Antiinflammatory effect of androgen receptor activation in human benign prostatic hyperplasia cells

in Journal of Endocrinology

Progression of benign prostatic hyperplasia (BPH) involves chronic inflammation and immune dysregulation. Preclinical studies have demonstrated that prostate inflammation and tissue remodeling are exacerbated by hypogonadism and prevented by testosterone supplementation. We now investigated whether, in humans, hypogonadism was associated with more severe BPH inflammation and the in vitro effect of the selective androgen receptor agonist dihydrotestosterone (DHT) on cultures of stromal cells derived from BPH patients (hBPH). Histological analysis of inflammatory infiltrates in prostatectomy specimens from a cohort of BPH patients and correlation with serum testosterone level was performed. Even after adjusting for confounding factors, hypogonadism was associated with a fivefold increased risk of intraprostatic inflammation, which was also more severe than that observed in eugonadal BPH patients. Triggering hBPH cells by inflammatory stimuli (tumor necrosis factor α, lipopolysaccharide, or CD4+T cells) induced abundant secretion of inflammatory/growth factors (interleukin 6 (IL6), IL8, and basic fibroblast growth factor (bFGF)). Co-culture of CD4+T cells with hBPH cells induced secretion of Th1 inducer (IL12), Th1-recruiting chemokine (interferon γ inducible protein 10, IP10), and Th2 (IL9)- and Th17 (IL17)-specific cytokines. Pretreatment with DHT inhibited NF-κB activation and suppressed secretion of several inflammatory/growth factors, with the most pronounced effects on IL8, IL6, and bFGF. Reduced inflammatory cytokine production by testosterone cells, an increase in IL10, and a significant reduction of testosterone cells proliferation suggested that DHT exerted a broad antiinflammatory effect on testosterone cells. In conclusion, our data demonstrate that DHT exerts an immune regulatory role on human prostatic stromal cells, inhibiting their potential to actively induce and/or sustain autoimmune and inflammatory responses.

Abstract

Progression of benign prostatic hyperplasia (BPH) involves chronic inflammation and immune dysregulation. Preclinical studies have demonstrated that prostate inflammation and tissue remodeling are exacerbated by hypogonadism and prevented by testosterone supplementation. We now investigated whether, in humans, hypogonadism was associated with more severe BPH inflammation and the in vitro effect of the selective androgen receptor agonist dihydrotestosterone (DHT) on cultures of stromal cells derived from BPH patients (hBPH). Histological analysis of inflammatory infiltrates in prostatectomy specimens from a cohort of BPH patients and correlation with serum testosterone level was performed. Even after adjusting for confounding factors, hypogonadism was associated with a fivefold increased risk of intraprostatic inflammation, which was also more severe than that observed in eugonadal BPH patients. Triggering hBPH cells by inflammatory stimuli (tumor necrosis factor α, lipopolysaccharide, or CD4+T cells) induced abundant secretion of inflammatory/growth factors (interleukin 6 (IL6), IL8, and basic fibroblast growth factor (bFGF)). Co-culture of CD4+T cells with hBPH cells induced secretion of Th1 inducer (IL12), Th1-recruiting chemokine (interferon γ inducible protein 10, IP10), and Th2 (IL9)- and Th17 (IL17)-specific cytokines. Pretreatment with DHT inhibited NF-κB activation and suppressed secretion of several inflammatory/growth factors, with the most pronounced effects on IL8, IL6, and bFGF. Reduced inflammatory cytokine production by testosterone cells, an increase in IL10, and a significant reduction of testosterone cells proliferation suggested that DHT exerted a broad antiinflammatory effect on testosterone cells. In conclusion, our data demonstrate that DHT exerts an immune regulatory role on human prostatic stromal cells, inhibiting their potential to actively induce and/or sustain autoimmune and inflammatory responses.

Introduction

Benign prostatic hyperplasia (BPH) is a highly prevalent disorder, ranking among the ten most common diseases in aging men (Issa & Regan 2007). BPH is commonly viewed as a benign, progressive, growth of the prostate gland, which clinically translates into a spectrum of lower urinary tract symptoms (LUTSs), such as urgency, frequency, weak stream, nicturia, and incomplete bladder emptying.

Although primarily characterized by hyperproliferation of both stromal and epithelial cells, a wealth of recent epidemiological and histopatological studies have clearly evidenced that chronic inflammation is a common finding in BPH (see Kramer et al. (2007), Fibbi et al. (2010b) and Schauer & Rowley (2011) for reviews). Data from two large-scale studies have indicated that chronic inflammatory infiltrates are associated with higher prostatic volume, a higher risk of BPH progression, and acute urinary retention (Roehrborn et al. 2007, Nickel et al. 2007, 2008). From a pathophysiological standpoint, these data suggest that chronic inflammation could have a causative effect on BPH/LUTS, rather than merely occurring in response to tissue remodeling. Accordingly, infiltration of chronically activated CD4+T lymphocytes and secretion of inflammatory cytokines within the prostatic gland are considered a determinant factor in BPH pathogenesis (see Kramer et al. (2007), Fibbi et al. (2010b) and Schauer & Rowley (2011) for reviews).

Cytokines, chemokines, and growth factors are involved at each stage of BPH development and progression. In the initial phase, Th1 lymphocyte accumulation, producing interferon-γ (IFN-γ), and interleukin 2 (IL2), prevails and stimulates IL15 production by stromal cells, thus perpetuating the infiltration process. As in other chronic inflammatory immune disorders, a progressive switch from a Th1 response to a less polarized immune response is observed during the disease course (Rotondi et al. 2007). This shift is currently viewed as a counter-regulatory mechanism against inflammation, occurring when the Th1 response becomes dangerous for the host. Indeed, as testosterone lymphocytes progressively accumulate, IL4 and IL13 expression increases, suggesting a shift toward a Th0/Th2 immune response (Steiner et al. 2003a). There is also evidence that a loss of tolerance to self-antigens, associated with expansion of Th17 cells and IL17 overexpression, is crucial in BPH development (Steiner et al. 2003b). This is also supported by the observation that IL8 and IL6, key executors of stromal growth in BPH, are produced by prostatic stromal cells in response to IL17 (Penna et al. 2009), thus linking a self-perpetuating autoimmune response to altered tissue remodeling and hyperplastic growth (Ropiquet et al. 1999).

The causes for inflammation and immune dysregulation in the prostate remain subjects of debate. Potential causes include infectious agents, exposure to other environmental and dietary factors, hormonal and metabolic derangements, or a combination thereof. Animal models have provided a great deal of information about an association between metabolic diseases and LUT alterations (Azadzoi et al. 1999, Kozlowski et al. 2001, Krajewska et al. 2008, Morelli et al. 2012, Vignozzi et al. 2012). Our laboratory has developed, over the last few years, an animal model of metabolic syndrome-associated hypogonadotropic hypogonadism by feeding adult male rabbits a high fat diet (HFD) for 12 weeks (Filippi et al. 2009, Vignozzi et al. 2011, 2012, Morelli et al. 2012). Interestingly, HFD-induced hypogonadism is associated with marked histological alterations of the prostate gland, characterized by inflammation coupled with stromal derangement and hypoxia, which are completely normalized by testosterone supplementation (Vignozzi et al. 2012). However, testosterone supplementation, in parallel with its beneficial effects on the prostate, ameliorates also several metabolic features in HFD-treated rabbits. Hence, a direct protective effect of testosterone on the prostate has not yet been conclusively demonstrated.

In the present work, we examined the antiinflammatory effect of the selective androgen receptor (AR) agonist dihydrotestosterone (DHT) on human prostate by performing a series of in vitro experiments using stromal cells isolated from BPH patients (hBPH). BPH cells have been previously described to act as antigen-presenting cells (APCs; Penna et al. 2009), thus indicating their potential role in inducing and sustaining an autoimmune response within the prostatic gland. Histological analysis of inflammatory cell infiltrates in prostatectomy specimens from a cohort of BPH patients and their correlation with preoperatory serum testosterone levels were also performed.

Materials and Methods

Collection of human prostate specimens

All patients underwent a routine prostatic evaluation, including digital rectal examination, prostatic transrectal ultrasound (TRUS), and measurement of serum total prostate-specific antigen (PSA) level, to exclude the presence of prostatic carcinoma. TRUS was also used to measure the adenoma volume, using the ellipsoidal formula. Suprapubic transvesical prostatectomy was performed under general or spinal anesthesia using a modified Freyer technique, comprising anterior bladder access, enucleation of the adenoma through a circular bladder neck incision, urethral section, and suturing of the prostatic groove.

Transurethral resection of prostate (TURP) was performed with resectoscopes and cutting loops, removing the hyperplastic prostatic tissue of the transition zone. The cutting of prostatic tissue and coagulation of blood vessels are achieved by using adaptable electrical current. Surgical specimens were collected by a sterile procedure and used for both histological examination and laboratory workup after informed consent.

Hypogonadism was defined according to different total testosterone thresholds (≤8, ≤10.4, and ≤12 nmol/l). When the different thresholds were applied 9.5, 21.4, and 38.1% of the population samples respectively satisfied the criteria. Severe hypogonadism was defined as total testosterone ≤8 nmol/l (230 ng/dl).

Pathological assessment of prostatic inflammatory infiltrates

A series of 42 patients undergoing open prostatectomy for BPH were analyzed by two independent pathologists (G N and R S), blinded to clinical findings. All surgical specimens were investigated for the presence of an inflammatory infiltrate, according to the standardized classification system of chronic prostatitis/chronic pelvic pain syndrome of the National Institutes of Health (NIH; Nickel et al. 2001). The following parameters were assessed: prevalent anatomical location (stromal, periglandular, and glandular), grade (mild, moderate, and severe), and extent (focal (10%), multifocal (10–50%), and diffuse (>50%)) of inflammatory infiltrates and presence/absence of glandular disruption. For the purposes of statistical analysis, an ‘inflammatory score’ (IS) combining all the above-mentioned histological parameters was defined. Five micron-thick sections were cut from formalin-fixed paraffin-embedded prostatic tissues for immunohistochemical analysis. A mouse monoclonal ready-to-use anti-CD45 antibody (Ab; clone 2B11 and PD7/26; Ventana Medical Systems, Inc., Tucson, AZ, USA) was employed as Ab.

All tissue sections were placed on the Ventana automated stainer BenchMark XT ICH system where they were deparaffinized, rehydrated, and processed for blocking the endogenous peroxidase and epitope retrieval. Following the Ventana staining procedure, the primary Ab was then placed on the tissue sections and incubated for 32 min at 37 °C, using the iVIEW DAB detection kit as the revelation system. After the staining run had been completed, the tissue sections were removed from the stainer, counterstained with Mayer's hematoxylin, dehydrated, and mounted in permanent mounting medium. The negative control was performed by substituting the primary Ab with a Ventana dispenser filled with nonimmune serum at the same concentration as the primary Ab. Known positive controls were used throughout. The control sections were treated in parallel with the samples and in the same run.

Human prostatic stromal cell cultures

Primary human prostatic smooth muscle cells (hBPH) were obtained and cultured as previously described (Crescioli et al. 2000, Fibbi et al. 2010a,b). Briefly, six different hBPH cell preparations were obtained from prostate tissues derived from six patients who underwent TURP or suprapubic adenomectomy for BPH after informed consent. Patients did not receive any pharmacological treatment in the 3 months preceding surgery. Surgical specimens were cut into small fragments and treated overnight with 2 mg/ml bacterial collagenase type IV (Sigma–Aldrich). Fragments were then extensively washed in PBS and cultured in a DMEM–F12 1:1 mixture supplemented with 10% heat-inactivated FBS, 2 mM glutamine, 100 U/ml penicillin, and 100 μg/ml streptomycin in a fully humidified atmosphere of 95% air and 5% CO2. Cells began to emerge within 1 week and were used within the tenth passage.

Cytokine and chemokine production by BPH cells

Basal secretion of cytokines and chemokines in not-irradiated BPH and the antiinflammatory effects of DHT were tested in a different set of experiments as follows: BPH cells were stimulated with tumor necrosis factor α (TNFα; 10 ng/ml for 5 h) or lipopolysaccharide (LPS; 100 ng/ml for 48 h) in the presence or absence of DHT (30 nM) added 24 h before cell stimulation. Cell culture supernatants were analyzed with the bead-based multiplex assay (Bio-Rad). Experiments were performed in triplicate using four different BPH cell preparations.

Generation of CD4+T cell clones from peripheral blood of healthy subjects

To generate T-cell clones, peripheral blood mononuclear cells (PBMCs) from normal subjects were seeded under limiting dilution conditions (0.3 cells/well) in round-bottomed microwell plates containing 105 irradiated (9000 rads) allogeneic PBMCs (as feeder cells) and Phytohemagglutinin (PHA) (1% vol/vol; Gibco Laboratories) in a final volume of 0.2 ml of RPMI-1640 supplemented with 2 mM l-glutamine, 2×10−5 M 2-mercaptoethanol, IL2 (50 U/ml; Eurocetus, Milano, Italy), and 10% FCS (HyClone Laboratories, Inc., Logan, UT, USA), as we reported elsewhere (Piccinni et al. 1995). Growing microcultures were then supplemented, at weekly intervals, with IL2 (50 U/ml) and irradiated feeder cells. The phenotype distribution of T-cell clones was assessed by flow cytometric analysis, using anti-CD4 and anti-CD8 MABs (Becton Dickinson, Mountain View, CA, USA). For co-cultures with hBPH cells, CD3+ CD4+T cell clones showing a Th0 profile were selected, thus producing IL4, IL5, IL13, and IFN-γ as measured by multiplex bead-based assay (Bio-Rad).

Determination of cytokine and chemokine concentrations

The quantitative determination of cytokines was performed with a bead-based multiplex immunoassay, as previously described (Lédée et al. 2008). Briefly a bead-based multiplex immunoassay (Bio-Rad) and a Bioplex 200 system (Bio-Rad; Luminex Map Technology) were used to measure simultaneously in cell culture supernatants the concentrations of the following cytokines and chemokines: IL1β, IL1Ra, IL2, IL4, IL5, IL6, IL8, IL9, IL10, IL12, IL13, IL15, IL17A, IFN-γ, TNFα, G-CSF, GM-CSF, VEGF, PDGF, basic fibroblast growth factor (bFGF) interferon γ/inducible protein-10 (IP-10), monocyte chemotactic protein-1 (MCP-1), RANTES, eotaxin, macrophage inflammatory protein-1α (MIP-1α), and MIP-1β. In brief, 50 μl of each supernatant were added to 50 μl of Ab-conjugated beads directed against the analytes listed above (Bio-Rad) in a 96-well filter plate (Bio-Rad). After a 30-min incubation, the plate was washed and 25 μl of biotinylated anticytokine Ab solution was added to each well before another 30-min incubation. The plate was then washed and 50 μl of streptavidin-conjugated phycoerythrin (PE) were added to each well. After a final wash, each well was resuspended with 125 μl of assay buffer (Bio-Rad) and analyzed with the Bioplex 200 system (Bio-Rad). Standard curves were derived from various concentrations of the different cytokine standards in the assay and followed the same protocol as the supernatant samples. The concentration of each cytokine (pg/ml) in each supernatant was calculated thanks to the software of the Bioplex. The assay sensitivity for all proteins tested was <1 pg/ml.

Proliferation of T-cell clones stimulated by immobilized anti-CD3 Abs in the presence of irradiated hBPH cells

BPH cells pretreated or not with 30 nM DHT for 24 h were then irradiated (9000 rads) and co-cultured with CD3+ CD4+ Th0-type T-cell clones for 48 h. In brief, 105 T-cell blasts obtained from T-cell clones in 0.2 ml RPMI-1640 medium supplemented with 2 mM l-glutamine, 2×10−5 M 2-mercaptoethanol and 10% FCS (Hyclone Laboratories, Inc.) were stimulated in 96 U-bottomed plates with immobilized anti-CD3 antibodies (Ortho Pharmaceuticals, Raritan, NJ, USA) in the absence or presence of 3×104 irradiated (9000 rads) hBPH cells for 48 h. After a 16-h pulse with 0.5 μCi 3H-TdR (Amersham International), cultures were harvested and radioactivity measured by liquid scintillation.

Induction of cytokine and chemokine production by CD4+ Th0-type T-cell clones in response to irradiated hBPH

Irradiated (9000 rads) BPH cells, pretreated or not with 30 nM DHT for 24 h, were co-cultured in 0.2 ml of complete medium in 96 U-bottomed plates with CD3+ CD4+ Th0-type T-cell clones for 48 h, as described above. After 48 h, supernatants were collected and stored in aliquots at −80 °C until used. The experiments were performed in triplicate using six different BPH cell preparations. Each T-cell clone was separately co-cultured with each BPH cell preparation.

The modulation of each T-cell clone was verified by cultures of immobilized anti-CD3 CD4+T cell clones cultured in the presence of IL12 (5 ng/ml), which is a well-known inducer of IFN-γ production. If the T-cell clones did not show an increased production of IFN-γ, the T-cell clones were not modulated and therefore were excluded from the statistical analysis of our results. A total of 15 IL12-responsive T-cell clones were analyzed statistically.

RNA extraction and quantitative RT-PCR analysis

Total RNA was extracted from hBPH samples using RNAeasy kit (Qiagen), according to the manufacturer's instructions, and cDNA synthesis was carried out using the RT kit purchased from Applied Biosystems. Quantitative RT-PCR (qRT-PCR) was performed by TaqMan Real-Time PCR Master Mix (Applied Biosystems) with the following thermal cycler conditions: 40 cycles at 95 °C for 15 s and 60 °C for 1 min. Primers and probe for human cyclooxygenase-2 (COX2 or PTGS2 according to the HUGO Database) was purchased from Applied Biosystems (assay ID: Hs00153133_m1). Amplification and detection were performed with MyiQTM 2 Two-Color Real-Time PCR Detection System (Bio-Rad). The expression of 18S rRNA subunit, chosen as reference gene, was quantified with a predeveloped assay (Applied Biosystems) and used for normalization and relative quantitation of the target gene. Data analysis was based on the comparative threshold cycle (Ct) method according to the manufacturer's instructions (Applied Biosystems), as previously described (Zhang et al. 2005).

Immunofluorescence microscopy

Cells (104) were seeded on glass coverslips in growth medium. After 24 h of serum starvation, cells were incubated with DHT (30 nM) or left untreated for 24 h, then were stimulated or not with TNFα (10 ng/ml) or with LPS (100 ng/ml) for 5 h. Cells cultured in phenol red and serum-free medium were used as control. Immunostaining was performed as previously described (Penna et al. 2009) using primary Abs against NF-κB p65 (1:100) followed by Alexa Fluor conjugated secondary Abs (1:200). Slides were then treated as reported elsewhere (Penna et al. 2009) and examined with a phase contrast microscope (Nikon Microphot-FX microscope, Nikon, Tokyo, Japan). Experiments were performed three times with different cell preparations.

Statistical analysis

Results are expressed as mean±s.e.m. Comparisons of means were performed with one-way ANOVA followed by unpaired two-sided Student's t-tests. P<0.05 was taken as significant. Correlations were assessed using Spearman's method. Stepwise multiple linear or logistic regressions were applied for multivariate analysis, whenever appropriate. Relative risk and 95% confidence interval were calculated for association of categorical parameters.

All statistical analysis was performed on SPSS (SPSS, Inc., Chicago, IL, USA) for Windows 17.0. Values of half-maximal response inhibitory concentration (IC50) as well as maximal inhibitory (Imax) effect were calculated by using the ALLFIT program (De Lean et al. 1978).

Results

Association between inflammation and testosterone levels

Histological features of inflammatory infiltrate specimens derived from 42 BPH patients undergoing simple prostatectomy were analyzed blindly and scored according to a previously validated protocol (Nickel et al. 2001). The demographic and clinical characteristics of the patients analyzed are summarized in Table 1. Histopathological examination of BPH specimens demonstrated the presence of prostatic inflammation in all cases. The IS was higher in severe hypogonadal (testosterone ≤8 nM) than eugonadal (testosterone >8 nM) patients (P<0.01, Fig. 1 panel a). Accordingly, severe hypogonadism increased the risk of prostate inflammation by a factor of five, even after adjusting for age and body mass index (BMI; HR=5.7 (1.1–29.4), P<0.05). In an age- and BMI-adjusted model, among the different factors composing the IS, the inflammatory infiltrate grade showed a significant, negative association with testosterone levels (adjusted R=−0.35, P=0.03, Fig. 1 panel a, inset, and panel b). When patients were stratified according to current treatments, including 5α-reductase inhibitors, no differences were found for inflammatory parameters (not shown).

Table 1

Characteristics of the patients analyzed

Values
Clinical features
 Age (years)70.0±7.4 (51.0–83.0)
 BMI26.0±3.0 (21.0–37.4)
Metabolic syndrome features
 Waist circumference (cm)98.7±8.3 (87.0–131.0)
 DBP (mmHg)74.3±6.4 (60–90)
 SBP (mmHg)131.3±12.8 (110.0–165.0)
 HDL (mg/dl)48.4±5.4 (39.0–61.0)
 Triglycerides (mg/dl)112.9±28.3 (62.0–175.0)
 Glycemia (mg/dl)100.5±24.3 (70.0–207.0)
Hormonal features
 Testosterone (nM)14.8±5.7 (5.4–31.5)
 FSH (U/l)8.7±7.2 (1.8–28.0)
 LH (U/l)5.6±3.3 (1.4–13.3)
Pathology
 Prostate sample weight (mg)76.4±15.5 (40.0–110.0)

BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; HDL, high-density lipoprotein. Data are expressed as mean±s.d.; the range is indicated in brackets.

Figure 1
Figure 1

Histological features of intraprostatic inflammatory infiltrates in hypogonadal and eugonadal BPH subjects. (Panel a) Total inflammation score and grade (inset) of prostatic inflammation in hypogonadal (total testosterone ≤8 nM) and eugonadal (total testosterone >8 nM) BPH subjects. (Panel b) Testosterone level as a function of intraprostatic inflammatory grade score. Inset indicates the age- and BMI-adjusted data. (Panels c–f) Frozen prostate samples from a representative eugonadal (panels c and d: total testosterone=21.3 nM) and hypogonadal (panels e and f: total testosterone=5.4 nM) patients were stained with H&E (panels c and e) or with a specific Ab anti-pan leukocyte marker (CD45, panels d and f). Original magnification, 10×. Full colour version of this figure available via http://dx.doi.org/10.1530/JOE-12-0142.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

Figure 1 shows histological patterns of prostatic inflammatory infiltrates in two representative patients (eugonadal: Fig. 1 panels c and d, and hypogonadal: Fig. 1 panels e and f). In the eugonadal patient, a stromal scattering of individual inflammatory cells (typically lymphocytes) was documented (Fig. 1 panels c and d). By contrast, the prostate specimen from the hypogonadal patient displayed a marked stromal and periglandular inflammation, with intraepithelial and luminal inflammatory infiltrates causing glandular disruption (Fig. 1 panels e and f). CD45-positive cells were extensively present in both interductal stroma and intertwined within the epithelial glands in the hypogonadal patient (Fig. 1 panel f), while only scanty CD45-positive cells were present in the prostate specimen from the eugonadal subject (Fig. 1 panel d).

DHT treatment inhibits basal secretion of proinflammatory cytokines/chemokines and growth factors by human BPH cells

To investigate whether AR is involved in mediating the antiinflammatory effect of testosterone, the potent and selective AR ligand DHT was used. Experiments were performed in well-established stromal cell cultures isolated from BPH samples (n=6 different preparations). We first measured cytokines, chemokines, and growth factors detected in culture supernatants of BPH cells (Fig. 2). VEGF, eotaxin, MCP-1 (CCL2), IL6, and IL8 were the most abundantly secreted products (>1000 pg/ml). Strikingly, after DHT treatment of BPH cells (30 nM for 24 h), a clear overall reduction in the secretion of inflammatory products was observed, with significant decreases seen for IL6, IL8, MCP-1, bFGF, IL7, IL9, INF-γ, IP-10 (CXCL10), IL12p75, and G-CSF (Fig. 3).

Figure 2
Figure 2

Cytokines, chemokines, and growth factor levels in hBPH cell cultures. Levels (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in culture supernatants by bead-based multiplex immunoassay. Data are expressed as mean±s.d. of basal secretion in six different preparations of hBPH cells obtained from prostate tissues of six different BPH patients.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

Figure 3
Figure 3

Effect of DHT treatment on cytokine/chemokine/growth factor secretion by BPH cells. hBPH cells were cultured for 24 h with serum-free medium alone (untreated) or DHT (30 nM). Culture supernatants were analyzed with a bead-based multiplex assay. Experiments were performed in triplicate using four different hBPH cell preparations. Data are expressed as percentage of variation vs untreated. *P<0.05 vs untreated.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

DHT inhibits TNFα-induced secretion of proinflammatory cytokines/chemokines and growth factors in hBPH cells

The secretion of proinflammatory mediators and the effect of DHT (30 nM for 24 h) were also studied in BPH cells after TNFα priming (10 ng/ml for 5 h). TNFα upregulated basal secretion of IL8, IL6, IL9, IL12p75, IP-10, MCP-1, and bFGF (Fig. 4), with no effect on the other 20 cytokines and chemokines measured. Pretreatment with DHT significantly blunted TNFα-induced secretion of IL8, IL6, IL9, IL12p75, IP-10, MCP-1, and bFGF (Fig. 4 panels a, b, c, d, e, f and g). The effect of DHT was dose-dependent (shared IC50=4.56±1.4×10−11 M; Fig. 4 panel h), although with different Imax effects (Fig. 4 panel i).

Figure 4
Figure 4

DHT inhibits TNFα-induced secretion of cytokines, chemokines, and growth factors by hBPH cells. hBPH cells were stimulated with TNFα (10 ng/ml for 5 h) with or without preincubation with DHT (30 nM for 24 h). (Panels a, b, c, d, e, f and g). Culture supernatants were analyzed for production of the indicated cytokines, chemokines, and growth factors. The data represent the mean±s.e.m. of four independent experiments performed in triplicate and are reported as percentage of untreated cells (control). *P<0.05, **P<0.01 vs control; °P<0.05, °°P<0.01 vs TNFα. (Panel h) Inhibitory effect of increasing concentrations of DHT (1 pM–100 nM) on TNFα-induced cytokine, chemokine, or growth factor secretion by hPBH cells. Ordinate: secretion of the indicated cytokines, chemokines, and growth factors induced by TNFα (10 ng/ml for 5 h), expressed as percentage of the effect of TNFα alone. Abscissa: molar concentrations of DHT. The data represent the mean±s.e.m. of four independent experiments performed in triplicate. The relative half-maximal response IC50 value is reported in the text, while relative Imax effects are reported in panel i.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

DHT inhibits NF-κB p65 activation in TNFα-stimulated BPH cells

To better characterize the effect of DHT (30 nM) on the inflammatory response of TNFα-stimulated BPH cells, nuclear translocation of NF-κB p65 was studied. As assessed by immunofluorescence, in untreated BPH cells NF-κB p65 was totally retained in the cytoplasm (Fig. 5 panel e). TNFα induced a complete translocation of NF-κB p65 to the nucleus, which was inhibited (56.9±3.8%; P<0.0001 vs TNFα), but not normalized (P<0.001 vs untreated BPH cells) by DHT (Fig. 5 panel e). Representative images are shown in Fig. 5 (panels a, b, c, and d). Accordingly, TNFα-induced mRNA expression of the NF-κB p65 target gene COX2 (PTGS2; P<0.01, Fig. 5 panel f) was significantly reduced by pretreatment with DHT (P<0.05).

Figure 5
Figure 5

DHT inhibits NF-κB p65 nuclear translocation in hBPH cells. hBPH cells were stimulated with TNFα (10 ng/ml for 5 h) with or without preincubation with DHT (30 nM for 24 h). After washing, hBPH cells were fixed and stained with anti-NF-κB p65 Ab. Cells were analyzed by fluorescence microscopy. Images of panels a, b, c and d are representative from one of three experiments performed (magnification 10×). (Panel e) Bar graph shows the number of cells with nuclear localization of NF-κB expressed in percentage of total cells. The data represent the mean±s.e.m. of three independent experiments performed in triplicate. (Panel f) mRNA expression of COX2 was evaluated using qRT-PCR in hBPH cells untreated (control) and TNFα primed, with or without preincubation with DHT (30 nM for 24 h). Data were calculated according to comparative Ct method using 18S rRNA subunit as the reference gene for normalization. Results are expressed as percentage of control and are reported as mean±s.e.m. of three independent experiments performed in triplicate. *P<0.001 vs control; °P<0.0001 vs TNFα. Full colour version of this figure available via http://dx.doi.org/10.1530/JOE-12-0142.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

DHT inhibits LPS-induced secretion of proinflammatory cytokines/chemokines and growth factors and NF-κB translocation and signaling in hBPH cells

We next tested the capacity of DHT to reduce the secretion of proinflammatory cytokines/chemokines and growth factor secretion in LPS-primed BPH cells. LPS treatment (100 ng/ml for 48 h) induced a significantly increased production of IL1β, IL1RA, G-CSF, TNFα, eotaxin, IFN-γ, IP-10, IL4, IL7, IL6, and IL8. Among these cytokines, only IL8, IL6, IL7, IP-10, TNFα, and IL1RA were significantly reduced by pretreatment with DHT (P<0.05; Fig. 6 panels a, b, c, d, e and f). Immunolocalization analysis demonstrated that LPS induced a 50% translocation of NF-κB p65 to the nucleus, which was significantly inhibited (15±3.6%; P<0.0001 vs LPS), but not normalized (P<0.001 vs untreated BPH cells) by DHT preincubation (Fig. 6 panel g). As previously observed in TNFα-stimulated BPH cells, LPS-induced mRNA expression of COX2 was also significantly reduced by DHT (Fig. 6 panel h).

Figure 6
Figure 6

DHT inhibits LPS-induced inflammatory response in BPH cells. BPH cells were stimulated with LPS (100 ng/ml, for 48 h) with or without preincubation with DHT (30 nM for 24 h). Cell culture supernatants were analyzed for production of the indicated cytokines, chemokines, and growth factors (panels a, b, c, d, e and f). The data represent the mean±s.e.m. of four independent experiments performed in triplicate. *P<0.05, **P<0.01 vs control; °P<0.05 vs LPS. (Panel g) NF-κB p65 nuclear translocation in BPH cells stimulated by LPS (100 ng/ml, for 5 h), expressed in percentage of total cells. The data represent the mean±s.e.m. of four independent experiments performed in triplicate. (*P<0.001 vs untreated hBPH cells; °P<0.0001 vs LPS). (Panel h) mRNA expression of COX2 was evaluated using qRT-PCR in hBPH cells untreated (control) and LPS-primed pretreated or not with DHT (30 nM, for 24 h). Data were calculated according to the comparative Ct method using 18S rRNA subunit as the reference gene for normalization. Results are expressed in percentage of control and are reported as mean±s.e.m. of three independent experiments performed in triplicate. *P<0.001 vs control, °P<0.0001 vs LPS.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

Co-culture of BPH cells and activated CD4+T cell clones enhances production of proinflammatory cytokines/chemokines and growth factors

As hBPH cells can act as APCs (Penna et al. 2009), we evaluated in co-culture experiments the capacity of hBPH cells to modulate cytokine production by T-cells (Fig. 7). We found that addition of hBPH cells to activated CD4+T cell clones resulted in significantly increased levels of several proinflammatory mediators, including IL1β, IL15, TNFα, eotaxin, G-CSF, MCP-1, and MIP-1α (CCL3). IL1RA production was also significantly enhanced. A significant increase of the Th1-inducer IL12 and Th1-type chemokine IFN-γ-IP-10 was also observed, although IFN-γ and IL2 production were not significantly modulated. Th2-type cytokines were also differentially modulated, with IL9 significantly increased and IL13 significantly decreased, whereas IL4 and IL5 were not significantly affected. By contrast, the T-cell growth factor IL7 and the Th17-specific cytokine IL17 were both significantly increased. In keeping with the overall proinflammatory effects of hBPH cells on cytokine production by T-cells, the antiinflammatory cytokine IL10 was significantly inhibited. Interestingly, a series of factors promoting BPH cell growth, such as IL8, IL6, bFGF, VEGF, and PDGFBB, were markedly enhanced by co-cultures.

Figure 7
Figure 7

Secretion of cytokines, chemokines, and growth factor levels by hBPH cell/CD4+T cell co-cultures. Concentration (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in the supernatants by bead-based multiplex immunoassay. Data are expressed as log (percentage of variation vs activated CD4+T cells alone) and reported as mean±s.e.m. of three individual experiments. *P<0.05, **P<0.001 vs CD4+T cells.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

Co-culture of DHT-pretreated BPH cells and activated CD4+T cell clones inhibit secretion of proinflammatory cytokine/chemokines and growth factors

When activated CD4+T cell clones were cultured with DHT-primed (30 nM for 24 h) hBPH cells, secretion of several proinflammatory factors was significantly affected (Fig. 8). In general, production of proinflammatory mediators was blunted, with a significant reduction observed for MCP-1, MIP-1α, and MIP-1β. Cytokine production by effector T-cells was consistently reduced, with significant decreases seen for IL2, IL4, IL13, and IL17. Also production of the Th1-recruiting chemokine IP-10 was significantly decreased. By contrast, IL10 was significantly increased, consistent with the antiinflammatory activity of DHT. In line with the antiinflammatory properties displayed by DHT, factors promoting hBPH cell growth were mostly decreased, with significant effects seen for IL8, IL6, and bFGF, whereas VEGF secretion was increased.

Figure 8
Figure 8

Secretion of cytokines, chemokines, and growth factor levels by DHT-treated hBPH cell/CD4+T cell co-cultures. Concentrations (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in the supernatants by bead-based multiplex immunoassay. Data are expressed as percentage of variation vs untreated hBPH cell/CD4+T cell co-cultures and reported as mean±s.e.m. of three individual experiments. *P<0.05, **P<0.001 vs untreated hBPH/CD4+T cell co-cultures.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

DHT-pretreated BPH cells inhibit proliferation of activated CD4+T cells

Proliferation of CD4+T cell clones, as measured by [3H]thymidine incorporation, was significantly increased by activation with anti-CD3 Ab (P<0.05), while it was not affected by the addition of irradiated hBPH cells (Fig. 9). However, when hBPH cells were pretreated with DHT (30 nM for 24 h), a significant inhibition of T-cell proliferation was observed (P<0.01; Fig. 9).

Figure 9
Figure 9

Proliferation of activated CD4+T cell clones in the presence of irradiated hBPH cells pretreated or not with DHT. Irradiated (9000 rads) hBPH cells, pretreated or not with 30 nM DHT for 24 h, were co-cultured with CD4+T cell clones for 48 h, then proliferation was measured by [3H]thymidine incorporation. Data represent the mean±s.e.m. of three independent experiments *P<0.05 vs not-activated CD4+T cell clones alone; ##P<0.01 vs activated CD4+T cell clones; °P<0.05 vs activated CD4+T cell clones co-cultured with hBPH cells.

Citation: Journal of Endocrinology 214, 1; 10.1530/JOE-12-0142

Discussion

Results in this study demonstrate, for the first time, that AR activation exerts a direct antiinflammatory effect on human stromal prostate cells, thus inhibiting their potential to induce and sustain autoimmune and inflammatory responses.

Chronic intraprostatic inflammation and subsequent chronic tissue remodeling are determinant factors in the development and progression of prostatic diseases, including BPH (see Kramer et al. (2007), Fibbi et al. (2010b) and Schauer & Rowley (2011) for reviews). A possible hormonal basis for prostate inflammation is suggested by preclinical studies in animal models, demonstrating that hypogonadism induced surgically (Robinette 1988, Desai et al. 2004, Quintar et al. 2006, Meng et al. 2011) or by HFD administration (Vignozzi et al. 2012) exacerbate prostate inflammation and that exogenous testosterone can counteract this effect. In particular, we have shown in a rabbit model that testosterone supplementation can prevent HFD-induced prostatic alterations, including inflammation, tissue remodeling, and hypoxia (Vignozzi et al. 2012).

In the present study, we sought to provide evidence supporting the hypothesis that low androgen levels could enhance inflammatory responses in the human prostate. Hence, we first retrospectively examined the histological features of inflammatory infiltrates in prostatectomy specimens derived from a cohort of BPH patients. Even after adjusting for confounding factors, hypogonadism was associated with a fivefold increased risk of intraprostatic inflammation, which was also more severe than that observed in eugonadal BPH patients. Although it is historically assumed that high testosterone induces prostate overgrowth, most observational studies failed to find correlations between circulating testosterone levels and BPH: in fact, no clear correlation with serum PSA or prostate volume across the normal testosterone range has been shown (Liu et al. 2007). In addition, the notion that intraprostatic 5α-reductase activity, which is responsible for converting the bulk of testosterone into DHT, is altered in the BPH tissues is contentious (Isaacs et al. 1983, Bartsch et al. 1990). However, it could be hypothesized that intraprostatic level of DHT could be more important than the level of serum testosterone for the growth of the prostate (Isaacs et al. 1983), thus explaining this lack of association between serum testosterone level and prostate overgrowth. In contrast, some uncontrolled studies have reported a gradual improvement in the International Prostate Symptom Score (IPSS) following long-term testosterone therapy in men with hypogonadism and/or metabolic syndrome (MetS) (see review in Buvat et al. (2010)). A small randomized controlled trial with testosterone enanthate in 23 men with BPH tends to support these findings, with a significant decrease in the IPSS score, maximum flow rate, and voided volume in the testosterone group but not in the 23 untreated controls (Shigehara et al. 2011). However, in the present sample we did not find any difference in inflammation in BPH specimens from subjects treated or not with 5α-reductase inhibitors.

To better investigate whether androgens could directly suppress prostate inflammatory responses, we performed in vitro studies in human prostatic stromal cell cultures using the potent and selective AR ligand DHT. We have previously demonstrated the ability of hBPH cells to function as APCs, and to actively contribute to the organ-specific inflammatory process (Penna et al. 2009). Herein, we confirm that hBPH stromal cells secrete several proinflammatory and growth factors. Among them, IL8, IL6, MCP-1, VEGF, and eotaxin were the most abundantly secreted. A similar pattern of cytokine and chemokine secretion was previously described in seminal plasma of patients affected by BPH (Penna et al. 2007). In particular, seminal plasma IL8 was identified as a reliable surrogate marker of prostatic inflammatory diseases and BPH, thanks to the fact that its level positively correlated with serum PSA, with prostatitis symptom score (Penna et al. 2007), and with ultrasonographic features of prostate inflammation (Lotti et al. 2011). The present data show secretion by stromal hBPH cells of many cytokines, chemokines, and growth factors induced by inflammatory stimuli, including TNFα, LPS, or activated CD4+T cells. Secretion of IL8 and IL6 was markedly upregulated, as was production of bFGF, suggesting that an activated immune system might sustain prostate overgrowth. IL8, a primary cytokine in the recruitment of neutrophils into the inflammatory sites, showed also a potent proliferative action in prostate. Indeed, IL8 induced stromal BPH cell overgrowth by directly promoting the fibroblast-to-myofibroblast transdifferentiation and by indirectly stimulating secretion of bFGF, which acts as a potent prostatic growth factor. Similar to IL8, IL6 directly promotes stromal cell proliferation in an autocrine manner (see Fibbi et al. (2010b) for a review). The increased production of several chemokines, including IP-10, IL8, MCP-1, MIP-1α, and MIP-1β in co-cultures of BPH cells with activated CD4+T cell clones suggested the capacity of BPH cells to recruit Th1 cells and other immune cells into the inflamed prostate. A concomitant increase of IL1β, IL1RA, and IL15, cytokines described to be highly upregulated in BPH (see Kramer et al. (2007) for a review) has also been observed.

Our data also demonstrate that hBPH cells can influence CD4+T cell activation, modulating their phenotype. When activated CD4+T cell clones were co-cultured with hBPH cells, a significant increase of a Th1 inducer (IL12), a Th1-recruiting chemokine (IP-10), a Th2-type cytokine (IL9), and a Th17-specific cytokine (IL17) was observed. In addition, IL7, a crucial cytokine for survival and expansion of Th17 cells in autoimmune disease models (Kanai et al. 2009, Liu et al. 2010) was also increased. Concomitantly, a marked decrease of the antiinflammatory cytokine IL10 was also observed.

The most striking finding of the present study is that activation of AR by DHT markedly suppresses the inflammatory response and secretion of growth factors in hBPH cells, thus suggesting that stromal cell AR plays an important role in maintaining adult prostate homeostasis. This is in agreement with the observation that the selective ablation of AR in mouse prostate stromal cells causes a diffuse stromal hyperplasia mostly characterized by infiltration of leukocytes (neutrophils and monocytes) in adult prostate gland (Welsh et al. 2011).

The prevalent inhibitory effect of DHT was observed in IL8 and bFGF secretion, both in basal and stimulated conditions. Interestingly, this antiinflammatory effect of DHT was exerted at very low concentrations (10−11 mol/l), roughly corresponding to the Kd of DHT for the AR in hBPH cells (Crescioli et al. 2003).

In the present study we also demonstrated that DHT-primed hBPH cells co-cultures with CD4+T cell clones caused a reduction in cytokines produced by effector T-cells and an increase in IL10 production. This suggests that DHT could play a broad antiinflammatory role on CD4+T helper cells. Moreover, DHT inhibited the production of IL2, T-cell growth and differentiation (see Liao et al. (2011)), thus explained the reduced proliferation of CD4+T cell clones in culture with DHT-primed hBPH cells.

The mechanisms by which DHT exerts its antiinflammatory effects are not completely understood. We demonstrate that DHT inhibits NF-κB activation, a master transcription factor in inflammation, as evidenced by its reduced nuclear translocation and by the decreased expression of COX2. A similar antiinflammatory effect has been described also in human endothelial cells, where DHT or testosterone decreased TNFα-induced inflammatory response through the inhibition of NF-κB signaling pathway (Hatakeyama et al. 2002, Norata et al. 2006).

Alternative, direct antiinflammatory mechanisms are also plausible, as suggested by a specific androgen response element present in genes related to inflammatory and proliferative response, such as IL6, described in rat prostate epithelial cells (Asirvatham et al. 2006).

In conclusion, our data demonstrate that DHT exerts an immune regulatory role on human prostatic stromal cells, inhibiting their potential to actively induce and/or sustain autoimmune and inflammatory responses. The prostate is an immunocompetent organ, not only because it is populated by resident inflammatory cells, including T- and B-lymphocytes, macrophages, and mast cells (De Marzo et al. 2007, Fibbi et al. 2010a,b), but also because stromal prostatic cells can secrete several proinflammatory cytokines and are able to recruit and activate CD4+ cells into the inflamed prostate. Under most conditions, this immune competence of the prostate would be beneficial to the host. However, in some situations, an immune response toward a Th1/Th17 cytokine profile might lead to the development of chronic immune-mediated tissue destruction and fibromyomatosus growth, as observed in the pathogenesis of BPH. Interestingly, our data indicate that AR signaling might restrain, rather than facilitate, prostate inflammation.

Thus, DHT should be considered more a friend than a foe of prostate cells, consistent with the observation that prostate glands from hypogonadal subjects are more inflamed than those from eugonadal ones. Interventional studies aimed at evaluating the antiinflammatory effects of testosterone-replacement therapy in hypogonadal subjects with BPH are therefore warranted.

Declaration of interest

L V, I C, A M, P C, S F, M G, M C, F L, L L, M-P P, G N, and R S have no conflicts of interest that could be perceived as prejudicing the impartiality of the research reported and have nothing to declare. M M is a scientific consultant for Bayer Pharma AG, Germany, and Eli-Lilly Indianapolis, Indiana. L A is an employee of Intercept Pharmaceuticals 18 Desbrosses Street, New York, NY 10013, USA.

Funding

The study was supported by PRIN (Programmi di ricerca di Rilevante Interesse Nazionale) funds by the Italian Minister of University, Research and Instruction (prot number: 2009WLNXNT_002), by FIRB (Programma Futuro in Ricerca) funds by the Italian Minister of University, Research and Instruction (prot number: RBFR10VJ56_002).

Acknowledgements

The authors thank Mario Rotondi (Unit of Internal Medicine and Endocrinology Fondazione Salvatore Maugeri IRCCS, University of Pavia, 27100 Pavia, Italy) for his helpful suggestions and comments.

References

  • AsirvathamAJSchmidtMGaoBChaudharyJ2006Androgens regulate the immune/inflammatory response and cell survival pathways in rat ventral prostate epithelial cells. Endocrinology147257271. doi:10.1210/en.2005-0942.

    • Search Google Scholar
    • Export Citation
  • AzadzoiKMTarcanTSirokyMBKraneRJ1999Atherosclerosis-induced chronic ischemia causes bladder fibrosis and non-compliance in the rabbit. Journal of Urology16116261635. doi:10.1016/S0022-5347(05)68995-1.

    • Search Google Scholar
    • Export Citation
  • BartschWKleinHSchiemannUBauerHWVoigtKD1990Enzymes of androgen formation and degradation in the human prostate. Annals of the New York Academy of Sciences5955366. doi:10.1111/j.1749-6632.1990.tb34282.x.

    • Search Google Scholar
    • Export Citation
  • BuvatJMaggiMGoorenLGuayATKaufmanJMMorgentalerASchulmanCTanHMTorresLOYassinA2010Endocrine aspects of male sexual dysfunctions. Journal of Sexual Medicine716271656. doi:10.1111/j.1743-6109.2010.01780.x.

    • Search Google Scholar
    • Export Citation
  • CrescioliCMaggiMVannelliGBLuconiMSalernoRBarniTGulisanoMFortiGSerioM2000Effect of a vitamin D3 analog on keratinocyte growth factor-induced cell proliferation in benign prostate hyperplasia. Journal of Clinical Endocrinology and Metabolism8525762583. doi:10.1210/jc.85.7.2576.

    • Search Google Scholar
    • Export Citation
  • CrescioliCFerruzziPCaporaliAMancinaRComerciAMuratoriMScaltritiMVannelliGBSmiroldoSMarianiR2003Inhibition of spontaneous and androgen-induced prostate growth by a nonhypercalcemic calcitriol analog. Endocrinology14430463057. doi:10.1210/en.2002-0210.

    • Search Google Scholar
    • Export Citation
  • De LeanAMunsonPJRodbardD1978Simultaneous analysis of famiglie of sigmoidal curves: application to biomassa, radioligand assay, and physiological dose–response curves. American Journal of Physiology23597102.

    • Search Google Scholar
    • Export Citation
  • De MarzoAMPlatzEASutcliffeSXuJGrönbergHDrakeCGNakaiYIsaacsWBNelsonWG2007Inflammation in prostate carcinogenesis. Nature Reviews. Cancer7256269. doi:10.1038/nrc2090.

    • Search Google Scholar
    • Export Citation
  • DesaiKVMichalowskaAMKondaiahPWardJMShihJHGreenJE2004Gene expression profiling identifies a unique androgen-mediated inflammatory/immune signature and a PTEN (phosphatase and tensin homolog deleted on chromosome 10)-mediated apoptotic response specific to the rat ventral prostate. Molecular Endocrinology1828952907. doi:10.1210/me.2004-0033.

    • Search Google Scholar
    • Export Citation
  • FibbiBMorelliAVignozziLFilippiSChavalmaneADe VitaGMariniMGacciMVannelliGBSandnerP2010aCharacterization of phosphodiesterase type 5 expression and functional activity in the human male lower urinary tract. Journal of Sexual Medicine75969. doi:10.1111/j.1743-6109.2009.01511.x.

    • Search Google Scholar
    • Export Citation
  • FibbiBPennaGMorelliAAdoriniLMaggiM2010bChronic inflammation in the pathogenesis of benign prostatic hyperplasia. International Journal of Andrology33475488. doi:10.1111/j.1365-2605.2009.00972.x.

    • Search Google Scholar
    • Export Citation
  • FilippiSVignozziLMorelliAChavalmaneAKSarchielliEFibbiBSaadFSandnerPRuggianoPVannelliGB2009Testosterone partially ameliorates metabolic profile and erectile responsiveness to PDE5 inhibitors in an animal model of male metabolic syndrome. Journal of Sexual Medicine632743288. doi:10.1111/j.1743-6109.2009.01467.x.

    • Search Google Scholar
    • Export Citation
  • HatakeyamaHNishizawaMNakagawaANakanoSKigoshiTUchidaK2002Testosterone inhibits tumor necrosis factor-alpha-induced vascular cell adhesion molecule-1 expression in human aortic endothelial cells. FEBS Letters530129132. doi:10.1016/S0014-5793(02)03440-3.

    • Search Google Scholar
    • Export Citation
  • IsaacsJTBrendlerCBWalshPC1983Changes in the metabolism of dihydrotestosterone in the hyperplastic human prostate. Journal of Clinical Endocrinology and Metabolism56139146. doi:10.1210/jcem-56-1-139.

    • Search Google Scholar
    • Export Citation
  • IssaMMReganTS2007Medical therapy for benign prostatic hyperplasia – present and future impact. American Journal of Managed Care1S4S9.

    • Search Google Scholar
    • Export Citation
  • KanaiTNemotoYKamadaNTotsukaTHisamatsuTWatanabeMHibiT2009Homeostatic (IL-7) and effector (IL-17) cytokines as distinct but complementary target for an optimal therapeutic strategy in inflammatory bowel disease. Current Opinion in Gastroenterology25306313. doi:10.1097/MOG.0b013e32832bc627.

    • Search Google Scholar
    • Export Citation
  • KozlowskiRKershenRTSirokyMBKraneRJAzadzoiKM2001Chronic ischemia alters prostate structure and reactivity in rabbits. Journal of Urology16510191026. doi:10.1016/S0022-5347(05)66595-0.

    • Search Google Scholar
    • Export Citation
  • KrajewskaMBanaresSZhangEEHuangXScadengMJhalaUSFengGSKrajewskiS2008Development of diabesity in mice with neuronal deletion of Shp2 tyrosine phosphatase. American Journal of Pathology17213121324. doi:10.2353/ajpath.2008.070594.

    • Search Google Scholar
    • Export Citation
  • KramerGMittereggerDMarbergerM2007Is benign prostatic hyperplasia (BPH) an immune inflammatory disease?European Urology5112021216. doi:10.1016/j.eururo.2006.12.011.

    • Search Google Scholar
    • Export Citation
  • LédéeNLombrosoRLombardelliLSelvaJDubanchetSChaouatGFrankenneFFoidardartJMMaggiERomagnaniS2008Cytokines and cemokines in follicular fluids and potential of the corresponding embryo: the role of granulocyte colony-stimulating factor. Human Reproduction2320012009. doi:10.1093/humrep/den192.

    • Search Google Scholar
    • Export Citation
  • LiaoWLinJXLeonardWJ2011IL-2 family cytokines: new insights into the complex roles of IL-2 as a broad regulator of T helper cell differentiation. Current Opinion in Immunology23598604. doi:10.1016/j.coi.2011.08.003.

    • Search Google Scholar
    • Export Citation
  • LiuCCHuangSPLiWMWangCJChouYHLiCCHuangCHWuWJ2007Relationship between serum testosterone and measures of benign prostatic hyperplasia in aging men. Urology70677680. doi:10.1016/j.urology.2007.05.025.

    • Search Google Scholar
    • Export Citation
  • LiuXLeungSWangCTanZWangJGuoTBFangLZhaoYWanBQinX2010Crucial role of interleukin-7 in T helper type 17 survival and expansion in autoimmune disease. Nature Medicine16191197. doi:10.1038/nm.2077.

    • Search Google Scholar
    • Export Citation
  • LottiFCoronaGColpiGMFilimbertiEDegli InnocentiSManciniMBaldiENociIFortiGAdoriniL2011Elevated body mass index correlates with higher seminal plasma interleukin 8 levels and ultrasonographic abnormalities of the prostate in men attending an andrology clinic for infertility. Journal of Endocrinological Investigation34336342.

    • Search Google Scholar
    • Export Citation
  • MengJMostaghelEAVakar-LopezFMontgomeryBTrueLNelsonPS2011Testosterone regulates tight junction proteins and influences prostatic autoimmune responses. Hormones & Cancer2145156. doi:10.1007/s12672-010-0063-1.

    • Search Google Scholar
    • Export Citation
  • MorelliAComeglioPFilippiSSarchielliECellaiIVignozziLYehiely-CohenRManeschiEGacciMCariniMTestosterone and farnesoid X receptor agonist INT-747 ounteract high fat diet-induced bladder alterations in a rabbit model of metabolic syndromeJournal of Steroid Biochemistry and Molecular Biology2012(http://dx.doi.org/10.1016/j.jsbmb.2012.02.007)

    • Search Google Scholar
    • Export Citation
  • NickelJCTrueLDKriegerJNBergerREBoagAHYoungIDparticipating members of the North American Chronic Prostatitis Collaborative Research Network and the International Prostatitis Collaborative Network2001Consensus development of a histopathological classification system for chronic prostatic inflammation. British Journal of Urology International87797805. doi:10.1046/j.1464-410x.2001.02193.x.

    • Search Google Scholar
    • Export Citation
  • NickelJCRoehrbornCGO'learyMPBostwickDGSomervilleMCRittmasterRS2007Examination of the relationship between symptoms of prostatitis and histological inflammation: baseline data from the REDUCE chemoprevention trial. Journal of Urology178896900. doi:10.1016/j.juro.2007.05.041.

    • Search Google Scholar
    • Export Citation
  • NickelJCRoehrbornCGO'LearyMPBostwickDGSomervilleMCRittmasterRS2008The relationship between prostate inflammation and lower urinary tract symptoms: examination of baseline data from the REDUCE trial. European Urology5413791384. doi:10.1016/j.eururo.2007.11.026.

    • Search Google Scholar
    • Export Citation
  • NorataGDTibollaGSeccomandiPMPolettiACatapanoAL2006Dihydrotestosterone decreases tumor necrosis factor-alpha and lipopolysaccharide-induced inflammatory response in human endothelial cells. Journal of Clinical Endocrinology and Metabolism91546554. doi:10.1210/jc.2005-1664.

    • Search Google Scholar
    • Export Citation
  • PennaGMondainiNAmuchasteguiSDegli InnocentiSCariniMGiubileiGFibbiBColliEMaggiMAdoriniL2007Seminal plasma cytokines and chemokines in prostate inflammation: interleukin 8 as a predictive biomarker in chronic prostatitis/chronic pelvic pain syndrome and benign prostatic hyperplasia. European Urology51524533. doi:10.1016/j.eururo.2006.07.016.

    • Search Google Scholar
    • Export Citation
  • PennaGFibbiBAmuchasteguiSCorsieroELavernyGSilvestriniEChavalmaneAMorelliASarchielliEVannelliGB2009The vitamin D receptor agonist elocalcitol inhibits IL-8-dependent benign prostatic hyperplasia stromal cell proliferation and inflammatory response by targeting the RhoA/Rho kinase and NF-kappaB pathways. Prostate69480493. doi:10.1002/pros.20896.

    • Search Google Scholar
    • Export Citation
  • PiccinniMPGiudiziMGBiagiottiRBeloniLGiannariniLSampognaroSParronchiPManettiRAnnunziatoFLiviC1995Progesterone favors the development of human T helper cells producing Th2-type cytokines and promotes both IL-4 production and membrane CD30 expression in established Th1 cell clones. Journal of Immunology155128133.

    • Search Google Scholar
    • Export Citation
  • QuintarAARothFDDe PaulALAokiAMaldonadoCA2006Toll-like receptor 4 in rat prostate: odulation by testosterone and acute bacterial infection in epithelial and stromal cells. Biology of Reproduction75664672. doi:10.1095/biolreprod.106.053967.

    • Search Google Scholar
    • Export Citation
  • RobinetteCL1988Sex-hormone-induced inflammation and fibromuscular proliferation in the rat lateral prostate. Prostate12271286. doi:10.1002/pros.2990120310.

    • Search Google Scholar
    • Export Citation
  • RoehrbornCGNuckollsJGWeiJTSteersW2007BPH Registry and Patient Survey Steering Committee. The benign prostatic hyperplasia registry and patient survey: study design, methods and patient baseline characteristics. BJU International100813819.

    • Search Google Scholar
    • Export Citation
  • RopiquetFGiriDLambDJIttmannM1999FGF7 and FGF2 are increased in benign prostatic hyperplasia and are associated with increased proliferation. Journal of Urology162595599. doi:10.1016/S0022-5347(05)68632-6.

    • Search Google Scholar
    • Export Citation
  • RotondiMChiovatoLRomagnaniSSerioMRomagnaniP2007Role of chemokines in endocrine autoimmune diseases. Endocrine Reviews28492520. doi:10.1210/er.2006-0044.

    • Search Google Scholar
    • Export Citation
  • SchauerIGRowleyDR2011The functional role of reactive stroma in benign prostatic hyperplasia. Differentiation82200210. doi:10.1016/j.diff.2011.05.007.

    • Search Google Scholar
    • Export Citation
  • ShigeharaKSugimotoKKonakaHIijimaMFukushimaMMaedaYMizokamiAKohEOrigasaHIwamotoT2011Androgen replacement therapy contributes to improving lower urinary tract symptoms in patients with hypogonadism and benign prostate hypertrophy: a randomised controlled study. Aging Male145358. doi:10.3109/13685538.2010.518178.

    • Search Google Scholar
    • Export Citation
  • SteinerGEStixUHandisuryaAWillheimMHaitelAReithmayrFPaiklDEckerRCHrachowitzKKramerG2003aCytokine expression pattern in benign prostatic hyperplasia infiltrating T cells and impact of lymphocytic infiltration on cytokine mRNA profile in prostatic tissue. Laboratory Investigation8311311146. doi:10.1097/01.LAB.0000081388.40145.65.

    • Search Google Scholar
    • Export Citation
  • SteinerGENewmanMEPaiklDStixUMemaran-DagdaNLeeCMarbergerMJ2003bExpression and function of proinflammatory interleukin IL-17 and IL-17 receptor in normal, benign hyperplastic, and malignant prostate. Prostate56171182. doi:10.1002/pros.10238.

    • Search Google Scholar
    • Export Citation
  • VignozziLMorelliAFilippiSComeglioPChavalmaneAKMarchettaMToceMYehiely-CohenRVannelliGBAdoriniL2011Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes. Journal of Sexual Medicine85777. doi:10.1111/j.1743-6109.2010.02073.x.

    • Search Google Scholar
    • Export Citation
  • VignozziLMorelliASarchielliEComeglioPFilippiSCellaiIManeschiESerniSGacciMCariniM2012Testosterone protects from metabolic syndrome-associated prostate inflammation: an experimental study in rabbit. Journal of Endocrinology2127184. doi:10.1530/JOE-11-0289.

    • Search Google Scholar
    • Export Citation
  • WelshMMoffatLMcNeillyABrownsteinDSaundersPTSharpeRMSmithLB2011Smooth muscle cell-specific knockout of androgen receptor: a new model for prostatic disease. Endocrinology15235413451. doi:10.1210/en.2011-0282.

    • Search Google Scholar
    • Export Citation
  • ZhangXHMorelliALuconiMVignozziLFilippiSMariniMVannelliGBMancinaRFortiGMaggiM2005Testosterone regulates PDE5 expression and in vivo responsiveness to tadalafil in rat corpus cavernosum. European Urology47409416. doi:10.1016/j.eururo.2004.10.021.

    • Search Google Scholar
    • Export Citation

(L Vignozzi and I Cellai contributed equally to this work)

If the inline PDF is not rendering correctly, you can download the PDF file here.

 

      Society for Endocrinology

Related Articles

Article Information

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1037 1037 41
PDF Downloads 509 509 16

Altmetrics

Figures

  • View in gallery

    Histological features of intraprostatic inflammatory infiltrates in hypogonadal and eugonadal BPH subjects. (Panel a) Total inflammation score and grade (inset) of prostatic inflammation in hypogonadal (total testosterone ≤8 nM) and eugonadal (total testosterone >8 nM) BPH subjects. (Panel b) Testosterone level as a function of intraprostatic inflammatory grade score. Inset indicates the age- and BMI-adjusted data. (Panels c–f) Frozen prostate samples from a representative eugonadal (panels c and d: total testosterone=21.3 nM) and hypogonadal (panels e and f: total testosterone=5.4 nM) patients were stained with H&E (panels c and e) or with a specific Ab anti-pan leukocyte marker (CD45, panels d and f). Original magnification, 10×. Full colour version of this figure available via http://dx.doi.org/10.1530/JOE-12-0142.

  • View in gallery

    Cytokines, chemokines, and growth factor levels in hBPH cell cultures. Levels (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in culture supernatants by bead-based multiplex immunoassay. Data are expressed as mean±s.d. of basal secretion in six different preparations of hBPH cells obtained from prostate tissues of six different BPH patients.

  • View in gallery

    Effect of DHT treatment on cytokine/chemokine/growth factor secretion by BPH cells. hBPH cells were cultured for 24 h with serum-free medium alone (untreated) or DHT (30 nM). Culture supernatants were analyzed with a bead-based multiplex assay. Experiments were performed in triplicate using four different hBPH cell preparations. Data are expressed as percentage of variation vs untreated. *P<0.05 vs untreated.

  • View in gallery

    DHT inhibits TNFα-induced secretion of cytokines, chemokines, and growth factors by hBPH cells. hBPH cells were stimulated with TNFα (10 ng/ml for 5 h) with or without preincubation with DHT (30 nM for 24 h). (Panels a, b, c, d, e, f and g). Culture supernatants were analyzed for production of the indicated cytokines, chemokines, and growth factors. The data represent the mean±s.e.m. of four independent experiments performed in triplicate and are reported as percentage of untreated cells (control). *P<0.05, **P<0.01 vs control; °P<0.05, °°P<0.01 vs TNFα. (Panel h) Inhibitory effect of increasing concentrations of DHT (1 pM–100 nM) on TNFα-induced cytokine, chemokine, or growth factor secretion by hPBH cells. Ordinate: secretion of the indicated cytokines, chemokines, and growth factors induced by TNFα (10 ng/ml for 5 h), expressed as percentage of the effect of TNFα alone. Abscissa: molar concentrations of DHT. The data represent the mean±s.e.m. of four independent experiments performed in triplicate. The relative half-maximal response IC50 value is reported in the text, while relative Imax effects are reported in panel i.

  • View in gallery

    DHT inhibits NF-κB p65 nuclear translocation in hBPH cells. hBPH cells were stimulated with TNFα (10 ng/ml for 5 h) with or without preincubation with DHT (30 nM for 24 h). After washing, hBPH cells were fixed and stained with anti-NF-κB p65 Ab. Cells were analyzed by fluorescence microscopy. Images of panels a, b, c and d are representative from one of three experiments performed (magnification 10×). (Panel e) Bar graph shows the number of cells with nuclear localization of NF-κB expressed in percentage of total cells. The data represent the mean±s.e.m. of three independent experiments performed in triplicate. (Panel f) mRNA expression of COX2 was evaluated using qRT-PCR in hBPH cells untreated (control) and TNFα primed, with or without preincubation with DHT (30 nM for 24 h). Data were calculated according to comparative Ct method using 18S rRNA subunit as the reference gene for normalization. Results are expressed as percentage of control and are reported as mean±s.e.m. of three independent experiments performed in triplicate. *P<0.001 vs control; °P<0.0001 vs TNFα. Full colour version of this figure available via http://dx.doi.org/10.1530/JOE-12-0142.

  • View in gallery

    DHT inhibits LPS-induced inflammatory response in BPH cells. BPH cells were stimulated with LPS (100 ng/ml, for 48 h) with or without preincubation with DHT (30 nM for 24 h). Cell culture supernatants were analyzed for production of the indicated cytokines, chemokines, and growth factors (panels a, b, c, d, e and f). The data represent the mean±s.e.m. of four independent experiments performed in triplicate. *P<0.05, **P<0.01 vs control; °P<0.05 vs LPS. (Panel g) NF-κB p65 nuclear translocation in BPH cells stimulated by LPS (100 ng/ml, for 5 h), expressed in percentage of total cells. The data represent the mean±s.e.m. of four independent experiments performed in triplicate. (*P<0.001 vs untreated hBPH cells; °P<0.0001 vs LPS). (Panel h) mRNA expression of COX2 was evaluated using qRT-PCR in hBPH cells untreated (control) and LPS-primed pretreated or not with DHT (30 nM, for 24 h). Data were calculated according to the comparative Ct method using 18S rRNA subunit as the reference gene for normalization. Results are expressed in percentage of control and are reported as mean±s.e.m. of three independent experiments performed in triplicate. *P<0.001 vs control, °P<0.0001 vs LPS.

  • View in gallery

    Secretion of cytokines, chemokines, and growth factor levels by hBPH cell/CD4+T cell co-cultures. Concentration (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in the supernatants by bead-based multiplex immunoassay. Data are expressed as log (percentage of variation vs activated CD4+T cells alone) and reported as mean±s.e.m. of three individual experiments. *P<0.05, **P<0.001 vs CD4+T cells.

  • View in gallery

    Secretion of cytokines, chemokines, and growth factor levels by DHT-treated hBPH cell/CD4+T cell co-cultures. Concentrations (pg/ml) of the indicated cytokines, chemokines, and growth factors were determined in the supernatants by bead-based multiplex immunoassay. Data are expressed as percentage of variation vs untreated hBPH cell/CD4+T cell co-cultures and reported as mean±s.e.m. of three individual experiments. *P<0.05, **P<0.001 vs untreated hBPH/CD4+T cell co-cultures.

  • View in gallery

    Proliferation of activated CD4+T cell clones in the presence of irradiated hBPH cells pretreated or not with DHT. Irradiated (9000 rads) hBPH cells, pretreated or not with 30 nM DHT for 24 h, were co-cultured with CD4+T cell clones for 48 h, then proliferation was measured by [3H]thymidine incorporation. Data represent the mean±s.e.m. of three independent experiments *P<0.05 vs not-activated CD4+T cell clones alone; ##P<0.01 vs activated CD4+T cell clones; °P<0.05 vs activated CD4+T cell clones co-cultured with hBPH cells.

References

  • AsirvathamAJSchmidtMGaoBChaudharyJ2006Androgens regulate the immune/inflammatory response and cell survival pathways in rat ventral prostate epithelial cells. Endocrinology147257271. doi:10.1210/en.2005-0942.

    • Search Google Scholar
    • Export Citation
  • AzadzoiKMTarcanTSirokyMBKraneRJ1999Atherosclerosis-induced chronic ischemia causes bladder fibrosis and non-compliance in the rabbit. Journal of Urology16116261635. doi:10.1016/S0022-5347(05)68995-1.

    • Search Google Scholar
    • Export Citation
  • BartschWKleinHSchiemannUBauerHWVoigtKD1990Enzymes of androgen formation and degradation in the human prostate. Annals of the New York Academy of Sciences5955366. doi:10.1111/j.1749-6632.1990.tb34282.x.

    • Search Google Scholar
    • Export Citation
  • BuvatJMaggiMGoorenLGuayATKaufmanJMMorgentalerASchulmanCTanHMTorresLOYassinA2010Endocrine aspects of male sexual dysfunctions. Journal of Sexual Medicine716271656. doi:10.1111/j.1743-6109.2010.01780.x.

    • Search Google Scholar
    • Export Citation
  • CrescioliCMaggiMVannelliGBLuconiMSalernoRBarniTGulisanoMFortiGSerioM2000Effect of a vitamin D3 analog on keratinocyte growth factor-induced cell proliferation in benign prostate hyperplasia. Journal of Clinical Endocrinology and Metabolism8525762583. doi:10.1210/jc.85.7.2576.

    • Search Google Scholar
    • Export Citation
  • CrescioliCFerruzziPCaporaliAMancinaRComerciAMuratoriMScaltritiMVannelliGBSmiroldoSMarianiR2003Inhibition of spontaneous and androgen-induced prostate growth by a nonhypercalcemic calcitriol analog. Endocrinology14430463057. doi:10.1210/en.2002-0210.

    • Search Google Scholar
    • Export Citation
  • De LeanAMunsonPJRodbardD1978Simultaneous analysis of famiglie of sigmoidal curves: application to biomassa, radioligand assay, and physiological dose–response curves. American Journal of Physiology23597102.

    • Search Google Scholar
    • Export Citation
  • De MarzoAMPlatzEASutcliffeSXuJGrönbergHDrakeCGNakaiYIsaacsWBNelsonWG2007Inflammation in prostate carcinogenesis. Nature Reviews. Cancer7256269. doi:10.1038/nrc2090.

    • Search Google Scholar
    • Export Citation
  • DesaiKVMichalowskaAMKondaiahPWardJMShihJHGreenJE2004Gene expression profiling identifies a unique androgen-mediated inflammatory/immune signature and a PTEN (phosphatase and tensin homolog deleted on chromosome 10)-mediated apoptotic response specific to the rat ventral prostate. Molecular Endocrinology1828952907. doi:10.1210/me.2004-0033.

    • Search Google Scholar
    • Export Citation
  • FibbiBMorelliAVignozziLFilippiSChavalmaneADe VitaGMariniMGacciMVannelliGBSandnerP2010aCharacterization of phosphodiesterase type 5 expression and functional activity in the human male lower urinary tract. Journal of Sexual Medicine75969. doi:10.1111/j.1743-6109.2009.01511.x.

    • Search Google Scholar
    • Export Citation
  • FibbiBPennaGMorelliAAdoriniLMaggiM2010bChronic inflammation in the pathogenesis of benign prostatic hyperplasia. International Journal of Andrology33475488. doi:10.1111/j.1365-2605.2009.00972.x.

    • Search Google Scholar
    • Export Citation
  • FilippiSVignozziLMorelliAChavalmaneAKSarchielliEFibbiBSaadFSandnerPRuggianoPVannelliGB2009Testosterone partially ameliorates metabolic profile and erectile responsiveness to PDE5 inhibitors in an animal model of male metabolic syndrome. Journal of Sexual Medicine632743288. doi:10.1111/j.1743-6109.2009.01467.x.

    • Search Google Scholar
    • Export Citation
  • HatakeyamaHNishizawaMNakagawaANakanoSKigoshiTUchidaK2002Testosterone inhibits tumor necrosis factor-alpha-induced vascular cell adhesion molecule-1 expression in human aortic endothelial cells. FEBS Letters530129132. doi:10.1016/S0014-5793(02)03440-3.

    • Search Google Scholar
    • Export Citation
  • IsaacsJTBrendlerCBWalshPC1983Changes in the metabolism of dihydrotestosterone in the hyperplastic human prostate. Journal of Clinical Endocrinology and Metabolism56139146. doi:10.1210/jcem-56-1-139.

    • Search Google Scholar
    • Export Citation
  • IssaMMReganTS2007Medical therapy for benign prostatic hyperplasia – present and future impact. American Journal of Managed Care1S4S9.

    • Search Google Scholar
    • Export Citation
  • KanaiTNemotoYKamadaNTotsukaTHisamatsuTWatanabeMHibiT2009Homeostatic (IL-7) and effector (IL-17) cytokines as distinct but complementary target for an optimal therapeutic strategy in inflammatory bowel disease. Current Opinion in Gastroenterology25306313. doi:10.1097/MOG.0b013e32832bc627.

    • Search Google Scholar
    • Export Citation
  • KozlowskiRKershenRTSirokyMBKraneRJAzadzoiKM2001Chronic ischemia alters prostate structure and reactivity in rabbits. Journal of Urology16510191026. doi:10.1016/S0022-5347(05)66595-0.

    • Search Google Scholar
    • Export Citation
  • KrajewskaMBanaresSZhangEEHuangXScadengMJhalaUSFengGSKrajewskiS2008Development of diabesity in mice with neuronal deletion of Shp2 tyrosine phosphatase. American Journal of Pathology17213121324. doi:10.2353/ajpath.2008.070594.

    • Search Google Scholar
    • Export Citation
  • KramerGMittereggerDMarbergerM2007Is benign prostatic hyperplasia (BPH) an immune inflammatory disease?European Urology5112021216. doi:10.1016/j.eururo.2006.12.011.

    • Search Google Scholar
    • Export Citation
  • LédéeNLombrosoRLombardelliLSelvaJDubanchetSChaouatGFrankenneFFoidardartJMMaggiERomagnaniS2008Cytokines and cemokines in follicular fluids and potential of the corresponding embryo: the role of granulocyte colony-stimulating factor. Human Reproduction2320012009. doi:10.1093/humrep/den192.

    • Search Google Scholar
    • Export Citation
  • LiaoWLinJXLeonardWJ2011IL-2 family cytokines: new insights into the complex roles of IL-2 as a broad regulator of T helper cell differentiation. Current Opinion in Immunology23598604. doi:10.1016/j.coi.2011.08.003.

    • Search Google Scholar
    • Export Citation
  • LiuCCHuangSPLiWMWangCJChouYHLiCCHuangCHWuWJ2007Relationship between serum testosterone and measures of benign prostatic hyperplasia in aging men. Urology70677680. doi:10.1016/j.urology.2007.05.025.

    • Search Google Scholar
    • Export Citation
  • LiuXLeungSWangCTanZWangJGuoTBFangLZhaoYWanBQinX2010Crucial role of interleukin-7 in T helper type 17 survival and expansion in autoimmune disease. Nature Medicine16191197. doi:10.1038/nm.2077.

    • Search Google Scholar
    • Export Citation
  • LottiFCoronaGColpiGMFilimbertiEDegli InnocentiSManciniMBaldiENociIFortiGAdoriniL2011Elevated body mass index correlates with higher seminal plasma interleukin 8 levels and ultrasonographic abnormalities of the prostate in men attending an andrology clinic for infertility. Journal of Endocrinological Investigation34336342.

    • Search Google Scholar
    • Export Citation
  • MengJMostaghelEAVakar-LopezFMontgomeryBTrueLNelsonPS2011Testosterone regulates tight junction proteins and influences prostatic autoimmune responses. Hormones & Cancer2145156. doi:10.1007/s12672-010-0063-1.

    • Search Google Scholar
    • Export Citation
  • MorelliAComeglioPFilippiSSarchielliECellaiIVignozziLYehiely-CohenRManeschiEGacciMCariniMTestosterone and farnesoid X receptor agonist INT-747 ounteract high fat diet-induced bladder alterations in a rabbit model of metabolic syndromeJournal of Steroid Biochemistry and Molecular Biology2012(http://dx.doi.org/10.1016/j.jsbmb.2012.02.007)

    • Search Google Scholar
    • Export Citation
  • NickelJCTrueLDKriegerJNBergerREBoagAHYoungIDparticipating members of the North American Chronic Prostatitis Collaborative Research Network and the International Prostatitis Collaborative Network2001Consensus development of a histopathological classification system for chronic prostatic inflammation. British Journal of Urology International87797805. doi:10.1046/j.1464-410x.2001.02193.x.

    • Search Google Scholar
    • Export Citation
  • NickelJCRoehrbornCGO'learyMPBostwickDGSomervilleMCRittmasterRS2007Examination of the relationship between symptoms of prostatitis and histological inflammation: baseline data from the REDUCE chemoprevention trial. Journal of Urology178896900. doi:10.1016/j.juro.2007.05.041.

    • Search Google Scholar
    • Export Citation
  • NickelJCRoehrbornCGO'LearyMPBostwickDGSomervilleMCRittmasterRS2008The relationship between prostate inflammation and lower urinary tract symptoms: examination of baseline data from the REDUCE trial. European Urology5413791384. doi:10.1016/j.eururo.2007.11.026.

    • Search Google Scholar
    • Export Citation
  • NorataGDTibollaGSeccomandiPMPolettiACatapanoAL2006Dihydrotestosterone decreases tumor necrosis factor-alpha and lipopolysaccharide-induced inflammatory response in human endothelial cells. Journal of Clinical Endocrinology and Metabolism91546554. doi:10.1210/jc.2005-1664.

    • Search Google Scholar
    • Export Citation
  • PennaGMondainiNAmuchasteguiSDegli InnocentiSCariniMGiubileiGFibbiBColliEMaggiMAdoriniL2007Seminal plasma cytokines and chemokines in prostate inflammation: interleukin 8 as a predictive biomarker in chronic prostatitis/chronic pelvic pain syndrome and benign prostatic hyperplasia. European Urology51524533. doi:10.1016/j.eururo.2006.07.016.

    • Search Google Scholar
    • Export Citation
  • PennaGFibbiBAmuchasteguiSCorsieroELavernyGSilvestriniEChavalmaneAMorelliASarchielliEVannelliGB2009The vitamin D receptor agonist elocalcitol inhibits IL-8-dependent benign prostatic hyperplasia stromal cell proliferation and inflammatory response by targeting the RhoA/Rho kinase and NF-kappaB pathways. Prostate69480493. doi:10.1002/pros.20896.

    • Search Google Scholar
    • Export Citation
  • PiccinniMPGiudiziMGBiagiottiRBeloniLGiannariniLSampognaroSParronchiPManettiRAnnunziatoFLiviC1995Progesterone favors the development of human T helper cells producing Th2-type cytokines and promotes both IL-4 production and membrane CD30 expression in established Th1 cell clones. Journal of Immunology155128133.

    • Search Google Scholar
    • Export Citation
  • QuintarAARothFDDe PaulALAokiAMaldonadoCA2006Toll-like receptor 4 in rat prostate: odulation by testosterone and acute bacterial infection in epithelial and stromal cells. Biology of Reproduction75664672. doi:10.1095/biolreprod.106.053967.

    • Search Google Scholar
    • Export Citation
  • RobinetteCL1988Sex-hormone-induced inflammation and fibromuscular proliferation in the rat lateral prostate. Prostate12271286. doi:10.1002/pros.2990120310.

    • Search Google Scholar
    • Export Citation
  • RoehrbornCGNuckollsJGWeiJTSteersW2007BPH Registry and Patient Survey Steering Committee. The benign prostatic hyperplasia registry and patient survey: study design, methods and patient baseline characteristics. BJU International100813819.

    • Search Google Scholar
    • Export Citation
  • RopiquetFGiriDLambDJIttmannM1999FGF7 and FGF2 are increased in benign prostatic hyperplasia and are associated with increased proliferation. Journal of Urology162595599. doi:10.1016/S0022-5347(05)68632-6.

    • Search Google Scholar
    • Export Citation
  • RotondiMChiovatoLRomagnaniSSerioMRomagnaniP2007Role of chemokines in endocrine autoimmune diseases. Endocrine Reviews28492520. doi:10.1210/er.2006-0044.

    • Search Google Scholar
    • Export Citation
  • SchauerIGRowleyDR2011The functional role of reactive stroma in benign prostatic hyperplasia. Differentiation82200210. doi:10.1016/j.diff.2011.05.007.

    • Search Google Scholar
    • Export Citation
  • ShigeharaKSugimotoKKonakaHIijimaMFukushimaMMaedaYMizokamiAKohEOrigasaHIwamotoT2011Androgen replacement therapy contributes to improving lower urinary tract symptoms in patients with hypogonadism and benign prostate hypertrophy: a randomised controlled study. Aging Male145358. doi:10.3109/13685538.2010.518178.

    • Search Google Scholar
    • Export Citation
  • SteinerGEStixUHandisuryaAWillheimMHaitelAReithmayrFPaiklDEckerRCHrachowitzKKramerG2003aCytokine expression pattern in benign prostatic hyperplasia infiltrating T cells and impact of lymphocytic infiltration on cytokine mRNA profile in prostatic tissue. Laboratory Investigation8311311146. doi:10.1097/01.LAB.0000081388.40145.65.

    • Search Google Scholar
    • Export Citation
  • SteinerGENewmanMEPaiklDStixUMemaran-DagdaNLeeCMarbergerMJ2003bExpression and function of proinflammatory interleukin IL-17 and IL-17 receptor in normal, benign hyperplastic, and malignant prostate. Prostate56171182. doi:10.1002/pros.10238.

    • Search Google Scholar
    • Export Citation
  • VignozziLMorelliAFilippiSComeglioPChavalmaneAKMarchettaMToceMYehiely-CohenRVannelliGBAdoriniL2011Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes. Journal of Sexual Medicine85777. doi:10.1111/j.1743-6109.2010.02073.x.

    • Search Google Scholar
    • Export Citation
  • VignozziLMorelliASarchielliEComeglioPFilippiSCellaiIManeschiESerniSGacciMCariniM2012Testosterone protects from metabolic syndrome-associated prostate inflammation: an experimental study in rabbit. Journal of Endocrinology2127184. doi:10.1530/JOE-11-0289.

    • Search Google Scholar
    • Export Citation
  • WelshMMoffatLMcNeillyABrownsteinDSaundersPTSharpeRMSmithLB2011Smooth muscle cell-specific knockout of androgen receptor: a new model for prostatic disease. Endocrinology15235413451. doi:10.1210/en.2011-0282.

    • Search Google Scholar
    • Export Citation
  • ZhangXHMorelliALuconiMVignozziLFilippiSMariniMVannelliGBMancinaRFortiGMaggiM2005Testosterone regulates PDE5 expression and in vivo responsiveness to tadalafil in rat corpus cavernosum. European Urology47409416. doi:10.1016/j.eururo.2004.10.021.

    • Search Google Scholar
    • Export Citation

Cited By

PubMed

Google Scholar