The CAD risk locus 9p21 increases the risk of vascular calcification in an iPSC-derived VSMC model

Abstract

Background Coronary artery disease (CAD) is the leading cause of death worldwide. Chromosome locus 9p21 was the first to be associated with increased risk of CAD and coronary artery calcification (CAC). Vascular calcification increases the risk for CAD. Vascular smooth muscle cells (VSMCs) are one of the major cell types involved in the development of vascular calcification. Methods So far, mainly animal models or primary SMCs have been used to model human vascular calcification. In this study, a human in vitro assay using iPSC-derived VSMCs was developed to examine vascular calcification. Human iPSCs were derived from a healthy non-risk (NR) and risk (R) donor carrying SNPs in the 9p21 locus. Additionally, 9p21 locus knockouts of each donor iPSC line (NR and R) were used. Following differentiation, the iPSC-derived VSMCs were characterized based on cell type, proliferation, and migration rate, along with calcium phosphate (CaP) deposits. CaP deposits were confirmed using Calcein and Alizarin Red S staining and then quantified. Results The data demonstrated significantly more proliferation, migration, and CaP deposition in VSMCs derived from the R and both KO iPSC lines than in those derived from the NR line. Molecular analyses confirmed upregulation of calcification markers. These results are consistent with recent data demonstrating increased calcification when the 9p21 murine ortholog is knocked-out. Conclusion Therefore, in conclusion, genetic variation or deletion of the CAD risk locus leads to an increased risk of vascular calcification. This in vitro human iPSC model of calcification could be used to develop new drug screening strategies to combat CAC.

Understanding genomic medicine for thoracic aortic disease through the lens of induced pluripotent stem cells

“…What this also means is that patient-specific differences in disease susceptibility due to genetic background, for example the effect of accompanying SNPs, can be modelled in the absence of the confounding “main” mutation. Several studies have used iPSCs and derived vascular cells—VSMCs, pericytes and ECs—to model a variety of vascular diseases including, pulmonary arterial hypertension ( 112 – 119 ), Hutchison-Gilford progeria ( 120 – 124 ), atherosclerosis ( 47 , 125 , 126 ), neurodegenerative cerebro-vascular conditions like Moyamoya disease ( 127 – 131 ), CADASIL ( 132 – 135 ), diabetes and its associated conditions ( 136 – 138 ).…”

“…Recent studies have highlighted the ability to employ iPSCs-derived cells, genomics, and machine learning-based analysis for predicting risk of occurrences of conditions like arrhythmia and heart failure susceptibility in cardiomyocytes ( 185 , 186 ). Risk loci of coronary artery disease (CAD) ( 125 ) and schizophrenia severity ( 187 ) were also determined using iPSC-derived VSMCs and neurons respectively. In a recent move, single cell multi-omics that combines transcriptomic and epigenetic data has been used to determine the genetic determinants of arrhythmia ( 188 ).…”

Beyond the Basics: Unraveling the Complexity of Coronary Artery Calcification

“…However, the exact DNA sequence that causes CAC and its connection to these SNPs remain unresolved [23]. The role of 9p21 and 6p24 loci in vascular calcification is currently being investigated [92,93].…”

The Genetics of Coronary Artery Disease: A Vascular Perspective

“…Along with genes involved in the cell cycle, DNA replication and repair, those involved with cell adhesion, muscle development and muscle contraction were differentially expressed, suggesting a potentially novel mechanism for CAD risk. Another study adopting a similar strategy to examine the effect of risk and non-risk haplotypes from iPSC-derived VSMCs demonstrated increased proliferation, migration and calcium phosphate deposits in cells harbouring the risk haplotype [ 56 ].…”