Página 1 dos resultados de 9813 itens digitais encontrados em 0.021 segundos

Major involvement of mTOR in the PPAR gamma-induced stimulation of adipose tissue lipid uptake and fat accretion

Blanchard, Pierre-Gilles; Festuccia, William Tadeu Lara; Houde, Vanessa P.; St-Pierre, Philippe; Brule, Sophie; Turcotte, Veronique; Cote, Marie; Bellmann, Kerstin; Marette, Andre; Deshaies, Yves
Fonte: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC; BETHESDA Publicador: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC; BETHESDA
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.42%
Evidence points to a role of the mammalian target of rapamycin (mTOR) signaling pathway as a regulator of adiposity, yet its involvement as a mediator of the positive actions of peroxisome proliferator-activated receptor (PPAR)gamma agonism on lipemia, fat accretion, lipid uptake, and its major determinant lipoprotein lipase (LPL) remains to be elucidated. Herein we evaluated the plasma lipid profile, triacylglycerol (TAG) secretion rates, and adipose tissue LPL-dependent lipid uptake, LPL expression/activity, and expression profile of other lipid metabolism genes in rats treated with the PPAR gamma agonist rosiglitazone (15 mg/kg/day) in combination or not with the mTOR inhibitor rapamycin (2 mg/kg/day) for 15 days. Rosiglitazone stimulated adipose tissue mTOR complex 1 and AMPK and induced TAG-derived lipid uptake (136%), LPL mRNA/activity (2- to 6-fold), and fat accretion in subcutaneous (but not visceral) white adipose tissue (WAT; 50%) and in brown adipose tissue (BAT; 266%). Chronic mTOR inhibition attenuated the upregulation of lipid uptake, LPL expression/activity, and fat accretion induced by PPAR gamma activation in both subcutaneous WAT and BAT, which resulted in hyperlipidemia. In contrast, rapamycin did not affect most of the other WAT lipogenic genes upregulated by rosiglitazone. Together these findings demonstrate that mTOR is a major regulator of adipose tissue LPL-mediated lipid uptake and a critical mediator of the hypolipidemic and lipogenic actions of PPAR gamma activation.-Blanchard...

A puberdade altera a responsividade à insulina do tecido adiposo assim como sua capacidade lipogênica.; Puberty alters adipose tissue insulin responsiveness and its lipogenic capacity.

Campaña, Amanda Baron
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/07/2013 Português
Relevância na Pesquisa
66.44%
O tecido adiposo, através da leptina, desempenha um papel permissivo sobre a maturação sexual do indivíduo. Apesar da importância do tecido adiposo para a puberdade, pouco se sabe a respeito do processo de formação deste tecido neste período da vida. Estudos em humanos têm descrito a presença de resistência à insulina puberal. Assim, frente à importância do tecido adiposo para a puberdade, o objetivo do trabalho foi investigar a resposta do tecido adiposo à insulina no período puberal. Foram utilizados os coxins adiposos subcutâneo e periepididimal. Na puberdade, paralelamente à intolerância à glicose transitória que ocorreu nas semanas iniciais, e, portanto, prejuízo da utilização da glicose pelos tecidos insulino-dependentes, o tecido adiposo (SC e PE) teve sua responsividade normal à insulina e uma melhor capacidade de incorporação de glicose em lipídeos o que leva a crer que há um desvio da utilização deste substrato energético, a glicose, para a formação do tecido adiposo.; The adipose tissue is critical to puberty. Leptin exerts a permissive role to hypothalamic-hypophysial-gonadal maturation and, thereby, adipose tissue is necessary to pubertal development. Despite its importance to puberty...

Correlation between carotenoid concentrations in serum and normal breast adipose tissue of women with benign breast tumor or breast cancer

Yeum, Kyung-Jin; Ahn, Sei-Hyun; Paiva, Sergio Alberto Rupp de; Lee-Kirn, Yang Cha; Krinsky, Norman I.; Russell, Robert M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1920-1926
Português
Relevância na Pesquisa
66.5%
To evaluate the relationship between carotenoid concentrations in serum and breast tissue, we measured serum carotenoid concentrations and endogenous carotenoid levels in breast adipose tissue of women with benign breast tumor (n = 46) or breast cancer (n = 44). Before extraction, serum was digested with lipase and cholesterol esterase, and breast adipose tissue was saponified. Serum and tissue carotenoids were extracted with ether/hexane and measured by using HPLC with a C30 column. Serum retinoic acid was extracted with chloroform/methanol and measured using HPLC with a C18 column. There were no significant differences in serum carotenoids [lutein, zeaxanthin, cryptoxanthin (both α- and β-), α-carotene, all-trans β-carotene, 13-cis β-carotene and lycopene], retinoids (retinol, all-trans and 13-cis retinoic acids), and α- and -γ- tocopherol concentrations between benign breast tumor patients and breast cancer patients. A substantial amount of 9-cis β- carotene was present in adipose tissue and was the only carotenoid that had a significantly lower level in benign breast tumor patients than in breast cancer patients. Correlations between carotenoid concentrations in serum and in breast adipose tissue were determined by combining the data of the two groups. Concentrations of the major serum carotenoids except cryptoxanthin showed significant correlations with breast adipose tissue carotenoid levels. When the concentrations of serum carotenoids were adjusted for serum triglycerides or LDL...

Expressão de genes envolvidos com a lactatogênese, lipogênese e lipólise em tecido adiposo isolado de humanos eutróficos e obesos; Expression of genes involved in lactatogenesis, lipogenesis and lipoysis in eutrophic and obese human isolated adipose tissue

Larissa Yuri Ishizu
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/02/2012 Português
Relevância na Pesquisa
66.47%
Dados do Laboratório de Estudo do Estresse revelaram que a produção de lactato por adipócitos isolados de tecido adiposo visceral de humanos eutróficos e obesos mórbidos está sob estímulo de adrenoceptores ?1. Observou-se também hiperlactatemia no jejum de obesos mórbidos, aumento na liberação de lactato e na lipólise basal e estimulada em adipócitos viscerais isolados destes indivíduos, comparados com eutróficos. Porém dados de nosso laboratório e da literatura sugerem uma relação antagônica entre lipólise e lactatogênese, da qual participa o receptor GPR81, o qual está envolvido com lactato, inibindo a lipólise. Dados da literatura também sugerem a supressão da lipogênese e maior lipólise basal e estimulada dos adipócitos de obesos, com aumento da expressão da aquaporina 7, pelo qual o glicerol gerado na lipólise, é liberado. Por outro lado, estudos da literatura relatam a ocorrência da reesterificação dos produtos liberados após a lipólise de triacilgliceróis (TAGs) no tecido adiposo, na obesidade. Possivelmente, este seria o processo que promoveria a manutenção de grandes estoques de TAGs no tecido adiposo, apesar da maior lipólise e menor lipogênese. Frente aos nossos dados funcionais e os presentes na literatura sobre tecido adiposo visceral na obesidade...

O efeito do treinamento físico sobre a resistência à insulina em animais tratados com dieta hiperlipídica : modulações de fatores inflamatórios sobre o tecido adiposo branco e marrom de ratos Wistar; The effect of exercise training on insulin resistance in animals treated with high-fat diet : modulation on inflammatory factors over white and brown adipose tissue of rats Wistar

Juliana Paula Leite
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/04/2014 Português
Relevância na Pesquisa
66.49%
A obesidade representa o maior fator de risco para o desenvolvimento de doenças como diabetes tipo 2, dislipidemia, esteatose hepática, doenças vasculares e alguns tipos de cânceres. Embora o aumento do tecido adiposo seja a principal característica da obesidade, nem todo depósito de gordura é prejudicial. Isso se deve ao fato do tecido adiposo ser subdividido em dois tipos: branco e marrom, os quais apresentam características bem distintas. O tecido adiposo branco estoca energia na forma de triglicerídeos, produz a secreção de vários tipos de citocinas inflamatórias e o seu aumento está associado a um estado inflamatório subclínico do organismo. Já o tecido adiposo marrom é especializado na dissipação da energia em forma de calor, estudos vêm mostrando a sua associação com a melhora da resistência à insulina e menor índice de massa corporal, por isso, o seu aumento pode ser potencial alvo para o tratamento de síndromes metabólicas. Paralelamente, estudos comprovaram que o exercício físico, quando praticado de forma crônica, pode exercer importante efeito anti-inflamatório nos obesos. Este efeito está associado à redução da massa de tecido adiposo branco e estudos comprovaram que o exercício também é capaz de promover o aumento da massa do tecido adiposo marrom. No entanto...

Regulation of adrenergic system in adipose tissue in obesity; Regulação do sistema adrenérgico no tecido adiposo na obesidade

Cabral, André Morais Sarmento Borges
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Português
Relevância na Pesquisa
66.41%
The prevalence of obesity is dramatically increasing worldwide, and is associated with an increased risk of cardiovascular disease and metabolic disorders. Adipose tissue is recognized as a major endocrine and secretory organ, producing a variety of adipokines which modulate energy homeostasis, lipid physiology, inflammation and immune function. It has been recently highlighted that the pattern of adipose tissue distribution (visceral or subcutaneous) might be a predictive of health risk. Visceral obesity is considered to be more pro-inflammatory and more strongly associated with cardiometabolic risk. The catecholamines (CA), adrenaline (AD) and noradrenaline (NA) are the major regulators of lipidic metabolism in adipocytes, also affecting the differentiation and proliferation of these cells and the secretion of adipokines. The recent finding that adipocytes are able to produce CA opens a new perspective about the role of these amines in obesity. The aim of this study was to investigate the localization and expression of two of the most important enzymes involved in CA synthesis, tyrosine hydroxylase (TH) and phenylethanolamine N-methyltrasnferase (PNMT), in metabolically distinct adipose tissue depots, using C57BL6 mice as dietary-induced obesity model. Two groups of male and female C57BL/6 mice with about 22-23 g were used. During 12 or 16 weeks...

The influence of fasting/refeeding on the lipoprotein lipase activity of adipose tissue and muscle

Botion,L.M.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2001 Português
Relevância na Pesquisa
66.43%
Lipoprotein lipase activity in adipose tissue and muscle is modulated by changes in the pattern of food intake. We have measured total lipoprotein lipase activity in adipose tissue and muscle of male Wistar rats (N = 6-10), weighing 200-250 g (~12 weeks), during the refeeding/fasting state following 24 h of fasting. Lipoprotein lipase activity in tissue homogenates was evaluated using a [³H]-triolein-containing substrate, and released [³H]-free fatty acids were extracted and quantified by liquid scintillation. Adipose tissue lipoprotein lipase activity did not completely recover within 2 h of refeeding (60% of refed ad libitum values). Cardiac lipoprotein lipase activity remained increased even 2 h after refeeding (100% of refed ad libitum values), whereas no significant changes were observed in the soleus and diaphragm muscles. Adipose tissue lipoprotein lipase activities were consistently higher than the highest skeletal muscle or heart values. It is therefore likely that adipose tissue, rather than muscle makes the major contribution to triacylglycerol clearance. There was concomitant relatively high lipoprotein lipase activity in both adipose tissue and cardiac muscle during the first few hours of refeeding, therefore cardiac muscle may contribute significantly to triacylglycerol clearance during this period. The results suggest that during fasting...

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

Demircelik,Muhammed Bora; Yilmaz,Omer Caglar; Gurel,Ozgul Malcok; Selcoki,Yusuf; Atar,Inci Asli; Bozkurt,Alper; Akin,Kayihan; Eryonucu,Beyhan
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
Relevância na Pesquisa
66.42%
OBJECTIVE: The aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. METHODS: The study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing <50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≥50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. RESULTS: The average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness...

Brown adipose tissue

Townsend, Kristy L; Tseng, Yu-Hua
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.4%
Obesity is currently a global pandemic, and is associated with increased mortality and co-morbidities including many metabolic diseases. Obesity is characterized by an increase in adipose mass due to increased energy intake, decreased energy expenditure, or both. While white adipose tissue is specialized for energy storage, brown adipose tissue has a high concentration of mitochondria and uniquely expresses uncoupling protein 1, enabling it to be specialized for energy expenditure and thermogenesis. Although brown fat was once considered only necessary in babies, recent morphological and imaging studies have provided evidence that, contrary to prior belief, this tissue is present and active in adult humans. In recent years, the topic of brown adipose tissue has been reinvigorated with many new studies regarding brown adipose tissue differentiation, function and therapeutic promise. This review summarizes the recent advances, discusses the emerging questions and offers perspective on the potential therapeutic applications targeting this tissue.

The effect of obesity on the ratio of type 3 17b-hydroxysteroid dehydrogenase mRNA to cytochrome P450 aromatase mRNA in subcutaneous abdominal and intro-abdominal adipose tissue of women

Corbould, A.; Bawden, M.; Lavranos, T.; Rodgers, R.; Judd, S.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
Relevância na Pesquisa
66.48%
OBJECTIVES: To investigate (1) whether type 3 17beta-hydroxysteroid dehydrogenase (17beta-HSD), the enzyme which catalyzes the conversion of androstenedione to testosterone in the testis, is co-expressed with P450aromatase in the preadipocytes of women, and (2) whether the relative expression of type 3 17beta-HSD and aromatase varies in subcutaneous abdominal vs intra-abdominal adipose tissue of women. SUBJECTS: Subcutaneous abdominal and intra-abdominal adipose tissue was obtained from women undergoing elective abdominal surgery (age 22-78 y, body mass index (BMI) 22.4-52.9 kg/m(2)). MEASUREMENTS: Expression of type 3 17beta-HSD in adipose cell fractions was determined using RT-PCR. Preadipocyte steroidogenesis was investigated in primary cultures using androstenedione as substrate. Messenger RNA levels for type 3 17beta-HSD and aromatase were measured in adipose tissue from the subcutaneous abdominal and intra-abdominal depots using a quantitative multiplex competitive RT-PCR assay. RESULTS: Type 3 17beta-HSD is co-expressed with aromatase in the abdominal preadipocytes of women. Cultured preadipocytes from both subcutaneous abdominal (n=5) and intra-abdominal (n=5) sites converted androstenedione to testosterone, and there was minimal conversion of androstenedione to estrone. Consistent with this...

Prolactin receptor gene expression and foetal adipose tissue

Symonds, M.; Phillips, I.; Anthony, R.; Owens, J.; McMillen, I.
Fonte: BLACKWELL SCIENCE LTD Publicador: BLACKWELL SCIENCE LTD
Tipo: Artigo de Revista Científica
Publicado em //1998 Português
Relevância na Pesquisa
66.47%
We have investigated the effects of increasing gestational age, maternal undernutrition or restricted placental growth on prolactin receptor (PRLR) gene expression in perirenal adipose tissue collected from foetal sheep during late gestation (term=147 d±3 d of gestation). Foetal nutrient supply was reduced by either restriction of placental growth following removal of endometrial caruncles before mating or by reducing maternal feed intake by 50% from 115 d of gestation. Total RNA was extracted from adipose tissue taken from foetal sheep between 90 and 145 d of gestation, and only at 141–145 d in placentally restricted, nutrient restricted and control foetuses. Messenger RNAs encoding the long (PRLR1) and short (PRLR2) forms of the PRLR and glyceraldehyde-phosphate-dehydrogenase (GAPDH) were detected and quantified in a ribonuclease protection assay using an antisense RNA probe complementary to ovine PRLR2 and GAPDH. There was a 7.5-fold increase in the amount of perirenal adipose tissue between 90 and 125 d of gestation, compared with a 1.3-fold increase between 125 and 145 d of gestation. The abundance of mRNA encoding PRLR1 and PRLR2 in perirenal adipose tissue increased 10- and sixfold, respectively, between 90 and 125 d of gestation...

Validation of cardiovascular magnetic resonance assessment of pericardial adipose tissue volume

Nelson, A.; Worthley, M.; Psaltis, P.; Carbone, A.; Dundon, B.; Duncan, R.; Piantadosi, C.; Lau, D.; Sanders, P.; Wittert, G.; Worthley, S.
Fonte: Marcel Dekker Inc Publicador: Marcel Dekker Inc
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
Relevância na Pesquisa
66.45%
Background Pericardial adipose tissue (PAT) has been shown to be an independent predictor of coronary artery disease. To date its assessment has been restricted to the use of surrogate echocardiographic indices such as measurement of epicardial fat thickness over the right ventricular free wall, which have limitations. Cardiovascular magnetic resonance (CMR) offers the potential to non-invasively assess total PAT, however like other imaging modalities, CMR has not yet been validated for this purpose. Thus, we sought to describe a novel technique for assessing total PAT with validation in an ovine model. Methods 11 merino sheep were studied. A standard clinical series of ventricular short axis CMR images (1.5T Siemens Sonata) were obtained during mechanical ventilation breath-holds. Beginning at the mitral annulus, consecutive end-diastolic ventricular images were used to determine the area and volume of epicardial, paracardial and pericardial adipose tissue. In addition adipose thickness was measured at the right ventricular free wall. Following euthanasia, the paracardial adipose tissue was removed from the ventricle and weighed to allow comparison with corresponding CMR measurements. Results There was a strong correlation between CMR-derived paracardial adipose tissue volume and ex vivo paracardial mass (R2 = 0.89...

Rosiglitazone increases the expression of peroxisome proliferator-activated receptor-γ target genes in adipose tissue, liver, and skeletal muscle in the sheep fetus in late gestation; Rosiglitazone increases the expression of peroxisome proliferator-activated receptor-gamma target genes in adipose tissue, liver, and skeletal muscle in the sheep fetus in late gestation

Muhlhausler, B.; Morrison, J.; McMillen, I.
Fonte: Endocrine Soc Publicador: Endocrine Soc
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
Relevância na Pesquisa
66.44%
Exposure to maternal overnutrition increases the expression of peroxisome proliferator-activated receptor-γ (PPARγ) in adipose tissue before birth, and it has been proposed that the precocial activation of PPARγ target genes may lead to increased fat deposition in postnatal life. In this study, we determined the effect of intrafetal administration of a PPARγ agonist, rosiglitazone, on PPARγ target gene expression in fetal adipose tissue as well indirect actions of rosiglitazone on fetal liver and skeletal muscle. Osmotic pumps containing rosiglitazone (n = 7) or vehicle (15% ethanol, n = 7) were implanted into fetuses at 123–126 d gestation (term = 150 ± 3 d gestation). At 137–141 d gestation, tissues were collected and mRNA expression of PPARγ, lipoprotein lipase (LPL), adiponectin, and glycerol-3-phosphate dehydrogenase (G3PDH) in adipose tissue, PPARα and PPARγ-coactivator 1α (PGC1α) in liver and muscle and phosphoenolpyruvate carboxykinase (PEPCK) in liver determined by quantitative real-time RT-PCR. Plasma insulin concentrations were lower in rosiglitazone-treated fetuses (P < 0.02). Rosiglitazone treatment resulted in increased expression of LPL and adiponectin mRNA (P < 0.01) in fetal adipose tissue. The expression of PPARα mRNA in liver (P < 0.05) and PGC1α mRNA (P < 0.02) in skeletal muscle were also increased by rosiglitazone treatment. Rosiglitazone treatment increased expression of PPARγ target genes within fetal adipose tissue and also had direct or indirect actions on the fetal liver and muscle. The effects of activating PPARγ in fetal adipose tissue mimic those induced by prenatal overnutrition...

Cardiovascular magnetic resonance of total and atrial pericardial adipose tissue: A validation study and development of a 3 dimensional pericardial adipose tissue model

Mahajan, R.; Kuklik, P.; Grover, S.; Brooks, A.; Wong, C.; Sanders, P.; Selvanayagam, J.
Fonte: Marcel Dekker Inc Publicador: Marcel Dekker Inc
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
Relevância na Pesquisa
66.46%
BACKGROUND Recently pericardial adipose tissue (PAT) has been shown to be an independent predictor of atrial fibrillation (AF). Atrial PAT may influence underlying atrial musculature creating a substrate for AF. This study sought to validate the assessment of total and atrial PAT by standard cardiovascular magnetic resonance (CMR) measures and describe and validate a three dimensional atrial PAT model. METHODS 10 merino cross sheep underwent CMR using a 1.5 Tesla system (Siemens, Sonata, Erlangen, Germany). Atrial and ventricular short axis (SA) images were acquired, using ECG -gated steady state free precession sequences. In order to quantify total volume of adipose tissue, a three dimensional model was constructed from consecutive end-diastolic images using semi-automated software. Regions of adipose tissue were marked in each slice followed by linear interpolation of pixel intensities in spaces between consecutive image slices. Total volume of adipose tissue was calculated as a total volume of the three dimensional model and the mass estimated from volume measurements. The sheep were euthanized and pericardial adipose tissue was removed and weighed for comparison to the corresponding CMR measurements. RESULTS All CMR adipose tissue estimates significantly correlated with autopsy measurements (ICC > 0.80; p < 0.03). Intra- observer reliability in CMR measures was high...

Untersuchung der Bedeutung des viszeralen Fettgewebes für die endotheliale Funktion bei Menschen mit erhöhtem Risiko für Diabetes mellitus Typ 2; The importance of visceral adipose tissue mass reduction for improving endothelial function in type 2 diabetes prone individuals

Hieronimus, Anja
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
Relevância na Pesquisa
66.47%
Obesity is an accepted risk factor for cardiovascular disease because of its many associated metabolic diseases (insulin resistance, hyperglycaemia, hypertriglyceridemia, dyslipoproteinemia, arterial hypertension, hyperuricemia etc.). Within the last years, research results showed that body weight alone is of only limited value for cardiovascular morbidity, even if the Body Mass Index (BMI) is determined that also takes account of the height. Against this background, the importance of body fat distribution and particularly the importance of visceral adipose tissue mass become potentially significant. Recent research data postulate an increased cardiovascular risk for visceral obesity compared with increased subcutaneous adipose tissue mass caused by increased expression and secretion of pro-inflammatory cytokines in visceral adipose tissue. On that assumption we performed a prospective intervention study to prove that reducing visceral adipose tissue mass is essential for improving endothelial function - as an early marker of atherogenesis – and for reducing systemic inflammation. Analyses were done in 189 individuals (age: 45.5 ± 0,8 years) at increased risk of type 2 diabetes (obesity, impaired glucose tolerance or positive family history). Endothelial function expressed as flow mediated dilation (FMD) of the brachial artery was measured by high resolution ultrasound (13 MHz). Further the vascular adhesion molecules sE-selectin...

Do adipose tissue macrophages promote insulin resistance or adipose tissue remodelling in humans?

Heilbronn, L.K.; Liu, B.
Fonte: De Gruyter Publicador: De Gruyter
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
Relevância na Pesquisa
66.42%
In diet induced and genetically obese rodent models, adipose tissue is associated with macrophage infiltration, which promotes a low grade inflammatory state and the development of insulin resistance. In humans, obesity is also closely linked with macrophage infiltration in adipose tissue, a pro-inflammatory phenotype and insulin resistance. However, whether macrophage infiltration is a direct contributor to the development of insulin resistance that occurs in response to weight gain, or is a later consequence of the obese state is unclear. There are a number of concomitant changes that occur during adipose tissue expansion, including the number and size of adipocytes, the vasculature and the extracellular matrix. In this review, we will examine evidence for and against the role of macrophage recruitment into adipose tissue in promoting the development of insulin resistance in rodents and humans, as well as discuss the emerging role of macrophages in mediating healthy adipose tissue expansion during periods of caloric excess.; Leonie K. Heilbronn and Bo Liu

Metabolic programming of adipose tissue structure and function in male rat offspring by prenatal undernutrition

Thompson, N.; Huber, K.; Beduerftig, M.; Hansen, K.; Miles-Chan, J.; Breier, B.H.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
Relevância na Pesquisa
66.46%
BACKGROUND: A number of different pathways to obesity with different metabolic outcomes are recognised. Prenatal undernutrition in rats leads to increased fat deposition in adulthood. However, the form of obesity is metabolically distinct from obesity induced through other pathways (e.g. diet-induced obesity). Previous rat studies have shown that maternal undernutrition during pregnancy led to insulin hyper-secretion and obesity in offspring, but not to systemic insulin resistance. Increased muscle and liver glycogen stores indicated that glucose is taken up efficiently, reflecting an active physiological function of these energy storage tissues. It is increasingly recognised that adipose tissue plays a central role in the regulation of metabolism and pathophysiology of obesity development. The present study investigated the cell size and endocrine responsiveness of subcutaneous and visceral adipose tissue from prenatally undernourished rats. We aimed to identify whether these adipose tissue depots contribute to the altered energy metabolism observed in these offspring. METHODS: Adipocyte size was measured in both subcutaneous (ScAT) and retroperitoneal adipose tissue (RpAT) in male prenatally ad libitum fed (AD) or prenatally undernourished (UN) rat offspring. Metabolic responses were investigated in adipose tissue explants stimulated by insulin and beta3 receptor agonists ex vivo. Expression of markers of insulin signalling was determined by Western blot analyses. Data were analysed by unpaired t-test or Two Way ANOVA followed by Fisher's PLSD post-hoc test...

Matrix-Derived Microcarriers for Adipose Tissue Engineering

TURNER, ALLISON EUGENIA BOGART
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
66.42%
In vivo, adipose tissue demonstrates only a limited capacity for self-repair, and the long-term treatment of subcutaneous defects remains an unresolved clinical problem. With the goal of regenerating healthy tissues, many tissue-engineering strategies have pointed to the potential of implementing three-dimensional (3-D), cell-seeded scaffolds for soft tissue augmentation and wound healing. In particular, microcarriers have shown promise as both cell expansion substrates and injectable cell-delivery vehicles for these applications. However, limited research has investigated the engineering of tissue-specific microcarriers, designed to closely mimic the native extracellular matrix (ECM) composition. In this work, methods were developed to fabricate microcarriers from decellularized adipose tissue (DAT) via non-cytotoxic protocols. Characterization by microscopy confirmed the efficacy of the fabrication protocols in producing stable beads, as well as the production of a microporous surface topography. The mean bead diameter was 934 ± 51 μm, while the porosity was measured to be 29 ± 4 % using liquid displacement. Stability and swelling behavior over 4 weeks indicated that the DAT-based microcarriers were effectively stabilized with the non-cytotoxic photochemical crosslinking agent rose bengal...

Human periprostatic adipose tissue promotes prostate cancer aggressiveness in vitro

Ribeiro, Ricardo; Monteiro, Cátia; Cunha, Virgínia; Oliveira, Maria José; Freitas, Mariana; Fraga, Avelino; Príncipe, Paulo; Lobato, Carlos; Lobo, Francisco; Morais, António; Silva, Vítor; Sanches-Magalhães, José; Oliveira, Jorge; Pina, Francisco;
Fonte: BioMed Central Ltd Publicador: BioMed Central Ltd
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.48%
Background - Obesity is associated with prostate cancer aggressiveness and mortality. The contribution of periprostatic adipose tissue, which is often infiltrated by malignant cells, to cancer progression is largely unknown. Thus, this study aimed to determine if periprostatic adipose tissue is linked with aggressive tumor biology in prostate cancer. Methods - Supernatants of whole adipose tissue (explants) or stromal vascular fraction (SVF) from paired fat samples of periprostatic (PP) and pre-peritoneal visceral (VIS) anatomic origin from different donors were prepared and analyzed for matrix metalloproteinases (MMPs) 2 and 9 activity. The effects of those conditioned media (CM) on growth and migration of hormone-refractory (PC-3) and hormone-sensitive (LNCaP) prostate cancer cells were measured. Results - We show here that PP adipose tissue of overweight men has higher MMP9 activity in comparison with normal subjects. The observed increased activities of both MMP2 and MMP9 in PP whole adipose tissue explants, likely reveal the contribution of adipocytes plus stromal-vascular fraction (SVF) as opposed to SVF alone. MMP2 activity was higher for PP when compared to VIS adipose tissue. When PC-3 cells were stimulated with CM from PP adipose tissue explants...

Impact of weight reduction on pericardial adipose tissue and cardiac structure in patients with atrial fibrillation

Abed, H.S.; Nelson, A.J.; Richardson, J.D.; Worthley, S.G.; Vincent, A.; Wittert, G.A.; Leong, D.P.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
Relevância na Pesquisa
66.42%
BACKGROUND: Obesity and pericardial adipose tissue are independent risk factors for atrial fibrillation (AF) and adverse cardiac structural remodeling. The effect of weight reduction on pericardial adipose tissue and cardiac structure remains unknown. METHODS: We prospectively performed cardiac magnetic resonance imaging on 87 participants with AF undergoing either structured weight management (intervention) or general lifestyle advice (control). We measured pericardial adipose tissue, atrial and ventricular volumes, and myocardial mass at baseline and 12 months. RESULTS: In total, 69 participants underwent baseline and 12-month follow-up cardiac magnetic resonance imaging (intervention n = 36 and controls n = 33). From baseline to 12 months, weight loss (kg, mean [95% CI]) was greater in the intervention group from 101.5 kg (97.2-105.8 kg) to 86.5 kg (81.2-91.9 kg) as compared with controls from 102.6 kg (97.2-108.1 kg) to 98.7 kg (91.0-106.3 kg) (time-group interaction P < .001). The intervention group showed a reduction in left atrial volumes (mL) from 105.0 mL (98.9-111.1 mL) to 96.4 mL (91.6-101.1 mL), whereas the change in the control group was from 108.8 mL (99.6-117.9 mL) to 108.9 mL (99.8-118.0 mL) (time-group interaction P < .001). There was a decline in pericardial adipose tissue (cm(3)) from 140.9 cm(3) (129.3-152.4 cm(3)) to 118.8 cm(3) (108.1-129.6 cm(3)) and myocardial mass (g) from 137.6 g (128.1-147.2 g) to 123.1 g (114.5-131.7 g) in the intervention group...