IRF4 is a key thermogenic transcriptional partner of PGC-1α.

Brown fat can reduce obesity through the dissipation of calories as heat. Control of thermogenic gene expression occurs via the induction of various coactivators, most notably PGC-1α. In contrast, the transcription factor partner(s) of these cofactors are poorly described. Here, we identify interferon regulatory factor 4 (IRF4) as a dominant transcriptional effector of thermogenesis. IRF4 is induced by cold and cAMP in adipocytes and is sufficient to promote increased thermogenic gene expression, energy expenditure, and cold tolerance. Conversely, knockout of IRF4 in UCP1(+) cells causes reduced thermogenic gene expression and energy expenditure, obesity, and cold intolerance. IRF4 also induces the expression of PGC-1α and PRDM16 and interacts with PGC-1α, driving Ucp1 expression. Finally, cold, ß-agonists, or forced expression of PGC-1α are unable to cause thermogenic gene expression in the absence of IRF4. These studies establish IRF4 as a transcriptional driver of a program of thermogenic gene expression and energy expenditure.

Cryo-EM structure of the ß3-adrenergic receptor reveals the molecular basis of subtype selectivity.

The ß3-adrenergic receptor (ß3AR) is predominantly expressed in adipose tissue and urinary bladder and has emerged as an attractive drug target for the treatment of type 2 diabetes, obesity, and overactive bladder (OAB). Here, we report the cryogenic electron microscopy structure of the ß3AR-Gs signaling complex with the selective agonist mirabegron, a first-in-class drug for OAB. Comparison of this structure with the previously reported ß1AR and ß2AR structures reveals a receptor activation mechanism upon mirabegron binding to the orthosteric site. Notably, the narrower exosite in ß3AR creates a perpendicular pocket for mirabegron. Mutational analyses suggest that a combination of both the exosite shape and the amino-acid-residue substitutions defines the drug selectivity of the ßAR agonists. Our findings provide a molecular basis for ßAR subtype selectivity, allowing the design of more-selective agents with fewer adverse effects.

The ß3-AR agonist BRL37344 ameliorates the main symptoms of X-linked nephrogenic diabetes insipidus in the mouse model of the disease.

X-linked nephrogenic diabetes insipidus (X-NDI) is a rare congenital disease caused by inactivating mutations of the vasopressin type-2 receptor (AVPR2), characterized by impaired renal concentrating ability, dramatic polyuria, polydipsia and risk of dehydration. The disease, which still lacks a cure, could benefit from the pharmacologic stimulation of other GPCRs, activating the cAMP-intracellular pathway in the kidney cells expressing the AVPR2. On the basis of our previous studies, we here hypothesized that the ß3-adrenergic receptor could be such an ideal candidate. We evaluated the effect of continuous 24 h stimulation of the ß3-AR with the agonist BRL37344 and assessed the effects on urine output, urine osmolarity, water intake and the abundance and activation of the key renal water and electrolyte transporters, in the mouse model of X-NDI. Here we demonstrate that the ß3-AR agonism exhibits a potent antidiuretic effect. The strong improvement in symptoms of X-NDI produced by a single i.p. injection of BRL37344 (1 mg/kg) was limited to 3 h but repeated administrations in the 24 h, mimicking the effect of a slow-release preparation, promoted a sustained antidiuretic effect, reducing the 24 h urine output by 27%, increasing urine osmolarity by 25% and reducing the water intake by 20%. At the molecular level, we show that BRL37344 acted by increasing the phosphorylation of NKCC2, NCC and AQP2 in the renal cell membrane, thereby increasing electrolytes and water reabsorption in the kidney tubule of X-NDI mice. Taken together, these data suggest that human ß3-AR agonists might represent an effective possible treatment strategy for X-NDI.

Age-dependent effects of the ß3 adrenoceptor agonist CL316,243 on human and rat detrusor muscle strips.

Motility of detrusor smooth muscle includes adrenergic relaxation and cholinergic contraction. Since the latter may be deregulated in overactive bladder (OAB) pathophysiology, anticholinergics are the standard therapy but occasionally less tolerated due to side effects such as dry mouth and constipation. ß3 adrenoceptor agonists also alleviate OAB symptoms by relaxing the detrusor muscle. Their age dependence, however, is far from understood. To address this issue, we induced contractions with KCl (60 mM) and carbachol (from 10 nM to 100 µM) in the presence of the ß3 adrenoceptor agonist CL316,243 (from 0.1 to 10 µM) in both human and rat muscle strips. Our results confirmed that both contractions were attenuated by ß3 adrenoceptor activation in both species, but with differing age dependence. In humans, specimens from mid-life subjects showed a significantly more pronounced effect of CL316,243 in attenuating carbachol-induced contractions than those from aged subjects (Cohen's d of maximal attenuation: 1.82 in mid-life versus 0.13 in aged) without altering EC50. Conversely, attenuation of KCl responses by CL316,243 increased during ageing (Spearman correlation coefficient = -0.584, P<0.01). In rats, both KCl- and carbachol-induced contractions were significantly more attenuated by CL316,243 in samples from adolescent as compared to aged samples. Immunohistochemistry in human detrusor sections proved ß3 adrenoreceptor abundance to remain unaltered during ageing. In conclusion, our findings suggest differential age-dependent changes in human ß3 adrenoceptor-dependent attenuation of detrusor contraction in terms of electromechanical versus pharmacomechanical coupling; they may help understand the differential responsiveness of OAB patients to ß3 agents.

IL-25-induced shifts in macrophage polarization promote development of beige fat and improve metabolic homeostasis in mice.

Beige fat dissipates energy and functions as a defense against cold and obesity, but the mechanism for its development is unclear. We found that interleukin (IL)-25 signaling through its cognate receptor, IL-17 receptor B (IL-17RB), increased in adipose tissue after cold exposure and ß3-adrenoceptor agonist stimulation. IL-25 induced beige fat formation in white adipose tissue (WAT) by releasing IL-4 and IL-13 and promoting alternative activation of macrophages that regulate innervation and up-regulate tyrosine hydroxylase (TH) up-regulation to produce more catecholamine including norepinephrine (NE). Blockade of IL-4Rα or depletion of macrophages with clodronate-loaded liposomes in vivo significantly impaired the beige fat formation in WAT. Mice fed with a high-fat diet (HFD) were protected from obesity and related metabolic disorders when given IL-25 through a process that involved the uncoupling protein 1 (UCP1)-mediated thermogenesis. In conclusion, the activation of IL-25 signaling in WAT may have therapeutic potential for controlling obesity and its associated metabolic disorders.

Comparison of mirabegron and vibegron for clinical efficacy and safety in female patients with overactive bladder: a multicenter prospective randomized crossover trial.

PURPOSE: To compare the efficacy and safety of mirabegron and vibegron in female OAB patients. METHODS: We conducted a multicenter, prospective, randomized crossover study of female patients with OAB. The patients were assigned to Group MV (mirabegron for 8 weeks, followed by vibegron for 8 weeks) or group VM (vibegron for 8 weeks, followed by mirabegron for 8 weeks). The primary endpoint was the change in OABSS from baseline, and the secondary endpoint was the change in FVC parameters. After completion of the study, each patient was asked which drug was preferable. RESULTS: A total of 83 patients were enrolled (40 and 43 in groups MV and VM, respectively). At 8th and 16th week, 33 and 29 in Group MV and 34 and 27 in Group VM continued to receive the treatment. The change in PVR was not significantly different between treatment with mirabegron and vibegron. The changes in OABSS, nighttime frequency, mean, and maximum voided volume were similar between mirabegron and vibegron. The mean change in the daytime frequency was greater in the vibegron than in the mirabegron. Of the 56 patients, 15 (27%) and 30 (53%) preferred mirabegron and vibegron, respectively. The remaining 11 patients (20%) showed no preference. The change in the urgency incontinence score during vibegron was better in patients who preferred vibegron to mirabegron. CONCLUSION: The efficacies of mirabegron and vibegron in female patients was similar. The patients' preference for vibegron could depend on the efficacy of vibegron for urgency incontinence.

Efficacy of transcutaneous electrical nerve stimulation combined with mirabegron therapy compared with mirabegron monotherapy for overactive bladder: a prospective randomized controlled study.

PURPOSE: The objective was to evaluate the efficacy of transcutaneous electrical nerve stimulation (TENS) combined with mirabegron therapy compared with mirabegron monotherapy in the treatment of female patients with overactive bladder (OAB). METHODS: In this randomized controlled study, 100 female outpatients with OAB were screened. Among these patients, 86 who met the inclusion criteria were randomly divided into the TENS combined with mirabegron treatment group and mirabegron monotherapy treatment group, with 43 patients in each group. The voiding diary, Overactive Bladder Symptom Score (OABSS), Overactive Bladder Questionnaire Symptom Bother Score (OAB-q SBS), total health-related quality of life (OAB-q HRQoL), and treatment satisfaction-visual analog scale (TS-VAS) score before and after treatment were recorded to evaluate the efficacy of OAB treatment. Seventy-nine of the 86 patients (40 in the TENS plus mirabegron group and 39 in the mirabegron monotherapy group) completed 12 weeks of treatment. RESULTS: TENS combined with mirabegron therapy was superior to mirabegron monotherapy in improving the primary endpoints, including the daily number of micturition episodes and the daily MVV/micturition and secondary endpoints, including the daily number of urgency episodes, the OABSS, the OAB-q SBS, the HRQoL score and TS-VAS score. There were no statistically significant differences in urgency urinary incontinence and nocturia between the groups. Some minor adverse effects were observed, including muscle pain, local paresthesia and constipation. CONCLUSIONS: The combination of TENS and mirabegron was more effective than mirabegron alone in the treatment of female patients with OAB. TRIAL REGISTRATION NUMBER: ChiCTR2400080528 (31.01.2024, retrospectively registered).

Safety and efficacy of an α1 -blocker plus mirabegron compared with an α1 -blocker plus antimuscarinic in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia and overactive bladder: A systematic review and network meta-analysis.

AIM: Antimuscarinics and the ß3-adrenoreceptor agonist, mirabegron, are commonly used for treating patients with overactive bladder (OAB) and α1 -adrenoreceptor antagonists (α1 -blockers) are the main pharmacological agents used for treating lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). As these conditions commonly occur together, the aim of this systematic review was to identify publications that compared the use of an α1 -blocker plus mirabegron with an α1 -blocker plus antimuscarinic in men with LUTS secondary to BPH and OAB. A meta-analysis was subsequently conducted to explore the safety and efficacy of these combinations. METHODS: Included records had to be from a parallel-group, randomized clinical trial that was ≥8 weeks in duration. Participants were male with LUTS secondary to BPH and OAB. The indirect analyses that were identified compared an α1 -blocker plus OAB agent with an α1 -blocker plus placebo. The PubMed/Medical Literature Analysis and Retrieval System Online, the Excerpta Medica Database, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry were searched for relevant records up until March 5, 2020. Safety outcomes included incidences of overall treatment-emergent adverse events (TEAEs) and urinary retention, postvoid residual volume, and maximum urinary flow (Qmax ). Primary efficacy outcomes were micturitions/day, incontinence episodes/day, and urgency episodes/day, and secondary outcomes were Overactive Bladder Symptom Score and International Prostate Symptom Score. A Bayesian network meta-analysis approach was used for the meta-analysis. RESULTS: Out of a total of 1039 records identified, 24 were eligible for inclusion in the meta-analysis. There were no statistically significant differences between the α1 -blocker plus mirabegron and α1 -blocker plus antimuscarinic groups in terms of the comparisons identified for all the safety and efficacy analyses conducted. Numerically superior results were frequently observed for the α1 -blocker plus mirabegron group compared with the α1 -blocker plus antimuscarinic group for the safety parameters, including TEAEs, urinary retention, and Qmax . For some of the efficacy parameters, most notably micturitions/day, numerically superior results were noted for the α1 -blocker plus antimuscarinic group. Inconsistency in reporting and study variability were noted in the included records, which hindered data interpretation. CONCLUSION: This systematic review and meta-analysis showed that an α1 -blocker plus mirabegron and an α1 -blocker plus antimuscarinic have similar safety and efficacy profiles in male patients with LUTS secondary to BPH and OAB. Patients may, therefore, benefit from the use of either combination within the clinical setting.

The impact of pharmacotherapy on sexual function in female patients being treated for idiopathic overactive bladder: a systematic review.

BACKGROUND: Overactive bladder (OAB) is a condition defined by urgency with or without incontinence which disproportionately affects female patients and has a negative impact on sexual enjoyment and avoidance behaviour. Pharmacotherapy can be considered one of the main options for treating OAB. This research set out to determine the impact of pharmacotherapy on sexual function in females with OAB. METHODS: This research used the robust methodology of a systematic review. The clinical question was formulated using the PICO (population, intervention, control, and outcomes) format to include females being treated with pharmacotherapy (anticholinergics or beta-3 adrenergic agonists) for idiopathic OAB with the use of a validated questionnaire assessing self-reported sexual function at baseline and post-treatment. The review incorporated the MEDLINE, PubMed and EMBASE databases. The AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) appraisal tool was used to guide the review process. Two reviewers worked independently in screening abstracts, deciding on the inclusion of full-texts, data extraction and risk of bias assessment. RESULTS: In female patients with OAB, pharmacotherapy does seem to offer at least partial improvement in self-reported sexual function outcomes after 12 weeks of therapy. Still, the value of this finding is limited by an overall poor quality of evidence. Patients with a higher degree of bother at baseline stand to benefit the most from treatment when an improvement within this health-related quality of life domain is sought. CONCLUSION: This research should form the basis for a well-conducted randomized controlled study to accurately assess sexual function improvements in females being treated with pharmacotherapy for OAB.

Effect of Pharmacotherapy for Overactive Bladder on the Incidence of and Factors Related to Urinary Tract Infection: A Systematic Review and Meta-analysis.

PURPOSE: The aim of this meta-analysis was to investigate the effect of pharmacotherapy for overactive bladder on the pathogenesis of urinary tract infection. MATERIALS AND METHODS: A comprehensive search was performed in MEDLINE and the Cochrane Library using terms for overactive bladder, antimuscarinic agents, and beta 3-adrenoceptor agonists. The primary end point was the emergence of urinary tract infection after pharmacotherapy for overactive bladder. The secondary end point was the emergence of urinary retention, dysuria, and/or increased residual urine volume after overactive bladder treatment. Meta-analyses were conducted using random-effects models. RESULTS: A total of 35,939 patients in 33 trials (29 trials of antimuscarinic agents vs placebo, and 9 trials of beta 3-adrenoceptor agonists vs placebo) that included patients with overactive bladder were identified. At 1-3 months after treatment, the incidence of urinary tract infections was statistically significantly higher in the patients treated with antimuscarinic agents (RR: 1.23, 95% CI: 1.04, 1.45; P = .013) than in the placebo control group. The incidence of urinary tract infections was not increased in the patients treated with beta 3-adrenoceptor agonists (RR: 1.04, 95% CI: 0.76, 1.42; P = .796). Antimuscarinic agents also statistically significantly increased the risks of urinary retention, dysuria, and/or increased residual urine volume (RR: 2.88, 95% CI: 1.79, 4.63; P < .001), whereas beta 3-adrenoceptor agonists did not (RR: 1.26, 95% CI: 0.38, 4.14; P = .708). CONCLUSIONS: This meta-analysis showed that antimuscarinic agents statistically significantly increased the incidences of urinary tract infection and lower urinary tract symptoms and dysfunction, but beta 3-adrenoceptor agonists did not. To prevent urinary tract infection emergence, beta 3-adrenoceptor agonists might be safer than antimuscarinic agents.

Effect of ß3-adrenoceptor agonist on the micromotion of bilateral major pelvic ganglion-excised rat bladder.

AIMS: Micromotion is an autonomous intramural movement of the bladder, and is believed to be an initial step in the generation of urinary urgency. Therefore, controlling micromotion may be a novel target in overactive bladder (OAB) treatment. However, developing micromotion treatment has been limited by the absence of a standardized animal model. We attempted to create a micromotion animal model and investigated the effectiveness of a ß3 -adrenoceptor agonist (CL316,243) on micromotion. METHODS: Bilateral major pelvic ganglia (MPGs) were excised in 18 male Sprague-Dawley rats, resulting in an almost completely denervated bladder. On postoperative Day 7, cystometry was performed. Rats were divided into three treatment groups: CL316,243; ß3- adrenoceptor antagonist (SR59230A) pretreated CL316,243; and a nonselective antimuscarinic agent (oxybutynin). Changes in micromotion were evaluated after the intra-arterial administration of each agent. RESULTS: Low-amplitude oscillations in intravesical pressure (micromotion) were observed 1 week after MPGs excision. Micromotion frequency significantly (p = 0.003) decreased (2.17 ± 3.54 times/5 min) with CL316,243 compared with vehicle (6.33 ± 1.97 times/5 min). Micromotion amplitude also decreased with CL316,243 (1.15 ± 1.93 cmH2 O) compared with vehicle (5.96 ± 5.12 cmH2 O), approaching conventional significance (p = 0.090). No significant decreases in frequency or amplitude were observed with oxybutynin treatment. CONCLUSIONS: Systemic administration of the ß3 -adrenoceptor agonist CL316,243 effectively controlled micromotion in bilateral MPGs-excised, almost completely denervated rat bladders. This result indicates that ß3 -adrenoceptor agonist may affect the bladder directly, suggesting that it might be effective for overall OAB, regardless of the presence or level of neurological deficits. Bilateral MPGs-excised rats are considered a plausible micromotion animal model suitable for future research.

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.

Study design of a phase 4, real-world study (COMPOSUR) to evaluate vibegron in patients with overactive bladder.

BACKGROUND: Overactive bladder (OAB) is defined as urinary urgency accompanied by frequency and nocturia, with or without urge urinary incontinence (UUI). Vibegron, a selective ß3-adrenergic receptor agonist approved in the US in December 2020, demonstrated efficacy in reducing symptoms of OAB and was safe and well tolerated in the 12-week EMPOWUR trial and its 40-week, double-blind extension trial. The goal of the COMPOSUR study is to evaluate vibegron in a real-world setting to assess patient treatment satisfaction, tolerability, safety, duration of treatment, and persistence. METHODS: This is a 12-month, prospective, observational, real-world study, with an optional 12-month extension to 24 months, in the US assessing adults ≥ 18 years old starting a new course of vibegron. Patients must be previously diagnosed with OAB with or without UUI, symptomatic for ≥ 3 months before enrollment, and receive prior treatment with an anticholinergic, with mirabegron, or with a combination of an anticholinergic and mirabegron. Enrollment is performed by the investigator following exclusion and inclusion criteria guided by US product labeling, reinforcing a real-world approach. Patients complete the OAB Satisfaction with Treatment Questionnaire (OAB-SAT-q) monthly and the OAB Questionnaire short form (OAB-q-SF) and Work Productivity and Activity Impairment Questionnaire (WPAI:US) at baseline and monthly for 12 months. Patients are followed up via phone call, in-person visits, or telehealth (ie, virtual) visits. The primary endpoint is patient treatment satisfaction as determined by the OAB-SAT-q satisfaction domain score. Secondary endpoints include percent positive responses to individual OAB-SAT-q questions, additional OAB-SAT-q domain scores, and safety. Exploratory endpoints include adherence and persistence. DISCUSSION: OAB leads to a significant decrease in quality of life, as well as impairment of work activities and productivity. Persistence with OAB treatments can be challenging, often due to lack of efficacy and adverse effects. COMPOSUR is the first study to provide long-term, prospective, pragmatic treatment data for vibegron in the US and the resultant effect on quality of life among patients with OAB in a real-world clinical setting. Trial registration ClinicalTrials.gov identifier: NCT05067478; registered: October 5, 2021.

Management of treatment-resistant nocturnal enuresis.

Nocturnal enuresis is defined as intermittent urinary incontinence during sleep in children 5 years of age and older, occurring at least once a month for at least 3 months. In Japan, pediatricians who do not specialize in nocturnal enuresis have become more proactive in treating the condition since 2016, when the guidelines for treating it were revised for the first time in 12 years. For monosymptomatic nocturnal enuresis, the first step is lifestyle guidance, with a focus on the restriction of fluid intake at night; however, if lifestyle guidance does not decrease the frequency of nocturnal enuresis, aggressive treatment should be added. The first choice of aggressive treatment is oral desmopressin, an antidiuretic hormone preparation, or alarm therapy. However, there remain patients whose wet nights do not decrease with oral desmopressin or alarm therapy. In such cases, it is necessary to reconfirm the method of desmopressin administration and check for factors that may decrease the efficacy of desmopressin. If alarm therapy does not increase the number of dry nights, it is possible that the patient is fundamentally unsuitable for alarm therapy. If dry nights do not increase with oral desmopressin or alarm therapy, the next treatment strategy should be considered immediately to keep the patient motivated for treatment.

Analysis of Urinary Retention Caused by Selective ß 3-adrenoceptor Agonists Using the Japanese Adverse Drug Event Report Database (JADER).

Overactive bladder (OAB) is a frequent chronic disorder which impairs quality of life by frequent, uncontrollable urination. Newly developed selectiveß 3-adrenoceptor agonists (sß 3-agonists) have the same efficacy in treating OAB but significantly fewer side effects than the traditionally used anti-muscarinics. However, safety data on these compounds are scarce. In this study, we analysed the occurrence of adverse effects in patients taking sß 3-agonists and their characteristics using the JADER database. The most frequently reported adverse effect associated with the use of sß 3-agonists was urinary retention [mirabegron; crude reporting odds ratios (ROR): 62.1, 95% confidence interval (CI): 52.0-73.6, P<0.001, vibegron; crude ROR: 250, 95% CI : 134-483, P<0.001]. Data from patients with urinary retention were stratified by sex. In both men and women, the rate of urinary retention was higher when using the mirabegron/anti-muscarinic drug when compared to mirabegron monotherapy; its occurrence was higher in men with a history of benign prostatic hypertrophy than in those without. Weibull analysis showed that approximately 50% of sß 3 agonist-induced urinary retention occurred within 15 days after initiation of treatment, and then gradually decreased. Although sß 3-agonists are useful against OAB, they may induce several side effects, especially urinary retention, which can further evolve into more severe conditions. Urinary retention occurs more frequently in patients concomitantly taking medication that either increases urethral resistance or has organic factors that block the urethra. When using sß 3-agonists, the concomitantly used medications and underlying diseases should be thoroughly reviewed, and safety monitoring should be instituted early during the treatment.

A systems biology analysis of adrenergically stimulated adiponectin exocytosis in white adipocytes.

Circulating levels of the adipocyte hormone adiponectin are typically reduced in obesity, and this deficiency has been linked to metabolic diseases. It is thus important to understand the mechanisms controlling adiponectin exocytosis. This understanding is hindered by the high complexity of both the available data and the underlying signaling network. To deal with this complexity, we have previously investigated how different intracellular concentrations of Ca2+, cAMP, and ATP affect adiponectin exocytosis, using both patch-clamp recordings and systems biology mathematical modeling. Recent work has shown that adiponectin exocytosis is physiologically triggered via signaling pathways involving adrenergic ß3 receptors (ß3ARs). Therefore, we developed a mathematical model that also includes adiponectin exocytosis stimulated by extracellular epinephrine or the ß3AR agonist CL 316243. Our new model is consistent with all previous patch-clamp data as well as new data (collected from stimulations with a combination of the intracellular mediators and extracellular adrenergic stimuli) and can predict independent validation data. We used this model to perform new in silico experiments where corresponding wet lab experiments would be difficult to perform. We simulated adiponectin exocytosis in single cells in response to the reduction of ß3ARs that is observed in adipocytes from animals with obesity-induced diabetes. Finally, we used our model to investigate intracellular dynamics and to predict both cAMP levels and adiponectin release by scaling the model from single-cell to a population of cells-predictions corroborated by experimental data. Our work brings us one step closer to understanding the intricate regulation of adiponectin exocytosis.

Cryo-EM structures of the ß3 adrenergic receptor bound to solabegron and isoproterenol.

The ß3-adrenergic receptor (ß3AR) is the most essential drug target for overactive bladder and has therapeutic potentials for the treatments of type 2 diabetes and obesity. Here, we report the cryo-electron microscopy structures of the ß3AR-Gs signaling complexes with the selective agonist, solabegron and the nonselective agonist, isoproterenol. Comparison of the isoproterenol-, mirabegron-, and solabegron-bound ß3AR structures revealed that the extracellular loop 2 changes its conformation depending on the bound agonist and plays an essential role in solabegron binding. Moreover, ß3AR has an intrinsically narrow exosite, regardless of the agonist type. This structural feature clearly explains why ß3AR prefers mirabegron and solabegron, as the narrow exosite is suitable for binding with agonists with elongated shapes. Our study deepens the understanding of the binding characteristics of ß3AR agonists and may pave the way for developing ß3AR-selective drugs.

ß3-Adrenoceptor Agonist for the Treatment of Bladder Dysfunction in Children: A Systematic Review and Meta-Analysis.

PURPOSE: ß3-adrenergic receptor agonists (ß3 agonists) have been used in treatment of overactive bladder (OAB) and neurogenic detrusor overactivity (NDO) in adults. However, their use in children has only recently been approved by the U.S. Food and Drug Administration for patients with NDO. As in adults, the role of ß3 agonists in children may include conditions such as OAB. This systematic review and meta-analysis aims to understand the intended use, efficacy and safety of ß3 agonists in the pediatric population. MATERIALS AND METHODS: A literature search was performed in February 2021 across MEDLINE®, Embase®, Scopus®, the Cochrane Library and ClinicalTrials.gov. No language restrictions were placed. All records describing the clinical use of ß3 agonists in pediatric patients (<18 years of age) were included, regardless of the methodological design or outcomes assessed. The identified records were screened by 2 independent authors. The reporting was compliant with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Data extraction was performed by 2 independent reviewers, blinded to each other's extractions. The data were pooled using the fixed effects model. RESULTS: Of 367 records identified, 8 studies were included in the review (3 prospective and 5 retrospective). ß3 agonists led to improvements in both urodynamics parameters and self-reported outcomes such as incontinence. Commonly reported side effects were headaches (3%‒5.9%), constipation (3.5%‒5.7%), rhinitis/nasopharyngitis (1.7%‒5.8%) and blurred vision (1.7%‒2.9%). Clinically meaningful changes in safety outcomes (blood pressure, heart rate, electrocardiogram-related changes, liver function) were rare. Before and after ß3 agonist use, pooled effect estimates for maximum cystometric capacity for 171 patients were mean difference of +98.84 ml (95% CI 74.72, 122.96); for complete dryness, assessment of 235 patients showed a Peto odds ratio of 8.68 (95% CI 5.22, 14.45). CONCLUSIONS: ß3 agonists appear to be a promising, effective and safe alternative/adjunctive therapy in management of pediatric NDO or OAB, with improvements in both objective urodynamics parameters and subjective patient-reported outcomes following their use.

Hepatic Scavenger Receptor Class B Type 1 Knockdown Reduces Atherosclerosis and Enhances the Antiatherosclerotic Effect of Brown Fat Activation in APOE*3-Leiden.CETP Mice.

[Figure: see text].

Utilization rate and long-term persistence of combination pharmacotherapy with ß3-agonists and antimuscarinics for overactive bladder refractory to monotherapy in a real-world setting.

AIM: To assess real-world treatment profiles, including utilization rate, time to and reasons for discontinuation of combination pharmacotherapy with ß3 -agonists and antimuscarinics for refractory overactive bladder (OAB) through a retrospective chart review. METHODS: We retrospectively reviewed the records of OAB patients who received ß3 -agonists or antimuscarinics at our hospital between 2012 and 2020 and analyzed the clinical course of patients who progressed to combination therapy. Data on age, sex, major complaints, OAB symptom score at the initiation of combination therapy, treatment persistence, and reasons for discontinuation were collected. Treatment persistence was assessed with respect to the median time to discontinuation and persistence rate at 12 months. RESULTS: Of the 2163 patients receiving ß3 -agonists or antimuscarinics, only 84 (3.8%) progressed to combination therapy with both drug classes. At therapy initiation, most (98%) of these patients had moderate to severe OAB symptoms. Median treatment duration and 12-month persistence rate for combination therapy were 595 days and 64.0%, respectively. The reasons for discontinuation were insufficient treatment efficacy followed by adverse effects including voiding impairment in nearly 10% of the patients. None of the baseline parameters was independently associated with persistence in the multivariate analysis. CONCLUSION: While underutilized among OAB patients refractory to monotherapy, combination pharmacotherapy showed a greater persistence rate than published mirabegron or antimuscarinic monotherapy when applied to patients with moderate to severe symptoms. Treatment-emergent voiding impairment is a concern associated with this mode of therapy. A small sample size at a single institution is the limitation of this study.