QUIMICA BIOLOGICA II-2013CLASE TALLER: METABOLISMO AMINOACIDICOTRANSAMINACIONES-CICLO DE LA UREA. -Contenidos procedimentales Analizar el formato y tipo de información científica contenida en los ABSTRACTS científicos en relación al tema: Ejercitación de traducción de inglés técnico referente a los metabolismos aminoacìdicos. Interpretación de la regulación e importancia del ciclo de la urea. -Contenidos conceptuales: Catabolismo aminoacídico. Desaminaciones oxidativas y no oxidativas. Transaminaciones. Rutas catabólicas de los esqueletos carbonados. Ciclo de la urea. Fallas en el metabolismo aminoacídico. -Contenidos actitudinales: Predisposición para la resolución de problemas con espíritu crítico y rigor científico. Autoconfianza. Precisión, sistematización y coherencia en los análisis.Responsabilidad para con las tareas encomendadas. - Consignas: 1) Se le presentan dos resúmenes de artículos científicos originales: Analice las partes de los abstracts e identifique sus características: partes del artículo, datos presentados (autores, lugares de trabajo), tipo de estudio (recopilaciones de estudios anteriores o desarrollos experimentales originales), extensión de la información, etc. 2) Redacte un breve informe de cada uno en función de lo analizado y que le aportó de nuevo en relación al tema tratado en clase. Extensión máxima: 2 carillas. Trabajo individual. Fecha de presentación: 16/9/13 Artículo científico: A role for cytosolic fumarate hydratase in urea cycle metabolism and renal neoplasia. Cell Rep. 2013 May 30;3(5):1440-8. doi: 10.1016/j.celrep.2013.04.006. Epub 2013 May 2. Adam J, Yang M, Bauerschmidt C, Kitagawa M, O'Flaherty L, Maheswaran P et al. Biology and Metabolism Group, Nuffield Department of Medicine, Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford OX3 7BN, UK. Abstract The identification of mutated metabolic enzymes in hereditary cancer syndromes has established a direct link between metabolic dysregulation and cancer. Mutations in the Krebs cycle enzyme, fumarate hydratase (FH), predispose affected individuals to leiomyomas, renal cysts, and cancers, though the respective pathogenic roles of mitochondrial and cytosolic FH isoforms remain undefined. On the basis of comprehensive metabolomic analyses, we demonstrate that FH1-deficient cells and tissues exhibit defects in the urea cycle/arginine metabolism. Remarkably, transgenic re-expression of cytosolic FH ameliorated both renal cyst development and urea cycle defects associated with renalspecific FH1 deletion in mice. Furthermore, acute arginine depletion significantly reduced the viability of FH1-deficient cells in comparison to controls. Our findings highlight the importance of extramitochondrial metabolic pathways in FH-associated oncogenesis and the urea cycle/arginine metabolism as a potential therapeutic target.
Artículo científico: Plasma kinetic of ingested essential amino acids in healthy elderly people.Condino AM, Aquilani R, Pasini E, Iadarola P, Viglio S, Verri M, D'Agostino L, Boschi F. Dipartimento di Scienze del Farmaco, Università degli Studi di Pavia, Viale Taramelli, 14, 27100, Pavia, Italy,
[email protected]. Aging Clin Exp Res. 2013 Aug 10. [Epub ahead of print] Abstract The purpose of this study was to investigate whether the documented difficulties of physiological amounts of essential amino acids (EAAs) (7 g) to induce protein synthesis could be reflected in a simple method adaptable to a clinical setting. Sixteen healthy individuals, nine elderly (75.3 ± 3.5 years), and seven young (28 ± 2.5 years) were enrolled in the study. Five minutes before EAA ingestion (baseline) and 20, 40, 60, 90, 120, 180 min after EAA ingestion, venous blood samples were taken from the ante-cubital vein to determine the concentrations of EAAs (μmol/L). The results show that plasma EAA increases were significantly higher in old than in young persons at the considered time points (from p < 0.004 to p < 0.001) (unpaired Student t test). However, the velocity rate of the increasing was slower in old subjects than in young group. The study shows that EAAs ingestion by old subject is associated with reduced muscle EAA uptake.
