Common coding variant in SERPINA1 increases the risk for large artery stroke

Abstract

Large artery atherosclerotic stroke (LAS) shows substantial heritability not explained by previous genome-wide association studies. Here, we explore the role of coding variation in LAS by analyzing variants on the HumanExome BeadChip in a total of 3,127 cases and 9,778 controls from Europe, Australia, and South Asia. We report on a nonsynonymous single-nucleotide variant in serpin family A member 1 (SERPINA1) encoding alpha-1 antitrypsin [AAT; p.V213A; P = 5.99E-9, odds ratio (OR) = 1.22] and confirm histone deacetylase 9 (HDAC9) as a major risk gene for LAS with an association in the 3′-UTR (rs2023938; P = 7.76E-7, OR = 1.28). Using quantitative microscale thermophoresis, we show that M1 (A213) exhibits an almost twofold lower dissociation constant with its primary target human neutrophil elastase (NE) in lipoprotein-containing plasma, but not in lipid-free plasma. Hydrogen/deuterium exchange combined with mass spectrometry further revealed a significant difference in the global flexibility of the two variants. The observed stronger interaction with lipoproteins in plasma and reduced global flexibility of the Val-213 variant most likely improve its local availability and reduce the extent of proteolytic inactivation by other proteases in atherosclerotic plaques. Our results indicate that the interplay between AAT, NE, and lipoprotein particles is modulated by the gate region around position 213 in AAT, far away from the unaltered reactive center loop (357-360). Collectively, our findings point to a functionally relevant balance between lipoproteins, proteases, and AAT in atherosclerosis.genetics | ischemic stroke | large artery stroke | antitrypsin | variation S troke is the leading cause of long-term disability and the second most common cause of death worldwide (1, 2). About a quarter of ischemic stroke cases are caused by large artery atherosclerotic stroke (LAS) (3, 4). Atherosclerosis is a chronic inflammatory condition that involves a number of well-characterized steps. Initial stages include the deposition of lipids in vascular endothelial cells, whereas more advanced stages are characterized by fibrotic changes with formation of a fibrotic cap and, eventually, plaque rupture (5). LAS exhibits the highest heritability of all stroke subtypes, with estimates ranging from 40.3 to 66.6% (6, 7). This fact is reflected by recent genome-wide association studies that found common variants for LAS at multiple genomic loci (8-10). The lead SNPs from these regions all reside within intergenic (4, 7, 11) or SignificanceCommon single-amino acid variations of proteins are traditionally regarded as functionally neutral polymorphisms because these substitutions are mostly located outside functionally relevant surfaces. In this study, we present an example of a functionally relevant coding sequence variation, which, as we show here, confers risk for large artery atherosclerotic stroke. The singleresidue variation M1(A213V) in serpin family A member 1 (SERPINA1) [encoding alpha-1 antitrypsin (AAT)] is situated outside the...

Preservation with α1-antitrypsin improves primary graft function of murine lung transplants

“…In accordance with our predictions, murine and human neutrophil elastase (NE) and proteinase 3 (PR3) were not inhibited by AAT mt ( Figure 3 B) produced in HEK293 cells, 18 whereas the purified recombinant AAT wt inhibited human and mouse NE and PR3 irreversibly. The sequence modifications of AAT introduced into the reactive center loop were intentionally designed to abolish its cleavability by various mammalian proteases, as assessed using Prosper, Cascleave 2.0, and PeptideCutter.…”

“…The cDNA constructs of AAT wt (human M1 [V213]) and AAT mt were transiently expressed in human embryonic kidney 293 (HEK293) cells, as described elsewhere. 18 Harvesting of supernatants and purification of recombinant AAT variants were performed as described elsewhere. 17 …”

Multi-omics Analysis of the Intermittent Fasting Response in Mice Identifies an Unexpected Role for HNF4α

“…Although the $3-fold decrease we observe is not enough to trigger such deleterious consequences, there may be more subtle effects of decreased a1-antitrypsin throughout the body that correlate with EODF phenotypes. For example, several non-canonical functions have been associated with a1-antitrypsin, including regulation of metabolic/cardiovascular disease risk (Inouye et al, 2012;Malik et al, 2017;Setoh et al, 2015), regulation of LDL particle function (Mashiba et al, 2001), control of adiponectin stability (Mansuy-Aubert et al, 2013), and the C-ter-minal peptide fragment of SERPINA1 regulating neutrophil activation and NET formation (Yost et al, 2016).…”

Stroke genetics: discovery, biology, and clinical applications

“…Rare variant detection requires this large-scale sequencing and benefits from analytical strategies that aggregate rare variants in a given gene into variant sets, enabling a comparison of the aggregate frequency across groups. 34 The two largest stroke studies 32,35 to date focused on coding regions (the exome) rather than the whole genome. While too small to detect robust associations with rare (allele frequency <0.5%) variants, these studies provide a first step towards future discovery.…”