Current and Emerging Pharmacological Targets and Treatments of Urinary Incontinence and Related Disorders.

Overactive bladder syndrome with and without urinary incontinence and related conditions, signs, and disorders such as detrusor overactivity, neurogenic lower urinary tract dysfunction, underactive bladder, stress urinary incontinence, and nocturia are common in the general population and have a major impact on the quality of life of the affected patients and their partners. Based on the deliberations of the subcommittee on pharmacological treatments of the 7th International Consultation on Incontinence, we present a comprehensive review of established drug targets in the treatment of overactive bladder syndrome and the aforementioned related conditions and the approved drugs used in its treatment. Investigational drug targets and compounds are also reviewed. We conclude that, despite a range of available medical treatment options, a considerable medical need continues to exist. This is largely because the existing treatments are symptomatic and have limited efficacy and/or tolerability, which leads to poor long-term adherence. SIGNIFICANCE STATEMENT: Urinary incontinence and related disorders are prevalent in the general population. While many treatments have been approved, few patients stay on long-term treatment despite none of them being curative. This paper provides a comprehensive discussion of existing and emerging treatment options for various types of incontinence and related disorders.

Ubiquitin Linkage-Specific Affimers Reveal Insights into K6-Linked Ubiquitin Signaling.

Several ubiquitin chain types have remained unstudied, mainly because tools and techniques to detect these posttranslational modifications are scarce. Linkage-specific antibodies have shaped our understanding of the roles and dynamics of polyubiquitin signals but are available for only five out of eight linkage types. We here characterize K6- and K33-linkage-specific "affimer" reagents as high-affinity ubiquitin interactors. Crystal structures of affimers bound to their cognate chain types reveal mechanisms of specificity and a K11 cross-reactivity in the K33 affimer. Structure-guided improvements yield superior affinity reagents suitable for western blotting, confocal fluorescence microscopy and pull-down applications. This allowed us to identify RNF144A and RNF144B as E3 ligases that assemble K6-, K11-, and K48-linked polyubiquitin in vitro. A protocol to enrich K6-ubiquitinated proteins from cells identifies HUWE1 as a main E3 ligase for this chain type, and we show that mitofusin-2 is modified with K6-linked polyubiquitin in a HUWE1-dependent manner.

Introduction: A Short History of Adrenoceptor Research.

This chapter provides a short history of adrenoceptor research starting from the initial discovery of adrenaline. It covers the evolving classification of adrenoceptor subtypes, the cloning of these subtypes from multiple species, and factors such as adrenoceptor regulation, inverse agonism and biased agonism. More details on many of these aspects are provided in other chapters of this volume of Handbook of Experimental Pharmacology.

Adrenoceptor Expression and Function in the Endocrine Pancreas.

The sympathetic nervous system plays an important role in the regulation of endocrine pancreatic function, most importantly insulin release. Among the nine adrenoceptor (AR) subtypes, the α2A-AR appears to be the subtype most abundantly expressed in the human pancreas. While α2- and ß-AR have opposing effects, the net response to sympathetic stimulation is inhibition of insulin secretion mediated by α2-AR located in the plasma membrane of pancreatic ß cells. This inhibition may be present physiologically as evidenced by increased insulin secretion in healthy and diabetic humans and animals in response to α2-AR antagonists, a finding that was confirmed in all studies. Based on such data and on an association of an α2A-AR polymorphism, that increases receptor expression levels, with an elevated risk for diabetes, increased α2A-AR signaling in the pancreatic ß cells has been proposed as a risk factor for the development of type 2 diabetes. Thus, the α2A-AR was proposed as a drug target for the treatment of some forms of type 2 diabetes. Drug research and development programs leveraging this mechanism have reached the clinical stage, but none have resulted in an approved medicine due to a limited efficacy. While ß-AR agonists can increase circulating insulin levels in vivo, it remains controversial whether this includes a direct effect on ß cells or occurs secondary to general metabolic effects. Therefore, the regulation of endocrine pancreatic function is physiologically interesting but may be of limited therapeutic relevance.

Natural Products in the Treatment of Lower Urinary Tract Dysfunction and Infection.

The popularity of natural products for the treatment of lower urinary tract symptoms (LUTS) differs considerably between countries. Here we discuss the clinical evidence for efficacy in two indications, male LUTS suggestive of benign prostatic hyperplasia and urinary tract infections, and the mechanistic evidence from experimental studies. Most evidence for male LUTS is based on extracts from saw palmetto berries, stinging nettle roots, and pumpkin seeds, whereas most evidence for urinary tract infection is available for European golden rod and combined preparations although this field appears more fragmented with regard to extract sources. Based on differences in sample collection and extraction, extracts from the same plants are likely to exhibit at least quantitative differences in potential active ingredients, which makes extrapolation of findings with one extract to those of others potentially difficult. While only limited information is available for most individual extracts, some extracts have been compared to placebo and/or active controls in adequately powered trials.

Are ß3 -adrenoceptor gene polymorphisms relevant for urology?

AIMS: ß3 -adrenoceptors (ARs) are an important drug target for the treatment of overactive bladder syndrome (OAB) and are under investigation for other indications. The human ß3 -AR gene is polymorphic; an exchange of amino acid tryptophan (Trp) for arginine (Arg) in position 64 of the receptor protein is the most frequent and best-studied polymorphism. A narrative review on the impact of ß3 -AR polymorphisms on urological disease and its treatment is presented. RESULTS: Two out of four studies have reported that the 64Arg allele was found more frequently in subjects with OAB than in healthy controls. A large study in a highly selective population (men undergoing prostatectomy for cancer treatment) did not confirm this. On the other hand, studies examining symptom severity typically found little difference between 64Arg and 64Trp carriers. In vitro studies with endogenously expressed ß3 -AR reported a decreased lipolytic response in human adipose tissue. Studies with heterologously expressed receptors sometimes found a decreased responsiveness to agonists including ß3 -AR agonists, but others did not confirm that. CONCLUSIONS: The overall evidence points to carriers of the 64Arg genotype expressing fewer and/or hypofunctional ß3 -ARs and being associated with the presence of OAB but such findings were only detected inconsistently. If this hypofunctionality exists, the consequences may be of insufficient magnitude to allow a robust detection. Only adequately powered studies comparing responses with a ß3 -AR agonist in 64Arg carriers versus wild-type patients can address this.

Assembly and specific recognition of k29- and k33-linked polyubiquitin.

Protein ubiquitination regulates many cellular processes via attachment of structurally and functionally distinct ubiquitin (Ub) chains. Several atypical chain types have remained poorly characterized because the enzymes mediating their assembly and receptors with specific binding properties have been elusive. We found that the human HECT E3 ligases UBE3C and AREL1 assemble K48/K29- and K11/K33-linked Ub chains, respectively, and can be used in combination with DUBs to generate K29- and K33-linked chains for biochemical and structural analyses. Solution studies indicate that both chains adopt open and dynamic conformations. We further show that the N-terminal Npl4-like zinc finger (NZF1) domain of the K29/K33-specific deubiquitinase TRABID specifically binds K29/K33-linked diUb, and a crystal structure of this complex explains TRABID specificity and suggests a model for chain binding by TRABID. Our work uncovers linkage-specific components in the Ub system for atypical K29- and K33-linked Ub chains, providing tools to further understand these unstudied posttranslational modifications.

Sex and Gender Differences in the Pharmacology of the Overactive Urinary Bladder.

Dysfunction of the lower urinary tract in general and the overactive bladder syndrome (OAB) in particular are prevalent and have major impact on the quality of life of the afflicted patients and their partners. We concisely review sex and gender differences in patients and animal models in physiological bladder function, its alterations in disease (mostly OAB), and its responses to treatment. Women appear to have a smaller functional bladder capacity and, therefore, must void more often than men. On the other hand, men have a greater bladder outlet resistance, which is partly attributed to a longer urethra and partly to the presence of the prostate. Sex and gender differences in bladder contractility appear small and were not found consistently. The ability of bladder smooth muscle to relax may be somewhat smaller in females. However, females are heavily underrepresented in experimental studies on bladder function. Stress urinary incontinence is found predominantly in women (particularly those after childbirth). OAB is similarly prevalent in men and women. Females seek treatment much more often and are overrepresented in clinical trials. Treatment responses in OAB patients are similar in both genders for oral medications, but improvements upon injections of onabotulinum toxin type A appear smaller in men. We conclude that there is no evidence for major sex and gender differences in bladder dysfunction as related to OAB and its treatment responses, but female animals are heavily underrepresented in experimental studies.

Adrenoceptors in the Lower Urinary Tract.

Adrenoceptors importantly contribute to the physiological regulation of lower urinary tract (LUT) function and have become a target of several clinically successful treatments for major LUT diseases. In the bladder dome, ß-adrenoceptor subtypes are found in multiple cell types and mediate relaxation of detrusor smooth muscle, perhaps partly indirectly by acting on afferent nerves and cells of the mucosa. ß3-adrenoceptor agonists such as mirabegron and vibegron are used to treat overactive bladder syndrome. In the bladder trigone and urethra, α1-adrenoceptors cause contraction and thereby physiologically contribute to bladder outlet resistance. α1-adrenoceptors in the prostate also cause contraction and pathophysiologically elevate bladder outlet resistance leading to voiding dysfunction in benign prostatic hyperplasia. α1-adrenoceptor antagonist such as tamsulosin is widely used as a first-line option to treat LUT symptoms in men, but it remains unclear to which extent and how smooth muscle relaxation contributes to symptom relief.

Associations between the Patient Perception of Bladder Condition score and overactive bladder syndrome symptoms at baseline and upon treatment.

BACKGROUND: Patient-reported outcomes such as the Patient Perception of Bladder Condition (PPBC) score are frequently used to characterize overactive bladder syndrome (OAB) patients and their treatment outcomes. However, little information is available on the relationship of such scores to OAB symptoms at the individual patient level. METHODS: We have performed a post hoc analysis of two large noninterventional studies (n = 1345 and 745) in which patients received propiverine extended release (30 or 45 mg/day) for 12 weeks to determine the strength of nonparametric correlations between PPBC and OAB symptoms at baseline, after treatment and with treatment-associated changes thereof. RESULTS: PPBC was not correlated with age but with episode frequencies of urgency, incontinence, micturitions, and nocturia, but the strength of correlations was only moderate (Spearman rank correlation coefficient 0.2045-0.3553). Similarly moderate correlations were observed after treatment and when changes in PPBC were compared to those of OAB symptoms, although these correlations were somewhat stronger. CONCLUSIONS: PPBC is only moderately correlated to OAB symptoms indicating that it characterizes patients beyond what is captured by their symptoms.

Validation of Fenoterol to Study ß2-Adrenoceptor Function in the Rat Urinary Bladder.

Fenoterol is a ß2-adrenoceptor (AR)-selective agonist that is commonly used to investigate relaxation responses mediated by ß2-AR in smooth muscle preparations. Some data have questioned this because fenoterol had low potency in the rat urinary bladder when a muscarinic agonist was used as a pre-contraction agent and because some investigators proposed that fenoterol may act in part via ß3-AR. We designed the present study to investigate whether fenoterol is a proper pharmacological tool to study ß2-AR-mediated relaxation responses in the rat urinary bladder. Firstly, we have compared the effect of pre-contraction agents on fenoterol potency and found that fenoterol potency was about 1.5 log units greater against KCl than carbachol (pEC50 7.19 ± 0.66 and 5.62 ± 1.09 of KCl and of carbachol, respectively). To test the selectivity of fenoterol, we have determined the effects of the ß2-AR antagonist ICI 118,551 and the ß3-AR antagonist L 748,337 on relaxation responses to fenoterol. While 300 nM L 748,337 had little effect on the potency of fenoterol (pEC50 6.56 ± 0.25 and 6.33 ± 0.61 in the absence and presence of L 748,337, respectively), the relaxation curve for fenoterol was right-shifted in the presence 300 nM ICI 118,551 (pEC50 5.03 ± 0.18). Thus, we conclude that fenoterol is a proper pharmacological tool to assess ß2-AR-mediated responses in the rat urinary bladder and most likely in other smooth-muscle preparations containing multiple subtypes of the ß-AR.

Impact of early vs. delayed initiation of dutasteride/tamsulosin combination therapy on the risk of acute urinary retention or BPH-related surgery in LUTS/BPH patients with moderate-to-severe symptoms at risk of disease progression.

PURPOSE: To evaluate the effect of delayed start of combination therapy (CT) with dutasteride 0.5 mg and tamsulosin 0.4 mg on the risk of acute urinary retention or benign prostatic hyperplasia (BPH)-related surgery (AUR/S) in patients with moderate-to-severe lower urinary tract symptoms (LUTS) at risk of disease progression. METHODS: Using a time-to-event model based on pooled data from 10,238 patients from Phase III/IV dutasteride trials, clinical trial simulations (CTS) were performed to assess the risk of AUR/S up to 48 months in moderate-to-severe LUTS/BPH patients following immediate and delayed start of CT for those not responding to tamsulosin monotherapy. Simulation scenarios (1300 subjects/arm) were investigated, including immediate start (reference) and alternative delayed start (six scenarios 1-24 months). AUR/S incidence was described by Kaplan-Meier survival curves and analysed using log-rank test. The cumulative incidence of events as well as the relative and attributable risks were summarised stratified by treatment. RESULTS: Survival curves for patients starting CT at month 1 and 3 did not differ from those who initiated CT immediately. By contrast, significant differences (p < 0.001) were observed when switch to CT occurs ≥ 6 months from the initial treatment. At month 48, AUR/S incidence was 4.6% vs 9.5%, 11.0% and 11.3% in patients receiving immediate CT vs. switchers after 6, 12 and 24 months, respectively. CONCLUSIONS: Start of CT before month 6 appears to significantly reduce the risk of AUR/S compared with delayed start by ≥ 6 months. This has implications for the treatment algorithm for men with LUTS/BPH at risk of disease progression.

Statistical inference in abstracts of three influential clinical pharmacology journals analyzed using a text-mining algorithm.

AIM: To describe the trend in the prevalence of statistical inference in three influential clinical pharmacology journals METHODS: We applied a computer-based algorithm to abstracts of three clinical pharmacology journals published in 1976 to 2016 to identify statistical inference and its subtypes. Furthermore, we manually reviewed a random sample of 300 articles to access algorithm's performance in finding statistical inference in abstracts and as a screening tool for presence and absence of statistical inference in full text. RESULT: The algorithm identified 59% (13,375/22,516 [mid p 95% CI, 59%-60%]) article abstracts with statistical inference. The percentage of abstracts with statistical inference was similar in 1976 and 2016, 48% (179/377 [mid p 95%CI, 42%-52%]) versus 49% (386/791 [mid p 95%CI, 45%-52%]). Statistical reporting pattern varied among journals. Among abstracts containing any statistical inference in the publications from 1976 to 2016 null-hypothesis significance testing was the most prevalent reported statistical inference. The algorithm had high sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for finding statistical inferences in abstract. While PPV for predicting the statistical inference in full text (including abstract, text, tables and figures) was high, NPV was low. CONCLUSION: Despite journal's editorials and statistical associations' guidelines, most authors focused on testing rather than estimation. In future, a better statistical reporting might be ensured by improving the statistical knowledge of authors and an addition of statistical guides to journals' instruction to authors to the extent that editors would like their statistical inference preferences to be incorporated into submitted manuscripts.

Model-based meta-analysis of the time to first acute urinary retention or benign prostatic hyperplasia-related surgery in patients with moderate or severe symptoms.

AIMS: Combination therapy of 5α-reductase inhibitor and α-blocker is a guideline-endorsed therapeutic approach for patients with moderate-to-severe lower urinary tract symptoms or benign prostatic hyperplasia (LUTS/BPH) who are at risk of disease progression. We aimed to disentangle the contribution of clinical and demographic baseline characteristics affecting the risk of acute urinary retention or BPH-related surgery (AUR/S) from the effect of treatment with drugs showing symptomatic and disease-modifying properties. METHODS: A time-to-event model was developed using pooled data from patients (n = 10 238) enrolled into six clinical studies receiving placebo, tamsulosin, dutasteride or tamsulosin-dutasteride combination therapy. A parametric hazard function was used to describe the time to first AUR/S. Covariate model building included the assessment of relevant clinical and demographic factors on baseline hazard. Predictive performance was evaluated by graphical and statistical methods. RESULTS: An exponential hazard model best described the time to first AUR/S in this group of patients. Baseline International Prostate Symptom Score, prostate-specific antigen, prostate volume and maximum urine flow were identified as covariates with hazard ratio estimates of 1.04, 1.08, 1.01 and 0.91, respectively. Dutasteride monotherapy and tamsulosin-dutasteride combination therapy resulted in a significant reduction in the baseline hazard (56.8% and 66.4%, respectively). By contrast, the effect of tamsulosin did not differ from placebo. CONCLUSIONS: Our analysis showed the implications of disease-modifying properties of dutasteride and tamsulosin-dutasteride combination therapy for the risk of AUR/S. It also elucidated the contribution of different baseline characteristics to the risk of these events. The use of tamsulosin monotherapy (symptomatic treatment) has no impact on individual long-term risk.

Effects of Nifedipine on Renal and Cardiovascular Responses to Neuropeptide Y in Anesthetized Rats.

Neuropeptide Y (NPY) acts via multiple receptor subtypes termed Y1, Y2 and Y5. While Y1 receptor-mediated effects, e.g., in the vasculature, are often sensitive to inhibitors of L-type Ca2+ channels such as nifedipine, little is known about the role of such channels in Y5-mediated effects such as diuresis and natriuresis. Therefore, we explored whether nifedipine affects NPY-induced diuresis and natriuresis. After pre-treatment with nifedipine or vehicle, anesthetized rats received infusions or bolus injections of NPY. Infusion NPY (1 µg/kg/min) increased diuresis and natriuresis, and this was attenuated by intraperitoneal injection of nifedipine (3 µg/kg). Concomitant decreases in heart rate and reductions of renal blood flow were not attenuated by nifedipine. Bolus injections of NPY (0.3, 1, 3, 10 and 30 µg/kg) dose-dependently increased mean arterial pressure and renovascular vascular resistance; only the higher dose of nifedipine (100 µg/kg/min i.v.) moderately inhibited these effects. We conclude that Y5-mediated diuresis and natriuresis are more sensitive to inhibition by nifedipine than Y1-mediated renovascular effects. Whether this reflects a general sensitivity of Y5 receptor-mediated responses or is specific for diuresis and natriuresis remains to be investigated.

21st century headache: mapping new territory.

BACKGROUND: With headache experienced by up to 75% of adults worldwide in the last year, primary headache disorders constitute a major public health problem, yet they remain under-diagnosed and under-treated. Headache prevalence and burden is changing as society evolves, with headache now occurring earlier in life. Contributing factors, mostly associated with changing life style, such as stress, bad posture, physical inactivity, sleep disturbance, poor diet and excess use of digital technology may be associated with the phenomenon that could be labelled as '21st century headache'. This is especially notable in workplace and learning environments where headache impacts mental clarity and therefore cognitive performance. The headache-related impact on productivity and absenteeism negatively influences an individual's behaviour and quality of life, and is also associated with a high economic cost. Since the majority of sufferers opt to self-treat rather than seek medical advice, substantial knowledge on headache prevalence, causation and burden is unknown globally. Mapping the entire population of headache sufferers can close this knowledge gap, leading to better headache management. The broad use of digital technology to gather real world data on headache triggers, burden and management strategies, in self-treated population will allow these sufferers to access appropriate support and medication, and therefore improve quality of life. CONCLUSION: These data can yield important insights into a substantial global healthcare issue and form the basis for improved patient awareness, professional education, clinical study design and drug development.

New Author Guidelines for Displaying Data and Reporting Data Analysis and Statistical Methods in Experimental Biology.

The American Society for Pharmacology and Experimental Therapeutics has revised the Instructions to Authors for Drug Metabolism and Disposition, Journal of Pharmacology and Experimental Therapeutics, and Molecular Pharmacology These revisions relate to data analysis (including statistical analysis) and reporting but do not tell investigators how to design and perform their experiments. Their overall focus is on greater granularity in the description of what has been done and found. Key recommendations include the need to differentiate between preplanned, hypothesis-testing, and exploratory experiments or studies; explanations of whether key elements of study design, such as sample size and choice of specific statistical tests, had been specified before any data were obtained or adapted thereafter; and explanations of whether any outliers (data points or entire experiments) were eliminated and when the rules for doing so had been defined. Variability should be described by S.D. or interquartile range, and precision should be described by confidence intervals; S.E. should not be used. P values should be used sparingly; in most cases, reporting differences or ratios (effect sizes) with their confidence intervals will be preferred. Depiction of data in figures should provide as much granularity as possible, e.g., by replacing bar graphs with scatter plots wherever feasible and violin or box-and-whisker plots when not. This editorial explains the revisions and the underlying scientific rationale. We believe that these revised guidelines will lead to a less biased and more transparent reporting of research findings.

New Author Guidelines for Displaying Data and Reporting Data Analysis and Statistical Methods in Experimental Biology.

The American Society for Pharmacology and Experimental Therapeutics has revised the Instructions to Authors for Drug Metabolism and Disposition, Journal of Pharmacology and Experimental Therapeutics, and Molecular Pharmacology These revisions relate to data analysis (including statistical analysis) and reporting but do not tell investigators how to design and perform their experiments. Their overall focus is on greater granularity in the description of what has been done and found. Key recommendations include the need to differentiate between preplanned, hypothesis-testing, and exploratory experiments or studies; explanations of whether key elements of study design, such as sample size and choice of specific statistical tests, had been specified before any data were obtained or adapted thereafter; and explanation of whether any outliers (data points or entire experiments) were eliminated and when the rules for doing so had been defined. Variability should be described by S.D. or interquartile range, and precision should be described by confidence intervals; S.E. should not be used. P values should be used sparingly; in most cases, reporting differences or ratios (effect sizes) with their confidence intervals will be preferred. Depiction of data in figures should provide as much granularity as possible, e.g., by replacing bar graphs with scatter plots wherever feasible and violin or box-and-whisker plots when not. This editorial explains the revisions and the underlying scientific rationale. We believe that these revised guidelines will lead to a less biased and more transparent reporting of research findings.