Mechanism of RhoA regulating benign prostatic hyperplasia: RhoA-ROCK-ß-catenin signaling axis and static & dynamic dual roles.

BACKGROUND: The pathogenesis of benign prostatic hyperplasia (BPH) has not been fully elucidated. Ras homology family member A (RhoA) plays an important role in regulating cell cytoskeleton, growth and fibrosis. The role of RhoA in BPH remains unclear. METHODS: This study aimed to clarify the expression, functional activity and mechanism of RhoA in BPH. Human prostate tissues, human prostate cell lines, BPH rat model were used. Cell models of RhoA knockdown and overexpression were generated. Immunofluorescence staining, quantitative real time PCR (qRT-PCR), Western blotting, cell counting kit-8 (CCK-8), flow cytometry, phalloidine staining, organ bath study, gel contraction assay, protein stability analysis, isolation and extraction of nuclear protein and cytoplasmic protein were performed. RESULTS: In this study we found that RhoA was localized in prostate stroma and epithelial compartments and was up-regulated in both BPH patients and BPH rats. Functionally, RhoA knockdown induced cell apoptosis and inhibited cell proliferation, fibrosis, epithelial-mesenchymal transformation (EMT) and contraction. Consistently, overexpression of RhoA reversed all aforementioned processes. More importantly, we found that ß-catenin and the downstream of Wnt/ß-catenin signaling, including C-MYC, Survivin and Snail were up-regulated in BPH rats. Downregulation of RhoA significantly reduced the expression of these proteins. Rho kinase inhibitor Y-27632 also down-regulated ß-catenin protein in a concentration-dependent manner. However, overexpression of ß-catenin did not affect RhoA-ROCK levels, suggesting that ß-catenin was the downstream of RhoA-ROCK regulation. Further data suggested that RhoA increased nuclear translocation of ß-catenin and up-regulated ß-catenin expression by inhibiting its proteasomal degradation, thereby activating Wnt/ß-catenin signaling. Overexpression of ß-catenin partially reversed the changes in cell growth, fibrosis and EMT except cell contraction caused by RhoA downregulation. Finally, Y-27632 partially reversed prostatic hyperplasia in vivo, further suggesting the potential of RhoA-ROCK signaling in BPH treatment. CONCLUSION: Our novel data demonstrated that RhoA regulated both static and dynamic factors of BPH, RhoA-ROCK-ß-catenin signaling axis played an important role in the development of BPH and might provide more possibilities for the formulation of subsequent clinical treatment strategies.

Glutathione Peroxidase 3 induced mitochondria-mediated apoptosis via AMPK /ERK1/2 pathway and resisted autophagy-related ferroptosis via AMPK/mTOR pathway in hyperplastic prostate.

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common disease in elderly men, mainly resulted from an imbalance between cell proliferation and death. Glutathione peroxidase 3 (GPX3) was one of the differentially expressed genes in BPH identified by transcriptome sequencing of 5 hyperplastic and 3 normal prostate specimens, which had not been elucidated in the prostate. This study aimed to ascertain the mechanism of GPX3 involved in cell proliferation, apoptosis, autophagy and ferroptosis in BPH. METHODS: Human prostate tissues, GPX3 silencing and overexpression prostate cell (BPH-1 and WPMY-1) models and testosterone-induced rat BPH (T-BPH) model were utilized. The qRT-PCR, CCK8 assay, flow cytometry, Western blotting, immunofluorescence, hematoxylin and eosin, masson's trichrome, immunohistochemical staining and transmission electron microscopy analysis were performed during in vivo and in vitro experiments. RESULTS: Our study indicated that GPX3 was localized both in the stroma and epithelium of prostate, and down-regulated in BPH samples. Overexpression of GPX3 inhibited AMPK and activated ERK1/2 pathway, thereby inducing mitochondria-dependent apoptosis and G0/G1 phase arrest, which could be significantly reversed by MEK1/2 inhibitor U0126 preconditioning. Moreover, overexpression of GPX3 further exerted anti-autophagy by inhibiting AMPK/m-TOR and up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4, mitochondrial GPX4 and cytoplasmic GPX4) to antagonize autophagy-related ferroptosis. Consistently, GPX3 deficiency generated opposite changes in both cell lines. Finally, T-BPH rat model was treated with GPX3 indirect agonist troglitazone (TRO) or GPX4 inhibitor RAS-selective lethal 3 (RSL3) or TRO plus RSL3. These treatments produced significant atrophy of the prostate and related molecular changes were similar to our in vitro observations. CONCLUSIONS: Our novel data manifested that GPX3, which was capable of inducing apoptosis via AMPK/ERK1/2 pathway and antagonizing autophagy-related ferroptosis through AMPK/m-TOR signalling, was a promising therapeutic target for BPH in the future.

Simvastatin Improves Benign Prostatic Hyperplasia: Role of Peroxisome-Proliferator-Activated Receptor-γ and Classic WNT/ß-Catenin Pathway.

Benign prostatic hyperplasia (BPH) is a common disease in elderly men with an uncertain etiology and mechanistic basis. Metabolic syndrome (MetS) is also a very common illness and is closely related to BPH. Simvastatin (SV) is one of the widely used statins for MetS. Peroxisome-proliferator-activated receptor gamma (PPARγ), crosstalking with the WNT/ß-catenin pathway, plays important roles in MetS. Our current study aimed to examine SV-PPARγ-WNT/ß-catenin signaling in the development of BPH. Human prostate tissues and cell lines plus a BPH rat model were utilized. Immunohistochemical, immunofluorescence, hematoxylin and eosin (H&E) and Masson's trichrome staining, construction of a tissue microarray (TMA), ELISA, CCK-8 assay, qRT-PCR, flow cytometry, and Western blotting were also performed. PPARγ was expressed in both prostate stroma and epithelial compartments and downregulated in BPH tissues. Furthermore, SV dose-dependently triggered cell apoptosis and cell cycle arrest at the G0/G1 phase and attenuated tissue fibrosis and the epithelial-mesenchymal transition (EMT) process both in vitro and in vivo. SV also upregulated the PPARγ pathway, whose antagonist could reverse SV produced in the aforementioned biological process. Additionally, crosstalk between PPARγ and WNT/ß-catenin signaling was demonstrated. Finally, correlation analysis with our TMA containing 104 BPH specimens showed that PPARγ was negatively related with prostate volume (PV) and free prostate-specific antigen (fPSA) and positively correlated with maximum urinary flow rate (Qmax). WNT-1 and ß-catenin were positively related with International Prostate Symptom Score (IPSS) and nocturia, respectively. Our novel data demonstrate that SV could modulate cell proliferation, apoptosis, tissue fibrosis, and the EMT process in the prostate through crosstalk between PPARγ and WNT/ß-catenin pathways.

The Emerging Role of Cell Adhesion Molecules on Benign Prostatic Hyperplasia.

Benign prostatic hyperplasia (BPH) is a common disease in elderly men. It is characterized by prostatic enlargement and urethral compression and often causes lower urinary tract symptoms (LUTs) such as urinary frequency, urgency, and nocturia. Existing studies have shown that the pathological process of prostate hyperplasia is mainly related to the imbalance of cell proliferation and apoptosis, inflammation, epithelial-mesenchymal transition (EMT), and growth factors. However, the exact molecular mechanisms remain incompletely elucidated. Cell adhesion molecules (CAMs) are a group of cell surface proteins that mediate cell-cell adhesion and cell migration. Modulating adhesion molecule expression can regulate cell proliferation, apoptosis, EMT, and fibrotic processes, engaged in the development of prostatic hyperplasia. In this review, we went over the important roles and molecular mechanisms of cell adhesion molecules (mainly integrins and cadherins) in both physiological and pathological processes. We also analyzed the mechanisms of CAMs in prostate hyperplasia and explored the potential value of targeting CAMs as a therapeutic strategy for BPH.

Changes in the Expression and Functional Activities of C-X-C Motif Chemokine Ligand 13 (CXCL13) in Hyperplastic Prostate.

BACKGROUND: C-X-C motif chemokine ligand 13 (CXCL13), a member of the CXC subtype in chemokine superfamily, affects numerous biological processes of various types of cells and the progress of a great number of clinical diseases. The purpose of the current study was to reveal the internal mechanism between CXCL13 and benign prostatic hyperplasia (BPH). METHODS: Human serum, prostate tissues and human prostate cell lines (BPH-1, WPMY-1) were utilized. The effect of recombinant human CXCL13 (rHuCXCL13) protein and the influences of the knockdown/overexpression of CXCL13 on two cell lines were studied. Rescue experiments by anti-CXCR5 were also conducted. In vivo, rHuCXCL13 was injected into the ventral prostate of rats. Additionally, a tissue microarray of hyperplastic prostate tissues was constructed to analyze the correlations between CXCL13 and clinical parameters. RESULTS: CXCL13 was highly expressed in the prostate tissues and upregulated in the BPH group. It was observed that CXCL13 modulated cell proliferation, apoptosis, and the epithelial-mesenchymal transition (EMT) through CXCR5 via AKT and the ERK1/2 pathway in BPH-1, while it contributed to inflammation and fibrosis through CXCR5 via the STAT3 pathway in WPMY-1. In vivo, rHuCXCL13 induced the development of rat BPH. Additionally, CXCL13 was positively correlated with the prostate volume and total prostate specific antigen. CONCLUSIONS: Our novel data demonstrated that CXCL13 modulated cell proliferation, cell cycle, the EMT of epithelial cells, and induced the fibrosis of prostatic stromal cells via a variety of inflammatory factors, suggesting that CXCL13 might be rediscovered as a potential therapeutic target for the treatment of BPH.

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.

Upregulated bone morphogenetic protein 5 enhances proliferation and epithelial-mesenchymal transition process in benign prostatic hyperplasia via BMP/Smad signaling pathway.

BACKGROUND: Benign prostatic hyperplasia (BPH) is one of the most common illnesses in aging men. Recent studies found that bone morphogenetic protein 5 (BMP5) is upregulated in BPH tissues, however, the role of BMP5 in the development of BPH has not been examined. The current study aims to elucidate the potential roles of BMP5 and related signaling pathways in BPH. METHODS: Human prostate cell lines (BPH-1, WPMY-1) and human/rat hyperplastic prostate tissues were utilized. Western blot, quantitative real-time polymerase chain reaction, immunofluorescent staining, and immunohistochemical staining were performed. BMP5-silenced and -overexpressed cell models were generated and then cell cycle progression, apoptosis, and proliferation were determined. The epithelial-mesenchymal transition (EMT) was also quantitated. And rescue experiments by BMP/Smad signaling pathway agonist or antagonist were accomplished. Moreover, BPH-related tissue microarray analysis was performed and associations between clinical parameters and expression of BMP5 were analyzed. RESULTS: Our study demonstrated that BMP5 was upregulated in human and rat hyperplastic tissues and localized both in the epithelial and stromal compartments of the prostate tissues. E-cadherin was downregulated in hyperplastic tissues, while N-cadherin and vimentin were upregulated. Overexpression of BMP5 enhanced cell proliferation and the EMT process via phosphorylation of Smad1/5/8, while knockdown of BMP5 induced cell cycle arrest at G0/G1 phase and blocked the EMT process. Moreover, a BMP/Smad signaling pathway agonist and antagonist reversed the effects of BMP5 silencing and overexpression, respectively. In addition, BMP5 expression positively correlated with prostate volume and total prostate-specific antigen. CONCLUSION: Our novel data suggest that BMP5 modulated cell proliferation and the EMT process through the BMP/Smad signaling pathway which could contribute to the development of BPH. However, further studies are required to determine the exact mechanism. Our study also indicated that BMP/Smad signaling may be rediscovered as a promising new therapeutic target for the treatment of BPH.

Changes in the expression and functional activities of Myosin II isoforms in human hyperplastic prostate.

Benign prostatic hyperplasia (BPH) is a common disease among aging males with the etiology remaining unclear. We recently found myosin II was abundantly expressed in rat and cultured human prostate cells with permissive roles in the dynamic and static components. The present study aimed to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in the hyperplastic prostate. Human prostate cell lines and tissues from normal human and BPH patients were used. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. We further created cell models with NMM II isoforms silenced and proliferation, cycle, and apoptosis of prostate cells were determined by cell counting kit-8 (CCK-8) assay and flow cytometry. Hyperplastic prostate SM expressed more SM1 and LC17b isoforms compared with their alternatively spliced counterparts, favoring a slower more tonic-type contraction and greater force generation. For BPH group, blebbistatin (BLEB, a selective myosin II inhibitor), exhibited a stronger effect on relaxing phenylephrine (PE) pre-contracted prostate strips and inhibiting PE-induced contraction. Additionally, NMMHC-A and NMMHC-B were up-regulated in hyperplastic prostate with no change in NMMHC-C. Knockdown of NMMHC-A or NMMHC-B inhibited prostate cell proliferation and induced apoptosis, with no changes in cell cycle. Our novel data demonstrate that expression and functional activities of myosin II isoforms are altered in human hyperplastic prostate, suggesting a new pathological mechanism for BPH. Thus, the myosin II system may provide potential new therapeutic targets for BPH/lower urinary tract symptoms (LUTS).

NELL2 modulates cell proliferation and apoptosis via ERK pathway in the development of benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is a quite common illness but its etiology and mechanism remain unclear. Neural epidermal growth factor-like like 2 (NELL2) plays multifunctional roles in neural cell growth and is strongly linked to the urinary tract disease. Current study aims to determine the expression, functional activities and underlying mechanism of NELL2 in BPH. Human prostate cell lines and tissues from normal human and BPH patients were utilized. Immunohistochemical staining, immunofluorescent staining, RT-polymerase chain reaction (PCR) and Western blotting were performed. We further generated cell models with NELL2 silenced or overexpressed. Subsequently, proliferation, cycle, and apoptosis of prostate cells were determined by cell counting kit-8 (CCK-8) assay and flow cytometry analysis. The epithelial-mesenchymal transition (EMT) and fibrosis process were also analyzed. Our study revealed that NELL2 was up-regulated in BPH samples and localized in the stroma and the epithelium compartments of human prostate tissues. NELL2 deficiency induced a mitochondria-dependent cell apoptosis, and inhibited cell proliferation via phosphorylating extracellular signal-regulated kinase 1/2 (ERK1/2) activation. Additionally, suppression of ERK1/2 with U0126 incubation could significantly reverse NELL2 deficiency triggered cell apoptosis. Consistently, overexpression of NELL2 promoted cell proliferation and inhibited cell apoptosis. However, NELL2 interference was observed no effect on EMT and fibrosis process. Our novel data demonstrated that up-regulation of NELL2 in the enlarged prostate could contribute to the development of BPH through enhancing cell proliferation and inhibited a mitochondria-dependent cell apoptosis via the ERK pathway. The NELL2-ERK system might represent an important target to facilitate the development of future therapeutic approaches in BPH.

Alterations in the phosphodiesterase type 5 pathway and oxidative stress correlate with erectile function in spontaneously hypertensive rats.

To explore how alterations in the phosphodiesterase type 5 (PDE5) signalling pathway and oxidative stress correlate with changes in the expression of relaxation and contraction molecules and erectile dysfunction (ED) in the corpus cavernosum smooth muscle (CCSM) of spontaneously hypertensive rats (SHR). In this study, SHR and Wistar-Kyoto (WKY) rats were used. Erectile function was determined by apomorphine test and electrical stimulation (ES) of cavernous nerve. Masson's trichrome staining and confocal microscopy were performed. Nitric oxide synthase (NOS), PDE5, phosphorylated-PDE5 and α1-adrenergic receptor (α1AR) were determined by RT-PCR and Western blotting while oxidative stress in CC was determined by colorimetric analysis. SHR exhibited obvious ED. CC of SHR showed less SM but more collagen fibres. The expression of NOS isoforms in SHR was significantly decreased while all α1AR isoforms were increased. In addition, PDE5 and phosphorylated-PDE5 were down-regulated and its activity attenuated in the hypertensive rats. Meanwhile, the SHR group suffered oxidative stress, which may be modulated by endoplasmic reticulum stress and NADPH oxidase up-regulation. Dysregulation of NOS and α1AR, histological changes and oxidative stress in CC may be associated with the pathophysiology of hypertension-induced ED. In addition, PDE5 down-regulation may lead to the decreased efficacy of PDE5 inhibitors in some hypertensive ED patients and treatment of oxidative stress could be used as a new therapeutic target for this type of ED.

Changes in the expression and function of the PDE5 pathway in the obstructed urinary bladder.

Our study aims to explore changes in bladder contractility and the phosphodiesterase type 5 (PDE5) signalling pathway in response to partial bladder outlet obstruction (PBOO). A surgically induced male rat PBOO model and human obstructed bladder tissues were used. Histological changes were examined by H&E and Masson's trichrome staining. Bladder strip contractility was measured via organ bath. The expressions of nitric oxide synthase (NOS) isoforms, PDE5, muscarinic cholinergic receptor (CHRM) isoforms and PDE4 isoforms in bladder were detected by RT-PCR and Western blotting. The immunolocalization of the PDE5 protein and its functional activity were also determined. PBOO bladder tissue exhibited significant SM hypertrophy and elevated responsiveness to KCl depolarization and the muscarinic receptor agonist carbachol. NOS isoforms, PDE5, CHRM2, CHRM3 and PDE4A were up-regulated in obstructed bladder tissue, whereas no change in PDE4B and PDE4D isoform expression was observed. With regard to PDE5, it was expressed in the SM bundles of bladder. Interestingly, obstructed bladder exhibited less relaxation responsiveness to sodium nitroprusside (SNP), but an exaggerated PDE5 inhibition effect. The up-regulation of PDE5 could contribute to the lack of effect on Qmax for benign prostatic hyperplasia/lower urinary tract symptom (BPH/LUTS) patients treated with PDE5 inhibitors. Moreover, PDE5 (with presence of NO) and PDE4 may serve as new therapeutic targets for bladder diseases such as BPH-induced LUTS and overactive bladder (OAB).

Testosterone regulates the expression and functional activity of sphingosine-1-phosphate receptors in the rat corpus cavernosum.

The bioactive lipid sphingosine-1-phosphate (S1P) regulates smooth muscle (SM) contractility predominantly via three G protein-coupled receptors. The S1P1 receptor is associated with nitric oxide (NO)-mediated SM relaxation, while S1P2 & S1P3 receptors are linked to SM contraction via activation of the Rho-kinase pathway. This study is to determine testosterone (T) modulating the expression and functional activity of S1P receptors in corpus cavernosum (CC). Adult male Sprague-Dawley rats were randomly divided into three groups: sham-operated controls, surgical castration and T supplemented group. Serum S1P levels were detected by high-performance liquid chromatography. The expression of S1P1-3 receptors and sphingosine kinases was detected by real-time RT-PCR. In vitro organ bath contractility and in vivo intracavernous pressure (ICP) measurement were also performed. T deprivation significantly decreased ICP rise. Meanwhile, surgical castration induced a significant increase in serum S1P level and the expression of S1P2-3 receptors by twofold (P < 0.05) but a decrease in the expression of S1P1 receptor. Castration also augmented exogenous phenylephrine (PE), S1P, S1P1,3 receptor agonist FTY720-P contractility and S1P2-specific antagonist JTE013 relaxation effect. T supplemented could restore the aforementioned changes. We provide novel data that castration increased serum S1P concentration and up-regulated the expression of S1P2-3 receptors in CC. Consistently, agonizing S1P receptors induced CCSM contraction and antagonizing mediated relaxation were augmented. This provides the first clear evidence that S1P system dysregulation may contribute to hypogonadism-related erectile dysfunction (ED), and S1P receptors may be expected as a potential target for treating ED.

The expression and functional activities of smooth muscle myosin and non-muscle myosin isoforms in rat prostate.

Benign prostatic hyperplasia (BPH) is mainly caused by increased prostatic smooth muscle (SM) tone and volume. SM myosin (SMM) and non-muscle myosin (NMM) play important roles in mediating SM tone and cell proliferation, but these molecules have been less studied in the prostate. Rat prostate and cultured primary human prostate SM and epithelial cells were utilized. In vitro organ bath studies were performed to explore contractility of rat prostate. SMM isoforms, including SM myosin heavy chain (MHC) isoforms (SM1/2 and SM-A/B) and myosin light chain 17 isoforms (LC17a/b ), and isoform ratios were determined via competitive RT-PCR. SM MHC and NM MHC isoforms (NMMHC-A, NMMHC-B and NMMHC-C) were further analysed via Western blotting and immunofluorescence microscopy. Prostatic SM generated significant force induced by phenylephrine with an intermediate tonicity between phasic bladder and tonic aorta type contractility. Correlating with this kind of intermediate tonicity, rat prostate mainly expressed LC17a and SM1 but with relatively equal expression of SM-A/SM-B at the mRNA level. Meanwhile, isoforms of NMMHC-A, B, C were also abundantly present in rat prostate with SMM present only in the stroma, while NMMHC-A, B, C were present both in the stroma and endothelial. Additionally, the SMM selective inhibitor blebbistatin could potently relax phenylephrine pre-contracted prostate SM. In conclusion, our novel data demonstrated the expression and functional activities of SMM and NMM isoforms in the rat prostate. It is suggested that the isoforms of SMM and NMM could play important roles in BPH development and bladder outlet obstruction.

Testosterone regulates myosin II isoforms expression and functional activity in the rat prostate.

BACKGROUND: Benign prostatic hyperplasia (BPH) is mainly caused by increased prostatic smooth muscle (SM) tone and prostatic volume. At the molecular level, SM myosin II (SMM II) and non-muscle myosin II (NMM II) mediate SM tone and cell proliferation while testosterone (T) plays a permissive role in the development of BPH. AIMS: The novel objective of this study was to elucidate the effects of T on the proliferation and apoptosis of rat prostatic cells and SM contractility as well as related regulatory signaling pathways. MATERIALS AND METHODS: Briefly, 36 male rats were divided into three groups (sham-operated, surgically castrated, and castrated with T supplementation). In vitro organ bath studies, competitive RT-PCR, Western-blotting analysis, Masson's trichrome staining, and immunofluorescence staining were performed. RESULTS: Our data showed that castration dramatically increased prostatic SM contractility and SM MHC immunostaining revealed a relatively increased SM cell numbers in the stroma. T deprivation altered prostate SMM II isoform composition with upregulation of SM-B and SM2 but downregulation of LC17a, favoring a faster more phasic-type contraction. Moreover, protein expressions of MLCK, p-MLCP, RhoB, ROCK1, and ROCK2 increased in castrated rats. Meanwhile NMM II heavy chain isoforms A, B, and C (NMMHC-A, B, and C isoforms) were altered by castration which may be linked to decreased cell proliferation and increased apoptosis. CONCLUSION: Our novel data demonstrated T regulates SMM II and NMM II and their functional activities in rat prostate and T ablation not only decreases prostate size (static component) but also changes the prostatic SM tone (dynamic component).

Blebbistatin modulates prostatic cell growth and contrapctility through myosin II signaling.

To investigate the effect of blebbistatin (BLEB, a selective myosin inhibitor) on regulating contractility and growth of prostate cells and to provide insight into possible mechanisms associated with these actions. BLEB was incubated with cell lines of BPH-1 and WPMY-1, and intraprostatically injected into rats. Cell growth was determined by flow cytometry, and in vitro organ bath studies were performed to explore muscle contractility. Smooth muscle (SM) myosin isoform (SM1/2, SM-A/B, and LC17a/b) expression was determined via competitive reverse transcriptase PCR. SM myosin heavy chain (MHC), non-muscle (NM) MHC isoforms (NMMHC-A and NMMHC-B), and proteins related to cell apoptosis were further analyzed via Western blotting. Masson's trichrome staining was applied to tissue sections. BLEB could dose-dependently trigger apoptosis and retard the growth of BPH-1 and WPMY-1. Consistent with in vitro effect, administration of BLEB to the prostate could decrease rat prostatic epithelial and SM cells via increased apoptosis. Western blotting confirmed the effects of BLEB on inducing apoptosis through a mechanism involving MLC20 dephosphorylation with down-regulation of Bcl-2 and up-regulation of BAX and cleaved caspase 3. Meanwhile, NMMHC-A and NMMHC-B, the downstream proteins of MLC20, were found significantly attenuated in BPH-1 and WPMY-1 cells, as well as rat prostate tissues. Additionally, BLEB decreased SM cell number and SM MHC expression, along with attenuated phenylephrine-induced contraction and altered prostate SMM isoform composition with up-regulation of SM-B and down-regulation of LC17a, favoring a faster contraction. Our novel data demonstrate BLEB regulated myosin expression and functional activity. The mechanism involved MLC20 dephosphorylation and altered SMM isoform composition.

Basic Science Evidence for the Link Between Erectile Dysfunction and Cardiometabolic Dysfunction.

INTRODUCTION: Although clinical evidence supports an association between cardiovascular/metabolic diseases (CVMD) and erectile dysfunction (ED), scientific evidence for this link is incompletely elucidated. AIM: This study aims to provide scientific evidence for the link between CVMD and ED. METHODS: In this White Paper, the Basic Science Committee of the Sexual Medicine Society of North America assessed the current literature on basic scientific support for a mechanistic link between ED and CVMD, and deficiencies in this regard with a critical assessment of current preclinical models of disease. RESULTS: A link exists between ED and CVMD on several grounds: the endothelium (endothelium-derived nitric oxide and oxidative stress imbalance); smooth muscle (SM) (SM abundance and altered molecular regulation of SM contractility); autonomic innervation (autonomic neuropathy and decreased neuronal-derived nitric oxide); hormones (impaired testosterone release and actions); and metabolics (hyperlipidemia, advanced glycation end product formation). CONCLUSION: Basic science evidence supports the link between ED and CVMD. The Committee also highlighted gaps in knowledge and provided recommendations for guiding further scientific study defining this risk relationship. This endeavor serves to develop novel strategic directions for therapeutic interventions.

Alteration of the Expression and Functional Activities of Myosin II Isoforms in Enlarged Hyperplastic Prostates.

INTRODUCTION: Benign prostatic hyperplasia (BPH) is a common pathologic process in aging men, and the contraction of the prostatic smooth muscles (SMs) in the stroma plays a vital role in this pathogenesis, leading to lower urinary tract symptoms (LUTSs). The isoforms of both the SM myosin (SMM) and non-muscle myosin (NMM) are associated with the contraction type of the prostatic SMs, but the mechanism has not been fully elucidated. METHODS: We collected prostate tissues from 30 BPH patients receiving surgical treatments, and normal human prostate samples were obtained from 12 brain-dead men. A testosterone-induced (T-induced) rat model was built, and the epithelial hyperplastic prostates were harvested. Competitive RT-PCR was used to detect the expression of SMM isoforms. We investigated the contractility of human prostate strips in vitro in an organ bath. RESULTS: The results regarding the comparisons of SMM isoforms varied between rat models and human samples. In comparison with T-induced rats and controls, competitive RT-PCR failed to show any statistically significant difference regarding the compositions of SMM isoforms. For human prostates samples, BPH patients expressed more SM-1 isoforms (66.8% vs. 60.0%, p < 0.001) and myosin light chain-17b (MLC17b) (35.9% vs. 28.5%, p < 0.05) when compared to young donors. There was a significant decrease in prostate myosin heavy chain (MHC) expression in BPH patients, with a 66.4% decrease in MHC at the mRNA level and a 51.2% decrease at the protein level. The upregulated expression of non-muscle myosin heavy chain-B (NMMHC-B) was 1.6-fold at the mRNA level and 2.1-fold at the protein level. The organ bath study showed that isolated prostate strips from BPH patients produced slower tonic contraction compared to normal humans. CONCLUSION: In this study, we claim that in the enlarged prostates of patients undergoing surgeries, MHC expression significantly decreased compared to normal tissues, with elevated levels of SM-1, MLC17b, and NMMHC-B isoforms. Modifications in SMM and NMM might play a role in the tonic contractile properties of prostatic SMs and the development of LUTS/BPH. Understanding this mechanism might provide insights into the origins of LUTS/BPH and facilitate the identification of novel therapeutic targets.

S100A4 modulates cell proliferation, apoptosis and fibrosis in the hyperplastic prostate.

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men worldwide that may result in lower urinary tract symptoms (LUTS). At present, the specific pathophysiological mechanism for BPH/LUTS LUTS remains unclear. S100 calcium binding protein A4 (S100A4), a member of the calcium binding protein family, regulates a variety of biological processes including cell proliferation, apoptosis and fibrosis. The aim of the current study was to explore and clarify the possible role of S100A4 in BPH/LUTS. The human prostate stromal cell line (WPMY-1), rat prostate epithelial cells, human prostate tissues and two BPH rat models were employed in this study. The expression and localization of S100A4 were detected by quantitative real time PCR (qRT-PCR), immunofluorescence microscopy, Western blotting and immunohistochemistry analysis. Also, S100A4 knockdown or overexpression cell models were constructed and a BPH rat model was induced with testosterone propionate (T) or phenylephrine (PE). The BPH animals were treated with Niclosamide, a S100A4 transcription inhibitor. Results demonstrated that S100A4 was mainly localized in human prostatic stroma and rat prostatic epithelium, and showed a higher expression in BPH. Knockdown of S100A4 induced cell apoptosis, cell proliferation arrest and a reduction of tissue fibrosis markers. Overexpression of S100A4 reversed the aforementioned changes. We also demonstrated that S100A4 regulated proliferation and apoptosis mainly through the ERK pathway and modulated fibrosis via Wnt/ß-catenin signaling. In conclusion, our novel data demonstrate that S100A4 could play a crucial role in BPH development and may be explored as a new therapeutic target of BPH.

STEAP4 modulates cell proliferation and oxidative stress in benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is a quite common chronic disease plagued elderly men and its etiology remains unclear. It was reported that the six-transmembrane epithelial antigen of prostate 4 (STEAP4) could modulate cell proliferation/apoptosis ratio and oxidative stress in cancers. Our current study aimed to explore the expression, biological function, and underlying mechanism of STEAP4 in BPH progress. Human prostate tissues and cell lines were utilized. qRT-PCR and immunofluorescence staining were employed. STEAP4 knockdown (STEAP4-KD) or STEAP4 overexpression (STEAP4-OE) cell models were established. Cell proliferation, cell cycle, apoptosis, and reactive oxygen species (ROS) were determined by cell counting kit-8 (CCK-8) assay and flow cytometry. Apoptosis-related proteins and antioxidant enzymes were identified by Western Blot. In addition, the epithelial-mesenchymal transition (EMT) process and fibrosis biomarker (collagen I and α-SMA) were analyzed. It was indicated that STEAP4 was mainly located in the prostate epithelium and upregulated in BPH tissues. STEAP4 deficiency induced apoptosis and inhibited cell survival, but had no effect on the cell cycle, fibrosis, and EMT process. In addition, ROS changes were observed in the STEAP4-KD model. Consistently, overproduction of STEAP4 suppressed apoptosis and promoted cell proliferation, as well as facilitated ROS production. We further examined AKT / mTOR, p38MAPK / p-p38MAPK, and WNT/ ß-Catenin signaling pathway and demonstrated that STEAP4 regulated the proliferation and apoptosis of prostate cells through AKT / mTOR signaling, rather than p38MAPK / p-p38MAPK and WNT/ ß-Catenin pathways. Furthermore, activating AKT / mTOR signaling with SC79 significantly reversed apoptosis triggered by STEAP4 deficiency, whereas suppressing AKT / mTOR signaling with MK2206 reduced the increase of cell viability triggered by STEAP4 overproduction. Our original data demonstrated that STEAP4 is crucial in the onset and progression of prostate hyperplasia and may become a new target for the treatment of BPH.

Expression and functional activity of myosin II in hyperplastic prostates of varying volumes.

Prostate volume (PV) differs dramatically among benign prostatic hyperplasia (BPH) patients. Estimation of PV is important to guide the most appropriate pharmacologic or interventional treatment approach. However, the underlying pathophysiological mechanisms for the differences in PV remain unknown. We recently found that the myosin II system might participate in the etiology and development of BPH via static and dynamic factors. Our present study aims to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in hyperplastic prostates with varied PV. Human hyperplastic prostates and the testosterone-induced rat BPH model were employed for this study. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. Also, a BPH tissue microarray (TMA) was constructed to determine the correlations between myosin II isoforms with clinical parameters of BPH patients. With the increase of PV, the expression of NMMHC-A, NMMHC-C, SM-A and LC17b isoforms were increased, and the contractility of prostate smooth muscle was enhanced but force developed more slowly. Consistently, NMMHC-A, NMMHC-C, SM-A and LC17b were correlated positively with PV. Similar outcomes were also observed in the BPH rat model with different PVs. Alterations in the expression and function of myosin the II system may be involved in the pathophysiological mechanism of PV differences between BPH patients.