Genome-wide Association Studies in Ancestrally Diverse Populations: Opportunities, Methods, Pitfalls, and Recommendations

Genome-wide association studies (GWASs) have focused primarily on populations of European descent, but it is essential that diverse populations become better represented. Increasing diversity among study participants will advance our understanding of genetic architecture in all populations and ensure that genetic research is broadly applicable. To facilitate and promote research in multi-ancestry and admixed cohorts, we outline key methodological considerations and highlight opportunities, challenges, solutions, and areas in need of development. Despite the perception that analyzing genetic data from diverse populations is difficult, it is scientifically and ethically imperative, and there is an expanding analytical toolbox to do it well.

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.

264The long noncoding RNA H19 modulates cardiac remodeling after infarction

Noncoding RNAs account for 80% of human transcripts, but functional studies on noncoding RNAs are relatively few and limited. Long noncoding RNAs (lncRNAs) are known to have an important role in cardiac development, and lately, high-throughput RNA sequencing has been extensively utilized to profile and explore the transcriptome landscape of lncRNAs in failing hearts. These studies have revealed that lncRNAs are mostly dysregulated in failing hearts and their expression signature can discriminate failing hearts of different etiologies.

H19 is abundantly expressed in failing human hearts and its polymorphism was shown to possess a significant correlation with the risk of coronary artery diseases. In our study using murine hearts, we discovered that H19 was significantly up regulated in the heart after ischemic injury, with predominant expression in cardiac fibroblasts. This finding piqued our interest to further investigate the function of H19 in the heart.

We demonstrated that ectopic overexpression of H19 using the AAV approach led to severe cardiac fibrosis in mouse hearts following myocardial infarction. In light of this finding, we generated H19 knockout mice to further investigate the functionality of H19 and we found that cardiac fibrosis was attenuated in these mice. Altogether, these findings suggested that H19 is a fibrosis regulator during cardiac remodeling process after infarction. Due to the multiple regulatory roles of lncRNAs, we then took advantage of chromatin isolation by RNA purification (ChIRP) to identify the H19-interacting protein, YB-1. Surprisingly, mice with YB-1 knockdown displayed severe cardiac fibrosis even without injury. Furthermore, we demonstrated that YB-1 is a transcriptional suppressor of collagen 1A1. Knockout of H19 in YB-1 knockdown partially suppressed Col1a1 expression, which suggests a negative regulatory role of H19 on YB-1 towards the expression of Col1a1.

Taking into account all of these findings, we concluded that H19 mediates collagen expression in fibroblasts through the inhibition of YB-1 activity during cardiac remodeling.

Penetrance and Pleiotropy of Polygenic Risk Scores for Schizophrenia in 106,160 Patients Across Four Health Care Systems

OBJECTIVE

Individuals at high risk for schizophrenia may benefit from early intervention, but few validated risk predictors are available. Genetic profiling is one approach to risk stratification that has been extensively validated in research cohorts. The authors sought to test the utility of this approach in clinical settings and to evaluate the broader health consequences of high genetic risk for schizophrenia.

METHODS

The authors used electronic health records for 106,160 patients from four health care systems to evaluate the penetrance and pleiotropy of genetic risk for schizophrenia. Polygenic risk scores (PRSs) for schizophrenia were calculated from summary statistics and tested for association with 1,359 disease categories, including schizophrenia and psychosis, in phenome-wide association studies. Effects were combined through meta-analysis across sites.

RESULTS

PRSs were robustly associated with schizophrenia (odds ratio per standard deviation increase in PRS, 1.55; 95% CI=1.4, 1.7), and patients in the highest risk decile of the PRS distribution had up to 4.6-fold higher odds of schizophrenia compared with those in the bottom decile (95% CI=2.9, 7.3). PRSs were also positively associated with other phenotypes, including anxiety, mood, substance use, neurological, and personality disorders, as well as suicidal behavior, memory loss, and urinary syndromes; they were inversely related to obesity.

CONCLUSIONS

The study demonstrates that an available measure of genetic risk for schizophrenia is robustly associated with schizophrenia in health care settings and has pleiotropic effects on related psychiatric disorders as well as other medical syndromes. The results provide an initial indication of the opportunities and limitations that may arise with the future application of PRS testing in health care systems.

P1604Validating previously reported Brugada syndrome-associated common variants identified in caucasian population in the Han Chinese BrS cohort in Taiwan: SADS-BrS registry

Background

Brugada syndrome (BrS) is a sudden arrhythmic death. The prevalence of BrS is higher in the Southeast Asian populations than that in Caucasian patients. A previous genome-wide association study (GWAS) has reported 13 SNPs significantly associated with BrS. However, no study was performed to validate whether these SNPs are enriched in BrS patients in Han Chinese (HC).

Purpose

Evaluating the common variants previously reported in Caucasian BrS patients could be generalized to HC BrS patients in Taiwan

Methods

We genotyped 200 unrelated BrS patients using Affymetrix TWB Array (N=653,291 SNPs, a customized array for HC in Taiwan). The controls are obtained from the Taiwan Biobank (N ≈ 16,000) using the same array. An imputation workflow was shown in Figure 1. To confirm the accuracy of the imputed genotype of each variant, Sanger sequencing was performed in 10% of randomly selected cases.

Results

Among the 3 most important common variants (rs11708996 in SCN5A, rs10428132 in SCN10A and rs9388451 in HEY2/NCOA7) reported in the previous GWAS mainly conducted in Caucasian BrS patients, 2 of them (rs10428132 and rs9388451) were successfully replicated in the HC population in Taiwan (P<0.01). We also found that the differences of minor allele frequency (dMAF: the MAF of cases minus the MAF of controls) of the two variants were relatively smaller between the BrS cases and healthy controls in HC population compared with that in Caucasian populations (dMAF, rs9388451: 0.15 (Caucasian) vs −0.07 (HC); rs10428132: 0.28 (Caucasian) vs 0.11 (HC)). For the remaining 10 common variants reaching genome-wide significance (P=5×10–8) in Caucasian BrS patients, 9 of them were also significantly enriched in the HC BrS patients after the Bonferroni correction (P<0.05/12=0.0042). We next analyzed the variants identified in the previous GWAS on ECG traits (PR interval, QRS duration, QTc interval, and heart rate) in the Caucasian population. Among the reported 75 variants associated with ECG traits, 5 common variants (rs6798015 (PR), rs1760876 (QRS), rs6795970 (PR/QRS), rs2074238 (QTc) and rs314370 (heart rate)) were significant after Bonferroni correction (P<0.05/75=0.00066).

Figure 1

Conclusions

The preliminary results indicated that 85% of common variants of SCN10A and HEY2/NCOA7 previously reported in Caucasian BrS patients are replicated in BrS patients in the HC population but not the common variant of SCN5A (rs11708996). Furthermore, the common variants of SCN10A and HEY2/NCOA7 related to cardiac depolarization or repolarization may also contribute to the development of BrS.

Acknowledgement/Funding

NTUH 106-S3469, NTUH106-S3458 and NTUH 106-018

[Impact of oxidative stress on renal dopamine D(1) receptor dysfunction in offspring of diabetic rat dams]

Objective: To explore the effects of oxidative stress on renal dopamine D(1) receptor dysfunction in offspring of diabetic rat dams. Methods: The pregnant Sprague Dawley (SD) rats (n=10) were randomly divided into the diabetic group (a single intraperitoneal injection of 35 mg/kg streptozotocin on day 0 of gestation) and control group (injected with the equal volume of 0.9% saline on day 0 of gestation) according to the random number table (n=5 each group). The offspring rats were divided into 4 groups including offspring of control dams treated with vehicle, offspring of control dams treated with antioxidant, offspring of diabetic dams treated with vehicle and offspring of diabetic dams treated with antioxidant (n=10 each group). After birth, the offspring rats were treated with normal drinking water or antioxidant (tempol, 1.0 mmol/L) from the age of 4 weeks until the end of the study (20 weeks). The blood pressure was monitored continuously by non-invasive tail-cuff method. The renal oxidative markers including superoxide dismutase (SOD) and malondialdehyde (MDA) activity and D(1) receptor agonist (fenoldopam)-mediated urinary and sodium excretion were detected. Furthermore, the protein expression of renal G protein-coupled receptor kinase 2 (GRK2), GRK4, dopamine D(1) receptor and the phosphorylation level of D(1) receptor were detected. Results: The mean arterial pressure of offspring from the diabetic dams treated with vehicle was significantly higher than that of offspring from control dams treated with vehicle (P=0.013), while the mean arterial pressure of offspring from diabetic dams treated with antioxidant was significantly lower than that of offspring from the diabetic dams treated with vehicle (P=0.038). The fenoldopam-mediated urinary flow and urinary sodium excretion rate were significantly lower in offspring of diabetic dams treated with vehicle than those in offspring of control dams treated with vehicle (P<0.01), which were significantly higher in offspring of diabetic dams treated with antioxidant as compared to offspring of diabetic dams treated with vehicle (both P<0.01). There was no significant difference in fenoldopam-mediated urinary flow and urinary sodium excretion rate in offspring of control dams treated with antioxidant or vehicle (urinary flow: P=0.772; urinary sodium excretion rate: P=0.716). Compared with offspring of control dams treated with vehicle, the renal MDA activity was significantly increased, while the SOD activity was significantly decreased in offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.013). The renal MDA activity was significantly decreased, while the SOD activity was significantly increased in offspring of diabetic dams treated with antioxidant in comparison with offspring of diabetic dams treated with vehicle (MDA: P<0.01; SOD: P=0.035).The renal GRK2 and GRK4 protein expression in offspring of diabetic dams treated with vehicle were significantly higher than those in offspring of control dams treated with vehicle (P<0.01), while the expression levels of renal GRK2 and GRK4 in offspring of diabetic dams treated with antioxidant were significantly downregulated compared with offspring of diabetic dams treated with vehicle (P<0.01). There was no significant difference in the protein expression of dopamine D(1) receptor among 4 groups (P=0.735). The level of dopamine D(1) receptor phosphorylation in offspring of diabetic dams treated with vehicle was significantly higher than that in offspring of control dams treated with vehicle (P<0.01), while the dopamine D(1) receptor phosphorylation level was significantly lower in offspring of diabetic dams treated with antioxidant compared to that in offspring of diabetic dams treated with vehicle (P<0.01). Conclusion: Oxidative stress is involved in the dopamine D(1) receptors dysfunction in the offspring of diabetic dams.

Contribution of Rare Copy Number Variants to Bipolar Disorder Risk Is Limited to Schizoaffective Cases

BACKGROUND

Genetic risk for bipolar disorder (BD) is conferred through many common alleles, while a role for rare copy number variants (CNVs) is less clear. Subtypes of BD including schizoaffective disorder bipolar type (SAB), bipolar I disorder (BD I), and bipolar II disorder (BD II) differ according to the prominence and timing of psychosis, mania, and depression. The genetic factors contributing to the combination of symptoms among these subtypes are poorly understood.

METHODS

Rare large CNVs were analyzed in 6353 BD cases (3833 BD I [2676 with psychosis, 850 without psychosis, and 307 with unknown psychosis history], 1436 BD II, 579 SAB, and 505 BD not otherwise specified) and 8656 controls. CNV burden and a polygenic risk score (PRS) for schizophrenia were used to evaluate the relative contributions of rare and common variants to risk of BD, BD subtypes, and psychosis.

RESULTS

CNV burden did not differ between BD and controls when treated as a single diagnostic entity. However, burden in SAB was increased relative to controls (p = .001), BD I (p = .0003), and BD II (p = .0007). Burden and schizophrenia PRSs were increased in SAB compared with BD I with psychosis (CNV p = .0007, PRS p = .004), and BD I without psychosis (CNV p = .0004, PRS p = 3.9 × 10-5). Within BD I, psychosis was associated with increased schizophrenia PRSs (p = .005) but not CNV burden.

CONCLUSIONS

CNV burden in BD is limited to SAB. Rare and common genetic variants may contribute differently to risk for psychosis and perhaps other classes of psychiatric symptoms.

Advanced Paternal Age and Early Onset of Schizophrenia in Sporadic Cases: Not Confounded by Parental Polygenic Risk for Schizophrenia

BACKGROUND

Whether paternal age effect on schizophrenia is a causation or just an association due to confounding by selection into late parenthood is still debated. We investigated the association between paternal age and early onset of schizophrenia in offspring, controlling for both paternal and maternal predisposition to schizophrenia as empirically estimated using polygenic risk score (PRS) derived from the Psychiatric Genomics Consortium.

METHODS

Among 2923 sporadic schizophrenia cases selected from the Schizophrenia Trio Genomic Research in Taiwan project, 1649 had parents' genotyping data. The relationships of paternal schizophrenia PRS to paternal age at first birth (AFB) and of maternal schizophrenia PRS to maternal AFB were examined. A logistic regression model of patients' early onset of schizophrenia (≤18 years old) on paternal age was conducted.

RESULTS

Advanced paternal age over 20 years exhibited a trend of an increasing proportion of early onset of schizophrenia (odds ratio per 10-year increase in paternal age = 1.28, p = .007) after adjusting for maternal age, sex, and age. Older paternal AFB also exhibited an increasing trend of paternal schizophrenia PRS. Additionally, a U-shaped relationship between maternal AFB and maternal schizophrenia PRS was observed. After adjusting for both paternal and maternal schizophrenia PRS, the association of paternal age with patients' early onset of schizophrenia remained (odds ratio = 1.29, p = .04).

CONCLUSIONS

The association between paternal age and early onset of schizophrenia was not confounded by parental PRS for schizophrenia, which partially captures parental genetic vulnerability to schizophrenia. Our findings support an independent role of paternal age per se in increased risk of early onset of schizophrenia in offspring.

Genome-wide analyses of psychological resilience in U.S. Army soldiers

Though a growing body of preclinical and translational research is illuminating a biological basis for resilience to stress, little is known about the genetic basis of psychological resilience in humans. We conducted genome-wide association studies (GWASs) of self-assessed (by questionnaire) and outcome-based (incident mental disorders from predeployment to postdeployment) resilience among European (EUR) ancestry soldiers in the Army study to assess risk and resilience in servicemembers. Self-assessed resilience (N = 11,492) was found to have significant common-variant heritability (h² = 0.162, se = 0.050, p = 5.37 × 10^-4 ), and to be significantly negatively genetically correlated with neuroticism (r_g  = -0.388, p = .0092). GWAS results from the EUR soldiers revealed a genome-wide significant locus on an intergenic region on Chr 4 upstream from doublecortin-like kinase 2 (DCLK2) (four single nucleotide polymorphisms (SNPs) in LD; top SNP: rs4260523 [p = 5.65 × 10^-9 ] is an eQTL in frontal cortex), a member of the doublecortin family of kinases that promote survival and regeneration of injured neurons. A second gene, kelch-like family member 36 (KLHL36) was detected at gene-wise genome-wide significance [p = 1.89 × 10^-6 ]. A polygenic risk score derived from the self-assessed resilience GWAS was not significantly associated with outcome-based resilience. In very preliminary results, genome-wide significant association with outcome-based resilience was found for one locus (top SNP: rs12580015 [p = 2.37 × 10^-8 ]) on Chr 12 downstream from solute carrier family 15 member 5 (SLC15A5) in subjects (N = 581) exposed to the highest level of deployment stress. The further study of genetic determinants of resilience has the potential to illuminate the molecular bases of stress-related psychopathology and point to new avenues for therapeutic intervention.

Sediment organic carbon and temperature effects on methylmercury concentration: A mesocosm experiment

The fate and mobility of mercury, and its bioaccumulation primarily as methylmercury (MeHg), in marine ecosystems are influenced by climate related environmental factors, including increased temperature and carbon loading. To investigate the interactions between sediment organic carbon and temperature MeHg bioaccumulation, mesocosm experiments were conducted examining relationships between sediment, water column and biota (sediment-dwelling amphipod and juvenile oyster) MeHg concentration. Experimental treatments consisted of a two by two design of high and low temperature (15 & 25 °C) and high and low sediment organic carbon (4-5% and 13% LOI, pre-experiment). Sediment organic carbon had significant individual effects on MeHg concentration in water and biota, with higher carbon associated with lower MeHg. Temperature individual effects were significant for sediment, water, and only amphipod MeHg concentration, with higher temperature treatments indicating higher MeHg concentration. There were significant temperature × carbon interactions observed for sediment, dissolved, and oyster MeHg concentration. Sediment carbon reduction had greater influence than temperature on increasing MeHg concentrations in both the water column and biota. MeHg concentrations in the bulk sediment were not correlated with MeHg in the water column or in the biota, indicating that even when sediments are the only source of MeHg, bulk sediment measurements do not provide a good proxy for bioaccumulation and that the concentration in bulk sediments is not the primary determinant of MeHg entry into the food web.

Polygenic prediction via Bayesian regression and continuous shrinkage priors

Polygenic risk scores (PRS) have shown promise in predicting human complex traits and diseases. Here, we present PRS-CS, a polygenic prediction method that infers posterior effect sizes of single nucleotide polymorphisms (SNPs) using genome-wide association summary statistics and an external linkage disequilibrium (LD) reference panel. PRS-CS utilizes a high-dimensional Bayesian regression framework, and is distinct from previous work by placing a continuous shrinkage (CS) prior on SNP effect sizes, which is robust to varying genetic architectures, provides substantial computational advantages, and enables multivariate modeling of local LD patterns. Simulation studies using data from the UK Biobank show that PRS-CS outperforms existing methods across a wide range of genetic architectures, especially when the training sample size is large. We apply PRS-CS to predict six common complex diseases and six quantitative traits in the Partners HealthCare Biobank, and further demonstrate the improvement of PRS-CS in prediction accuracy over alternative methods.

Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults: A 2-Sample Mendelian Randomization Study

Importance

Increasing evidence shows that physical activity is associated with reduced risk for depression, pointing to a potential modifiable target for prevention. However, the causality and direction of this association are not clear; physical activity may protect against depression, and/or depression may result in decreased physical activity.

Objective

To examine bidirectional relationships between physical activity and depression using a genetically informed method for assessing potential causal inference.

Design, Setting, and Participants

This 2-sample mendelian randomization (MR) used independent top genetic variants associated with 2 physical activity phenotypes-self-reported (n = 377 234) and objective accelerometer-based (n = 91 084)-and with major depressive disorder (MDD) (n = 143 265) as genetic instruments from the largest available, nonoverlapping genome-wide association studies (GWAS). GWAS were previously conducted in diverse observational cohorts, including the UK Biobank (for physical activity) and participating studies in the Psychiatric Genomics Consortium (for MDD) among adults of European ancestry. Mendelian randomization estimates from each genetic instrument were combined using inverse variance weighted meta-analysis, with alternate methods (eg, weighted median, MR Egger, MR-Pleiotropy Residual Sum and Outlier [PRESSO]) and multiple sensitivity analyses to assess horizontal pleiotropy and remove outliers. Data were analyzed from May 10 through July 31, 2018.

Main Outcomes and Measures

MDD and physical activity.

Results

GWAS summary data were available for a combined sample size of 611 583 adult participants. Mendelian randomization evidence suggested a protective relationship between accelerometer-based activity and MDD (odds ratio [OR], 0.74 for MDD per 1-SD increase in mean acceleration; 95% CI, 0.59-0.92; P = .006). In contrast, there was no statistically significant relationship between MDD and accelerometer-based activity (β = -0.08 in mean acceleration per MDD vs control status; 95% CI, -0.47 to 0.32; P = .70). Furthermore, there was no significant relationship between self-reported activity and MDD (OR, 1.28 for MDD per 1-SD increase in metabolic-equivalent minutes of reported moderate-to-vigorous activity; 95% CI, 0.57-3.37; P = .48), or between MDD and self-reported activity (β = 0.02 per MDD in standardized metabolic-equivalent minutes of reported moderate-to-vigorous activity per MDD vs control status; 95% CI, -0.008 to 0.05; P = .15).

Conclusions and Relevance

Using genetic instruments identified from large-scale GWAS, robust evidence supports a protective relationship between objectively assessed-but not self-reported-physical activity and the risk for MDD. Findings point to the importance of objective measurement of physical activity in epidemiologic studies of mental health and support the hypothesis that enhancing physical activity may be an effective prevention strategy for depression.

[Mycophenolate mofetil versus cyclosporine A in children with primary refractory nephrotic syndrome]

Objective: To compare the efficacy and safety of mycophenolate mofetil versus cyclosporine A in treating children with primary refractory nephrotic syndrome. Methods: Conducted a prospective randomized controlled clinical trial in 62 pediatric patients (including 44 boys and 18 girls), age ranged from 2.1 to 17.0 years; 32 cases presented with frequently relapsing nephrotic syndrome (FRNS) and 30 cases presented with steroid-resistant nephrotic syndrome (SRNS), who were admitted to department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics from October 2013 to October 2015. The patients received either mycophenolate mofetil (20-30)mg/(kg·d) or cyclosporine A (3-5)mg/(kg·d) randomly, on the basis of prednisone treatment. Follow-up interview was conducted regularly for at least one year. Efficacy rate, relapse rate, time required for induction of remission, relapse-free period and prednisone dosage were compared between the two groups. Results: (1) Renal histologic examination, which was available for 17 patients, revealed minimal change disease in 8 patients, mesangial proliferative glomerulonephritis (MsPGN) in five, membranous nephropathy in two, and focal segmental glomerulosclerosis (FSGS) in two. (2) Comparison of mycophenolate mofetil versus cyclosporine A in children with FRNS: There were 14 patients with FRNS in mycophenolate mofetil group and 18 patients with FRNS in cyclosporine A group respectively. The relapse rate (episodes/year) in cyclosporine A group was lower than that of mycophenolate mofetil group (1.0 (0.0, 1.0) vs. 1.0 (1.0, 3.0), Z=-2.405, P=0.016). The relapse-free period (months) in cyclosporine A group was longer than that of mycophenolate mofetil group (10.0 (5.7, 12.1) vs. 5.0 (1.0, 11.0), Z=-1.984, P=0.047). No significant difference in dosage of prednisone was found between cyclosporine A and mycophenolate mofetil groups when followed up for 1 year. (3) Comparison of mycophenolate mofetil versus cyclosporine A in children with SRNS: The efficacy rate was 6/14 in mycophenolate mofetil group and 13/16 in cyclosporine A group. The complete remission rate was 4/14 in mycophenolate mofetil group and 12/16 in cyclosporine A group (P<0.05). The time (months) required for induction of remission in cyclosporine A group was significantly shorter than that of mycophenolate mofetil group (1.0 (1.0, 2.0) vs. 3.0 (2.5, 4.0), Z=-2.529, P=0.011). No significant differences were found between the two groups with respect to relapse-free period and relapse rate. (4) Except that one patient developed hypertensive encephalopathy in cyclosporine A group, no other serious adverse events were recorded. There were no significant differences between two groups with respect to adverse events. Conclusion: Our results indicated that both mycophenolate mofetil and cyclosporine A were effective in the treatment of children with refractory nephrotic syndrome. Cyclosporine A was superior to mycophenolate mofetil in preventing relapses in patients with FRNS and inducing complete remission in patients with SRNS. Although most patients were able to tolerate mycophenolate mofetil and cyclosporine A, but the toxicity and safety of cyclosporine A should be monitored closely.

First trimester placental vascular indices and volume by three-dimensional ultrasound in pre-gravid overweight women

OBJECTIVES

To investigate changes of placental vascular indices and volume in pre-gravid overweight Chinese women during the first trimester using three-dimensional power Doppler ultrasound.

METHODS

This was a prospective observational study of the morphology of placentas in pre-gravid overweight (body mass index (BMI) ≥ 24 kg/m²) and non-overweight (BMI < 24 kg/m²) Chinese women during the first trimester of pregnancy. Data on placental vascular indices (vascularization index, flow index, and vascularization flow index (VFI)), placental volume, uterine artery pulsatility index (PI), and neonatal outcomes were obtained during the first trimester and analyzed. Linear regression analysis was used to evaluate confounding factors between BMI and ultrasound indices.

RESULTS

Of the 429 pregnant women enrolled, 68 (15.9%) were pre-gravid overweight. Placental VFI was significantly lower in the overweight group (p = 0.037). Conversely, placental volume was significantly larger in the overweight group (p = 0.044), and uterine artery PI was significantly higher in the overweight group (p = 0.021). After adjustments for confounding factors, there were still significant differences in placental VFI (unstandardized coefficient (B) -0.666, 95% confidence interval (CI) -1.306 - (-0.025)), placental volume (B 2.458, 95% CI 0.071-4.844), and uterine artery PI (B 0.152, 95% CI 0.030-0.274) between the two groups.

CONCLUSIONS

Placental vascular indices using three-dimensional power Doppler ultrasound can provide an insight into placental vascularization in pre-gravid overweight women in early pregnancy. Alterations in placental VFI, placental volume, and uterine artery PI occur during the first trimester in pre-gravid overweight women.

Organic carbon content drives methylmercury levels in the water column and in estuarine food webs across latitudes in the Northeast United States

Estuaries are dynamic ecosystems which vary widely in loading of the contaminant methylmercury (MeHg), and in environmental factors which control MeHg exposure to the estuarine foodweb. Inputs of organic carbon and rates of primary production are important influences on MeHg loading and bioaccumulation, and are predicted to increase with changes in climate and land use pressures. To further understand these influences on MeHg levels in estuarine biota, we used a field study approach in sites across different temperature regions, and with varying organic carbon levels. In paired comparisons of sites with high vs. low organic carbon, fish had lower MeHg bioaccumulation factors (normalized to water concentrations) in high carbon sites, particularly subsites with large coastal wetlands and large variability in dissolved organic carbon levels in the water column. Across sites, MeHg level in the water column was strongly tied to dissolved organic carbon, and was the major driver of MeHg concentrations in fish and invertebrates. Higher primary productivity (chlorophyll-a) was associated with increased MeHg partitioning to suspended particulates, but not to the biota. These findings suggest that increased inputs of MeHg and loss of wetlands associated with climate change and anthropogenic land use pressure will increase MeHg concentrations in estuarine food webs.

Genome-wide association analyses of risk tolerance and risky behaviors in over 1 million individuals identify hundreds of loci and shared genetic influences

Humans vary substantially in their willingness to take risks. In a combined sample of over 1 million individuals, we conducted genome-wide association studies (GWAS) of general risk tolerance, adventurousness, and risky behaviors in the driving, drinking, smoking, and sexual domains. Across all GWAS, we identified hundreds of associated loci, including 99 loci associated with general risk tolerance. We report evidence of substantial shared genetic influences across risk tolerance and the risky behaviors: 46 of the 99 general risk tolerance loci contain a lead SNP for at least one of our other GWAS, and general risk tolerance is genetically correlated ([Formula: see text] ~ 0.25 to 0.50) with a range of risky behaviors. Bioinformatics analyses imply that genes near SNPs associated with general risk tolerance are highly expressed in brain tissues and point to a role for glutamatergic and GABAergic neurotransmission. We found no evidence of enrichment for genes previously hypothesized to relate to risk tolerance.

GWAS Identifies Risk Locus for Erectile Dysfunction and Implicates Hypothalamic Neurobiology and Diabetes in Etiology

Erectile dysfunction (ED) is a common condition affecting more than 20% of men over 60 years, yet little is known about its genetic architecture. We performed a genome-wide association study of ED in 6,175 case subjects among 223,805 European men and identified one locus at 6q16.3 (lead variant rs57989773, OR 1.20 per C-allele; p = 5.71 × 10⁻¹⁴), located between MCHR2 and SIM1. In silico analysis suggests SIM1 to confer ED risk through hypothalamic dysregulation. Mendelian randomization provides evidence that genetic risk of type 2 diabetes mellitus is a cause of ED (OR 1.11 per 1-log unit higher risk of type 2 diabetes). These findings provide insights into the biological underpinnings and the causes of ED and may help prioritize the development of future therapies for this common disorder.

Large-scale meta-analysis highlights the hypothalamic-pituitary-gonadal axis in the genetic regulation of menstrual cycle length

The normal menstrual cycle requires a delicate interplay between the hypothalamus, pituitary and ovary. Therefore, its length is an important indicator of female reproductive health. Menstrual cycle length has been shown to be partially controlled by genetic factors, especially in the follicle-stimulating hormone beta-subunit (FSHB) locus. A genome-wide association study meta-analysis of menstrual cycle length in 44 871 women of European ancestry confirmed the previously observed association with the FSHB locus and identified four additional novel signals in, or near, the GNRH1, PGR, NR5A2 and INS-IGF2 genes. These findings not only confirm the role of the hypothalamic-pituitary-gonadal axis in the genetic regulation of menstrual cycle length but also highlight potential novel local regulatory mechanisms, such as those mediated by IGF2.

Modelling the outbreak of infectious disease following mutation from a non-transmissible strain

In-host mutation of a cross-species infectious disease to a form that is transmissible between humans has resulted with devastating global pandemics in the past. We use simple mathematical models to describe this process with the aim to better understand the emergence of an epidemic resulting from such a mutation and the extent of measures that are needed to control it. The feared outbreak of a human–human transmissible form of avian influenza leading to a global epidemic is the paradigm for this study. We extend the SIR approach to derive a deterministic and a stochastic formulation to describe the evolution of two classes of susceptible and infected states and a removed state, leading to a system of ordinary differential equations and a stochastic equivalent based on a Markov process. For the deterministic model, the contrasting timescale of the mutation process and disease infectiousness is exploited in two limits using asymptotic analysis in order to determine, in terms of the model parameters, necessary conditions for an epidemic to take place and timescales for the onset of the epidemic, the size and duration of the epidemic and the maximum level of the infected individuals at one time. Furthermore, the basic reproduction number R0 is determined from asymptotic analysis of a distinguished limit. Comparisons between the deterministic and stochastic model demonstrate that stochasticity has little effect on most aspects of an epidemic, but does have significant impact on its onset particularly for smaller populations and lower mutation rates for representatively large populations. The deterministic model is extended to investigate a range of quarantine and vaccination programmes, whereby in the two asymptotic limits analysed, quantitative estimates on the outcomes and effectiveness of these control measures are established.

[Lipoxin A4 inhibits the invasion and migration of endometrial stromal cells by down-regulating NF-κB signaling-mediated autophagy]

Objective: To investigate whether the suppressive effects of lipoxin A4 (LXA4) on endometriosis are mediated by the regulation of autophagic activity, and to further explore the actual molecular mechanism. Methods: (1) Eutopic and ectopic endometria were obtained from 13 patients with endometriosis, and 10 eutopic endometria collected from non-endometriosis patients were used as control. The expression of the autophagy-related biochemical markers [microtubule-associated protein 1 light chain 3 (LC3) and p62] were detected by western blot. Levels of LXA4 in the biopsies were measured by ELISA. (2) Primary human endometrial stromal cells (ESC) were isolated and cultured in vitro from eutopic endometria of infertility patients with endometriosis. After treatment with exogenous LXA4 or autophagy inhibitor 3-methyladenine (3-MA) or autophagy inducer rapamycin, cell migration and invasion were evaluated by transwell assay, and autophagy was detected by western blot. (3) ESC were treated with LXA4, the gene expressions of nuclear factor kappa B (NF-κB) etc. were examined by quantitative real-time PCR, and the activation of NF-κB signaling was detected by western blot. (4) ESC were incubated with 10 μmol/L NF-κB inhibitor BAY11-7080, the autophagic activation was detected by western blot. Results: (1) Autophagy-related marker, LC3-Ⅱ and LC3-Ⅱ/LC3-Ⅰ ratio, showed a significant up-regulation in ectopic lesions of endometriosis compared with eutopic endometria of affected or healthy women (all P<0.05) . However, the LXA4 level significantly decreased in ectopic tissue (P<0.05) . There was a significant negative correlation between LXA4 concentration and relative expression of LC3-Ⅱ in ectopic lesions (r= -0.780, P=0.002) . (2) 10 and 100 nmol/L exogenous LXA4 could significantly down-regulate the LC3-Ⅱ protein expression and up-regulate the p62 protein expression (all P<0.05) . LXA4 markedly inhibited the invasion and migration of ESC (P<0.05) ;while the reactivation of autophagy by rapamycin almost reversed the anti-invasion and anti-migration effects of LXA4. (3) After LXA4 treatment, the expression level of NF-κB gene significantly decreased (P<0.05) . Furthermore, the results of western blot analysis showed that the nuclear translocation of NF-κB p65 was markedly down-regulated under LXA4 treatment (P<0.05) . (4) The NF-κB inhibitor BAY11-7080 markedly suppressed the autophagic activation of LXA4 (P<0.05) . Conclusion: LXA4 could inhibit the invasion and migration of ESC by down-regulating the NF-κB signaling-mediated autophagy.

Polygenic pleiotropy and potential causal relationships between educational attainment, neurobiological profile, and positive psychotic symptoms

Event-related potential (ERP) components have been used to assess cognitive functions in patients with psychotic illness. Evidence suggests that among patients with psychosis there is a distinct heritable neurophysiologic phenotypic subtype captured by impairments across a range of ERP measures. In this study, we investigated the genetic basis of this "globally impaired" ERP cluster and its relationship to psychosis and cognitive abilities. We applied K-means clustering to six ERP measures to re-derive the globally impaired (n = 60) and the non-globally impaired ERP clusters (n = 323) in a sample of cases with schizophrenia (SCZ = 136) or bipolar disorder (BPD = 121) and healthy controls (n = 126). We used genome-wide association study (GWAS) results for SCZ, BPD, college completion, and childhood intelligence as the discovery datasets to derive polygenic risk scores (PRS) in our study sample and tested their associations with globally impaired ERP. We conducted mediation analyses to estimate the proportion of each PRS effect on severity of psychotic symptoms that is mediated through membership in the globally impaired ERP. Individuals with globally impaired ERP had significantly higher PANSS-positive scores (β = 3.95, P = 0.005). The SCZ-PRS was nominally associated with globally impaired ERP (unadjusted P = 0.01; R² = 3.07%). We also found a significant positive association between the college-PRS and globally impaired ERP (FDR-corrected P = 0.004; R² = 6.15%). The effect of college-PRS on PANSS positivity was almost entirely (97.1%) mediated through globally impaired ERP. These results suggest that the globally impaired ERP phenotype may represent some aspects of brain physiology on the path between genetic influences on educational attainment and psychotic symptoms.

Obesity-associated cardiac pathogenesis in broiler breeder hens: Development of metabolic cardiomyopathy

Feed intake is typically restricted (R) in broiler hens to avoid obesity and improve egg production and livability. To determine whether improved heart health contributes to improved livability, fully adult 45-week-old R hens were allowed to consume feed to appetite (ad libitum; AL) up to 10 wk (70 d). Mortality, contractile functions, and morphology at 70 d, and measurements of cardiac hypertrophic remodeling at 7 d and 21 d were made and compared between R and AL hens. Outcomes for cardiac electrophysiology and mortality, reported separately, found increased mortality in AL hens in association with cardiac pathological hypertrophy and contractile dysfunction. The present study aimed to delineate metabolic cardiomyopathies underlying the etiology of obesity-associated cardiac pathology. Metabolic measurements were made in hens continued on R rations or assigned to AL feeding after 7 d and 21 days. AL feeding increased plasma insulin, glucose, and non-esterified fatty acid (NEFA) concentrations by 21 d (P < 0.05). Metabolic cardiomyopathy in AL-hens was confirmed by cardiac triacylglycerol (TG) and ceramide accumulation consistent with up-regulation of related enzyme gene expressions, and by increased indices of oxidation stress (P < 0.05). In contrast to R hens, cardiac pyruvate dehydrogenase (PDH) activity and glucose transporter (GLUT) gene expressions increased progressively while carnitine palmitoyltransferase-1 (CPT-1) transcript levels in AL hens declined from 7 d to 21 d (P < 0.05), reflecting a shift from an oxidative to a more glycolytic metabolism, a typical metabolic derangement associated with cardiac hypertrophic remodeling. Cardiac pathogenesis in AL hens was further indicated by increased leukocyte infiltrates, interleukin-1β (IL-1β) and IL-6 production, cellular apoptosis, interstitial fibrosis, and expression of the heart failure marker myosin heavy chain (MHC-β; cardiac muscle beta) (P < 0.05). Results support the conclusion that diabetic conditions, cardiac inflammation and lipotoxic metabolic derangements act as pathological cues to trigger pathogenic changes along cardiac hypertrophy in AL hens.

Obesity-associated cardiac pathogenesis in broiler breeder hens: Pathological adaption of cardiac hypertrophy

Broiler hens consuming feed to appetite (ad libitum; AL) show increased mortality. Feed restriction (R) typically improves reproductive performance and livability of hens. Rapidly growing broilers can exhibit increased mortality due to cardiac insufficiency but it is unknown whether the increased mortality of non-R broiler hens is also due to cardiac compromise. To assess cardiac growth and physiology in fully mature birds, 45-week-old hens were either continued on R rations or assigned to AL feeding for 7 or 21 days. AL hens exhibited increased bodyweight, adiposity, absolute and relative heart weight, ventricular hypertrophy, and cardiac protein/DNA ratio by d 21 (P < 0.05). Increased heart weights due to hypertrophic growth was attributed to enhanced IGF-1-Akt-FoxO1 signaling and its downstream target, translation initiation factor 4E-BP1 in conjunction with down-regulation of ubiquitin ligase atrogin-1/MAFbx (P < 0.05). Reduced activation of cardiac AMPK and downstream activation of ACC-1 in parallel with increased cardiac nitric oxide levels, calcineurin activity, and MAPK activation in AL hens (P < 0.05) suggested that metabolic derangement develops along the cardiovascular remodeling. These indictors of cardiac maladaptive hypertrophic growth were further supported by uregulation of heart failure markers, BNP and MHC-β (P < 0.05). Hens allowed AL feeding for 70 d exhibited a higher incidence of mortality (40% vs. 10%) in association with ascites, pericardial effusion, and ventricle dilation. A higher incidence of irregular ECG patterns and rhythmicity consistent with persistently elevated systolic blood pressure and ventricle fibrosis were observed in AL hens (P < 0.05). These observations support the conclusion that AL feeding in broiler hens results in maladaptive cardiac hypertrophy that progresses to overt pathogenesis in contractility and thereby increases mortality. Feed restriction provides clear physiological benefit to heart function of adult broiler hens.