Differential Calcium Independent Regulation of Matrix Metalloproteinases and Tissue Inhibitors of Matrix Metalloproteinases by Interleukin-1β and Transforming Growth Factor-β in Peyronie's Plaque Fibroblasts

Research advances in Peyronie's disease: a comprehensive review on genomics, pathways, phenotypic manifestation, and therapeutic targets

INTRODUCTION

Penile induration disease, commonly known as Peyronie's disease (PD), is a connective tissue disorder that affects the penis, leading to the development of fibrous plaques, penile curvature, and erectile dysfunction. PD is a common male reproductive system disease with a complex etiology involving multiple genes, signaling pathways, and different phenotypes.

OBJECTIVES

The etiology and pathogenesis of PD remain poorly understood, hindering the development of effective treatment strategies. By understanding the underlying mechanisms of PD, we can pave the way for targeted therapies and improved patient outcomes.

METHODS

We reviewed the epidemiology and pathophysiology of PD. We performed database searches on Google Scholar, PubMed, Medline, and Web of Science from inception to September 2023. The literature reviewed included priapism guidelines, review articles, current trial studies, and various literature related to PD.

RESULTS

This article provides a comprehensive overview of the current research progress on the disease, focusing on its genetic factors, signaling pathways, cellular mechanisms, phenotypic manifestations, and therapeutic targets. It can help identify individuals at higher risk, aid in early detection and intervention, and provide insights into fibrosis and tissue remodeling. It can also reveal potential therapeutic targets, guide accurate diagnoses and treatment strategies, and address the impact of the disease on patients' quality of life.

CONCLUSION

By integrating insights from genomics, molecular pathways, clinical phenotypes, and therapeutic potentials, our research aims to achieve a deeper and more comprehensive understanding of PD, propelling the field toward innovative strategies that enhance the lives of those affected by PD. The complex manifestations and pathogenesis of PD necessitate the use of multiple treatment methods for personalized care.

Characterization of a novel rabbit model of Peyronie's disease

Peyronie's disease (PD) is a debilitating pathology which is associated with penile curvature and erectile dysfunction due to the formation of fibrotic plaques in the penile tunica albuginea. In the present study, we developed a novel rabbit model of PD via subtunical injection of recombinant transforming growth factor (TGF)-β1 protein and characterized erectile function and histopathological endpoints following plaque formation. Ten adult male, New Zealand white rabbits were randomized into 3 experimental groups including nonsurgical controls (NSC, N = 3) and those receiving subtunical injections of vehicle (N = 3) or TGF-β1 protein (0.5 µg/50 µl; N = 4). Following 1 month post-op, focal fibrous plaques composed of disorganized collagen type I and III bundles as well as fragmented elastin fibers at TGF-β1 injection sites were observed in contrast to control groups. Cavernosometric and cavernosographic evaluations revealed no significant differences in maximum intracorporal pressures or substantial curvature during papaverine-induced erection in either the vehicle or TGF-β1 cohorts. Immunohistochemical and histomorphometric analyses demonstrated significant increases in elastase 2B expression in TGF-β1-induced plaques as well as significant declines in matrix metalloproteinase (MMP)-2 and -9 expression relative to control levels. Our results demonstrate that PD-like fibrotic plaques can be created in the rabbit penile tunica albuginea following TGF-β1 injection.

Unveiling the molecular Hallmarks of Peyronie's disease: a comprehensive narrative review

Peyronie's disease, a fibroinflammatory disorder, detrimentally impacts the sexual well-being of men and their partners. The manifestation of fibrotic plaques within penile tissue, attributed to dysregulated fibrogenesis, is pathognomonic for this condition. The onset of fibrosis hinges on the perturbation of the equilibrium between matrix metalloproteinases (MMPs), crucial enzymes governing the extracellular matrix, and tissue inhibitors of MMPs (TIMPs). In the context of Peyronie's disease, there is an elevation in TIMP levels coupled with a decline in MMP levels, culminating in fibrogenesis. Despite the scant molecular insights into fibrotic pathologies, particularly in the context of Peyronie's disease, a comprehensive literature search spanning 1995 to 2023, utilizing PubMed Library, was conducted to elucidate these mechanisms. The findings underscore the involvement of growth factors such as FGF and PDGF, and cytokines like IL-1 and IL-6, alongside PAI-1, PTX-3, HIF, and IgG4 in the fibrotic cascade. Given the tissue-specific modulation of fibrosis, comprehending the molecular underpinnings of penile fibrosis becomes imperative for the innovation of novel and efficacious therapies targeting Peyronie's disease. This review stands as a valuable resource for researchers and clinicians engaged in investigating the molecular basis of fibrotic diseases, offering guidance for advancements in understanding Peyronie's disease.

Molecular Mechanisms and Risk Factors Related to the Pathogenesis of Peyronie's Disease

Peyronie's disease (PD) is a benign condition caused by plaque formation on the tunica albuginea of the penis. It is associated with penile pain, curvature, and shortening, and contributes to erectile dysfunction, which worsens patient quality of life. In recent years, research into understanding of the detailed mechanisms and risk factors involved in the development of PD has been increasing. In this review, the pathological mechanisms and several closely related signaling pathways, including TGF-β, WNT/β-catenin, Hedgehog, YAP/TAZ, MAPK, ROCK, and PI3K/AKT, are described. Findings regarding cross-talk among these pathways are then discussed to elucidate the complicated cascade behind tunica albuginea fibrosis. Finally, various risk factors including the genes involved in the development of PD are presented and their association with the disease summarized. The purpose of this review is to provide a better understanding regarding the involvement of risk factors in the molecular mechanisms associated with PD pathogenesis, as well as to provide insight into disease prevention and novel therapeutic interventions.

Peyronie's Disease: An Outcomes-Based Guide to Non-Surgical and Novel Treatment Modalities

The clinical landscape of Peyronie's disease is everchanging. There has been growing interest in non-invasive therapeutic options that could assist patients with achieving a meaningful reduction in penile curvature without surgical intervention. These therapies are wide-ranging in terms of their mechanisms of action, efficacies, and short- and long-term safety profiles. Recently, an abundance of outcomes literature on longstanding and novel non-surgical treatment modalities has been published. For sexual medicine providers hoping to offer patients the most up-to-date and evidence-based treatments for the management of Peyronie's disease, it can be challenging to gain a thorough understanding of this body of literature. In this clinical management review, the workup and current theories on the pathophysiology of Peyronie's disease are reviewed, and the most recent outcomes data on the currently available non-surgical treatment modalities are presented. With an accurate understanding of the current landscape of Peyronie's disease treatment, sexual health providers will be able to better evaluate and engage in evidence-based shared decision-making with their patients.

Role of Oxidative Stress in Peyronie's Disease: Biochemical Evidence and Experiences of Treatment with Antioxidants

BACKGROUND

Peyronie's disease (PD) is a chronic inflammatory condition affecting adult males, involving the tunica albuginea of the corpora cavernosa of the penis. PD is frequently associated with penile pain, erectile dysfunction, and a secondary anxious-depressive state. The etiology of PD has not yet been completely elucidated, but local injury is generally recognized to be a triggering factor. It has also been widely proven that oxidative stress is an essential, decisive component in all inflammatory processes, whether acute or chronic. Current conservative medical treatment comprises oral substances, penile injections, and physical therapy.

AIM

This article intends to show how antioxidant therapy is able to interfere with the pathogenetic mechanisms of the disease.

METHOD

This article consists of a synthetic narrative review of the current scientific literature on antioxidant therapy for this disease.

RESULTS

The good results of the antioxidant treatment described above also prove that the doses used were adequate and the concentrations of the substances employed did not exceed the threshold at which they might have interacted negatively with the mechanisms of the redox regulation of tissue.

CONCLUSIONS

We believe new, randomized, controlled studies are needed to confirm the efficacy of treatment with antioxidants. However, we consider the experiences of antioxidant treatment which can already be found in the literature useful for the clinical practice of urologists in the treatment of this chronic inflammatory disease.

Use of penile shear wave elastosonography for the diagnosis of Peyronie's Disease: a prospective case-control study

BACKGROUND

To evaluate the stiffness of the tunica albuginea (TA), we used a new noninvasive diagnostic technique called shear wave elastography (SWE). We determined whether SWE values are correlated with the degree of penile curvature, the time of disease onset, and pain severity experienced by patients during erection. This study analyzed the elasticity of the TA of patients with Peyronie's disease compared to that of the control group. We also analyzed any correlations between the stiffness of the cavernous bodies and the degree of curvature, time from diagnosis to curvature onset, and erectile pain severity. This was a prospective case-control study involving 100 men enrolled from September 2020 to August 2021. Participants were divided into group A (case group, n = 50), which included men with PD, with or without pain, and with penile curvature, or group B (control group, n = 50), which included healthy patients older than 18 years who visited the urology clinic for reasons other than PD. The medical history was collected for all patients who also underwent objective examination, B-mode ultrasound evaluation, and SWE. The International Index of Erectile Function (IIEF-15) visual analog scale (VAS) questionnaire was administered to all participants.

RESULTS

There were no significant between-group differences regarding age, weight, and height (p > 0.05); however, there was a significant difference in the stiffness values (p < 0.05). An inverse correlation was observed between stiffness and the VAS score (p < 0.0001). A positive correlation was observed between the degree of curvature (p < 0.0001) and the time of curvature onset (p < 0.0001). The IIEF-15 scores were poorer in group A than in group B (p < 0.0001).

CONCLUSION

SWE is an inexpensive, noninvasive method that can be used to measure the stiffness of PD patients.

Testosterone replacement therapy and erectile dysfunction

Testosterone (T) deficiency and erectile dysfunction (ED) are independently functionally and socially impairing, and their concurrence in men can be challenging to treat. Successful management requires an understanding of the mechanisms through which T underlies normal erectile function. While the literature elucidating some of these mechanisms is vast (e.g., androgen regulation of the activity of nitric oxygen synthase and phosphodiesterase type 5) for others it is scarce (e.g., catalysts of castration-induced corporal fibrosis). The randomized controlled trial data for the efficacy of T replacement as mono- or combination therapy to treat ED has been conflicting. Positive results were frequently not clinically meaningful. Meta-analyses have been helpful in illuminating trends that seem to be promising. Consensus is still lacking in several areas, such as the threshold of low T severity for which replacement therapy is most beneficial; the timing for initiating combination therapy; and the duration of treatment.

New in vivo model to assess macroscopic, histological, and molecular changes in Peyronie's disease

BACKGROUND

Peyronie's Disease (PD) is a connective tissue disorder that affects the tunica albuginea (TA) of the penis causing curvature and erectile dysfunction. The pathophysiology is not well understood and, for this reason, treatment options are limited.

OBJECTIVE

The aim of the present study is to analyze and compare whether single or multiple instillations of plasma in the TA of rats is capable of triggering macroscopic, histopathological, and molecular changes consistent with PD.

MATERIAL/METHODS

Fifty male Wistar rats were divided into four groups: Group 1: a single instillation of plasma in the TA; Group 2: a single instillation of distilled water in the TA; Group 3: four instillations of plasma in the TA (1x per week); and Group 4: four instillations of distilled water in the TA (1× per week). Forty-five days after the last instillation a manual inspection of the corpus cavernosum, a penile erection test and a penectomy were performed to obtain material for histopathological and molecular analysis.

RESULTS

It was observed that 31.25% of the rats that received repeated instillations of plasma presented penile curvature according to the erection test, while none of the rats from the control group or group with one instillation of plasma presented curvature. In the animals that received four instillations of plasma, the following differences were observed in relation to the control group: increase in fibrosis and the deposition of collagen I. The protein expression of heparanase (HPSE) and TGF-β increased in the groups that received a single or four instillations of plasma, and the protein expression of heparanase-2 (HPSE-2), metalloproteinases (MMP-2, MMP-9) and metalloproteinase inhibitor (TIMP-2) showed an increase in the group that received four instillations of plasma. There was a significant increase in the gene expression of HPSE, MMP-9, and TGF-β in the group that received four instillations of plasma. In the analysis of the glycosaminoglycans, an increase was observed in the secretion of galactosaminoglycans chondroitin sulfate and dermatan sulfate (CS/DS) in the group that received four instillations of plasma.

DISCUSSION

Previous studies have demonstrated increased protein expression. of HPSE, MMP-9 and TGF-β with instillation of blood in the TA; however, there was no increase in gene expression. In the present study, the increase in the expression of TGF-β with plasma instillations, proved to be more reliable. The two models with plasma (one or four instillations) demonstrated significant histopathological and molecular changes when compared to the control group. However, only in the group with four plasma instillations there was a macroscopic change. The idea is that repeatedly extravasation of TGF-β present in plasma of predisposed individuals acts as a trigger for the development and maintenance of changes in the extracellular matrix that perpetuate an anomalous inflammatory process present in PD.

CONCLUSION

The present study shows that the repeated instillation of plasma is a low cost in vivo model for the study of PD.

Molecular Mechanisms and Current Pharmacotherapy of Peyronie's Disease: A Review

Peyronie’s disease (PD) is a localized fibrotic lesion of the penis that has adverse effects on men’s health. In this review, we summarized the molecular mechanisms and pharmacotherapies of PD. A literature search was conducted using PubMed and Cochrane Library during 2001–2020. Although no oral or topical medication demonstrated efficacy in monotherapy of PD, several intralesional medications have yielded promising results. Currently, the effective strategy in management of PD should be combined modality therapy, including but not limited to pharmacotherapy, mechanical therapy, and psychotherapy. Meanwhile, basic research is still necessary to facilitate the development of novel and more reliable treatments. In future, more attention should be given simultaneously to epigenetic changes, inflammatory cytokines, the abnormal wound-healing process, and profibrotic and anti-fibrotic factors to provide more options for this refractory disease.

Fibroproliferative disorders and diabetes: Understanding the pathophysiologic relationship between Peyronie's disease, Dupuytren disease and diabetes

Introduction

Fibrosis is characterized by dysregulation and accumulation of extracellular matrix. Peyronie's disease and Dupuytren disease are fibroproliferative disorders of the tunica albuginea of the penis and fascia of the hand, respectively. Chronic hyperglycaemia due to diabetes mellitus can also lead to tissue injury and fibrosis. A meta-analysis has shown a relationship between Dupuytren disease and diabetes (overall odds ratio, 3.1; 95% confidence interval, 2.7-3.5). This review explores commonalities in the pathogenesis of Peyronie's disease, Dupuytren disease and diabetes.

Methods

A search of the PubMed database was conducted using the search terms "diabetes" AND "Peyronie's disease"; and "diabetes" AND "Dupuytren."

Results

Genome-wide association and gene expression studies conducted with tissue from people with Peyronie's disease or Dupuytren disease identified signalling pathways associated with wingless-type mammary-tumour virus integration site signalling, extracellular matrix modulation and inflammation. Biochemical studies confirmed the importance of these pathways in the pathogenesis of fibrosis with Peyronie's disease and Dupuytren disease. Dysregulation of matrix metalloproteinase activity associated with extracellular matrix breakdown was implicated in fibroproliferative complications of diabetes and in the aetiology of Peyronie's disease and Dupuytren disease. A notable percentage of people with diabetes have comorbid Peyronie's disease and/or Dupuytren disease.

Conclusions

Studies have not been performed to identify fibroproliferative pathways that all 3 conditions might have in common, but data suggest that common pathways are involved in the fibroproliferative processes of Peyronie's disease, Dupuytren disease, and diabetes.

Peyronie's disease: pharmacological treatments and limitations

Introduction: Peyronie's disease (PD) is a disorder of the tunica albuginea from disordered and excessive deposition of collagen resulting in a palpable scar, pain, erect penile deformity and erectile dysfunction that significantly impacts patients both physically and emotionally.Areas Covered: Several treatment options have been described for PD, including shockwave therapy, traction therapy, both oral and intralesional pharmacological options, and surgery. This review seeks to examine the data for different types of non-surgical treatments for PD. We review how various treatment modalities impact several relevant clinical endpoints for Peyronie's disease, including effects on pain, penile curvature, plaque formation, and erectile function. We performed a literature search using PubMed and SCOPUS while referencing AUA, EAU, and CUA guidelines for management of Peyronie's Disease for studies published 1980-2020.Expert opinion: Intralesional collagenase injections have the strongest evidence and are the only FDA approved intralesional treatment for PD. Penile traction therapy (PTT) is low risk and may be beneficial in patients willing to invest significant time using the devices. Furthermore, oral combination therapy with other modalities may provide some benefit. Further investigation is required to better understand pathophysiology of PD and clarify the therapeutic utility of existing treatments, potentially with a multimodal strategy.

Implications of Calcification in Peyronie's Disease, A Review of the Literature

A common characteristic of Peyronie's Disease (PD) is plaque calcification, which is associated with decreased response to treatments and higher rates of surgical intervention. Despite its prevalence in the PD population, the literature on plaque calcification is limited. While the diagnosis of PD is mostly clinical, imaging modalities such as ultrasound can be used to identify plaque calcification. The proper identification of plaque calcification is crucial for guiding management and setting therapeutic expectations for patients with PD. Herein we discuss what is known about PD plaque calcification, including epidemiology, etiology, diagnosis, and management.

Medical, non-invasive, and minimally invasive treatment for Peyronie's disease: A systematic review

BACKGROUND

The treatment of Peyronie's disease (PD) remains a dilemma as the true pathogenesis of PD remains an enigma. Consequently, new molecules and therapies continue to evolve. The safety and efficacy of conservative treatment for PD have not yet established.

OBJECTIVES

To provide the available information of the status of conservative therapy for PD.

METHODS

A systematic literature search was conducted using PubMed, EMBASE, and the Cochrane Library for English-language journal articles between January 2000 and July 2019, using the terms "Conservative treatment for PD", "medical treatment for PD", "non-invasive therapies for PD" and "minimally invasive therapies for PD". This systematic review was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system. We also manually reviewed references from selected articles. The risk of bias in the included RCTs was assessed using the Cochrane Risk of Bias Assessment tool (RoB 2).

RESULTS

Conservative treatment is accepted as the initial treatment step in most of the cases. This kind of therapy includes various methods of treatment such as medical, non-invasive, and minimally invasive therapies. Ideal management of PD is not yet available. It is not possible to assess the value of treatment without well-designed, randomized, placebo-controlled, large-scale clinical studies.

CONCLUSION

Optimistically, in the near future, we may witness emergence of efficacious new agents and modalities to revolutionize medical, non-invasive, and minimally invasive treatment of this devastating condition.

New insights into the pathogenesis of Peyronie's disease: A narrative review

Peyronie's disease (PD) is a benign, progressive fibrotic disorder characterized by scar or plaques within the tunica albuginea (TA) of the penis. This study provides new insights into the pathogenesis of PD based on data from different studies regarding the roles of cytokines, cell signaling pathways, biochemical mechanisms, genetic factors responsible for fibrogenesis. A growing body of literature has shown that PD is a chronically impaired, localized, wound healing process within the TA and the Smith space. It is caused by the influence of different pathological stimuli, most often the effects of mechanical stress during sexual intercourse in genetically sensitive individuals with unusual anatomical TA features, imbalanced matrix metalloproteinase/tissue inhibitor of metalloproteinase (MMP/TIMP), and suppressed antioxidant systems during chronic inflammation. Other intracellular signal cascades are activated during fibrosis along with low expression levels of their negative regulators and transforming growth factor-β1 signaling. The development of multikinase agents with minimal side effects that can block several signal cell pathways would significantly improve fibrosis in PD tissues by acting on common downstream mediators.

The Natural History of Peyronie's Disease

Peyronie's disease (PD), a fibrotic disorder of the tunica albuginea fully described in 1793 by French physician Francois de la Peyronie, is characterized by pain, plaque formation, penile deformity, and ultimately sexual function decline. The epidemiological data on PD vary considerably across previous studies, with recent evidence reporting a prevalence of up to 9%. PD is generally divided into two different phases: active or acute and stable or chronic. Plaque formation generally occurs during the acute phase, while during chronic phase pain usually tends to complete resolution and penile deformity stabilizes. PD's pathophysiology is still subject of great discussion. Tunical mechanical stress and microvascular trauma are major contributory factors. However, better understanding of the molecular pathophysiology of this condition remains paramount towards an in-depth comprehension of the disorder and the development of newer and more effective disease-targeted interventions. In this review we provide a detailed overview of natural history of PD, specifically focusing on clinical manifestations and the underlying molecular regulation patterns.

Peyronie's disease: Contemporary evaluation and management

Peyronie's disease is a common yet poorly understood condition characterized by penile pain, curvature, sexual dysfunction and psychological bother. Peyronie's disease represents a penile wound healing disorder, and is thought to arise from exuberant scarring in response to penile trauma in genetically predisposed men. In the absence of active treatment, the majority of men experience stable or worsening symptoms, with few reporting spontaneous resolution in penile curvature or other deformity. In contrast, penile pain improves or resolves in the majority of men. Treatment options vary based on symptom severity and stability. Several oral therapies are commonly prescribed, although to date there are no strong data to support any oral agents as monotherapy for Peyronie's disease. Other options including penile traction therapy and intralesional injections result in modest improvements for many patients, particularly when used early after symptom onset. Penile straightening through approaches, such as penile plication and plaque incision or partial excision and grafting, represent the most rapid and reliable approach to correct penile curvature once the symptoms have stabilized. Side-effects vary based on the type of surgery carried out, and include penile shortening, sensation changes and erectile dysfunction in the minority of men. In patients with drug refractory erectile dysfunction and Peyronie's disease, placement of a penile prosthesis will address both issues, and is associated with high levels of patient satisfaction. The current review provides a practical approach to the modern evaluation and management of patients presenting with Peyronie's disease.

Evolving therapies for Peyronie's disease: how can we work towards new drugs?

Peyronie's disease (PD) is an idiopathic chronic fibrotic disease that causes a penile curvature (PC), subsequent erectile dysfunction (ED) and impaired sexual intercourse in patients. As of yet, there are no reliable non-surgical treatment options available. Intralesional injection with collagenase Clostridum Histolyticum has been FDA approved since 2013, but post-approval studies have not been unanimously positive. Moreover, it renders a curvature improvement of only 30% on average, usually still requiring surgical intervention to remedy PC. Therefore, there is a need for drugs which could prevent surgery altogether. Development of new drugs can either be through a target-based or phenotypic assay-based approach. The current in vivo model for PD is dependent on treatment of primary PD-derived fibroblasts with transforming growth factor-β1. Moreover, despite the existence of a genetic in vivo PD model, it does not allow for drug screening or testing. While some advances have been made in the past few years, new in vivo and in vivo systems and well-designed studies are urgently needed for the non-surgical treatment of PD.

Devices for penile traction: the long and winding road to treating Peyronie's disease

INTRODUCTION

Penile traction therapy (PTT) is increasingly being recognized as a viable nonsurgical approach to Peyronie's disease (PD). The goal of this article is to review the current literature on PTT with attention to traction protocols, devices, and outcomes.

AREAS COVERED

Literature on the pathophysiology of PD, PTT as primary and adjunctive treatment for PD, perioperative use of PTT, and vacuum erection devices are all reviewed. Pertinent literature was obtained from the PubMed database. The key words 'penile traction,' 'mechanotransduction,' and 'Peyronie's disease' were searched and results were narrowed down based on relevance to the review.

EXPERT COMMENTARY

PTT appears beneficial but the true magnitude of effect is difficult to discern. Most studies are not randomized, have small sample sizes, lack control arms, or have varying traction protocols. Patient compliance is critical and new devices and traction protocols are needed to maximize the benefit of PTT.

Intralesional collagenase Clostridium histolyticum in the management of Peyronie's disease: current best practice

The use of Clostridium histolyticum collagenase (CCH) has become increasingly widespread for the treatment of Peyronie's disease (PD) in recent years. Numerous trials have confirmed both its safety and efficacy in appropriately selected patients with this condition. The purpose of this review is to examine pivotal trials demonstrating the efficacy of CCH, revisit viable candidates for treatment with intralesional injection therapy, and provide a summary of injection technique and appropriate management of patients receiving this treatment at the time of therapy and in follow up.

Recent Pathophysiological Aspects of Peyronie's Disease: Role of Free Radicals, Rationale, and Therapeutic Implications for Antioxidant Treatment-Literature Review

Peyronie's disease (PD) is a chronic inflammation of tunica albuginea of the corpora cavernosa that causes an inelastic plaque resulting in penis deformation. Although its etiology is not completely known, there is general consensus that PD is genetically transmitted and secondary to penile trauma. In recent years, numerous studies demonstrated the role played by oxidative stress in PD pathogenesis, and other studies have described successful use of antioxidants in PD treatment. Oxidative stress is an integral part of this disease, influencing its progression. In the early stages of PD, the inflammatory infiltrate cells produce high quantities of free radicals and proinflammatory and profibrotic cytokines, with consequent activation of transcription factor NF-κB. While conservative therapies commonly used in the early stages of PD include oral substances (Potaba, tamoxifen, colchicine, and vitamin E), intralesional treatment (verapamil, interferon, steroids, and more recently collagenase clostridium histolyticum-Xiaflex), and local physical treatment (iontophoresis, extracorporeal shock wave therapy, and penile extender), the significant results obtained by emerging treatments with the antioxidants cited in this article suggest these therapeutic agents interfere at several levels with the disease's pathogenetic mechanisms. Antioxidants therapy outcomes are interesting for good clinical practice and also confirm the fundamental role played by oxidative stress in PD.

Understanding the cellular basis and pathophysiology of Peyronie's disease to optimize treatment for erectile dysfunction

Erectile dysfunction (ED) is a common condition that significantly impacts a man’s physical and psychological well-being. ED is often associated with Peyronie’s disease (PD), which is an abnormal curvature of the penis. Delayed treatment of or surgical invention for PD often results in ED and therefore unsatisfied patients. The pathophysiology of PD is incompletely understood, but has been studied extensively and based on our current understanding of PD physiology, many medical treatment options have been proposed. In this paper, we will review what is known about the pathophysiology of PD and the medical treatment options that have been trialed as a result. More investigations in regards to the basic science of PD need to be carried out in order to elucidate the exact mechanisms of the fibrosis, and propose new, more successful treatment options which should be implemented prior to the onset of ED.

Collagenase Clostridium histolyticum in the management of Peyronie's disease: a review of the evidence

OBJECTIVES

Peyronie's disease (PD) is a connective tissue disorder resulting in the abnormal accumulation of scar or plaques in the tunica albuginea of the penis. The condition is characterized by two phases: an active, inflammatory phase, and a stable, chronic phase. Collagenase Clostridium histolyticum (CCH) was isolated in the mid-1900s and postulated as a potential pharmacologic strategy for breaking down the abnormal connective tissue plaques of PD. Prior to the introduction of CCH, a wide variety of treatment modalities for PD were used in clinical practice, including oral and topical medications, intralesional injections, electromotive drug administration, extracorporeal shockwave therapy, traction, and invasive surgery, all with variable results. This review aims to examine the known data surrounding the use of intralesional CCH injections in the treatment of PD.

METHODS

CCH is a recently US Food and Drug Administration approved pharmacologic treatment for PD. Clinical trials using intralesional CCH injection therapy for the treatment of PD were reviewed for clinical safety and efficacy of treatment.

RESULTS

Studies demonstrated that CCH treatment administered in multiple cycles led to significant benefit in both the psychological and physical aspects of PD. The strongest evidence for CCH's effectiveness was revealed in large, multicenter randomized controlled trials (Investigation for Maximal Peyronie's Reduction Efficacy and Safety Studies I and II) in which intralesional CCH was combined with manual modeling of the penis. Although adverse events from treatment are relatively common, the majority are mild to moderate in degree, including penile pain, swelling, and bruising, which all resolve spontaneously.

CONCLUSION

Overall, evidence indicates that CCH is a valuable, effective, and safe minimally invasive treatment option for men with PD.

The Genetic Basis of Peyronie Disease: A Review

INTRODUCTION

Peyronie disease (PD) is a progressive fibrotic disorder of the penile tunica albuginea that results in fibrotic penile plaques and can lead to penile deformity. Characterized by aberrant fibrosis resulting in part from the persistence of myofibroblasts and altered gene expression, the molecular factors underpinning PD and other related fibrotic diatheses are just being elucidated. A genetic link to PD was first identified three decades ago using pedigree analyses. However, the specific genetic factors that predispose patients to aberrant fibrosis remain unknown, and the relations between these fibrotic conditions and other heritable diseases, including malignancy, are uncharacterized.

AIM

To review the current landscape linking molecular and genetic factors to aberrant fibrosis in PD and related fibrotic diatheses, including Dupuytren disease.

METHODS

Review and evaluation of the literature from 1970 to the present for genetic factors associated with PD were performed.

MAIN OUTCOME MEASURES

Data describing the genetic factors associated with PD were obtained.

RESULTS

We describe the known structural chromosomal abnormalities and single-nucleotide polymorphisms associated with fibrotic diatheses and discuss the spectrum of differential gene expression data comparing normal tissues with those derived from men with PD or Dupuytren disease. We discuss epigenetic mechanisms that might regulate gene expression and alter predisposition to fibrosis.

CONCLUSION

Although the current understanding of the genetic factors associated with PD is limited, significant advances have been made during the past three decades. Further research is necessary to provide a more comprehensive understanding of the landscape of genetic factors responsible for the development of PD.

The History of Collagenase Clostridium Histolyticum

INTRODUCTION

After its U.S. FDA approval in 2013, Collagenase Clostridium histolyticum (CCh) has seen increasing use as a nonoperative treatment for Peyronie's disease (PD). We review the history of CCh and trials that led to its adoption.

AIM

To provide a historical and contemporary context for the evolution of Collagenase Clostridium histolyticum as a treatment modality for Peyronie's disease.

METHODS

A comprehensive search of peer-reviewed literature was performed pertaining to CCh and its biochemical and clinical significance.

MAIN OUTCOME MEASURE

The main outcome studied was the efficacy and safety profile of CCh in PD. CCh use in other diseases processes and its associated outcomes are also described.

RESULTS

CCh injection yields objective improvement in penile curvature across multiple trials in PD patients. Recently, level 1 strength of evidence has emerged supporting its widespread use. As such, CCh stands as the only FDA-approved injectable therapy for PD. Adverse events were namely limited to local reactions. Serious systemic complications and need for intervention were rare.

CONCLUSIONS

CCh is a safe and effective treatment for PD patients with deformities and plaque configuration amenable to injectable therapy. Multiple trials have demonstrated improvements in objective and subjective metrics such as penile curvature and bother scores. However, multiyear follow-up is needed to assess durability and its sustained clinical significance. Currently, refinement in dosing and technique has established a niche for CCh in PD patients who are affected by their symptoms but are not yet committed to surgical intervention. Yang KK and Bennett N. The history of collagenase clostridium histolyticum.

Pharmacologic therapy for Peyronie's disease: what should we prescribe?

INTRODUCTION

Peyronie's disease (PD) is a wound healing disorder of the penis with a myriad of proposed treatment options reported in the literature. Evaluating the available data and therapeutic management of PD can be challenging and confusing, even for the most experienced treating physician. This review provides a comprehensive overview of pharmacologic treatment options for PD, focusing on the best available evidence.

AREAS COVERED

A comprehensive literature search for published articles evaluating oral, topical, and injectable pharmacologic agents for PD was completed. Prospective, controlled trials were given precedence for inclusion.

EXPERT OPINION

Although a multitude of oral agents have been proposed and evaluated in PD patients, results vary widely and a reproducible objective benefit has not yet been strongly established for any single oral agent. Well-designed, large-scale, randomized controlled trials evaluating oral agents in PD patients are lacking. Consistent objective benefit from injectable agents has been supported for years by various non-controlled trials. Recently, injectable collagenase Clostridium histolyticum became the first pharmacologic agent to obtain FDA approval for use in PD patients, supported by data from a large-scale, Phase III randomized controlled trial. Further elucidation of the genetic and mechanistic pathways involved in the development and progression of PD will help define future therapeutic targets.

Adipose tissue-derived stem cell therapy for prevention and treatment of erectile dysfunction in a rat model of Peyronie's disease

Peyronie's disease (PD) is a localized connective tissue disorder that involves the tunica albuginea (TA) of the penis. While surgical correction remains the gold standard, the search for an effective and less invasive therapy continues. The objective of this study was to evaluate the effects of intratunical injection of adipose tissue-derived stem cells (ADSCs) for the prevention and treatment of erectile dysfunction in a rat model of PD. Twenty-four male Sprague-Dawley rats (300-350 g) were randomly divided into four groups: sham, PD, PD + ADSC (prevention) and PD + ADSC (treatment). All rats underwent penile injections into the TA with 50 μL vehicle (sham) or 0.5 μg transforming growth factor (TGF)-β1 (remaining groups). The ADSC groups received intratunical injections with 0.5 million rat-labelled ADSCs on day 0 (prevention) or day 30 (treatment). Forty-five days following TGF-β1 injection, rats underwent cavernous nerve stimulation (CNS) with total intracavernous-to-mean arterial pressure ratio (ICP/MAP) and total ICP recorded to measure response to therapy. Tissues were evaluated histologically and for mRNA expression of tissue inhibitors of metalloproteinases (TIMPs), matrix metalloproteinases (MMPs) and zymographic activity of MMPs. Statistical analysis was performed by analysis of variance followed by the Tukey test for post hoc comparisons. In both prevention and treatment groups, intratunical injection of ADSCs resulted in significantly higher ICP/MAP and total ICP in response to CNS compared with the PD group. Local injection of ADSCs prevented and/or reduced Peyronie's-like changes by decreasing the expression of TIMPs, and stimulating expression and activity of MMPs. This study documents the preventive and therapeutic benefits of ADSC on penile fibrosis and erectile function in an animal model of PD.

Evaluation of verapamil efficacy in Peyronie's disease comparing with pentoxifylline

INTRODUCTION

Peyronie's disease described as penile curvature, fibromathosis and pain that occur most often in men aged 40 to 60 years. The main complaint that caused the patient to visit the clinic is nodules on the upper surface of the penis, causing curvature and distortion particularly during erection, but they don't have any urinary problem. In this study, we evaluated the effect of verapamil compared to pentoxifylline in Peyronie's disease.

METHODS

In this study, 90 patients with signs and symptoms of Peyronie's disease which were diagnosed and were in the age range 40 to 70 years enrolled. The patients were randomly divided into 3 groups. First group received pentoxifylline orally at a dose of 400 mg three times a day, in the second group verapamil (10 mg every other week for up to 12 sessions) was injected into the lesion and the third group received both treatments in combination.

RESULTS

In patients, who received pentoxifylline, curvature reduction was 26.7%, plaque size reduction was 30%, the recovery rate of erectile dysfunction was 46.7% and pain reduced was 73.3%. Each of these cases in patients, who used beta-blockers, was 36.7%, 33.3%, 66.7% and 76.6%. In combination therapy, curvature reduction was 36.7%, plaque size reduction was 33.3%, the recovery rate of erectile dysfunction was 86.7% and pain reduced was 80%.

CONCLUSION

In our study there was no significant difference between two groups using verapamil or pentoxifylline, but there was a significant improvement in combination therapy group. Due to our results we propose that combination therapy can improve results and should be considered as a choice in treatment of Peyronie's disease. 

Peyronie's disease: A contemporary review of non-surgical treatment

In this review I discuss the current non-surgical treatment options for Peyronie’s disease (PD), which remains a therapeutic dilemma for the treating physician. This is despite a large array of treatments that have been used since the time of de la Peyronie in the mid-18th century. Part of the problem with finding an effective treatment is the incomplete understanding of the aetiopathophysiology of this scarring disorder. Published articles in peer-reviewed journals were assessed, recognising that most of the reported trials are compromised by being single-centre studies with no placebo control. Various treatment options have emerged, most with limited and unreliable benefit, but a few treatments have shown a consistent, albeit incomplete, response rate. Currently the only scientifically sensible oral agents appear to be pentoxifylline, l-arginine, and possibly the phosphodiesterase type-5 inhibitors. The current intralesional injection treatment options include verapamil and interferon, with a reported benefit in reducing deformity and improving sexual function. Intralesional clostridial collagenase is in the midst of phase-3 trial analysis by the USA Food and Drug Administration. External mechanical traction therapy has recently emerged as a technique to reduce the curvature, recover lost length, and possibly obviate surgery. Currently there is no clear, reliable and effective non-surgical treatment for PD, but it appears that several of the available treatments can reduce the deformity and improve sexual function, and might at least stabilise the disease process.

Peyronie's disease: contemporary review of non-surgical treatment

BACKGROUND

Peyronie's disease (PD) remains a therapeutic dilemma for the treating physician. This is in spite of a large array of treatments which have been used since the time of de la Peyronie in the mid 18(th) century. Part of this problem is due to an incomplete understanding of the etiopathophysiology of this scarring disorder. Having a better understanding of the how and why the scarring occurs may help prevent progression, but ultimately reversing the existing scar remains the real challenge.

METHODS

This review discusses the current non-surgical treatment options for Peyronie's disease. Published articles in peer-reviewed journals are used, recognizing that the majority of the published trials are compromised by being single-center studies without a placebo control.

RESULTS

A variety of treatments options have emerged, most with limited and unreliable benefit, but a few treatments have shown a consistent albeit incomplete response rate. Could this suggest that all PD is not the same and that the heterogeneous nature of this scarring disorder may account for why some patients respond and others do not? Further investigation of this diverse response rate may yield insights into the pathophysiology of PD. In the meantime, there have been many oral treatments offered for PD. Currently the only scientifically sensible treatments appear to be pentoxifylline, L-arginine, and possibly the phosphodiesterase type-5 inhibitors. Intralesional injection has been used for many years. The current treatment options include verapamil and interferon, with reported benefit with respect to reduced deformity and improved sexual function. Intralesional clostridial collagenase is in the midst of phase 3 trial analysis by the FDA in the USA and may become the newest and only FDA approved treatment for Peyronie's disease. External mechanical traction therapy has also recently emerged as a technique to reduce curvature, recover lost length, enhance girth, and possibly obviate surgery.

CONCLUSIONS

It appears at this time that there is no clear, reliable and effective non-surgical treatment for Peyronie's disease, but it does appear from the published literature that several of the available treatments can result in reduction of deformity, improved sexual function, and may at a minimum stabilize the disease process so that deformity does not get worse particularly during the acute phase of this scarring disorder. Combination therapy in an effort to create a synergy between the chemical effects of oral and injectable drugs with the mechanical effects of external traction therapy may provide the best opportunity today for reduction of deformity in the man with Peyronie's disease.

Current and emerging treatment options for Peyronie's disease

Peyronie’s disease (PD) is a condition of the penis, characterized by the presence of localized fibrotic plaque in the tunica albuginea. PD is not an uncommon disorder, with recent epidemiologic studies documenting a prevalence of 3–9% of adult men affected. The actual prevalence of PD may be even higher. It is often associated with penile pain, anatomical deformities in the erect penis, and difficulty with intromission. As the definitive pathophysiology of PD has not been completely elucidated, further basic research is required to make progress in the understanding of this enigmatic condition. Similarly, research on effective therapies is limited. Currently, nonsurgical treatments are used for those men who are in the acute stage of PD, whereas surgical options are reserved for men with established PD who cannot successfully penetrate. Intralesional treatments are growing in clinical popularity as a minimally invasive approach in the initial treatment of PD. A surgical approach should be considered when men with PD do not respond to conservative, medical, or minimally invasive therapies for approximately 1 year and cannot have satisfactory sexual intercourse. As scientific breakthroughs in the understanding of the mechanisms of this disease process evolve, novel treatments for the many men suffering with PD are anticipated.

Rat as an animal model for Peyronie's disease research: a review of current methods and the peer-reviewed literature

While the exact mechanism of Peyronie's disease (PD) remains an enigma, the pathophysiology of PD is considered to be multifactorial, with interactions of genetic predisposition, trauma, tissue inflammation and aberrant wound healing. A non-systematic review of the existing English language literature pertaining to the use of rodent models in the evaluation of PD was performed using the Medline database. Multiple free-text searches were performed on key words: animal models of PD, transforming growth factor β1 (TGF β1), tunical and/or corporal fibrosis, subtunical injection and penile myofibroblasts. The most frequently reported models of PD can be classified as TGF β1, fibrin and surgical trauma-induced models. In vitro studies using Peyronie's fibroblast culture media have also provided further insights into cellular mechanism of PD. At the present time, the research in PD is hampered by the lack of universally accepted animal model and this is likely attributed to the limited insight into PD mechanisms and the difficulties faced by current animal models to truly represent the complexity and complete spectrum of human disease.

Review of non-surgical treatment options for Peyronie's disease

Non-surgical treatment of Peyronie's disease (PD) has come a long way since it was first described in 1743. A myriad of treatment options are currently available, including oral, intralesional and external energy therapies. The purpose of this article is to review the contemporary literature on non-surgical therapies for PD, and where possible, focus on randomized, placebo-controlled trials, as well as review the latest guidelines for the management of PD from the International Committee on Sexual Medicine, which conveyed its findings in July 2009. At this time, it appears that a combination of oral agents and/or intralesional injection with traction therapy may provide a synergy between the chemical effects of the drugs and the mechanical effects of traction. Until a reliable treatment emerges, it does appear that some of the non-surgical treatments discussed can be used to stabilize the scarring process and may result in some reduction of deformity with improved sexual function.

Peyronie's disease: perspectives on therapeutic targets

INTRODUCTION

Peyronie's disease (PD) is an acquired benign connective tissue disorder of the penis, characterized by the development of fibrotic plaques, that can cause different degrees of bending, narrowing or shortening. Medical treatment for PD remains a major challenge. Impressive progress in our understanding of the molecular mechanisms of PD pathogenesis has uncovered several promising molecular targets for antifibrotic treatments.

AREAS COVERED

This review covers the literature pertaining to the exploration of therapeutic targets for PD. The search included: i) a MEDLINE search from 1941 to January 2011, limited to English-language medical literature, ii) relevant abstracts from 2009 and 2010, iii) relevant textbooks and iv) a pipeline search for therapeutics in development.

EXPERT OPINION

Rapid translational research depends on our ability to develop rational therapies targeted to penile tunical fibrosis, which necessitate a sound knowledge of the biology, biochemistry and the physiological role of fibroblasts, myofibroblasts and stem cells in PD. Much remains to be learned about the pathogenesis of PD. Although there are many interesting therapeutic targets, we are confronted with some questions when identifying new targets, or when validating potential therapeutic options.

The relationship between androgens, regulators of collagen metabolism, and Peyronie's disease: a case control study

INTRODUCTION

Changes in collagen metabolism have been postulated to play a pivotal role in the pathogenesis of Peyronie's Disease (PD). Androgens such as dehydroepiandrosterone sulfate (DHEA-S) and testosterone influence collagen metabolism by modulating the activity of matrix metalloproteases (MMP) and tissue inhibitors of metalloproteases (TIMP).

AIM

The aim of this study was to evaluate the interrelationship between androgens (DHEA-S and testosterone), key regulators of collagen metabolism such as insulin-like growth factor (IGF) 1 and IGF Binding Protein 3 (IGF-BP3), the MMP/TIMP system, and PD.

METHODS

Age matched PD patients (14) and healthy men (10) who acted as controls were recruited. Blood samples were collected from all subjects in the early morning hours after an overnight fast.

MAIN OUTCOME MEASURES

Serum levels of testosterone, sex hormone binding globulin, DHEA-S, 3-α-androstanediol glucuronide, pro-MMP-1, MMP-1, MMP-2, TIMP-1, TIMP-2, IGF-1 and IGF-BP3 were measured in both groups. Statistical methods included univariate, bivariate, and multivariate regression models.

RESULTS

Levels of DHEA-S (114.5 vs. 169.5 µg/dL; p = 0.03), IGF-BP3 (2.96 vs. 3.79 µg/mL; p = 0.01), and TIMP-1 (173.1 vs. 195 ng/mL; p = 0.01) were significantly lower in PD patients. In contrast, the level of TIMP-2 (102 vs. 85 ng/mL; p = 0.001) was significantly lower in the control group. Using stepwise regression analysis, only TIMP-2 (p < 0.001) and DHEA-S (p = 0.04) were significantly related to PD in the final model (R(2) = 0.63). TIMP-1 and DHEA-S (r = 0.55, p < 0.05) were positively correlated in the PD group, whereas IGF-1 and testosterone (r = -0.54, p < 0.05), and IGF-BP3 and testosterone (r = -0.68, p < 0.05) were negatively correlated in PD patients.

CONCLUSIONS

Our findings suggest that decreased levels of adrenal androgens may be implicated in the pathogenesis of PD. The mechanism and clinical relevance of this observation remain to be established.

The management of Peyronie's disease: evidence-based 2010 guidelines

INTRODUCTION

The field of Peyronie's disease is evolving and there is need for a state-of-the-art information in this area.

AIM

To develop an evidence-based state-of-the-art consensus report on the management of Peyronie's disease.

METHODS

To provide state-of-the-art knowledge regarding the prevalence, etiology, medical and surgical management of Peyronie's Disease, representing the opinion of leading experts developed in a consensus process over a 2-year period.

MAIN OUTCOME MEASURES

Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

CONCLUSIONS

The real etiology of Peyronie's disease and the mechanisms of formation of the plaque still remain obscure. Although conservative management is obtaining a progressively larger consensus among the experts, surgical correction still remains the mainstay treatment for this condition.

Pentoxifylline attenuates transforming growth factor-β1-stimulated collagen deposition and elastogenesis in human tunica albuginea-derived fibroblasts part 1: impact on extracellular matrix

INTRODUCTION

Transforming growth factor-β1 (TGF-β1) has been implicated in the pathogenesis of Peyronie's disease (PD) and also plays a role in collagen and elastin metabolism. Pentoxifylline (PTX) antagonizes the effects of TGF-β1 and has been utilized in our clinic for the management of PD.

AIM

We studied the effects of TGF-β1 and PTX on collagen metabolism and elastogenesis in tunica albuginea-derived fibroblasts (TADFs).

METHODS

TADFs from men with and without PD were cultured and treated with TGF-β1 and PTX as monotherapy at differing concentrations and time points. Combination treatment (TGF-β1 followed by PTX and vice versa) was also investigated.

MAIN OUTCOME MEASURES

Cell proliferation assay, enzyme-linked immunosorbent assay, and immunohistochemistry were utilized to assess the impact of TGF-β1 and PTX on TADF with respect to elastin and collagen I metabolism.

RESULTS

PTX inhibited fibroblast proliferation at doses of 100 µM. TGF-β1 stimulated elastogenesis and collagen I fiber deposition in TADF in a dose- and time-dependent fashion. Pretreatment with PTX dramatically attenuated TGF-β1-mediated elastogenesis and collagen fiber deposition in TADF from men with and without PD. Interestingly, production of collagen I was higher in untreated Peyronie's tunica (PT) cells relative to normal tunica (NT) cells; furthermore, PTX attenuated collagen production to levels similar to untreated control TADF in PT cells but not in NT cells, suggesting important intrinsic differences between PT and NT cells.

CONCLUSION

Both elastin and collagen are upregulated by TGF-β1 in TADF. This likely contributes to the PD phenotype. Pretreatment with PTX attenuates both collagen fiber deposition and elastogenesis in TADF exposed to TGF-β1; these effects suggest a useful role for PTX in the management of PD.

Experimental models of Peyronie's disease. Implications for new therapies

INTRODUCTION

Despite its high prevalence and impact on the quality of life of patients, and that it is an excellent model for the study of fibrotic processes, Peyronie's disease (PD) is an orphan disease in biomedical research. The development of animal and cell culture models has advanced substantially the understanding of its molecular and cellular pathology and the proposal of new therapies.

AIM

To review the literature pertaining to the use of these models for the study of PD.

METHODS

PubMed search conducted from the first report of an animal model for PD.

RESULTS

This model, based on the finding that transforming growth factor beta1 (TGF beta 1) is overexpressed in the PD plaque, consists on the injection of TGF beta 1 into the tunica albuginea of the rat. This leads to a PD-like plaque retaining many of the histological and biochemical features of human PD. Another rat model, based on the hypothesis that the PD plaque arises from trauma to the penis, causing fibrinogen extravasation that initiates as fibrin a fibrotic response, consists on injection of fibrin into the tunica. The cell culture model is based on the demonstration that myofibroblasts are abundant in the human PD plaque.

CONCLUSIONS

These models have: (i) clarified the role of microtrauma, myofibroblasts, and oxidative stress in plaque development; (ii) demonstrated that this tissue is under sustained turnover by fibrotic and antifibrotic mechanisms; (iii) showed the interplay of collagenolytic and fibrinolytic systems and their inhibitors; (iv) detected an endogenous antifibrotic process consisting of the expression of inducible nitric oxide synthase that counteracts oxidative stress, collagen synthesis, and myofibroblast generation; (v) characterized the antifibrotic effects of chronic treatment with phosphodiesterase type 5 (PDE5) inhibitors; (vi) discovered the cytogenetic instability of PD cells and alterations in their gene expression; and (vii) detected stem cells in the tunica albuginea with a potential role in fibrosis and ossification.