Efficacy of Targeted Mast Cell Inhibition Therapy in Chronic Prostatitis/Chronic Pelvic Pain Syndrome.

OBJECTIVE: To identify a subgroup of patients with mast cell dysfunction in chronic prostatitis/chronic pelvic pain syndrome and evaluate efficacy of mast cell-directed therapy. MATERIALS AND METHODS: Men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) were recruited and evaluated in an open-label, interventional uncontrolled trial after therapy with cromolyn sodium and cetirizine hydrochloride. The primary endpoint was a change in mast cell tryptase concentrations after treatment while secondary endpoints were changes in the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and AUA-SI. Isolated cells from postprostatic massage urine were evaluated for immune changes using mRNA expression analysis. RESULTS: 31 patients with a diagnoses of Category III CP/CPPS were consented, 25 patients qualified and 20 completed the study after meeting a prespecified threshold for active tryptase in expressed prostatic secretions. After treatment with cromolyn sodium and cetirizine dihydrochloride for 3-week, active tryptase concentrations were significantly reduced from 49.03±14.05 ug/mL to 25.49±5.48 ug/mL (P<.05). The NIH-CPSI total score was reduced with a mean difference of 5.2±1 along with reduction in the pain, urinary and quality of life subscores (P<.001). A reduction in the AUA-SI was observed following treatment (P<.05). NanoString mRNA analysis of isolated cells revealed downregulation of immune-related pathways including Th1 and Th17 T cell differentiation and TLR signaling. Marked reduction in CD45+ cells and specifically macrophages and neutrophil abundance was observed. CONCLUSION: Identification of CP/CPPS patients with mast cell dysfunction may be achieved using tryptase as a discriminating biomarker. Mast cell-directed therapy in this targeted subgroup may be effective in reducing symptoms and modulating the immune inflammatory environment.

Mast cell function in prostate inflammation, fibrosis, and smooth muscle cell dysfunction.

Intraurethral inoculation of mice with uropathogenic Escherichia coli (CP1) results in prostate inflammation, fibrosis, and urinary dysfunction, recapitulating some but not all of the pathognomonic clinical features associated with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). In both patients with LUTS and CP1-infected mice, we observed increased numbers and activation of mast cells and elevated levels of prostate fibrosis. Therapeutic inhibition of mast cells using a combination of a mast cell stabilizer, cromolyn sodium, and the histamine 1 receptor antagonist cetirizine di-hydrochloride in the mouse model resulted in reduced mast cell activation in the prostate and significant alleviation of urinary dysfunction. Treated mice showed reduced prostate fibrosis, less infiltration of immune cells, and decreased inflammation. In addition, as opposed to symptomatic CP1-infected mice, treated mice showed reduced myosin light chain-2 phosphorylation, a marker of prostate smooth muscle contraction. These results show that mast cells play a critical role in the pathophysiology of urinary dysfunction and may be an important therapeutic target for men with BPH/LUTS.NEW & NOTEWORTHY LUTS-associated benign prostatic hyperplasia is derived from a combination of immune activation, extracellular matrix remodeling, hyperplasia, and smooth muscle cell contraction in prostates of men. Using a mouse model, we describe the importance of mast cells in regulating these multiple facets involved in the pathophysiology of LUTS. Mast cell inhibition alleviates both pathology and urinary dysfunction in this model, suggesting the potential for mast cell inhibition as a therapeutic that prevents and reverses pathology and associated symptomology.

Gastrokine-1, an anti-amyloidogenic protein secreted by the stomach, regulates diet-induced obesity.

Obesity and its sequelae have a major impact on human health. The stomach contributes to obesity in ways that extend beyond its role in digestion, including through effects on the microbiome. Gastrokine-1 (GKN1) is an anti-amyloidogenic protein abundantly and specifically secreted into the stomach lumen. We examined whether GKN1 plays a role in the development of obesity and regulation of the gut microbiome. Gkn1-/- mice were resistant to diet-induced obesity and hepatic steatosis (high fat diet (HFD) fat mass (g) = 10.4 ± 3.0 (WT) versus 2.9 ± 2.3 (Gkn1-/-) p < 0.005; HFD liver mass (g) = 1.3 ± 0.11 (WT) versus 1.1 ± 0.07 (Gkn1-/-) p < 0.05). Gkn1-/- mice also exhibited increased expression of the lipid-regulating hormone ANGPTL4 in the small bowel. The microbiome of Gkn1-/- mice exhibited reduced populations of microbes implicated in obesity, namely Firmicutes of the class Erysipelotrichia. Altered metabolism consistent with use of fat as an energy source was evident in Gkn1-/- mice during the sleep period. GKN1 may contribute to the effects of the stomach on the microbiome and obesity. Inhibition of GKN1 may be a means to prevent obesity.

Neuronal/astrocytic expression of chemokine (C-C motif) ligand 2 is associated with monocyte/macrophage recruitment in male chronic pelvic pain.

Chronic pelvic pain syndrome is a multisymptom syndrome with unknown etiology. The experimental autoimmune prostatitis (EAP) mouse model of chronic pelvic pain syndrome is associated with immune cell infiltration into the prostate, expression of C-C chemokine ligand 2 (CCL2), and neuroinflammation in the spinal cord. Here, we studied CCL2 expression in tissues along the nociceptive pathway and its association with neuroimmune cells during pain development. Examination of prostate tissues at days 14 and 28 after EAP induction revealed CCL2 expression was increased in epithelial cells and was associated with increased numbers of macrophages lying in close apposition to PGP9.5-positive afferent neuronal fibers. C-C Chemokine ligand 2 immunoreactivity was elevated to a similar degree in the dorsal root ganglia at day 14 and day 28. D14 of EAP was associated with elevated IBA1 cells in the dorsal root ganglia that were not evident at D28. Adoptive transfer of green fluorescent protein+ leukocytes into EAP mice demonstrated monocytes are capable of infiltrating the spinal cord from peripheral blood with what seemed to be a proinflammatory phenotype. In the lower dorsal spinal cord, CCL2 expression localized to NeuN expressing neurons and GFAP-expressing astrocytes. Myeloid derived cell infiltration into the spinal cord in EAP was observed in the L6-S2 dorsal horn. Myeloid-derived CD45 IBA1+ cells were localized with IBA1+ TMEM199+ microglia in the dorsal horn of the spinal cord in EAP, with intimate association of the 2 cell types suggesting cell-cell interactions. Finally, intrathecal administration of liposomal clodronate ameliorated pelvic pain symptoms, suggesting a mechanistic role for macrophages and microglia in chronic pelvic pain.

A novel immunocompetent model of metastatic prostate cancer-induced bone pain.

BACKGROUND: Over 70% to 85% of men with advanced prostate cancer (PCa) develop bone metastases characterized by severe bone pain and increased likelihood of bone fracture. These clinical features result in decreased quality of life and act as a predictor of higher mortality. Mechanistically, the skeletal pathologies such as osteolytic lesions and abnormal osteoblastic activity drive these symptoms. The role of immune cells in bone cancer pain remains understudied, here we sought to recapitulate this symptomology in a murine model. METHODS: The prostate cancer bone metastasis-induced pain model (CIBP) was established by transplanting a mouse prostate cancer cell line into the femur of immunocompetent mice. Pain development, gait dynamics, and the changes in emotional activities like depression and anxiety were evaluated. Animal tissues including femurs, dorsal root ganglion (DRG), and spinal cord were collected at killing and microcomputed tomography (µCT), histology/immunohistochemistry, and quantitative immunofluorescent analysis were performed. RESULTS: Mice receiving prostate cancer cells showed a significantly lower threshold for paw withdrawal responses induced by mechanical stimulation compared with their control counterparts. Zero maze and DigiGait analyses indicated reduced and aberrant movement associated emotional activity compared with sham control at 8-weeks postinjection. The µCT analysis showed osteolytic and osteoblastic changes and a 50% reduction of the trabecular volumes within the prostate cancer group. Neurologically we demonstrated, increased calcitonin gene-related peptide (CGRP) and neuronal p75NTR immune-reactivities in both the projected terminals of the superficial dorsal horn and partial afferent neurons in DRG at L2 to L4 level in tumor-bearing mice. Furthermore, our data show elevated nerve growth factor (NGF) and TrkA immunoreactivities in the same segment of the superficial dorsal horn that were, however, not colocalized with CGRP and p75NTR . CONCLUSIONS: This study describes a novel immunocompetent model of CIBP and demonstrates the contribution of NGF and p75NTR to chronic pain in bone metastasis.

Protease-activated receptor 2 activates CRAC-mediated Ca2+ influx to cause prostate smooth muscle contraction.

Protease activated receptor 2 (PAR2) is a G-protein coupled receptor that contributes to prostate fibrosis and lower urinary tract symptoms (LUTS). In addition to fibrosis, aberrant smooth muscle tone in the prostate has been hypothesized to play a role. We therefore examined PAR2 expression in primary human prostate smooth muscle cells (PSMC) and studied the downstream signaling effects of PAR2 activation. Signaling pathways involved in the process were assessed using the PAR2 activating peptide SLIGKV-NH2. We show that PAR2 is expressed in PSMC and that PAR2 activation mediates a biphasic elevation in intracellular Ca2+ and phosphorylation of myosin light chain 20 (MLC20), causing cellular contraction as assessed in a gel contraction assay. Intracellular Ca2+ flux was inhibited by a phosphoinositide hydrolysis inhibitor, U73122, showing a requirement for phospholipase C ß (PLCß) activation. PSMC expressed mRNA for L-type voltage dependent Ca2+ channels (VDCC) as well as Ca2+ release activated channels (CRAC), a hitherto unreported finding. Secondary intracellular Ca2+ oscillations were abrogated only by BTP2, the CRAC channel inhibitor, but not by nifedipine, an inhibitor of VDCC. These data suggest that, PAR2 activation and subsequent Ca2+ entry through CRAC channels are important mechanisms in prostate smooth muscle contraction.

Role of gram-positive bacteria in chronic pelvic pain syndrome (CPPS).

INTRODUCTION: Chronic pelvic pain syndrome (CPPS) is a complex disorder that affects a large proportion of all men. A limited understanding of its etiology and pathogenesis is reflected by the absence of effective therapies. Although CPPS is deemed clinically non-infectious with no well-defined etiological role for microbes, bacteria is readily isolated from both healthy and patient prostate secretion and urine samples. Our laboratory has previously demonstrated that a specific gram-negative bacterial isolate can induce CPPS-like symptoms in mice. Here we aimed to expand on these findings examining the role of gram-positive patient-derived bacteria in CPPS. METHODS: A retrospective analysis of bacterial cultures from CPPS patients from a single center was performed. Gram-positive bacteria were isolated from the expressed prostatic secretion (EPS) of three CPPS-patients (pain inducers, PI) and one from a healthy volunteer (non-pain inducer, NPI). These bacteria were inoculated intra-urethrally in two mouse backgrounds and analyzed for their ability to induce tactile allodynia, voiding dysfunction, and colonize the murine prostate. Host immune responses to bacterial instillation were analyzed by flow cytometry. RESULTS: PI strains (Staphylococcus haemolyticus 2551, Enterococcus faecalis 427, and Staphylococcus epidermidis 7244) induced and maintained tactile allodynia responses (200% increase above baseline) for 28 days in NOD/ShiLtJ mice. Conversely the healthy subject derived strain (Staphylococcus epidermidis NPI) demonstrated no significant pelvic allodynia induction. Intra-urethral inoculation of the four bacterial strains into C57BL/6 mice did not induce significant increases in pain responses. Infected NOD/ShiLtJ displayed significant voiding dysfunction compared to their control counterparts. Colony counts of prostate tissues from both NOD/ShiLtJ and C57BL/6 mice at day 28 demonstrated that bacterial strains colonized equally well, including NPI. We also determined that mechanistically, the patient-isolates induced prostate inflammation specifically involving T-cells and monocytes. CONCLUSIONS: Gram-positive isolates from CPPS patients showed enhanced ability to induce tactile allodynia compared to a single taxonomically similar gram-positive strain isolated from a healthy control. Responses were shown to be dependent on host genetic background and not on colonization differences between strains.

A prostate derived commensal Staphylococcus epidermidis strain prevents and ameliorates induction of chronic prostatitis by UPEC infection.

Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) is a common syndrome with limited therapies and an unknown etiology. Previously, our laboratory has defined a potential role for pathogenic infection in disease onset. Intra-urethral infection with a uropathogenic Escherichia coli strain isolated from a CP/CPPS patient, CP1, induces prostatic inflammation and tactile allodynia in mice. We have also demonstrated that a prostate specific Staphylococcus epidermidis bacterial isolate, NPI (non-pain inducing), from a healthy subject reduces pain and inflammation in an experimental autoimmune prostatitis (EAP) murine model. Here we focus on the interplay between these human isolates in the context of prostatitis development and resolution. NOD/ShiLtJ mice were inoculated with either NP1 or CP1, or combinations of both. Infection with CP1 induced pelvic tactile allodynia after 7 days, while NPI instillation alone induced no such response. Instillation with NPI 7 days following CP1 infection resolved pelvic tactile allodynia and prophylactic instillation 7 days prior to CPI infection prevented its onset. Prophylactic NPI instillation also prevented CP1 colonization of both prostate and bladder tissues. In vitro analyses revealed that CP1 and NPI do not directly inhibit the growth or invasive potential of one another. Immunological analyses revealed that specific markers associated with CP1-induced pelvic allodynia were decreased upon NPI treatment or repressed by prophylactic colonization. This study demonstrates that a commensal bacterial isolate can inhibit the colonization, pain responses, and immunological activation to uropathogenic bacteria, emphasizing the power of a healthy prostatic microflora in controlling health and disease.

Commensal bacterial modulation of the host immune response to ameliorate pain in a murine model of chronic prostatitis.

The human commensal microflora plays an essential role in modulating the immune response to control homeostasis. Staphylococcus epidermidis, a commensal bacterium most commonly associated with the skin exerts such effects locally, modulating local immune responses during inflammation and preventing superinfection by pathogens such as Staphylococcus aureus. Although the prostate is considered by many to be sterile, multiple investigations have shown that small numbers of gram-positive bacterial species such as S. epidermidis can be isolated from the expressed prostatic secretions of both healthy and diseased men. Chronic pelvic pain syndrome is a complex syndrome with symptoms including pain and lower urinary tract dysfunction. It has an unknown etiology and limited effective treatments but is associated with modulation of prostate immune responses. Chronic pelvic pain syndrome can be modeled using murine experimental prostatitis (EAP), where CD4+ve IL17A+ve T cells have been shown to play a critical role in disease orchestration and development of pelvic tactile allodynia. Here, we report that intraurethral instillation of a specific S. epidermidis strain (designated NPI [non-pain inducing]), isolated from the expressed prostatic secretion of a healthy human male, into EAP-treated mice reduced the pelvic tactile allodynia responses and increased CD4+ve IL17A+ve T-cell numbers associated with EAP. Furthermore, a cell wall constituent of NPI, lipoteichoic acid, specifically recapitulates these effects and mediates increased expression of CTLA4-like ligands PDL1 and PDL2 on prostatic CD11b+ve antigen-presenting cells. These results identify a new potential therapeutic role for commensal S. epidermidis NPI lipoteichoic acid in the treatment of prostatitis-associated pain.

Role of PAR2 in the Development of Lower Urinary Tract Dysfunction.

PURPOSE: Lower urinary tract symptoms are a common finding in patients with chronic prostatitis/chronic pelvic pain syndrome. We previously reported that the mast cell-tryptase-PAR2 (protease activated receptor 2) axis has a critical role in the development of chronic pain in experimental autoimmune prostatitis, a mouse model of chronic prostatitis/chronic pelvic pain syndrome. Therefore, we examined whether PAR2 activation mediates lower urinary tract dysfunction. MATERIALS AND METHODS: Functional cystometry was done in male B6 mice along with immunoblotting and immunohistochemistry for the expression of COL1A1 (collagen type I α I) and α-SMA (α-smooth muscle actin). Flow cytometry analysis was performed on single cell suspensions of the prostate, bladder, lymph nodes and spleen. RESULTS: Experimental autoimmune prostatitis resulted in increased urinary voiding frequency and decreased bladder capacity 30 days after initiation. Concurrently, there was increased expression of COL1A1 and α-SMA in the prostates and bladders. In contrast, induction of experimental autoimmune prostatitis in PAR2 knockout mice did not result in altered urodynamics or increased markers of fibrosis in the prostate or the bladder. Single cell suspensions of the prostate, bladder, lymph nodes and spleen demonstrated that in the absence of PAR2 cellular inflammatory mechanisms were still initiated in experimental autoimmune prostatitis but PAR2 expression may be required to maintain chronic inflammation. Finally, antibody mediated PAR2 neutralization normalized urinary voiding frequency and bladder capacity, and attenuated chronic pelvic pain. CONCLUSIONS: PAR2 activation in the prostate may contribute to the development of lower urinary tract dysfunction through proinflammatory as well as profibrotic pathways.

Predictive factors for colonic resection in patients less than 49 years with symptomatic diverticular disease.

BACKGROUND: Diverticular disease is a condition strongly associated with low-fiber intake and obesity. There have been reports of an increasing incidence in younger individuals ranging from 12% to 21% of all cases. The aim of this study was to evaluate the management of complicated diverticular disease in patients less than 49 years and attempt to identify factors predictive of a more virulent course. METHODS: An analysis of a prospectively updated database of all patients admitted with a primary diagnosis of acute diverticulitis from 2005 to 2013 was performed. Data collected included age, length of stay, inflammatory markers on admission, use of computed tomography (CT), and Hinchey Classification. SPSS version 22 was used for statistical analysis, and a P value of .05 or less was considered significant. RESULTS: A total of 120 (54 female and 66 male) patients less than 49 (28 to 49, 42.1) years were noted to have a diagnosis of acute diverticulitis. Twelve patients (10%) required colonic resection for complicated diverticulitis. Histological evaluation revealed 5 cases of stricture, 2 obstruction, and 5 perforations. On multivariate analysis, predictors of operative intervention and/or colonic resection included, (hazard ratio [95% confidence interval]) patients aged 40 to 49 years (.92 [.9 to .95]) and elevated C-reactive protein on index admission (1.4 [1.32 to 1.54]). Females were less likely to undergo colonic resection compared with males (1.18 [1.15 to 1.2]). Median length of stay was 4 days (1 to 48) for patients managed nonoperatively and 13 days (5 to 27) for those who underwent surgery. CONCLUSIONS: Most younger patients with acute diverticulitis can be treated successfully by conservative means. However, a proportion of patients require aggressive surgical management.

The Thr300Ala variant in ATG16L1 is associated with improved survival in human colorectal cancer and enhanced production of type I interferon.

OBJECTIVE: ATG16L1 is an autophagy gene known to control host immune responses to viruses and bacteria. Recently, a non-synonymous single-nucleotide polymorphism in ATG16L1 (Thr300Ala), previously identified as a risk factor in Crohn's disease (CD), was associated with more favourable clinical outcomes in thyroid cancer. Mechanisms underlying this observation have not been proposed, nor is it clear whether an association between Thr300Ala and clinical outcomes will be observed in other cancers. We hypothesised that Thr300Ala influences clinical outcome in human colorectal cancer (CRC) and controls innate antiviral pathways in colon cancer cells. DESIGN: We genotyped 460 patients with CRC and assessed for an association between ATG16L1 Thr300Ala and overall survival and clinical stage. Human CRC cell lines were targeted by homologous recombination to examine the functional consequence of loss of ATG16L1, or introduction of the Thr300Ala variant. RESULTS: We found an association between longer overall survival, reduced metastasis and the ATG16L1 Ala/Ala genotype. Tumour sections from ATG16L1 Ala/Ala patients expressed elevated type I interferons (IFN-I)-inducible, MxA, suggesting that differences in cytokine production may influence disease progression. When introduced into human CRC cells by homologous recombination, the Thr300Ala variant did not affect bulk autophagy, but increased basal production of type I IFN. Introduction of Thr300Ala resulted in increased sensitivity to the dsRNA mimic poly(I:C) through a mitochondrial antiviral signalling (MAVS)-dependent pathway. CONCLUSIONS: The CD-risk allele, Thr300Ala, in ATG16L1 is associated with improved overall survival in human CRC, generating a rationale to genotype ATG16L1 Thr300Ala in patients with CRC. We found that Thr300A alters production of MAVS-dependent type I IFN in CRC cells, providing a mechanism that may influence clinical outcomes.

IL17 Mediates Pelvic Pain in Experimental Autoimmune Prostatitis (EAP).

Chronic pelvic pain syndrome (CPPS) is the most common form of prostatitis, accounting for 90-95% of all diagnoses. It is a complex multi-symptom syndrome with unknown etiology and limited effective treatments. Previous investigations highlight roles for inflammatory mediators in disease progression by correlating levels of cytokines and chemokines with patient reported symptom scores. It is hypothesized that alteration of adaptive immune mechanisms results in autoimmunity and subsequent development of pain. Mouse models of CPPS have been developed to delineate these immune mechanisms driving pain in humans. Using the experimental autoimmune prostatitis (EAP) in C57BL/6 mice model of CPPS we examined the role of CD4+T-cell subsets in the development and maintenance of prostate pain, by tactile allodynia behavioral testing and flow cytometry. In tandem with increased CD4+IL17A+ T-cells upon EAP induction, prophylactic treatment with an anti-IL17 antibody one-day prior to EAP induction prevented the onset of pelvic pain. Therapeutic blockade of IL17 did not reverse pain symptoms indicating that IL17 is essential for development but not maintenance of chronic pain in EAP. Furthermore we identified a cytokine, IL7, to be associated with increased symptom severity in CPPS patients and is increased in patient prostatic secretions and the prostates of EAP mice. IL7 is fundamental to development of IL17 producing cells and plays a role in maturation of auto-reactive T-cells, it is also associated with autoimmune disorders including multiple sclerosis and type-1 diabetes. More recently a growing body of research has pointed to IL17's role in development of neuropathic and chronic pain. This report presents novel data on the role of CD4+IL17+ T-cells in development and maintenance of pain in EAP and CPPS.

Intestinal epithelial expression of TNFAIP3 results in microbial invasion of the inner mucus layer and induces colitis in IL-10-deficient mice.

Tumor necrosis factor-induced protein 3 (TNFAIP3; also known as A20) negatively regulates NF-κB and MAPK signals to control inflammatory responses. TNFAIP3 also protects against TNF-induced cell death. Intestinal epithelial cell (IEC) expression of TNFAIP3 improves barrier function and tight junction integrity and prevents dextran sulfate sodium (DSS)-induced IEC death and colitis. We therefore investigated the effects of TNFAIP3 expression in IEC on immune homeostasis in the intestines of immune-compromised mice. Villin-TNFAIP3 (v-TNFAIP3) transgenic mice were interbred with IL-10(-/-) mice (v-TNFAIP3 × IL-10(-/-)) and incidence, onset, and severity of colitis was assessed. v-TNFAIP3 × IL-10(-/-) mice displayed severe, early onset, and highly penetrant colitis that was not observed in IL-10(-/-) or v-TNFAIP3 mice. V-TNFAIP3 mice displayed altered expression of mucosal cytokines, increased numbers of mucosal regulatory T cells, and altered expression of mucosal antimicrobial peptides (AMPs). Microbial colonization of the inner mucus layer of v-TNFAIP3 mice was observed, along with alterations in the microbiome, but this was not sufficient to induce colitis in v-TNFAIP3 mice. The relative sterility of the inner mucus layer observed in wild-type and IL-10(-/-) mice was lost in v-TNFAIP3 × IL-10(-/-) mice. Thus IEC-derived factors, induced by signals that are inhibited by TNFAIP3, suppress the onset of inflammatory bowel disease in IL-10(-/-) mice. Our results indicate that IEC expression of TNFAIP3 alters AMP expression and allows microbial colonization of the inner mucus layer, which activates an IL-10-dependent anti-inflammatory process that is necessary to prevent colitis.

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.

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-ß 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-ß 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-ß and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-ß 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.