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Background: Little is known about the interplay between n-3 fatty acids and genetic variants for diabetes-related traits at the genome-wide level. The present study aimed to examine variance contributions of genotype by environment (GxE) interactions for different erythrocyte n-3 fatty acids and genetic variants for diabetes-related traits at the genome-wide level in a non-Hispanic white population living in the U.S.A. (n = 820). A tool for Genome-wide Complex Trait Analysis (GCTA) was used to estimate the genome-wide GxE variance contribution of four diabetes-related traits: HOMA-Insulin Resistance (HOMA-IR), fasting plasma insulin, glucose and adiponectin. A GxE genome-wide association study (GWAS) was conducted to further elucidate the GCTA results. Replication was conducted in the participants of the Boston Puerto Rican Health Study (BPRHS) without diabetes (n = 716). Results: In GOLDN, docosapentaenoic acid (DPA) contributed the most significant GxE variance to the total phenotypic variance of both HOMA-IR (26.5%, P-nominal = 0.034) and fasting insulin (24.3%, P-nominal = 0.042). The ratio of arachidonic acid to eicosapentaenoic acid + docosahexaenoic acid contributed the most significant GxE variance to the total variance of fasting glucose (27.0%, P-nominal = 0.023). GxE variance of the arachidonic acid/eicosapentaenoic acid ratio showed a marginally significant contribution to the adiponectin variance (16.0%, P-nominal = 0.058). None of the GCTA results were significant after Bonferroni correction (P < 0.001). For each trait, the GxE GWAS identified a far larger number of significant single-nucleotide polymorphisms (P-interaction ≤ 10E-5) for the significant E factor (significant GxE variance contributor) than a control E factor (non-significant GxE variance contributor). In the BPRHS, DPA contributed a marginally significant GxE variance to the phenotypic variance of HOMA-IR (12.9%, P-nominal = 0.068) and fasting insulin (18.0%, P-nominal = 0.033). Conclusion: Erythrocyte n-3 fatty acids contributed a significant GxE variance to diabetes-related traits at the genome-wide level. [ABSTRACT FROM AUTHOR]

DNA oxidative stress has been suggested as an important pathogenic mechanism in cognitive impairment and dementia. With baseline data collected from 2004 to 2008, the authors examined whether urinary 8-hydroxy-2-deoxyguanosine (8-OHdG), a biomarker of global DNA oxidation, was associated with cognitive function in a sample of 1,003 Puerto Rican adults, aged 45–75 years, living in Boston, Massachusetts, and the surrounding area. Cognitive function was measured by using a battery of 7 tests: the Mini-Mental State Examination, word list learning, digit span, clock drawing and figure copying, Stroop, and verbal fluency tests. The primary outcome was a global cognitive score, averaging standardized scores across all cognitive tests. A higher 8-OHdG concentration was significantly associated with lower global cognitive scores, after adjustment for age, education, status of the gene for apolipoprotein E (APOE), and other covariates (Ptrend = 0.01). The difference in the global score, comparing participants in the 2 extreme 8-OHdG quartiles, was −0.11 (95% confidence interval: −0.20, −0.02), which was equivalent to accelerating cognitive aging by about 4 years, as observed in this population. Prospective studies are needed to elucidate whether elevated urinary 8-OHdG concentrations can predict the rate of cognitive decline and incident dementia. [ABSTRACT FROM PUBLISHER]

Older Puerto Ricans living in the continental U.S. suffer from higher rates of diabetes, obesity, cardiovascular disease and depression compared to non-Hispanic White populations. Complex diseases, such as these, are likely due to multiple, potentially interacting, genetic, environmental and social risk factors. Presumably, many of these environmental and genetic risk factors are contextual. We reasoned that racial background may modify some of these risk factors and be associated with health disparities among Puerto Ricans. The contemporary Puerto Rican population is genetically heterogeneous and originated from three ancestral populations: European settlers, native Taíno Indians, and West Africans. This rich-mixed ancestry of Puerto Ricans provides the intrinsic variability needed to untangle complex gene–environment interactions in disease susceptibility and severity. Herein, we determined whether a specific ancestral background was associated with either of four major disease outcomes (diabetes, obesity, cardiovascular disease, and depression). We estimated the genetic ancestry of 1,129 subjects from the Boston Puerto Rican Health Study based on genotypes of 100 ancestry informative markers (AIMs). We examined the effects of ancestry on tests of association between single AIMs and disease traits. The ancestral composition of this population was 57.2% European, 27.4% African, and 15.4% Native American. African ancestry was negatively associated with type 2 diabetes and cardiovascular disease, and positively correlated with hypertension. It is likely that the high prevalence rate of diabetes in Africans, Hispanics, and Native Americans is not due to genetic variation alone, but to the combined effects of genetic variation interacting with environmental and social factors. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Individuals with type 2 diabetes exhibit higher DNA damage and increased risk of cardiovascular disease (CVD). However, mechanisms underlying the association between DNA damage and development of type 2 diabetes and CVD are not understood. We sought to link peroxisome proliferator-activated receptor-γ coactivator-1 α (PPARGC1A), a master transcriptional regulator of mitochondrial oxidative phosphorylation and cellular energy metabolism, with DNA damage, type 2 diabetes, and CVD. RESEARCH DESIGN AND METHODS--We measured DNA damage as urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration and examined the relationship between nine PPARGC1A genetic variants, DNA damage, type 2 diabetes, and self-reported CVD in 959 participants of the Boston Puerto Rican Health Study. RESULTS--With respect to urinary 8-OHdG, PPARGC1A variants showed significant association, and PPARGC1A haplotypes exhibited significant association after correction for multiple testing. Two independent PPARGC1A variants associated significantly with type 2 diabetes (odds ratios [ORs] 1.35 and 2.46; P = 0.045 and <0.001). Carriers of minor alleles of two other PPARGC1A variants, both in strong linkage disequilibrium and associated with lower DNA damage, showed lower prevalence of CVD (ORs 0.53 and 0.65; P = 0.030 and 0.175). Moreover, we found that physical activity correlated negatively with DNA damage. CONCLUSIONS--It is plausible that low physical activity combined with risk haplotyes contribute to the high prevalence of type 2 diabetes in this population. We propose that PPARGC1A influences development of type 2 diabetes and CVD via DNA damage. Increasing physical activity, which induces PPARGC1A expression, is a potential strategy to slow DNA damage, thereby decreasing the risk of CVD for individuals with type 2 diabetes. [ABSTRACT FROM AUTHOR]

Diet is an important environmental factor interacting with our genes to modulate the likelihood of developing lipid disorders and, consequently, cardiovascular disease risk. Our objective was to study whether dietary intake modulates the association between APOA5 gene variation and body weight in a large population-based study. Specifically, we have examined the interaction between the APOA5–1131T>C and 56C>G (S19W) polymorphisms and the macronutrient intake (total fat, carbohydrate, and protein) in their relation to the body mass index (BMI) and obesity risk in 1,073 men and 1,207 women participating in the Framingham Offspring Study. We found a consistent and statistically significant interaction between the −1131T>C single-nucleotide polymorphism (SNP; but not the 56C>G) and total fat intake for BMI. This interaction was dose-dependent, and no statistically significant heterogeneity by gender was detected. In subjects homozygous for the −1131T major allele, BMI increased as total fat intake increased. Conversely, this increase was not present in carriers of the −1131C minor allele. Accordingly, we found significant interactions in determining obesity and overweight risks. APOA5–1131C minor allele carriers had a lower obesity risk (OR, 0.61, 95%; CI, 0.39–0.98; P = 0.032) and overweight risk (OR, 0.63, 95%; CI, 0.41–0.96; P = 0.031) compared with TT subjects in the high fat intake group (≥30% of energy ) but not when fat intake was low (OR, 1.16, 95%; CI, 0.77–1.74; P = 0.47 and OR = 1.15, 95%; CI, 0.77–1.71; P = 0.48) for obesity and overweight, respectively). When specific fatty acid groups were analyzed, monounsaturated fatty acids showed the highest statistical significance for these interactions. In conclusion, the APOA5–1131T>C SNP, which is present in approximately 13% of this population, modulates the effect of fat intake on BMI and obesity risk in both men and women. [ABSTRACT FROM AUTHOR]

We developed a rapid, economical method for high-resolution quantitative trait locus (QTL) mapping using microarrays for selective genotyping of pooled DNA samples. We generated 21,207 F2 flies from two inbred Drosophila melanogaster strains with known QTLs affecting lifespan, and hybridized DNA pools of young and old flies to microarrays. We used changes of gene frequency of 2,326 single-feature polymorphisms (SFPs) to map previously identified and additional QTLs affecting lifespan. [ABSTRACT FROM AUTHOR]

The field of nutrigenomics shows tremendous promise for improved understanding of the effects of dietary intake on health. The knowledge that metabolic pathways may be altered in individuals with genetic variants in the presence of certain dietary exposures offers great potential for personalized nutrition advice. However, although considerable re- sources have gone into improving technology for measurement of the genome and biological systems, dietary intake assessment remains in-adequate. Each of the methods currently used has limitations that may be exaggerated in the context of gene x nutrient interaction in large multiethnic studies. Because of the specificity of most gene x nutrient interactions, valid data are needed for nutrient intakes at the individual level. Most statistical adjustment efforts are designed to improve estimates of nutrient intake distributions in populations and are unlikely to solve this problem. An improved method of direct measurement of individual usual dietary intake that is unbiased across populations is urgently needed. [ABSTRACT FROM AUTHOR]

Mixed linear model (MLM) methods have proven useful in controlling for population structure and relatedness within genome-wide association studies. However, MLM-based methods can be computationally challenging for large datasets. We report a compression approach, called 'compressed MLM', that decreases the effective sample size of such datasets by clustering individuals into groups. We also present a complementary approach, 'population parameters previously determined' (P3D), that eliminates the need to re-compute variance components. We applied these two methods both independently and combined in selected genetic association datasets from human, dog and maize. The joint implementation of these two methods markedly reduced computing time and either maintained or improved statistical power. We used simulations to demonstrate the usefulness in controlling for substructure in genetic association datasets for a range of species and genetic architectures. We have made these methods available within an implementation of the software program TASSEL. [ABSTRACT FROM AUTHOR]

Objective: We aimed to identify hemoglobin A1c (HbA1c)-associated genetic variants and examine their implications for glycemic status evaluated by HbA1c in U.S. Hispanics/Latinos with diverse genetic ancestries.Research Design and Methods: We conducted a genome-wide association study (GWAS) of HbA1c in 9,636 U.S. Hispanics/Latinos without diabetes from the Hispanic Community Health Study/Study of Latinos, followed by a replication among 4,729 U.S. Hispanics/Latinos from three independent studies.Results: Our GWAS and replication analyses showed 10 previously known and novel loci associated with HbA1c at genome-wide significance levels (P < 5.0 × 10-8). In particular, two African ancestry-specific variants, HBB-rs334 and G6PD-rs1050828, which are causal mutations for sickle cell disease and G6PD deficiency, respectively, had ∼10 times larger effect sizes on HbA1c levels (β = -0.31% [-3.4 mmol/mol]) and -0.35% [-3.8 mmol/mol] per minor allele, respectively) compared with other HbA1c-associated variants (0.03-0.04% [0.3-0.4 mmol/mol] per allele). A novel Amerindian ancestry-specific variant, HBM-rs145546625, was associated with HbA1c and hematologic traits but not with fasting glucose. The prevalence of hyperglycemia (prediabetes and diabetes) defined using fasting glucose or oral glucose tolerance test 2-h glucose was similar between carriers of HBB-rs334 or G6PD-rs1050828 HbA1c-lowering alleles and noncarriers, whereas the prevalence of hyperglycemia defined using HbA1c was significantly lower in carriers than in noncarriers (12.2% vs. 28.4%, P < 0.001). After recalibration of the HbA1c level taking HBB-rs334 and G6PD-rs1050828 into account, the prevalence of hyperglycemia in carriers was similar to noncarriers (31.3% vs. 28.4%, P = 0.28).Conclusions: This study in U.S. Hispanics/Latinos found several ancestry-specific alleles associated with HbA1c through erythrocyte-related rather than glycemic-related pathways. The potential influences of these nonglycemic-related variants need to be considered when the HbA1c test is performed. [ABSTRACT FROM AUTHOR]

We recently reported that epicatechin, a bioactive compound that occurs naturally in various common foods, promoted general health and survival of obese diabetic mice. It remains to be determined whether epicatechin extends health span and delays the process of aging. In the present study, epicatechin or its analogue epigallocatechin gallate (EGCG) (0.25% w/v in drinking water) was administered to 20-mo-old male C57BL mice fed a standard chow. The goal was to determine the antiaging effect. The results showed that supplementation with epicatechin for 37 wk strikingly increased the survival rate from 39 to 69%, whereas EGCG had no significant effect. Consistently, epicatechin improved physical activity, delayed degeneration of skeletal muscle (quadriceps), and shifted the profiles of the serum metabolites and skeletal muscle general mRNA expressions in aging mice toward the profiles observed in young mice. In particular, we found that dietary epicatechin significantly reversed age-altered mRNA and protein expressions of extracellular matrix and peroxisome proliferator-activated receptor pathways in skeletal muscle, and reversed the age-induced declines of the nicotinate and nicotinamide pathway both in serum and skeletal muscle. The present study provides evidence that epicatechin supplementation can exert an antiaging effect, including an increase in survival, an attenuation of the aging-related deterioration of skeletal muscles, and a protection against the aging-related decline in nicotinate and nicotinamide metabolism. [ABSTRACT FROM AUTHOR]

Background: Insect metamorphosis relies on temporal and spatial cues that are precisely controlled. Previous studies in Drosophila have shown that untimely activation of genes that are essential to metamorphosis results in growth defects, developmental delay and death. Multiple factors exist that safeguard these genes against dysregulated expression. The list of identified negative regulators that play such a role in Drosophila development continues to expand. Results: By using RNAi transgene-induced gene silencing coupled to spatio/temporal assessment, we have unraveled an important role for the Drosophila dopamine 1-like receptor, Dop1R2, in development. We show that Dop1R2 knockdown leads to pre-adult lethality. In adults that escape death, abnormal wing expansion and/or melanization defects occur. Furthermore we show that salivary gland expression of this GPCR during the late larval/prepupal stage is essential for the flies to survive through adulthood. In addition to RNAi-induced effects, treatment of larvae with the high affinity D1-like receptor antagonist flupenthixol, also results in developmental arrest, and in morphological defects comparable to those seen in Dop1R2 RNAi flies. To examine the basis for pupal lethality in Dop1R2 RNAi flies, we carried out transcriptome analysis. These studies revealed up-regulation of genes that respond to ecdysone, regulate morphogenesis and/or modulate defense/immunity. Conclusion: Taken together our findings suggest a role for Dop1R2 in the repression of genes that coordinate metamorphosis. Premature release of this inhibition is not tolerated by the developing fly. [ABSTRACT FROM AUTHOR]

Background: Omega-3 (n-3) fatty acid (FA) consumption is thought to improve depressive symptoms. However, current evidence is limited, and whether this association exists among Puerto Ricans, a population burdened by depression, remains uncertain.Objectives: We examined the association between ω-3 FA biomarkers and depressive symptoms as well as the potential influence of oxidative stress.Methods: Baseline and longitudinal analyses were conducted in the Boston Puerto Rican Health Study (n= 787; participants aged 57 ± 0.52 y, 73% women). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration, a measure of oxidative stress, and erythrocyte FA composition were collected at baseline. We calculated the omega-3 index as the sum of eicosapentaenoic and docosahexaenoic acids, expressed as a percentage of total FAs. Baseline and 2-y depressive symptoms were characterized by using the Center for Epidemiological Studies-Depression Scale (CES-D). Statistical analyses included linear and logistic regression.Results: Urinary 8-OHdG concentration tended to modify the relation between the erythrocyte omega-3 index and baseline CES-D score (P-interaction = 0.10). In stratified analyses, the omega-3 index was inversely associated with CES-D score (β = -1.74, SE = 0.88;P= 0.02) among those in the top quartile of 8-OHdG concentration but not among those in the lower quartiles. The relation between the omega-3 index and CES-D at 2 y was more clearly modified by 8-OHdG concentration (P-interaction = 0.04), where the omega-3 index was inversely associated with CES-D at 2 y, adjusted for baseline (β = -1.66, SE = 0.66;P= 0.02), only among those with elevated 8-OHdG concentrations. Among individuals not taking antidepressant medications and in the top tertile of urinary 8-OHdG concentration, the omega-3 index was associated with significantly lower odds of a CES-D score ≥16 at baseline (OR: 0.72; 95% CI: 0.53, 0.96) but not at 2 y (OR: 0.83; 95% CI: 0.60, 1.15).Conclusions: An inverse association between the omega-3 index and depressive symptoms was observed among participants with elevated oxidative stress biomarkers. These data suggest that oxidative stress status may identify those who might benefit from ω-3 FA consumption to improve depressive symptoms. [ABSTRACT FROM AUTHOR]

Lipoprotein subclass concentrations are modifiable markers of cardiovascular disease risk. Fenofibrate is known to show beneficial effects on lipoprotein subclasses, but little is known about the role of genetics in mediating the responses of lipoprotein subclasses to fenofibrate. A recent genomewide association study (GWAS) associated several single nucleotide polymorphisms (SNPs) with lipoprotein measures, and validated these associations in two independent populations. We used this information to construct genetic risk scores (GRSs) for fasting lipoprotein measures at baseline (pre-fenofibrate), and aimed to examine whether these GRSs also associated with the responses of lipoproteins to fenofibrate. Fourteen lipoprotein subclass measures were assayed in 817 men and women before and after a three week fenofibrate trial. We set significance at a Bonferroni corrected alpha <0.05 (p < 0.004). Twelve subclass measures changed with fenofibrate administration (each p = 0.003 to <0.0001). Mixed linear models which controlled for age, sex, body mass index (BMI), smoking status, pedigree and study-center, revealed that GRSs were associated with eight baseline lipoprotein measures (p < 0.004), however no GRS was associated with fenofibrate response. These results suggest that the mechanisms for changes in lipoprotein subclass concentrations with fenofibrate treatment are not mediated by the genetic risk for fasting levels. [ABSTRACT FROM AUTHOR]

In murine schistosomiasis, immunopathology and cytokine production in response to parasite eggs are uneven and strain dependent. CBA/J (CBA) mice develop severe hepatic granulomatous inflammation associated with prominent Th17 cell responses driven by dendritic cell (DC)-derived IL-1β and IL-23. Such Th17 cells fail to develop in low-pathology C57BL/6 (BL/6) mice, and the reasons for these strain-specific differences in APC reactivity to eggs remain unclear.We show by gene profiling that CBA DCs display an 18- fold higher expression of the C-type lectin receptor CD209a, a murine homolog of human DC-specific ICAM-3-grabbing nonintegrin, compared with BL/6 DCs. Higher CD209a expression was observed in CBA splenic and granuloma APC subpopulations, but only DCs induced Th17 cell differentiation in response to schistosome eggs. Gene silencing in CBA DCs and overexpression in BL/6 DCs demonstrated that CD209a is essential for egg-elicited IL-1β and IL-23 production and subsequent Th17 cell development, which is associated with SRC, RAF-1, and ERK1/2 activation. These findings reveal a novel mechanism controlling the development of Th17 cell-mediated severe immunopathology in helminthic disease. [ABSTRACT FROM AUTHOR]

The interaction between a functional apolipoprotein A2 gene (APOA2) variant and saturated fatty acids (SFAs) for the outcome of body mass index (BMI) is among the most widely replicated gene-nutrient interactions. Whether this interaction can be extrapolated to food-based sources of SFAs, specifically dairy foods, is unexplored. Cross-sectional analyses were performed in 2 U.S. population--based samples. We evaluated interactions between dairy foods and APOA2 2265T > C (rs5082) for BMI in the Boston Puerto Rican Health Study (n = 955) and tested for replication in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study (n = 1116). Dairy products were evaluated as total dairy, higher-fat dairy (>1%), and low-fat dairy (≤1%) in servings per day, dichotomized into high and low based on each population median and also as continuous variables. We identified a statistically significant interaction between the APOA2 2265T > C variant and higher-fat dairy food intake in the Boston Puerto Ricans (P-interaction = 0.028) and replicated this relation in the GOLDN study (P-interaction = 0.001). In both groups, individuals with the previously demonstrated SFA-sensitive genotype (CC) who consumed a greater amount of higher-fat dairy foods had greater BMI (P = 0.013 in Boston Puerto Ricans; P = 0.0007 in GOLDN women) compared with those consuming less of the higher-fat dairy foods. The results expand the understanding of the metabolic influence of dairy products, an important food group for which variable relations to body weight may be in part genetically based. Moreover, these findings suggest that other strongly demonstrated gene-nutrient relations might be investigated through appropriate food-based, translatable avenues and may be relevant to dietary management of obesity. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Insulin receptor substrate 1 (IRS1) is central to insulin signaling pathways. This study aimed to examine the association of IRS 1 variants with insulin resistance (IR) and related phenotypes, as well as potential modification by diet. RESEARCH DESIGN AND METHODS--Two IRS1 variants (rs7578326 and rs2943641) identified by genome-wide association studies as related to type 2 diabetes were tested for their associations with IR and related traits and interaction with diet in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study (n = 820) and the Boston Puerto Rican Health Study (BPRHS) (n = 844). RESULTS--Meta-analysis indicated that rs7578326 G-allele carriers and rs2943641 T-allele carriers had a lower risk of IR, type 2 diabetes, and metabolic syndrome (MetS). Significant interactions on IR and MetS were found for these two variants and their haplotypes with diet. In GOLDN, rs7578326 G-allele carriers and rs2943641 T-allele carriers and their haplotype G-T carriers had a significantly lower risk of IR and MetS than noncarriers only when the dietary saturated fatty acid-to-carbohydrate ratio was low (≤0.24). In both GOLDN (P = 0.0008) and BPRHS (P = 0.011), rs7578326 G-allele carriers had a lower risk of MetS than noncarriers only when dietary monounsaturated fatty acids were lower than the median intake of each population. CONCLUSIONS--IRS1 variants are associated with IR and related traits and are modulated by diet in two populations of different ancestries. These findings suggest that IRS1 variants have important functions in various metabolic disorders and that dietary factors could modify these associations. [ABSTRACT FROM AUTHOR]

Objective: Published data concerning associations between 1RS1 variants and type 2 diabetes and related traits have been inconsistent. We examined the relationship between common variants in IRS1, type 2 diabetes, and related traits including insulin resistance, hyperglycemia and DNA damage in the Boston Puerto Rican Health Study. Methods: We genotyped six common 1RS1 variants in an adult Puerto Rican population (n=1132) and tested for association with risk of type 2 diabetes and related traits. Results: SNPs rs934167 and rs 1801123 showed significant association with fasting glucose concentrations (p = 0.005 and p = 0.016, respectively) and rs934167 showed significant association with plasma insulin levels (p = 0.005). Carriers of the rs934167 minor allele had significantly higher HOMA-IR and lower QUICKI (p = 0.001 andp = 0.001, respectively), and a 40% and 58% greater likelihood of being hyperglycaemic or hyperinsulinemic (OR = 1.40 and 1.58; p = 0.013 and 0.002, respectively). However, they exhibited only a marginally significant trend towards having type 2 diabetes (OR=1.27, p = 0.077). Furthermore, carriers of the haplotype C-T of the rs934167 and rsl801123 minor alleles showed consistent patterns of associations after correction for multiple testing. In addition, the G972R (rs 1801278) minor allele was significantly associated with higher urinary 8-OHdG concentrations (p = 0.020) and plasma CRP levels (p = 0.035). Conclusions: Our results support 1RS1 variants associated with type 2 diabetes risk in adult Puerto Ricans. Moreover, we report the novel finding that IRS1 variant G972R (rs 1801278) may contribute to oxidative DNA damage and inflammation. [ABSTRACT FROM AUTHOR]

PSMD3 encodes subunit 3 of the 26S proteasome, which is involved in regulating insulin signal transduction, and dietary factors could potentially regulate the function of this gene. We aimed to investigate the associations of PSMD3 variants with glucose-related traits and the interactions of those variants with dietary fat and carbohydrate for glucose-related traits in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study and to replicate the findings in the Boston Puerto Rican Health Study (BPRHS). Ten single nucleotide polymorphisms (SNPs) were selected, covering 90% the genetic variations in or near PSMD3. Minor allele (C) carriers of rs4065321 had higher homeostasis model assessment of insulin resistance (HOMA-IR) than noncarriers in males of both the GOLDN (P = 0.022) and BPRHS (P = 0.036). Minor allele (T) carriers of rs709592 had significantly higher HOMA-IR (P = 0.032) than C homozygotes in the GOLDN, whereas the T allele carriers of rs709592 tended to have higher HOMA-IR (P= 0.08) than C homozygotes in the BPRHS. In the GOLDN, there was an interaction between rs709592 and dietary carbohydrate on HOMA-IR (P = 0.049). Subjects carrying the T allele of rs709592 had higher HOMA-IR compared only with noncarriers with low carbohydrate intake (≤49.1% energy; P = 0.004). SNPs rs4065321 and rs709592 both significantly interacted with dietary MUFAs and carbohydrate on glucose concentrations in the GOLDN. Our study suggests that PSMD3 variants are associated with insulin resistance in populations of different ancestries and that these relationships may also be modified by dietary factors. [ABSTRACT FROM AUTHOR]

The antibacterial activity of royalisin, an antimicrobial peptide from the royal jelly produced by honeybees, has been addressed extensively. However, its mechanism of action remains unclear. In this study, a recombinant royalisin, RAcc-royalisin from the royal jelly of Asian honeybee Apis cerana cerana, was expressed by fusing with glutathione S-transferase (GST) in Escherichia coli BL21, isolated and purified. The agar dilution assays with inhibition zone showed that RAcc-royalisin, similar to nisin, inhibits the growth of Gram-positive bacteria. The antibacterial activity of RAcc-royalisin was associated with its concentration, and was weakened by heat treatment ranging from 55°C to 85°C for 15 min. Both RAcc-royalisin and nisin exhibited the minimum inhibitory concentrations (MIC) of 62.5 µg/ml, 125 µg/ml, and 250 µg/ml against Gram-positive bacterial strains, Bacillus subtilis and Micrococcus flavus and Staphyloccocus aureus in the microplate assay, respectively. However, RAcc-royalisin did not show antimicrobial activity against tested Gram-negative bacterial and fungal strains. The antibacterial activity of RAcc-royalisin agrees well with the decrease in bacterial cell hydrophobicity, the leakage of 260-nm absorbing materials, and the observation by transmission electron microscopy, all indicating that RAcc-royalisin induced the disruption and dysfunction of cell walls and membranes. This is the first report detailing the antibacterial mechanism of royalisin against Gram-positive bacteria, and provides insight into the application of recombinant royalisin in food and pharmaceutical industries as an antimicrobial agent. [ABSTRACT FROM AUTHOR]

The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene differs in frequency in various ethnic groups that have differing prevalence of age-related cognitive impairments. We used a series of neuro-psychological tests to examine the association of the MTHFR C677T polymorphism with cognition and depression and also to assess whether genotype modifies the association of folate and homocysteine with these outcomes. This study analyzed pooled cross-sectional data from 2 ethnically diverse cohorts of community-living adults: the Boston Puerto Ricen Health Study (n = 939) and the Nutrition, Aging, and Memory in Elders study (n = 1017). Individuals in both cohorts underwent anthropometric and laboratory measurements and dietary and health assessments using validated questionnaires between the years 2003 and 2007. Cognitive outcomes included measures of global cognition [Mini-Mental Status Exam (MMSE)], depression (Center for Epidemiological Studies Depression Scale), and 3 factor scores for the domains of attention, executive function, and memory that were derived from a detailed set of neuropsychological tests. Low plasma vitamin B-12 concentrations were associated with poorer MMSE scores and higher depression scores, and low vitamin B-6 concentrations were associated with lower MMSE and worse attention and executive function in the multivariate analysis. In contrast, MTHFR genotype, folate, and homocysteine were not associated with cognition or depression in either ethnicity-pooled or stratified analysis. The current study did not find evidence of an association between the MTHFR C677T TT genotype and impaired cognition or depression in a population with adequate folate status and a high prevalence of cognitive impairment and depression. [ABSTRACT FROM AUTHOR]

Evidence that physical activity (PA) modulates the association between the fat mass and obesity-associated gene (FTO) and BMI is emerging; however, information about dietary factors modulating this association is scarce. We investigated whether fat and carbohydrate intake modified the association of FTO gene variation with BMI in two populations, including participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study (n = 1069) and in the Boston Puerto Rican Health (BPRHS) study (n = 1094). We assessed energy, nutrient intake, and PA using validated questionnaires. Genetic variability at the FTO locus was characterized by polymorphisms rs9939609 (in the GOLDN) and rs1121980 (in the GOLDN and BPRHS). We found significant interactions between PA and FTO on BMI in the GOLDN but not in the BPRHS. We found a significant interaction between SFA intake and FTO on BMI, which was stronger than that of total fat and was present in both populations (P-interaction = 0.007 in the GOLDN and P-interaction = 0.014 in BPRHS for categorical; and P-interaction = 0.028 in the GOLDN and P-interaction = 0.041 in BPRHS for continuous SFA). Thus, homozygous participants for the FTO-risk allele had a higher mean BMI than the other genotypes only when they had a high-SFA intake (above the population mean: 29.7 ± 0.7 vs. 28.1 ± 0.5 kg/m²; P = 0.037 in the GOLDN and 33.6. ± 0.8 vs. 31.2 ± 0.4 kg/m²; P = 0.006 in BPRHS). No associations with BMI were found at lower SFA intakes. We found no significant interactions with carbohydrate intake. In conclusion, SFA intake modulates the association between FTO and BMI in American populations. [ABSTRACT FROM AUTHOR]

PLIN4 is a member of the PAT family of lipid storage droplet (LSD) proteins. Associations between seven single nucleotide polymorphisms (SNPs) at human PLIN4 with obesity related phenotypes were investigated using meta-analysis followed by a determination if these phenotypes are modulated by interactions between PLIN4 SNPs and dietary PUFA. Samples consisted of subjects from two populations of European ancestry. We demonstrated association of rs8887 with anthropometrics. Meta-analysis demonstrated significant interactions between the rs8887 minor allele with PUFA n3 modulating anthropometrics. rs884164 showed interaction with both n3 and n6 PUFA modulating anthropometric and lipid phenotypes. In silico analysis of the PLIN4 39UTR sequence surrounding the rs8887 minor A allele predicted a seed site for the human microRNA-522 (miR-522), suggesting a functional mechanism. Our data showed that a PLIN4 3′UTR luciferase reporter carrying the A allele of rs8887 was reduced in response to miR-522 mimics compared to the G allele. These results suggest variation at the PLIN4 locus, and its interaction with PUFA as a modulator of obesity related phenotypes, acts in part through creation of a miR-522 regulatory site. [ABSTRACT FROM AUTHOR]

Although methylenetetrahydrofolate reductase (MTHFR) genetic variants are associated with plasma homocysteine lHcy) and cardiovascular disease (CVD), little is known whether dietary fatty acid intake modulates these associations. The goal was to examine the interaction of MTHFR variants with dietary fatty acids influencing plasma Hcy in 995 Boston Puerto Rican adults. We found that plasma Hcy concentration was negatively correlated with )n-3) PUFA intake (r= -0.117; P= 0.022), and the ratio of (n-3):(n-6) PUFA in the diet )r= -0.122; P= 0.009). Further, 2 functional MTHFRvariants, 1 298A>C and 677C>T, which are not in linkage disequilibrium in this population, were significantly associated with hypertension (OR F 1.72, P = 0.024, and OR = 1.60, P = 0.002, respectively). In addition, the 1298A>C variant was significantly associated with CVD (OR = 3.32; P = 0.030). Importantly, this variant exhibited significant interactions with intakes of total and )n-6) PUFA and the ln-3(:(n-6( PUFA ratio of the diet. The plasma Hcy concentration of carriers of risk allele 1 298C was greater than that of noncarriers only when participants had consumed a high-PUFA diet (>7.8% energy) but was not greater when they had low intake of PUFA (>7.8% energy). In addition, participants with combined genotypes of both SNP (677 with 1298 AC or CC) who consumed high levels of (n-3) PUFA (>0.66% energy) had lower plasma Hcy compared with those who had the same genotype and consumed low levels of (n-3) PUFA (<0.66% energy). Our study suggests that dietary PUFA intake modulates the effect of 2 MTHFR variants on plasma Hcy in Boston Puerto Rican adults. [ABSTRACT FROM AUTHOR]

Despite the importance of total energy intake in circadian system regulation, no study has related human CLOCK gene polymorphisms and food-intake measures. The aim of this study was to analyze the associations of CLOCK single-nucleotide polymorphisms (SNPs) with food intake and to explore the specific role of the cytokine system. A total of 1100 individual participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study were included. Dietary intake was estimated with a validated questionnaire. Interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP1), tumor necrosis factor-α (TNF-α), IL-2 soluble receptor-α (IL-2sR-α) and adiponectin plasma concentrations were measured. Our results showed that four of five CLOCK SNPs selected were significantly associated with total energy intake (P<0.05). For SNP rs3749474, the energy intake and total fat, protein and carbohydrate intakes were significantly higher in minor allele carriers than in non-carriers. Frequency of the minor allele was greater in subjects with high energy intake than in those with low intake. Subjects with the minor allele were 1.33 times more likely to have high energy intake than non-carriers (95% CI 1.09–1.72, P=0.0350). All CLOCK SNPs were associated with plasma cytokine values, in particular with those that were highly correlated with energy intake: MCP1, IL-6 and adiponectin. Interestingly, minor allele carriers with high energy intake showed decreased cytokine values, which could be related with a lower anorectic effect and decreased sleep in these subjects. In conclusion, we show a novel association of genetic variation at CLOCK with total energy intake, which was particularly relevant for SNP rs3749474. Associations could be mediated through the alteration of cytokine levels that may influence energy intake and sleep pattern. [ABSTRACT FROM AUTHOR]

The article presents a study on the interaction among functional APOA2 polymorphism, food intake and body mass index (BMI) through the replication of a gene-diet interaction in three independent populations. It outlines the importance of characterizing gene-environment interactions since they are essential for the translation of genomics into clinical medicine. It notes that the gene-diet interaction which influence BMI and obesity have been strongly and consistently replicated.

Background: Apolipoprotein C3 (APOC3) modulates triglyceride metabolism through inhibition of lipoprotein lipase, but is itself regulated by insulin, so that APOC3 represents a potential mechanism by which glucose metabolism may affect lipid metabolism. Unfavorable lipoprotein profiles and impaired glucose metabolism are linked to cognitive decline, and all three conditions may decrease lifespan. Associations between apolipoprotein C3 (APOC3) gene polymorphisms and impaired lipid and glucose metabolism are well-established, but potential connections between APOC3 polymorphisms, cognitive decline and diabetes deserve further attention. Methods: We examined whether APOC3 single nucleotide polymorphisms (SNPs) m482 (rs2854117) and 3u386 (rs5128) were related to cognitive measures, whether the associations between cognitive differences and genotype were related to metabolic differences, and how diabetes status affected these associations. Study subjects were Hispanics of Caribbean origin (n = 991, aged 45-74) living in the Boston metropolitan area. Results: Cognitive and metabolic measures differed substantially by type II diabetes status. In multivariate regression models, APOC3 m482 AA subjects with diabetes exhibited lower executive function (P = 0.009), Stroop color naming score (P = 0.014) and Stroop color-word score (P = 0.022) compared to AG/GG subjects. APOC3 m482 AA subjects with diabetes exhibited significantly higher glucose (P = 0.032) and total cholesterol (P = 0.028) compared to AG/GG subjects. APOC3 3u386 GC/GG subjects with diabetes exhibited significantly higher triglyceride (P = 0.004), total cholesterol (P = 0.003) and glucose (P = 0.016) compared to CC subjects. Conclusions: In summary, we identified significant associations between APOC3 polymorphisms, impaired cognition and metabolic dysregulation in Caribbean Hispanics with diabetes. Further research investigating these relationships in other populations is warranted. [ABSTRACT FROM AUTHOR]

The scaffolding protein PDZ domain containing 1 (PDZK1) regulates the HDL receptor scavenger receptor class B type I. However, the effect of PDZKI genetic variants on lipids and metabolic syndrome lMetSl traits remains unknown. This study evaluated the association of 3 PDZK1 single nucleotide polymorphisms (SNP) (i33968C > T, i15371G > A, and i19738C > T) with lipids and risk of MetS and their potential interactions with diet. PDZK1 SNP were genotyped in 1000 participants (481 men, 519 women) included in the Genetics of Lipid Lowering Drugs and Diet Network study. Lipoprotein subfractions were measured by proton NMR spectroscopy and dietary intake was estimated using a validated questionnaire. The PDZK1_i33968C > T polymorphism was associated with MetS (P = 0.034), mainly driven by the association of the minor T allele with higher plasma triglycerides IP = 0.004) and VLDL (P= 0.021), and lower adiponectin concentrations (P = 0.022) than in participants homozygous for the major allele (C). We found a significant gene × BMI × diet interaction, in which the deleterious association of the i33968T allele with MetS was observed in obese participants with high PUFA and carbohydrate (P-values ranging from 0.004 to 0.020) intakes. Conversely, a there was a protective effect in nonobese participants with high PUFA intake (P< 0.05). These findings suggest that PDZK1_133968C >T genetic variants may be associated with a higher risk of exhibiting MetS. This gene × BMI × diet interaction offers the potential to identify dietary and other lifestyle changes that may obviate the onset of MetS in individuals with a specific genetic background. [ABSTRACT FROM AUTHOR]

The transcription factor 7-like 2 (TCF7L2) has been recently associated with diabetes risk, and it may exert its effect through metabolic syndrome (MetS)-related traits and be subjected to modification by environmental factors. We investigated the effect of single nucleotide polymorphisms (SNP), rs7903146 and rs12255372, within the TCF7L2 locus on postprandial lipemia and other MetS-related traits and their modulation by dietary fat. Data were collected from 1083 European Americans participating in the Genetics of Lipid Lowering Drugs and Diet Network Study. Carriers of the minor T allele at the CIT rs79031 46 SNP had higher fasting plasma glucose (P = 0.012), lower homeostasis model assessment of β cell function (P = 0.041), higher plasma VLDL (P = 0.035), and lower large LDL particle (P = 0.0071 concentrations and higher risk of MetS (P = 0.011) than CC individuals. Moreover, we identified significant interactions between this SNP and PUFA intake modulating fasting VLDL particle concentrations (P = 0.016) and postprandial triglycerides (TG) (P = 0.028), chylomicrons (P = 0.025), total VLDL (P = 0.026), and large VLDL (P= 0.018) concentrations. Thus, only T allele carriers with a PUFA intake ⩾7.36% of energy had elevated fasting plasma VLDL concentrations and postprandial TG-rich lipoproteins. These variables did not differ in I allele carriers and noncarriers in the low-PUFA intake group. Moreover, these significant interactions were due exclusively to (n-6) PUFA intake. In summary, high (n-6) PUFA intakes (⩾6.62% of energy intake) were associated with atherogenic dyslipidemia in carriers of the minor T allele at the TCF7L2 rs7903146 SNP and may predispose them to MetS, diabetes, and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Perilipin (PLIN) is the major protein surrounding lipid droplets in adipocytes and regulates adipocyte metabolism by modulating the interaction between lipases and triacylglycerol stores. Associations between PLIN gene polymorphisms and obesity risk have been described, but interactions with dietary macronutrients require further attention. We examined whether dietary macronutrients (e.g. carbohydrates and fats) modulated the associations of the common PLIN1 1482G > A (rs894160) single nucleotide polymorphism with obesity. We studied a population-based sample of Caribbean-origin Hispanics (n = 920, aged 45-74 y) living in the Boston area. Obesity measures (waist and hip circumference, BMI) did not differ between GG subjects and carriers of the A allele (GA and AA). In multivariate linear regression models, we found a significant interaction between complex carbohydrate intake as a continuous variable and PLIN1 1482 G > A genotype for waist circumference (P= 0.002). By dichotomizing complex carbohydrate intake, we found significantly different effects across PLIN 1 1482G > A genotypes. When complex carbohydrate intake was <144 g/d, waist circumference was larger in PLIN11482G > A carriers (P= 0.0241. Conversely, when complex carbohydrate intake was < 144 g/d, waist and hip circumferences were less in PLIN 1 1482G > A carriers (P< 0.05). These interactions were not found for simple sugars or total carbohydrates. We identified a significant gene-diet interaction associated with obesity at the PLIN locus. In subjects with higher complex carbohydrate intake, the minor allele was protective against obesity, whereas in subjects with lower carbohydrate intake, the minor allele was associated with increased obesity. These interactions may be relevant to dietary management of obesity. [ABSTRACT FROM AUTHOR]

The scavenger receptor class B type 1 ( SCARB1) gene is a key component in the reverse cholesterol transport pathway and thus plays an important role in lipid metabolism. Studies suggest that the SCARB1 gene may contribute to variation in plasma lipid levels at fasting; however, the results have been inconsistent, and it is unclear whether SCARB1 may also influence lipid response to dietary and pharmacologic interventions. In this study, we examined genetic variation in the SCARB1 gene in participants of the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study for associations with basal lipid levels, changes in lipid measures after dietary fat intake, and fenofibrate treatment. We found that the exon 1 variant SCARB1_G2S was significantly associated with postfenofibrate change for triglycerides (TG) ( P = 0.004). Subjects bearing SCARB1_G2S minor allele A tend to have higher responsiveness to fenofibrate in lowering TG. In summary, our study suggested that the SCARB1 gene may serve as a useful marker that predicts variation in baseline lipid levels, postprandial lipid response, and response to fenofibrate intervention. [ABSTRACT FROM AUTHOR]

The discovery of fetal mRNA transcripts in the maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma gene transcripts that were common to 9 term pregnant women and their newborns but absent or reduced in the mothers postpartum. RNA was isolated from peripheral or umbilical blood and hybridized to gene expression arrays. Gene expression, paired Student's t test, and pathway analyses were performed. In whole blood, 157 gene transcripts met statistical significance. These fetal biomarkers included 27 developmental genes, 5 sensory perception genes, and 22 genes involved in neonatal physiology. Transcripts were predominantly expressed or restricted to the fetus, the embryo, or the neonate. Real-time RT-PCR amplification confirmed the presence of specific gene transcripts; SNP analysis demonstrated the presence of 3 fetal transcripts in maternal antepartum blood. Comparison of whole blood and plasma samples from the same pregnant woman suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women. Transcriptional analysis of maternal whole blood identifies a unique set of biologically diverse fetal genes and has a multitude of clinical applications. [ABSTRACT FROM AUTHOR]

Chronic inflammation has been identified as an important component of the metabolic syndrome (MetS). Therefore, environmental and genetic factors contributing to the variation of inflammatory responses could affect individuals' susceptibility to MetS. We investigated the association between common IL β genetic polymorphisms, inflammation, and the MetS, and the modulation of diet-related variables (i.e., erythrocyte membrane fatty acid composition) in a white U.S. population. ILβ single nucleotide polymorphisms (SNP) )-1473G > C, -511G > A, -31T> C, 3966C > T, 6054G > AL clinical and biochemical measurements were characterized in a total of 1120 subjects 1540 males and 580 females) participating in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study. The 6054 G > A SNP was significantly associated with plasma C-reactive protein (P = 0.054), adiponectin (P = 0.021), and the prevalence of MetS IP = 0.0041. Moreover, there was a significant interaction between the 6054G > A SNP and erythrocyte membrane (n-3) PUFA (P = 0.019). Among subjects with low (n-3) PUFA content (below the median), the 6054 G allele was associated with increased risk of the MetS (OR = 3.29, 95%Cl = 1.49-7.26 for GG and OR = 1.95, 95%C) = 0.85-4.46 for GA, P< 0.001) compared with the AA genotype, but there were no significant genotype associations among subjects with high (n-3) PUFA content (above the medianl. Furtheranalyses supported a significant haplotype global effect on the MetS (P= 0.017) among subjects with low (n-3) PUFA content. These results suggested that IL β genetic variants were associated with measures of chronic inflammation and the MetS risk, and that genetic influences were more evident among subjects with low (n-3) PUFA intake. [ABSTRACT FROM AUTHOR]

Experimentally restricting dietary calories, while maintaining adequate dietary nutrient content, extends lifespan in phylogenetically diverse species; thus suggesting the existence of conserved pathways which can modify lifespan in response to energy intake. However, in some cases the impact on longevity may depend on the quality of the energy source. In Drosophila, restriction of dietary yeast yields considerable lifespan extension whereas isocaloric restriction of dietary sugar yields only modest extension, indicating that other diet-responsive pathways can modify lifespan in this species. In rodents, restricting intake of a single amino acid -- methionine - extends lifespan. Here we show that dietary methionine can modify lifespan in adult female, non-virgin Oregon-R strain Drosophila fed a chemically defined media. Compared to a diet containing 0.135% methionine and 15% glucose, high dietary methionine (0.405%) shortened maximum lifespan by 2.33% from 86 to 84 days and mean lifespan by 9.55% from 71.7 to 64.9 days. Further restriction of metbionine to 0.045% did not extend maximum lifespan and shortened mean lifespan by 1.95% from 71.1 to 70.3 days. Restricting glucose from 15% to 5% while holding methionine at a concentration of 0.135%, modestly extended maximum lifespan by 5.8% from 86 to 91 days, without extending mean lifespan. All these diet-induced changes were highly significant (log-rank p<0.0001). Notably, all four diets resulted in considerably longer life spans than those typically reported for flies fed conventional yeast and sugar based diets. Such defined diets can be used to identify lifespan-modifying pathways and specific gene-nutrient interactions in Drosophila. [ABSTRACT FROM AUTHOR]

Fibrates lower triglycerides and raise HDL cholesterol in dyslipidemic patients, but show heterogeneous treatment response. We used k-means clustering to identify three representative NMR lipoprotein profiles for 775 subjects from the GOLDN population, and study the response to fenofibrate in corresponding subgroups. The subjects in each subgroup showed differences in conventional lipid characteristics and in presence/absence of cardiovascular risk factors at baseline; there were subgroups with a low, medium and high degree of dyslipidemia. Modeling analysis suggests that the difference between the subgroups with low and medium dyslipidemia is influenced mainly by hepatic uptake dysfunction, while the difference between subgroups with medium and high dyslipidemia is influenced mainly by extrahepatic lipolysis disfunction. The medium and high dyslipidemia subgroups showed a positive, yet distinct lipid response to fenofibrate treatment. When comparing our subgroups to known subgrouping methods, we identified an additional 33% of the population with favorable lipid response to fenofibrate compared to a standard baseline triglyceride cutoff method. Compared to a standard HDL cholesterol cutoff method, the addition was 18%. In conclusion, by using constructing subgroups based on representative lipoprotein profiles, we have identified two subgroups of subjects with positive lipid response to fenofibrate therapy and with different underlying disturbances in lipoprotein metabolism. The total subgroup with positive lipid response to fenofibrate is larger than subgroups identified with baseline triglyceride and HDL cholesterol cutoffs. [ABSTRACT FROM AUTHOR]