Unraveling the effect of silent, intronic and missense mutations on VWF splicing: contribution of next generation sequencing in the study of mRNA

Large studies in von Willebrand disease patients, including Spanish and Portuguese registries, led to identification of >250 different mutations. It is a challenge to determine the pathogenic effect of potential splice site mutations on VWF mRNA. This study aimed to elucidate the true effects of 18 mutations on VWF mRNA processing, investigate the contribution of next-generation sequencing to in vivo mRNA study in von Willebrand disease, and compare the findings with in silico prediction. RNA extracted from patient platelets and leukocytes was amplified by RT-PCR and sequenced using Sanger and next generation sequencing techniques. Eight mutations affected VWF splicing: c.1533+1G>A, c.5664+2T>C and c.546G>A (p.=) prompted exon skipping; c.3223-7_3236dup and c.7082-2A>G resulted in activation of cryptic sites; c.3379+1G>A and c.7473G>A (p.=) demonstrated both molecular pathogenic mechanisms simultaneously; and the p.Cys370Tyr missense mutation generated two aberrant transcripts. Of note, the complete effect of 3 mutations was provided by next generation sequencing alone because of low expression of the aberrant transcripts. In the remaining 10 mutations, no effect was elucidated in the experiments. However, the differential findings obtained in platelets and leukocytes provided substantial evidence that 4 of these would have an effect on VWF levels. In this first report using next generation sequencing technology to unravel the effects of VWF mutations on splicing, the technique yielded valuable information. Our data bring to light the importance of studying the effect of synonymous and missense mutations on VWF splicing to improve the current knowledge of the molecular mechanisms behind von Willebrand disease.info:eu-repo/semantics/publishedVersio

Unraveling the effect of silent, intronic and missense mutations on VWF splicing: contribution of next generation sequencing in the study of mRNA

Large studies in von Willebrand disease patients, including Spanish and Portuguese registries, led to the identification of >250 different mutations. It is a challenge to determine the pathogenic effect of potential splice site mutations on VWF mRNA. This study aimed to elucidate the true effects of 18 mutations on VWF mRNA processing, investigate the contribution of next-generation sequencing to in vivo mRNA study in von Willebrand disease, and compare the findings with in silico prediction. RNA extracted from patient platelets and leukocytes was amplified by RT-PCR and sequenced using Sanger and next generation sequencing techniques. Eight mutations affected VWF splicing: c.1533+1G>A, c.5664+2T>C and c.546G>A (p.=) prompted exon skipping; c.3223-7_3236dup and c.7082-2A>G resulted in activation of cryptic sites; c.3379+1G>A and c.7437G>A) demonstrated both molecular pathogenic mechanisms simultaneously; and the p.Cys370Tyr missense mutation generated two aberrant transcripts. Of note, the complete effect of three mutations was provided by next generation sequencing alone because of low expression of the aberrant transcripts. In the remaining 10 mutations, no effect was elucidated in the experiments. However, the differential findings obtained in platelets and leukocytes provided substantial evidence that four of these would have an effect on VWF levels. In this first report using next generation sequencing technology to unravel the effects of VWF mutations on splicing, the technique yielded valuable information. Our data bring to light the importance of studying the effect of synonymous and missense mutations on VWF splicing to improve the current knowledge of the molecular mechanisms behind von Willebrand disease. clinicaltrials.gov identifier:02869074

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

H. pylori and mitochondrial changes in epithelial cells: The role of oxidative stress H. pylori y alteraciones mitocondriales en células epiteliales: Relación con estrés oxidativo

Infection with H. pylori plays a role in the pathogenesis of gastritis, peptic ulcer, gastric carcinoma, and gastric lymphoma, but mechanisms leading to the various clinical manifestations remain obscure and are the primary focus of research in this field. Proliferation and apoptosis are essential in the maintenance of gastric tissue homeostasis, and changes seen in their balance may condition gastric mucosal changes during infection. Thus, excessive apoptosis or proliferation inhibition will result in cell mass loss, which is observed in gastric ulcers. On the other hand, accelerated epithelial cell turnover is characteristic of carcinogenic mucosas. There is also scientific evidence that demonstrates an association between H. pylori infection and exacerbated synthesis of free radicals, the latter being well known as a primary cause of cell death. A thorough review of the literature and the results of our experimental research lead to conclude that H. pylori-induced oxidative stress activates the intrinsic pathway of apoptosis. Structural and functional changes caused by this process on mitochondrial organelles lie at the origin of gastric mucosal toxicity, and lead to the development of the various manifestations associated with this infection. Based on these data we suggest that therapy with antioxidants should prove beneficial for the clinical management of patients with H. pylori infection

H. pylori and mitochondrial changes in epithelial cells. The role of oxidative stress

Fundacion para la Investigacion Sanitaria en Castilla La-Mancha (FISCAM) [GC02025]; Instituto de Salud Carlos III [CA07/00157

Flow cytometric analysis of the in situ hybridization of cyclooxygenase isoforms in mesangial cells treated with cyclosporine A

4 p.Background: Cyclosporine A increases oxidative stress in kidney and we hypothesized that cyclooxygenase (COX) may be involved in this effect. Material and Methods: Mesangial cells of Cyclosporine A-treated (4, 7 or 10 days) rats were obtained to evaluate mRNA expression of COX-isoforms (COX-1, constitutive and COX-2, inducible) by ??in situ?? hybridization. Probes were labelled using ??Gene Image Random Prime Labelling Protocol?? and COX expression was measured by flow cytometry. Results and Discussion: ??In situ?? hybridization by flow cytometry is an useful method to detect mRNA. We observed an increased COX-2 expression in a time-dependent manner in parallel with Reactive Oxygen Species synthesis. COX-1 expression increased only at 10 days.Junta de Comunidades de Castilla-La Manch