92 research outputs found

    Mitochondrial Homeostasis Mediates Lipotoxicity in the Failing Myocardium

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    Heart failure remains the most common cause of death in the industrialized world. In spite of new therapeutic interventions that are constantly being developed, it is still not possible to completely protect against heart failure development and progression. This shows how much more research is necessary to understand the underlying mechanisms of this process. In this review, we give a detailed overview of the contribution of impaired mitochondrial dynamics and energy homeostasis during heart failure progression. In particular, we focus on the regulation of fatty acid metabolism and the effects of fatty acid accumulation on mitochondrial structural and functional homeostasis

    Accessibility Rating Form for Websites and Other Online Platforms

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    Background. This file provides a coding form developed to judge how accessible websites and other online platforms are to users. Accessibility may be defined as the ease to which a person can perceive content and navigate material (Ross & Ross, 2021). Users are encouraged to adapt this form for their use. Purpose. The rating form can be used to judge the pages of online media, using 14 criteria under two areas: Accessible Media and Accessible Design. One of three grades could be assigned to each criterion: Not Accessible (0 point), Somewhat Accessible (1 point), Accessible (2 points), adapted from published research by Wallace et al. (2010). Initially, this form was developed to rate the website created using the Learning Management System platform, Canvas (Instructure, n.d.), which was adapted as a research survey website. Form validity and reliability. This form was based on guidelines for accessible websites, provided from the World Wide Web Consortium (Zahra, 2019). This form was found to have excellent rater agreement within a preliminary study, which was presented at the 2022 Southwest Chapter Conference Meeting of the American College of Sports Medicine (October 28-29, Costa Mesa, California). The intraclass coefficient statistic was used (four raters, M = .91, LL = .82, UL = .94; Landers, 2015). Results were interpreted using Cicchetti’s (1994) interpretive cut-points. Further detail is reported in the published abstract to the study’s presentation (Wu et al., in press)

    Evaluating Research Survey Websites in Kinesiology: A Case Study Using An Accessibility Rating Form

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    Advancing equity in the research and educational practice of kinesiology requires intentional efforts to ensure access divides do not widen nor persist (Ross et al., in press, JOPERD). PURPOSE: Given knowledge of suitability assessment of materials (SAM) principles supports the equitable design of lay print and online material, we evaluated the extent they would also support developing a research survey website consistent with accessibility guidelines for digital technology. METHODS: The study website was adapted from the Canvas learning management system. A cross-sectional formative assessment was performed. Using their knowledge of SAM principles (eg, clear layout, text ≤ 8th grade reading level), the second and third author (JDT, RFH) constructed the website webpages (eg, site welcome page, online questionnaire; Jun.-Jul. 2022). The first author (YSW), using guidelines from two reputable sources (ie, a Canvas tutorial and W3C website), developed a 14-item accessibility rating form to critically appraise the website’s 10 webpages (ie, 1 = Not Accessible, 2 = Somewhat Accessible, 3 = Accessible; Wallace et al., 2010, JPAH). Authors 1-4 then performed a formative assessment of the adapted Canvas websites’ accessibility independently (Jul.-Aug. 2022). Form reliability was assessed using the intraclass correlation coefficient and its interpretive cut-points for average absolute-rater agreement (Cicchetti, 1994, Psych Assess; Landers, 2015, Winnower). RESULTS: Average rater agreement was excellent per webpage (M = .91, LL = .82, UL = .94). Mean webpage score ranged between 2.55 (±0.78) to 2.77 (±0.58). Informational pages (eg, welcome page) had greater accessibility than interactive pages (eg, forms). Five discrepant items were systematic, resulting in redundant rater differences (eg, keyboard navigation was hard to notice). All discrepancies were resolved with 100% consensus. CONCLUSION: The findings of the present study suggest knowledge of SAM principles ensures developers can design lay friendly and accessible research survey websites. They further suggest rating forms inclusive of digital accessibility guidelines should be used as a supplement to further meet accessibility and equity goals. We will share our form, then discuss our results using the universal design for learning framework

    Long-Chain and Very Long-Chain Ceramides Mediate Doxorubicin-Induced Toxicity and Fibrosis

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    Doxorubicin (Dox) is a chemotherapeutic agent with cardiotoxicity associated with profibrotic effects. Dox increases ceramide levels with pro-inflammatory effects, cell death, and fibrosis. The purpose of our study was to identify the underlying ceramide signaling pathways. We aimed to characterize the downstream effects on cell survival, metabolism, and fibrosis. Human fibroblasts (hFSF) were treated with 0.7 µM of Dox or transgenically overexpressed ceramide synthase 2 (FLAG-CerS2). Furthermore, cells were pre-treated with MitoTempo (MT) (2 h, 20 µM) or Fumonisin B1 (FuB) (4 h, 100 µM). Protein expression was measured by Western blot or immunofluorescence (IF). Ceramide levels were determined with mass spectroscopy (MS). Visualizations were conducted using laser scanning microscopy (LSM) or electron microscopy. Mitochondrial activity was measured using seahorse analysis. Dox and CerS2 overexpression increased CerS2 protein expression. Coherently, ceramides were elevated with the highest peak for C24:0. Ceramide- induced mitochondrial ROS production was reduced with MT or FuB preincubation. Mitochondrial homeostasis was reduced and accompanied by reduced ATP production. Our data show that the increase in pro-inflammatory ceramides is an essential contributor to Dox side-effects. The accumulation of ceramides resulted in a lipotoxic shift and subsequently mitochondrial structural and functional damage, which was partially reversible following inhibition of ceramide synthesis

    BCL11A enhancer edited hematopoietic stem cells persist in rhesus monkeys without toxicity

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    Gene editing of the erythroid-specific BCL11A enhancer in hematopoietic stem and progenitor cells (HSPCs) from sickle cell disease (SCD) patients induces fetal hemoglobin (HbF) without detectable toxicity as assessed by mouse xenotransplant. Here, we evaluated autologous engraftment and HbF induction potential of erythroid-specific BCL11A enhancer edited HSPCs in four non-human primates. We utilized a single guide RNA (sgRNA) with identical human and rhesus target sequences to disrupt a GATA1 binding site at the BCL11A +58 erythroid enhancer. Cas9 protein and sgRNA ribonucleoprotein complex (RNP) was electroporated into rhesus HSPCs, followed by autologous infusion after myeloablation. We found that gene edits persisted in peripheral blood (PB) and bone marrow (BM) for up to 101 weeks similarly for BCL11A enhancer or control locus (AAVS1) targeted cells. Biallelic BCL11A enhancer editing resulted in robust gamma-globin induction, with the highest levels observed during stress erythropoiesis. Indels were evenly distributed across PB and BM lineages. Off-target edits were not observed. Non-homologous end-joining repair alleles were enriched in engrafting HSCs. In summary, we find that edited HSCs can persist for at least 101 weeks post-transplant, and biallelic edited HSCs provide substantial HbF levels in PB red blood cells, together supporting further clinical translation of this approach

    Genetic drivers of heterogeneity in type 2 diabetes pathophysiology.

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    Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P < 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care

    Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants

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    Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Peer reviewe

    Copy Number Variants Are Ovarian Cancer Risk Alleles at Known and Novel Risk Loci

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    BACKGROUND: Known risk alleles for epithelial ovarian cancer (EOC) account for approximately 40% of the heritability for EOC. Copy number variants (CNVs) have not been investigated as EOC risk alleles in a large population cohort. METHODS: Single nucleotide polymorphism array data from 13 071 EOC cases and 17 306 controls of White European ancestry were used to identify CNVs associated with EOC risk using a rare admixture maximum likelihood test for gene burden and a by-probe ratio test. We performed enrichment analysis of CNVs at known EOC risk loci and functional biofeatures in ovarian cancer-related cell types. RESULTS: We identified statistically significant risk associations with CNVs at known EOC risk genes; BRCA1 (PEOC = 1.60E-21; OREOC = 8.24), RAD51C (Phigh-grade serous ovarian cancer [HGSOC] = 5.5E-4; odds ratio [OR]HGSOC = 5.74 del), and BRCA2 (PHGSOC = 7.0E-4; ORHGSOC = 3.31 deletion). Four suggestive associations (P < .001) were identified for rare CNVs. Risk-associated CNVs were enriched (P < .05) at known EOC risk loci identified by genome-wide association study. Noncoding CNVs were enriched in active promoters and insulators in EOC-related cell types. CONCLUSIONS: CNVs in BRCA1 have been previously reported in smaller studies, but their observed frequency in this large population-based cohort, along with the CNVs observed at BRCA2 and RAD51C gene loci in EOC cases, suggests that these CNVs are potentially pathogenic and may contribute to the spectrum of disease-causing mutations in these genes. CNVs are likely to occur in a wider set of susceptibility regions, with potential implications for clinical genetic testing and disease prevention
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