Abstract 397: Perivascular Fat Tissue Plays An Atheroprotective Role In Neointimal Formation After Angioplasty
Background: Obesity is associated with chronic inflammation and increases risk for cardiovascular disease and type 2 diabetes. Recently visceral, as opposed to subcutaneous, fat tissue confers the most cardio-metabolic risk. The aim of the present study is to determine whether perivascular fat tissue contributes to neointimal formation after angioplasty.
Methods and Results: An endovascular injury was induced in the femoral arteries of wild-type mice without or with removal of perivascular adipose tissue. Neointimal area and Neointima/Media ratio were markedly enhanced by removal of perivascular adipose mice (P=0.05). Visceral fat tissue (VAT) or subcutaneous fat tissue (SAT) were harvested from GFP-transgenic mice and transplanted around the injured femoral without endogenous perivascular fat. Neointimal formation was markedly enhanced in the VAT-transplantation group compared with the SAT-transplantation group (P=0.05). Real-time PCR analysis showed that the transplanted VAT had significantly higher proinflammatory cytokines, TNF alpha, IL-6, MCP-1, and PAI-1, mRNA levels than the SAT (P=0.05). Next, the effects of VAT and SAT on smooth muscle cell proliferation were investigated in vitro. Conditioned medium was prepared from extracts of VAT and SAT. Cell proliferation was measured by MTS assay. VAT stimulated smooth muscle cell proliferation compared with SAT (P=0.05).
Conclusions: The present study demonstrates that perivascular adipose tissue protects neointimal formation after angioplasty. VAT stimulates neointimal formation and smooth muscle cell proliferation, probably by secreting proinflammatory cytokines, at least in part. Adipocytokines, particularly secreted from perivascular fat tissue, may play a role in the pathogenesis of neointimal formation after angioplasty.