Expression of TGF-β1 and β3 but not apoptosis factors relates to flow-induced aortic enlargement

Background Cell proliferation and apoptosis are both involved in arterial wall remodeling. Increase in blood flow induces arterial enlargement. The molecular basis of flow-induced remodeling in large elastic arteries is largely unknown.Methods An aortocaval fistula (ACF) model in rats was used to induce enlargement in the abdominal aorta. Aortic gene expression of transforming growth factors beta (TGF-beta) and apoptosis-related factors was assessed at 1 and 3 days and 1, 2, 4, and 8 weeks. Expression levels were determined using a ribonuclease protection assay and western blotting. Cell proliferation and apoptosis were analyzed using BrdU incorporation and TUNEL techniques.Results Blood flow increased 5-fold immediately after ACF (PConclusions Gene expression of TGF-beta1 and beta3 precedes arterial enlargement. Expression of apoptosis related factors is little regulated in the early stage of the flow-induced arterial remodeling.