Hyperglycemic Arterial Disturbed Flow Niche as an In Vitro Model of Atherosclerosis

Abstract

Type 2 diabetes significantly elevates the risk of cardiovascular disease. This can be largely attributed to the adverse effects of hyperglycemic conditions on normal endothelial cell (EC) function. ECs in both large and small vessels are influenced by hyperglycemic conditions, which increase susceptibility to EC dysfunction and atherosclerotic lesion formation. Fluid shear stress and flow patterns play an essential role in atherogenesis: lesions form only at locations where fluid flow behavior can be classified as "disturbed flow" (i.e., low shear stress recirculation and/or retrograde flow). Since regions of disturbed flow are the focal points of atherosclerotic cardiovascular disease, we hypothesized that the combinatorial effects of high glucose and disturbed flow conditions elicit significantly different responses from ECs than high glucose alone. To validate our hypothesis, we used our endothelial cell culture model (ECCM) to establish vascular niches associated with "normal" and "disturbed" flow conditions typically seen in vivo along with physiological pressure and stretch. We subjected human aortic endothelial cells (HAECs) to hyperglycemic conditions under both "normal" and "disturbed" flow. Our results confirm significant and quantifiable differences in phenotypic and functional markers between cells cultured under conditions of "normal" and "disturbed flow" under hyperglycemic conditions suggesting that elevated glucose in conjunction with "disturbed" flow conditions results in significantly higher level of EC dysfunction. The ECCM can therefore be used as a physiologically relevant model to study early stage hyperglycemia induced atherosclerosis for basic research, drug discovery, and screening and toxicity studies.

Microfluidic Adaptation of Density-Gradient Centrifugation for Isolation of Particles and Cells

“…Microfluidic devices were fabricated using methods previously established in our laboratory [ 35 ]. Briefly, a 2D layout of the channel architecture was created using AutoCAD layout software (Autodesk, Inc., San Rafael, CA, USA) and printed using a high-resolution printer on a mylar sheet (Fineline Imaging, Colorado Springs, CO, USA).…”

Biomimetic Cardiac Tissue Model Enables the Adaption of Human Induced Pluripotent Stem Cell Cardiomyocytes to Physiological Hemodynamic Loads

“…Cell culture chambers were fabricated using standard soft-lithography using (poly) dimethyl siloxane (PDMS) (Sylgard 184, Dow Corning, Midland, MI) as previously described 28 . Figure 1A shows the cell culture chamber within the BCTM.…”

Glucose-Regulated Protein 78 Autoantibodies Are Associated with Carotid Atherosclerosis in Chronic Obstructive Pulmonary Disease Patients

“…Confocal microscopy showed that GRP78 expression was limited among HAECs cultured in conditions of normal pulsatile flow, whereas this autoantigen was significantly increased by stresses imposed by disturbed flow, as seen at arterial bifurcations ( Fig. 4C-E) (27).…”

“…To establish that the GRP78 autoantigen is present among HAEC, and to explore conditions that might modify production of this autoantigen, we examined GRP78 expression in vascular cells exposed to various stresses. A microfluidic device (27) was used to examine effects of altering culture media flow conditions (Fig. 4A, 4B) on GRP78 expression.…”

“…GRP78 expression on HAECs exposed to stresses of disturbed media flow and UPR induction.Shear stress patterns of normal pulsatile flow (A) or disturbed flow (B) generated inside the microfluidic ECCM chamber(27).Confocal microscopy showed that GRP78 (red stain) on HAECs grown under conditions of normal pulsatile flow was limited (C), in contrast to GRP78 expression on HAECs subjected to stressful conditions that mimic disturbed fluid flows (D) as seen in vascular niches where atherosclerotic plaques tend to develop. Blue stain denotes DAPI.…”