Microvascular networks on a chip to investigate how hyperglycemia induces microangiopathy in type 1 diabetes

Key Words: type 1 diabetes, microvasculature, endothelial cells, pericytes, microfluidics, hyperglycemia

Type 1 diabetes is a significant chronic pediatric illness that can lead to multi-organ dysfunction driven by microangiopathy. While hyperglycemia is causative, the mechanisms underlying microvascular disease progression are complex and poorly understood. These include (but are not limited to) induction of cell death, matrix remodeling, upregulation of reactive oxygen species, and activation of the receptor of advanced glycation endproducts. Within the microvasculature, endothelial cells and mural supporting cells known as pericytes establish and maintain microvessel integrity. Despite strong evidence that they are critical in the pathogenesis of microangiopathy in type 1 diabetes, pericytes have been understudied. Because animal models are expensive and may not truly reflect human pathophysiology, new model systems are needed. We have been developing an in vitro microfluidic system that incorporates human endothelial cells and pericytes. Under defined conditions, these vascular cells self-assemble into perfusable microvascular networks that are easily visualized and maintain their 3D orientations. We believe that this is an ideal system to further investigate the microangiopathy of type 1 diabetes. Using new protocols that we have developed, we will quantify microvascular network density and microvessel morphology, ultrastructure, explore cell death, and signaling pathways in hyperglycemia. We will test the effects of pericyte incorporation. We will use advanced microscopy techniques, biochemical assays, and genetic modification of the vascular cells to interrogate our system and test hypotheses. We will take an unbiased approach towards understanding disease pathogenesis by using single cell RNA-seq on cells within the devices after exposure to hyperglycemia. Knowledge gained during the course of proposed experiments will improve our understanding and help us design therapies to prevent or treat microangiopathy of type 1 diabetes in the future.