Prostate secretions from men with chronic pelvic pain syndrome inhibit proinflammatory mediators. J Urol. 2010;184:1536-1542. [PMID: 20723928 DOI: 10.1016/j.juro.2010.05.086]

Loss of the Sympathetic Signal Produces Sterile Inflammation of the Prostate

Neural innervations exert essential roles in the prostate. However, spatial distribution and regulatory function of such neural inputs are incompletely characterized. Here, we exploited the advanced whole-tissue immunolabeling and optical clearing technique to assess the 3D anatomy of autonomic innervations in the mouse and human prostate for the first time. We observed that sympathetic and parasympathetic inputs in the mouse prostate remained unaffected during castration-induced tissue regression. However, the pharmacologic destruction of sympathetic innervations in the mouse prostate led to sterile inflammation of the tissue, mimicking the disease condition of chronic non-bacterial prostatitis. Also, the genetic ablation of sympathetic inputs produced a similar inflammatory response. Furthermore, we showed that treatment of the specific β2-adrenergic receptor agonists could effectively mitigate the prostate inflammation caused by such sympathetic loss. Together, these results have elucidated the new immunomodulatory function of the sympathetic signal via the β2-adrenergic receptor in prostate inflammatory disease.

mMCP7, a Mouse Ortholog of δ Tryptase, Mediates Pelvic Tactile Allodynia in a Model of Chronic Pelvic Pain

Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) is a condition that affects a large number of men and has unknown etiology. We have previously demonstrated the presence of elevated levels of mast cell tryptase in expressed prostatic secretions (EPS) of CP/CPPS patients. In a murine model of CP/CPPS, we showed tryptase and its cognate receptor PAR2 as critical to the development of pelvic pain and lower urinary tract symptoms. Here, we extend these observations to demonstrate that an isoform of tryptase called delta (δ)-tryptase, is elevated in the EPS of patients with CP/CPPS and is correlated with pelvic pain symptoms. Using an Escherichia coli (CP1) -induced murine model of CP/CPPS, we demonstrated a differential response in C57BL/6J and NOD/ShiLtJ mice, with C57BL6/J mice being resistant to an increase in pelvic tactile allodynia, despite having equivalent levels of activated mast cells in the prostate. Activated tryptase+ve mast cells were observed to be in closer apposition to PGP9.5+ve nerve fibers in the prostate stroma of NOD/ShiLtJ in comparison to C57BL/6J mice. The mouse ortholog of δ-tryptase, mouse mast cell protease 7 (mMCP7) has been reported to be unexpressed in C57BL/6J mice. We confirmed the absence of mMCP7 in the prostates of C57BL/6J and its presence in NOD/ShiLtJ mice. To evaluate a role for mMCP7 in the differential allodynia responses, we performed direct intra-urethral instillations of mMCP7 and the beta (β)-tryptase isoform ortholog, mMCP6 in the CP1-infection model. mMCP7, but not mMCP6 was able to induce an acute pelvic allodynia response in C57BL/6J mice. In-vitro studies with mMCP7 on cultured mast cells as well as dissociated primary neurons demonstrated the ability to induce differential activation of pain and inflammation associated molecules compared to mMCP6. We conclude that mMCP7, and possibility its human ortholog δ-tryptase, may play an important role in mediating the development of pelvic tactile allodynia in the mouse model of pelvic pain and in patients with CP/CPPS.

Li-ESWT treatment reduces inflammation, oxidative stress, and pain via the PI3K/AKT/FOXO1 pathway in autoimmune prostatitis rat models

BACKGROUND

Due to limited data on the pathogenesis of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and the suboptimal therapeutic effect, the development of new and effective treatment modalities was needed urgently. Low-intensity extracorporeal shock wave therapy (Li-ESWT) has been reported for the treatment of CP/CPPS. However, the underlying mechanism remains to be elucidated.

OBJECTIVE

To interrogated the efficacy and the mechanism of Li-ESWT in the treatment of CP/CPPS.

MATERIALS AND METHODS

According to different treatments, RWPE-1 cells (human prostate epithelial cells) were randomly divided into three groups: control group, LPS(lipopolysaccharide) group, or Li-ESWT group (LPS induced RWPE-1 managed by Li-ESWT). Following the Li-ESWT treatment, the levels of oxidative stress was assayed. We then established a rat model of experimental autoimmune prostatitis (EAP) by injecting prostatic protein homogenate mixed with complete Freund's adjuvant. The Sprague-Dawley rats were randomly divided into the control group, EAP group, or Li-ESWT group. Von Frey Filament was used to quantify pelvic hyperalgesia in the rats. Prostates tissues from each group were collected for immunohistochemistry, oxidation stress, and western blot analysis.

RESULTS

Histological analysis showed reduced inflammation and expression of cytokines (TNF-α, IL-1β, IL-6, COX-2, SP) in prostate tissues from the Li-ESWT group compared with those from the EAP group (all P < 0.05). Similarly, there was reduced pelvic pain and allergic symptoms in the Li-ESWT group compared with the EAP group (all P < 0.05). Besides, Li-ESWT treatment could decrease oxidative stress in the prostate and in RWPE-1 cells, respectively (both P < 0.05). Moreover, the Li-ESWT up-regulated the expression of CAT through the inhibition of phosphorylation of AKT/FOXO1 signaling pathway.

DISCUSSION AND CONCLUSIONS

Li-ESWT may reduce inflammation, oxidative stress and pain in rats with autoimmunity-induced prostatitis via the PI3K/AKT/FOXO1 pathway. It implies that Li-ESWT can present a potential therapeutic option for the treatment of CP/CPPS.

Lycopene attenuates chronic prostatitis/chronic pelvic pain syndrome by inhibiting oxidative stress and inflammation via the interaction of NF-κB, MAPKs, and Nrf2 signaling pathways in rats

Background

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is identified as a urinary andrological diseases that afflict men due to various discomforts. It is urgent and meaningful to develop the novel and effective treatments as a result of the unclear etiology and dismal therapeutic effect of CP/CPPS. Lycopene exerts a crucial role in numerous chronic inflammatory diseases owing to its potent antioxidant capacity.

Objective

This study aimed to observe the effect of lycopene on CP/CPPS and to explore the underlying mechanisms.

Materials and Methods

A CP/CPPS model with complete Freund's adjuvant was established in this study. Afterward, intragastric lycopene or corn oil was administered daily for 4 consecutive weeks. Finally, the cardiac blood and prostate tissue samples were collected from rats to carry out related evaluation and testing.

Results

It was found in this study that lycopene alleviated changes in prostate histopathology compared with those in the complete Freund's adjuvant‐induced CP/CPPS model rats without lycopene treatment. Furthermore, lycopene was suggested to reduce the levels of chemokines MCP1 and MIP‐1α, down‐regulate the expression levels of cytokines (such as TNFα, IL‐1β, IL‐2, and IL‐6), and up‐regulate those of CAT, GSH‐PX, and T‐SOD, decrease that of malondialdehyde. Moreover, it also inhibited the phosphorylation of MAPKs, NF‐κB, and enhanced phosphorylation of the Nrf2 in the CP/CPPS rat model.

Discussion and Conclusions

The findings in this study suggest that lycopene exerts potent anti‐ CP/CPPS Seffects through alleviating inflammatory response and oxidative stress, which is probably attributed to the interaction of NF‐κB, MAPKs, and Nrf2 signaling pathways in rats. As a natural antioxidant, lycopene may serve as a promising pharmaceutical preparation for treating CP/CPPS.

Effect of alcohol on chronic pelvic pain and prostatic inflammation in a mouse model of experimental autoimmune prostatitis

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a prevalent disease of the urogenital system. Alcohol has been reported to be closely related to CP/CPPS. Thus, we intended to verify the role of alcohol in CP/CPPS and determine the underlying mechanism.

METHODS

We induced experimental autoimmune prostatitis (EAP) mouse model by intradermally injecting a mixture of prostate antigens (PAgs) and complete Freund's adjuvant on days 0 and 28. Mice were treated with alcohol (control-alcohol and EAP-alcohol groups) or vehicle (control-vehicle, and EAP-vehicle groups) from day 32 to 42. Forty-two days after PAg injection, the pathological appearance of the prostate tissues was evaluated, and histological analyses of the prostate were performed. Chronic pelvic pain was assessed by applying von Frey filaments to the lower abdomen. Proinflammatory cytokines were detected by enzyme-linked immunosorbent assay tests. Then, we explored the effects of the NLRP3 inhibitor MCC950 on chronic pelvic pain and prostatic inflammation in this model.

RESULTS

Histological analyses showed diffuse inflammation in the stromal tissues that were characterized by severe infiltration of neutrophils and mononuclear cells in mice in the EAP-alcohol group compared with EAP-vehicle group. Chronic pain tests showed that the response frequency was significantly increased using a von Frey filament at forces of 0.4, 1.0, and 4.0 g in EAP-alcohol group compared with EAP-vehicle (P < .05). The levels of proinflammatory cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17, and IL-1β were all significantly elevated in EAP-alcohol group compared with the EAP-vehicle group (P < .05). However, between the control-alcohol and control-vehicle groups, chronic pain tests, histological assays, and cytokine determinations showed no differences. Furthermore, our results demonstrated that MCC950 could decrease the expression level of NLRP3 inflammasome-related proteins including NLRP3, ASC, and caspase-1. The chronic pain tests, histological assays, and cytokine determinations showed that MCC950 could attenuate the chronic pain and prostatic inflammation through the inhibition of the NLRP3 inflammasome.

CONCLUSIONS

This study indicated that alcohol could aggravate the severity of prostatic inflammation in EAP model though activating the NLRP3 inflammasome. Furthermore, the role of MCC950 in inhibiting NLRP3 inflammasome and decreasing IL-1β secretion to alleviate EAP severity may show that it is a promising therapeutic agent for CP/CPPS.

Chronic pelvic pain and prostate inflammation in rat experimental autoimmune prostatitis: Effect of a single treatment with phosphodiesterase 5 inhibitors on chronic pelvic pain

BACKGROUND

Experimental autoimmune prostatitis (EAP) is most often used as a nonbacterial model of chronic prostatitis/chronic pelvic pain. We investigated the development of chronic pelvic pain and inflammatory changes in rat EAP and examined the effect of a single treatment with phosphodiesterase 5 (PDE5) inhibitors on the chronic pelvic pain.

METHODS

EAP was induced in rats by intradermal injection of rat prostate antigen and complete Freund's adjuvant on days 0 and 28. On day 42, after antigen injection, prostatic inflammatory changes, including the mRNA and protein levels of cytokines/chemokines, were measured and histological analysis of the prostate was performed. Pelvic pain was measured by applying von Frey filaments to the lower abdomen. To confirm that this model is appropriate for evaluating pelvic pain, we tested two drugs, celecoxib and pregabalin, which are clinically used for the treatment of prostatitis-related pain. Subsequently, we examined the effects of single treatments with three phosphodiesterase 5 inhibitors, including tadalafil, on pelvic pain in this model.

RESULTS

On day 42, after antigen injection, the mRNA levels of 44 of 84 kinds of cytokines/chemokines and their receptors increased significantly in EAP rats, as did the protein levels of seven of 23 kinds of cytokines/chemokines. Histological analysis revealed inflammation characterized by neutrophils and/or mononuclear cells in the glandular and stromal tissue of the ventral prostate from rats in the EAP group. Some animals in this group showed fibrosis and hemorrhage in the stromal tissue. Pelvic pain had developed in EAP rats, which was attenuated by a single treatment with celecoxib or pregabalin, suggesting that EAP is an appropriate model for prostatitis-related pain. A single treatment with any of the three PDE5 inhibitors tested attenuated the chronic pelvic pain.

CONCLUSIONS

Prostatitis leads to inflammatory changes in the prostate, which may contribute to the development and maintenance of chronic pelvic pain. PDE5 inhibitors, including tadalafil, may have the ability to block chronic pelvic pain.

Urine chemokine levels correlate with treatment response to phosphodiesterase 4 inhibitor in prostatitis

AIM

To investigate the association of urinary chemokines with the treatment response in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) patients.

METHODS

Between 2007-2011, 18 out of 21 male CP/CPPS patients met the exclusion/inclusion criteria of the 16 wk longitudinal study on twice daily oral treatment with Phosphodiesterase 4 inhibitor called Apremilast for 12 wk. Symptom scores and urine specimen were collected at baseline and every visit at 4 wk interval from CP/CPPS patients who completed at least 8 wk of drug treatment. Urine collected at each visit was frozen and then analyzed together after thawing for chemokines and growth factors using MILLIPLEX™ MAP immunoassay. Cross sectional association of Chronic Prostatitis Symptom Index (CPSI) and visual analog scale (VAS) with chemokine levels in urine collected at baseline was assessed in 18 CP/CPPS patients relative to 10 asymptomatic male subjects. Longitudinal association between urine chemokine levels and symptom scores was assessed in 8 treatment-adherent CP/CPPS patients at baseline and at 4, 8, 12 and 16 wk.

RESULTS

Urine chemokines levels of CXCL-1 (GRO-a), CXCL-8 (IL-8), CXCL-10 (IP-10) and CCL5 (RANTES) in CP/CPPS patients at baseline were significantly elevated relative to asymptomatic subjects, whereas levels of sIL-1RA in CP/CPPS were significantly lower compared to controls (P < 0.05). Quantitatively, urine levels of CXCL-10 were higher than other chemokines in CP/CPPS, but its 5 fold change relative to controls was lower than the 20 fold change noted for CXCL-8. The mean age of enrolled patients who completed at least 8 wk of treatment (n = 8) was 46.5 ± 9.4 years and analysis found that elevation of CXCL-8 and CCL5 increased the odds for higher score of CPSI by 54% and 25%, respectively (F test, P = 0.00007). Urine levels of CCL2 (MCP-1) and CXCL-10 together explained approximately 85% of variance in longitudinal data on multivariate analysis. Bivariate analysis of 5 patients who fully complied and completed the assigned dose regimen, showed strong linear correlation of reduced urine levels of CXCL-10, CXCL-8, CCL5, CCL2 and PDGF with improvement in clinical activity as measured by pain VAS and CPSI (Pearson r = 0.83-0.97; P < 0.05).

CONCLUSION

Urine levels of CXCL-10, CCL2 and PDGF can be sensitive, objective and non-invasive markers of response to new therapeutic intervention in CP/CPPS patients.

Updates on therapies for chronic prostatitis/chronic pelvic pain syndrome

Prostatitis comprises of a group of syndromes that affect almost 50% of men at least once in their lifetime and makeup the majority of visits to the Urology Clinics. After much debate, it has been divided into four distinct categories by National Institutes of Health namely (1) acute bacterial prostatitis; (2) chronic bacterial prostatitis; (3) chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) which is further divided into inflammatory and non-inflammatory CP/CPPS; and (4) asymptomatic inflammatory prostatitis. CP/CPPS has been a cause of great concern for both patients and physicians because of the lack of presence of thorough information about the etiological factors along with the difficult-to-treat nature of the syndrome. For the presented manuscript an extensive search on PubMed was conducted for CP/CPPS aimed to present an updated review on the evaluation and treatment options available for patients with CP/CPPS. Several diagnostic criteria’s have been established to diagnose CP/CPPS, with prostatic/pelvic pain for at least 3 mo being the major classifying symptom along with the presence of lower urinary tract symptoms and/or ejaculatory pain. Diagnostic tests can help differentiate CP/CPPS from other syndromes that come under the heading of prostatitis by ruling out active urinary tract infection and/or prostatic infection with uropathogen by performing urine cultures, Meares-Stamey Four Glass Test, Pre- and Post-Massage Two Glass Test. Asymptomatic inflammatory prostatitis is confirmed through prostate biopsy done for elevated serum prostate-specific antigen levels or abnormal digital rectal examination. Researchers have been unable to link a single etiological factor to the pathogenesis of CP/CPPS, instead a cluster of potential etiologies including atypical bacterial or nanobacterial infection, autoimmunity, neurological dysfunction and pelvic floor muscle dysfunction are most commonly implicated. Initially monotherapy with anti-biotics and alpha adrenergic-blockers can be tried, but its success has only been observed in treatment naïve population. Other pharmacotherapies including phytotherapy, neuromodulatory drugs and anti-inflammatories achieved limited success in trials. Complementary and interventional therapies including acupuncture, myofascial trigger point release and pelvic floor biofeedback have been employed. This review points towards the fact that treatment should be tailored individually for patients based on their symptoms. Patients can be stratified phenotypically based on the UPOINT system constituting of Urinary, Psychosocial, Organ-specific, Infectious, Neurologic/Systemic and symptoms of muscular Tenderness and the treatment algorithm should be proposed accordingly. Treatment of CP/CPPS should be aimed towards treating local as well as central factors causing the symptoms. Surgical intervention can cause significant morbidity and should only be reserved for treatment-refractory patients that have previously failed to respond to multiple drug therapies.

Tryptase-PAR2 axis in experimental autoimmune prostatitis, a model for chronic pelvic pain syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) affects up to 15% of the male population and is characterized by pelvic pain. Mast cells are implicated in the murine experimental autoimmune prostatitis (EAP) model as key to chronic pelvic pain development. The mast cell mediator tryptase-β and its cognate receptor protease-activated receptor 2 (PAR2) are involved in mediating pain in other visceral disease models. Prostatic secretions and urines from CP/CPPS patients were examined for the presence of mast cell degranulation products. Tryptase-β and PAR2 expression were examined in murine EAP. Pelvic pain and inflammation were assessed in the presence or absence of PAR2 expression and upon PAR2 neutralization. Tryptase-β and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-β was capable of inducing pelvic pain and was increased in EAP along with its receptor PAR2. PAR2 was required for the development of chronic pelvic pain in EAP. PAR2 signaling in dorsal root ganglia led to extracellular signal-regulated kinase (ERK)1/2 phosphorylation and calcium influx. PAR2 neutralization using antibodies attenuated chronic pelvic pain in EAP. The tryptase-PAR2 axis is an important mediator of pelvic pain in EAP and may play a role in the pathogenesis of CP/CPPS.

Inflammatory response of prostate epithelial cells to stimulation by Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis is known as the most common cause of sexually transmitted infection. However, its prevalence may have been underestimated. Trichomonads are detected in prostatic tissue in benign prostatic hyperplasia, prostatitis, and prostate cancer. Our objective was to investigate whether T. vaginalis could induce an inflammatory response in prostate epithelium.

METHODS

The cytokine production by human prostate epithelial cell (RWPE-1) activated with T. vaginalis was determined by ELISA and real-time PCR. Intracellular ROS was evaluated by flow cytometry or spectrofluorometry. The protein levels of MAP kinase, NF-κB were analyzed by Western blot. The migration of neutrophil and monocyte were performed in 24-well microplates with filter insert.

RESULTS

Incubation of cells of a human prostate epithelial cell line with a live T. vaginalis T016 isolate increased expression of the inflammatory mediators IL-1β, CCL2, and CXCL8. In addition, ROS, MAPK, and NF-κB activities increased, while inhibitors of ROS, ERK, and NF-κB reduced IL-1β production. Medium conditioned by incubation of RWPE-1 cells with T. vaginalis contained IL-1β and stimulated the migration of human neutrophils and monocytes (THP-1 cell line).

CONCLUSIONS

We conclude that T. vaginalis may increase IL-1β expression in human prostate epithelium through activation of ROS, ERK, and NF-κB, and this in turn may induce the migration of neutrophils and monocytes and lead to an inflammatory response. This research is the first attempt to confirm inflammatory reaction caused by T. vaginalis in prostate epithelial cell.

Immune mediators of chronic pelvic pain syndrome

The cause of chronic pelvic pain syndrome (CPPS) has yet to be established. Since the late 1980s, cytokine, chemokine, and immunological classification studies using human samples have focused on identifying biomarkers for CPPS, but no diagnostically beneficial biomarkers have been identified, and these studies have done little to deepen our understanding of the mechanisms underlying chronic prostatic pain. Given the large number of men thought to be affected by this condition and the ineffective nature of current treatments, there is a pressing need to elucidate these mechanisms. Prostatitis types IIIa and IIIb are classified according to the presence of pain without concurrent presence of bacteria; however, it is becoming more evident that, although levels of bacteria are not directly associated with levels of pain, the presence of bacteria might act as the initiating factor that drives primary activation of mast-cell-mediated inflammation in the prostate. Mast cell activation is also known to suppress regulatory T cell (Treg) control of self-tolerance and also activate neural sensitization. This combination of established autoimmunity coupled with peripheral and central neural sensitization can result in the development of multiple symptoms, including pelvic pain and bladder irritation. Identifying these mechanisms as central mediators in CPPS offers new insight into the prospective treatment of the disease.

Etiology of chronic prostatitis/chronic pelvic pain syndrome: psychoimmunoneurendocrine dysfunction (PINE syndrome) or just a really bad infection?

PURPOSE

To review the etiology and pathogenesis of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

METHODS

A literature review for the years 1985-2012 was performed using the MEDLINE database of the United States National Library of Medicine.

RESULTS

The evidence for ongoing infection in men with CP/CPPS is lacking. However, men with CP/CPPS are twice as likely to have had a sexually transmitted disease (STD), and bacteria from men with CP/CPPS may be phenotypically different from those that cause cystitis or acute prostatitis. Evidence continues to support an alteration in both the afferent and efferent autonomic nervous systems. Functional brain imaging suggests changes in the gray matter as well as the importance of the anterior insula and anterior cingulated gyrus in pain processing. Neural function can be modulated by immune and endocrine factors. Alterations in cytokine function and autoimmunity appear to play a role in the immune dysfunction. Alterations in the hypothalamic-pituitary-adrenal axis can mediate the endocrine effects, similar to many other chronic pain conditions. Genetics may play a role in who may develop chronic pain after an initial insult. Finally, any biological changes must then be processed through the psychosocial environment, including the tendency to catastrophize, and degree of spousal support, to produce a given individual patient's pain experience.

CONCLUSIONS

Infection with atypical bacteria or sequelae of an STD may lead to CP/CPPS in some men. Such a biological insult in the context of alterations in psychoimmunoneurendocrine factors produces the chronic pain experience.

PCR for diagnosis of male Trichomonas vaginalis infection with chronic prostatitis and urethritis

The aim of this study was to assess the usefulness of PCR for diagnosis of Trichomonas vaginalis infection among male patients with chronic recurrent prostatitis and urethritis. Between June 2001 and December 2003, a total of 33 patients visited the Department of Urology, Hanyang University Guri Hospital and were examined for T. vaginalis infection by PCR and culture in TYM medium. For the PCR, we used primers based on a repetitive sequence cloned from T. vaginalis (TV-E650). Voided bladder urine (VB1 and VB3) was sampled from 33 men with symptoms of lower urinary tract infection (urethral charge, residual urine sensation, and frequency). Culture failed to detect any T. vaginalis infection whereas PCR identified 7 cases of trichomoniasis (21.2%). Five of the 7 cases had been diagnosed with prostatitis and 2 with urethritis. PCR for the 5 prostatitis cases yielded a positive 330 bp band from bothVB1 and VB3, whereas positive results were only obtained from VB1 for the 2 urethritis patients. We showed that the PCR method could detect T. vaginalis when there was only 1 T. vaginalis cell per PCR mixture. Our results strongly support the usefulness of PCR on urine samples for detecting T. vaginalis in chronic prostatitis and urethritis patients.

New paradigms in understanding chronic pelvic pain syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common male pain condition that is associated with significant discomfort and disability. Despite significant efforts, there remains no definitive etiology or treatment of the spectrum of pelvic symptoms reported by these patients. The purpose of this review is to summarize important clinical and scientific findings related to CP/CPPS from the previous 2 years, and to evaluate their impact on our understanding of, and approach to, the disease.