Abstract 11373: Computational Approach in Target Discovery and Its Validation: In Search for Inhibitors of Vascular Calcification

Abstract

Introduction: Vascular calcification is cardiovascular disorder which has no therapeutic options. We previously reported that O-octanoyltransferase (CROT) suppression can inhibit calcification in vivo and in vitro through ameliorating mitochondrial function and fatty acid metabolism. Hypothesis: Small molecule compound inhibiting calcification via CROT-associated mechanisms will be excellent candidate for non-invasive treatment of vascular calcification. Here we used a computational approach to identify existing drugs that can inhibit vascular calcification through CROT. Methods: For screening of the compounds that reduce CROT expression, we utilized L1000 computational platform, which contains gene expression profiles in various cell lines and substances. We identified and tested 17 compounds in human primary smooth muscle cells (hSMCs) treated with calcification inducing osteogenic media. Niclosamide, an FDA-improved anthelminthic drug, inhibited calcification along with reduced CROT mRNA expression. To validate this compound in vivo , oral doses of Niclosamide (0 or 750 ppm admixed with diet) were given to Ldlr-deficient mice fed with high fat diet for 10 weeks. At sacrifice, the aortic calcification was visualized and quantified using optical molecular imaging employing near-infrared calcium tracer (Osteosense680) and then examined by histopathology. Samples from the aorta were collected to perform proteomics analysis at intermittent and terminal time points. Results: Molecular imaging and histological analyses of mouse aortas showed significant decrease of calcification after 10 weeks of Niclosamide treatment. Niclosamide improved fatty liver changes with decreased cholesterol levels in the liver along with decreased CROT expression, while plasma total cholesterol levels did not change. Proteomics analysis showed that lipid metabolism and transportation of fatty acid or cholesterol were increased with AMPK or Wnt pathways alteration. Conclusions: We identified a small molecule, which can inhibit calcification in vivo and in vitro with reduced CROT expression. Our computational strategy suggests that repurposing of an “old” drug could present novel treatment for vascular calcification.