Peroxisome is a critical organelle for fatty acid oxidation (FAO) and metabolism of reactive oxygen species (ROS). Increased oxidative stress in white adipose tissue (WAT) is crucial for the development of insulin resistance and metabolic syndrome in obesity. The present study aimed to investigate the role of peroxisomal fitness in maintaining adipocyte function. Reduced adipose peroxisomal genes in obesity suggested a close correlation between peroxisomes and obesity. Pex5 siRNA increased cellular ROS and inflammatory mediators in 3T3-L1 adipocytes. On the other hands, H2O2 or TNFα treatment decreased peroxisomal genes. Therefore, a vicious cycle of ROS/inflammation and peroxisomal dysfunction may apparently exacerbate adipose dysfunction. Correspondingly, catalase (a major peroxisomal antioxidant) deficiency mice with high-fat diet exhibited severe oxidative stress, suppressed peroxisomal genes, and accelerated obesity. Fenofibrate, a peroxisomal proliferator, increased peroxisomal biogenesis in wild-type, but not PPAR-α null obese mice. Restoration of peroxisomal fitness was in parallel with attenuated metabolic phenotypes and improved peroxisomal FAO in obese mice. Adipose peroxisomal homeostasis plays an important role in modulating metabolic phenotype of obesity which can be a potential therapeutic target of obesity.

To: 要旨(抄録)