This thesis focuses on the effects of n-3 polyunsaturated fatty acids (n-3 PUFA) on development of non-alcoholic fatty liver disease (NAFLD) in experiment, on prevalence of this condition in patients with type 2 diabetes mellitus and metabolic syndrome and also on non-invasive diagnostics. The aim was to study the effect of n-3 PUFA on NAFLD development in an experimental model and based on analysis of a group of patients with type 2 diabetes and metabolic syndrome to assess the prevalence of this condition. Lastly we aimed to evaluate non-invasive diagnostic methods of liver fibrosis and NASH. We demonstrated beneficial effects of n-3 PUFA administration on NAFLD development in a C57/Bl6 mice high fat methionin-cholin defficient dietary model of NAFLD. n-3 PUFA administration led to biochemical improvement, decrease of lipid accumulation in the liver as well as improvement of histology. These effects are determined by complex modulation of lipid metabolism, mainly due to decrease in availability of fatty acids for triglyceride synthesis in the liver, changes of adipokine levels and amelioration of proinflammatory status in the liver. In a group of type 2 diabetics we found NAFLD prevalence of almost 80%, 14% of these patients had also signs of liver fibrosis or cirrhosis. Non-invasive methods...

Les patients atteints de stéatose hépatique non alcoolique (NAFLD) développent fréquemment des manifestations cardiovasculaires. Bien que souvent liées à l'obésité, ces anomalies peuvent également se développer chez des patients non obèses atteints de NAFLD impliquant que cette pathologie hépatique joue, en soi, un rôle dans la pathogenèse des complications cardiaques. Pour répondre à cette question et étudier les mécanismes sous-jacents indépendamment de toutes perturbations métaboliques et comorbidités préexistantes, nous avons utilisé un modèle murin arborant une déficience mitochondriale hépatique associée à un défaut d'assemblage du complexe IV de la chaîne respiratoire. Ce modèle murin avait préalablement été caractérisé au niveau hépatique mettant alors en évidence le développement d'une stéatose microvésiculaire et un profil lipidomique similaire à celui observé chez les patients atteints d'une NAFLD sans obésité. L'identification des mécanismes qui sous-tendent le développement et la progression de la NAFLD sans obésité et de ces répercussions extra-hépatiques ne faisant pas l'objet d'un très grand nombre d'études fondamentales, l'objectif principal était donc d'étudier l'axe foie-coeur. Dans le cadre des travaux de ce mémoire, nous avons cherché à approfondir la caractérisation hépatique, préalablement faite à l'âge de 5 semaines et ayant fait l'objet de publications par des laboratoires collaborateurs. Nous avons par la suite investigué la glycémie, l'insulinémie et le profil des lipoprotéines plasmatiques pour finir par l'analyse du métabolisme et de la fonction cardiaque. L'ensemble de ces expériences ont été faites en prenant en compte l'impact non négligeable du sexe sur la physiopathologie de la NAFLD. Nos résultats ont dévoilé un important remodelage phénotypique sexe-dépendant allant au-delà des lésions hépatiques. Les mâles un peu plus que les femelles présentaient une hypoglycémie à jeun et une sensibilité accrue à l'insuline. Ils présentaient un léger dysfonctionnement diastolique soutenu par un remodelage des lipoprotéines circulantes et dans une certaine mesure, par un remodelage du lipidome cardiaque. À l'inverse, les femelles ne manifestaient aucun dysfonctionnement cardiaque, mais présentaient des déficiences cardiométaboliques soutenues par une altération de l’intégrité et la fonction mitochondriale, un remodelage des lipoprotéines circulantes et une accumulation intracardiaque de triglycérides. À la lumière de ces résultats, cette étude souligne que les défauts métaboliques dans le foie peuvent entraîner des anomalies significatives et dépendantes du sexe affectant à la fois le phénotype mitochondrial/métabolique et la fonction contractile indépendamment de l'obésité. Ce modèle expérimental pourrait s'avérer utile dans la compréhension des mécanismes sous-jacents à la variabilité liée au sexe dans la progression de la NAFLD chez l'homme non obèse. / Cardiac abnormalities often develop in patients with non-alcoholic fatty liver disease (NAFLD). Although frequently linked to obesity, these abnormalities can also develop in patients with lean-NAFLD, implying that the liver pathology per se plays a role in the pathogenesis of cardiac complications. To address this question and investigate the underlying mechanisms independent of any pre-existent metabolic disruptions and comorbidities, we used a murine model of hepatic mitochondrial deficiency associated with a defect in the assembly of respiratory chain complex IV. This mouse model had previously been characterized at the hepatic level, showing the presence of microvesicular steatosis, and a lipidomic profile similar to that observed in patients with lean-NAFLD. Because few fundamental studies have adressed the identification of mechanisms underlying the development and progression of lean-NAFLD and its extrahepatic repercussions, the main aim was to study the liver-heart axis. As a part of this master's project, we sought to deepen the hepatic characterization of this mouse model, previously done at 5-weeks of age, and published by collaborators. We then investigated glycemia, insulinemia and plasma lipoprotein profile, and finally examined cardiac metabolism and function. All these experiments were done in consideration of the non-negligible impact of sexe on the pathophysiology of NAFLD. Our results unveiled a sex-dependent multi-faceted phenotypic remodeling that went beyond liver damage. Males, slightly more than females, showed fasting hypoglycemia and increased insulin sensitivity. They exhibited mild diastolic dysfunction supported by remodeling of the circulating lipoproteins, and to some extent remodeling of cardiac lipidome. Conversely, females did not manifest cardiac dysfunction, but exhibited cardiometabolic impairments supported by impaired mitochondrial integrity and function, remodeling of circulating lipoproteins, and intracardiac accumulation of triglycerides. In light of these findings, this study underscores that metabolic defects in the liver can result in significant sex-dependent abnormalities that affect both the mitochondrial/metabolic phenotype and contractile function independent of obesity. This experimental model may prove useful to better understand the mechanisms underlying the sex-related variability in the progression of lean-NAFLD in humans.

Pour le diagnostic et la stratification de la fibrose hépatique, la rigidité du foie est un biomarqueur quantitatif estimé par des méthodes d'élastographie. L'élastographie par ondes de cisaillement (« shear wave », SW) utilise des ultrasons médicaux non invasifs pour évaluer les propriétés mécaniques du foie sur la base des propriétés de propagation des ondes de cisaillement. La vitesse des ondes de cisaillement (« shear wave speed », SWS) et l'atténuation des ondes de cisaillement (« shear wave attenuation », SWA) peuvent fournir une estimation de la viscoélasticité des tissus. Les tissus biologiques sont intrinsèquement viscoélastiques et un modèle mathématique complexe est généralement nécessaire pour calculer la viscoélasticité en imagerie SW. Le calcul précis de l'atténuation est essentiel, en particulier pour une estimation précise du module de perte et de la viscosité. Des études récentes ont tenté d'augmenter la précision de l'estimation du SWA, mais elles présentent encore certaines limites. Comme premier objectif de cette thèse, une méthode de décalage de fréquence revisitée a été développée pour améliorer les estimations fournies par la méthode originale de décalage en fréquence [Bernard et al 2017]. Dans la nouvelle méthode, l'hypothèse d'un paramètre de forme décrivant les caractéristiques spectrales des ondes de cisaillement, et assumé initialement constant pour tous les emplacements latéraux, a été abandonnée permettant un meilleur ajustement de la fonction gamma du spectre d'amplitude. En second lieu, un algorithme de consensus d'échantillons aléatoires adaptatifs (« adaptive random sample consensus », A-RANSAC) a été mis en œuvre pour estimer la pente du paramètre de taux variable de la distribution gamma afin d’améliorer la précision de la méthode. Pour valider ces changements algorithmiques, la méthode proposée a été comparée à trois méthodes récentes permettant d’estimer également l’atténuation des ondes de cisaillements (méthodes de décalage en fréquence, de décalage en fréquence en deux points et une méthode ayant comme acronyme anglophone AMUSE) à l'aide de données de simulations ou fantômes numériques. Également, des fantômes de gels homogènes in vitro et des données in vivo acquises sur le foie de canards ont été traités. Comme deuxième objectif, cette thèse porte également sur le diagnostic précoce de la stéatose hépatique non alcoolique (NAFLD) qui est nécessaire pour prévenir sa progression et réduire la mortalité globale. À cet effet, la méthode de décalage en fréquence revisitée a été testée sur des foies humains in vivo. La performance diagnostique de la nouvelle méthode a été étudiée sur des foies humains sains et atteints de la maladie du foie gras non alcoolique. Pour minimiser les sources de variabilité, une méthode d'analyse automatisée faisant la moyenne des mesures prises sous plusieurs angles a été mise au point. Les résultats de cette méthode ont été comparés à la fraction de graisse à densité de protons obtenue de l'imagerie par résonance magnétique (« magnetic resonance imaging proton density fat fraction », MRI-PDFF) et à la biopsie du foie. En outre, l’imagerie SWA a été utilisée pour classer la stéatose et des seuils de décision ont été établis pour la dichotomisation des différents grades de stéatose. Finalement, le dernier objectif de la thèse consiste en une étude de reproductibilité de six paramètres basés sur la technologie SW (vitesse, atténuation, dispersion, module de Young, viscosité et module de cisaillement). Cette étude a été réalisée chez des volontaires sains et des patients atteints de NAFLD à partir de données acquises lors de deux visites distinctes. En conclusion, une méthode robuste de calcul du SWA du foie a été développée et validée pour fournir une méthode de diagnostic de la NAFLD. / For diagnosis and staging of liver fibrosis, liver stiffness is a quantitative biomarker estimated by elastography methods. Ultrasound shear wave (SW) elastography utilizes noninvasive medical ultrasound to assess the mechanical properties of the liver based on the monitoring of the SW propagation. SW speed (SWS) and SW attenuation (SWA) can provide an estimation of tissue viscoelasticity. Biological tissues are inherently viscoelastic in nature and a complex mathematical model is usually required to compute viscoelasticity in SW imaging. Accurate computation of attenuation is critical, especially for accurate loss modulus and viscosity estimation. Recent studies have made attempts to increase the precision of SWA estimation, but they still face some limitations. As a first objective of this thesis, a revisited frequency-shift method was developed to improve the estimates provided by the original implementation of the frequency-shift method [Bernard et al 2017]. In the new method, the assumption of a constant shape parameter of the gamma function describing the SW magnitude spectrum has been dropped for all lateral locations, allowing a better gamma fitting. Secondly, an adaptive random sample consensus algorithm (A-RANSAC) was implemented to estimate the slope of the varying rate parameter of the gamma distribution to improve the accuracy of the method. For the validation of these algorithmic changes, the proposed method was compared with three recent methods proposed to estimate SWA (frequency-shift, two-point frequency-shift and AMUSE methods) using simulation data or numerical phantoms. In addition, in vitro homogenous gel phantoms and in vivo animal (duck) liver data were processed. As a second objective, this thesis also aimed at improving the early diagnosis of nonalcoholic fatty liver disease (NAFLD), which is necessary to prevent its progression and decrease the overall mortality. For this purpose, the revisited frequency-shift method was tested on in vivo human livers. The new method's diagnosis performance was investigated with healthy and NAFLD human livers. To minimize sources of variability, an automated analysis method averaging measurements from several angles has been developed. The results of this method were compared to the magnetic resonance imaging proton density fat fraction (MRI-PDFF) and to liver biopsy. SWA imaging was used for grading steatosis and cut-off decision thresholds were established for dichotomization of different steatosis grades. As a third objective, this thesis is proposing a reproducibility study of six SW-based parameters (speed, attenuation, dispersion, Young’s modulus, viscosity and shear modulus). The assessment was performed in healthy volunteers and NAFLD patients using data acquired at two separate visits. In conclusion, a robust method for computing the liver’s SWA was developed and validated to provide a diagnostic method for NAFLD.

[ES] El síndrome metabólico se define como un conjunto de trastornos (e.g., niveles elevados de presión arterial, niveles elevados de glucosa en sangre, exceso de grasa abdominal o niveles elevados de colesterol o triglicéridos) que afectan a un individuo al mismo tiempo. La presencia de uno de estos factores no implica un riesgo elevado para la salud, sin embargo, presentar varios de ellos aumenta la probabilidad de sufrir enfermedades secundarias como la enfermedad cardiovascular o la diabetes tipo II. Las enfermedades difusas hepáticas son todas aquellas enfermedades que afectan a las células funcionales del hígado, los hepatocitos, alterando, de este modo, la función hepática. En estos procesos, los hepatocitos se ven sustituidos por adipocitos y tejido fibroso. La enfermedad de hígado graso no alcohólico es una afección reversible originada por la acumulación de triglicéridos en los hepatocitos. El alcoholismo, la obesidad, y la diabetes son las causas más comunes de esta enfermedad. Este estado del hígado es reversible si se cambia la dieta del paciente, sin embargo, si este no se cuida, la enfermedad puede ir avanzando hacia estadios más severos, desencadenando fibrosis, cirrosis e incluso carcinoma hepatocelular (CHC). La temprana detección de todos estos procesos es de gran importancia en la mejora del pronóstico de los pacientes. Así, las técnicas de imagen en combinación con modelos computacionales permiten caracterizar el tejido mediante la extracción de parámetros objetivos, conocidos como biomarcadores de imagen, relacionados con estos procesos fisiológicos y patológicos, permitiendo una estadificación más precisa de las enfermedades. Además, gracias a las técnicas de inteligencia artificial, se pueden desarrollar algoritmos de segmentación automática que permitan realizar dicha caracterización de manera completamente automática y acelerar, de este modo, el flujo radiológico. Por todo esto, en la presente tesis doctoral, se presenta una metodología para el desarrollo de modelos de segmentación y cuantificación automática, siendo aplicada a tres casos de uso. Para el estudio del síndrome metabólico se propone un método de segmentación automática de la grasa visceral y subcutánea en imágenes de tomografía computarizada (TC), para el estudio de la enfermedad hepática difusa se propone un método de segmentación hepática y cuantificación de la grasa y hierro hepáticos en imágenes de resonancia magnética (RM), y, finalmente, para el estudio del CHC, se propone un método de segmentación hepática y cuantificación de los descriptores de la curva de perfusión en imágenes de RM. Todo esto se ha integrado en una plataforma que permite su integración en la práctica clínica. Así, se han adaptado los algoritmos desarrollados para ser ejecutados en contenedores Docker de forma que, dada una imagen de entrada, generen los parámetros cuantitativos de salida junto con un informe que resuma dichos resultados; se han implementado herramientas para que los usuarios puedan interactuar con las segmentaciones generadas por los algoritmos de segmentación automática desarrollados; finalmente, éstos se han implementado de forma que generen dichas segmentaciones en formatos estándar como DICOM RT Struct o DICOM Seg, para garantizar la interoperabilidad con el resto de sistemas sanitarios. / [CA] La síndrome metabòlica es defineix com un conjunt de trastorns (e.g., nivells elevats de pressió arterial, nivells elevats de glucosa en sang, excés de greix abdominal o nivells elevats de colesterol o triglicèrids) que afecten un individu al mateix temps. La presència d'un d'aquests factors no implica un risc elevat per a la salut, no obstant això, presentar diversos d'ells augmenta la probabilitat de patir malalties secundàries com la malaltia cardiovascular o la diabetis tipus II. Les malalties difuses hepàtiques són totes aquelles malalties que afecten les cèl·lules funcionals del fetge, els hepatòcits, alterant, d'aquesta manera, la funció hepàtica. En aquests processos, els hepatòcits es veuen substituïts per adipòcits i teixit fibrós. La malaltia de fetge gras no alcohòlic és una afecció reversible originada per l'acumulació de triglicèrids en els hepatòcits. L'alcoholisme, l'obesitat, i la diabetis són les causes més comunes d'aquesta malaltia. Aquest estat del fetge és reversible si es canvia la dieta del pacient, no obstant això, si aquest no es cuida, la malaltia pot anar avançant cap a estadis més severs, desencadenant fibrosis, cirrosis i fins i tot carcinoma hepatocel·lular (CHC). La primerenca detecció de tots aquests processos és de gran importància en la millora del pronòstic dels pacients. Així, les tècniques d'imatge en combinació amb models computacionals permeten caracteritzar el teixit mitjançant l'extracció paràmetres objectius, coneguts com biomarcadores d'imatge, relacionats amb aquests processos fisiològics i patològics, permetent una estratificació més precisa de les malalties. A més, gràcies a les tècniques d'intel·ligència artificial, es poden desenvolupar algorismes de segmentació automàtica que permeten realitzar aquesta caracterització de manera completament automàtica i accelerar, d'aquesta manera, el flux radiològic. Per tot això, en la present tesi doctoral, es presenta una metodologia per al desenvolupament de models de segmentació i quantificació automàtica, sent aplicada a tres casos d'ús. Per a l'estudi de la síndrome metabòlica es proposa un mètode de segmentació automàtica del greix visceral i subcutani en imatges de tomografia computada (TC), per a l'estudi de la malaltia hepàtica difusa es proposa un mètode segmentació hepàtica i quantificació del greix i ferro hepàtics en imatges de ressonància magnètica (RM), i, finalment, per a l'estudi del CHC, es proposa un mètode de segmentació hepàtica i quantificació dels descriptors de la corba de perfusió en imatges de RM. Tot això s'ha integrat en una plataforma que permet la seua integració en la pràctica clínica. Així, s'han adaptat els algorismes desenvolupats per a ser executats en contenidors Docker de manera que, donada una imatge d'entrada, generen els paràmetres quantitatius d'eixida juntament amb un informe que resumisca aquests resultats; s'han implementat eines perquè els usuaris puguen interactuar amb les segmentacions generades pels algorismes de segmentació automàtica desenvolupats; finalment, aquests s'han implementat de manera que generen aquestes segmentacions en formats estàndard com DICOM RT Struct o DICOM Seg, per a garantir la interoperabilitat amb la resta de sistemes sanitaris. / [EN] Metabolic syndrome is defined as a group of disorders (e.g., high blood pressure, high blood glucose levels, excess abdominal fat, or high cholesterol or triglyceride levels) that affect an individual at the same time. The presence of one of these factors does not imply an elevated health risk; however, having several of them increases the probability of secondary diseases such as cardiovascular disease or type II diabetes. Diffuse liver diseases are all those diseases that affect the functional cells of the liver, the hepatocytes, thus altering liver function. In these processes, the hepatocytes are replaced by adipocytes and fibrous tissue. Non-alcoholic fatty liver disease is a reversible condition caused by the accumulation of triglycerides in hepatocytes. Alcoholism, obesity, and diabetes are the most common causes of this disease. This liver condition is reversible if the patient's diet is changed; however, if the patient is not cared for, the disease can progress to more severe stages, triggering fibrosis, cirrhosis and even hepatocellular carcinoma (HCC). Early detection of all these processes is of great importance in improving patient prognosis. Thus, imaging techniques in combination with computational models allow tissue characterization by extracting objective parameters, known as imaging biomarkers, related to these physiological and pathological processes, allowing a more accurate statification of diseases. Moreover, thanks to artificial intelligence techniques, it is possible to develop automatic segmentation algorithms that allow to perform such characterization in a fully automatic way and thus accelerate the radiological workflow. Therefore, in this PhD, a methodology for the development of automatic segmentation and quantification models is presented and applied to three use cases. For the study of metabolic syndrome, a method of automatic segmentation of visceral and subcutaneous fat in computed tomography (CT) images is proposed; for the study of diffuse liver disease, a method of liver segmentation and quantification of hepatic fat and iron in magnetic resonance imaging (MRI) is proposed; and, finally, for the study of HCC, a method of liver segmentation and quantification of perfusion curve descriptors in MRI is proposed. All this has been integrated into a platform that allows its integration into clinical practice. Thus, the developed algorithms have been adapted to be executed in Docker containers so that, given an input image, they generate the quantitative output parameters together with a report summarizing these results; tools have been implemented so that users can interact with the segmentations generated by the automatic segmentation algorithms developed; finally, these have been implemented so that they generate these segmentations in standard formats such as DICOM RT Struct or DICOM Seg, to ensure interoperability with other health systems. / Jimenez Pastor, AM. (2023). Aprendizaje profundo y biomarcadores de imagen en el estudio de enfermedades metabólicas y hepáticas a partir de resonancia magnética y tomografía computarizada [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202602

INTRODUÇÃO: A esteato-hepatite não alcóolica (NASH) é considerada problema de saúde pública, dada sua crescente incidência e seu possível papel na carcinogênese hepato-celular. Terapias atuais envolvem alterações de dieta e estilo de vida, mas têm seu resultado prejudicado pela baixa aderência dos pacientes. Abordagens farmacológicas ainda são precárias. Uma grande dificuldade no manejo de NASH reside no limitado entendimento de sua fisiopatologia, que parece envolver complexas alterações metabólicas e inflamatórias. Ácidos graxos poli-insaturados ômega-3 (AGPIs n-3) são reconhecidos por suas propriedades moduladoras do metabolismo lipídico e da inflamação, e estão diminuídos em pacientes com NASH. O uso clínico de AGPIs n-3 tem mostrado benefício no controle da esteatose e na produção de marcadores da resposta metabólica e inflamatória em NASH, embora com algumas observações contraditórias. A compreensão de mecanismos moleculares modulados por AGPIs n-3 em NASH podem ser úteis para identificar alvos moleculares que auxiliem no desenho de intervenção farmacológica efetiva. Nesse sentido, ciências ômicas são particularmente úteis para a compreensão de mecanismos moleculares com alto valor translacional para a prática clínica e podem contribuir para a identificação desses alvos. OBJETIVO: O presente estudo avaliou a resposta proteômica hepática e lipidômica plasmática de pacientes com NASH perante o tratamento com AGPIs n-3. MÉTODO: As avaliações proteômicas e lipidômicas foram desenvolvidas por espectometria de massas e/ou cromatografia gasosa em amostras de biópsias hepáticas e plasma coletadas de pacientes envolvidos em estudo preliminar, realizado no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O referido estudo envolveu pacientes adultos, de ambos os sexos e com diagnóstico de NASH tratados diariamente, durante 6 meses, com 3 cápsulas contendo mistura de óleo de linhaça e óleo de peixe [0,315 g AGPIs: sendo 0,065 g de ácido eicosapentaenoico (EPA), 0,050 g de docosahexaenoico (DHA) e 0,2 g alfa linolênico (ALA) por cápsula]. Pacientes, após o tratamento com AGPIs n-3, que apresentaram altas concentrações plasmáticas de ALA e/ou DHA e/ou baixas de ácido araquidônico (AA) mostraram melhora parcial das alterações de histologia hepática. No presente estudo, avaliamos as vias proteômicas e marcadores lipidômicos resultantes do tratamento com AGPIs n-3. Isto foi feito por meio da comparação, antes (grupo AT) e depois do tratamento (grupo DT), de pools de tecido hepático (análise por interactoma) e amostras de plasma (OPLS-DA). RESULTADOS: Foram identificadas proteínas hepáticas, exclusivamente e/ou alteradamente expressas, no grupo DT, relacionadas com vias de matriz celular, metabolismo lipídico, de estresse oxidativo, e de retículo endoplasmático e respiração celular. Com excessão da via de matriz celular, a análise do interactoma revelou alteração funcional significativa das vias moduladas por essas proteínas. Em conjunto, essas alterações foram sugestivas de diminuição de lipotoxicidade, estresse oxidativo e respiração anaeróbia, e aumento de respiração aeróbia após tratamento com AGPIs n-3. Estas modificações são marcadores potenciais de melhora de função de retículo endoplasmático e mitocondrial. Em adição, após o tratamento com AGPIs n-3, o perfil lipidômico plasmático mostrou-se alterado com significativo aumento de glicerofosfolípides, ALA e EPA, e diminuição de ácido araquidônico (n-6) e da razão AGPIs n-6/n-3. Estes dados são concordantes com potencial melhora das funções de retículo endoplasmático e mitocondriais. CONCLUSÃO: O tratamento com AGPIs n-3 em pacientes com NASH influenciou favoravelmente o perfil proteômico hepático e lipidômico sistêmico. Em conjunto, essas alterações sugerem melhora da função de retículo endoplasmático e mitocondrial, com potencial impacto na homeostase celular, por meio da modulação de diferentes vias biológicas / INTRODUCTION: Non-alcoholic steatohepatitis (NASH) is considered a public health problem, given its increasing incidence and its possible role in hepatocellular carcinogenesis. Current therapies involve diet and lifestyle changes, but its applicability suffers from low patients adherence. Pharmacological approaches are still missing. A main difficulty in the NASH management lies in the limited understanding of its pathophysiology, which seems to involve complex metabolic and inflammatory disturbances. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are recognized for its modulatory properties on lipid metabolism and inflammation and are decreased in patients with NASH. The clinical use of these PUFAs has shown benefit in controlling steatosis and the production of metabolic and inflammatory response markers in NASH, despite some conflicting reports. Understanding mechanisms modulated by n-3 PUFAs in NASH may be useful for identifying molecular targets that could assist in the design of effective pharmacologic interventions. In this sense, omics sciences are particularly useful for understanding molecular mechanisms with high translational value to clinical practice and may contribute to the identification of these targets. AIM: This study evaluated the liver proteomic and plasma lipidomics responses of patients with NASH towards treatment with n-3 PUFAs. METHODS: The proteomic and lipidomic evaluations were studied by mass spectrometry and / or gas chromatography in samples from liver biopsies and plasma collected from patients enrolled in a preliminary clinical trial of the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. This study involved adult patients of both sexes diagnosed with NASH treated daily for 6 months, with 3 capsules containing a mixture of linseed and fish oils [0.315 g PUFAs: 0.065 g eicosapentaenoic acid (EPA) , 0.050 g docosahexaenoic (DHA) and 0.2 g alpha linolenic acid (ALA) per capsule]. Patients, after treatment with n-3 PUFAs, with higher concentrations of ALA and DHA and lower arachidonic acid (AA) showed improvement of liver histology alterations. In the present study we evaluated the proteomics pathways and lipidomics markers resulted from treatment with PUFAs n-3. This was performed by comparing, before (BT group) and after (AT group) treatment, liver tissue pools (analysis interactome) and plasma samples (OPLS-DA). RESULTS: It was identified, in a way exclusive and altered, the expressed liver proteins in AT group, related to pathways of cellular matrix, lipid metabolism, oxidative and endoplasmic reticulum stress and cellular respiration. With the exception of cell matrix, the analysis of the interactome revealed substantial functional alterations of the pathways modulated by these proteins. Together, these changes were suggestive of decreased lipotoxicity, oxidative stress and anaerobic respiration and increased aerobic respiration following treatment with PUFAs n-3. These modifications are potential markers of endoplasmic reticulum and mitochondrial functions improvement. In addition, after treatment with n-3 PUFAs, the lipidomics profile was modified, with significant increase in glycerophospholipids, ALA and EPA and decrease of arachidonic acid (AA) and n-6/n-3 AGPIs ratio. These findings are concordant with potential improvement of reticulum endoplasmic and mitochondrial functions. CONCLUSION: In patients with NASH the treatment with n-3 PUFAs favorably influenced hepatic proteomic and systemic lipidomics profiles. Together, these changes suggest improved endoplasmic reticulum and mitochondrial functions, with potential impact on cellular homeostasis through the modulation of different biological pathways

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INTRODUÇÃO: A esteato-hepatite não alcóolica (NASH) é considerada problema de saúde pública, dada sua crescente incidência e seu possível papel na carcinogênese hepato-celular. Terapias atuais envolvem alterações de dieta e estilo de vida, mas têm seu resultado prejudicado pela baixa aderência dos pacientes. Abordagens farmacológicas ainda são precárias. Uma grande dificuldade no manejo de NASH reside no limitado entendimento de sua fisiopatologia, que parece envolver complexas alterações metabólicas e inflamatórias. Ácidos graxos poli-insaturados ômega-3 (AGPIs n-3) são reconhecidos por suas propriedades moduladoras do metabolismo lipídico e da inflamação, e estão diminuídos em pacientes com NASH. O uso clínico de AGPIs n-3 tem mostrado benefício no controle da esteatose e na produção de marcadores da resposta metabólica e inflamatória em NASH, embora com algumas observações contraditórias. A compreensão de mecanismos moleculares modulados por AGPIs n-3 em NASH podem ser úteis para identificar alvos moleculares que auxiliem no desenho de intervenção farmacológica efetiva. Nesse sentido, ciências ômicas são particularmente úteis para a compreensão de mecanismos moleculares com alto valor translacional para a prática clínica e podem contribuir para a identificação desses alvos. OBJETIVO: O presente estudo avaliou a resposta proteômica hepática e lipidômica plasmática de pacientes com NASH perante o tratamento com AGPIs n-3. MÉTODO: As avaliações proteômicas e lipidômicas foram desenvolvidas por espectometria de massas e/ou cromatografia gasosa em amostras de biópsias hepáticas e plasma coletadas de pacientes envolvidos em estudo preliminar, realizado no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. O referido estudo envolveu pacientes adultos, de ambos os sexos e com diagnóstico de NASH tratados diariamente, durante 6 meses, com 3 cápsulas contendo mistura de óleo de linhaça e óleo de peixe [0,315 g AGPIs: sendo 0,065 g de ácido eicosapentaenoico (EPA), 0,050 g de docosahexaenoico (DHA) e 0,2 g alfa linolênico (ALA) por cápsula]. Pacientes, após o tratamento com AGPIs n-3, que apresentaram altas concentrações plasmáticas de ALA e/ou DHA e/ou baixas de ácido araquidônico (AA) mostraram melhora parcial das alterações de histologia hepática. No presente estudo, avaliamos as vias proteômicas e marcadores lipidômicos resultantes do tratamento com AGPIs n-3. Isto foi feito por meio da comparação, antes (grupo AT) e depois do tratamento (grupo DT), de pools de tecido hepático (análise por interactoma) e amostras de plasma (OPLS-DA). RESULTADOS: Foram identificadas proteínas hepáticas, exclusivamente e/ou alteradamente expressas, no grupo DT, relacionadas com vias de matriz celular, metabolismo lipídico, de estresse oxidativo, e de retículo endoplasmático e respiração celular. Com excessão da via de matriz celular, a análise do interactoma revelou alteração funcional significativa das vias moduladas por essas proteínas. Em conjunto, essas alterações foram sugestivas de diminuição de lipotoxicidade, estresse oxidativo e respiração anaeróbia, e aumento de respiração aeróbia após tratamento com AGPIs n-3. Estas modificações são marcadores potenciais de melhora de função de retículo endoplasmático e mitocondrial. Em adição, após o tratamento com AGPIs n-3, o perfil lipidômico plasmático mostrou-se alterado com significativo aumento de glicerofosfolípides, ALA e EPA, e diminuição de ácido araquidônico (n-6) e da razão AGPIs n-6/n-3. Estes dados são concordantes com potencial melhora das funções de retículo endoplasmático e mitocondriais. CONCLUSÃO: O tratamento com AGPIs n-3 em pacientes com NASH influenciou favoravelmente o perfil proteômico hepático e lipidômico sistêmico. Em conjunto, essas alterações sugerem melhora da função de retículo endoplasmático e mitocondrial, com potencial impacto na homeostase celular, por meio da modulação de diferentes vias biológicas / INTRODUCTION: Non-alcoholic steatohepatitis (NASH) is considered a public health problem, given its increasing incidence and its possible role in hepatocellular carcinogenesis. Current therapies involve diet and lifestyle changes, but its applicability suffers from low patients adherence. Pharmacological approaches are still missing. A main difficulty in the NASH management lies in the limited understanding of its pathophysiology, which seems to involve complex metabolic and inflammatory disturbances. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are recognized for its modulatory properties on lipid metabolism and inflammation and are decreased in patients with NASH. The clinical use of these PUFAs has shown benefit in controlling steatosis and the production of metabolic and inflammatory response markers in NASH, despite some conflicting reports. Understanding mechanisms modulated by n-3 PUFAs in NASH may be useful for identifying molecular targets that could assist in the design of effective pharmacologic interventions. In this sense, omics sciences are particularly useful for understanding molecular mechanisms with high translational value to clinical practice and may contribute to the identification of these targets. AIM: This study evaluated the liver proteomic and plasma lipidomics responses of patients with NASH towards treatment with n-3 PUFAs. METHODS: The proteomic and lipidomic evaluations were studied by mass spectrometry and / or gas chromatography in samples from liver biopsies and plasma collected from patients enrolled in a preliminary clinical trial of the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. This study involved adult patients of both sexes diagnosed with NASH treated daily for 6 months, with 3 capsules containing a mixture of linseed and fish oils [0.315 g PUFAs: 0.065 g eicosapentaenoic acid (EPA) , 0.050 g docosahexaenoic (DHA) and 0.2 g alpha linolenic acid (ALA) per capsule]. Patients, after treatment with n-3 PUFAs, with higher concentrations of ALA and DHA and lower arachidonic acid (AA) showed improvement of liver histology alterations. In the present study we evaluated the proteomics pathways and lipidomics markers resulted from treatment with PUFAs n-3. This was performed by comparing, before (BT group) and after (AT group) treatment, liver tissue pools (analysis interactome) and plasma samples (OPLS-DA). RESULTS: It was identified, in a way exclusive and altered, the expressed liver proteins in AT group, related to pathways of cellular matrix, lipid metabolism, oxidative and endoplasmic reticulum stress and cellular respiration. With the exception of cell matrix, the analysis of the interactome revealed substantial functional alterations of the pathways modulated by these proteins. Together, these changes were suggestive of decreased lipotoxicity, oxidative stress and anaerobic respiration and increased aerobic respiration following treatment with PUFAs n-3. These modifications are potential markers of endoplasmic reticulum and mitochondrial functions improvement. In addition, after treatment with n-3 PUFAs, the lipidomics profile was modified, with significant increase in glycerophospholipids, ALA and EPA and decrease of arachidonic acid (AA) and n-6/n-3 AGPIs ratio. These findings are concordant with potential improvement of reticulum endoplasmic and mitochondrial functions. CONCLUSION: In patients with NASH the treatment with n-3 PUFAs favorably influenced hepatic proteomic and systemic lipidomics profiles. Together, these changes suggest improved endoplasmic reticulum and mitochondrial functions, with potential impact on cellular homeostasis through the modulation of different biological pathways

This study explores the possible efficacy of a low carbohydrate and high fat nutritional intervention (LCHF) as a treatment possibility aiming to improve the ability of self-control and regulation in the context of carbohydrate-addiction. The study first outlines why increased simple carbohydrate consumption has been implicated as a risk-factor in numerous chronic conditions, and then explores the possibility that a reduction of such consumption could lower general medical expenditure in the healthcare sector of already overburdened institutions, especially in developing countries like South Africa. Since the neurobiological evidence for food addiction is compelling, this study investigates the impact of a low carbohydrate and high fat eating (LCHF) regimen by measuring the change in the severity of addictive behaviour in relation to a reduced carbohydrate consumption. Results indicate that a LCHF nutritional intervention lessened addictive behaviour after just 30 days, resulting in a statistically significant decrease in addiction symptoms from day 1 to day 30. The weight and BMI values of the participants recorded at the end of the study showed a reduction from those obtained during the pre- treatment stage, and the self-perceived ‘feeling in control’ also improved in all participants after the intervention. The introduction of a LCHF nutritional intervention presents a relatively cost-effective treatment and preventative measure to combat carbohydrate over-consumption and its numerous health complications, and it is therefore hoped that the positive findings of this study will foster further research, using larger samples, into this type of nutritional intervention against addictive eating behaviour. / Psychology / M.A. (Psychology)