Elevated insulin and reduced insulin like growth factor binding protein-3/prostate specific antigen ratio with increase in prostate size in Benign Prostatic Hyperplasia

Intrinsic and extrinsic factors causing hyperplasia of the prostate

Prostatic hyperplasia is very common in elderly men and is a typical disease that reduces quality of life. Histologically, hyperplasia of the prostate gland causes obstruction at the bladder outlet, resulting in symptoms such as a weak urine stream. Various factors have been considered to cause histological enlargement of the prostate, but the underlying cause is still unknown. The factors that cause prostate hyperplasia can be broadly classified into intrinsic and extrinsic ones. Extrinsic factors include things that we directly come into contact with such as bacteria and food. On the other hand, intrinsic factors are those that cause changes in functions originally provided in the body due to some cause, including extrinsic factors, such as chronic inflammation and an imbalance of sex hormones. A large number of reports have been made to date regarding the etiology of prostatic hyperplasia, although they have not yet clarified the fundamental cause(s). The various factors currently known should be outlined for future research. Should it be possible to prevent this highly prevalent prostatic hyperplasia which is mainly cause of dcreasing quality of life, there is no doubt that it would be a huge contribution to humanity.

Immune Cell Proinflammatory Microenvironment and Androgen-Related Metabolic Regulation During Benign Prostatic Hyperplasia in Aging

To review the role of inflammation in the occurrence and development of benign prostatic hyperplasia (BPH), we searched PubMed for the latest published articles up to February 2021 using the following key words: "benign prostatic hyperplasia", "inflammation", "pathogenesis" and "disease development". Articles were obtained and reviewed to provide a systematic review of the current progress of the role of inflammation in the pathogenesis and progression of BPH. Inflammation contributes to the initiation and maintenance of unregulated cell proliferation and is closely related to the occurrence and development of BPH. Its action pathways include tissue damage and subsequent chronic healing, autoimmunity, and coaction with androgens. During the progression of inflammation, macrophages, interleukin-8 (IL-8), interleukin-1 (IL-1) and other inflammatory-related substances aggregate locally and cause BPH through various biochemical pathways. At the same time, BPH can also counteract inflammation to expand its scope and aggravate the situation. Inflammation can independently affect the development of BPH in a variety of ways, and it can also interact with androgens. In the course of treatment, early intervention in the occurrence and development of inflammation in prostate tissue can slow down the progression of BPH. The combination of standard therapies and anti-inflammatory measures may provide valuable new ideas for the treatment of BPH.

Impact of Diabetes Mellitus on Lower Urinary Tract Symptoms in Benign Prostatic Hyperplasia Patients: A Meta-Analysis

Background

Benign prostatic hyperplasia (BPH) is a disease that causes lower urinary tract symptoms (LUTS), which are the most common urological problem in approximately one-third of the male population aged over 50 years. Some studies have suggested that diabetes may be a risk factor for the development of BPH. However, whether diabetes aggravates the LUTS of BPH patients is still controversial.

Aim

To investigate the impact of diabetes mellitus on LUTS in BPH patients.

Methods

A literature search was conducted using Web of Science, Embase, PubMed, and China National Knowledge Infrastructure literature databases. This meta-analysis was registered in PROSPERO (registration number: CRD 42020200794). Fixed- or random-effects models were used for analysis according to heterogeneity. The results of the systematic analysis are presented as weighted mean difference (WMD) with the corresponding 95% confidence intervals (CI).

Results

In total, 1308 studies were retrieved from databases and 18 articles comprising 1685 cases and 4653 controls were selected for meta-analysis. The results of the meta-analysis showed that the International Prostate Symptom Score (IPSS) value and prostate volume of BPH patients with diabetes was significantly higher than that of BPH patients without diabetes.

Conclusions

This systematic review is the first to evaluate the impact of diabetes mellitus on LUTS in BPH patients. The results of our meta-analysis support the hypothesis that LUTS in BPH patients is increased in patients with diabetes mellitus compared with controls, which suggests that physicians should pay more attention to BPH patients with diabetes mellitus.

Systematic Review Registration

PROSPERO [https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=200794], identifier CRD 42020200794.

Aerobic exercises ameliorate benign prostatic hyperplasia via IGF-1/IGF-1R/ERK/AKT signalling pathway in prostate tissue of high-fat-diet-fed mice with insulin resistance

This study investigated the changes in the prostate of high-fat diet (HFD)-fed mice with insulin resistance (IR) and explored the possible mechanisms of the effects of 8-week treadmill aerobic exercise on prostatic hyperplasia in insulin-resistant mice through the IGF-1/IGF-1R/ERK/AKT signalling pathway. Results showed IR in mice caused an increase in prostate-related indicators, such as prostate weight (PW) and prostate volume (PV), resulting in prostatic hyperplasia. The area of the glandular lumen and the height of the glandular epithelium in mice with IR were increased, which indicating that it caused prostatic hyperplasia through epithelial cell proliferation. In addition, the level of IGF-1 in serum and the expression of IGF-1R, ERK and AKT in prostate tissue of high-fat diet induced IR mice increased significantly, which might be related to the proliferation of prostate cells. However, aerobic exercise lowered the blood sugar, serum insulin and IGF-1; inhibited the combination of IGF-1 and IGF-1R on the prostate; down-regulated the expression of IGF-1R, ERK and AKT proteins; and then suppressed the expression of downstream proliferation genes, thereby achieving the purpose of inhibiting the proliferation of prostate epithelial cells. In conclusion. Eight weeks of aerobic exercise might improve the prostate hyperplasia in mice via down-regulating the serum insulin and IGF-1, thus enhancing the insulin sensitivity of insulin-resistant mice and regulating the IGF-1/IGF-1R/ERK/AKT signalling pathway by inhibiting the expression of IGF-1R, ERK and AKT in the prostate tissue. However, this exercise had no significant effect on PV, PW and prostate index (PI).

Over expression of PI3K-AkT reduces apoptosis and increases prostate size in benign prostatic hyperplasia

INTRODUCTION

Even though the role of the phosphatidylinositol 3-kinase (PI3K)/AKT pathways and apoptosis has been well established in prostate cancer, there are no studies regarding alteration in the gene expression of PI3K/AKT pathway and protein expression of apoptotic components and their association with prostate size in Benign prostatic hyperplasia (BPH). Hence the study was designed to analyze the expression pattern of PI3K/AKT and apoptotic components in patients with BPH.

MATERIALS AND METHODS

A total of 27 BPH patients aged between 55 and 75 years were recruited in the study and prostatic tissues were obtained after transurethral resection of the prostate. Gene expression levels of PI3K and AKT were assessed by q-PCR. Apoptotic components like BcL-2, caspase-3, caspase-9, BAD, and p-BAD were analyzed by western blotting and immunohistochemistry.

RESULTS

Gene expression of PI3K (p85-A) (p = .02), AKT1 (p < .01) and AKT2 (p < .01), and protein expression of BcL-2 (p < .01) and caspase-9 (p < .01) were significantly increased in BPH patients with larger prostate size compared to smaller prostate size.

CONCLUSIONS

Overexpression of PI3K/AKT pathway and BcL-2 were associated with reduced apoptosis and increased prostate size in BPH.

Benign prostatic hyperplasia - what do we know?

OBJECTIVES

To present historical and contemporary hypotheses on the pathogenesis of benign prostatic hyperplasia (BPH), and the potential implications for current medical therapies.

METHODS

The literature on BPH was reviewed. BPH is a prevalent disease with significant health and economic impacts on patients and health organisations across the world, whilst the cause/initiation of the disease process has still not been fully determined.

RESULTS

In BPH, pathways involving androgens, oestrogens, insulin, inflammation, proliferative reawakening, stem cells and telomerase have been hypothesised in the pathogenesis of the disease. A number of pathways first described >40 years ago have been first rebuked and then have come back into favour. A system of an inflammatory process within the prostate, which leads to growth factor production, stem cell activation, and cellular proliferation encompassing a number of pathways, is currently in vogue. This review also highlights the physiology of the prostate cell subpopulations and how this may account for the delay/failure in treatment response for certain medical therapies.

CONCLUSION

BPH is an important disease, and as the pathogenesis is not fully understood it impacts the effectiveness of medical therapies. This impacts patients, with further research potentially highlighting novel therapeutic avenues.

The role of insulin-like growth factors in the development of prostate cancer

INTRODUCTION

Preclinical, clinical, and population studies have provided robust evidence for an important role for the insulin-like growth factor (IGF) system in the development of prostate cancer.

AREAS COVERED

An overview of the IGF system is provided. The evidence implicating the IGF system in the development of prostate cancer is summarized. The compelling evidence culminated in a number of clinical trials of agents targeting the system; the reasons for the failure of these trials are discussed.

EXPERT OPINION

Clinical trials of agents targeting the IGF system in prostate cancer were terminated due to limited objective clinical responses and are unlikely to be resumed unless a convincing predictive biomarker is identified that would enable the selection of likely responders. The aging population and increased screening will lead to greater diagnosis of prostate cancer. Although the vast majority will be indolent disease, the epidemics of obesity and diabetes will increase the proportion that progress to clinical disease. The increased population of worried men will result in more trials aimed to reduce the risk of disease progression; actual clinical endpoints will be challenging and the IGFs remain the best intermediate biomarkers to indicate a response that could alter the course of disease.

Insulin exacerbated high glucose-induced epithelial-mesenchymal transition in prostatic epithelial cells BPH-1 and prostate cancer cells PC-3 via MEK/ERK signaling pathway

As two most common progressive diseases of aging, type 2 diabetes mellitus (T2DM) and benign prostatic hyperplasia (BPH) were all characterized by endocrine and metabolic disorders. Here, our clinical study showed that there were significant differences in fasting blood glucose (FBG), fasting insulin (FINS), insulin resistance index (HOMA-IR) and prostate volume (PV) between simple BPH patients and BPH complicated with T2DM patients. Further analysis showed that HOMA-IR was positively correlated with PV in BPH complicated with T2DM patients. The in vitro experiment results showed that high glucose (HG) promoted EMT process in a glucose-dependent manner in human prostate hyperplasia cells (BPH-1) and prostate cancer cells (PC-3), and this pathological process was exacerbated by co-culture with insulin. Mechanistically, insulin-induced exacerbation of EMT was depended on the activation of MEK/ERK signaling pathway, and we suggested that insulin and its analogs should be used very carefully for the clinical antihyperglycemic treatment of BPH complicated with T2DM patients.

Can Botulinum Toxin A Still Have a Role in Treatment of Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia Through Inhibition of Chronic Prostatic Inflammation?

Patients with benign prostatic hyperplasia (BPH) can exhibit various lower urinary tract symptoms (LUTS) owing to bladder outlet obstruction (BOO), prostatic inflammation, and bladder response to BOO. The pathogenesis of BPH involves an imbalance of internal hormones and chronic prostatic inflammation, possibly triggered by prostatic infection, autoimmune responses, neurogenic inflammation, oxidative stress, and autonomic dysfunction. Botulinum toxin A (BoNT-A) is well recognized for its ability to block acetylcholine release at the neuromuscular junction by cleaving synaptosomal-associated proteins. Although current large clinical trials have shown no clinical benefits of BoNT-A for the management of LUTS due to BPH, BoNT-A has demonstrated beneficial effects in certain subsets of BPH patients with LUTS, especially in males with concomitant chronic prostatitis/chronic pelvic pain syndrome and smaller prostate. We conducted a review of published literature in Pubmed, using Botulinum toxin, BPH, BOO, inflammation, LUTS, and prostatitis as the key words. This article reviewed the mechanisms of BPH pathogenesis and anti-inflammatory effects of BoNT-A. The results suggested that to achieve effectiveness, the treatment of BPH with BoNT-A should be tailored according to more detailed clinical information and reliable biomarkers.

Pathophysiology of Benign Prostatic Hyperplasia and Benign Prostatic Enlargement: A Mini-Review

Benign prostatic hyperplasia (BPH), benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) belong to the most frequent diseases in ageing men. Beyond the 6th decade of life, more than 30% of men suffer from moderate to severe LUTS requiring intervention. The pathophysiology of BPH/BPE is still incompletely understood. The dominant role of the androgen system and the androgen receptor is well defined. Androgen receptors are expressed in BPH tissue in which they are activated by the potent androgen dihydrotestosterone. Synthesis of dihydrotestosterone is under control of the 5α-reductase enzyme, activity of which is antagonized by finasteride and dutasteride. More recently, the impact of prostatic inflammation and metabolic parameters particularly for the development of BPE and LUTS has increasingly been recognized. A better understanding of the pathophysiology is a prerequisite for the development of novel, more effective medical treatment options.

Gene expression of insulin receptor, insulin-like growth factor increases and insulin-like growth factor-binding protein-3 reduces with increase in prostate size in benign prostatic hyperplasia

INTRODUCTION

Although the role of insulin in the development of benign prostatic hyperplasia (BPH) is well established, there are no studies regarding alteration in the gene expression of components of insulin-signaling pathway and their association with prostate size in BPH. Hence, the study was designed to analyze the gene and protein expression of insulin receptor and its related components in patients with BPH.

MATERIALS AND METHODS

Twenty-seven BPH patients aged between 55 and 75 years were recruited in the study and prostatic tissues were obtained after transurethral resection of the prostate. Gene expression levels of Insulin receptor (IR), insulin receptor substrate (IRS), insulin-like growth factor (IGF) and insulin-like growth factor-binding protein-3 (IGFBP-3) were assessed by q-PCR.

RESULTS

Insulin receptor (IR-A and B) and insulin-like growth factors (IGF-1 and IGF-2) gene expression were significantly increased and IGFBP-3 gene expression was reduced in BPH patients with larger prostate size. Also, serum insulin was significantly increased and IGFBP-3 was significantly reduced in patients with larger prostate size.

CONCLUSION

Increased expression of IR-A, B and IGF-1, 2 genes and reduced IGFBP-3 gene expression was associated with larger prostate size in BPH.