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1.
Clin Diabetes Endocrinol ; 10(1): 9, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38659082

RESUMO

BACKGROUND & AIMS: Despite its high prevalence in the western world metabolic dysfunction-associated steatotic liver disease (MASLD) does not benefit from targeted pharmacological therapy. We measured healthcare utilisation and identified factors associated with high-cost MASLD patients in France. METHODS: The prevalent population with MASLD (including non-alcoholic steatohepatitis) in the CONSTANCES cohort, a nationally representative sample of 200,000 adults aged between 18 and 69, was linked to the French centralised national claims database (SNDS). Study participants were identified by the fatty liver index (FLI) over the period 2015-2019. MASLD individuals were classified according as "high-cost" (above 90th percentile) or "non-high cost" (below 90th percentile). Factors significantly associated with high costs were identified using a multivariate logistic regression model. RESULTS: A total of 14,437 predominantly male (69%) participants with an average age of 53 ± SD 12 years were included. They mainly belonged to socially deprived population groups with co-morbidities such as diabetes, high blood pressure, mental health disorders and cardiovascular complications. The average expenditure was €1860 ± SD 4634 per year. High-cost MASLD cost €10,863 ± SD 10,859 per year. Conditions associated with high-cost were mental health disorders OR 1.79 (1.44-2.22), cardiovascular diseases OR 1.54 (1.21-1.95), metabolic comorbidities OR 1.50 (1.25-1.81), and respiratory disease OR 1.50 (1.11-2.00). The 10% high-cost participants accounted for 58% of the total national health care expenditures for MASLD. CONCLUSION: Our results emphasize the need for comprehensive management of the comorbid conditions which were the major cost drivers of MASLD.


Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in European countries, affecting 4­50% of the European population. Confirmation of diagnosis requires liver biopsy which is an invasive procedure. We studied the healthcare costs of patients with MASLD in order to identify cost predictors and cost drivers. We found that patients cost on average €1860 per year. Conditions associated with high-cost were mental health disorders, cardiovascular diseases, metabolic comorbidities, and respiratory disease.

3.
Nat Commun ; 15(1): 1879, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424041

RESUMO

Cancer cells integrate multiple biosynthetic demands to drive unrestricted proliferation. How these cellular processes crosstalk to fuel cancer cell growth is still not fully understood. Here, we uncover the mechanisms by which the transcription factor Carbohydrate responsive element binding protein (ChREBP) functions as an oncogene during hepatocellular carcinoma (HCC) development. Mechanistically, ChREBP triggers the expression of the PI3K regulatory subunit p85α, to sustain the activity of the pro-oncogenic PI3K/AKT signaling pathway in HCC. In parallel, increased ChREBP activity reroutes glucose and glutamine metabolic fluxes into fatty acid and nucleic acid synthesis to support PI3K/AKT-mediated HCC growth. Thus, HCC cells have a ChREBP-driven circuitry that ensures balanced coordination between PI3K/AKT signaling and appropriate cell anabolism to support HCC development. Finally, pharmacological inhibition of ChREBP by SBI-993 significantly suppresses in vivo HCC tumor growth. Overall, we show that targeting ChREBP with specific inhibitors provides an attractive therapeutic window for HCC treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias Hepáticas/metabolismo , Transdução de Sinais , Carcinogênese , Proliferação de Células , Linhagem Celular Tumoral
4.
JHEP Rep ; 6(2): 100878, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38298740

RESUMO

Background & Aims: O-GlcNAcylation is a reversible post-translational modification controlled by the activity of two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). In the liver, O-GlcNAcylation has emerged as an important regulatory mechanism underlying normal liver physiology and metabolic disease. Methods: To address whether OGT acts as a critical hepatic nutritional node, mice with a constitutive hepatocyte-specific deletion of OGT (OGTLKO) were generated and challenged with different carbohydrate- and lipid-containing diets. Results: Analyses of 4-week-old OGTLKO mice revealed significant oxidative and endoplasmic reticulum stress, and DNA damage, together with inflammation and fibrosis, in the liver. Susceptibility to oxidative and endoplasmic reticulum stress-induced apoptosis was also elevated in OGTLKO hepatocytes. Although OGT expression was partially recovered in the liver of 8-week-old OGTLKO mice, hepatic injury and fibrosis were not rescued but rather worsened with time. Interestingly, weaning of OGTLKO mice on a ketogenic diet (low carbohydrate, high fat) fully prevented the hepatic alterations induced by OGT deletion, indicating that reduced carbohydrate intake protects an OGT-deficient liver. Conclusions: These findings pinpoint OGT as a key mediator of hepatocyte homeostasis and survival upon carbohydrate intake and validate OGTLKO mice as a valuable model for assessing therapeutical approaches of advanced liver fibrosis. Impact and Implications: Our study shows that hepatocyte-specific deletion of O-GlcNAc transferase (OGT) leads to severe liver injury, reinforcing the importance of O-GlcNAcylation and OGT for hepatocyte homeostasis and survival. Our study also validates the Ogt liver-deficient mouse as a valuable model for the study of advanced liver fibrosis. Importantly, as the severe hepatic fibrosis of Ogt liver-deficient mice could be fully prevented upon feeding on a ketogenic diet (i.e. very-low-carbohydrate, high-fat diet) this work underlines the potential interest of nutritional intervention as antifibrogenic strategies.

5.
J Magn Reson Imaging ; 59(1): 97-107, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37158252

RESUMO

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is increasing worldwide and is a growing cause of liver cirrhosis and cancer. The performance of the magnetic resonance elastography (MRE) visco-elastic parameters in diagnosing progressive forms of NAFLD, including nonalcoholic steatohepatitis (NASH) and substantial fibrosis (F ≥ 2), needs to be clarified. PURPOSE: To assess the value of three-dimensional MRE visco-elastic parameters as markers of NASH and substantial fibrosis in mice with NAFLD. STUDY TYPE: Prospective. ANIMAL MODEL: Two mouse models of NAFLD were induced by feeding with high fat diet or high fat, choline-deficient, amino acid-defined diet. FIELD STRENGTH/SEQUENCE: 7T/multi-slice multi-echo spin-echo MRE at 400 Hz with motion encoding in the three spatial directions. ASSESSMENT: Hepatic storage and loss moduli were calculated. Histological analysis was based on the NASH Clinical Research Network criteria. STATISTICAL TESTS: Mann-Whitney, Kruskal-Wallis tests, Spearman rank correlations and multiple regressions were used. Diagnostic performance was assessed with areas under the receiver operating characteristic curves (AUCs). P value <0.05 was considered significant. RESULTS: Among the 59 mice with NAFLD, 21 had NASH and 20 had substantial fibrosis (including 8 mice without and 12 mice with NASH). The storage and loss moduli had similar moderate accuracy for diagnosing NASH with AUCs of 0.67 and 0.66, respectively. For diagnosing substantial fibrosis, the AUC of the storage modulus was 0.73 and the AUC of the loss modulus was 0.81, indicating good diagnostic performance. Using Spearman correlations, histological fibrosis, inflammation and steatosis, but not ballooning, were significantly correlated with the visco-elastic parameters. Using multiple regression, fibrosis was the only histological feature independently associated with the visco-elastic parameters. CONCLUSION: MRE in mice with NAFLD suggests that the storage and loss moduli have good diagnostic performance for detecting progressive NAFLD defined as substantial fibrosis rather than NASH. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY STAGE: 2.


Assuntos
Técnicas de Imagem por Elasticidade , Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Estudos Prospectivos , Biópsia , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/etiologia , Fibrose
6.
JHEP Rep ; 5(8): 100794, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37520673

RESUMO

Background & Aims: Liver regeneration is a repair process in which metabolic reprogramming of parenchymal and inflammatory cells plays a major role. Monoacylglycerol lipase (MAGL) is an ubiquitous enzyme at the crossroad between lipid metabolism and inflammation. It converts monoacylglycerols into free fatty acids and metabolises 2-arachidonoylglycerol into arachidonic acid, being thus the major source of pro-inflammatory prostaglandins in the liver. In this study, we investigated the role of MAGL in liver regeneration. Methods: Hepatocyte proliferation was studied in vitro in hepatoma cell lines and ex vivo in precision-cut human liver slices. Liver regeneration was investigated in mice treated with a pharmacological MAGL inhibitor, MJN110, as well as in animals globally invalidated for MAGL (MAGL-/-) and specifically invalidated in hepatocytes (MAGLHep-/-) or myeloid cells (MAGLMye-/-). Two models of liver regeneration were used: acute toxic carbon tetrachloride injection and two-thirds partial hepatectomy. MAGLMye-/- liver macrophages profiling was analysed by RNA sequencing. A rescue experiment was performed by in vivo administration of interferon receptor antibody in MAGLMye-/- mice. Results: Precision-cut human liver slices from patients with chronic liver disease and human hepatocyte cell lines exposed to MJN110 showed reduced hepatocyte proliferation. Mice with global invalidation or mice treated with MJN110 showed blunted liver regeneration. Moreover, mice with specific deletion of MAGL in either hepatocytes or myeloid cells displayed delayed liver regeneration. Mechanistically, MAGLHep-/- mice showed reduced liver eicosanoid production, in particular prostaglandin E2 that negatively impacts on hepatocyte proliferation. MAGL inhibition in macrophages resulted in the induction of the type I interferon pathway. Importantly, neutralising the type I interferon pathway restored liver regeneration of MAGLMye-/- mice. Conclusions: Our data demonstrate that MAGL promotes liver regeneration by hepatocyte and macrophage reprogramming. Impact and Implications: By using human liver samples and mouse models of global or specific cell type invalidation, we show that the monoacylglycerol pathway plays an essential role in liver regeneration. We unveil the mechanisms by which MAGL expressed in both hepatocytes and macrophages impacts the liver regeneration process, via eicosanoid production by hepatocytes and the modulation of the macrophage interferon pathway profile that restrains hepatocyte proliferation.

7.
Nat Rev Endocrinol ; 19(6): 336-349, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37055547

RESUMO

Excessive sugar consumption and defective glucose sensing by hepatocytes contribute to the development of metabolic diseases including type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD). Hepatic metabolism of carbohydrates into lipids is largely dependent on the carbohydrate-responsive element binding protein (ChREBP), a transcription factor that senses intracellular carbohydrates and activates many different target genes, through the activation of de novo lipogenesis (DNL). This process is crucial for the storage of energy as triglycerides in hepatocytes. Furthermore, ChREBP and its downstream targets represent promising targets for the development of therapies for the treatment of NAFLD and T2DM. Although lipogenic inhibitors (for example, inhibitors of fatty acid synthase, acetyl-CoA carboxylase or ATP citrate lyase) are currently under investigation, targeting lipogenesis remains a topic of discussion for NAFLD treatment. In this Review, we discuss mechanisms that regulate ChREBP activity in a tissue-specific manner and their respective roles in controlling DNL and beyond. We also provide in-depth discussion of the roles of ChREBP in the onset and progression of NAFLD and consider emerging targets for NAFLD therapeutics.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Humanos , Carboidratos , Diabetes Mellitus Tipo 2/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fatores de Transcrição/metabolismo
8.
Front Endocrinol (Lausanne) ; 14: 1095440, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36923222

RESUMO

Carbohydrate response element binding protein (ChREBP) is a glucose responsive transcription factor recognized by its critical role in the transcriptional control of glycolysis and de novo lipogenesis. Substantial advances in the field have revealed novel ChREBP functions. Indeed, due to its actions in different tissues, ChREBP modulates the inter-organ communication through secretion of peptides and lipid factors, ensuring metabolic homeostasis. Dysregulation of these orchestrated interactions is associated with development of metabolic diseases such as type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). Here, we recapitulate the current knowledge about ChREBP-mediated inter-organ crosstalk through secreted factors and its physiological implications. As the liver is considered a crucial endocrine organ, we will focus in this review on the role of ChREBP-regulated hepatokines. Lastly, we will discuss the involvement of ChREBP in the progression of metabolic pathologies, as well as how the impairment of ChREBP-dependent signaling factors contributes to the onset of such diseases.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Humanos , Regulação da Expressão Gênica , Fatores de Transcrição/metabolismo
9.
Ann N Y Acad Sci ; 1523(1): 38-50, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36960914

RESUMO

Immunometabolism considers the relationship between metabolism and immunity. Typically, researchers focus on either the metabolic pathways within immune cells that affect their function or the impact of immune cells on systemic metabolism. A more holistic approach that considers both these viewpoints is needed. On September 5-8, 2022, experts in the field of immunometabolism met for the Keystone symposium "Immunometabolism at the Crossroads of Obesity and Cancer" to present recent research across the field of immunometabolism, with the setting of obesity and cancer as an ideal example of the complex interplay between metabolism, immunity, and cancer. Speakers highlighted new insights on the metabolic links between tumor cells and immune cells, with a focus on leveraging unique metabolic vulnerabilities of different cell types in the tumor microenvironment as therapeutic targets and demonstrated the effects of diet, the microbiome, and obesity on immune system function and cancer pathogenesis and therapy. Finally, speakers presented new technologies to interrogate the immune system and uncover novel metabolic pathways important for immunity.


Assuntos
Neoplasias , Humanos , Neoplasias/metabolismo , Sistema Imunitário , Redes e Vias Metabólicas , Obesidade/terapia , Obesidade/metabolismo , Microambiente Tumoral
10.
Front Immunol ; 13: 960226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36275699

RESUMO

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy derived from early T cell progenitors. Since relapsed T-ALL is associated with a poor prognosis improving initial treatment of patients is essential to avoid resistant selection of T-ALL. During initiation, development, metastasis and even in response to chemotherapy, tumor cells face strong metabolic challenges. In this study, we identify mitochondrial UnCoupling Protein 2 (UCP2) as a tricarboxylic acid (TCA) cycle metabolite transporter controlling glutamine metabolism associated with T-ALL cell proliferation. In T-ALL cell lines, we show that UCP2 expression is controlled by glutamine metabolism and is essential for their proliferation. Our data show that T-ALL cell lines differ in their substrate dependency and their energetic metabolism (glycolysis and oxidative). Thus, while UCP2 silencing decreases cell proliferation in all leukemia cells, it also alters mitochondrial respiration of T-ALL cells relying on glutamine-dependent oxidative metabolism by rewiring their cellular metabolism to glycolysis. In this context, the function of UCP2 in the metabolite export of malate enables appropriate TCA cycle to provide building blocks such as lipids for cell growth and mitochondrial respiration. Therefore, interfering with UCP2 function can be considered as an interesting strategy to decrease metabolic efficiency and proliferation rate of leukemia cells.


Assuntos
Glutamina , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Proteína Desacopladora 2/genética , Proteína Desacopladora 2/metabolismo , Glutamina/metabolismo , Malatos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proliferação de Células , Ácidos Tricarboxílicos , Lipídeos
11.
Cell Rep ; 39(10): 110910, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35675775

RESUMO

In hepatocytes, peroxisome proliferator-activated receptor α (PPARα) orchestrates a genomic and metabolic response required for homeostasis during fasting. This includes the biosynthesis of ketone bodies and of fibroblast growth factor 21 (FGF21). Here we show that in the absence of adipose triglyceride lipase (ATGL) in adipocytes, ketone body and FGF21 production is impaired upon fasting. Liver gene expression analysis highlights a set of fasting-induced genes sensitive to both ATGL deletion in adipocytes and PPARα deletion in hepatocytes. Adipose tissue lipolysis induced by activation of the ß3-adrenergic receptor also triggers such PPARα-dependent responses not only in the liver but also in brown adipose tissue (BAT). Intact PPARα activity in hepatocytes is required for the cross-talk between adipose tissues and the liver during fat mobilization.


Assuntos
Lipólise , PPAR alfa , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Hepatócitos/metabolismo , Corpos Cetônicos/metabolismo , Lipólise/fisiologia , PPAR alfa/metabolismo
12.
Cell Rep ; 39(2): 110674, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35417722

RESUMO

Liver physiology is circadian and sensitive to feeding and insulin. Food intake regulates insulin secretion and is a dominant signal for the liver clock. However, how much insulin contributes to the effect of feeding on the liver clock and rhythmic gene expression remains to be investigated. Insulin action partly depends on changes in insulin receptor (IR)-dependent gene expression. Here, we use hepatocyte-restricted gene deletion of IR to evaluate its role in the regulation and oscillation of gene expression as well as in the programming of the circadian clock in the adult mouse liver. We find that, in the absence of IR, the rhythmicity of core-clock gene expression is altered in response to day-restricted feeding. This change in core-clock gene expression is associated with defective reprogramming of liver gene expression. Our data show that an intact hepatocyte insulin receptor is required to program the liver clock and associated rhythmic gene expression.


Assuntos
Fatores de Transcrição ARNTL , Relógios Circadianos , Fatores de Transcrição ARNTL/genética , Fatores de Transcrição ARNTL/metabolismo , Animais , Proteínas CLOCK/genética , Proteínas CLOCK/metabolismo , Relógios Circadianos/genética , Ritmo Circadiano/genética , Expressão Gênica , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Camundongos , Receptor de Insulina/genética , Receptor de Insulina/metabolismo
13.
Sci Adv ; 8(12): eabg9055, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35333579

RESUMO

Dysregulations of lipid metabolism in the liver may trigger steatosis progression, leading to potentially severe clinical consequences such as nonalcoholic fatty liver diseases (NAFLDs). Molecular mechanisms underlying liver lipogenesis are very complex and fine-tuned by chromatin dynamics and multiple key transcription factors. Here, we demonstrate that the nuclear factor HMGB1 acts as a strong repressor of liver lipogenesis. Mice with liver-specific Hmgb1 deficiency display exacerbated liver steatosis, while Hmgb1-overexpressing mice exhibited a protection from fatty liver progression when subjected to nutritional stress. Global transcriptome and functional analysis revealed that the deletion of Hmgb1 gene enhances LXRα and PPARγ activity. HMGB1 repression is not mediated through nucleosome landscape reorganization but rather via a preferential DNA occupation in a region carrying genes regulated by LXRα and PPARγ. Together, these findings suggest that hepatocellular HMGB1 protects from liver steatosis development. HMGB1 may constitute a new attractive option to therapeutically target the LXRα-PPARγ axis during NAFLD.

14.
JCI Insight ; 7(4)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35041621

RESUMO

Impaired glucose metabolism is observed in obesity and type 2 diabetes. Glucose controls gene expression through the transcription factor ChREBP in liver and adipose tissues. Mlxipl encodes 2 isoforms: ChREBPα, the full-length form (translocation into the nucleus is under the control of glucose), and ChREBPß, a constitutively nuclear shorter form. ChREBPß gene expression in white adipose tissue is strongly associated with insulin sensitivity. Here, we investigated the consequences of ChREBPß deficiency on insulin action and energy balance. ChREBPß-deficient male and female C57BL6/J and FVB/N mice were produced using CRISPR/Cas9-mediated gene editing. Unlike global ChREBP deficiency, lack of ChREBPß showed modest effects on gene expression in adipose tissues and the liver, with variations chiefly observed in brown adipose tissue. In mice fed chow and 2 types of high-fat diets, lack of ChREBPß had moderate effects on body composition and insulin sensitivity. At thermoneutrality, ChREBPß deficiency did not prevent the whitening of brown adipose tissue previously reported in total ChREBP-KO mice. These findings revealed that ChREBPß is dispensable for metabolic adaptations to nutritional and thermic challenges.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Glicemia/metabolismo , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2/genética , Metabolismo Energético/genética , Regulação da Expressão Gênica , RNA/genética , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/biossíntese , Células Cultivadas , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
15.
Mol Metab ; 57: 101438, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35007789

RESUMO

OBJECTIVE: A common feature of metabolic diseases is their association with chronic low-grade inflammation. While enhanced gut permeability and systemic bacterial endotoxin translocation have been suggested as key players of this metaflammation, the mechanistic bases underlying these features upon the diabesity cascade remain partly understood. METHODS: Here, we show in mice that, independently of obesity, the induction of acute and global insulin resistance and associated hyperglycemia, upon treatment with an insulin receptor (IR) antagonist (S961), elicits gut hyperpermeability without triggering systemic inflammatory response. RESULTS: Of note, S961-treated diabetic mice display major defects of gut barrier epithelial functions, such as increased epithelial paracellular permeability and impaired cell-cell junction integrity. We also observed in these mice the early onset of a severe gut dysbiosis, as characterized by the bloom of pro-inflammatory Proteobacteria, and the later collapse of Paneth cells antimicrobial defense. Interestingly, S961 treatment discontinuation is sufficient to promptly restore both the gut microbial balance and the intestinal barrier integrity. Moreover, fecal transplant approaches further confirm that S961-mediated dybiosis contributes at least partly to the disruption of the gut selective epithelial permeability upon diabetic states. CONCLUSIONS: Together, our results highlight that insulin signaling is an indispensable gatekeeper of intestinal barrier integrity, acting as a safeguard against microbial imbalance and acute infections by enteropathogens.


Assuntos
Diabetes Mellitus Experimental , Microbioma Gastrointestinal , Resistência à Insulina , Animais , Disbiose/metabolismo , Disbiose/microbiologia , Microbioma Gastrointestinal/fisiologia , Inflamação/metabolismo , Camundongos
16.
Gut ; 71(4): 807-821, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33903148

RESUMO

OBJECTIVE: We evaluated the influence of sex on the pathophysiology of non-alcoholic fatty liver disease (NAFLD). We investigated diet-induced phenotypic responses to define sex-specific regulation between healthy liver and NAFLD to identify influential pathways in different preclinical murine models and their relevance in humans. DESIGN: Different models of diet-induced NAFLD (high-fat diet, choline-deficient high-fat diet, Western diet or Western diet supplemented with fructose and glucose in drinking water) were compared with a control diet in male and female mice. We performed metabolic phenotyping, including plasma biochemistry and liver histology, untargeted large-scale approaches (liver metabolome, lipidome and transcriptome), gene expression profiling and network analysis to identify sex-specific pathways in the mouse liver. RESULTS: The different diets induced sex-specific responses that illustrated an increased susceptibility to NAFLD in male mice. The most severe lipid accumulation and inflammation/fibrosis occurred in males receiving the high-fat diet and Western diet, respectively. Sex-biased hepatic gene signatures were identified for these different dietary challenges. The peroxisome proliferator-activated receptor α (PPARα) co-expression network was identified as sexually dimorphic, and in vivo experiments in mice demonstrated that hepatocyte PPARα determines a sex-specific response to fasting and treatment with pemafibrate, a selective PPARα agonist. Liver molecular signatures in humans also provided evidence of sexually dimorphic gene expression profiles and the sex-specific co-expression network for PPARα. CONCLUSIONS: These findings underscore the sex specificity of NAFLD pathophysiology in preclinical studies and identify PPARα as a pivotal, sexually dimorphic, pharmacological target. TRIAL REGISTRATION NUMBER: NCT02390232.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Humanos , Metabolismo dos Lipídeos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/metabolismo
18.
JHEP Rep ; 3(6): 100346, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34667947

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease worldwide. It is characterised by steatosis, liver inflammation, hepatocellular injury and progressive fibrosis. Several preclinical models (dietary and genetic animal models) of NAFLD have deepened our understanding of its aetiology and pathophysiology. Despite the progress made, there are currently no effective treatments for NAFLD. In this review, we will provide an update on the known molecular pathways involved in the pathophysiology of NAFLD and on ongoing studies of new therapeutic targets.

19.
iScience ; 24(3): 102218, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33748706

RESUMO

TxNIP (Thioredoxin-interacting protein) is considered as a potential drug target for type 2 diabetes. Although TxNIP expression is correlated with hyperglycemia and glucotoxicity in pancreatic ß cells, its regulation in liver cells has been less investigated. In the current study, we aim at providing a better understanding of Txnip regulation in hepatocytes in response to physiological stimuli and in the context of hyperglycemia in db/db mice. We focused on regulatory pathways governed by ChREBP (Carbohydrate Responsive Element Binding Protein) and FoxO1 (Forkhead box protein O1), transcription factors that play central roles in mediating the effects of glucose and fasting on gene expression, respectively. Studies using genetically modified mice reveal that hepatic TxNIP is up-regulated by both ChREBP and FoxO1 in liver cells and that its expression strongly correlates with fasting, suggesting a major role for this protein in the physiological adaptation to nutrient restriction.

20.
Mol Metab ; 43: 101108, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33137488

RESUMO

OBJECTIVE: Glucose production in the blood requires the expression of glucose-6 phosphatase (G6Pase), a key enzyme that allows glucose-6 phosphate (G6P) hydrolysis into free glucose and inorganic phosphate. We previously reported that the hepatic suppression of G6Pase leads to G6P accumulation and to metabolic reprogramming in hepatocytes from liver G6Pase-deficient mice (L.G6pc-/-). Interestingly, the activity of the transcription factor carbohydrate response element-binding protein (ChREBP), central for de novo lipid synthesis, is markedly activated in L.G6pc-/- mice, which consequently rapidly develop NAFLD-like pathology. In the current work, we assessed whether a selective deletion of ChREBP could prevent hepatic lipid accumulation and NAFLD initiation in L.G6pc-/- mice. METHODS: We generated liver-specific ChREBP (L.Chrebp-/-)- and/or G6Pase (L.G6pc-/-)-deficient mice using a Cre-lox strategy in B6.SACreERT2 mice. Mice were fed a standard chow diet or a high-fat diet for 10 days. Markers of hepatic metabolism and cellular stress were analysed in the liver of control, L. G6pc-/-, L. Chrebp-/- and double knockout (i.e., L.G6pc-/-.Chrebp-/-) mice. RESULTS: We observed that there was a dramatic decrease in lipid accumulation in the liver of L.G6pc-/-.Chrebp-/- mice. At the mechanistic level, elevated G6P concentrations caused by lack of G6Pase are rerouted towards glycogen synthesis. Importantly, this exacerbated glycogen accumulation, leading to hepatic water retention and aggravated hepatomegaly. This caused animal distress and hepatocyte damage, characterised by ballooning and moderate fibrosis, paralleled with acute endoplasmic reticulum stress. CONCLUSIONS: Our study reveals the crucial role of the ChREBP-G6Pase duo in the regulation of G6P-regulated pathways in the liver.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Metabolismo dos Lipídeos/fisiologia , Monoéster Fosfórico Hidrolases/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Glucose/metabolismo , Glucose-6-Fosfatase/metabolismo , Glucose-6-Fosfato/metabolismo , Hepatócitos/metabolismo , Hidrólise , Lipídeos/fisiologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Monoéster Fosfórico Hidrolases/genética
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