Investigating the Effects of Hutchinson-Gilford Progeria Syndrome Mutation Correction in Tissue-Engineered Blood Vessels - PROJECT SUMMARY Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare, accelerated aging disease caused by a single point mutation (SNP) in the LMNA gene. This mutation results in the production of an aberrant protein called progerin which disrupts proper nuclear function within cells. Patients with HGPS die at an early age most often due to complications from severe atherosclerosis. The progression of this atherosclerosis is not fully understood. Animal models that exclusively express progerin in either vascular smooth muscle (vSMC) or endothelial (EC) cells still exhibit thickening of the vessel adventitia despite no progerin-positive cells in this region. This suggests multiple vascular cell types can influence the same pathological characteristics, possibly through paracrine signaling. Having a better understanding of which cell types within the vasculature contribute most to the fibrosis, calcification, and stiffening that occur during atherosclerosis would be useful in generating more effective, targeted therapies. Treating HGPS has proven difficult, with only one therapy approved for clinical use. Other treatment options have been effective in animal models but have shown only modest benefits in patients. A new genetic engineering therapy using an adenine base editor (ABE) can correct the LMNA point mutation and significantly improved survival in an HGPS mouse model. Understanding what level of mutation correction is required in the vasculature to alleviate pathological features would aid in translating this new technology to the clinic. The goal of this proposal is to use an in vitro human vascular model of HGPS to better understand the influence of different vascular cells on the progression of HGPS-induced atherosclerosis and to estimate what level of mutation correction would be needed to improve the vascular pathology. We hypothesize the adventitial fibroblasts are the primary contributors to vascular fibrosis, calcification, and stiffening in HGPS, and that mutation correction within these cells will effectively reduce these disease characteristics. To test this hypothesis, we will generate a tissue-engineered blood vessel (TEBV) disease model using cells from HGPS patients. In Aim 1, we will determine the relative contributions of fibroblasts, vSMCs, and ECs on HGPS vascular disease by testing different combinations of progerin-expressing cells in the TEBV model and evaluating disease progression. For Aim 2, we will treat HGPS TEBVs with different doses of ABE, delivered by adeno-associated virus, and evaluate editing efficiency in each cell type and progression of atherosclerosis. When completed, these aims will provide a more physiologically relevant human model of HGPS vascular disease for testing new treatments. Additionally, they will improve our understanding of how different vascular cells contribute to HGPS disease progression and to what extent correcting the LMNA mutation within these cells will abate or reverse atherosclerosis. Broadly, this work will also show the utility of using human microphysiological systems to model disease and test the efficacy of new therapeutics.
