Abstract

Human Microphysiological System of Arteriole Scale Blood Vessels for Disease Modeling and Toxicity Testing

George Truskey, R. Eugene and Susie E. Goodson Professor of Biomedical Engineering, Duke University

We have developed an endothelialized tissue engineered blood vessel (eTEBV)  microphysiological system by rapid generation of small-diameter vessels (400-800 µm inner diameter) by plastic compression. For the medial cell layer, we used human neonatal dermal fibroblasts (hNDFs), mesenchymal stem cells (hMSCs), induced pluripotent stem cells (iPSCs), or SMCs derived from hiPSCs. TEBVs were mechanically strong enough to allow endothelialization and perfusion at physiological shear stresses immediately after fabrication.  eTEBVs perfused at physiological shear stresses for 1- 5 weeks expressed von Willebrand factor (vWF) and demonstrated EC-specific release of NO, indicating a confluent layer of ECs. After 1-5 weeks of perfusion, eTEBVs exhibited dose-dependent contraction and relaxation following exposure to phenylephrine and acetylcholine (ACh), respectively. In contrast, TEBVs without ECs or eTEBVs pre-treated with the NO synthase inhibitor L-NG-Nitroarginine methyl ester underwent vasoconstriction in response to ACh consistent with vasodilation by EC release of NO. TEBVs elicited reversible activation by acute stimulation by TNFa which transiently inhibited ACh-induced relaxation, and was eliminated by pre-exposure of eTEBVs to therapeutic doses of statins. Using smooth muscle cells derived from iPSCs, we produced a functional three-dimensional model of Hutchison-Gilford Progeria Syndrome (HGPS) is a rare, accelerated aging disorder caused by an altered form of the lamin A (LMNA) gene termed progerin.  eTEBVs fabricated with smooth muscle cells from individuals with HGPS show reduced vasoactivity, increased medial wall thickness, increased calcification and apoptosis in comparison to eTEBVs fabricated with smooth muscle cells from normal individuals or primary MSCs.  In addition, treatment with the rapamycin analog, RAD001, for one week increases HGPS TEBV vasoactivity.  These results indicate that we can use human eTEBVs to model diseases in vitro. This work was supported by NIH grants UH2TR000505, 4UH3TR000505, and the NIH Common Fund for the Microphysiological Systems Initiative.