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

Molecular genetics of Dupuytren's contracture

Dupuytren's contracture (DC) is a fibroproliferative disorder of the palmar fascia characterised by the digits' flexion contractures and is associated with abnormal build-up of type III collagen. The prevalence of the disease is reported to be highest among Northern European descendants. However, the disease is widespread globally with varying prevalence. DC is a multifactorial disease, having both genetic and environmental factors contributing to the causality of the disease. Over the years, various studies have been conducted to understand the molecular mechanism and genetic aspects of DC but there is a lack of reports on the variants found in the exonic regions. Most reports are backdated making it necessary to re-evaluate the variants to further understand the genetic aetiology of DC. In this review, we first highlight the genetic aspects and previous genetic studies on DC. The report is followed by a discussion on the molecular pathways suggested to be associated with DC and a summary of the genetic variants in the exonic regions found in DC and their connections with the molecular pathways. A total of nine variants were reported originating from six genes comprising three pathways. Most variants reported are involved in the Wnt signalling pathway. Moreover, all variants identified are in European/Caucasian subjects and the variants found in the exonic regions are missense variants. A comparison of these findings with variants from populations of other regions can be conducted to identify the variants with the most occurrence to act as biomarkers or therapeutic targets for DC.

Proteomic Analysis of Dupuytren's Contracture-Derived Sweat Glands Revealed the Synthesis of Connective Tissue Growth Factor and Initiation of Epithelial-Mesenchymal Transition as Major Pathogenetic Events

Dupuytren's contracture (DC) is a chronic and progressive fibroproliferative disorder restricted to the palmar fascia of the hands. Previously, we discovered the presence of high levels of connective tissue growth factor in sweat glands in the vicinity of DC nodules and hypothesized that sweat glands have an important role in the formation of DC lesions. Here, we shed light on the role of sweat glands in the DC pathogenesis by proteomic analysis and immunofluorescence microscopy. We demonstrated that a fraction of sweat gland epithelium underwent epithelial-mesenchymal transition illustrated by negative regulation of E-cadherin. We hypothesized that the increase in connective tissue growth factor expression in DC sweat glands has both autocrine and paracrine effects in sustaining the DC formation and inducing pathological changes in DC-associated sweat glands.

Fibrosis-Associated Signaling Molecules Are Differentially Expressed in Palmar Connective Tissues of Patients with Carpal Tunnel Syndrome and Dupuytren's Disease

Carpal tunnel syndrome (CTS) and Dupuytren's disease (DD) are fibrotic conditions that affect the connective tissue of the hand and limit its functionality. The exact molecular mechanism underlying the fibrosis is unknown, and only some profibrotic factors have been investigated. In this cross-sectional study, we analyzed the expression of FGF signaling pathway molecules associated with fibrotic changes in the palmar fascia and the flexor retinaculum of 15 CTS patients and both clinically affected and unaffected palmar fascia of 15 DD patients, using immunofluorescence techniques. The expression of FGFR1, FGFR2, and CTGF in the blood vessel walls and surrounding connective tissue cells differed significantly between the analyzed groups, with changes in expression present even in clinically unremarkable tissues from DD patients. We also found altered expression of the analyzed factors, as well as TGF-β1 and syndecan-1 in DD-associated sweat glands, possibly implicating their role in the pathophysiology of the disease. The increased expression of profibrotic factors in the clinically unaffected palmar fascia of DD patients may indicate that more extensive excision is needed during surgical treatment, while the profibrotic factors could be potential targets for developing pharmacological therapeutic strategies against DD-associated fibrosis.

Biological Targets for Dupuytren Disease

ABSTRACT

Dupuytren disease is a connective tissue disorder occurring on the palm, causing flexion contractures of fingers. There is a pressing need for therapeutic interventions that can slow, stop, or even incrementally reverse the progression of the disease. Numerous in vitro studies have shed light on cellular and molecular agents that contribute to contractures. This article comprehensively reviews various growth factors that can be targeted to prevent and limit the progression and recurrence of Dupuytren contracture (DC). Fibroblasts are the major cell population that has been reported for the contractures in DC, and they are also known to exacerbate the cytokine production. Limiting the fibroblast function by targeting the growth factor production will be of great benefit in treating DC. This review will focus on the studies that have shown to limit the exaggerated function of fibroblasts by reducing the expression of profibrotic growth factors by using antagonizing agents.

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.

Metabolomics technology and bioinformatics for precision medicine

Precision medicine is rapidly emerging as a strategy to tailor medical treatment to a small group or even individual patients based on their genetics, environment and lifestyle. Precision medicine relies heavily on developments in systems biology and omics disciplines, including metabolomics. Combination of metabolomics with sophisticated bioinformatics analysis and mathematical modeling has an extreme power to provide a metabolic snapshot of the patient over the course of disease and treatment or classifying patients into subpopulations and subgroups requiring individual medical treatment. Although a powerful approach, metabolomics have certain limitations in technology and bioinformatics. We will review various aspects of metabolomics technology and bioinformatics, from data generation, bioinformatics analysis, data fusion and mathematical modeling to data management, in the context of precision medicine.

Assessment of palmar subcutaneous tissue vascularization in patients with Dupuytren’s contracture

AIM

To investigate the structural and functional characteristics of palmar hypodermal tissue vascularization in Dupuytren’s contracture patients of different age groups.

METHODS

Eighty-seven Dupuytren’s contracture patients underwent partial fasciectomy. Twenty-two of them were less than 55 years old (Y-group, n = 22); the others were 55 and older (O-group, n = 65). In surgically excised representative tissue samples, a histomorphometric analysis of the perforating arteries of the palmar aponeurosis and stereologic analysis of hypodermis vascularity were performed. The method of laser flowmetry estimated the microcirculation of the skin of the palm.

RESULTS

Frequency of cases with rapid development of contracture (less than 5 years) was 13.6% in the Y-group and 40% in the O-group, P < 0.05. The external and luminal diameters of perforating arteries in palmar fascia were decreased more severely in Y. The thickness of intima increased three times compared with healthy control, and the intima/media relation also increased, especially in O. Increased numerical and volumetric micro-vessel densities in hypodermis, percentage of large vessels (more than 12 μm in diameter), and percentage of vessels with signs of periadventitial inflammatory infiltration were noted in Y. The percentage of vessels with adventitial fibrosis was greater in O than in Y. Base capillary flow in Y was increased compared to healthy control subjects and to O, and peak capillary flow was increased in comparison with control.

CONCLUSION

Compared to the O-group, Y-group patients exhibited more severe constrictive remodeling of palmar fascia perforating arteries supplying hypodermis but more expressed compensatory changes of its capillarization.

Embryonic Stem Cell-Like Population in Dupuytren's Disease Expresses Components of the Renin-Angiotensin System

The renin-angiotensin system (RAS) mediates cardiac and renal fibrosis. Dupuytren's disease (DD) is a proliferative fibromatosis affecting the hands. This study investigated the expression of the RAS in DD.

METHODS

3,3-Diaminobenzidine (DAB) and immunofluorescent immunohistochemical (IHC) staining for (pro)renin receptor (PRR), angiotensin-converting enzyme (ACE), angiotensin II receptor 1 (ATIIR1), and angiotensin II receptor 2 (ATIIR2) was performed on 4-μm thick formalin-fixed paraffin-embedded sections of DD cords and nodules from 6 patients. Western blotting (WB) and NanoString mRNA analysis were performed to confirm RAS protein expression and transcriptional activation, respectively.

RESULTS

IHC staining demonstrated the expression of PRR, ACE, ATIIR1, and ATIIR2 on the ERG⁺ and CD34⁺ endothelium of the micro vessels surrounding the DD cords and nodules. PRR was also expressed on the pericyte layer of these microvessels. WB confirmed protein expression of PRR, ACE, and ATIIR2 but not ATIIR1. NanoString analysis confirmed transcriptional activation of PRR, ACE, ATIIR1, but ATIIR2 was below detectable levels.

CONCLUSIONS

We demonstrated expression of PRR, ATIIR1, ATIIR2, and ACE on the embryonic stem cell-like cell population on the microvessels surrounding DD nodules and cords by IHC staining, although the expression of ATIIR1 was not confirmed by WB and that of ATIIR2 was below detectable levels on NanoString analysis. These findings suggest the embryonic stem cell-like cell population as a potential therapeutic target for DD, by using RAS modulators.

Evidence-Based Medicine: Options for Dupuytren's Contracture: Incise, Excise, and Dissolve

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand updates in the basic science, epidemiology, and treatment of Dupuytren's disease. 2. Understand treatment with needle aponeurotomy, collagenase, and fasciectomy. 3. Understand advanced needle techniques for Dupuytren's contracture. 4. Understand the safety and effectiveness of a new treatment, collagenase.

SUMMARY

The literature on Dupuytren's disease encompasses many specialties. Its treatment is generally by perforating, excising, or dissolving the affected tissues. This article reviews the changing understanding of this disease and treatment options.

Embryonic Stem Cell-like Population in Dupuytren's Disease

Supplemental Digital Content is available in the text.

Background:

Recent research has identified mesenchymal stem cells (MSCs) within Dupuytren’s disease (DD) tissue and they have been proposed to give rise to the myofibroblasts, implicated in the progression of this condition. The aim of this study was to identify and characterize the primitive population that might be upstream of the MSC population, within DD.

Methods:

Formalin-fixed paraffin-embedded 4-µm-thick sections of DD cords and nodules obtained from 6 patients underwent 3,3-diaminobenzidine and immunofluorescent immunohistochemical staining for embryonic stem cell (ESC) markers OCT4, NANOG, SOX2, pSTAT3, and SALL4 and endothelial markers CD34 and ERG. NanoString gene expression analysis was performed to determine the transcriptional activation of these markers.

Results:

Immunohistochemical staining demonstrated the expression of ESC markers OCT4, NANOG, SOX2, pSTAT3, and SALL4 on the endothelium of the microvessels expressing CD34 and ERG, particularly those surrounding the DD nodules. NanoString analysis confirmed the transcriptional activation of OCT4, NANOG, STAT3, and SALL4, but not SOX2.

Conclusion:

This article demonstrates the novel finding of an ESC-like population expressing ESC markers OCT4, NANOG, SOX2, pSTAT3, and SALL4, localized to the endothelium of the microvessels within DD tissue, suggesting a potential therapeutic target for this condition.

Connective Tissue Degeneration: Mechanisms of Palmar Fascia Degeneration (Dupuytren's Disease)

Dupuytren's disease is a connective tissue disorder of the hand causing excessive palmar fascial fibrosis with associated finger contracture and disability. The aetiology of the disease is heterogeneous, with both genetic and environmental components. The connective tissue is abnormally infiltrated by myofibroblasts that deposit collagen and other extracellular matrix proteins. We describe the clinical profile of Dupuytren's disease along with current therapeutic schemes. Recent findings on molecular and cellular parameters that are dysregulated in Dupuytren's disease, which may contribute to the onset of the disease, and the role of resident inflammation promoting fibrosis, are highlighted. We review recent literature focusing on non-myofibroblast cell types (stem cell-like cells), their pro-inflammatory and pro-fibrotic role that may account for abnormal wound healing response.

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.