Adipose Tissue

Abstract

Adipose tissue, when carried around in excessive amounts, predisposes to a large number of diseases. Epidemiological data show that the prevalence of obesity has significantly increased over the past 20 years and continues to do so at an alarming rate. Here, some molecular aspects of the key constituent of adipose tissue, the adipocyte, are reviewed. While the adipocyte has been studied for many years and remarkable insights have been gained about some processes, many areas of the physiology of the fat cell remain unexplored. Our understanding of how cellular events in the adipocyte affect the local environment through paracrine interactions and how systemic effects are achieved through endocrine interactions is rudimentary. While storage and release of lipids are major functions of adipocytes, the adipocyte also uses specific lipid molecules for intracellular signaling and uses a host of protein factors to communicate with essentially every organ system in the body. The intensity and complexity of these signals are highly regulated, differ in each fat pad, and are dramatically affected by various disease states. Diabetes 55: 1537-1545, 2006

Physiological and pathophysiological roles of adiponectin and adiponectin receptors in the integrated regulation of metabolic and cardiovascular diseases

“…Genetic studies on single nucleotide polymorphisms of the adiponectin gene, as well as functional analyses, including transgenic or knockout mice suggested that reduced adiponectin levels play a causal role in the development of insulin resistance, metabolic syndrome, diabetes and atherosclerosis. [8][9][10][11] Moreover, human adiponectin mutation analysis 20 led to the identification of HMW adiponectin as the most active form. 21 We then developed an enzyme-linked immunosorbent assay system and showed that measurement of HMW is useful for the prediction of insulin resistance and metabolic syndrome.…”

“…Reduced adiponectin levels can also be caused by lifestyle changes causing obesity, such as a high-fat diet. Both functional [5][6][7] and genetic studies on adiponectin strongly suggest that reduced adiponectin levels play a causal role in the development of insulin resistance, metabolic syndrome, type 2 diabetes and atherosclerosis [8][9][10][11] (Figure 1).…”

Obesity, overweight, and weight gain over adult life are main determinants of elevated hs-CRP in a cohort of Mediterranean women

“…Obesity is associated with increased risk of developing coronary heart disease, stroke, hypertension, type 2 diabetes, and dyslipidemia (Wannamethee et al, 2005;Pérez Pérez et al, 2007). Recently, low-grade inflammation has been considered as a possible new risk factor (Ridker, 2007) associated with obesity and visceral adiposity (Scherer, 2006). Traditional cardiovascular risk factors such as central obesity, high blood pressure, and insulin resistance, especially if components of the metabolic syndrome (MS) have been associated with increased levels of C-reactive protein (CRP), are a marker of low-grade inflammation that may have a major function in the pathogenesis of cardiovascular diseases (Ridker, 2007).…”

Zinc-α2-glycoprotein: an adipokine modulator of body fat mass?

“…[2][3][4][5][6][7] These adipokines, which include leptin, adiponectin, tumor necrosis factor-a (TNFa), interleukin (IL)-6, visfatin and the recently described chemerin, act locally in an autocrine/paracrine manner and/or as endocrine signals to regulate appetite, energy expenditure and a range of other physiological processes such as insulin sensitivity, inflammation, angiogenesis and extracellular matrix remodeling. [8][9][10] In addition, as the largest energy reserve in the body, adipose tissue has a major impact on energy flux, plasma lipid levels and glucose uptake. A large body of evidence indicates that alterations in adipose tissue mass and metabolism have profound effects on whole body energy homeostasis.…”