Generation and Validation of Disease Models for Port-Wine Birthmarks - Project Summary Vascular malformations (VMs) are resulted from developmental abnormalities in vasculatures including veins, arteries, capillaries, and lymphatic vessels. Treatment of VMs is a big challenge due to the large variety of lesion types, complexity of symptoms, and limited interventional options, which results in unsatisfied therapeutic outcomes. Port Wine Birthmarks (PWB) is one of the most common types of VMs. It mainly appears on the face and can be highly associated with Sturge Weber Syndrome (SWS) with brain blood vessels’ involvement and seizure disorders. One long-term obstacle to our understanding of the disease causes of PWB and the therapeutic development for it has been a lack of clinically relevant cell and animal models. In this proposal, we will take advantages of utilizing our current advancements in the generation of PWB-derived induced pluripotent stem cells (IPSCs) and their differentiated lineages such as endothelial cells (ECs) and vascular spheroids/organoids (VSs). VSs derived from PWB show larger diameters, longer lengths, and more tortuous branches as compared to the VSs derived from normal IPSCs. In addition, such vascular phenotypes can be reproduced in vivo after an implantation of spheroids/organoids into the mouse skin. These proof-of-principle and feasibility studies let us propose to develop in vitro and in vivo clinically relevant cell and organoid models derived from PWB patient’s IPSCs and validate them subsequently. For evaluation of in vitro cell and organoid models, we will perform a series of molecular and phenotypic characterizations of ECs and VSs derived from PWB IPSCs as compared to normal IPSCs. Furthermore, next generation sequencing approaches will be used to explore and integrate the molecular, epigenetic, and signaling pathway profiles that underlie the abnormal cell-fate and lineage-specification in PWB. These molecular pathological features will be further validated with PWB skin lesions. For evaluation of the in vivo model, we will implant VSs into skins in mice, monitor and characterize the dynamics of the vasculature formation and remodeling. We will determine the recapitulated PWB pathologies in this in vivo model as compared to the existing data from PWB skin lesions. The project is highly innovative as it aims to develop clinically relevant and paradigm-shift cell and organoid models for mechanistic and therapeutic studies of PWB. The use of patient-derived IPSCs, ECs, and VSs are unprecedented; the data is translational. These models are not only a significant evolution in disease model development for understanding of pathological characteristics of PWB, but also a substantial advancement in development of a novel platform for clinical therapeutic studies.
