Presence of vasculature results in faster insulin response in adipocytes in vascularized adipose tissue model.

Besides being an energy storage, adipose tissue is an endocrine organ closely associated with vascular system. Human relevant in vitro models are needed to study adipose tissue and related diseases. Vasculature plays a central role in the development and inhibition of adipose tissue related diseases. Here, adipocyte culture was established from hASC (human adipose stromal cells), and a vascularized adipose tissue model was established from hASC and HUVEC (human umbilical cord vein endothelial cell) co-culture, utilizing the same differentiation procedure. Using these models together allowed analysis of the effect of vascularization on adipocytes. Adipocyte culture and Vascularized adipose tissue model were characterized on gene (adipocyte and vasculature-related), protein (von Willebrand factor, CollagenIV, CD140b and CD144, secretion of leptin, adiponectin and FABP4) and functional (triglyceride accumulation, glucose uptake and lipolysis) levels. Additionally, vascularized adipose tissue model was exposed to chemicals with known effects on adipogenesis and angiogenesis (rosiglitazone, chlorpyrifos, prochloraz, mancozeb, butylparaben, 15-deoxy-δ12,14-prostaglandin j2, bisphenol a, bis-(2-ethylhexyl) phthalate, tributyltin chloride) to compare their effects to the literature. The in vitro vascularized adipose tissue model showed presence of functional adipocytes and extensive vascular network. Adipocytes and the vasculature showed relevant gene and protein markers. Insulin induced glucose uptake, inhibited lipolysis and influenced vasculature-related genes. The results showed that vasculature led to faster insulin response in lipolysis inhibition and modulated responses to chemicals. This novel thoroughly characterized vascularized adipose tissue model is a promising new tool for studying adipose tissue as well as effect of chemicals on adipogenesis and angiogenesis in adipose tissue.