Glucose Metabolism and the Response to Insulin by Human Adipose Tissue in Spontaneous and Experimental Obesity

Abstract. Using the tissue culture technique we have recently demonstrated that long-term exposure of human adipose tissue to human growth hormone (GH) in vitro leads to an impairment in glucose incorporation into triglycerides. This effect was further studied in the present investigation. Biopsies of human adipose tissue which had been cultured for one week with or without GH were studied in subsequent short-term incubations where the conversion of glucose to CO2 and to total lipids was determined. The formation of CO2 was not changed by previous exposure of the biopsies to GH whereas the incorporation of glucose into triglycerides was reduced by about one third. Total glucose metabolism, as determined from the sum of the two pathways, was significantly reduced. The activities of three glycolytic enzymes were determined in biopsies of human adipose tissue which had been cultured with or without GH for one week. The activity of phosphofructokinase was reduced, while the hexokinase and the glucose-6-phosphate dehydrogenase activities were unchanged. The diminished activity of phosphofructokinase, the enzyme considered to be rate-limiting for glycolysis in human fat cells, may be responsible for the decreased rate of glucose metabolism found.

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Glucose metabolism in human adipose tissue studied by13C‐glucose and microdialysis

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.1080/00365510600995259 ◽

2007 ◽

Vol 67 (2) ◽

pp. 155-164 ◽

Cited By ~ 11

Author(s):

J. Gustafsson ◽

J. Eriksson ◽

C. Marcus

Keyword(s):

Adipose Tissue ◽

Glucose Metabolism ◽

Human Adipose Tissue

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The effects of bisphenol A and bisphenol S on adipokine expression and glucose metabolism in human adipose tissue

Toxicology ◽

10.1016/j.tox.2020.152600 ◽

2020 ◽

Vol 445 ◽

pp. 152600

Author(s):

Fozia Ahmed ◽

Assel Sarsenbayeva ◽

Petros Katsogiannos ◽

Céline Aguer ◽

Maria J Pereira

Keyword(s):

Adipose Tissue ◽

Glucose Metabolism ◽

Bisphenol A ◽

Human Adipose Tissue ◽

Bisphenol S

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The color of fat and its central role in the development and progression of metabolic diseases

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2017-0060 ◽

2017 ◽

Vol 31 (1) ◽

Cited By ~ 3

Author(s):

Melania Gaggini ◽

Fabrizia Carli ◽

Amalia Gastaldelli

Keyword(s):

Adipose Tissue ◽

Glucose Metabolism ◽

Subcutaneous Adipose Tissue ◽

Metabolic Diseases ◽

Caloric Intake ◽

Human Adipose Tissue ◽

Normal Weight ◽

Metabolic Characteristics ◽

Subcutaneous Adipose

AbstractExcess caloric intake does not always translate to an expansion of the subcutaneous adipose tissue (SAT) and increase in fat mass. It is now recognized that adipocyte type (white, WAT, or brown, BAT), size (large vs. small) and metabolism are important factors for the development of cardiometabolic diseases. When the subcutaneous adipose tissue is not able to expand in response to increased energy intake the excess substrate is stored as visceral adipose tissue or as ectopic fat in tissues as muscle, liver and pancreas. Moreover, adipocytes become dysfunctional (adiposopathy, or sick fat), adipokines secretion is increased, fat accumulates in ectopic sites like muscle and liver and alters insulin signaling, increasing the demand for insulin secretion. Thus, there are some subjects that despite having normal weight have the metabolic characteristics of the obese (NWMO), while some obese expand their SAT and remain metabolically healthy (MHO). In this paper we have reviewed the recent findings that relate the metabolism of adipose tissue and its composition to metabolic diseases. In particular, we have discussed the possible role of dysfunctional adipocytes and adipose tissue resistance to the antilipolytic effect of insulin on the development of impaired glucose metabolism. Finally we have reviewed the possible role of BAT vs. WAT in the alteration of lipid and glucose metabolism and the recent studies that have tried to stimulate browning in human adipose tissue.

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Angiopoietin-Like Protein 4 Overexpression in Visceral Adipose Tissue from Obese Subjects with Impaired Glucose Metabolism and Relationship with Lipoprotein Lipase

International Journal of Molecular Sciences ◽

10.3390/ijms21197197 ◽

2020 ◽

Vol 21 (19) ◽

pp. 7197 ◽

Cited By ~ 2

Author(s):

Ilaria Barchetta ◽

Caterina Chiappetta ◽

Valentina Ceccarelli ◽

Flavia Agata Cimini ◽

Laura Bertoccini ◽

...

Keyword(s):

Adipose Tissue ◽

Glucose Metabolism ◽

Lipoprotein Lipase ◽

Human Adipose Tissue ◽

Normal Glucose Tolerance ◽

Protective Mechanism ◽

Loss Of Function ◽

Adipocyte Size ◽

Abnormal Glucose Metabolism ◽

Size Heterogeneity

Angiopoietin-like protein 4 (ANGPTL4) regulates lipid partitioning by inhibiting circulating and tissue lipoprotein lipase (LPL); ANGPTL4 loss-of-function variants improve insulin sensitivity and reduce type 2 diabetes (T2D) risk with mechanisms partially unknown. This study was designed to explore metabolic implications of differential ANGPTL4 and LPL expression in human adipose tissue (AT). We recruited eighty-eight obese individuals, with and without abnormal glucose metabolism (AGM), undergoing bariatric surgery; visceral AT (VAT) fragments were obtained intra-operatively and analyzed by immunohistochemistry and mRNA by rt-PCR. Data on hepatic ANGPTL4 mRNA were available for 40 participants. VAT ANGPTL4 expression was higher in AGM individuals than in those with normal glucose tolerance (NGT) and associated with VAT inflammation, insulin resistance, and presence of adipocyte size heterogeneity. Increased ANGPTL4 was associated with AGM with OR = 5.1 (95% C.I.: 1.2–23; p = 0.02) and AUROC = 0.76 (95% C.I.: 1.2–23; p < 0.001). High LPL was associated with the detection of homogeneous adipocyte size, reduced microvessel density, and higher HIF-1α levels and inversely correlated to blood transaminases. In conclusion, in obese individuals, VAT ANGPTL4 levels are increased in the presence of local inflammation and AGM. Conversely, higher LPL expression describes a condition of increased lipid storage in adipocytes, which may serve as a protective mechanism against ectopic fat accumulation and related metabolic disease in obesity.

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