Β-adrenoceptor Agonist Research Articles

Comparison of Cardioprotective Potential of Cannabidiol and β-Adrenergic Stimulation against Hypoxia/Reoxygenation Injury in Rat Atria and Ventricular Papillary Muscles

Background: Hypoxia is one of the most significant pathogenic factors in cardiovascular diseases. Preclinical studies suggest that nonpsychoactive cannabidiol (CBD) and β-adrenoceptor stimulation might possess cardioprotective potential against ischemia-reperfusion injury. The current study evaluates the influence of hypoxia-reoxygenation (H/R) on the function of atria and ventricular papillary muscles in the presence of CBD and the nonselective β-adrenoceptor agonist isoprenaline (ISO). Methods: The concentration curves for ISO were constructed in the presence of CBD (1 µM) before or after H/R. In chronic experiments (CBD 10 mg/kg, 14 days), the left atria isolated from spontaneously hypertensive (SHR) and their normotensive control (WKY) rats were subjected to H/R following ISO administration. Results: Hypoxia decreased the rate and force of contractions in all compartments. The right atria were the most resistant to hypoxia regardless of prior β-adrenergic stimulation. Previous β-adrenergic stimulation improved recovery in isolated left atria and right (but not left) papillary muscles. Acute (but not chronic) CBD administration increased the effects of ISO in left atria and right (but not left) papillary muscles. Hypertension accelerates left atrial recovery during reoxygenation. Conclusion: H/R directly modifies the function of particular cardiac compartments in a manner dependent on cardiac region and β-adrenergic prestimulation. The moderate direct cardioprotective potential of CBD and β-adrenergic stimulation against H/R is dependent on the cardiac region, and it is less than in the whole heart with preserved coronary flow. In clinical terms, our research expands the existing knowledge about the impact of cannabidiol on cardiac ischemia, the world′s leading cause of death.

Comparative Efficacy and Safety of the β3-Adrenoceptor Agonist Vibegron for Urgency and Mixed Urinary Incontinence: A Post Hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled Phase 3 Study

Comparative Efficacy and Safety of the β3-Adrenoceptor Agonist Vibegron for Urgency and Mixed Urinary Incontinence: A Post Hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled Phase 3 Study

Risk of dementia associated with the use of anticholinergic medications: a review of recent literature.

While there is an established association between the use of anticholinergic medications and its effects on cognition, the extent of this impact remains unclear. We outline recent studies addressing this topic. We describe a series of recent articles discussing the risk of dementia associated with anticholinergic medication use in general, with further focus on the risk of overactive bladder (OAB) anticholinergic use, detailing short & long-term use effects, risk variation based on age and gender, and reporting alternative treatment options. Anticholinergic medication use bears an increased risk of dementia development, and accelerated cognitive decline in individuals with preexisting dementia, with the risk being related to the medications dosages, length of exposure, and pharmacological profile. β3-adrenoceptor agonists have proven to be a potent alternative for OAB anticholinergics, owing to its safe profile in regards of no clear effects on cognitive function, and having similar efficacy in OAB treatment.

β-Adrenoceptor Agonists Attenuate Thrombin-Induced Impairment of Human Lung Endothelial Cell Barrier Function and Protect the Lung Vascular Barrier during Resuscitation from Hemorrhagic Shock.

β-adrenoceptor (β-AR) agonists are known to antagonize thrombin-induced impairment (TII) of bovine and ovine lung endothelial barrier function. The effects of adrenoceptor agonists and other vasoactive agents on human lung microvascular endothelial cell (HULEC-5a) barrier function upon thrombin exposure have not been studied. Furthermore, it is unknown whether the in vitro effects of adrenoceptor agonists translate to lung protective effects in vivo. We observed that epinephrine, norepinephrine, and phenylephrine enhanced normal and prevented TII of HULEC-5a barrier function. Arginine vasopressin and angiotensin II were ineffective. α1B-, α2A/B-, and β1/2-ARs were detectable in HULEC-5a by RT-PCR. Propranolol but not doxazosin blocked the effects of all adrenoceptor agonists. Phenylephrine stimulated β2-AR-mediated Gαs activation with 13-fold lower potency than epinephrine. The EC50 to inhibit TII of HULEC-5a barrier function was 1.8 ± 1.9 nM for epinephrine and >100 nM for phenylephrine. After hemorrhagic shock and fluid resuscitation in rats, Evans blue extravasation into the lung increased threefold (p < 0.01 vs. sham). Single low-dose (1.8 μg/kg) epinephrine administration at the beginning of resuscitation had no effects on blood pressure and reduced Evans blue extravasation by 60% (p < 0.05 vs. vehicle). Our findings confirm the effects of β-adrenoceptor agonists in HULEC-5a and suggest that low-dose β-adrenoceptor agonist treatment protects lung vascular barrier function after traumatic hemorrhagic shock.

Cilostazol attenuates mirabegron-induced hepatic and renal toxicity in rats: regulation of metabolic, oxidative, and inflammatory pathways

Background Mirabegron (MIRG) is a type of β3 adrenoceptor agonist that is considered an alternative therapy for the treatment of overactive bladder (OAB) symptoms. Cilostazol (CITZ) is a selective inhibitor of phosphodiesterase (III) that has various pharmacological effects. Objectve The current study aimed to highlight the regulatory effects of CITZ on MIRG-induced toxicity. Materials and Methods Male rats were divided into six groups. Blood samples were collected to determine different hepatic and kidney function levels along with serum protein electrophoresis and inflammatory factor levels. Histopathological studies and oxidative stress (OS) were also assessed. Kidney and hepatic damage were detected following the administration of MIRG, especially at high doses, due to elevated OS, inflammation, and apoptotic marker levels. Results Rats receiving CITZ exhibited significant improvements in both hepatic and kidney functions, with decreased inflammation and OS. Conclusion CITZ administration plays a beneficial role in alleviating hepatic and nephrotoxicity induced by MIRG by inhibiting OS and inflammation.

β2-adrenoceptor agonist formoterol attenuates NLRP3 inflammasome activation and GSDMD-mediated pyroptosis in microglia through enhancing IκBα/NF-κB inhibition, SQSTM1/p62-dependent selective autophagy and ESCRT-III-mediated plasma membrane repair

Microglia are immune cells that play important roles in the formation of the innate immune response within the central nervous system (CNS). The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a multiple protein complex that is crucial for innate immunity, and excessive activation of the inflammasome for various reasons contributes to the pathogenesis of neurodegenerative diseases (NDs). β2-adrenoceptor agonists have become the focus of attention in studies on NDs due to the high synthesis of β2-adrenoceptors in the central nervous system (CNS). Promising results have been obtained from these studies targeting anti-inflammatory and neuroprotective effects. Formoterol is an effective, safe for long-term use, and FDA-approved β2-adrenoceptor agonist with demonstrated anti-inflammatory features in the CNS. In this study, we researched the effects of formoterol on LPS/ATP-stimulated NLRP3 inflammasome activation, pyroptosis, NF-κB, autophagy, and ESCRT-III-mediated plasma membrane repair pathways in the N9 microglia cells. The results showed that formoterol, through the IκBα/NF-κB axis, significantly inhibited NLRP3 inflammasome activation, reduced the level of active caspase-1, secretion of IL-1β and IL-18 proinflammatory cytokine levels, and the levels of pyroptosis. Additionally, we showed that formoterol activates autophagy, autophagosome formation, and ESCRT-III-mediated plasma membrane repair, which are significant pathways in the inhibition of NLRP3 inflammasome activation and pyroptosis. Our study suggests that formoterol efficaciously prevents the NLRP3 inflammasome activation and pyroptosis in microglial cells regulation through IκBα/NF-κB, autophagy, autophagosome formation, and ESCRT-III-mediated plasma membrane repair.

Comparison of the Genomic Activity of an EP4-Receptor and β2-Adrenoceptor Agonist in BEAS-2B Human Bronchial Epithelial Cells: In Search of Compartmentalized, cAMP-Dependent Gene Expression.

It has been proposed that inhaled E-prostanoid 4 (EP4)-receptor agonists could represent a new class of bronchodilators for the treatment of asthma that are as effective as β 2-adrenoceptor agonists. However, the genomic impact of such drugs is unknown despite being potentially deleterious to respiratory health. Herein, we used mRNA-seq to compare the transcriptomic responses produced by 2-[3-[(1R,2S,3R)-3-hydroxy-2-[(E,3S)-3-hydroxy-5-[2-(methoxymethyl)phenyl]pent-1-enyl]-5-oxo-cyclopentyl]sulphanylpropylsulphanyl] acetic acid (ONO-AE1-329; an EP4-receptor agonist) and vilanterol (a β 2-adrenoceptor agonist) in BEAS-2B human airway epithelial cells. We also determined if an increase in cAMP mediated by different G protein-coupled receptors (GPCRs) promoted distinct transcriptional signatures by expanding this inquiry to include the adenosine A2B- and I-prostanoid receptor agonists, 2-[[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]-2-pyridinyl]thio]-acetamide (Bay60-6583) and taprostene, respectively. Maximally-effective concentrations of ONO-AE1-329 and vilanterol significantly regulated (q ≤ 0.05; ≥1.5-/≤0.67-fold) 232 and 320 genes, respectively of which 217 were shared. Spearman analysis showed these gene expression changes to be highly rank order correlated, indicating that the functional overlap between the two interventions should be considerable. Unexpectedly, the genomic effects of ONO-AE1-329, vilanterol, Bay 60-6583, and taprostene were also highly rank order correlated. This finding suggests that cAMP generated by any GPCR would initiate the same transcriptional program. Nevertheless, relative to vilanterol, ONO-AE1-329 typically behaved as a partial agonist that varied across transcripts. These data indicate that each ONO-AE1-329-regulated gene differs in sensitivity to cAMP and is defined by a unique receptor occupancy-response relationship. Moreover, if this relatively modest genomic response in BEAS-2B cells is retained in vivo, then inhaled EP4-receptor agonists could represent an alternative, and possibly safer, class of bronchodilators. SIGNIFICANCE STATEMENT: The genomic consequences of β 2-adrenoceptor agonists in asthma are often overlooked despite being potentially harmful to lung health. We determined that ONO-AE1-329, an EP4-receptor agonist and effective bronchodilator, produced gene expression changes in BEAS-2B cells that were typically modest relative to the β 2-adrenoceptor agonist vilanterol. Furthermore, ONO-AE1-329 behaved as a partial agonist that varied across transcripts. If this genomic activity is reproduced in vivo, then EP4-receptor agonists could represent an alternative, and possibly safer, class of bronchodilators.

Ligand-Receptor Interactions and Structure-Function Relationships in Off-Target Binding of the β3-Adrenergic Agonist Mirabegron to α1A-Adrenergic Receptors.

The β3-adrenoceptor agonist mirabegron is available for the treatment of storage symptoms of overactive bladder, including frequency, urgency, and incontinence. The off-target effects of mirabegron include binding to α1-adrenoceptors, which are central in the treatment of voiding symptoms. Here, we examined the structure-function relationships in the binding of mirabegron to a cryo-electron microscopy structure of α1A. The binding was simulated by docking mirabegron to a 3D structure of a human α1A-adrenoceptor (7YMH) using Autodock Vina. The simulations identified two binding states: slope orientation involving 10 positions and horizontal binding to the receptor surface involving 4 positions. No interactions occurred with positions constituting the α1A binding pocket, including Asp-106, Ser-188, or Phe-312, despite the positioning of the phenylethanolamine moiety in transmembrane regions close to the binding pocket by contact with Phe-288, -289, and Val-107. Contact with the unique positions of α1A included the transmembrane Met-292 during slope binding and exosite Phe-86 during horizontal binding. Exosite binding in slope orientation involved contact of the anilino part, rather than the aminothiazol end, to Ile-178, Ala-103, and Asn-179. In conclusion, contact with Met-292 and Phe-86, which are unique positions of α1A, accounts for mirabegron binding to α1A. Because of its lack of interactions with the binding pocket, mirabegron has lower affinity compared to α1A-blockers and no effects on voiding symptoms.

The Effects of Vibegron Add-on Therapy on Alpha 1-Blocker Therapy for Sexual Function and Overactive Bladder Symptoms in Benign Prostatic Hyperplasia: A Prospective, Open-Label Study.

Background: The effect of combining an α1-adrenergic receptor blocker (α1-blocker) and the β3-adrenoceptor agonist vibegron for treating persistent overactive bladder (OAB) symptoms associated with benign prostatic hyperplasia (BPH) on sexual function remains uncertain. Therefore, we aimed to evaluate the effects of vibegron as an add-on to α1-blocker therapy on both OAB and sexual function. Methods: Forty-three patients with BPH in whom OAB symptoms were inadequately controlled by α1-blocker treatment were included in this prospective open-label study. The OAB Symptom Score (OABSS), International Prostate Symptom Score (IPSS), 15-item International Index of Erectile Function (IIEF-15), and Erection Hardness Score (EHS), as well as the residual urine volume and serum-free testosterone (FT) and C-reactive protein (CRP) levels, were evaluated before and 8 weeks after the daily administration of 50 mg vibegron/α1-blocker combination therapy. Results: Vibegron/α1-blocker combination therapy significantly improved the OABSS (from 6.9 ± 2.6 to 5.1 ± 2.9, p < 0.0001) and IIEF intercourse satisfaction domain (from 1.1 ± 2.3 to 1.9 ± 2.6, p = 0.02). No significant differences were observed for the IPSS, EHS, total IIEF-15 score, residual urine volume, and serum FT and CRP levels. Conclusions: The study findings suggest that vibegron/α1-blocker combination therapy improves OAB and sexual satisfaction.

Effects on cerebral blood flow after single doses of the β2 agonist, clenbuterol, in healthy volunteers and patients with mild cognitive impairment or Parkinson's disease.

Cerebral hypometabolism occurs years prior to a diagnosis of neurodegenerative diseases and coincides with reduced cerebral perfusion and declining noradrenergic transmission from the locus coeruleus. In pre-clinical models, β-adrenoceptor (β-AR) agonists increase cerebrocortical glucose metabolism, and may have therapeutic potential for neurodegenerative diseases. This study investigated the safety and effects on regional cerebral blood flow (rCBF) of the oral, brain-penetrant β2-AR agonist, clenbuterol, in healthy volunteers (HV) and patients with mild cognitive impairment (MCI) or Parkinson's disease (PD). This study evaluated the safety and effects on cerebral activity of the oral, brain-penetrant, β2-AR agonist clenbuterol (20-160 μg) in healthy volunteers and patients with MCI or PD. Regional CBF, which is tightly coupled to glucose metabolism, was measured by arterial spin labelling MRI in 32 subjects (25 HV and 8 MCI or PD) across five cohorts. In some cohorts, low doses of nadolol (1-5mg), a β-AR antagonist with minimal brain penetration, were administered with clenbuterol to control peripheral β2-AR responses. Significant, dose-dependent increases in rCBF were seen in multiple brain regions, including hippocampus, amygdala and thalamus, following the administration of clenbuterol to HVs (mean changes from baseline in hippocampal rCBF of -1.7%, 7.3%, 22.9%, 28.4% 3h after 20, 40, 80 and 160 μg clenbuterol, respectively). In patients with MCI or PD, increases in rCBF following 80 μg clenbuterol were observed both without and with 5mg nadolol (in hippocampus, 18.6%/13.7% without/with nadolol). Clenbuterol was safe and well-tolerated in all subjects; known side effects of β2-agonists, including increased heart rate and tremor, were mild in intensity and were blocked by low-dose nadolol. The effects of clenbuterol on rCBF were evident both in the absence and presence of low-dose nadolol, suggesting central nervous system (CNS) involvement. Concomitant inhibition of the peripheral effects of clenbuterol by nadolol confirms that meaningful β2-AR antagonism in the periphery was achieved without interrupting the central effects of clenbuterol on rCBF.

Non-invasive mapping of brown adipose tissue activity with magnetic resonance imaging

Thermogenic brown adipose tissue (BAT) has a positive impact on whole-body metabolism. However, in vivo mapping of BAT activity typically relies on techniques involving ionizing radiation, such as [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) and computed tomography (CT). Here we report a noninvasive metabolic magnetic resonance imaging (MRI) approach based on creatine chemical exchange saturation transfer (Cr-CEST) contrast to assess in vivo BAT activity in rodents and humans. In male rats, a single dose of the β3-adrenoceptor agonist (CL 316,243) or norepinephrine, as well as cold exposure, triggered a robust elevation of the Cr-CEST MRI signal, which was consistent with the [18F]FDG PET and CT data and 1H nuclear magnetic resonance measurements of creatine concentration in BAT. We further show that Cr-CEST MRI detects cold-stimulated BAT activation in humans (both males and females) using a 3T clinical scanner, with data-matching results from [18F]FDG PET and CT measurements. This study establishes Cr-CEST MRI as a promising noninvasive and radiation-free approach for in vivo mapping of BAT activity.

Role of Phenylethanolamine-N-methyltransferase on Nicotine-Induced Vasodilation in Rat Cerebral Arteries.

The sympathetic-parasympathetic (or axo-axonal) interaction mechanism mediated that neurogenic relaxation, which was dependent on norepinephrine (NE) releases from sympathetic nerve terminal and acts on β2-adrenoceptor of parasympathetic nerve terminal, has been reported. As NE is a weak β2-adrenoceptor agonist, there is a possibility that synaptic NE is converted to epinephrine by phenylethanolamine-N-methyltransferase (PNMT) and then acts on the β2-adrenoceptors to induce neurogenic vasodilation. Blood vessel myography technique was used to measure relaxation and contraction responses of isolated basilar arterial rings of rats. Nicotine-induced relaxation was sensitive to propranolol, guanethidine (an adrenergic neuronal blocker), and Nω-nitro-l-arginine. Nicotine- and exogenous NE-induced vasorelaxation was partially inhibited by LY-78335 (a PNMT inhibitor), and transmural nerve stimulation depolarized the nitrergic nerve terminal directly and was not inhibited by LY-78335; it then induced the release of nitric oxide (NO). Epinephrine-induced vasorelaxation was not affected by LY-78335. However, these vasorelaxations were completely inhibited by atenolol (a β1-adrenoceptor antagonist) combined with ICI-118,551 (a β2-adrenoceptor antagonist). These results suggest that NE may be methylated by PNMT to form epinephrine and cause the release of NO and vasodilation. These results provide further evidence supporting the physiological significance of the axo-axonal interaction mechanism in regulating brainstem vascular tone.

Diaryl pyrrolone fluorescent probing strategy for Mirabegron determination through condensation with ninhydrin and phenylacetaldehyde: Application to dosage forms, human urine and plasma

Mirabegron (MRB) is a β3-adrenoceptor agonist used for managing overactive bladder syndrome. A cost-effective, environmentally friendly, and highly sensitive spectrofluorimetric method was suggested to serve the purpose of quantifying MRB in its pure state, pharmaceutical tablets, spiked human plasma and urine, and testing content uniformity. In the present study, ninhydrin and phenylacetaldehyde react with the amino group moiety of MRB in Teorell-Stenhagen buffer (pH 7.5) to generate a strongly fluorescent diaryl pyrrolone compound that emits fluorescence at a wavelength of 477 nm upon excitation at 385 nm. The obtained calibration curve showed a linear relationship with a high correlation coefficient (r = 0.9997) in the concentration range of 0.25 to 5.0 µg mL−1. Limits of detection (LOD) and quantitation (LOQ) were 0.082 and 0.248 µg mL−1 respectively. The procedure was verified in accordance with the ICH guidelines. The suggested approach could be utilized for the selective analysis of MRB in its pharmaceuticals, either containing a single drug or co-formulated with solifenacin succinate. The greenness of the suggested method was confirmed using different green analytical metrics.

First-In-Man Trial of β3-Adrenoceptor Agonist Treatment in Chronic Heart Failure: Impact on Diastolic Function.

Diastolic dysfunction (DD) in heart failure is associated with increased myocardial cytosolic calcium and calcium-efflux through the sodium-calcium exchanger depends on the sodium gradient. Beta-3-adrenoceptor (β3-AR) agonists lower cytosolic sodium and have reversed organ congestion. Accordingly, β3-AR agonists might improve diastolic function, which we aimed to assess. In a first-in-man, randomized, double-blinded trial, we assigned 70 patients with HF with reduced ejection fraction, New York Heart Association II-III, and left ventricular ejection fraction <40% to receive the β3-AR agonist mirabegron (300 mg/day) or placebo for 6 months, in addition to recommended heart failure therapy. We performed echocardiography and cardiac computed tomography and measured N-terminal probrain natriuretic peptide at baseline and follow-up. DD was graded per multiple renowned algorithms. Baseline and follow-up data were available in 57 patients (59 ± 11 years, 88% male, 49% ischemic heart disease). No clinically significant changes in diastolic measurements were found within or between the groups by echocardiography (E/e' placebo: 13 ± 7 to 13 ± 5, P = 0.21 vs. mirabegron: 12 ± 6 to 13 ± 8, P = 0.74, between-group follow-up difference 0.2 [95% CI, -3 to 4], P = 0.89) or cardiac computed tomography (left atrial volume index: between-group follow-up difference 9 mL/m 2 [95% CI, -3 to 19], P = 0.15). DD gradings did not change within or between the groups following 2 algorithms ( P = 0.72, P = 0.75). N-terminal probrain natriuretic peptide remained unchanged in both the groups ( P = 0.74, P = 0.64). In patients with HF with reduced ejection fraction, no changes were identified in diastolic measurements, gradings or biomarker after β3-AR stimulation compared with placebo. The findings add to the previous literature questioning the role of impaired Na + -Ca 2+ -mediated calcium export as a major culprit in DD. NCT01876433.

In vitro effects of β3-adrenoceptor agonist mirabegron on the human ureter.

This study aimed to investigate the effect of mirabegron, a β3-adrenoceptor agonist with widespread clinical use for treating overactive bladder disease, on isolated healthy human ureter strips. This was a prospective study employing a series of in vitro organ bath experiments using ureteral tissues of kidney grafts from 10 healthy donors. The ureteral strips were subjected to cumulative mirabegron concentrations (10-9-10-4.5 M). Effects on frequency or amplitude of spontaneous, 10 mM KCl- or EFS-induced contractions were evaluated. Mirabegron decreased the frequency of spontaneous ureteric contraction in a concentration-dependent manner. Statistically significant decrease in the frequency of spontaneous contraction was observed at 10-8-10-4.5 M. In 10 mM KCl medium, statistically significant change in frequency was observed at 10-9-10-4.5 M. Statistically significant decrease in the amplitudes of spontaneous contraction was observed at 10-7-10-4.5 M. In a 10 mM KCl medium, statistically significant change in amplitudes was observed at 10-8-10-4.5 M. Mirabegron reduced the amplitude and frequency of human ureter activity in in vitro organ bath studies. This effect was achieved in a dose-dependent manner on isolated tissue strips. Although monotherapy with mirabegron remains uncertain, this study has the potential to elucidate the mechanism underlying the effectiveness of mirabegron, particularly in combination therapy for ureteral stones.

Abstract 6276: In vitro neuroendocrine differentiation of BPH-1 cells under beta-adrenergic stimulation

Abstract Recent studies have shown that adrenergic fibers from the sympathetic nervous system (SNS), acting through stromal β2-adrenergic receptors, play an important role in the initial phases of cancer development by promoting tumor cell survival. Recent epidemiological data suggest that β-blocker intake is associated with improved survival of prostate cancer patients. Hypertension and high blood pressure have been suggested to increase prostate cancer development suggesting that the use of β-blockers in these patients could also reduce prostate cancer risk. β-adrenoceptors signal through the cAMP/PKA pathway that is known to promote neuroendocrine differentiation (NED) in LNCaP prostate cancer cell line. While neuroendocrine (NE) cells expressing synaptophysin (SYN) represent a minor cell population in the epithelial compartment of normal prostate glands, the population of NE-like cells, exhibiting NE phenotypes and expressing NE markers, is increased in, and correlates with, cancer progression, androgen-independent state and poor prognosis. Expression of the routine tissue biomarker of prostate cancer AMACR in NE-like cells discriminates them from NE cells. Our aim was to investigate whether NED could also be associated with benign prostatic hyperplasia (BPH) as recent studies showed that an increase in neuroendocrine cell density occurred before development of BPH in hypertensive rats. Our results showed that a 10-day treatment with 100µM IBMX (blocking cAMP degradation) and 10µM forskolin (FSK, adenylate cyclase activator) to trigger sustained activation of the cAMP/PKA pathway led to an increase in SYN and AMACR expression in BPH-1 cells (qPCR and WB). Similar results were observed by combining the effect of the β-adrenoceptor agonist isoproterenol (1µM) and FSK. The same treatments reduced BPH-1 cell proliferation rates by 40% and 60%, respectively, as expected for NED. Effects on AMACR and SYN expression and cell proliferation were fully reversed by the β-blocker carvedilol (5µM). This data suggests that β-adrenoceptors could be linked to the development of NE-like cells in BPH, a non-lethal disease affecting the transition zone (TZ). As 20% of the prostate cancer occur in this TZ, this observation may need further investigation. Citation Format: Natascha Pigat, Laura N. Garrido, Coline Lefevre, Manon Baures, Vincent Goffin, Anne-Sophie Armand, Thierry Capiod. In vitro neuroendocrine differentiation of BPH-1 cells under beta-adrenergic stimulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6276.

Effect of folic acid on isoprenaline-induced myocardial injury in rats.

Isoprenaline (ISO), a synthetic catecholamine and a β-adrenoceptor agonist, is widely used to develop an experimental model of myocardial injury (MI) in rats. The leading hypothesis for ISO-induced MI in rats is that it results from catecholamine overstimulation, oxidative stress, inflammatory responses, and development of cardiomyopathy during ISO administration. Folic acid (FA) reduces oxidative stress, improves endothelial function and prevents apoptosis, thereby contributing to cardiovascular protection. This study aimed to investigate the potentially protective effect of FA pretreatment on ISO-induced MI in rats. For 7 days, adult male Wistar albino rats were pretreated with 5 mg/kg/day of FA. On the sixth and seventh days, MI in rats was induced by administering 85 mg/kg/day of ISO. Prooxidant markers in plasma samples, antioxidant capacity in erythrocyte lysates, cardiac damage markers, lipid profile, electrocardiography (ECG) and histopathological analysis were evaluated. FA pretreatment significantly alleviated changes induced by ISO; it decreased the homocysteine and high-sensitivity troponin I level. FA moderately decreased the reactive oxygen species (ROS) levels (superoxide anion radical, hydrogen peroxide and thiobarbituric acid reactive substances) and improved the antioxidant activities of catalase, superoxide dismutase and reduced glutathione. ISO reduced the nitrite level and FA significantly alleviated this change. It can be concluded that FA, as a mild antioxidant, could be an appropriate cardioprotective substance in the rat model of ISO-induced MI.

Pathophysiology of Overactive Bladder and Pharmacologic Treatments Including β3-Adrenoceptor Agonists -Basic Research Perspectives.

Overactive bladder (OAB) is a symptom-based syndrome defined by urinary urgency, frequency, and nocturia with or without urge incontinence. The causative pathology is diverse; including bladder outlet obstruction (BOO), bladder ischemia, aging, metabolic syndrome, psychological stress, affective disorder, urinary microbiome, localized and systemic inflammatory responses, etc. Several hypotheses have been suggested as mechanisms of OAB generation; among them, neurogenic, myogenic, and urothelial mechanisms are well-known hypotheses. Also, a series of local signals called autonomous myogenic contraction, micromotion, or afferent noises, which can occur during bladder filling, may be induced by the leak of acetylcholine (ACh) or urothelial release of adenosine triphosphate (ATP). They can be transmitted to the central nervous system through afferent fibers to trigger coordinated urgency-related detrusor contractions. Antimuscarinics, commonly known to induce smooth muscle relaxation by competitive blockage of muscarinic receptors in the parasympathetic postganglionic nerve, have a minimal effect on detrusor contraction within therapeutic doses. In fact, they have a predominant role in preventing signals in the afferent nerve transmission process. β3-adrenergic receptor (AR) agonists inhibit afferent signals by predominant inhibition of mechanosensitive Aδ-fibers in the normal bladder. However, in pathologic conditions such as spinal cord injury, it seems to inhibit capsaicin-sensitive C-fibers. Particularly, mirabegron, a β3-agonist, prevents ACh release in the BOO-induced detrusor overactivity model by parasympathetic prejunctional mechanisms. A recent study also revealed that vibegron may have 2 mechanisms of action: inhibition of ACh from cholinergic efferent nerves in the detrusor and afferent inhibition via urothelial β3-AR.

Discovery and Identification of Novel 5-Hydroxy-4H-benzo[1,4]oxazin-3-one Derivatives as Potent β2-Adrenoceptor Agonists through Structure-Based Design, Synthesis, and Biological Evaluation.

Although β2-agonists are crucial for treatment of chronic respiratory diseases, optimizing β2-agonistic activity and selectivity remains essential for achieving favorable therapeutic outcomes. A structure-based molecular design workflow was employed to discover a novel class of β2 agonists featuring a 5-hydroxy-4H-benzo[1,4]oxazin-3-one scaffold, which potently stimulated β2 adrenoceptors (β2-ARs). Screening for the β2-agonistic activity and selectivity led to the identification of compound A19 (EC50 = 3.7 pM), which functioned as a partial β2-agonist in HEK-293 cells containing endogenous β2-ARs. Compound A19 exhibited significant relaxant effects, rapid onset time (Ot50 = 2.14 min), and long duration of action (>12 h) on isolated guinea pig tracheal strips, as well as advantageous pharmacokinetic characteristics in vivo, rendering A19 suitable for inhalation administration. Moreover, A19 suppressed the upregulation of inflammatory cytokines and leukocytes and improved lung function in a rat model of COPD, thereby indicating that A19 is a potential β2 agonist candidate for further study.

Sex-specific regulation of miR-22 and ERα in white adipose tissue of obese dam's female offspring impairs the early postnatal development of functional beige adipocytes in mice

During inguinal adipose tissue (iWAT) ontogenesis, beige adipocytes spontaneously appear between postnatal 10 (P10) and P20 and their ablation impairs iWAT browning capacity in adulthood. Since maternal obesity has deleterious effects on offspring iWAT function, we aimed to investigate its effect in spontaneous iWAT browning in offspring. Female C57BL/6 J mice were fed a control or obesogenic diet six weeks before mating. Male and female offspring were euthanized at P10 and P20 or weaned at P21 and fed chow diet until P60. At P50, mice were treated with saline or CL316,243, a β3-adrenoceptor agonist, for ten days. Maternal obesity induced insulin resistance at P60, and CL316,243 treatment effectively restored insulin sensitivity in male but not female offspring. This discrepancy occurred due to female offspring severe browning impairment. During development, the spontaneous iWAT browning and sympathetic nerve branching at P20 were severely impaired in female obese dam's offspring but occurred normally in males. Additionally, maternal obesity increased miR-22 expression in the iWAT of male and female offspring during development. ERα, a target and regulator of miR-22, was concomitantly upregulated in the male's iWAT. Next, we evaluated miR-22 knockout (KO) offspring at P10 and P20. The miR-22 deficiency does not affect spontaneous iWAT browning in females and, surprisingly, anticipates iWAT browning in males. In conclusion, maternal obesity impairs functional iWAT development in the offspring in a sex-specific way that seems to be driven by miR-22 levels and ERα signaling. This impacts adult browning capacity and glucose homeostasis, especially in female offspring.