Urothelial dysfunction and chronic inflammation in patients with spinal cord injuries at different levels and correlation with urodynamic findings

Beyond the urothelium: Interplay between autonomic nervous system and bladder inflammation in urinary tract infection, bladder pain syndrome with interstitial cystitis and neurogenic lower urinary tract dysfunction in spinal cord injury-ICI-RS 2023

INTRODUCTION

Inflammation and neuronal hypersensitivity are reactive protective mechanisms after urothelial injury. In lower urinary tract dysfunctions (LUTD), such as urinary tract infection (UTI), bladder pain syndrome with interstitial cystitis (BPS/IC) and neurogenic LUTD after spinal cord injury (SCI), chronic inflammation can develop. It is unclear how the protective reactionary inflammation escalates into chronic disease in some patients.

METHODS

During its 2023 meeting in Bristol, the International Consultation on Incontinence-Research Society (ICI-RS) reviewed the urothelial and inflammatory changes after UTI, BPS/IC and SCI. Potential factors contributing to the evolution into chronic disease were explored in a think-tank.

RESULTS

Five topics were discussed. (1) Visceral fat metabolism participates in the systemic pro-inflammatory effect of noradrenalin in BPS/IC and SCI. Sympathetic nervous system-adipocyte-bladder crosstalk needs further investigation. (2) Sympathetic hyperactivity also potentiates immune depression in SCI and needs to be investigated in BPS/IC. Gabapentin and tumor necrosis factor-α are promising research targets. (3) The exact peripheral neurons involved in the integrative protective unit formed by nervous and immune systems need to be further identified. (4) Neurotransmitter changes in SCI and BPS/IC: Neurotransmitter crosstalk needs to be considered in identifying new therapeutic targets. (5) The change from eubiosis to dysbiosis in SCI can contribute to UTI susceptibility and needs to be unraveled.

CONCLUSIONS

The think-tank discussed whether visceral fat metabolism, immune depression through sympathetic hyperactivity, peripheral nerves and neurotransmitter crosstalk, and the change in microbiome could provide explanations in the heterogenic development of chronic inflammation in LUTD. High-priority research questions were identified.

System failure: Systemic inflammation following spinal cord injury

Spinal cord injury (SCI) affects hundreds of thousands of people in the United States, and while some effects of the injury are broadly recognized (deficits to locomotion, fine motor control, and quality of life), the systemic consequences of SCI are less well-known. The spinal cord regulates systemic immunological and visceral functions; this control is often disrupted by the injury, resulting in viscera including the gut, spleen, liver, bone marrow, and kidneys experiencing local tissue inflammation and physiological dysfunction. The extent of pathology depends on the injury level, severity, and time post-injury. In this review, we describe immunological and metabolic consequences of SCI across several organs. Since infection and metabolic disorders are primary reasons for reduced lifespan after SCI, it is imperative that research continues to focus on these deleterious aspects of SCI to improve life span and quality of life for individuals with SCI.

Immune Status of Individuals with Traumatic Spinal Cord Injury: A Systematic Review and Meta-Analysis

Individuals with spinal cord injury (SCI) have higher infection rates compared to those without SCI. In this review, the immune status difference between individuals with and without traumatic SCI is investigated by examining their peripheral immune cells and markers. PubMed, Cochrane, EMBASE, and Ovid MEDLINE were searched without language or date restrictions. Studies reporting peripheral immune markers' concentration and changes in functional capabilities of immune cells that compared individuals with and without SCI were included. Studies with participants with active infection, immune disease, and central nervous system (CNS) immune markers were excluded. The review followed the PRISMA guidelines. Effect estimates were measured by Weighted Mean Difference (WMD) using a random-effects model. Study quality was assessed using the National Heart, Lung, and Blood Institute Quality Assessment Tool. Fifty-four studies (1813 with SCI and 1378 without SCI) contributed to the meta-analysis. Leukocytes (n = 23, WMD 0.78, 95% CI 0.17; 1.38, I2 83%), neutrophils (n = 11, WMD 0.76, 95% CI 0.09; 1.42, I2 89%), C-reactive protein (CRP) (n = 12, WMD 2.25, 95% CI 1.14; 3.56, I2 95%), and IL6 (n = 13, WMD 2.33, 95% CI 1.20; 3.49, I2 97%) were higher in individuals with SCI vs. without SCI. Clinical factors (phase of injury, completeness of injury, sympathetic innervation impairment, age, sex) and study-related factors (sample size, study design, and serum vs. plasma) partially explained heterogeneity. Immune cells exhibited lower functional capability in individuals with SCI vs. those without SCI. Most studies (75.6%) had a moderate risk of bias. The immune status of individuals with SCI differs from those without SCI and is clinically influenced by the phase of injury, completeness of injury, sympathetic innervation impairment, age, and sex. These results provide information that is vital for monitoring and management strategies to effectively improve the immune status of individuals with SCI.

Sex Differences in Immune Cell Infiltration and Hematuria in SCI-Induced Hemorrhagic Cystitis

Rats manifest a condition called hemorrhagic cystitis after spinal cord injury (SCI). The mechanism of this condition is unknown, but it is more severe in male rats than in female rats. We assessed the role of sex regarding hemorrhagic cystitis and pathological chronic changes in the bladder. We analyzed the urine of male and female Sprague-Dawley and Fischer 344 rats after experimental spinal cord contusion, including unstained microscopic inspections of the urine, differential white blood cell counts colored by the Wright stain, and total leukocyte counts using fluorescent nuclear stains. We examined bladder histological changes in acute and chronic phases of SCI, using principal component analysis (PCA) and clustered heatmaps of Pearson correlation coefficients to interpret how measured variables correlated with each other. Male rats showed a distinct pattern of macroscopic hematuria after spinal cord injury. They had higher numbers of red blood cells with significantly more leukocytes and neutrophils than female rats, particularly hypersegmented neutrophils. The histological examination of the bladders revealed a distinct line of apoptotic umbrella cells and disrupted bladder vessels early after SCI and progressive pathological changes in multiple bladder layers in the chronic phase. Multivariate analyses indicated immune cell infiltration in the bladder, especially hypersegmented neutrophils, that correlated with red blood cell counts in male rats. Our study highlights a hitherto unreported sex difference of hematuria and pathological changes in males and females' bladders after SCI, suggesting an important role of immune cell infiltration, especially neutrophils, in SCI-induced hemorrhagic cystitis.

Inflammation and Barrier Function Deficits in the Bladder Urothelium of Patients with Chronic Spinal Cord Injury and Recurrent Urinary Tract Infections

Patients with spinal cord injury (SCI) commonly experience neurogenic voiding dysfunctions and urinary tract complications, including recurrent urinary tract infections (rUTI). The bladder mucosa barrier function contributes to UTI prevention. This study investigated changes in bladder urothelium protein expression in patients with SCI and rUTI. From June 2011 to November 2017, 23 patients (19 men and 4 women) with chronic SCI were enrolled (mean age: 43 years. Bladder tissues from 6 healthy adults served as the normal control group. Biopsy samples (9 partial cystectomies and 14 bladder biopsies) were analyzed for functional biomarkers using western blot and immunohistochemistry analysis. The barrier function proteins E-cadherin, zonula occludens 1 (ZO-1) and uroplakin III (UPK-3) were significantly reduced, whereas tumor protein p63 (TP63) was significantly increased in SCI patients compared with controls. No significant differences in basal cell progenitor proteins were observed between groups. The proliferation marker Ki-67, the proapoptotic marker BCL-2-associated X protein (BAX), and proinflammatory proteins were increased in patients with SCI compared with controls. No significant differences were observed between SCI patients with and without recently rUTI. These results suggest that SCI patients experience chronic bladder inflammation, increased apoptosis, and reduced barrier function, contributing to rUTI.

Urine biomarkers in ESSIC type 2 interstitial cystitis/bladder pain syndrome and overactive bladder with developing a novel diagnostic algorithm

This study aimed to investigate the diagnostic values of urine cytokines in interstitial cystitis/bladder pain syndrome (IC/BPS) and overactive bladder (OAB) patients, and to develop a novel diagnostic algorithm. Urine samples were collected from 40 IC/BPS, 40 OAB patients, and 30 controls. Commercially available multiplex immunoassays were used to analyze 31 targeted cytokines. Urine cytokine profiles were significantly different among study groups and controls. MIP-1β showed the highest sensitivity (92.2%) for identifying diseased study patients from controls. The cytokines with high diagnostic values for distinguishing between IC and OAB included IL-10, RANTES, eotaxin, CXCL10, IL-12p70, NGF, IL-6, IL-17A, MCP-1, and IL-1RA. The diagnostic algorithm was subsequently developed according to the diagnostic values obtained. MIP-1β was selected for the initial screening test to diagnose diseased patients and controls with diagnostic rates of 81.6% and 68.4%, respectively. As confirmation tests for IC/BPS, the diagnostic rates of eotaxin, CXCL10, and RANTES were 73.3%, 72.7%, and 69.7%, respectively. As the confirmation test for OAB, the diagnostic rate of IL-10 was 60%. Urine cytokine profiles of IC/BPS and OAB patients differed from those of controls and might be useful as biomarkers for diagnosis. A novel pilot diagnostic algorithm was developed based on these profiles.

Deficits of urothelial cell proliferation, cytoskeleton, and barrier function protein expressions in patients with recurrent and persistent urinary tract infections

OBJECTIVES

Recurrent urinary tract infection (rUTI) is a common infectious disease in women. This study investigated the urothelial cell proliferation, the cytoskeleton, barrier proteins, and inflammatory protein expression in women with rUTIs.

METHODS

Female patients with recurrent or persistent UTIs were recruited. Bladder mucosal specimens were investigated by Western blot and immunohistochemical staining for the urothelial cytoskeleton proteins cytokeratin 5 (CK5), CK14, and CK20; proteins involved in cellular proliferation, including CD34, sonic hedgehog (SHH), and tumor protein 63 (TP63); barrier proteins zonula occludens 1 (ZO-1) and E-cadherin; inflammatory proteins p38 and tryptase; and proapoptotic proteins Bcl2-associated agonist of cell death protein (BAD), Bcl2-associated X protein (BAX), and caspase-3. Women with stress urinary incontinence without bladder symptoms served as controls. Bladder specimens from 18 recurrent UTI patients with rUTIs and 12 persistent UTIs, and 17 controls were analyzed, and protein expressions were compared between the three groups.

RESULTS

Cell proliferation protein expression for CD34, SHH, and TP63 was significantly lower in the urothelium of patients with rUTIs than in controls. Expression of CK5 increased, whereas CK20 decreased significantly in rUTIs compared with those of controls. Apoptotic proteins BAD, BAX, and caspase-3 were significantly higher in patients with rUTIs. However, barrier proteins ZO-1 and E-cadherin, and tryptase were not significantly lower in patients with rUTIs.

CONCLUSION

Deficits in expression of proteins involved in urothelial cell proliferation, cytoskeleton, and barrier function were noted in patients with rUTIs. These urothelial deficits may be due to deficient proliferation and differentiation resulting in inadequate urothelial barrier function and further in rUTIs.

The influence of Potentilla chinensis aqueous extract on urinary bladder function in retinyl acetate-induced detrusor overactivity in rats

INTRODUCTION & OBJECTIVES

In overactive bladder (OAB) therapy several herbal medicines presented promising effects, however the results are sparse to provide their efficacy. Herbals may become a popular alternative for OAB therapy. Therefore, we investigated whether Potentilla chinensis extract (PCE) would reverse retinyl acetate (RA)-induced detrusor overactivity (DO).

MATERIAL & METHODS

60 rats were divided into 4 groups, as follows: I - control, II - rats with RA-induced DO, III - rats received PCE in dose of 500 mg/kg, and IV - rats with RA-induced DO which received PCE. PCE or vehicle were administered orally for 14 days. The cystometry and bladder blood flow assessment were performed 3 days after the last dose of the PCE. Then the rats were put into the metabolic cages for 24 h. Next, urothelium thickness measurement and biochemical analyses were performed. < /p><p> Results. Intravesical infusion of RA solution induced DO. PCE had no influence on the urinary bladder function and&nbsp; micturition cycles in normal rats. PCE diminished the severity of RA-induced DO. In the urothelium the RA induced the elevation of ATP, CGRP, substance P, VEGF-A, OTC3, and ERK1/2. The concentration of NOS2, CDH1, and ZO1 decreased. Moreover, RA affected the concentration of SNARE proteins (increased concentration of SNAP23, SNAP25, and SV2A). Also in detrusor the elevated level of ROCK1 and VAChT were observed. In turn, PCE in RA-induced DO caused a reversal of the described biochemical changes within urothelium, detrusor muscle and urine. < /p><p> Conclusions. PCE attenuates detrusor overactivity. The potential mechanisms of action of PCE in the urinary bladder seem to be multifactorial and complex. PCE seems to become a reasonable novel OAB therapy.

Will repeated botulinum toxin A improve detrusor overactivity and bladder compliance in patients with chronic spinal cord injury?

Chronic spinal cord injury (SCI) can induce neurogenic detrusor overactivity (NDO), leading to urinary incontinence and renal damage due to low bladder compliance and high detrusor pressure during the storage and voiding of urine. In 2011, Botox^® (onabotulinumtoxinA, botulinum neurotoxin serotype A [BoNT-A]) was approved by the Food and Drug Administration for the treatment of NDO. Intradetrusor injection of BoNT-A has been shown to have clinical utility for the treatment of urinary incontinence, with consequent improvements in quality of life for patients. In the past 20 years, this treatment has been shown to be an effective treatment for patients with SCI refractory to antimuscarinic medication. The present review focused on publications in MEDLINE/PubMed relating to botulinum toxin to evaluate the treatment outcomes of repeated injection of BoNT-A, the mechanisms of action, results of clinical and urodynamic studies, and adverse effects.

Therapeutic potential of intravesical injections of platelet-rich plasma in the treatment of lower urinary tract disorders due to regenerative deficiency

The bladder urothelium plays an important role of barrier function to prevent influx of urinary toxic substance and bacteria. When there is insult to the urinary bladder, the urothelium will start to regenerate on injury. However, several factors might affect the regenerative function of bladder urothelium, including aging, chronic inflammation, and system diseases such as diabetes and chronic kidney diseases (CKDs). Impairment of bladder mucosal regenerative function might result in defective urothelial cell differentiation as well as barrier function, which might be the underlying pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS) and recurrent bacterial cystitis. Our previous immunohistochemistry (IHC) study and electron microscopic study revealed that the loss of normal umbrella cells and defective junction proteins in IC/BPS and recurrent cystitis. Platelet-rich plasma (PRP) has been previously used in many medical aspects as regenerative medicine therapy. PRP is rich in many growth factors and cytokines which modulate the process of inflammation and regeneration in the wound healing process. Recent pilot studies have shown that intravesical PRP injections improve IC symptoms and yield a success rate of 70% at 3 months after treatment. The results highly suggest that PRP injection could improve urothelial regenerative function and reduce chronic inflammation in IC patients. This article reviews recently published researches on the urothelial dysfunction biomarkers, urothelial cell differentiation, and urinary regenerative and inflammatory proteins in patients with IC/BPS or recurrent bacterial cystitis. The pathophysiology of the insufficient urothelial regeneration and differentiation; and chronic inflammation may induce urothelial dysfunction and further affect the regenerative ability of the diseased bladder urothelium in IC/BPS and recurrent bacterial cystitis are discussed.

Single onabotulinumtoxinA 200U dose improved clinical symptoms but not urothelial dysfunction in neurogenic detrusor overactivity due to spinal cord injury

OBJECTIVE

To evaluate the changes in urothelial dysfunction protein expressions in bladder after onabotulinumtoxin injection and correlate that with clinical outcomes in spinal cord injury (SCI) patients.

METHODS

Twenty-six patients with neurogenic detrusor overactivity (NDO) and urinary incontinence due to suprasacral SCI were treated with onabotulinumtoxinA 200U detrusor injection. Urodynamic studies and bladder biopsies were obtained at baseline, 3, and 6 months after treatment. Biopsy tissues were investigated for E-cadherin, zonula occludens-1 (ZO-1), mast cell activity, and urothelial cell apoptosis, sensory protein expression including purinergic receptor P2X3, endothelial NOS, inducible NOS, β3-adrenoceptors, and muscarinic receptors M2 and M3. Differences in functional protein expression between controls and SCI patients and between successful and failed treatment groups were analyzed.

RESULTS

SCI patients had significantly lower E-cadherin, higher mast cell activity, increased apoptosis, decreased M3 and eNOS expressions than the controls at baseline. Of the 26 patients, 17 (65%) showed improvement in bladder capacity by >50% at 3 months; however, improvement declined by 6 months after treatment. The urothelial expression of E-cadherin and ZO-1 increased at 3 months but had declined at 6 months. The urothelial sensory protein expression did not change significantly after treatment. M3 receptor density was significantly decreased in SCI patients at baseline and patients with treatment success 3 months after injection (p = 0.01).

CONCLUSION

A single injection of onabotulinumtoxinA 200U improved clinical symptoms but did not significantly alter urothelial sensory protein expression. The results imply that a single 200U onabotulinumtoxinA dose might not be adequate for urothelial dysfunction in NDO. IRB: TCGH 098-53.

Urothelial proliferation and regeneration after spinal cord injury

The basal, intermediate, and superficial cell layers of the urothelium undergo rapid and complete recovery following acute injury; however, the effects of chronic injury on urothelial regeneration have not been well defined. To address this discrepancy, we employed a mouse model to explore urothelial changes in response to spinal cord injury (SCI), a condition characterized by life-long bladder dysfunction. One day post SCI there was a focal loss of umbrella cells, which are large cells that populate the superficial cell layer and normally express uroplakins (UPKs) and KRT20, but not KRT5, KRT14, or TP63. In response to SCI, regions of urothelium devoid of umbrella cells were replaced with small superficial cells that lacked KRT20 expression and appeared to be derived in part from the underlying intermediate cell layer, including cells positive for KRT5 and TP63. We also observed KRT14-positive basal cells that extended thin cytoplasmic extensions, which terminated in the bladder lumen. Both KRT14-positive and KRT14-negative urothelial cells proliferated 1 day post SCI, and by 7 days, cells in the underlying lamina propria, detrusor, and adventitia were also dividing. At 28 days post SCI, the urothelium appeared morphologically patent, and the number of proliferative cells decreased to baseline levels; however, patches of small superficial cells were detected that coexpressed UPKs, KRT5, KRT14, and TP63, but failed to express KRT20. Thus, unlike the rapid and complete restoration of the urothelium that occurs in response to acute injuries, regions of incompletely differentiated urothelium were observed even 28 days post SCI.

Functional and structural changes of the urinary bladder following spinal cord injury; treatment with alpha lipoic acid

BACKGROUND & AIM

Alpha lipoic acid (LA) was shown to exert neuroprotection in trauma-induced spinal cord injury (SCI), which is frequently associated with urinary bladder complaints in patients with SCI. Accordingly, the protective effects of LA on biochemical and histological changes in bladder as well as functional studies were assessed.

METHODS

Wistar albino rats were divided as control, SCI, and LA (50 mg/kg/day, ip) treated SCI groups (SCI+LA). The standard weight-drop (100 g/cm force at T10) method was used to induce a moderately severe SCI. One week after the injury, neurological examination was performed and the rats were decapitated. Bladder samples were taken for histological examination, functional (isolated tissue bath) studies, and for the measurement of biochemical parameters (malondialdehyde, MDA; gluthathione, GSH; nerve growth factor, NGF; caspase-3, luminol and lucigenin chemiluminescences).

RESULTS

SCI caused a significant (P < 0.001) increase in the detrusor muscle thickness. It increased the contractility responses to carbachol and relaxation responses to papaverine (P < 0.05-0.001). There were also significant alterations in MDA, caspase-3, luminol, and lucigenin chemiluminescences with concomitant decreases in NGF and GSH (P < 0.05). LA treatment reversed histological and functional (contraction and relaxation responses) changes induced by SCI (P < 0.05-0.001), but no significant recovery was observed in the impaired neurological functions.

CONCLUSION

These results indicate that LA have a beneficial effect in improving the bladder tonus via its antioxidant and anti-inflammatory actions following SCI.

Clinical Efficacy and Changes of Urothelial Dysfunction after Repeated Detrusor Botulinum Toxin A Injections in Chronic Spinal Cord-Injured Bladder

Chornic spinal cord injury (SCI) will induce bladder urothelium dysfunction. This study investigated the therapeutic effects on urothelial dysfunction after repeated detrusor injections of onabotulinumtoxinA (BoNT-A) in SCI patients with neurogenic detrusor overactivity (NDO). Twenty chronic suprasacral SCI patients with NDO were enrolled. The patients received 300 U BoNT-A injection into the detrusor every six months. The urothelium was assessed by cystoscopic biopsy at baseline and six months after each BoNT-A treatment. Immunofluorescence staining for urothelial dysfunction, including E-cadherin, zonula occludens-1 (ZO-1), tryptase for mast cell activity, and urothelial apoptosis were investigated. The outcome of urothelial dysfunction parameters after BoNT-A injection were compared between baseline and six months after each treatment. Repeated 300 U BoNT-A injections showed a sustained decrease of detrusor pressure compared with baseline. After three repeated BoNT-A detrusor injections, significantly greater distributions of E-cadherin (p = 0.042) and ZO-1 (p = 0.003) expressions, but no significant changes, of urothelial apoptosis and mast cell activation were found after repeated BoNT-A therapy. Urothelial dysfunction, such as adhesive and junction protein concentrations in SCI patients’ bladders, recovered after three repeated cycles of BoNT-A treatment. The therapeutic effects sustained. However, urothelial inflammation and apoptosis after SCI were not significantly improved after three repeated BoNT-A injections.

Effect of detrusor botulinum toxin a injection on urothelial dysfunction in patients with chronic spinal cord injury: a clinical and immunohistochemistry study before and after treatment

OBJECTIVE

The objective of this study is to investigate the changes of urothelial junction proteins, apoptosis and suburothelial inflammation after detrusor injection of botulinum toxin A (BoNT-A) in patients with spinal cord injury (SCI) and neurogenic detrusor overactivity (NDO).

METHODS

A total of 26 patients with chronic suprasacral SCI and NDO were enroled. The urothelium was assessed by cystoscopic biopsy at baseline, 3 and 6 months after a single treatment of 300 U BoNT-A into the detrusor. Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1) and tryptase for mast cell activity were performed. Urothelial apoptosis was also evaluated. The differences in urothelial dysfunction were compared between baseline and 3 and 6 months after treatment. Bladder biopsies from patients undergoing anti-incontinence surgery served as controls.

RESULTS

A single 300-U BoNT-A injection into the detrusor significantly decreased detrusor pressure and increased bladder compliance at 3 and 6 months after treatment. Significantly lower E-cadherin and ZO-1 expressions and increased mast cell and apoptotic cell counts were noted in SCI bladders compared with controls (all P<0.001). Significantly greater distributions of E-cadherin (P<0.001) and ZO-1 (P=0.05) expressions were noted 3 months after BoNT-A injection. However, these changes had declined by 6 months after treatment. Activated mast cells and urothelial apoptosis showed no significant differences between baseline and 3 or 6 months.

CONCLUSION

Urothelial dysfunction and adhesive and junction protein concentrations in SCI patients' bladders recovered after BoNT-A treatment. However, this effect decreased with time. Thus, neurogenic inflammation after SCI was not adequately improved after a single BoNT-A injection.

Possible pathophysiology of ketamine-related cystitis and associated treatment strategies

Ketamine-related cystitis is characterized by ketamine-induced urinary frequency and bladder pain. It has become a serious problem in recent years. The most typical grossly pathological bladder change with ketamine related cystitis is a contracted bladder and bladder wall thickening. Ulcerative cystitis with an easily bleeding mucosa is a common cystoscopic finding. Microscopically, the urothelium is denuded and is infiltrated by inflammatory cells, such as mast cells and eosinophils. The pathogenesis of ketamine-related cystitis is complicated and involves many different pathways. Past evidence suggests a direct toxic effect, bladder barrier dysfunction, neurogenic inflammation, immunoglobulin-E-mediated inflammation, overexpression of carcinogenic genes, abnormal apoptosis and nitric oxide synthase-mediated inflammation contribute to the pathogenesis of ketamine-related cystitis. The first step to managing ketamine-related cystitis is always asking patients to cease ketamine. Medical treatment might be helpful in patients with early ketamine-related cystitis and abstinence from ketamine. Several case studies showed that the intravesical installation of hyaluronic acid and intravesical injection of botulinum toxin type A were effective for symptom relief in selected patients. For patients with irreversible pathological change, such as contracted bladder, augmentation enterocystoplasty might be the only solution to increase bladder capacity and relieve intractable bladder pain.