Fibromuscular dysplasia (FMD) is an arteriopathy associated with hypertension, stroke and myocardial infarction, affecting mostly women. We report results from the first genome-wide association meta-analysis of six studies including 1556 FMD cases and 7100 controls. We find an estimate of SNP-based heritability compatible with FMD having a polygenic basis, and report four robustly associated loci (PHACTR1, LRP1, ATP2B1, and LIMA1). Transcriptome-wide association analysis in arteries identifies one additional locus (SLC24A3). We characterize open chromatin in arterial primary cells and find that FMD associated variants are located in arterial-specific regulatory elements. Target genes are broadly involved in mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, central to vascular contraction. We find significant genetic overlap between FMD and more common cardiovascular diseases and traits including blood pressure, migraine, intracranial aneurysm, and coronary artery disease.

Galectin-3 is a galectin with a unique flexible N-terminal tail (NT) connected to the conserved carbohydrate recognition domain (CRD). Galectin-3 is associated with tumor immune tolerance and exhibits an ability to induce T cell apoptosis. We used Jurkat, Jurkat E6-1 and CEM T-cell lines and human peripheral blood mononuclear cells (PBMCs) to investigate the specific roles of the CRD and NT in inducing T cell apoptosis. Galectin-3 triggered sustained extracellular signal-regulated kinase (ERK) phosphorylation that induced apoptosis. ERK was situated upstream of caspase-9 and was independently activated by reactive oxygen species (ROS) and protein kinase C (PKC). The first twelve NT residues had no role in the apoptosis. Residues 13-68 were essential for activating ROS, but did not activate PKC. However, residues 69-110 were required for activation of PKC. An NT fragment and a NT-specific antibody antagonized the apoptosis triggered by full-length galectin-3 further supporting our findings. These findings indicate the CRD and NT play important roles during induction of T cell apoptosis, which suggests their potential as therapeutic targets for reversing cancer immune tolerance.

Spontaneous coronary artery dissection (SCAD) is an understudied cause of myocardial infarction primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Here we present a genome-wide association meta-analysis (1,917 cases and 9,292 controls) identifying 16 risk loci for SCAD. Integrative functional annotations prioritized genes that are likely to be regulated in vascular smooth muscle cells and artery fibroblasts and implicated in extracellular matrix biology. One locus containing the tissue factor gene F3, which is involved in blood coagulation cascade initiation, appears to be specific for SCAD risk. Several associated variants have diametrically opposite associations with CAD, suggesting that shared biological processes contribute to both diseases, but through different mechanisms. We also infer a causal role for high blood pressure in SCAD. Our findings provide novel pathophysiological insights involving arterial integrity and tissue-mediated coagulation in SCAD and set the stage for future specific therapeutics and preventions.

Spontaneous coronary artery dissection (SCAD) is an understudied cause of acute myocardial infarction primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Through a meta-analysis of genome-wide association studies including 1917 cases and 9292 controls of European ancestry, we identified 17 risk loci, including 12 new, with odds ratios ranging from 2.04 (95%CI 1.77-2.35) on chr21 to 1.25 (95%CI 1.16-1.35) on chr4. A locus on chr1 containing the tissue factor gene (F3), which is involved in blood coagulation cascade, appears to be specific for SCAD risk. Prioritized genes were mainly expressed in vascular smooth muscle cells and fibroblasts of arteries and are implicated predominantly in extracellular matrix biology (e.g. COL4A1/A2, HTRA1 and TIMP3). We found that several variants associated with SCAD had diametrically opposite associations with CAD suggesting that shared biological processes contribute to both diseases but through different mechanisms. We also demonstrated an inferred causal role for high blood pressure, but not other CAD risk factors, in SCAD. Our findings provide novel pathophysiological insights involving arterial integrity and tissue-mediated coagulation in SCAD and set the stage for future specific therapeutics and prevention for this disease.