The prevalence and predictive factors of nocturnal polyuria in Japanese patients with nocturia: a multicentral retrospective cohort study.

The aims of this study were to determine the prevalence and predictors of nocturnal polyuria (NP) in Japanese patients. This multicentral, observational study enrolled patients with the chief complaint of nocturia at 17 Japanese institutions between January 2018 and December 2022. The frequency of daily voiding and volume of urination were evaluated using bladder diaries. NP was diagnosed in patients with an NP index of > 33%. The primary endpoint was NP prevalence in patients with nocturia. The secondary endpoints were the prevalence of NP according to sex and age and the identification of factors predicting NP. This study analyzed 875 eligible patients. NP was present in 590 (67.4%) patients, with prevalence rates of 66.6% and 70.0% in men and women, respectively. Age ≥ 78 years, body mass index (BMI) < 23.0 kg/m2, and patients with ischemic heart or cerebrovascular disease were significant predictors of NP (P < 0.001, P < 0.001, P = 0.014, P = 0.016, respectively). This is the first large multicenter study to investigate the prevalence of NP in Japanese patients with nocturia. NP has a prevalence of 67.4%. Significant predictors of NP include age, BMI, and cardiovascular disease.

G protein-coupled receptor 55 activated by palmitoylethanolamide is associated with the development of nocturia associated with circadian rhythm disorders.

AIMS: Bladder function is regulated by clock genes and dysregulation of circadian bladder function can cause nocturia. The blood concentration of palmitoylethanolamide (PEA), a fatty acid metabolite, changes with circadian rhythm. Clock gene abnormalities demonstrate the highest PEA levels during the sleep phase. PEA is a GPR55 agonist that influences urination; therefore, increased PEA during the sleep phase may cause nocturia. Herein, we investigated the function of GPR55 to evaluate the relationship between GPR55 and nocturia that evoked higher PEA during the sleep phase in patients with circadian rhythm disorders. MAIN METHODS: Male C57BL/6 mice were used. GPR55 localization was evaluated by immunofluorescence staining, qRT-PCR, and western blotting. Variations in PEA-induced intracellular Ca2+ concentrations were measured in primary cultured mouse urothelial cells (UCs) using Ca2+ imaging. PEA-induced NGF and PGI2 release in UCs was measured by ELISA. The micturition reflex pathway after PEA administration was evaluated using immunofluorescence staining. KEY FINDINGS: GPR55 was predominant in the UC layer. PEA induced release of Ca2+ from the endoplasmic reticulum into the UC cytoplasm. ELISA and immunofluorescence staining revealed that NGF and PGI2 were released from bladder UCs, stimulated the pontine micturition center in mice, and induced nocturia. SIGNIFICANCE: The loss of regular circadian metabolizing rhythm in fatty acids causes higher blood PEA levels during the sleep phase. Binding of PEA to GPR55 in UC may activate the downstream processes of the micturition reflex, leading to nocturia. These findings suggest a new mechanism for nocturia and its potential as a therapeutic target.

Neuroendocrine prostate cancer treated with multimodal examination and therapy: A case report.

Neuroendocrine prostate cancer (NEPC) is rare, with short overall survival, and no established standard therapy. Therefore, the management of NEPC is often challenging. We report a case of a 63-year-old male diagnosed with NEPC and treated with multimodal examinations and therapies. Chemotherapy of cisplatin and etoposide for 6 months had a certain effect. However, his cancer progressed, and he took genetic screening exams. It revealed that his tumor mutational burden was high, and pembrolizumab was started. In this report, we suggested several new treatments.

Mirabegron for overactive bladder in frail patients 80 years or over (HOKUTO study).

BACKGROUND: We assessed the efficacy and safety of mirabegron, a ß3-adrenoceptor agonist, in older adults (≥ 80 years old) with overactive bladder (OAB). METHODS: OAB patients aged ≥ 80 years were enrolled in this prospective, single-arm observational study. OAB was diagnosed based on the OAB symptom score (OABSS); i.e., a total score of ≥ 3 points and an urgency score of ≥ 2 points. Patients who received 50 mg mirabegron once daily were evaluated at the baseline and at 4, 8, and 12 weeks. The changes from the baseline in the OABSS, International Prostate Symptom Score (IPSS), OAB questionnaire (OAB-q) score, and Vulnerable Elders Survey (VES-13) score were determined. Adverse events, laboratory tests, 12-lead electrocardiography, the QT interval according to Fridericia's formula (QTcF), uroflowmetry, the post-void residual urine volume (PVR), and the Mini-Mental State Examination (MMSE) score were used to assess safety. RESULTS: Forty-three patients (median age: 84 years, range: 80-96 years) were examined. They had high rates of comorbidities and polypharmacy. Mirabegron significantly improved in total score of the OABSS, including urgency and urge incontinence. The total IPSS, IPSS quality-of-life (QOL) index, and OAB-q scores also significantly improved. Mirabegron improved in the VES-13 score. There were no significant changes in laboratory test values, uroflowmetry findings, PVR, the QTcF, or MMSE score. Two patients (4.7%) withdrew from the study after experiencing adverse events. CONCLUSIONS: Mirabegron was well tolerated and significantly improved in OAB symptoms, and QOL in older patients. Trial registration The present clinical study was approved by University of Yamanashi Institutional Review Board prior to study initiation (ID1447) and was retrospectively registered with the UMIN Clinical Trials Registry (UMIN-CTR), Japan (UMIN000045996) on Nov 6, 2021.

Effects of fatty acid metabolites on nocturia.

Dysregulation of circadian rhythm can cause nocturia. Levels of fatty acid metabolites, such as palmitoylethanolamide (PEA), 9-hydroxy-10E,12Z-octadecadienoic acid (9-HODE), and 4-hydroxy-5E,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid (4-HDoHE), are higher in the serum of patients with nocturia; however, the reason remains unknown. Here, we investigated the circadian rhythm of fatty acid metabolites and their effect on voiding in mice. WT and Clock mutant (ClockΔ19/Δ19) mice, a model for nocturia with circadian rhythm disorder, were used. Levels of serum PEA, 9-HODE, and 4-HDoHEl were measured every 8 h using LC/MS. Voiding pattern was recorded using metabolic cages after administration of PEA, 9-HODE, and 4-HDoHE to WT mice. Levels of serum PEA and 9-HODE fluctuated with circadian rhythm in WT mice, which were lower during the light phase. In contrast, circadian PEA and 9-HODE level deteriorated or retreated in ClockΔ19/Δ19 mice. Levels of serum PEA, 9-HODE, and 4-HDoHE were higher in ClockΔ19/Δ19 than in WT mice. Voiding frequency increased in PEA- and 4-HDoHE-administered mice. Bladder capacity decreased in PEA-administered mice. The changes of these bladder functions in mice were similar to those in elderly humans with nocturia. These findings highlighted the novel effect of lipids on the pathology of nocturia. These may be used for development of biomarkers and better therapies for nocturia.

Potential Targets for Overactive Bladder in Older Men Based on Urinary Analysis of Metabolomics.

OBJECTIVE: We investigated the association between overactive bladder (OAB) and urinary metabolites in men. METHODS: This prospective observational study included 42 men aged 65-80 years. The 3-day frequency volume chart (FVC), International Prostate Symptom Score (IPSS), and quality of life score were adapted to assess the micturition behavior. Participants with IPSS urgency score ≥2 were included in the OAB group, and those with IPSS urgency score <2 were included in the control group. We performed a comprehensive metabolomic analysis using urine samples. Metabolites were compared between the groups using an unpaired t test and Fisher's exact test in a nonadjusted analysis. Multivariable logistic regression analysis was performed to investigate the association between OAB and the metabolites. RESULTS: Overall, 23 men were included in the OAB group and 19 in the control group. There were no differences in the background factors except age between the groups. FVC analysis demonstrated that nocturnal urine volume, 24-h micturition frequency, and nocturnal micturition frequency were significantly higher, and the maximum voided volume was significantly lower in the OAB group than in the controls. Metabolomic analysis revealed 14 metabolites that were differentially expressed between the groups. Multivariate analysis indicated that an increase in the levels of 5-iso prostaglandin F2α-VI (5-iPF2a-VI) and 5-methoxyindoleacetic acid was associated with OAB. CONCLUSION: Abnormal urinary metabolites, including metabolites in the tryptophan (5-methoxyindoleacetic acid, 3-indoleacetonitrile, and 3-hydroxyanthranilic acid) and arachidonic acid (5-iPF2a-VI) pathways, play a role in the pathogenesis of OAB in older men.

Mayo Adhesive Probability Score Is Associated with the Operative Time in Laparoscopic Adrenalectomy.

Background: Laparoscopic adrenalectomy (LA) is the standard treatment for adrenal benign tumors, including primary aldosteronism (PA) or Cushing's syndrome (CS). Several obesity-related factors were associated with prolonged total operative time (OT), but perinephric fat characteristics were not assessed. We investigated whether the Mayo adhesive probability (MAP) score, which evaluates perinephric fat characteristics, was associated with OT for LA. Methods: This single-center, retrospective cohort study examined 141 consecutive patients who underwent LA for PA or CS. We reviewed patients' characteristics and OT. MAP scores were recorded using preoperative imaging. The correlation among characteristics data, MAP score, and OT was evaluated. Results: Overall, we assessed 82 women and 59 men. Adrenal tumors were found in 80 PA and 61 CS patients. There were 74 left-sided and 67 right-sided tumors. For all patients, the median age, body mass index, and tumor size were 56 years (interquartile range [IQR] 46-65), 24.1 kg/m2 (IQR 21.7-26.8), and 19 mm (IQR 13-26), respectively. A total of 91 patients had MAP scores of 0, and 50 had MAP >0. The median OT was 183.5 minutes (IQR: 156-224 minutes) in the MAP >0 group and 162 minutes (IQR: 135-194 minutes) in the MAP = 0 group. In single variable analysis (unadjusted), MAP scores >0 and left-sided tumors were correlated with longer OT. Multivariable regression analysis revealed that this correlation was only significant for MAP scores >0. Conclusions: MAP score may be useful in preoperative planning for PA or CS patients undergoing LA.

Different effects of GsMTx4 on nocturia associated with the circadian clock and Piezo1 expression in mice.

OBJECTIVES: Nocturia is a major problem in geriatric patients. Clock genes regulate circadian bladder function and Piezo type mechanosensitive ion channel component 1 (Piezo1) that senses bladder fullness. We utilized WT and Clock mutant (ClockΔ19/Δ19: nocturia phenotype) mice to determine if the effects of GsMTx4, a Piezo1 inhibitor, is dependent on circadian Piezo1 expression in the bladder. METHODS: We compared voiding behavior in mice after the administration of vehicle, low dose, or high dose of GsMTx4. Intraperitoneal injections (IP) were performed at Zeitgeber time (ZT) 0, lower Piezo1 expression phase (ZT0-IP) and ZT12, higher Piezo1 expression phase (ZT12-IP). Urine volume (Uvol), voiding frequency (VF), and urine volume per void (Uvol/v) were measured using metabolic cages. RESULTS: VF decreased at ZT12-IP in WT mice only with high dose of GsMTx4 but showed no effects in ClockΔ19/Δ19 mice. VF decreased significantly at ZT0-IP in WT mice after both doses, but only decreased after high dose in ClockΔ19/Δ19 mice. Uvol/v increased in WT mice at ZT0-IP after both doses and at ZT12-IP after high dose. Uvol/v increased in ClockΔ19/Δ19 mice only at ZT0-IP after high dose. GsMTx4 did not affect Uvol in both mice at ZT12-IP. A decrease in Uvol was observed in both mice at ZT0-IP; however, it was unrelated to GsMTx4-IP. CONCLUSIONS: The effects of GsMTx4 changed associated with the circadian clock and Piezo1 expression level. The maximum effect occurred during sleep phase in WT. These results may lead to new therapeutic strategies against nocturia.

Risk Factors for Atelectasis or Pneumomediastinum After Robot-Assisted Partial Nephrectomy.

Purpose Several complications of robot-assisted partial nephrectomy (RAPN) have been reported; however, there are limited data on thoracic findings and complications. We investigated the risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy. Methods This retrospective cohort study included 84 consecutive patients who underwent robot-assisted partial nephrectomy with the da Vinci Si System and the AirSealTM Insufflation System. Based on chest radiography findings obtained postoperatively in the operating room, patients with and without atelectasis or pneumomediastinum were categorized into Groups A and B, respectively. Patient characteristics (age, sex, body mass index (BMI), RENAL nephrometry score, tumor size, and surgical approach) and perioperative outcomes (total operative time, console time, warm ischemic time, and estimated blood loss) were compared using the Mann-Whitney U test and chi-square test. A multivariate logistic regression analysis was performed to identify the risk factors associated with atelectasis or pneumomediastinum. Results Groups A and B included 31 and 53 patients, respectively. Although the rate of the retroperitoneal approach was significantly higher in Group A than in Group B, the other parameters and perioperative outcomes did not differ. The multivariate logistic regression analysis showed that the retroperitoneal approach and high body mass index were risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy. However, these abnormal findings disappeared spontaneously without requiring postoperative treatment. Conclusions The retroperitoneal approach and high body mass index may be risk factors for atelectasis or pneumomediastinum after robot-assisted partial nephrectomy.

Feasibility and necessity of the fourth arm of the da Vinci Si surgical system for robot-assisted partial nephrectomy.

BACKGROUND: To investigate the feasibility of the fourth arm of the da Vinci Si system for robot-assisted partial nephrectomy (RAPN). METHODS: Fifty-eight consecutive patients underwent RAPN with the same port placements. After reviewing the surgical videos and records, 38 patients showing usefulness of the fourth arm were categorized into Group A and those not showing usefulness into Group B. The background data, tumor characteristics, and perioperative outcomes were compared between the groups. RESULTS: Group B had a larger proportion of tumors located on the inner side of the kidney, and the console time was significantly longer. Multivariable logistic regression analysis showed that tumors located on the inner side of the kidney were associated with the non-use of the fourth arm of the da Vinci Si system during RAPN. CONCLUSIONS: Our findings suggested that use of fourth arm in RAPN by da Vinci Si should be considered for each tumor location.

Metabolism of fatty acids and bile acids in plasma is associated with overactive bladder in males: potential biomarkers and targets for novel treatments in a metabolomics analysis.

OBJECTIVES: The present study was conducted to identify metabolites using a metabolomics approach and investigate the relationship between these metabolites and urgency as a major symptom of overactive bladder (OAB). PATIENTS AND METHODS: In 47 male participants without any apparent neurological disease, OAB was defined as an urgency score on the International Prostate Symptom Score of 2 and higher (OAB group, n = 26), while patients with a score of 1 or 0 were placed in a control group (n = 21). A comprehensive study on plasma metabolites was conducted, and metabolites were compared between the OAB and control groups. RESULTS: Age was significantly higher in the OAB group, while prostate volume did not differ between the groups. A 24-h bladder diary revealed that nocturnal urine volume, 24-h micturition frequency, nocturnal micturition frequency, and the nocturnal index were significantly higher in the OAB group, whereas maximum voided volume was significantly lower in this group. The metabolomics analysis identified 79 metabolites from the plasma of participants. The multivariate analysis showed that increases in the fatty acids (22:1), erucic acid and palmitoleic acid, and a decrease in cholic acid correlated with incidence of male OAB. A decrease in acylcarnitine (18:2)-3 and an increase in cis-11-eicosenoic acid also appeared to be associated with OAB in males. CONCLUSIONS: OAB in males may occur through the abnormal metabolism of fatty acids and bile acids. Further studies on these pathways will contribute to the detection of new biomarkers and development of potential targets for novel treatments.

Urinary metabolites identified using metabolomic analysis as potential biomarkers of nocturia in elderly men.

PURPOSE: To investigate the association between nocturia and urinary metabolites in elderly men using metabolomic analysis. METHODS: We recruited 66 men aged 65-80 years. The 3-day frequency volume chart (FCV), International Prostate Symptom Score (IPSS), and quality of life score were used to assess micturition behavior. Participants with the total IPSS > 0 and ≥ 1.5 micturition on an average for three nights were included in the nocturia group. Participants with the total IPSS < 8 and < 1.5 micturition at night were included in the control group. We conducted a comprehensive metabolomic analysis of urine samples. Metabolites were compared between the groups using an unpaired t test. A multivariable logistic regression analysis was used to determine the relationship between nocturia and these metabolites. RESULTS: The nocturia and control groups consisted of 45 and 21 men, respectively. There were no differences in the background factors between the groups except for receiving anticholinergic drug and having life style-related diseases. The FVC revealed that nocturnal urine volume, 24 h micturition frequency, and nocturnal micturition frequency were significantly higher in the nocturia group than in the control group. The metabolomic analysis revealed 16 metabolites, which were differentially expressed between the groups. The multivariate analysis showed that increased serotonin level and decreased 3-hydroxypropionic acid and 3-indoleacetonitrile levels were associated with nocturia. CONCLUSIONS: These findings suggest that abnormal urinary metabolites including serotonin, 3-hydroxypropionic acid, and 3-indoleacetonitrile are involved in the pathogenesis of nocturia in elderly men.

Author Correction: Intermittent restraint stress induces circadian misalignment in the mouse bladder, leading to nocturia.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Intermittent restraint stress induces circadian misalignment in the mouse bladder, leading to nocturia.

Intermittent stress disrupts the circadian rhythm in clock genes such as Per2 only in peripheral organs without any effect on the central circadian clock in the suprachiasmatic nucleus. Here, the effect of restraint stress (RS) on circadian bladder function was investigated based on urination behavior and gene expression rhythms. Furthermore, PF670462 (PF), a Per2 phosphorylation enzyme inhibitor, was administered to investigate the effects on circadian bladder re-alignment after RS. Two-hour RS during the light (sleep) phase was applied to mice (RS mice) for 5 days. The following parameters were then examined: urination behaviors; clock gene expression rhythms and urinary sensory-related molecules such as piezo type mechanosensitive ion channel component 1 (Piezo1), transient receptor potential cation channel subfamily V member 4 (TRPV4), and Connexin26 (Cx26) in the bladder mucosa; Per2 expression in the excised bladder of Per2luciferase knock-in mice (Per2::luc); in vivo Per2 expression rhythms in the bladder of Per2::luc mice. Control mice did not show altered urination behavior in the light phase, whereas RS mice exhibited a higher voiding frequency and lower bladder capacity. In the bladder mucosa, RS mice also showed abrogated or misaligned Piezo1, TRPV4, Connexin26, and clock gene expression. The rhythmic expression of Per2 was also altered in RS mice both in excised- and in vivo bladder, compared with control mice. After PF administration, voiding frequency was reduced and bladder capacity was increased during the light phase in RS mice; the in vivo Per2 expression rhythm was also fully restored. Therefore, RS can alter circadian gene expression in the bladder during the light phase and might cause nocturia via changes in circadian bladder function due the dysregulation of clock genes. Amending the circadian rhythm therapeutically could be applied for nocturia.

Metabolomics analysis of blood identifies potential biomarkers and possible treatment targets for nocturia.

BACKGROUND: Our aim was to investigate the association between serum metabolites and nocturia. METHODS: A total of 66 males aged 65-80 years were enrolled in this study and stratified according to micturition behavior, which was characterized in terms of the 24 h frequency volume chart (FVC) for 3 consecutive days, the International Prostate Symptom Score (IPSS), and quality-of-life score. The nocturia group included participants with any total IPSS and ⩾1.5 micturitions/night as the mean of 3 nights, while the control group included participants with total IPSS < 8 and <1.5 micturitions/night. We conducted a comprehensive capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) study of plasma metabolites. Between-group comparisons of metabolite levels employed the Welch t test. The relationship between nocturia and metabolite profiles was determined using multivariable logistic regression analysis. RESULTS: Of 66 participants, 45 were included in the nocturia group and 21 in the control group. There were no differences in background factors between the two groups. FVC analysis revealed that urine production during night-time, as well as micturition frequency during daytime and night-time were significantly higher in the nocturia group. CE-TOFMS identified eight metabolites whose plasma levels differed between the two groups. Multivariate analysis indicated that increased levels of lauric acid and imidazolelactic acid, as well as decreased levels of thiaproline and glycerol, contribute to the etiology of nocturia in aged men. CONCLUSIONS: Our findings suggest that abnormal serum levels of metabolites in several pathways play a role in the pathogenesis of nocturia in aged men.

Liquid chromatography-mass spectrometry identification of serum biomarkers for nocturia in aged men.

PURPOSE: We aimed to investigate the association between nocturia and serum metabolites identified using metabolomics analysis. METHODS: This study enrolled 66 men aged 65-80 years, recruited from the outpatient department of a university hospital. The participants were stratified as follows: Nocturia group [45 men with any total international prostate symptom score (IPSS) and an average of 3 nights ≥ 1.5 micturitions/night] and Control group (21 men with total IPSS < 8 and an average of 3 nights < 1.5 micturitions/night). The 24-h frequency-volume chart, IPSS, and Quality-of-Life questionnaire were used to evaluate micturition behavior. Serum metabolite profiles were obtained using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics analysis and compared between the two groups using the unpaired t test. The relationship between serum metabolites and nocturia was determined using multivariable logistic regression analysis. RESULTS: There were no differences in background factors between the Nocturia and Control groups. In the IPSS, mean total scores in the Nocturia and Control groups were 12.4 and 4.0, respectively. On frequency-volume chart analysis, nocturnal urine volume and micturition frequency during daytime and nighttime were significantly higher in the Nocturia group. LC-MS highlighted 13 serum metabolites as potential biomarkers of nocturia. On multivariate analysis, increased levels of palmitoylethanolamide, 4-hydroxydocosahexaenoic acid, 9-hydroxyoctadecadienoic acid, 20-hydroxydocosahexaenoic acid, 13-hydroxyoctadecadienoic acid, arachidonoylethanolamide, eicosapentaenoic acid, 12-hydroxy-eicosatetraenoic acid, and arachidonic acid were associated with nocturia. CONCLUSIONS: In aged men, the pathogenesis of nocturia involves abnormal metabolism in several signaling pathways involving omega-3 and omega-6 polyunsaturated fatty acids, as well as endocannabinoids.

A method of producing genetically manipulated mouse mammary gland.

BACKGROUND: To obtain a deep understanding of the mechanism by which breast cancer develops, the genes involved in tumorigenesis should be analyzed in vivo. Mouse mammary gland can regenerate completely from a mammary stem cell (MaSC), which enables us to analyze the effect of gene expression and repression on tumorigenesis in mammary gland regenerated from genetically manipulated MaSCs. Although lentiviral and retroviral systems have usually been applied for gene transduction into MaSCs, they are associated with difficulty in introducing long, repeated, or transcriptional termination sequences. There is thus a need for an easier and quicker gene delivery system. METHODS: We devised a new system for gene delivery into MaSCs using the piggyBac transposon vectors and electroporation. Compared with viral systems, this system enables easier and quicker transfection of even long, repeated, or transcriptional termination DNA sequences. We designed gene expression vectors of the transposon system, equipped with a luciferase (Luc) expression cassette for monitoring gene transduction into regenerative mammary gland in mice by in-vivo imaging. A doxycycline (Dox)-inducible system was also integrated for expressing the target gene after mammary regeneration to mimic the actual mechanism of tumorigenesis. RESULTS: With this new gene delivery system, genetically manipulated mammary glands were successfully reconstituted even though the vector size was > 200 kb and even in the presence of DNA elements such as promoters and transcription termination sequences, which are major obstacles to viral vector packaging. They differentiated correctly into both basal and luminal cells, and showed normal morphological change and milk production after pregnancy, as well as self-renewal capacity. Using the Tet-On system, gene expression can be controlled by the addition of Dox after mammary reconstitution. In a case study using polyoma-virus middle T antigen (PyMT), oncogene-induced tumorigenesis was achieved. The histological appearance of the tumor was highly similar to that of the mouse mammary tumor virus-PyMT transgenic mouse model. CONCLUSIONS: With this system, gene transduction in the mammary gland can be easily and quickly achieved, and gene expression can be controlled by Dox administration. This system for genetic manipulation could be useful for analyzing genes involved in breast cancer.

The time-dependent variation of ATP release in mouse primary-cultured urothelial cells is regulated by the clock gene.

AIMS: The sensation of bladder fullness (SBF) is triggered by the release of ATP. Therefore, the aim of this study was to investigate whether time-dependent changes in the levels of stretch-released ATP in mouse primary-cultured urothelial cells (MPCUCs) is regulated by circadian rhythm via clock genes. METHODS: MPCUCs were derived from wild-type and Clock mutant mice (ClockΔ19/Δ19 ), presenting a nocturia phenotype. They were cultured in elastic silicone chambers. Stretch-released ATP was quantified every 4 h by ATP photon count. An experiment was also performed to determine whether ATP release correlated with the rhythm of the expression of Piezo1, TRPV4, VNUT, and Connexin26 (Cx26) in MPCUCs regulated by clock genes with circadian rhythms. MPCUCs were treated with carbenoxolone, an inhibitor of gap junction protein; were derived from VNUT-KO mice; or treated with Piezo1-siRNA, TRPV4-siRNA, and Cx26-siRNA. RESULTS: Stretch-released ATP showed time-dependent changes in wild-type mice and correlated with the rhythm of the expression of Piezo1, TRPV4, VNUT, and Cx26. However, these rhythms were disrupted in ClockΔ19/Δ19 mice. Carbenoxolone eliminated the rhythmicity of ATP release in wild-type mice. However, time-dependent ATP release changes were maintained when a single gene was deficient such as VNUT-KO, Piezo1-, TRPV4-, and Cx26-siRNA. CONCLUSIONS: ATP release in the bladder urothelium induces SBF and may have a circadian rhythm regulated by the clock genes. In the bladder urothelium, clock gene abnormalities may disrupt circadian ATP release by inducing Piezo1, TRPV4, VNUT, and Cx26. All these genes can trigger nocturia.

Metabolomic Analysis of Overactive Bladder in Male Patients: Identification of Potential Metabolite Biomarkers.

OBJECTIVES: To identify metabolites that are associated with an overactive bladder (OAB) using metabolomics. MATERIALS AND METHODS: A total of 58 male patients without apparent neurologic disease completed 24-hour bladder diaries of their micturition behavior and International Prostate Symptom Score (IPSS) for the assessment of micturition behavior and lower urinary tract symptoms. Urgency was defined as an IPSS urgency score of ≥2 (OAB group), and patients with IPSS urgency scores of ≤1 belonged to the control group. A comprehensive study of plasma metabolites was also conducted using capillary electrophoresis time-of-flight mass spectrometry. Metabolite levels were compared between the control and OAB groups using the Mann-Whitney U test. Potential metabolite biomarkers were selected using multivariate logistic regression analysis. RESULTS: Of the 58 subjects, the control and OAB groups consisted of 32 and 26 male patients, respectively. Nocturnal urinary volume, 24-hour micturition frequency, nocturnal micturition frequency, and the nocturia index were significantly higher in the OAB group. Metabolomic analysis revealed 60 metabolites in the subjects' plasma. The levels of 11 metabolites differed between the control and OAB groups. Multivariate analysis showed that an increased glutamate level and reduced arginine, glutamine, and inosine monophosphate levels are significantly associated with OAB in male patients. Reduced levels of asparagine and hydroxyproline could also be associated with OAB. CONCLUSIONS: Urgency is associated with abnormal metabolism. Analyses of amino acid profiles might aid the search for new treatment targets for OAB.