Project Summary
Vascular calcification is a hallmark of atherosclerotic cardiovascular diseases such as myocardial infarction
and stroke, which are the leading causes of morbidity and mortality in the world. Although coronary artery
calcification (CAC) is a strong independent risk factor for cardiovascular disease, the genetic determinants of
CAC and the molecular mechanisms of vascular calcification remain incompletely elucidated. In a multi-cohort
study with more than 22,000 participants, we identified single nucleotide polymorphisms in the arylsulfatase E
(ARSE) locus that are associated with coronary artery calcification. In an in vitro model of calcification, our
preliminary experiments demonstrated that inhibition of ARSE or a related protein sulfatase 1 (SULF1)
prevented the calcification of coronary and aortic vascular smooth muscle cells (VSMCs). Furthermore, we
found that SULF1-deficient mice are protected from developing vascular calcification. Based on our preliminary
evidence, combining a human genome-wide association study, in vitro VSMC experiments, and an in vivo
murine model of vascular calcification, we have identified ARSE and SULF1 to be novel activators of vascular
calcification. The overall objective of this proposal is to understand the molecular mechanisms by which these
sulfatases promote vascular calcification and atherosclerosis. First, using a series of VSMC functional assays,
we propose to determine the specific role of ARSE and SULF1 in promoting VSMC osteogenic phenotype
switch and calcification. We will also ascertain whether the sulfatases induce the development of vascular
calcification and atherosclerosis in vivo using mouse models. Second, we have uncovered an important role for
ARSE and SULF1 in regulating autophagy and bone morphogenetic protein (BMP) signaling. We will
determine if the effects of ARSE and SULF1 on VSMC-mediated vascular calcification is dependent on their
effects on autophagy and/or BMP signaling. Lastly, we will examine the associations of the ARSE index variant
with a range of electronic health record phenotypes, as well as with additional vascular calcification
phenotypes including aortic calcium volume and density, aortic valve calcification and mitral annular
calcification. Furthermore, we will conduct the first genome-wide association study to identify novel genetic
determinants of coronary calcification density. The experiments proposed will provide important mechanistic
insights into the function of sulfatases in the vasculature and into the underlying molecular and genetic
mechanisms of vascular calcification and atherosclerosis.