Correlation of urinary nerve growth factor level with pathogenesis of overactive bladder

The effect of bladder function on the efficacy of transurethral prostatectomy in patients with benign prostatic hyperplasia: a retrospective, single-center study

We investigated the impact and predictive value of bladder function in patients with benign prostatic hyperplasia (BPH) on the efficacy of transurethral prostatectomy. Symptomatic, imaging, and urodynamic data of patients who underwent transurethral prostatectomy at West China Hospital of Sichuan University (Chengdu, China) from July 2019 to December 2021 were collected. Follow-up data included the quality of life (QoL), International Prostate Symptom Score (IPSS), and IPSS storage and voiding (IPSS-s and IPSS-v). Moreover, urinary creatinine (Cr), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and prostaglandin estradiol (PGE2) were measured in 30 patients with BPH and 30 healthy participants. Perioperative indicators were determined by subgroup analyses and receiver operating characteristic (ROC) curve analysis. Among the 313 patients with BPH included, patients with severe micturition problems had more improvements but higher micturition grades postoperatively than those with moderate symptoms. Similarly, good bladder sensation, compliance, and detrusor contractility (DC) were predictors of low postoperative IPSS and QoL. The urinary concentrations of BDNF/Cr, NGF/Cr, and PGE2/Cr in patients were significantly higher than those in healthy participants (all P < 0.001). After evaluation, only DC was significantly related to both urinary indicators and postoperative recovery of patients. Patients with good DC, as predicted by urinary indicators, had lower IPSS and IPSS-v than those with reduced DC at the 1 st month postoperatively (both P < 0.05). In summary, patients with impaired bladder function had poor recovery. The combined levels of urinary BDNF/Cr, NGF/Cr, and PGE2/Cr in patients with BPH may be valid predictors of preoperative bladder function and postoperative recovery.

Urine Biomarkers in the Management of Adult Neurogenic Lower Urinary Tract Dysfunction: A Systematic Review

BACKGROUND

Neurogenic lower urinary tract dysfunction requires lifelong surveillance and management for the perseveration of patients' quality of life and the prevention of significant morbidity and mortality. Urine biomarkers are an attractive noninvasive method of surveillance for these patients. The aim of this systematic review is to search for and critically appraise studies that investigate the clinical usefulness of urine biomarkers in the management of neurogenic lower urinary tract dysfunction (NLUTD) in adults.

METHODS

This review was conducted according to PRISMA and MOOSE guidelines. Search strategy included PubMed, CENTRAL, and Scopus (until October 2022). Studies investigating potential urine biomarkers for the management of adults with NLUTD were included.

RESULTS

Fifteen studies fulfilled the criteria. To date, a variety of different urine molecules have been investigated for the diagnosis and management of neurogenic overactive bladder and detrusor overactivity (nerve growth factor, brain-derived neurotrophic factor, prostaglandin E2, prostaglandin F2α, transformation growth factor β-1, tissue inhibitor metalloproteinase-2, matrix metalloproteinase-2, substance P, microRNA), diagnosis of vesicoureteral reflux (exosomal vitronectin), urinary tract infection (neutrophil gelatinase-associated lipocalin, interleukin 6) and bladder cancer screening (cytology, BTA stat, survivin) in neurological patients.

CONCLUSION

Further studies are needed to specify the utility of each molecule in the management algorithm of adult NLUTD.

The urothelium, the urinary microbioma and men LUTS: a systematic review

INTRODUCTION

The pathophysiology and management of male patients with lower urinary tract symptoms (LUTS) is still a matter of debate. In the past few years, the urothelium and the urinary microbiota represented important areas of research to improve the understanding and management of these patients. Aim of the present review was to summarize the available data on the urothelium and the microbiota related to male LUTS.

EVIDENCE ACQUISITION

A National Center for Biotechnology Information (NCBI) PubMed search for relevant articles published between January 2000 and December 2019 was performed using the medical subjects heading "urothelium," "microbioma," "microbiota," "urobioma," "urobiota," "benign prostatic hyperplasia," "benign prostatic enlargement," "lower urinary tract symptoms," "lower urinary tract dysfunction," "men," "male," "overactive bladder," "receptors." Exclusion criteria included: animal studies and studies on muscarinic and adrenergic pathways.

EVIDENCE SYNTHESIS

The urothelium has been recently evaluated in humans to evaluate new possible markers and pathways. New possible targets for the treatment of male LUTS include the neural growth factor, the cannabinoid, the vanilloid and the ATP pathways. However, studies in humans are still needed to elucidate the exact role of these pathways in the management of male patients with LUTS. The available evidence on the urinary microbioma in male is poor. Standing to the available, urinary microbioma is evident in healthy urine in males. Moreover, the urinary microbioma varies depending on the method of collection, sexually transmitted disease status, inflammation and urinary symptoms. A possible role of probiotics in the management of LUTS in women has been proposed and may have a role in male patients as well.

CONCLUSIONS

The urothelium and the urinary microbiota are still poorly studied in men with LUTS. Most of the evidence and the hypothesis on the relationship between urothelium/urinary microbiota and LUTS comes from animal/in-vitro evidence while clinical trials are lacking. These pathways seem interesting even in LUTS pathogenesis in men but their possible role as a new therapeutic target is still an open debate.

Partners in Crime: NGF and BDNF in Visceral Dysfunction

Neurotrophins (NTs), particularly Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF), have attracted increasing attention in the context of visceral function for some years. Here, we examined the current literature and presented a thorough review of the subject. After initial studies linking of NGF to cystitis, it is now well-established that this neurotrophin (NT) is a key modulator of bladder pathologies, including Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) and Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS. NGF is upregulated in bladder tissue and its blockade results in major improvements on urodynamic parameters and pain. Further studies expanded showed that NGF is also an intervenient in other visceral dysfunctions such as endometriosis and Irritable Bowel Syndrome (IBS). More recently, BDNF was also shown to play an important role in the same visceral dysfunctions, suggesting that both NTs are determinant factors in visceral pathophysiological mechanisms. Manipulation of NGF and BDNF improves visceral function and reduce pain, suggesting that clinical modulation of these NTs may be important; however, much is still to be investigated before this step is taken. Another active area of research is centered on urinary NGF and BDNF. Several studies show that both NTs can be found in the urine of patients with visceral dysfunction in much higher concentration than in healthy individuals, suggesting that they could be used as potential biomarkers. However, there are still technical difficulties to be overcome, including the lack of a large multicentre placebo-controlled studies to prove the relevance of urinary NTs as clinical biomarkers.

Diminished long-term recovery of peak flow rate (PFR) after robotic prostatectomy in men with baseline PFR <10 mL/s and incidental association with high-risk prostate cancer

OBJECTIVE

The aim of this study was to evaluate the effects of robot-assisted radical prostatectomy (RARP) on uroflowmetry (UF) parameters among men with baseline peak flow rates (PFR) <10 mL/s.

METHODS

A single-surgeon RARP database of 1082 men who underwent prospective UF testing was analyzed. Men filled out International Prostate Symptom Score questionnaires and underwent uroflowmetry and post-void bladder ultrasound before surgery and at each follow-up visit. Patients were divided into 2 groups based on preoperative PFR: those with PFR <10 mL/s (n = 158) and those with PFR ≥10 mL/s (n = 924). Univariate and multivariate regression models tested the association of preoperative characteristics in predicting postoperative PFR improvement. Within the PFR <10 mL/s group, preoperative variables were analyzed to predict pathologic outcomes.

RESULTS

Three months after RARP, men with baseline PFR <10 mL/s had a 3-fold improvement in PFR (from mean of 7.0 to 24.2 mL/s), whereas in men with PFR ≥10 mL/s there was a 50% improvement (from mean of 19.7 to 28.9 mL/s; P < .001). Improvement in PFR remained stable for >5 years, but mean postoperative PFR was 20% lower in men with baseline PFR <10 mL/s. Preoperative prostate-specific antigen (odds ratio [OR] 0.75; 95% confidence interval [CI] 0.59-0.95) and PFR (OR 0.52; 95% CI 0.34-0.80) were independent predictors of the percentage improvement in men with baseline PFR <10 mL/s. Preoperative PFR ≤7 mL/s was an independent predictor of Gleason score ≥8 (P = .016), seminal vesicle invasion (P = .010), and lymph node invasion (0.029).

CONCLUSIONS

After RARP, PFR improved significantly, with the improvement persisting over long-term follow-up. However, men with baseline PFR <10 mL/s had a 20% lower postoperative PFR over 5 years, suggesting permanent damage to the bladder and the need for early treatment to maintain bladder health. There appears to be an association between baseline PFR ≤7 mL/s and adverse pathologic features.

Nerve growth factor does not seem to be a biomarker for neurogenic lower urinary tract dysfunction after spinal cord injury

AIM

To prospectively investigate the association of bladder function with the nerve growth factor (NGF) concentration in the urine of individuals with neurogenic lower urinary tract dysfunction (NLUTD) after spinal cord injury (SCI).

METHODS

Individuals with chronic SCI and NLUTD presenting for a routine urologic examination at a tertiary urologic referral center were recruited for the study. Patient characteristics, the current bladder evacuation method and urodynamic parameters were collected. As controls, individuals with normal bladder function were recruited from the staff of a SCI rehabilitation center. The urinary NGF concentration was measured in triplicates by enzyme linked immunosorbent assay with a minimal sensitivity of 10 pg/ml.

RESULTS

The data of 10 and 37 individuals with normal bladder function and NLUTD, respectively, were analyzed. The urinary NGF concentration was below 10 pg/ml in all investigated samples.

CONCLUSIONS

The urinary NGF concentration did not differentiate between individuals with normal bladder function and those with NLUTD. At least in patients with SCI, the urinary NGF concentration does not seem to be a clinically relevant biomarker for NLUTD. Neurourol. Urodynam. 36:659-662, 2017. © 2016 Wiley Periodicals, Inc.

Potential Biomarkers Utilized to Define and Manage Overactive Bladder Syndrome

Clinical diagnosis of overactive bladder (OAB) syndrome has great variation and usually can only be based on subjective symptoms. Measurement of urgency severity score in adjunct with voiding diary may reflect the occurrence of OAB and incontinence severity in daily life. Urodynamic study can detect detrusor overactivity (DO), but not in all OAB patients. A more objective way and less invasive tool to diagnose and assess therapeutic outcome in OAB patients is needed. Recent investigations of the potential biomarkers for OAB include urinary and serum biomarkers and bladder wall thickness. Evidence has also shown that urinary proteins, such as nerve growth factor (NGF) and prostaglandin E2 (PGE2 ) levels increase in patients with OAB, bladder outlet obstruction (BOO) and DO. Patients with OAB have significantly higher urinary NGFlevels and urinary NGF levels decrease after antimuscarinic therapy and further decrease after detrusor botulinum toxin injections. However, the sensitivity of single urinary protein in the diagnosis of OAB is not high and several lower urinary tract diseases may also have elevated urinary NGF levels. Searching for a group of inflammatory biomarkers by microsphere-based array in urine might be a better method in differential diagnosis of OAB from interstitial cystitis, urinary tract infection (UTI) or urolithiasis. Bladder wall thickness has been widely investigated in the diagnosis of BOO and pediatric voiding dysfunction.The role of bladder wall thickness in the diagnosis of OAB, however, has not reach a consistent conclusion. We hereby review the latest medical advances in this field.

Research Findings on Overactive Bladder

Several physiopathologic conditions lead to the manifestation of overactive bladder (OAB). These conditions include ageing, diabetes mellitus, bladder outlet obstruction, spinal cord injury, stroke and brain injury, Parkinson's disease, multiple sclerosis, interstitial cystitis, stress and depression. This review has discussed research findings in human and animal studies conducted on the above conditions. Several structural and functional changes under these conditions have not only been observed in the lower urinary tract, but also in the brain and spinal cord. Significant changes were observed in the following areas: neurotransmitters, prostaglandins, nerve growth factor, Rho-kinase, interstitial cells of Cajal, and ion and transient receptor potential channels. Interestingly, alterations in these areas showed great variation in each of the conditions of the OAB, suggesting that the pathophysiology of the OAB might be different in each condition of the disease. It is anticipated that this review will be helpful for further research on new and specific drug development against OAB.

[The role of urinary markers in the assessment and follow-up of lower urinary tract disorders: a literature review]

OBJECTIVES

To conduct a literature review on the role of urinary biomarkers in the initial assessment and follow-up of lower urinary tract symptoms.

METHODS

A literature review was conducted in August 2014 using the Medline/Pubmed database limiting the search to work in English or French.

RESULTS

Most studies were of level of evidence 2 or 3 (prospective cohort, controlled or not) and mainly about overactive bladder and bladder pain syndrome. Nerve Growth Factor (NGF) was the most studied and apparently the most promising in the evaluation of overactive bladder (OAB) and neurogenic detrusor overactivity (NDO). Urinary levels of ATP, prostaglandin E2 (PGE2), Brain-Derived Neurotrophic Factor (BDNF) and some cytokines were also significantly higher in most studies in patients with NDO or OAB. Epidermal Growth Factor (EGF), Heparin-Binding EGF (HBEGF) and Antiproliferative Factor (APF) were the most studied urinary markers in bladder pain syndrome, with a significant increase (EGF APF) or decrease (HBEGF) in cases of interstitial cystitis (compared to healthy controls). The urinary N-terminal-telopeptide (NTx) could be predictive of a failed mid-urethral sling. However, few studies reported the diagnostic values of the markers, their association with urodynamic parameters were rarely evaluated and the existence of a publication bias is likely. No randomized controlled study has so far compared the urinary markers to urodynamic evaluation.

CONCLUSION

In the future, urinary markers could complete or replace urodynamic examination. However, to date, there is no high level of evidence study comparing these markers to urodynamics and their use can therefore not be recommended in daily practice.

Decreased urinary nerve growth factor reflects prostatic volume reduction and relief of outlet obstruction in patients with benign prostatic enlargement treated with dutasteride

OBJECTIVES

To examine urinary nerve growth factor before and after dutasteride treatment, and to analyze correlations between clinical parameters and change of urinary nerve growth factor in patients with benign prostatic enlargement.

METHODS

We prospectively studied 30 patients with benign prostatic enlargement who had not been satisfied with α-adrenergic antagonist monotherapy for more than 3 months. Before and 24 weeks after dutasteride add-on treatment, we assessed International Prostate Symptom Score, prostatic volume, filling cystometry and pressure-flow study. Urinary nerve growth factor was measured by enzyme-linked immunosorbent assay, and normalized to the urinary creatinine (nerve growth factor/creatinine) before and 24 weeks after dutasteride add-on treatment.

RESULTS

In baseline characteristics before dutasteride, there was no significant correlation between urinary nerve growth factor/creatinine and any clinical parameters including age, International Prostate Symptom Score, prostatic volume, presence of detrusor overactivity, detrusor pressure at maximum flow rate, bladder outlet obstruction index or bladder contractility index. Dutasteride significantly reduced prostatic volume (from 68 ± 31 mL to 49 ± 28 mL) and improved International Prostate Symptom Score (from 17.2 ± 8.7 to 13.1 ± 6.8), storage (from 8.0 ± 4.3 to 6.0 ± 2.9) and voiding symptom subscore of International Prostate Symptom Score (from 9.3 ± 5.7 to 7.1 ± 4.5). In urodynamic study, detrusor pressure at maximum flow rate (from 77 ± 32 cmH2 O to 59 ± 24 cmH2 O) and bladder outlet obstruction index (from 62 ± 32 to 42 ± 27) were significantly decreased after dutasteride treatment. Urinary nerve growth factor/creatinine was significantly decreased after dutasteride from 2.61 ± 2.50 to 1.64 ± 1.68. The change of urinary nerve growth factor/creatinine significantly correlated only with the change of prostatic volume (r = 0.38) and bladder outlet obstruction index (r = 0.36).

CONCLUSIONS

Urinary nerve growth factor decreases in association with reduction of prostatic volume and relief of bladder outlet obstruction. Urinary nerve growth factor might be useful as a biomarker to monitor the improvement of bladder outlet obstruction in patients with benign prostatic enlargement.

Urinary nerve growth factor in patients with detrusor overactivity

Background

Detrusor overactivity (DO) is one of the most frequent bladder dysfunctions in children up to the age of 18. Nowadays, the only way to confirm DO is by urodynamic investigation, which is an invasive procedure. Among the many mediators influencing bladder function, nerve growth factor (NGF) plays an important role. The present study was designed to measure urinary NGF (uNGF) levels in patients with DO diagnosed by urodynamic study in comparison with healthy controls.

Methods

The investigation was conducted on 44 children, divided into two groups (24 patients with DO, 20 healthy children). Uroflowmetry was performed in all enrolled to the study and cystometry only to patients. uNGF levels were estimated in both studied groups.

Results

The median uNGF level in patients with DO before treatment was higher compared with healthy controls. There were no differences between uNGF levels in patients after anticholinergic treatment and the controls. We found differences in uroflowmetry parameters between the reference group and the patients. We found correlations between uroflowmetry parameters and uNGF/cr. level.

Conclusions

The uNGF level could be used for detecting DO in children and adolescents.

Measuring uNGF level is a simple, noninvasive procedure and very useful for choosing therapy in patients with DO in various clinical conditions.

Neurotrophins in bladder function: what do we know and where do we go from here?

AIMS

Neurotrophins (NTs) have attracted considerable attention in the urologic community. The reason for this resides in the recognition of their ability to induce plastic changes of the neuronal circuits that govern bladder function. In many pathologic states, urinary symptoms, including urgency and urinary frequency, reflect abnormal activity of bladder sensory afferents that results from neuroplastic changes. Accordingly, in pathologies associated with increased sensory input, such as the overactive bladder syndrome (OAB) or bladder pain syndrome/interstitial cystitis (BPS/IC), significant amounts of NTs have been found in the bladder wall.

METHODS

Here, current knowledge about the importance of NTs in bladder function will be reviewed, with a focus on the most well-studied NTs, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF).

RESULTS

Both NTs are present in the bladder and regulate bladder sensory afferents and urothelial cells. Experimental models of bladder dysfunction show that upregulation of these NTs is strongly linked to bladder hyperactivity and, in some cases, pain. NT manipulation has been tested in animal models of bladder dysfunction, and recently, NGF downregulation, achieved by administration of a monoclonal antibody, has also been tested in patients with BPS/IC and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). NTs have also been found in high quantities in the urine of OAB and BPS/IC patients, raising the possibility of NTs serving as biomarkers.

CONCLUSIONS

Available data show that our knowledge of NTs has greatly increased in recent years and that some results may have future clinical application.

Increased TRPV4 expression in urinary bladder and lumbosacral dorsal root ganglia in mice with chronic overexpression of NGF in urothelium

Transient receptor potential vanilloid (TRPV) family member 4 (TRPV4) expression has been demonstrated in urothelial cells and dorsal root ganglion (DRG) neurons, and roles in normal micturition reflexes as well as micturition dysfunction have been suggested. TRP channel expression and function is dependent upon target tissue expression of growth factors. These studies expand upon the target tissue dependence of TRPV4 expression in the urinary bladder and lumbosacral DRG using a recently characterized transgenic mouse model with chronic overexpression of nerve growth factor (NGF-OE) in the urothelium. Immunohistochemistry with image analyses, real-time quantitative polymerase chain reaction, and Western blotting were used to determine TRPV4 protein and transcript expression in the urinary bladder (urothelium + suburothelium, detrusor) and lumbosacral DRG from littermate wild-type (WT) and NGF-OE mice. Antibody specificity controls were performed in TRPV4(-/-) mice. TRPV4 transcript and protein expression was significantly (p ≤ 0.001) increased in the urothelium + suburothelium and suburothelial nerve plexus of the urinary bladder and in small- and medium-sized lumbosacral (L1, L2, L6-S1) DRG cells from NGF-OE mice compared to littermate WT mice. NGF-OE mice exhibit significant (p ≤ 0.001) increases in NGF transcript and protein in the urothelium + suburothelium and lumbosacral DRG. These studies demonstrate regulation of TRPV4 expression by NGF in lower urinary tract tissues. Ongoing studies are characterizing the functional roles of TRPV4 expression in the sensory limb (DRG, urothelium) of the micturition reflex.

Nerve growth factor (NGF): a potential urinary biomarker for overactive bladder syndrome (OAB)?

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The search for a biomarker in overactive bladder syndrome (OAB) is an emerging field of interest, as bladder dysfunction is a common complaint that causes significant morbidity. A biomarker may give us insight as a diagnostic tool, and also inform us about how severe the condition is, how it may progress and how it may best be treated. The protein of interest here is nerve growth factor (NGF) and it has been shown to be a dynamic molecule in the bladder of patients with OAB. Urinary levels have been seen to rise in patients with OAB and fall in those who respond to treatment. However, there have also been many studies that examine this trend in numerous other conditions, e.g. interstitial cystitis, bladder outflow obstruction, renal stone disease and patients with neurological impairment after stroke. As a result the specificity of this as a potential urinary biomarker for OAB is questioned. This is a review of published studies, which discusses the pros and cons of NGF as a potential urinary biomarker. The evidence is examined and the studies are summarised together in a Table. Questions remain about the reliability, practicality and specificity of NGF as a biomarker for OAB. These questions need to be addressed by further studies that could clarify the points raised.

OBJECTIVE

To review the current literature on the use of urinary nerve growth factor (NGF) as a potential biomarker for overactive bladder syndrome (OAB).

METHOD

A comprehensive electronic literature search was conducted using the PubMed database to identify publications relating to urinary NGF.

RESULTS

There are a growing number of publications that have measured urinary NGF levels in different types of bladder dysfunction. These range from OAB, bladder pain syndrome, idiopathic and neurogenic detrusor overactivity, bladder oversensitivity and bladder outflow obstruction. Urinary NGF levels do appear to be raised in these pathological states when compared with healthy control samples. In patients with OAB, these raised urinary NGF levels appear to also reduce after successful treatment with antimuscarinics and botulinum toxin A, which indicates a potential use in monitoring responses to treatment. However, raised levels are not limited to OAB, which questions its specificity. Urinary NGF measurements are performed with an enzyme-linked immunosorbent assay using polyclonal antibodies to NGF. The technique requires standardisation, and the different antibodies to NGF require validating. Also a definition of what is the 'normal' range of NGF in urine is still required before it can be used as a diagnostic and prognostic tool.

CONCLUSIONS

Whilst the evidence for an increased urinary NGF in OAB appears convincing, many questions about its validity remain including: specificity, sensitivity, cost- and time-effectiveness. Many criteria for what constitutes a biomarker still need to be evaluated and met before this molecule can be considered for this role.

Neurotrophins in the lower urinary tract: becoming of age

The lower urinary tract (LUT) comprises a storage unit, the urinary bladder, and an outlet, the urethra. The coordination between the two structures is tightly controlled by the nervous system and, therefore, LUT function is highly susceptible to injuries to the neuronal pathways involved in micturition control. These injuries may include lesions to the spinal cord or to nerve fibres and result in micturition dysfunction. A common trait of micturition pathologies, irrespective of its origin, is an upregulation in synthesis and secretion of neurotrophins, most notably Nerve Growth Factor (NGF) and Brain Derived Neurotrophic Factor (BDNF). These neurotrophins are produced by neuronal and non-neuronal cells and exert their effects upon binding to their high-affinity receptors abundantly expressed in the neuronal circuits regulating LUT function. In addition, NGF and BDNF are present in detectable amounts in the urine of patients suffering from various LUT pathologies, suggesting that analysis of urinary NGF and BDNF may serve as likely biomarkers to be studied in tandem with other factors when diagnosing patients. Studies with experimental models of bladder dysfunction using antagonists of NGF and BDNF receptors as well as scavenging agents suggest that those NTs may be key elements in the pathophysiology of bladder dysfunctions. In addition, available data indicates that NGF and BDNF might constitute future targets for designing new drugs for better treatment of bladder dysfunction.

Autonomic dysfunction and plasticity in micturition reflexes in human α-synuclein mice

Although often overshadowed by the motor dysfunction associated with Parkinson's disease (PD), autonomic dysfunction including urinary bladder and bowel dysfunctions are often associated with PD and may precede motoric changes; such autonomic dysfunction may permit early detection and intervention. Lower urinary tract symptoms are common in PD patients and result in significant morbidity. This studies focus on nonmotor symptoms in PD using a transgenic mouse model with overexpression of human α-synuclein (hSNCA), the peptide found in high concentrations in Lewy body neuronal inclusions, the histopathologic hallmark of PD. We examined changes in the physiological, molecular, chemical, and electrical properties of neuronal pathways controlling urinary bladder function in transgenic mice. The results of these studies reveal that autonomic dysfunction (i.e., urinary bladder) can precede motor dysfunction. In addition, mice with hSNCA overexpression in relevant neuronal populations is associated with alterations in expression of neurotransmitter/neuromodulatory molecules (PACAP, VIP, substance P, and neuronal NOS) within neuronal pathways regulating bladder function as well as with increased NGF expression in the urinary bladder. Changes in the electrical and synaptic properties of neurons in the major pelvic ganglia that provide postganglionic innervation to urogenital tissues were not changed as determined with intracellular recording. The urinary bladder dysfunction observed in transgenic mice likely reflects changes in peripheral (i.e., afferent) and/or central micturition pathways or changes in the urinary bladder. SYN-OE mice provide an opportunity to examine early events underlying the molecular and cellular plasticity of autonomic nervous system pathways underlying synucleinopathies.

[Participation of the pudendal innervation in the detrusor overactivity of the detrusor and in the overactive bladder syndrome]

OBJECTIVES

The functional symptoms of the filling phase and detrusor overactivity are two inter-related dysfunctions of the lower urinary tract. We have aimed to study the participation of the lesion of the pudendal nerve in both urinary dysfunctions.

MATERIAL AND METHODS

A cross-sectional cutoff study in a series of 108 women was carried out. The study consisted in the questioning on the presence of functional symptoms of the lower urinary tract, cystomanometry and determination of peripheral pudendal nerve latency time, selective electromyography of the external anal sphincter and determination of the sacral reflex latency time.

RESULTS

A tendency was observed towards significance between the presence of pollakiuria amplitude of motor unit potentials (greater in presence of pollakiuria) and the presence of urgency-incontinence and time of sacral latency (greater in the presence of urge incontinence) and a significant relation between the score on the King's Health Questionnaire and peripheral pudendal nerve latency time. Regarding detrusor hyperactivity, greater sacral latency time was observed in patients with overactivity with tendency towards significance.

CONCLUSIONS

There is a relation between pudendal innervation alterations and presence of symptoms in the filling phase and detrusor overactivity. This relation would explain the therapeutic action of the perineal rehabilitation on these dysfunctions.

[Value of nerve growth factor levels in overactive bladder syndrome: alterations after botulinum toxin therapy]

OBJECTIVES

Several studies discussing the pathology of overactive bladder suggested changes in urinary proteins. The neurotrophin "nerve growth factor" (NGF) seems to be an important marker in overactive bladder syndrome (OAB). In this prospectively designed study we evaluated NGF blood levels (sNGF) initially and after injection of botulinum toxin type A (BTX-A) in the detrusor muscle in patients suffering from idiopathic OAB.

MATERIALS AND METHODS

Blood samples were obtained from 26 patients (66.5 years, 28-83) with idiopathic OAB. sNGF levels were measured before and 4 weeks after BTX-A treatment by enzyme-linked immunosorbent assay (ELISA). A group of 32 healthy persons with normal bladder function served as controls (41 years, 19-60). sNGF was evaluated in relation to clinical data and the severity of OAB (wet/dry).

RESULTS

Significantly higher sNGF levels were detected in patients with OAB compared to the control group (58.8 vs 2.0 pg/ml, p<0.005). Further, sNGF levels were elevated in patients with wet OAB compared to patients with dry OAB (85.0 vs 0.73 pg/ml, p<0.005). Patients > 60 years showed significantly higher sNGF levels (77.2 vs 8.9 pg/ml, p<0.05) compared to younger OAB patients. After BTX-A therapy sNGF levels decreased significantly compared to baseline (p<0.005).

CONCLUSION

NGF appears to play a decisive role in OAB. Its use as a biomarker in both the diagnostics and follow-up after therapy seems promising. To what extent sNGF can be useful as a biomarker or in therapy monitoring needs to be examined prospectively in a larger population.

Non-invasive techniques in the diagnosis of bladder storage disorders

AIMS

To review clinical studies thus have been conducted to develop non-invasive diagnostic tools in the storage phase of the micturition cycle.

METHODS

Pub Med and Web of Science searches were carried out. The search covered the published data of non-invasive diagnostic techniques for detrusor overactivity (DO) and/or low compliance bladder in patients with urinary storage symptoms. The patho-physiological and clinical relevance of these methods were addressed. Diagnostic accuracy of these techniques was scrutinized.

RESULTS

Eighteen studies were included in the review. Ultrasonography and biomarkers were the most investigated techniques in the diagnosis of storage disorders. Assessment of diagnostic accuracy was possible in four studies. The heterogeneity in data reporting was too high to conduct a meta-analysis. Ultrasonographic parameters and cut-off values have been developed to define DO; such as bladder wall thickness (BWT), detrusor wall thickness and bladder weight. The likelihood ratio of vaginal ultrasonography in measurement of BWT was good. Guidelines are currently developing to standardize the methodologies applied in these techniques. Laboratory biomarkers of DO are gaining more attention recently, but their specificity for DO should be carefully defined. Near infrared spectroscopy (NIRS) is potential non-invasive diagnostic method that is able to detect the DO episodes in real time. However, a solution needs to be found for motion artifacts in this technique.

CONCLUSION

Non-invasive diagnostic techniques for storage disorders show limited progress with some limitations. Yet these techniques still cannot replace the standard filling cystometry in standard clinical practice.

Biomarkers in overactive bladder: a new objective and noninvasive tool?

Overactive bladder syndrome (OAB) is a highly prevalent urinary dysfunction, with considerable economic and human costs. Clinical diagnosis of OAB is still based on subjective symptoms. A new accurate, objective and noninvasive test to diagnose OAB and assess therapeutic outcome is lacking. Recent studies in lower urinary tract (LUT) dysfunctions, particularly in OAB patients, indicate that urinary proteins (neurotrophins, prostaglandins, and cytokines), serum C reactive protein, and detrusor wall thickness are altered, and such changes could be used as biomarkers of the disease. Nowadays, increasing emphasis has been given to the role of urinary neurotrophins, namely nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF), as key players in some urinary dysfunctions. Although recently considered to be a bladder dysfunction biomarker, urinary NGF presents low sensitivity and specificity. Preliminary results suggest that BDNF may serve as a more efficient biomarker. Even though we have to wait for future studies to confirm the potential role of NGF and BDNF as OAB biomarkers, it is already clear that neurotrophins will contribute to elucidate the physiopathological basis of OAB. Herein are reviewed the latest advances in this new and exciting field, the detection and clinical application of emerging OAB biomarkers.

Effect of hyaluronic acid on urine nerve growth factor in cyclophosphamide-induced cystitis

OBJECTIVES

To investigate how hyaluronic acid (HA) affects nerve growth factor (NGF) production and bladder overactivity in a cyclophosphamide (CYP)-induced cystitis rat model.

METHODS

Female Sprague-Dawley rats received three intermittent intraperitoneal injections of CYP (75 mg/kg) or saline. Before or after CYP injection, HA was given intravesically and urine NGF was checked with creatinine correction. Bladder function was evaluated by cystometrograms under Zoletil anesthesia. Furthermore, the effect of HA was counteracted with hyaluronidase (HYAL). Bladder structural change was compared among groups with trichrome stain.

RESULTS

The intercontraction interval (ICI) significantly decreased in CYP-injected rats in comparison to the saline-injected controls. In the CYP-injected groups, bladder HA instillation significantly increased the ICI, but did not change the maximum voiding pressure in comparison to the saline instillation. NGF production significantly increased in CYP-injected rats, but decreased significantly with HA treatment. Treatment with HA had a more significant effect on urine NGF and the use of HYAL would eliminate this effect. Specific staining showed mucosa swelling after CYP treatment. Little HA coating on bladder mucosa could be found in HA-treated rats.

CONCLUSIONS

Present findings raise the possibility that HA could be an effective treatment for CYP-related bladder overactivity through the involvement of NGF signaling.

Differential profile analysis of urinary cytokines in patients with overactive bladder

INTRODUCTION AND HYPOTHESIS

We hypothesize that overactive bladder (OAB) can produce inflammatory cytokines due to afferent neural plasticity or urothelial dysfunction. This study aimed to detect abnormal cytokine levels in urine of patients with OAB compared to urinary tract infections (UTI) and controls.

METHODS

This was a prospective, single blind study including 20 premenopausal women (control), 20 with OAB and 16 with UTI. Urine samples were collected, centrifuged, and stored (-80°C). Urinary total proteins were quantified and detected by antibody-based array chip for release of 120 human cytokines in the two groups relative to the controls.

RESULTS

Majority of cytokines showed the same expression in the OAB compared with the controls. Cytokines exclusively expressed in OAB were: monocyte chemoattractant protein (MCP) 1, TARC, PARC, and Fas/TNFRSF6. MCP-2, MCP-3, tumor necrosis factor-β, GCSF and eotaxin-3 showed a shared expression in UTI and OAB. Conversely, few of the cytokines were downregulated in OAB (IL-5, IL-6, IL-7, and GM-CSF).

CONCLUSIONS

Taken together, the results suggest that a subset of inflammatory cytokines and chemokines provides a framework for development of highly optimized urinary biomarker assay for differential diagnosis and treatment of OAB.

Novel biomarkers for overactive bladder

Biomarkers constitute any objectively measurable indicator of a biological process. The classic biomarker used in the diagnosis of overactive bladder (OAB) has been detrusor overactivity, which is assessed urodynamically. In the search for a reliable, noninvasive alternative to urodynamics, interest has focused on genetic, imaging, and urinary factors. Along with other cytokines detectable in urine, prostaglandin E2 and nerve growth factor are indicators of low-grade inflammation. Although they correlate with OAB symptom severity, they have not been shown to have independent prognostic benefit. Imaging biomarkers have been investigated since the earliest days of video urodynamics. Despite extensive research on the ultrasonographic estimation of bladder wall thickness, further standardization of the technique is required before conclusions can be reached regarding diagnostic accuracy. Genetic factors contribute approximately half of the total risk for urgency incontinence. Functional polymorphisms of the cytochrome P450 IID6 gene significantly alter the metabolism of some commonly used anticholinergic drugs, but no genetic loci that influence risk of OAB have been definitively identified. The first genome-wide association studies for OAB are in progress, and should identify new susceptibility genes. Although current putative biomarkers correlate with OAB severity, much future work is required to assess their prognostic value, and establish their role in clinical practice.

Promise of Urinary Nerve Growth Factor for Assessment of Overactive Bladder Syndrome

Overactive bladder syndrome (OAB) is highly prevalent bladder disorder in men and women. About 10-15% of the population suffers from urgency frequency with or without urgency urinary incontinence. It is estimated that 50-75% of patients with OAB may have urodynamic detrusor overactivity (DO). Urodynamic study invasive and most of the OAB patients might not accept it as a routine assessment. Therefore, a more objective and non-invasive test for diagnosis and assessing DO from OAB patients is needed. Recently, urinary nerve growth factor (NGF) has gained great interest in detecting DO in patients with OAB. Urinary NGF level was found to increase in OAB and urodynamic DO. Urinary NGF levels correlated with severity of OAB symptoms. Patients with either idiopathic or neurogenic DO may have increased urinary NGF levels. Urinary NGF levels have been shown to decrease in patients with patients with OAB and DO who have been well treated with antimuscarinics or botulinum toxin injection, but not in those with persistent OAB after treatment. Not all patients with OAB can have an elevated urinary NGF level; it may also be increased in patients with interstitial cystitis/painful bladder syndrome and other lower urinary tract diseases, suggesting urinary NGF expression could be a product of bladder inflammation and a limited specificity of urinary NGF for diagnosing DO. The source of urinary NGF has not yet been fully explored yet. Nevertheless, urinary NGF level is likely to be a promising biomarker for diagnosis of DO from OAB patients, to monitor therapeutic outcome and predict disease progression.

Neurotrophin/receptor expression in urinary bladder of mice with overexpression of NGF in urothelium

Urothelium-specific overexpression of nerve growth factor (NGF) in the urinary bladder of transgenic mice stimulates neuronal sprouting in the urinary bladder, produces increased voiding frequency, and results in increased referred somatic hypersensitivity. Additional NGF-mediated pleiotropic changes might contribute to the increased voiding frequency and pelvic hypersensitivity observed in these transgenic mice, such as modulation of other growth factor/receptor systems. Chronic overexpression of NGF in the urothelium was achieved through the use of a highly urothelium-specific uroplakin II promoter. In the present study, we examined NGF, brain-derived neurotrophic factor (BDNF), and associated receptor [p75(NTR), tyrosine kinase (Trk)A, TrkB] transcript and protein expression in urothelium and detrusor smooth muscle of NGF-overexpressing (OE) and littermate wild-type mice, using real-time quantitative reverse transcription-polymerase chain reaction, ELISAs, and semiquantitation of immunohistochemistry. We focused on these growth factor/receptors given the established roles of NGF/TrkA, NGF/p75(NTR), and BDNF/TrkB systems in bladder function. Increased voiding frequency in NGF-OE mice was confirmed by examining urination patterns. BDNF, TrkA, and TrkB protein expression was significantly (P ≤ 0.01) reduced and p75(NTR) protein expression was significantly (P ≤ 0.01) increased in urinary bladder of NGF-OE mice. The NGF-OE-induced changes in neurotrophic factor/receptor expression in urinary bladder may represent compensatory changes to reduce voiding frequency in the NGF-OE mouse.

Modulation of urinary bladder innervation: TRPV1 and botulinum toxin A

The persisting interest around neurotoxins such as vanilloids and botulinum toxin (BoNT) derives from their marked effect on detrusor overactivity refractory to conventional antimuscarinic treatments. In addition, both are administered by intravesical route. This offers three potential advantages. First, intravesical therapy is an easy way to provide high concentrations of pharmacological agents in the bladder tissue without causing unsuitable levels in other organs. Second, drugs effective on the bladder, but inappropriate for systemic administration, can be safely used as it is the case of vanilloids and BoNT. Third, the effects of one single treatment might be extremely longlasting, contributing to render these therapies highly attractive to patients despite the fact that the reasons to the prolonged effect are still incompletely understood. Attractive as it may be, intravesical pharmacological therapy should still be considered as a second-line treatment in patients refractory to conventional oral antimuscarinic therapy or who do not tolerate its systemic side effects. However, the increasing off-label use of these neurotoxins justifies a reappraisal of their pharmacological properties.

Afferent mechanism in the urinary tract

Much of the current research on lower urinary tract dysfunction is focused on afferent mechanisms. The main goals are to define and modulate the signaling pathways by which afferent information is generated and conveyed to the central nervous system. Alterations in bladder afferent mechanisms are a potential source of voiding dysfunction and an emerging source of drug targets. Even some established drug therapies such as muscarinic receptor antagonists, as well as emerging therapies such as botulinum toxin type-A, may act partly through afferent mechanisms. This review presents up-to-date findings on the localization of afferent fiber types within the bladder wall, afferent receptors and transmitters, and how these may communicate with the urothelium, interstitial cells, and detrusor smooth muscle to regulate micturition in normal and pathological bladders. Peripheral and central mechanisms of afferent sensitization and myogenic mechanisms that lead to detrusor overactivity, overactive bladder symptoms, and urgency sensations are also covered as well as new therapeutic approaches and new and established methods of measuring afferent activity.

Nerve growth factor level in the prostatic fluid of patients with chronic prostatitis/chronic pelvic pain syndrome is correlated with symptom severity and response to treatment

OBJECTIVE

• To explore whether levels of nerve growth factor (NGF) in expressed prostatic secretions (EPS) are correlated with symptom severity in chronic prostatitis (CP) and chronic pelvic pain syndrome (CPPS).

PATIENTS AND METHODS

• All patients with CP/CPPS underwent a complete history and physical examination, and were scored according to the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). • Expressed prostatic secretion samples from 20 patients with CP/CPPS and from four asymptomatic control patients were collected and frozen, and NGF levels in EPS were measured by enzyme-linked immunosorbent assay. • Patients were asked to complete NIH-CPSI questionnaires at baseline and 8 weeks after treatment and patients with at least a 25% decrease in total NIH-CPSI score from the baseline values were classified as responders to treatment.

RESULTS

• The mean (± sd) NGF levels in EPS of patients with CP/CPPS and asymptomatic control patients were 7409 (± 3788) pg/mL and 4174 (± 1349) pg/mL, respectively. The NGF level in patients with CP/CPPS correlated directly with pain severity (P= 0.014, r= 0.541). • There were no significant differences between NGF levels in EPS before and after treatment. However, successful treatment significantly decreased NGF levels in responders (P= 0.001).

CONCLUSION

• Nerve growth factor might contribute to the pathophysiology of CP/CPPS as changes in NGF level in EPS occurred in proportion to pain severity. Therefore, these results suggest that NGF could be used as a new biomarker to evaluate the symptoms of CP/CPPS and the effects of treatment.

Urinary Nerve Growth Factor Levels in Urinary Tract Diseases With or Without Frequency Urgency Symptoms

OBJECTIVES

To measure urinary nerve growth factor (NGF) levels in patients with several urinary tract diseases under different conditions and compare with NGF levels in patients with overactive bladder (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS).

METHODS

Urinary NGF levels were measured using enzyme-linked immunosorbent assay (ELISA) and normalized by urinary creatinine concentration. Patients with acute bacterial cystitis, urinary tract stone, urothelial cell carcinoma, and OAB patients after antimuscarinic therapy were evaluated. The urinary NGF levels of OAB, IC/PBS and controls from previous studies were used for comparison. NGF levels were compared among subgroups and between urinary tract diseases with or without associated OAB symptoms. The urinary NGF levels were also compared among natural filling, after normal saline filling and after potassium chloride test in a group of OAB and IC/PBS patients.

RESULTS

Patients with acute bacterial cystitis, urinary tract stones or urothelial cell carcinoma had elevated NGF levels that were not associated with the presence of OAB symptoms. Symptomatic cystitis patients who had resolved OAB symptoms after antibiotic treatment had a significant decrease in urinary NGF levels. The urinary NGF levels decreased significantly in OAB patients with effective antimuscarinic treatment for 6 months, but remained stationary and higher than the controls for up to 12 months after treatment.

CONCLUSION

Urinary NGF is not produced solely in patients with OAB or IC/PBS. Acute bacterial cystitis, urinary tract stones and urothelial cell carcinoma can have high urinary NGF production.

Overexpression of NGF in mouse urothelium leads to neuronal hyperinnervation, pelvic sensitivity, and changes in urinary bladder function

NGF has been suggested to play a role in urinary bladder dysfunction by mediating inflammation, as well as morphological and functional changes, in sensory and sympathetic neurons innervating the urinary bladder. To further explore the role of NGF in bladder sensory function, we generated a transgenic mouse model of chronic NGF overexpression in the bladder using the urothelium-specific uroplakin II (UPII) promoter. NGF mRNA and protein were expressed at higher levels in the bladders of NGF-overexpressing (NGF-OE) transgenic mice compared with wild-type littermate controls from postnatal day 7 through 12-16 wk of age. Overexpression of NGF led to urinary bladder enlargement characterized by marked nerve fiber hyperplasia in the submucosa and detrusor smooth muscle and elevated numbers of tissue mast cells. There was a marked increase in the density of CGRP- and substance P-positive C-fiber sensory afferents, neurofilament 200-positive myelinated sensory afferents, and tyrosine hydroxylase-positive sympathetic nerve fibers in the suburothelial nerve plexus. CGRP-positive ganglia were also present in the urinary bladders of transgenic mice. Transgenic mice had reduced urinary bladder capacity and an increase in the number and amplitude of nonvoiding bladder contractions under baseline conditions in conscious open-voiding cystometry. These changes in urinary bladder function were further associated with an increased referred somatic pelvic hypersensitivity. Thus, chronic urothelial NGF overexpression in transgenic mice leads to neuronal proliferation, focal increases in urinary bladder mast cells, increased urinary bladder reflex activity, and pelvic hypersensitivity. NGF-overexpressing mice may, therefore, provide a useful transgenic model for exploring the role of NGF in urinary bladder dysfunction.

Nerve growth factor as a signaling molecule for nerve cells and also for the neuroendocrine-immune systems

Nerve growth factor (NGF) is a signaling molecule, originally discovered for its role on differentiation and survival of peripheral sensory and sympathetic neurons. It has also been associated with functional activities of cells of the immune and endocrine systems. NGF biological activity is mediated by two classes of receptors: (i) p75 neurotrophin receptor (p75(NTR)), a 75 kDa glycoprotein, belonging to a superfamily of cytokine receptors including TNF receptors, and (ii) TrkA, a transmembrane tyrosine kinase of 140 kDa. Both TrkA and p75(NTR) are known to play a marked action in neurodegenerative disorders, immune-related deficits, and neuroendocrine (including adipoendocrine) mechanisms. This review focuses on these cellular events and presents a working model which attempts to explain the close interrelationships of the neuro-endocrine-immune triad via a modulatory action of NGF.

Decrease of urinary nerve growth factor levels after antimuscarinic therapy in patients with overactive bladder

OBJECTIVE

To determine urinary nerve growth factor (NGF) levels in patients with overactive bladder (OAB) and after treatment with antimuscarinics.

PATIENTS AND METHODS

Urinary NGF levels were measured in 38 'normal' controls and 70 patients with OAB. Patients were treated with tolterodine 4 mg once daily. Urinary NGF levels were measured by enzyme-linked immunosorbent assay method and normalized by urinary creatinine levels (NGF/Cr). The urinary NGF/Cr levels and urgency severity scale (USS) were compared at baseline, 1, 2 and 3 months after antimuscarinics, and 1 month after discontinuing treatment.

RESULTS

The urinary NGF/Cr level was very low in normal controls with a mean (sem) of 0.005 (0.003). Patients with OAB had significantly higher baseline urinary NGF/Cr levels than the controls. Urinary NGF/Cr levels were significantly reduced at 3 months in 50 responders (1.10 [0.26] before vs 0.41 [0.09] after, P = 0.008) but not in the 20 non-responders (1.38 [0.54] before vs 1.30 [0.46] after, P = 0.879). However, after discontinuing antimuscarinic treatment for 1 month, the urinary NGF/Cr level was elevated in 23 responders at 0.83 (0.33) and in five non-responders at 2.72 (1.41). The USS scores significantly changed with the change of urinary NGF/Cr levels in responders at different time points. The voided volume increased but maximum urinary flow rate and postvoid residual volume did not increase in responders after 3-months of antimuscarinic treatment. The limitation of this study was the lack of a control arm for comparison.

CONCLUSIONS

Changes in the urinary NGF levels were associated with the changes of the USS scores after antimuscarinic treatment and discontinued medication. The urinary NGF level could be a potential biomarker for evaluating therapeutic results of antimuscarinics therapy.