The profile of urinary biomarkers in overactive bladder

Decrease in the Ratio proBDNF/BDNF in the Urine of Aging Female Patients with OAB

Imbalance in the levels of neurotrophins, growth factors crucial in the development, function, and survival of neurons is commonly observed in many pathological states. Concentrations of brain-derived neurotrophic factor (BDNF) and its precursor (proBDNF) were measured in the urine of a cohort of aging female patients with overactive bladder disease (OAB). When reported to creatinine, levels were similar between OAB patients and healthy controls. However, the ratio proBDNF/BDNF was significantly decreased in the OAB group. Receiver operating characteristic (ROC) curve analysis of the ratio proBDNF/BDNF displayed a good diagnostic value for OAB (AUC = 0.729). Clinical questionnaires of symptom severity (OABSS and IIQ-7) were negatively correlated with this ratio. On the other hand, microRNAs (miRNA) involved in proBDNF gene translation were expressed at comparable levels between groups. However, urinary enzymatic activity of matrix metalloproteinase-9 (MMP-9), the enzyme that cleaves proBDNF into BDNF, was increased in OAB compared to controls. Levels of miR-491-5p, the main miRNA that downregulates MMP-9 synthesis, were greatly decreased in urine from OAB patients. These results suggest that the ratio proBDNF/BDNF could be useful in the phenotyping of OAB in an aging population, and the difference could originate from enhanced MMP-9 enzymatic activity rather than translational control.

Urinary Oxidative Stress Biomarker Levels Might Be Useful in Identifying Functional Bladder Disorders in Women with Frequency and Urgency Syndrome

Purpose: lower urinary tract dysfunctions (LUTDs) are difficult to diagnose based on symptoms. This study used a cluster of urinary biomarkers, including inflammatory cytokines, neurogenic proteins, and oxidative stress biomarkers, to identify LUTDs in women with frequency and urgency symptoms. Methods: in total, 253 women with video urodynamics (VUDS)- and cystoscopy-confirmed detrusor overactivity (DO), interstitial cystitis/bladder pain syndrome (IC/BPS), dysfunctional voiding (DV), and hypersensitive bladder (HSB), and normal controls were included. Before diagnosis and treatment, urine samples were collected for analysis of biomarkers. The urine levels of biomarkers were compared between groups with bladder dysfunctions and controls and were combined to test the sensitivity in identifying total pathological bladder diseases and specific bladder diseases. Results: After video urodynamic study, VUDS, and urological examinations, bladder dysfunctions were classified into DO (n = 31), IC/BPS (n = 114), DV (n = 45), HSB (n = 29), and control (n = 34) groups. By using a cystomeric bladder capacity of ≤350 mL, 186/219 (84.9%) of the patients with DO, IC/BPS, DV, and HSB can be discriminated from the controls. Among these urine biomarkers, oxidative stress biomarkers 8-isoprostane, 8-hydroxydeoxyguanosine (8-OHdG), or total antioxidant capacity (TAC) are useful for identifying pathological bladder dysfunction (DO, IC/BPS, and DV) and HSB. With elevated IL-1β and lower IL-2, and elevated TNF-α levels, most patients with DV can be identified. Between DO and IC/BPS, a higher NGF level can identify 58.3% of IC/BPS cases, whereas a lower NGF level can identify 75.0% of DO cases. Conclusion: by using a cluster of urine biomarkers, DO, IC/BPS, and DV cases can be identified based on elevated levels of urine oxidative stress biomarkers 8-isoprostane, TAC, or 8-OHdG, and HSB cases with a low TAC. These urine biomarkers are useful for identifying specific LUTDs in women with frequency and urgency symptoms.

Discriminating Different Bladder and Bladder Outlet Dysfunctions by Urinary Biomarkers in Women with Frequency–Urgency Syndrome

Objectives: To investigate the role of urinary biomarkers in discriminating different bladder and bladder outlet dysfunctions in women with frequency–urgency syndrome. Materials and Methods: Urine samples collected from 146 women with frequency–urgency syndrome and 34 controls were investigated. All patients were included in previous clinical trials of functional urology studies and underwent a videourodynamic study. Patients with frequency–urgency syndrome were subdivided into idiopathic detrusor overactivity (IDO), neurogenic detrusor overactivity (NDO), dysfunctional voiding (DV), and hypersensitive bladder (HSB) subgroups. Urine samples were collected before any treatment, and urinary inflammatory proteins (interleukin- (IL-) 1β, IL-2, IL-6, IL-8, tumor necrosis factor-α (TNF-α), and vascular endothelial growth factor (VEGF)), neurogenic proteins (nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and prostaglandin E2 (PGE2)), and oxidative stress biomarkers (8-isoprostane, total antioxidant capacity (TAC), and 8-hydroxydeoxyguanosine (8-OHdG)) were measured and compared between the different OAB subgroups and controls. Results: Of the 146 patients, 31 had IDO, 41 had NDO, 45 had DV, and 29 had HSB. The control group included 34 women. The patients with HSB had lower urinary TAC and IL-2 levels than the controls. The patients with IDO, NDO, and DV had significantly higher urinary TNF-α levels than those with HSB. The patients with IDO and NDO showed an increase in the urinary 8-isoprostane levels, whereas the patients with IDO had higher urinary IL-2, NGF, and BDNF levels than those with NDO. The other urinary inflammatory biomarkers did not show enough significant differences to discriminate between the different bladder and bladder outlet dysfunctions. Conclusions: The urinary levels of inflammatory, neurogenic, and oxidative stress biomarkers varied widely among the patients with bladder and bladder outlet dysfunction. This study’s results provide evidence that women with frequency–urgency syndrome and different urodynamic subtypes have varying bladder inflammation and oxidative stress conditions, which might have an impact on treatment outcomes.

Development and validation of brain-derived neurotrophic factor measurement in human urine samples as a non-invasive effect biomarker

Background

Brain-derived neurotrophic factor (BDNF), a neurotrophic growth factor mainly expressed in the brain, has been proposed as a potential effect biomarker; that is, as a measurable biomarker whose values could be associated with several diseases, including neurological impairments. The European Human Biomonitoring Initiative (HBM4EU) has also recognized effect biomarkers as a useful tool for establishing link between exposure to environmental pollutants and human health. Despite the well-establish protocol for measuring serum BDNF, there is a need to validate its assessment in urine, a non-invasive sample that can be easily repeated over time. The aim of this study was to develop, standardize and validate a methodology to quantify BDNF protein levels in urine samples before its implementation in biomonitoring studies.

Methods

Different experimental conditions and non-competitive commercial enzyme-linked immunosorbent assay (ELISA) kits were tested to determine the optimal analytical procedure, trying to minimize the shortcomings of ELISA kits. The fine-tune protocol was validated in a pilot study using both upon awakening (n = 150) and prior to sleeping (n = 106) urine samples from the same Spanish adolescent males in a well-characterized study population (the Spanish INMA-Granada cohort).

Results

The best results were obtained in 0.6 ml of urine after the acidification and extraction (pre-concentration) of samples. The highest reproducibility was obtained with the ELISA kit from Raybiotech. Urinary BDNF concentrations of adolescent males were within the previously reported range (morning = 0.047-6.801 ng/ml and night = 0.047-7.404 ng/ml). Urinary BDNF levels in the awakening and pre-sleep samples did not follow a normal distribution and were not correlated.

Conclusion

The developed methodology offers good sensitivity and reproducibility. Having reliable markers in urine may facilitate both diagnosis and monitoring possible diseases (and treatment). Further studies are needed to implement urinary BDNF in biomonitoring studies to further elucidate its usefulness and biological significance for neurological impairments.

New Kid on the Block: The Efficacy of Phytomedicine Extracts Urox® in Reducing Overactive Bladder Symptoms in Rats

The aim of the current study was to determine if phytomedicine (Urox^®) would reverse retinyl acetate (RA)–induced changes characteristic of bladder overactivity. There were 60 rats divided into the following 4 groups: I—control, II—received RA to induce detrusor overactivity (DO), III—received Urox (840 mg daily for 14 days), and IV—received combination of RA and Urox^®. The cystometry was performed 2 days after the last dose of Urox^®. Next, urothelium thickness and biochemical parameter measurements were performed. In group IV, a decrease in basal pressure and detrusor overactivity index was noted when compared to group II. Furthermore, in group IV the following parameters were increased: threshold pressure, voided volume, intercontraction interval, and bladder compliance in comparison with group II. There were significant elevations in c-Fos expression in the neuronal voiding centers in group II, while the expression of c-Fos in group IV was normalized. No significant changes in the values of the analyzed biomarkers in group III were found, while in group II, an elevation in BDNF, NGF, CGRP, ATP, Rho kinase, malondialdehyde, 3-nitrotyrosine, TRPV1, OCT-3, and VAChT and then a decrease in E-cadherin and Z01 were found. A successful restoration of all the abovementioned biomarkers’ levels was observed in group IV. Phytomedicine extracts (Urox^®) were found to be potent in reversing RA-induced changes in several cystometric and biochemical parameters that are determinants of overactive bladder (OAB). The actions of Urox^® were proved to be dependent on several factors, such as growth factors and several OAB biomarkers but not pro-inflammatory cytokines.

The use of urinary biomarkers in the diagnosis of overactive bladder in female patients. A systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and other proteins are related to overactive bladder (OAB) syndrome, as their urinary concentrations are significantly different from those of the general non-OAB population. This review aims to systematically assess whether NGF, BDNF, and other urinary by-products can be used as potential biomarkers to manage women with OAB.

METHODS

This was a systematic review and metanalysis that was conducted according to PRISMA guidelines. Studies were identified by electronic search of Medline, Scopus, ScienceDirect, Embase, and Cochrane Register until October 2020. The included studies investigated the correlation of OAB with NGF, BDNF, and other potential biomarkers in symptomatic women and their controls.

RESULTS

Twelve studies (581 female OAB patients and 394 female controls) were included. Urinary NGF, NGF/Cr, BDNF/Cr, ATP/Cr, and PGE2/Cr ratios were identified as potential biomarkers in female OAB patients. Results of the meta-analysis indicated that uNGF [standard mean difference (SMD) 1.45, 95% CI 0.53-2.36], NGF/Cr ratio (SMD 1.23, 95% CI 0.67-1.78), BDNF/Cr ratio (SMD 0.78, 95% CI 0.006-1.50), and BDNF/Cr ratio (RR 0.78, 95% CI 0.006-1.50) were increased in female OAB patients compared to healthy controls, whereas no difference was found for the PGE2/Cr and ATP/Cr ratios. Current data are inadequate to assess any other potential biomarkers, such as urinary MDA, ATP, and cytokines, in the management of OAB in female patients.

CONCLUSIONS

uNGF, NGF/Cr, and BDNF/Cr ratio could be used in the assessment of female OAB patients. Further studies are needed to specify OAB urinary titer levels in OAB subgroups and healthy women and their potential as diagnostic and management tools in OAB women.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.