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1.
Front Cardiovasc Med ; 11: 1342388, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38317864

RESUMEN

Introduction: Totum-070 is a combination of five plant extracts enriched in polyphenols to target hypercholesterolemia, one of the main risk factors for cardiovascular diseases. The aim of this study was to investigate the effects of Totum-070 on cholesterol levels in an animal model of diet-induced hypercholesterolemia. Methods: C57BL/6JOlaHsd male mice were fed a Western diet and received Totum-070, or not, by daily gavage (1g/kg and 3g/kg body weight) for 6 weeks. Results: The Western diet induced obesity, fat accumulation, hepatic steatosis and increased plasma cholesterol compared with the control group. All these metabolic perturbations were alleviated by Totum-070 supplementation in a dose-dependent manner. Lipid excretion in feces was higher in mice supplemented with Totum-070, suggesting inhibition of intestinal lipid absorption. Totum-070 also increased the fecal concentration of short chain fatty acids, demonstrating a direct effect on intestinal microbiota. Discussion: The characterization of fecal microbiota by 16S amplicon sequencing showed that Totum-070 supplementation modulated the dysbiosis associated with metabolic disorders. Specifically, Totum-070 increased the relative abundance of Muribaculum (a beneficial bacterium) and reduced that of Lactococcus (a genus positively correlated with increased plasma cholesterol level). Together, these findings indicate that the cholesterol-lowering effect of Totum-070 bioactive molecules could be mediated through multiple actions on the intestine and gut microbiota.

2.
Nutrients ; 15(24)2023 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-38140315

RESUMEN

Atherosclerotic cardiovascular disease is the leading cause of mortality worldwide, and hypercholesterolemia is a central risk factor for atherosclerosis. This study evaluated the effects of Totum-070, a plant-based polyphenol-rich supplement, in hamsters with high-fat diet (HFD)-induced dyslipidemia. The molecular mechanisms of action were explored using human Caco2 enterocytes. Totum-070 supplementation reduced the total cholesterol (-41%), non-HDL cholesterol (-47%), and triglycerides (-46%) in a dose-dependent manner, compared with HFD. HFD-induced hepatic steatosis was also significantly decreased by Totum-070, an effect associated with the reduction in various lipid and inflammatory gene expression. Upon challenging with olive oil gavage, the post-prandial triglyceride levels were strongly reduced. The sterol excretion in the feces was increased in the HFD-Totum-070 groups compared with the HFD group and associated with reduction of intestinal cholesterol absorption. These effects were confirmed in the Caco2 cells, where incubation with Totum-070 inhibited cholesterol uptake and apolipoprotein B secretion. Furthermore, a microbiota composition analysis revealed a strong effect of Totum-070 on the alpha and beta diversity of bacterial species and a significant decrease in the Firmicutes to Bacteroidetes ratio. Altogether, our findings indicate that Totum-070 lowers hypercholesterolemia by reducing intestinal cholesterol absorption, suggesting that its use as dietary supplement may be explored as a new preventive strategy for cardiovascular diseases.


Asunto(s)
Aterosclerosis , Hipercolesterolemia , Hiperlipidemias , Cricetinae , Animales , Humanos , Hipercolesterolemia/etiología , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismo , Dieta Alta en Grasa/efectos adversos , Polifenoles/farmacología , Polifenoles/metabolismo , Células CACO-2 , Mesocricetus , Colesterol/metabolismo , Hiperlipidemias/metabolismo , Triglicéridos/metabolismo , Aterosclerosis/etiología , Aterosclerosis/prevención & control , Aterosclerosis/metabolismo , Hígado/metabolismo
3.
Nutr Res ; 118: 70-84, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37598559

RESUMEN

Global prevalence of obesity and type 2 diabetes are rapidly increasing to pandemic proportions. A novel supplement composed of 5 plant extracts from olive leaf, bilberry, artichoke, chrysanthellum, and black pepper was designed to prevent type 2 diabetes development in people at risk. It was previously shown to improve body weight and glucose control in preclinical rodent models, with these effects being accompanied by increased fecal energy excretion and in vitro inhibition of several digestive enzymes. Thus, we hypothesized that, in mice fed a high-fat diet (HFD), a single dose of this botanical supplementation would decrease the responses to oral fat and carbohydrate tolerance tests, and that chronic supplementation would result in increased fecal triglyceride content. We showed that acute administration in HFD-fed mice (1.452 g/kg body weight) markedly reduced circulating triglycerides following an oral lipid gavage, whereas glycemic responses to various carbohydrate tests were only mildly affected. When incorporated into the food (2.5%) of HFD-fed mice, chronic supplementation prevented body weight gain and improved glucose homeostasis and lipid tolerance. Fecal free fatty acid content, but not triglyceride, was significantly increased in supplemented animals, suggesting reduced lipid absorption in the digestive tract. Congruently, this botanical supplementation downregulated several genes associated with fatty acid transport whose expression was increased by HFD, principally in the jejunum. This study provides novel insights as for the mode of action behind the antiobesity effect of this plant-based supplementation, in HFD-fed mice.


Asunto(s)
Diabetes Mellitus Tipo 2 , Extractos Vegetales , Humanos , Animales , Ratones , Dieta Alta en Grasa/efectos adversos , Polifenoles/farmacología , Diabetes Mellitus Tipo 2/metabolismo , Hígado/metabolismo , Aumento de Peso , Peso Corporal , Triglicéridos/metabolismo , Nutrientes , Carbohidratos , Ratones Endogámicos C57BL
4.
Diabetes Obes Metab ; 24(12): 2331-2340, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35837981

RESUMEN

AIM: The plant-based polyphenol-rich extract TOTUM-63 improves glucose homeostasis in various preclinical models of obesity and type 2 diabetes (T2D). A pilot exploratory study showed that TOTUM-63 has good safety and tolerability profiles, and beneficial effects on postprandial glucose control in healthy individuals with overweight. The aim of this study was to assess the effects of TOTUM-63 on glycaemic control in individuals with prediabetes or early stage newly-diagnosed T2D (which does not require pharmacological treatment). MATERIALS AND METHODS: This study was a multicentre, randomized, double-blind, placebo-controlled trial. Individuals with prediabetes or early stage newly-diagnosed T2D and with overweight/abdominal obesity received TOTUM-63 (5 g/day) or placebo for 6 months. The primary outcome was the change in fasting blood glucose. RESULTS: Fifty-one participants (age: 57.1 ± 10 years; body mass index: 31.3 ± 5.7 kg.m2 ; 35 women and 16 men) completed the study (n = 38 TOTUM-63, n = 13 placebo). After 6 months, blood glucose concentration after fasting and after the 2-h oral glucose tolerance test was reduced in the TOTUM-63-treated group compared with the placebo group (placebo-corrected difference between baseline and month 6: -0.71 mmol/L, p < .05, and -1.93 mmol/L, p < .05, respectively). TOTUM-63 was safe and well tolerated and significantly reduced body weight gain (-1.9 kg; p < .05), waist circumference (-4.5 cm; p < .001), circulating triglycerides (-0.54 mmol/L; p < .01) and low-density lipoprotein-cholesterol (-0.38 mmol/L; p < .05) compared with placebo. CONCLUSIONS: TOTUM-63 lowered fasting blood glucose in participants with impaired fasting glycaemia and glucose intolerance. Moreover, TOTUM-63 showed a good safety and tolerability profile and improved several metabolic syndrome features. Therefore, TOTUM-63 is a promising candidate for T2D prevention.


Asunto(s)
Diabetes Mellitus Tipo 2 , Estado Prediabético , Masculino , Femenino , Humanos , Persona de Mediana Edad , Anciano , Estado Prediabético/diagnóstico , Estado Prediabético/tratamiento farmacológico , Glucemia/metabolismo , Polifenoles/uso terapéutico , Control Glucémico , Sobrepeso/complicaciones , Sobrepeso/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Método Doble Ciego , Obesidad/complicaciones , Obesidad/tratamiento farmacológico
5.
Int J Obes (Lond) ; 45(9): 2016-2027, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34079069

RESUMEN

BACKGROUND/OBJECTIVES: The worldwide prevalence of obesity, metabolic syndrome and type 2 diabetes (T2D) is reaching epidemic proportions that urge the development of new management strategies. Totum-63 is a novel, plant-based polyphenol-rich active principle that has been shown to reduce body weight, fasting glycemia, glucose intolerance, and fatty liver index in obese subjects with prediabetes. Here, we investigated the effects and underlying mechanism(s) of Totum-63 on metabolic homeostasis in insulin-resistant obese mice. METHODS: Male C57Bl6/J mice were fed a high-fat diet for 12 weeks followed by supplementation with Totum-63 for 4 weeks. The effects on whole-body energy and metabolic homeostasis, as well as on tissue-specific inflammation and insulin sensitivity were assessed using a variety of immunometabolic phenotyping tools. RESULTS: Totum-63 decreased body weight and fat mass in obese mice, without affecting lean mass, food intake and locomotor activity, and increased fecal energy excretion and whole-body fatty acid oxidation. Totum-63 reduced fasting plasma glucose, insulin and leptin levels, and improved whole-body insulin sensitivity and peripheral glucose uptake. The expression of insulin receptor ß and the insulin-induced phosphorylation of Akt/PKB were increased in liver, skeletal muscle, white adipose tissue (WAT) and brown adipose tissue (BAT). Hepatic steatosis was also decreased by Totum-63 and associated with a lower expression of genes involved in fatty acid uptake, de novo lipogenesis, inflammation, and fibrosis. Furthermore, a significant reduction in pro-inflammatory macrophages was also observed in epidydimal WAT. Finally, a potent decrease in BAT mass associated with enhanced tissue expression of thermogenic genes was found, suggesting BAT activation by Totum-63. CONCLUSIONS: Our results show that Totum-63 reduces inflammation and improves insulin sensitivity and glucose homeostasis in obese mice through pleiotropic effects on various metabolic organs. Altogether, plant-derived Totum-63 might constitute a promising novel nutritional supplement for alleviating metabolic dysfunctions in obese people with or without T2D.


Asunto(s)
Composición Corporal/efectos de los fármacos , Inflamación/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Extractos Vegetales/farmacología , Polifenoles/farmacología , Animales , Composición Corporal/fisiología , Modelos Animales de Enfermedad , Inflamación/prevención & control , Resistencia a la Insulina/fisiología , Ratones , Ratones Endogámicos C57BL/metabolismo
6.
Am J Physiol Endocrinol Metab ; 320(6): E1119-E1137, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33938234

RESUMEN

Global prevalence of type 2 diabetes (T2D) is rising and may affect 700 million people by 2045. Totum-63 is a polyphenol-rich natural composition developed to reduce the risk of T2D. We first investigated the effects of Totum-63 supplementation in high-fat diet (HFD)-fed mice for up to 16 wk and thereafter assessed its safety and efficacy (2.5 g or 5 g per day) in 14 overweight men [mean age 51.5 yr, body mass index (BMI) 27.6 kg·m-2] for 4 wk. In HFD-fed mice, Totum-63 reduced body weight and fat mass gain, whereas lean mass was unchanged. Moreover, fecal energy excretion was higher in Totum-63-supplemented mice, suggesting a reduction of calorie absorption in the digestive tract. In the gut, metagenomic analyses of fecal microbiota revealed a partial restoration of HFD-induced microbial imbalance, as shown by principal coordinate analysis of microbiota composition. HFD-induced increase in HOMA-IR score was delayed in supplemented mice, and insulin response to an oral glucose tolerance test was significantly reduced, suggesting that Totum-63 may prevent HFD-related impairments in glucose homeostasis. Interestingly, these improvements could be linked to restored insulin signaling in subcutaneous adipose tissue and soleus muscle. In the liver, HFD-induced steatosis was reduced by 40% (as shown by triglyceride content). In the subsequent study in men, Totum-63 (5 g·day-1) improved glucose and insulin responses to a high-carbohydrate breakfast test (84% kcal carbohydrates). It was well tolerated, with no clinically significant adverse events reported. Collectively, these data suggest that Totum-63 could improve glucose homeostasis in both HFD-fed mice and overweight individuals, presumably through a multitargeted action on different metabolic organs.NEW & NOTEWORTHY Totum-63 is a novel polyphenol-rich natural composition developed to reduce the risk of T2D. Totum-63 showed beneficial effects on glucose homeostasis in HFD-fed mice, presumably through a multitargeted action on different metabolic organs. Totum-63 was well tolerated in humans and improved postprandial glucose and insulin responses to a high-carbohydrate breakfast test.


Asunto(s)
Glucemia/efectos de los fármacos , Hiperglucemia/prevención & control , Extractos Vegetales/farmacología , Adulto , Animales , Glucemia/metabolismo , Chrysanthemum/química , Cynara scolymus/química , Control Glucémico/métodos , Homeostasis/efectos de los fármacos , Humanos , Hiperglucemia/sangre , Hiperglucemia/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Olea/química , Sobrepeso/sangre , Sobrepeso/tratamiento farmacológico , Sobrepeso/metabolismo , Proyectos Piloto , Piper nigrum/química , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Periodo Posprandial/efectos de los fármacos , Investigación Biomédica Traslacional , Vaccinium myrtillus/química
7.
Metabolism ; 97: 57-67, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31153978

RESUMEN

BACKGROUND: Muscle atrophy is defined as decreased muscle mass, associated with aging as well as with various chronic diseases and is a fundamental cause of frailty, functional decline and disability. Frailty represents a huge potential public health issue worldwide with high impact on healthcare costs. A major clinical issue is therefore to devise new strategies preventing muscle atrophy. In this study, we tested the efficacy of Vital01, a novel oral nutritional supplement (ONS), on body weight and muscle mass using a caloric restriction-induced mouse model for muscle atrophy. METHODS: Mice were calorically restricted for 2 weeks to induce muscle atrophy: one control group received 60% kcal of the normal chow diet and one intervention group received 30% kcal chow and 30 kcal% Vital01. The effects on body weight, lean body mass, muscle histology and transcriptome were assessed. In addition, the effects of Vital01, in mice with established muscle atrophy, were assessed and compared to a standard ONS. To this end, mice were first calorically restricted on a 60% kcal chow diet and then refed with either 100 kcal% chow, a mix of Vital01 (receiving 60% kcal chow and 40 kcal% Vital01) or with a mix of standard, widely prescribed ONS (receiving 60 kcal% chow and 40 kcal% Fortisip Compact). RESULTS: Vital01 attenuated weight loss (-15% weight loss for Vital01 vs. -25% for control group, p < 0.01) and loss of muscle mass (Vital01 with -13%, -12% and -18%, respectively, for gastrocnemius, quadriceps and tibialis vs. 25%, -23% and -28%, respectively, for control group, all p < 0.05) and also restored body weight, fat and muscle mass more efficiently when compared to Fortisip Compact. As assessed by transcriptome analysis and Western blotting of key proteins (e.g. phospoAKT, mTOR and S6K), Vital01 attenuated the catabolic and anabolic signaling pathways induced by caloric restriction and modulated inflammatory and mitochondrial pathways. In addition, Vital01 affected pathways related to matrix proteins/collagens homeostasis and tended to reduce caloric restriction-induced collagen fiber density in the quadriceps (with -27%, p = 0.051). CONCLUSIONS: We demonstrate that Vital01 preserves muscle mass in a calorically restricted mouse model for muscle atrophy. Vital01 had preventive effects when administered during development of muscle atrophy. Furthermore, when administered in a therapeutic setting to mice with established muscle atrophy, Vital01 rapidly restored body weight and accelerated the recurrence of fat and lean body mass more efficiently than Fortisip Compact. Bioinformatics analysis of gene expression data identified regulatory pathways that were specifically influenced by Vital01 in muscle.


Asunto(s)
Peso Corporal/fisiología , Músculo Esquelético/fisiología , Atrofia Muscular/fisiopatología , Animales , Composición Corporal/fisiología , Índice de Masa Corporal , Restricción Calórica/métodos , Suplementos Dietéticos , Modelos Animales de Enfermedad , Ingestión de Energía/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Pérdida de Peso/fisiología
8.
PLoS One ; 13(5): e0196165, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29723205

RESUMEN

The indigestible mannan oligosaccharides (MOS) derived from the outer cell wall of yeast Saccharomyces cerevisiae have shown potential to reduce inflammation. Since inflammation is one of the underlying mechanisms involved in the development of obesity-associated metabolic dysfunctions, we aimed to determine the effect of dietary supplementation with MOS on inflammation and metabolic homeostasis in lean and diet-induced obese mice. Male C57BL/6 mice were fed either a low fat diet (LFD) or a high fat diet (HFD) with, respectively, 10% or 45% energy derived from lard fat, with or without 1% MOS for 17 weeks. Body weight and composition were measured throughout the study. After 12 weeks of intervention, whole-body glucose tolerance was assessed and in week 17 immune cell composition was determined in mesenteric white adipose tissue (mWAT) and liver by flow cytometry and RT-qPCR. In LFD-fed mice, MOS supplementation induced a significant increase in the abundance of macrophages and eosinophils in mWAT. A similar trend was observed in hepatic macrophages. Although HFD feeding induced a classical shift from the anti-inflammatory M2-like macrophages towards the pro-inflammatory M1-like macrophages in both mWAT and liver from control mice, MOS supplementation had no effect on this obesity-driven immune response. Finally, MOS supplementation did not improve whole-body glucose homeostasis in both lean and obese mice.Altogether, our data showed that MOS had extra-intestinal immune modulatory properties in mWAT and liver. However these effects were not substantial enough to significantly ameliorate HFD-induced glucose intolerance or inflammation.


Asunto(s)
Dieta Alta en Grasa/efectos adversos , Intolerancia a la Glucosa/inmunología , Mananos/química , Obesidad/inmunología , Oligosacáridos/química , Oligosacáridos/farmacología , Saccharomyces cerevisiae/química , Tejido Adiposo Blanco/efectos de los fármacos , Tejido Adiposo Blanco/inmunología , Animales , Recuento de Células , Suplementos Dietéticos , Eosinófilos/citología , Eosinófilos/efectos de los fármacos , Intolerancia a la Glucosa/inducido químicamente , Factores Inmunológicos/química , Factores Inmunológicos/farmacología , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/citología , Monocitos/efectos de los fármacos , Obesidad/inducido químicamente
9.
BMC Infect Dis ; 15: 133, 2015 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-25888525

RESUMEN

BACKGROUND: Insulin resistance is a strong predictor of the development of type 2 diabetes mellitus. Chronic helminth infections might protect against insulin resistance via a caloric restriction state and indirectly via T-helper-2 polarization of the immune system. Therefore the elimination of helminths might remove this beneficial effect on insulin resistance. METHODS/DESIGN: To determine whether soil-transmitted helminth infections are associated with a better whole-body insulin sensitivity and whether this protection is reversible by anthelmintic treatment, a household-based cluster-randomized, double blind, placebo-controlled trial was conducted in the area of Nangapanda on Flores Island, Indonesia, an area endemic for soil-transmitted helminth infections. The trial incorporates three monthly treatment with albendazole or matching placebo for one year, whereby each treatment round consists of three consecutive days of supervised drug intake. The presence of soil-transmitted helminths will be evaluated in faeces using microscopy and/or PCR. The primary outcome of the study will be changes in insulin resistance as assessed by HOMA-IR, while the secondary outcomes will be changes in body mass index, waist circumference, fasting blood glucose, 2 h-glucose levels after oral glucose tolerance test, HbA1c, serum lipid levels, immunological parameters, and efficacy of anthelmintic treatment. DISCUSSION: The study will provide data on the effect of helminth infections on insulin resistance. It will assess the relationship between helminth infection status and immune responses as well as metabolic parameters, allowing the establishment of a link between inflammation and whole-body metabolic homeostasis. In addition, it will give information on anthelmintic treatment efficacy and effectiveness. TRIAL REGISTRATION: This study has been approved by the ethical committee of Faculty of Medicine Universitas Indonesia (ref: 549/H2.F1/ETIK/2013), and has been filed by the ethics committee of Leiden University Medical Center, clinical trial number: ISRCTN75636394. The study is reported in accordance with the CONSORT guidelines for cluster-randomised trials.


Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Diabetes Mellitus Tipo 2/inmunología , Helmintiasis/tratamiento farmacológico , Helmintiasis/inmunología , Resistencia a la Insulina/inmunología , Adolescente , Adulto , Albendazol/administración & dosificación , Animales , Antihelmínticos/administración & dosificación , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Método Doble Ciego , Femenino , Helmintiasis/complicaciones , Humanos , Indonesia , Masculino , Persona de Mediana Edad , Placebos , Resultado del Tratamiento , Adulto Joven
10.
Front Biosci (Landmark Ed) ; 14(1): 19-44, 2009 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-19273052

RESUMEN

AMP-activated protein kinase (AMPK), a phylogenetically conserved serine/threonine protein kinase, has been proposed to function as a fuel gauge to monitor cellular energy status in response to nutritional environmental variations. AMPK system is a regulator of energy balance that, once activated by low energy status, switches on ATP-producing catabolic pathways (such as fatty acid oxidation and glycolysis), and switches off ATP-consuming anabolic pathways (such as lipogenesis), both by short-term effect on phosphorylation of regulatory proteins and by long-term effect on gene expression. Numerous observations obtained with pharmacological activators and agents that deplete intracellular ATP have been supportive of AMPK playing a role in the control of energy metabolism but none of these studies have provided conclusive evidence. Relatively recent developments in our understanding of precisely how AMPK complexes might operate to control energy metabolism is due in part to the development of transgenic and knockout mouse models. Although there are inevitable caveats with genetic models, some important findings have emerged. In the present review, we discuss recent findings obtained from animal models with inhibition or activation of AMPK signaling pathway.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/química , Tejido Adiposo/enzimología , Animales , Animales Modificados Genéticamente , Vasos Sanguíneos/enzimología , Vasos Sanguíneos/fisiología , Metabolismo Energético , Técnicas de Inactivación de Genes , Humanos , Hipoglucemiantes/farmacología , Hipotálamo/enzimología , Resistencia a la Insulina , Hígado/enzimología , Modelos Animales , Músculo Esquelético/enzimología , Miocardio/enzimología , Conformación Proteica
11.
J Hepatol ; 50(3): 489-500, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19155087

RESUMEN

BACKGROUND/AIMS: Peroxisome proliferator-activated receptor gamma (PPARgamma) agonist drugs, like pioglitazone (PGZ), are proposed as treatments for steatohepatitis. Their mechanisms of action remain ill-clarified. METHODS: To test the hypothesis that PGZ improves steatohepatitis through adiponectin-dependent stimulation of AMPK and/or PPARalpha, mice lacking adiponectin (Adipo(-/-)) or the AMPKalpha1 catalytic subunit (AMPKalpha1(-/-)) or wild-type (Wt) mice were fed the methionine and choline deficient (MCD) diet, supplemented or not with PGZ. RESULTS: In Wt mice, PGZ increased circulating levels of adiponectin and reduced the severity of MCD-induced steatohepatitis but there was no evidence of activation of AMPK or PPARalpha and their downstream targets. By contrast, PGZ completely repressed nuclear translocation of SREBP-1c, a key transcription factor for de novo lipogenesis. This effect was lacking in Adipo(-/-) mice in which PGZ failed to prevent steatohepatitis. Surprisingly, AMPKalpha1(-/-) mice were resistant to MCD-induced steatohepatitis, a status also associated with repression of SREBP-1c. CONCLUSIONS: The preventive effect of PGZ on MCD-induced steatohepatitis depends on adiponectin upregulation but apparently does not involve AMPK or PPARalpha activation. The inhibition of SREBP-1c and dependent repression of lipogenesis are likely to participate in this effect. The mechanisms by which PGZ and adiponectin control SREBP-1c and inflammation remain to be elucidated.


Asunto(s)
Adiponectina/fisiología , Hígado Graso/prevención & control , Inflamación/prevención & control , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/antagonistas & inhibidores , Tiazolidinedionas/uso terapéutico , Quinasas de la Proteína-Quinasa Activada por el AMP , Adiponectina/deficiencia , Animales , Deficiencia de Colina/complicaciones , Cartilla de ADN , Femenino , Hígado/enzimología , Hígado/patología , Metionina/deficiencia , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Pioglitazona , Proteínas Quinasas/deficiencia , Proteínas Quinasas/genética , ARN/genética , ARN/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética
13.
Med Sci (Paris) ; 22(4): 381-8, 2006 Apr.
Artículo en Francés | MEDLINE | ID: mdl-16597407

RESUMEN

The 5' AMP-activated protein kinase (AMPK) is a sensor of cellular energy homeostasis well conserved in all eukaryotic cells. AMPK is activated by rising AMP and falling ATP, either by inhibiting ATP production or by accelerating ATP consumption, by a complex mechanism that results in an ultrasensitive response. AMPK is a heterotrimeric enzyme complex consisting of a catalytic subunit alpha and two regulatory subunits beta and gamma. AMP activates the system by binding to the gamma subunit that triggers phosphorylation of the catalytic alpha subunit by the upstream kinases LKB1 and CaMKKbeta. Once activated, it switches on catabolic pathways (such as fatty acid oxidation and glycolysis) and switches off ATP-consuming pathways (such as lipogenesis) both by short-term effect on phosphorylation of regulatory proteins and by long-term effect on gene expression. Dominant mutations in the regulatory gamma subunit isoforms cause hypertrophy of cardiac and skeletal muscle providing a link in human diseases caused by defects in energy metabolism. As well as acting at the level of the individual cell, the system also regulates food intake and energy expenditure at the whole body level, in particular by mediating the effects of adipokines such as leptin and adiponectin. Moreover, the AMPK system is one of the probable target for the anti-diabetic drug metformin and rosiglitazone. The relationship between AMPK activation and beneficial metabolic effects provides the rationale for the development of new therapeutic strategies. Thus, pharmacological AMPK activation may, through signaling, metabolic and gene expression effects, reduce the risk of Type 2 diabetes, metabolic syndrome and cardiac diseases.


Asunto(s)
Enfermedades Cardiovasculares/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Metabolismo Energético/fisiología , Ácidos Grasos/metabolismo , Glucosa/metabolismo , Lipogénesis/fisiología , Complejos Multienzimáticos/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Proteínas Quinasas Activadas por AMP , Adenosina Monofosfato/fisiología , Adenosina Trifosfato/metabolismo , Adipogénesis/efectos de los fármacos , Regulación Alostérica , Animales , Enfermedades Cardiovasculares/enzimología , Colesterol/metabolismo , Diabetes Mellitus Tipo 2/enzimología , Diseño de Fármacos , Ingestión de Energía , Activación Enzimática , Ácidos Grasos/biosíntesis , Homeostasis/fisiología , Humanos , Hipotálamo/fisiología , Lipogénesis/efectos de los fármacos , Mamíferos/metabolismo , Metformina/farmacología , Metformina/uso terapéutico , Modelos Biológicos , Complejos Multienzimáticos/química , Complejos Multienzimáticos/genética , Miocardio/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/enzimología , Fosforilación , Procesamiento Proteico-Postraduccional/fisiología , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/genética , Estructura Terciaria de Proteína , Subunidades de Proteína , Rosiglitazona , Tiazolidinedionas/farmacología , Tiazolidinedionas/uso terapéutico
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