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1.
J Hum Nutr Diet ; 35(5): 791-803, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34967062

RESUMO

BACKGROUND: Lifestyle intervention studies to treat type 2 diabetes (T2D) are on the rise. However, in-depth research is lacking into the dietary changes that participants make. METHODS: The present study aimed to observe the dietary intake of participants following the group program 'Reverse Diabetes2 Now' (RD2N) over 12 months. The web-based 24-h dietary recall-tool Compl-eat was used to collect dietary intake data. RESULTS: In total, 147 T2D patients were included in a cross-sectional study (n = 37 at baseline, n = 58 at 6 months, n = 52 at 12 months). A lower intake of total energy, carbohydrates and iodine was found for the groups at 6 and 12 months compared to the baseline group. The absolute consumption of total fat and saturated fat did not differ between the groups; only the percentage as total calorie consumption decreased. Consumption of vegetables and full-fat yoghurt was higher in groups at 6 and 12 months compared to the group at baseline. Consumption of bread, cakes and sweet biscuits, pasta/rice/tortillas, artificially sweetened soft drinks, and crisps were lower in the groups at 6 and 12 months compared to the group at baseline. Similar results were observed in a separate prospective study in 22 participants over 12 months following the same lifestyle-intervention. CONCLUSIONS: Overall, participants shifted their dietary intake somewhat towards a healthier dietary pattern with overall lower energy and carbohydrates and more vegetables. Moreover, participants largely maintained this healthier pattern over 12 months. There were some concerns regarding iodine intake. These promising results need to be confirmed in a fully-scaled study, as well in a comparison with controls.


Assuntos
Diabetes Mellitus Tipo 2 , Iodo , Estudos Transversais , Diabetes Mellitus Tipo 2/terapia , Carboidratos da Dieta , Gorduras na Dieta , Ingestão de Energia , Humanos , Estilo de Vida , Estudos Prospectivos , Edulcorantes , Verduras
2.
FASEB J ; 31(3): 989-997, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27895108

RESUMO

We investigated the independent and interactive impact of the common APOE genotype and marine n-3 polyunsaturated fatty acids (PUFAs) on the development of obesity and associated cardiometabolic dysfunction in a murine model. Human APOE3 and APOE4 targeted replacement mice were fed either a control high-fat diet (HFD) or an HFD supplemented with 3% n-3 PUFAs from fish oil (HFD + FO) for 8 wk. We established the impact of intervention on food intake, body weight, and visceral adipose tissue (VAT) mass; plasma, lipids (cholesterol and triglycerides), liver enzymes, and adipokines; glucose and insulin during an intraperitoneal glucose tolerance test; and Glut4 and ApoE expression in VAT. HFD feeding induced more weight gain and higher plasma lipids in APOE3 compared to APOE4 mice (P < 0.05), along with a 2-fold higher insulin and impaired glucose tolerance. Supplementing APOE3, but not APOE4, animals with dietary n-3 PUFAs decreased body-weight gain, plasma lipids, and insulin (P < 0.05) and improved glucose tolerance, which was associated with increased VAT Glut4 mRNA levels (P < 0.05). Our findings demonstrate that an APOE3 genotype predisposes mice to develop obesity and its metabolic complications, which was attenuated by n-3 PUFA supplementation.-Slim, K. E., Vauzour, D., Tejera, N., Voshol, P. J., Cassidy, A., Minihane, A. M. The effect of dietary fish oil on weight gain and insulin sensitivity is dependent on APOE genotype in humanized targeted replacement mice.


Assuntos
Apolipoproteínas E/genética , Óleos de Peixe/farmacologia , Genótipo , Resistência à Insulina , Obesidade/prevenção & controle , Aumento de Peso/efeitos dos fármacos , Alelos , Animais , Apolipoproteínas E/metabolismo , Dieta Hiperlipídica/efeitos adversos , Óleos de Peixe/uso terapêutico , Humanos , Gordura Intra-Abdominal/efeitos dos fármacos , Masculino , Camundongos , Obesidade/etiologia , Obesidade/genética , Aumento de Peso/genética
3.
Proc Natl Acad Sci U S A ; 112(45): 13850-5, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26508640

RESUMO

Adipose triglyceride lipase (ATGL) initiates intracellular triglyceride (TG) catabolism. In humans, ATGL deficiency causes neutral lipid storage disease with myopathy (NLSDM) characterized by a systemic TG accumulation. Mice with a genetic deletion of ATGL (AKO) also accumulate TG in many tissues. However, neither NLSDM patients nor AKO mice are exceedingly obese. This phenotype is unexpected considering the importance of the enzyme for TG catabolism in white adipose tissue (WAT). In this study, we identified the counteracting mechanisms that prevent excessive obesity in the absence of ATGL. We used "healthy" AKO mice expressing ATGL exclusively in cardiomyocytes (AKO/cTg) to circumvent the cardiomyopathy and premature lethality observed in AKO mice. AKO/cTg mice were protected from high-fat diet (HFD)-induced obesity despite complete ATGL deficiency in WAT and normal adipocyte differentiation. AKO/cTg mice were highly insulin sensitive under hyperinsulinemic-euglycemic clamp conditions, eliminating insulin insensitivity as a possible protective mechanism. Instead, reduced food intake and altered signaling by peroxisome proliferator-activated receptor-gamma (PPAR-γ) and sterol regulatory element binding protein-1c in WAT accounted for the phenotype. These adaptations led to reduced lipid synthesis and storage in WAT of HFD-fed AKO/cTg mice. Treatment with the PPAR-γ agonist rosiglitazone reversed the phenotype. These results argue for the existence of an adaptive interdependence between lipolysis and lipid synthesis. Pharmacological inhibition of ATGL may prove useful to prevent HFD-induced obesity and insulin resistance.


Assuntos
Adaptação Fisiológica , Dieta Hiperlipídica , Comportamento Alimentar , Lipase/fisiologia , Lipólise , Obesidade/prevenção & controle , Animais , Lipase/genética , Camundongos , Camundongos Knockout , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Fenótipo
4.
Proc Natl Acad Sci U S A ; 111(11): E1043-52, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24591600

RESUMO

Physical activity increases energy metabolism in exercising muscle. Whether acute exercise elicits metabolic changes in nonexercising muscles remains unclear. We show that one of the few genes that is more highly induced in nonexercising muscle than in exercising human muscle during acute exercise encodes angiopoietin-like 4 (ANGPTL4), an inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. Using a combination of human, animal, and in vitro data, we show that induction of ANGPTL4 in nonexercising muscle is mediated by elevated plasma free fatty acids via peroxisome proliferator-activated receptor-δ, presumably leading to reduced local uptake of plasma triglyceride-derived fatty acids and their sparing for use by exercising muscle. In contrast, the induction of ANGPTL4 in exercising muscle likely is counteracted via AMP-activated protein kinase (AMPK)-mediated down-regulation, promoting the use of plasma triglycerides as fuel for active muscles. Our data suggest that nonexercising muscle and the local regulation of ANGPTL4 via AMPK and free fatty acids have key roles in governing lipid homeostasis during exercise.


Assuntos
Angiopoietinas/metabolismo , Exercício Físico/fisiologia , Homeostase/fisiologia , Metabolismo dos Lipídeos/fisiologia , Músculo Esquelético/fisiologia , Adulto , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/sangue , Angiopoietinas/fisiologia , Ácidos Graxos/metabolismo , Imunofluorescência , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade
5.
Arterioscler Thromb Vasc Biol ; 34(6): 1187-92, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24675658

RESUMO

OBJECTIVE: Platelets abundantly express the membrane receptor CD36 and store its ligand thrombospondin-1 (TSP1) in the α-granules. We investigated whether released TSP1 can support platelet adhesion and thrombus formation via interaction with CD36. APPROACH AND RESULTS: Mouse platelets deficient in CD36 showed reduced adhesion to TSP1 and subsequent phosphatidylserine expression. Deficiency in either CD36 or TSP1 resulted in markedly increased dissolution of thrombi formed on collagen, although thrombus buildup was unchanged. In mesenteric vessels in vivo, deficiency in CD36 prolonged the time to occlusion and enhanced embolization, which was in agreement with earlier observations in TSP1-deficient mice. Thrombi formed using wild-type blood stained positively for secreted TSP1. Releasate from wild-type but not from TSP1-deficient platelets enhanced platelet activation, phosphatidylserine expression, and thrombus formation on collagen. The enhancement was dependent on CD36 because it was without effect on thrombus formation by CD36-deficient platelets. CONCLUSIONS: These results demonstrate an anchoring role of platelet-released TSP1 via CD36 in platelet adhesion and collagen-dependent thrombus stabilization. Thus, the TSP1-CD36 tandem is another platelet ligand-receptor axis contributing to the maintenance of a stable thrombus.


Assuntos
Antígenos CD36/fisiologia , Colágeno/metabolismo , Trombose/etiologia , Trombospondina 1/fisiologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Ativação Plaquetária , Adesividade Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/fisiologia
6.
Proc Natl Acad Sci U S A ; 109(51): 20943-8, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23213245

RESUMO

Synucleins are a family of homologous proteins principally known for their involvement in neurodegeneration. γ-Synuclein is highly expressed in human white adipose tissue and increased in obesity. Here we show that γ-synuclein is nutritionally regulated in white adipose tissue whereas its loss partially protects mice from high-fat diet (HFD)-induced obesity and ameliorates some of the associated metabolic complications. Compared with HFD-fed WT mice, HFD-fed γ-synuclein-null mutant mice display increased lipolysis, lipid oxidation, and energy expenditure, and reduced adipocyte hypertrophy. Knockdown of γ-synuclein in adipocytes causes redistribution of the key lipolytic enzyme ATGL to lipid droplets and increases lipolysis. γ-Synuclein-deficient adipocytes also contain fewer SNARE complexes of a type involved in lipid droplet fusion. We hypothesize that γ-synuclein may deliver SNAP-23 to the SNARE complexes under lipogenic conditions. Via these independent but complementary roles, γ-synuclein may coordinately modulate lipid storage by influencing lipolysis and lipid droplet formation. Our data reveal γ-synuclein as a regulator of lipid handling in adipocytes, the function of which is particularly important in conditions of nutrient excess.


Assuntos
Tecido Adiposo/metabolismo , Lipólise , Obesidade/metabolismo , Células 3T3 , Adipócitos/citologia , Animais , Dieta , Genótipo , Lipídeos/química , Lipogênese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , gama-Sinucleína
7.
J Lipid Res ; 55(7): 1434-47, 2014 07.
Artigo em Inglês | MEDLINE | ID: mdl-24837748

RESUMO

Here, we investigated how LDL receptor deficiency (Ldlr(-/-)) modulates the effects of testosterone on obesity and related metabolic dysfunctions. Though sham-operated Ldlr(-/-) mice fed Western-type diet for 12 weeks became obese and showed disturbed plasma glucose metabolism and plasma cholesterol and TG profiles, castrated mice were resistant to diet-induced obesity and had improved glucose metabolism and reduced plasma TG levels, despite a further deterioration in their plasma cholesterol profile. The effect of hypogonadism on diet-induced weight gain of Ldlr(-/-) mice was independent of ApoE and Lrp1. Indirect calorimetry analysis indicated that hypogonadism in Ldlr(-/-) mice was associated with increased metabolic rate. Indeed, mitochondrial cytochrome c and uncoupling protein 1 expression were elevated, primarily in white adipose tissue, confirming increased mitochondrial metabolic activity due to thermogenesis. Testosterone replacement in castrated Ldlr(-/-) mice for a period of 8 weeks promoted diet-induced obesity, indicating a direct role of testosterone in the observed phenotype. Treatment of sham-operated Ldlr(-/-) mice with the aromatase inhibitor exemestane for 8 weeks showed that the obesity of castrated Ldlr(-/-) mice is independent of estrogens. Overall, our data reveal a novel role of Ldlr as functional modulator of metabolic alterations associated with hypogonadism.


Assuntos
Gorduras na Dieta/efeitos adversos , Hipogonadismo/metabolismo , Obesidade/metabolismo , Receptores de LDL/metabolismo , Testosterona/metabolismo , Animais , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Gorduras na Dieta/farmacologia , Hipogonadismo/induzido quimicamente , Hipogonadismo/genética , Hipogonadismo/patologia , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Masculino , Camundongos , Camundongos Knockout , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/patologia , Receptores de LDL/genética , Testosterona/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
8.
Nat Med ; 12(6): 650-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16732281

RESUMO

Here we report the presence of hyperphagia, obesity and insulin resistance in knockout mice deficient in IL-18 or IL-18 receptor, and in mice transgenic for expression of IL-18 binding protein. Obesity of Il18-/- mice resulted from accumulation of fat tissue based on increased food intake. Il18-/- mice also had hyperinsulinemia, consistent with insulin resistance and hyperglycemia. Insulin resistance was secondary to obesity induced by increased food intake and occurred at the liver level as well as at the muscle and fat-tissue level. The molecular mechanisms responsible for the hepatic insulin resistance in the Il18-/- mice involved an enhanced expression of genes associated with gluconeogenesis in the liver of Il18-/- mice, resulting from defective phosphorylation of STAT3. Recombinant IL-18 (rIL-18) administered intracerebrally inhibited food intake. In addition, rIL-18 reversed hyperglycemia in Il18-/- mice through activation of STAT3 phosphorylation. These findings indicate a new role of IL-18 in the homeostasis of energy intake and insulin sensitivity.


Assuntos
Hiperfagia , Resistência à Insulina , Interleucina-18/deficiência , Obesidade , Animais , Peso Corporal , Ingestão de Alimentos , Metabolismo Energético , Gluconeogênese/fisiologia , Glucose/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Homeostase , Hiperfagia/genética , Hiperfagia/metabolismo , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular , Interleucina-18/genética , Subunidade alfa de Receptor de Interleucina-18 , Fígado/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Obesidade/genética , Obesidade/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Receptores de Interleucina-18 , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fator de Transcrição STAT3/metabolismo
9.
J Lipid Res ; 52(9): 1712-22, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21700834

RESUMO

Insulin signaling in the central nervous system (CNS) is required for the inhibitory effect of insulin on glucose production. Our aim was to determine whether the CNS is also involved in the stimulatory effect of circulating insulin on the tissue-specific retention of fatty acid (FA) from plasma. In wild-type mice, hyperinsulinemic-euglycemic clamp conditions stimulated the retention of both plasma triglyceride-derived FA and plasma albumin-bound FA in the various white adipose tissues (WAT) but not in other tissues, including brown adipose tissue (BAT). Intracerebroventricular (ICV) administration of insulin induced a similar pattern of tissue-specific FA partitioning. This effect of ICV insulin administration was not associated with activation of the insulin signaling pathway in adipose tissue. ICV administration of tolbutamide, a K(ATP) channel blocker, considerably reduced (during hyperinsulinemic-euglycemic clamp conditions) and even completely blocked (during ICV administration of insulin) WAT-specific retention of FA from plasma. This central effect of insulin was absent in CD36-deficient mice, indicating that CD36 is the predominant FA transporter in insulin-stimulated FA retention by WAT. In diet-induced insulin-resistant mice, these stimulating effects of insulin (circulating or ICV administered) on FA retention in WAT were lost. In conclusion, in insulin-sensitive mice, circulating insulin stimulates tissue-specific partitioning of plasma-derived FA in WAT in part through activation of K(ATP) channels in the CNS. Apparently, circulating insulin stimulates fatty acid uptake in WAT but not in BAT, directly and indirectly through the CNS.


Assuntos
Tecido Adiposo Branco/metabolismo , Sistema Nervoso Central/metabolismo , Ácidos Graxos/metabolismo , Insulina/sangue , Canais KATP/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Animais , Antígenos CD36/genética , Antígenos CD36/metabolismo , Dieta , Insulina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/fisiopatologia , Transdução de Sinais/fisiologia
10.
J Lipid Res ; 52(5): 942-50, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21357939

RESUMO

Low-grade inflammation in different tissues, including activation of the nuclear factor κB pathway in liver, is involved in metabolic disorders such as type 2 diabetes and cardiovascular diseases (CVDs). In this study, we investigated the relation between chronic hepatocyte-specific overexpression of IkB kinase (IKK)-ß and hypertriglyceridemia, an important risk factor for CVD, by evaluating whether activation of IKK-ß only in the hepatocyte affects VLDL-triglyceride (TG) metabolism directly. Transgenic overexpression of constitutively active human IKK-ß specifically in hepatocytes of hyperlipidemic APOE*3-Leiden mice clearly induced hypertriglyceridemia. Mechanistic in vivo studies revealed that the hypertriglyceridemia was caused by increased hepatic VLDL-TG production rather than a change in plasma VLDL-TG clearance. Studies in primary hepatocytes showed that IKK-ß overexpression also enhances TG secretion in vitro, indicating a direct relation between IKK-ß activation and TG production within the hepatocyte. Hepatic lipid analysis and hepatic gene expression analysis of pathways involved in lipid metabolism suggested that hepatocyte-specific IKK-ß overexpression increases VLDL production not by increased steatosis or decreased FA oxidation, but most likely by carbohydrate-responsive element binding protein-mediated upregulation of Fas expression. These findings implicate that specific activation of inflammatory pathways exclusively within hepatocytes induces hypertriglyceridemia. Furthermore, we identify the hepatocytic IKK-ß pathway as a possible target to treat hypertriglyceridemia.


Assuntos
Apolipoproteína E3/metabolismo , Hepatócitos/metabolismo , Quinase I-kappa B/metabolismo , Lipoproteínas VLDL/biossíntese , Fígado/metabolismo , Triglicerídeos/biossíntese , Animais , Apolipoproteínas E/metabolismo , Western Blotting , Células Cultivadas , Humanos , Hipertrigliceridemia/genética , Hipertrigliceridemia/metabolismo , Quinase I-kappa B/genética , Masculino , Camundongos
11.
Am J Physiol Endocrinol Metab ; 301(6): E1099-107, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21862721

RESUMO

Systemic inflammation is strongly involved in the pathophysiology of the metabolic syndrome, a cluster of metabolic risk factors that includes hypertriglyceridemia. Aspirin treatment lowers inflammation via inhibition of NF-κB activity but also reduces hypertriglyceridemia in humans. The aim of this study was to investigate the mechanism by which aspirin improves hypertriglyceridemia. Human apolipoprotein CI (apoCI)-expressing mice (APOC1 mice), an animal model with elevated plasma triglyceride (TG) levels, as well as normolipidemic wild-type (WT) mice were fed a high-fat diet (HFD) and treated with aspirin. Aspirin treatment reduced hepatic NF-κB activity in HFD-fed APOC1 and WT mice, and in addition, aspirin decreased plasma TG levels (-32%, P < 0.05) in hypertriglyceridemic APOC1 mice. This TG-lowering effect could not be explained by enhanced VLDL-TG clearance, but aspirin selectively reduced hepatic production of VLDL-TG in both APOC1 (-28%, P < 0.05) and WT mice (-33%, P < 0.05) without affecting VLDL-apoB production. Aspirin did not alter hepatic expression of genes involved in FA oxidation, lipogenesis, and VLDL production but decreased the incorporation of plasma-derived FA by the liver into VLDL-TG (-24%, P < 0.05), which was independent of hepatic expression of genes involved in FA uptake and transport. We conclude that aspirin improves hypertriglyceridemia by decreasing VLDL-TG production without affecting VLDL particle production. Therefore, the inhibition of inflammatory pathways by aspirin could be an interesting target for the treatment of hypertriglyceridemia.


Assuntos
Aspirina/farmacologia , Dieta Hiperlipídica , Hipertrigliceridemia/prevenção & controle , Lipoproteínas VLDL/metabolismo , Triglicerídeos/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Apolipoproteína C-I/genética , Aspirina/uso terapêutico , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Hipertrigliceridemia/sangue , Hipertrigliceridemia/etiologia , Hipertrigliceridemia/metabolismo , Lipoproteínas VLDL/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/metabolismo , Triglicerídeos/sangue
12.
Am J Physiol Endocrinol Metab ; 301(4): E618-27, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21712535

RESUMO

Cardiac patients often are obese and have hypertension, but in most studies these conditions are investigated separately. Here, we aimed at 1) elucidating the interaction of metabolic and mechanophysical stress in the development of cardiac dysfunction in mice and 2) preventing this interaction by ablation of the fatty acid transporter CD36. Male wild-type (WT) C57Bl/6 mice and CD36(-/-) mice received chow or Western-type diet (WTD) for 10 wk and then underwent a sham surgery or transverse aortic constriction (TAC) under anesthesia. After a 6-wk continuation of the diet, cardiac function, morphology, lipid profiles, and molecular parameters were assessed. WTD administration affected body and organ weights of WT and CD36(-/-) mice, but it affected only plasma glucose and insulin concentrations in WT mice. Cardiac lipid concentrations increased in WT mice receiving WTD, decreased in CD36(-/-) on chow, and remained unchanged in CD36(-/-) receiving WTD. TAC induced cardiac hypertrophy in WT mice on chow but did not affect cardiac function and cardiac lipid concentrations. WTD or CD36 ablation worsened the outcome of TAC. Ablation of CD36 protected against the WTD-related aggravation of cardiac functional and structural changes induced by TAC. In conclusion, cardiac dysfunction and remodeling worsen when the heart is exposed to two stresses, metabolic and mechanophysical, at the same time. CD36 ablation prevents the metabolic stress resulting from a WTD. Thus, metabolic conditions are a critical factor for the compromised heart and provide new targets for metabolic manipulation in cardioprotection.


Assuntos
Antígenos CD36/genética , Cardiomegalia/metabolismo , Miocárdio/metabolismo , Animais , Estenose da Valva Aórtica/complicações , Glicemia/metabolismo , Antígenos CD36/metabolismo , Cardiomegalia/etiologia , Cardiomegalia/fisiopatologia , Dieta , Coração/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , Miocárdio/patologia , Obesidade/complicações
13.
Circ Res ; 105(1): 99-107, 2009 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-19478200

RESUMO

Chronic inflammation in white adipose tissue (WAT) is positively associated with obesity, insulin resistance (IR) and the development of type 2 diabetes. The proinflammatory cytokine MIF (macrophage migration inhibitory factor) is an essential, upstream component of the inflammatory cascade. This study examines whether MIF is required for the development of obesity, IR, glucose intolerance, and atherosclerosis in the LDL receptor-deficient (Ldlr(-/-)) mouse model of disease. Ldlr(-/-) mice develop IR and glucose intolerance within 15 weeks, whereas Mif(-/-)Ldlr(-/-) littermates are protected. MIF deficiency does not affect obesity and lipid risk factors but specifically reduces inflammation in WAT and liver, as reflected by lower plasma serum amyloid A and fibrinogen levels at baseline and under inflammatory conditions. Conversely, MIF stimulates the in vivo expression of human C-reactive protein, an inflammation marker and risk factor of IR and cardiovascular disease. In WAT, MIF deficiency reduces nuclear c-Jun levels and improves insulin sensitivity; MIF deficiency also reduces macrophage accumulation in WAT and blunts the expression of two proteins that regulate macrophage infiltration (intercellular adhesion molecule-1, CD44). Mechanistic parallels to WAT were observed in aorta, where the absence of MIF reduces monocyte adhesion, macrophage lesion content, and atherosclerotic lesion size. These data highlight the physiological importance of chronic inflammation in development of IR and atherosclerosis and suggest that MIF is a potential therapeutic target for reducing the inflammatory component of metabolic and cardiovascular disorders.


Assuntos
Tecido Adiposo Branco/patologia , Inflamação/etiologia , Resistência à Insulina , Fatores Inibidores da Migração de Macrófagos/deficiência , Animais , Aterosclerose/etiologia , Biomarcadores/sangue , Doença Crônica , Intolerância à Glucose/etiologia , Humanos , Fígado/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptores de LDL/deficiência
14.
J Lipid Res ; 51(1): 97-102, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19564641

RESUMO

The cholesteryl ester transfer protein (CETP) facilitates the bidirectional transfer of cholesteryl esters and triglycerides (TG) between HDL and (V)LDL. By shifting cholesterol in plasma from HDL to (V)LDL in exchange for VLDL-TG, CETP aggravates atherosclerosis in hyperlipidemic APOE*3-Leiden (E3L) mice. The aim of this study was to investigate the role of CETP in TG metabolism and high-fat diet-induced obesity by using E3L mice with and without the expression of the human CETP gene. On chow, plasma lipid levels were comparable between both male and female E3L and E3L.CETP mice. Further mechanistic studies were performed using male mice. CETP expression increased the level of TG in HDL. CETP did not affect the postprandial plasma TG response or the hepatic VLDL-TG and VLDL-apolipoprotein B production rate. Moreover, CETP did not affect the plasma TG clearance rate or organ-specific TG uptake after infusion of VLDL-like emulsion particles. In line with the absence of an effect of CETP on tissue-specific TG uptake, CETP also did not affect weight gain in response to a high-fat diet. In conclusion, the CETP-induced increase of TG in the HDL fraction of E3L mice is not associated with changes in the production of TG or with tissue-specific clearance of TG from the plasma.


Assuntos
Aterosclerose/metabolismo , Proteínas de Transferência de Ésteres de Colesterol/metabolismo , VLDL-Colesterol/metabolismo , Triglicerídeos/biossíntese , Animais , Apolipoproteína E3/genética , Aterosclerose/sangue , HDL-Colesterol/sangue , HDL-Colesterol/metabolismo , VLDL-Colesterol/sangue , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/metabolismo , Feminino , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Transgênicos , Obesidade/sangue , Obesidade/metabolismo , Transgenes/fisiologia , Triglicerídeos/sangue
15.
Biochim Biophys Acta ; 1791(6): 479-85, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19168150

RESUMO

The obesity epidemic is associated with an increased incidence of type 2 diabetes, cardiovascular morbidity and various types of cancer. A better insight into the molecular mechanisms that underlie adipogenesis and obesity may result in novel therapeutic handles to fight obesity and these associated diseases. Adipogenesis is determined by the balance between uptake of fatty acids (FA) from plasma into adipocytes, intracellular FA oxidation versus esterification of FA into triglycerides (TG), lipolysis of TG by intracellular lipases, and secretion of FA from adipocytes. Here, we review the mechanisms that are specifically involved in the entry of FA into adipose tissue. In plasma, these originating FA are either present as TG within apoB-containing lipoproteins (i.e. chylomicrons and VLDL) or as free FA bound to albumin. Kinetic studies, however, have revealed that TG are the major source of FA entering adipose tissue, both in the fed and fasted condition. In fact, studies with genetically engineered mice have revealed that the activity of lipoprotein lipase (LPL) is a major determinant for the development of obesity. As a general rule, high fat diet-induced adipogenesis is aggravated by stimulated LPL activity (e.g. by adipose tissue-specific overexpression of LPL or deficiency for apoCIII), and attenuated by inhibited LPL activity (e.g. by adipose-specific deficiency for LPL, overexpression of apoCI or angptl4, or by deficiency for apoE or the VLDL receptor). In addition, we describe that the trans-membrane transport of FA and cytoplasmic binding of FA in adipocytes can also dramatically affect adipogenesis. The relevance of these findings for human pathophysiology is discussed.


Assuntos
Adipogenia , Tecido Adiposo/metabolismo , Ácidos Graxos/metabolismo , Obesidade/metabolismo , Triglicerídeos/sangue , Tecido Adiposo/enzimologia , Tecido Adiposo/fisiopatologia , Animais , Apolipoproteínas B/metabolismo , Transporte Biológico , Modelos Animais de Doenças , Ácidos Graxos/sangue , Humanos , Cinética , Lipase Lipoproteica/genética , Lipase Lipoproteica/metabolismo , Camundongos , Camundongos Transgênicos , Obesidade/genética , Obesidade/fisiopatologia
16.
Am J Physiol Endocrinol Metab ; 298(3): E477-88, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19934402

RESUMO

Postnatal development and puberty are times of strong physical maturation and require large quantities of energy. The hypothalamic neuropeptide melanin-concentrating hormone (MCH) regulates nutrient intake and energy homeostasis, but the underlying mechanisms are not completely understood. Here we use a novel rat knockout model in which the MCH precursor Pmch has been inactivated to study the effects of loss of MCH on energy regulation in more detail. Pmch(-/-) rats are lean, hypophagic, osteoporotic, and although endocrine parameters were changed in pmch(-/-) rats, endocrine dynamics were normal, indicating an adaptation to new homeostatic levels rather than disturbed metabolic mechanisms. Detailed body weight growth and feeding behavior analysis revealed that Pmch expression is particularly important during early rat development and puberty, i.e., the first 8 postnatal weeks. Loss of Pmch resulted in a 20% lower set point for body weight that was determined solely during this period and remained unchanged during adulthood. Although the final body weight is diet dependent, the Pmch-deficiency effect was similar for all diets tested in this study. Loss of Pmch affected energy expenditure in both young and adult rats, although these effects seem secondary to the observed hypophagia. Our findings show an important role for Pmch in energy homeostasis determination during early development and indicate that the MCH receptor 1 system is a plausible target for childhood obesity treatment, currently a major health issue in first world countries.


Assuntos
Peso Corporal/fisiologia , Ingestão de Energia/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Homeostase/fisiologia , Hormônios Hipotalâmicos/metabolismo , Hormônios Hipotalâmicos/fisiologia , Melaninas/metabolismo , Hormônios Hipofisários/metabolismo , Precursores de Proteínas/fisiologia , Animais , Ratos
17.
Biochem Biophys Res Commun ; 392(3): 436-41, 2010 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-20079709

RESUMO

The present study addresses the insulin sensitivity in mice deficient in LXRbeta (LXRbeta(-/-)) as well as in wild type (wt) mice assessed by hyperinsulinemic euglycemic clamp. Wt and LXRbeta(-/-) mice were fed either a normal chow diet or a high fat and high cholesterol diet (HFCD), and insulin sensitivity was assessed by hyperinsulinemic euglycemic clamps. We show that LXRbeta(-/-) mice have reduced insulin clearance during hyperinsulinemic clamps upon feeding both HFCD and a regular chow diet. Moreover we also observed reduced hepatic inflammation in LXRbeta(-/-) mice compared to wt mice upon feeding an HFCD, despite equal levels of hepatic steatosis. In summary, our results indicate that LXRbeta(-/-) mice have reduced insulin clearance during hyperinsulinemic euglycemic clamps and also reduced hepatic inflammation upon feeding an HFCD for 26weeks.


Assuntos
Hepatite/genética , Resistência à Insulina/genética , Insulina/metabolismo , Fígado/metabolismo , Receptores Nucleares Órfãos/fisiologia , Animais , Colesterol na Dieta/administração & dosagem , Colesterol na Dieta/efeitos adversos , Dieta/efeitos adversos , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/efeitos adversos , Fígado Gorduroso/genética , Técnica Clamp de Glucose , Insulina/farmacologia , Fígado/patologia , Receptores X do Fígado , Masculino , Camundongos , Camundongos Knockout , Receptores Nucleares Órfãos/genética , Triglicerídeos/metabolismo
18.
BMJ Nutr Prev Health ; 2(1): 43-50, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33235957

RESUMO

INTRODUCTION: Prevalence of type 2 diabetes (T2D) is increasing rapidly and lifestyle interventions to reverse diabetes are seen as a possible solution to stop this trend. New practice-based evidence is needed to gain more insight in the actual, and above all scientific, basis for these claims. METHODS: This observational study with a pretest post-test design aimed to pilot a 6-month multicomponent outpatient group-based nutrition and lifestyle intervention programme on glycaemic control and use of glucose lowering medication in motivated T2D patients with a body mass index (BMI) >25 kg/m2 in the Netherlands (February 2015-March 2016). RESULTS: 74 T2D patients (56% female) aged 57.4±8.0 years with mean BMI 31.2±4.2 kg/m2 and mean waist circumference 105.4±10.2 cm were included in the study. Compared with baseline, mean HbA1c levels at 6 months were 5 mmol/mol lower (SD=10, p<0.001) and the number of participants with HbA1c levels ≤53 mmol/mol after intervention had increased (from 36% (n=26/72) to 60% (n=43/72)). At baseline, 90% of participants were taking at least one type of glucose lowering medication. At 6 months, 49% (n=35/72) of the participants had reduced their medication or eliminated it completely (13%). Secondary outcomes were significantly lower fasting glucose levels (- 1.2±2.6 mmol/L), body weight (-4.9±5.1 kg), BMI (-1.70±1.69 kg/m2) and waist circumference (-9.4±5.0 cm). Plasma lipids remained unchanged except for a decrease in triglyceride levels. Furthermore, self-reported quality of life was significantly higher while experienced fatigue and sleep problems were significantly lower. CONCLUSION: This pilot study showed that a 6-month multicomponent group-based program in a routine care setting could improve glycaemic control and reduce the use of glucose lowering medication in motivated T2D diabetics. A fully scaled study is needed to confirm these results.

19.
FEBS J ; 275(19): 4796-809, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18754772

RESUMO

Obesity is a central feature of the metabolic syndrome and is associated with increased risk for insulin resistance and typeII diabetes. Here, we investigated the contribution of human apoliproteinE3 and mouse apoliproteinE to the development of diet-induced obesity in response to western-type diet. Our data show that apolipoproteinE contributes to the development of obesity and other related metabolic disorders, and that human apolipoproteinE3 is more potent than mouse apolipoproteinE in promoting obesity in response to western-type diet. Specifically, we found that apolipoproteinE3 knock-in mice fed western-type diet for 24 weeks became obese and developed hyperglycemia, hyperinsulinemia, hyperleptinemia, glucose intolerance and insulin resistance that were more severe than in C57BL/6 mice. In contrast, apolipoproteinE-deficient mice fed western-type diet for the same period were resistant to diet-induced obesity, had normal plasma glucose, leptin and insulin levels, and exhibited normal responses to glucose tolerance and insulin resistance tests. Furthermore, low-density lipoprotein receptor-deficient mice were more sensitive to the development of diet-induced obesity and insulin resistance than apolipoprotein E-deficient mice, but were still more resistant than C57BL/6 mice, raising the possibility that low-density lipoprotein receptor mediates, at least in part, the effects of apolipoproteinE on obesity. Taken together, our findings suggest that, in addition to other previously identified mechanisms of obesity, apolipoproteinE and possibly the chylomicron pathway are also important contributors to the development of obesity and related metabolic dysfunctions in mice.


Assuntos
Apolipoproteínas E/fisiologia , Intolerância à Glucose/etiologia , Resistência à Insulina/fisiologia , Obesidade/etiologia , Tecido Adiposo/metabolismo , Animais , Apolipoproteína E3/fisiologia , Apolipoproteínas E/deficiência , Glicemia/metabolismo , Composição Corporal , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/efeitos adversos , Feminino , Humanos , Insulina/sangue , Leptina/sangue , Lipídeos/sangue , Fígado/metabolismo , Camundongos , Obesidade/fisiopatologia , Receptores de LDL/deficiência , Receptores de LDL/fisiologia , Triglicerídeos/metabolismo
20.
Arterioscler Thromb Vasc Biol ; 27(11): 2420-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17761937

RESUMO

BACKGROUND: Dysregulation of plasma lipoprotein levels may increase the risk for atherosclerosis. Recently, angiopoietin-like protein 4, also known as fasting-induced adipose factor Fiaf, was uncovered as a novel modulator of plasma lipoprotein metabolism. Here we take advantage of the fasting-dependent phenotype of Angptl4-transgenic (Angptl4-Tg) mice to better characterize the metabolic function of Angptl4. METHODS AND RESULTS: In 24-hour fasted mice, Angptl4 overexpression increased plasma triglycerides (TG) by 24-fold, which was attributable to elevated VLDL-, IDL/LDL- and HDL-TG content. Angptl4 overexpression decreased post-heparin LPL activity by stimulating conversion of endothelial-bound LPL dimers to circulating LPL monomers. In fasted but not fed state, Angptl4 overexpression severely impaired LPL-dependent plasma TG and cholesteryl ester clearance and subsequent uptake of fatty acids and cholesterol into tissues. Consequently, hepatic cholesterol content was significantly decreased, leading to universal upregulation of cholesterol and fatty acid synthesis pathways and increased rate of cholesterol synthesis. CONCLUSIONS: The hypertriglyceridemic effect of Angptl4 is attributable to inhibition of LPL-dependent VLDL lipolysis by converting LPL dimers to monomers, and Angptl4 upregulates cholesterol synthesis in liver secondary to inhibition of LPL- and HL-dependent hepatic cholesterol uptake.


Assuntos
Proteínas Sanguíneas/fisiologia , Colesterol/biossíntese , Ácidos Graxos/biossíntese , Lipase Lipoproteica/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas , Animais , Vias Biossintéticas , Glicemia/metabolismo , Colesterol/metabolismo , Jejum/metabolismo , Resistência à Insulina/fisiologia , Lipólise/fisiologia , Camundongos , Camundongos Transgênicos
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