Genetic and environmental risk factors for atherosclerosis regulate transcription of phosphatase and actin regulating gene PHACTR1.
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Publication Date
2016-07Journal Title
Atherosclerosis
ISSN
0021-9150
Publisher
Elsevier BV
Volume
250
Pages
95-105
Language
eng
Type
Article
This Version
VoR
Physical Medium
Print-Electronic
Metadata
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Reschen, M. E., Lin, D., Chalisey, A., Soilleux, E., & O'Callaghan, C. A. (2016). Genetic and environmental risk factors for atherosclerosis regulate transcription of phosphatase and actin regulating gene PHACTR1.. Atherosclerosis, 250 95-105. https://doi.org/10.1016/j.atherosclerosis.2016.04.025
Abstract
BACKGROUND AND AIMS: Coronary artery disease (CAD) risk is associated with non-coding genetic variants at the phosphatase and actin regulating protein 1(PHACTR1) gene locus. The PHACTR1 gene encodes an actin-binding protein with phosphatase regulating activity. The mechanism whereby PHACTR1 influences CAD risk is unknown. We hypothesized that PHACTR1 would be expressed in human cell types relevant to CAD and regulated by atherogenic or genetic factors. METHODS AND RESULTS: Using immunohistochemistry, we demonstrate that PHACTR1 protein is expressed strongly in human atherosclerotic plaque macrophages, lipid-laden foam cells, adventitial lymphocytes and endothelial cells. Using a combination of genomic analysis and molecular techniques, we demonstrate that PHACTR1 is expressed as multiple previously uncharacterized transcripts in macrophages, foam cells, lymphocytes and endothelial cells. Immunoblotting confirmed a total absence of PHACTR1 in vascular smooth muscle cells. Real-time quantitative PCR showed that PHACTR1 is regulated by atherogenic and inflammatory stimuli. In aortic endothelial cells, oxLDL and TNF-alpha both upregulated an intermediate length transcript. A short transcript expressed only in immune cells was upregulated in macrophages by oxidized low-density lipoprotein, and oxidized phospholipids but suppressed by lipopolysaccharide or TNF-alpha. In primary human macrophages, we identified a novel expression quantitative trait locus (eQTL) specific for this short transcript, whereby the risk allele at CAD risk SNP rs9349379 is associated with reduced PHACTR1 expression, similar to the effect of an inflammatory stimulus. CONCLUSIONS: Our data demonstrate that PHACTR1 is a key atherosclerosis candidate gene since it is regulated by atherogenic stimuli in macrophages and endothelial cells and we identify an effect of the genetic risk variant on PHACTR1 expression in macrophages that is similar to that of an inflammatory stimulus.
Keywords
Muscle, Smooth, Vascular, Coronary Vessels, Macrophages, Endothelial Cells, Humans, Inflammation, Microfilament Proteins, Lipopolysaccharides, Tumor Necrosis Factor-alpha, Gene Expression Regulation, Genotype, Polymorphism, Single Nucleotide, Alleles, Adult, Aged, Middle Aged, Atherosclerosis, Coronary Artery Disease, Young Adult, Gene-Environment Interaction
Identifiers
External DOI: https://doi.org/10.1016/j.atherosclerosis.2016.04.025
This record's URL: https://www.repository.cam.ac.uk/handle/1810/287125
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