生体分子イメージングでみる肥満動物における脂肪組織炎症・免疫異常

In vivo imaging reveals chronic inflammation and abnormal immunity in obese adipose tissue

最近の研究により各種生活習慣病の背景には，慢性炎症を基盤とした異常な細胞間作用が生体内で生じていることが明らかになってきた．筆者らは，一光子・二光子レーザー顕微鏡を用いた“生体分子イメージング手法”を開発した．本手法を肥満脂肪組織に適応したところ，肥満脂肪組織で，脂肪細胞分化・血管新生が空間的に共存して生じ，微小循環では炎症性の細胞動態が生じていた．肥満脂肪組織にはCD8陽性T細胞が存在し肥満・糖尿病病態に寄与していた．

Metabolic syndrome is a major risk factor of cardiovascular events, and obese visceral adipose tissue remodeling and malfunctioning based on chronic inflammation and local immunological changes plays a central role.　To assess dynamic interplay between multiple cell-types in obese adipose, a visualization technique in vivo was therefore developed.　In vivo imaging revealed close spatial and temporal interrelationships between angiogenesis and adipogenesis in obese adipose.　Increased leukocyte-platelet-endothelial cell interactions in the microcirculation of obese adipose were also observed, a hallmark of inflammation.　We also found that large numbers of CD8^＋ effector T cells infiltrated into obese adipose.　CD8^＋ T cells contribute to the macrophage recruitment in obese adipose tissue, and adipose tissues inflammation in obesity.