Investigation of the antifibrotic effect of IFN-gamma on fibroblasts in a cell culture model of Peyronie's disease

The pathogenic role of the immune system in erectile dysfunction and Peyronie's disease: focusing on immunopathophysiology and potential therapeutic strategies

INTRODUCTION

Erectile dysfunction (ED) represents the major cause of male sexual dysfunction, which is often associated with obesity, diabetes mellitus, atherosclerotic cardiovascular disease, and cigarette smoking. Peyronie's disease is a chronic disorder associated with irreversible fibrotic damage of the tunica albuginea leading to ED, painful erection, coital disturbance, and physical and social complaints. Both conditions are characterized by chronic inflammation, oxidative stress, and significant changes in intracavernous hydrodynamics. In this scenario, oxidized lipoproteins, M1-polarized macrophages, proinflammatory cytokines (such as the tumor necrosis factor α), endothelial nitric oxide synthase, penile smooth muscle cells, and toll-like receptors represent the main triggers of the inflammatory process in ED. Phosphodiesterase-5 inhibitors are the most common treatment for ED. This treatment is used intermittently, as it is conceived as a symptomatic and not curative therapy. Moreover, not all patients respond to phosphodiesterase-5 inhibitors (35%-85%), particularly those with dysmetabolic phenotypes. Additional or alternative treatments are therefore desirable, mostly in refractory cases.

OBJECTIVES

In this review, we describe the immune-mediated pathogenesis of ED and Peyronie's disease (PD). In our literature search we placed particular emphasis on potentially practical therapeutic approaches, including natural products (such as polyphenols), due to their anti-inflammatory and antioxidant activities, stem cell therapy, and platelet-derived preparations.

METHODS

We searched PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, Google Scholar, and institutional websites. Original studies, narrative reviews, systematic reviews, and meta-analyses written in English were searched, screened, and selected.

RESULTS

In animal models of ED and PD, therapeutic approaches, including anti-inflammatory and antioxidant agents, stem cell therapy, and platelet-derived preparations, have provided positive results, including improved penile function, reduced inflammation and oxidative stress, and promotion of tissue repair. However, clinical evidence of improvement in human patients is still insufficient.

CONCLUSION

Promising results for treating ED and PD have been shown in preclinical and pilot clinical studies, but specific clinical trials are needed to validate the efficacy of these therapeutic approaches in men with ED.

A systematic review of non-surgical management in Peyronie's disease

The efficacy of many non-surgical treatments for Peyronie's disease is unclear. This systematic review aims to critically assess the currently available options and provide a recommendation for treatment based on this. A systematic literature search utilising the Medline (Pubmed), Embase, global health and Cochrane library databases was conducted up to May 2021. All randomised controlled trials assessing non-surgical treatment modalities for Peyronie's Disease were included. Individual study risk of bias was evaluated using the Cochrane tool and GRADE was used to assess evidence strength. Outcome measures were the change in penile curvature (degrees), plaque size (volume or size), International Index of Erectile Function score, pain scores and change in penile length. Prospero registration number: CRD42017064618. Amongst the 5549 articles identified, 41 studies (42 reports) were included. Seven different oral treatment options including vitamin E supplementation showed evidence for improving outcomes such as penile curvature and plaque size. Of the intralesional treatments, Collagenase Clostridium Histolyticum showed evidence for improving penile curvature (Range: 16.3-17 degrees, moderate level certainty of evidence). Intralesional Interferon demonstrated some improvement in curvature (Range: 12-13.5 degrees), plaque size (Range: 1.67-2.2 cm2) and pain, whilst intralesional calcium channel blockers such as Verapamil showed variable evidence for changes in the plaque size and pain. Extracorporeal Shockwave Therapy consistently demonstrated evidence for improving penile pain in stable disease, and two mechanical traction devices improved curvature. Iontophoresis, topical medications, and combination therapies did not demonstrate any consistent improvements in outcome measures. Intralesional options demonstrate the best potential. Overall, results varied with few high-quality randomised trials present.

TNFα and IFNγ cooperate for efficient pro- to anti-inflammatory transition of macrophages during muscle regeneration

IFNγ is traditionally known as a proinflammatory cytokine with diverse roles in antimicrobial and antitumor immunity. Yet, findings regarding its sources and functions during the regeneration process following a sterile injury are conflicting. Here, we show that natural killer (NK) cells are the main source of IFNγ in regenerating muscle. Beyond this cell population, IFNγ production is limited to a small population of T cells. We further show that NK cells do not play a major role in muscle regeneration following an acute injury or in dystrophic mice. Surprisingly, the absence of IFNγ per se also has no effect on muscle regeneration following an acute injury. However, the role of IFNγ is partially unmasked when TNFα is also neutralized, suggesting a compensatory mechanism. Using transgenic mice, we showed that conditional inhibition of IFNGR1 signaling in muscle stem cells or fibro-adipogenic progenitors does not play a major role in muscle regeneration. In contrast to common belief, we found that IFNγ is not present in the early inflammatory phase of the regeneration process but rather peaks when macrophages are acquiring an anti-inflammatory phenotype. Further transcriptomic analysis suggests that IFNγ cooperates with TNFα to regulate the transition of macrophages from pro- to anti-inflammatory states. The absence of the cooperative effect of these cytokines on macrophages, however, does not result in significant regeneration impairment likely due to the presence of other compensatory mechanisms. Our findings support the arising view of IFNγ as a pleiotropic inflammatory regulator rather than an inducer of the inflammatory response.

Pathological Significance of Macrophages in Erectile Dysfunction Including Peyronie's Disease

Erectile function is regulated by complex mechanisms centered on vascular- and nerve-related systems. Hence, dysregulation of these systems leads to erectile dysfunction (ED), which causes mental distress and decreases the quality of life of patients and their partners. At the molecular level, many factors, such as fibrosis, lipid metabolism abnormalities, the immune system, and stem cells, play crucial roles in the etiology and development of ED. Although phosphodiesterase type 5 (PDE5) inhibitors are currently the standard treatment agents for patients with ED, they are effective only in a subgroup of patients. Therefore, further insight into the pathological mechanism underlying ED is needed to discuss ED treatment strategies. In this review, we focused on the biological and pathological significance of macrophages in ED because the interaction of macrophages with ED-related mechanisms have not been well explored, despite their important roles in vasculogenic and neurogenic diseases. Furthermore, we examined the pathological significance of macrophages in Peyronie’s disease (PD), a cause of ED characterized by penile deformation (visible curvature) during erection and pain. Although microinjury and the subsequent abnormal healing process of the tunica albuginea are known to be important processes in this disease, the detailed etiology and pathophysiology of PD are not fully understood. This is the first review on the pathological role of macrophages in PD.

Penile Extra-Tunical Graft Reconstruction of Peyronie's Disease Concavity Deformities

OBJECTIVES

To report our initial experience with the extra-tunical grafting (ETG) procedure. This procedure was recently introduced by UCSF investigators as a tunica-sparing technique for management of penile concavity deformities.

METHODS

We retrospectively reviewed records of patients who underwent ETG at our tertiary-care referral center between 2017 - 2020.  A collagen graft made from bovine pericardium (Lyoplant) was placed overlying the defect without violating the tunica albuginea or mobilizing the neurovascular bundle. The stretched penile length (SPL) and circumference at the location of deformity were measured intra-operatively. Patient reported outcomes were evaluated by an anonymous 10-question online survey.

RESULTS

19 men underwent ETG with a median follow-up of 59 (IQR: 24 - 708) days. ETG was performed via either a window (15/19, 78%) or a de-gloving (4/19, 21%) incision with concomitant penile plication performed in 16/19 (84%) patients. Penile circumference increased by an average of 1.4 cm + 0.5 (P = 0.03) at the location of deformity, while pre- and post-operative SPL were similar (14.0 + 1.4 vs 14.0 + 1.3 cm, P = 0.95). Overall patient satisfaction was reported by 13/15 (86%) patients. Twelve out of 15 (80%) patients reported concavity deformity to be "improved", with 73% reporting "much better". Among 8 patients with follow up greater than six months, graft palpability was reported in 4/8 (50%) patients but was not bothersome.

CONCLUSION

The ETG procedure appears to be safe and effective for the treatment of penile concavity deformities.  Patient outcomes and satisfaction are favorable at intermediate follow up.

Antioxidant Mechanism of Xiaojin Pill () for Treatment of Peyronie's Disease in Rats Based on Matrix Metalloproteinases

OBJECTIVE

To evaluate the effects of Xiaojin Pill () in the treatment of Peyronie's disease (PD) in a rat model.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into four groups with 6 in each: sham operation, PD model, vehicle control and Xiaojin Pill groups. The rats in the sham operation group received penile tunica albsginea (TA) injection with 50 μL vehicle, while the rats in the other 3 groups received 50 μL penile TA injection of 50 μg transforming growth factor (TGF)-β1. Forty-two days after the injection, rats in the vehicle control and Xiaojin Pill groups received 0.5 mL water and Xiaojin Pill solution (107 mg/kg of body weight), respectively by gavage for 28 days, while those in the sham operation and PD model groups did not receive any intervention. After intervention, the expressions of matrix metalloproteinase 2/9 (MMP2/9), nitric oxidesynthase (NOS), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured.

RESULTS

Rats in the PD model and vehicle control groups presented obvious fibrosis in corpus cavernosum (CC) and demonstrated a significantly increased expressions of MMP2 and MMP9 in the CC compared with the sham operation group (all P<0.01). In contrast, the expressions of MMP2 and MMP9 in the Xiaojin Pill group were significantly down-regulated (both P<0.01). In addition, the levels of NOS and MDA in CC were significantly increased while the activity of SOD was decreased in the PD model and vehicle control groups compared with the sham operation group (all P<0.01). After Xiaojin Pill treatment, the levels of MDA, NOS and SOD appeared to be corrected (all P<0.01).

CONCLUSIONS

Xiaojin Pill could reduce fibrosis in the CC by decreasing the expressions of MMPs, NOS and MDA, and by increasing the activity of SOD. Therefore, Xiaojin Pill might be a therapeutic option for 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.

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.

Skin wound healing with chitosan thin films containing supported silver nanospheres

Dermal wound healing involves complex histo-molecular events aimed to repair the discontinuity of the epithelium. Employing nanometric silver particles provides an efficient antimicrobial effect for several dermal infections. The aim is to elucidate imminent advantages of silver nanoparticles, such as the possibility of modulating the epithelial cell repair process. Through the nanostructural implementation of chitosan thin films supporting silver nanoparticles, it was feasible to evaluate in vivo the efficacy and evolution of dermal recuperation after surgical damage. The characterization of chitosan silver nanoparticle films was performed by UV–visible spectra and Fourier transform infrared spectroscopy, X-ray diffraction, and high-resolution electron microscopy. An important dermal healing was accomplished in animals that were treated with chitosan films supporting silver nanoparticles, as confirmed by a histopathological analysis of the skin after 12 days of treatment. The developed chitosan thin film supporting an optimized amount of silver nanoparticles could be employed to treat diseases related to wound healing.

Peyronie's Disease: AUA Guideline

PURPOSE

The purpose of this guideline is to provide a clinical framework for the diagnosis and treatment of Peyronie's disease.

MATERIALS AND METHODS

A systematic review of the literature using the PubMed®, EMBASE® and Cochrane databases (search dates 1/1/1965 to 1/26/15) was conducted to identify peer-reviewed publications relevant to the diagnosis and treatment of PD. The review yielded an evidence base of 303 articles after application of inclusion/exclusion criteria.

RESULTS

The systematic review was used to create guideline statements regarding treatment of PD. When sufficient evidence existed, the body of evidence for a particular treatment was assigned a strength rating of A (high quality evidence; high certainty), B (moderate quality evidence; moderate certainty), or C (low quality evidence; low certainty). Evidence-based statements of Strong, Moderate, or Conditional Recommendation were developed based on benefits and risks/burdens to patients. Additional consensus statements related to the diagnosis of PD are provided as Clinical Principles and Expert Opinions due to insufficient published evidence.

CONCLUSIONS

There is a continually expanding literature on PD; the Panel notes that this document constitutes a clinical strategy and is not intended to be interpreted rigidly. The most effective approach for a particular patient is best determined by the individual clinician and patient in the context of that patient's history, values, and goals for treatment. As the science relevant to PD evolves and improves, the strategies presented here will be amended to remain consistent with the highest standards of clinical care.

Cytokine Gene Expression in the Tunica Albuginea of Patients with Peyronie's Disease. Pilot Study with a Control Group

Introduction and objective

Cytokines may be involved in the pathogenesis of Peyronie's disease (PD). In this case, biological drugs, acting on specific cytokines, could be adopted in the pharmacological treatment of the disease.

Materials and Methods

Twenty PD patients and 8 patients affected by congenital recurvatum penis (control group) who underwent corporoplasty were enrolled in the study Histological examination and measurement by Real Time PCR of the expression of the encoding genes for IL-2, IL-4, IL-6, IL-10, IL-13, TGF-β, TNF-α and IFN-γ were performed on the removed tunica albuginea (TA). For the normalization of data GAPDH (glucerldehyde-3fosfatehydrogenase) and GUSB (β-glucuronidase), housekeeping genes were used. The analysis of the data was performed using the comparative method of ΔCt. The results were reported with the Fold of induction (FOI) method.

Results

The histological exams of TA showed only fibrous tissue without cavernous tissue. The analysis of gene expression of IL-6, IL-10, IFN-γ and TGF-β1 showed in all samples very low levels. The levels were lower in PD patients although the differences were not statistically significant. An exception was represented by TGF-β that showed a higher level in PD patients, although not statistically significant. The expression of IL-4, IL-13 and TNF-α was undetectable.

Conclusions

The expressions of cytokines in TA of PD patients compared to those of the controls do not show any significant difference. A bias of our study is that the groups were not age-matched. This is a bias already present in similar experiences and due to the different pathogenesis of the diseases. Cytokines promoting inflammation resulted undetectable and do not seem to be involved in PD pathogenesis. The higher level of TGF-β, a pro-fibrotic cytokine, detected in PD could explain the presence of fibrotic tissue. Presently, there is no data suggesting a possible role of biological drugs in PD.

Silver nanoparticles as real topical bullets for wound healing

Nanotechnology is on the threshold of providing a host of new materials and approaches, revolutionizing the medical and pharmaceutical fields. Several areas of medical care are already profiting from the advantage that nanotechnology offers. Recently, silver nanoparticles are attracting interest for a clinical application because of its potential biological properties such as antibacterial activity, anti-inflammatory effects, and wound healing efficacy, which could be exploited in developing better dressings for wounds and ulcers. This article reviews the role of silver nanoparticles in wound healing.

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.

Nanoscale particle therapies for wounds and ulcers

‘Small is beautiful’ – this should be the slogan of nanoscientists. Indeed, working with particles less than 100 nm in size, nanotechnology is on the verge of providing a host of new materials and approaches, revolutionizing applied medicine. The obvious potential of nanotechnology has attracted considerable investment from governments and industry hoping to drive its economic development. Several areas of medical care already benefit from the advantages that nanotechnology provides and its application in wound healing will be reviewed in this article.

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.

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.