The first knock-in rat model for glutaric aciduria type I allows further insights into pathophysiology in brain and periphery.

Glutaric aciduria type I (GA-I, OMIM # 231670) is an inborn error of metabolism caused by a deficiency of glutaryl-CoA dehydrogenase (GCDH). Patients develop acute encephalopathic crises (AEC) with striatal injury most often triggered by catabolic stress. The pathophysiology of GA-I, particularly in brain, is still not fully understood. We generated the first knock-in rat model for GA-I by introduction of the mutation p.R411W, the rat sequence homologue of the most common Caucasian mutation p.R402W, into the Gcdh gene of Sprague Dawley rats by CRISPR/CAS9 technology. Homozygous Gcdhki/ki rats revealed a high excretor phenotype, but did not present any signs of AEC under normal diet (ND). Exposure to a high lysine diet (HLD, 4.7%) after weaning resulted in clinical and biochemical signs of AEC. A significant increase of plasmatic ammonium concentrations was found in Gcdhki/ki rats under HLD, accompanied by a decrease of urea concentrations and a concomitant increase of arginine excretion. This might indicate an inhibition of the urea cycle. Gcdhki/ki rats exposed to HLD showed highly diminished food intake resulting in severely decreased weight gain and moderate reduction of body mass index (BMI). This constellation suggests a loss of appetite. Under HLD, pipecolic acid increased significantly in cerebral and extra-cerebral liquids and tissues of Gcdhki/ki rats, but not in WT rats. It seems that Gcdhki/ki rats under HLD activate the pipecolate pathway for lysine degradation. Gcdhki/ki rat brains revealed depletion of free carnitine, microglial activation, astroglyosis, astrocytic death by apoptosis, increased vacuole numbers, impaired OXPHOS activities and neuronal damage. Under HLD, Gcdhki/ki rats showed imbalance of intra-and extracellular creatine concentrations and indirect signs of an intracerebral ammonium accumulation. We successfully created the first rat model for GA-I. Characterization of this Gcdhki/ki strain confirmed that it is a suitable model not only for the study of pathophysiological processes, but also for the development of new ther-apeutic interventions. We further brought up interesting new insights into the pathophysiology of GA-I in brain and periphery

NEUROPATHOGENESIS IN ORGANIC ACIDURIAS AND PHENYLKETONURIA

Notre groupe de recherche a précédemment obtenu des résultats intéressants sur les mécanismes engendrant les dommages cérébraux observés dans deux aciduries organiques, l'acidurie méthylmalonique (MMAuria) et l'acidurie glutarique de type I (GA-I), en utilisant des modèles in vitro dans lesquels des cellules cérébrales de rats wild type ont été exposé à différentes concentrations de métabolites toxiques connus pour accumuler dans ces maladies. Le but de cette thèse était de développer de meilleurs modèles in vitro et in vivo pour ces deux maladies et de plus déchiffrer les mécanismes engendrant des dommages cérébraux dans MMAuria et GA-I. Modèle MMAuria : Nous avons développé un nouveau modèle in vitro en utilisant des aggrégats 3D de cellules cérébrales dérivés de cerveaux d'embryons de souris knock-out avec un déficit cérébral du gène Mut. Nous avons ainsi prouvé pour la première fois que des cellules cérébrales, déficientes pour le gène Mut, sont capables de produire les métabolites caractéristiques de MMAuria. Nous avons confirmé une accumulation massive d'ammonium (NH4+) dans les milieux de culture Mut7", avons fourni des hypothèses préliminaires de mécanismes pouvant expliquer cette augmentation de NH/ dans les cellules Mut"/_ et avons montré l'implication de processus neuro-inflammatoires dans la neuropathophysiologie de MMAuria. Modèle GA-I : Nous avons développé un nouveau modèle in vivo en créant un modèle de rat knock-in par technologie CRISPR/Cas9 auquel nous avons inséré une des mutations les plus fréquemment observées chez des patients atteints de GA-I. Les premiers résultats ont révélé un phénotype biochimique et histologique caractéristique pour GA-I. Cependant, les rats Gcdhkl/klne développaient pas spontanément de crises encéphalopatiques ni de lésions cérébrales au niveau du striatum. Des analyses complémentaires devront être réalisées à l'aide d'une alimentation riche en protéines ou riche en lysine pour déclencher un stress catabolique. La dernière partie de cette thèse fut dédiée à la phénylcétonurie (PCU) dans le but d'étudier la toxicité potentielle de sépiaptérine, un précurseur stable de la tetrahydrobiopterin (BH4), sur des cellules cérébrales de rat en développement. La saproptérine (SD), une forme synthétique de BH4, est utilisée chez des patients atteints de PCU dans le but de réduire leur concentrations sanguines de phénylalanine. Récemment, l'hyperactivité a été reportée comme un effet secondaire du traitement par SD suite à des observations post-marketing. Cette observation nous a poussé à réaliser cette étude. Nous avons montré des effets délétères de sépiaptérine sur des cellules cérébrales en développement dans un modèle in vitro de rat. Curieusement, aucun de ces effets n'était observé sur des cellules cérébrales d'un stade développemental plus avancé. Des analyses de séquençage d'ARN et d'enrichissement GO ont permis d'identifier des voies biologiques clés qui pourraient expliquer la toxicité observée. Suite à ces observations, il se pose la question si l'utilisation de la SD chez les patients atteints de PCU à partir de l'âge de 4 mois peut être recommandée comme licencié en Europe depuis 2015

Amrita ::designing a support system for new food recipes for phytonutrition

In this paper, we describe a mobile service, which is aimed at cooking chefs and that generates list of ingredients for recipes made of local products. We focus on a specific type of cooking recipes based on plants, which are used in cultural food practices worldwide to support wellbeing ("phytonutrition"). Researchers in food technology have been successfully developing food recommenders but there is a gap concerning the notion of phytonutrition changes the set of required functions and the theoretical framework to assess the software. We describe an endtoend support system for recipe design in compliance with European regulations concerning phytonutrients. Results of a longitudinal test, which was done in a hotel in the Alpine region, show that our software allows chefs to conceive a set of dishes, which increase the satisfaction of customers and have a positive effect on their wellbeing

CIOCU. A Crowdsourced Inter-Organizational Crisis Unit

The current paper focuses on category dynamics resulting from changes in the moral character of a category. We explore the process of stigma transfer from individual category members to the overall category, particularly when category members have transgressed evaluators’ moral expectations. We suggest that the stigma associated with the transgressing actions of individual category members leads to stronger and more intense reactions by evaluators in the form of lower ratings and more negative feelings towards all organizations belonging to that category. However, when self-identifying with the transgressing actor evaluators exhibit stronger positive evaluations while the intensity of their sentiments remain unchanged. Drawing on 24.000+ guests’ reviews on 145 luxury hotels in major US cities, we test our arguments within the context of the luxury hotel industry in the U.S. We model the victory of hotelier Donald Trump in the 2016 U.S. presidential elections as an exogenous shock and explain how and why it affected evaluation and category dynamics in the hotel industry. Our findings support our view that audience members vividly express the intensity and direction of their evaluations when in disagreement with the transgressing actor. Furthermore, our results also suggest that audience members are more vocal with respect to the intensity of their evaluations rather than the direction of their sentiments when they identify with the transgressing actor

Mitochondrial remodeling in hepatic differentiation and dedifferentiation

Mitochondrial biogenesis and metabolism have recently emerged as important actors of stemness and differentiation. On the one hand, the differentiation of stem cells is associated with an induction of mitochondrial biogenesis and a shift from glycolysis toward oxidative phosphorylations (OXPHOS). In addition, interfering with mitochondrial biogenesis or function impacts stem cell differentiation. On the other hand, some inverse changes in mitochondrial abundance and function are observed during the reprogramming of somatic cells into induced pluripotent stem cells (iPSCs). Yet although great promises in cell therapy might generate better knowledge of the mechanisms regulating the stemness and differentiation of somatic stem cells (SSCs)-which are preferred over embryonic stem cells (ESCs) and iPSCs because of ethical and safety considerations-little interest was given to the study of their mitochondria. This study provides a detailed characterization of the mitochondrial biogenesis occurring during the hepatogenic differentiation of bone marrow-mesenchymal stem cells (BM-MSCs). During the hepatogenic differentiation of BM-MSCs, an increased abundance of mitochondrial DNA (mtDNA) is observed, as well as an increased expression of several mitochondrial proteins and biogenesis regulators, concomitant with increased OXPHOS activity, capacity, and efficiency. In addition, opposite changes in mitochondrial morphology and in the abundance of several OXPHOS subunits were found during the spontaneous dedifferentiation of primary hepatocytes. These data support reverse mitochondrial changes in a different context from genetically-engineered reprogramming. They argue in favor of a mitochondrial involvement in hepatic differentiation and dedifferentiation

The first knock-in rat model for glutaric aciduria type I allows further insights into pathophysiology in brain and periphery

Glutaric aciduria type I (GA-I, OMIM # 231670) is an inborn error of metabolism caused by a deficiency of glutaryl-CoA dehydrogenase (GCDH). Patients develop acute encephalopathic crises (AEC) with striatal injury most often triggered by catabolic stress. The pathophysiology of GA-I, particularly in brain, is still not fully understood. We generated the first knock-in rat model for GA-I by introduction of the mutation p.R411W, the rat sequence homologue of the most common Caucasian mutation p.R402W, into the Gcdh gene of Sprague Dawley rats by CRISPR/CAS9 technology. Homozygous Gcdhki/ki rats revealed a high excretor phenotype, but did not present any signs of AEC under normal diet (ND). Exposure to a high lysine diet (HLD, 4.7%) after weaning resulted in clinical and biochemical signs of AEC. A significant increase of plasmatic ammonium concentrations was found in Gcdhki/ki rats under HLD, accompanied by a decrease of urea concentrations and a concomitant increase of arginine excretion. This might indicate an inhibition of the urea cycle. Gcdhki/ki rats exposed to HLD showed highly diminished food intake resulting in severely decreased weight gain and moderate reduction of body mass index (BMI). This constellation suggests a loss of appetite. Under HLD, pipecolic acid increased significantly in cerebral and extra-cerebral liquids and tissues of Gcdhki/ki rats, but not in WT rats. It seems that Gcdhki/ki rats under HLD activate the pipecolate pathway for lysine degradation. Gcdhki/ki rat brains revealed depletion of free carnitine, microglial activation, astroglyosis, astrocytic death by apoptosis, increased vacuole numbers, impaired OXPHOS activities and neuronal damage. Under HLD, Gcdhki/ki rats showed imbalance of intra- and extracellular creatine concentrations and indirect signs of an intracerebral ammonium accumulation. We successfully created the first rat model for GA-I. Characterization of this Gcdhki/ki strain confirmed that it is a suitable model not only for the study of pathophysiological processes, but also for the development of new therapeutic interventions. We further brought up interesting new insights into the pathophysiology of GA-I in brain and periphery