The prevalence of diabetes and related cardiovascular complications is dramatically increasing worldwide. Patients with diabetes and glucose intolerance carry up to eight times the risk of cardiovascular events compared to nondiabetic individuals and cardiovascular disease is the largest cause of mortality in this population. Although the molecular mechanisms that underlie the abnormal vascular function in diabetic conditions have been examined in in-vitro and in rodent models, their exact role in collateral vessel formation are largely unknown. The validation and extension of these concepts in studies with large animals and patients is lacking. This understanding is an essential prerequisite to their application in humans. We will induce insulin resistance in Yorkshire pigs with high fat feeding creating a model that recreates many of the metabolic, molecular, and microcirculatory abnormalities present in diabetic patients. Our prior studies and preliminary data show that porcine models of diabetes closely resemble the disease in patients and lead to diminish myocardial and vascular regeneration and we will use the model in this proposal. Our focus is on functional changes in collateral dependent flow, vascular density, and microvascular function together with key molecular events involved in the altered collateral formation process in vivo. We will use mechanistic approach to understand molecular interactions in pathways and networks and functional attributes to unravel the molecular base of impaired angiogenesis in diabetes. Our published and preliminary data suggests for involvement and functional interactions in the hexosamine biosynthetic pathway (HBP), protein O- GlcNAcylation, and insulin signaling. The proposed integrated approach will result in the identification of crucial pathways, molecular targets, and strategies in pro-angiogenic therapy and cell based regeneration and tissue engineering, the clinical importance of this proposal is evident. The use of a large animal model with type 2 diabetes and metabolic syndrome is a strong aspect of the project.
We do not currently understand the basic mechanisms of collateral vessel formation and the reasons for unsuccessful angiogenic and cell therapy clinical trials in patients with severe coronary artery disease. The proposed integrated approach will result in the identification of crucial pathways, molecular targets, and strategies in pro-angiogenic therapy.
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