Targeted Inhibition of Plasminogen Activator Inhibitor-1 Attenuates Weight Gain and Prevents Vascular Dysfunction Following a High Fat Diet

Introduction: Elevated plasminogen activator inhibitor-1 (PAI-1) is associated with obesity, but there is controversy whether PAI-1 causes or is a consequence of obesity. We sought to determine whether targeted PAI-1 inhibition with a novel small molecule antagonist (TM5441) alters the development of obesity and/or obesity-induced vascular dysfunction in a diet-induced obesity model. Methods and Results: C57BL/6J mice were fed control, high fat diet (HFD), or high fat diet with TM5441 (HFD+TM5441) for 12 weeks. The HFD had marked weight gain (77±5%) as compared with control (32±2%). TM5441 significantly attenuated weight gain (49±8%, p=0.0075, Figure). HFD-induced hepatic triglyceride accumulation was attenuated by TM5441 (116±31 vs. 76±35 mg trig/g liver, p=0.03). Energy expenditure was reduced in the HFD compared to control (11.1±0.4 vs. 12.9±0.4 kcal/h/kg, p=0.005). However, HFD+TM5441 maintained a level of energy expenditure that was similar to control (13.2±0.6 kcal/h/kg, p=NS). The HFD group demonstrated higher systolic and diastolic blood pressure (141±3; 112±3 mm Hg) compared with control (122±7, 94±8; P Conclusions: Inhibition of PAI-1 with TM5441 attenuates weight gain, enhances energy expenditure, and prevents obesity-related vascular dysfunction in a murine model of obesity.