Adipose Tissue Remodeling, Chronic Inflammation and T-cell-macrophage Interactions in Obesity Visualized by in vivo Molecular Imaging Method

Obese visceral adipose tissue remodeling and dysfunction, based on chronic inflammation and local immunological changes, play major roles in the metabolic syndrome. Therefore, to assess the dynamic interplay between multiple cell types in obese adipose, an in vivo visualization technique was developed. In vivo imaging revealed close spatial and temporal interrelationships between angiogenesis and adipogenesis, which were augmented in obese adipose tissue. In addition, increased leukocyte-platelet-endothelial cell interactions were observed in the microcirculation, a hallmark of inflammation. Upregulated expression of adhesion molecules contribute to local activation of inflammatory processes. We also found that large numbers of CD8+ effector T cells infiltrated into the obese adipose tissue, playing major roles in inflammatory macrophage infiltration into obese adipose tissue, induction and maintenance of inflammation, and systemic insulin resistance. Our results demonstrate the power of our imaging technique to analyze multi-cellular interactions in inflammation in vivo and to evaluate new therapeutic interventions. © 2009, Birkhäuser Verlag, Basel.