Unraveling the signaling pathways promoting fibrosis in Dupuytren's disease reveals TNF as a therapeutic target

Alterations in the Structure, Composition, and Organization of Galactosaminoglycan-Containing Proteoglycans and Collagen Correspond to the Progressive Stages of Dupuytren's Disease

Dupuytren's disease (DD) is a prevalent fibroproliferative disorder of the hand, shaped by genetic, epigenetic, and environmental influences. The extracellular matrix (ECM) is a complex assembly of diverse macromolecules. Alterations in the ECM's content, structure and organization can impact both normal physiological functions and pathological conditions. This study explored the content and organization of glycosaminoglycans, proteoglycans, and collagen in the ECM of patients at various stages of DD, assessing their potential as prognostic indicators. This research reveals, for the first time, relevant changes in the complexity of chondroitin/dermatan sulfate structures, specifically an increase of disaccharides containing iduronic acid residues covalently linked to either N-acetylgalactosamine 6-O-sulfated or N-acetylgalactosamine 4-O-sulfated, correlating with the disease's severity. Additionally, we noted an increase in versican expression, a high molecular weight proteoglycan, across stages I to IV, while decorin, a small leucine-rich proteoglycan, significantly diminishes as DD progresses, both confirmed by mRNA analysis and protein detection via confocal microscopy. Coherent anti-Stokes Raman scattering (CARS) microscopy further demonstrated that collagen fibril architecture in DD varies importantly with disease stages. Moreover, the urinary excretion of both hyaluronic and sulfated glycosaminoglycans markedly decreased among DD patients.Our findings indicate that specific proteoglycans with galactosaminoglycan chains and collagen arrangements could serve as biomarkers for DD progression. The reduction in glycosaminoglycan excretion suggests a systemic manifestation of the 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.

β1 integrin signaling governs necroptosis via the chromatin-remodeling factor CHD4

Fibrosis, characterized by sustained activation of myofibroblasts and excessive extracellular matrix (ECM) deposition, is known to be associated with chronic inflammation. Receptor-interacting protein kinase 3 (RIPK3), the central kinase of necroptosis signaling, is upregulated in fibrosis and contributes to tumor necrosis factor (TNF)-mediated inflammation. In bile-duct-ligation-induced liver fibrosis, we found that myofibroblasts are the major cell type expressing RIPK3. Genetic ablation of β1 integrin, the major profibrotic ECM receptor in fibroblasts, not only abolished ECM fibrillogenesis but also blunted RIPK3 expression via a mechanism mediated by the chromatin-remodeling factor chromodomain helicase DNA-binding protein 4 (CHD4). While the function of CHD4 has been conventionally linked to the nucleosome-remodeling deacetylase (NuRD) and CHD4-ADNP-HP1(ChAHP) complexes, we found that CHD4 potently repressed a set of genes, including Ripk3, with high locus specificity but independent of either the NuRD or the ChAHP complex. Thus, our data uncover that β1 integrin intrinsically links fibrotic signaling to RIPK3-driven inflammation via a novel mode of action of CHD4.

C-X-C domain ligand 14-mediated stromal cell-macrophage interaction as a therapeutic target for hand dermal fibrosis

Dupuytren's contracture, a superficial dermal fibrosis, causes flexion contracture of the affected finger, impairing hand function. Specific single-nucleotide polymorphisms within genes in the Wnt signalling pathway are associated with the disease. However, the precise role of Wnt signalling dysregulation in the onset and progression of Dupuytren's contracture remains unclear. Here, using a fibrosis mouse model and clinical samples of human Dupuytren's contractures, we demonstrate that the activation of Wnt/β-catenin signalling in Tppp3-positive cells in the dermis of the paw is associated with the development of fibrosis. Fibrosis development and progression via Wnt/β-catenin signalling are closely related to stromal cell-macrophage interactions, and Wnt/β-catenin signalling activation in Tppp3-positive stromal cells causes M2 macrophage infiltration via chemokine Cxcl14, resulting in the formation of a TGF-β-expressing fibrotic niche. Inhibition of Cxcl14 mitigates fibrosis by decreasing macrophage infiltration. These findings suggest that Cxcl14-mediated stromal cell-macrophage interaction is a promising therapeutic target for Wnt/β-catenin-induced fibrosis.

Let's Focus on the Fibrosis in Dupuytren Disease: Cell Communication Network Factor 2 as a Novel Target

Dupuytren disease is a progressive, benign fibroproliferative disorder of the hands that can lead to debilitating hand contractures. Once symptomatic, treatment involves either surgical intervention, specifically fasciectomy or percutaneous needle aponeurotomy, or enzymatic degradation with clostridial collagenase. Currently, collagenase is the only pharmacotherapy that has been approved for the treatment of Dupuytren contracture. There is a need for a pharmacotherapeutic that can be administered to limit disease progression and prevent recurrence after treatment. Targeting the underlying fibrotic pathophysiology is critical. We propose a novel target to be considered in Dupuytren disease-cell communication network factor 2/connective tissue growth factor-an established mediator of musculoskeletal tissue fibrosis.

Advanced Dupuytren Contracture: Approach to Management

Dupuytren disease is a common pathologic condition that can be especially challenging to hand surgeons in recurrent or severe contractures. Recurrence risk may be reduced with a variety of techniques, including skin grafting, external fixator application, radiation, and many others described in this article. Management of recurrence requires special attention to anatomy at risk. Adjuvant therapy may help to prevent the progression or recurrence of severe disease.

Pharmacotherapies in Dupuytren Disease: Current and Novel Strategies

Dupuytren disease is a benign, progressive fibroproliferative disorder of the hands. To date, only one pharmacotherapy (clostridial collagenase) has been approved for use in Dupuytren disease. There is a great need for additional nonsurgical methods that can be used to either avoid the risks of invasive treatments or help minimize recurrence rates following treatment. A number of nonsurgical modalities have been discussed in the past and continue to appear in discussions among hand surgeons, despite highly variable and often poor or no long-term clinical data. This article reviews many of the pharmacotherapies discussed in the treatment of Dupuytren disease and novel therapies used in inflammation and fibrosis that offer potential treatment options.

Dupuytren's contracture-associated SNPs increase SFRP4 expression in non-immune cells including fibroblasts to enhance inflammation development

Dupuytren's contracture (DC) is an inflammatory fibrosis characterized by fibroproliferative disorders of the palmar aponeurosis, for which there is no effective treatment. Although several genome-wide association studies have identified risk alleles associated with DC, the functional linkage between these alleles and the pathogenesis remains elusive. We here focused on two single nucleotide polymorphisms (SNPs) associated with DC, rs16879765 and rs17171229, in secreted frizzled related protein 4 (SFRP4). We investigated the association of SRFP4 with the IL-6 amplifier, which amplifies the production of IL-6, growth factors and chemokines in non-immune cells and aggravates inflammatory diseases via NF-κB enhancement. Knockdown of SFRP4 suppressed activation of the IL-6 amplifier in vitro and in vivo, whereas the overexpression of SFRP4 induced the activation of NF-κB-mediated transcription activity. Mechanistically, SFRP4 induced NF-κB activation by directly binding to molecules of the ubiquitination SFC complex, such as IkBα and βTrCP, followed by IkBα degradation. Furthermore, SFRP4 expression was significantly increased in fibroblasts derived from DC patients bearing the risk alleles. Consistently, fibroblasts with the risk alleles enhanced activation of the IL-6 amplifier. These findings indicate that the IL-6 amplifier is involved in the pathogenesis of DC, particularly in patients harboring the SFRP4 risk alleles. Therefore, SFRP4 is a potential therapeutic target for various inflammatory diseases and disorders, including DC.

TNF superfamily control of tissue remodeling and fibrosis

Fibrosis is the result of extracellular matrix protein deposition and remains a leading cause of death in USA. Despite major advances in recent years, there remains an unmet need to develop therapeutic options that can effectively degrade or reverse fibrosis. The tumor necrosis super family (TNFSF) members, previously studied for their roles in inflammation and cell death, now represent attractive therapeutic targets for fibrotic diseases. In this review, we will summarize select TNFSF and their involvement in fibrosis of the lungs, the heart, the skin, the gastrointestinal tract, the kidney, and the liver. We will emphasize their direct activity on epithelial cells, fibroblasts, and smooth muscle cells. We will further report on major clinical trials targeting these ligands. Whether in isolation or in combination with other anti-TNFSF member or treatment, targeting this superfamily remains key to improve efficacy and selectivity of currently available therapies for fibrosis.

Anti-TNF (adalimumab) injection for the treatment of adults with frozen shoulder during the pain predominant stage protocol for a multi-centre, randomised, double blind, parallel group, feasibility trial

Objectives

The Anti-Freaze-F trial will assess the feasibility of conducting a large randomised controlled trial to assess whether intra-articular injection of anti-TNF (adalimumab) can reduce pain and improve function in people with pain predominant early stage frozen shoulder.

Methods and analysis

We are conducting a multi-centre, randomised feasibility study, with an embedded qualitative sub-study. We will recruit adults ≥18 years with a new episode of shoulder pain attributable to early stage frozen shoulder, recruited from at least five UK NHS musculoskeletal and related physiotherapy services. Participants (n=84) will be randomised (centralised computer generated 1:1 allocation) to receive either: 1) intra-articular injection of anti-TNF (adalimumab 160mg) or 2) placebo injection (saline [0.9% sodium chloride]), both under ultrasound guidance. A second injection of the allocated treatment (adalimumab 80mg) or equivalent volume of placebo will be administered 2-3 weeks later. All participants will receive a physiotherapy advice leaflet providing education and advice about frozen shoulder and pain management. The primary feasibility objectives are: 1) the ability to screen and identify potential participants with pain predominant early stage frozen shoulder; 2) willingness of eligible participants to consent and be randomised to intervention; 3) practicalities of delivering the intervention, including time to first injection and number of participants receiving second injection; 4) standard deviation of the Shoulder Pain and Disability Index (SPADI) score and attrition rate at 3 months (i.e. 12 weeks) post-randomisation in order to estimate the sample size for a definitive trial. We will also assess follow up rates and viability of patient-reported outcome measures and range of shoulder motion for a definitive trial. Research Ethics Committee approval (REC 21/NE/0214).

Trial registration number

ISRCTN 27075727; EudraCT number: 2021-003509-23; ClinicalTrials.gov NCT05299242.

Dupuytren's disease: a localised and accessible human fibrotic disorder

We review the biology of Dupuytren's disease (DD), a common localised fibrotic disorder of the hand. The disease develops through a complex interplay of genetic and environmental factors, and epigenetic signalling. The early-stage disease nodules comprise a complex milieu of stromal and immune cells which interact to promote disease development. Recently, inhibition of tumour necrosis factor (TNF) locally resulted in softening and a decrease in nodule size, potentially controlling disease progression. Unlike fibrotic disorders of the visceral organs, the easy access to tissue in DD patients enables dissection of the cellular landscape and molecular signalling pathways. In addition, the study of DD may have wider benefits in enhancing our understanding of less-accessible fibrotic tissues.

Treatments for early-stage Dupuytren's disease: an evidence-based approach

Current treatments for Dupuytren's disease are limited to late-stage disease when patients have developed flexion contractures and have impaired hand function. They all have limitations, including the risk of recurrence and complications. The use of treatments for early-stage disease, such as intralesional steroid injections or radiotherapy which lack a clear biological basis or evidence of effectiveness based robust randomized, double blind, placebo-controlled trials, highlights the desire of patients to access treatments before they develop significant flexion contractures. A detailed understanding of the cellular landscape and molecular signalling in nodules of early-stage disease would permit the identification of potential therapeutic targets. This approach led to the identification of tumour necrosis factor (TNF) as a target. A phase 2a clinical trial identified 40 mg in 0.4 mL adalimumab as the most efficacious dose and a subsequent randomized, double blind, placebo-controlled phase 2b trial showed that four intranodular injections at 3-month intervals resulted in decrease in nodule hardness and size on ultrasound scan at 12 months, and both parameters continued to decrease further at 18 months, 9 months after the final injection. This type of approach provides clinicians with a robust evidence base for advising their patients.

Why does understanding the biology of fibroblasts in immunity really matter?

Fibroblasts are known for their ability to make and modify the extracellular matrix. However, there is more to them than meets the eye. It is now clear that they help define tissue microenvironments and support immune responses in organs. As technology advances, we have started to uncover the secrets of fibroblasts. In this Essay, we present fibroblasts as not only the builders and renovators of tissue environments but also the rheostat cells for immune circuits. Although they perform location-specific functions, they do not have badges of fixed identity. Instead, they display a spectrum of functional states and can swing between these states depending on the needs of the organ. As fibroblasts participate in a range of activities both in health and disease, finding the key factors that alter their development and functional states will be an important goal to restore homeostasis in maladapted tissues.

Melanocortin therapies to resolve fibroblast-mediated diseases

Stromal cells have emerged as central drivers in multiple and diverse diseases, and consequently, as potential new cellular targets for the development of novel therapeutic strategies. In this review we revise the main roles of fibroblasts, not only as structural cells but also as players and regulators of immune responses. Important aspects like fibroblast heterogeneity, functional specialization and cellular plasticity are also discussed as well as the implications that these aspects may have in disease and in the design of novel therapeutics. An extensive revision of the actions of fibroblasts on different conditions uncovers the existence of numerous diseases in which this cell type plays a pathogenic role, either due to an exacerbation of their 'structural' side, or a dysregulation of their 'immune side'. In both cases, opportunities for the development of innovative therapeutic approaches exist. In this regard, here we revise the existing evidence pointing at the melanocortin pathway as a potential new strategy for the treatment and management of diseases mediated by aberrantly activated fibroblasts, including scleroderma or rheumatoid arthritis. This evidence derives from studies involving models of in vitro primary fibroblasts, in vivo models of disease as well as ongoing human clinical trials. Melanocortin drugs, which are pro-resolving mediators, have shown ability to reduce collagen deposition, activation of myofibroblasts, reduction of pro-inflammatory mediators and reduced scar formation. Here we also discuss existing challenges, both in approaching fibroblasts as therapeutic targets, and in the development of novel melanocortin drug candidates, that may help advance the field and deliver new medicines for the management of diseases with high medical needs.

Sustained AWT1 expression by Dupuytren's disease myofibroblasts promotes a proinflammatory milieu

Palmar fibromatosis, also known as Dupuytren's disease (DD), is a common and heritable fibrosis of the hand. It is characterized by the formation of myofibroblastic nodules that can progress to palmar-digital contractures and permanent loss of dexterity. The presence of inflammatory cell infiltrate within these nodules has been interpreted to suggest a pathogenesis mediated by a proinflammatory microenvironment. However, the molecular mechanisms driving the formation of pro-fibrotic microenvironments in this and other fibroses remain unclear. To gain insights into this process, we have assessed the contributions of an alternatively spliced, multi-functional transcription factor, Wilms Tumor 1 (WT1), previously shown to be upregulated in primary myofibroblasts derived from DD tissues. Proinflammatory cytokine stimuli of DD myofibroblasts enhanced the expression of several distinct WT1 variants, the most sustained being a 5' truncated version of WT1, alternative WT1 (AWT1). Constitutive adenoviral expression of AWT1 in myofibroblasts derived from phenotypically non-fibrotic palmar fascia significantly induced the expression and secretion of proinflammatory cytokines, including some with potential as novel therapeutic targets. In summary, these data implicate roles for sustained AWT1 expression in DD as a transcriptional driver of a proinflammatory fascial milieu.

Cost-effectiveness of adalimumab for early-stage Dupuytren’s disease

Aims

To estimate the potential cost-effectiveness of adalimumab compared with standard care alone for the treatment of early-stage Dupuytren’s disease (DD) and the value of further research from an NHS perspective.

Methods

We used data from the Repurposing anti-TNF for Dupuytren’s disease (RIDD) randomized controlled trial of intranodular adalimumab injections in patients with early-stage progressive DD. RIDD found that intranodular adalimumab injections reduced nodule hardness and size in patients with early-stage DD, indicating the potential to control disease progression. A within-trial cost-utility analysis compared four adalimumab injections with no further treatment against standard care alone, taking a 12-month time horizon and using prospective data on EuroQol five-dimension five-level questionnaire (EQ-5D-5L) and resource use from the RIDD trial. We also developed a patient-level simulation model similar to a Markov model to extrapolate trial outcomes over a lifetime using data from the RIDD trial and a literature review. This also evaluated repeated courses of adalimumab each time the nodule reactivated (every three years) in patients who initially responded.

Results

The within-trial economic evaluation found that adalimumab plus standard care cost £503,410 per quality-adjusted life year (QALY) gained versus standard care alone over a 12-month time horizon. The model-based extrapolation suggested that, over a lifetime, repeated courses of adalimumab could cost £14,593 (95% confidence interval £7,534 to £42,698) per QALY gained versus standard care alone. If the NHS was willing to pay £20,000/QALY gained, there is a 77% probability that adalimumab with retreatment is the best value for money.

Conclusion

Repeated courses of adalimumab are likely to be a cost-effective treatment for progressive early-stage DD. The value of perfect parameter information that would eliminate all uncertainty around the parameters estimated in RIDD and the duration of quiescence was estimated to be £105 per patient or £272 million for all 2,584,411 prevalent cases in the UK. Cite this article: Bone Jt Open 2022;3(11):898–906.

A role for metformin in the treatment of Dupuytren disease?

Dupuytren disease (DD) is a hand-localized fibrotic disorder characterized by a scar-like, collagen-rich cord. Treatment usually comprises surgical removal of the cord, but is associated with a high relapse rate, in some cases requiring finger amputation. There is currently no consensual medical approach for treating DD. Numerous preclinical studies have highlighted antifibrotic properties of metformin, and the aim of this study was to assess a potential antifibrotic role of metformin in DD. Fibroblasts from DD cords (DF) and phenotypically normal palmar fascia (PF) were extracted from surgical specimens and cultured. The fibrotic status of DF and PF was compared at baseline, and under profibrotic (TGF-β stimulation) and antifibrotic (metformin stimulation) conditions, using quantitative RT-PCR, western blot, immunocytochemistry, and a functional fibroblast contraction assay. At baseline, DF showed higher levels of fibrotic markers and contraction capacity compared with PF. Both types of fibroblasts responded to TGF-β stimulation. Treatment of DF and PF with metformin did not affect basal levels of fibrotic markers and contraction but largely prevented their induction by TGF-β. In conclusion, our data show that metformin inhibits TGF-β-induced expression of fibrotic markers and contraction in hand-derived fibroblasts. This supports the case for a clinical trial to assess the repurposing of metformin as an adjuvant to surgery, to prevent, reduce, or delay recurrence in at-risk DD patients.

Anti-tumour necrosis factor therapy for early-stage Dupuytren's disease (RIDD): a phase 2b, randomised, double-blind, placebo-controlled trial

Background

Dupuytren’s disease is a common fibrotic condition that causes the fingers to flex irreversibly into the palm. Treatments for late-stage disease all have limitations, and there is no approved treatment for early-stage disease. We identified tumour necrosis factor as a therapeutic target in Dupuytren’s disease, and in a dose ranging trial found 40 mg adalimumab in 0·4 mL to be most efficacious. Here we aimed to assess the effects of intranodular injection of adalimumab in early-stage disease.

Methods

In this phase 2b, randomised, double-blind, placebo-controlled trial adults with early-stage Dupuytren’s disease and an established clinically distinct nodule with a clear history of progression in the preceding 6 months were recruited from two clinical centres in the UK and were randomly assigned 1:1 to receive four injections of adalimumab or saline every 3 months. Participants and assessors were masked. The primary outcome was nodule hardness measured with a durometer at 12 months. Data were analysed by linear mixed effects regression models in the intention-to-treat population with multiple imputation for missing primary outcome data. The trial is registered at the ISRCTN registry, ISRCTN 27786905 and is complete.

Findings

Between Feb 17, 2017, and Jan 11, 2019, 284 participants were screened in the UK and 140 were enrolled. 47 (34%) participants were female and 93 (66%) were male. Mean age of participants was 59·7 years (SD 10·0). Primary outcome data were available from 113 participants. Nodule hardness was lower (−4·6 AU [95% CI −7·1 to −2·2], p=0·0002) in the adalimumab compared with the saline group at 12 months. There were no related serious adverse events; the most common adverse events were minor injection site reactions.

Interpretation

Intranodular injections of adalimumab in participants with early-stage Dupuytren’s disease resulted in softening and reduction in size of the nodules. Longer follow-up would be required to assess the effect of tumour necrosis factor inhibition on disease progression, extension deficit and hand function.

Disease Course of Primary Dupuytren Disease: 5-Year Results of a Prospective Cohort Study

BACKGROUND

Predicting progression of Dupuytren disease becomes relevant in an upcoming era with progression-preventing treatment. This study aimed to determine the course of Dupuytren disease and identify factors associated with progression.

METHODS

Two hundred fifty-eight patients with Dupuytren disease participated in this prospective cohort study, obtaining 17,645 observations in 5 years. Outcomes were disease extent (surface area) and contracture severity (total passive extension deficit). Demographics, lifestyle, health status, exposure to manual work, and genetic risk scores were gathered as potential predictors. Subject-specific, mixed-effects models were used to estimate disease course, and logistic regression with least absolute shrinkage and selection operator was used to evaluate factors associated with the presence of progression.

RESULTS

On average, Dupuytren disease was progressive in all finger rays with regard to area [yearly increase, 0.07 cm2 (95% CI, 0.02 to 0.13 cm2) to 0.25 cm2 (95% CI, 0.11 to 0.39 cm2)]. Progression in total passive extension deficit was only present on the small finger side [yearly increase, 1.75 degrees (95% CI, 0.30 to 3.20 degrees) to 6.25 degrees (95% CI, 2.81 to 9.69 degrees)]. Stability or regression in area and total passive extension deficit was observed in 11 and 13 percent and 16 and 15 percent (dominant and nondominant hands), respectively. Smoking, cancer, genetic risk score, and hand injury were univariate associated with progression in area, but after multivariate variable selection, none of these associations remained. No predictors for progression in total passive extension deficit were found.

CONCLUSIONS

Dupuytren disease is progressive, especially with respect to disease extent. Progression in contracture severity is mainly present on the small finger side of the hand. None of the traditional risk and diathesis factors were associated with progression, indicating that new hypotheses about Dupuytren disease progression might be needed.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Study on the Action Mechanism of Dkk-1, TGF-β1 and TNF-α Expression Levels in Dupuytren's Contracture

BACKGROUND

The biological mechanism of Dupuytren's contracture needs to be further studied in order to minimize postoperative recurrence and provide a pathological basis for the development of new therapeutic targets.

METHODS

HE staining, immunohistochemistry, PCR and western blotting were performed in pathological palmar aponeurosis specimens and normal palmar aponeurosis tissues for comparative study.

RESULTS

(1) TNF-α expression was up-regulated: TNF-α mRNA was more highly expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (2) Dkk-1 expression was down-regulated: Dkk-1 mRNA was lower expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (3) TGF-β1 expression was up-regulated: TGF-β1 mRNA was higher expressed in the pathological tissues of DD patients than in the CT group, P < 0.05, and the difference between the two groups was statistically significant; (4) Pearson correlation analysis suggested that TNF-α expression was positively correlated with TGF-β1 expression, TNF-α expression was negatively correlated with DKK-1 expression, and TGF-β1 expression was negatively correlated with DKK-1 expression.

CONCLUSION

TNF-α, DKK-1 and TGF-β1 may play a role in the pathogenesis of palmar aponeurosis contracture, and there is a relationship between them. The study of the relationship between the three and their related signaling pathways provides a therapeutic target and a basis for the prevention and early treatment of palmar aponeurotic contracture.

The Deep Fascia and its Role in Chronic Pain & Pathological Conditions: A Review

INTRODUCTION

The deep fascia is a three-dimensional continuum of connective tissue surrounding the bones, muscles, nerves and blood vessels throughout our body. Its importance in chronically debilitating conditions has recently been brought to light. This work investigates changes in these tissues in pathological settings.

MATERIALS AND METHODS

A state-of-the-art review was conducted in PubMed and Google Scholar following a two-stage process. A first search was performed to identify main types of deep fasciae. A second search was performed to identify studies considering a deep fascia, common pathologies of this deep fascia and the associated alterations in tissue anatomy.

RESULTS

We find that five main deep fasciae pathologies are chronic low back pain, chronic neck pain, Dupuytren's disease, plantar fasciitis and iliotibial band syndrome. The corresponding fasciae are respectively the thoracolumbar fascia, the cervical fascia, the palmar fascia, the plantar fascia and the iliotibial tract. Pathological fascia is characterized by increased tissue stiffness along with alterations in myofibroblast activity and the extra-cellular matrix, both in terms of collagen and Matrix Metalloproteases (MMP) levels. Innervation changes such as increased density and sensitization of nociceptive nerve fibers are observed. Additionally, markers of inflammation such as pro-inflammatory cytokines and immune cells are documented. Pain originating from the deep fascia likely results from a combination of increased nerve density, sensitization and chronic nociceptive stimulation, whether physical or chemical.

CONCLUSIONS

The pathological fascia is characterized by changes in innervation, immunology and tissue contracture. Further investigation is required to best benefit both research opportunities and patient care.

A vasculature niche orchestrates stromal cell phenotype through PDGF signaling: Importance in human fibrotic disease

Tissue fibrotic diseases, for example of the liver and lung, represent a huge unmet medical need. In this study, using single-cell RNA sequencing, cytometry by time of flight (CyTOF), tissue imaging, and functional assays, we identify a complex vascular niche in Dupuytren’s disease (DD), a common localized fibrotic condition of the palm, where early-disease-stage tissue can be accessed readily. We uncover a population of myofibroblast precursors within the pericyte compartment and demonstrate that the endothelium instructs the differentiation of functionally distinct stromal cells, thereby orchestrating discrete microenvironments in the fibrotic milieu. Together, these findings provide a basis for the concept of targeting blood vessel signaling to control the progression of human fibrosis.

Fibrosis is characterized by excessive matrix protein accumulation and contributes to significant morbidity and mortality in the Western world. The relative lack of effective antifibrotic therapeutics for the majority of these conditions reflects the difficulty in identifying targets for human fibrosis. Animal models fail to recapitulate all of the facets of human disease, and the limited clinical samples from patients with fibrosis of visceral organs are usually of late-stage disease [J. Nanchahal, B. Hinz, Proc. Natl. Acad. Sci. U.S.A. 113, 7291–7293 (2016)]. Here, we use Dupuytren’s disease (DD), a localized fibrotic condition of the hand, as a model to profile the vasculature niche of human fibrosis at single-cell resolution. Our spatially resolved molecular taxonomy of fibrotic blood vessels identifies distinct endothelial and pericyte populations and demonstrates a complex topological organization in the fibrotic microenvironment. In developing fibrosis, we show that the endothelium acts to promote immune regulatory fibroblast phenotype through platelet-derived growth factor (PDGF) signaling, thereby sustaining an immune cell–enriched perivascular niche. Moreover, we highlight pericytes as “housing” a putative myofibroblast precursor in DD. Overall, our results elucidate a tightly coupled vasculature niche in fibrosis that instructs the differentiation of functionally distinct stromal cells. These findings provide an important translational resource and highlight the therapeutic potential of targeting blood vessel signaling in human fibrosis.

Circulating inflammatory cytokines alter transcriptional activity within fibrotic tissue of Dupuytren's disease patients

Dupuytren's disease is a benign fibroproliferative disorder of the hand that results in disabling digital contractures that impair function and diminish the quality of life. The incidence of this disease has been correlated with chronic inflammatory states, but any direct association between inflammatory cytokines and Dupuytren's disease is not known. We hypothesized that advanced fibroproliferation is associated with increased levels of circulating inflammatory cytokines. Blood and fibrotic cord tissue were collected preoperatively from patients with severe contracture and control patients. Blood plasma concentrations of known inflammatory cytokines were evaluated using a multiplex immunoassay. Proteins from the cord tissue were analyzed by RNA sequencing and immunohistochemistry. Moreover, collagen-rich cords were analyzed using Fourier-transform infrared spectroscopy. The results indicate that patients exhibited significantly elevated circulating inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-2, and IL-12p70, as compared with controls. Similarly, IL-4 and IL-13 were detected significantly more frequently in Dupuytren's disease as compared with control. RNA sequencing revealed 5311 differentially expressed genes and distinct clustering between diseased and control samples. In addition to increased expression of genes associated with fibroproliferation, we also observed upregulation of transcripts activated by inflammatory cytokines, including prolactin inducible protein and keratin intermediate filaments. IL-2, but not TNF-α, was detected in fibrotic cord tissue by immunohistochemistry. Finally, spectroscopic assays revealed a significant reduction of the collagen content and alterations of collagen cross-linking within the Dupuytren's disease tissues. In total, our results illustrate that patients with severe Dupuytren's disease exhibit substantially elevated circulating inflammatory cytokines that may drive fibroproliferation. Clinical Significance: The results from this study establish the basis for a specific cytokine profile that may be useful for diagnostic testing and therapeutic intervention in Dupuytren's disease.

Quantitative predictive approaches for Dupuytren disease: a brief review and future perspectives

In this study we review the current state of the art for Dupuytren's disease (DD), while emphasising the need for a better integration of clinical, experimental and quantitative predictive approaches to understand the evolution of the disease and improve current treatments. We start with a brief review of the biology of this disease and current treatment approaches. Then, since certain aspects in the pathogenesis of this disorder have been compared to various biological aspects of wound healing and malignant processes, next we review some in silico (mathematical modelling and simulations) predictive approaches for complex multi-scale biological interactions occurring in wound healing and cancer. We also review the very few in silico approaches for DD, and emphasise the applicability of these approaches to address more biological questions related to this disease. We conclude by proposing new mathematical modelling and computational approaches for DD, which could be used in the absence of animal models to make qualitative and quantitative predictions about the evolution of this disease that could be further tested in vitro.

Deciphering Mesenchymal Drivers of Human Dupuytren's Disease at Single-Cell Level

Dupuytren's disease (DD) is a common, progressive fibroproliferative disease affecting the palmar fascia of the hands, causing fingers to irreversibly flex toward the palm with significant loss of function. Surgical treatments are limited; therefore, effective new therapies for DD are urgently required. To identify the key cellular and molecular pathways driving DD, we employed single-cell RNA sequencing, profiling the transcriptomes of 35,250 human single cells from DD, nonpathogenic fascia, and healthy dermis. We identify a DD-specific population of pathogenic PDPN+/FAP+ mesenchymal cells displaying an elevated expression of fibrillar collagens and profibrogenic genes. In silico trajectory analysis reveals resident fibroblasts to be the source of this pathogenic population. To resolve the processes governing DD progression, genes differentially expressed during fibroblast differentiation were identified, including upregulated TNFRSF12A and transcription factor SCX. Knockdown of SCX and blockade of TNFRSF12A inhibited the proliferation and altered the profibrotic gene expression of cultured human FAP+ mesenchymal cells, demonstrating a functional role for these genes in DD. The power of single-cell RNA sequencing is utilized to identify the major pathogenic mesenchymal subpopulations driving DD and the key molecular pathways regulating the DD-specific myofibroblast phenotype. Using this precision medicine approach, inhibition of TNFRSF12A has shown potential clinical utility in the treatment of DD.

Fibroblast Activation Protein Targeted Photodynamic Therapy Selectively Kills Activated Skin Fibroblasts from Systemic Sclerosis Patients and Prevents Tissue Contraction

Systemic sclerosis (SSc) is a rare, severe, auto-immune disease characterized by inflammation, vasculopathy and fibrosis. Activated (myo)fibroblasts are crucial drivers of this fibrosis. By exploiting their expression of fibroblast activation protein (FAP) to perform targeted photodynamic therapy (tPDT), we can locoregionally deplete these pathogenic cells. In this study, we explored the use of FAP-tPDT in primary skin fibroblasts from SSc patients, both in 2D and 3D cultures. Method: The FAP targeting antibody 28H1 was conjugated with the photosensitizer IRDye700DX. Primary skin fibroblasts were obtained from lesional skin biopsies of SSc patients via spontaneous outgrowth and subsequently cultured on plastic or collagen type I. For 2D FAP-tPDT, cells were incubated in buffer with or without the antibody-photosensitizer construct, washed after 4 h and exposed to λ = 689 nm light. Cell viability was measured using CellTiter Glo^®®. For 3D FAP-tPDT, cells were seeded in collagen plugs and underwent the same treatment procedure. Contraction of the plugs was followed over time to determine myofibroblast activity. Results: FAP-tPDT resulted in antibody-dose dependent cytotoxicity in primary skin fibroblasts upon light exposure. Cells not exposed to light or incubated with an irrelevant antibody-photosensitizer construct did not show this response. FAP-tPDT fully prevented contraction of collagen plugs seeded with primary SSc fibroblasts. Even incubation with a very low dose of antibody (0.4 nM) inhibited contraction in 2 out of 3 donors. Conclusions: Here we have shown, for the first time, the potential of FAP-tPDT for the treatment of fibrosis in SSc skin.

Metabolic Messengers: tumour necrosis factor

Tumour necrosis factor (TNF) is a classical, pleiotropic pro-inflammatory cytokine. It is also the first 'adipokine' described to be produced from adipose tissue, regulated in obesity and proposed to contribute to obesity-associated metabolic disease. In this review, we provide an overview of TNF in the context of metabolic inflammation or metaflammation, its discovery as a metabolic messenger, its sites and mechanisms of action and some critical considerations for future research. Although we focus on TNF and the studies that elucidated its immunometabolic actions, we highlight a conceptual framework, generated by these studies, that is equally applicable to the complex network of pro-inflammatory signals, their biological activity and their integration with metabolic regulation, and to the field of immunometabolism more broadly.

Snail regulation in fibroblast-like synoviocytes by a histone deacetylase or glycogen synthase kinase inhibitor affects cell proliferation and gene expression

BACKGROUND

Snail has been linked to the pathogenesis of rheumatoid arthritis (RA). We plan to investigate the regulation of Snail in response to TNF-α, histone acetylation, and glycogen synthase kinase-3 (GSK)-3 inhibition in fibroblast-like synoviocytes (FLSs).

METHODS

FLSs from rats with collagen-induced arthritis (CIA) were collected and treated with TNF-α alone or a combination with trichostatin A (TSA), a pan-histone deacetylase inhibitor and lithium chloride (LiCl), a glycogen synthase kinase-3 (GSK)-3 inhibitor.

RESULTS

We demonstrated for the first time that nuclear expression of Snail in FLSs from rats with CIA was correlated with the levels of extracellular TNF-α and acetylation status. Cell proliferation and viability of CIA FLSs were reduced in response to TSA treatment and short-hairpin RNA specific to Snail. LiCl treatment increased Snail and cadherin-11 (Cad-11) expression in CIA FLSs.

CONCLUSION

We suggested from this study that targeting TNF-α-histone deacetylase-Snail signaling axis or the Wnt signaling pathway in FLSs might provide therapeutic interventions for the treatment of RA in the future.

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.

Evaluation of WNT Signaling Pathway Gene Variants WNT7B rs6519955, SFRP4 rs17171229 and RSPO2 rs611744 in Patients with Dupuytren's Contracture

Dupuytren’s contracture (DC) represents a chronic fibroproliferative pathology of the palmar aponeurosis, which leads to flexion contractures of finger joints and hand disability. In recent decades, the WNT signaling pathway has been revealed to play a significant role in the manifestation and pathogenesis of DC. Our study aimed to evaluate the associations between Dupuytren’s contracture and WNT-related single-nucleotide polymorphisms: Wnt Family Member 7B (WNT7B) rs6519955 (G/T), Secreted Frizzled Related Protein 4 (SFRP4) rs17171229 (C/T) and R-spondin 2 (RSPO2) rs611744 (A/G). We enrolled 216 patients (113 DC cases and 103 healthy controls), and DNA samples were extracted from the peripheral blood. Genotyping of WNT7B rs6519955, SFRP4 rs17171229 and RSPO2 rs611744 was performed using the Real-Time PCR System 7900HT from Applied Biosystems. WNT7B rs6519955 genotype TT carriers were found to possess a higher prevalence of DC (OR = 3.516; CI = 1.624–7.610; p = 0.001), whereas RSPO2 rs611744 genotype GG appears to reduce the likelihood of the manifestation of DC nearly twofold (OR = 0.484, CI = 0.258–0.908, p = 0.024). In conclusion, SNPs WNT7B rs6519955 and RSPO2 rs611744 are associated with the development of Dupuytren’s contracture: WNT7B rs6519955 TT genotype increases the chances by 3.5-fold, and RSPO2 rs611744 genotype GG appears to attenuate the likelihood of the manifestation of DC nearly twofold. Findings of genotype distributions among DC patients and control groups suggest that SFRP4 rs17171229 is not significantly associated with development of the disease.

Network Pharmacology-Based Mechanistic Investigation of Jinshui Huanxian Formula Acting on Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic respiratory disease with high incidence, morbidity, and mortality rates. Jinshui Huanxian formula (JHF) is an empirical formula that targets the pathogenesis of lung-kidney qi deficiency and phlegm-blood stasis in pulmonary fibrosis (PF). The purpose of this study was to explore JHF's potential pharmacological mechanisms in IPF therapy using network intersection analysis. JHF's primary active components and corresponding target genes were predicted using various databases. Two sets of IPF disease genes were obtained from the DisGeNET and GEO databases and two sets of IPF drug targets were collected. The disease and drug target genes were analyzed. The JHF target genes that intersected with IPF's differentially expressed genes were identified to predict JHF's targets of action in IPF. The functions and pathways of predicted targets acting on IPF were analyzed using the DAVID and KEGG pathway databases. Finally, the resulting drug target mechanisms were validated in a rat model of PF. The initial analyses identified 494 active compounds and 1,304 corresponding targets for JHF. The intersection analysis revealed four common genes for the JHF targets, IPF disease, and anti-IPF drugs in the KEGG database. Furthermore, these genes were targeted by several JHF compounds. Seventy-two JHF targets were closely related to IPF, which suggests that they are therapeutically relevant. Target screening revealed that they regulate IPF through 18 pathways. The targets' molecular functions included regulation of oxidoreductase activity, kinase regulator activity, phosphotransferase activity, and transmembrane receptor protein kinase activity. In vivo experiments showed that JHF alleviated the degree of PF, including decreases in collagen deposition and epithelial-mesenchymal transition. This study systematically explored JHF's mechanisms to identify the specific target pathways involved in IPF. The generated pharmacological network, paired with in vivo validation, elucidates the potential roles and mechanisms of JHF in IPF therapy.

Biomimetic analyses of interactions between macrophages and palmar fascia myofibroblasts derived from Dupuytren's disease reveal distinct inflammatory cytokine responses

Dupuytren's disease (DD) is a common and heritable fibrosis of the hand. It is characterized by the shortening and thickening of the palmar fascia into myofibroblastic nodules that can progress to palmar-digital contractures and permanent loss of dexterity. Molecular analyses of DD tissues and the presence of inflammatory cell infiltrates suggest a pathogenesis initiated by a proinflammatory fascial milieu that promotes myofibroblast activation and palmar fascia contractures. However, the relative contributions of vascular and/or tissue derived immune system cells and cytokine-sensitive stromal myofibroblasts to the development of this proinflammatory microenvironment are poorly understood. To gain insights into this process, we have developed and tested a collagen-based 3D tissue biomimetic co-culture system to assess paracrine interactions between THP-1-derived pro-inflammatory macrophages and primary human palmar fascia myofibroblasts (PFMs). We observed significant and reproducible impacts of collagen-adherent macrophage and PFM co-cultures on the cytokine gene expression profiles of these cells compared to their respective monocultures, and significant changes to the resulting cytokine milieu in their shared culture media, notably TNF and IL-6. Our findings are consistent with central roles for PFMs in cytokine production and immunoregulation of the pro-inflammatory milieu hypothesized to promote DD development.

Coenzyme Q10: Clinical Applications beyond Cardiovascular Diseases

Coenzyme Q10 (CoQ10) is an essential cofactor in oxidative phosphorylation (OXPHOS), present in mitochondria and cell membranes in reduced and oxidized forms. Acting as an energy transfer molecule, it occurs in particularly high levels in the liver, heart, and kidneys. CoQ10 is also an anti-inflammatory and antioxidant agent able to prevent the damage induced by free radicals and the activation of inflammatory signaling pathways. In this context, several studies have shown the possible inverse correlation between the blood levels of CoQ10 and some disease conditions. Interestingly, beyond cardiovascular diseases, CoQ10 is involved also in neuronal and muscular degenerative diseases, in migraine and in cancer; therefore, the supplementation with CoQ10 could represent a viable option to prevent these and in some cases might be used as an adjuvant to conventional treatments. This review is aimed to summarize the clinical applications regarding the use of CoQ10 in migraine, neurodegenerative diseases (including Parkinson and Alzheimer diseases), cancer, or degenerative muscle disorders (such as multiple sclerosis and chronic fatigue syndrome), analyzing its effect on patients' health and quality of life.

Fibroproliferative disorders and diabetes: Understanding the pathophysiologic relationship between Peyronie's disease, Dupuytren disease and diabetes

Introduction

Fibrosis is characterized by dysregulation and accumulation of extracellular matrix. Peyronie's disease and Dupuytren disease are fibroproliferative disorders of the tunica albuginea of the penis and fascia of the hand, respectively. Chronic hyperglycaemia due to diabetes mellitus can also lead to tissue injury and fibrosis. A meta-analysis has shown a relationship between Dupuytren disease and diabetes (overall odds ratio, 3.1; 95% confidence interval, 2.7-3.5). This review explores commonalities in the pathogenesis of Peyronie's disease, Dupuytren disease and diabetes.

Methods

A search of the PubMed database was conducted using the search terms "diabetes" AND "Peyronie's disease"; and "diabetes" AND "Dupuytren."

Results

Genome-wide association and gene expression studies conducted with tissue from people with Peyronie's disease or Dupuytren disease identified signalling pathways associated with wingless-type mammary-tumour virus integration site signalling, extracellular matrix modulation and inflammation. Biochemical studies confirmed the importance of these pathways in the pathogenesis of fibrosis with Peyronie's disease and Dupuytren disease. Dysregulation of matrix metalloproteinase activity associated with extracellular matrix breakdown was implicated in fibroproliferative complications of diabetes and in the aetiology of Peyronie's disease and Dupuytren disease. A notable percentage of people with diabetes have comorbid Peyronie's disease and/or Dupuytren disease.

Conclusions

Studies have not been performed to identify fibroproliferative pathways that all 3 conditions might have in common, but data suggest that common pathways are involved in the fibroproliferative processes of Peyronie's disease, Dupuytren disease, and diabetes.

Attenuation of Dupuytren's fibrosis via targeting of the STAT1 modulated IL-13Rα1 response

Fibrotic disorders represent common complex disease pathologies that are therapeutically challenging. Inflammation is associated with numerous fibrotic pathogeneses; however, its role in the multifaceted mechanisms of fibrosis remains unclear. IL-13 is implicated in aberrant responses involved in fibrotic disease, and we aimed to understand its role in the inflammatory processes of a common fibrotic disorder, Dupuytren's disease. We demonstrated T-cells produced IFN-g, which induced IL-13 secretion from mast cells and up-regulated IL-13Ra1 on fibroblasts, rendering them more reactive to IL-13. Consequently, diseased myofibroblasts demonstrated enhanced fibroproliferative effects upon IL-13 stimulation. We established IFN-g and IL-13 responses involved STAT dependent pathways, and STAT targeting (tofacitinib) could inhibit IL-13 production from mast cells, IL-13Ra1 up-regulation in fibroblasts and fibroproliferative effects of IL-13 on diseased myofibroblasts. Accordingly, utilizing Dupuytren's as an accessible human model of fibrosis, we propose targeting STAT pathways may offer previously unidentified therapeutic approaches in the management of fibrotic disease.

Cellular census of human fibrosis defines functionally distinct stromal cell types and states

Fibrotic disorders are some of the most devastating and poorly treated conditions in developed nations, yet effective therapeutics are not identified for many of them. A major barrier for the identification of targets and successful clinical translation is a limited understanding of the human fibrotic microenvironment. Here, we construct a stromal cell atlas of human fibrosis at single cell resolution from patients with Dupuytren’s disease, a localized fibrotic condition of the hand. A molecular taxonomy of the fibrotic milieu characterises functionally distinct stromal cell types and states, including a subset of immune regulatory ICAM1⁺ fibroblasts. In developing fibrosis, myofibroblasts exist along an activation continuum of phenotypically distinct populations. We also show that the tetraspanin CD82 regulates cell cycle progression and can be used as a cell surface marker of myofibroblasts. These findings have important implications for targeting core pathogenic drivers of human fibrosis.

New anti-fibrotics aided by a better understanding of fibrotic cell subsets and their functions are needed. Here the authors perform single-cell RNA-seq and CyTOF on nodules from patients with Dupuytren’s disease to map subsets and the state of mesenchymal cells during pathogenic fibrogenesis.

The Role of IL-6 in Skin Fibrosis and Cutaneous Wound Healing

The timely resolution of wound healing is critical for restoring the skin as a protective barrier. The switch from a proinflammatory to a reparative microenvironment must be tightly regulated. Interleukin (IL)-6 is a key modulator of the inflammatory and reparative process: it is involved in the differentiation, activation, and proliferation of leukocytes, endothelial cells, keratinocytes, and fibroblasts. This review examines the role of IL-6 in the healing of cutaneous wounds, and how dysregulation of IL-6 signaling can lead to either fibrosis or a failure to heal. The role of an IL-6/TGF-β feedback loop is discussed in the context of fibrogenesis, while IL-6 expression and responses in advanced age, diabetes, and obesity is outlined regarding the development of chronic wounds. Current research on therapies that modulate IL-6 is explored. Here, we consider IL-6′s diverse impact on cutaneous wound healing.

Single cell force profiling of human myofibroblasts reveals a biophysical spectrum of cell states

Mechanical force is a fundamental regulator of cell phenotype. Myofibroblasts are central mediators of fibrosis, a major unmet clinical need characterised by the deposition of excessive matrix proteins. Traction forces of myofibroblasts play a key role in remodelling the matrix and modulate the activities of embedded stromal cells. Here, we employ a combination of unsupervised computational analysis, cytoskeletal profiling and single cell traction force microscopy as a functional readout to uncover how the complex spatiotemporal dynamics and mechanics of living human myofibroblast shape sub-cellular profiling of traction forces in fibrosis. We resolve distinct biophysical communities of myofibroblasts, and our results provide a new paradigm for studying functional heterogeneity in human stromal cells.

Identification of TNFR2 and IL-33 as therapeutic targets in localized fibrosis

Dissecting the molecular landscape of fibrotic disease, a major unmet need, will inform the development of novel treatment strategies to target disease progression and identify desperately needed therapeutic targets. Here, we provide a detailed single-cell analysis of the immune landscape in Dupuytren's disease, a localized fibrotic condition of the hand, and identify a pathogenic signaling circuit between stromal and immune cells. We demonstrate M2 macrophages and mast cells as key cellular sources of tumor necrosis factor (TNF) that promotes myofibroblast development. TNF acts via the inducible TNFR2 receptor and stimulates interleukin-33 (IL-33) secretion by myofibroblasts. In turn, stromal cell IL-33 acts as a potent stimulus for TNF production from immune cells. Targeting this reciprocal signaling pathway represents a novel therapeutic strategy to inhibit the low-grade inflammation in fibrosis and the mechanism that drives chronicity.

In vitro evaluation of anti-fibrotic effects of select cytokines for vocal fold scar treatment

Scarring of the vocal fold lamina propria (LP) can cause considerable voice disorders due to reduced pliability in scar tissue, attributed in part to abnormal extracellular matrix (ECM) deposition produced by the fibrotic vocal fold fibroblast (fVFF). Cytokines with anti-fibrotic potential have been investigated to limit abnormal LP ECM, but are limited by the need for repeat injections. Moreover, the potentially significant role played by activated macrophages (AMOs) is usually not considered even though the interaction between AMO and fibrotic fibroblasts is known to regulate scar formation across different tissues. AMO are also regulated by cytokines that are used for LP scar removal, but little is known about AMO behaviors in response to these cytokines within the context of LP scar. In the present study, we evaluated anti-fibrotic effects of hepatocyte growth factor (HGF), interleukin-10 (IL-10) and interleukin-6 (IL-6) in a 3D, in vitro fVFF-AMO co-culture system using poly(ethylene glycol) diacrylate (PEGDA) hydrogels. Data from all cytokines was synthesized into a heat-map that enabled assessment of specific associations between AMO and fVFF phenotypes. Cumulatively, our results indicated that both HGF and IL-10 are potentially anti-fibrotic (reduction in fibrotic markers and enhancement in normal, anti-fibrotic VFF markers), while IL-6 displays more complex, marker specific effects. Possible associations between AMO and fVFF phenotypes were found and may highlight a potential desirable macrophage phenotype. These data support the therapeutic potential of HGF and IL-10 for LP scar treatment, and shed light on future strategies aimed at targeting specific AMO phenotypes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1056-1067, 2019.

Pathological mechanisms and therapeutic outlooks for arthrofibrosis

Arthrofibrosis is a fibrotic joint disorder that begins with an inflammatory reaction to insults such as injury, surgery and infection. Excessive extracellular matrix and adhesions contract pouches, bursae and tendons, cause pain and prevent a normal range of joint motion, with devastating consequences for patient quality of life. Arthrofibrosis affects people of all ages, with published rates varying. The risk factors and best management strategies are largely unknown due to a poor understanding of the pathology and lack of diagnostic biomarkers. However, current research into the pathogenesis of fibrosis in organs now informs the understanding of arthrofibrosis. The process begins when stress signals stimulate immune cells. The resulting cascade of cytokines and mediators drives fibroblasts to differentiate into myofibroblasts, which secrete fibrillar collagens and transforming growth factor-β (TGF-β). Positive feedback networks then dysregulate processes that normally terminate healing processes. We propose two subtypes of arthrofibrosis occur: active arthrofibrosis and residual arthrofibrosis. In the latter the fibrogenic processes have resolved but the joint remains stiff. The best therapeutic approach for each subtype may differ significantly. Treatment typically involves surgery, however, a pharmacological approach to correct dysregulated cell signalling could be more effective. Recent research shows that myofibroblasts are capable of reversing differentiation, and understanding the mechanisms of pathogenesis and resolution will be essential for the development of cell-based treatments. Therapies with significant promise are currently available, with more in development, including those that inhibit TGF-β signalling and epigenetic modifications. This review focuses on pathogenesis of sterile arthrofibrosis and therapeutic treatments.

Could coenzyme Q10 be the treatment for Dupuytren's disease?

A patient with Dupuytren's disease noted progressive disappearance of the contractures of both hands over a 3-year period while taking coenzyme Q10 daily for an unrelated condition. The function and appearance of his hands were restored to almost normal.

Recent advances in the understanding of Dupuytren's disease

Dupuytren's disease (DD) is a common fibrotic disorder of the hand and can significantly impair hand function. Although the exact pathogenesis of this disorder remains to be elucidated, immunological, genetic and cellular factors likely interact. In this review, we summarise recent advances in the understanding of DD pathogenesis and look to the future for potential novel therapeutic targets. In addition, we discuss the therapeutic options in DD with a focus on the need for more rigorous evidence to allow a meaningful comparison of different treatment modalities.

WISP1 silencing confers protection against epithelial-mesenchymal transition of renal tubular epithelial cells in rats via inactivation of the wnt/β-catenin signaling pathway in uremia

Uremia can affect hepatic metabolism of drugs by regulating the clearance of drugs, but it has not been clarified whether gene silencing could modulate the epithelial-mesenchymal transition (EMT) process in uremia. Hence, we investigated the effect of WISP1 gene silencing on the renal tubular EMT in uremia through the wnt/β-catenin signaling pathway. Initially, microarray-based gene expression profiling of uremia was used to identify differentially expressed genes. Following the establishment of uremia rat model, serum creatinine, and urea nitrogen of rats were detected. Renal tubular epithelial cells (TECs) were transfected with shRNA-WISP1 lentivirus interference vectors and LiCI (the wnt/β-catenin signaling pathway activator) to explore the regulatory mechanism of WISP1 in uremia in relation to the wnt/β-catenin signaling pathway. Then, expression of WISP1, wnt2b, E-cadherin, α-SMA, c-myc, Cyclin D1, MMP-2, and MMP-9 was determined. Furthermore, TEC migration and invasion were evaluated. Results suggested that WISP1 and the wnt/β-catenin signaling pathway were associated with uremia. Uremic rats exhibited increased serum creatinine and urea nitrogen levels, upregulated WISPl, and activated wnt/β-catenin signaling pathway. Subsequently, WISP1 silencing decreased wnt2b, c-myc, Cyclin D1, α-SMA, MMP-2, and MMP-9 expression but increased E-cadherin expression, whereas LiCI treatment exhibited the opposite trends. In addition, WISP1 silencing suppressed TEC migration and invasion, whereas LiCI treatment promoted TEC migration and invasion. The findings indicate that WISP1 gene silencing suppresses the activation of the wnt/β-catenin signaling pathway, thus reducing EMT of renal TECs in uremic rats.

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.

Anti-Tumour Necrosis Factor Therapy for Dupuytren's Disease: A Randomised Dose Response Proof of Concept Phase 2a Clinical Trial

Background

Dupuytren's disease is a common fibrotic condition of the hand that causes irreversible flexion contractures of the fingers, with no approved therapy for early stage disease. Our previous analysis of surgically-excised tissue defined tumour necrosis factor (TNF) as a potential therapeutic target. Here we assessed the efficacy of injecting nodules of Dupuytren's disease with a TNF inhibitor.

Methods

Patients were randomised to receive adalimumab on one occasion in dose cohorts of 15 mg in 0.3 ml, 35 mg in 0.7 ml, or 40 mg in 0.4 ml, or an equivalent volume of placebo in a 3:1 ratio. Two weeks later the injected tissue was surgically excised and analysed. The primary outcome measure was levels of mRNA expression for α-smooth muscle actin (ACTA2). Secondary outcomes included levels of α-SMA and collagen proteins. The trial was registered with ClinicalTrial.gov (NCT03180957) and the EudraCT (2015-001780-40).

Findings

We recruited 28 patients, 8 assigned to the 15 mg, 12 to the 35 mg and 8 to the 40 mg adalimumab cohorts. There was no change in mRNA levels for ACTA2, COL1A1, COL3A1 and CDH11. Levels of α-SMA protein expression in patients treated with 40 mg adalimumab (1.09 ± 0.09 ng per μg of total protein) were significantly lower (p = 0.006) compared to placebo treated patients (1.51 ± 0.09 ng/μg). The levels of procollagen type I protein expression were also significantly lower (p < 0.019) in the sub group treated with 40 mg adalimumab (474 ± 84 pg/μg total protein) compared with placebo (817 ± 78 pg/μg). There were two serious adverse events, both considered unrelated to the study drug.

Interpretation

In this dose-ranging study, injection of 40 mg of adalimumab in 0.4 ml resulted in down regulation of the myofibroblast phenotype as evidenced by reduction in expression of α-SMA and type I procollagen proteins at 2 weeks. These data form the basis of an ongoing phase 2b clinical trial assessing the efficacy of intranodular injection of 40 mg adalimumab in 0.4 ml compared to an equivalent volume of placebo in patients with early stage Dupuytren's disease.

Funding

Health Innovation Challenge Fund (Wellcome Trust and Department of Health) and 180 Therapeutics LP.