Coronary artery disease (CAD) results from progression of atherosclerosis in the coronary vessels and is the main cause of death in Sweden and worldwide. Novel treatment strategies for the primary and secondary prevention of CAD are needed, in part because the LDL-lowering drugs prescribed currently increase the risk of diabetes. Genome-wide association studies (GWAS) identified hundreds of genetic loci that are associated with CAD and its risk factors, like LDL cholesterol and triglyceride levels, blood pressure, insulin resistance and diabetes. However, the genes and mechanisms through which the identified loci influence CAD and its risk factors are yet unknown.
The objective of this project is to identify targets that can be translated into efficient therapeutics for prevention and treatment of CAD without adverse side effects. The specific aims are to: 1) identify genes that influence CAD and its risk factors; 2) identify small molecules or biological drugs that have beneficial effects without adverse side effects; 3) identify the mechanisms of action for the most promising genes, compounds and drugs.
My group developed and validated high-throughput, image-based model systems for dyslipidaemia, early-stage atherosclerosis, diabetes, blood pressure and cardiac rhythm in zebrafish larvae. Zebrafish orthologues of the most promising candidate genes in genetic loci associated with CAD and it risk factors are targeted in multiplex using CRISPR-Cas9, in reporter lines with fluorescently labelled transgenes. Together with a dye that labels lipids, these transgenes allow quantification of vascular deposition of lipids, macrophages and neutrophils, ß-cell number, liver size, fat accumulation in liver and adipocytes, and cardiac rhythm. Thanks to an automated positioning system that is mounted on the stage of a fluorescence microscopy, and custom-written image analysis pipelines, these traits can be captured and quantified in >100 offspring (F1) of founder mutants per day, which allows us to efficiently characterise 384 larvae per multiplex of eight targeted genes. Whole body triglyceride, glucose, and LDL, HDL and total cholesterol levels are enzymatically assessed after imaging, followed by sequencing of the CRISPR-Cas9 targeted sites. The most promising putative causal genes - for which mutants show a consistently beneficial (or detrimental) cardiometabolic risk profile - will be used to inform the selection of small molecules or biological drugs that can be taken forward for testing in the same pipelines. The most promising causal genes and compounds will be selected for cell-type specific transcriptomic and metabolomics profiling.
This research program will: a) provide a framework for novel in vivo model systems to identify drug targets and compounds; b) further increase our understanding of CAD pathophysiology; and c) provide a new set of drug targets and small molecules or biological drugs that can be taken forward for additional testing.