Adipokines and Adipose Tissue Angiogenesis in Obesity

Initially described as an inert fat store, adipose tissue (AT) has been extensively studied in recent years and shown to have multifaceted roles in appetite regulation, vascular homeostasis, energy balance and systemic inflammation in chronic diseases. Composed mainly of adipocytes and stromal vascular fraction (SVCs), comprising preadipocytes, macrophages, mesenchymal stem cells (MSCs), T cells, B cells, mast cells and endothelial progenitor cells (EPCs), AT performs an endocrine role in secretion of growth factors and cytokines (termed adipocytokines). AT is extensively vascularized and, as in other tissues and organs, the growth and maintenance of AT is critically dependent on angiogenic processes. The microvasculature network surrounding the adipocytes provides efficient pathways for crosstalk with the surrounding environment. AT undergoes constant expansion and shrinkage during its entire life span. To cope with this increased metabolic demand during expansion, AT vasculature undergoes extensive remodelling, and changes to vessel density are observed. To facilitate these processes, AT secretes angiogenic/growth factors. Dysregulation in the secretion of these factors is known to play an important role in obesity and insulin-resistant states. In this article we will discuss novel therapeutic strategies to combat obesity and inflammation by inducing changes to the AT vascular network.