CCR2+ monocytes/macrophages drive steroid hormone imbalance-related prostatic fibrosis.

Benign Prostatic Hyperplasia (BPH) is a complex condition leading to Lower Urinary Tract Symptoms in aging men, characterized by cellular proliferation, smooth muscle dysfunction, inflammation, and fibrosis. While BPH is known to involve heightened macrophage infiltration, the specific contribution of infiltrating monocytes/macrophages to the disease mechanism remains uncertain. This research explores the impact of reducing circulating monocytes and subsequently limiting their tissue infiltration by using Ccr2 knockout (Ccr2-KO) mice. Ccr2-KO and wild type mice were implanted with testosterone and estradiol (T + E2, 25 mg + 2.5 mg) pellets. Urinary function was assessed via weekly void spot assays over 12 weeks, and prostatic macrophage levels were visualized and quantified in tissue sections using an F4/80 antibody. Additionally, Ki-67 staining was used to evaluate cell proliferation, and picrosirius red staining to assess collagen accumulation. Increased voiding frequency which developed in T + E2 mice, was significantly ameliorated in Ccr2-KO mice, however, both Ccr2-KO and wild type (WT) mice showed increased bladder weights after three month, representing a hypertrophic response to bladder outlet obstruction. T + E2 substantially increased the density of macrophages in WT but not Ccr2-KO mouse prostate. Proliferation rate, as indicated by Ki-67 positivity, was elevated in the vental and anterior prostate lobes but was only marginally reduced in Ccr2-KO mice. Most importantly, a significant prostatic collagen accumulation was observed in WT mice that was markedly reduced by Ccr2 deficiency post T + E2 treatment. The absence of Ccr2 mitigates urinary dysfunction and alters prostatic macrophage levels and collagen accumulation in steroid hormone imbalance. These findings suggest a crucial role for monocyte infiltration, giving rise to macrophages or other cell derivatives, to drive fibrosis.

Steroid hormone imbalance drives macrophage infiltration and Spp1/osteopontin+ foam cell differentiation in the prostate.

Benign prostatic hyperplasia (BPH) occurs progressively with aging in men and drives deteriorating symptoms collectively known as lower urinary tract symptoms (LUTS). Age-associated changes in circulating steroid hormones, and prostate inflammation have been postulated in the etiology of BPH/LUTS. The link between hormones and inflammation in the development of BPH/LUTS is conflicting because they may occur independently or as sequential steps in disease pathogenesis. This study aimed to decipher the prostatic immune landscape in a mouse model of lower urinary tract dysfunction (LUTD). Steroid hormone imbalance was generated by the surgical implantation of testosterone (T) and estradiol (E2) pellets into male C57BL/6J mice and gene expression analysis was performed on ventral prostates (VPs). These experiments identified an increase in the expression of macrophage markers and Spp1/osteopontin (OPN). Localization studies of OPN pinpointed that OPN+ macrophages travel to the prostate lumen and transition into lipid-accumulating foam cells. We also observed a significant increase in the number of tissue macrophages in the VP which was prevented in OPN-knockout (OPN-KO) mice. In contrast, mast cells, but not macrophages, were significantly elevated in the dorsal prostate of T + E2-treated mice which was diminished in OPN-KO mice. Steroid hormone implantation progressively increased urinary frequency, which was ameliorated in OPN-KO mice. Our study underscores the role of age-associated steroid hormone imbalances as a mechanism of expanding the prostatic macrophage population, their luminal translocation, and foam cell differentiation. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Osteopontin Deficiency Ameliorates Prostatic Fibrosis and Inflammation.

Fibrogenic and inflammatory processes in the prostate are linked to the development of lower urinary tract symptoms (LUTS) in men. Our previous studies identified that osteopontin (OPN), a pro-fibrotic cytokine, is abundant in the prostate of men with LUTS, and its secretion is stimulated by inflammatory cytokines potentially to drive fibrosis. This study investigates whether the lack of OPN ameliorates inflammation and fibrosis in the mouse prostate. We instilled uropathogenic E. coli (UTI89) or saline (control) transurethrally to C57BL/6J (WT) or Spp1tm1Blh/J (OPN-KO) mice and collected the prostates one or 8 weeks later. We found that OPN mRNA and protein expression were significantly induced by E. coli-instillation in the dorsal prostate (DP) after one week in WT mice. Deficiency in OPN expression led to decreased inflammation and fibrosis and the prevention of urinary dysfunction after 8 weeks. RNAseq analysis identified that E. coli-instilled WT mice expressed increased levels of inflammatory and fibrotic marker RNAs compared to OPN-KO mice including Col3a1, Dpt, Lum and Mmp3 which were confirmed by RNAscope. Our results indicate that OPN is induced by inflammation and prolongs the inflammatory state; genetic blockade of OPN accelerates recovery after inflammation, including a resolution of prostate fibrosis.

Fetal bisphenol A and ethinylestradiol exposure alters male rat urogenital tract morphology at birth: Confirmation of prior low-dose findings in CLARITY-BPA.

Bisphenol A (BPA) is a contaminant in virtually all Americans. To examine BPA's adverse effects, the FDA-NCTR, NIEHS, and 14 groups of academic scientists formed a consortium: CLARITY-BPA. The purpose of our study was to investigate the effects of a wide range of doses of BPA on fetal development of the NCTR CD-SD male rat urogenital sinus (UGS). Pregnant rats were administered BPA or positive control ethinylestradiol (EE2) daily, via oral gavage, from gestational day 6 through parturition. Tissues were collected on postnatal day 1 and the UGS was analyzed using computer-assisted 3-D reconstruction. Importantly, only low doses of BPA, as well as EE2, significantly changed birth weight and UGS morphology, including an increased size of the colliculus and decreased size of the urethra, consistent with prior reported BPA and EE2 effects. Our findings provide further evidence that BPA mediates nonmonotonic developmental effects on the fetal urogenital sinus.

Prostate Transition Zone Fibrosis is Associated with Clinical Progression in the MTOPS Study.

PURPOSE: Medications targeting androgen receptor activity (eg finasteride) or smooth muscle contractility (eg doxazosin) do not resolve lower urinary tract symptoms indicative of lower urinary tract dysfunction in an important subgroup of men. Recently fibrosis has been implicated as another pathobiology contributing to male lower urinary tract symptoms but to our knowledge no systematic studies have been done to assess fibrosis in the context of medical treatment. We determine whether fibrotic changes in the prostate transition zone are associated with an increased risk of clinical progression in participants treated with doxazosin, finasteride or finasteride plus doxazosin in the MTOPS (Medical Therapy of Prostatic Symptoms) study. MATERIALS AND METHODS: Transition zone biopsy tissues from men who did or did not experience clinical progression on placebo, doxazosin, finasteride or combination therapy were assessed for collagen content and architectural changes using picrosirius red birefringence and CT-FIRE (Curvelet Transform-Fiber Extraction) analysis. Correlations were made with annotated demographic and clinical data. Statistical analyses were done with the Pearson correlation coefficient, ANOVA and the t-test. RESULTS: High levels of wavy, aligned prostate transition zone collagen significantly correlated with an increased risk of clinical progression among MTOPS trial participants treated with doxazosin plus finasteride, particularly those with a high body mass index. CONCLUSIONS: Fibrotic changes in the prostate transition zone are associated with an increased risk of clinical progression in men treated with doxazosin plus finasteride. Antifibrotic therapeutics might provide a new treatment approach in men with lower urinary tract dysfunction who do not respond to current medical treatment approaches.

Estrogen receptor-α is a key mediator and therapeutic target for bladder complications of benign prostatic hyperplasia.

PURPOSE: Estrogens are important in prostate growth and have a role in benign prostatic hyperplasia. However, to our knowledge no current therapy directly targets estrogen action. Estrogens act primarily via estrogen receptors α and ß. In a mouse model we evaluated the relative contribution of these receptors to bladder complications of benign prostatic hyperplasia. We also evaluated the prevention of these bladder complications using the selective estrogen receptor modulators raloxifene and tamoxifen (estrogen receptor-α selective antagonists), and R,R-THC (estrogen receptor-ß selective antagonist). MATERIALS AND METHODS: Adult male C57bl/6 mice received implants of 25 mg testosterone and 2.5 mg 17ß-estradiol slow release pellets. Untreated controls underwent sham surgery. We evaluated the contributions of the estrogen receptor subtypes in ERαKO and ERßKO mice compared to their respective wild-type litter mates. Wild-type mice treated with testosterone plus 17ß-estradiol were compared to mice treated with testosterone plus 17ß-estradiol and 25 mg selective estrogen receptor modulators to evaluate the prevention of benign prostatic hyperplasia complications by selective estrogen receptor modulators. RESULTS: Large bladders with urinary retention developed in ERαWT and ERßWT litter mates treated with testosterone plus 17ß-estradiol but such bladders did not develop in ERαKO mice treated with testosterone plus 17ß-estradiol. ERßKO mice treated with testosterone plus 17ß-estradiol had large bladders with urinary retention and increased bladder mass. Cotreatment with the estrogen receptor-α antagonist raloxifene resulted in decreased bladder mass compared to that in wild-type mice treated with testosterone plus 17ß-estradiol. Bladders in mice treated with the estrogen receptor-ß antagonist R,R-THC were similar to those in testosterone plus 17ß-estradiol treated mice. CONCLUSIONS: Estrogen receptor-α but not ß is a key mediator of bladder complications of benign prostatic hyperplasia and a potential target for future therapies.

Renal capsule xenografting and subcutaneous pellet implantation for the evaluation of prostate carcinogenesis and benign prostatic hyperplasia.

New therapies for two common prostate diseases, prostate cancer (PrCa) and benign prostatic hyperplasia (BPH), depend critically on experiments evaluating their hormonal regulation. Sex steroid hormones (notably androgens and estrogens) are important in PrCa and BPH; we probe their respective roles in inducing prostate growth and carcinogenesis in mice with experiments using compressed hormone pellets. Hormone and/or drug pellets are easily manufactured with a pellet press, and surgically implanted into the subcutaneous tissue of the male mouse host. We also describe a protocol for the evaluation of hormonal carcinogenesis by combining subcutaneous hormone pellet implantation with xenografting of prostate cell recombinants under the renal capsule of immunocompromised mice. Moreover, subcutaneous hormone pellet implantation, in combination with renal capsule xenografting of BPH tissue, is useful to better understand hormonal regulation of benign prostate growth, and to test new therapies targeting sex steroid hormone pathways.