187 Induced Pluripotent Stem Cell (IPSC) Model of Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL)

Abstract

<h3></h3> CADASIL is the most common form of hereditary stroke disorder. Currently no treatment is available to patients, in part, due to a poor understanding of the basic pathological mechanism. CADASIL is caused by stereotyped mutations in NOTCH<i>3</i>, expressed highly in vascular smooth muscle cells (VSMC), pathology therefore is most striking in the VSMC but there is also deficiency in the endothelium ability to sense and respond to shear stress and maintain capillary structures. It is therefore critical to understand cross-talk between these two cell types to grasp the aetiology of CADASIL. Current transgenic murine models do not recapitulate the disease fully and are not amenable to high throughput screening of therapeutic molecules. We have derived multiple CADASIL patient and non-effected sibling (control) iPSC lines. These iPSCs have been characterised for differentiation to the three germ layers, chromosomal normality and presence of the NOTCH<i>3</i> mutation. We have developed highly reproducible, defined differentiation protocols to differentiate multiple pluripotent cell lines to endothelium (iPSC-EC), with 38% efficiency of VE-CADHERIN and PECAM-1 positive cells. We have also developed a differentiation protocol for deriving neuroectroderm-derived VSMCs, with ˜80% efficiency (iPSC-VSMC). The endothelial cells have the ability to form tube like structures<i> in-vitro </i>that can be used to model the capillary structures that commonly degenerate in CADASIL patients. By co-culturing these tube structures with patient and disease iPSC-VSMC we can observe changes in how CADASIL VSMC differentially supports endothelial capillary-like structures. This simple <i>in-vitro </i>model can act as a cellular assay for screening drugs that can restore VSMC function in a high throughput manner. This model can also be used to define early signalling involved in recruitment and cell adhesion between EC-VSMC that may be altered by mutations in<i> NOTCH3</i>.