An integrated proteomics approach for studying the molecular pathogenesis of Dupuytren's disease

Inflammatory Markers Involved in the Pathogenesis of Dupuytren's Contracture

Dupuytren's disease is a common fibroproliferative disease that can result in debilitating hand deformities. Partial correction and return of deformity are common with surgical or clinical treatments at present. While current treatments are limited to local procedures for relatively late effects of the disease, the pathophysiology of this connective tissue disorder is associated with both local and systemic processes (e.g., fibrosis, inflammation). Hence, a better understanding of the systemic circulation of Dupuytren related cytokines and growth factors may provide important insights into disease progression. In addition, systemic biomarker analysis could yield new concepts for treatments of Dupuytren that attenuate circulatory factors (e.g., anti-inflammatory agents, neutralizing antibodies). Progress in the development of any disease modifying biologic treatment for Dupuytren has been hampered by the lack of clinically useful biomarkers. The characterization of nonsurgical Dupuytren biomarkers will permit disease staging from diagnostic and prognostic perspectives, as well as allows evaluation of biologic responses to treatment. Identification of such markers may transcend their use in Dupuytren treatment, because fibrotic biological processes fundamental to Dupuytren are relevant to fibrosis in many other connective tissues and organs with collagen-based tissue compartments. There is a wide range of potential Dupuytren biomarker categories that could be informative, including disease determinants linked to genetics, collagen metabolism, as well as immunity and inflammation (e.g., cytokines, chemokines). This narrative review provides a broad overview of previous studies and emphasizes the importance of inflammatory mediators as candidate circulating biomarkers for monitoring Dupuytren's disease.

The Molecular Pathogenesis of Dupuytren Disease: Review of the Literature and Suggested New Approaches to Treatment

BACKGROUND

Ever since the classification of Dupuytren disease into the proliferative, involutional, and residual stages, extensive research has been performed to uncover the molecular underpinnings of the disease and develop better treatment modalities for patients. The aim of this article is to systematically review the basic science literature pertaining to Dupuytren disease and suggest a new approach to treatment.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review was conducted using the MEDLINE database to identify basic science literature on Dupuytren pathophysiology falling under 1 or more of the following categories: (1) Molecular alterations, (2) Structural alterations, and (3) Genetic predisposition.

RESULTS

A total of 177 articles were reviewed of which 77 studies met inclusion criteria. Articles were categorized into respective sections outlined in the study methods.

CONCLUSION

The pathophysiological changes involved in Dupuytren's disease can be divided into a number of molecular and structural alterations with genetic predisposition playing a contributory role. Understanding these changes can allow for the development of biologics which may disrupt and halt the disease process.

Blue light irradiation and its beneficial effect on Dupuytren's fibroblasts

Dupuytren's contracture is a fibroproliferative disorder affecting the palmar fascia of the hand. Most affected are the ring fingers, and little fingers of middle-aged men. Symptomatic for this disease is the increased proliferation and differentiation of fibroblasts to myofibroblasts, which is accompanied by an elevated α-SMA expression. The present study evaluated the therapeutic benefit of blue light (λ = 453 nm, 38 mW/cm2, continuous radiance, spot size 10-12 cm2) as well as the molecular mechanism mediating this effect. It could be determined that blue light significantly diminished the induced α-SMA protein expression in both normal palmar fibroblasts and Duypuytren's fibroblasts. The beneficial effect mediated by this irradiance, radiant exposure and wavelength was associated with an elevated reactive oxygen species generation. Furthermore, the data underlines the potential usefulness of blue light irradiation as a promising therapy option for Dupuytren's disease, especially for relapse prevention, and may represent a useful strategy to treat further fibrotic diseases, such as keloids, hypertrophic scarring, and scleroderma.

Alternative and Adjunctive Treatments for Dupuytren Disease

Clinicians struggle with limited efficacy and durability of standard treatments when treating patients with Dupuytren disease diathesis. Alternative treatments such as low-dose radiation therapy in early phase of disease, supplemental pharmacotherapy with anti-inflammatory and/or anti-mitotic drugs, as well as other pharmacologic targets, and more aggressive surgery such as dermofasciectomy all have been reported with variable success or with serious side effects that hamper their standard use. This article gives an overview of the available literature.

Update on the role of molecular factors and fibroblasts in the pathogenesis of Dupuytren's disease

The mechanism by which the fibroblast is able to trigger palmar fibromatosis is still not yet fully understood. It would appear certain that the "abnormal" fibroblasts continuously synthesise profibrotic cytokines which are able to determine the activation to myofibroblasts, to stimulate them to the further proliferation and synthesis of other cytokines, to modify the cells' differentiation and ultrastructural characteristics, as well as the production of matrix and other proteins. Several fibroblast growth factors have been suggested to be responsible of an abnormal cell activation with an aberrantly elevated collagen synthesis and extracellular deposition in Dupuytren's disease, as TGF-Beta, TNF-Alfa, PDGF, GM-CSF, free radicals, metalloproteinases, sex hormones, gene modified expression, mechanical stimulation. The Authors review the current state of knowledge in the field, by analyzing the role of these cytokines in the palmar fibromatosis.

Characterisation of the inflammatory response in Dupuytren's disease

BACKGROUND

Dupuytren's disease is characterised by fibrotic nodule and cord formation in the palmar aponeurosis. The pathophysiology of the disease is still unknown, although cell stress and subsequent activation of immune mechanisms seems to be crucial.

MATERIALS AND METHODS

Surgically obtained tissue and blood samples of 100 Dupuytren patients were processed by immunohistochemistry, flow cytometry, as well as immunoscope analysis. Macroscopically normal aponeurotic tissue served as control.

RESULTS

Locally, microvascular alterations and massive infiltration by mononuclear cells (CD3+, CD4 > CD8, CD45RO > CD45RA, S100 protein, CD56, CD68, scarce CD19 and mast cells) forming perivascular clusters were found in DD tissue. Cytokine profiling of fibromatosis tissue-derived T-cells showed a Th1/TH17-weighted immune response. Immunoscope analysis revealed a restricted T-cell receptor α/β repertoire pointing to an (auto)antigen-driven process.

CONCLUSION

The striking accumulation of immune cells, expression of leukocyte adhesion molecules, as well as pro-inflammatory and pro-fibrotic cytokines near markedly narrowed vessels supports the theory that the abnormal proliferation of fibroblasts and production of extracellular matrix proteins in DD seems to be related to immune-mediated microvascular damage. The restricted T-cell receptor repertoire of intra-lesional T-cells points to an antigen-driven process. T-cells seem to play an important role in the development of Dupuytren's disease.

Inflammatory Gene Expression Upon TGF-β1-Induced p38 Activation in Primary Dupuytren's Disease Fibroblasts

OBJECTIVES

Inflammation is an underlying mechanism behind fibrotic processes and differentiation of cells into myofibroblasts. Presented study therefore provides new data on activation of autoimmune and inflammatory immune response genes that accompany activation of p38 and cell differentiation in primary cells derived from Dupuytren's disease (DD) patients.

METHODS

Primary non-Dupuytren's disease cells (ND) were isolated from macroscopically unaffected palmar fascia adjacent to diseased tissue obtained from patients diagnosed with the last stage of DD and cultured in vitro. Gene expression, collagen gel contraction assay and analysis of secreted proteins were performed in ND cells treated with TGF-β1 and/or inhibitor of p38 phosphorylation.

RESULTS

During differentiation of ND fibroblasts, increased expression of immune response genes PAI-1, TIMP-1, CCL11, and IL-6 was found. These changes were accompanied by increased cell contractility and activation of p38 and its target kinase MK2. Inhibition of p38 phosphorylation reversed these processes in vitro.

CONCLUSIONS

TGF-β1 induced p38 phosphorylation in ND cells grown from macroscopically unaffected palmar fascia adjacent to diseased tissue from DD patients. This was accompanied by activation of the cytokine genes CCL-11 and IL-6 and secretion of extracellular matrix regulatory proteins PAI-1 and TIMP-1. A combined approach directed toward inflammation and p38 MAPK-mediated processes in DD might be considered for improving management of DD patients and prevention of recurrence.

Laminin-rich blood vessels display activated growth factor signaling and act as the proliferation centers in Dupuytren's contracture

INTRODUCTION

Dupuytren's contracture (DC) is a chronic fibroproliferative disease of the hand, which is characterized by uncontrolled proliferation of atypical myofibroblasts at the cellular level. We hypothesized that specific areas of the DC tissue are sustaining the cell proliferation and studied the potential molecular determinants that might contribute to the formation of such niches.

METHODS

We studied the expression pattern of cell proliferation marker Ki67, phosphorylated AKT (Ak mouse strain thymoma) kinase, DC-associated growth factors (connective tissue growth factor (CTGF), basic fibroblast growth factor (bFGF), insulin-like growth factor 2 (IGF-2)) and extracellular matrix components (laminins, fibronectin, collagen IV) in DC tissue and normal palmar fascia using immunofluorescence microscopy and quantitative real-time polymerase chain reaction (qPCR).

RESULTS

We found that proliferative cells in the DC nodules were concentrated in the immediate vicinity of small blood vessels and localized predominantly in the myofibroblast layer. Correspondingly, the DC-associated blood vessels contained increased levels of phosphorylated AKT, a hallmark of activated growth factor signaling. When studying the expression of potential activators of AKT signaling we found that the expression of bFGF was confined to the endothelium of the small blood vessels, IGF-2 was present uniformly in the DC tissue and CTGF was expressed in the DC-associated sweat gland acini. In addition, the blood vessels in DC nodules contained increased amounts of laminins 511 and 521, which have been previously shown to promote the proliferation and stem cell properties of different cell types.

CONCLUSIONS

Based on our findings, we propose that in the DC-associated small blood vessels the presence of growth factors in combination with favorable extracellular matrix composition provide a supportive environment for sustained proliferation of myofibroblasts and thus the blood vessels play an important role in DC pathogenesis.

Screening of candidate genes in fibroblasts derived from patients with Dupuytren's contracture using bioinformatics analysis

Our study aimed to identify candidate genes associated with Dupuytren's contracture (DC) and elucidate their roles in DC development. The microarray data of GSE21221 were downloaded from Gene Expression Omnibus database, including six samples from carpal tunnel-derived fibroblasts and six samples from DC-derived fibroblasts. The differentially expressed genes (DEGs) in DC samples were screened using limma package. GO annotation and KEGG pathway analyses were performed by DAVID online tool. Protein-protein interaction network and expression correlation network were constructed to identify crucial relationships between DEGs. Finally, candidate DC-associated genes were predicted based on comparative toxicogenomics database. A total of 529 DEGs (138 up- and 391 down-regulated) in DC-derived fibroblasts were screened and compared with carpal tunnel-derived fibroblasts. Only ten DC-associated genes, such as neurotrophin 3 (NTF3) and protein kinase C, epsilon (PRKCE), were further screened. In addition, NTF3 was significantly enriched in MAPK signaling pathway, in which other DEGs, such as nuclear receptor subfamily 4, group A, member 1 (NR4A1), fibroblast growth factor 22 (FGF22) and BDNF, were enriched. Besides, NTF3 could co-express with fibrillin 2 (FBN2), and PRKCE could co-express with zinc finger protein 516 (ZNF516), solute carrier organic anion transporter family, member 2A1 (SLCO2A1), chromosome 10 open reading frame 10 (C10orf10) and Kelch domain containing 7A (KLHDC7A). Our study indicates that these DEGs, including NTF3, FBN2, NR4A1, FGF22, BDNF, PRKCE, ZNF516, SLCO2A1, C10orf10 and KLHDC7A, may play important roles in DC development and serve as candidate molecular targets for treating DC.

Microarray analysis of Dupuytren's disease cells: the profibrogenic role of the TGF-β inducible p38 MAPK pathway

BACKGROUND

Dupuytren's disease (DD) is a nodular palmar fibromatosis that causes irreversible permanent contracture of fingers and results in the loss of hand function. Surgery still remains the only available solution for DD patients but cannot permanently cure the disease nor reduce high recurrence rates. With this rationale, we designed a study aimed at an improved understanding of the molecular mechanisms underlying DD. Our major focus was an analysis of the global gene expression profile and signalling pathways in DD cells with the aim of identifying novel biomarkers and/or therapeutic targets.

METHODS

Primary cells were cultured from surgically removed diseased and healthy tissue. Microarray expression analysis (HG-U133A array, Affymetrix) and qPCR was performed with total RNA isolated from primary DD cells. Mechanistic studies involving inhibition of p38 phosphorylation were performed on normal human fibroblasts' and primary DD cells' in vitro models. Expression of stem cell markers in primary fibroblasts/myofibroblasts was assessed as well.

RESULTS

We identified 3 p38MAPK signalling pathway regulatory genes, THBS1, GADD45α and NUAK1, all involved in cellular proliferation and production of the extracellular matrix proteins. Inhibition of the p38MAPK signalling pathway induced down-regulation of myofibroblast markers, α-smooth muscle actin and palladin. A stem-cell like subpopulation positive for CD90 marker was identified among primary DD cells.

CONCLUSION

The study reveals involvement of the p38 MAPK pathway as a possible signalling cascade in the pathogenesis of Dupuytren's disease. Moreover, a particular stem cell-like CD90(+) subpopulation was identified that might contribute to DD development.

Fibroblasts from phenotypically normal palmar fascia exhibit molecular profiles highly similar to fibroblasts from active disease in Dupuytren's Contracture

BACKGROUND

Dupuytren's contracture (DC) is a fibroproliferative disorder characterized by the progressive development of a scar-like collagen-rich cord that affects the palmar fascia of the hand and leads to digital flexion contractures. DC is most commonly treated by surgical resection of the diseased tissue, but has a high reported recurrence rate ranging from 27% to 80%. We sought to determine if the transcriptomic profiles of fibroblasts derived from DC-affected palmar fascia, adjacent phenotypically normal palmar fascia, and non-DC palmar fascial tissues might provide mechanistic clues to understanding the puzzle of disease predisposition and recurrence in DC.

METHODS

To achieve this, total RNA was obtained from fibroblasts derived from primary DC-affected palmar fascia, patient-matched unaffected palmar fascia, and palmar fascia from non-DC patients undergoing carpal tunnel release (6 patients in each group). These cells were grown on a type-1 collagen substrate (to better mimic their in vivo environments). Microarray analyses were subsequently performed using Illumina BeadChip arrays to compare the transcriptomic profiles of these three cell populations. Data were analyzed using Significance Analysis of Microarrays (SAM v3.02), hierarchical clustering, concordance mapping and Venn diagram.

RESULTS

We found that the transcriptomic profiles of DC-disease fibroblasts and fibroblasts from unaffected fascia of DC patients exhibited a much greater overlap than fibroblasts derived from the palmar fascia of patients undergoing carpal tunnel release. Quantitative real time RT-PCR confirmed the differential expression of select genes validating the microarray data analyses. These data are consistent with the hypothesis that predisposition and recurrence in DC may stem, at least in part, from intrinsic similarities in the basal gene expression of diseased and phenotypically unaffected palmar fascia fibroblasts. These data also demonstrate that a collagen-rich environment differentially alters gene expression in these cells. In addition, Ingenuity pathway analysis of the specific biological pathways that differentiate DC-derived cells from carpal tunnel-derived cells has identified the potential involvement of microRNAs in this fibroproliferative disorder.

CONCLUSIONS

These data show that the transcriptomic profiles of DC-disease fibroblasts and fibroblasts from unaffected palmar fascia in DC patients are highly similar, and differ significantly from the transcriptomic profiles of fibroblasts from the palmar fascia of patients undergoing carpal tunnel release.

Using functional genomics to identify drug targets: a Dupuytren's disease example

Research into the molecular mechanism of Dupuytren's disease (DD) illustrates all the problems common to drug discovery in orphan diseases, but also in more commonly investigated ailments. Current findings characterize DD as a disease with complex molecular pathology, with changes in expression of multiple genes and proteins as well as many contributing risk factors. Some of the observed changes include genes and proteins that have been identified in a number of other pathological processes, such as TGF-β, some which may be more specific to DD, such as ADAM12, and undoubtedly also some that have yet to be discovered in future studies. When all these results are taken into consideration, it can be deduced that DD is an end result of several pathological processes that can have many points of origin, and probably involves several subtypes that give rise to sufficiently similar clinical symptoms to be unified under a single medical term. Such breadth of view has become possible with the advent of functional genomics methods and system-wide overview of the molecular processes, which highlight molecular players and processes that might not be intuitively obvious from symptoms, as is the case with the observed parallels with wound-healing processes. As functional genomics methods allow researchers to compile a more complete image of the molecular mechanisms involved in DD pathogenesis, they also help to propose new drug targets that can be employed to develop an effective pharmacological treatment for DD. Identification of key molecular players in DD has already benefited from the integration of functional genomics and biocomputational methods, and such approach may reveal new ways how we can interfere with the emergence of the DD phenotype.

Dupuytren's: a systems biology disease

Dupuytren's disease (DD) is an ill-defined fibroproliferative disorder of the palm of the hands leading to digital contracture. DD commonly occurs in individuals of northern European extraction. Cellular components and processes associated with DD pathogenesis include altered gene and protein expression of cytokines, growth factors, adhesion molecules, and extracellular matrix components. Histology has shown increased but varying levels of particular types of collagen, myofibroblasts and myoglobin proteins in DD tissue. Free radicals and localised ischaemia have been suggested to trigger the proliferation of DD tissue. Although the existing available biological information on DD may contain potentially valuable (though largely uninterpreted) information, the precise aetiology of DD remains unknown. Systems biology combines mechanistic modelling with quantitative experimentation in studies of networks and better understanding of the interaction of multiple components in disease processes. Adopting systems biology may be the ideal approach for future research in order to improve understanding of complex diseases of multifactorial origin. In this review, we propose that DD is a disease of several networks rather than of a single gene, and show that this accounts for the experimental observations obtained to date from a variety of sources. We outline how DD may be investigated more effectively by employing a systems biology approach that considers the disease network as a whole rather than focusing on any specific single molecule.

[Dupuytren's disease: state of knowledge and research in physiopathology]

From Baron Dupuytren's historical description up to the advent of molecular biology, many hypotheses about the etiology of Dupuytren's disease have been proposed. This bibliography of the last ten years' publications describes tissue anomalies from the macroscopic down to the ultrastructural level of pathology. The myofibroblast, which is the principal cell of the disease, is the seat of genetics anomalies involving proto-oncogenes (c-myc and MafB). Similarly, glycoproteins implicated in cellular adhesion like fibronectins and catenins are modified and overexpressed in the disease. Extracellular proteins of the metalloproteinase family exhibit many dysfunctions responsible for collagenic proliferation. Finally, growth factors like Transforming Growth Factor (TGF) and Epidermal Growth Factor (EGF) receptor maintain and worsen the disease and could be therapeutic targets in the future.

Unique microRNA profile in Dupuytren's contracture supports deregulation of β-catenin pathway

Dupuytren's contracture, a proliferative disease of unknown origin, is characterized by an abnormal fibroblast proliferation process. Evidence from numerous microRNA (miRNA) studies shows that miRNAs have a vital function in many biological processes, for instance, in cellular signaling networks, cell growth, tissue differentiation, and cell proliferation. Our aim was to characterize, to our knowledge for the first time, the miRNA-expression profile of Dupuytren's contracture. The miRNAs identified may have a function in the pathogenesis of Dupuytren's contracture by targeting and regulating important pathways. We compared the miRNA-expression profile of 29 Dupuytren's contracture patients with that of control samples (fibroblast cells and palmar fascia). Some of the miRNAs identified in our Dupuytren's contracture samples, including miR-29c, miR-130b, miR-101, miR-30b, and miR-140-3p, were found to regulate important genes related to the β-catenin pathway: WNT5A, ZIC1, and TGFB1. Expression profiles of these genes reanalyzed from published gene-expression data from similar patient material correlated with our miRNA results. Analysis was also performed for groups of patients with recurrent/non-recurrent and patients with hereditary/non-hereditary Dupuytren's contracture, but no significant differences appeared in miRNA-expression profiles of these groups. Identification of unique miRNA expression in Dupuytren's contracture may lead to the development of novel molecular therapy for its treatment.

Molecular mechanisms and treatment strategies for Dupuytren's disease

Dupuytren’s disease (DD) is a common disease of the hand and is characterized by thickening of the palmar fascia and formation of tight collagenous disease cords. At present, the disease is incurable and the molecular pathophysiology of DD is unknown. Surgery remains the most commonly used treatment for DD, but this requires extensive postoperative therapy and is associated with high rates of recurrence. Over the past decades, more indepth exploration of the molecular basis of DD has raised the hopes of developing new treatment modalities. This paper reviews the clinical presentation and molecular pathophysiology of this disease, as well as current and emerging treatment. It also explores the implications of new findings in the laboratory for future treatment.

Antifibrotic medication using a combination of N-acetyl-L-cystein (NAC) and ACE inhibitors can prevent the recurrence of Dupuytren's disease

Dupuytren's disease is a progress fibromatosis of unknown origin first described in 1831. Nonoperative treatment options have been suggested involving radiation therapy, vitamin E, local injection therapy suing calcium channel blockers, interferon, corticosteroids or collagenase. Transforming growth factor-beta1 (TGF-beta1) and its downstream Smad signalling system is well established as a key player during fibrogenesis. A number of in vitro experiments have been assessed the blockade of TGF-beta1 and TGF-beta 2. Clinically, a number of antifibrotic agents are available such as N-acetyl-L-cysteins (NAC) as well as angiotensin-converting enzyme (ACE) inhibitors or AT II antagonists. However, to date none of the well known substances has been tested clinically in fibromatosis such as Dupuytren's disease especially to prevent recurrences after surgical release. Antifibrotic medication using a combination of N-acetyl-L-cystein (NAC) and ACE inhibitor can prevent the recurrence of Dupyutren's disease. Given the fact that recurrence rate in Dupuytren's disease is high and unpredictable after surgical release, an antifibrotic intervention might be worthwhile to consider in the clinical setting. Antifibrotic agents inhibit TGF-beta1, which play a key role in fibromatosis. Thus, antifibrotic medication might reduce the recurrence rate in fibromatosis such as Dupuytren's disease in a clinical significant way.