Adipose Tissue Overexpression of Vascular Endothelial Growth Factor Protects Against Diet-Induced Obesity and Insulin Resistance

During the expansion of fat mass in obesity, vascularization of adipose tissue is insufficient to maintain tissue normoxia. Local hypoxia develops and may result in altered adipokine expression, proinflammatory macrophage recruitment, and insulin resistance. We investigated whether an increase in adipose tissue angiogenesis could protect against obesity-induced hypoxia and, consequently, insulin resistance. Transgenic mice overexpressing vascular endothelial growth factor (VEGF) in brown adipose tissue (BAT) and white adipose tissue (WAT) were generated. Vessel formation, metabolism, and inflammation were studied in VEGF transgenic mice and wild-type littermates fed chow or a high-fat diet. Overexpression of VEGF resulted in increased blood vessel number and size in both WAT and BAT and protection against high-fat diet-induced hypoxia and obesity, with no differences in food intake. This was associated with increased thermogenesis and energy expenditure. Moreover, whole-body insulin sensitivity and glucose tolerance were improved. Transgenic mice presented increased macrophage infiltration, with a higher number of M2 anti-inflammatory and fewer M1 proinflammatory macrophages than wild-type littermates, thus maintaining an anti-inflammatory milieu that could avoid insulin resistance. These studies suggest that overexpression of VEGF in adipose tissue is a potential therapeutic strategy for the prevention of obesity and insulin resistance

Utilización conjunta del gen de la insulina y del gen de la glucoquinasa en el desarrollo de aproximaciones terapéuticas para la diabetes mellitus

Utilización conjunta del gen de la insulina y del gen de la glucoquinasa en el desarrollo de aproximaciones terapéuticas para la diabetes mellitus. La presente invención se refiere a un animal doble transgénico que expresa simultáneamente el gen o el cDNA (ADN complementario) de la insulina y el gen o el cDNA (ADN complementario) de la glucoquinasa dirigidos por un promotor o fusión de promotores que permiten expresar insulina y glucoquinasa en músculo y su utilización en el desarrollo de aproximaciones terapéuticas para la diabetes mellitus. La presente invención también se refiere a un vector o vectores de expresión que permite expresar conjuntamente dichos genes quiméricos en células musculares. Dichos vectores pueden ser un plásmido, un vector viral o un vector no viral

Modelo de animal transgénico para el desarrollo de nuevas aproximaciones terapéuticas

Modelo de animal transgénico para el desarrollo de nuevas aproximaciones terapéuticas. Dicho animal transgénico no humano contiene una mutación dirigida en el gen que codifica para la 6-fosfofructo-1-quinasa muscular. El procedimiento para producir el animal transgénico no humano comprende las etapas de: i) crear una construcción de recombinación; ii) transfectar dicha construcción de recombinación en células pluripotenciales; iii) seleccionar las células transfectadas de la etapa (ii) que expresan dicho(s) marcador(es); iv) introducir dicha célula transfectada en un embrión en estadio de blastocito; v) transferencia de los blastocitos manipulados a hembras receptoras para obtener ratones quimera; vi) cruce de los animales quimera con animales control para producir un animal heterocigoto para la mutación; y vii) cruce de los animales heterocigotos obtenidos en (vi) para obtener animales homocigotos para la mutación en el gen que codifica para la PFK1 muscular. Dicho modelo de animal transgénico se puede utilizar en el desarrollo de nuevas aproximaciones terapéuticas para el tratamiento de enfermedades como la glucogenosis, la diabetes tipo II y el Alzheimer

The E1a Adenoviral Gene Upregulates the Yamanaka Factors to Induce Partial Cellular Reprogramming

The induction of pluripotency by enforced expression of different sets of genes in somatic cells has been achieved with reprogramming technologies first described by Yamanaka’s group. Methodologies for generating induced pluripotent stem cells are as varied as the combinations of genes used. It has previously been reported that the adenoviral E1a gene can induce the expression of two of the Yamanaka factors (c-Myc and Oct-4) and epigenetic changes. Here, we demonstrate that the E1a-12S over-expression is sufficient to induce pluripotent-like characteristics closely to epiblast stem cells in mouse embryonic fibroblasts through the activation of the pluripotency gene regulatory network. These findings provide not only empirical evidence that the expression of one single factor is sufficient for partial reprogramming but also a potential mechanistic explanation for how viral infection could lead to neoplasia if they are surrounded by the appropriate environment or the right medium, as happens with the tumorogenic niche

Phosphofructo-1-kinase deficiency leads to a severe cardiac and hematological disorder in addition to skeletal muscle glycogenosis

Mutations in the gene for muscle phosphofructo-1-kinase (PFKM), a key regulatory enzyme of glycolysis, cause Type VII glycogen storage disease (GSDVII). Clinical manifestations of the disease span from the severe infantile form, leading to death during childhood, to the classical form, which presents mainly with exercise intolerance. PFKM deficiency is considered as a skeletal muscle glycogenosis, but the relative contribution of altered glucose metabolism in other tissues to the pathogenesis of the disease is not fully understood. To elucidate this issue, we have generated mice deficient for PFKM (Pfkm−/−). Here, we show that Pfkm−/− mice had high lethality around weaning and reduced lifespan, because of the metabolic alterations. In skeletal muscle, including respiratory muscles, the lack of PFK activity blocked glycolysis and resulted in considerable glycogen storage and low ATP content. Although erythrocytes of Pfkm−/− mice preserved 50% of PFK activity, they showed strong reduction of 2,3-biphosphoglycerate concentrations and hemolysis, which was associated with compensatory reticulocytosis and splenomegaly. As a consequence of these haematological alterations, and of reduced PFK activity in the heart, Pfkm−/− mice developed cardiac hypertrophy with age. Taken together, these alterations resulted in muscle hypoxia and hypervascularization, impaired oxidative metabolism, fiber necrosis, and exercise intolerance. These results indicate that, in GSDVII, marked alterations in muscle bioenergetics and erythrocyte metabolism interact to produce a complex systemic disorder. Therefore, GSDVII is not simply a muscle glycogenosis, and Pfkm−/− mice constitute a unique model of GSDVII which may be useful for the design and assessment of new therapies