Interrelation of adipose tissue macrophages and fibrosis in obesity.

Obesity is characterized by adipose tissue expansion, extracellular matrix remodelling and unresolved inflammation that contribute to insulin resistance and fibrosis. Adipose tissue macrophages represent the most abundant class of immune cells in adipose tissue inflammation and could be key mediators of adipocyte dysfunction and fibrosis in obesity. Although macrophage activation states are classically defined by the M1/M2 polarization nomenclature, novel studies have revealed a more complex range of macrophage phenotypes in response to external condition or the surrounding microenvironment.

Localization, traffic and function of Rab34 in adipocyte lipid and endocrine functions.

Background: Excessive lipid accumulation in the adipose tissue in obesity alters the endocrine and energy storage functions of adipocytes. Adipocyte lipid droplets represent key organelles coordinating lipid storage and mobilization in these cells. Recently, we identified the small GTPase, Rab34, in the lipid droplet proteome of adipocytes.

Rab18 Drift in Lipid Droplet and Endoplasmic Reticulum Interactions of Adipocytes under Obesogenic Conditions.

The adipose tissue stores excess energy in the form of neutral lipids within adipocyte lipid droplets (LDs). The correct function of LDs requires the interaction with other organelles, such as the endoplasmic reticulum (ER) as well as with LD coat-associated proteins, including Rab18, a mediator of intracellular lipid trafficking and ER-LD interaction. Although perturbations of the inter-organelle contact sites have been linked to several diseases, such as cancer, no information regarding ER-LD contact sites in dysfunctional adipocytes from the obese adipose tissue has been published to date.

Influence of Protein Carbonylation on Human Adipose Tissue Dysfunction in Obesity and Insulin Resistance.

Background: Obesity is characterized by adipose tissue dysregulation and predisposes individuals to insulin resistance and type 2 diabetes. At the molecular level, adipocyte dysfunction has been linked to obesity-triggered oxidative stress and protein carbonylation, considering protein carbonylation as a link between oxidative stress and metabolic dysfunction. The identification of specific carbonylated proteins in adipose tissue could provide novel biomarkers of oxidative damage related to metabolic status (i.

Understanding the adipose tissue acetylome in obesity and insulin resistance.

Obesity is a widely prevalent pathology with a high exponential growth worldwide. Altered lipid accumulation by adipose tissue is one of the main causes of obesity and exploring lipid homeostasis in this tissue may represent a source for the identification of possible therapeutic targets. The study of the proteome and the post-translational modifications of proteins, specifically acetylation due to its involvement in energy metabolism, may be of great interest to understand the molecular mechanisms involved in adipose tissue dysfunction in obesity.

The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology.

Discovery of the adipose tissue as a major source of signaling molecules almost three decades ago set a novel physiological paradigm that paved the way for the identification of metabolic organs as endocrine organs. Adipocytes, the main adipose tissue cell type, do not only represent the principal site of energy storage in form of triglycerides, but also produce a variety of molecules for short and long distance intercellular communication, named adipokines, which coordinate systemic responses. Although the best known adipokines identified and characterized hitherto are leptin and adiponectin, novel adipokines are continuously being described, what have significantly helped to elucidate the role of adipocyte biology in obesity and associated comorbidities.

Adipose tissue depot-specific intracellular and extracellular cues contributing to insulin resistance in obese individuals.

Adipose tissue dysregulation in obesity strongly influences systemic metabolic homeostasis and is often linked to insulin resistance (IR). However, the molecular mechanisms underlying adipose tissue dysfunction in obesity are not fully understood. Herein, a proteomic analysis of subcutaneous (SC) and omental (OM) fat from lean subjects and obese individuals with different degrees of insulin sensitivity was performed to identify adipose tissue biomarkers related to obesity-associated metabolic disease.