Matrix metalloproteinases in the pathogenesis of estradiol-induced nonbacterial prostatitis in the lateral prostate lobe of the Wistar rat

Preclinical models and evaluation criteria of prostatitis

Prostatitis is a common urological condition that affects almost half of all men at some point in their life. The prostate gland has a dense nerve supply that contributes to the production of fluid to nourish sperm and the mechanism to switch between urination and ejaculation. Prostatitis can cause frequent urination, pelvic pain, and even infertility. Long-term prostatitis increases the risk of prostate cancer and benign prostate hyperplasia. Chronic non-bacterial prostatitis presents a complex pathogenesis, which has challenged medical research. Experimental studies of prostatitis require appropriate preclinical models. This review aimed to summarize and compare preclinical models of prostatitis based on their methods, success rate, evaluation, and range of application. The objective of this study is to provide a comprehensive understanding of prostatitis and advance basic research.

Influence of Experimental Autoimmune Prostatitis on Sexual Function and the Anti-inflammatory Efficacy of Celecoxib in a Rat Model

Experimental autoimmune prostatitis (EAP) is a well-established model induced by an autoimmune response to prostate antigen. The symptomatic, pathological, and immunological characteristics of EAP animals are highly consistent with human chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), which makes EAP an ideal model for this disease. Here, we investigate the influence of EAP on male rat sexual function and the efficacy of anti-inflammatory therapy with celecoxib. EAP rat models were established using male Wistar rats. Rats were randomly assigned to a normal control group, an EAP model group, or an EAP model with celecoxib treatment group (celecoxib group). Behavioral changes, sexual behavioral changes, and erectile function were estimated using an open-field test, a sucrose consumption test, mating experiments, and by intracavernous pressure/mean arterial pressure ratio (ICP/MAP). Histological changes in the prostate were observed by HE staining, and the serum inflammatory factors IL-1β and TNF-α levels were measured by enzyme-linked immunosorbent assay. In addition, serotonin (5-hydroxytryptamine, 5-HT), 5-HT_1A receptor, 5-HT_2C receptor, and serotonin transporter (SERT) expression levels in the hippocampus and spinal cord (T13–L1, L5–S2) were examined by immunohistochemistry and western blot analysis. Results showed that EAP rats exhibited characteristics of depression, decreased sexual drive, premature ejaculation, and increased threshold of penile erection. Moreover, all these changes were effectively alleviated by celecoxib. Significant increases in prostatic interstitial infiltration by inflammatory cells and in serum IL-1β and TNF-α levels were observed in EAP rats, and these were partially reduced by celecoxib. Additionally, the expression pattern of serotonin system regulators in the hippocampus and spinal cord were altered in EAP model rats, including a decrease in 5-HT levels and an increase in 5-HT_1A receptor levels. In conclusion, autoimmune prostatitis impaired rat sexual function, and this was effectively prevented by anti-inflammatory therapy with celecoxib. Moreover, a serotonin system disorder in the central nervous system was likely mediated via inflammation in EAP rats.

Characterization a model of prostatic diseases and obstructive voiding induced by sex hormone imbalance in the Wistar and Noble rats

Background

Chronic nonbacterial prostatitis associated with lower urinary tract symptoms (LUTS) is a prevalent condition in men. One potential pathophysiological factor is change in sex hormone, testosterone and estrogen, balance. Inflammation, cancer and obstructive voiding has been induced in the Noble rat strain by altering levels of sex hormones. We evaluated if imbalance of sex hormones could induce comparable diseases also in a less estrogen sensitive Wistar strain rats.

Methods

Subcutaneous testosterone (830 µg/day) and 17β-estradiol (83 µg/day) hormone pellets were used in male Wistar and Noble strain rats to induce prostatic diseases. The rats were followed for 13 and 18 weeks. Urodynamical measurements were performed at the end of the study under anesthesia. Prostates were collected for further histological analysis. A panel of cytokines were measured from collected serum samples.

Results

Noble rats exhibited stromal and glandular inflammation after 13 weeks that progressed into more severe forms after 18 weeks of hormonal treatment. CD68-positive macrophages were observed in the stromal areas and inside the inflamed acini. CD163-positive macrophages were present in the stromal compartment but absent inside inflammatory foci or prostate acini. Thirteen-week hormonal treatment in Noble rats induced obstructive voiding, which progressed to urinary retention after 18-weeks treatment. In the Wistar rats 18-week treatment was comparable to the 13-week-treated Noble rats judged by progression of prostatic inflammation, being also evident for obstructive voiding. Incidence of PIN-like lesions and carcinomas in the periurethal area in Noble rats were high (100%) but lower (57%) and with smaller lesions in Wistar rats. Serum cytokines leptin, CCL5, and VEGF concentrations showed a decrease in the hormone-treated rats compared to placebo-treated rats.

Conclusions

Prostate inflammation and obstructive voiding developed also in the Wistar rats but more slowly than in Noble rats. Male non-castrated Wistar strain rats may thus be suitable to use in studies of pathophysiology and hormone-dependent prostate inflammation and obstructive voiding.

Male accessory gland inflammation, infertility, and sexual dysfunctions: a practical approach to diagnosis and therapy

The role of urogenital inflammation in causing infertility and sexual dysfunctions has long been a matter of debate in the international scientific literature. The most recent scientific evidences show that male accessory gland infection/inflammation could alter, with various mechanisms, both conventional and biofunctional sperm parameters, and determine worst reproductive outcome. At the same time, the high prevalence of erectile dysfunction and premature ejaculation in patients with male accessory gland infection/inflammation underlines the close link between these diseases and sexual dysfunctions. The aim of this review was to provide the reader the basis for a correct diagnosis of male accessory gland infection/inflammation and a subsequent appropriate therapeutic approach, particularly in patients with infertility and/or sexual dysfunction.

Chronic Pelvic Pain Development and Prostate Inflammation in Strains of Mice With Different Susceptibility to Experimental Autoimmune Prostatitis

BACKGROUND

Experimental autoimmune prostatitis (EAP) is an autoimmune inflammatory disease of the prostate characterized by peripheral prostate-specific autoimmune responses associated with prostate inflammation. EAP is induced in rodents upon immunization with prostate antigens (PAg) plus adjuvants and shares important clinical and immunological features with the human disease chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

METHODS

EAP was induced in young NOD, C57BL/6, and BALB/c male mice by immunization with PAg plus complete Freund́s adjuvant. Tactile allodynia was assessed using Von Frey fibers as a measure of pelvic pain at baseline and at different time points after immunization. Using conventional histology, immunohistochemistry, FACS analysis, and protein arrays, an interstrain comparative study of prostate cell infiltration and inflammation was performed.

RESULTS

Chronic pelvic pain development was similar between immunized NOD and C57BL/6 mice, although the severity of leukocyte infiltration was greater in the first case. Coversely, minimal prostate cell infiltration was observed in immunized BALB/c mice, who showed no pelvic pain development. Increased numbers of mast cells, mostly degranulated, were detected in prostate samples from NOD and C57BL/6 mice, while lower total counts and resting were observed in BALB/c mice. Prostate tissue from NOD mice revealed markedly increased expression levels of inflammatory cytokines, chemokines, adhesion molecules, vascular endothelial growth factor, and metalloproteinases. Similar results, but to a lesser extent, were observed when analyzing prostate tissue from C57BL/6 mice. On the contrary, the expression of the above mediators was very low in prostate tissue from immunized BALB/c mice, showing significantly slight increments only for CXCL1 and IL4.

CONCLUSIONS

Our results provide new evidence indicating that NOD, C57BL/6, and BALB/c mice develop different degrees of chronic pelvic pain, type, and amount of prostate cell infiltration and secretion of inflammatory mediators. Our results corroborate and support the notion that mice with different genetic background have different susceptibility to EAP induction. Prostate 77:94-104, 2017. © 2016 Wiley Periodicals, Inc.

Hyperestrogenism and low serum testosterone-17β-estradiol ratio are associated with non-bacterial male accessory gland inflammation

This study evaluated the serum concentrations of the main sex hormones in selected patients with non-bacterial male accessory gland infection (MAGI). The results suggest that the mean serum concentrations of 17β-estradiol (method : chemiluminescence) in these patients are significantly higher compared to the controls (55.0 ± 15.0 vs. 26.5 ± 12.0 pg/mL; P <0.05) and the percentage of patients with MAGI and associated hyperestrogenism (according to the laboratory range used in this study) was significantly higher (25.00% vs. 3.00%; P <0.05). Moreover, the percentage of patients with non-bacterial MAGI and associated testosterone deficiency (serum total testosterone <2.49 ng/mL) was significantly higher (18.00% vs. 2.00%; P <0.05). Finally, patients with non-bacterial MAGI showed a significantly lower total testosterone-17β-estradiol ratio compared to the controls (72.7 vs. 173.0; P <0.05). The results of this study, with some limitations (in particular the method applied for the determination of serum concentrations of 17β-estradiol) represent in our opinion, a topic worthy of further investigation for a correct endocrinological characterization of these patients, useful for clinical practice.

Serum quantitative proteomic analysis reveals potential zinc-associated biomarkers for nonbacterial prostatitis

BACKGROUND

Prostatitis is one of the most common urological problems afflicting adult men. The etiology and pathogenesis of nonbacterial prostatitis, which accounts for 90-95% of cases, is largely unknown. As serum proteins often indicate the overall pathologic status of patients, we hypothesized that protein biomarkers of prostatitis might be identified by comparing the serum proteomes of patients with and without nonbacterial prostatitis.

METHODS

All untreated samples were collected from subjects attending the Fangchenggang Area Male Health and Examination Survey (FAMHES). We profiled pooled serum samples from four carefully selected groups of patients (n = 10/group) representing the various categories of nonbacterial prostatitis (IIIa, IIIb, and IV) and matched healthy controls using a mass spectrometry-based 4-plex iTRAQ proteomic approach. More than 160 samples were validated by ELISA.

RESULTS

Overall, 69 proteins were identified. Among them, 42, 52, and 37 proteins were identified with differential expression in Category IIIa, IIIb, and IV prostatitis, respectively. The 19 common proteins were related to immunity and defense, ion binding, transport, and proteolysis. Two zinc-binding proteins, superoxide dismutase 3 (SOD3), and carbonic anhydrase I (CA1), were significantly higher in all types of prostatitis than in the control. A receiver operating characteristic curve estimated sensitivities of 50.4 and 68.1% and specificities of 92.1 and 83.8% for CA1 and SOD3, respectively, in detecting nonbacterial prostatitis. The serum CA1 concentration was inversely correlated to the zinc concentration in expressed-prostatic secretions.

CONCLUSIONS

Our findings suggest that SOD3 and CA1 are potential diagnostic markers of nonbacterial prostatitis, although further large-scale studies are required. The molecular profiles of nonbacterial prostatitis pathogenesis may lay a foundation for discovery of new therapies.

Therapeutic Effects of Oligonol, Acupuncture, and Quantum Light Therapy in Chronic Nonbacterial Prostatitis

This research aimed to compare anti-inflammatory effects of oligonol, acupuncture, and quantum light therapy in rat models of estrogen-induced prostatitis. Adult male Wistar albino rats were grouped as follows: Group I, control (n = 10); Group II, chronic prostatitis (n = 10); Group III, oligonol (n = 10); Group IV, acupuncture (n = 10); Group V, quantum (n = 10); Group VI, oligonol plus quantum (n = 10); Group VII, acupuncture plus oligonol (n = 10); Group VIII, quantum plus acupuncture (n = 10); and Group IX, acupuncture plus quantum plus oligonol (n = 10). Chronic prostatitis (CP) was induced by the administration of 17-beta-estradiol (E2) and dihydrotestosterone (DHT). Oligonol was given for 6 weeks at a dose of 60 mg/day. Acupuncture needles were inserted at CV 3/4 and bilaterally B 32/35 points with 1-hour manual stimulation. Quantum therapy was administered in 5-minute sessions three times weekly for 6 weeks. Lateral lobes of prostates were dissected for histopathologic evaluation. Although all of the treatment modalities tested in this study showed anti-inflammatory effects in the treatment of CP in male rats, a synergistic effect was observed for oligonol plus quantum light combination. Monotherapy with oligonol showed a superior anti-inflammatory efficacy as compared to quantum light and acupuncture monotherapies.

Histopathological classification criteria of rat model of chronic prostatitis/chronic pelvic pain syndrome

OBJECTIVE

A variety of murine models of experimental prostatitis that mimic the phenotype of human chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) have been developed. However, there is still a lack of explicit diagnosis criteria about those animal model. Our study is to establish histopathological classification criteria, which will be conducive to evaluate the animal models.

METHODS

We firstly established a rat model of experimental autoimmune prostatitis that is considered a valid model for CP/CPPS. For modelling, male Sprague-Dawley rats were immunized with autologous prostate tissue homogenate supernatant emulsified with complete Freund's adjuvant by subcutaneous injection into abdominal flank and simultaneously immunized with pertussis-diphtheria-tetanus vaccine by intraperitoneal injection. Three immunizations were administered semimonthly. At the 45th day, animals were killed, and prostate tissues were examined for morphology.

RESULTS

Histologically, the prostate tissues were characterized by lymphoproliferation, atrophy of acini, and chronic inflammatory cells infiltration in the stromal connective tissue around the acini or ducts. Finally, we built histopathological classification criteria incorporating inflammation locations (mesenchyme, glands, periglandular tissues), ranges (focal, multifocal, diffuse), and grades (grade I-IV). To verify the effectiveness and practicability of the histopathological classification criteria, we conducted the treatment study with one of the alpha blockers, tamsulosin.

CONCLUSION

The histopathological classification criteria of rat model of CP/CPPS will serve for further research of the pathogenesis and treatment strategies of the disease.

Protective effect of γ-tocopherol-enriched diet on N-methyl-N-nitrosourea-induced epithelial dysplasia in rat ventral prostate

Despite recent advances in understanding the biological basis of prostate cancer (PCa), the management of this disease remains a challenge. Chemoprotective agents have been used to protect against or eradicate prostate malignancies. Here, we investigated the protective effect of γ-tocopherol on N-methyl-N-nitrosourea (MNU)-induced epithelial dysplasia in the rat ventral prostate (VP). Thirty-two male Wistar rats were divided into four groups (n = 8): control (CT): healthy control animals fed a standard diet; control+γ-tocopherol (CT+γT): healthy control animals without intervention fed a γ-tocopherol-enriched diet (20 mg/kg); N-methyl-N-nitrosourea (MNU): rats that received a single dose of MNU (30 mg/kg) plus testosterone propionate (100 mg/kg) and were fed a standard diet; and MNU+γ-tocopherol (MNU+γT): rats that received the same treatment of MNU plus testosterone and were fed with a γ-tocopherol-enriched diet (20 mg/kg). After 4 months, the VPs were excised to evaluate morphology, cell proliferation and apoptosis, as well as cyclooxygenase-2 (Cox-2), glutathione-S-transferase-pi (GST-pi) and androgen receptor (AR) protein expression, and matrix metalloproteinase-9 (MMP-9) activity. An increase in the incidence of epithelial dysplasias, such as stratified epithelial hyperplasia and squamous metaplasia, in the MNU group was accompanied by augmented cell proliferation, GST-pi and Cox-2 immunoexpression and pro-MMP-9 activity. Stromal thickening and inflammatory foci were also observed. The administration of a γ-tocopherol-enriched diet significantly attenuated the adverse effects of MNU in the VP. The incidence of epithelial dysplasia decreased, along with the cell proliferation index, GST-pi and Cox-2 immunoexpression. The gelatinolytic activity of pro-MMP-9 returned to the levels observed for the CT group. These results suggest that γ-tocopherol acts as a protective agent against MNU-induced prostatic disorders in the rat ventral prostate.

Diagnostic and prognostic role of matrix metalloproteases in cancer

BACKGROUND

Matrix metalloproteases (MMPs) are key players in the progression and metastasis of cancer. MMPs cleave extracellular matrix components and in this way promote tumor growth, invasion and vascularization. MMPs also affect tumor progression by regulating availability and activity of growth factors, inflammatory cytokines and chemokines. Accordingly, several MMPs have been found to serve as prognostic indicators in solid tumors. Usually the increased levels of MMPs in patients' tumor tissue or serum/plasma are associated with poor outcome. Interestingly, recent results show that certain MMPs also serve as tumor suppressors.

OBJECTIVE

This review discusses the latest view on MMPs as diagnostic and prognostic indicators in cancer patients.

METHODS

Studies with clinical samples of 70 or more patients are included in particular. In addition, the possible roles of MMPs in future molecular diagnostics and in the evaluation of therapeutic responses are discussed.

CONCLUSION

MMP-9 in particular has shown prognostic value in various types of tumor, and its measurement in circulation, urine or tumor tissue might help in clinical surveillance of otherwise problematic patient cases. There is upcoming new knowledge on MMPs in therapy response evaluation, in which MMPs might be useful together with CT scans and other clinically more established prognostic factors. Certain MMPs have a dual role in terms of cancer-modulating properties and thus it is essential to evaluate their expression and function in tumor cells and host environment to select validated therapy targets but spare MMP antitargets.

Effects of 17β-estradiol on human corneal wound healing in vitro

PURPOSE

To investigate the effect of 17β-estradiol on corneal wound healing, particularly on epithelial mitosis and migration.

METHODS

Immortalized human corneal epithelial cells (HCECs) were cultured in media with different concentrations of 17β-estradiol (10, 50, 100, and 200 pg/mL), Dulbecco modified Eagle medium: Nutrient Mixture F-12 (negative control), and serum-containing Dulbecco modified Eagle medium: Nutrient Mixture F-12 (positive control). After 6 or 24 hours of hormone treatment, to evaluate the migratory potential of 17β-estradiol, wound healing assays were conducted via the manual scraping of HCECs and western blot analysis of fibronectin and matrix metalloproteinase 9 (MMP9). The proliferative potential of 17β-estradiol was evaluated via a proliferation assay using western blot analysis for proliferating cell nuclear antigen. In addition, epidermal growth factor (EGF) was measured by reverse transcription-polymerase chain reaction, and for the inhibition of epidermal growth factor receptor (EGFR)-mediated signal transduction, a wound healing assay was conducted after HCECs cultured with EGFR small interfering RNA were stimulated with 100 pg/mL 17β-estradiol.

RESULTS

Wound healing assay rates were enhanced as 17β-estradiol increased, with statistically significant changes seen in 50, 100, and 200 pg/mL 17β-estradiol-treated and positive control cells, compared with negative control cells (P < 0.05, in each group). Western blot analysis revealed that the expression of the MMP9 gene was upregulated by 17β-estradiol, and the expression of the fibronectin gene was downregulated by 17β-estradiol. The mitosis assay via western blot analysis showed that the expression cell cycle-associated protein, proliferating cell nuclear antigen, increased gradually as a result of 17β-estradiol treatment. Reverse transcription-polymerase chain reaction showed that EGF was upregulated by 17β-estradiol, and the EGFR small interfering RNA did not totally block the wound healing of the 17β-estradiol-treated cells but statistically significantly reduced the wound healing rate (P = 0.031).

CONCLUSIONS

17β-Estradiol facilitated the maintenance of the beneficial effect on corneal epithelial migration and proliferation, and the promoting effect of 17β-estradiol is partially related to increased EGF in vitro.

Preventive effects of oligomerized polyphenol on estradiol-induced prostatitis in rats

PURPOSE

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS, NIH category III) accounts for 90-95% of prostatitis cases. However, standard treatment has not yet been established. It is known that polyphenols have an inhibitory effect on inflammation by their antioxidative capacity, and oligonol, a polyphenol derivative, has much higher bioavailability and bioactivity than common polyphenols. We investigated the anti-inflammatory effects and mechanisms of oligonol in estradiol-induced prostatitis rat models.

MATERIALS AND METHODS

Prostatitis was induced by 17 beta-estradiol (E2) and dihydrotestosterone (DHT) in Wistar male rats (n = 20). Ten rats were placed in the oligonol-treated group and 10 in the E2 + DHT-treated group. The other 10 rats were also included as normal control group. Oligonol (60 mg/kg/day) was administered via gavage tube for 4 weeks. Superoxide dismutase (SOD), glutathione peroxidase (GPx), and tumor necrosis factor-alpha (TNF-alpha) were quantified, and phosphorylation of IkappaBa and histological changes were also evaluated in prostatic tissue.

RESULTS

The SOD and GPx activity showed tendencies to increase in the oligonol-treated group compared to the normal control group. TNF-alpha expression was slightly reduced in the oligonol-treated group. Western blotting demonstrated that phosphorylation of IkappaBa in the oligonol-treated group was significantly lower than in the normal control group. The E2 + DHT-treated group revealed severe atrophy of acinar epithelial cells and infiltration of leukocytes and lymphocytes in the prostate, however, the oligonol-treated group showed overall reduction in inflammatory features.

CONCLUSION

This study demonstrates that oligonol improves estradiol-induced non-bacterial prostatitis by regulating phosphorylation of IkappaBa. These findings suggest that oligonol has a beneficial effect on prevention and treatment of CP/CPPS.

Influence of inflammation and aging on macrophage inhibitory cytokine-1 gene expression in rat ventral prostate

OBJECTIVES

We have previously reported that the macrophage inhibitory cytokine-1 (MIC-1) gene is downregulated in human symptomatic benign prostatic hyperplasia. The aim of this study was to investigate the histologic changes and MIC-1 gene expression in the prostate of young nonbacterial prostatitis model (Y-NBP) and aging rats.

METHODS

A total of 35 Wistar male rats, 13 weeks old, were castrated and subjected to (a) castration alone for 14 days, (b) Y-NBP-14d (0.25 mg/2 mL/kg beta-estradiol injection for 14 days), or (c) Y-NBP-30d (beta-estradiol injection for 30 days). A total of 5 male rats, 10 months old, were also analyzed. We used 21 male rats, 13 weeks old, who had undergone sham surgery as the controls. The ventral lobes of the prostate were histologically examined with Masson's trichrome staining or immunostaining using an anti-macrophage antibody. The MIC-1 mRNA levels were quantitatively assessed using real-time reverse transcriptase-polymerase chain reaction.

RESULTS

The MIC-1 gene mRNA levels in the castration alone, Y-NBP-14d, and Y-NBP-30d rat prostates were greater than those in the control rats (P < .005). In contrast, those of the 10-month-old rats were lower than those of the controls (P = .0093). The mean stroma-to-epithelium ratio in the Y-NBP-30d rats, 10-month-old rats, and 13-week-old controls was 1.28, 0.26, and 0.10, respectively (Y-NBP-30d vs 10-month-old rats, P = .0008; 10-month-old vs 13-week-old rats, P = .001). The number of infiltrating macrophages in the Y-NBP-14d, Y-NBP-30d, and 10-month-old rats was greater than that of the 13-week-old controls (P < .001).

CONCLUSIONS

Castration causes induction of MIC-1 gene expression. Estradiol treatment has little effect on MIC-1 gene expression but causes a significant increase in the stroma-to-epithelium ratio. The aging rat prostate is more similar to human benign prostatic hyperplasia than is the Y-NBP model in light of MIC-1 gene expression and histologic changes.

ZapA, a virulence factor in a rat model of Proteus mirabilis-induced acute and chronic prostatitis

Our knowledge of pathogenesis has benefited from a better understanding of the roles of specific virulence factors in disease. To determine the role of the virulence factor ZapA, a 54-kDa metalloproteinase of Proteus mirabilis, in prostatitis, rats were infected with either wild-type (WT) P. mirabilis or its isogenic ZapA(-) mutant KW360. The WT produced both acute and chronic prostatitis showing the typical histological progressions that are the hallmarks of these diseases. Infection with the ZapA(-) mutant, however, resulted in reduced levels of acute prostatitis, as determined from lower levels of tissue damage, bacterial colonization, and inflammation. Further, the ZapA(-) mutant failed to establish a chronic infection, in that bacteria were cleared from the prostate, inflammation was resolved, and tissue was seen to be healing. Clearance from the prostate was not the result of a reduced capacity of the ZapA(-) mutant to form biofilms in vitro. These finding clearly define ZapA as an important virulence factor in both acute and chronic bacterial prostatitis.

The effect of dietary supplementation with limonene or myo-inositol on the induction of neoplasia and matrix metalloproteinase and plasminogen activator activities in accessory sex organs of male Lobund-Wistar rats

Prostate cancer, the most prevalent non-cutaneous cancer in men, is associated with increased age. This suggests that dietary chemopreventive measures could be effective in delaying the onset or decreasing the severity of the disease. We utilized the Lobund-Wistar rat nitrosomethylurea induced, testosterone promoted (NMU-T) model of male sex accessory gland cancer to test the potential chemopreventive effects of myo-inositol and limonene on tumor incidence and associated protease activities. Tumors were found to arise in the seminal vesicles and dorsal and anterior prostate lobes. There were also some tumors that appeared to arise in both the seminal vesicles and anterior prostate, and in some cases the tissue of origin was not clear. The distribution of tumors as to site of origin in limonene or myo-inositol treated animals did not vary from that of the starch fed control animals, and the number of animals presenting with metastases did not vary significantly between treatment groups. There was a statistically significant delay in onset of tumors in myo-inositol, but not limonene fed rats, at 10 months post-induction of carcinogenesis; however, at 12 and 15 months this was not significant. The ventral prostate and seminal vesicles expressed pro-MMP-2 and plasminogen activator (PA) activities. Based on sensitivity to amiloride, the PA activities were predominately urokinase (uPA) in the ventral prostate and a mixture of tissue-type activator (tPA) and uPA in the seminal vesicles of non-treated rats. Sex accessory gland tumors, and metastases, expressed increased levels PA and pro- and active forms of MMP-2 and -9. The PA activities of the tumors were a mixture of uPA and tPA. There was no difference in the levels of these protease activities based on the tissue of tumor origin, nor in tumor vs metastasis. These studies indicate that MMP and PA activities play a role in sex accessory gland tumor biology and that dietary supplementation with myo-inositol can delay but not ultimately prevent the development of such tumors.

Epithelial expression of TIMP-1 does not alter sensitivity to bleomycin-induced lung injury in C57BL/6 mice

Matrix metalloproteinases (MMPs) are mediators of lung injury, and their activity has been associated with the development of pulmonary fibrosis. To understand how MMPs regulate the development of pulmonary fibrosis, we examined MMP expression in two strains of mice with differing sensitivities to the fibrosis-inducing drug bleomycin. After a single intratracheal injection of the drug, bleomycin-sensitive C57BL/6 mice showed increased expression for MMPs (-2, -7, -9, -13) at both 7 and 14 days posttreatment compared with the bleomycin-resistant BALB/c strain. In addition, TIMP-1, an endogenous inhibitor of MMPs, was upregulated in the lungs of C57BL/6 mice but not BALB/c mice. We designed two strategies to decrease MMP expression to potentially decrease sensitivity of C57BL/6 mice: 1) we engineered C57BL/6 mice that overexpressed TIMP-1 in their lungs via surfactant protein C (SP-C) promoter; and 2) we inhibited expression of MMPs independent of TIMP-1 by knocking out metallothionein (MT), a critical zinc binding protein. SP-C-TIMP-1 mice reduced MMP expression in response to bleomycin. However, they were equally sensitive to bleomycin as their wild-type counterparts, displaying similar levels of hydroxyproline in the lung tissue. MT null mice displayed decreased lung activity of MMPs with no change in TIMP-1. Nonetheless, there was no difference between the MT null and wild-type control littermates with regards to any of the lung injury parameters measured. We conclude that although TIMP-1 expression is differentially regulated in fibrosis-sensitive and fibrosis-resistant strains, epithelial overexpression of TIMP-1 does not appear to substantially alter fibrotic lung disease in mice.

Autoimmune prostatitis: state of the art

The prostate is one of the main male sex accessory glands and the target of many pathological conditions affecting men of all ages. Pathological conditions of the prostate gland range from infections, chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) of a still unknown aetiology to benign hyperplasia and cancer. CP/CPPS is one of the most prevalent diseases in the urologic clinic and affects men younger than 50 years old. A significant advance in the understanding of CP/CPPS was made when an autoimmune response against prostate antigens was revealed in a considerable number of patients. During the last 30 years, extensive work has been done regarding the development and characterization of different rodent models of experimental autoimmune prostatitis (EAP). It has been demonstrated that tolerance to prostate antigens can be disrupted in some strains of rats and mice and cellular and humoral responses to prostate antigens are elicited. A Th1 pattern has been described and the cellular response seems to be the major pathogenic mechanism involved. Immune cells infiltrate the gland and induce prostate lesions. The genetic background and hormonal imbalance are factors that could contribute to the onset of the disease in susceptible young males. Moreover, spontaneous autoimmune prostatitis could also occur with advanced age in susceptible strains. In this review, we summarize the current knowledge regarding rodent models of EAP and the immunological alterations present in CP/CPPS patients. We also discuss the reliability of these experimental approaches as genuine tools for the study of human disease.

The complex role of estrogens in inflammation

There is still an unresolved paradox with respect to the immunomodulating role of estrogens. On one side, we recognize inhibition of bone resorption and suppression of inflammation in several animal models of chronic inflammatory diseases. On the other hand, we realize the immunosupportive role of estrogens in trauma/sepsis and the proinflammatory effects in some chronic autoimmune diseases in humans. This review examines possible causes for this paradox. This review delineates how the effects of estrogens are dependent on criteria such as: 1) the immune stimulus (foreign antigens or autoantigens) and subsequent antigen-specific immune responses (e.g., T cell inhibited by estrogens vs. activation of B cell); 2) the cell types involved during different phases of the disease; 3) the target organ with its specific microenvironment; 4) timing of 17beta-estradiol administration in relation to the disease course (and the reproductive status of a woman); 5) the concentration of estrogens; 6) the variability in expression of estrogen receptor alpha and beta depending on the microenvironment and the cell type; and 7) intracellular metabolism of estrogens leading to important biologically active metabolites with quite different anti- and proinflammatory function. Also mentioned are systemic supersystems such as the hypothalamic-pituitary-adrenal axis, the sensory nervous system, and the sympathetic nervous system and how they are influenced by estrogens. This review reinforces the concept that estrogens have antiinflammatory but also proinflammatory roles depending on above-mentioned criteria. It also explains that a uniform concept as to the action of estrogens cannot be found for all inflammatory diseases due to the enormous variable responses of immune and repair systems.

Experimental rodent models of prostatitis: limitations and potential

Prostatitis is a polyetiological inflammation of the prostate gland in men characterized by pelvic pain, irritative voiding symptoms, and sexual dysfunction. Histologically prostatitis is characterized by poly- and mononuclear cell infiltrates (neutrophils, lymphocytes, macrophages and plasma cells) in the stromal connective tissue around the acini or ducts. Prostatitis is an important worldwide health problem in men. The pathogenesis and diagnostic criteria for the condition are obscure, with the result that the development of management programs for this condition has been hindered. Animal model(s) might be useful in elucidating mechanisms involved in the molecular pathogenesis of chronic nonbacterial prostatitis and chronic pelvic pain syndrome. Given that prostatitis might have a multifactorial etiology, several animal models with unique features may prove helpful. This review examines a number of experimental rodent models of prostatitis and evaluates their advantages and limitations.

Intraprostatic Lymphocyte Profiles in Aged Wistar Rats With Estradiol Induced Prostate Inflammation

PURPOSE

We report LS phenotypes in aged Wistar rats (Charles Rivers, Wilmington, Massachusetts) with EPI.

MATERIALS AND METHODS

EPI was induced in 36 to 40-week-old male rats by castration with subcutaneous injections of 17beta-estradiol (0.25 mg/kg daily) plus dihydrotestosterone propionate (2.5 mg/kg daily) in sesame oil for 30 days. Controls were sham castrated, aged rats that were injected with sesame oil. Prostate, spleen and blood LSs in aged and young (10 to 12-week-old) rats were identified by flow cytometry in a cluster of differentiation system.

RESULTS

All prostates in 6, 17beta-estradiol plus dihydrotestosterone propionate treated rats and in 3 of 7 controls (43%) showed inflammation foci. All studied LSs in Aged-SPIs and Aged-EPIs were similar. Blood LSs in Aged-SPIs, Aged-EPIs, Aged-NPIs and Youngs showed no differences. Levels of lymphocytes bearing the natural killer marker were decreased, and levels of total T and CD4(+) T cells were increased in prostates with age. Intraprostatic and splenic levels of CD4(+) natural killer T cells were down-regulated significantly in Aged-SPIs and Aged-EPIs compared to those in Aged-NPIs and Youngs. Levels of CD45RC(+)CD4(+)alphabetaTCR(+) T cells were decreased 2-fold in the spleen and up-regulated 2-fold in the prostate of Aged-SPIs and Aged-EPIs compared to those in Aged-NPIs and Youngs.

CONCLUSIONS

Similar LS features in Aged-SPIs and Aged-EPIs may indicate that the EPI model is appropriate for studies of the immune aspects of prostate inflammation. Imbalance between suppressive CD4(+) natural killer T cells and autoreactive CD45RC(+)CD4(+)alphabetaTCR(+) T cells in Aged-SPIs and Aged-EPIs may suggest their role in prostate inflammation in this model.

Estrogen Stimulation of Proinflammatory Cytokine and Matrix Metalloproteinase Gene Expression in Human Corneal Epithelial Cells

PURPOSE

Researchers have proposed that the secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs) by corneal epithelial cells contributes to the development of ocular surface inflammation in dry eye syndromes. We hypothesize that this cytokine and MMP production is promoted by estrogens, given that dry eye syndromes occur predominantly in women and estrogen therapy is associated with an increase in dry eye signs and symptoms. Moreover, corneal epithelial cells contain estrogen receptors and estrogens are known to influence other aspects of corneal immunity. The purpose of this study was to test our hypothesis.

METHODS

Immortalized human corneal epithelial cells were exposed to vehicle, lipopolysaccharide (LPS), or varying concentrations of 17beta-estradiol. After 6 or 24 hours of hormone treatment, cells were harvested and processed for total RNA isolation, cDNA synthesis, and the analysis of cytokine and MMP mRNA levels by multiplex and real-time PCR methods.

RESULTS

Our results demonstrate that 17beta-estradiol upregulates the expression of proinflammatory cytokine and MMP genes in human corneal epithelial cells. Estrogen administration significantly increased the levels of IL-1beta, IL-6, IL-8, and GM-CSF mRNAs, as well as MMP 2, 7, and 9 mRNAs, compared with those of placebo-treated controls. This estrogen effect was found after 6 and/or 24 hours of hormone treatment. An analogous stimulation of gene expression was observed following cellular exposure to LPS.

CONCLUSIONS

Our findings show that 17beta-estradiol increases the expression of inflammatory genes in human corneal epithelial cells. This hormone action may play an etiologic role in the ocular surface inflammation of dry eye.