Abstract 655: Endovascular Injury Affects Adipocytokine Profile of the Periadventitial Adipose Tissue
Background: It is well known that adipose tissue secretes not only inflammatory cytokines but also anti-inflammatory cytokines such as adiponectin. Arteries are surrounded by abundant periadventitial fat tissues, which have been suggested to play a role in maintenance of vascular homeostasis. Here, we investigated whether endovascular injury affects the profile of adipocytokines expressed by perivascular adipose tissue.
Methods and Results: First, the femoral artery of male C57BL/6 mice was overstretched by insertion of a large wire. Total RNA was isolated from the perivascular adipose tissues of the injured and uninjured arteries 1 day after overstretch. Real-time PCR analysis revealed that wire mediated injury markedly down-regulated adiponectin expression (0.64±0.09 fold, p<0.01) and up-regulated expression of IL-6, PAI, and MCP-1. A transmission electron microscopic observation revealed that vascular injury increased the pool of cytosolic lipid droplets and mitochondria in perivascular adipocyte, suggesting more differentiation and proliferation of adipocyte. Second, the iliac artery of Wistar rats was dilated percutaneously with a balloon for 1 minute. There were up-regulation of MCP-1 and down-regulation of adiponectin 1 day after endovascular injury. Third, abdominal aortas removed from Wistar rat with perivascular adipose were dilated with a balloon PTCA catheter for 1 minute ex vivo. After stretching, arteries with perivascular adipose tissue were cultured for 6 hours, and we observed increased synthesis of proinflammatory cytokines and decreased synthesis of adiponectin within perivascular tissue around the stretched arteries.
Conclusions: Angioplasty may induce the changes of perivascular cytokines expression and adipocyte morphology. Increased proinflammatory cytokines and decreased anti-inflammatory cytokine adiponectin in perivascular tissue possibly may have a role in vascular remodeling following balloon-mediated vascular injury.