Proteomic analysis of podocyte exosome-enriched fraction from normal human urine.

Urine results from a coordinated activity of glomerular and tubular compartments of the kidney. As a footprint of these cellular functional processes, urinary exosomes, and 40-80 nm membrane vesicles released after fusion with the plasma membrane into the extracellular environment by renal epithelial cells, are a source for identification of proteins and investigation of their role in the kidney. The aim of the present study was the identification of podocyte exosome proteins based on urine immunoabsorption using podocyte-specific CR1-immunocoated beads followed by proteomic analysis using LC MS/MS techniques.

Proteomic analysis of a podocyte vesicle-enriched fraction from human normal and pathological urine samples.

Podocytes (glomerular visceral epithelial cells) release vesicles into urine. Podocyte vesicle-enriched fractions from normal and pathological human urine samples were prepared for proteomic analysis. An immunoadsorption method was applied and enrichment of podocyte vesicles was assessed.

Decreased fat mass in interleukin-1 receptor antagonist-deficient mice: impact on adipogenesis, food intake, and energy expenditure.

Interleukin (IL)-1 is a regulator of inflammation but is also implicated in the control of energy homeostasis. Because the soluble IL-1 receptor antagonist (IL-1Ra) is markedly increased in the serum of obese patients and is overexpressed in white adipose tissue in obesity, we studied the metabolic consequences of genetic IL-1Ra ablation in mice. We have shown that IL-1Ra-/- mice have a lean phenotype due to decreased fat mass, related to a defect in adipogenesis and increased energy expenditure.

Production of chemokines by perivascular adipose tissue: a role in the pathogenesis of atherosclerosis?

Objective: Obesity is associated with an increased risk for cardiovascular disease. Although it is known that white adipose tissue (WAT) produces numerous proinflammatory and proatherogenic cytokines and chemokines, it is unclear whether adipose-derived chemotactic signals affect the chronic inflammation in atherosclerosis.

Methods And Results: Histological examination showed that perivascular WAT (pWAT) is in close proximity to vascular walls, particularly at sites that have a tendency to develop atherosclerosis.

Adipose tissue is a regulated source of interleukin-10.

White adipose tissue (WAT) is the source of pro- and anti-inflammatory cytokines and we have recently shown that this tissue is a major source of the anti-inflammatory interleukin (IL)-1 receptor antagonist (IL-1Ra). We now aimed at identifying additional adipose-derived cytokines, which might serve as regulators of IL-1Ra. We demonstrate here for the first time that the antiinflammatory cytokine IL-10 is secreted by human WAT explants and that it is up-regulated by LPS and TNF-alpha in vitro, as well as in obesity in humans (2- and 6-fold increase in subcutaneous and visceral WAT, respectively) and rodents (4-fold increase).

Regulatory effects of interleukin (IL)-1, interferon-beta, and IL-4 on the production of IL-1 receptor antagonist by human adipose tissue.

Adipose tissue is the source of production and site of action of several pro- and antiinflammatory cytokines. We have recently shown that white adipose tissue (WAT) is a major producer of the antiinflammatory IL-1 receptor antagonist (IL-1Ra). Because IL-1Ra serum levels are elevated 7-fold in human obesity and an excess of this protein has been implicated in the acquired resistance to leptin and insulin, we investigated the regulation of IL-1Ra in human WAT.

Adipose tissue is a major source of interleukin-1 receptor antagonist: upregulation in obesity and inflammation.

The secreted form of the interleukin-1 receptor antagonist (IL-1Ra) is an acute-phase protein intervening in the counterregulation of inflammatory processes. We previously showed that this cytokine antagonist is upregulated in the serum of obese patients, correlating with BMI and insulin resistance. In this study, we examined the expression pattern of IL-1Ra and showed that it is highly expressed not only in liver and spleen, but also in white adipose tissue (WAT), where it is upregulated in obesity.