Ventral prostate fibrosis in the Akita mouse is associated with macrophage and fibrocyte infiltration

E-cadherin deficiency promotes prostate macrophage inflammation and bladder overactivity in aged male mice

Decreased E-cadherin immunostaining is frequently observed in benign prostatic hyperplasia (BPH) and was recently correlated with increased inflammation in aging prostate. Homozygous E-cadherin deletion in the murine prostate results in prostate inflammation and bladder overactivity at 6 months of age. However, this model is limited in that while E-cadherin is significantly reduced in BPH, it is not completely lost; BPH is also strongly associated with advanced age and is infrequent in young men. Here, we examined the functional consequences of aging in male mice with prostate luminal epithelial cell-specific E-cadherin heterozygosity. In control mice, aging alone resulted in an increase in prostate inflammation and changes in bladder voiding function indicative of bladder underactivity. At 24 months of age, mice with prostate-specific Cre-mediated heterozygous deletion of E-cadherin induced at 7 weeks of age developed additional prostatic defects, particularly increased macrophage inflammation and stromal proliferation, and bladder overactivity compared to age-matched control mice, which are similar to BPH/LUTS in that the phenotype is slow-progressing and age-dependent. These findings suggest that decreased E-cadherin may promote macrophage inflammation and fibrosis in the prostate and subsequent bladder overactivity in aging men, promoting the development and progression of BPH/LUTS.

Male Lower Urinary Tract Dysfunction: An Underrepresented Endpoint in Toxicology Research

Lower urinary tract dysfunction (LUTD) is nearly ubiquitous in men of advancing age and exerts substantial physical, mental, social, and financial costs to society. While a large body of research is focused on the molecular, genetic, and epigenetic underpinnings of the disease, little research has been dedicated to the influence of environmental chemicals on disease initiation, progression, or severity. Despite a few recent studies indicating a potential developmental origin of male LUTD linked to chemical exposures in the womb, it remains a grossly understudied endpoint in toxicology research. Therefore, we direct this review to toxicologists who are considering male LUTD as a new aspect of chemical toxicity studies. We focus on the LUTD disease process in men, as well as in the male mouse as a leading research model. To introduce the disease process, we describe the physiology of the male lower urinary tract and the cellular composition of lower urinary tract tissues. We discuss known and suspected mechanisms of male LUTD and examples of environmental chemicals acting through these mechanisms to contribute to LUTD. We also describe mouse models of LUTD and endpoints to diagnose, characterize, and quantify LUTD in men and mice.

M2a macrophage can rescue proliferation and gene expression of benign prostate hyperplasia epithelial and stroma cells from insulin-like growth factor 1 knockdown

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common disease in elderly men and is often accompanied by chronic inflammation. Macrophages (several subtypes) are the main inflammatory cells that infiltrate the hyperplastic prostate and are found to secrete cytokines and growth factors. The current study aims to explore the effect of M2a macrophages on the development of BPH via insulin-like growth factor 1 (IGF-1).

METHODS

Human prostate tissues, prostate, and monocyte cell lines (WPMY-1, BPH-1, and THP-1) were used. THP-1 was polarized into several subtypes with cytokines. The expression and localization of IGF-1 and M2 macrophages were determined via immunofluorescent staining, quantitative real-time polymerase chain reaction, and Western blot analysis. Flow cytometry and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays were used to investigate the effects of different subtypes of macrophages on prostate cells. IGF-1 in WPMY-1 and BPH-1 cells was silenced and cocultured with or without M2a macrophages. Cell proliferation, apoptosis, cell cycle, epithelial-mesenchymal transition (EMT), and fibrosis processes were examined.

RESULTS

The polarized subtypes of macrophages were verified by amplifying their specific markers. M2a macrophages enhanced prostate cell proliferation more significantly and CD206 was more expressed in hyperplastic prostate. IGF-1 was localized in both epithelial and stromal components of prostate and upregulated in BPH tissues. M2a macrophages expressed more IGF-1 than other subtypes. Knockdown of IGF-1 in WPMY-1 and BPH-1 cells attenuated cell proliferation, promoted cell apoptosis, retarded cell cycle at the G0/G1 phase, and suppressed the EMT process in BPH-1 cells as well as the fibrotic process in WPMY-1 cells, which was reversible when cocultured with M2a macrophages.

CONCLUSION

These data demonstrated that knockdown of IGF-1 expression in cultured BPH epithelial and stromal cells reduces proliferation and increases apoptosis. These effects are reversed by coculture with M2a macrophages.

Potential ameliorative effects of grape seed-derived polyphenols against cadmium induced prostatic deficits

Grape (Vitis vinifera) is consumed as fruit and wine for people. In this study, rat model of prostatic deficits was induced by orally receiving 60mg/L cadmium chlorine (CdCl₂) through drinking water for 20 weeks. Grape seed-derived polyphenols extract (GSP) was orally given for 20 weeks. Finally, the prostatic levels of E-cadherin, fibronectin, and α-smooth muscle actin were measured by immunohistochemical and qPCR analysis. The oxidative stress was measured by detecting the levels of malondialdehyde, nitric oxide, reduced glutathione/oxidized glutathione and enzymatic antioxidant status. Additionally, the prostatic expressions of transforming growth factor-β1 (TGF-β1), type I TGF-β receptor (TGF-βRI), Smad3, phosphorylation-Smad3 (p-Smad3), Smad7, nuclear related factor-2 (Nrf-2), heme oxygenase-1 (HO-1) and γ-glutamate cysteine ligase catalytic subunit (γ-GCLC) were measured by western blot. The levels of microRNA (miR)-133a/b were measured by qPCR. It was observed that GSP ameliorated the prostatic oxidative stress and fibrosis induced by CdCl₂. GSP also inhibited the over-generation of TGF-β1 and p-Smad3, as well as enhanced the levels of Smad7, Nrf-2, HO-1, γ-GCLC and miR-133a/b. These results showed that GSP could attenuate Cd-induced prostatic deficits.

Custom 4-Plex DiLeu Isobaric Labels Enable Relative Quantification of Urinary Proteins in Men with Lower Urinary Tract Symptoms (LUTS)

The relative quantification of proteins using liquid chromatography mass spectrometry (LC-MS) has allowed researchers to compile lists of potential disease markers. These complex quantitative workflows often include isobaric labeling of enzymatically-produced peptides to analyze their relative abundances across multiple samples in a single LC-MS run. Recent efforts by our lab have provided scientists with cost-effective alternatives to expensive commercial labels. Although the quantitative performance of these dimethyl leucine (DiLeu) labels has been reported using known ratios of complex protein and peptide standards, their potential in large-scale proteomics studies using a clinically relevant system has never been investigated. Our work rectifies this oversight by implementing 4-plex DiLeu to quantify proteins in the urine of aging human males who suffer from lower urinary tract symptoms (LUTS). Protein abundances in 25 LUTS and 15 control patients were compared, revealing that of the 836 proteins quantified, 50 were found to be differentially expressed (>20% change) and statistically significant (p-value <0.05). Gene ontology (GO) analysis of the differentiated proteins showed that many were involved in inflammatory responses and implicated in fibrosis. While confirmation of individual protein abundance changes would be required to verify protein expression, this study represents the first report using the custom isobaric label, 4-plex DiLeu, to quantify protein abundances in a clinically relevant system.