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The evidence of the last 20 years shows a link between viral infections and obesity in animals and humans. There are five adenovirus which have been associated with development of obesity in animals. SMAM-1 virus was the first studied in humans associated with obesity. There is compelling evidence that Ad-36 virus could contribute to the development of obesity in humans and it is related with body mass index (BMI). This manuscript reviews the association between Ad-36 and the other four virus infections with obesity. An electronic search of articles in the databases PubMed and Scielo, with use of key words: obesity, infection, adipose tissue, Ad-36, 3T3-L1 was performed. The search was restricted “human” and “animals”. The importance of the relationship between virus infections and obesity has increased over the past two decades. Ad-36 shows more compelling evidence in humans. There are reports involving this virus in the enhancement of adipogenesis, adipocyte differentiation, a lower secretion of leptin and an increased insulin sensitivity. Future work should focus in larger cohort studies to confirm this association, which explains the global obesity epidemic from a new perspective.

Caveolina-1es una proteína con un importante papel en el tejido adiposo, donde participa en la respuesta a insulina y el metabolismo de lípidos. La expresión de Caveolina-1 aumenta durante la adipogénesis de células 3T3-L1, pero se desconocen los mecanismos que regulan su expresión. Trabajos preliminares sugieren la participación de receptores nucleares en dicha regulación. El objetivo de este trabajo fue analizar el efecto de la modulación farmacológica de los receptores PPARγ y de Glucocorticoides sobre la expresión de Cav-1 en células 3T3-L1. Células diferenciadas por 4 días fueron tratadas con Rosiglitazona o Dexametasona, analizando la expresión de Cav-1 por RT-PCR. Rosiglitazona no indujo cambios significativos en los niveles de su ARNm. En contraste, el tratamiento por 48 h con Dexametasona 1μM, aumentó tres veces la expresión del ARNm de Cav1 respecto a las células control. Estos resultados sugieren que el receptor de glucocorticoides sería un regulador positivo de la expresión de Cav-1 en células 3T3-L1. / Abstract. Caveolin-1 is a protein with an important role in adipose tissue, where it has been involved in insulin response and lipid metabolism. Caveolin-1 expression increases during adipogenesis of 3T3-L1 cells, but the mechanisms regulating its expression remain unknown. Preliminary work suggests the involvement of nuclear receptors in such regulation. The aim of this work was to analyze the effect of PPARγ and Glucocorticoid receptor’s pharmacological modulation on Cav-1 gene expression in 3T3-L1 cells. Cells at day 4 of differentiation were treated with rosiglitazone or dexamethasone, and Cav-1 expression was analyzed by RT-PCR. Rosiglitazone did not significantly change its mRNA levels. In contrast, treatment with 1 μM dexamethasone by 48 h led to a three-fold increase in Cav1 mRNA levels compared to control cells. These results suggest that the glucocorticoid receptor would be a positive regulator of the Cav-1 gene expression in 3T3-L1 cells. Maestría

Adipogénesis es el proceso mediante el cual células multipotenciales se diferencian a adipocitos maduros para cumplir un importante papel metabólico y endocrino. El objetivo de este trabajo fue implementar en nuestro laboratorio un modelo de adipogénesis in vitro que nos permitiera posteriormente, estudiar mecanismos de acción farmacológica a nivel molecular. En el trabajo se describe la utilización del modelo de preadipocitos 3T3-L1 y se muestran algunas de las características de crecimiento del cultivo, así como los cambios morfológicos y celulares que acompañan el proceso de diferenciación. Adipogenesis is the process by which multipotent cells are differentiated into mature fat cells to fulfill a key metabolic and endocrine role. The aim of this work was to implement in our lab an in vitro model of adipogenesis, to be used later on in pharmacological studies on drug action mechanisms at a molecular level. Here we describe the implementation of the pre-adipocytes 3T3-L1 model, showing some culture growth features together with a set of morphological and cellular changes accompanying the differentiation process.