Ghrelin Aggravates Prostate Enlargement in Rats with Testosterone-Induced Benign Prostatic Hyperplasia, Stromal Cell Proliferation, and Smooth Muscle Contraction in Human Prostate Tissues

Smooth muscle contractility of laser-enucleated prostate tissues and impacts of preoperative α1-blocker treatment in patients with and without catheterization

Prostate smooth muscle contraction is central in treatment of voiding symptoms in benign prostatic hyperplasia (BPH). Tissues from transurethral resection of the prostate (TURP) and radical prostatectomy (RP) for prostate cancer are widely used to study contractions. However, findings are limited by traumatization in TURP, and uncertain relationship to BPH in RP tissues. This study aims to examine contractions of laser-enucleated tissues. Tissues from holmium/thulium laser enucleation (HoLEP/ThuLEP) and TURP were contracted by KCl, noradrenaline and electric field stimulation (EFS) in an organ bath. Contractions were compared to RP tissues in previous studies. KCl-induced contractions averaged 2.5 mN, 0.7 mN and 3.3 mN in tissues from HoLEP/ThuLEP, TURP and RP, with non-responsive tissues included (2.4% HoLEP/ThuLEP, 37% TURP). Maximum EFS-induced contractions (Emax) averaged 47% of KCl in HoLEP/ThuLEP tissues, 27% in TURP tissues, and 68-235% in 21 previous studies with RP tissues. Emax values for noradrenaline averaged 99.7% in HoLEP/ThuLEP tissues, 56% in TURP tissues, and ranged from 92 to 260% in RP tissues. Preoperative α1-blocker treatment reduced EFS- and noradrenaline-induced contractions, and increased EC50 values for noradrenaline in laser-enucleated, catheterized patients, but not in patients without catheterization. Also, the ex vivo application of α1-blockers increased the EC50 values for noradrenaline and reduced Emax for EFS. Laser-enucleated tissues allow investigation of prostate smooth muscle contraction in medication-refractory voiding symptoms. Different impacts of preoperative α1-blocker treatment on ex vivo contractility in tissues from patients with and without catheterization point to clinically relevant heterogeneity of patients undergoing surgery for BPH.

Asthma-associated prostate enlargement and bladder smooth muscle hypercontractility: unveiling a potential link to LUTS

BACKGROUND

In male patients, benign prostate hyperplasia (BPH) and overactive bladder (OAB) secondary to BPH are the primary causes of Lower Urinary Tract Symptoms (LUTS). Recent clinical studies have reported an increased risk of LUTS, particularly severe LUTS conditions, in male asthmatic patients. However, the potential link and mechanism remain unclear. In this study, we investigated the structural and molecular characteristics of the prostate, and the structural and functional characteristics of the bladder in an asthma rat model.

METHODS

An asthma model was induced in rats through the intraperitoneal injection of ovalbumin. Prostate and bladder tissue structure was examined with Hematoxylin and Eosin (H&E) and Masson's trichrome (MT) staining, respectively. Prostatic smooth muscle contraction-related and synthesis-related protein levels were assessed using western blotting. Detrusor contractions were examined in an organ bath.

RESULTS

Prostate epithelial thickness was significantly increased in asthmatic rats, accompanied by changes in molecular markers, including increased expression of desmin and tropomyosin and decreased expression of vimentin in the prostate tissue. The bladder wall structure and bladder weight were similar in both the asthma and control groups. Acetylcholine induced concentration-dependent bladder smooth muscle contractions, which were significantly enhanced in strips from asthmatic rats, however, acetyl-β-methylcholine and carbachol induced concentration-dependent bladder smooth muscle contractions were similar in both groups.

CONCLUSIONS

Our findings suggest a potential association between asthma and LUTS, with asthma possibly contributing to organ-specific changes, including prostate enlargement and increased smooth muscle contraction in the prostate and bladder. These results provide evidence for a biological connection between asthma and LUTS, laying a promising foundation for exploring new therapeutic strategies to manage LUTS in patients with asthma.

Inhibition of integrin receptors reduces extracellular matrix levels, ameliorating benign prostate hyperplasia

Although a high prevalence of benign prostate hyperplasia (BPH) has been documented, the risk factors are poorly understood. Metabolic syndrome increases the risk of BPH. Succinylation, a type of posttranslational modification, mostly targets metabolic processes. The level of succinylation was investigated in 4 BPH patients and 4 healthy controls. Additionally, 176 patients with BPH were analyzed by using pan-antisuccinyllysine antibody blotting. TMT-labeling proteomic and sc-RNAseq Cellchat analyses were employed to identify key signaling factors involved in the development of BPH. In vivo and in vitro experiments were used to confirm the role of integrin receptors. The global succinylation level in BPH was higher than that in the healthy prostate. Positive correlations of prostate volume with IHC score sand urodynamics testing were found in large clinical cohorts. The extracellular matrix (ECM), metabolic processes and immune signaling were involved in succinylation in BPH, as indicated by using TMT-labeling proteomic analysis, and this finding was also confirmed by sc-RNAseq CellChat analysis. The proteins upregulated in SIRT5 knockout WPMY-1 cells were also enriched in the extracellular matrix and metabolic processes. More importantly, integrin receptor inhibition in a mouse model of BPH significantly ameliorated prostate hyperplasia. High levels of succinylation modifications were found in BPH, and succinylated proteins influenced the activation of the ECM. Inhibition of ECM signaling further ameliorated prostate hyperplasia in mice.

Leptin Mediates Prostate Stromal Cell Proliferation, Smooth Muscle Contraction, and Mitochondrial Function in Benign Prostate Hyperplasia

Introduction

Leptin is a metabolic peptide hormone produced by adipocytes, with proven roles in proliferation of prostate cancer cells and of prostate cells in animal models of benign prostatic hyperplasia (BPH). Thus, the role of leptin as a molecular link connecting BPH and lower urinary tract symptoms (LUTS) suggestive of BPH with metabolic symptoms appears feasible but is still unknown. In fact, a connection between metabolic syndrome and BPH is becoming increasingly evident from epidemiologic studies. Key factors of Lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH/LUTS) are increased prostate smooth muscle tone, and prostate enlargement. Here, we examined the effects of leptin on contraction of human prostate smooth muscle and on growth of stromal cells.

Methods

We performed microarray analysis to identify genes (fold change ≥ 1.5) associated with BPH/LUTS progression, such as those involved in proliferation, apoptosis, and mitochondrial metabolism, in rat prostate tissue (data from GSE129561). We then used electric field stimulation (EFS) to induce frequency-dependent, neurogenic contractions of human prostate strips, which were enhanced by leptin. We also examined the effect of leptin on human prostate stromal cells (WPMY-1) and found increased cell proliferation and viability upon exposure. To explore the underlying mechanism, we conducted mitochondrial stress assay using near-infrared (NIR) fluorescent dye and flow cytometry (FACS) analysis and observed reduced cellular apoptosis and preserved mitochondrial membrane potential (∆ψM) after leptin treatment.

Results

Microarray analysis reveals that leptin regulates prostate smooth muscle contraction and stromal cell proliferation, shedding new light on its involvement in BPH/LUTS pathogenesis and mitochondrial function. We found that leptin enhanced the proliferation rate of prostate stromal cells relative to the control group (0.67 ± 0.05 vs 0.54 ± 0.08, p-value= 0.024). Moreover, leptin (100 ng/mL) potentiated the frequency-dependent, neurogenic contractions of prostate strips elicited by EFS (p= 0.047 between leptin and control group). We also show that leptin treatment increased the mitochondrial membrane potential of prostate stromal cells and inhibited mitochondrial apoptosis.

Discussion

Our results indicate that leptin stimulates the contractility and proliferation of smooth muscle and stromal cells in the human prostate, implying a potential role for leptin in exacerbating BPH/LUTS in obese men. Leptin modulation may be a beneficial therapeutic strategy for patients with metabolic syndrome and BPH/LUTS. Further studies are warranted to elucidate the mechanisms and implications of the leptin system in BPH/LUTS.

Evaluation of the Therapeutic Effect of the Traditional Herbal Medicine Atrifil and Oshagh Gum on Testosterone-Induced Benign Prostatic Hyperplasia in Wistar Rats

Benign prostatic hyperplasia (BPH) is a common disease that affects elderly men with various complications. This study evaluates the effects of an Iranian traditional herbal medicine "Atrifil and Oshagh gum" on BPH in male Wistar rats. Atrifil is a combination of three medicinal plants: Emblica officinalis Gaertn, Terminalia chebula Retz, and Terminalia bellerica Retz" extracts, and Oshagh gum is Dorema ammoniacum D. Dono gum. In this study, 30 male Wistar rats were divided into five groups: normal control, disease, finasteride, and extract with 300 and 600 mg/kg groups. The extract is a combination of hydroalcoholic Atrifil extract and Oshagh gum. All groups received intramuscular testosterone enanthate to induce BPH except the normal control group. On the twenty-eighth day, prostate glands were separated. Histopathological changes were observed. Furthermore, the prostate-specific antigen (PSA) and prostate weights were measured. The binding propensities of finasteride, equol, and flavonoids present in this extract such as quercetin, rutin, and kaempferol for 5α-reductase, estrogen receptor alpha and beta, and estrogen-related receptor gamma were assessed using in silico docking approach. Histopathological evaluation, biochemical parameter, and PSA level results indicated significant inhibition of accruing and progression of BPH in groups treated with 600 mg/kg extract (p < 0.01). Furthermore, molecular docking showed that rutin had a high affinity to bind the receptors 5α-reductase, estrogen receptor beta, and estrogen-related receptor gamma even more than finasteride, and on average, quercetin had a higher affinity to all these receptors. In the end, it can be concluded that Atrifil and Oshagh gum is effective in preventing BPH.

Metabolic characterization and metabolism-score of tumor to predict the prognosis in prostate cancer

Tumor metabolism patterns have been reported to be associated with the prognosis of many cancers. However, the metabolic mechanisms underlying prostate cancer (PCa) remain unknown. This study aimed to explore the metabolic characteristics of PCa. First, we downloaded mRNA expression data and clinical information of PCa samples from multiple databases and quantified the metabolic pathway activity level using single-sample gene set enrichment analysis (ssGSEA). Through unsupervised clustering and principal component analyses, we explored metabolic characteristics and constructed a metabolic score for PCa. Then, we independently validated the prognostic value of our metabolic score and the nomogram based on the metabolic score in multiple databases. Next, we found the metabolic score to be closely related to the tumor microenvironment and DNA mutation using multi-omics data and ssGSEA. Finally, we found different features of drug sensitivity in PCa patients in the high/low metabolic score groups. In total, 1232 samples were analyzed in the present study. Overall, an improved understanding of tumor metabolism through the characterization of metabolic clusters and metabolic score may help clinicians predict prognosis and aid the development of more personalized anti-tumor therapeutic strategies for PCa.

The active fragments of ghrelin cross the blood-brain barrier and enter the brain to produce antinociceptive effects after systemic administration

G (1-5)-NH₂, G (1-7)-NH₂, and G (1-9) are the active fragments of ghrelin. The aim of this study was to investigate the antinociceptive effects, their ability to cross the blood-brain barrier, and the receptor mechanism(s) of these fragments using the tail withdrawal test in male Kunming mice. The antinociceptive effects of these fragments (2, 6, 20, and 60 nmol/mouse) were tested at 5, 10, 20, 30, 40, 50, and 60 min after intravenous (i.v.) injection. These fragments induced dose- and time-related antinociceptive effects relative to saline. Using the near infrared fluorescence imaging experiments, our results showed that these fragments could cross the brain-blood barrier and enter the brain. The antinociceptive effects of these fragments were completely antagonized by naloxone (intracerebroventricular, i.c.v.); however, naloxone methiodide (intraperitoneal, i.p.), which is the peripheral restricted opioid receptor antagonist, did not antagonize these antinociceptive effects. Furthermore, the GHS-R1α antagonist [D-Lys³]-GHRP-6 (i.c.v.) completely antagonized these antinociceptive effects, too. These results suggested that these fragments induced antinociceptive effects through central opioid receptors and GHS-R1α. In conclusion, our studies indicated that these active fragments of ghrelin could cross the brain-blood barrier and enter the brain and induce antinociceptive effects through central opioid receptors and GHS-R1α after intravenous injection.

Effects of shRNA-mediated silencing of PDE5A3 on intracellular cGMP and free Ca2+ levels and human prostate smooth muscle cell proliferation from benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS) is a common disease among elderly men, for which safe and effective treatment strategies remain limited. The aim of the present study was to explore the potential effects of phosphodiesterase 5A3 (PDE5A3) silencing on human prostate smooth muscle cells (HPSMCs). HPSMCs were initially obtained from patients with BPH/LUTS. Short hairpin RNA (shRNA) targeting the PDE5A3 gene was subsequently transfected into cultured HPSMCs. The expression of PDE5A3 was measured using reverse transcription-quantitative PCR and western blotting. cGMP levels were then measured using western blotting and immunocytochemical staining and intracellular Ca²⁺ concentration was measured using rhod2-AM in HPSMCs after transfection. HPSMC proliferation was also observed within 4 days. Cells transfected with PDE5A3-shRNA2 exhibited the most notable decline in PDE5A3 expression compared with that in the Control or NC groups. cGMP levels in HPSMCs transfected with PDE5A3-shRNA2 was significantly increased compared with those in the Control or NC groups, whereas intracellular Ca²⁺ concentrations in cells in the PDE5A3-shRNA2 group were decreased compared with that in the Control or NC groups. The proliferation of HPSMCs in the PDE5A3-shRNA2 group was also inhibited compared with that in the Control or NC groups after 72 h of culture. In conclusion, shRNA-mediated silencing of PDE5A3 was able to increase the levels of cGMP whilst reducing the concentration of Ca²⁺ in HPSMCs, in turn suppressing their proliferation. These findings may potentially provide a novel therapeutic target for treating BPH/LUTS.

LncRNA DIO3OS regulated by TGF-β1 and resveratrol enhances epithelial mesenchymal transition of benign prostatic hyperplasia epithelial cells and proliferation of prostate stromal cells

Background

The etiopathogenesis of benign prostatic hyperplasia (BPH) is extremely complicated which involving epithelial-mesenchymal transition (EMT) of epithelial cells and growth of stromal cells. Long non-coding RNAs (lncRNAs) belong to a group of noncoding RNAs which has been widely studied in other diseases but rarely in BPH. Here, we intend to investigate the roles of a lncRNA DIO3 opposite strand (DIO3OS) in BPH progression.

Methods

BPH-1 cells were used to study EMT and WPMY-1 cells were applied to study proliferation induced by TGF-β1, resveratrol, DIO3OS and miRNAs.

Results

DIO3OS was over-expressed in BPH tissues and could be upregulated by Transforming growth factor beta 1 (TGF-β1) and downregulated by resveratrol. Smad2/Smad3/Smad4 complex could bind to the DIO3OS promotor region and thereby enhanced its transcription which was responsible for the regulation of TGF-β1 and resveratrol on DIO3OS expression. TGF-β1 promoted BPH-1 cells EMT and WPMY-1 cells proliferation via DIO3OS and this effect could be blocked by resveratrol. MiR-656-3p and miR-485-5p were targets of DIO3OS and DIO3OS promoted BPH-1 cells EMT and WPMY-1 cells proliferation via miR-656-3p and miR-485-5p. Connective tissue growth factor (CTGF) and zinc finger e-box binding homeobox 1 (ZEB1) were confirmed to be targets of both miR-656-3p and miR-485-5p and could be modulated by TGF-β1, resveratrol, DIO3OS, miR-656-3p and miR-485-5p.

Conclusions

DIO3OS is highly expressed in BPH tissues and regulated by TGF-β1 as well as resveratrol in a Smads dependent manner. DIO3OS facilitates BPH-1 cells EMT and WPMY-1 cells proliferation by upregulating CTGF and ZEB1 via miR-656-3p and miR-485-5p.

The Role of Cancer-Associated Fibroblasts in Prostate Cancer Tumorigenesis

Tumors strongly depend on their surrounding tumor microenvironment (TME) for growth and progression, since stromal elements are required to generate the optimal conditions for cancer cell proliferation, invasion, and possibly metastasis. Prostate cancer (PCa), though easily curable during primary stages, represents a clinical challenge in advanced stages because of the acquisition of resistance to anti-cancer treatments, especially androgen-deprivation therapies (ADT), which possibly lead to uncurable metastases such as those affecting the bone. An increasing number of studies is giving evidence that prostate TME components, especially cancer-associated fibroblasts (CAFs), which are the most abundant cell type, play a causal role in PCa since the very early disease stages, influencing therapy resistance and metastatic progression. This is highlighted by the prognostic value of the analysis of stromal markers, which may predict disease recurrence and metastasis. However, further investigations on the molecular mechanisms of tumor-stroma interactions are still needed to develop novel therapeutic approaches targeting stromal components. In this review, we report the current knowledge of the characteristics and functions of the stroma in prostate tumorigenesis, including relevant discussion of normal prostate homeostasis, chronic inflammatory conditions, pre-neoplastic lesions, and primary and metastatic tumors. Specifically, we focus on the role of CAFs, to point out their prognostic and therapeutic potential in PCa.