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Genome-wide association studies have identified breast cancer risk variants in over 150 genomic regions, but the mechanisms underlying risk remain largely unknown. These regions were explored by combining association analysis with in silico genomic feature annotations. We defined 205 independent risk-associated signals with the set of credible causal variants in each one. In parallel, we used a Bayesian approach (PAINTOR) that combines genetic association, linkage disequilibrium and enriched genomic features to determine variants with high posterior probabilities of being causal. Potentially causal variants were significantly over-represented in active gene regulatory regions and transcription factor binding sites. We applied our INQUSIT pipeline for prioritizing genes as targets of those potentially causal variants, using gene expression (expression quantitative trait loci), chromatin interaction and functional annotations. Known cancer drivers, transcription factors and genes in the developmental, apoptosis, immune system and DNA integrity checkpoint gene ontology pathways were over-represented among the highest-confidence target genes.
The missing heritability of breast cancer could be partially attributed to rare variants (MAF < 0.5%). To identify breast cancer-associated rare coding variants, we conducted whole-exome sequencing (~50×) in genomic DNA samples obtained from 831 breast cancer cases and 839 controls of Chinese females. Using burden tests for each gene that included rare missense or predicted deleterious variants, we identified 29 genes showing promising associations with breast cancer risk. We replicated the association for two genes, OGDHL and BRCA2, at a Bonferroni-corrected p < 0.05, by genotyping an independent set of samples from 1,628 breast cancer cases and 1,943 controls. The association for OGDHL was primarily driven by three predicted deleterious variants (p.Val827Met, p.Pro839Leu, p.Phe836Ser; p < 0.01 for all). For BRCA2, we characterized a total of 27 disruptive variants, including 18 nonsense, six frameshift and three splicing variants, whereas they were only detected in cases, but none of the controls. All of these variants were either very rare (AF < 0.1%) or not detected in >4,500 East Asian women from the genome Aggregation database (gnomAD), providing additional support to our findings. Our study revealed a potential novel gene and multiple disruptive variants of BRCA2 for breast cancer risk, which may identify high-risk women in Chinese populations.
© 2019 UICC.
Behavioral studies have shown discrepant results regarding the role of phonology in predicting math gains. The objective of this study was to use fMRI to study the role of activation during a rhyming judgment task in predicting behavioral gains on math fluency, multiplication, and subtraction skill. We focused within the left middle/superior temporal gyrus and left inferior frontal gyrus, brain areas associated with the storage of phonological representations and with their access, respectively. We ran multiple regression analyses to determine whether activation predicted gains in the three math measures, separately for younger (i.e. 10 years old) and older (i.e 12 years old) children. Results showed that activation in both temporal and frontal cortex only predicted gains in fluency and multiplication skill, and only for younger children. This study suggests that both temporal and frontal cortex activation during phonological processing are important in predicting gains in math tasks that involve the retrieval of facts that are stored as phonological codes in memory. Moreover, these results were specific to younger children, suggesting that phonology is most important in the early stages of math development. When the math task involved subtractions, which relies on quantity representations, phonological processes were not important in driving gains.
Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.
BACKGROUND AND OBJECTIVES - Impacts of mindfulness-based programs on blood pressure remain equivocal, possibly because the programs are not adapted to engage with determinants of hypertension, or due to floor effects. Primary objectives were to create a customized Mindfulness-Based Blood Pressure Reduction (MB-BP) program, and to evaluate acceptability, feasibility, and effects on hypothesized proximal self-regulation mechanisms. Secondary outcomes included modifiable determinants of blood pressure (BP), and clinic-assessed systolic blood pressure (SBP).
METHODS - This was a Stage 1 single-arm trial with one year follow-up. Focus groups and in-depth interviews were performed to evaluate acceptability and feasibility. Self-regulation outcomes, and determinants of BP, were assessed using validated questionnaires or objective assessments. The MB-BP curriculum was adapted from Mindfulness-Based Stress Reduction to direct participants' mindfulness skills towards modifiable determinants of blood pressure.
RESULTS - Acceptability and feasibility findings showed that of 53 eligible participants, 48 enrolled (91%). Of these, 43 (90%) attended at least 7 of the 10 MB-BP classes; 43 were followed to one year (90%). Focus groups (n = 19) and semi-structured interviews (n = 10) showed all participants viewed the delivery modality favorably, and identified logistic considerations concerning program access as barriers. A priori selected primary self-regulation outcomes showed improvements at one-year follow-up vs. baseline, including attention control (Sustained Attention to Response Task correct no-go score, p<0.001), emotion regulation (Difficulties in Emotion Regulation Score, p = 0.02), and self-awareness (Multidimensional Assessment of Interoceptive Awareness, p<0.001). Several determinants of hypertension were improved in participants not adhering to American Heart Association guidelines at baseline, including physical activity (p = 0.02), Dietary Approaches to Stop Hypertension-consistent diet (p<0.001), and alcohol consumption (p<0.001). Findings demonstrated mean 6.1 mmHg reduction in SBP (p = 0.008) at one year follow-up; effects were most pronounced in Stage 2 uncontrolled hypertensives (SBP≥140 mmHg), showing 15.1 mmHg reduction (p<0.001).
CONCLUSION - MB-BP has good acceptability and feasibility, and may engage with self-regulation and behavioral determinants of hypertension.
Fluorescence recovery after photobleaching (FRAP) has been useful in delineating cardiac myofilament biology, and innovations in fluorophore chemistry have expanded the array of microscopic assays used. However, one assumption in FRAP is the irreversible photobleaching of fluorescent proteins after laser excitation. Here we demonstrate reversible photobleaching regarding the photoconvertible fluorescent protein mEos3.2. We used CRISPR/Cas9 genome editing in human induced pluripotent stem cells (hiPSCs) to knock-in mEos3.2 into the COOH terminus of titin to visualize sarcomeric titin incorporation and turnover. Upon cardiac induction, the titin-mEos3.2 fusion protein is expressed and integrated in the sarcomeres of hiPSC-derived cardiomyocytes (CMs). STORM imaging shows M-band clustered regions of bound titin-mEos3.2 with few soluble titin-mEos3.2 molecules. FRAP revealed a baseline titin-mEos3.2 fluorescence recovery of 68% and half-life of ~1.2 h, suggesting a rapid exchange of sarcomeric titin with soluble titin. However, paraformaldehyde-fixed and permeabilized titin-mEos3.2 hiPSC-CMs surprisingly revealed a 55% fluorescence recovery. Whole cell FRAP analysis in paraformaldehyde-fixed, cycloheximide-treated, and untreated titin-mEos3.2 hiPSC-CMs displayed no significant differences in fluorescence recovery. FRAP in fixed HEK 293T expressing cytosolic mEos3.2 demonstrates a 58% fluorescence recovery. These data suggest that titin-mEos3.2 is subject to reversible photobleaching following FRAP. Using a mouse titin-eGFP model, we demonstrate that no reversible photobleaching occurs. Our results reveal that reversible photobleaching accounts for the majority of titin recovery in the titin-mEos3.2 hiPSC-CM model and should warrant as a caution in the extrapolation of reliable FRAP data from specific fluorescent proteins in long-term cell imaging.
Roux-en-Y gastric bypass surgery (RYGB) is known to improve whole-body glucose metabolism in patients with type 2 diabetes (T2D), although the mechanisms are not entirely clear and are likely multifactorial. The aim of this study was to assess fasting hepatic glucose metabolism and other markers of metabolic activity before and after RYGB in patients with and without T2D. Methods: Metabolic characteristics of patients who are obese with T2D were compared with those without the disease (non-T2D) before and 1 and 6 mo after RYGB. Fasting plasma insulin and the insulin:glucagon ratio were markedly reduced as early as 1 mo after RYGB in both patients with T2D and without T2D. Despite this reduction, endogenous glucose production and fasting plasma glucose levels were lower in both groups after RYGB, with the reductions being much larger in T2D. Plasma kisspeptin, an inhibitor of insulin secretion, was reduced only in T2D after surgery. Improved hepatic glucose metabolism and lower plasma kisspeptin in T2D after RYGB may link improved hepatic function with enhanced insulin responsiveness after surgery. Our manuscript is the first, to the best of our knowledge, to present data showing that Roux-en-Y gastric bypass surgery (RYGB) lowers fasting kisspeptin levels in patients who are obese with type 2 diabetes. This lowering of kisspeptin is important because it could link improvements in liver glucose metabolism after RYGB with increased insulin responsiveness also seen after surgery.
Nonalcoholic steatohepatitis (NASH) has increased in Western countries due to the prevalence of obesity. Current interests are aimed at identifying the type and function of immune cells that infiltrate the liver and key factors responsible for mediating their recruitment and activation in NASH. We investigated the function and phenotype of CD8 T cells under obese and nonobese NASH conditions. We found an elevation in CD8 staining in livers from obese human subjects with NASH and cirrhosis that positively correlated with α-smooth muscle actin, a marker of hepatic stellate cell (HSC) activation. CD8 T cells were elevated 3.5-fold in the livers of obese and hyperlipidemic NASH mice compared with obese hepatic steatosis mice. Isolated hepatic CD8 T cells from these mice expressed a cytotoxic IL-10-expressing phenotype, and depletion of CD8 T cells led to significant reductions in hepatic inflammation, HSC activation, and macrophage accumulation. Furthermore, hepatic CD8 T cells from obese and hyperlipidemic NASH mice activated HSCs in vitro and in vivo. Interestingly, in the lean NASH mouse model, depletion and knockdown of CD8 T cells did not impact liver inflammation or HSC activation. We demonstrated that under obese/hyperlipidemia conditions, CD8 T cell are key regulators of the progression of NASH, while under nonobese conditions they play a minimal role in driving the disease. Thus, therapies targeting CD8 T cells may be a novel approach for treatment of obesity-associated NASH. Our study demonstrates that CD8 T cells are the primary hepatic T cell population, are elevated in obese models of NASH, and directly activate hepatic stellate cells. In contrast, we find CD8 T cells from lean NASH models do not regulate NASH-associated inflammation or stellate cell activation. Thus, for the first time to our knowledge, we demonstrate that hepatic CD8 T cells are key players in obesity-associated NASH.
OBJECTIVES - Proton pump inhibitors (PPIs) are often used in pediatrics to treat common gastrointestinal disorders, and there are growing concerns for infectious adverse events. Because CYP2C19 inactivates PPIs, genetic variants that increase CYP2C19 function may decrease PPI exposure and infections. We tested the hypothesis that CYP2C19 metabolizer phenotypes are associated with infection event rates in children exposed to PPIs.
METHODS - This retrospective biorepository cohort study included individuals aged 0 to 36 months at the time of PPI exposure. Respiratory tract and gastrointestinal tract infection events were identified by using codes in the year after the first PPI mention. Variants defining , , , , , and were genotyped, and all individuals were classified as CYP2C19 poor or intermediate, normal metabolizers (NMs), or rapid or ultrarapid metabolizers (RM/UMs). Infection rates were compared by using univariate and multivariate analyses.
RESULTS - In all, 670 individuals were included (median age 7 months; 44% girls). CYP2C19 NMs ( = 267; 40%) had a higher infection rate than RM/UMs ( = 220; 33%; median 2 vs 1 infections per person per year; = .03). There was no difference between poor or intermediate ( = 183; 27%) and NMs. In multivariable analysis of NMs and RM/UMs adjusting for age, sex, PPI dose, and comorbidities, CYP2C19 metabolizer status remained a significant risk factor for infection events (odds ratio 0.70 [95% confidence interval 0.50-0.97] for RM/UMs versus NMs).
CONCLUSIONS - PPI therapy is associated with higher infection rates in children with normal CYP2C19 function than in those with increased CYP2C19 function, highlighting this adverse effect of PPI therapy and the relevance of genotypes to PPI therapeutic decision-making.
Copyright © 2019 by the American Academy of Pediatrics.
BACKGROUND - Abiraterone and enzalutamide are recently-approved androgen deprivation therapies (ADTs) for metastatic prostate cancer, with unknown cardiac safety profiles. Abiraterone has a propensity to hypermineralocorticism on top of androgen deprivation, so might carry an additional risk for atrial tachyarrhythmia (AT) and heart failure (HF) compared with other ADTs.
AIM - To determine if abiraterone was associated with an increased proportion of AT and HF reports among all suspected adverse drug reactions (ADRs) reported in several pharmacovigilance databases compared with enzalutamide, other ADTs and all other drugs.
METHODS - In this observational retrospective pharmacovigilance study, we performed a disproportionality analysis of reports of suspected ADRs in men in the French pharmacovigilance database, the European pharmacovigilance database and the international pharmacovigilance database VigiBase, to evaluate the reporting odds ratios (RORs) of AT and HF for abiraterone compared with enzalutamide, other ADTs and all other drugs.
RESULTS - In the 5,759,781 ADR reports in men in VigiBase, 55,070 pertained to ADTs. The RORs for AT for abiraterone versus enzalutamide, other ADTs and all other drugs were 4.1 (95% confidence interval 3.1-5.3), 3.7 (3-4.5) and 3.2 (2.7-3.7), respectively (P<0.0001 for all). The corresponding RORs for HF were 2.5 (2-3), 1.5 (1.3-1.7) and 2 (1.7-2.3), respectively (P<0.0001 for all). These results were concordant with the French and European pharmacovigilance databases. Mean times to AT and HF onset were shorter with abiraterone (5.2±0.8 and 4.5±0.6 months, respectively) versus other ADTs (13.3±3.2 and 9.2±1.1 months, respectively) (both P<0.05). Cases on abiraterone versus other ADTs were more frequently associated with at least two ADR terms, including AT, HF, hypokalaemia, hypertension and oedema (13.6% vs 6%; P<0.0001). For abiraterone, age, but not dose, was associated with reporting of AT and HF versus any other ADR.
CONCLUSIONS - Compared with other ADTs, abiraterone was associated with higher reporting of AT and HF, associated with hypokalaemia, hypertension and oedema. These findings are consistent with the hypermineralocorticism induced by abiraterone, but not by other ADTs.
Copyright © 2019 Elsevier Masson SAS. All rights reserved.