cardiovascular changes found in homocystinuria remain unclear. In this work, we evaluated the lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, oxidized LDL cholesterol, apolipoprotein A-1) and the activities of the enzymes paraoxonase (PON1) and butyrylcholinesterase (BuChE) in plasma of patients with homocystinuria due CBS deficiency, at diagnosis and during the treatment. It was verified a significant decrease in HDL cholesterol and apolipoprotein A1 levels in the both groups of CBS-deficient patients (at diagnosis and under treatment) when compared to controls. PON1 activity was also significantly lower in the both groups of CBS-deficient patients when compared to controls which may be related with an Hcy-dependent oxidation of any group important to catalytic activity of the enzyme that favors the atherogenesis. BuChE activity was significantly increased only in CBS-deficient patients at diagnosis and it is known that this enzymatic activity is positively associated with cardiovascular risk factors. Evaluated together, our results demonstrated that treated or not CBS-deficient patients presented important alterations in lipid metabolism. This work contributes to the understanding of the responsible mechanisms of vascular lesions in CBS-deficient patients.
- A Novel SUCLA2 Mutation in a Portuguese Child Associated With "Mild" Methylmalonic AciduriaPublication . Nogueira, Célia; Meschini, M.C.; Nesti, C.; Garcia, P.; Diogo, L.; Valongo, C.; Costa, R.; Videira, A.; Vilarinho, L.; Santorelli, F.M.Succinyl-coenzyme A synthase is a mitochondrial matrix enzyme that catalyzes the reversible synthesis of succinate and adenosine triphosphate (ATP) from succinyl-coenzyme A and adenosine diphosphate (ADP) in the tricarboxylic acid cycle. This enzyme is made up of α and β subunits encoded by SUCLG1 and SUCLA2, respectively. We present a child with severe muscular hypotonia, dystonia, failure to thrive, sensorineural deafness, and dysmorphism. Metabolic investigations disclosed hyperlactacidemia, moderate urinary excretion of methylmalonic acid, and elevated levels of C4-dicarboxylic carnitine in blood. We identified a novel homozygous p.M329V in SUCLA2. In cultured cells, the p.M329V resulted in a reduced amount of the SUCLA2 protein, impaired production of mitochondrial ATP, and enhanced production of reactive oxygen species, which was partially reduced by using 5-aminoimidazole-4-carboxamide ribonucleotide in the culture medium. Expanding the array of SUCLA2 mutations, we suggested that reactive oxygen species scavengers are likely to impact on disease prognosis.