The genetics and immunology of Peyronie's disease

The relationship between testosterone levels and Peyronie's disease

Aetiologic and predisposing factors are still controversial about Peyronie's disease (PD). However, it is thought to be the result of connective tissue disorder or healing defect. Androgens are known to affect collagen metabolism and wound healing in the body. The aim of this study was to investigate the relationship between PD and low testosterone levels. One hundred and forty-seven Peyronie patients and 137 healthy volunteers were included in the study. In both groups, demographic data, medical history, physical examination and erectile capacity were recorded. Blood samples were collected from all subjects in the early morning hours after an overnight fast. The mean level of serum total testosterone was lower in men with PD compared with the controls (3.9 ± 1.1 vs. 4.2 ± 1.7 ng/ml respectively) (p = .062). However, statistically significant relationship was not found between PD and low serum testosterone levels. There was no significant correlation between penile plaque dimension or penile curvature degree and testosterone levels. Large randomised-controlled prospective studies are needed to reveal this possible association.

Peyronie's disease: is it genetic or not?

Peyronie's disease (PD) is a devastating disease that affects up to 13% of adult men. While trauma to the erect penis is common prior to onset, it is clear that trauma alone is not sufficient to cause PD. Over the past 40 years, multiple lines of evidence have pointed to a genetic factor that predisposes some men to develop PD. Despite dramatic technological advances in the field of genetics, we have made little progress in identifying the genetic contributors to the disease. This review will critically evaluate the literature concerning the genetics of PD published to date. Particular focus will be placed on study design as much of the data are contradictory yet may still give some insight into the etiology of PD. The challenges in identifying the genetic underpinnings of PD will be discussed along with the potential mechanisms that can overcome these challenges.

Advances in stem cell therapy for the treatment of Peyronie's disease

Peyronie's disease (PD) is a connective tissue disorder of the penis characterized by fibrosis and plaque formation within the tunica albuginea. PD is characterized by painful penile curvature that impairs sexual intercourse. Stem cell therapy is one of the recent non-invasive treatment options for patients with PD and it has promising results. Stem cells are undifferentiated cells that are capable of self-renewal and differentiation, promoting the repair of tissues via their immunomodulatory and anti-inflammatory action. Adipose-derived stem cells (ADSC) are used most widely due to their abundant tissue source and ease of isolation. Multiple studies have indicated the efficacy of stem cell therapy as a potential treatment for fibrotic diseases. Clearly, ADSCs may represent a way to treat and prevent PD in both rat and human models. Further clinical studies are needed to confirm the efficacy of stem cell therapy for PD in humans.

The Etiology of Peyronie's Disease: Pathogenesis and Genetic Contributions

INTRODUCTION

Peyronie's disease (PD) is a chronic fibrosing condition that contributes to penile deformity, curvature, and pain. Initial familial studies demonstrated potential genetic links to PD. Since that time, very few investigations have significantly advanced the science in this area. Hence, there is a large opportunity and significant need to better study the underlying genomics and pathogenesis of PD.

AIM

To summarize the current genomic literature relevant to PD.

METHODS

A review was performed of all PubMed-indexed literature from 1970-2018 relating to the pathophysiology and genetics of PD. Key findings were categorically summarized to include epidemiology, risk factors, inheritance patterns, chromosomal instability, genetic associations, epigenetics, differential gene expression, and preclinical models of PD.

MAIN OUTCOME MEASURES

Summary of the current literature on the genetics of PD.

RESULTS

PD is a common condition and has several known risk factors and comorbid disease associations. Although men with PD are believed to be genetically predisposed, there are likely several subtypes of the condition, each with varied pathophysiological disorders and contributing factors. Available data suggest that PD is associated with underlying genetic instability, including dysregulation of genes relating to fibrosis and cellular degradation, thus, resulting in abnormal plaque development and penile deformity. Preclinical models, including cell cultures and rat models, demonstrate several consistencies with PD clinical and histopathologic characteristics; however, an ideal model with spontaneous development of PD is lacking.

CONCLUSION

Based on limited data, PD likely represents a heterogeneous condition, with both heritable and environmentally-driven epigenetic factors contributing to its development and progression. However, there remains a significant gap in the literature on the underlying cause and pathophysiology of the condition, suggesting a substantial need for further investigation and study. Sharma KL, Alom M, Trost L. The Etiology of Peyronie's Disease: Pathogenesis and Genetic Contributions. Sex Med Rev 2020;8:314-323.

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.

PEYRONIE'S DISEASE: A REVIEW OF ETIOLOGY, DIAGNOSIS, AND MANAGEMENT

Peyronie's Disease (PD) is a superficial fibrosing disorder of the penis resulting in plaque formation and penile deformity. Once considered rare, PD has more recently been found in up to 13% of men, and can negatively affect sexual and psychosocial function of both patients and their partners. While the etiology of PD is unclear, it is thought to result from an inciting traumatic event followed by aberrant fibrosis or dysregulated wound healing. The evaluation of men presenting with PD includes a detailed history and physical exam, focusing on the penis in both the flaccid and erect states. PD is often associated with erectile dysfunction (ED), as well as several other comorbidities. Laboratory testing is not needed to diagnose PD, although given the associations between PD and systemic diseases including hypogonadism, diabetes, and cardiovascular disease, screening and work-up for these conditions in men with PD may be warranted. Treatment modalities for PD are diverse and include oral, topical, intralesional, mechanical, and surgical therapies. Oral, topical, and mechanical therapies generally have little evidence supporting their efficacy. Several intralesional therapies, including interferon α2b and collagenase Clostridium hystiolyticum have demonstrated efficacy in the treatment of PD. Surgical treatment, indicated in men with significant, stable deformity, includes plication of the tunica albuginea, plaque incision/excision and grafting, and placement of inflatable penile prosthesis (IPP) with or without additional maneuvers to achieve desired results, and has high success rates.

The role of intrinsic pathway in apoptosis activation and progression in Peyronie's disease

Peyronie's disease (PD) is characterized with formation of fibrous plaques which result in penile deformity, pain, and erectile dysfunction. The aim of this study was to investigate the activation of the intrinsic apoptotic pathway in plaques from PD patients. Tunica albuginea from either PD or control patients was assessed for the expression of bax, bcl-2 and caspases 9 and 3 using immunohistochemistry and by measurement of apoptotic cells using TUNEL assay. Bax overexpression was observed in metaplastic bone tissue, in fibroblasts, and in myofibroblast of plaques from PD patients. Little or no bcl-2 immunostaining was detected in samples from either patients or controls. Caspase 3 immunostaining was very strong in fibrous tissue, in metaplasic bone osteocytes, and in primary ossification center osteoblasts. Moderate caspase 9 immunostaining was seen in fibrous cells plaques and in osteocytes and osteoblasts of primary ossification centers from PD patients. Control samples were negative for caspase 9 immunostaining. In PD patients the TUNEL immunoassay showed intense immunostaining of fibroblasts and myofibroblasts, the absence of apoptotic cells in metaplasic bone tissue and on the border between fibrous and metaplastic bone tissue. Apoptosis occurs in stabilized PD plaques and is partly induced by the intrinsic pathway.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its death receptor (DR5) in Peyronie's disease. A biomolecular study of apoptosis activation

INTRODUCTION

Peyronie's disease (PD) is a connective tissue disorder of tunica albuginea (TA), a thick fibrous sheath surrounding the corpora cavernosa of the penis. Relatively, little is known about the disease itself.

AIM

To investigate whether the apoptosis cascade in degenerated and macroscopically deformed TA from men with PD is activated through the extrinsic pathway, by assessing the immunoexpression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its death receptor, DR5.

METHODS

TA plaques from 15 men with PD and from four unaffected men were processed for TRAIL and DR5 immunohistochemistry and Western blot analysis.

MAIN OUTCOME MEASURES

A greater understanding of the pathophysiology of PD through a molecular approach, to gain insights that may lead to novel forms of treatment.

RESULTS

Activation of the apoptosis mechanisms through the extrinsic pathway was demonstrated by TRAIL and DR5 overexpression in fibroblasts and myofibroblasts from affected TA.

CONCLUSION

The finding that apoptosis activation in TA plaques occurs, at least in part, via the extrinsic pathway may help devise novel therapeutic options for these patients.

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.

Gene expression in Peyronie's disease

Currently, surgical intervention is the only efficacious treatment for Peyronie's disease (PD), a fibromatosis of the tunica albuginea of the penis. Therapies based on the molecular pathways for this disease could provide alternatives to surgical treatment but only recently has the pathophysiology of the Peyronie's disease plaque been investigated at the molecular level. In this review, we examine the current knowledge of gene expression in the PD plaque and the relationship of PD with other fibrotic conditions such as Dupytren's disease. TGFbeta1, along with other growth factors, pro-fibrotic genes, and collagen, are expressed in fibroblasts and myofibroblasts. Myofibroblasts are normally involved in wound contracture and largely eliminated via apoptosis during the late stages of wound remodeling. In the PD plaque, however, these cells persist and may play an important role in the PD plaque fibrosis. The expression levels of TGFbeta1 and pro- and anti-fibrotic gene products, along with the nitric oxide/reactive oxygen species (NO/ROS) ratio in the tunica albuginea, appear to be essential for the formation and progression of the PD plaque and effect the expression of multiple genes. This can be assessed with the recently developed DNA-based chip arrays and results with the PD plaque have been encouraging. OSF-1 (osteoblast recruitment), MCP-1 (macrophage recruitment), procollagenase IV (collagenase degradation), and other fibrotic genes have been identified as being possible candidate regulatory genes. Finally, possible therapeutic avenues for gene-based therapy in the treatment of PD are discussed that may eventually reduce the need for surgical intervention.

New advances in Peyronie's disease

The formation of Peyronie's disease plaques is a process that seems to involve a cascade of genetic, structural and immunologic events. Clinical manifestations include penile deformity and possible erectile dysfunction. Rational strategies have been forthcoming, with both minimally invasive and surgical treatments of Peyronie's disease available. This article reviews and updates current scientific and clinical advances in Peyronie's disease.