Genetic manipulation of the pancreas : cell and gene therapy approaches for type 1 diabetes /

Consultable des del TDXLa diabetes de tipo 1 resulta de la destrucción autoinmune de las células ß pancreáticas, que conduce a una falta en la producción de insulina y la consiguiente hiperglucemia. La terapia sustitutiva con inyecciones subcutáneas de insulina permite a los pacientes llevar un vida activa, sin embargo esta terapia es imperfecta y no evita la aparición de graves complicaciones secundarias. El transplante de páncreas o islotes pancreáticos se ha realizado con éxito en algunos pacientes, sin embargo la escasez de donantes impide que esta terapia se pueda aplicar a todos los individuos diabéticos. Por ello, una gran cantidad de esfuerzos se han centrado en la diferenciación de células madre, embrionarias o adultas, en células ß. Las células de la médula ósea (BMC) poseen propiedades de célula madre adulta y además son fáciles de obtener, por ello se han propuesto como una fuente alternativa para la formación de nuevas células ß. El factor de crecimiento a la insulina de tipo I (IGF-I) participa en la regeneración muscular e incrementa la atracción y diferenciación de BMC en el músculo dañado. Además, la expresión de IGF-I específicamente en células ß de ratones diabéticos es capaz de regenerar la masa de células ß. Así, el primer objetivo de este trabajo fue estudiar la capacidad de la expresión de IGF-I en las células ß para atraer y diferenciar las BMC en nuevas células ß, tanto en ratones sanos como en ratones diabéticos. Con esta finalidad se transplantó la médula ósea de ratones transgénicos que expresaban la proteína verde fluorescente (GFP) constitutivamente, en los ratones transgénicos para IGF-I. Los resultados obtenidos demostraron que ni la sobreexpresión de IGF-I en células ß, ni la inducción de diabetes mediante estreptozotocina fueron causa suficiente para atraer y diferenciar las BMC en células ß pancreáticas in vivo. Estos datos sugerían que la regeneración del páncreas endocrino observada en los ratones transgénicos para IGF-I no era mediada por las BMC, indicando que la replicación de células ß preexistentes o bien la diferenciación a partir de precursores no hematopoyéticos son los mecanismos que actuarían en la regeneración de las células ß mediada por IGF-I. La diabetes se ha intentando curar mediante estrategias de terapia génica, sin embargo hasta el momento no se ha conseguido ninguna terapia efectiva. La recuperación completa del paciente diabético de tipo 1 requeriría la regeneración de las células ß. Una aproximación para conseguir este objetivo es la manipulación genética del páncreas endocrino in vivo, con la finalidad de expresar factores que induzcan replicación o neogénesis de las células ß y además contrarrestar la respuesta inmune. Sin embargo, el riesgo de inducir pancreatitis al manipular el páncreas es elevado, y por tanto se han realizado escasos intentos de modificar genéticamente este órgano hasta la fecha. Por ello, nuevas aproximaciones de transferencia génica in vivo son necesarias para avanzar en el desarrollo de nuevas aproximaciones de terapia génica para la diabetes. En este trabajo hemos estudiado la eficiencia de diferentes vectores virales y diferentes vías de administración para transducir el páncreas in vivo, tanto en ratones como en perros. En primer lugar, observamos que las células ß pancreáticas fueron transducidas eficientemente por adenovirus inyectados vía sistémica en ratones a los cuales se les había cerrado la circulación hepática. Este resultado obtenido con vectores adenovirales de primera generación también se obtuvo cuando usamos vectores adenovirales de última generación, también llamados gutless. Además de vectores adenovirales, también se estudio la capacidad de transducir el páncreas de los vectores adenoasociados de serotipo 8 (AAV8). Así, se demostró que la vía de administración de los vectores AAV8 por el conducto pancreático era más efectiva que la administración de estos vectores por vía endovenosa o intraperitoneal. El páncreas del perro presenta una estructura lobular y una vascularización similar al humano, por tanto constituye un buen modelo para ensayar estrategias de transferencia génica a páncreas. En este trabajo se estudió la capacidad de los vectores adenovirales para transferir genes a páncreas in vivo en animales sometidos a un clamp circulatorio de los vasos pancreáticos. Adenovirus con el gen marcador de la ß-galactosidasa se inyectaron en la vena pancreaticoduodenal y el clamp se mantuvo durante 10 minutos. Usando esta técnica se consiguió transducir células acinares, ductales y también islotes pancreáticos sin evidencias de daño pancreático. Esta técnica también se ensayó con éxito en un perro diabético. Por consiguiente, la metodología descrita en este trabajo puede ser usada para transducir el páncreas in vivo, ya sea en ratones o en perros, con la finalidad de estudiar la biología de las células ß o bien para desarrollar nuevas aproximaciones terapéuticas para la diabetes mellitus y otras enfermedades pancreáticas.Type 1 diabetes is characterized by progressive destruction of pancreatic ?-cells, resulting in insulin deficiency and hyperglycemia. Insulin replacement therapy allows diabetic patients to lead active lives, but this therapy is imperfect and does not prevent development of severe secondary complications. Transplantation of pancreatic tissue or islets has been performed successfully in a limited numbers of patients. However, the shortage of donors is a primary obstacle that prevents this treatment from becoming more widespread. Therefore, many efforts have been focused on differentiating embryonic or adult stem cells into ß-cells. Bone marrow cells (BMCs) are an important source of easily procurable adult stem cells and have been proposed as an alternative source of ß-cells. Insulin-like growth factor-I (IGF-I) participates in skeletal muscle regeneration and enhances the recruitment of BMCs at the sites of muscle injury. In addition, IGF-I expression in ß-cells of diabetic transgenic mice regenerates pancreatic ß-cell mass. Therefore one of the objectives of this study was to investigate whether IGF-I expression in ß-cells could increase BMC recruitment and differentiation into ß-cells under steady-state conditions or after STZ treatment. To this end, BMCs from ß-actin/GFP transgenic donor mice were transplanted into IGF-I transgenic mice. Our experiments have demonstrated that IGF-I overexpression or STZ-induced pancreatic damage were not sufficient to recruit and differentiate GFP-labelled BMCs into ß-cells in vivo, indicating that these cells did not contribute to the endocrine pancreas regeneration observed in IGF-I transgenic mice. These data suggest that replication of pre-existing ß-cells and/or differentiation from non-BMC precursors is the most likely mechanism for IGF-I-mediated regeneration. Diabetes mellitus has long been targeted, as yet unsuccessfully, as being curable with gene therapy. Recovery from type 1 diabetes requires ß-cell regeneration. One approach to do so is by genetically engineering the endocrine pancreas in vivo to express factors that induce ß-cell replication and neogenesis and counteract the immune response. However, the pancreas is difficult to manipulate and pancreatitis is a serious concern, which has made effective gene transfer to this organ elusive. Thus, new approaches for gene delivery to the pancreas in vivo are required. In this study we have examined different viral vectors and routes of administration in rodents and also in large animals, to determine the most efficient method to deliver exogenous genes to the pancreas. First, we observed that pancreatic ß-cells were efficiently transduced to express ß-galactosidase after systemic injection of adenoviral vectors in mice with clamped hepatic circulation. This was true both for first generation as well as for helper-dependent adenoviral vectors. In addition to adenoviruses, we have compared the ability of AAV vectors to transduce the pancreas in vivo after intravascular, intraperitoneal or intraductal delivery, being the last the most efficient route of administration. Like the human pancreas, the canine pancreas is compact, with similar vascularization and lobular structure. It is therefore a suitable model in which to assess gene transfer strategies. Here we examined the ability of adenoviral vectors to transfer genes into the pancreas of dogs in which pancreatic circulation has been clamped. Adenoviruses carrying the ß-galactosidase (ß-gal) gene were injected into the pancreatic-duodenal vein and the clamp was released 10 min later. These dogs showed ß-gal-positive cells throughout the pancreas, with no evidence of pancreatic damage. ß-gal was expressed mainly in acinar cells, but also in ducts and islets. ß-gal expression in the exocrine pancreas of a diabetic dog was also found to be similar to that observed in healthy dogs. Thus, the methodology described herein may be used to transfer genes of interest to murine and canine pancreas in vivo, both for the study of islet biology and to develop new gene therapy approaches for diabetes mellitus and other pancreatic disorders

Towards a clinical staging for bipolar disorder: defining patient subtypes based on functional outcome.

BACKGROUND: The functional outcome of Bipolar Disorder (BD) is highly variable. This variability has been attributed to multiple demographic, clinical and cognitive factors. The critical next step is to identify combinations of predictors that can be used to specify prognostic subtypes, thus providing a basis for a staging classification in BD. METHODS: Latent Class Analysis was applied to multiple predictors of functional outcome in a sample of 106 remitted adults with BD. RESULTS: We identified two subtypes of patients presenting "good" (n=50; 47.6%) and "poor" (n=56; 52.4%) outcome. Episode density, level of residual depressive symptoms, estimated verbal intelligence and inhibitory control emerged as the most significant predictors of subtype membership at the p<0.05 level. Their odds ratio (OR) and confidence interval (CI) with reference to the "good" outcome group were: episode density (OR=4.622, CI 1.592-13.418), level of residual depressive symptoms (OR=1.543, CI 1.210-1.969), estimated verbal intelligence (OR=0.969; CI 0.945-0.995), and inhibitory control (OR=0.771, CI 0.656-0.907). Age, age of onset and duration of illness were comparable between prognostic groups. LIMITATIONS: The longitudinal stability or evolution of the subtypes was not tested. CONCLUSIONS: Our findings provide the first empirically derived staging classification of BD based on two underlying dimensions, one for illness severity and another for cognitive function. This approach can be further developed by expanding the dimensions included and testing the reproducibility and prospective prognostic value of the emerging classes. Developing a disease staging system for BD will allow individualised treatment planning for patients and selection of more homogeneous patient groups for research purposes

Onderwijskwaliteit aan Nederlandse universiteiten

In discussies over de onderwijskwaliteit wordt continu beweerd dat deze daalt. In dit onderzoek wordt aangetoond dat er juist een stijging is van de ervaren onderwijskwaliteit. Een verdere stijging kan vooral worden gerealiseerd door het primaire onderwijsproces te verbeteren

Hypothalamic-Specific Manipulation of Fto, the Ortholog of the Human Obesity Gene FTO, Affects Food Intake in Rats

Sequence variants in the first intron of FTO are strongly associated with human obesity and human carriers of the risk alleles show evidence for increased appetite and food intake. Mice globally lacking Fto display a complex phenotype characterised by both increased energy expenditure and increased food intake. The site of action of FTO on energy balance is unclear. Fasting reduces levels of Fto mRNA in the arcuate nucleus (ARC) of the hypothalamus, a site where Fto expression is particularly high. In this study, we have extended this nutritional link by demonstrating that consumption of a high fat diet (45%) results in a 2.5 fold increase in Arc Fto expression. We have further explored the role of hypothalamic Fto in the control of food intake by using stereotactic injections coupled with AAV technology to bi-directionally modulate Fto expression. An over expression of Fto protein by 2.5-fold in the ARC results in a 14% decrease in average daily food intake in the first week. In contrast, knocking down Arc Fto expression by 40% increases food intake by 16%. mRNA levels of Agrp, Pomc and Npy, ARC-expressed genes classically associated with the control of food intake, were not affected by the manipulation of Fto expression. However, over expression of Fto resulted in a 4-fold increase in the mRNA levels of Stat3, a signalling molecule critical for leptin receptor signalling, suggesting a possible candidate for the mediation of Fto's actions. These data provide further support for the notion that FTO itself can influence key components of energy balance, and is therefore a strong candidate for the mediation of the robust association between FTO intronic variants and adiposity. Importantly, this provide the first indication that selective alteration of FTO levels in the hypothalamus can influence food intake, a finding consistent with the reported effects of FTO alleles on appetite and food intake in man

Validity and reliability of the Functioning Assessment Short Test (FAST) in bipolar disorder

doi:10.1186/1745-0179-3

FoxO3a overexpression prevents both glycogen overload and autophagic buildup in skeletal muscle of Pompe disease

FoxO3a overexpression prevents both glycogen overload and autophagic buildup in skeletal muscle of Pompe disease. 6eme congrès international de Myologi

Intraductal Delivery Of Adenoviruses Targets Pancreatic Tumors In Transgenic Ela-myc Mice And Orthotopic Xenografts

Gene-based anticancer therapies delivered by adenoviruses are limited by the poor viral distribution into the tumor. In the current work we have explored the feasibility of targeting pancreatic tumors through a loco-regional route. We have taken advantage of the ductal network in the pancreas to retrogradelly inject adenoviruses through the common bile duct in two different mouse models of pancreatic carcinogenesis: The transgenic Ela-myc mice that develop mixed neoplasms displaying both acinar-like and duct-like neoplastic cells affecting the whole pancreas; and mice bearing PANC-1 and BxPC-3 orthotopic xenografts that constitute a model of localized human neoplastic tumors. We studied tumor targeting and the anticancer effects of newly thymidine kinase-engineered adenoviruses both in vitro and in vivo, and conducted comparative studies between intraductal or intravenous administration. Our data indicate that the intraductal delivery of adenovirus efficiently targets pancreatic tumors in the two mouse models. The in vivo application of AduPARTK(T) plus ganciclovir (GCV) treatment induced tumor regression in Ela-myc mice. Moreover, the intraductal injection of ICOVIR15-TKT oncolytic adenoviruses significantly improved mean survival of mice bearing PANC-1 and BxPC-3 pancreatic xenografts from 30 to 52 days and from 20 to 68 days respectively (p<0.0001) when combined with GCV. Of notice, both AduPARTK(T) and ICOVIR15-TKT antitumoral responses were stronger by ductal viral application than intravenously, in line with the 38-fold increase in pancreas transduction observed upon ductal administration. In summary our data show that cytotoxic adenoviruses retrogradelly injected to the pancreas can be a feasible approach to treat localized pancreatic tumors

The Diversity of Parvovirus Telomeres

Parvoviridae are small viruses composed of a 4–6 kb linear single-stranded DNA protected by an icosahedral capsid. The viral genes coding non-structural (NS), capsid, and accessory proteins are flanked by intriguing sequences, namely the telomeres. Telomeres are essential for parvovirus genome replication, encapsidation, and integration. Similar (homotelomeric) or different (heterotelomeric) at the two ends, they all contain imperfect palindromes that fold into hairpin structures. Up to 550 nucleotides in length, they harbor a wide variety of motifs and structures known to be recognized by host cell factors. Our study aims to comprehensively analyze parvovirus ends to better understand the role of these particular sequences in the virus life cycle. Forty Parvoviridae terminal repeats (TR) were publicly available in databases. The folding and specific DNA secondary structures, such as G4 and triplex, were systematically analyzed. A principal component analysis was carried out from the prediction data to determine variables signing parvovirus groups. A special focus will be put on adeno-associated virus (AAV) inverted terminal repeats (ITR), a member of the genus Dependoparvovirus used as vectors for gene therapy. This chapter highlights the diversity of the Parvoviridae telomeres regarding shape and secondary structures, providing information that could be relevant for virus-host interactions studies

Visual decline in aged mice is delayed by proinsulin

1 p.Visual decline is normally associated to the aging process.We search for cellular and molecular processes associated to normal aging. In addition, we have previously shown that human proinsulin (hPi) delays vision loss, as determined by electroretinography (ERG),and retinal degeneration, as determined by photoreceptor counting,in the rd10 mouse and the P23H rat models of Retinitis Pigmentosa.Our aim is to reveal additional potential benets of a hPi-based treatment in the aged retina.CONSOLIDER CSD2010-00045 SpainPeer reviewe

La expresión de proinsulina atenúa los trastornos de la retina asociados a la edad en distintos modelos de envejecimiento fisiopatológico

Póster presentado en el XXXVI Congreso de la Sociedad Española de Bioquímica y Biología Molecular SEBBM, celebrada del 3 al 6 de septiembre de 2013 en Madrid (España)Peer Reviewe