Abstract 40: Increased Expression of Transforming Growth Factor-Beta 1 in the Gastrocnemius of Patients with Peripheral Artery Disease is a Localized Response in the Ischemic Muscle

Introduction: Patients with peripheral artery disease (PAD) develop a myopathy in their ischemic lower extremities, which is characterized by myofiber degeneration and myofibrosis. We previously showed that increased expression of transforming growth factor-beta 1 (TGF-β1), which stimulates collagen deposition, is associated with increased fibrosis in PAD gastrocnemius. Expression was localized to the microvasculature, suggesting that elevated TGF-β1 may be a systemic condition rather than a local response in PAD patients. Hypothesis: We hypothesize that increased expression of TGF-β1 in PAD gastrocnemius is a localized response in the ischemic muscle, which contributes to the myofibrosis of PAD. To test this hypothesis, we evaluated TGF-β1 expression and collagen deposition in the gastrocnemius of the diseased and contralateral legs of patients with unilateral PAD. Methods: Gastrocnemius biopsies were collected from both limbs of PAD patients with unilateral disease (n=10). Muscle homogenates were analyz...