478-P: Accelerating Atherosclerosis by Autoimmune Process in Nonobese Diabetic Mice Made ApoE Deficient by CRISPR/Cas9 Gene Editing

Abstract

Although metabolic risk factors that accelerate atherosclerosis are shared between people with type 1 (T1D) and 2 (T2D) diabetes, it remains unknown whether autoimmunity in T1D contribute to cardiovascular pathologies, which have been reported for other autoimmune diseases. In order to determine the role of autoimmunity with and without overt diabetes, we generated ApoE deficient NOD (ApoE-/--NOD) mice by CRISPR/Cas9 gene editing. The ApoE-/- NOD mice spontaneously developed autoimmune diabetes and atherosclerosis. We also generated congenic ApoE-/--NOD mice that do not carry a protective MHC class II allele (CongNOD), and these mice are prone to atherosclerosis but do not develop insulitis or diabetes to control for the effects of the NOD background independently of autoimmunity. ApoE deficiency in NOD mice was ascertained by PCR and DNA sequencing in both ApoE-/--NOD mice and ApoE-/--CongNOD mice The ApoE protein expression levels in the liver and plasma of ApoE-/--NOD mice was also confirmed by immunoblot analysis and ELISA. Female and male ApoE-/--NOD mice exhibited diabetes frequencies (blood glucoses >500 mg/dL) of 70% and 25%, respectively. Histological analysis of pancreatic islets sections by H&E staining showed peri-insulitis (25%) and insulitis (75%), similar rates as hyperglycemia in NOD mice. Nondiabetic ApoE-/--NOD mice developed more severe atherosclerosis than ApoE-/--CongNOD mice after fed Western diet (6% vs. 1.5% plaque, P<0.01). Preliminary studies showed that greater extent of atherosclerosis was observed in diabetic ApoE-NOD than nondiabetic ApoE-/-NOD mice by 3.2 folds. Total plasma cholesterol (884mg/dL vs. 945mg/dL) and triglyceride (185mg/dL vs. 211mg/dL) levels were high but not significant different between ApoE-/--NOD mice and ApoE-/--CongNOD mice on either a regular diet or WD. These studies indicate that T1D autoimmunity with or without hyperglycemia can exacerbate the development of atherosclerosis. Disclosure K. Park: None. Q. Li: None. H. Wang: None. R. St-Louis: None. H. Yokomizo: None. E. Maddaloni: Speaker's Bureau; Self; Merck & Co., Inc., Pikdare. T. Shinjo: None. J. Fu: None. I. Wu: None. S. Kissler: None. G.L. King: Research Support; Self; Sanofi. Funding Sanofi-Aventis; National Institute of Diabetes and Digestive and Kidney Diseases (R01DK053105-17)