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1.
Mol Metab ; 85: 101962, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38815625

RESUMEN

OBJECTIVE: p63 is a transcription factor involved in multiple biological functions. In the liver, the TAp63 isoform induces lipid accumulation in hepatocytes. However, the role of liver TAp63 in the progression of metabolic dysfunction-associated steatohepatitis (MASH) with fibrosis is unknown. METHODS: We evaluated the hepatic p63 levels in different mouse models of steatohepatitis with fibrosis induced by diet. Next, we used virogenetic approaches to manipulate the expression of TAp63 in adult mice under diet-induced steatohepatitis with fibrosis and characterized the disease condition. Finally, we performed proteomics analysis in mice with overexpression and knockdown of hepatic TAp63. RESULTS: Levels of TAp63, but not of ΔN isoform, are increased in the liver of mice with diet-induced steatohepatitis with fibrosis. Both preventive and interventional strategies for the knockdown of hepatic TAp63 significantly ameliorated diet-induced steatohepatitis with fibrosis in mice fed a methionine- and choline-deficient diet (MCDD) and choline deficient and high fat diet (CDHFD). The overexpression of hepatic TAp63 in mice aggravated the liver condition in mice fed a CDHFD. Proteomic analysis in the liver of these mice revealed alteration in multiple proteins and pathways, such as oxidative phosphorylation, antioxidant activity, peroxisome function and LDL clearance. CONCLUSIONS: These results indicate that liver TAp63 plays a critical role in the progression of diet-induced steatohepatitis with fibrosis, and its inhibition ameliorates the disease.


Asunto(s)
Hígado Graso , Cirrosis Hepática , Hígado , Ratones Endogámicos C57BL , Animales , Ratones , Hígado/metabolismo , Hígado/patología , Masculino , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Hígado Graso/metabolismo , Hígado Graso/patología , Modelos Animales de Enfermedad , Dieta Alta en Grasa/efectos adversos , Transactivadores/metabolismo , Transactivadores/genética , Proteómica , Metionina/deficiencia , Metionina/metabolismo
2.
Hepatology ; 2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38761407

RESUMEN

BACKGROUND AND AIMS: Mitochondrial antiviral signaling protein (MAVS) is a critical regulator that activates the host's innate immunity against RNA viruses, and its signaling pathway has been linked to the secretion of proinflammatory cytokines. However, the actions of MAVS on inflammatory pathways during the development of metabolic dysfunction-associated steatotic liver disease (MASLD) have been little studied. APPROACH AND RESULTS: Liver proteomic analysis of mice with genetically manipulated hepatic p63, a transcription factor that induces liver steatosis, revealed MAVS as a target downstream of p63. MAVS was thus further evaluated in liver samples from patients and in animal models with MASLD. Genetic inhibition of MAVS was performed in hepatocyte cell lines, primary hepatocytes, spheroids, and mice. MAVS expression is induced in the liver of both animal models and people with MASLD as compared with those without liver disease. Using genetic knockdown of MAVS in adult mice ameliorates diet-induced MASLD. In vitro, silencing MAVS blunts oleic and palmitic acid-induced lipid content, while its overexpression increases the lipid load in hepatocytes. Inhibiting hepatic MAVS reduces circulating levels of the proinflammatory cytokine TNFα and the hepatic expression of both TNFα and NFκß. Moreover, the inhibition of ERK abolished the activation of TNFα induced by MAVS. The posttranslational modification O -GlcNAcylation of MAVS is required to activate inflammation and to promote the high lipid content in hepatocytes. CONCLUSIONS: MAVS is involved in the development of steatosis, and its inhibition in previously damaged hepatocytes can ameliorate MASLD.

3.
Cell Rep Med ; 5(2): 101401, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38340725

RESUMEN

The p63 protein has pleiotropic functions and, in the liver, participates in the progression of nonalcoholic fatty liver disease (NAFLD). However, its functions in hepatic stellate cells (HSCs) have not yet been explored. TAp63 is induced in HSCs from animal models and patients with liver fibrosis and its levels positively correlate with NAFLD activity score and fibrosis stage. In mice, genetic depletion of TAp63 in HSCs reduces the diet-induced liver fibrosis. In vitro silencing of p63 blunts TGF-ß1-induced HSCs activation by reducing mitochondrial respiration and glycolysis, as well as decreasing acetyl CoA carboxylase 1 (ACC1). Ectopic expression of TAp63 induces the activation of HSCs and increases the expression and activity of ACC1 by promoting the transcriptional activity of HER2. Genetic inhibition of both HER2 and ACC1 blunt TAp63-induced activation of HSCs. Thus, TAp63 induces HSC activation by stimulating the HER2-ACC1 axis and participates in the development of liver fibrosis.


Asunto(s)
Células Estrelladas Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Enfermedad del Hígado Graso no Alcohólico/patología , Activación Metabólica , Cirrosis Hepática/genética , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/metabolismo , Fibrosis , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo
4.
Gut ; 72(3): 472-483, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35580962

RESUMEN

OBJECTIVE: p63 is a transcription factor within the p53 protein family that has key roles in development, differentiation and prevention of senescence, but its metabolic actions remain largely unknown. Herein, we investigated the physiological role of p63 in glucose metabolism. DESIGN: We used cell lines and mouse models to genetically manipulate p63 in hepatocytes. We also measured p63 in the liver of patients with obesity with or without type 2 diabetes (T2D). RESULTS: We show that hepatic p63 expression is reduced on fasting. Mice lacking the specific isoform TAp63 in the liver (p63LKO) display higher postprandial and pyruvate-induced glucose excursions. These mice have elevated SIRT1 levels, while SIRT1 knockdown in p63LKO mice normalises glycaemia. Overexpression of TAp63 in wild-type mice reduces postprandial, pyruvate-induced blood glucose and SIRT1 levels. Studies carried out in hepatocyte cell lines show that TAp63 regulates SIRT1 promoter by repressing its transcriptional activation. TAp63 also mediates the inhibitory effect of insulin on hepatic glucose production, as silencing TAp63 impairs insulin sensitivity. Finally, protein levels of TAp63 are reduced in obese persons with T2D and are negatively correlated with fasting glucose and homeostasis model assessment index. CONCLUSIONS: These results demonstrate that p63 physiologically regulates glucose homeostasis.


Asunto(s)
Diabetes Mellitus Tipo 2 , Sirtuina 1 , Transactivadores , Animales , Ratones , Glucosa/metabolismo , Hígado/metabolismo , Piruvatos/metabolismo , Sirtuina 1/metabolismo , Transactivadores/metabolismo
5.
JHEP Rep ; 4(5): 100463, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35462858

RESUMEN

Background & Aims: Organic solute transporter (OST) subunits OSTα and OSTß facilitate bile acid efflux from the enterocyte into the portal circulation. Patients with deficiency of OSTα or OSTß display considerable variation in the level of bile acid malabsorption, chronic diarrhea, and signs of cholestasis. Herein, we generated and characterized a mouse model of OSTß deficiency. Methods: Ostß -/- mice were generated using CRISR/Cas9 and compared to wild-type and Ostα -/- mice. OSTß was re-expressed in livers of Ostß -/- mice using adeno-associated virus serotype 8 vectors. Cholestasis was induced in both models by bile duct ligation (BDL) or 3.5-diethoxycarbonyl-1.4-dihydrocollidine (DDC) feeding. Results: Similar to Ostα -/- mice, Ostß -/- mice exhibited elongated small intestines with blunted villi and increased crypt depth. Increased expression levels of ileal Fgf15, and decreased Asbt expression in Ostß -/- mice indicate the accumulation of bile acids in the enterocyte. In contrast to Ostα -/- mice, induction of cholestasis in Ostß -/- mice by BDL or DDC diet led to lower survival rates and severe body weight loss, but an improved liver phenotype. Restoration of hepatic Ostß expression via adeno-associated virus-mediated overexpression did not rescue the phenotype of Ostß -/- mice. Conclusions: OSTß is pivotal for bile acid transport in the ileum and its deficiency leads to an intestinal phenotype similar to Ostα -/- mice, but it exerts distinct effects on survival and the liver phenotype, independent of its expression in the liver. Our findings provide insights into the variable clinical presentation of patients with OSTα and OSTß deficiencies. Lay summary: Organic solute transporter (OST) subunits OSTα and OSTß together facilitate the efflux of conjugated bile acids into the portal circulation. Ostα knockout mice have longer and thicker small intestines and are largely protected against experimental cholestatic liver injury. Herein, we generated and characterized Ostß knockout mice for the first time. Ostα and Ostß knockout mice shared a similar phenotype under normal conditions. However, in cholestasis, Ostß knockout mice had a worsened overall phenotype which indicates a separate and specific role of OSTß, possibly as an interacting partner of other intestinal proteins.

6.
Nat Commun ; 13(1): 1096, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35232994

RESUMEN

Altered methionine metabolism is associated with weight gain in obesity. The methionine adenosyltransferase (MAT), catalyzing the first reaction of the methionine cycle, plays an important role regulating lipid metabolism. However, its role in obesity, when a plethora of metabolic diseases occurs, is still unknown. By using antisense oligonucleotides (ASO) and genetic depletion of Mat1a, here, we demonstrate that Mat1a deficiency in diet-induce obese or genetically obese mice prevented and reversed obesity and obesity-associated insulin resistance and hepatosteatosis by increasing energy expenditure in a hepatocyte FGF21 dependent fashion. The increased NRF2-mediated FGF21 secretion induced by targeting Mat1a, mobilized plasma lipids towards the BAT to be catabolized, induced thermogenesis and reduced body weight, inhibiting hepatic de novo lipogenesis. The beneficial effects of Mat1a ASO were abolished following FGF21 depletion in hepatocytes. Thus, targeting Mat1a activates the liver-BAT axis by increasing NRF2-mediated FGF21 secretion, which prevents obesity, insulin resistance and hepatosteatosis.


Asunto(s)
Tejido Adiposo Pardo , Resistencia a la Insulina , Metionina Adenosiltransferasa , Obesidad , Oligonucleótidos Antisentido , Tejido Adiposo Pardo/metabolismo , Animales , Metabolismo Energético , Hígado/metabolismo , Metionina Adenosiltransferasa/genética , Metionina Adenosiltransferasa/metabolismo , Ratones , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Obesidad/genética , Obesidad/metabolismo , Obesidad/prevención & control , Oligonucleótidos Antisentido/metabolismo , Oligonucleótidos Antisentido/farmacología
7.
J Hepatol ; 77(1): 15-28, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35167910

RESUMEN

BACKGROUND & AIMS: The pathogenesis of liver fibrosis requires activation of hepatic stellate cells (HSCs); once activated, HSCs lose intracellular fatty acids but the role of fatty acid oxidation and carnitine palmitoyltransferase 1A (CPT1A) in this process remains largely unexplored. METHODS: CPT1A was found in HSCs of patients with fibrosis. Pharmacological and genetic manipulation of CPT1A were performed in human HSC cell lines and primary HCSs. Finally, we induced fibrosis in mice lacking CPT1A specifically in HSCs. RESULTS: Herein, we show that CPT1A expression is elevated in HSCs of patients with non-alcoholic steatohepatitis, showing a positive correlation with the fibrosis score. This was corroborated in rodents with fibrosis, as well as in primary human HSCs and LX-2 cells activated by transforming growth factor ß1 (TGFß1) and fetal bovine serum (FBS). Furthermore, both pharmacological and genetic silencing of CPT1A prevent TGFß1- and FBS-induced HSC activation by reducing mitochondrial activity. The overexpression of CPT1A, induced by saturated fatty acids and reactive oxygen species, triggers mitochondrial activity and the expression of fibrogenic markers. Finally, mice lacking CPT1A specifically in HSCs are protected against fibrosis induced by a choline-deficient high-fat diet, a methionine- and choline-deficient diet, or treatment with carbon tetrachloride. CONCLUSIONS: These results indicate that CPT1A plays a critical role in the activation of HSCs and is implicated in the development of liver fibrosis, making it a potentially actionable target for fibrosis treatment. LAY SUMMARY: We show that the enzyme carnitine palmitoyltransferase 1A (CPT1A) is elevated in hepatic stellate cells (HSCs) in patients with fibrosis and mouse models of fibrosis, and that CPT1A induces the activation of these cells. Inhibition of CPT1A ameliorates fibrosis by preventing the activation of HSCs.


Asunto(s)
Carnitina O-Palmitoiltransferasa , Células Estrelladas Hepáticas , Animales , Carnitina O-Palmitoiltransferasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Colina , Ácidos Grasos/metabolismo , Fibrosis , Células Estrelladas Hepáticas/metabolismo , Humanos , Hígado/patología , Cirrosis Hepática/metabolismo , Cirrosis Hepática/prevención & control , Ratones
8.
Nat Metab ; 3(10): 1415-1431, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34675439

RESUMEN

Current pharmacological therapies for treating obesity are of limited efficacy. Genetic ablation or loss of function of AMP-activated protein kinase alpha 1 (AMPKα1) in steroidogenic factor 1 (SF1) neurons of the ventromedial nucleus of the hypothalamus (VMH) induces feeding-independent resistance to obesity due to sympathetic activation of brown adipose tissue (BAT) thermogenesis. Here, we show that body weight of obese mice can be reduced by intravenous injection of small extracellular vesicles (sEVs) delivering a plasmid encoding an AMPKα1 dominant negative mutant (AMPKα1-DN) targeted to VMH-SF1 neurons. The beneficial effect of SF1-AMPKα1-DN-loaded sEVs is feeding-independent and involves sympathetic nerve activation and increased UCP1-dependent thermogenesis in BAT. Our results underscore the potential of sEVs to specifically target AMPK in hypothalamic neurons and introduce a broader strategy to manipulate body weight and reduce obesity.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Tejido Adiposo Pardo/enzimología , Vesículas Extracelulares/metabolismo , Hipotálamo/enzimología , Obesidad/metabolismo , Animales , Metabolismo Energético , Ratones , Termogénesis , Pérdida de Peso
9.
Nat Commun ; 12(1): 5068, 2021 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-34417460

RESUMEN

p53 regulates several signaling pathways to maintain the metabolic homeostasis of cells and modulates the cellular response to stress. Deficiency or excess of nutrients causes cellular metabolic stress, and we hypothesized that p53 could be linked to glucose maintenance. We show here that upon starvation hepatic p53 is stabilized by O-GlcNAcylation and plays an essential role in the physiological regulation of glucose homeostasis. More specifically, p53 binds to PCK1 promoter and regulates its transcriptional activation, thereby controlling hepatic glucose production. Mice lacking p53 in the liver show a reduced gluconeogenic response during calorie restriction. Glucagon, adrenaline and glucocorticoids augment protein levels of p53, and administration of these hormones to p53 deficient human hepatocytes and to liver-specific p53 deficient mice fails to increase glucose levels. Moreover, insulin decreases p53 levels, and over-expression of p53 impairs insulin sensitivity. Finally, protein levels of p53, as well as genes responsible of O-GlcNAcylation are elevated in the liver of type 2 diabetic patients and positively correlate with glucose and HOMA-IR. Overall these results indicate that the O-GlcNAcylation of p53 plays an unsuspected key role regulating in vivo glucose homeostasis.


Asunto(s)
Acetilglucosamina/metabolismo , Glucosa/metabolismo , Hígado/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Secuencia de Bases , Restricción Calórica , Línea Celular , Colforsina/farmacología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Epinefrina/metabolismo , Glucagón/metabolismo , Glucocorticoides/metabolismo , Gluconeogénesis/efectos de los fármacos , Glicosilación , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Hidrocortisona/metabolismo , Hiperglucemia/complicaciones , Hiperglucemia/metabolismo , Resistencia a la Insulina , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hígado/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/complicaciones , Obesidad/metabolismo , Fosfoenolpiruvato Carboxiquinasa (GTP)/metabolismo , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Estabilidad Proteica/efectos de los fármacos , Ácido Pirúvico/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transcripción Genética/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética
10.
Hepatology ; 73(2): 606-624, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32329085

RESUMEN

BACKGROUND AND AIMS: G protein-coupled receptor (GPR) 55 is a putative cannabinoid receptor, and l-α-lysophosphatidylinositol (LPI) is its only known endogenous ligand. Although GPR55 has been linked to energy homeostasis in different organs, its specific role in lipid metabolism in the liver and its contribution to the pathophysiology of nonalcoholic fatty liver disease (NAFLD) remains unknown. APPROACH AND RESULTS: We measured (1) GPR55 expression in the liver of patients with NAFLD compared with individuals without obesity and without liver disease, as well as animal models with steatosis and nonalcoholic steatohepatitis (NASH), and (2) the effects of LPI and genetic disruption of GPR55 in mice, human hepatocytes, and human hepatic stellate cells. Notably, we found that circulating LPI and liver expression of GPR55 were up-regulated in patients with NASH. LPI induced adenosine monophosphate-activated protein kinase activation of acetyl-coenzyme A carboxylase (ACC) and increased lipid content in human hepatocytes and in the liver of treated mice by inducing de novo lipogenesis and decreasing ß-oxidation. The inhibition of GPR55 and ACCα blocked the effects of LPI, and the in vivo knockdown of GPR55 was sufficient to improve liver damage in mice fed a high-fat diet and in mice fed a methionine-choline-deficient diet. Finally, LPI promoted the initiation of hepatic stellate cell activation by stimulating GPR55 and activation of ACC. CONCLUSIONS: The LPI/GPR55 system plays a role in the development of NAFLD and NASH by activating ACC.


Asunto(s)
Lisofosfolípidos/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/complicaciones , Receptores de Cannabinoides/metabolismo , Acetil-CoA Carboxilasa/antagonistas & inhibidores , Acetil-CoA Carboxilasa/metabolismo , Adulto , Anciano , Animales , Biopsia , Agonistas de Receptores de Cannabinoides/farmacología , Línea Celular , Estudios de Cohortes , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Femenino , Técnicas de Silenciamiento del Gen , Células Estrelladas Hepáticas , Hepatocitos , Humanos , Lipogénesis/efectos de los fármacos , Hígado/patología , Lisofosfolípidos/sangre , Masculino , Ratones , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/patología , Obesidad/sangre , Obesidad/metabolismo , Receptores de Cannabinoides/genética , Regulación hacia Arriba
11.
Nat Commun ; 11(1): 5808, 2020 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-33199701

RESUMEN

Skeletal muscle promotes metabolic balance by regulating glucose uptake and the stimulation of multiple interorgan crosstalk. We show here that the catalytic activity of Vav2, a Rho GTPase activator, modulates the signaling output of the IGF1- and insulin-stimulated phosphatidylinositol 3-kinase pathway in that tissue. Consistent with this, mice bearing a Vav2 protein with decreased catalytic activity exhibit reduced muscle mass, lack of proper insulin responsiveness and, at much later times, a metabolic syndrome-like condition. Conversely, mice expressing a catalytically hyperactive Vav2 develop muscle hypertrophy and increased insulin responsiveness. Of note, while hypoactive Vav2 predisposes to, hyperactive Vav2 protects against high fat diet-induced metabolic imbalance. These data unveil a regulatory layer affecting the signaling output of insulin family factors in muscle.


Asunto(s)
Biocatálisis , Homeostasis , Metabolismo , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/metabolismo , Proteínas Proto-Oncogénicas c-vav/metabolismo , Transducción de Señal , Adipocitos Blancos/efectos de los fármacos , Adipocitos Blancos/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Biocatálisis/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Línea Celular , Tamaño de la Célula/efectos de los fármacos , Genotipo , Glucosa/farmacología , Homeostasis/efectos de los fármacos , Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Células Musculares/citología , Células Musculares/efectos de los fármacos , Células Musculares/metabolismo , Músculo Esquelético/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Proteína de Unión al GTP rac1/metabolismo
12.
Nat Metab ; 1(8): 811-829, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31579887

RESUMEN

Dopamine signaling is a crucial part of the brain reward system and can affect feeding behavior. Dopamine receptors are also expressed in the hypothalamus, which is known to control energy metabolism in peripheral tissues. Here we show that pharmacological or chemogenetic stimulation of dopamine receptor 2 (D2R) expressing cells in the lateral hypothalamic area (LHA) and the zona incerta (ZI) decreases body weight and stimulates brown fat activity in rodents in a feeding-independent manner. LHA/ZI D2R stimulation requires an intact sympathetic nervous system and orexin system to exert its action and involves inhibition of PI3K in the LHA/ZI. We further demonstrate that, as early as 3 months after onset of treatment, patients treated with the D2R agonist cabergoline experience an increase in energy expenditure that persists for one year, leading to total body weight and fat loss through a prolactin-independent mechanism. Our results may provide a mechanistic explanation for how clinically used D2R agonists act in the CNS to regulate energy balance.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Dopamina/metabolismo , Hipotálamo/metabolismo , Transducción de Señal , Termogénesis/fisiología , Animales , Bromocriptina/administración & dosificación , Bromocriptina/farmacología , Femenino , Humanos , Hipotálamo/efectos de los fármacos , Inyecciones Intraventriculares , Masculino , Ratas
13.
Nutrients ; 11(4)2019 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-30935076

RESUMEN

The gastrointestinal-brain axis is a key mediator of the body weight and energy homeostasis regulation. Uroguanylin (UGN) has been recently proposed to be a part of this gut-brain axis regulating food intake, body weight and energy expenditure. Expression of UGN is regulated by the nutritional status and dependent on leptin levels. However, the exact molecular mechanisms underlying this UGN-leptin metabolic regulation at a hypothalamic level still remains unclear. Using leptin resistant diet-induced obese (DIO) mice, we aimed to determine whether UGN could improve hypothalamic leptin sensitivity. The present work demonstrates that the central co-administration of UGN and leptin potentiates leptin's ability to decrease the food intake and body weight in DIO mice, and that UGN activates the hypothalamic signal transducer and activator of transcription 3 (STAT3) and phosphatidylinositide 3-kinases (PI3K) pathways. At a functional level, the blockade of PI3K, but not STAT3, blunted UGN-mediated leptin responsiveness in DIO mice. Overall, these findings indicate that UGN improves leptin sensitivity in DIO mice.


Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Leptina/metabolismo , Péptidos Natriuréticos/metabolismo , Obesidad/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Dieta/efectos adversos , Hipotálamo/metabolismo , Ratones , Ratones Obesos , Obesidad/etiología , Fosfatidilinositol 3-Quinasa/metabolismo , Factor de Transcripción STAT3/metabolismo
14.
Cell Rep ; 26(11): 3011-3026.e5, 2019 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-30865890

RESUMEN

Chronic low-grade inflammation and increased serum levels of the cytokine IL-6 accompany obesity. For brain-produced IL-6, the mechanisms by which it controls energy balance and its role in obesity remain unclear. Here, we show that brain-produced IL-6 is decreased in obese mice and rats in a neuroanatomically and sex-specific manner. Reduced IL-6 mRNA localized to lateral parabrachial nucleus (lPBN) astrocytes, microglia, and neurons, including paraventricular hypothalamus-innervating lPBN neurons. IL-6 microinjection into lPBN reduced food intake and increased brown adipose tissue (BAT) thermogenesis in male lean and obese rats by increasing thyroid and sympathetic outflow to BAT. Parabrachial IL-6 interacted with leptin to reduce feeding. siRNA-mediated reduction of lPBN IL-6 leads to increased weight gain and adiposity, reduced BAT thermogenesis, and increased food intake. Ambient cold exposure partly normalizes the obesity-induced suppression of lPBN IL-6. These results indicate that lPBN-produced IL-6 regulates feeding and metabolism and pinpoints (patho)physiological contexts interacting with lPBN IL-6.


Asunto(s)
Peso Corporal , Ingestión de Alimentos , Metabolismo Energético , Interleucina-6/metabolismo , Núcleos Parabraquiales/metabolismo , Termogénesis , Tejido Adiposo Pardo/metabolismo , Animales , Astrocitos/metabolismo , Femenino , Interleucina-6/genética , Leptina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Neuronas/metabolismo , Núcleos Parabraquiales/fisiología , Ratas , Ratas Sprague-Dawley , Sistema Nervioso Simpático/fisiología , Hormonas Tiroideas/metabolismo
15.
Sci Rep ; 8(1): 17978, 2018 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-30552365

RESUMEN

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

16.
Genes Nutr ; 13: 28, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30519364

RESUMEN

BACKGROUND: Energy homeostasis is regulated by the hypothalamus but fails when animals are fed a high-fat diet (HFD), and leptin insensitivity and obesity develops. To elucidate the possible mechanisms underlying these effects, a microarray-based transcriptomics approach was used to identify novel genes regulated by HFD and leptin in the mouse hypothalamus. RESULTS: Mouse global array data identified serpinA3N as a novel gene highly upregulated by both a HFD and leptin challenge. In situ hybridisation showed serpinA3N expression upregulation by HFD and leptin in all major hypothalamic nuclei in agreement with transcriptomic gene expression data. Immunohistochemistry and studies in the hypothalamic clonal neuronal cell line, mHypoE-N42 (N42), confirmed that alpha 1-antichymotrypsin (α1AC), the protein encoded by serpinA3, is localised to neurons and revealed that it is secreted into the media. SerpinA3N expression in N42 neurons is upregulated by palmitic acid and by leptin, together with IL-6 and TNFα, and all three genes are downregulated by the anti-inflammatory monounsaturated fat, oleic acid. Additionally, palmitate upregulation of serpinA3 in N42 neurons is blocked by the NFκB inhibitor, BAY11, and the upregulation of serpinA3N expression in the hypothalamus by HFD is blunted in IL-1 receptor 1 knockout (IL-1R1 -/- ) mice. CONCLUSIONS: These data demonstrate that serpinA3 expression is implicated in nutritionally mediated hypothalamic inflammation.

17.
Mol Metab ; 8: 132-143, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29290620

RESUMEN

OBJECTIVE: Recent reports have implicated the p53 tumor suppressor in the regulation of lipid metabolism. We hypothesized that the pharmacological activation of p53 with low-dose doxorubicin, which is widely used to treat several types of cancer, may have beneficial effects on nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). METHODS: We used long-term pharmacological activation of p53 by i.p. or oral administration of low-dose doxorubicin in different animal models of NAFLD (high fat diet containing 45% and 60% kcal fat) and NASH (methionine- and choline-deficient diet and choline deficiency combined with high fat diet). We also administered doxorubicin in mice lacking p53 in the liver and in two human hepatic cells lines (HepG2 and THLE2). RESULTS: The attenuation of liver damage was accompanied by the stimulation of fatty acid oxidation and decrease of lipogenesis, inflammation, and ER stress. The effects of doxorubicin were abrogated in mice with liver-specific ablation of p53. Finally, the effects of doxorubicin on lipid metabolism found in animal models were also present in two human hepatic cells lines, in which the drug stimulated fatty acid oxidation and inhibited de novo lipogenesis at doses that did not cause changes in apoptosis or cell viability. CONCLUSION: These data provide new evidence for targeting p53 as a strategy to treat liver disease.


Asunto(s)
Doxorrubicina/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Inhibidores de Topoisomerasa II/uso terapéutico , Proteína p53 Supresora de Tumor/metabolismo , Animales , Línea Celular , Dieta Alta en Grasa/efectos adversos , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Células Hep G2 , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/etiología , Inhibidores de Topoisomerasa II/administración & dosificación , Inhibidores de Topoisomerasa II/farmacología , Proteína p53 Supresora de Tumor/genética
18.
Diabetologia ; 60(12): 2453-2462, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28956081

RESUMEN

AIMS/HYPOTHESIS: The identification of mediators in the pathogenesis of type 2 diabetes mellitus is essential for the full understanding of this disease. Protein kinases are especially important because of their potential as pharmacological targets. The goal of this study was to investigate whether mammalian sterile-20 3 (MST3/STK24), a stress-regulated kinase, is involved in metabolic alterations in obesity. METHODS: Glucose regulation of Mst3 (also known as Stk24)-knockout mice was analysed both in 129;C57 mixed background mice and in C57/BL6J mice fed normally or with a high-fat diet (HFD). This work was complemented with an analysis of the insulin signalling pathway in cultured human liver cells made deficient in MST3 using RNA interference. RESULTS: MST3 is phosphorylated in the livers of mice subject to an obesity-promoting HFD, and its deficiency lowers the hyperglycaemia, hyperinsulinaemia and insulin resistance that the animals develop with this diet, an effect that is seen even without complete inactivation of the kinase. Lack of MST3 results in activation of the insulin signalling pathway downstream of IRS1, in both cultured liver cells and the liver of animals after HFD. This effect increases the inhibition of forkhead box (FOX)O1, with subsequent downregulation of the expression of gluconeogenic enzymes. CONCLUSIONS/INTERPRETATION: MST3 inhibits the insulin signalling pathway and is important in the development of insulin resistance and impaired blood glucose levels after an HFD.


Asunto(s)
Glucemia/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa/efectos adversos , Ayuno/sangre , Femenino , Gluconeogénesis/fisiología , Células Hep G2 , Humanos , Resistencia a la Insulina/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas/genética
19.
Eur J Pharmacol ; 815: 241-250, 2017 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-28943102

RESUMEN

Behavioral studies have suggested that (p-ClPhSe)2 elicits an anorectic-like action in rats by inducing multiple effects such as satiety-enhancing effect, malaise and specific flavor; however, the molecular mechanisms underlying its anorexigenic action remain unclarified. Here, male Sprague-Dawley rats received acute and sub-chronic intraperitoneal treatments with (p-ClPhSe)2; thereafter, in vivo and ex vivo analyses were carried out. The present study reveals that the reduction of food intake resulting from a single treatment with (p-ClPhSe)2 (1mg/kg, i.p.) was associated with decreased hypothalamic levels of pro-melanin-concentrating hormone (pro-MCH) and orexin precursor. In addition, repeated administrations of (p-ClPhSe)2 (10mg/kg; i.p.) for 7 days induced sustained food intake suppression, body weight loss and white fat reduction. Measurements of brown adipose tissue content and temperature as well as data obtained from a pair-fed group indicated that the effects of (p-ClPhSe)2 on the body weight are closely related to its anorexigenic actions, ruling out the possibility of increased thermogenesis. Furthermore, (p-ClPhSe)2 reduced the hypothalamic orexin precursor levels when repeatedly administered to rats. Sub-chronic treatment with (p-ClPhSe)2 caused a decrease of serum triglyceride levels and down-regulation of hepatic cholesterol content. Therefore, the current study characterized the anorectic and reducing body weight actions of (p-ClPhSe)2 in Sprague-Dawley rats. Besides, the set of results suggests that food intake suppressant effects triggered after (p-ClPhSe)2 administration to rats are mainly related with the lower orexin levels in hypothalamus after acute and sub-chronic treatments.


Asunto(s)
Anorexia/inducido químicamente , Anorexia/patología , Hipotálamo/efectos de los fármacos , Hipotálamo/patología , Compuestos de Organoselenio/efectos adversos , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/metabolismo , Animales , Anorexia/sangre , Anorexia/psicología , Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Hipotálamo/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Respuesta de Saciedad/efectos de los fármacos , Factores de Tiempo , Triglicéridos/sangre
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