The relationship between the Trp 64 Arg polymorphism of the beta 3-adrenoceptor gene and idiopathic overactive bladder

Inside the Biology of the β3-Adrenoceptor

Since the first discovery in 1989, the β3-adrenoceptor (β3-AR) has gained great attention because it showed the ability to regulate many physiologic and metabolic activities, such as thermogenesis and lipolysis in brown and white adipose tissue, respectively (BAT, WAT), negative inotropic effects in cardiomyocytes, and relaxation of the blood vessels and the urinary bladder. The β3-AR has been suggested as a potential target for cancer treatment, both in adult and pediatric tumors, since under hypoxia its upregulation in the tumor microenvironment (TME) regulates stromal cell differentiation, tumor growth and metastases, signifying that its agonism/antagonism could be useful for clinical benefits. Promising results in cancer research have proposed the β3-AR being targeted for the treatment of many conditions, with some drugs, at present, undergoing phase II and III clinical trials. In this review, we report the scientific journey followed by the research from the β3-Ars' discovery, with focus on the β3-Ars' role in cancer initiation and progression that elects it an intriguing target for novel antineoplastic approaches. The overview highlights the great potential of the β3-AR, both in physiologic and pathologic conditions, with the intention to display the possible benefits of β3-AR modulation in cancer reality.

Functional Polymorphism in the ADRB3 Gene, Encoding the Beta-3 Adrenergic Receptor, and Response to Intra-Detrusor Injection of Botulinum Toxin-A in Women with Overactive Bladder

BACKGROUND

There are reports suggesting an association between the rs4994 polymorphism in the ADRB3 gene encoding the beta-3 adrenergic receptor and OAB risk in females. The injection of botulinum toxin-A into the bladder wall is recommended as a possible treatment for OAB patients in whom first-line therapies have failed. The aim of our study was to analyze the possible association between the ADRB3:rs4994 polymorphism and the patient-perceived response to a single intra-detrusor injection of botulinum toxin-A in Polish women with overactive bladder.

METHODS

The study group consisted of 115 consecutive female patients with OAB. The response to botulinum toxin-A was evaluated at three months after injection, as absolute or relative reductions in OAB symptoms or in scores from questionnaires ICIQ-OAB (parts A and B) and ICIQ-LUTS-QoL (parts A and B). ADRB3:rs4994 variants were identified by the sequencing of genomic DNA extracted from buccal swabs.

RESULTS

There were no statistically significant differences between ADRB3:rs4994 [T];[T] homozygotes and [T];[C]+[C];[C] subjects for absolute or relative reductions in symptoms or in scores from all four questionnaire parts at three months after the injection of botulinum toxin-A.

CONCLUSIONS

Our results do not support the hypothesis that ADRB3:rs4994 polymorphism is associated with the response to the intra-detrusor injection of botulinum toxin-A in Polish females with overactive bladder.

Association Between Trp64Arg Polymorphism of Beta-3 Adrenergic Receptor Gene and Susceptibility to Overactive Bladder: A Meta-Analysis

Objective: Some studies have been carried out to investigate the association between Trp64Arg polymorphism in beta-3 adrenergic receptor gene (ADRB3) and susceptibility to overactive bladder (OAB), but the results remain inconsistent. We carried out a meta-analysis to acquire a more accurate estimation.

Methods: All eligible studies were searched in PubMed, Web of Science, Embase, and Cochrane Library. Pooled odds ratios, with 95% confidence intervals, were assessed for the association using fixed and random effects models.

Results: The overall results of this meta-analysis demonstrated that there might be an association between Trp64Arg polymorphism and susceptibility to OAB in allele model, dominant model, and heterozygote comparison with a relative risk of 2.00 (95% CI 1.36–2.93), 2.13 (95% CI 1.20–3.76), and 2.07 (95% CI: 1.13–3.79), respectively. However, in the recessive model and homozygote comparison, no significant association between ESR1 Trp64Arg polymorphism and susceptibility to OAB was observed, with a relative risk of 2.47 (95% CI 0.63–9.73) and 3.12 (95% CI: 0.79–12.35), respectively. Based on trail sequential analysis, the results turned out to be true positive in the allele model, false positive in the dominant model and heterozygote comparison, and negative in the recessive model and homozygote comparison, respectively.

Conclusion: Our analysis indicated that Trp64Arg polymorphisms in ADRB3 might increase the risk of OAB twice in the allele model, but further well-designed studies with large sample sizes are required to confirm the present findings in other modes and comparisons.

ADRB3, ROCK2, and GEF Levels in Overactive Bladder Patients

Purpose

The aim of this study was to evaluate changes in levels of adrenergic receptor β3 (ADRB3), Rho-related kinase 2 (ROCK2), and guanine nucleotide exchange factor (GEF), which play key roles in the adrenergic and cholinergic pathways of contraction-relaxation harmony in voiding physiology, and to explore the relationship between these proteins and overactive bladder (OAB).

Methods

This study included 60 idiopathic OAB patients and a healthy control group. A validated OAB-validated 8 questionnaire was completed by all participants. Serum levels of ADRB3, ROCK2, and GEF were examined with enzyme-linked immunosorbent assays. Patient and control groups were compared in terms of these levels, and receiver operating characteristic (ROC) curves were generated for all parameters.

Results

The levels of ROCK2 were significantly elevated, but there were no correlations between the OAB symptom score and the serum levels of ROCK2, ADRB3, and GEF in OAB patients. In the ROC analysis, ROCK2 alone provided the strongest potential relationship (area under the curve=0.651) with 84.9% sensitivity. The ROCK2+GEF combination provided a satisfactory relationship (AUC=0.755). The AUC for the ADRB3+ROCK2+GEF combination was 0.752, with 64.2% sensitivity and 88.2% specificity.

Conclusions

The study results suggest that alterations in serum ROCK2 levels and the use of this parameter in combination with ADRB3 and GEF levels can shed light on the pathophysiology of idiopathic OAB syndrome and provide a new perspective for treatment.

Association of gene polymorphisms with women urinary incontinence

Aim of study was set to investigate the association of women urinary incontinence (UI) with serotonin receptor HTR2A T102C and beta 3-adrenergic receptor ADRB3 Trp64Arg genes polymorphisms. The study included 110 women with Urge, Stress, and Mixed UI types and the control group – 105 continent women. Both groups have filled in the ICIQ-FLUTS questionnaire and their blood genotyping was performed. Urge UI subgroup was older and had higher body mass index (BMI) in comparison to other UI types and control group. More than half of all women had family history of UI in Stress UI and Mixed UI subgroups. The frequency of HTR2A T102C gene polymorphism’s minor allele C and genotype CC was significantly more expressed in Urge UI subgroup, as compared with control group (C-77.3 vs 58.7%, p = 0.007 and CC-57.6 vs 31.1%, p = 0.015). The ADRB3 Trp64Arg gene polymorphism did not differ between groups. The regression analysis revealed CC genotype (OR = 3.06, 95% CI: 1.11–8.43; p = 0.030) and allele C (OR = 2.53, 95% CI: 1.16–5.53; p = 0.020) were risk factors for development of Urge UI. We conclude that HTR2A T102C gene polymorphism affected the development of Urge UI.

Association between the Trp64Arg polymorphism of the ADRB3 gene and overactive bladder

BACKGROUND

The β₃ -adrenergic receptor (ADRB3) is very important in the regulation of the human detrusor muscle function. The well-known tryptophan64arginine polymorphism of the ADRB3 gene alters the response of the receptor to various stimuli, including adrenalin and noradrenalin, and may increase the susceptibility to develop overactive bladder (OAB). Therefore, this study was performed to determine whether ADRB3 Trp64Arg polymorphism is associated with the pathophysiology of OAB syndrome.

METHODS

The study group (n = 150) consists of 72 patients with OAB and 78 controls without OAB. Venous blood samples were taken from all participants to analyze the ADRB3 gene Trp64Arg polymorphism using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay. We compared the distribution of Trp64Arg polymorphism and symptom severity in both OAB and non-OAB subjects using χ² test and Mann-Whitney's U test, respectively.

RESULTS

The frequency of the 64Arg variant (heterozygous plus homozygous) in OAB and non-OAB subjects was 15.3% and 14.1%, respectively. There was no statistically significant difference between the OAB and non-OAB groups in regard to the distribution frequency of ADRB3 Trp64Arg polymorphism. The total frequency (OAB + non-OAB, 76 women and 74 men) of the Arg64 variant allele was 5.9% and 10.8% in women and in men, respectively. Although the frequency of the Arg64 variant was nearly twofold higher in men compared to women, the difference was not statistically significant.

CONCLUSIONS

These results demonstrated that the ADRB3 Trp64Arg polymorphism is not significantly associated with OAB syndrome in a sample of Turkish OAB patients.

Urinary Biomarkers in Overactive Bladder: Revisiting the Evidence in 2019

CONTEXT

In overactive bladder (OAB), after an initial outbreak of research, it is more consensual that biomarkers may be better used to phenotype patients. Herein, we revisit this topic, including some of the most promising biomarkers.

OBJECTIVE

To provide a comprehensive analysis of the actual role of biomarkers in OAB.

EVIDENCE ACQUISITION

A PubMed-based literature search was conducted, including the most relevant articles published in the last 15 yr, on nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), adenosine triphosphate (ATP), genomics, and microbiota as OAB biomarkers. Articles with no full text available or not written in English were excluded. Additional reviews were included.

EVIDENCE SYNTHESIS

Urinary NGF, BDNF, and ATP are increased in many OAB patients. These biomarkers can help identify OAB phenotypes and select the ideal candidates for new therapies directed to neurotrophic and purinergic pathways. Circulating urinary miRNA may be useful for establishing the ideal moment for bladder outlet obstruction relief and will eventually lead to the development of therapeutic agents that inhibit or reverse fibrotic pathways in the bladder. Urinary microbiota seems to be related to OAB symptoms, in particular urgency urinary incontinence, and may have strong implications in the prevention, diagnosis, and treatment of OAB.

CONCLUSIONS

In the future, physicians may consider the use of biomarkers to identify distinct OAB phenotypes, with distinct causal mechanisms, selecting patients for specific target therapies with expected better outcomes.

PATIENT SUMMARY

Overactive bladder biomarkers can be useful for phenotype patients and for selecting more effective target therapies.

Exploring biomarkers in the overactive bladder: Alterations in miRNA levels of a panel of genes in patients with OAB

AIMS

It has been demonstrated that there are abundant stable microRNAs (miRNAs) in plasma, which is potentially disease-specific. Adrenergic and muscarinic pathways play an important role in voiding physiology. Alterations in the levels of miRNAs are thought to influence the regulation of these pathways at the molecular level. The aim of this study was to investigate the relationship of miRNAs with overactive bladder pathogenesis and to provide a new perspective to treatment approaches.

METHODS

This study included patients with an overactive bladder (OAB) diagnosis and a healthy control group. All patients completed a validated OAB-V8 questionnaire. The relative expression levels of 12 miRNAs were examined in plasma by PCR. Receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic qualification of miRNAs.

RESULTS

The relative expression levels of let-7b-5p, miR-92a-3p, miR-98-5p, miR-142-3p, and miR-200c-3p were significantly upregulated and miR-139-5p was significantly downregulated in patients with OAB and no correlation was determined between the levels of miRNAs with OAB symptom score. Among the miRNAs, miR-98-5p provided the highest diagnostic accuracy alone (area under curve [AUC] = 0.79) in ROC analysis. The combination of miR-98-5p + miR-139-5p was seen to be a good indicator (AUC = 0.839).

CONCLUSIONS

These results suggest that alteration of the miRNA levels can be used as auxiliary parameters to explain the pathophysiology of OAB syndrome and could shed light on new treatment options.

Role of β-3 adrenergic receptor polymorphism in overactive bladder

AIMS

Women with overactive bladder (OAB) have a higher frequency of a single-nucleotide polymorphism (SNP) at codon 64 of the β-3 adrenergic receptor gene (ADRB3). Since the SNP results in an amino acid substitution that could theoretically alter receptor protein function, we hypothesized that those with the SNP would display greater OAB symptom severity. Therefore we aimed to compare OAB severity between women with this SNP and women with the wild type genotype.

METHODS

A retrospective cohort study was performed in women with bothersome OAB from two academic institutions. Banked blood samples were tested for the codon 64 SNP. Women were divided into two groups based on genotype: wild-type (WT) and heterozygous (HZ). We compared mean OAB Symptom Severity questionnaire (OAB-q) scores between groups using t tests. Linear regression was performed to control for potential confounders.

RESULTS

Of the 303 women with OAB, 254 (83.8%) had the WT genotype, and 49 (16.2%) the HZ genotype. There were no homozygous women for the rare allele. The majority were Caucasian (86%) and non-Hispanic (97%). There were no significant differences in mean OAB-q symptom severity scores (WT 21.2 ± 7 vs HZ 22.0 ± 6.6; P = 0.49) and quality of life scores (WT 39.6 ± 15.5 vs HZ 39.1 ± 16.6; P = 0.83) between groups. These remained nonsignificant in a linear regression model.

CONCLUSIONS

In a predominantly non-Hispanic, Caucasian population of women with bothersome OAB, symptom severity was not related to ADRB3 codon 64 SNP genotype.

Expressions of urothelial functional proteins in idiopathic detrusor overactivity patients refractory to antimuscarinic therapy with different urodynamic characteristics

AIMS

This study investigated the expressions of PGP9.5, P₂  X ₃ , muscarinic receptor (M3) and beta-3 adrenoreceptor (AR) in idiopathic detrusor overactivity (IDO) patients refractory to antimuscarinic treatment, and analyzed the correlation between protein expressions and clinical symptoms of IDO bladders with different urodynamic characteristics.

METHODS

Specimens of 48 IDO and 10 control patients without lower urinary tract symptoms were included. The levels of these proteins from bladder mucosa were determined by Western blotting.

RESULTS

The expression levels of β3-AR and M3 receptor were similar between IDO patients and controls. When IDO patients were divided into two subgroups, phasic DO and terminal DO, the results showed that β3-AR level in the patients with phasic DO was significantly higher than that of the controls and terminal DO (Both P < 0.05). PGP9.5 and P₂  X ₃ levels were also significantly increased in phasic DO subgroup than controls. P₂  X ₃ receptor was positively correlated with PGP9.5 and β3-AR, and negatively correlated with the first sensation of bladder filling and voided volume in phasic DO.

CONCLUSIONS

Similar expression M3 receptor and increased P₂  X ₃ levels in phasic DO, compared with the controls, indicate that dysregulation of purinergic bladder signaling may contribute to the pathogenesis of phasic DO refractory to antimuscarinics. Elevated expression of β3-AR in phasic DO but not in terminal DO patients may explain the different urodynamic characteristics of DO between the two subgroups. Our findings suggest that β3-AR agonist or P₂  X ₃ antagonist might be a good treatment choice for patients with phasic DO refractory to antimuscarinic therapy.

Biomarkers in lower urinary tract symptoms/overactive bladder: a critical overview

PURPOSE OF REVIEW

Biomarkers constitute objectively measurable characteristics that can be evaluated as indicators of physiological and pathogenic processes and might be used as diagnostic, prognostic or predictive tools in clinical care. This review examines the availability of biomarkers to treat the dynamic and complex symptoms of overactive bladder (OAB).

RECENT FINDINGS

OAB biomarkers may contribute to reveal the origin of storage symptoms in otherwise healthy individuals. The research encompassing the changes that occur in the bladder or in the peripheral (and central) nervous system might be determined through blood or urinary molecules (neurotrophins, ATP, prostaglandins, C-reactive protein and cytokines) or the measurement of events occurring in the bladder wall (bladder wall or detrusor wall thickness, oxyhemoglobin and deoxyhemoglobin concentration). These biomarkers might contribute to a better understanding of the pathophysiologic mechanisms underlying OAB.

SUMMARY

The word biomarker to name all the parameters described above, from bladder wall thickness to urinary molecules, has been introduced to call the attention to a field wherein objective noninvasive parameters were nonexistent. OAB treatment based on a biomarker, in comparison to the treatment based on a diagnosis made from a careful history and exclusion of urinary tract infection, is not supported by current literature.

Systematic review and metaanalysis of genetic association studies of urinary symptoms and prolapse in women

OBJECTIVE

Family studies and twin studies demonstrate that lower urinary tract symptoms and pelvic organ prolapse are heritable. This review aimed to identify genetic polymorphisms tested for an association with lower urinary tract symptoms or prolapse, and to assess the strength, consistency, and risk of bias among reported associations.

STUDY DESIGN

PubMed and HuGE Navigator were searched up to May 1, 2014, using a combination of genetic and phenotype key words, including "nocturia," "incontinence," "overactive bladder," "prolapse," and "enuresis." Major genetics, urology, and gynecology conference abstracts were searched from 2005 through 2013. We screened 889 abstracts, and retrieved 78 full texts. In all, 27 published and 7 unpublished studies provided data on polymorphisms in or near 32 different genes. Fixed and random effects metaanalyses were conducted using codominant models of inheritance. We assessed the credibility of pooled associations using the interim Venice criteria.

RESULTS

In pooled analysis, the rs4994 polymorphism of the ADRB3 gene was associated with overactive bladder (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.6; n = 419). The rs1800012 polymorphism of the COL1A1 gene was associated with prolapse (OR, 1.3; 95% CI, 1.0-1.7; n = 838) and stress urinary incontinence (OR, 2.1; 95% CI, 1.4-3.2; n = 190). Other metaanalyses, including those for polymorphisms of COL3A1,LAMC1,MMP1,MMP3, and MMP9 did not show significant effects. Many studies were at high risk of bias from genotyping error or population stratification.

CONCLUSION

These metaanalyses provide moderate epidemiological credibility for associations of variation in ADRB3 with overactive bladder, and variation of COL1A1 with prolapse. Clinical testing for any of these polymorphisms cannot be recommended based on current evidence.

What is the role for biomarkers for lower urinary tract disorders? ICI-RS 2013

AIMS

A biomarker is an entity that measures a normal or pathological process, or the response to an intervention. A biomarker must measure exclusively and be sufficiently sensitive to the process of interest. Alternatively, a biomarker may give clues regarding the underlying pathology of the condition and be a useful research or specialist tool. If a biomarker is to be of practical benefit then it must also be economical and practical to use. This article will consider chemical moieties as biomarkers, although in principle physical markers (e.g., bladder wall thickness) could also be defined as such.

RESULTS AND CONCLUSIONS

The validation of a biomarker for detrusor overactivity (DO) must appreciate the fact that the condition is likely to multifactorial and thus no single entity may be sufficiently selective and sensitive. However, more specific conditions, such as bladder pain associated with DO, may make the biomarker search easier. Several prospective agents including antiproliferative factor (APF) and epidermal growth factors (EGF) are discussed. Several urinary biomarkers, including neurotrophins (NGF, BDNF) and cytokines, and a serum marker, C-reactive protein, are considered as reaching the above criteria. All suffer from relatively poor lack of discrimination, as they all change in response to other, often inflammatory, conditions; BDNF may offer the highest expectations. Urinary ATP has also been proposed as a DO/OAB biomarker but requires further evaluation. Finally genetic markers offer potential to understand more about the pathophysiology of DO/OAB. The increasing availability of genome-wide association studies and micro-RNA assays offer genetic markers as a new generation of biomarkers. Neurourol. Urodynam. 33:602-605, 2014. © 2014 Wiley Periodicals, Inc.

Biomarkers in overactive bladder

A biomarker is an indicator of a particular disease. It is generally used to define the presence (diagnostic biomarker), severity, progression (prognostic biomarker) of a condition and/or its response to a specific treatment (predictive biomarker). Biomarkers can be specific cells, enzymes, hormones, genes or gene products, which can be detected and measured in parts of the body such as blood, urine or tissue. Therefore, biomarkers have been suggested to play an important role in both the clinical assessment and the management of patients, as well as in the research setting. Recently, interest has gathered in urinary biomarkers as a tool to assess overactive bladder (OAB), potentially playing a role in the diagnosis, disease progression and monitoring response to treatment. Urinary biomarkers identified so far include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), prostaglandins, cytokines and C-reactive protein. The aim of this review was to review the published literature on biomarkers in OAB. A literature review using Pub Med, clinicaltrials.gov and the controlled trials online registries was performed from 1970 up to June 2012. The search keywords were: the International Continence Society (ICS) definition of "OAB", "nerve growth fac- tor" (NGF), "brain derived growth factor" (BDNF), "prostaglandins," "cytokines," "genetic biomarkers" and "C reactive protein".The results were limited for fully published English-language articles. The search was then subsequently expanded to include urinary biomarkers in interstitial cystitis and bladder pain where relevant. Each of the studies/articles was reviewed, interpreted and discussed to consider the role of urinary biomarkers in OAB. Using the search criteria, a total of 20 studies (animal and human) that investigated the role of urinary biomarkers in OAB were identified. Full text versions of these articles were obtained and reviewed. Studies on NGF suggested that urinary levels were higher in OAB patients and decreased with antimuscarinic and botulinum toxin treatment. BDNF studies have demonstrated raised levels in OAB and also increased levels in situations of acute bladder inflammation. The role of urinary prostaglandins, cytokines and CRP does not appear to be specific to the OAB disease process according to the current available evidence. Based on the evidence so far NGF and BDNF appear to be the most promising biomarkers in OAB. Although still in their infancy these neurotrophic factors could potentially diagnose OAB, replacing urodynamics and aiding in monitoring disease progression and response to treatment in addition to clinical symptoms.