Extracellular signal-regulated kinase 1/2 activity is not required in mammalian cells during late G2 for timely entry into or exit from mitosis

Author Posting. © American Society for Cell Biology, 2006. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 17 (2006): 5227-5240, doi:10.1091/mbc.E06-04-0284.Extracellular signal-regulated kinase (ERK)1/2 activity is reported to be required in mammalian cells for timely entry into and exit from mitosis (i.e., the G2-mitosis [G2/M] and metaphase-anaphase [M/A] transitions). However, it is unclear whether this involvement reflects a direct requirement for ERK1/2 activity during these transitions or for activating gene transcription programs at earlier stages of the cell cycle. To examine these possibilities, we followed live cells in which ERK1/2 activity was inhibited through late G2 and mitosis. We find that acute inhibition of ERK1/2 during late G2 and through mitosis does not affect the timing of the G2/M or M/A transitions in normal or transformed human cells, nor does it impede spindle assembly, inactivate the p38 stress-activated checkpoint during late G2 or the spindle assembly checkpoint during mitosis. Using CENP-F as a marker for progress through G2, we also show that sustained inhibition of ERK1/2 transiently delays the cell cycle in early/mid-G2 via a p53-dependent mechanism. Together, our data reveal that ERK1/2 activity is required in early G2 for a timely entry into mitosis but that it does not directly regulate cell cycle progression from late G2 through mitosis in normal or transformed mammalian cells.This research was supported by National Institutes of Health Grant GMS-40198 to C.L.R., by National Institutes of Health/National Cancer Institute Grant CA109182, and Samuel Waxman Cancer Research Foundation grants to J.A.A.-G

Effect of a 5-HT2c receptor agonist on urethral closure mechanisms in female rats

Aims: The serotonin (5-HT2c) receptor is known to be involved in the mechanism of urethral closure in a model of stress incontinence. Lorcaserin (Belviq®) has received Food and Drug Administration approval for the treatment of obesity. However, it is unclear whether this selective 5-HT2c receptor agonist enhances urethral closure in stress urinary incontinence (SUI) models. Therefore, we investigated whether lorcaserin could enhance urethral closure in female rats with vaginal distention (VD). Methods: Normal female rats and rats with stress incontinence induced by VD were tested. We evaluated the effect of a single dose of lorcaserin (0.03, 0.3, or 0.9 mg/kg with cumulative administration) on the urethral pressure amplitude during electrical stimulation (A-URE) and on the urethral baseline pressure (UBP). The manual compression-induced leak point pressure (LPP) was also measured. Results: In VD rats, a single intravenous injection of lorcaserin (0.3 and 0.9 mg/kg) significantly increased both A-URE and LPP compared to saline (P < 0.05). In normal rats, intravenous lorcaserin (0.3 and 0.9 mg/kg) also significantly increased A-URE and LPP compared to saline (P < 0.05). The changes of A-URE and LPP, which are parameters of active urethral closure, were significantly larger in normal rats than in VD rats. Conclusions: We showed that lorcaserin can activate the external urethral sphincter and pelvic floor muscles, suggesting an influence on active closure mechanisms. 5-HT2c receptors agonists may have dual effects in patients with SUI, not only by reducing obesity but also by enhancing active urethral closure

Examination of pelvic floor muscle elasticity in patients with interstitial cystitis/bladder pain syndrome using real-time tissue elastography

Introduction and hypothesis The aim was to compare pelvic floor muscle (PFM) elasticity between interstitial cystitis/bladder pain syndrome (IC/BPS) patients and healthy women using real-time tissue elastography. Methods The subjects were 17 IC/BPS female patients (IC/BPS group; age 34-84 years), 10 healthy middle-aged women (middle-aged group; 50-80 years), and 17 healthy young adult women (young group; 23-37 years). The target sites of elastography were the striated urethral sphincter (SUS) and adipose tissue as the reference site; muscle elasticity was calculated as the strain ratio (SR) of the SUS to the reference site. Evaluations were performed at rest and during PFM contraction. The IC/BPS group completed lower urinary tract symptom and pain questionnaires. SUS SR was compared among the three groups. SUS SR at rest and during PFM contraction was compared among the three groups with the t-test and the Wilcoxon test. Associations between questionnaire results and SUS SR were evaluated by correlation analysis. Results There was no significant difference in age between the IC/BPS and middle-aged groups, but the young group was significantly younger than the other groups (p < 0.001). SUS SR at rest was significantly higher in the IC/BPS group than in the middle-aged (p = 0.014) and young groups (p = 0.002). Furthermore, in the IC/BPS group, there was no significant difference in SUS SR between at rest and during PFM contraction. SUS SR was not significantly correlated with questionnaire results for lower urinary tract symptoms. Conclusions SUS SR at rest was significantly higher in the IC/BPS group than in the young and middle-aged groups

Lower urinary tract function improves after laparoscopic sacrocolpopexy for elderly patients with pelvic organ prolapse

Objectives Pelvic organ prolapse (POP) is relatively common in the elderly population. Laparoscopic sacrocolpopexy (LSC) has been reported by several studies to be a less invasive treatment option as compared to open sacrocolpopexy. However, almost all prior reports focused on the complications or surgical obstacles. The present study was designed to examine POP patients of all ages and assess lower urinary tract function before and after LSC. Methods This retrospective study examined the results of LSC performed in POP patients. Urodynamic studies were performed pre- and postoperatively in 50 patients, with the subjects divided into two groups containing those less than and those older than 65 years of age. We performed a pressure flow study. We examined bladder functions by evaluating bladder capacity, detrusor pressure at maximum flow (PdetQmax), maximum flow rate (Qmax), normal desire to void, strong desire to void, voided volume, and postvoid residual volume (PVR). Statistical analysis was performed using Wilcoxon signed rank test. Values of P = 65 age group. After the operation, there was a significant increase in the mean postoperative Qmax and voided volume, while there was a significant decrease in the PdetQmax and PVR as compared to the preoperative values only in the >= 65 age group. Conclusions Results show that in elderly patients with POP, LSC might be a valid option with regard to potentially regaining urinary tract function

Reliability of manometry for assessing pelvic floor muscle function in healthy men

Objectives To the best of our knowledge, no study has examined the reliability of assessment methods for male pelvic floor muscle (PFM) function. Therefore, this study aimed to clarify the reliability of manometry with an anal sensor (Peritron cat 9300A) to assess PFM function in healthy men. Methods Healthy male subjects (n = 21) without urinary leakage underwent testing to assess PFM function, and intra- and interrater reliability tests among examiners were performed. The PFM function included maximal anorectal squeeze pressure, endurance, mean anorectal squeeze pressure, gradient, and area under the curve during PFM voluntary contraction. Results Participants had a median age of 38 years (range 26-51), and a mean BMI of 23.2 +/- 2.0 kg/m(2). Satisfactory intra- and interrater reliability scores were found for resting pressure, anorectal squeeze pressure, and endurance. The intra-rater reliability of resting pressure, anorectal squeeze pressure, and endurance were 0.71, 0.89, and 0.75 for examiner 1 and 0.72, 0.89, and 0.87 for examiner 2. The interrater reliability for resting pressure, anorectal squeeze pressure, and endurance were 0.58, 0.93, and 0.61, respectively. Conclusions This is the first prospective study showing the favorable intra- and interrater reliability of manometry for PFM function in healthy men. Our findings demonstrated that manometry can provide both reliable and reproducible data regarding PFM function in continent men, suggesting Peritron cat 9300A can be used to evaluate the PFM function in men

Mechanisms of D1/D2-like dopaminergic agonist, rotigotine, on lower urinary tract function in rat model of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative condition caused by the loss of dopaminergic neurons in the substantia nigra pars compacta. As activation of dopaminergic receptors is fundamentally involved in the micturition reflex in PD, the objective of this study was to determine the effect of a single dose of rotigotine ([-]2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin) on intercontraction interval (ICI) and voiding pressure (VP) in a rat model of PD. We used 27 female rats, PD was induced by injecting 6-hydroxydopamine (6-OHDA; 8 mu g in 2 mu L of 0.9% saline containing 0.3% ascorbic acid), and rotigotine was administrated at doses of 0.125, 0.25, or 0.5 mg/kg, either intravenous or subcutaneous injection. In rats with 6-OHDA-induced PD, intravenous injection of 0.25 or 0.5 mg/kg rotigotine led to a significantly lower ICI than after vehicle injection (p < 0.05). Additionally, VP was significantly lower in animals administered rotigotine compared to those injected with vehicle (p < 0.05). Compared to vehicle-injected animals, subcutaneous administration of rotigotine (0.125, 0.25, or 0.5 mg/kg) led to a significantly higher ICI at 2 h after injection (p < 0.05); however, there was no change in ICI after injection with (+)-SCH23390 hydrochloride. Dermal administration of rotigotine in a rat model of PD could suppress an overactive bladder