The association between local atherosclerosis of the prostatic artery and benign prostatic enlargement in humans: Putative mechanism of chronic ischemia for prostatic enlargement

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 LC_17b 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 LC_17b 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.

Possible Clinical Benefits of Cardio-Ankle Vascular Index Measurement in Urological Diseases

Many factors are considered to affect vascular physiology. It is known that one of the reasons for many diseases is a pathology at the microvascular level. Therefore, the relationship between endothelial dysfunction and many diseases is currently being investigated. The clinical evaluations of arterial stiffness have made it possible to perform necessary risk assessment regarding cardiovascular diseases. In this way, protective measures can be taken against microvascular pathologies in many organs. In this paper, we present a review of studies investigating the relationship between urological conditions and the cardio-ankle vascular index (CAVI), a marker of arterial stiffness. As with erectile dysfunction, some studies have shown that conditions such as lower urinary tract symptoms, overactive bladder, and chronic kidney disease are also associated with an elevated CAVI. The association of erectile dysfunction and chronic kidney disease with vascular pathologies has been clearly demonstrated. In addition, lower urinary tract symptoms may be the first sign of silent vascular dysfunction. Assessing arterial stiffness with CAVI can help prevent future cardiovascular events in these patients.

Use of the triple coaxial (triaxial) microcatheter system in superselective arterial embolisation for complex interventional cases: an initial experience with the system

LEARNING OBJECTIVE

To share our experience in utilising the triple coaxial (triaxial) system in superselective cannulation of arteries for complex embolisation procedures.

BACKGROUND

Percutaneous transcatheter selective embolisation is widely performed for a myriad of oncologic (e.g., trans-arterial chemo- or radio-embolisation) and non-oncologic (e.g., for embolisation of bleeding and benign conditions such as uterine fibroid and benign prostate hyperplasia) purposes. The cornerstone of such embolisation procedures is to achieve superselective cannulation of the arterial supply to the tumour/organ, preventing the complication of non-target embolisation. However, a multitude of factors, such as complex vascular anatomy, can pose challenges to achieving this goal.

CLINICAL FINDINGS/PROCEDURAL DETAILS

The triaxial system utilises two smaller microcatheters telescoped through each other over a microwire. We have adopted the triaxial system for specific cases due to its perceived superior torquability and trackability compared to the conventional coaxial system, in which superselective cannulation is anticipated to be challenging. The triaxial system is also favourable in situations where the inner microcatheter needs to be "sacrificed" after administering the embolics (e.g., after administering radioisotopes in radioembolisation, N-butyl cyanoacrylate [NBCA] glue or ethylene-vinyl alcohol copolymer [EvOH] Onyx). Through a case series with procedural details such as fluoroscopic time, contrast administered, etc., we hope to illustrate the utility and efficacy of the triaxial system as well as present pitfalls in its usage.

CONCLUSION

The triaxial system appears to be a valuable system for certain complex embolisation procedures and could be better suited than the conventional coaxial systems in these specific circumstances.

Clinical features and urodynamic findings in elderly men with chronic prostatitis

OBJECTIVES

To investigate the complication rate of chronic prostatitis/chronic pelvic pain syndrome in men with lower urinary tract symptoms, and to clarify their clinical features and urodynamic findings.

METHODS

We retrospectively reviewed the clinical data of treatment-naïve men with lower urinary tract symptoms. Patients were divided into two groups (chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms and lower urinary tract symptoms only) according to the presence or absence of chronic prostatitis/chronic pelvic pain syndrome, and the patient characteristics as well as the parameters of lower urinary tract symptoms and lower urinary tract function assessed by urodynamics were compared. The diagnostic criteria for chronic prostatitis/chronic pelvic pain syndrome included a complaint of pelvic pain for ≥3 months, National Institutes of Health Chronic Prostatitis Symptom Index pain subscore ≥4, and negative culture of a urine specimen collected after prostate massage.

RESULTS

Out of 386 men, 123 (31.9%) had chronic prostatitis/chronic pelvic pain syndrome. Parameters of lower urinary tract symptoms and National Institutes of Health Chronic Prostatitis Symptom Index scores were significantly higher in the chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms group. Although there were no significant intergroup differences in voiding parameters such as maximum flow rate and bladder outlet obstruction index, storage functions such as the incidence of detrusor overactivity and bladder compliance were significantly reduced in the chronic prostatitis/chronic pelvic pain syndrome + lower urinary tract symptoms group. The multivariable regression analysis revealed that a low serum total testosterone level (<3.5 ng/mL), complications of hyperlipidemia, and presence of overactive bladder and detrusor overactivity were significantly associated with the development of chronic prostatitis/chronic pelvic pain syndrome.

CONCLUSIONS

Chronic prostatitis causes a significant decrease in storage function, such as an increase in detrusor overactivity. Additionally, low serum testosterone levels and hyperlipidemia were found to be significantly associated with the development of chronic prostatitis/chronic pelvic pain syndrome in men with lower urinary tract symptoms.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Therapeutic effects of losartan on prostatic hyperplasia in spontaneously hypertensive rats

AIMS

We investigated the therapeutic effects of losartan, an angiotensin II type 1 receptor blocker, on prostatic hyperplasia in spontaneously hypertensive rats (SHRs).

MAIN METHODS

Male SHRs (age, 36 weeks) were perorally treated with losartan (3 or 10 mg·kg^-1) or vehicle once daily for 18 weeks. Age-matched Wistar Kyoto rats (WKYs) were used as vehicle-treated controls (n = 8). The effects of losartan were evaluated by analyzing prostate weight, blood pressure, and prostatic blood flow. The tissue malondialdehyde (MDA), interleukin-6 (IL-6), and basic fibroblast growth factor (bFGF) levels were measured. Histological analysis for the ventral prostate involved hematoxylin and eosin staining and TdT-mediated dUTP nick-end labeling (TUNEL) assay.

KEY FINDINGS

Compared to the vehicle-treated WKYs, the vehicle-treated SHRs had significantly higher prostate weight, prostate weight/body weight ratio (PBR), blood pressure, glandular epithelial area, and tissue MDA, IL-6, and bFGF levels in the ventral prostate and lower prostatic blood flow. Treatment with losartan caused significant recovery of blood flow and decreased PBR and glandular epithelial area as well as tissue MDA, IL-6, and bFGF levels in the SHR ventral prostate without affecting blood pressure. High-dose losartan significantly decreased blood pressure and increased TUNEL-positive cells in the ventral prostate in SHRs.

SIGNIFICANCE

Chronic losartan treatment could ameliorate prostatic hyperplasia via recovery of reduced prostatic blood flow and induction of apoptosis in the ventral prostate in SHRs. Losartan might have therapeutic effects on not only hypertension but also prostatic hyperplasia in humans.

The FGF/FGFR system in the physiopathology of the prostate gland

Fibroblast growth factors (FGFs) are a family of proteins possessing paracrine, autocrine, or endocrine functions in a variety of biological processes, including embryonic development, angiogenesis, tissue homeostasis, wound repair, and cancer. Canonical FGFs bind and activate tyrosine kinase FGF receptors (FGFRs), triggering intracellular signaling cascades that mediate their biological activity. Experimental evidence indicates that FGFs play a complex role in the physiopathology of the prostate gland that ranges from essential functions during embryonic development to modulation of neoplastic transformation. The use of ligand- and receptor-deleted mouse models has highlighted the requirement for FGF signaling in the normal development of the prostate gland. In adult prostate, the maintenance of a functional FGF/FGFR signaling axis is critical for organ homeostasis and function, as its disruption leads to prostate hyperplasia and may contribute to cancer progression and metastatic dissemination. Dissection of the molecular landscape modulated by the FGF family will facilitate ongoing translational efforts directed toward prostate cancer therapy.

The association between local arteriosclerosis of the prostatic arteries and chronic inflammation in human benign prostatic enlargement

BACKGROUND

To elucidate the pathogenesis of benign prostatic enlargement (BPE) in humans due to chronic inflammation caused by arteriosclerosis, the relationships between prostate size and the degree of chronic inflammation induced by local arteriosclerosis were investigated.

METHODS

The present cohort included 50 subjects who underwent robot-assisted radical prostatectomy (RARP) in a prospective study. The presence or absence of local arteriosclerosis in the prostatic arteries removed during RARP was evaluated by microscopic assessment. Chronic inflammation in the prostate was judged according to both the density and the extent of inflammatory cells. The expression of lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and the infiltration of macrophages in the prostate, which are high in arteriosclerosis, were investigated by immunohistochemistry.

RESULTS

Local arteriosclerosis was observed in 28% (14/50). Prostate size and the inflammation score were significantly increased in the presence of arteriosclerosis (P = 0.006, P < 0.001, respectively). There was also a significant increase of LOX-1 in the epithelial and stromal cells of the prostate in the presence of arteriosclerosis (all, P < 0.001). Concerning the presence of macrophages, subjects with arteriosclerosis had significantly more positive expression of ionized calcium-binding adapter molecule-1 (IBA-1), a marker of macrophages, than subjects without arteriosclerosis (P < 0.001).

CONCLUSIONS

In human surgical specimens, chronic inflammation owing to local arteriosclerosis of the prostatic arteries was significantly related to prostatic enlargement. Given the immunohistochemical analyses, the putative pathogenesis for this relationship is that LOX-1 induces macrophage infiltration, leading to BPE.

Phosphodiesterase type 5 inhibitor attenuates chronic ischemia-induced prostatic hyperplasia in a rat model

BACKGROUND

Many elderly men suffer from benign prostatic hyperplasia (BPH). Recently, chronic ischemia in the prostate has been suggested to be related to BPH. Thus, the impact of chronic ischemia on the development of prostatic hyperplasia and the efficacy of phosphodiesterase type 5 (PDE5) inhibitor for hyperplasia were evaluated in a rat model with chronic ischemia induced by local atherosclerosis.

METHODS

Eighteen male Sprague-Dawley rats were divided into three groups: sham operation, regular diet, placebo (SRP); arterial endothelial injury, high cholesterol diet, placebo (AHP); or arterial endothelial injury, high cholesterol diet, and tadalafil as a PDE5 inhibitor (AHT). The endothelial injury in the common iliac arteries was performed using a 2-Fr Fogarty arterial embolectomy catheter through an incision in the femoral artery into the common iliac artery. Diet and oral drugs were administrated for 8 weeks after surgery. At 8 weeks, blood flow to the ventral prostate (VP) was measured using laser speckle blood flow analysis, and the VP was histologically evaluated.

RESULTS

In the AHP group, prostatic blood flow was reduced, and mean VP weight and the interstitial area were significantly enlarged compared with the SRP group. In the AHT group, tadalafil administration obviously ameliorated the reduction of prostatic blood flow relative to the AHP group. Importantly, mean VP weight and the morphological changes in the AHT group were significantly smaller than those in the AHP group.

CONCLUSIONS

Enlargement of the VP resulted from chronic ischemia induced by local arteriosclerosis. Also, administration of tadalafil attenuated VP enlargement. Chronic ischemia in the prostate might thus contribute to the development of BPH, and PDE5 inhibitors might provide an innovative approach to preventing BPH.

[Prostatic blood flow as prominent targets on benign prostatic hyperplasia]

Benign prostatic hyperplasia/benign prostatic enlargement (BPH/BPE) is a common proliferative disease, and giving rise to associate with lower urinary tract symptoms (LUTS). However, the pathogenesis is not well clarified, and thought to be multifactorial. There are some lines of evidence that impairment in the blood supply of the lower urinary tract causes development of BPH/BPE. Clinical data showed an association between the development of BPH/BPE and atherosclerotic disease such as hypertension, diabetes and hyperlipidemia. The spontaneously hypertensive rat (SHR) has been used as model of genetic hypertension. SHR also shows decreased blood flow and hyperplastic morphological abnormalities in the ventral prostate. Our previous studies demonstrated that chronic treatment with vasodilative drugs nicorandil (ATP sensitive potassium channel opener) and silodosin (alpha1 adrenoceptor antagonist) increased blood flow and suppressed the growth factor and morphological abnormalities in the SHR ventral prostate. These data suggested that prostatic blood flow could be therapeutic targets for BPH/LUTS.