Deuterium brain imaging at 7T during D2O dosing

Purpose: To characterize the (2H) deuterium MR signal measured from human brain at 7T in participants loading with D2O to ~1.5% enrichment over a six-week period. Method(s): 2H spectroscopy and imaging measurements were used to track the time-course of 2H enrichment within the brain during the initial eight-hour loading period in two participants. Multi-echo gradient echo (MEGE) images were acquired at a range of TR values from four participants during the steady-state loading period and used for mapping 2H T1 and T2 * relaxation times. Co-registration to higher resolution 1H images allowed T1 and T2 * relaxation times of deuterium in HDO in cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) to be estimated. Result(s): 2H concentrations measured during the eight-hour loading were consistent with values estimated from cumulative D2O dose and body mass. Signal changes measured from three different regions of the brain during loading showed similar time-courses. After summing over echoes, gradient echo brain images acquired in 7.5 minutes with a voxel volume of 0.36 ml showed an SNR of ~16 in subjects loaded to 1.5%. T1-values for deuterium in HDO were significantly shorter than corresponding values for 1H in H2O, while T2 * values were similar. 2H relaxation times in CSF were significantly longer than in GM or WM. Conclusion(s): Deuterium MR Measurements at 7T were used to track the increase in concentration of 2H in brain during heavy water loading. 2H T1 and T2 * relaxation times from water in GM, WM, and CSF are reported.Copyright © 2022 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.https://doi.org/10.1002/mrm.2953

Stromal fibroblasts support dendritic cells to maintain IL-23/Th17 responses after exposure to ionizing radiation

Dendritic cell function is modulated by stromal cells, including fibroblasts. Although poorly understood, the signals delivered through this crosstalk substantially alter dendritic cell biology. This is well illustrated with release of TNF-0/IL-113 from activated dendritic cells, promoting PGE2 secretion from stromal fibroblasts. This instructs dendritic cells to up-regulate IL-23, a key Th17-polarizing cytokine. We previously showed that ionizing radiation inhibited IL-23 production by human dendritic cells in vitro. In the present study, we investigated the hypothesis that dendritic cell-fibroblast crosstalk over¬comes the suppressive effect of ionizing radiation to support appropriately polarized Th17 responses. Radia¬tion (1–6 Gy) markedly suppressed IL-23 secretion by activated dendritic cells (P < 0.0001) without adversely impacting their viability and consequently, inhibited the generation of Th17 responses. Cytokine suppression by ionizing radiation was selective, as there was no effect on IL-10, -6, -10, and -27 or TNF-a and only a modest (11%) decrease in IL-12p70 secretion. Coculture with fibroblasts augmented IL-23 secretion by irradiated dendritic cells and increased Th17 responses. Impor¬tantly, in contrast to dendritic cells, irradiated fibroblasts maintained their capacity to respond to TNF-0/IL-10 and produce PGE2, thus providing the key intermediary signals for successful dendritic cell-fibroblasts crosstalk. In summary, stromal fibroblasts support Th17-polarizing cytokine production by dendritic cells that would other¬wise be suppressed in an irradiated microenvironment. This has potential ramifications for understanding the immune response to local radiotherapy. These findings underscore the need to account for the impact of microenvironmental factors, including stromal cells, in understanding the control of immunity. J. Leukoc. Biol. 100: 000–000; 2016

Evaluation of the MOVE online exercise programme for young people aged 13–30

PurposeTo evaluate the MOVE exercise programme in supporting the recovery of young people affected by cancer.MethodsParticipants in an 8-week exercise rehabilitation programme delivered online by cancer rehabilitation specialists completed self-reported questionnaires at baseline and after programme completion. Assessments included cancer-related fatigue (FACIT fatigue scale) and health-related quality of life (EORTC-QLC-30). Qualitative data were provided through written accounts of participant experiences and underwent content analysis.ResultsSeventy-one participants commenced the exercise rehabilitation programme and 57 completed the programme and provided data for analysis (63% female; median age 22 years). Statistically significant improvements were observed in post-programme scores for all measured outcomes (cancer-related fatigue, quality of life, physical functioning, role functioning, emotional functioning). Content analysis of written experiences generated ten unique codes. The highest frequency codes were enjoyment (n = 34), motivation (n = 14) and fitness (n = 13).ConclusionsThese findings indicate feasibility of delivery, acceptability to patients and physical and psychological benefits of a personalised online exercise rehabilitation programme for young people living with and beyond cancer. Further research involving a control arm and long-term follow-up would be beneficial.Implications for cancer survivorsThese results support the inclusion of a personalised exercise programme as part of cancer rehabilitation for young people living with and beyond cancer

Deuterium brain imaging at 7T during D 2 O dosing

PurposeTo characterize the (2H) deuterium MR signal measured from human brain at 7T in participants loading with D2O to ˜1.5% enrichment over a six-week period.Methods2H spectroscopy and imaging measurements were used to track the time-course of 2H enrichment within the brain during the initial eight-hour loading period in two participants. Multi-echo gradient echo (MEGE) images were acquired at a range of TR values from four participants during the steady-state loading period and used for mapping 2H T1 and T2* relaxation times. Co-registration to higher resolution 1H images allowed T1 and T2* relaxation times of deuterium in HDO in cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) to be estimated.Results2H concentrations measured during the eight-hour loading were consistent with values estimated from cumulative D2O dose and body mass. Signal changes measured from three different regions of the brain during loading showed similar time-courses. After summing over echoes, gradient echo brain images acquired in 7.5 minutes with a voxel volume of 0.36 ml showed an SNR of ˜16 in subjects loaded to 1.5%. T1-values for deuterium in HDO were significantly shorter than corresponding values for 1H in H2O, while T2* values were similar. 2H relaxation times in CSF were significantly longer than in GM or WM.ConclusionDeuterium MR Measurements at 7T were used to track the increase in concentration of 2H in brain during heavy water loading. 2H T1 and T2* relaxation times from water in GM, WM, and CSF are reported

Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits

Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.Peer reviewe

Ligand-directed covalent labelling of a GPCR with a fluorescent tag in live cells

© 2020, The Author(s). To study the localisation of G protein-coupled receptors (GPCR) in their native cellular environment requires their visualisation through fluorescent labelling. To overcome the requirement for genetic modification of the receptor or the limitations of dissociable fluorescent ligands, here we describe rational design of a compound that covalently and selectively labels a GPCR in living cells with a fluorescent moiety. We designed a fluorescent antagonist, in which the linker incorporated between pharmacophore (ZM241385) and fluorophore (sulfo-cyanine5) is able to facilitate covalent linking of the fluorophore to the adenosine A2A receptor. We pharmacologically and biochemically demonstrate irreversible fluorescent labelling without impeding access to the orthosteric binding site and demonstrate its use in endogenously expressing systems. This offers a non-invasive and selective approach to study function and localisation of native GPCRs

Large-scale exome array summary statistics resources for glycemic traits to aid effector gene prioritization

Abstract Background: Genome-wide association studies for glycemic traits have identified hundreds of loci associated with these biomarkers of glucose homeostasis. Despite this success, the challenge remains to link variant associations to genes, and underlying biological pathways. Methods: To identify coding variant associations which may pinpoint effector genes at both novel and previously established genome-wide association loci, we performed meta-analyses of exome-array studies for four glycemic traits: glycated hemoglobin (HbA1c, up to 144,060 participants), fasting glucose (FG, up to 129,665 participants), fasting insulin (FI, up to 104,140) and 2hr glucose post-oral glucose challenge (2hGlu, up to 57,878). In addition, we performed network and pathway analyses. Results: Single-variant and gene-based association analyses identified coding variant associations at more than 60 genes, which when combined with other datasets may be useful to nominate effector genes. Network and pathway analyses identified pathways related to insulin secretion, zinc transport and fatty acid metabolism. HbA1c associations were strongly enriched in pathways related to blood cell biology. Conclusions: Our results provided novel glycemic trait associations and highlighted pathways implicated in glycemic regulation. Exome-array summary statistic results are being made available to the scientific community to enable further discoveries.Abstract Background: Genome-wide association studies for glycemic traits have identified hundreds of loci associated with these biomarkers of glucose homeostasis. Despite this success, the challenge remains to link variant associations to genes, and underlying biological pathways. Methods: To identify coding variant associations which may pinpoint effector genes at both novel and previously established genome-wide association loci, we performed meta-analyses of exome-array studies for four glycemic traits: glycated hemoglobin (HbA1c, up to 144,060 participants), fasting glucose (FG, up to 129,665 participants), fasting insulin (FI, up to 104,140) and 2hr glucose post-oral glucose challenge (2hGlu, up to 57,878). In addition, we performed network and pathway analyses. Results: Single-variant and gene-based association analyses identified coding variant associations at more than 60 genes, which when combined with other datasets may be useful to nominate effector genes. Network and pathway analyses identified pathways related to insulin secretion, zinc transport and fatty acid metabolism. HbA1c associations were strongly enriched in pathways related to blood cell biology. Conclusions: Our results provided novel glycemic trait associations and highlighted pathways implicated in glycemic regulation. Exome-array summary statistic results are being made available to the scientific community to enable further discoveries

A genome-wide association search for type 2 diabetes genes in African Americans

African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P<0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P<0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P<2.5×10(-8)). SNP rs7560163 (P = 7.0×10(-9), OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P<0.05) and reached more nominal levels of significance (P<2.5×10(-5)) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations