scholarly journals Do Cerebral Small Vessel Disease and Multiple Sclerosis Share Common Mechanisms of White Matter Injury?

Stroke ◽  
2019 ◽  
Vol 50 (8) ◽  
pp. 1968-1972 ◽  
Author(s):  
Robin B. Brown ◽  
Matthew Traylor ◽  
Stephen Burgess ◽  
Stephen Sawcer ◽  
Hugh S. Markus

Background and Purpose— The role of inflammation in ischemic white matter disease is increasingly recognized, and further understanding of the pathophysiology might inform future treatment strategies. Multiple sclerosis (MS) is a chronic autoimmune condition in which inflammation plays a central role that also affects the white matter. We hypothesized that white matter injury might share common mechanisms and used statistical genetics techniques to assess whether having genetically elevated white matter hyperintensity (WMH) volume was associated with increased MS risk. Methods— We investigated the genetic association in 2 cohorts with magnetic resonance imaging-quantified ischemic white matter lesion volume (WMH in stroke; n=2797 and UK Biobank; n=8353) and 14 802 cases of MS and 26 703 controls from the International Multiple Sclerosis Genetics Consortium. We further performed individual-level polygenic risk score calculations for MS and measures of structural white matter disease in UK Biobank. Finally, we looked for evidence of overlapping risk across the whole genome. Results— There was no association of genetic variants influencing MS with WMH volume using summary statistics in the WMH in stroke cohort (relative risk score =1.014; 95% CI, 0.936–1.110) or in the UK Biobank cohort (relative risk score =1.030; 95% CI, 0.932–1.117). Conversely, assessing the contribution of single nucleotide polymorphisms significantly associated with WMH on the risk of MS there was no significant association (relative risk score =0.930; 95% CI, 0.736–1.191). There were no significant associations between polygenic risk scores calculations; these results were robust to the selection of single nucleotide polymorphisms at a range of significance thresholds. Whole genome analysis did not reveal any overlap of risk between the traits. Conclusions— Our results do not provide evidence to suggest a shared mechanism of white matter damage in ischemia and MS. We propose that inflammation acts in distinct pathways because of the differing nature of the primary insult.

Author(s):  
Nguyễn Trần Thế Hùng ◽  
Lê Đức Hậu

Recent technological advancements and availability of genetic databases have facilitated the integration of genetic factors into risk prediction models. A Polygenic Risk Score (PRS) combines the effect of many Single Nucleotide Polymorphisms (SNP) into a single score. This score has lately been shown to have a clinically predictive value in various common diseases. Some clinical interpretations of PRS are summarized in this review for coronary artery disease, breast cancer, prostate cancer, diabetes mellitus, and Alzheimer’s disease. While these findings gave support to the implementation of PRS in clinical settings, the populations of interest were derived mainly from European ancestry. Therefore, applying these findings to non-European ancestry (Vietnamese in this context) requires many efforts and cautions. This review aims to articulate the evidence supporting the clinical use of PRS, the concepts behind the validity of PRS, approach to implement PRS in Vietnamese population, and cautions in selecting methods and thresholds to develop an appropriate PRS.


2018 ◽  
Author(s):  
Miruna C. Barbu ◽  
Yanni Zeng ◽  
Xueyi Shen ◽  
Simon R. Cox ◽  
Toni-Kim Clarke ◽  
...  

AbstractBackgroundMajor Depressive Disorder (MDD) is a clinically heterogeneous psychiatric disorder with a polygenic architecture. Genome-wide association studies have identified a number of risk-associated variants across the genome, and growing evidence of NETRIN1 pathway involvement. Stratifying disease risk by genetic variation within the NETRIN1 pathway may provide an important route for identification of disease mechanisms by focusing on a specific process excluding heterogeneous risk-associated variation in other pathways. Here, we sought to investigate whether MDD polygenic risk scores derived from the NETRIN1 signaling pathway (NETRIN1-PRS) and the whole genome excluding NETRIN1 pathway genes (genomic-PRS) were associated with white matter integrity.MethodsWe used two diffusion tensor imaging measures, fractional anisotropy (FA) and mean diffusivity (MD), in the most up-to-date UK Biobank neuroimaging data release (FA: N = 6,401; MD: N = 6,390).ResultsWe found significantly lower FA in the superior longitudinal fasciculus (β = -0.035, pcorrected = 0.029) and significantly higher MD in a global measure of thalamic radiations (β = 0.029, pcorrected = 0.021), as well as higher MD in the superior (β = 0.034, pcorrected = 0.039) and inferior (β = 0.029, pcorrected = 0.043) longitudinal fasciculus and in the anterior (β = 0.025, pcorrected = 0.046) and superior (β = 0.027, pcorrected = 0.043) thalamic radiation associated with NETRIN1-PRS. Genomic-PRS was also associated with lower FA and higher MD in several tracts.ConclusionsOur findings indicate that variation in the NETRIN1 signaling pathway may confer risk for MDD through effects on thalamic radiation white matter microstructure.


Author(s):  
Emmanuel Lecorche ◽  
Côme Daniau ◽  
Kevin La ◽  
Faiza Mougari ◽  
Hanaa Benmansour ◽  
...  

Abstract Background Post-surgical infections due to Mycobacterium chimaera appeared as a novel nosocomial threat in 2015, with a worldwide outbreak due to contaminated heater-cooler units used in open chest surgery. We report the results of investigations conducted in France including whole genome sequencing comparison of patient and HCU isolates. Methods We sought M. chimaera infection cases from 2010 onwards through national epidemiological investigations in healthcare facilities performing cardiopulmonary bypass together with a survey on good practices and systematic heater-cooler unit microbial analyses. Clinical and HCU isolates were subjected to whole genome sequencing analyzed with regards to the reference outbreak strain Zuerich-1. Results Only two clinical cases were shown to be related to the outbreak, although 23% (41/175) heater-cooler units were declared positive for M. avium complex. Specific measures to prevent infection were applied in 89% (50/56) healthcare facilities although only 14% (8/56) of them followed the manufacturer maintenance recommendations. Whole genome sequencing comparison showed that the clinical isolates and 72% (26/36) of heater-cooler unit isolates belonged to the epidemic cluster. Within clinical isolates, 5 to 9 non-synonymous single nucleotide polymorphisms were observed, among which an in vivo mutation in a putative efflux pump gene observed in a clinical isolate obtained for one patient under antimicrobial treatment. Conclusions Cases of post-surgical M. chimaera infections were declared to be rare in France, although heater-cooler units were contaminated as in other countries. Genomic analyses confirmed the connection to the outbreak and identified specific single nucleotide polymorphisms, including one suggesting fitness evolution in vivo.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Juliane Hannemann ◽  
Julia Zummack ◽  
PATRICIA SIQUES ◽  
JULIO BRITO ◽  
Rainer Boeger

Introduction: Chronic (CH) and chronic-intermittent (CIH) exposure to hypoxia at high altitude causes acute or chronic mountain sickness and elevation of mean pulmonary arterial pressure (mPAP). This is paralleled by increased plasma levels of ADMA, an endogenous inhibitor of NO synthesis. ADMA is cleaved by dimethylarginine dimethylaminohydrolase (DDAH1 and DDAH2), whilst symmetric dimethylarginine (SDMA) is cleaved by AGXT2. Arginase (ARG1 and ARG2) competes with endothelial NO synthase (NOS3) for L-arginine as substrate. We have shown previously that baseline ADMA (at sea level) determines mPAP after six months of CIH; cut-off values of 25 mm Hg and 30 mm Hg are being used to diagnose high altitude pulmonary hypertension. Hypothesis: We hypothesized that genetic variability in genes coding for core enzymes of ADMA, SDMA, and L-arginine metabolism may predispose individuals for high altitude disease and pulmonary hypertension. Methods: We genotyped 16 common single nucleotide polymorphisms in the NOS3, DDAH1, DDAH2, AGXT2, ARG1 and ARG2 genes of 69 healthy male Chilean subjects. Study participants adhered to a CIH regimen (5d at 3,550m, 2d at sea level) for six months. Metabolites were measured by LC-MS/MS; mPAP was estimated by echocardiography at six months, and altitude acclimatization was assessed by Lake Louise Score and arterial oxygen saturation. Results: Carriers of the minor allele of DDAH1 rs233112 had a higher mean baseline ADMA level (0.76±0.03 vs. 0.67±0.02 μmol/l; p<0.05), whilst the major allele of DDAH2 rs805304 was linked to an exacerbated increase of ADMA in hypoxia (0.10±0.03 vs. 0.04±0.04 μmol/l; p<0.02). Study participants carrying the minor allele of ARG1 rs2781667 had a relative risk of elevated mPAP (>25 mm Hg) of 1.70 (1.56-1.85; p<0.0001), and carriers of the minor allele of NOS3 rs2070744 had a relative risk of elevated mPAP (>30 mm Hg) of 1.58 (1.47-1.69; p<0.0001). The NOS3 and DDAH2 genes were associated with the incidence of acute mountain sickness. Conclusions: We conclude that genetic variability in the L-arginine / ADMA / NO pathway is an important determinant of high altitude pulmonary hypertension and acute mountain sickness. DDAH1 is linked to baseline ADMA, whilst DDAH2 determines the response of ADMA to hypoxia.


Diabetes ◽  
2021 ◽  
Vol 70 (Supplement 1) ◽  
pp. 1134-P
Author(s):  
SANGHYUK JUNG ◽  
DOKYOON KIM ◽  
MANU SHIVAKUMAR ◽  
HONG-HEE WON ◽  
JAE-SEUNG YUN

2018 ◽  
Vol 281 ◽  
pp. 78-84 ◽  
Author(s):  
Niccolò Piaggio ◽  
Simona Schiavi ◽  
Matteo Martino ◽  
Giulia Bommarito ◽  
Matilde Inglese ◽  
...  

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