Plasma methionine metabolic profile is associated with longevity in mammals

Methionine metabolism arises as a key target to elucidate the molecular adaptations underlying animal longevity due to the negative association between longevity and methionine content. The present study follows a comparative approach to analyse plasma methionine metabolic profile using a LC-MS/MS platform from 11 mammalian species with a longevity ranging from 3.5 to 120 years. Our findings demonstrate the existence of a species-specific plasma profile for methionine metabolism associated with longevity characterised by: i) reduced methionine, cystathionine and choline; ii) increased non-polar amino acids; iii) reduced succinate and malate; and iv) increased carnitine. Our results support the existence of plasma longevity features that might respond to an optimised energetic metabolism and intracellular structures found in long-lived species.This work was supported by the Spanish Ministry of Science, Innovation and Universities (RTI2018-099200-B-I00), and the Generalitat of Catalonia (Agency for Management of University and Research Grants (2017SGR696) and Department of Health (SLT002/16/00250)) to R.P. This study has been co-financed by FEDER funds from the European Union (“A way to build Europe”). IRBLleida is a CERCA Programme/Generalitat of Catalonia. M.J. is a ‘Serra Hunter’ Fellow. N.M.M. received a predoctoral fellowship from the Generalitat of Catalonia (AGAUR, ref 2018FI_B2_00104)

Colonic Microbiota Profile Characterization of the Responsiveness to Dietary Fibre Treatment in Hypercholesterolemia

This study aimed to determine how the microbiota profile might be predisposed to a better response in blood lipid profiles due to dietary fibre supplementation. A three-arm intervention study that included three different fibre types (mainly insoluble, soluble, and antioxidant fibre) supplemented (19.2 g/day) during 2 months in individuals with hypercholesterolemia was developed. Changes in faecal microbiota and blood lipid profile after fibre supplementation were determined. In all volunteers, regardless of fibre type, an increase in the abundance of Bifidobacterium was observed, and similarly, an inverse relationship between faecal propionic acid and blood LDL-cholesterol, LDL particle size, and LDL/HDL particle ratio (p-values 0.0067, 0.0002, and 0.0067, respectively) was observed. However, not all volunteers presented an improvement in lipid profile. The non-responders to fibre treatment showed a decrease in microbiota diversity (Shannon and Simpson diversity index p-values of 0.0110 and 0.0255, respectively) after the intervention; where the reduction in short-chain fatty acids (SCFAs) producing bacterial genera such as Clostridium XIVa and Ruminococcus after dietary fibre treatment was the main difference. It was concluded that the non-responsiveness to dietary fibre treatment might be mediated by the lack of ability to maintain a stable SCFA producing bacteria diversity and composition after extra fibre intake.The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the Seventh Framework Programme of the European Union (FP7/2007-2013) under REA grant agreement no. 600388 (TECNIOspring Progamme) and from the Agency for Business Competitiveness of the Government of Catalonia ACCIÓ that support the fellowship given to Ana Belén Granado-Serrano (TECSPR14-0-0023

Metabolic adaptations in spontaneously immortalized PGC-1α knock-out mouse embryonic fibroblasts increase their oncogenic potential

PGC-1α controls, to a large extent, the capacity of cells to respond to changing nutritional requirements and energetic demands. The key role of metabolic reprogramming in tumor development has highlighted the potential role of PGC-1α in cancer. To investigate how loss of PGC-1α activity in primary cells impacts the oncogenic characteristics of spontaneously immortalized cells, and the mechanisms involved, we used the classic 3T3 protocol to generate spontaneously immortalized mouse embryonic fibroblasts (iMEFs) from wild-type (WT) and PGC-1α knockout (KO) mice and analyzed their oncogenic potential in vivo and in vitro. We found that PGC-1α KO iMEFs formed larger and more proliferative primary tumors than WT counterparts, and fostered the formation of lung metastasis by B16 melanoma cells. These characteristics were associated with the reduced capacity of KO iMEFs to respond to cell contact inhibition, in addition to an increased ability to form colonies in soft agar, an enhanced migratory capacity, and a reduced growth factor dependence. The mechanistic basis of this phenotype is likely associated with the observed higher levels of nuclear β-catenin and c-myc in KO iMEFs. Evaluation of the metabolic adaptations of the immortalized cell lines identified a decrease in oxidative metabolism and an increase in glycolytic flux in KO iMEFs, which were also more dependent on glutamine for their survival. Furthermore, glucose oxidation and tricarboxylic acid cycle forward flux were reduced in KO iMEF, resulting in the induction of compensatory anaplerotic pathways. Indeed, analysis of amino acid and lipid patterns supported the efficient use of tricarboxylic acid cycle intermediates to synthesize lipids and proteins to support elevated cell growth rates. All these characteristics have been observed in aggressive tumors and support a tumor suppressor role for PGC-1α, restraining metabolic adaptations in cancer.This work was funded by grants from the Spanish “Ministerio de Ciencia, Innovación y Universidades” (MICINN) and ERDF/FEDER funds, SAF2012-37693, SAF2015-63904-R, SAF2015-71521-REDC, RTI2018-093864-B-I00 to M.M., SAF2017-83043-R and B2017/BMD-3724 to S·C., PI15/00107 to A.M.R, the University of the Basque Country UPV/EHU grant GIU16/62) to J.l.R.S. and M.B.R.L., and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement 721236-TREATMENT to M.M

Gut microbes shape microglia and cognitive function during malnutrition

Fecal-oral contamination promotes malnutrition pathology. Lasting consequences of early life malnutrition include cognitive impairment, but the underlying pathology and influence of gut microbes remain largely unknown. Here, we utilize an established murine model combining malnutrition and iterative exposure to fecal commensals (MAL-BG). The MAL-BG model was analyzed in comparison to malnourished (MAL mice) and healthy (CON mice) controls. Malnourished mice display poor spatial memory and learning plasticity, as well as altered microglia, non-neuronal CNS cells that regulate neuroimmune responses and brain plasticity. Chronic fecal-oral exposures shaped microglial morphology and transcriptional profile, promoting phagocytic features in MAL-BG mice. Unexpectedly, these changes occurred independently from significant cytokine-induced inflammation or blood-brain barrier (BBB) disruption, key gut-brain pathways. Metabolomic profiling of the MAL-BG cortex revealed altered polyunsaturated fatty acid (PUFA) profiles and systemic lipoxidative stress. In contrast, supplementation with an ω3 PUFA/antioxidant-associated diet (PAO) mitigated cognitive deficits within the MAL-BG model. These findings provide valued insight into the malnourished gut microbiota-brain axis, highlighting PUFA metabolism as a potential therapeutic target

Molecular phenomics of a high-calorie diet-induced porcine model of prepubertal obesity

As obesity incidence is alarmingly rising among young individuals, we aimed to characterize an experimental model of this situation, considering the similarity between human and porcine physiology. For this reason, we fed prepubertal (63 days old) Duroc breed females (n=21) either with a standard growth diet (3800 kcal/day) or one with a high-calorie content (5200 kcal/day) during 70 days. Computerized tomography, mass-spectrometry-based metabolomics and lipidomics, as well as peripheral blood mononuclear cell transcriptomics, were applied to define traits linked to high-calorie intake. Samples from a human cohort confirmed potential lipidomic markers. Compared to those fed a standard growth diet, pigs fed a high-calorie diet showed an increased weight gain (13%), much higher adiposity (53%), hypertriacylglyceridemia and hypercholesterolemia in parallel to insulin resistance. This diet induced marked changes in the circulating lipidome, particularly in phosphatidylethanolamine-type molecules. Also, circulating specific diacylglycerol and monoacylglycerol contents correlated with visceral fat and intrahepatic triacylglycerol concentrations. Specific lipids associated with obesity in swine (mainly belonging to glycerophospholipid, triacylglyceride and sterol classes) were also linked with obesity traits in the human cohort, reinforcing the usefulness of the chosen approach. Interestingly, no overt inflammation in plasma or adipose tissue was evident in this model. The presented model is useful as a preclinical surrogate of prepubertal obesity in order to ascertain the pathophysiology interactions between energy intake and obesity development.Supported by Centro para el Desarrollo Tecnológico e Industrial, Spain, Project reference: IPT-20111008, and Generalitat de Catalunya grants 2017SGR1719 and 2017SGR696. MJ is a "Serra Hunter" program fellow. Supported by Instituto de Salud Carlos III, Spain, Project reference: 17-00134, co-financed by FEDER Funds A way to make Europe

Fisiopatologia molecular de l'obesitat prepuberal induïda per una dieta hipercalòrica i la seva modulació per composts probiòtics en un model preclínic porcí

Avui en dia, l’obesitat és considerada “l’epidèmia del segle XXI”, tant pel seu increment constant en la prevalença com pel seu impacte en la mortalitat, morbiditat, qualitat de vida i cost sanitari. L’obesitat es caracteritza per un excés d’acumulació de greix corporal relacionat amb desequilibris en la ingesta calòrica i la despesa energètica bàsicament vinculat amb els canvis en l’estil de vida de la població caracteritzats per un consum de dietes hipercalòriques, riques en greixos i sucres juntament amb un estil de vida sedentari. Dades recents indiquen un increment alarmant de l’obesitat infantil amb major probabilitat de que l’obesitat que comença en la infància perduri per tota la vida. Per abordar aquest problema, les primeres línies de tractament són l’adequació de la ingesta calòrica i l’activitat física. No obstant això, aquestes recomanacions són difícils de seguir a llarg termini i la incorporació de diferents suplements a la dieta podria ser una alternativa útil per al tractament d’aquesta patologia. En aquest sentit, l’estratègia proposada en aquesta tesi, com a alternativa per reduir els riscos i minimitzar la gravetat i les complicacions associades a l’obesitat, és l’ús de probiòtics, basant-nos en la relació entre la microbiota intestinal i l’obesitat, per tal de manipular la composició de la microbiota a favor d’una microbiota específica i, d’aquesta manera, poder prevenir o millorar els efectes deleteris de l’obesitat. Per tant, aquesta tesi s’ha dissenyat amb l’objectiu de: i) avaluar, en primer lloc, quin és l’efecte d’una dieta hipercalòrica en un model animal prepuberal en mostres de plasma i d’escorça frontal, degut a la manca d’estudis de l’afectació de l’obesitat infantil en aquest teixit, i ii) estudiar l’efecte d’uns probiòtics com a possible intervenció nutricional utilitzant tècniques metabolòmiques. Per assolir aquests objectius, s’ha escollit, entre els diferents models animals utilitzats per a l’estudi de l’obesitat, un model animal porcí, degut a les nombroses similituds amb els humans, al que, per una banda, se li ha induït obesitat amb una dieta hipercalòrica i, per altra banda, s’ha tractat amb els probiòtics dins d’un context de dieta hipercalòrica. Els resultats obtinguts mostren que el model porcí utilitzat és un bon model per a estudiar l’obesitat. A més, es demostra l’existència d’un perfil metabolòmic i lipidòmic específic tant en plasma com en cervell, així com canvis específics en el metaboloma i lipidoma després de la ingesta d’una dieta hipercalòrica on, la intervenció nutricional basada en probiòtics reverteix parcialment alguns dels canvis derivats de l’obesitat i genera una remodelació específica en els dos tipus de mostra estudiats. De forma general, es pot concloure que l’efecte induït per la dieta hipercalòrica en el metabolisme pot ser parcialment revertit gràcies a la utilització de probiòtics específics.Hoy en día, la obesidad está considerada “la epidemia del siglo XXI”, tanto por su incremento constante en la prevalencia como por su impacto en la mortalidad, morbilidad, calidad de vida y coste sanitario. La obesidad se caracteriza por un exceso de acumulación de grasa corporal relacionada con desequilibrios en la ingesta calórica y el gasto energético básicamente vinculado con los cambios en el estilo de vida de la población caracterizados por un consumo de dietas hipercalóricas, ricas en grasas y azúcares junto con un estilo de vida sedentario. Datos recientes indican un incremento de la obesidad infantil con mayor probabilidad de que la obesidad que empieza en la infancia perdure para toda la vida. Para abordar este problema, las primeras líneas de tratamiento son la adecuación de la ingesta calórica y la actividad física. Sin embargo, estas recomendaciones son difíciles de aplicar a largo plazo y la incorporación de diferentes suplementos a la dieta podría ser una alternativa para el tratamiento de esta patología. En este sentido, la estrategia propuesta en esta tesis, como alternativa para reducir los riesgos y minimizar la gravedad y las complicaciones asociadas a la obesidad, es el uso de probióticos, basándonos en la relación entre la microbiota intestinal y la obesidad, para manipular la composición de la microbiota a favor de una microbiota específica y, de este modo, poder prevenir o mejorar los efectos deletéreos de la obesidad. Por tanto, esta tesis se ha diseñado con el objetivo de: i) evaluar, en primer lugar, cual es el efecto de una dieta hipercalórica en un modelo animal prepuberal en muestras de plasma y de corteza frontal, debido a la falta de estudios de la afectación de la obesidad infantil en este tejido, y ii) estudiar el efecto de unos probióticos como posible intervención nutricional utilizando técnicas metabolómicas. Para alcanzar estos objetivos, se ha escogido, entre los diferentes modelos animales utilizados para el estudio de la obesidad, un modelo animal porcino, debido a las numerosas similitudes con los humanos, al que, por un lado, se le ha inducido obesidad con una dieta hipercalórica y, por otro lado, se ha tratado con los probióticos dentro de un contexto de dieta hipercalórica. Los resultados obtenidos muestran que el modelo porcino utilizado es un buen modelo para estudiar la obesidad. Además, se muestra la existencia de un perfil metabolómico y lipidómico específico tanto en plasma como en cerebro, así como cambios específicos en el metaboloma y el lipidoma tras la ingesta de una dieta hipercalórica donde la intervención nutricional basada en probióticos revierte parcialmente algunos de los cambios derivados de la obesidad y genera una remodelación específica en los dos tipos de muestra estudiados. De forma general, se puede concluir que el efecto inducido por la dieta hipercalórica en el metabolismo puede ser parcialmente revertido gracias a la utilización de probióticos específicos.Nowadays, obesity is considered “the epidemic of the 21st century”, both for its constant increase in prevalence and for its impact on mortality, morbidity, quality of life and health cost. Obesity is characterized by an excess accumulation of body fat related to imbalances in caloric intake and energy expenditure basically linked to changes in the lifestyle population characterized by a consumption of hypercaloric diets, rich in fat and sugars along with a sedentary lifestyle. Recent data indicate an increase in childhood obesity with higher probability that the obesity that begins in childhood will last a lifetime. To address this problem, the first lines of treatment are the adequacy of caloric intake and physical activity. However, these recommendations are difficult to apply in a long term, and the incorporation of different supplements to the diet could be an alternative for the treatment of this pathology. In this sense, the strategy proposed in this thesis, as an alternative to reduce risks and minimize the severity and complications associated with obesity, is the use of probiotics, given the relationship between the intestinal microbiota and obesity, to manipulate the composition of the microbiota in favor of a specific microbiota and, thus, be able to prevent or improve the deleterious effects of obesity. Therefore, this thesis has been designed with the objective of: i) evaluating the effect of the hypercaloric diet in a prepubertal animal model in plasma and frontal cortex samples, due the lack of the studies on the involvement of childhood obesity in this tissue and ii) study the effect of probiotics as a possible nutritional intervention using metabolomic techniques. To achieve these objectives, a pig animal model has been used, among the different animal models used for the study of obesity, due to the numerous similarities with humans, which, on the one hand, has been induced obesity with a hypercaloric diet and, on the other hand, it has been treated with probiotics within a context of hypercaloric diet. The results obtained show that the pig model used is a good model to study obesity. In addition, it shows the existence of a specific metabolomic and lipidomic profile in both plasma and brain, as well as specific changes in the metabolome and lipidome after the ingestion of a hypercaloric diet where the probiotic-based nutritional intervention partially reverses some of the changes derived from obesity and generates a specific remodeling in both the metabolome and lipidome of the two types of samples studied. In general, it can be concluded that the effects induced by the hypercaloric diet on the metabolism can be partially reversed thanks to the use of specific probiotics