IL-1 induces IGF-dependent epithelial proliferation in prostate development and reactive hyperplasia

Hill R, Awe O, Bhola O, Orumwense O, Deosaran P, Seecharan P, Avula P, Mohammed R, Terapalli A, Jardine RM. A retrospective study of prostate-specific antigen and international prostate symptoms scores from participants at a men's health screening initiative in Trinidad

Background

This study describes the characteristics of men attending a primary health care screening initiative, determines the proportion of men who have elevated International Prostate Symptom Score (IPSS) scores and prostate-specific antigen (PSA) levels, and determines any correlation between these scores as indicators for benign prostatic hyperplasia (BPH) or prostate cancer.

Methods

Data were collected from all patient records during men's health screening initiatives that occurred in December 2018, January 2019, and March 2019 in Trinidad and Tobago. A total of 350 medical records were analyzed to record patient demographics, PSA levels, and IPSS scores. Analysis of the data was performed with the use of Statistical Package for the Social Sciences software (version 27).

Results

Most men who attended the screening initiative belonged to the 61-65 age group (20.57%), with more than half of the men being married (57.71%) and employed (52.57%) and of patients with comorbidities (17%), the most prevalent included hypertension (6%) and diabetes mellitus (3.7%). A mean PSA level of 2.94 ng/ml and a mean IPSS of 7.62 were recorded. Moreover, 11.5% of the males had elevated PSA levels (>4 ng/ml) and 32.9% had elevated IPSS levels (>8). There were correlations between PSA and IPSS values (r = 0.161 and P = 0.006). Age was a predictor of both IPSS and PSA values (r = 0.214, P = 0.000 and r = 0.192, P = 0.000, respectively). Among diabetic participants, a small but significant correlation between IPSS and diabetes was shown (r = 0.223, P = 0.028). As a predictor of elevated IPSS, diabetes had an odds ratio of 1.132 (95% confidence interval (CI): 1.021-1.255).

Conclusion

Our findings are similar to those described in previous studies; however, further investigations are required to fully describe the relationship between PSA and IPSS. This may assist in advancing screening measures and improving health outcomes for men with BPH and prostate cancer. Primary care physicians should recognize the possible association between BPH and diabetes mellitus and offer appropriate screening where indicated.

2,4-dichlorophenoxyacetic acid (2,4-D) exposure during postnatal development alters the effects of western diet on mouse prostate

Western diet (WD), abundant in saturated fats and simple carbohydrates, has been associated with the development of prostate diseases. In addition, 2,4-dichlorophenoxyacetic acid (2,4-D), an herbicide used in agricultural and non-agricultural settings, may interfere with the endocrine system impacting reproductive health. The association of both factors is something common in everyday life, however, there are no relevant studies associating them as possible modulators of prostatic diseases. This study evaluated the action of the herbicide 2,4-D on the postnatal development of the prostate in mice fed with WD. Male C57Bl/6J mice received simultaneously a WD and 2,4-D at doses of 0.02, 2.0, or 20.0 mg/kg b.w./day for 6 months. The prolongated WD intake induced obesity and glucose intolerance, increasing body weight and fat. WD induced morphological changes and increased PCNA-positive epithelial cells in prostate. Additionally, the WD increased gene expression of AR, antioxidant targets, inflammation-related cytokines, cell repair and turnover, and targets related to methylation and miRNAs biosynthesis compared to the counterpart (basal diet). 2,4-D (0.02 and 2.0) changed prostate morphology and gene expression evoked by WD. In contrast, the WD group exposed to 20 mg/kg of 2,4-D reduced feed intake and body weight, and increased expression of androgen receptor and genes related to cell repair and DNA methylation compared to the negative control. Our results showed that 2,4-D was able to modulate the effects caused by WD, mainly at lower doses. However, further studies are needed to elucidate the mechanisms of 2,4-D on the obesogenic environment caused by the WD.

Human prostate organoid generation and the identification of prostate development drivers using inductive rodent tissues

The reactivation of developmental genes and pathways during adulthood may contribute to pathogenesis of diseases such as prostate cancer. Analysis of the mechanistic links between development and disease could be exploited to identify signalling pathways leading to disease in the prostate. However, the mechanisms underpinning prostate development require further characterisation to interrogate fully the link between development and disease. Previously, our group developed methods to produce prostate organoids using induced pluripotent stem cells (iPSCs). Here, we show that human iPSCs can be differentiated into prostate organoids using neonatal rat seminal vesicle mesenchyme in vitro. The organoids can be used to study prostate development or modified to study prostate cancer. We also elucidated molecular drivers of prostate induction through RNA-sequencing analyses of the rat urogenital sinus and neonatal seminal vesicles. We identified candidate drivers of prostate development evident in the inductive mesenchyme and epithelium involved with prostate specification. Our top candidates included Spx, Trib3, Snai1, Snai2, Nrg2 and Lrp4. This work lays the foundations for further interrogation of the reactivation of developmental genes in adulthood, leading to prostate disease.

Vasectomy has No Impact on Future Lower Urinary Tract Symptoms Diagnoses: A Retrospective Cohort Claims Database Analysis

Purpose

The aim of this study was to assess whether there is an association between vasectomy and benign prostatic hyperplasia with associated lower urinary tract symptoms (BPH/LUTS) due to inflammatory etiology.

Materials and Methods

We assessed the incidence of BPH/LUTS in men who had undergone vasectomy in a matched cohort analysis using the TriNetX Research Network. We identified men aged 30 to 60 years who underwent vasectomy and had a follow-up visit within 6 months to 5 years after vasectomy from January 2010 through December 2022 and compared them with matched controls. Outcomes recorded include diagnoses of BPH (N40, N40.1), BPH-related medication prescriptions, and BPH-related procedures. We accounted for confounding variables through propensity score-matching for age; race; and history of comorbid medical conditions: hyperlipidemia (International Classification of Disease-10: E78), metabolic syndrome (E88.81), overweight or obesity (E66), testicular hypofunction (E29.1), hypertension (I10-I16), nicotine dependence (F17), and obstructive sleep apnea (G47.33).

Results

There was no significant difference in BPH diagnosis between postvasectomy men vs controls (0.84% vs 0.80%, RR: 0.95, 95% CI 0.86-1.05) or BPH/LUTS diagnosis (0.48% vs 0.44%, RR: 0.92, 95% CI 0.81-1.05) within 6 months to 5 years after vasectomy, respectively. No differences in BPH medication prescription (0.94% vs 0.84%) or rate of BPH procedures (0.022% vs 0.017%) were detected between the 2 groups.

Conclusions

This study suggests that vasectomy does not increase the risk of BPH development and/or LUTS worsening compared with the general population, providing assurance to both patients and health care providers who may consider vasectomy as a safe family planning option.

Lipidic extract of whole tomato reduces hyperplasia, oxidative stress and inflammation on testosterone-induced BPH in obese rats

PURPOSE

Tomato is an important source of lycopene, a carotenoid that has been emerging as a natural preventive agent for prostate disease. Moreover, tomato contains other components with a wide range of physiological properties, but their potential beneficial effects on prostatic hyperplasia (PH) during obesity have not been completely established. In this study, we compared the effect of a lipidic extract of tomato saladette (STE) with Serenoa repens (SR) on obese rats with PH.

METHODS

Forty-eight Wistar rats were divided in Control (C) and Obese (Ob) treated without (n = 12) and with (n = 36) testosterone enanthate (TE), once a week for 8 weeks to induce PH. After 4 weeks, SR and STE were administered. Biochemical parameters, oxidative stress markers and inflammatory cytokines production were determined.

RESULTS

TE increased prostate weight and caused prostatic hyperplasia in C group, and these effects were exacerbated by obesity. SR and STE reverted the increase in prostate weight and hyperplasia caused by TE in C and Ob groups. Obesity increased LDL, TGs, NOx and MAD, but decreased HDLc, GSx, SOD and CAT. SR reverted the effects of obesity, but these were significantly reduced and HDLc increased with STE. Obesity and TE increased TNFα, IL-1β and IL-6 levels, but these were partially reverted by STE compared with SR.

CONCLUSIONS

Excess of fat tissue increases the alterations by PH. STE diminishes these alterations compared with SR, suggesting its beneficial effect to improve prostate function. Whole tomato lipid extract could serve as sole therapy or as an adjunct to pharmacological treatment for PH.

Role of prostate stem cells and treatment strategies in benign prostate hyperplasia

Benign prostate hyperplasia (BPH) is a progressive disease with a direct correlation between incidence and age. Since the treatment and management of BPH involve harmful side effects and decreased quality of life for the patient, the primary focus of research should be to find better and longer-lasting therapeutic options. The mechanisms regulating prostate stem cells in development can be exploited to decrease prostate growth. BPH is defined as the overgrowth of the prostate, and BPH is often diagnosed when lower urinary tract symptoms (LUTS) of urine storage or voiding symptoms cause patients to seek treatment. While multiple factors are involved in the hyperplastic growth of the stromal and epithelial compartments of the prostate, the clonal proliferation of stem cells is considered one of the main reasons for BPH initiation and regrowth of the prostate after therapies for BPH fail. Several theories explain possible reasons for the involvement of stem cells in the development, progression, and pathogenesis of BPH. The aim of the current review is to discuss current literature on the fundamentals of prostate development and the role of stem cells in BPH. This review examines the rationale for the hypothesis that unregulated stem cell properties can lead to BPH and therapeutic targeting of stem cells may reduce treatment-related side effects and prevent the regrowth of the prostate.

A Review of Prostate Organogenesis and a Role for iPSC-Derived Prostate Organoids to Study Prostate Development and Disease

The prostate is vulnerable to two major age-associated diseases, cancer and benign enlargement, which account for significant morbidity and mortality for men across the globe. Prostate cancer is the most common cancer reported in men, with over 1.2 million new cases diagnosed and 350,000 deaths recorded annually worldwide. Benign prostatic hyperplasia (BPH), characterised by the continuous enlargement of the adult prostate, symptomatically afflicts around 50% of men worldwide. A better understanding of the biological processes underpinning these diseases is needed to generate new treatment approaches. Developmental studies of the prostate have shed some light on the processes essential for prostate organogenesis, with many of these up- or downregulated genes expressions also observed in prostate cancer and/or BPH progression. These insights into human disease have been inferred through comparative biological studies relying primarily on rodent models. However, directly observing mechanisms of human prostate development has been more challenging due to limitations in accessing human foetal material. Induced pluripotent stem cells (iPSCs) could provide a suitable alternative as they can mimic embryonic cells, and iPSC-derived prostate organoids present a significant opportunity to study early human prostate developmental processes. In this review, we discuss the current understanding of prostate development and its relevance to prostate-associated diseases. Additionally, we detail the potential of iPSC-derived prostate organoids for studying human prostate development and disease.

IL-1β Promotes Expansion of IL-33+ Lung Epithelial Stem Cells Following RSV Infection During Infancy

Respiratory syncytial virus (RSV)-induced immunopathogenesis and disease severity in neonatal mice and human infants have been related to elevated pulmonary IL-33. Thus, targeting IL-33 has been suggested as a potential therapy for respiratory viral infections. Yet, the regulatory mechanisms on IL-33 during early life remain unclear. Here, using a neonatal mouse model of RSV, we demonstrate that IL-1β positively regulates but is not required for RSV-induced expression of pulmonary IL-33 in neonatal mice early after the initial infection. Exogenous IL-1β upregulates RSV-induced IL-33 expression by promoting the proliferation of IL-33pos lung epithelial stem/progenitor cells (EpiSPC). These cells are exclusively detected in RSV-infected neonatal rather than adult mice, partially explaining the IL-1β-independent IL-33 expression in RSV-infected adult mice. Furthermore, IL-1β aggravates IL-33 mediated Th2 biased immunopathogenesis upon reinfection. Collectively, our study demonstrates that IL-1β exacerbates IL-33 mediated RSV immunopathogenesis by promoting the proliferation of IL-33pos EpiSPC in early life.

Ras/ERK and PI3K/AKT signaling differentially regulate oncogenic ERG mediated transcription in prostate cells

The TMPRSS2/ERG gene rearrangement occurs in 50% of prostate tumors and results in expression of the transcription factor ERG, which is normally silent in prostate cells. ERG expression promotes prostate tumor formation and luminal epithelial cell fates when combined with PI3K/AKT pathway activation, however the mechanism of synergy is not known. In contrast to luminal fates, expression of ERG alone in immortalized normal prostate epithelial cells promotes cell migration and epithelial to mesenchymal transition (EMT). Migration requires ERG serine 96 phosphorylation via endogenous Ras/ERK signaling. We found that a phosphomimetic mutant, S96E ERG, drove tumor formation and clonogenic survival without activated AKT. S96 was only phosphorylated on nuclear ERG, and differential recruitment of ERK to a subset of ERG-bound chromatin associated with ERG-activated, but not ERG-repressed genes. S96E did not alter ERG genomic binding, but caused a loss of ERG-mediated repression, EZH2 binding and H3K27 methylation. In contrast, AKT activation altered the ERG cistrome and promoted expression of luminal cell fate genes. These data suggest that, depending on AKT status, ERG can promote either luminal or EMT transcription programs, but ERG can promote tumorigenesis independent of these cell fates and tumorigenesis requires only the transcriptional activation function.

ERG is the most common oncogene in prostate cancer. The ERG protein can bind DNA and can activate some genes and repress others. Previous studies indicated that ERG cannot promote cancer by itself, but that ERG works together with mutations that activate the protein AKT. In this study we found that activation of AKT changes the genes that ERG regulates, leading to luminal epithelial differentiation, which is a hallmark of most prostate tumors. However, we also found that a mutant version of ERG that can activate, but cannot repress genes, can drive prostate tumorigenesis without activation of AKT, but this mutant ERG cannot promote luminal differentiation. Our findings suggest that ERG mediated tumorigenesis only requires ERG’s activation function and can occur independent of luminal cell differentiation.

IL1A and IL1B gene polymorphisms and keratoconus susceptibility: evidence from an updated meta-analysis

Background: Several single-nucleotide polymorphisms (SNPs) in IL1B genes have been associated with KTCN. However, the results of these studies were not conclusive. This meta-analysis association study is aimed to quantitatively estimate the association of IL1B rs16944 (g.4490T>C) and rs1143627 (g.4970C>T), and IL1A rs2071376 (c.615 + 169C>A) polymorphisms with KTCN susceptibility.Materials and Methods: Systematic literature search was performed in Web of Science, MEDLINE, PubMed, Scopus, and Google Scholar databases. The odds ratios (ORs) and 95% confidence intervals (CI) were calculated assuming different contrasted genetic models.Results: The reference T allele of IL1B (g.4490T>C) polymorphism was significantly associated with decreased KTCN risk under all assessed genetic models. Regarding the reference C allele of IL1B (g.4970C>T) polymorphism, decreased risk of KTCN was found. The reference C allele of IL1A (c.615 + 169C>A) polymorphism conferred a decreased risk of KTCN under heterozygous codominant (AC vs. AA), homozygous codominant (CC vs. AA), and dominant (AC+CC vs. AA) genetic models. The pooling estimates showed that the T C haplotype was associated with a significant increase in KTCN risk. In contrast, the T T haplotype was correlated with a decreased risk of KTCN. With the assumption of a prior probability of 0.25, the false-positive report probability (FPRP) values were less than 0.2, indicating the observed significant associations were notable.Conclusion: These findings propose that the studied IL1B polymorphisms and the IL1A variation have opposite effects on KTCN susceptibility. More large-scale replication studies are warranted to illuminate the precise role of these SNPs on the etiology of eye disorders.

Plasma Rich in Growth Factors (PRGF) Increases the Number of Retinal Müller Glia in Culture but Not the Survival of Retinal Neurons

Plasma rich in growth factors (PRGF) is a subtype of platelet-rich plasma (PRP) that stimulates tissue regeneration and may promote neuronal survival. It has been employed in ophthalmology to achieve tissue repair in some retinal pathologies, although how PRGF acts in the retina is still poorly understood. As a part of the central nervous system, the retina has limited capacity for repair capacity following damage, and retinal insult can provoke the death of retinal ganglion cells (RGCs), potentially producing irreversible blindness. RGCs are in close contact with glial cells, such as Müller cells, that help maintain homeostasis in the retina. In this study, the aim was to determine whether PRGF can protect RGCs and whether it increases the number of Müller cells. Therefore, PRGF were tested on primary cell cultures of porcine RGCs and Müller cells, as well as on co-cultures of these two cell types. Moreover, the inflammatory component of PRGF was analyzed and the cytokines in the different PRGFs were quantified. In addition, we set out to determine if blocking the inflammatory components of PRGF alters its effect on the cells in culture. The presence of PRGF compromises RGC survival in pure cultures and in co-culture with Müller cells, but this effect was reversed by heat-inactivation of the PRGF. The detrimental effect of PRGF on RGCs could be in part due to the presence of cytokines and specifically, to the presence of pro-inflammatory cytokines that compromise their survival. However, other factors are likely to be present in the PRGF that have a deleterious effect on the RGCs since the exposure to antibodies against these cytokines were insufficient to protect RGCs. Moreover, PRGF promotes Müller cell survival. In conclusion, PRGF hinders the survival of RGCs in the presence or absence of Müller cells, yet it promotes Müller cell survival that could be the reason of retina healing observed in the in vivo treatments, with some cytokines possibly implicated. Although PRGF could stimulate tissue regeneration, further studies should be performed to evaluate the effect of PRGF on neurons and the implication of its potential inflammatory role in such processes.

Cellular Senescence in Renal and Urinary Tract Disorders

Cellular senescence is a state of cell cycle arrest induced by repetitive cell mitoses or different stresses, which is implicated in various physiological or pathological processes. The beneficial or adverse effects of senescent cells depend on their transitory or persistent state. Transient senescence has major beneficial roles promoting successful post-injury repair and inhibiting malignant transformation. On the other hand, persistent accumulation of senescent cells has been associated with chronic diseases and age-related illnesses like renal/urinary tract disorders. The deleterious effects of persistent senescent cells have been related, in part, to their senescence-associated secretory phenotype (SASP) characterized by the release of a variety of factors responsible for chronic inflammation, extracellular matrix adverse remodeling, and fibrosis. Recently, an increase in senescent cell burden has been reported in renal, prostate, and bladder disorders. In this review, we will summarize the molecular mechanisms of senescence and their implication in renal and urinary tract diseases. We will also discuss the differential impacts of transient versus persistent status of cellular senescence, as well as the therapeutic potential of senescent cell targeting in these diseases.

The role of the androgen receptor in prostate development and benign prostatic hyperplasia: A review

Benign prostatic hyperplasia (BPH) is a benign enlargement of the prostate in which incidence increases linearly with age, beginning at about 50 years old. BPH is a significant source of morbidity in aging men by causing lower urinary tract symptoms and acute urinary retention. Unfortunately, the etiology of BPH incidence and progression is not clear. This review highlights the role of the androgen receptor (AR) in prostate development and the evidence for its involvement in BPH. The AR is essential for normal prostate development, and individuals with defective AR signaling, such as after castration, do not experience prostate enlargement with age. Furthermore, decreasing dihydrotestosterone availability through therapeutic targeting with 5α-reductase inhibitors diminishes AR activity and results in reduced prostate size and symptoms in some BPH patients. While there is some evidence that AR expression is elevated in certain cellular compartments, how exactly AR is involved in BPH progression has yet to be elucidated. It is possible that AR signaling within stromal cells alters intercellular signaling and a "reawakening" of the embryonic mesenchyme, loss of epithelial AR leads to changes in paracrine signaling interactions, and/or chronic inflammation aids in stromal or epithelial proliferation evident in BPH. Unfortunately, a subset of patients fails to respond to current medical approaches, forcing surgical treatment even though age or associated co-morbidities make surgery less attractive. Fundamentally, new therapeutic approaches to treat BPH are not currently forthcoming, so a more complete molecular understanding of BPH etiology is necessary to identify new treatment options.

Urinary Metabolomic and Proteomic Analyses in a Mouse Model of Prostatic Inflammation

Lower urinary tract symptoms (LUTS) are common among aging men. Since prostatic inflammation is one of its etiologies, it is plausible that urinary metabolite and protein biomarkers could be identified and used to diagnose inflammation-induced LUTS. We characterized the urine metabolome and proteome in a mouse model of bacterial-induced prostatic inflammation. Mass Spectrometry (MS)-based multi-omics analysis was employed to discover urinary protein and metabolite-based biomarkers. The investigation of isobaric dimethylated leucine (DiLeu) labeling on metabolites allowed metabolomics and proteomics analysis on the same liquid chromatography (LC)-MS platform. In total, 143 amine-containing metabolites and 1058 urinary proteins were identified and quantified (data are available via ProteomeXchange with identifier PXD018023); among them, 14 metabolites and 168 proteins were significantly changed by prostatic inflammation. Five metabolic pathways and four inflammation-related biological processes were potentially disrupted. By comparing our findings with urinary biomarkers identified in a mouse model of genetic-induced prostate inflammation and with those previously found to be associated with LUTS in older men, we identified creatine, haptoglobin, immunoglobulin kappa constant and polymeric Ig receptor as conserved biomarkers for prostatic inflammation associated with LUTS. These data suggest that these putative biomarkers could be used to identify men in which prostate inflammation is present and contributing to LUTS.

Comprehensive urinary metabolomic characterization of a genetically induced mouse model of prostatic inflammation

Dysfunction of the lower urinary tract commonly afflicts the middle-aged and aging male population. The etiology of lower urinary tract symptoms (LUTS) is multifactorial. Benign prostate hyperplasia, fibrosis, smooth muscle contractility, and inflammation likely contribute. Here we aim to characterize the urinary metabolomic profile associated with prostatic inflammation, which could inform future personalized diagnosis or treatment, as well as mechanistic research. Quantitative urinary metabolomics was conducted to examine molecular changes following induction of inflammation via conditional Interleukin-1β expression in prostate epithelia using a novel transgenic mouse strain. To advance method development for urinary metabolomics, we also compared different urine normalization methods and found that normalizing urine samples based on osmolality prior to LC-MS most completely separated urinary metabolite profiles of mice with and without prostate inflammation via principal component analysis. Global metabolomics was combined with advanced machine learning feature selection and classification for data analysis. Key dysregulated metabolites and pathways were identified and were relevant to prostatic inflammation, some of which overlapped with our previous study of human LUTS patients. A binary classification model was established via the support vector machine algorithm to accurately differentiate control and inflammation groups, with an area-under-the-curve value of the receiver operating characteristic of 0.81, sensitivity of 0.974 and specificity of 0.995, respectively. This study generated molecular profiles of non-bacterial prostatic inflammation, which could assist future efforts to stratify LUTS patients and develop new therapies.

Growth hormone-releasing hormone antagonists reduce prostatic enlargement and inflammation in carrageenan-induced chronic prostatitis

BACKGROUND

Inflammation plays a key role in the etiology of benign prostatic hyperplasia (BPH) through multiple pathways involving the stimulation of proliferation by cytokines and growth factors as well as the induction of the focal occurrence of epithelial-to-mesenchymal transition (EMT). We have previously reported that GHRH acts as a prostatic growth factor in experimental BPH and in autoimmune prostatitis models and its blockade with GHRH antagonists offer therapeutic approaches for these conditions. Our current study was aimed at the investigation of the beneficial effects of GHRH antagonists in λ-carrageenan-induced chronic prostatitis and at probing the downstream molecular pathways that are implicated in GHRH signaling.

METHODS

To demonstrate the complications triggered by recurrent/chronic prostatic inflammation in Sprague-Dawley rats, 50 μL 3% carrageenan was injected into both ventral prostate lobes two times, 3 weeks apart. GHRH antagonist, MIA-690, was administered 5 days after the second intraprostatic injection at 20 μg daily dose for 4 weeks. GHRH-induced signaling events were identified in BPH-1 and in primary prostate epithelial (PrEp) cells at 5, 15, 30, and 60 min with Western blot.

RESULTS

Inflammation induced prostatic enlargement and increased the area of the stromal compartment whereas treatment with the GHRH antagonist significantly reduced these effects. This beneficial activity was consistent with a decrease in prostatic GHRH, inflammatory marker COX-2, growth factor IGF-1 and inflammatory and EMT marker TGF-β1 protein levels and the expression of multiple genes related to EMT. In vitro, GHRH stimulated multiple pathways involved in inflammation and growth in both BPH-1 and PrEp cells including NFκB p65, AKT, ERK1/2, EGFR, STAT3 and increased the levels of TGF-β1 and Snail/Slug. Most interestingly, GHRH also stimulated the transactivation of the IGF receptor.

CONCLUSIONS

The study demonstrates that GHRH antagonists could be beneficial for the treatment of prostatic inflammation and BPH in part by inhibiting the growth-promoting and inflammatory effects of locally produced GHRH.

Inflammation and NF-κB Signaling in Prostate Cancer: Mechanisms and Clinical Implications

Prostate cancer is a highly prevalent form of cancer that is usually slow-developing and benign. Due to its high prevalence, it is, however, still the second most common cause of death by cancer in men in the West. The higher prevalence of prostate cancer in the West might be due to elevated inflammation from metabolic syndrome or associated comorbidities. NF-κB activation and many other signals associated with inflammation are known to contribute to prostate cancer malignancy. Inflammatory signals have also been associated with the development of castration resistance and resistance against other androgen depletion strategies, which is a major therapeutic challenge. Here, we review the role of inflammation and its link with androgen signaling in prostate cancer. We further describe the role of NF-κB in prostate cancer cell survival and proliferation, major NF-κB signaling pathways in prostate cancer, and the crosstalk between NF-κB and androgen receptor signaling. Several NF-κB-induced risk factors in prostate cancer and their potential for therapeutic targeting in the clinic are described. A better understanding of the inflammatory mechanisms that control the development of prostate cancer and resistance to androgen-deprivation therapy will eventually lead to novel treatment options for patients.

Phage Therapy in Prostatitis: Recent Prospects

Prostatitis has various etiology including bacterial infection and dysregulated immunity; some of its forms remain a serious therapeutic challenge. Inflammation occurs in all forms of this disorder and is proposed to predispose to the development of prostate cancer (PC). There are reports that phage therapy is effective in chronic bacterial prostatitis. Recent findings suggest that phages not only eliminate bacteria, but also mediate immunomodulating (for example, anti-inflammatory) functions. The immunomodulating effects of phages could be beneficial in treating all forms of prostatitis and play some role in the prevention of the development of PC. As the etiological factors contributing to the majority of prostatitis cases remains largely unknown, and management options are often likewise limited, phage therapy merits further research as an attractive therapeutic option given its immunomodulating effects irrespective of the underlying causative factor(s).

Dual regulation of decorin by androgen and Hedgehog signaling during prostate morphogenesis

BACKGROUND

Prostate ductal branching morphogenesis involves a complex spatiotemporal regulation of cellular proliferation and remodeling of the extracellular matrix (ECM) around the developing ducts. Decorin (Dcn) is a small leucine-rich proteoglycan known to sequester several growth factors and to act as a tumor suppressor in prostate cancer.

RESULTS

Dcn expression in the developing prostate paralleled branching morphogenesis and was dynamically regulated by androgen and Hedgehog (Hh) signaling. DCN colocalized with collagen in the periductal stroma and acellular interstitium. Exogenous DCN decreased epithelial proliferation in ex vivo organ cultures of developing prostate, whereas genetic ablation of Dcn resulted in increased epithelial proliferation in the developing prostate.

CONCLUSIONS

Dcn expression and localization in the developing prostate is consistent with a primary role in organizing collagen around the developing ducts. Regulation of Dcn expression appears to be complex, involving both androgen and Hh signaling. The growth inhibitory effect of Dcn suggests a unique linkage between a structural proteoglycan and epithelial growth regulation. This may serve to coordinate two elements of the morphogenetic process: ductal growth and organization of the collagen matrix around the nascent duct. Developmental Dynamics 247:679-685, 2018. © 2018 Wiley Periodicals, Inc.

Morphoregulatory pathways in prostate ductal development

The mouse prostate is a male sex-accessory gland comprised of a branched ductal network arranged into three separate bilateral lobes: the anterior, dorsolateral, and ventral lobes. Prostate ductal development is the primary morphogenetic event in prostate development and requires a complex regulation of spatiotemporal factors. This review provides an overview of prostate development and the major genetic regulators and signaling pathways involved. To identify new areas for further study, we briefly highlight the likely important, but relatively understudied, role of the extracellular matrix (ECM). Finally, we point out the potential importance of the ECM in influencing the behavior and prognosis of prostate cancer. Developmental Dynamics 246:89-99, 2017. © 2016 Wiley Periodicals, Inc.

Intraurethral injection with LPS: an effective experimental model of prostatic inflammation

OBJECTIVE

Chronic inflammation has been recognized as having a prominent role pathogenesis of benign prostatic hyperplasia (BPH) and cancer. It is believed that chronic inflammation induces prostatic fibromuscular growth. This correlation has been clearly illustrated by both in vivo and in vitro studies; however, current experimental models of BPH require complex surgery or hormonal treatment. Therefore, the aim of the present study was to propose a new murine model of BPH/prostatitis induced by intraurethral injection of LPS.

METHODS

Male Swiss and C57Bl/6 mice were then sacrificed 3, 7, 10, and 14 days after intraurethral injection of LPS. The prostates were quickly dissected and fixed for morphological and immunohistochemical analyses.

RESULTS

The results showed that LPS played an important role in the cell proliferation of the prostate. Histological and ultrastructural analysis showed epithelial hyperplasia, clear stromal cells, little inflammatory infiltration, and heavy bleeding. Treatment with LPS also promoted the increase of growth factor (FGF-7 and TGF-β), α-actin, and proinflammatory cytokines (IL-1, IL-6, IL-17), both in the stroma and epithelium.

CONCLUSION

According to the present findings, it can be concluded that the intraurethral administration of LPS promotes tissue remodeling, as well as stimulating the pattern of pro-inflammatory cytokines, and therefore, constitutes an effective experimental model of BPH/inflammation.

Prostate organogenesis: tissue induction, hormonal regulation and cell type specification

Prostate organogenesis is a complex process that is primarily mediated by the presence of androgens and subsequent mesenchyme-epithelial interactions. The investigation of prostate development is partly driven by its potential relevance to prostate cancer, in particular the apparent re-awakening of key developmental programs that occur during tumorigenesis. However, our current knowledge of the mechanisms that drive prostate organogenesis is far from complete. Here, we provide a comprehensive overview of prostate development, focusing on recent findings regarding sexual dimorphism, bud induction, branching morphogenesis and cellular differentiation.

Is there room for behavioral and modifiable health-related targets in the lower urinary tract symptoms' scenario

PURPOSE

To better understand potential modifiable risk factors guiding preventive interventions against lower urinary tract symptoms (LUTS).

METHODS

A prospective cross-sectional study, including healthy men aged 40-70 years under routine urological evaluation, measured the strength of association between the International Prostate Symptom Score (IPSS) and socio-demographic, lifestyle, and health-related factors using logistic and linear regression adjusted for confounding factors. Men with urethral or prostate surgery were excluded.

RESULTS

Among 743 men, mean age 59.64 ± 9.66, 22.6% reported moderate, and 5.0% severe LUTS. The adjusted odds of severe LUTS increased with: increasing age (OR = 1.07, 95% CI = 1.05-1.09, p < .0001), increasing prostate volume (OR = 1.02, 95% CI = 1.01-1.04, p = .004), decreasing education (tertiary qualification, no versus yes, OR = 2.34; 95% CI = 1.16-4.70; p = .0133), delayed ejaculation (yes versus no, OR = 2.63, 95% CI = 1.43-4.83, p < .0001), and increasing blood pressure (systolic ≥130 mmHg, OR = 2.03, 95% CI = 1.44-2.86, p < .0001 or diastolic ≥85 mmHg, OR = 1.47, 95% CI = 1.03-2.10, p = .0345); severe LUTS decreased with: increasing the weekly sexual frequency (OR = 0.80, 95% CI = 0.69-0.91, p = .0012) and increasing HDL cholesterol (OR = 0.98, 95% CI = 0.97-0.99, p = .037). Odds were not significant for age of sexual initiation, precocious ejaculation, masturbatory pattern, physical activity, smoking, alcohol consumption, penile length (objective and subjective), abdominal circumference, obesity, comorbid conditions, metabolic syndrome, serum glycaemia, testosterone, SHBG, PSA, and estradiol.

CONCLUSIONS

One in every four men under routine urological evaluation who considered themselves healthy present moderate and severe LUTS. Modifiable behavioral (education, sexual frequency, and ejaculation) and health-related (blood pressure and HDL cholesterol) targets were identified for future interventional studies and potential preventive actions and patient counseling.

Atorvastatin attenuates testosterone-induced benign prostatic hyperplasia in rats: role of peroxisome proliferator-activated receptor-γ and cyclo-oxygenase-2

Diabetes and obesity have been reported to alter sex steroid hormone metabolism. In this study, an attempt was made to investigate the protective effect of atorvastatin (ATR) in combination with celecoxib (CEL) or pioglitazone (PIO) on testosterone-induced BPH in rats. Male Wistar rats (200-250 g) were randomly divided into nine groups (n = 8) and orally treated as follows for 28 consecutive days: group 1: vehicle control (10 mL/kg); group 2: vehicle testosterone (10 mL/kg); groups 3 - 5: ATR (0.5, 2.5, and 5 mg/kg, respectively); group 6: CEL (20 mg/kg); group 7: PIO (20 mg/kg); and groups 8-9: ATR 0.5 mg/kg, and 15 min later, animals were given CEL (20 mg/kg) or PIO (20 mg/kg), respectively. One hour post-treatment, animals in groups 2-9 were given testosterone propionate (3 mg/kg, s.c.). Twenty-four hours after last treatment on day 28, blood was collected for serum testosterone and prostate-specific antigen (PSA) analysis. Prostate was harvested for biochemical and histological assays. Subcutaneous injection of testosterone increased serum levels of testosterone and PSA which was ameliorated by pretreatments of rat with ATR, celecoxib, or pioglitazone. Similarly, testosterone-induced increase in MDA and reduction in the activity of GSH, superoxide dismutase (SOD), and catalase were attenuated by ATR. Conversely, celecoxib or pioglitazone treatment failed to affect the activity of antioxidant enzymes. The histology of the prostate showed significant improvement in prostatic cells of ATR, celecoxib, or pioglitazone treated. Findings from the study showed that atorvastatin attenuated testosterone-induced BPH. Moreover, synergistic effect was observed when atorvastatin was combined with celecoxib.

Review of Prostate Anatomy and Embryology and the Etiology of Benign Prostatic Hyperplasia

Prostate development follows a common pattern between species and depends on the actions of androgens to induce and support ductal branching morphogenesis of buds emerging from the urogenital sinus. The human prostate has a compact zonal anatomy immediately surrounding the urethra and below the urinary bladder. Rodents have a lobular prostate with lobes radiating away from the urethra. The human prostate is the site of benign hyperplasia, prostate cancer, and prostatitis. The rodent prostate has little naturally occurring disease. Rodents can be used to model aspects of human benign hyperplasia, but care should be taken in data interpretation and extrapolation to the human condition.

Non-Cell-Autonomous Regulation of Prostate Epithelial Homeostasis by Androgen Receptor

Prostate inflammation has been suggested as an etiology for benign prostatic hyperplasia (BPH). We show that decreased expression of the androgen receptor (AR) in luminal cells of human BPH specimens correlates with a higher degree of regional prostatic inflammation. However, the cause-and-effect relationship between the two events remains unclear. We investigated specifically whether attenuating AR activity in prostate luminal cells induces inflammation. Disrupting luminal cell AR signaling in mouse models promotes cytokine production cell-autonomously, impairs epithelial barrier function, and induces immune cell infiltration, which further augments local production of cytokines and chemokines including Il-1 and Ccl2. This inflammatory microenvironment promotes AR-independent prostatic epithelial proliferation, which can be abolished by ablating IL-1 signaling or depleting its major cellular source, the macrophages. This study demonstrates that disrupting luminal AR signaling promotes prostate inflammation, which may serve as a mechanism for resistance to androgen-targeted therapy for prostate-related diseases.

The role of prostate inflammation and fibrosis in lower urinary tract symptoms

Lower urinary tract symptoms (LUTS) in aging men are extremely common. They have historically been attributed to benign prostatic hyperplasia (BPH), enlargement of the prostate, and bladder outlet obstruction. However, recent studies have revealed acute and chronic inflammation to be highly associated with LUTS, correlated with prostatic enlargement, and implicated as a cause of prostatic fibrosis that contributes to bladder outlet obstruction. This review examines the evidence implicating inflammation and fibrosis in BPH/LUTS. It identifies potential mechanisms by which inflammation may drive nociceptive signaling as well as hyperplastic growth and fibrosis and identifies targets for pharmacological intervention. This is a promising area for research and development of novel therapies to prevent or more effectively treat LUTS in aging men.

Coordinated induction of cell survival signaling in the inflamed microenvironment of the prostate

PURPOSE

Both prostate cancer and benign prostatic hyperplasia are associated with inflammatory microenvironments. Inflammation is damaging to tissues, but it is unclear how the inflammatory microenvironment protects specialized epithelial cells that function to proliferate and repair the tissue. The objective of this study is to characterize the cell death and cell survival response of the prostatic epithelium in response to inflammation.

METHODS

We assessed induction of cell death (TNF, TRAIL, TWEAK, FasL) and cell survival factors (IGFs, hedgehogs, IL-6, FGFs, and TGFs) in inflamed and control mouse prostates by ELISA. Cell death mechanisms were determined by immunoblotting and immunofluorescence for cleavage of caspases and TUNEL. Survival pathway activation was assessed by immunoblotting and immunofluorescence for Mcl-1, Bcl-2, Bcl-XL, and survivin. Autophagy was determined by immunoblotting and immunofluorescence for free and membrane associated light chain 3 (LC-3).

RESULTS

Cleavage of all four caspases was significantly increased during the first 2 days of inflammation, and survival protein expression was substantially increased subsequently, maximizing at 3 days. By 5 days of inflammation, 50% of prostatic epithelial cells expressed survivin. Autophagy was also evident during the recovery phase (3 days). Finally, immunofluorescent staining of human specimens indicates strong activation of survival proteins juxtaposed to inflammation in inflamed prostate specimens.

CONCLUSIONS

The prostate responds to deleterious inflammation with induction of cell survival mechanisms, most notably survivin and autophagy, demonstrating a coordinated induction of survival factors that protects and expands a specialized set of prostatic epithelial cells as part of the repair and recovery process during inflammation.

Effect of obesity and hyperglycemia on benign prostatic hyperplasia in elderly patients with newly diagnosed type 2 diabetes

PURPOSE

To investigate the relationship between blood glucose levels, age, body mass index (BMI), and benign prostatic hyperplasia (BPH) in patients with newly diagnosed type 2 diabetes.

METHODS

A total of 141 BPH patients with newly diagnosed type 2 diabetes participated in this study. Their glucose level, international prostate symptom score (IPSS), prostate volume (PV), and maximum urinary flow rate (Qmax) were determined and analyzed.

RESULTS

Compared to patients in 60-69 years of age, those in 70-79 years of age had higher IPSS and PV values (11.10±2.68 vs. 16.09±2.64, respectively; P<0.01; 38.67±4.65 vs. 44.76±2.84, respectively; P<0.01) as did patients ≥80 y (11.10±2.68 vs. 19.87±3.35, respectively; P<0.01; 38.67±4.65 vs. 51.38±3.74, respectively; P<0.01). The Qmax was lower in the ≥80 y group compared to the 60-69 y group (7.91±2.13 vs. 13.50±1.75, respectively; P<0.01). IPSS, PV, and insulin resistance index (HOMA-IR) were higher in patients with a BMI ≥28 kg/m(2) group as compared to those with a BMI <24 kg/m(2) group. IPSS and PV values were higher in patients with HbA1c levels ≥6.5% than in those with HbA1c<6.5% (16.30±3.31 vs. 9.87±1.07, respectively; P<0.01; 45.69±3.97 vs. 36.64±3.30, respectively; P<0.01), and the Qmax was lower (10.61±1.98 vs. 14.40±0.82, respectively; P<0.01).

CONCLUSIONS

Aging, obesity, high glucose level, and insulin resistance increase the risk of BPH progression in elderly patients with newly diagnosed type 2 diabetes. Managing body weight and lowering the level of glycosylated hemoglobin may slow the progression of BPH in people with type 2 diabetes.

Expansion of prostate epithelial progenitor cells after inflammation of the mouse prostate

Prostatic inflammation is a nearly ubiquitous pathological feature observed in specimens from benign prostate hyperplasia and prostate cancer patients. The microenvironment of the inflamed prostate is highly reactive, and epithelial hyperplasia is a hallmark feature of inflamed prostates. How inflammation orchestrates epithelial proliferation as part of its repair and recovery action is not well understood. Here, we report that a novel epithelial progenitor cell population is induced to expand during inflammation. We used sphere culture assays, immunofluorescence, and flow cytometry to show that this population is increased in bacterially induced inflamed mouse prostates relative to naïve control prostates. We confirmed from previous reports that this population exclusively possesses the ability to regrow entire prostatic structures from single cell culture using renal grafts. In addition, putative progenitor cells harvested from inflamed animals have greater aggregation capacity than those isolated from naïve control prostates. Expansion of this critical cell population requires IL-1 signaling, as IL-1 receptor 1-null mice exhibit inflammation similar to wild-type inflamed animals but exhibit significantly reduced progenitor cell proliferation and hyperplasia. These data demonstrate that inflammation promotes hyperplasia in the mouse prostatic epithelium by inducing the expansion of a selected epithelial progenitor cell population in an IL-1 receptor-dependent manner. These findings may have significant impact on our understanding of how inflammation promotes proliferative diseases such as benign prostatic hyperplasia and prostate cancer, both of which depend on expansion of cells that exhibit a progenitor-like nature.

Prostatic inflammation induces urinary frequency in adult mice

Lower urinary tract symptoms (LUTS) including urinary frequency and nocturia are common in aging men. Recent studies have revealed a strong association of prostatic inflammation with LUTS. We developed an animal model of bacterial induced, isolated prostatic inflammation and examined the effect of prostatic inflammation on voiding behavior in adult C57BL/6J mice. Prostatic inflammation was induced by transurethral inoculation of uropathogenic E. coli—1677. Bacterial cystitis was prevented by continuous administration of nitrofurantoin. Hematoxylin and eosin (H&E) staining and bacterial culture were preformed to validate our animal model. Voiding behavior was examined by metabolic cage testing on post-instillation day 1 (PID 1), PID 4, PID 7 and PID 14 and both voiding frequency and volume per void were determined. Mice with prostatic inflammation showed significantly increased voiding frequency at PID 1, 7 and 14, and decreased volume per void at all time points, as compared to mice instilled with saline and receiving nitrofurantoin (NTF). Linked analysis of voiding frequency and voided volumes revealed an overwhelming preponderance of high frequency, low volume voiding in mice with prostatic inflammation. These observations suggest that prostatic inflammation may be causal for symptoms of urinary frequency and nocturia.

Interleukin-driven insulin-like growth factor promotes prostatic inflammatory hyperplasia

Prostatic inflammation is of considerable importance to urologic research because of its association with benign prostatic hyperplasia and prostate cancer. However, the mechanisms by which inflammation leads to proliferation and growth remain obscure. Here, we show that insulin-like growth factors (IGFs), previously known as critical developmental growth factors during prostate organogenesis, are induced by inflammation as part of the proliferative recovery to inflammation. Using genetic models and in vivo IGF receptor blockade, we demonstrate that the hyperplastic response to inflammation depends on interleukin-1-driven IGF signaling. We show that human prostatic hyperplasia is associated with IGF pathway activation specifically localized to foci of inflammation. This demonstrates that mechanisms of inflammation-induced epithelial proliferation and hyperplasia involve the induction of developmental growth factors, further establishing a link between inflammatory and developmental signals and providing a mechanistic basis for the management of proliferative diseases by IGF pathway modulation.

Stromal androgen receptor in prostate development and cancer

The androgen receptor (AR) in stromal cells contributes significantly to the development and growth of prostate during fetal stages as well as during prostate carcinogenesis and cancer progression. During prostate development, stromal AR induces and promotes epithelial cell growth, as observed from tissue recombinant and mouse knockout studies. During prostate carcinogenesis and progression, the stromal cells begin to lose AR expression as early as at the stage of high-grade prostatic intraepithelial neoplasia. The extent of loss of stromal AR is directly proportional to the degree of differentiation (Gleason grade) and progression of prostate cancer (PCa). Co-culture studies suggested that stromal AR inhibits the growth of malignant epithelial cells, possibly through expression of certain paracrine factors in the presence of androgens. This functional reversal of stromal AR, from growth promotion during fetal prostate development to mediating certain growth-inhibiting effects in cancer, explains to some extent the reason that loss of AR expression in stromal cells may be crucial for development of resistance to androgen ablation therapy for PCa. From a translational perspective, it generates the need to re-examine the current therapeutic options and opens a fundamental new direction for therapeutic interventions, especially in advanced PCa.

Beneficial autoimmunity at body surfaces - immune surveillance and rapid type 2 immunity regulate tissue homeostasis and cancer

Epithelial cells (ECs) line body surface tissues and provide a physicochemical barrier to the external environment. Frequent microbial and non-microbial challenges such as those imposed by mechanical disruption, injury or exposure to noxious environmental substances including chemicals, carcinogens, ultraviolet-irradiation, or toxins cause activation of ECs with release of cytokines and chemokines as well as alterations in the expression of cell-surface ligands. Such display of epithelial stress is rapidly sensed by tissue-resident immunocytes, which can directly interact with self-moieties on ECs and initiate both local and systemic immune responses. ECs are thus key drivers of immune surveillance at body surface tissues. However, ECs have a propensity to drive type 2 immunity (rather than type 1) upon non-invasive challenge or stress – a type of immunity whose regulation and function still remain enigmatic. Here, we review the induction and possible role of type 2 immunity in epithelial tissues and propose that rapid immune surveillance and type 2 immunity are key regulators of tissue homeostasis and carcinogenesis.

Prostate angiogenesis in development and inflammation

BACKGROUND

Prostatic inflammation is an important factor in development and progression of BPH/LUTS. This study was performed to characterize the normal development and vascular anatomy of the mouse prostate and then examine, for the first time, the effects of prostatic inflammation on the prostate vasculature.

METHODS

Adult mice were perfused with India ink to visualize the prostatic vascular anatomy. Immunostaining was performed on the E16.5 UGS and the P5, P20, and adult prostate to characterize vascular development. Uropathogenic E. coli 1677 was instilled transurethrally into adult male mice to induce prostate inflammation. RT-PCR and BrdU labeling was performed to assay anigogenic factor expression and endothelial proliferation, respectively.

RESULTS

An artery on the ventral surface of the bladder trifurcates near the bladder neck to supply the prostate lobes and seminal vesicle. Development of the prostatic vascular system is associated with endothelial proliferation and robust expression of pro-angiogenic factors Pecam1, Tie1, Tek, Angpt1, Angpt2, Fgf2, Vegfa, Vegfc, and Figf. Bacterial-induced prostatic inflammation induced endothelial cell proliferation and increased vascular density but surprisingly decreased pro-angiogenic factor expression.

CONCLUSIONS

The striking decrease in pro-angiogenic factor mRNA expression associated with endothelial proliferation and increased vascular density during inflammation suggests that endothelial response to injury is not a recapitulation of normal development and may be initiated and regulated by different regulatory mechanisms.

The senescence-associated secretory phenotype promotes benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is characterized by increased tissue mass in the transition zone of the prostate, which leads to obstruction of urine outflow and considerable morbidity in a majority of older men. Senescent cells accumulate in human tissues, including the prostate, with increasing age. Expression of proinflammatory cytokines is increased in these senescent cells, a manifestation of the senescence-associated secretory phenotype. Multiplex analysis revealed that multiple cytokines are increased in BPH, including GM-CSF, IL-1α, and IL-4, and that these are also increased in senescent prostatic epithelial cells in vitro. Tissue levels of these cytokines were correlated with a marker of senescence (cathepsin D), which was also strongly correlated with prostate weight. IHC analysis revealed the multifocal epithelial expression of cathepsin D and coexpression with IL-1α in BPH tissues. In tissue recombination studies in nude mice with immortalized prostatic epithelial cells expressing IL-1α and prostatic stromal cells, both epithelial and stromal cells exhibited increased growth. Expression of IL-1α in prostatic epithelial cells in a transgenic mouse model resulted in increased prostate size and bladder obstruction. In summary, both correlative and functional evidence support the hypothesis that the senescence-associated secretory phenotype can promote the development of BPH, which is the single most common age-related pathology in older men.

Pathogenic intestinal bacteria enhance prostate cancer development via systemic activation of immune cells in mice

A role for microbes has been suspected in prostate cancer but difficult to confirm in human patients. We show here that a gastrointestinal (GI) tract bacterial infection is sufficient to enhance prostate intraepithelial neoplasia (PIN) and microinvasive carcinoma in a mouse model. We found that animals with a genetic predilection for dysregulation of wnt signaling, Apc^Min/+ mutant mice, were significantly susceptible to prostate cancer in an inflammation-dependent manner following infection with Helicobacter hepaticus. Further, early neoplasia observed in infected Apc^Min/+ mice was transmissible to uninfected mice by intraperitoneal injection of mesenteric lymph node (MLN) cells alone from H. hepaticus-infected mutant mice. Transmissibility of neoplasia was preventable by prior neutralization of inflammation using anti-TNF-α antibody in infected MLN donor mice. Taken together, these data confirm that systemic inflammation triggered by GI tract bacteria plays a pivotal role in tumorigenesis of the prostate gland.

ETS transcription factor ESE1/ELF3 orchestrates a positive feedback loop that constitutively activates NF-κB and drives prostate cancer progression

Chromosomal translocations leading to deregulated expression of ETS transcription factors are frequent in prostate tumors. Here, we report a novel mechanism leading to oncogenic activation of the ETS factor ESE1/ELF3 in prostate tumors. ESE1/ELF3 was overexpressed in human primary and metastatic tumors. It mediated transforming phenotypes in vitro and in vivo and induced an inflammatory transcriptome with changes in relevant oncogenic pathways. ESE1/ELF3 was induced by interleukin (IL)-1β through NF-κB and was a crucial mediator of the phenotypic and transcriptional changes induced by IL-1β in prostate cancer cells. This linkage was mediated by interaction of ESE1/ELF3 with the NF-κB subunits p65 and p50, acting by enhancing their nuclear translocation and transcriptional activity and by inducing p50 transcription. Supporting these findings, gene expression profiling revealed an enrichment of NF-κB effector functions in prostate cancer cells or tumors expressing high levels of ESE1/ELF3. We observed concordant upregulation of ESE1/ELF3 and NF-κB in human prostate tumors that was associated with adverse prognosis. Collectively, our results define an important new mechanistic link between inflammatory signaling and the progression of prostate cancer.

Melatonin suppresses proinflammatory mediators in lipopolysaccharide-stimulated CRL1999 cells via targeting MAPK, NF-κB, c/EBPβ, and p300 signaling

Melatonin is an indoleamine secreted by the pineal gland as well as a plant-derived product that exerts potential anti-inflammatory properties, but the mechanisms of action remain unclear. Here, we investigated the roles of melatonin in regulation of proinflammatory mediators and identified the underlying mechanisms in human vascular smooth muscle (VSM) cell line CRL1999 stimulated by lipopolysaccharide (LPS). We found that treatment with melatonin significantly inhibited the production and expression of TNF-α and interleukin (IL)-1β, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase, prostaglandin E(2) (PGE2), and nitric oxide (NO) in a dose-dependent manner. Moreover, we also found that the suppression of proinflammatory mediators by melatonin was mediated through inhibition of MAPK, NF-κB, c/EBPβ, and p300 signaling in LPS-stimulated CRL1999 cells. Treatment with melatonin markedly inhibited phosphorylation of ERK1/2, JNK, p38 MAPK, IκB-α, and c/EBPβ, blocked binding of NF-κB and c/EBPβ to promoters, and suppressed p300 histone acetyltransferase (HAT) activity and p300 HAT-mediated NF-κB acetylation. Transfection with an ERK-, IκB-, or c/EBPβ-specific siRNA or pretreatment with an ERK-, p38 MAPK-, or p300-selective inhibitor considerably abrogated the melatonin-mediated inhibition of proinflammatory mediators. Conversely, exogenous overexpression of a constitutively active p300, but not its HAT mutant, effectively reversed the melatonin-mediated inhibitions. Collectively, these results indicate that melatonin suppresses proinflammatory mediators by simultaneously targeting the multiple signaling such as ERK/p38 MAPK, c/EBPβ, NF-κB, and p300, in LPS-stimulated VSM cell line CRL1999, and suggest that melatonin is a potential candidate compound for the treatment of proinflammatory disorders.

Intracellular insulin-like growth factor-1 induces Bcl-2 expression in airway epithelial cells

Bcl-2, a prosurvival protein, regulates programmed cell death during development and repair processes, and it can be oncogenic when cell proliferation is deregulated. The present study investigated what factors modulate Bcl-2 expression in airway epithelial cells and identified the pathways involved. Microarray analysis of mRNA from airway epithelial cells captured by laser microdissection showed that increased expression of IL-1β and insulin-like growth factor-1 (IGF-1) coincided with induced Bcl-2 expression compared with controls. Treatment of cultured airway epithelial cells with IL-1β and IGF-1 induced Bcl-2 expression by increasing Bcl-2 mRNA stability with no discernible changes in promoter activity. Silencing the IGF-1 expression using short hairpin RNA showed that intracellular IGF-1 (IC-IGF-1) was increasing Bcl-2 expression. Blocking epidermal growth factor receptor or IGF-1R activation also suppressed IC-IGF-1 and abolished the Bcl-2 induction. Induced expression and colocalization of IC-IGF-1 and Bcl-2 were observed in airway epithelial cells of mice exposed to LPS or cigarette smoke and of patients with cystic fibrosis and chronic bronchitis but not in the respective controls. These studies demonstrate that IC-IGF-1 induces Bcl-2 expression in epithelial cells via IGF-1R and epidermal growth factor receptor pathways, and targeting IC-IGF-1 could be beneficial to treat chronic airway diseases.

Acute bacterial inflammation of the mouse prostate

BACKGROUND

Prostatic inflammation is gaining increasing attention as a potential etiologic factor in prostate cancer, benign prostatic hyperplasia, lower urinary tract symptoms, and CPPS. This study was performed to address the need for a well characterized model of acute prostatic inflammation that may be used to study the effect of acute inflammation on epithelial and stromal cell proliferation, voiding behavior, and neurovascular physiology.

METHODS

Uropathogenic E. coli 1677 was instilled transurethrally into adult C57BL/6J male mice. Prostates were analyzed at 1, 2, 3, 5, 7, or 14 days post-instillation and compared to saline-instilled and naïve controls. Time course and severity of inflammation were characterized by the quantity and type of inflammatory infiltrate present, hemorrhage, proliferation, and reactive hyperplasia. RT-PCR was performed to characterize inflammatory mediators including IL-1α, IL-1β, IL-1RA, IL-18, IL-6, IL-10, IL-8, TNFα, and COX-2.

RESULTS

Inflammation was evident in all lobes of the prostate with the DLP most severely affected. Infection consistently led to a significant increase in neutrophils and macrophages in the early stages of prostate infection, followed by lymphocytic inflammation at the later time points. Inflammation was accompanied by induction of several inflammatory genes, including IL-1 family members, IL-6, and COX-2, and induced a significant increase in epithelial proliferation and reactive hyperplasia in all three prostate lobes.

CONCLUSIONS

Transurethral inoculation of uropathogenic E. coli 1677 reliably infects the mouse prostate, produces a significant inflammatory response, and induces quantifiable epithelial proliferation and reactive hyperplasia.

Role of interleukins, IGF and stem cells in BPH

The condition known as benign prostatic hyperplasia may be defined as a benign enlargement of the prostate gland resulting from a proliferation of both benign epithelial and stromal elements. It might also be defined clinically as a constellation of lower urinary tract symptoms (LUTSs) in aging men. The purpose of this review is to consider the ways in which inflammatory cytokines belonging to the interleukin family, members of the IFG family, and stem cells may contribute to the development and progression of BPH-LUTS. This might occur in three mechanisms: One, interleukin signaling, IFG signaling and stem cells may contribute to reactivation of developmental growth mechanisms in the adult prostate leading to tissue growth. Two, given that epidemiologic studies indicate an increased incidence of BPH-LUTS in association with obesity and diabetes, IFG signaling may provide the mechanistic basis for the effect of diabetes and obesity on prostate growth. Three, expression of interleukins in association with inflammation in the prostate may induce sensitization of afferent fibers innervating the prostate and result in increased sensitivity to pain and noxious sensations in the prostate and bladder and heightened sensitivity to bladder filling.

PPARγ: a molecular link between systemic metabolic disease and benign prostate hyperplasia

The emergent epidemic of metabolic syndrome and its complex list of sequelae mandate a more thorough understanding of benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS) in the context of systemic metabolic disease. Here we discuss the nature and origins of BPH, examine its role as a component of LUTS and review retrospective clinical studies that have drawn associations between BPH/LUTS and type II diabetes, inflammation and dyslipidemia. PPARγ signaling, which sits at the nexus of systemic metabolic disease and BPH/LUTS through its regulation of inflammation and insulin resistance, is proposed as a candidate for molecular manipulation in regard to BPH/LUTS. Finally, we introduce new cell and animal models that are being used to study the consequences of obesity, diabetes and inflammation on benign prostatic growth.

Regulation of phosphatase homologue of tensin protein expression by bone morphogenetic proteins in prostate epithelial cells

BACKGROUND

Phosphatase homologue of tensin (PTEN) is the most commonly mutated gene in prostate cancer. Bone morphogenetic proteins (BMPs) are known to promote differentiation and inhibit proliferation. Previously published reports from other organ systems led us to investigate a mechanistic relationship between PTEN and BMP signaling in prostate epithelial cells.

METHODS

We analyzed growth rate and PTEN expression in E6, BPH-1, and C4-2B prostate epithelial cells treated with BMP-4. We also treated doxacyclin-inducible PTEN-C4-2B cells with BMP-4 and doxacyclin to determine the effect of BMP on growth and PTEN expression in conditions of increasing PTEN expression. We determined the dependency of BMP-mediated growth inhibition via siRNA knockdown of PTEN expression and BMP treatment. We determined PTEN protein stability by determining the effect of BMP-4 on PTEN protein at time points after treatment with cyclohexamide, a translation inhibitor.

RESULTS

We found that BMP-4 induces PTEN in E6 and BPH-1 cells and reduces proliferation. Knockdown of PTEN attenuated the growth-inhibiting effects of BMP-4 in these cells. BMP-4 had no effect in PTEN-negative C4-2B cells, but doxacyclin-driven PTEN C4-2B cells responded to BMP-4 with enhanced PTEN and growth inhibition. BMP-4 also increased PTEN protein stability.

CONCLUSIONS

BMP signaling induces PTEN expression and sustains PTEN protein expression resulting in inhibition of prostate epithelial cell growth. These data are the first to identify a mechanistic linkage between BMP signaling and PTEN in the prostate, both of which are independently identified as tumor suppressors and suggest possible coordinate dysregulation in prostate cancer.

Diabetes, growth hormone-insulin-like growth factor pathways and association to benign prostatic hyperplasia

Diabetes significantly increases the risk of benign prostatic hyperplasia (BPH) and low urinary tract symptoms (LUTS). The major endocrine aberration in connection with the metabolic syndrome is hyperinsulinemia. Insulin is an independent risk factor and a promoter of BPH. Insulin resistance may change the risk of BPH through several biological pathways. Hyperinsulinemia stimulates the liver to produce more insulin-like growth factor (IGF), another mitogen and an anti-apoptotic agent which binds insulin receptor/IGF receptor and stimulates prostate growth. The levels of IGFs and IGF binding proteins (IGFBPs) in prostate tissue and in blood are associated with BPH risk, with the regulation of circulating androgen and growth hormone. Stromal-epithelial interactions play a critical role in the development and growth of the prostate gland and BPH. Previously, we have shown that the expression of c-Jun in the fibroblastic stroma can promote secretion of IGF-I, which stimulates prostate epithelial cell proliferation through activating specific target genes. Here, we will review the epidemiologic, clinical, and molecular findings which have evaluated the relation between diabetes and development of BPH.

Epithelial decision makers: in search of the 'epimmunome'

Frequent microbial and nonmicrobial challenges to epithelial cells trigger discrete pathways, promoting molecular changes such as the secretion of specific cytokines and chemokines and alterations to molecules displayed at the epithelial cell surface. In combination, these molecules impose key decisions on innate and adaptive immune cells. Depending on context, those decisions can be as diverse as those imposed by professional antigen-presenting cells, benefiting the host by balancing immune competence with the avoidance of immunopathology. Nonetheless, this potency of epithelial cells is also consistent with the causal contribution of epithelial dysregulation to myriad inflammatory diseases. This pathogenic axis provides an attractive target for tissue-specific clinical manipulation. In this context, a research goal should be to identify all molecules used by epithelial cells to instruct immune cells. We term this the 'epimmunome'.

Sulfatase 1 is an inhibitor of ductal morphogenesis with sexually dimorphic expression in the urogenital sinus

The prostate gland develops from the urogenital sinus in response to circulating androgens. Androgens initiate and stimulate branching morphogenesis in the urogenital sinus via unknown mediators. Heparan sulfate proteoglycans are important extracellular molecules that sequester many growth factors in the extracellular matrix and facilitate signaling by some growth factors as part of ternary complexes that include growth factors, receptors, and heparan sulfate chains. Several enzymes modify the chemical structure of heparan sulfate to further regulate its activity. An examination of these enzymes for sexually dimorphic expression in the urogenital sinus identified Sulfatase 1 (Sulf1) as an enzyme that was down-regulated in the male urogenital sinus coincident with the initiation of prostatic morphogenesis. Down-regulation of Sulf1 was accompanied by an increase in the most highly sulfated forms of heparan sulfate, and a similar increase was observed in female urogenital sinuses treated with testosterone. Inhibiting de novo sulfation of heparan sulfate blocked prostatic morphogenesis, supporting the importance of heparan sulfate modification for prostate development. To functionally test the specific role of Sulf1 during prostate development, Sulf1 was ectopically expressed in the urogenital sinus. It partially inhibited testosterone-stimulated ductal morphogenesis, and it reduced the activation of fibroblast growth factor receptors as well as the ERK1 and ERK2 MAPKs. These data identify sulfatase 1 as an inhibitor of prostatic branching morphogenesis and growth factor signaling that is down-regulated as part of the normal response to androgen action in the male urogenital sinus.