Abstract 19212: The Zinc-finger Protein 148(zfp148) Attenuates Aortic Aneurysm Formation and is a Novel Smooth Muscle Cell Regulator

Objective: Previously, we found that the zinc-finger protein 148(ZFP148) binds to smooth muscle(SMC) genes following ligation injury; however, it has no known role in aortic aneurysm formation. The study objective was to determine whether ZFP148 is important in AA formation. Methods: ZFP148 was examined via qPCR in human aortic aneurysms(n=12/group). 8-12 week male C57/B6 mice (n=6/group) underwent elastase perfusion and were harvested at 3, 7, and 14 days for qPCR for ZFP148. Separately, 8-12 week male (n=10/group) ZFP flx/flx Myh11 Cre+(SMC tamoxifen ZFP148 KO), Myh11 ZFP148 flx/wt Cre+ and Myh11 ZFP wt/wt Cre+ underwent elastase perfusion. At 14 days, maximal aortic dilation was measured with video micrometry. ZFP148 flx/flx ERT Cre+ (n=10/group) and ZFP148 flx/flx ERT Cre-(WT) mice also underwent elastase perfusion. A separate set of mice were bred to an ApoE-/- background and administered Angiotensin II via osmotic pump. Aortic samples were evaluated with histology for α-actin, macrophages, neutrophils, T lymphocytes, caspase3, Ki67, and elastin. In vitro ZFP148 was knocked down using siRNA in smooth muscle cells and stimulated with elastase, or IL-1β. Results: ZFP148 expression was elevated in human and murine AA. Maximal aortic dilation was significantly reduced in SMC ZFP148 KO mice compared with controls (55.7 ± 6.32% versus 106.4 ± 8.43%, p<0.05). Maximal aortic dilation of ERT Cre+ ZFP148 mice was significantly decreased versus WT controls (50.4± 8.65% versus 101.3± 9.43%, p<0.05). Knock-out of ZFP148 in both elastase models demonstrated reduced macrophage, T-cell, Ki-67, Caspase3 and neutrophil staining. Kaplan-Meier curves demonstrated increased survival in SM-MHC ZFP148 flx/flx (Chi2=4.357, p=0.0421) and flx/wt mice (Chi2=4.169, p=0.0476) compared to their WT controls following Angiotensin II infusion. Knock-down of ZFP148 followed by treatment with elastase or IL-1β in SMCs attenuated the down-regulation of SM22α, SM-MHC, and SMαA. ZFP148 bound via ChIP analysis to SMC marker genes in vitro and in vivo and was found to bind within the proximal promoter region of SmαA and SM22α. Conclusions: ZFP148 KO attenuates AA formation and binds to smooth muscle marker genes. ZFP148 could represent a novel regulator of vascular disease.