Silencing Histone Deacetylase 7 Alleviates Transforming Growth Factor-β1-Induced Profibrotic Responses in Fibroblasts Derived from Peyronie's Plaque

Kindlin-2 mediates Peyronie's disease through activation of TGF-β/Smad signaling pathway under the presence of TGF-β1

BACKGROUND

Peyronie's disease (PD) causes benign plaques or induration in tunica albuginea (TA). Kindlin-2 regulates the TGF-β1/Smad3 pathway, which accelerates kidney fibrosis. The study is aimed mainly to investigate the impact of Kindlin-2 on PD formation and its signaling pathways, notably the TGF-β/Smad pathway in the presence of TGF-β1.

METHODS

In this mouse investigation, adenovirus TGF-β1 was injected into TA to produce PD. The model was successfully induced 45 days later. Western Blot (WB) and immunohistochemistry (IHC) were utilized to measure Kindlin-2 in PD model tissue. WB and immunofluorescence assays were utilized to confirm the impact of TGF-β1 on Kindlin-2 levels in vitro. The interaction among Kindlin-2, TβRI, and Smad3 was detected using immunoprecipitation (IP) experiments. We examined how TGF-β1 affects Smad3 phosphorylation and downstream gene activation process. Finally, Kindlin-2 and the level of tissue fibrosis were examined in PD model.

RESULTS

Kindlin-2 levels were elevated in the TGF-β1-induced PD model, confirming that TGF-β1 can increase Kindlin-2 levels in primary PD cells. Moreover, Kindlin-2 mediates Smad3-TβRI interaction, activates p-Smad3, and enhances TGF-β1 target gene expression. In vivo investigations reveal that Kindlin-2 promotes PD development and tissue fibrosis. The regulatory effects of Kindlin-2 need the presence of TGF-β1. Tissue fibrosis can be reduced by downregulating Kindlin-2.

CONCLUSION

Kindlin-2 does not directly activate Smad3 to induce tissue fibrosis. Instead, it exerts its effect through the combined influence of TGF-β1. Inhibiting Kindlin-2 could potentially be a treatment for PD.

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.

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.

Histone deacetylase 7: a signalling hub controlling development, inflammation, metabolism and disease

Histone deacetylases (HDACs) catalyse removal of acetyl groups from lysine residues on both histone and non-histone proteins to control numerous cellular processes. Of the 11 zinc-dependent classical HDACs, HDAC4, 5, 7 and 9 are class IIa HDAC enzymes that regulate cellular and developmental processes through both enzymatic and non-enzymatic mechanisms. Over the last two decades, HDAC7 has been associated with key roles in numerous physiological and pathological processes. Molecular, cellular, in vivo and disease association studies have revealed that HDAC7 acts through multiple mechanisms to control biological processes in immune cells, osteoclasts, muscle, the endothelium and epithelium. This HDAC protein regulates gene expression, cell proliferation, cell differentiation and cell survival and consequently controls development, angiogenesis, immune functions, inflammation and metabolism. This review focuses on the cell biology of HDAC7, including the regulation of its cellular localisation and molecular mechanisms of action, as well as its associative and causal links with cancer and inflammatory, metabolic and fibrotic diseases. We also review the development status of small molecule inhibitors targeting HDAC7 and their potential for intervention in different disease contexts.

Aberrant expression of histone deacetylase 8 in endometriosis and its potential as a therapeutic target

Purpose

To screen Zn2+-dependent histone deacetylase (HDAC) 1-11 in endometriotic cells and then evaluated the HDACs identified from the screening in ovarian endometrioma (OE) and deep endometriotic (DE) lesions, and to evaluate the therapeutic potential of HDAC8 inhibition in mice.

Methods

Quantification of gene and protein expression levels of HDAC1-11 in endometriotic cells stimulated by TGF-β1, and immunohistochemistry analysis of Class I HDACs and HDAC6 in OE/DE lesion samples. The therapeutic potential of HDAC8 inhibition was evaluated by a mouse model of deep endometriosis.

Results

The screening identified Class I HDACs and HDAC6 as targets of interest. Immunohistochemistry analysis found a significant elevation in HDAC8 immunostaining in both OE and DE lesions, which was corroborated by gene and protein expression quantification. For other Class I HDACs and HDAC6, their lesional expression was more subtle and nuanced. HDAC1 and HDAC6 staining was significantly elevated in DE lesions while HDAC2 and HDAC3 staining was reduced in DE lesions. Treatment of mice with induced deep endometriosis with an HDAC8 inhibitor resulted in significantly longer hotplate latency, a reduction of lesion weight by nearly two-thirds, and significantly reduced lesional fibrosis.

Conclusions

These findings highlight the progression-dependent nature of specific HDAC aberrations in endometriosis, and demonstrate, for the first titme, the therapeutic potential of suppressing HDAC8.

HDAC5-mediated Smad7 silencing through MEF2A is critical for fibroblast activation and hypertrophic scar formation

Transforming growth factor-β (TGF-β) signaling plays a key role in excessive fibrosis. As a class IIa family histone deacetylase (HDAC), HDAC5 shows a close relationship with TGF-β signaling and fibrosis. However, the effect and regulatory mechanism of HDAC5 in hypertrophic scar (HS) formation remain elusive. We show that HDAC5 was overexpressed in HS tissues and depletion of HDAC5 attenuated HS formation in vivo and inhibited fibroblast activation in vitro. HDAC5 knockdown (KD) significantly downregulated TGF-β1 induced Smad2/3 phosphorylation and increased Smad7 expression. Meanwhile, Smad7 KD rescued the Smad2/3 phosphorylation downregulation and scar hyperplasia inhibition mediated by HDAC5 deficiency. Luciferase reporter assays and ChIP-qPCR assays revealed that HDAC5 interacts with myocyte enhancer factor 2A (MEF2A) suppressing MEF2A binding to the Smad7 promoter region, which results in Smad7 promoter activity repression. HDAC4/5 inhibitor, LMK235, significantly alleviated hypertrophic scar formation. Our study provides clues for the development of HDAC5 targeting strategies for the therapy or prophylaxis of fibrotic diseases.

Molecular mechanisms of histone deacetylases and inhibitors in renal fibrosis progression

Renal fibrosis is a common progressive manifestation of chronic kidney disease. This phenomenon of self-repair in response to kidney damage seriously affects the normal filtration function of the kidney. Yet, there are no specific treatments for the condition, which marks fibrosis as an irreversible pathological sequela. As such, there is a pressing need to improve our understanding of how fibrosis develops at the cellular and molecular levels and explore specific targeted therapies for these pathogenic mechanisms. It is now generally accepted that renal fibrosis is a pathological transition mediated by extracellular matrix (ECM) deposition, abnormal activation of myofibroblasts, and epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells under the regulation of TGF-β. Histone deacetylases (HDACs) appear to play an essential role in promoting renal fibrosis through non-histone epigenetic modifications. In this review, we summarize the mechanisms of renal fibrosis and the signaling pathways that might be involved in HDACs in renal fibrosis, and the specific mechanisms of action of various HDAC inhibitors (HDACi) in the anti-fibrotic process to elucidate HDACi as a novel therapeutic tool to slow down the progression of renal fibrosis.

Targeting Histone Deacetylases in Idiopathic Pulmonary Fibrosis: A Future Therapeutic Option

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with limited therapeutic options, and there is a huge unmet need for new therapies. A growing body of evidence suggests that the histone deacetylase (HDAC) family of transcriptional corepressors has emerged as crucial mediators of IPF pathogenesis. HDACs deacetylate histones and result in chromatin condensation and epigenetic repression of gene transcription. HDACs also catalyse the deacetylation of many non-histone proteins, including transcription factors, thus also leading to changes in the transcriptome and cellular signalling. Increased HDAC expression is associated with cell proliferation, cell growth and anti-apoptosis and is, thus, a salient feature of many cancers. In IPF, induction and abnormal upregulation of Class I and Class II HDAC enzymes in myofibroblast foci, as well as aberrant bronchiolar epithelium, is an eminent observation, whereas type-II alveolar epithelial cells (AECII) of IPF lungs indicate a significant depletion of many HDACs. We thus suggest that the significant imbalance of HDAC activity in IPF lungs, with a “cancer-like” increase in fibroblastic and bronchial cells versus a lack in AECII, promotes and perpetuates fibrosis. This review focuses on the mechanisms by which Class I and Class II HDACs mediate fibrogenesis and on the mechanisms by which various HDAC inhibitors reverse the deregulated epigenetic responses in IPF, supporting HDAC inhibition as promising IPF therapy.

The contribution of the immune system to genitourinary fibrosis

Fibrotic diseases of the genitourinary tract are devastating and incompletely understood pathologies. These diseases include urethral and ureteral strictures, retroperitoneal fibrosis, and Peyronie's disease. They can contribute to obstructive uropathy and sexual dysfunction. Poor understanding of the pathophysiology of these diseases severely limits our ability to prevent and treat them. Genitourinary fibrotic diseases likely represent related pathologies that share common underlying mechanisms involving wound healing in response to injury. These diseases share the common feature of extracellular matrix abnormalities-such as collagen deposition, transforming growth factor-β accumulation, and dysregulation of collagen maturation-leading to abnormal tissue stiffness. Given the association of many of these diseases with autoimmunity, a systemic pro-inflammatory state likely contributes to their associated fibrogenesis. Herein, we explore the immunologic contribution to fibrogenesis in several fibrotic diseases of the genitourinary system. Better understanding how the immune system contributes to fibrosis in these diseases may improve prevention and therapeutic strategies and elucidate the functions of immunologic contributors to fibrosis in general.

Histone deacetylase 7 mediates endothelin-1-induced connective tissue growth factor expression in human lung fibroblasts through p300 and activator protein-1 activation

Background

Histone deacetylase (HDAC) inhibition was reported to ameliorate lung fibrosis in animal models. However, little is known about the underlying mechanism of HDAC7 in the regulation of CTGF production in lung fibroblasts.

Methods

The role of HDAC7 in CTGF production caused by ET-1 stimulation in WI-38 cells (human lung fibroblast) was examined. We also evaluated the expression of HDAC7 in the lung of ovalbumin-induced airway fibrosis model. Statistical data were shown as mean ± standard error.

Results

ET-1-stimulated CTGF and α-SMA expression was attenuated by small interfering (si)RNA interference of HDAC7. ET-1 promoted HDAC7 translocation from the cytosol to nucleus. ET-1-stimulated CTGF expression was reduced by the transfection of p300 siRNA. ET-1 induced an increase in p300 activity. Furthermore, the acetylation of c-Jun was time-dependently induced by ET-1 stimulation, which was reduced by transfection of either HDAC7 or p300 siRNA. Both transfection of HDAC7 and p300 siRNA suppressed the ET-1-increased activity of AP-1-luciferase. Moreover, the presence of HDAC7 was required for ET-1-stimulated formation of HDAC7, p300, and AP-1 complex and recruitment to the CTGF promoter region. In an ovalbumin-induced airway fibrosis model, the protein level of HDAC7 was increased in the lung tissue, and the distribution of HDAC7 was colocalized with α-SMA-positive cells in the subepithelial layer of the airway.

Conclusions

ET-1 activates HDAC7 to initiate AP-1 transcriptional activity by recruiting p300 and eventually promotes the production of CTGF. HDAC7 might play a vital role in airway fibrosis and have the potential to be developed as a therapeutic target.

HDAC7 Inhibition by Phenacetyl and Phenylbenzoyl Hydroxamates

The zinc-containing histone deacetylase enzyme HDAC7 is emerging as an important regulator of immunometabolism and cancer. Here, we exploit a cavity in HDAC7, filled by Tyr303 in HDAC1, to derive new inhibitors. Phenacetyl hydroxamates and 2-phenylbenzoyl hydroxamates bind to Zn²⁺ and are 50-2700-fold more selective inhibitors of HDAC7 than HDAC1. Phenylbenzoyl hydroxamates are 30-70-fold more potent HDAC7 inhibitors than phenacetyl hydroxamates, which is attributed to the benzoyl aromatic group interacting with Phe679 and Phe738. Phthalimide capping groups, including a saccharin analogue, decrease rotational freedom and provide hydrogen bond acceptor carbonyl/sulfonamide oxygens that increase inhibitor potency, liver microsome stability, solubility, and cell activity. Despite being the most potent HDAC7 inhibitors to date, they are not selective among class IIa enzymes. These strategies may help to produce tools for interrogating HDAC7 biology related to its catalytic site.

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.

Salt-inducible kinase 1 maintains HDAC7 stability to promote pathologic cardiac remodeling

Salt-inducible kinases (SIKs) are key regulators of cellular metabolism and growth, but their role in cardiomyocyte plasticity and heart failure pathogenesis remains unknown. Here, we showed that loss of SIK1 kinase activity protected against adverse cardiac remodeling and heart failure pathogenesis in rodent models and cardiomyocytes derived from human induced pluripotent stem cells. We found that SIK1 phosphorylated and stabilized histone deacetylase 7 (HDAC7) protein during cardiac stress, an event that is required for pathologic cardiomyocyte remodeling. Gain- and loss-of-function studies of HDAC7 in cultured cardiomyocytes implicated HDAC7 as a prohypertrophic signaling effector that can induce c-Myc expression, indicating a functional departure from the canonical MEF2 corepressor function of class IIa HDACs. Taken together, our findings reveal what we believe to be a previously unrecognized role for a SIK1/HDAC7 axis in regulating cardiac stress responses and implicate this pathway as a potential target in human heart failure.

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.

TGFβ-induced fibroblast activation requires persistent and targeted HDAC-mediated gene repression

Tissue fibrosis is a chronic disease driven by persistent fibroblast activation that has recently been linked to epigenetic modifications. Here, we screened a small library of epigenetic small-molecule modulators to identify compounds capable of inhibiting or reversing TGFβ-mediated fibroblast activation. We identified pracinostat, an HDAC inhibitor, as a potent attenuator of lung fibroblast activation and confirmed its efficacy in patient-derived fibroblasts isolated from fibrotic lung tissue. Mechanistically, we found that HDAC-dependent transcriptional repression was an early and essential event in TGFβ-mediated fibroblast activation. Treatment of lung fibroblasts with pracinostat broadly attenuated TGFβ-mediated epigenetic repression and promoted fibroblast quiescence. We confirmed a specific role for HDAC-dependent histone deacetylation in the promoter region of the anti-fibrotic gene PPARGC1A (PGC1α) in response to TGFβ stimulation. Finally, we identified HDAC7 as a key factor whose siRNA-mediated knockdown attenuates fibroblast activation without altering global histone acetylation. Together, these results provide novel mechanistic insight into the essential role HDACs play in TGFβ-mediated fibroblast activation via targeted gene repression.

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.

Extracorporeal Shock Wave Therapy in Peyronie's Disease: Clinical Efficacy and Safety from a Single-Arm Observational Study

Purpose

In this study, we aimed to determine the role of extracorporeal shockwave therapy (ESWT) in the management of Peyronie's disease (PD).

Materials and Methods

A total of 325 patients suffering from PD were enrolled in this single-arm clinical study. All patients were received ESWT using a schedule of 1 treatment/wk. Penile curvature was measured by a goniometer after intracavernosal drug-induced erection using Alprostadil. Plaque size was measured with a ruler and sexual function assessed by the international index of erectile function (IIEF)-15 score. Severity of erectile dysfunction was classified as severe (IIEF-15 ≤10), moderate (IIEF-15 between 11 and 16), or mild (IIEF-15 between 17 and 25). Results were evaluated at baseline and 3 months after the treatment.

Results

All the patients completed the study protocol. Median age was 59.0 years (55.0–64.0 years). After treatment, the median (interquartile range, IQR) plaque size reduced from 1.78 cm² (1.43–2.17 cm²) to 1.53 cm² (1.31–1.96 cm²) (p<0.001); the median (IQR) penile length in erection increased from 13.0 cm (12.0–14.0 cm) to 14 cm (13.0–15.0 cm) (p<0.001) and the median (IQR) penile curvature from 30.4° (22.2°–35.4°) to 25.0° (20.2°–30.4°) (p<0.001). We also observed a decrease in pain assessed by visual analogue scale (7 vs. 3; p<0.001), an improvement in each of the IIEF sub-domains (p<0.001) and an improvement in all three PD questionnaire domains (p<0.001).

Conclusions

Based on our findings, ESWT could be considered a safe and efficient minimally invasive option for the management of the patients suffering from PD.