A nonenzymatic DNA cross-replicator uses temperature cycling to overcome product inhibition and thus survives exponential dilution conditions.

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...

BackgroundThe Dystrophin Glycoprotein Complex (DGC) is at the center of significant inheritable diseases, such as muscular dystrophies that can be fatal and impair neuronal function in addition to muscle degeneration. Recent evidence has shown that it can control cellular homeostasis and work via Dystrophin signaling to regulate microRNA gene expression which implies that disease phenotypes hide an entourage of regulatory and homeostatic anomalies. Uncovering these hidden processes could shed new light on the importance of proper DGC function for an organism’s overall welfare and bring forth new ideas for treatments.ResultsTo better understand a role for the DGC in these processes, we used the genetically advantageous Drosophila muscular dystrophy model to conduct a whole animal microarray screen. Since we have recently found that dystrophic symptoms can be caused by stress even in wild type animals and are enhanced in mutants, we screened stressed animals for microRNA misregulation as well. We were able to define microRNAs misregulated due to stress and/or dystrophy. Our results support the hypothesis that there is a Dystrophin and Dystroglycan dependent circuitry of processes linking stress response, dystrophic conditions and cellular signaling and that microRNAs play an important role in this network. Verification of a subset of our results was conducted via q-PCR and revealed that miR-956, miR-980 and miR-252 are regulated via a Dystroglycan-Dystrophin-Syntrophin dependent pathway.ConclusionsThe results presented in this study support the hypothesis that there is a Dystrophin and Dystroglycan dependent circuitry of processes that includes regulation of microRNAs. Dystrophin signaling has already been found to occur in mammalian musculature; however, our data reveals that this regulation is evolutionarily conserved and also present in at least neuronal tissues. Our data imply that Dystroglycan-Dystrophin-Syntrophin signaling through control of multiple microRNAs is involved in highly managed regulation of gene expression required to adapt cellular homeostasis that is compromised under stress and dystrophic conditions.