The GNB3 C825T polymorphism as a pharmacogenetic marker in the treatment of hypertension, obesity, and depression

Genetic variants of accessory proteins and G proteins in human genetic disease

We present a series of three articles on the genetics and pharmacogenetics of G protein- coupled receptors (GPCR). In the first article, we discuss genetic variants of the G protein subunits and accessory proteins that are associated with human phenotypes; in the second article, we build upon this to discuss "G protein-coupled receptor (GPCR) gene variants and human genetic disease" and in the third article, we survey "G protein-coupled receptor pharmacogenomics". In the present article, we review the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane in the context of human genetic disease resulting from pathogenic variants of accessory proteins and G proteins. Pathogenic variants of the genes encoding G protein α and β subunits are examined in diverse phenotypes. Variants in the genes encoding accessory proteins that modify or organize G protein coupling have been associated with disease; these include the contribution of variants of the regulator of G protein signaling (RGS) to hypertension; the role of variants of activator of G protein signaling type III in phenotypes such as hypoxia; the contribution of variation at the RGS10 gene to short stature and immunological compromise; and the involvement of variants of G protein-coupled receptor kinases (GRKs), such as GRK4, in hypertension. Variation in genes that encode proteins involved in GPCR signaling are outlined in the context of the changes in structure and function that may be associated with human phenotypes.

Identification and validation of cholesterol metabolism-related gene GNB3 as prognosis biomarker for pancreatic adenocarcinoma

Patients with pancreatic cancer have a poor prognosis. The role of cholesterol metabolism-related genes (CMGs) pattern in pancreatic adenocarcinoma (PAAD) clinical prognostic significance is still unsuspected. In this study, 13 CMGs were eventually chosen as the prognostic signature to construct a risk model in PAAD. GNB3 as an independent prognosis factor linked to CMGs was ultimately found in PAAD. Kaplan-Meier (KM) and area under the curve (AUC) analysis indicated that the overall survival (OS) for GNB3 in the low-risk group was higher than that of PAAD patients compared with those in the high-risk group. Radiotherapy can significantly increase the GNB3 expression and the survival time in PAAD. GNB3 was differentially expressed and significantly associated with survival prognosis, immune checkpoints, and immune-infiltrating cells in pan-cancer. Specifically, survival analysis further identified that GNB3 was significantly associated with OS, progression-free survival, disease-free survival, and disease-specific survival in PAAD. The IHC scores indicated that the protein expression of GNB3 was lower in tumor tissues. The current study offers fresh insights into the possibility of GNB3 associated with CMGs as new biomarkers for the clinical diagnosis and prognostic for PAAD.

Identification of differentially expressed genes in the medial prefrontal cortex of rats subjected to chronic unpredictable mild stress and treated with electroacupuncture

Major depressive disorder is a chronic mental health condition that seriously impacts afflicted individuals. Although electroacupuncture has proven to be an effective therapy for depression, its underlying biological mechanism remains largely unknown. In this study, we aimed to investigate the effects of electroacupuncture on depression-like behavior and to identify potential target genes related to those effects. To achieve this, we subjected rats to chronic unpredictable mild stress (CUMS) and used sucrose preference, forced swimming, and open-field tests to determine their depression-like behavior in the absence or after receipt of electroacupuncture treatment. RNA sequencing technology was then used to reveal the differentially expressed genes associated with depression and electroacupuncture treatment effects in the medial prefrontal cortex (mPFC). Repeated electroacupuncture treatments at the Baihui (GV20) and Taichong (LR3) acupoints significantly alleviated depression-like behavioral defects in the animals. Genomic RNA sequencing revealed several significant changes in the mPFC transcriptome of rats that received treatment. Through differential gene expression analysis, we found that electroacupuncture reversed the CUMS-induced downregulation of 46 genes and upregulation of 13 genes. Among the differentially expressed genes, Casr, Bdkrb2, Gnb3, and Ccl1 were found to be associated with depression and electroacupuncture treatment effects. In conclusion, we verified that electroacupuncture treatment has an effective antidepressant effect, and the underlying mechanism involves multiple systems and targets.

The mechanism of miR-665 targeting GNB3 in aluminum-induced neuronal apoptosis

BACKGROUND

Aluminum exerts neurotoxic effects through various mechanisms, mainly manifested as impaired learning and memory function.

METHODS

Forty SD rats were divided into 0, 10, 20, and 40 mM maltol aluminum [Al(mal)3] groups. Cell experiments are divided into 0, 100, 200, and 400 μM Al(mal)3 dose group and control, Al(mal)3, Al(mal)3+inhibitor NC, Al(mal)3+miR-665 inhibitor intervention group. Water maze was used to detect the learning and memory function of rats, HE staining was used to observe the morphology and number of neurons in the CA1 area of the rat hippocampus, Flow cytometry was used to detect the apoptosis of PC12 cells, PCR and Western blotting were used to detect the expression of Caspase3, miR-665 and GNB3/PI3K/AKT proteins. The target binding relationship between miR-665 and GNB3 was verified by double luciferase reporter gene experiment.

RESULTS

In vivo experimental results showed that with the increase of Al(mal)3 concentration, the escape latency of rats was prolonged, the target quadrant dwell time was shortened, and the number of crossing platform was reduced. Moreover, the arrangement of neurons was loose and the number decreased; the expression of Caspase3 and miR-665 increased, while the expression of GNB3/PI3K/AKT proteins decreased. In vitro experiments, with the increase of Al(mal)3 concentration, apoptosis rate of PC12 cells increased, the expression of Caspase3, miR-665 and GNB3/PI3K/AKT proteins were consistent with rat results. After inhibiting miR-665 in the intervention group experiment, apoptosis rate of PC12 cells in the aluminum exposure group decreased, the expression of Caspase3 and miR-665 decreased, and the expression of GNB3/PI3K/AKT proteins increased.

CONCLUSION

MiR-665 plays an important role in aluminum induced neuronal apoptosis by targeting GNB3 and regulating the PI3K/AKT pathway.

High-fat diet alters immune cells in spleen, kidney and tumor and impacts the volume growth of renal cell carcinoma

Renal cell carcinoma (RCC) is strongly associated with abnormal or excessive fat deposition in the body, whose processes include persistent adipose inflammation and other disturbances with the development and function of immune cells. Researchers have recently become more and more interested in understanding how high-fat diet (HFD) affects the development and course of RCC by causing immunological dysfunction. Consequently, we explore the effect of HFD on the changes of immune cell groups in spleens, normal kidneys and tumors, mainly revealing the changes of T cells, B cells and NK cells, and further preliminarily exploring the changes of NK cell phenotype. Our findings demonstrate that: (1) HFD impacts the volume growth of ACHN tumor; (2) HFD increases the frequency of CD3+ T cell in spleen, normal kidney, and in tumor, while there are no significant change in CD19+ B cell in spleen, normal kidney and tumor; (3) HFD increases the frequency of NKp46+ NK cell in tumor, while HFD decrease the frequency of NKp46+ NK cell in spleen; (4) HFD increases the frequency of cNK in spleen, normal kidney and tumor, while HFD decreases the frequency of ILC1 in spleen, normal kidney and tumor. These data will open up new avenues for immunotherapy in individuals with obese renal cell carcinoma.

Integrated bioinformatics analysis and screening of hub genes in polycystic ovary syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is one of the most common endocrine and metabolic disorders, posing a serious threat to the health of women. Herein, we aimed to explore new biomarkers and potential therapeutic targets for PCOS by employing integrated bioinformatics tools.

METHODS

Three gene expression profile datasets (GSE138518, GSE155489, GSE106724) were obtained from the Gene Expression Omnibus database and the differentially expressed genes in PCOS and normal groups with an adjusted p-value < 0.05 and a |log fold change (FC) | > 1.2 were first identified using the DESeq package. The weighted correlation network analysis (WGCNA) R package was used to identify clusters of highly correlated genes or modules associated with PCOS. Protein-protein interaction (PPI) network analysis and visualization of genes in the key module were performed using the STRINGdb database and the NetworkX package (edge > 5), respectively. The genes overlapping among the key module genes and PCOS-associated genes were further analyzed. Ligand molecules with strong binding energy < -10 kJ/mol to GNB3 were screened in the drug library using MTiOpenScreen. AutoDock, ChimeraX, and BIOVIA Discovery Studio Visualizer were further used to elucidate the mechanism of ligand interaction with GNB3. Finally, the relationship between GNB3 and PCOS was verified using experimental models in vivo and in vitro.

RESULTS

Of the 11 modules identified by WGCNA, the black module had the highest correlation with PCOS (correlation = 0.96, P = 0.00016). The PPI network of 351 related genes revealed that VCL, GNB3, MYH11, LMNA, MLLT4, EZH2, PAK3, and CHRM1 have important roles in PCOS. The hub gene GNB3 was identified by taking the intersection of PCOS-related gene sets. MTiOpenScreen revealed that five compounds interacted with GNB3. Of these five, compound 1 had the strongest binding ability and can bind amino acids in the WD40 motif of GNB3, which in turn affects the function of the G protein-coupled receptor β subunit. GNB3 was also significantly downregulated in PCOS models.

CONCLUSION

We identified the hub gene GNB3 as the most important regulatory gene in PCOS. We suggest that compound 1 can target the WD40 motif of GNB3 to affect related functions and must be considered as a lead compound for drug development. This study will provide new insights into the development of PCOS-related drugs.

GNB3 c.825C>T (rs5443) Polymorphism and Risk of Acute Cardiovascular Events after Renal Allograft Transplant

The c.825C>T single-nucleotide polymorphism (rs5443) of the guanine nucleotide-binding protein subunit β3 (GNB3) results in increased intracellular signal transduction via G-proteins. The present study investigated the effect of the GNB3 c.825C>T polymorphism on cardiovascular events among renal allograft recipients posttransplant. Our retrospective study involved 436 renal allograft recipients who were followed up for up to 8 years after transplant. The GNB3 c.825C>T polymorphism was detected with restriction fragment length polymorphism (RFLP) polymerase chain reaction (PCR). The GNB3 TT genotype was detected in 43 (10%) of 436 recipients. Death due to an acute cardiovascular event occurred more frequently among recipients with the TT genotype (4 [9%]) than among those with the CC/CT genotypes (7 [2%]; p = 0.003). The rates of myocardial infarction (MI)−free survival (p = 0.003) and acute peripheral artery occlusive disease (PAOD)−free survival (p = 0.004) were significantly lower among T-homozygous patients. A multivariate analysis showed that homozygous GNB3 c.825C>T polymorphism exerted only a mild effect for the occurrence of myocardial infarction (relative risk, 2.2; p = 0.065) or acute PAOD (relative risk, 2.4; p = 0.05) after renal transplant. Our results suggest that the homozygous GNB3 T allele exerts noticeable effects on the risk of MI and acute PAOD only in the presence of additional nonheritable risk factors.

The GNB3 c.825C>T (rs5443) polymorphism and protection against fatal outcome of corona virus disease 2019 (COVID-19)

Background and aims: Albeit several factors which influence the outcome of corona virus disease (COVID-19) are already known, genetic markers which may predict the outcome of the disease in hospitalized patients are still very sparse. Thus, in this study, we aimed to analyze whether the single-nucleotide polymorphism (SNP) rs5443 in the gene GNB3, which was associated with higher T cell responses in previous studies, might be a suitable biomarker to predict T cell responses and the outcome of COVID-19 in a comprehensive German cohort.

Methods: We analyzed the influence of demographics, pre-existing disorders, laboratory parameters at the time of hospitalization, and GNB3 rs5443 genotype in a comprehensive cohort (N = 1570) on the outcome of COVID-19. In a sub cohort, we analyzed SARS-CoV-2-specific T cell responses and associated GNB3 rs5443 genotypes. We investigated the influence of all factors on COVID-19 fatality in multivariable analysis.

Results: We found a younger patient age, normotension or absence of diabetes mellitus or cardiovascular diseases, normal blood cell counts, and low inflammatory markers at hospital admission were protective factors against fatal course of disease. In addition, the rs5443 TT genotype was significantly associated with protection against COVID-19 fatality (OR: 0.60, 95% CI: 0.40–0.92, p = 0.02). We also observed significantly increased SARS-CoV-2-specific T cell responses in rs5443 TT genotype carriers (p = 0.01). Although we observed a significant association of the factors described previously in univariate analysis, only a younger age of the patients, normal blood cell counts, and the GNB3 rs5443 TT genotype remained independent predictors against COVID-19 fatality in multivariable analysis.

Conclusion: Immutable predictors for COVID-19 fatality are relatively rare. In this study we could show that the TT genotype of the SNP rs5443 in the gene GNB3 is associated with protection against COVID-19 fatality. It was as well correlated to higher SARS-CoV-2-specific T cell responses, which could result in a milder course of disease in those patients. Based on those observations we hereby provide a further prognostic biomarker, which might be used in routine diagnostics as a predictive factor for COVID-19 mortality already upon hospitalization.

Association of miRNA targetome variants in LAMC1 and GNB3 genes with colorectal cancer and obesity

Background

Colorectal cancer (CRC) is one of the most common obesity‐associated cancers. Inflammation is also considered the most important factor between obesity and CRC. This study aimed to examine miRNAs binding sites variants on inflammatory genes identified using bioinformatics and systematic approach on clinical samples that were collected from CRC patients and controls.

Methods

The candidate variants related to CRC inflammatory genes were obtained from genome‐wide association studies and their population‐specific haplotypes. The variants were analyzed according to their genomic position on the miRNA targetome. Targetome variants in inflammation‐related genes were selected for genetic association study by TaqMan genotyping assay.

Results

The GG genotype of rs7473 decreased the risk of obesity (p < 0.05). Heterozygous genotype (GA) of rs1547715 decreased the risk of CRC (p < 0.05). In the rs7473/rs1547715 genotype and haplotype, the frequencies of AA/GA and GG/AA lessened in CRC and obesity, respectively (p < 0.05).

Conclusions

The variants of rs7473 and rs1547715 were associated with obesity and CRC, respectively. The above‐mentioned associations could be made based on the interactions of these variants with miRNAs.

PET-CT and RNA sequencing reveal novel targets for acupuncture-induced lowering of blood pressure in spontaneously hypertensive rats

Manual acupuncture (MA) can be used to manage high blood pressure; however, the underlying molecular mechanism remains unknown. To explore the mechanism of acupuncture in the treatment of hypertension, Wistar Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) were subjected to either MA stimulation or the corresponding sham procedure as a negative control (Sham-MA) for 1 week. PET-CT scans, transcriptomics and molecular biology were used to evaluate the effect of MA. The results show that MA can regulate blood pressure in SHRs, change the glucose metabolism of the paraventricular hypothalamus (PVH), and affect the mRNA and protein expression levels of differentially expressed genes in the PVH. These genes may lower blood pressure by regulating angiotensin, endothelial function and inflammation. These findings reveal that MA regulates multiple biological processes and genes/proteins of the PVH, and provide a solid theoretical basis for exploring the mechanisms by which MA regulates hypertension.

Preeclampsia: inflammatory signature of decidual cells in early manifestation of disease

INTRODUCTION

Preeclampsia is a pregnancy-specific complication characterized by hypertension in combination with proteinuria and/or various manifestations of multiple organ failure. It is believed that etiology of preeclampsia lies in dysfunction of the placenta and disorder of the maternal-fetal interactions. In preeclampsia decidual membrane, the maternal part of the placenta which normally supports immunological tolerance of the maternal organism to the semi-allogeneic fetus, becomes a site of inflammation.

METHODS

The aim of our study was to characterize the phenotype of decidual macrophages and plasma profiles in patients with late- and early-onset preeclampsia as compared with controls (n = 43). Decidual cells were obtained by enzymatic digestion method and characterized by flow cytometry analysis, real-time PCR, bioinformatics analysis, immunohistochemistry, and Western blot. Plasma samples were analyzed by multiplex assay.

RESULTS

The number of inflammation-associated CD86+ and CX3CR1+ cells was significantly higher in the early-onset preeclampsia while the portion of CD163+ cells was significantly higher among studied groups. We observed significant increase of endothelin-1 gene expression and a significant decrease in eNOS and GNB3 expression and TGFβ relative protein level in decidual cells of the early-onset preeclampsia samples. We also revealed elevation of pro- and anti-inflammatory cytokines in plasma of preeclampsia groups.

DISCUSSION

Our findings reflect profound early-onset preeclampsia-associated alterations in the decidua and emphasize the importance of the decidua as a link in the development of preeclampsia.

[Characteristics of arterial hypertension clinical course in patients with obesity and anxiety-depressive disorders]

This article covers an important subject clinical course of arterial hypertension in patients with metabolic abnormalities with obesity and anxiety-depressive disorders. Relevance of this topic is defined with high incidence of each aforementioned conditions and their influence on quality of life and social functioning of patients. Review of literature covers subjects of comorbidity and multimorbidity. Relevant data are presented which are focusing on complex management of arterial hypertension co-existing with obesity and anxiety-depressive disorders.

Meta-analysis of the genetic association between maternal GNB3 C825T polymorphism and risk of pre-eclampsia

BACKGROUND

The relationship between the C825T polymorphism of GNB3 (encoding G-protein β3 subunit) and pre-eclampsia risk is unclear.

OBJECTIVE

To systematically explore the association between GNB3 C825T and pre-eclampsia.

SEARCH STRATEGY

PubMed, EMBASE, Google Scholar, and Chinese National Knowledge Infrastructure (CNKI) databases were searched to September 1, 2020, using keywords including "GNB3 C825T" and "pre-eclampsia".

SELECTION CRITERIA

Case-control and cohort studies investigating the relationship between GNB3 C825T polymorphism and pre-eclampsia were included.

DATA COLLECTION AND ANALYSIS

Two reviewers collected the data independently and calculate odds ratios (ORs) with 95% confidence intervals (CIs).

MAIN RESULTS

The meta-analysis involved eight studies from seven publications, including 2071 cases and 3419 controls. Overall analysis showed that GNB3 C825T was associated with increased pre-eclampsia risk in the recessive model (OR, 1.21; 95% CI, 1.01-1.44; P = 0.04). Subgroup analysis stratified by Hardy-Weinberg equilibrium revealed a relationship between GNB3 C825T and increased risk of pre-eclampsia in the allelic (OR, 1.66; 95% CI, 1.34-2.05; P < 0.001), homozygous (OR, 2.12, 95% CI, 1.04-4.32; P  = 0.04), dominant (OR, 1.91; 95% CI, 1.18-3.11; P = 0.009), and recessive (OR, 1.70; 95% CI, 1.03-2.81; P = 0.04) models.

CONCLUSIONS

Maternal GNB3 C825T polymorphism seems to be a risk factor for pre-eclampsia.

WD40-Repeat Proteins in Ciliopathies and Congenital Disorders of Endocrine System

WD40-repeat (WDR)-containing proteins constitute an evolutionarily conserved large protein family with a broad range of biological functions. In human proteome, WDR makes up one of the most abundant protein-protein interaction domains. Members of the WDR protein family play important roles in nearly all major cellular signalling pathways. Mutations of WDR proteins have been associated with various human pathologies including neurological disorders, cancer, obesity, ciliopathies and endocrine disorders. This review provides an updated overview of the biological functions of WDR proteins and their mutations found in congenital disorders. We also highlight the significant role of WDR proteins in ciliopathies and endocrine disorders. The new insights may help develop therapeutic approaches targeting WDR motifs.

Lack of association between the GNB3 rs5443, HIF1A rs11549465 polymorphisms, physiological and functional characteristics

The aim was to examine the association between the hypoxia-inducible factor-1α (HIF1A) gene and the guanine nucleotide binding protein beta polypeptide 3 (GNB3) gene polymorphisms and the endurance/power athlete status and relative aerobic capacity. Another goal of this study was to reveal the connection between GNB3, blood pressure (BP), body composition and body mass index (BMI). Two hundred thirty-eight people participated in this study: 148 elite athletes (men = 107, women = 41) and 90 controls (men = 51, women = 39). The athletes were divided into two groups: the power and the endurance athletes. BMI and body fat percentage (fat%) were calculated. Fifty of the athletes underwent an incremental treadmill test to exhaustion; BP was monitored before and after the test. There were differences in the genotype frequencies of HIF1A between the endurance and the control group (ProPro: 64% vs.79%, ProSer: 27% vs.19%, SerSer: 9% vs. 2%; p = .0351); in the allele prevalences among the three groups (Pro: 87% vs. 77% vs. 88%; Ser: 13% vs. 23% vs. 12%; p = .0103) and between the endurance and control group (p = .0049) as well. The GNB3 allele proportions differed in the three groups (C: 74% vs. 61% vs. 71%, T: 26% vs. 39% vs. 29%; p = .0436). There were no connections between the genotypes and the relative aerobic capacity and neither between GNB3 genotypes and BP, BMI and fat%. The connection of GNB3 T allele to the endurance performance still remained contradictable.

Genetic variability in postoperative nausea and vomiting: A systematic review

BACKGROUND

Postoperative nausea and vomiting (PONV) is the most frequent side effect following anaesthesia. Predisposition to developing PONV is multifactorial with patient risk factors and anaesthetic techniques both being contributory. However, there is also a genetic susceptibility to PONV, and several studies have aimed to identify polymorphisms contributing to a genetic PONV risk.

OBJECTIVE

We summarised previous published studies investigating genetic contribution to PONV risk.

DESIGN

Systematic review without meta-analysis.

DATA SOURCE

We searched MEDLINE until June 2019.

ELIGIBILITY CRITERIA

Articles were chosen for review when PONV and polymorphisms were included. Exclusion criteria were reviews/meta-analysis/comments, articles not in the English language, nonappropriate content (e.g. PONV not as primary aim of the study, study investigated opioid-induced nausea) or if articles were pharmacogenetic studies addressing treatment of PONV.

RESULTS

A total of 59 studies were screened and 14 articles were reviewed including one genome-wide association study (GWAS). Seven studies were performed in East Asians, and seven in Caucasians. Seventeen polymorphisms have been positively associated with PONV in at least one study. Allele frequency of the investigated polymorphisms differs widely between the ethnicities. Furthermore, the anaesthesia regimen and the postoperative time point at which the association with PONV was reported were quite different. Only two polymorphisms, the CHRM3 rs2165870 and the KCNB2 rs349358 (both first associated with PONV in a GWAS), have been significantly associated with PONV incidence in Caucasians in independent studies.

CONCLUSION

There is a genetic susceptibility to the development of PONV. Two single nucleotide polymorphisms (SNPs), the CHRM3 rs2165870 and the KCNB2 rs349358 SNP, seem to have a major influence on PONV incidence, at least in Caucasians. Both SNPs were primarily identified in a GWAS and this association may lead to a better understanding of the disease aetiology. Further high-quality studies are needed to reveal more insights in genetic PONV susceptibility, particularly so in non-Caucasian ethnicities.

Excess body weight as a predictor of response to treatment with antidepressants in patients with depressive disorder

BACKGROUND

Depression and obesity are debilitating conditions representing an enormous health and economic burden worldwide. Depression is common among patients with excess weight, but more importantly, these patients may be at risk for poor response when treated with antidepressant medications (AD).

METHODS

We conducted a comprehensive scoping review to summarize the evidence regarding the difference in response to treatment of depression with AD among patients with excess weight as compared to normal weight patients and to identify knowledge gaps.

RESULTS

The search of the Medline and PsycINFO (2004-2019) identified twelve relevant studies. Tabulation and frequency analysis of the charted data along with a narrative synthesis were performed. Nine studies (75%) reported clinically relevant negative association between patients' high BMI or obesity and treatment response to either nortriptyline, fluoxetine, or various AD; one study (8.3%) reported no difference in response to various AD combinations between BMI groups. One study showed benefits of bupropion and escitalopram combination in patients with morbid obesity (BMI > 35 kg/m²) as compared with escitalopram monotherapy. Another study reported benefits when using venlafaxine-XR in patients with morbid obesity. We also acknowledge the possible role of sex and genetic factors predicting AD treatment response.

LIMITATIONS

The search was restricted to two most relevant sources, publications in four languages and adult population.

CONCLUSION

The synthesized data may be useful to physicians in their decision regarding the choice of AD in patients with excess weight. Researchers need to address causality of association between obesity and treatment response to individual AD types.

Evaluating Prevalence and Patterns of Prescribing Medications for Depression for Patients With Obesity Using Large Primary Care Data (Canadian Primary Care Sentinel Surveillance Network)

Introduction: Depression is a serious disorder that brings a tremendous health and economic burden. Many antidepressants (AD) have obesogenic effects, increasing the population of obese patients at increased risk for a more severe disease course and poor treatment response. In addition, obese patients with depression may not be receiving the recommended standard of care due to "obesity bias." It is important to evaluate prescribing pharmacological treatment of depression in patients with obesity. Objectives: To describe the prevalence and patterns of AD prescribing for patients with depression and comorbid obesity compared with normal weight patients, and to examine the association of prescribing prevalence with obesity class. Methods: Study sample of adult patients (>18 years old) with depression was extracted from the national Canadian Primary Care Sentinel Surveillance Network (CPCSSN) Electronic Medical Records database for 2011-2016. Measures were prescribing of at least one AD (outcome) and body mass index (BMI) to categorize patients into weight categories (exposure). Data were analyzed cross-sectionally using descriptive statistics and mixed effects logistic regression model with clustering on CPCSSN networks and adjusting for age, sex, and the comorbidities. Results: Of 120,381 patients with depression, 63,830 patients had complete data on studied variables (complete cases analysis). Compared with normal weight patients, obese patients were more likely to receive an AD prescription (adjusted Odds Ratio [aOR] = 1.17; 95% Confidence Interval [CI]: 1.12-1.22). Patients with obesity classes II and III were 8% (95% CI: 1.00, 1.16) and 6% (95% CI: 0.98, 1.16) more likely, respectively, to receive AD. After imputing missing data using Multiple Imputations by Chained Equations, the results remained unchanged. The prevalence of prescribing >3 AD types was higher in obese category (7.27%, [95% CI: 6.84, 7.73]) than in normal weight category (5.6%; [95% CI: 5.24, 5.99]). Conclusion: The association between obesity and high prevalence of AD prescribing and prescribing high number of different AD to obese patients, consistent across geographical regions, raises a public health concern. Study results warrant qualitative studies to explore reasons behind the difference in prescribing, and quantitative longitudinal studies evaluating the association of AD prescribing patterns for obese patients with health outcomes.

Analysis of HCRTR2, GNB3, and ADH4 Gene Polymorphisms in a Southeastern European Caucasian Cluster Headache Population

Studies point to an increased hereditary risk of cluster headache. HCRTR2 gene rs2653349 and ADH4 gene rs1800759 polymorphisms have been associated with cluster headache susceptibility. Also, GNB3 rs5443 polymorphism, associated with increased signal transduction via GPCRs, seems to influence triptan treatment response. DNA from 114 cluster headache patients and 570 non-related controls, representing a general Southeastern European Caucasian (SEC) population, was extracted from buccal swabs and genotyped using real-time PCR. Gene distribution for the rs2653349 was GG = 79.8%, GA = 18.4%, and AA = 1.8% for patients and GG = 79.1%, GA = 19.1%, and AA = 1.8% for controls. The frequency of the mutated A allele was 11.0% for patients and 11.3% for controls. The frequencies for rs5443 were CC = 44.7%, CT = 44.7%, and TT = 10.5% for patients and CC = 43.9%, CT = 42.6%, and TT = 13.5% for controls. The frequency of the mutated T allele was 32.9% for patients and 34.8% for controls. A 2.7-fold more frequent appearance of the mutated T allele was observed in patients with better triptan treatment response, although not statistically significant. For rs1800759, the frequencies were CC = 36.0%, CA = 43.0%, and AA = 21.0% for patients and CC = 34.0%, CA = 50.2%, and AA = 15.8% for controls. The frequency of the mutated A allele was 42.5% and 40.9% for patients and controls, respectively. The mutated T allele of GNB3 rs5443 polymorphism was more prevalent in patients with better triptan treatment response, indicating a possible trend of association between this polymorphism and triptan treatment response in SEC population. According to our observation, no association of HCRTR2 rs2653349 and ADH4 rs1800759 polymorphisms and cluster headache in SEC population could be documented.

Gene Polymorphisms and Susceptibility to Functional Dyspepsia: A Systematic Review and Meta-Analysis

Functional dyspepsia (FD) is a common chronic gastrointestinal disorder with a complex, undefined mechanism. Clustering of patients with FD in families highlights the role of genetic factors in the pathogenesis of FD. We performed a systematic review and meta-analysis to clarify the associations between specific gene polymorphisms and FD susceptibility. PubMed, EMBASE, the Cochrane Library, and HuGE database were searched. An additive model was adopted to determine whether previous studied genes are associated with FD susceptibility. Carriers of minor allele in GNB3 825C>T (OR = 1.15, 95% CI 0.99-1.34, P = 0.07), SCL6A4 5HTTLPR (OR = 0.92, 95% CI 0.75-1.12, P = 0.40), and CCK-1R 779T>C (OR = 0.86, 95% CI 0.72-1.03, P = 0.09) genes failed to demonstrate susceptibility to FD. In a subgroup analysis, only minor allele (T) in GNB3 825C>T was associated with an increased susceptibility to the epigastric pain syndrome subtype (OR = 1.34, 95% CI 1.10-1.63, P = 0.003). Our meta-analysis based on available studies using an additive model failed to show that GNB3, SCL6A4, and CCK-1R polymorphisms are associated with FD susceptibility.

Response to sertraline is influenced by GNβ3 gene G-350A variant in patients with major depressive disorder

PURPOSE

Heterotrimeric guanine nucleotide-binding proteins (G proteins) are a major group of human genome membrane protein receptors. Genetic variation in the β3 subunit (GNβ3) associated with gene splicing and increased activity is associated with major depressive disorder (MDD). However, the effect of G-350A GNβ3 genetic polymorphism and therapeutic outcome of selective serotonin reuptake inhibitors (SSRIs) in MDD has not yet been studied.

METHOD

One hundred newly diagnosed MDD patients were treated with sertraline for 6 weeks. The severity of depressive symptoms was weekly assessed by Hamilton Rating Scale for Depression (HRSD). A 50% decrease in HRSD was defined as response to treatment. GNβ3 polymorphisms (G-350A, A657T) were determined in each individual using a PCR-RFLP technique.

RESULTS

Our results suggested that subjects with GG genotype of G-350A responded 5.9-folds more to sertraline compared to carriers of other variants (P = 0.004, OR = 5.9; 95% CI = 1.66-21.99). In addition, carriers of the G allele responded 1.9-folds more to sertraline than carriers of the A allele (P = 0.032, OR = 1.92; 95% CI = 1.05-3.65). However, no association was observed between A657T variants and response to sertraline (P = 0.920, OR = 0.9; 95% CI = 0.31-2.69).

CONCLUSION

The results suggest that G-350A variant of GNβ3 plays a foremost part as a predictor of response to antidepressant treatment.

Population-Based Analysis of Cluster Headache-Associated Genetic Polymorphisms

Cluster headache is a disorder with increased hereditary risk. Associations between cluster headache and polymorphism rs2653349 of the HCRTR2 gene have been demonstrated. The less common allele (A) seems to reduce disease susceptibility. The polymorphism rs5443 of the GNB3 gene positively influences triptan treatment response. Carriers of the mutated T allele are more likely to respond positively compared to C:C homozygotes, when treated with triptans. DNA was extracted from buccal swabs obtained from 636 non-related Southeastern European Caucasian individuals and was analyzed by real-time PCR. Gene distribution for the rs2653349 was G:G = 79.1%, G:A = 19.2%, and A:A = 1.7%. The frequency of the wild-type G allele was 88.7%. The frequencies for rs5443 were C:C = 44.0%, C:T = 42.6%, and T:T = 13.4%. The frequency of the wild-type C allele was 65.3%. The frequency distribution of rs2653349 in the Southeastern European Caucasian population differs significantly when compared with other European and East Asian populations, and the frequency distribution of rs5443 showed a statistically significant difference between Southeastern European Caucasian and African, South Asian, and East Asian populations. For rs2653349, a marginal statistically significant difference between genders was found (p = 0.080) for A:A versus G:G and G:A genotypes (OR = 2.78), indicating a higher representation of male homozygotes for the protective mutant A:A allele than female. No statistically significant difference was observed between genders for rs5443. Cluster headache pathophysiology and pharmacotherapy response may be affected by genetic factors, indicating the significant role of genotyping in the overall treatment effectiveness of cluster headaches.

G protein beta 3(GNβ3) C825T polymorphism and irritable bowel syndrome susceptibility: an updated meta-analysis based on eleven case-control studies

Several studies have reported an association between GNβ3 C825T polymorphism and irritable bowel syndrome (IBS). However, the results remain inconclusive and controversial, particularly for the data derived from different ethnicities and IBS subtypes. Therefore, we performed an updated meta-analysis to evaluate this association. All eligible case-control studies that met the search criteria were retrieved from multiple databases, and eleven case-control studies were included for detailed evaluation. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to assess the strengths of the association between GNβ3 C825T polymorphism and susceptibility to IBS and its subtypes. Our meta-analysis found no significantly associations of GNβ3 C825T polymorphism with IBS risk in all populations. Whereas the C allele was demonstrated to be a decreased risk factor for constipation predominant IBS (IBS-C) in allele model. Additionally, the CC genotype was found to be associated with increased diarrhea predominant IBS (IBS-D) risk in recessive model. Subgroup analysis by ethnicity revealed that these associations held true for the Asian subpopulation. In conclusion, this meta-analysis suggests the C allele of GNβ3 C825T might be associated with a decreased risk of IBS-C, and the CC genotype of GNβ3 might be associated with increased IBS-D risk.

GNB3 overexpression causes obesity and metabolic syndrome

The G-protein beta subunit 3 (GNB3) gene has been implicated in obesity risk; however, the molecular mechanism of GNB3-related disease is unknown. GNB3 duplication is responsible for a syndromic form of childhood obesity, and an activating DNA sequence variant (C825T) in GNB3 is also associated with obesity. To test the hypothesis that GNB3 overexpression causes obesity, we created bacterial artificial chromosome (BAC) transgenic mice that carry an extra copy of the human GNB3 risk allele. Here we show that GNB3-T/+ mice have increased adiposity, but not greater food intake or a defect in satiety. GNB3-T/+ mice have elevated fasting plasma glucose, insulin, and C-peptide, as well as glucose intolerance, indicating type 2 diabetes. Fasting plasma leptin, triglycerides, cholesterol and phospholipids are elevated, suggesting metabolic syndrome. Based on a battery of behavioral tests, GNB3-T/+ mice did not exhibit anxiety- or depressive-like phenotypes. GNB3-T/+ and wild-type animals have similar activity levels and heat production; however, GNB3-T/+ mice exhibit dysregulation of acute thermogenesis. Finally, Ucp1 expression is significantly lower in white adipose tissue (WAT) in GNB3-T/+ mice, suggestive of WAT remodeling that could lead to impaired cellular thermogenesis. Taken together, our study provides the first functional link between GNB3 and obesity, and presents insight into novel pathways that could be applied to combat obesity and type 2 diabetes.

WD40 repeat domain proteins: a novel target class?

Antagonism of protein-protein interactions (PPIs) with small molecules is becoming more feasible as a therapeutic approach. Successful PPI inhibitors tend to target proteins containing deep peptide-binding grooves or pockets rather than the more common large, flat protein interaction surfaces. Here, we review one of the most abundant PPI domains in the human proteome, the WD40 repeat (WDR) domain, which has a central peptide-binding pocket and is a member of the β-propeller domain-containing protein family. Recently, two WDR domain-containing proteins, WDR5 and EED, as well as other β-propeller domains have been successfully targeted by potent, specific, cell-active, drug-like chemical probes. Could WDR domains be a novel target class for drug discovery? Although the research is at an early stage and therefore not clinically validated, cautious optimism is justified, as WDR domain-containing proteins are involved in multiple disease-associated pathways. The druggability and structural diversity of WDR domain binding pockets suggest that understanding how to target this prevalent domain class will open up areas of disease biology that have so far resisted drug discovery efforts.

Genetic association analysis of serotonin and signal transduction pathways in suicide attempters from an Italian sample of psychiatric patients

Genetic factors have been reported to contribute to the liability of suicide. We aimed to investigate functional polymorphisms in eight genes (serotonin transporter, SLC6A4; receptors, 5HTR1A, 1B, 5HTR2A; Tryptophan Hydroxylase, TPH1, TPH2; Monoamine Oxidase, MAOA and G Protein Subunit Beta 3, GNB3) to investigate their predictive value for suicide. The possible confounding effects of gender and phenotypic patients dissection were also valued. A sample of 111 consecutive psychiatric inpatients was recruited and assessed using specific psychometric instruments. Genomic DNA was isolated from peripheral white blood cell samples and polymorphisms were genotyped by pyrosequencing technology. Although no differences were observed between allele and genotype frequencies for all polymorphisms and suicide attempt (SA), a polygenic risk score was detected for three genes HTR2A (A-1438G), TPH1 and TPH2 increasing the prediction of SA risk (Thresh=0.43, p=0.038, R²=0.053). Moreover some nominal associations were obtained after gender and phenotypic dissection stratification (TEMPS-A, TEMPs-H, GSMD, SHSS, GAF, CGI) for SLC6A4 (5-HTTLPR), HTR1A (C-1019G), HTR2A (A-1438G), TPH1 (A799C) and GNB3 (C825T) genes, that were lost after Bonferroni correction. This is a first evidence that specific additive combinations of genes could increase the prediction of SA risk and that gender and phenotypic dissection could influence the association of the genes with SA. This could represent a further study also for future meta-analyses on larger samples.

Hypertension-associated C825T polymorphism impairs the function of Gβ3 to target GRK2 ubiquitination

Population-based and case-control studies in different ethnicities have linked a polymorphism, C825T, in exon 10 of GNB3 gene to hypertension and several additional diseases. The 825T allele is associated with alternative splicing and results in a shortened Gβ3 protein, referred to as Gβ3s, which loses 41 amino acids encompassing one WD40 repeat domain. The mechanism of how Gβ3 C825T polymorphism is associated with hypertension has remained unclear, but an impairment of its canonical function in G-protein-coupled receptor signaling has been ruled out. Here, we report that Gβ3, like other Gβ proteins, binds to DDB1 and assembles a DDB1-CUL4A-ROC1 E3 ubiquitin ligase (CRL4A(Gβ3)) to target GRK2 ubiquitination. The loss of the 41 amino-acid residues disrupts the Gβ3-DDB1 binding and impairs the function of Gβ3s to ubiquitinate GRK2. GRK2 ubiquitination levels were decreased and protein levels were accumulated in the blood samples of Gβ3 825T allele carriers. Deletion of Cul4a in mice resulted in systolic pressure increased and weakened heart function in male mice that can be partially rescued by the deletion of one Grk2 allele. These results reveal a mechanism explaining the link between Gβ3 C825T polymorphism and hypertension.

A longitudinal study of the association between the GNB3 C825T polymorphism and metabolic disturbance in bipolar II patients treated with valproate

This longitudinal study aimed to investigate the associations between the polymorphisms of guanine nucleotide-binding protein subunit β-3 (GNB3) C825T and metabolic disturbance in bipolar II disorder (BP-II) patients being treated with valproate (VPA). A 100 BP-II patients received a 12-week course of VPA treatment, and their body weight and metabolic indices were measured. At baseline, the GNB3 C825T polymorphisms were associated with the triglyceride level (P=0.032) in BP-II patients. During the VPA treatment course, the polymorphisms were not only associated with body mass index (BMI) and waist circumference (P-values=0.009 and 0.001, respectively), but also with total cholesterol, triglyceride, low-density lipoprotein and leptin levels (P-values=0.004, 0.002, 0.031 and 0.015, respectively). Patients with the TT genotype had a lower BMI, smaller waist circumference, and lower levels of lipids and leptin than those with the CT or CC genotypes undergoing the VPA treatment course.

Novel Genetic Loci Associated With Retinal Microvascular Diameter

BACKGROUND

There is increasing evidence that retinal microvascular diameters are associated with cardiovascular and cerebrovascular conditions. The shared genetic effects of these associations are currently unknown. The aim of this study was to increase our understanding of the genetic factors that mediate retinal vessel size.

METHODS AND RESULTS

This study extends previous genome-wide association study results using 24 000+ multiethnic participants from 7 discovery cohorts and 5000+ subjects of European ancestry from 2 replication cohorts. Using the Illumina HumanExome BeadChip, we investigate the association of single-nucleotide polymorphisms and variants collectively across genes with summary measures of retinal vessel diameters, referred to as the central retinal venule equivalent and the central retinal arteriole equivalent. We report 4 new loci associated with central retinal venule equivalent, one of which is also associated with central retinal arteriole equivalent. The 4 single-nucleotide polymorphisms are rs7926971 in TEAD1 (P=3.1×10(-) (11); minor allele frequency=0.43), rs201259422 in TSPAN10 (P=4.4×10(-9); minor allele frequency=0.27), rs5442 in GNB3 (P=7.0×10(-10); minor allele frequency=0.05), and rs1800407 in OCA2 (P=3.4×10(-8); minor allele frequency=0.05). The latter single-nucleotide polymorphism, rs1800407, was also associated with central retinal arteriole equivalent (P=6.5×10(-12)). Results from the gene-based burden tests were null. In phenotype look-ups, single-nucleotide polymorphism rs201255422 was associated with both systolic (P=0.001) and diastolic blood pressures (P=8.3×10(-04)).

CONCLUSIONS

Our study expands the understanding of genetic factors influencing the size of the retinal microvasculature. These findings may also provide insight into the relationship between retinal and systemic microvascular disease.

Pharmacogenetics of erectile dysfunction: navigating into uncharted waters

Sildenafil and other PDE-5 inhibitors have revolutionized erectile dysfunction (ED) treatment. However, a significant number of patients do not respond or present adverse reactions to these drugs. While genetic polymorphisms may underlie this phenomenon, very little research has been undertaken in this research field. Most of the current knowledge is based on sildenafil, thus almost completely ignoring other important pharmacological therapies. Currently, the most promising genes with pharmacogenetic implications in ED are related to the nitric oxide and cGMP pathway, although other genes are likely to affect the responsiveness to treatment of ED. Nevertheless, the small number of studies available opens the possibility of further exploring other genes and phenotypes related to ED. This article provides a comprehensive overview of the genes being tested for their pharmacogenetic relevance in the therapy of ED.

The C825T Polymorphism of the G-Protein β3 Gene as a Risk Factor for Depression: A Meta-Analysis

Background

TheG-protein β3 gene (GNβ3) has been implicated in psychiatric illness through its effects upon intracellular transduction of several neurotransmitter receptors. Multiple studies have investigated the relationship of the C825T polymorphism of the GNβ3 gene (GNβ3 C825T) to depression and antidepressant response. However, the relationship between GNβ3 C825T and depression remains inconsistent. Therefore, here we performed a meta-analysis to investigate the role of GNβ3 C825Tin depression risk.

Methods

Published case-control studies examining the association between GNβ3 C825T and depression were systematically searched for through several electronic databases (PubMed, Scopus, Science Direct, Springer, Embase, psyINFO, and CNKI). The association between GNβ3 C825T and depression risk were assessed by odd ratios (ORs) and their 95% confidence intervals (CIs) for each study. Pooled ORs were constructed for allele contrast (C versus T), homozygote (CC versus TT) model, heterozygote (CC versus CT) model, dominant model (CC + CT versus TT), and recessive (CC versus TT+CT) model. In order to evaluate possible biases, a sensitivity analysis was conducted by sequential deletion of individual studies in an attempt to assess the contribution of each individual dataset to the pooled OR.

Results

Nine studies, including 1055 depressed patients and 1325 healthy controls, were included. A significant association between GNβ3 C825Tand depression was found to exist, suggesting that the T-allele of GNβ3 C825Tcan increase susceptibility to depression. After stratification by ethnicity, the same association was found in the Asian subpopulation, but not the Caucasian subpopulation.

Conclusions

This is the first meta-analysis to reveal a relationship between GNβ3 C825T and depression. Asian T-allele carriers of GNβ3 C825T appear to be more susceptible to depression.

Pharmacogenetics of major depressive disorder: top genes and pathways toward clinical applications

The pharmacogenetics of antidepressants has been not only a challenging but also frustrating research field since its birth in the 1990s. Indeed, great expectations followed the first evidence of familiar aggregation of antidepressant response. Despite the progress from candidate gene studies to genome-wide association studies (GWAS), results fell out the expectations and they were often inconsistent. Anyway, the cumulative evidence supports the involvement of some genes and molecular pathways in antidepressant efficacy. The best single genes are SLC6A4, HTR2A, BDNF, GNB3, FKBP5, ABCB1, and cytochrome P450 genes (CYP2D6 and CYP2C19). Molecular pathways involved in inflammation and neuroplasticity show the greatest support. The first studies evaluating benefits of genotype-guided antidepressant treatments provided encouraging results and confirmed the relevance of SLC6A4, HTR2A, ABCB1, and cytochrome P450 genes. Further progress in genotyping and data analysis would allow to move forward and complete the understanding of antidepressant pharmacogenetics and its translation into clinical applications.

Purinergic system dysfunction in mood disorders: a key target for developing improved therapeutics

Uric acid and purines (such as adenosine) regulate mood, sleep, activity, appetite, cognition, memory, convulsive threshold, social interaction, drive, and impulsivity. A link between purinergic dysfunction and mood disorders was first proposed a century ago. Interestingly, a recent nationwide population-based study showed elevated risk of gout in subjects with bipolar disorder (BD), and a recent meta-analysis and systematic review of placebo-controlled trials of adjuvant purinergic modulators confirmed their benefits in bipolar mania. Uric acid may modulate energy and activity levels, with higher levels associated with higher energy and BD spectrum. Several recent genetic studies suggest that the purinergic system - particularly the modulation of P1 and P2 receptor subtypes - plays a role in mood disorders, lending credence to this model. Nucleotide concentrations can be measured using brain spectroscopy, and ligands for in vivo positron emission tomography (PET) imaging of adenosine (P1) receptors have been developed, thus allowing potential target engagement studies. This review discusses the key role of the purinergic system in the pathophysiology of mood disorders. Focusing on this promising therapeutic target may lead to the development of therapies with antidepressant, mood stabilization, and cognitive effects.

Influence of GNB3 C825T polymorphism on the efficacy of antidepressants in the treatment of major depressive disorder: A meta-analysis

OBJECTIVE

We performed the present meta-analysis in order to evaluate the influence of a common polymorphism (C825T, rs5443 C>T) in the GNB3 gene on the efficacy of antidepressants in the treatment of major depressive disorder (MDD).

METHOD

A relevant literature was searched using the PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CBM and CNKI databases without any language restrictions. STATA Version 12.0 software (Stata Corporation, College Station, Texas USA) was used for this meta-analysis. Odds ratio (OR) and its corresponding 95% confidence interval (95% CI) were calculated.

RESULTS

Our findings suggested that the GNB3 C825T polymorphism was significantly correlated with a higher response rate to antidepressants in MDD patients under the allele and dominant models. Furthermore, we found significant associations between GNB3 C825T polymorphisms and antidepressant-induced remission in MDD patients. Ethnicity-stratified analysis indicated that GNB3 C825T polymorphisms may be strongly related to the efficacy of antidepressants in the treatment of MDD among Asians, but not in Caucasians (all P>0.05).

CONCLUSION

Our findings provide empirical evidence that GNB3 C825T polymorphisms may be correlated with the efficacy of antidepressants in the treatment of MDD, especially among Asians patients.

Gene-environment interaction in major depression: focus on experience-dependent biological systems

Major depressive disorder (MDD) is a multifactorial and polygenic disorder, where multiple and partially overlapping sets of susceptibility genes interact each other and with the environment, predisposing individuals to the development of the illness. Thus, MDD results from a complex interplay of vulnerability genes and environmental factors that act cumulatively throughout individual's lifetime. Among these environmental factors, stressful life experiences, especially those occurring early in life, have been suggested to exert a crucial impact on brain development, leading to permanent functional changes that may contribute to lifelong risk for mental health outcomes. In this review, we will discuss how genetic variants (polymorphisms, SNPs) within genes operating in neurobiological systems that mediate stress response and synaptic plasticity, can impact, by themselves, the vulnerability risk for MDD; we will also consider how this MDD risk can be further modulated when gene × environment interaction is taken into account. Finally, we will discuss the role of epigenetic mechanisms, and in particular of DNA methylation and miRNAs expression changes, in mediating the effect of the stress on the vulnerability risk to develop MDD. Taken together, we aim to underlie the role of genetic and epigenetic processes involved in stress- and neuroplasticity-related biological systems on the development of MDD after exposure to early life stress, thereby building the basis for future research and clinical interventions.

Impact of GNB3-C825T, ADRB3-Trp64Arg, UCP2-3'UTR 45 bp del/ins, and PPARγ-Pro12Ala polymorphisms on Bofutsushosan response in obese subjects: a randomized, double-blind, placebo-controlled trial

Obesity is known to be influenced by a number of genes, including the β3 subunit of G protein (GNB3), β3-adrenergic receptor (ADRB3), uncoupling protein 2 (UCP2), and peroxisome proliferator activated receptor gamma (PPARγ). The single nucleotide polymorphisms (SNPs) of the above genes, such as GNB3-C825T, ADRB3-Trp64Arg, UCP2-3'UTR 45 bp del/ins, and PPARγ-Pro12Ala, are associated with obesity and body mass index. The present study evaluates the impact of Bofutsushosan, a traditional Eastern Asian herbal medicine with known anti-obesity properties, on obese subjects according to the presence of the above-mentioned SNPs. Upon randomization, the volunteers were allocated to receive Bofutsushosan (n=55) or placebo (n=56) treatments for 8 weeks. Following the treatment schedule, significant reductions in total cholesterol and significant improvement in the Korean version of obesity-related quality of life scale were seen in the Bofutsushosan-treated group, but not in placebo. Bofutsushosan exerted significant anti-obesity effects on a number of parameters in the carriers of the GNB3-825T allele, but only on waist circumference in the GNB3-C/C homozygote. Significant anti-obesity impact of Bofutsushosan was also seen on a number of obesity-indices in both ADRB3-Arg64 carriers and ADRB3-Trp64 homozygotes, as well as in UCP2-D/D carriers, but not in UCP2-D/I+I/I variants. The effect of Bofutsushosan was more pronounced in PPARγ-Pro/Pro genotype compared to PPARγ-Pro/Ala variants. Thus, the results revealed differential responses of the subjects to the anti-obesity effects of Bofutsushosan treatment according to the polymorphism of the vital obesity-related genes. Our study provides new insight into individualized clinical applications of Bofutsushosan for obesity.

Meta-analyses between 18 candidate genetic markers and overweight/obesity

Aims

The goal of our study is to investigate the associations between 18 candidate genetic markers and overweight/obesity.

Methods

A total of 72 eligible articles were retrieved from literature databases including PubMed, Embase, SpingerLink, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang. Meta-analyses of 18 genetic markers among 56,738 controls and 48,148 overweight/obese persons were done by Review Manager 5.0.

Results

Our results showed that SH2B1 rs7498665 polymorphism was significantly associated with the risk of overweight/obesity (overall odds ratio (OR) = 1.21, 95% confidence interval (CI) = 1.09-1.34, P = 0.0004). Increased risk of overweight/obesity was also observed in FAIM2 rs7138803 polymorphism (overall OR = 1.11, 95% CI = 1.01-1.22, P = 0.04).

Conclusion

Our meta-analyses have shown the important role of 2 polymorphisms (SH2B1 rs7498665 and FAIM2 rs7138803) in the development of overweight/obesity. This study highlighted the importance of above two candidate genes (SH2B1 and FAIM2) in the risk of overweight/obesity.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2785487401176182.

G protein-coupled receptor accessory proteins and signaling: pharmacogenomic insights

The identification and characterization of the genes encoding G protein-coupled receptors (GPCRs) and the proteins necessary for the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane are discussed in the context of human genetic disease. In addition to functional GPCR variants, the identification of genetic disruptions affecting proteins necessary to GPCR functions have provided insights into the function of these pathways. Gsα and Gβ subunit polymorphisms have been found to result in complex phenotypes. Disruptions in accessory proteins that normally modify or organize heterotrimeric G-protein coupling may also result in disease states. These include the contribution of variants of the regulator of G protein signaling (RGS) protein to hypertension; the role variants of the activator of G protein signaling (AGS) proteins to phenotypes (such as the type III AGS8 variant to hypoxia); the contribution of G protein-coupled receptor kinase (GRK) proteins, such as GRK4, in disorders such as hypertension. The role of accessory proteins in GPCR structure and function is discussed in the context of genetic disorders associated with disruption of the genes that encode them. An understanding of the pharmacogenomics of GPCR and accessory protein signaling provides the basis for examining both GPCR pharmacogenetics and the genetics of monogenic disorders that result from disruption of given receptor systems.

Mouse model implicates GNB3 duplication in a childhood obesity syndrome

Obesity is a highly heritable condition and a risk factor for other diseases, including type 2 diabetes, cardiovascular disease, hypertension, and cancer. Recently, genomic copy number variation (CNV) has been implicated in cases of early onset obesity that may be comorbid with intellectual disability. Here, we describe a recurrent CNV that causes a syndrome associated with intellectual disability, seizures, macrocephaly, and obesity. This unbalanced chromosome translocation leads to duplication of over 100 genes on chromosome 12, including the obesity candidate gene G protein β3 (GNB3). We generated a transgenic mouse model that carries an extra copy of GNB3, weighs significantly more than its wild-type littermates, and has excess intraabdominal fat accumulation. GNB3 is highly expressed in the brain, consistent with G-protein signaling involved in satiety and/or metabolism. These functional data connect GNB3 duplication and overexpression to elevated body mass index and provide evidence for a genetic syndrome caused by a recurrent CNV.

The C825T polymorphism of the G-protein β3 subunit gene and its association with hypertension and stroke: an updated meta-analysis

OBJECTIVE

Several epidemiological studies have evaluated the association between the GNB3 C825T polymorphism and hypertension or stroke. The results of these studies were inconsistent; therefore, we performed a meta-analysis to clarify these discrepancies.

METHODS

We systematically searched the PubMed, Embase, Web of Science, CNKI, and CBM databases, and manually searched reference lists of relevant papers, meeting abstracts, and relevant journals. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for dominant, recessive, and allelic models. A fixed or random effects model was separately adopted depending on study heterogeneity. Subgroup and sensitivity analyses were performed to detect study heterogeneity and examine result stability, respectively. Publication bias was tested using funnel plots, the Egger's regression test, and Begg's test.

RESULTS

We screened 66 studies regarding hypertension and eight concerning stroke. A combined analysis showed that only the allelic model found a marginal association with hypertension (OR = 1.07, 95% CI = 1.01-1.13) and female gender (OR = 1.11, 95% CI = 0.99-1.24). However, no comparison models found an association with stroke (allelic model: OR = 1.11, 95% CI = 0.94-1.32; dominant model: OR = 1.16, 95% CI = 0.92-1.48; and recessive model: OR = 1.05, 95% CI = 0.97-1.14). Sensitivity analysis suggested that all models did not yield a relationship to hypertension or stroke among Asians. Besides, there was a lack of statistical association with hypertension in Caucasians, which maybe due to a small sample size. When we restricted the included studies to normal populations according to the Hardy-Weinberg equilibrium, no association was found.

CONCLUSIONS

There was no evidence indicating that the 825T allele or TT genotype was associated with hypertension or stroke in Asians or hypertension in Caucasians. However, further studies regarding Africans and other ethnicities are needed to identify further correlations.

Interactions between the FTO and GNB3 genes contribute to varied clinical phenotypes in hypertension

BACKGROUND

The genes FTO and GNB3 are implicated in essential hypertension but their interaction remains to be explored. This study investigates the role of interaction between the two genes in the pathophysiology of essential hypertension.

METHODS/PRINCIPAL FINDINGS

In a case-control study comprising 750 controls and 550 patients, interaction between the polymorphisms of FTO and GNB3 was examined using multifactor dimensionality reduction (MDR). The influence of interaction on clinical phenotypes like systolic and diastolic blood pressure, mean arterial pressure and body mass index was also investigated. The 3-locus MDR model comprising FTO rs8050136C/A and GNB3 rs1129649T/C and rs5443C/T emerged as the best disease conferring model. Moreover, the interacted-genotypes having either 1, 2, 3, 4 or 5 risk alleles correlated with linearly increasing odds ratios of 1.91 (P = 0.027); 3.93 (P = 2.08E-06); 4.51 (P = 7.63E-07); 7.44 (P = 3.66E-08) and 11.57 (P = 1.18E-05), respectively, when compared with interacted-genotypes devoid of risk alleles. Furthermore, interactions among haplotypes of FTO (H1-9) and GNB3 (Ha-d) differed by >1.5-fold for protective-haplotypes, CTGGC+TC [H2+Ha] and CTGAC+TC [H4+Ha] (OR = 0.39, P = 0.003; OR = 0.22, P = 6.86E-05, respectively) and risk-haplotypes, AAAGC+CT [H3+Hc] and AAAGC+TT [H3+Hd] (OR = 2.91, P = 9.98E-06; OR = 2.50, P = 0.004, respectively) compared to individual haplotypes. Moreover, the effectiveness of gene-gene interaction was further corroborated with a 1.29-, 1.25- and 1.38-fold higher SBP, MAP and BMI, respectively, in patients having risk interacted-haplotype H3+Hc and 2.48-fold higher SBP having risk interacted-haplotype H3+Hd compared to individual haplotypes.

CONCLUSION

Interactions between genetic variants of FTO and GNB3 influence clinical parameters to augment hypertension.

Common genetic variants in ARNTL and NPAS2 and at chromosome 12p13 are associated with objectively measured sleep traits in the elderly

STUDY OBJECTIVES

To determine the association between common genetic variation in the clock gene pathway and objectively measured acti-graphic sleep and activity rhythm traits.

DESIGN

Genetic association study in two population-based cohorts of elderly participants: the Study of Osteoporotic Fractures (SOF) and the Osteoporotic Fractures in Men (MrOS) study.

SETTING

Population-based.

PARTICIPANTS

SOF participants (n = 1,407, 100% female, mean age 84 years) and MrOS participants (n = 2,527, 100% male, mean age 77 years) with actigraphy and genotype data.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Common genetic variation in 30 candidate genes was captured using 529 single nucleotide polymorphisms (SNPs). Sleep and activity rhythm traits were objectively measured using wrist actigraphy. In a region of high linkage disequilibrium on chromosome 12p13 containing the candidate gene GNB3, the rs1047776 A allele and the rs2238114 C allele were significantly associated with higher wake after sleep onset (meta-analysis: rs1047776 PADD = 2 × 10(-5), rs2238114 PADD = 5 × 10(-5)) and lower LRRC23 gene expression (rs1047776: ρ = -0.22, P = 0.02; rs2238114: ρ = -0.50, P = 5 × 10(-8)). In MrOS participants, SNPs in ARNTL and NPAS2, genes coding for binding partners, were associated with later sleep and wake onset time (sleep onset time: ARNTL rs3816358 P2DF = 1 × 10(-4), NPAS2 rs3768984 P2DF = 5 × 10(-5); wake onset time: rs3816358 P2DF = 3 × 10(-3), rs3768984 P2DF = 2 × 10(-4)) and the SNP interaction was significant (sleep onset time PINT = 0.003, wake onset time PINT = 0.001). A SNP association in the CLOCK gene replicated in the MrOS cohort, and rs3768984 was associated with sleep duration in a previously reported study. Cluster analysis identified four clusters of genetic associations.

CONCLUSIONS

These findings support a role for common genetic variation in clock genes in the regulation of inter-related sleep traits in the elderly.

CITATION

Evans DS; Parimi N; Nievergelt CM; Blackwell T; Redline S; Ancoli-Israel S; Orwoll ES; Cummings SR; Stone KL; Tranah GJ. Common genetic variants in ARNTL and NPAS2 and at chromosome 12p13 are associated with objectively measured sleep traits in the elderly. SLEEP 2013;36(3):431-446.

Institutional Profile: Institute of Pharmacogenetics at the University Hospital Essen

Established in 2005, the Institute of Pharmacogenetics at the University Hospital Essen (Essen, Germany), headed by Winfried Siffert, is devoted to the discovery and validation of genetic variants that may impact upon drug responses especially in the field of cardiovascular disorders and cancer. Moreover, the institute provides pharmacogenetic testing for those drugs for which pharmacogenetic testing is recommended in order to prevent adverse drug reactions.

Single nucleotide polymorphisms in G protein signaling pathway genes in preeclampsia

Preeclampsia is a pregnancy specific disorder and a risk factor for later cardiovascular disease. The cause and detailed pathophysiology remains unknown. G protein signaling is involved in a variety of physiological processes, including blood pressure regulation. We assessed whether distributions of 3 single nucleotide polymorphisms in genes coding for components of G protein signaling pathways that have been associated with hypertension differ between women with preeclampsia and normotensive pregnant women; the G protein β3 subunit gene (GNB3) C825T polymorphism (rs5443), the angiotensin II type 1 receptor gene (AGTR1) 3'UTR A1166C polymorphism (rs5186), and the regulator of G protein signaling 2 gene (RGS2) 3'UTR C1114G polymorphism (rs4606). Two separate Norwegian study populations were used; a large population based study and a smaller, but clinically well-described pregnancy biobank. A descriptive study of 43 women with eclampsia was additionally included. In the population-based study, an increased odds of preeclampsia (odds ratio, 1.21; [95% confidence interval, 1.05-1.40]; P=0.009) and recurrent preeclampsia (odds ratio, 1.43; [95% confidence interval, 1.06-1.92];, P=0.017) was found in women carrying the rs4606 CG or GG genotype. In early-onset preeclamptic patients with decidual spiral artery biopsies available (n=24), the rs4606 CG or GG genotype was more frequent in those with acute atherosis (resembling early stage of atherosclerosis) compared with those without: odds ratio, 15.0; (95% confidence interval, 2.02-111.2); P=0.004. No association was found between preeclampsia and the rs5443 or the rs5186. The genotype distribution in eclamptic women was not different from preeclamptic women. In conclusion, RGS2 rs4606 may affect the risk and progression of preeclampsia.

The Gβ3 splice variant associated with the C825T gene polymorphism is an unstable and functionally inactive protein

A splice variant of Gβ3, termed Gβ3s, has been associated with the C825T polymorphism in the Gβ3 gene and linked with many human disorders. However, the biochemical properties and functionality of Gβ3s remain controversial. Here, using multidisciplinary approaches including co-immunoprecipitation analysis and bioluminescence resonance energy transfer (BRET) measurements, we showed that unlike Gβ3, Gβ3s failed to form complexes with either Gγ or Gα subunits. Moreover, using a mutant Gγ2 deficient in lipid modification to purify Gβ3s from Sf9 cells without the use of detergents, we further showed that the failure of Gβ3s to form dimers with Gγ was not due to the instability of the dimers in detergents, but rather, reflected the intrinsic properties of Gβ3s. Additional studies indicated that Gβ3s is unstable, and unable to localize properly to the plasma membrane and to activate diverse Gβγ effectors including PLCβ2/3, PI3Kγ, ERKs and the Rho guanine exchange factor (RhoGEF) PLEKHG2. Thus, these data suggest that the pathological effects of Gβ3 C825T polymorphism may result from the downregulation of Gβ3 function. However, we found that the chemokine SDF1α transmits signals primarily through Gβ1 and Gβ2, but not Gβ3, to regulate chemotaxis of several human lymphocytic cell lines, indicating the effects of Gβ3 C825T polymorphism are likely to be tissue and/or stimuli specific and its association with various disorders in different tissues should be interpreted with great caution.

Association of the C825T polymorphism in the GNB3 gene with obesity and metabolic phenotypes in a Taiwanese population

The relationship between obesity and a single nucleotide polymorphism (SNP), rs5443 (C825T), in the guanine nucleotide binding protein beta polypeptide 3 (GNB3) gene is currently inconsistent. In this study, we aimed to reassess whether the GNB3 rs5443 SNP could influence obesity and obesity-related metabolic traits in a Taiwanese population. A total of 983 Taiwanese subjects with general health examinations were genotyped. Based on the criteria defined by the Department of Health in Taiwan, the terms "overweight" and "obesity" are defined as 24 ≦ BMI < 27 and BMI ≧ 27, respectively. Compared to the carrier of the combined CT + TT genotypes of the GNB3 rs5443 polymorphism, triglyceride was significantly higher for the carrier of CC genotype in the complete sample population (128.2 ± 93.2 vs. 114.3 ± 79.1 mg/dl; P = 0.041). In addition, the carriers of CC variant had a higher total cholesterol than those with the combined CT + TT variants (194.5 ± 36.8 vs. 187.9 ± 33.0 mg/dl; P = 0.019) in the complete sample population. In the normal controls, both triglyceride (P = 0.018) and total cholesterol (P = 0.011) were also significantly higher in the CC homozygotes than in the combined CT + TT genotypes. However, the GNB3 rs5443 SNP did not exhibit any significant association with obesity or overweight among the subjects. Our study indicates that the CC genotype of the GNB3 rs5443 SNP may predict higher obesity-related metabolic traits such as triglyceride and total cholesterol in non-obese Taiwanese subjects (but not in obese subjects).