An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances

Insights into β3-adrenoceptor agonism through comprehensive in silico investigation

Research onβ₃-AR, the new member of the adrenoceptor family, is in its infancy and few β₃-AR agonists have been approved for marketing to date. Meanwhile, β₃-AR exhibited obvious species differences in pharmacological properties, such as between human and animals, however, the 3D structure of human β₃-AR has not been published, which makes it difficult to understand the interaction between human β₃-AR and its agonists. Herein, binding patterns of β₃-AR agonists are explored starting from the Alphafold predicted structural model, and the obtained model was optimized by using molecular dynamics simulations. Moreover, the human β₃-AR and its agonists were subjected to molecular docking, dynamics simulations, binding free energy calculations and pharmacophore modeling to elucidate the characteristics of human β₃-AR activity pockets and agonist conformational relationships, including a hydrophobic group, a positively charged group as well as two hydrogen-bonded donors, which provide comprehensive insights into the interactions between human β₃-AR and its agonists.

Effect of β3‐adrenergic receptor gene polymorphism and lifestyle on overweight Japanese rural residents: A cross‐sectional study

Objectives

The β3‐adrenergic receptor (ADRB3) gene polymorphism has been implicated in obesity. Therefore, the contribution of ADRB3 Trp64Arg polymorphism to obesity‐related indicators was investigated, taking into account the lifestyle‐related factors in a Japanese rural population.

Methods

A total of 600 Japanese adults aged ≥40 years in a population‐based cohort study were analyzed. The ADRB3 polymorphism was determined using peripheral blood samples. Associations between genotype and body mass index (BMI), waist circumference (WC), and body fat (BF) percentage were examined, adjusting for lifestyle‐related factors, including daily nutrient intake.

Results

The frequency of Arg64 allele carriers was 36%. There was no significant difference in BMI, WC, or BF between the groups with or without the Trp64Arg polymorphism. Multivariable logistic regression analysis showed that the Trp64Arg polymorphism was not associated with these three indicators, but lifestyle factors including physical inactivity, higher energy and sodium consumption, and less animal protein intake were significantly related to increased WC and BF percentages.

Conclusions

The Trp64Arg polymorphism of ADRB3 gene did not contribute to increased BMI, WC, or BF. However, lifestyle‐related factors impacted these indicators in middle‐aged and older Japanese individuals living in rural areas.

Adrenergic receptors gene polymorphisms and autonomic nervous control of heart and vascular tone

Adrenergic receptors (ARs) are the primary targets of catecholamines released from the sympathetic nerve endings during their activation. ARs play a central role in autonomic nervous system and serve as important targets of widely used drugs. Several ARs gene polymorphisms were found to be associated with cardiovascular disease in previous clinical studies. Although more precise mechanism of the polymorphisms influence on autonomic control of cardiovascular system was studied in many previous physiological studies, their results are not unequivocal. This paper reviews the results of clinical and physiological studies focused on the impact of selected common single nucleotide polymorphisms of ARs genes involved in sympathetic control on cardiovascular system and its control. In summary, many studies assessed only a very limited range of cardiovascular control related parameters providing only very limited view on the complex cardiovascular control. The overview of partially contradicting results underlines a need to examine wider range of cardiovascular measures including their reactivity under various stress conditions requiring further study. It is expected that an effect of one given polymorphism is not very prominent, but it is suggested that even subtle differences in cardiovascular control could – on a longer time scale – lead to the development of severe pathological consequences.

The Association of Trp64Arg Polymorphism in the Beta-Adrenergic Receptor With Insulin Resistance: Meta-Analysis

BACKGROUND

Insulin resistance is a metabolic disorder that occurs in type 2 diabetes mellitus and obesity. Genetic factors such as β3-adrenoceptor polymorphism (Trp64Arg) may be involved in IR and insulin secretion. However, their association is controversial. Therefore, the current meta-analysis was conducted to clarify the relationship between the Trp64Arg and IR.

METHODS

The literature search was performed in PubMed, Embase, and Web of Science using the keywords "Receptors, Adrenergic, beta-3, Receptors, Adrenergic, Insulin Resistance, Protein-Coupled Receptor Kinase 3" from 2005 to February 7, 2021. We used a random-effects model to calculate the pooled effect size. We conducted subgroup analysis and regression analysis to identify sources of heterogeneity; and Egger's test and funnel plot were used to test publication bias. Finally, we conducted a sensitivity analysis.

RESULTS

We included eight papers with 1,586 subjects. There was a positive correlation between Trp64Arg mutation and insulin level (standardized mean difference = 0.20, 95% confidence intervals: 0.00 to 0.39, I² = 57.6%, p = 0.016). However, there was no association between Trp64Arg and the homeostasis model (HOMA-IR) assessment. Egger's tests showed no publication bias; the sensitivity analysis showed that our results were stable. Regression analysis revealed no source of heterogeneity.

CONCLUSION

Trp64Arg may be associated with IR. European ancestry, obesity, plasma insulin level, and test status may be potential factors affecting the relationship between Trp64Arg and IR.

Association analysis of potentially functional variants within 8p12 with schizophrenia in the Han Chinese population

OBJECTIVES

Chromosome 8p12 was first identified as a schizophrenia (SCZ) risk locus in Chinese populations and replicated in European populations. However, the underlying functional variants still need to be further explored. In this study, we sought to identify plausible causal variants within this locus.

METHODS

A total of 386 potentially functional variants from 29 genes within the 8p12 locus were analysed in 2403 SCZ cases and 2594 control subjects in the Han Chinese population using Affymetrix customised genotyping assays. SHEsisplus was used for association analysis. A multiple testing corrected p value (false discovery rate (FDR)) < .05 was considered significant, and an unadjusted p value < .05 was considered nominal evidence of an association.

RESULTS

We did not find significant associations between the tested variants and SCZ. However, nominal associations were found for rs201292574 (unadjusted p = .033, FDR p = .571; 95% confidence interval (CI): 0.265-0.945; TACC1, NP_006274.2:p.Ala211Thr) and rs45563241 (unadjusted p = .039, FDR p = .571; 95% CI: 1.023-1.866; a synonymous mutation in ADRB3).

CONCLUSIONS

Our results provide limited evidence for the associations between variants from protein coding regions in 8p12 and SCZ in the Chinese population. Analyses of both coding and regulatory variants in larger sample sizes are required to further clarify the causal variants for SCZ with this risk locus.

Can study of the ADRB3 gene help improve weight loss programs in obese individuals?

INTRODUCTION

Obesity is a chronic disease of multifactorial origin characterized by excess weight and excess fat accumulation, and whose etiology includes intrinsic (genetic, physiological, and metabolic) and extrinsic (social and cultural) factors. Fat accumulation is caused by a prolonged imbalance in the energy balance influenced, among other factors, by adaptive thermogenesis, which is triggered by cold environmental conditions, or by hypercaloric intake. Thermogenesis is regulated by the sympathetic nervous system and occurs in the muscle and brown adipose tissue. There are adrenergic receptors in brown adipose tissue, including the beta-3 adrenergic receptor (ADRB3), the main receptor for the regulation of thermogenesis. The presence in heterozygosis of an SNP-type polymorphism in the ADRB3 gene (Trp64Arg; rs4994) is associated with a lower lipolytic activity, a predisposition to obesity, and resistance to weight loss. The objective of this study was to analyze through a systematic review the weight loss program most appropriate for carriers.

METHODS

A retrospective study of published papers on rs4994 polymorphism in the SNP and PubMed databases was conducted.

RESULTS

Most published studies suggest the presence of obesity and resistance to weight loss in carriers, and report significant improvements in anthropometric parameters when patients receive fat-rich hypocaloric diets.

CONCLUSIONS

Based on these conclusions, specific nutritional and physical exercise guidelines are proposed for individuals carrying the Trp64Arg allele.

Beta-3-adrenergic Receptor rs4994 Polymorphism Is a Potential Biomarker for the Development of Nonalcoholic Fatty Liver Disease in Overweight/Obese Individuals

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases. Obesity is the most common and well-established risk factor for NAFLD, but there are large interindividual differences in the relationship between weight status and the development of NAFLD. Beta-3-adrenergic receptor (ADRB3) plays a key role in the development of visceral obesity and insulin resistance; however, the effect of ADRB3 polymorphisms on the risk of NAFLD remains unclear. We investigated whether or not a common rs4994 polymorphism (T190C) in the ADRB3 gene is associated with the risk of NAFLD through an increase in the body mass index (BMI) among the general population. We performed cross-sectional and longitudinal analyses in a total of 591 Japanese health screening program participants. Among the overweight or obese subjects, but not normal-weight subjects, individuals with the C/C genotype had a higher risk of developing NAFLD in comparison to those with other genotypes in the cross-sectional analysis (odds ratio: 4.40, 95% confidence interval (CI): 1.08–17.93). Meanwhile, the receiver operating characteristic curve indicated that the association between an increase in the BMI and the presence of NAFLD in subjects with the C/C genotype (area under the curve: 0.91, 95% CI: 0.78–1.00) was more pronounced in comparison to subjects with other genotypes. These above-described findings were verified by the analyses using a replicated data set consisting of 5,000 random samples from original data sets. Furthermore, among the 291 subjects for whom longitudinal medical information could be collected and who did not have NAFLD at baseline, the Cox proportional hazard model also confirmed that overweight or obese status and the C/C genotype were concertedly related to the increased risk of NAFLD development. These results suggest that genotyping the ADRB3 rs4994 polymorphism may provide useful information supporting the development of personalized BMI-based preventive measures against NAFLD.

Association Between Trp64arg Polymorphism of the β3 adrenoreceptor Gene and Female Sex in Obese Turkish Children and Adolescents

PURPOSE

The β3-adrenergic receptor (ADRB3) is expressed in visceral adipose tissue and has been speculated to contribute to lipolysis, energy metabolism, and regulation of the metabolic rate. In this study, we aimed to investigate the association of polymorphism of the ADRB3 gene with the sex of children with obesity and related pathologies.

METHODS

ADRB3 gene trp64arg genotyping was conducted in 441 children aged 6-18 years. Among these subjects, 264 were obese (103 boys; 161 girls) and 179 were of normal weight (81 boys; 98 girls). In the obese group, fasting lipids, glucose and insulin levels, and blood pressure were measured. Metabolic syndrome (MS) was defined according to the modified World Health Organization criteria adapted for children.

RESULTS

The frequency of trp64arg genotype was similar in obese and normal weight children. In obese children, serum lipid, glucose, and insulin levels; homeostasis model assessment of insulin resistance (HOMA-IR) scores; and MS were not different between arg allele carriers (trp64arg) and noncarriers (trp64trp). In 264 obese children, genetic analysis results revealed that the arg allele carriers were significantly higher in girls than in boys (p=0.001). In the normal weight group, no statistically significant difference was found between genotypes of boys and girls (p=0.771).

CONCLUSION

Trp64arg polymorphism of the ADRB3 gene was not associated with obesity and MS in Turkish children and adolescents. Although no relationships were observed between the genotypes and lipids, glucose/insulin levels, or HOMA-IR, the presence of trp64arg variant was frequent in obese girls, which can lead to weight gain as well as difficulty in losing weight in women.

Beta 1, Beta 2 and Beta 3 Adrenergic Receptor Gene Polymorphisms in a Southeastern European Population

Genetic polymorphisms in β₁-, β₂- and β₃-adrenergic receptors (β-ARs) have been associated with chronic non-communicable disorders, such as cardiovascular diseases, asthma, chronic obstructive pulmonary disease (COPD) and obesity, as well as β-agonists and antagonists response and toxicity. The purpose of this study was to determine the frequency distribution of ADRB1 genetic variants Ser49Gly and Arg389Gly, ADRB2 variants Gly16Arg and Gln27Glu, ADRB3 variant Trp64Arg in a Southeastern European Caucasian (SEC) population sample and to establish a comparison with existing data from other human populations. A sample of 431 men and 590 women volunteered to participate in this genotyping analysis after anonymization and de-identification. Real Time PCR (Melting Curve Analysis) followed DNA extraction from buccal swabs and statistical analysis of the results was performed. The allele frequencies in the SEC population were Ser49 (90.3%), Arg389 (69.49%), Gly16 (61.61%), Gln27 (65.72%), and Trp64 (94.52%), while a Hardy-Weinberg Equilibrium (HWE) was detected in the population studied. Comparisons for the Ser49Gly, Gln27Glu, and Trp64Arg allele distributions demonstrated significant differences between SEC and the European group. European subgroups comparisons showed that allele distributions were similar for four of the five SNPs between SEC and Southwestern European Caucasians (SWC), while they were quite distinct from the Northwestern European Caucasians (NWC). These data underline the importance of interethnic variability of β-ARs genetic polymorphisms.

Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links

Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.

The mutation of Trp64Arg in β3-adrenoreceptor-encoding gene is significantly associated with increased hypertension risk and elevated blood pressure: a meta-analysis

This meta-analysis was implemented to test the association of a missense mutation, Trp64Arg, in β3-adrenoreceptor-encoding gene (ADRB3) with both hypertension risk and blood pressure (BP) changes. A systematic search of three publicly-available databases was launched to look for articles published as of December 2016. Qualification appraisal and data extraction were independently done by two researchers. Pooled estimates were expressed as odds ratio (OR) or weighted mean difference (WMD), and their 95% confidence intervals (95% CIs). There were separately 21 (3750/4225 patients/controls) and 17 (6100 subjects) individual studies for hypertension risk and BP changes. Integral analyses revealed that Trp64Arg mutation was associated with the significantly increased risk of hypertension, and particularly, the 64Trp/64Arg heterozygote carriers were 1.23-times more likely to develop hypertension compared with the 64Trp/64Trp homozygote carriers (OR = 1.23, 95% CI: 1.02∼1.46, P = 0.021). Publication bias was extremely low for all integral comparisons. In stratified analyses, significance was spotted in populations of Chinese descent, in retrospective studies, in hospital-based studies, in age-matched case-control studies, in studies enrolling patients with mean body mass index < 25 kg/m² and in studies with total sample size ≥ 240. Heterogeneity was improved for most stratified comparisons. Further in hypertensive patients, the 64Trp/64Arg heterozygote carriers had significantly higher systolic (WMD = 0.87 mmHg, 95% CI: 0.39∼1.35, P < 0.001) and diastolic (WMD = 0.88 mmHg, 95% CI: 0.59∼1.17, P < 0.001) BP than 64Trp/64Trp homozygote carriers. Altogether, ADRB3 gene Trp64Arg mutation was significantly associated with an increased predisposition toward hypertension and elevated systolic/diastolic BP in hypertensive patients, suggesting that Trp64Arg is an important hypertension-susceptibility marker.

ADRB3 polymorphism rs4994 (Trp64Arg) associates significantly with bodyweight elevation and dyslipidaemias in Saudis but not rs1801253 (Arg389Gly) polymorphism in ARDB1

Background

In some populations, obesity and body weight related disorders show a correlation with polymorphisms in three subtypes of beta-adrenoceptor (β1, β2, and β3) [ADRB1, ADRB2 and ADRB3] genes. We scanned for the polymorphism of Arg389Gly (rs1801253) in ADRB1 and Trp64Arg (rs4994) in ADRB3 genes in Saudi population to determine association, if any, of these polymorphisms with obesity and related disorders.

Methods

We studied 329 non-related adults (33.1% men and 66.9% women), aged 18–36 years. Anthropometric measurements were recorded, and Body mass index (BMI) and waist/hip ratio were calculated; leptin, insulin, lipidogram, and glucose concentrations were determined. ADRB1 and ADRB3 polymorphisms (Arg389Gly and Trp64Arg, respectively) were screened by DNA sequencing. The subjects were divided into three groups according to BMI: normal weight (BMI < 25 kg/m²), overweight (BMI ≥25.1–29.9 kg/m²) subjects, and obese (≥30 kg/m²).

Results

In the age-matched groups of the normal weight, overweight and obese male and female subjects, all anthropometric parameters were found to be significantly higher, and in the obese group, all biochemical parameters were significantly elevated compared to the normal weight controls. The allelic frequency of Gly389 ADRB1 did not differ amongst the three groups, whereas the frequency of Arg64 of ADRB3 gene was significantly higher in the overweight and obese subjects, compared with the normal weight subjects. In addition, subjects carrying Arg64 allele regardless of their BMI had a greater waist and hip circumference, W/H ratio, plasma cholesterol, triglyceride, LDL, leptin, insulin, and glucose level compared to those with the wild-type Trp allele.

Conclusion

The results of this study have shown a significant association between the Trp64Arg polymorphism in ADRB3 gene and the development of overweight and obesity in Saudi populations. It also has an influence on the levels of lipid, insulin, leptin, and glucose, whereas, Arg389Gly polymorphism in ADRB1 is not associated with overweight, obesity or dyslipidaemias in Saudis.

Majid H. Non-Synonymous Single-Nucleotide Polymorphisms and Physical Activity Interactions on Adiposity Parameters in Malaysian Adolescents

BACKGROUND

Several non-synonymous single-nucleotide polymorphisms (nsSNPs) have been shown to be associated with obesity. Little is known about their associations and interactions with physical activity (PA) in relation to adiposity parameters among adolescents in Malaysia.

METHODS

We examined whether (a) PA and (b) selected nsSNPs are associated with adiposity parameters and whether PA interacts with these nsSNPs on these outcomes in adolescents from the Malaysian Health and Adolescents Longitudinal Research Team study (n = 1,151). Body mass indices, waist-hip ratio, and percentage body fat (% BF) were obtained. PA was assessed using Physical Activity Questionnaire for Older Children (PAQ-C). Five nsSNPs were included: beta-3 adrenergic receptor (ADRB3) rs4994, FABP2 rs1799883, GHRL rs696217, MC3R rs3827103, and vitamin D receptor rs2228570, individually and as combined genetic risk score (GRS). Associations and interactions between nsSNPs and PAQ-C scores were examined using generalized linear model.

RESULTS

PAQ-C scores were associated with % BF (β = -0.44 [95% confidence interval -0.72, -0.16], p = 0.002). The CC genotype of ADRB3 rs4994 (β = -0.16 [-0.28, -0.05], corrected p = 0.01) and AA genotype of MC3R rs3827103 (β = -0.06 [-0.12, -0.00], p = 0.02) were significantly associated with % BF compared to TT and GG genotypes, respectively. Significant interactions with PA were found between ADRB3 rs4994 (β = -0.05 [-0.10, -0.01], p = 0.02) and combined GRS (β = -0.03 [-0.04, -0.01], p = 0.01) for % BF.

CONCLUSION

Higher PA score was associated with reduced % BF in Malaysian adolescents. Of the nsSNPs, ADRB3 rs4994 and MC3R rs3827103 were associated with % BF. Significant interactions with PA were found for ADRB3 rs4994 and combined GRS on % BF but not on measurements of weight or circumferences. Targeting body fat represent prospects for molecular studies and lifestyle intervention in this population.

Targeting β3-Adrenergic Receptors in the Heart: Selective Agonism and β-Blockade

Cardiac diseases, such as heart failure, remain leading causes of morbidity and mortality worldwide, with myocardial infarction as the most common etiology. HF is characterized by β-adrenergic receptor (βAR) dysregulation that is primarily due to the upregulation of G protein–coupled receptor kinases that leads to overdesensitization of β₁ and β₂ARs, and this clinically manifests as a loss of inotropic reserve. Interestingly, the “minor” βAR isoform, the β₃AR, found in the heart, lacks G protein–coupled receptor kinases recognition sites, and is not subject to desensitization, and as a consequence of this, in human failing myocardium, the levels of this receptor remain unchanged or are even increased. In different preclinical studies, it has been shown that β₃ARs can activate different signaling pathways that can protect the heart. The clinical relevance of this is also supported by the effects of β-blockers which are well known for their proangiogenic and cardioprotective effects, and data are emerging showing that these are mediated, at least in part, by enhancement of β₃AR activity. In this regard, targeting of β₃ARs could represent a novel potential strategy to improve cardiac metabolism, function, and remodeling.

Association of β3-adrenergic receptor rs4994 polymorphisms with the risk of type 2 diabetes: A systematic review and meta-analysis

AIM

The association of ADRB3 polymorphism with the risk of T2DM remains unclear perhaps due to different ethnicities and small study sizes. We systemically evaluated the association of β3-adrenergic receptor(ADRB3)rs4994 and type 2 diabetes(T2DM) by pooling all of the case-control studies reported, and also elucidated the association according to the ethnicity and obesity of the subjects.

METHODS

A literature search was conducted using PubMed, EMBASE, Cochrane Library, Korean scientific database, Chinese medical databases, and the Indian medical database to identify eligible studies for determining the association of ADRB3 rs4994 and T2DM risk. The association was examined in five genetic models: the allelic(AG), recessive(RG), dominant(DG), homozygous(HMG), and heterozygous(HTG) genetic models. Subgroup analyses stratified by ethnicity(Asians and others) were assessed.

RESULTS

This meta-analysis included 17 eligible studies meeting Hardy-Weinberg equilibrium consisting of 4864 patients with T2DM(cases) and 8779 people without diabetes(controls). All models had no heterogeneity or publication bias in the meta-analysis including all subjects. ADRB3 rs4994 polymorphism of all subjects was significantly associated with an increased risk of T2DM in all genetic models with random effects: AG(OR=1.18, 95% CI: 1.05-1.32), RG(OR=1.76, 95% CI: 1.27-2.42), DG(OR=1.16, 95% CI: 1.03-1.30), HMG (OR=1.78, 95% CI: 1.25-2.52), and HTG(OR=1.11, 95% CI: 1.01-1.23). Furthermore, in sub-group analysis all models except HTG exhibited significant associations between T2DM and ADRB3 in Asians. However, the non-Asian group had no significant association in any genetic models with random effects.

CONCLUSIONS

Middle-age adult Asians with the ADRB3 rs4994 minor alleles are at increased risk of T2DM.

Association between Genetic Polymorphisms of the Beta Adrenergic Receptor and Diurnal Intraocular Pressure in Chinese Volunteers and Glaucoma Patients

PURPOSE

To evaluate the relationship between genetic polymorphisms of the beta adrenergic receptor (ADR) and diurnal intraocular pressure (IOP) in Chinese healthy volunteers, normal tension glaucoma (NTG) patients, and primary open-angle glaucoma (POAG) patients.

METHODS

Fifty healthy volunteers (control group), 55 untreated NTG patients, and 55 untreated POAG patients were recruited. IOP of both eyes was measured at 3-hour intervals from 0600 to 2400 hours. For control group, IOP data from the eye with better mean deviation (MD) of visual field was used for statistical analysis. For glaucoma patients, IOP data from the eye with a greater visual field defect was used for statistical analysis. Genetic polymorphisms of ADR were determined by direct DNA sequencing. The relationship between IOP and genetic polymorphisms was statistically analyzed.

RESULTS

R16G (A/G), L84L (G/A), and R175R (C/A) in β2-ADR showed significantly different allele in the three groups (p = 0.005, p = 0.045, and p = 0.045, respectively). For the POAG group, C/C of R389G (C/G) in β1-ADR had a significantly lower diurnal mean IOP (p < 0.001), peak IOP (p = 0.010), trough IOP (p < 0.001), and larger IOP range (p = 0.047) than G carriers; C/C of R389G (C/G) in β1-ADR and G carriers had parallel diurnal IOP curves but significantly different diurnal IOP levels (p = 0.001); C/C of Q27E (C/G) in β2-ADR had a significantly higher diurnal mean IOP (p = 0.045) than G carriers; G/G of L84L (G/A) in β2-ADR had a significantly higher diurnal mean IOP (p = 0.044) than A carriers; C/C of R175R (C/A) in β2-ADR had a significantly higher diurnal mean IOP (p = 0.044) than A carriers; T/T of W64R (T/C) in β3-ADR had a significantly smaller IOP range (p = 0.001) than C carriers.

CONCLUSION

Certain polymorphisms of β2-ADR showed significantly different genotype frequencies in healthy volunteers untreated NTG patients, and POAG patients. Polymorphisms of the β-ADR gene may alter the untreated IOP level of POAG patients.

Effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance related to beta-3 adrenergic receptor gene polymorphism Trp64Arg(C/T): Results from the Japan Diabetes Prevention Program

The beta‐3 adrenergic receptor (ADRB3), primarily expressed in adipose tissue, is involved in the regulation of energy metabolism. The present study hypothesized that ADRB3 (Trp64Arg, rs4994) polymorphisms modulate the effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance. Data were analyzed from 112 patients with impaired glucose tolerance in the Japan Diabetes Prevention Program, a lifestyle intervention trial, randomized to either an intensive lifestyle intervention group or usual care group. Changes in weight and metabolic parameters were measured after the 6‐month intervention. The ADRB3 polymorphisms were determined using the polymerase chain reaction restriction fragment length polymorphism method. Non‐carriers showed a greater weight reduction compared with the carriers in both the lifestyle intervention group and usual care group, and a greater increase of high‐density lipoprotein cholesterol levels than the carriers only in the lifestyle intervention group. ADRB3 polymorphisms could influence the effects of lifestyle interventions on weight and lipid parameters in impaired glucose tolerance patients.

Genetic association of APOA5 and APOE with metabolic syndrome and their interaction with health-related behavior in Korean men

BACKGROUND

Genome-wide association studies have been used extensively to identify genetic variants linked to metabolic syndrome (MetS), but most of them have been conducted in non-Asian populations. This study aimed to evaluate the association between MetS and previously studied single nucleotide polymorphisms (SNPs), and their interaction with health-related behavior in Korean men.

METHODS

Seventeen SNPs were genotyped and their association with MetS and its components was tested in 1193 men who enrolled in the study at Seoul National University Hospital.

RESULTS

We found that rs662799 near APOA5 and rs769450 in APOE had significant association with MetS and its components. The SNP rs662799 was associated with increased risk of MetS, elevated triglyceride (TG) and low levels of high-density lipoprotein, while rs769450 was associated with a decreased risk of TG. The SNPs showed interactions between alcohol drinking and physical activity, and TG levels in Korean men.

CONCLUSIONS

We have identified the genetic association and environmental interaction for MetS in Korean men. These results suggest that a strategy of prevention and treatment should be tailored to personal genotype and the population.

Effect of Zingiber officinale Supplementation on Obesity Management with Respect to the Uncoupling Protein 1 -3826A>G and ß3-adrenergic Receptor Trp64Arg Polymorphism

The present study aimed to investigate the effect of ginger (Zingiber officinale) supplementation on some obesity-associated parameters, with nutrigenetics approach. Accordingly, 80 eligible obese women (aged 18-45 years) were randomly assigned to receive either ginger (2-g ginger rhizomes powder as two 1-g tablets per day) or placebo supplements (corn starch with the same amount) for 12 weeks. Subjects were tested for changes in body weight, body mass index, waist and hip circumferences, body composition, appetite score, and dietary intake. Moreover, participants were genotyped for the -3826A>G and Trp64Arg polymorphisms of uncoupling protein 1 and ß3-adrenergic receptor genes, respectively. Over 12 weeks, ginger supplementation resulted in a slight but statistically significant decrease in all anthropometric measurements and total appetite score as compared with placebo group, which were more pronounced in subjects with the AA genotype for uncoupling protein 1 and Trp64Trp genotype for ß3-adrenergic receptor gene. However, there was no significant difference in changes of body composition and total energy and macronutrients intake between groups. In conclusion, our findings suggest that ginger consumption has potential in managing obesity, accompanying with an intervention-genotype interaction effect. However, further clinical trials need to explore ginger's efficacy as an anti-obesity agent in the form of powder, extract, or its active components.

β-3AR W64R Polymorphism and 30-Minute Post-Challenge Plasma Glucose Levels in Obese Children

OBJECTIVE

In this study, we aimed to investigate the association of W64R polymorphism of the β3-adrenergic receptor gene (β-3AR) with childhood obesity and related pathologies.

METHODS

β-3AR gene W64R genotyping was carried out in 251 children aged 6-18 years. Of these subjects, 130 were obese (62 boys) and 121 were normal-weight (53 boys). In the obese group, fasting lipids, glucose and insulin levels were measured. Oral glucose tolerance test (OGTT) was performed in 75 of the obese patients.

RESULTS

The frequency of W64R genotype was similar in obese and non-obese children. In obese children, relative body mass index, waist-to-hip ratio, serum lipid, glucose and insulin levels, as well as homeostasis model assessment of insulin resistance (HOMA-IR) scores were not different between Arg allele carriers (W64R and R64R) and noncarriers (W64W). In 75 obese children, OGTT results showed that Arg allele carriers had significantly higher 30-minute glucose levels (p=0.027).

CONCLUSION

W64R polymorphism of the β-3AR gene is not associated with obesity and waist-to-hip ratio in Turkish children. Although there were no relationships between the genotypes and lipid, glucose/insulin levels or HOMA-IR, the presence of W64R variant seemed to have an unfavorable influence on early glucose excursion after glucose loading.

Obesity is associated with a decrease in expression but not with the hypermethylation of thermogenesis-related genes in adipose tissues

Background

Impaired thermogenesis can promote obesity. Therefore, the aim of this study was to investigate whether the expression of thermogenesis-related genes is altered in adipose tissues of obese individuals and whether excessive methylation of their promoters is involved in this phenomenon.

Methods

The expression of genes encoding β adrenergic receptors (ADRBs), thyroid hormone receptors (THRs), 5’-iodothyronine deiodinases (DIOs), and uncoupling proteins (UCPs) was measured by real-time PCR in visceral and in subcutaneous adipose tissues of 58 obese (BMI >40 kg/m²) and 50 slim (BMI 20-24.9 kg/m²) individuals. The methylation status of these genes was studied by the methylation-sensitive digestion/real-time PCR method.

Results

The expression of ADRB2, ADRB3, THRA, THRB, DIO2, UCP2 was significantly lower in the adipose tissues of obese patients than in tissues of normal-weight individuals (P < 0.00001). In the obese, the expression of ADRB2, ADRB3, DIO2 was lower in visceral adipose tissue than in subcutaneous adipose tissue (P = 0.008, P = 0.002, P = 0.001, respectively). However, the mean methylation of CpG islands of these genes was similar in tissues with their high and low expression, and there was no correlation between the level of expression and the level of methylation.

Conclusions

Decreased expression of thermogenesis-related genes in adipose tissues of obese patients might result in the reduced reactivity to both hormonal and adrenergic stimuli and therefore in a lower potential to activate thermogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0395-2) contains supplementary material, which is available to authorized users.

ADRB3 gene promoter DNA methylation in blood and visceral adipose tissue is associated with metabolic disturbances in men

AIM

ADRB3 DNA hypermethylation was recently associated with dyslipidemia in familial hypercholesterolemia (FH). In this study, we verified whether ADRB3 DNA methylation in blood and visceral adipose tissue (VAT) was associated with obesity and its related complications.

METHODS

DNA methylation levels were measured in the blood of 61 FH men, and the blood and VAT of 30 severely obese men. Common ADRB3 polymorphisms were genotyped in all subjects.

RESULTS

Higher ADRB3 DNA methylation levels were significantly associated with lower low-density lipoprotein cholesterol levels (r = -0.40; p = 0.01) in FH, and with a lower waist-to-hip ratio (r = -0.55; p = 0.01) and higher blood pressure (r = 0.43; p = 0.05) in severely obese men. ADRB3 g.-843C>T and p.W64R polymorphisms were found to be strongly associated (p < 0.001) with ADRB3 DNA methylation and mRNA levels.

CONCLUSION

Although further studies are needed, these results suggest that epigenetic changes at the ADRB3 gene locus might be involved in the development of obesity and its related metabolic complications.

Association between single-nucleotide polymorphisms in six hypertensive candidate genes and hypertension among northern Han Chinese individuals

Hypertension is one of the leading risk factors for mortality. The renin-angiotensin-aldosterone system (RAAS) is a potent and powerful mediator in the homeostasis of hypertension. Here, the association between six candidate genes, renin, adrenoceptor β3, angiotensinogen, aldosterone synthase, angiotensin II receptor type 1 and angiotensin II receptor type 2, that are related to RAAS and essential hypertension (EH) was evaluated and explored in northern Chinese Han individuals. A case-control study including 1090 EH cases and 700 controls was performed. Eight single-nucleotide polymorphisms (SNPs), rs699, rs4762, rs5707, rs5186, rs4994, rs1799998, rs5193 and rs5194, located in the six genes were genotyped with TaqMan real-time PCR method. Statistical analysis software (SPSS 17.0) was used for descriptive statistics and association analyses. Among the six genes related to RAAS, the frequencies of rs4994 (ADRB3) and rs5194 (AGTR2) were found to be significantly different between the EH cases and controls (P < 0.05). Logistic regression analyses adjusted for covariates showed rs4994 to be closely associated with EH under the recessive (P = 0.019, odds ratio (OR) = 0.373, 95% confidence interval (CI) 0.163-0.851) and homozygous (P = 0.028, OR = 0.394, 95% CI 0.172-0.903) models. The association was also significantly close in the male subset (P < 0.05). Significant association was also observed between rs1799998 (CYP11B2) and EH (P < 0.05) in the dominant, additive and allelic models. These data demonstrated that ADRB3 rs4994 and CYP11B2 rs1799998 were significantly closely associated with EH in northern Han Chinese individuals. The CC of rs4994 and CC or C allele of rs1799998 might be protective genetic factors of hypertension.

The association of leptin with dyslipidemia, arterial hypertension and obesity in Kyrgyz (Central Asian nation) population

BACKGROUND

Leptin, an adipocytokine produced by adipose tissue, along with the traditional cardiometabolic risk factors, contributes to the development of cardiovascular complications. At the same time, ethnic features of adipocytokines have been insufficiently investigated, especially among Asians, who have an increased risk of cardiovascular complications compared with Europeans. Aim of study was to investigate the relationship between leptin levels and age, gender, anthropometric parameters, lipid parameters, arterial hypertension (AH), and obesity in the adult population of ethnic Kyrgyz people living in Central Asia.

RESULTS

In total, 322 ethnic Kyrgyz (145 men, 177 women) aged ≥ 30 years were studied. Waist and hip circumference, body mass index, blood glucose, lipids, leptin, and homeostatic model assessment were measured. Patients in the upper quartile of leptin levels had high values of BMI, WC, systolic and diastolic blood pressure, glucose, and HOMA index compared with patients with lower leptin levels. The prevalence of metabolic syndrome and AH increased with higher levels of leptin. Leptin positively correlated with BMI, WC, triglycerides, and glucose concentrations in patients of both sexes. According to the multivariate logistic regression analysis, elevated leptin levels increased by 30 times the risk of obesity in men, regardless of the presence of type 2 diabetes, and 17.7 times in women.

CONCLUSION

Leptin is associated with general and abdominal obesity, dyslipidemia, and insulin resistance in Kyrgyz patients.

Carnitine palmitoyltransferase 1B 531K allele carriers sustain a higher respiratory quotient after aerobic exercise, but β3-adrenoceptor 64R allele does not affect lipolysis: a human model

Carnitine palmitoyltransferase IB (CPT1B) and adrenoceptor beta-3 (ADRB3) are critical regulators of fat metabolism. CPT1B transports free acyl groups into mitochondria for oxidation, and ADRB3 triggers lipolysis in adipocytes, and their respective polymorphisms E531K and W64R have been identified as indicators of obesity in population studies. It is therefore important to understand the effects of these mutations on ADRB3 and CPT1B function in adipose and skeletal muscle tissue, respectively. This study aimed to analyze the rate of lipolysis of plasma indicators (glycerol, free fatty acids, and beta hydroxybutyrate) and fat oxidation (through the non-protein respiratory quotient). These parameters were measured in 37 participants during 30 min of aerobic exercise at approximately 62% of maximal oxygen uptake, followed by 30 min of recovery. During recovery, mean respiratory quotient values were higher in K allele carriers than in non-carriers, indicating low post-exercise fatty acid oxidation rates. No significant differences in lipolysis or lipid oxidation were observed between R and W allele carriers of ADRB3 at any time during the aerobic load. The substitution of glutamic acid at position 531 by lysine in the CPT1B protein decreases the mitochondrial beta-oxidation pathway, which increases the non-protein respiratory quotient value during recovery from exercise. This may contribute to weight gain or reduced weight-loss following exercise.

Whole-transcriptome, high-throughput RNA sequence analysis of the bovine macrophage response to Mycobacterium bovis infection in vitro

Background

Mycobacterium bovis, the causative agent of bovine tuberculosis, is an intracellular pathogen that can persist inside host macrophages during infection via a diverse range of mechanisms that subvert the host immune response. In the current study, we have analysed and compared the transcriptomes of M. bovis-infected monocyte-derived macrophages (MDM) purified from six Holstein-Friesian females with the transcriptomes of non-infected control MDM from the same animals over a 24 h period using strand-specific RNA sequencing (RNA-seq). In addition, we compare gene expression profiles generated using RNA-seq with those previously generated by us using the high-density Affymetrix® GeneChip® Bovine Genome Array platform from the same MDM-extracted RNA.

Results

A mean of 7.2 million reads from each MDM sample mapped uniquely and unambiguously to single Bos taurus reference genome locations. Analysis of these mapped reads showed 2,584 genes (1,392 upregulated; 1,192 downregulated) and 757 putative natural antisense transcripts (558 upregulated; 119 downregulated) that were differentially expressed based on sense and antisense strand data, respectively (adjusted P-value ≤ 0.05). Of the differentially expressed genes, 694 were common to both the sense and antisense data sets, with the direction of expression (i.e. up- or downregulation) positively correlated for 693 genes and negatively correlated for the remaining gene. Gene ontology analysis of the differentially expressed genes revealed an enrichment of immune, apoptotic and cell signalling genes. Notably, the number of differentially expressed genes identified from RNA-seq sense strand analysis was greater than the number of differentially expressed genes detected from microarray analysis (2,584 genes versus 2,015 genes). Furthermore, our data reveal a greater dynamic range in the detection and quantification of gene transcripts for RNA-seq compared to microarray technology.

Conclusions

This study highlights the value of RNA-seq in identifying novel immunomodulatory mechanisms that underlie host-mycobacterial pathogen interactions during infection, including possible complex post-transcriptional regulation of host gene expression involving antisense RNA.

Identification of shared genetic susceptibility locus for coronary artery disease, type 2 diabetes and obesity: a meta-analysis of genome-wide studies

Type 2 diabetes (2DM), obesity, and coronary artery disease (CAD) are frequently coexisted being as key components of metabolic syndrome. Whether there is shared genetic background underlying these diseases remained unclear. We performed a meta-analysis of 35 genome screens for 2DM, 36 for obesity or body mass index (BMI)-defined obesity, and 21 for CAD using genome search meta-analysis (GSMA), which combines linkage results to identify regions with only weak evidence and provide genetic interactions among different diseases. For each study, 120 genomic bins of approximately 30 cM were defined and ranked according to the best linkage evidence within each bin. For each disease, bin 6.2 achieved genomic significanct evidence, and bin 9.3, 10.5, 16.3 reached suggestive level for 2DM. Bin 11.2 and 16.3, and bin 10.5 and 9.3, reached suggestive evidence for obesity and CAD respectively. In pooled all three diseases, bin 9.3 and 6.5 reached genomic significant and suggestive evidence respectively, being relatively much weaker for 2DM/CAD or 2DM/obesity or CAD/obesity. Further, genomewide significant evidence was observed of bin 16.3 and 4.5 for 2DM/obesity, which is decreased when CAD was added. These findings indicated that bin 9.3 and 6.5 are most likely to be shared by 2DM, obesity and CAD. And bin 16.3 and 4.5 are potentially common regions to 2DM and obesity only. The observed shared susceptibility regions imply a partly overlapping genetic aspects of disease development. Fine scanning of these regions will definitely identify more susceptibility genes and causal variants.