El xenotrasplantament: el porc com a donant d'òrgans

Treball presentat a l'assignatura de Deontologia i Veterinària Legal (21223

In Vivo Adeno-Associated Viral Vector-Mediated Genetic Engineering of White and Brown Adipose Tissue in Adult Mice

Adipose tissue is pivotal in the regulation of energy homeostasis through the balance of energy storage and expenditure and as an endocrine organ. An inadequate mass and/or alterations in the metabolic and endocrine functions of adipose tissue underlie the development of obesity, insulin resistance, and type 2 diabetes. To fully understand the metabolic and molecular mechanism(s) involved in adipose dysfunction, in vivo genetic modification of adipocytes holds great potential. Here, we demonstrate that adeno-associated viral (AAV) vectors, especially serotypes 8 and 9, mediated efficient transduction of white (WAT) and brown adipose tissue (BAT) in adult lean and obese diabetic mice. The use of short versions of the adipocyte protein 2 or uncoupling protein-1 promoters or micro-RNA target sequences enabled highly specific, long-term AAV-mediated transgene expression in white or brown adipocytes. As proof of concept, delivery of AAV vectors encoding for hexokinase or vascular endothelial growth factor to WAT or BAT resulted in increased glucose uptake or increased vessel density in targeted depots. This method of gene transfer also enabled the secretion of stable high levels of the alkaline phosphatase marker protein into the bloodstream by transduced WAT. Therefore, AAV-mediated genetic engineering of adipose tissue represents a useful tool for the study of adipose pathophysiology and, likely, for the future development of new therapeutic strategies for obesity and diabetes

BMP7 overexpression in adipose tissue induces white adipogenesis and improves insulin sensitivity in ob/ob mice

Altres ajuts: ICREA Academia AwardBackground/objectives: During obesity, hypertrophic enlargement of white adipose tissue (WAT) promotes ectopic lipid deposition and development of insulin resistance. In contrast, WAT hyperplasia is associated with preservation of insulin sensitivity. The complex network of factors that regulates white adipogenesis is not fully understood. Bone morphogenic protein 7 (BMP7) can induce brown adipogenesis, but its role on white adipogenesis remains to be elucidated. Here, we assessed BMP7-mediated effects on white adipogenesis in ob/ob mice. Methods: BMP7 was overexpressed in either WAT or liver of ob/ob mice using adeno-associated viral (AAV) vectors. Analysis of gene expression, histological and morphometric alterations, and metabolites and hormones concentrations were carried out. Results: Overexpression of BMP7 in adipocytes of subcutaneous and visceral WAT increased fat mass, the proportion of small-size adipocytes and the expression of adipogenic and mature adipocyte genes, suggesting induction of adipogenesis irrespective of fat depot. These changes were associated with reduced hepatic steatosis and improved insulin sensitivity. In contrast, liver-specific overproduction of BMP7 did not promote WAT hyperplasia despite BMP7 circulating levels were similar to those achieved after genetic engineering of WAT. Conclusions: This study unravels a new autocrine/paracrine role of BMP7 on white adipogenesis and highlights that BMP7 may modulate WAT plasticity and increase insulin sensitivity

FGF21 gene therapy as treatment for obesity and insulin resistance

Prevalence of type 2 diabetes (T2D) and obesity is increasing worldwide. Currently available therapies are not suited for all patients in the heterogeneous obese/T2D population, hence the need for novel treatments. Fibroblast growth factor 21 (FGF21) is considered a promising therapeutic agent for T2D/obesity. Native FGF21 has, however, poor pharmacokinetic properties, making gene therapy an attractive strategy to achieve sustained circulating levels of this protein. Here, adeno-associated viral vectors (AAV) were used to genetically engineer liver, adipose tissue, or skeletal muscle to secrete FGF21. Treatment of animals under long-term high-fat diet feeding or of ob/ob mice resulted in marked reductions in body weight, adipose tissue hypertrophy and inflammation, hepatic steatosis, inflammation and fibrosis, and insulin resistance for > 1 year. This therapeutic effect was achieved in the absence of side effects despite continuously elevated serum FGF21. Furthermore, FGF21 overproduction in healthy animals fed a standard diet prevented the increase in weight and insulin resistance associated with aging. Our study underscores the potential of FGF21 gene therapy to treat obesity, insulin resistance, and T2D.This work was supported by grants from Ministerio de Economía y Competi- tividad (MINECO) and FEDER, Plan Nacional I+D+I (SAF2014-54866R), andGeneralitat de Catalunya (2014SGR1669and ICREA Academia Award to F.B.), Spain, from the European Commission (MYOCURE, PHC-14-2015 667751) and the European Foundation for the Study of Diabetes (EFSD/MSD European Research Programme on Novel Therapies for Type 2 Diabetes,2013). V.J. was recipient of a post-doctoral research fellowship from EFSD/ Lilly. E.C., V.S., and C.M. received a predoctoral fellowship from Ministerio de Educación, Cultura y Deporte, and J.R. from Ministerio de Economía y Competitividad, Spain. The authors thank Marta Moya and Maria Molas for technical assistance.S

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Tratamiento de la diabetes y la obesidad mediante una terapia génica con FGF21

La prevalencia de la diabetes tipo 2 (T2D) y la obesidad está incrementando a nivel mundial. Actualmente, las terapias disponibles no son apropiadas para todos los pacientes dada la heterogeneidad de la población obesa y con DT2 y por lo tanto, existe la necesidad de desarrollar nuevos tratamientos. El factor de crecimiento fibroblástico 21 (FGF21) es considerado como un prometedor agente terapéutico para la DT2 y la obesidad. No obstante, la proteína nativa FGF21 posee escasas propiedades farmacocinéticas, haciendo de la terapia génica una estrategia atractiva para obtener niveles circulantes de esta proteína elevados y contantes. En este trabajo, se han utilizado vectores virales adenoasociados (AAV) para modificar genéticamente el hígado y hacer que secrete FGF21. El tratamiento a ratones con obesidad inducida por una dieta alta en lípidos y ratones ob/ob causó una marcada reducción del peso corporal, de la hipertrofia y la inflamación del tejido adiposo, de la esteatosis, inflamación y fibrosis hepáticas y de la resistencia a la insulina durante más de un año. Este efecto terapéutico la obtuvo con ausencia de efectos adversos aunque el FGF21 sérico se mantuvo elevado durante todo el periodo. Por lo tanto, este estudio corroboró la seguridad del tratamiento y enfatizó el potencial de esta estrategia de terapia génica con FGF21 para tratar en un futuro la DT2 y la obesidad.The prevalence of type 2 diabetes (T2D) and obesity is increasing worldwide. Currently available therapies are not suited for all patients in the heterogeneous obese/T2D population, and there is a need for novel treatments. Fibroblast growth factor 21 (FGF21) is considered a promising therapeutic agent for T2D/obesity. Native FGF21 has, however, poor pharmacokinetic properties, making gene therapy an attractive strategy to achieve sustained circulating levels of this protein. Here, we used adeno-associated viral vectors (AAV) to genetically engineer the liver to secrete FGF21. Treatment of animals fed a high-fat diet for a long time or of ob/ob mice resulted in marked reductions in body weight, adipose tissue hypertrophy and inflammation, hepatic steatosis, inflammation and fibrosis and insulin resistance for >1 year. This therapeutic effect was achieved in the absence of side effects despite continuously elevated serum FGF21. Our study underscores the security of this treatment and the potential of FGF21 gene therapy to treat T2D and obesity

El xenotrasplantament: el porc com a donant d'òrgans

Treball presentat a l'assignatura de Deontologia i Veterinària Legal (21223

Tratamiento de la diabetes y la obesidad mediante una terapia génica con FGF21

La prevalencia de la diabetes tipo 2 (T2D) y la obesidad está incrementando a nivel mundial. Actualmente, las terapias disponibles no son apropiadas para todos los pacientes dada la heterogeneidad de la población obesa y con DT2 y por lo tanto, existe la necesidad de desarrollar nuevos tratamientos. El factor de crecimiento fibroblástico 21 (FGF21) es considerado como un prometedor agente terapéutico para la DT2 y la obesidad. No obstante, la proteína nativa FGF21 posee escasas propiedades farmacocinéticas, haciendo de la terapia génica una estrategia atractiva para obtener niveles circulantes de esta proteína elevados y contantes. En este trabajo, se han utilizado vectores virales adenoasociados (17V) para modificar genéticamente el hígado y hacer que secrete FGF21. El tratamiento a ratones con obesidad inducida por una dieta alta en lípidos y ratones ob/ob causó una marcada reducción del peso corporal, de la hipertrofia y la inflamación del tejido adiposo, de la esteatosis, inflamación y fibrosis hepáticas y de la resistencia a la insulina durante más de un año. Este efecto terapéutico la obtuvo con ausencia de efectos adversos aunque el FGF21 sérico se mantuvo elevado durante todo el periodo. Por lo tanto, este estudio corroboró la seguridad del tratamiento y enfatizó el potencial de esta estrategia de terapia génica con FGF21 para tratar en un futuro la DT2 y la obesidad

Integrated gene expression profiles reveal a transcriptomic network underlying the thermogenic response in adipose tissue

Obesity and type 2 diabetes are two closely related diseases representing a serious threat worldwide. An increase in metabolic rate through enhancement of non-shivering thermogenesis in adipose tissue may represent a potential therapeutic strategy. Nevertheless, a better understanding of thermogenesis transcriptional regulation is needed to allow the development of new effective treatments. Here, we aimed to characterize the specific transcriptomic response of white and brown adipose tissues after thermogenic induction. Using cold exposure to induce thermogenesis in mice, we identified mRNAs and miRNAs that were differentially expressed in several adipose depots. In addition, integration of transcriptomic data in regulatory networks of miRNAs and transcription factors allowed the identification of key nodes likely controlling metabolism and immune response. Moreover, we identified the putative role of the transcription factor PU.1 in the regulation of PPARγ-mediated thermogenic response of subcutaneous white adipose tissue. Therefore, the present study provides new insights into the molecular mechanisms that regulate non-shivering thermogenesis