Pathogenesis of scleroderma. Collagen

[Juvenile localized scleroderma]

Juvenile scleroderma, often referred to as juvenile localized scleroderma or "morphea", is a rare inflammatory disease of the skin and skin-related structures, accompanied by local sclerosis and tissue fibrosis. Depending on the clinical manifestation, four different subtypes can be defined: limited, generalized, linear, and mixed. To prevent possible sequelae of the disease, the diagnosis should be made as early as possible and therapy should be initiated at specialized centers in multiprofessional pediatric and dermatologic collaboration. In this review, we present the main clinical, laboratory, and therapeutic characteristics of juvenile localized scleroderma and summarize recommendations.

A modest proposal: targeting αv integrin-mediated activation of latent TGFbeta as a novel therapeutic approach to treat scleroderma fibrosis

INTRODUCTION

The potent profibrotic cytokine transforming growth factor-β (TGF-β) has been associated with the onset and progression of the fibrosis seen in the autoimmune connective tissue disease scleroderma (systemic sclerosis, SSc).

AREA COVERED

This review explores the data supporting the notion that TGF-β contributes to SSc fibrosis and examines why initiating clinical trials in SSc aimed at targeting integrin-mediated latent TGF-β activation is timely.

EXPERT OPINION

Targeting TGF-β directly has not been proven to be clinically effective in this disease. Conversely, targeting matrix stiffness, which perpetuates fibrosis, may have more promise. Intriguingly, targeting integrin-mediated activation of latent TGF-β, which bridges these concepts, may have therapeutic value.

Mechanotransduction in Skin Inflammation

In the process of mechanotransduction, the cells in the body perceive and interpret mechanical stimuli to maintain tissue homeostasis and respond to the environmental changes. Increasing evidence points towards dysregulated mechanotransduction as a pathologically relevant factor in human diseases, including inflammatory conditions. Skin is the organ that constantly undergoes considerable mechanical stresses, and the ability of mechanical factors to provoke inflammatory processes in the skin has long been known, with the Koebner phenomenon being an example. However, the molecular mechanisms and key factors linking mechanotransduction and cutaneous inflammation remain understudied. In this review, we outline the key players in the tissue's mechanical homeostasis, the available data, and the gaps in our current understanding of their aberrant regulation in chronic cutaneous inflammation. We mainly focus on psoriasis as one of the most studied skin inflammatory diseases; we also discuss mechanotransduction in the context of skin fibrosis as a result of chronic inflammation. Even though the role of mechanotransduction in inflammation of the simple epithelia of internal organs is being actively studied, we conclude that the mechanoregulation in the stratified epidermis of the skin requires more attention in future translational research.

Engineering cryoelectrospun elastin-alginate scaffolds to serve as stromal extracellular matrices

Scaffold-based regenerative strategies that emulate physical, biochemical, and mechanical properties of the native extracellular matrix (ECM) of the region of interest can influence cell growth and function. Existing ECM-mimicking scaffolds, including nanofiber (NF) mats, sponges, hydrogels, and NF-hydrogel composites are unable to simultaneously mimic typical composition, topography, pore size, porosity, and viscoelastic properties of healthy soft-tissue ECM. In this work, we used cryoelectrospinning to fabricate 3D porous scaffolds with minimal fibrous backbone, pore size and mechanical properties similar to soft-tissue connective tissue ECM. We used salivary glands as our soft tissue model and found the decellularized adult salivary gland (DSG) matrix to have a fibrous backbone, 10-30μm pores, 120 Pa indentation modulus, and ∼200 s relaxation half time. We used elastin and alginate as natural, compliant biomaterials and water as the solvent for cryoelectrospinning scaffolds to mimic the structure and viscoelasticity of the connective tissue ECM of the DSG. Process parameters were optimized to produce scaffolds with desirable topography and compliance similar to DSG, with a high yield of >100 scaffolds/run. Using water as solvent, rather than organic solvents, was critical to generate biocompatible scaffolds with desirable topography; further, it permitted a green chemistry fabrication process. Here, we demonstrate that cryoelectrospun scaffolds (CESs) support penetration of NIH 3T3 fibroblasts 250-450µm into the scaffold, cell survival, and maintenance of a stromal cell phenotype. Thus, we demonstrate that elastin-alginate CESs mimic many structural and functional properties of ECM and have potential for future use in regenerative medicine applications.

NADPH-derived ROS generation drives fibrosis and endothelial-to-mesenchymal transition in systemic sclerosis: Potential cross talk with circulating miRNAs

Systemic sclerosis (SSc) is an immune disorder characterized by diffuse fibrosis and vascular abnormalities of the affected organs. Although the etiopathology of this disease is largely unknown, endothelial damage and oxidative stress appear implicated in its initiation and maintenance. Here, we show for the first time that circulating factors present in SSc sera increased reactive oxygen species (ROS) production, collagen synthesis, and proliferation of human pulmonary microvascular endothelial cells (HPMECs). The observed phenomena were also associated with endothelial to mesenchymal transition (EndMT) as indicated by decreased von Willebrand factor (vWF) expression and increased alpha-smooth muscle actin, respectively, an endothelial and mesenchymal marker. SSc-induced fibroproliferative effects were prevented by HPMECs exposition to the NADPH oxidase inhibitor diphenyleneiodonium, demonstrating ROS's causative role and suggesting their cellular origin. Sera from SSc patients showed significant changes in the expression of a set of fibrosis/EndMT-associated microRNAs (miRNA), including miR-21, miR-92a, miR-24, miR-27b, miR-125b, miR-29c, and miR-181b, which resulted significantly upregulated as compared to healthy donors sera. However, miR29b resulted downregulated in SSc sera, whereas no significant differences were found in the expression of miR-29a in the two experimental groups of samples. Taking together our data indicate NADPH oxidase-induced EndMT as a potential mechanism of SSc-associated fibrosis, suggesting fibrosis-associated miRNAs as potentially responsible for initiating and sustaining the vascular alterations observed in this pathological condition.

Emerging importance of ACE2 in external stratified epithelial tissues

Angiotensin converting enzyme 2 (ACE2), a component of the renin-angiotensin system (RAS), has been identified as the receptor for the SARS-CoV-2. Several RAS components including ACE2 and its substrate Ang II are present in both eye and skin, two stratified squamous epithelial tissues that isolate organisms from external environment. Our recent findings in cornea and others in both skin and eye suggest contribution of this system, and specifically of ACE2 in variety of physiological and pathological responses of these organ systems. This review will focus on the role RAS system plays in both skin and cornea, and will specifically discuss our recent findings on ACE2 in corneal epithelial inflammation, as well as potential implications of ACE2 in patients with COVID-19.

PDGF-BB induces conversion, proliferation, migration, and collagen synthesis of oral mucosal fibroblasts through PDGFR-β/PI3K/ AKT signaling pathway

OBJECTIVE

To explore the pathogenesis of oral submucosal fibrosis (OSF) by analyzing the impact of Platelet Derived Growth Factor (PDGF)-BB on oral mucosal fibroblasts (FB) and PDGFR-β/Phosphoinositide 3-kinase (PI3K)/serine/threonine protein kinase (AKT) signaling pathway.

METHODS

The isolated and purified oral mucosal fibroblasts were divided into four groups: the control group (CON, 10% FBS DMEM), the PDGF-BB group (40 ng/ml PDGF-BB), the PDGF-BB+IMA group (40 ng/ml PDGF-BB and 60 μmol/L IMA), and the PDGF-BB+LY294002 group (40 ng/ml PDGF-BB and 48 μmol/L LY294002). Primary human FB cells were isolated and cultured for detecting the effects of PDGF-BB on α-smooth muscle actin (α-SMA) by indirect immunofluorescence. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide (MTT) method and scratch test were used to detect the proliferation and migration of FB. Western blots were used to detect the synthesis of type I collagen (Col I) and the expression of PDGFR-β/PI3K/AKT signaling pathway-related proteins. The effects of PDGFR-β inhibitor and PI3K inhibitor were observed.

RESULTS

Compared with group CON, group IMA, and group LY294002, α-SMA was upregulated in group PDGF-BB (p< 0.05), with higher OD490 nm value (p< 0.05), narrower average scratch width, and higher relative cell migration rate (p< 0.05). The expression levels of Col I, p-PDGFR-β, p-PI3K, and p-AKT were higher in group PDGF-BB (p< 0.05).

CONCLUSIONS

PDGF-BB induces FB to transform into myofibroblasts (MFB) through the PDGFR-β/PI3K/AKT signaling pathway, and promotes the proliferation, migration, and collagen synthesis.

Quantifying Dermatology: Method and Device for User-Independent Ultrasound Measurement of Skin Thickness

A device and technique to acquire and construct 3D ultrasound volumes of the skin of the hand and arm were developed. The Repeated Skin Thickness Measurement (RSTM) Device moves a high frequency ultrasound probe linearly in 3 axes in a water tank and images a submerged arm. These images are combined into an ultrasound volume, the skin layer segmented, and the thickness extracted. One particular application is measuring progression of scleroderma, a skin thickening disease. The current ultrasound-based scleroderma diagnostic processes assess skin thickness based on a single ultrasound image taken by a clinician holding the ultrasound probe, resulting in low measurement repeatability. The imagery that results from the instrumentation and analysis presented here can be used to create quantitative maps of skin thickness, to monitor the progression of skin-thickening diseases, and to observe the structures of tendons, ligaments, and the other soft tissue of the hand.

B cell depletion treatment decreases CD4+IL4+ and CD4+CD40L+ T cells in patients with systemic sclerosis

Recent data suggests that rituximab may favorably affect skin fibrosis and lung function in patients with systemic sclerosis. Based on experimental data suggesting a key role of B and T cells in scleroderma we aimed to explore the effect(s) of rituximab treatment on T cell subpopulations. Fifteen patients with scleroderma who received rituximab treatment and six who received standard treatment alone were recruited. Peripheral CD4+IL4+, CD4+INFγ+, CD4+IL17+ and CD4+CD40L+ T cells were assessed using flow cytometry. Using ELISA, serum levels of IL4 were assessed. Skin CD4+IL4+ T cells were assessed with confocal microscopy from skin biopsies. Following rituximab treatment skin CD4+IL4+ T cells obviously decreased as seen with confocal microscopy. Moreover, peripheral CD4+IL4+ T cells decreased significantly compared to those from patients who received standard treatment alone: median (IQR): 14.9 (22.63-12.88) vs 7.87 (12.81-4.9)%, p = 0.005 and 9.43 (19.53-7.50)% vs 14.86 (21.96-6.75)%, p = NS at baseline and 6 months later respectively, whereas there was no difference in serum IL4 levels. Peripheral CD4+CD40L+ T cells also decreased significantly following rituximab treatment compared to those from patients who received standard treatment alone: median (IQR): 17.78 (25.64-14.44)% vs 8.15 (22.85-3.08)%, p = 0.04 and 22.13 (58.77-8.20)% vs 72.11 (73.05-20.45)%, p = NS at baseline and 6 months later respectively. Furthermore, peripheral CD4+INFγ+ and CD4+IL17+ T cells revealed no differences following rituximab treatment. Our study demonstrates a link between rituximab treatment and CD4+IL4+ T cell decrease both in the skin and peripheral blood of patients with SSc.

Unraveling the ECM-Immune Cell Crosstalk in Skin Diseases

The extracellular matrix (ECM) is a complex network of proteins and proteoglycans secreted by keratinocytes, fibroblasts and immune cells. The function of the skin ECM has expanded from being a scaffold that provides structural integrity, to a more dynamic entity that is constantly remodeled to maintain tissue homeostasis. The ECM functions as ligands for cell surface receptors such as integrins, dystroglycans, and toll-like receptors (TLRs) and regulate cellular signaling and immune cell dynamics. The ECM also acts as a sink for growth factors and cytokines, providing critical cues during epithelial morphogenesis. Dysregulation in the organization and deposition of ECMs lead to a plethora of pathophysiological conditions that are exacerbated by aberrant ECM-immune cell interactions. In this review, we focus on the interplay between ECM and immune cells in the context of skin diseases and also discuss state of the art therapies that target the key molecular players involved.

The concentration-dependent effect of anethole on collagen, MMP-2 and GAG in human skin fibroblast cultures

PURPOSE

In aging skin and some skin disorders, components of skin extracellular matrix (ECM) are disturbed and therefore research to find skin drugs is important. Evaluation of anethole impact on collagen, GAGs and MMP-2 in human skin fibroblasts was the aim of this study.

MATERIALS AND METHODS

For collagen assay the Sircol dye, 5-[³H]proline and real time-PCR were used. MMP-2 activity was detected by zymography. GAG concentration was determined using 1,9-dimethylmethylene blue (DMMB). Cell viability was assayed with MTT.

RESULTS

In cells treated with 1 and 10 μM anethole, a significant increase in collagen synthesis was demonstrated. In contrast, collagen synthesis was significantly decreased in cells exposed to 100 μM anethole. Similar alterations were found in collagen type I expression. The concentration of collagen secreted into the medium was higher only in cells exposed to 1 μM anethole, while it was lower under the influence of higher compound concentrations. It may be due to the lack of pro-MMP-2 activation at 1 μM and a significant increase in the level of MMP-2 at 10 and 100 μM anethole. GAG concentration was reduced under the influence of 100 μM anethole, whereas anethole at lower concentrations revealed the ability to prevent H₂O₂-induced GAG increase. No significant cytotoxicity of anethole to fibroblasts was noted.

CONCLUSIONS

Our findings demonstrate the concentration-dependent action of anethole on the crucial components of ECM in cultured skin fibroblasts, which may be somewhat beneficial and may possibly be developed towards a therapeutic use in some skin disorders.

YAP/TAZ regulates TGF-β/Smad3 signaling by induction of Smad7 via AP-1 in human skin dermal fibroblasts

Background

Transcription factors YAP and TAZ function as the primary mediators of the Hippo pathway. Yet, crosstalk of YAP and TAZ with other signaling pathways remains relatively unexplored. We have explored the impact of YAP and TAZ levels on the TGF-β/Smad signaling pathway in human skin dermal fibroblasts.

Methods

YAP and TAZ levels in dermal fibroblasts were reduced in dermal fibroblasts by siRNA-mediated knockdown. The effects of YAP and TAZ reduction on TGF-β/Smad signaling were examined by quantitative real-time PCR, Western analysis, and immunostaining. Luciferase reporter assays and electrophoretic mobility shift assays were conducted to investigate the transcription factor DNA-binding and transcriptional activities.

Results

Knockdown of both YAP and TAZ (YAP/TAZ), but not either separately, impaired TGF-β1-induced Smad3 phosphorylation and Smad3 transcriptional activity, thereby inhibiting the expression of TGF-β target genes. This reduction by reduced levels of YAP/TAZ results from induction of inhibitory Smad7, which inhibits Smad3 phosphorylation and activity by TGF-β1. Conversely, prevention of Smad7 induction restores Smad3 phosphorylation and Smad3 transcriptional activity in fibroblasts that have reduced YAP/TAZ. In agreement with these findings, inhibition of YAP/TAZ transcriptional activity, similar to the reduction of YAP/TAZ levels, also significantly induced Smad7 and impaired TGF-β/Smad signaling. Further investigations revealed that reduced levels of YAP/TAZ led to induction of activator protein-1 (AP-1) activity, Activated AP-1 bound to DNA sequences in the Smad7 gene promoter, and deletion of these AP-1 binding sequences substantially reduced Smad7 promoter reporter activity.

Conclusion

YAP/TAZ functions in concert with transcription factor AP-1 and Smad7 to regulate TGF-β signaling, in human dermal fibroblasts. Reduction of YAP/TAZ levels leads to activation of AP-1 activity, which induces Smad7. Smad7 suppresses the TGF-β pathway.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0232-3) contains supplementary material, which is available to authorized users.

Clinical Characteristics of Systemic Sclerosis With Interstitial Lung Disease

Objectives

This study aims to compare the clinical characteristics of systemic sclerosis (SSc) patients with or without interstitial lung disease (ILD), and figure out whether the differences can be useful to suspect ILD in SSc.

Patients and methods

We retrospectively collected the clinical data of 108 patients with SSc (13 males, 95 females; mean age 50.1±13.5 years; range 14 to 78 years) and compared them according to the presence of ILD. ILD was confirmed by chest computed tomography, and pulmonary arterial hypertension was suspected when right ventricular systolic pressure was ≥40 mmHg based on echocardiography.

Results

Of the 108 patients, 49 (45.4) had diffuse type and 59 (54.6) had limited type SSc. Disease duration, percentages of positive anti-scleroderma 70 (anti-Scl70) antibody and anti-centromere antibody, white blood cell, platelet, erythrocyte sedimentation rate (ESR), and presence of pulmonary hypertension differed significantly. On multivariate logistic analysis, positive titer of anti-Scl70 antibody (odds ratio [OR]=15.65, p<0.001), platelet (OR=1.01, p=0.026), ESR (OR=1.02, p=0.037) and pulmonary hypertension (OR=21.97, p=0.003) were associated with ILD in patients with SSc.

Conclusion

In SSc patients with ILD, disease duration was longer and positive titer of anti-Scl70 antibody was more frequent, positive titer of anti- centromere antibody was less frequent, and white blood cell and platelet counts, ESR levels, and incidence of possible pulmonary hypertension were significantly higher than in those without ILD. Positive titer of anti-Scl70 antibody, platelet, ESR, and combination of pulmonary hypertension were independently associated with the presence of ILD in SSc patients.

The impact of high-dose narrowband ultraviolet A1 on dermal thickness, collagen and matrix-metalloproteinases in animal model of scleroderma

OBJECTIVE

The main purpose of the present study was to define the impact of high-dose of 365±5nm ultraviolet A1 (UVA1) on dermal fibrosis in the pre-established, bleomycin-induced mouse model of scleroderma.

METHODS

DBA/2 strain mice with the pre-established, bleomycin-induced scleroderma were irradiated with cumulative UVA1 dose of 1200J/cm² and in parallel were challenged with prolonged administration of bleomycin. Non-treated groups served as the control. Light source emitting a narrow band UVA1 light of 365±5nm and 21mW/cm² power density was used in the study. Histological analysis was performed for the evaluation of dermal thickness. The expressions of matrix-metalloproteinase-1 (MMP-1), matrix-metalloproteinase-3 (MMP-3), collagen types I and III were evaluated by immunohistochemical analyses. The Mann - Whitney U test was used for statistical analysis.

RESULTS

Dermal thickness in mice injected with bleomycin during all the experiment (8weeks) and irradiated with UVA1 for the last 5weeks was significantly lower than that in mice challenged only with bleomycin for 8weeks (253.96±31.83μm and 497.43±57.83μm, respectively; P=0.002). The dermal thickness after phototherapy was lower as compared with the pre-existing fibrotic changes observed after 3weeks of bleomycin injections (253.96±31.83μm and 443.87±41.76μm, respectively; P=0.002). High-dose of UVA1 induced the 5.8- and 5.2-fold increase in MMP-1 and MMP-3 expressions, respectively, and the 1.2- and 1.4-fold decrease in collagen type I and collagen type III expressions in the pre-established, bleomycin-induced scleroderma model as compared to that in the control non-irradiated mice (P=0.002).

CONCLUSIONS

Our study has demonstrated that a cumulative 365±5nm UVA1 radiation dosage of 1200J/cm² not only prevents the progression of dermal fibrosis, but also induces a regression of pre-existing fibrotic changes.

Periostin in Mature Stage Localized Scleroderma

BACKGROUND

Periostin is a novel matricellular protein expressed in many tissues, including bone, periodontal ligament, and skin. Although its expression is prominent in various fibrotic conditions, studies of periostin in localized scleroderma are rare.

OBJECTIVE

To investigate the expression of periostin and other molecules in localized scleroderma.

METHODS

A retrospective study of 14 patients with confirmed mature stage localized scleroderma was undertaken. Fourteen age-matched and biopsy site-matched subjects with normal skin were included as controls. Collagen fiber deposition, periostin, procollagen, transforming growth factor-β, and matrix metalloproteinase (MMP)-1 expression were assessed and compared between the two groups. Co-localization of α-smooth muscle actin and periostin was evaluated using confocal microscopy.

RESULTS

Periostin was predominantly expressed along the dermo-epidermal junction in the controls. Conversely, patients with localized scleroderma demonstrated increased collagen fiber deposition and periostin expression that was more widely distributed along the entire dermis. MMP-1 staining showed increased expression in the epidermis and dermis of patients compared to scanty expression in the controls. A semi-quantitative evaluation showed a higher proportion of excessive collagen bundle deposition (57.1% vs. 7.1%, p=0.013), diffuse periostin positivity (42.9% vs. 0%, p=0.016), and moderate MMP-1 positivity (71.4% vs. 7.1%, p=0.001) in patients than in the controls.

CONCLUSION

Compared to the controls, patients with localized scleroderma had enhanced periostin expression corresponding to increased collagen fiber deposition and unexpected overexpression of MMP-1. The results of this human in vivo study may implicate the pathogenesis of localized scleroderma.

Human Fibrotic Diseases: Current Challenges in Fibrosis Research

Human fibrotic diseases constitute a major health problem worldwide owing to the large number of affected individuals, the incomplete knowledge of the fibrotic process pathogenesis, the marked heterogeneity in their etiology and clinical manifestations, the absence of appropriate and fully validated biomarkers, and, most importantly, the current void of effective disease-modifying therapeutic agents. The fibrotic disorders encompass a wide spectrum of clinical entities including systemic fibrotic diseases such as systemic sclerosis (SSc), sclerodermatous graft vs. host disease, and nephrogenic systemic fibrosis, as well as numerous organ-specific disorders including radiation-induced fibrosis and cardiac, pulmonary, liver, and kidney fibrosis. Although their causative mechanisms are quite diverse and in several instances have remained elusive, these diseases share the common feature of an uncontrolled and progressive accumulation of fibrotic tissue in affected organs causing their dysfunction and ultimate failure. Despite the remarkable heterogeneity in the etiologic mechanisms responsible for the development of fibrotic diseases and in their clinical manifestations, numerous studies have identified activated myofibroblasts as the common cellular element ultimately responsible for the replacement of normal tissues with nonfunctional fibrotic tissue. Critical signaling cascades, initiated primarily by transforming growth factor-β (TGF-β), but also involving numerous cytokines and signaling molecules which stimulate profibrotic reactions in myofibroblasts, offer potential therapeutic targets. Here, we briefly review the current knowledge of the molecular mechanisms involved in the development of tissue fibrosis and point out some of the most important challenges to research in the fibrotic diseases and to the development of effective therapeutic approaches for this often fatal group of disorders. Efforts to further clarify the complex pathogenetic mechanisms of the fibrotic process should be encouraged to attain the elusive goal of developing effective therapies for these serious, untreatable, and often fatal disorders.

Proteomic Investigation of Dermal Fibroblasts Isolated from Affected and Unaffected Skin Samples from Patients with Limited Cutaneous Systemic Sclerosis: 2 Distinct Entities?

Objective.

To identify using proteomic analysis the proteins of altered abundance in the affected and unaffected limited cutaneous systemic sclerosis (lcSSc) skin fibroblasts.

Methods.

Excision biopsies (3 mm) were obtained from the affected and unaffected skin of 5 patients with lcSSc. Dermal fibroblasts were isolated enzymatically. Two-dimensional gel electrophoresis was used to separate and define proteins in affected and unaffected fibroblast lysates. Proteins of altered abundance were identified by mass spectrometry. Differences among skin samples were confirmed also by immunohistochemistry (IHC) and by quantitative real-time PCR (qRT-PCR) for type I collagen (Col-1) and vimentin (VIM).

Results.

Proteomic analysis revealed different expressions of proteins involved in cytoskeleton organization (27%), extracellular matrix remodeling (11%), response to oxidative stress (22%), energy metabolism (19%), protein metabolism (5%), cellular homeostasis (5%), signal transduction (3%), and protein transcription, synthesis, and turnover (8%). IHC analysis showed that SSc-affected epidermis is thickened and the dermis is strongly reactive to Col-1 and VIM (typical markers of activated myofibroblasts) compared to SSc-unaffected skin, whose stainings are comparable to those of control healthy skin. Overexpression of Col-1 and VIM mRNA levels in affected lcSSc fibroblasts compared to unaffected lcSSc ones was confirmed by qRT-PCR.

Conclusion.

Consistent with previous studies, these findings are important for 2 reasons: first, because they reveal the opposite behavior of dermal fibroblasts in the unaffected and affected skin areas of the same patient with lcSSc; second, because they demonstrate the histological/histochemical similarities between unaffected skin from patients with lcSSc and healthy control skin.

German guidelines for the diagnosis and therapy of localized scleroderma

Localized scleroderma designates a heterogeneous group of sclerotic skin disorders. Depending on the subtype, severity, and site affected, adjacent structures such as adipose tissue, muscles, joints, and bones may be involved. This is an update of the existing German AWMF (Association of the Scientific Medical Societies in Germany) guidelines (classification: S2k). These guidelines provide an overview of the definition, epidemiology, classification, pathogenesis, laboratory workup, histopathology, clinical scoring systems, as well as imaging and device-based workup of localized scleroderma. Moreover, consensus-based recommendations are given on the management of localized scleroderma depending on its clinical subtype. Treatment recommendations are presented in a therapeutic algorithm. No financial support was given by any pharmaceutical company. The guidelines are valid until July 2019.

Ultrastructural evaluation of gingival connective tissue in hereditary gingival fibromatosis

OBJECTIVE

To describe the ultrastructural features of hereditary gingival fibromatosis (HGF) in affected family members and compare microscopic findings with normal gingival (NG) tissue.

STUDY DESIGN

Gingival tissue samples from nine patients with HGF from five unrelated families were evaluated by transmission electron microscopy. Nine NG tissue samples were used for comparison.

RESULTS

Areas containing collagen fibrils forming loops and folds were observed in both groups, whereas oxytalan fibers were frequently identified in the HGF group. The diameter of collagen fibrils and the interfibrillar space among them were more uniform in the NG group than in the HGF group. Fibroblasts were the most common cells found in both the HGF and NG groups and exhibited enlarged, rough endoplasmic reticulum, mitochondria with well-preserved crests, conspicuous nucleoli, and euchromatic chromatin. Other cells, such as mast cells, plasma cells, and macrophages, were also observed.

CONCLUSIONS

HGF tissues had ultrastructural characteristics that were very similar to those of NG tissues. Oxytalan fibers were observed more frequently in the HGF samples than in the NG samples. Other studies of HGF in patients from different families should be performed to better understand the pathogenesis of this hereditary condition.

Endothelial to Mesenchymal Transition (EndoMT) in the Pathogenesis of Human Fibrotic Diseases

Fibrotic diseases encompass a wide spectrum of clinical entities including systemic fibrotic diseases such as systemic sclerosis, sclerodermatous graft versus host disease, nephrogenic systemic fibrosis, and IgG₄-associated sclerosing disease, as well as numerous organ-specific disorders including radiation-induced fibrosis, and cardiac, pulmonary, liver, and kidney fibrosis. Although their causative mechanisms are quite diverse, these diseases share the common feature of an uncontrolled and progressive accumulation of fibrous tissue macromolecules in affected organs leading to their dysfunction and ultimate failure. The pathogenesis of fibrotic diseases is complex and despite extensive investigation has remained elusive. Numerous studies have identified myofibroblasts as the cells responsible for the establishment and progression of the fibrotic process. Tissue myofibroblasts in fibrotic diseases originate from several sources including quiescent tissue fibroblasts, circulating CD34+ fibrocytes, and the phenotypic conversion of various cell types including epithelial and endothelial cells into activated myofibroblasts. However, the role of the phenotypic transition of endothelial cells into mesenchymal cells (Endothelial to Mesenchymal Transition or EndoMT) in the pathogenesis of fibrotic disorders has not been fully elucidated. Here, we review the evidence supporting EndoMT's contribution to human fibrotic disease pathogenesis.

Non-viral gene therapy: Gains and challenges of non-invasive administration methods

Gene therapy is becoming an influential part of the rapidly increasing armamentarium of biopharmaceuticals for improving health and combating diseases. Currently, three gene therapy treatments are approved by regulatory agencies. While these treatments utilize viral vectors, non-viral alternative technologies are also being developed to improve the safety profile and manufacturability of gene carrier formulations. We present an overview of gene-based therapies focusing on non-viral gene delivery systems and the genetic therapeutic tools that will further revolutionize medical treatment with primary focus on the range and development of non-invasive delivery systems for dermal, transdermal, ocular and pulmonary administrations and perspectives on other administration methods such as intranasal, oral, buccal, vaginal, rectal and otic delivery.

Arecoline increases basic fibroblast growth factor but reduces expression of IL-1, IL-6, G-CSF and GM-CSF in human umbilical vein endothelium

BACKGROUND

Areca nut chewing is associated with oral submucous fibrosis (OSF). Raised vascular basic fibroblast growth factor may induce fibrosis. Arecoline is a muscarinic alkaloid in areca nut, which we earlier reported causes injury and necrosis of human endothelium.

MATERIALS AND METHODS

Human umbilical vein endothelial cells were exposed to arecoline with or without tumor necrosis factor-α, and separately to acetylcholine, muscarine, or nicotine. Protein levels of basic fibroblast growth factor, as well as the inflammatory cytokines: granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor, and Interleukins-6, 1-α and 1-β, were determined by enzyme-linked immunosorbent assay. mRNA levels were established by real-time reverse transcription polymerase chain reaction.

RESULTS

Basic fibroblast growth factor was released into the culture medium at arecoline levels causing necrosis (P < 0.05). This contrasted with an opposite effect of arecoline on levels of the inflammatory cytokines (P < 0.05). Tumor necrosis factor-α increased IL-6 and granulocyte-macrophage colony stimulated factor, but arecoline reduced this stimulated expression (P < 0.05). Arecoline had no effect on mRNA for basic fibroblast growth factor, although there was reduced mRNA for the separate inflammatory cytokines studied. The effect of acetylcholine, muscarine, and nicotine was minimal and dissimilar to that of arecoline.

CONCLUSIONS

Data raise the possibility that arecoline-induced, vascular basic fibroblast growth factor contributes to OSF, by combining increased growth factor expression with endothelial necrosis, and thus driving fibroblast proliferation.

Implications of polyadenylation in health and disease

Polyadenylation is the RNA processing step that completes the maturation of nearly all eukaryotic mRNAs. It is a two-step nuclear process that involves an endonucleolytic cleavage of the pre-mRNA at the 3'-end and the polymerization of a polyadenosine (polyA) tail, which is fundamental for mRNA stability, nuclear export and efficient translation during development. The core molecular machinery responsible for the definition of a polyA site includes several recognition, cleavage and polyadenylation factors that identify and act on a given polyA signal present in a pre-mRNA, usually an AAUAAA hexamer or similar sequence. This mechanism is tightly regulated by other cis-acting elements and trans-acting factors, and its misregulation can cause inefficient gene expression and may ultimately lead to disease. The majority of genes generate multiple mRNAs as a result of alternative polyadenylation in the 3'-untranslated region. The variable lengths of the 3' untranslated regions created by alternative polyadenylation are a recognizable target for differential regulation and clearly affect the fate of the transcript, ultimately modulating the expression of the gene. Over the past few years, several studies have highlighted the importance of polyadenylation and alternative polyadenylation in gene expression and their impact in a variety of physiological conditions, as well as in several illnesses. Abnormalities in the 3'-end processing mechanisms thus represent a common feature among many oncological, immunological, neurological and hematological disorders, but slight imbalances can lead to the natural establishment of a specific cellular state. This review addresses the key steps of polyadenylation and alternative polyadenylation in different cellular conditions and diseases focusing on the molecular effectors that ensure a faultless pre-mRNA 3' end formation.

Recent advances in understanding the pathogenesis of scleroderma-interstitial lung disease

Systemic sclerosis (scleroderma, SSc) is a heterogeneous autoimmune connective tissue disease of unknown etiology. Interstitial lung disease (ILD) is a frequent complication, and a significant contributor to morbidity and mortality among SSc patients. SSc-ILD most commonly occurs within 10 years of diagnosis, and may be seen in patients with either the limited or diffuse cutaneous subset of SSc. SSc-ILD is a multifaceted disease process in which different factors and pathways are involved. Aberrant function of a variety of lung cells, cytokines, growth factors, peptides, and bioactive proteins, in combination with genetic and epigenetic regulators, have crucial functions in the pathogenesis of this disease. Here we present our view on recent advances regarding the pathogenesis of SSc-ILD.

The plasma cell signature in autoimmune disease

OBJECTIVE

Production of pathogenic autoantibodies by self-reactive plasma cells (PCs) is a hallmark of autoimmune diseases. We undertook this study to investigate the prevalence of PCs and their relationship to known pathogenic pathways to increase our understanding of the role of PCs in disease progression and treatment response.

METHODS

We developed a sensitive gene expression-based method to overcome the challenges of measuring PCs using flow cytometry. Whole-genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA1, IGJ, IGKC, IGKV4-1, and TNFRSF17, expressed predominantly in PCs. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy, for evaluating the relationship between PCs and other autoimmune disease-related genes, and for estimating PC levels in affected blood and tissue from patients with multiple autoimmune diseases.

RESULTS

The PC signature was highly sensitive and capable of detecting a change in as few as 360 PCs. The PC signature was reduced more than 90% in scleroderma patients following anti-CD19 treatment, and this reduction was highly correlated (r = 0.80) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed that 30-35% of lupus and rheumatoid arthritis patients had increased levels of PCs.

CONCLUSION

This newly developed PC signature provides a robust and accurate method of measuring PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases who may benefit from PC-depleting therapy.

Altered MCM protein levels and autophagic flux in aged and systemic sclerosis dermal fibroblasts

Aging is a common risk factor of many disorders. With age, the level of insoluble extracellular matrix increases leading to increased stiffness of a number of tissues. Matrix accumulation can also be observed in fibrotic disorders, such as systemic sclerosis (SSc). Although the intrinsic aging process in skin is phenotypically distinct from SSc, here we demonstrate similar behavior of aged and SSc skin fibroblasts in culture. We have used quantitative proteomics to characterize the phenotype of dermal fibroblasts from healthy subjects of various ages and from patients with SSc. Our results demonstrate that proteins involved in DNA and RNA processing decrease with age and in SSc, while those involved in mitochondrial and other metabolic processes behave the opposite. Specifically, mini-chromosome maintenance (MCM) helicase proteins are less abundant with age and SSc, and they exhibit an altered subcellular distribution. We observed that lower levels of MCM7 correlate with reduced cell proliferation, lower autophagic capacity and higher intracellular protein expression phenotypes of aged and SSc cells. Additionally, we show that SSc fibroblasts exhibit higher levels of senescence than their healthy counterparts, suggesting further similarities between the fibrotic disorder and the aging process. Hence, at the molecular level, SSc fibroblasts exhibit intrinsic characteristics of fibroblasts from aged skin.

Adenosine A2A receptor (A2AR) is a fine-tune regulator of the collagen1:collagen3 balance

Adenosine is a potent endogenous anti-inflammatory and immunosuppressive metabolite that is a potent modulator of tissue repair. However, the adenosine A2A receptor (A2AR)-mediated promotion of collagen synthesis is detrimental in settings such as scarring and scleroderma. The signaling cascade from A2AR stimulation to increased collagen production is complex and obscure, not least because cAMP and its downstream molecules PKA and Epac1 have been reported to inhibit collagen production. We therefore examined A2AR-stimulated signaling for collagen production by normal human dermal fibroblasts (NHDF). Collagen1 (Col1) and collagen3 (Col3) content after A2AR activation by CGS21680 was studied by western blotting. Contribution of PKA and Epac was analyzed by the PKA inhibitor PKI and by knockdowns of the PKA-Cα, -Cβ, -Cγ, Epac1, and Epac2. CGS21680 stimulates Col1 expression at significantly lower concentrations than those required to stimulate Col3 expression. A2AR stimulates Col1 expression by a PKA-dependent mechanism since PKA inhibition or PKA-Cα and -Cβ knockdown prevents A2AR-mediated Col1 increase. In contrast, A2AR represses Col3 via PKA but stimulates both Col1 and Col3 via an Epac2-dependent mechanism. A2AR stimulation with CGS21680 at 0.1 μM increased Col3 expression only upon PKA blockade. A2AR activation downstream signaling for Col1 and Col3 expression proceeds via two distinct pathways with varying sensitivity to cAMP activation; more highly cAMP-sensitive PKA activation stimulates Col1 expression, and less cAMP-sensitive Epac activation promotes both Col1 and Col3 expression. These observations may explain the dramatic change in Col1:Col3 ratio in hypertrophic and immature scars, where adenosine is present in higher concentrations than in normal skin.

Chemokine receptors CCR2 and CX3CR1 regulate skin fibrosis in the mouse model of cytokine-induced systemic sclerosis

BACKGROUND

Skin fibrotic disorders such as systemic sclerosis (SSc) are characterized by an excessive accumulation of extracellular matrix (ECM), and develop under the influence of certain cytokines. We previously established a mouse model of skin fibrosis induced by exogenous application of cytokines. We have revealed that both the number of macrophages and the levels of macrophage chemoattractant protein-1 (MCP-1) mRNA positively correlate with the extent of skin fibrosis. Macrophages can be divided into two subsets, the first expressing CCR2, and the second expressing CX3CR1.

OBJECTIVE

To elucidate the role of skin infiltrating macrophages based on CCR2 and CX3CR1 in this cytokine-induced murine fibrosis model.

METHODS

We examined the amounts of collagen deposited in granulation tissues, the numbers of macrophages and the levels of several mRNA in wild type (WT) mice, CCR2(-/-) mice, and CX3CR1(-/-) mice during injections of transforming growth factor-β (TGF-β) followed by injections of connective tissue growth factor (CTGF).

RESULTS

TGF-β injection increased the expressions of MCP-1, fractalkine, CCR2 and CX3CR1 mRNA in WT mice. The overproduction of collagen induced by TGF-β was significantly reduced by CCR2 deficiency, while collagen contents induced by CTGF were restored to wild-type levels. In contrast, overproduction of collagen in CX3CR1-deficient mice decreased nearly 50% by both TGF-β and CTGF stimulations.

CONCLUSION

The involvement of CCR2/MCP-1 interaction (CCR2-dependent loop) was during the TGF-β phase. In contrast, the fractalkine/CX3CR1 interaction contributes to the initiation of fibrosis by TGF-β and its maintenance by CTGF. Collectively, two subsets of macrophages both cooperatively and independently play important roles in the development of fibrosis.

The periprosthetic capsule and connective tissue diseases: a piece in the puzzle of autoimmune/autoinflammatory syndrome induced by adjuvants

Breast prostheses have been criticized for being responsible for triggering systemic autoimmune disease. The presence of breast implants causes a natural foreign body reaction characterized by the infiltration of macrophages and T-cells. Using PubMed, Medline and eMedicine, we performed a systematic literature review on the stages of periprosthetic capsule formation and cells involved in order to understand which immunological pathways could be responsible for giving rise to, and the development of, connective tissue disease such as systemic sclerosis. We focused on the relationship between tissue growth factor- β, interleukin (IL)-1, IL-6 and T helper 17 or T regulatory cells, as well as on their effects on the different steps of capsular tissue formation. A disturbance in the modulation of these key cytokines may be responsible, in susceptible individuals, for a perpetuation of the inflammatory reaction which can locally lead to capsular contracture and at the systemic level may contribute to triggering autoimmune diseases.

Vascular leak is a central feature in the pathogenesis of systemic sclerosis

OBJECTIVE

The main histopathological focus of systemic sclerosis (SSc) has concentrated on fibrotic changes. We investigated the microvasculature alterations in the skin of patients with SSc at various stages of disease duration with whole-field digital microscopy.

METHODS

Twenty consecutive patients with SSc, 1 with Raynaud's phenomenon (RP) without SSc, and 4 healthy controls underwent punch biopsy on the medial forearm. Eighteen patients were included in the primary analysis. Two with recent-onset diffuse cutaneous disease, 1 repeat SSc biopsy, and 1 patient with RP without SSc were also evaluated. All specimens were processed with histochemical stains and immunohistochemistry. We analyzed microvasculature abnormalities in an objective and systematic manner taking advantage of recent advances in whole-field digital microscopy. This analysis was coupled with ultrastructural evaluation performed with transmission electron microscopy (TEM).

RESULTS

Whole-field digital microscopy and TEM of SSc skin biopsies revealed that endothelial abnormalities are a universal feature regardless of clinical features and/or duration of disease. These features were not seen in any healthy control specimens or in the single RP patient samples. Whole-field digital microscopy identified increased interstitial edema (31.0% ± 9.6% vs 17.6% ± 3.3% in controls; p = 0.009) and fibrosis (75.6% ± 5.7% vs 66.1% ± 9.8% in controls; p = 0.02) in all patients with SSc. Lower CD34 staining was seen in SSc compared to healthy controls (0.32% ± 0.22% vs 1.31% ± 0.34%; p < 0.0001) and within the SSc population with interstitial lung disease (0.55% ± 0.22% vs 0.15% ± 0.16%; p = 0.01). Perivascular and interstitial infiltrate of mast cells was present in all SSc specimens.

CONCLUSION

Whole-field digital microscopy offers a means of rapidly carrying out objective, fully quantitative, and reproducible measurements of microscopic features of SSc microvascular change. The universal morphologically abnormal endothelial cells and interstitial edema in all patients with SSc biopsied suggests that SSc may be intrinsically a disease of the endothelium characterized by vascular leak.

Activation of COL1A2 promoter in human fibroblasts by Escherichia coli

The relationship between bacterial infection and collagen production was investigated using human fibroblasts transfected with the promoter of COL1A2 , which encodes the α1 chain of human type I collagen, linked to a luciferase reporter. The cells were used to assess the gene promoter activity of COL1A2 following bacterial stimulation. The COL1A2 promoter was activated by stimulation with fixed Escherichia coli in a dose-dependent manner, but not by fixed Staphylococcus aureus. Enhancement of collagen production was observed in the E. coli-stimulated fibroblasts compared to those without stimulation. Both anti-human Toll-like receptor (TLR) 4 antibody and polymyxin B clearly blocked the COL1A2 promoter activity stimulated by E. coli, while antibodies against human TLR2 and human transforming growth factor-β (TGF-β) receptor type II did not. These results indicate that E. coli can directly interact with TLR4 expressed on the surface of fibroblasts and can further induce human type I collagen gene expression and collagen production in these cells. These data also suggest that infection by gram-negative bacteria may cause fibrosis.

Intrinsic gene expression subsets of diffuse cutaneous systemic sclerosis are stable in serial skin biopsies

Skin biopsy gene expression was analyzed by DNA microarray from 13 diffuse cutaneous systemic sclerosis (dSSc) patients enrolled in an open-label study of rituximab, 9 dSSc patients not treated with rituximab, and 9 healthy controls. These data recapitulate the patient "intrinsic" gene expression subsets described previously, including fibroproliferative, inflammatory, and normal-like groups. Serial skin biopsies showed consistent and non-progressing gene expression over time, and importantly, the patients in the inflammatory subset do not move to the fibroproliferative subset, and vice versa. We were unable to detect significant differences in gene expression before and after rituximab treatment, consistent with an apparent lack of clinical response. Serial biopsies from each patient stayed within the same gene expression subset, regardless of treatment regimen or the time point at which they were taken. Collectively, these data emphasize the heterogeneous nature of SSc and demonstrate that the intrinsic subsets are an inherent, reproducible, and stable feature of the disease that is independent of disease duration. Moreover, these data have fundamental importance for the future development of personalized therapy for SSc; drugs targeting inflammation are likely to benefit those patients with an inflammatory signature, whereas drugs targeting fibrosis are likely to benefit those with a fibroproliferative signature.

The p65 subunit of NF-κB inhibits COL1A1 gene transcription in human dermal and scleroderma fibroblasts through its recruitment on promoter by protein interaction with transcriptional activators (c-Krox, Sp1, and Sp3)

Transcriptional mechanisms regulating type I collagen genes expression in physiopathological situations are not completely known. In this study, we have investigated the role of nuclear factor-κB (NF-κB) transcription factor on type I collagen expression in adult normal human (ANF) and scleroderma (SF) fibroblasts. We demonstrated that NF-κB, a master transcription factor playing a major role in immune response/apoptosis, down-regulates COL1A1 expression by a transcriptional control involving the -112/-61 bp sequence. This 51-bp region mediates the action of two zinc fingers, Sp1 (specific protein-1) and Sp3, acting as trans-activators of type I collagen expression in ANF and SF. Knockdown of each one of these trans factors by siRNA confirmed the trans-activating effect of Sp1/Sp3 and the p65 subunit of NF-κB trans-inhibiting effect on COL1A1 expression. Despite no existing κB consensus sequence in the COL1A1 promoter, we found that Sp1/Sp3/c-Krox and NF-κB bind and/or are recruited on the proximal promoter in chromatin immunoprecipitation (ChIP) assays. Attempts to elucidate whether interactions between Sp1/Sp3/c-Krox and p65 are necessary to mediate the NF-κB inhibitory effect on COL1A1 in ANF and SF were carried out; in this regard, immunoprecipitation assays revealed that they interact, and this was validated by re-ChIP. Finally, the knockdown of Sp1/Sp3/c-Krox prevents the p65 inhibitory effect on COL1A1 transcription in ANF, whereas only the siRNAs targeting Sp3 and c-Krox provoked the same effect in SF, suggesting that particular interactions are characteristic of the scleroderma phenotype. In conclusion, our findings highlight a new mechanism for COL1A1 transcriptional regulation by NF-κB, and these data could allow the development of new antifibrotic strategies.

Clinical significance of serum levels of secretory leukocyte protease inhibitor in patients with systemic sclerosis

We aimed to investigate the clinical significance of serum levels of secretory leukocyte protease inhibitor (SLPI), which is widely expressed in lung tissues and serves as a useful marker reflecting the activity of various lung diseases, in patients with systemic sclerosis (SSc). Serum SLPI levels were measured by a specific enzyme-linked immunosorbent assay (ELISA) in 58 SSc patients and 16 healthy controls. Serum SLPI levels in diffuse cutaneous SSc and in limited cutaneous SSc with interstitial lung disease (ILD) were significantly higher than those in healthy controls (43.1 ± 18.4 vs. 30.9 ± 3.76 ng/ml, p < 0.05 and 39.8 ± 10.3 vs. 30.9 ± 3.76 ng/ml, p < 0.01, respectively). The incidences of decreased percent diffusing capacity for carbon monoxide (%DLco) and decreased percent vital capacity (%VC) were significantly greater in SSc patients with elevated SLPI levels than in those with normal levels (73 vs. 31%, p < 0.01 and 24 vs. 4%, p < 0.05, respectively). Furthermore, serum SLPI levels were inversely correlated with %DLco (r = -0.40, p < 0.01), while they were positively correlated with surfactant protein D (r = 0.28, p < 0.05). Longitudinal study revealed the association of serum SLPI levels with the disease activity of SSc-ILD. SLPI serves as a useful serum marker for evaluating SSc-ILD.

Fibroblast abnormalities in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is a chronic systemic disease characterized by autoimmunity, vascular lesions and progressive fibrosis. The fibrotic component is dominant in SSc compared with other vascular or autoimmune diseases and determines its prognosis and therapeutic refractoriness. Fibroblasts are responsible for abnormal extracellular matrix accumulation. Studies in cultured SSc skin fibroblasts have facilitated the identification of potential pathways involved in their profibrotic phenotype. Profibrotic fibroblasts characterized by abnormal growth and extracellular matrix synthesis may differentiate or expand from normal resident fibroblasts. Recruitment of bone marrow-derived progenitors and transdifferentiation of different cell lineages might also be involved. Multiple factors and signaling pathways appear to be involved in the development or persistence of the SSc fibroblast phenotype. Although their relative relevance and interplay are unclear, aberrant TGF-β signaling seems pivotal and constitutes the best characterized therapeutic target.

Scleroderma-like properties of skin from caveolin-1-deficient mice: implications for new treatment strategies in patients with fibrosis and systemic sclerosis

Caveolin-1 (Cav-1), the principal structural component of caveolae, participates in the pathogenesis of several fibrotic diseases, including systemic sclerosis (SSc). Interestingly, affected skin and lung samples from patients with SSc show reduced levels of Cav-1, as compared to normal skin. In addition, restoration of Cav-1 function in skin fibroblasts from SSc patients reversed their pro-fibrotic phenotype. Here, we further investigated whether Cav-1 mice are a useful pre-clinical model for studying the pathogenesis of SSc. For this purpose, we performed quantitative transmission electron microscopy, as well as biochemical and immuno-histochemical analysis, of the skin from Cav-1 (-/-) null mice. Using these complementary approaches, we now show that skin from Cav-1 null mice exhibits many of the same characteristics as SSc skin from patients, including a decrease in collagen fiber diameter, increased tensile strength, and stiffness, as well as mononuclear cell infiltration. Furthermore, an increase in autophagy/mitophagy was observed in the stromal cells of the dermis from Cav-1 (-/-) mice. These findings suggest that changes in cellular energy metabolism (e.g., a shift towards aerobic glycolysis) in these stromal cells may be a survival mechanism in this "hostile" or pro-inflammatory microenvironment. Taken together, our results demonstrate that Cav-1 (-/-) null mice are a valuable new pre-clinical model for studying scleroderma. Most importantly, our results suggest that inhibition of autophagy and/or aerobic glycolysis may represent a new promising therapeutic strategy for halting fibrosis in SSc patients. Finally, Cav-1 (-/-) null mice are also a pre-clinical model for a "lethal" tumor micro-environment, possibly explaining the link between fibrosis, tumor progression, and cancer metastasis.

Lidocaine for systemic sclerosis: a double-blind randomized clinical trial

BACKGROUND

Systemic sclerosis (scleroderma; SSc) is an orphan disease with the highest case-specific mortality of any connective-tissue disease. Excessive collagen deposit in affected tissues is a key for the disease's pathogenesis and comprises most of the clinical manifestations. Lidocaine seems to be an alternative treatment for scleroderma considering that: a) the patient's having excessive collagen deposits in tissues affected by scleroderma; b) the patient's demonstrating increased activity of the enzyme prolyl hydroxylase, an essential enzyme for the biosynthesis of collagen; and c) lidocaine's reducing the activity of prolyl hydroxylase. The aim of this study was to evaluate the efficacy and safety of lidocaine in treating scleroderma.

METHODS

A randomized double-blind clinical trial included 24 patients with scleroderma randomized to receive lidocaine or placebo intravenously in three cycles of ten days each, with a one-month interval between them.

OUTCOMES

cutaneous (modified Rodnan skin score), oesophageal (manometry) and microvascular improvement (nailfold capillaroscopy); improvement in subjective self-assessment and in quality of life (HAQ).

RESULTS

There was no statistically significant difference between the groups for any outcome after the treatment and after 6-months follow-up. Improvement in modified Rodnan skin score occurred in 66.7% and 50% of placebo and lidocaine group, respectively (p = 0.408). Both groups showed an improvement in subjective self-assessment, with no difference between them.

CONCLUSIONS

Despite the findings of a previous cohort study favouring the use of lidocaine, this study demonstrated that lidocaine at this dosage and means of administration showed a lack of efficacy for treating scleroderma despite the absence of significant adverse effects. However, further similar clinical trials are needed to evaluate the efficacy of lidocaine when administered in different dosages and by other means.

Decreased expression of caveolin 1 in patients with systemic sclerosis: crucial role in the pathogenesis of tissue fibrosis

OBJECTIVE

Recent studies have implicated caveolin 1 in the regulation of transforming growth factor beta (TGFbeta) downstream signaling. Given the crucial role of TGFbeta in the pathogenesis of systemic sclerosis (SSc), we sought to determine whether caveolin 1 is also involved in the pathogenesis of tissue fibrosis in SSc. We analyzed the expression of CAV1 in affected SSc tissues, studied the effects of lack of expression of CAV1 in vitro and in vivo, and analyzed the effects of restoration of caveolin 1 function on the fibrotic phenotype of SSc fibroblasts in vitro.

METHODS

CAV1 expression in tissues was analyzed by immunofluorescence and confocal microscopy. The extent of tissue fibrosis in Cav1-knockout mice was assessed by histologic/histochemical analyses and quantified by hydroxyproline assays. Cav1-null and SSc fibroblast phenotypes and protein production were analyzed by real-time polymerase chain reaction, immunofluorescence, Western blot, and multiplexed enzyme-linked immunosorbent assay techniques. The effects of restoration of caveolin 1 function in SSc fibroblasts in vitro were also examined using a cell-permeable recombinant CAV1 peptide.

RESULTS

CAV1 was markedly decreased in the affected lungs and skin of SSc patients. Cav1-knockout mice developed pulmonary and skin fibrosis. Down-regulation of caveolin 1 was maintained in cultured SSc fibroblasts, and restoration of caveolin 1 function in vitro normalized their phenotype and abrogated TGFbeta stimulation through inhibition of Smad3 activation.

CONCLUSION

Caveolin 1 appears to participate in the pathogenesis of tissue fibrosis in SSc. Restoration of caveolin 1 function by treatment with a cell-permeable peptide corresponding to the CAV1 scaffolding domain may be a novel therapeutic approach in SSc.

Clinical Use of Interferon-gamma

Interferon gamma (IFN-gamma), a pleotropic cytokine, has been shown to be important to the function of virtually all immune cells and both innate and adaptive immune responses. In 1986, early clinical trials of this cytokine began to evaluate its therapeutic potential. The initial studies focused on the tolerability and pharmacology of IFN-gamma and systematically determined its antitumor and anti-infection activities. In the 20-plus years since those first trials, IFN-gamma has been used in a wide variety of clinical indications, which are reviewed in this article.

[AWMF Guideline no. 013/066. Diagnosis and therapy of circumscribed scleroderma]

Localized scleroderma is a rare autoimmune disease with primary affection of the skin, and occasional involvement of the fat tissue, muscle, fascia, and bone. Depending on the clinical subtype, the spectrum of skin lesions ranges from singular plaque lesions to severe generalized or linear subtypes which may lead to movement restrictions and permanent disability. This German S1-guideline proposes a classification of localized scleroderma that, considering the extent and depth of fibrosis, distinguishes limited, generalized, linear, and deep forms of localized scleroderma, together with its associated subtypes. The guideline includes a description of the pathogenesis, of differential diagnoses, and particular aspects of juvenile localized scleroderma, as well as recommendations for histopathologic, serologic, and biometric diagnostic procedures. Based on studies of topical and systemic treatments as well as phototherapy for localized scleroderma published in international literature, a treatment algorithm was developed which takes account of the different subtypes and the extent of disease.

Study of thymic size and function in children and adolescents with treatment refractory systemic sclerosis eligible for immunoablative therapy

Following hematopoietic stem cell transplantation (HSCT), thymic reconstitution of peripheral T lymphocytes is essential to avoid a chronically immunodeficient state and disease recurrence. The purpose of this study was to determine if children and adolescents with treatment refractory SSc, awaiting HSCT, have sufficient thymic function to reconstitute T lymphocyte function after transplantation. Thirteen children with systemic scleroderma were enrolled and assessed by physical exam, chest MRI, measurement of autoantibodies, B and T cell immuno-phenotyping, and quantization of T cell receptor rearrangement excision circles (TREC) as a marker of thymopoiesis. MRI detected thymic tissue in 9/13 children. TREC levels were detectable in all but one child but were significantly reduced (p<0.001) when compared to a control population. SSc patients also had a reduced percentage of naïve (CD45RA+CD31+) CD4+ T lymphocytes, further indicating diminished thymopoiesis. Our data suggest that thymic function in children with SSc might be insufficient for an adequate immunoreconstitution following transplantation in some patients. A thorough evaluation of immune and thymic functions to identify those patients prior to HSCT is recommended.