Therapeutic interleukin-6 blockade reverses transforming growth factor-beta pathway activation in dermal fibroblasts: insights from the faSScinate clinical trial in systemic sclerosis

Nifuroxazide-loaded cubosomes exhibit an advancement in pulmonary delivery and attenuate bleomycin-induced lung fibrosis by regulating the STAT3 and NF-κB signaling: A new challenge for unmet therapeutic needs

Pulmonary fibrosis (PF) is a chronic progressive disease that portends a very poor prognosis. It has been suggested that STAT3 is a potential target in PF. This study highlights the importance of cubosomes as a drug delivery system in enhancing the bioavailability of nifuroxazide (NXZD), a poorly soluble STAT3 inhibitor. NXZD-loaded cubosomes (NXZD-LC) were in vitro and in vivo evaluated. In vitro, cubosomes presented a poly-angular nanosized particles with a mean size and zeta potential of 223.73 ± 4.73 nm and - 20.93 ± 2.38 mV, respectively. The entrapment efficiency of nifuroxazide was 90.56 ± 4.25%. The in vivo pharmacokinetic study and the lung tissue accumulation of NXZD were performed by liquid chromatography-tandem mass spectrometry after oral administration to rats. The nanoparticles exhibited a two-fold increase and 1.33 times of bioavailability and lung tissue concentration of NXZD compared to NXZD dispersion, respectively. In view of this, NXZD-LC effectively attenuated PF by targeting STAT3 and NF-κB signals. As a result, NXZD-LC showed a potential anti-inflammatory effect as revealed by the significant decrease in MCP-1, ICAM-1, IL-6, and TNF-α and suppressed fibrogenic mediators as indicated by the significant reduction in TGF-β, TIMP-1, and PDGF-BB in lung tissues. Besides, NXZD-LC improved antioxidant defense mechanisms and decreased LDH and BALF total protein. These effects contributed to decreased collagen deposition. To conclude, cubosomes represent an advantageous pharmaceutical delivery system for enhancing pulmonary delivery of poorly soluble drugs. Additionally, repurposing NXZD as an antifibrotic agent is a promising challenge and new therapeutic approach for unmet therapeutic needs.

Self-Assembled Human Skin Equivalents Model Macrophage Activation of Cutaneous Fibrogenesis in Systemic Sclerosis

OBJECTIVE

The development of precision therapeutics for systemic sclerosis (SSc) has been hindered by the lack of models that accurately mimic the disease in vitro. This study was undertaken to design and test a self-assembled skin equivalent (saSE) system that recapitulates the cross-talk between macrophages and fibroblasts in cutaneous fibrosis.

METHODS

SSc-derived dermal fibroblasts (SScDFs) and normal dermal fibroblasts (NDFs) were cultured with CD14+ monocytes from SSc patients or healthy controls to allow de novo stroma formation. Monocyte donor-matched plasma was introduced at week 3 prior to seeding keratinocytes to produce saSE with a stratified epithelium. Tissue was characterized by immunohistochemical staining, atomic force microscopy, enzyme-linked immunosorbent assay, and quantitative reverse transcriptase-polymerase chain reaction.

RESULTS

Stroma synthesized de novo from NDFs and SScDFs supported a fully stratified epithelium to form saSE. A thicker and stiffer dermis was generated by saSE with SScDFs, and more interleukin-6 and transforming growth factor β (TGFβ) was secreted by saSE with SScDFs compared to saSE with NDFs, regardless of the inclusion of monocytes. Tissue with SSc monocytes and plasma had amplified dermal thickness and stiffness relative to control tissue. Viable CD163+ macrophages were found within the stroma of saSE 5 weeks after seeding. Additionally, SSc saSE contained greater numbers of CD163+ and CD206+ macrophages compared to control saSE. TGFβ blockade inhibited stromal stiffness to a greater extent in SSc saSE compared to control saSE.

CONCLUSION

These data suggest reciprocal activation between macrophages and fibroblasts that increases tissue thickness and stiffness, which is dependent in part on TGFβ activation. The saSE system may serve as a platform for preclinical therapeutic testing and for molecular characterization of SSc skin pathology through recapitulation of the interactions between macrophages and fibroblasts.

Therapeutic Options for Systemic Sclerosis: Current and Future Perspectives in Tackling Immune-Mediated Fibrosis

Systemic sclerosis (SSc) is a severe auto-immune, rheumatic disease, characterized by excessive fibrosis of the skin and visceral organs. SSc is accompanied by high morbidity and mortality rates, and unfortunately, few disease-modifying therapies are currently available. Inflammation, vasculopathy, and fibrosis are the key hallmarks of SSc pathology. In this narrative review, we examine the relationship between inflammation and fibrosis and provide an overview of the efficacy of current and novel treatment options in diminishing SSc-related fibrosis based on selected clinical trials. To do this, we first discuss inflammatory pathways of both the innate and acquired immune systems that are associated with SSc pathophysiology. Secondly, we review evidence supporting the use of first-line therapies in SSc patients. In addition, T cell-, B cell-, and cytokine-specific treatments that have been utilized in SSc are explored. Finally, the potential effectiveness of tyrosine kinase inhibitors and other novel therapeutic approaches in reducing fibrosis is highlighted.

Targeting Systemic Sclerosis from Pathogenic Mechanisms to Clinical Manifestations: Why IL-6?

Systemic sclerosis (SS) is a chronic autoimmune disorder, which has both cutaneous and systemic clinical manifestations. The disease pathogenesis includes a triad of manifestations, such as vasculopathy, autoimmunity, and fibrosis. Interleukin-6 (IL-6) has a special role in SS development, both in vascular damage and in the development of fibrosis. In the early stages, IL-6 participates in vascular endothelial activation and apoptosis, leading to the release of damage-associated molecular patterns (DAMPs), which maintain inflammation and autoimmunity. Moreover, IL-6 plays an important role in the development of fibrotic changes by mediating the transformation of fibroblasts into myofibroblasts. All of these are associated with disabling clinical manifestations, such as skin thickening, pulmonary fibrosis, pulmonary arterial hypertension (PAH), heart failure, and dysphagia. Tocilizumab is a humanized monoclonal antibody that inhibits IL-6 by binding to the specific receptor, thus preventing its proinflammatory and fibrotic actions. Anti-IL-6 therapy with Tocilizumab is a new hope for SS patients, with data from clinical trials supporting the favorable effect, especially on skin and lung damage.

Systemic Sclerosis-Associated Interstitial Lung Disease: How to Incorporate Two Food and Drug Administration-Approved Therapies in Clinical Practice

Systemic sclerosis (SSc; scleroderma) has the highest individual mortality of all rheumatic diseases, and interstitial lung disease (ILD) is among the leading causes of SSc-related death. Two drugs are now approved by the US Food and Drug Administration (FDA) and indicated for slowing the rate of decline in pulmonary function in patients with SSc-associated ILD (SSc-ILD): nintedanib (a tyrosine kinase inhibitor) and tocilizumab (the first biologic agent targeting the interleukin-6 pathway in SSc). In addition, 2 generic drugs with cytotoxic and immunoregulatory activity, mycophenolate mofetil and cyclophosphamide, have shown comparable efficacy in a phase II trial but are not FDA-approved for SSc-ILD. In light of the heterogeneity of the disease, the optimal therapeutic strategy for the management of SSc-ILD is still to be determined. The objectives of this review are 2-fold: 1) review the body of research focused on the diagnosis and treatment of SSc-ILD; and 2) propose a practical approach for diagnosis, stratification, management, and therapeutic decision-making in this clinical context. This review presents a practical classification of SSc patients in terms of disease severity (subclinical versus clinical ILD) and associated risk of progression (low versus high risk). The pharmacologic and nonpharmacologic options for first- and second-line therapy, as well as potential combination approaches, are discussed in light of the recent approval of tocilizumab for SSc-ILD.

IL-11 Is Elevated and Drives the Profibrotic Phenotype Transition of Orbital Fibroblasts in Thyroid-Associated Ophthalmopathy

Orbital fibrosis is a hallmark of tissue remodeling in thyroid-associated ophthalmopathy (TAO). Previous studies have shown that interleukin (IL)-11 plays a pivotal profibrotic role in various inflammatory and autoimmune diseases. However, the expression pattern of IL-11 in patients with TAO and whether IL-11 is mechanistically linked with pathological fibrosis remains unknown. In this study, we investigated IL-11 levels in the serum and orbital connective tissue of patients with TAO, and evaluated the correlation of these levels with the patient's clinical activity score. We also evaluated the expression pattern of IL-11Rα in orbital connective tissue. Furthermore, we elucidated the regulatory factors, profibrotic function, and downstream signaling pathways for IL-11 in TAO using in vitro studies. IL-11 levels in serum and orbital connective tissues were increased in patients with TAO, as compared with healthy controls. In addition, both levels were positively correlated with disease activity. Single-cell RNA sequencing of orbital connective tissue indicated that IL-11Rα was dominantly expressed in orbital fibroblasts (OFs). RNA sequencing of paired unstimulated and transforming growth factor (TGF)-β1-stimulated samples demonstrated that upregulation of IL-11 expression defined the dominant transcriptional response. IL-11 signaling was also confirmed to be downstream of TGF-β1 and IL-1β. Therefore, we deduced that IL-11 protein is secreted in an autocrine loop in TAO. We also indicated that IL-11 mediated the profibrotic phenotype switch by inducing the expression of myofibroblast differentiation markers, including α-smooth muscle actin and collagen type I α1, which could be abrogated by an anti-IL-11 neutralizing antibody. Furthermore, we revealed that extracellular regulated protein kinase may be a crucial factor in the pro-fibrotic, translationally specific signaling activity of IL-11. These data demonstrate that IL-11 plays a crucial role in orbital fibroblast phenotype switching and may be a potential therapeutic target candidate for the treatment of TAO.

DRUGGING "UNDRUGGABLE" DISEASE-CAUSING PROTEINS: FOCUS ON SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION (STAT) 3

Signal transducer and activator of transcription (STAT) 3 has been assigned to the group of "undruggable" disease-causing proteins, despite its containing a Src-homology (SH) 2 domain, a potential Achilles' heel that has eluded successful targeting by academic and pharmaceutical groups over the past 30 years. Based on mutational and modeling studies, our group developed a unique virtual ligand screening strategy targeting the STAT3 SH2 domain that was coupled to robust biochemical and cellular assays and structure-based medicinal chemistry and led to the identification of TTI-101. TTI-101 represents one of the most advanced, direct, small-molecule inhibitors of an SH2 domain-containing, disease-causing protein in clinical development. TTI-101 is currently being evaluated in a Phase 1 study to determine safety and tolerability in addition to pharmacodynamic effects and efficacy in patients with advanced solid tumors.

Molecular Basis of Accelerated Aging with Immune Dysfunction-Mediated Inflammation (Inflamm-Aging) in Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic connective tissue disorder characterized by immune dysregulation, chronic inflammation, vascular endothelial cell dysfunction, and progressive tissue fibrosis of the skin and internal organs. Moreover, increased cancer incidence and accelerated aging are also found. The increased cancer incidence is believed to be a result of chromosome instability. Accelerated cellular senescence has been confirmed by the shortening of telomere length due to increased DNA breakage, abnormal DNA repair response, and telomerase deficiency mediated by enhanced oxidative/nitrative stresses. The immune dysfunctions of SSc patients are manifested by excessive production of proinflammatory cytokines IL-1, IL-6, IL-17, IFN-α, and TNF-α, which can elicit potent tissue inflammation followed by tissue fibrosis. Furthermore, a number of autoantibodies including anti-topoisomerase 1 (anti-TOPO-1), anti-centromere (ACA or anti-CENP-B), anti-RNA polymerase enzyme (anti-RNAP III), anti-ribonuclear proteins (anti-U1, U2, and U11/U12 RNP), anti-nucleolar antigens (anti-Th/T0, anti-NOR90, anti-Ku, anti-RuvBL1/2, and anti-PM/Scl), and anti-telomere-associated proteins were also found. Based on these data, inflamm-aging caused by immune dysfunction-mediated inflammation exists in patients with SSc. Hence, increased cellular senescence is elicited by the interactions among excessive oxidative stress, pro-inflammatory cytokines, and autoantibodies. In the present review, we will discuss in detail the molecular basis of chromosome instability, increased oxidative stress, and functional adaptation by deranged immunome, which are related to inflamm-aging in patients with SSc.

Esophageal Dysfunction in Systemic Sclerosis: An Update

Esophageal motility disorders are prevalent in 90% of patients with systemic sclerosis [scleroderma (SSc)], with an increased mortality rate in patients with severe esophageal involvement. Esophageal smooth muscle damage caused by ischemia, nerve damage, and inflammatory factors may be responsible for discomfort and various complications in these patients. The clinical manifestations are diverse. Most hospitals still use traditional esophageal manometry and 24-h pH monitoring to diagnose esophageal function in patients with SSc. The aim of this review article is to provide an overview of SSc-related esophageal motility disorders and related research progress, including the pathogenesis and clinical features of these disorders and the progress made in endoscopic diagnosis. We also discuss the possible pathogenesis and potential therapeutic targets.

Cellular and Molecular Diversity in Scleroderma

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.

Management of Progressive Fibrosing Interstitial Lung Diseases (PF-ILD)

Progressive fibrosing interstitial lung diseases (PF-ILD) consist of a diverse group of interstitial lung diseases (ILD) characterized by a similar clinical phenotype of accelerated respiratory failure, frequent disease exacerbation and earlier mortality. Regardless of underlying disease process, PF-ILD progresses through similar mechanisms of self-sustained dysregulated cell repair, fibroblast proliferation and alveolar dysfunction that can be therapeutically targeted. Antifibrotic therapy with nintedanib or pirfenidone slow lung function decline and are the backbone of treatment for IPF with an expanded indication of PF-ILD for nintedanib. Immunosuppression is utilized for some subtypes of PF-ILD, including connective tissue disease ILD and hypersensitivity pneumonitis. Inhaled treprostinil is a novel therapy that improves exercise tolerance in individuals with PF-ILD and concomitant World Health Organization (WHO) group 3 pulmonary hypertension. Lung transplantation is the only curative therapy and can be considered in an appropriate and interested patient. Supportive care, oxygen therapy when appropriate, and treatment of comorbid conditions are important aspects of PF-ILD management. This review summarizes the current data and recommendations for management of PF-ILD.

Contribution of monocytes and macrophages to the pathogenesis of systemic sclerosis: recent insights and therapeutic implications

PURPOSE OF REVIEW

To discuss recent studies addressing the role of monocytes and macrophages in the pathogenesis of systemic sclerosis (SSc) based on human and mouse models.

RECENT FINDINGS

Studies indicate that monocyte adhesion could be increased in SSc secondary to an interferon-dependent loss of CD52, and chemotaxis up-regulated through the CCR3/CCL24 pathway. Beyond the conventional M1/M2 paradigm of macrophage subpopulations, new subpopulations of macrophages have been recently described in skin and lung biopsies from SSc patients. Notably, single-cell ribonucleic acid sequencing has provided evidence for SPP1+ lung macrophages or FCGR3A+ skin macrophages in SSc. Impaired pro-resolving capacities of macrophages such as efferocytosis, i.e. the ability to phagocyte apoptotic cells, could also participate in the inflammatory and autoimmune features in SSc.

SUMMARY

Through their potential pro-fibrotic and pro-inflammatory properties, macrophages are at the cross-road of key SSc pathogenic processes and associated manifestations. Investigative drugs targeting macrophage polarization, such as pan-janus kinase inhibitors (tofacitinib or ruxolitinib) impacting both M1 and M2 activations, or Romilkimab inhibiting IL-4 and IL-13, have shown promising results in preclinical models or phase I/II clinical trials in SSc and other fibro-inflammatory disorders. Macrophage-based cellular therapy may also represent an innovative approach for the treatment of SSc, as initial training of macrophages may modulate the severity of fibrotic and autoimmune manifestations of the disease.

Investigation of the Expression of Inflammatory Markers in Oral Biofilm Samples in Patients with Systemic Scleroderma and the Association with Clinical Periodontal Parameters-A Preliminary Study

BACKGROUND

Systemic scleroderma (SSc) has multiple orofacial effects. The aim of this study was to analyze the expression of inflammatory mediators in biofilm samples. It was hypothesized that different expression levels and clinical associations might be drawn.

METHODS

A total of 39 biofilm samples from group 1 = SSc and group 2 = healthy control were examined for the expression levels of interleukin (IL)-2,-6, and -10; matrix metalloprotease (MMP)-9; and surface antigens CD90 and CD34 by quantitative real-time PCR and clinical parameters. Relative quantitative (RQ) gene expression was determined using the ∆∆CT method.

RESULTS

The mean bleeding on probing values (p = 0.006), clinical attachment loss (CAL) (p = 0.009), gingival recession (p = 0.020), limited mouth opening (p = 0.001) and cervical tooth defects (p = 0.011) were significantly higher in group 1. RQ expressions of IL-2 and CD34 were significantly lower, IL-6, MMP-9, and CD90 were significantly higher. There was a significant positive correlation of IL-6/MMP-9 and negative correlation of mouth opening/CAL and IL-6/CAL.

CONCLUSION

Different expression levels of IL-2, IL-6, MMP-9, CD34 and CD90 were detected in biofilm samples from patients with SSc compared to control. An immunological correlation to the clinical parameters of mouth opening and CAL was shown; thus, we conclude that SSc might have an impact on periodontal tissues.

Emerging roles for IL-11 in inflammatory diseases

Interleukin-11 (IL-11) is a cytokine that has been strongly implicated in the pathogenesis of fibrotic diseases and solid malignancies. Elevated IL-11 expression is also associated with several non-malignant inflammatory diseases where its function remains less well-characterized. Here, we summarize current literature surrounding the contribution of IL-11 to the pathogenesis of autoimmune inflammatory diseases, including rheumatoid arthritis, multiple sclerosis, diabetes and systemic sclerosis, as well as other chronic inflammatory conditions such as periodontitis, asthma, chronic obstructive pulmonary disease, psoriasis and colitis.

Fibroblast pathology in inflammatory diseases

Fibroblasts are important cells for the support of homeostatic tissue function. In inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease, fibroblasts take on different roles (a) as inflammatory cells themselves and (b) in recruiting leukocytes, driving angiogenesis, and enabling chronic inflammation in tissues. Recent advances in single-cell profiling techniques have transformed the ability to examine fibroblast states and populations in inflamed tissues, providing evidence of previously underappreciated heterogeneity and disease-associated fibroblast populations. These studies challenge the preconceived notion that fibroblasts are homogeneous and provide new insights into the role of fibroblasts in inflammatory pathology. In addition, new molecular insights into the mechanisms of fibroblast activation reveal powerful cell-intrinsic amplification loops that synergize with primary fibroblast stimuli to result in striking responses. In this Review, we focus on recent developments in our understanding of fibroblast heterogeneity and fibroblast pathology across tissues and diseases in rheumatoid arthritis and inflammatory bowel diseases. We highlight new approaches to, and applications of, single-cell profiling techniques and what they teach us about fibroblast biology. Finally, we address how these insights could lead to the development of novel therapeutic approaches to targeting fibroblasts in disease.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. The 2020 Highly morbid forms report

Chronic graft-versus-host disease (GVHD) can be associated with significant morbidity, in part because of nonreversible fibrosis, which impacts physical functioning (eye, skin, lung manifestations) and mortality (lung, gastrointestinal manifestations). Progress in preventing severe morbidity and mortality associated with chronic GVHD is limited by a complex and incompletely understood disease biology and a lack of prognostic biomarkers. Likewise, treatment advances for highly morbid manifestations remain hindered by the absence of effective organ-specific approaches targeting "irreversible" fibrotic sequelae and difficulties in conducting clinical trials in a heterogeneous disease with small patient numbers. The purpose of this document is to identify current gaps, to outline a roadmap of research goals for highly morbid forms of chronic GVHD including advanced skin sclerosis, fasciitis, lung, ocular and gastrointestinal involvement, and to propose strategies for effective trial design. The working group made the following recommendations: (1) Phenotype chronic GVHD clinically and biologically in future cohorts, to describe the incidence, prognostic factors, mechanisms of organ damage, and clinical evolution of highly morbid conditions including long-term effects in children; (2) Conduct longitudinal multicenter studies with common definitions and research sample collections; (3) Develop new approaches for early identification and treatment of highly morbid forms of chronic GVHD, especially biologically targeted treatments, with a special focus on fibrotic changes; and (4) Establish primary endpoints for clinical trials addressing each highly morbid manifestation in relationship to the time point of intervention (early versus late). Alternative endpoints, such as lack of progression and improvement in physical functioning or quality of life, may be suitable for clinical trials in patients with highly morbid manifestations. Finally, new approaches for objective response assessment and exploration of novel trial designs for small populations are required.

Resolution of inflammation in bone regeneration: From understandings to therapeutic applications

Impaired bone healing occurs in 5-10% of cases following injury, leading to a significant economic and clinical impact. While an inflammatory response upon injury is necessary to facilitate healing, its resolution is critical for bone tissue repair as elevated acute or chronic inflammation is associated with impaired healing in patients and animal models. This process is governed by important crosstalk between immune cells through mediators that contribute to resolution of inflammation in the local healing environment. Approaches modulating the initial inflammatory phase followed by its resolution leads to a pro-regenerative environment for bone regeneration. In this review, we discuss the role of inflammation in bone repair, the negative impact of dysregulated inflammation on bone tissue regeneration, and how timely resolution of inflammation is necessary to achieve normal healing. We will discuss applications of biomaterials to treat large bone defects with a specific focus on resolution of inflammation to modulate the immune environment following bone injury, and their observed functional benefits. We conclude the review by discussing future strategies that could lead to the realization of anti-inflammatory therapeutics for bone tissue repair.

Perspiration promotes the effect of sulphite on the shielding response of rodent skin

Perspiration and environmental chemicals, such as air pollutants, are two of the complicating factors of skin disease. It has not been studied how perspiration affect the skin responding to air pollutants. We applied topically artificial eccrine perspiration, sulphite or both to the mouse skin for one and two weeks to examine the influence of both factors on the shielding ability of healthy skin. Morphological examination showed apparent thickening of the epidermal layer in the skin samples with combined treatment at 1 week, and in the sections applied with sulphite and combined treatment at 2 weeks without significant difference in the extent of epidermal hyperplasia between two groups. The outcomes of immunohistochemical (IHC) analysis showed elevated percentages of dermal fibroblasts expressing interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), tumor necrosis factor β (TNF-β) and cyclooxygenase-2 (Cox-2). Results of two-way repeated measured analysis of variance (two-way RMANOVA) showed that both perspiration and sulphite, but not the interaction between them, were significant factors affecting the expression of proinflammatory cytokines. The evidences indicated that perspiration induced cytokines expressions in the dermal fibroblasts and promoted the effect of sulphite on the shielding response of the skin by inducing epidermis hyperplasia.

Efficacy and safety of biological drugs in interstitial lung disease associated with connective tissue diseases

INTRODUCTION

Interstitial lung disease (ILD) is one of the most important manifestations of connective tissue diseases (CTD) due to its association with high morbidity and mortality.

AREAS COVERED

Literature review focused on the evidence on efficacy and safety of biological therapy.

EXPERT OPINION

Rituximab (RTX) is the most studied drug, though tocilizumab (TCZ) has methodologically more robust evidence, whereas abatacept (ABA) has only anecdotal reports. RTX studies suggest a clinically relevant effect on lung function and fibrosis in refractory to conventional treatment patients, with a good safety profile. Its multi-level efficacy in systemic sclerosis and the potentially more favorable response of anti-synthetase syndrome, especially when administered early in acute-onset or exacerbated ILD stand out over current standard of care, pending the availability of randomized controlled clinical trials. The significant and clinically meaningful benefit found in lung function and fibrosis with TCZ in faSScinate and focuSSced trials represents a change with respect to the usual practice, reinforcing the importance of treatment in early subclinical or clinical SSc-ILD patients with risk factors for ILD progression. This evidence has led to the inclusion of both RTX and TCZ in the expert-based therapeutic algorithms or recommendations for CTD-ILD management.

30 Years of Biotherapeutics Development-What Have We Learned?

Since the birth of biotechnology, hundreds of biotherapeutics have been developed and approved by the US Food and Drug Administration (FDA) for human use. These novel medicines not only bring significant benefit to patients but also represent precision tools to interrogate human disease biology. Accordingly, much has been learned from the successes and failures of hundreds of high-quality clinical trials. In this review, we discuss general and broadly applicable themes that have emerged from this collective experience. We base our discussion on insights gained from exploring some of the most important target classes, including interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), IL-6, IL-12/23, IL-17, IL-4/13, IL-5, immunoglobulin E (IgE), integrins and B cells. We also describe current challenges and speculate about how emerging technological capabilities may enable the discovery and development of the next generation of biotherapeutics.

Redefining IL11 as a regeneration-limiting hepatotoxin and therapeutic target in acetaminophen-induced liver injury

Acetaminophen (N-acetyl-p-aminophenol; APAP) toxicity is a common cause of liver damage. In the mouse model of APAP-induced liver injury (AILI), interleukin 11 (IL11) is highly up-regulated and administration of recombinant human IL11 (rhIL11) has been shown to be protective. Here, we demonstrate that the beneficial effect of rhIL11 in the mouse model of AILI is due to its inhibition of endogenous mouse IL11 activity. Our results show that species-matched IL11 behaves like a hepatotoxin. IL11 secreted from APAP-damaged human and mouse hepatocytes triggered an autocrine loop of NADPH oxidase 4 (NOX4)-dependent cell death, which occurred downstream of APAP-initiated mitochondrial dysfunction. Hepatocyte-specific deletion of Il11 receptor subunit alpha chain 1 (Il11ra1) in adult mice protected against AILI despite normal APAP metabolism and glutathione (GSH) depletion. Mice with germline deletion of Il11 were also protected from AILI, and deletion of Il1ra1 or Il11 was associated with reduced c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) activation and quickly restored GSH concentrations. Administration of a neutralizing IL11RA antibody reduced AILI in mice across genetic backgrounds and promoted survival when administered up to 10 hours after APAP. Inhibition of IL11 signaling was associated with the up-regulation of markers of liver regenerations: cyclins and proliferating cell nuclear antigen (PCNA) as well as with phosphorylation of retinoblastoma protein (RB) 24 hours after AILI. Our data suggest that species-matched IL11 is a hepatotoxin and that IL11 signaling might be an effective therapeutic target for APAP-induced liver damage.

Tocilizumab Prevents Progression of Early Systemic Sclerosis-Associated Interstitial Lung Disease

OBJECTIVE

Tocilizumab (TCZ) has demonstrated lung function preservation in 2 randomized controlled trials in early systemic sclerosis (SSc). This effect has yet to be characterized in terms of radiographically evident quantitative lung involvement. We undertook this study to assess the impact of TCZ on lung function preservation in a post hoc analysis, stratifying treatment arms according to the degree of lung involvement.

METHODS

The focuSSced trial was a phase III randomized placebo-controlled trial of TCZ in patients with SSc and progressive skin disease. Participants underwent baseline and serial spirometry along with high-resolution chest computed tomography at baseline and at week 48. Quantitative interstitial lung disease (QILD) and fibrosis scores were assessed by computer software. We classified QILD into the following categories of lung involvement: mild (>5-10%), moderate (>10-20%), and severe (>20%).

RESULTS

Of 210 participants recruited for the trial, 136 patients (65%) had ILD. The majority of these patients (77%) had moderate-to-severe involvement (defined as >10% lung involvement). The TCZ arm demonstrated preservation of forced vital capacity percent predicted (FVC%) over 48 weeks (least squares mean change in FVC% = -0.1) compared to placebo (-6.3%). For mild, moderate, and severe QILD, the mean ± SD change in FVC% in the TCZ arm at 48 weeks were -4.1 ± 2.5% (n = 11), 0.7 ± 1.9% (n =19), and 2.1 ± 1.6% (n = 26), respectively, and in the placebo group were -10.0 ± 2.6% (n = 11), -5.7 ± 1.6% (n = 26), and -6.7 ± 2.0% (n = 16), respectively. Similar treatment-related preservation findings were seen independent of fibrosis severity.

CONCLUSION

TCZ in early SSc-associated ILD with progressive skin disease stabilized FVC% over 48 weeks, independent of the extent of radiographically evident QILD.

Natural Formulations: Novel Viewpoint for Scleroderma Adjunct Treatment

BACKGROUND

Scleroderma is a complex disease involving autoimmune, vascular, and connective tissues, with unknown etiology that can progress through any organ systems.

OBJECTIVE

Yet, no cure is available; the thorough treatment of scleroderma and current treatments are based on controlling inflammation. Nowadays, medicinal plants/natural-based formulations are emerging as important regulators of many diseases, including autoimmune diseases. Here, we provided an overview of scleroderma, also focused on recent studies on medicinal plants/natural-based formulations that are beneficial in scleroderma treatment/prevention.

METHODS

This study is the result of a search in PubMed, Scopus, and Cochrane Library with "scleroderma", "systemic sclerosis", "plant", "herb", and "phytochemical" keywords. Finally, 22 articles were selected from a total of 1513 results entered in this study.

RESULTS

Natural products can modulate the inflammatory and/or oxidative mediators, regulate the production or function of the immune cells, and control the collagen synthesis, thereby attenuating the experimental and clinical manifestation of the disease.

CONCLUSION

Natural compounds can be considered an adjunct treatment for scleroderma to improve the quality of life of patients suffering from this disease.

New Insights into Profibrotic Myofibroblast Formation in Systemic Sclerosis: When the Vascular Wall Becomes the Enemy

In systemic sclerosis (SSc), abnormalities in microvessel morphology occur early and evolve into a distinctive vasculopathy that relentlessly advances in parallel with the development of tissue fibrosis orchestrated by myofibroblasts in nearly all affected organs. Our knowledge of the cellular and molecular mechanisms underlying such a unique relationship between SSc-related vasculopathy and fibrosis has profoundly changed over the last few years. Indeed, increasing evidence has suggested that endothelial-to-mesenchymal transition (EndoMT), a process in which profibrotic myofibroblasts originate from endothelial cells, may take center stage in SSc pathogenesis. While in arterioles and small arteries EndoMT may lead to the accumulation of myofibroblasts within the vessel wall and development of fibroproliferative vascular lesions, in capillary vessels it may instead result in vascular destruction and formation of myofibroblasts that migrate into the perivascular space with consequent tissue fibrosis and microvessel rarefaction, which are hallmarks of SSc. Besides endothelial cells, other vascular wall-resident cells, such as pericytes and vascular smooth muscle cells, may acquire a myofibroblast-like synthetic phenotype contributing to both SSc-related vascular dysfunction and fibrosis. A deeper understanding of the mechanisms underlying the differentiation of myofibroblasts inside the vessel wall provides the rationale for novel targeted therapeutic strategies for the treatment of SSc.

Idiopathic pulmonary fibrosis and systemic sclerosis: pathogenic mechanisms and therapeutic interventions

Fibrotic diseases take a very heavy toll in terms of morbidity and mortality equal to or even greater than that caused by metastatic cancer. In this review, we examine the pathogenesis of fibrotic diseases, mainly addressing triggers for induction, processes that lead to progression, therapies and therapeutic trials. For the most part, we have focused on two fibrotic diseases with lung involvement, idiopathic pulmonary fibrosis, in which the contribution of inflammatory mechanisms may be secondary to non-immune triggers, and systemic sclerosis in which the contribution of adaptive immunity may be predominant.

Fibroblast-macrophage reciprocal interactions in health, fibrosis, and cancer

Fibroblasts and macrophages are present in all tissues, and mounting evidence supports that these cells engage in direct communication to influence the overall tissue microenvironment and affect disease outcomes. Here, we review the current understanding of the molecular mechanisms that underlie fibroblast-macrophage interactions in health, fibrosis, and cancer. We present an integrated view of fibroblast-macrophage interactions that is centered on the CSF1-CSF1R axis and discuss how additional molecular programs linking these cell types can underpin disease onset, progression, and resolution. These programs may be tissue and context dependent, affected also by macrophage and fibroblast origin and state, as seen most clearly in cancer. Continued efforts to understand these cells and the means by which they interact may provide therapeutic approaches for the treatment of fibrosis and cancer.

Altered CD4+ T cell and cytokine levels in peripheral blood and skin samples from systemic sclerosis patients and IL35 in CD4+ T cell growth

OBJECTIVE

This study explored the role of IL-35 in CD4+ T lymphocyte and skin fibroblast (HSF) activity and cytokine levels in systemic sclerosis.

METHODS

Blood and skin biopsies were collected from 41 patients and 39 healthy controls to assess CD4+ T lymphocytes and IL-35-related factors. CD4+ T lymphocytes were co-cultured with HSFs, rhIL-35, and IL-35 mAb to evaluate the cell viability, activation of CD4+T lymphocytes, and HSF cells.

RESULTS

The proportion of blood Th1/Th2 was lower and Th17/regulatory T cells (Treg) were higher in patients than in controls (p < 0.05). IL-35 and IL-17A levels were higher and IFN-γ, IL-10, and TGF-β levels were lower in patients than in controls. IL-17A, FoxP3, TGF-β1, and COL-1 mRNA and p-STAT1 and p-STAT4 were higher in skin tissues from patients than in those from controls (p < 0.05). IL-6 levels were higher, whereas IL-10 levels were lower in cell culture supernatants. α-SMA and COL-1 proteins and Ki67 positivity were higher in CD4+ T + HSF cells from patients than in those from controls. rhIL-35 treatment inhibited proliferation (p < 0.001), but increased IL-10 and decreased IL-17A, α-SMA, and COL-1 secretion into the conditioned medium of CD4+ T lymphocytes + HSFs from patients compared with those from controls. IL-35 mAb blocked the effects of IL-35 in CD4+ T + HSF cells (p < 0.05).

CONCLUSIONS

IL-35 plays an inhibitory role in CD4+ T lymphocyte proliferation but induces Treg cell differentiation by STAT1 signalling activation, HSF proliferation, and collagen expression in systemic sclerosis.

Engineering Advanced In Vitro Models of Systemic Sclerosis for Drug Discovery and Development

Systemic sclerosis (SSc) is a complex multisystem disease with the highest case-specific mortality among all autoimmune rheumatic diseases, yet without any available curative therapy. Therefore, the development of novel therapeutic antifibrotic strategies that effectively decrease skin and organ fibrosis is needed. Existing animal models are cost-intensive, laborious and do not recapitulate the full spectrum of the disease and thus commonly fail to predict human efficacy. Advanced in vitro models, which closely mimic critical aspects of the pathology, have emerged as valuable platforms to investigate novel pharmaceutical therapies for the treatment of SSc. This review focuses on recent advancements in the development of SSc in vitro models, sheds light onto biological (e.g., growth factors, cytokines, coculture systems), biochemical (e.g., hypoxia, reactive oxygen species) and biophysical (e.g., stiffness, topography, dimensionality) cues that have been utilized for the in vitro recapitulation of the SSc microenvironment, and highlights future perspectives for effective drug discovery and validation.

The Role of Pro-fibrotic Myofibroblasts in Systemic Sclerosis: from Origin to Therapeutic Targeting

Systemic sclerosis (SSc, scleroderma) is a complex connective tissue disorder characterized by multisystem clinical manifestations resulting from immune dysregulation/autoimmunity, vasculopathy and, most notably, progressive fibrosis of the skin and internal organs. In recent years, it has emerged that the main drivers of SSc-related tissue fibrosis are myofibroblasts, a type of mesenchymal cells with both the extracellular matrix-synthesizing features of fibroblasts and the cytoskeletal characteristics of contractile smooth muscle cells. The accumulation and persistent activation of pro-fibrotic myofibroblasts during SSc development and progression result into elevated mechanical stress and reduced matrix plasticity within the affected tissues and may be ascribed to a reduced susceptibility of these cells to pro-apoptotic stimuli, as well as their increased formation from tissue-resident fibroblasts or transition from different cell types. Given the crucial role of myofibroblasts in SSc pathogenesis, finding the way to inhibit myofibroblast differentiation and accumulation by targeting their formation, function and survival may represent an effective approach to hamper the fibrotic process or even halt or reverse established fibrosis. In this review, we discuss the role of myofibroblasts in SSc-related fibrosis, with a special focus on their cellular origin and the signaling pathways implicated in their formation and persistent activation. Furthermore, we provide an overview of potential therapeutic strategies targeting myofibroblasts that may be able to counteract fibrosis in this pathological condition.

Case Report: Pansclerotic Morphea-Clinical Features, Differential Diagnoses and Modern Treatment Concepts

Pansclerotic morphea (PSM) is a rare skin disease characterized by progressive stiffening of the skin with or without the typical superficial skin changes usually seen in morphea (localized scleroderma). Standard therapy, consisting of a combination of systemic glucocorticoids and methotrexate or mycophenolate mofetil, does rarely stop disease progression, which may lead to severe cutaneous sclerosis and secondary contractures. Little is known about the efficacy of newer biologicals such as abatacept, a fusion protein antibody against CTLA-4, or tocilizumab, a fully humanized IL-6R antibody, in the treatment of this pathology. We present the case of an 8 years old girl with an unusual, progressive stiffening of the skin, which was eventually diagnosed as pansclerotic morphea. A treatment with systemic glucocorticoids and methotrexate combined with tocilizumab led to a good clinical response within 2 months after initiation. In this paper, we discuss differential diagnoses to be considered and this new promising treatment option based on a case review of the literature.

Systemic sclerosis (scleroderma): remaining challenges

Despite progress in treating internal organ involvement in systemic sclerosis (scleroderma) (SSc), such as pulmonary disease, effective treatments for the hallmark of the disease, cutaneous fibrosis, remain elusive. None of the disease-modifying antirheumatic drugs (DMARDS) have shown proven efficacy for SSc skin fibrosis, and there remain no FDA-approved medications, all of which are off-label, for cutaneous fibrosis in SSc. This review article will briefly summarize conventional therapies, biologics and hematopoietic stem cell transplants and select ongoing clinical trials in SSc. The gold standard for measuring skin fibrosis in SSc is the modified Rodnan skin score (MRSSS). This is a validated test that measures skin thickness (0 to 3) at 17 locations for a total score of 51. Improvements in skin score over time are used in clinical trials to quantitate skin fibrosis. Although recording the Rodnan skin score is technically straightforward, requiring no special equipment, and noninvasive, the fluctuating natural history of the disease includes improvement over time without interventions, rendering meaningful trials difficult to assess. Understanding of the basic molecular mechanisms driving pathologic fibrosis in SSc remains lacking, and underpins the often empiric nature and likely the lack of efficacy of many therapeutics that have been tried. Although repeated skin biopsies might be a more precise way to follow disease progression and regression, this is necessarily invasive and requires special tools. Here, this review will look at conventional therapies, biologics, autologous hematopoietic stem cell transplantation, and catalog some of the ongoing clinical trials in SSc with a focus on cutaneous fibrosis.

IL11 is elevated in systemic sclerosis and IL11-dependent ERK signaling underlies TGFβ-mediated activation of dermal fibroblasts

Objectives

Interleukin 11 (IL11) is highly upregulated in skin and lung fibroblasts from patients with systemic sclerosis (SSc). Here we tested whether IL11 is mechanistically linked with activation of human dermal fibroblasts (HDFs) from patients with SSc or controls.

Methods

We measured serum IL11 levels in volunteers and patients with early diffuse SSc and manipulated IL11 signalling in HDFs using gain- and loss-of-function approaches that we combined with molecular and cellular phenotyping.

Results

In patients with SSc, serum IL11 levels are elevated as compared with healthy controls. All transforming growth factor beta (TGFβ) isoforms induced IL11 secretion from HDFs, which highly express IL11 receptor α-subunit and the glycoprotein 130 (gp130) co-receptor, suggestive of an autocrine loop of IL11 activity in HDFs. IL11 stimulated ERK activation in HDFs and resulted in HDF-to-myofibroblast transformation and extracellular matrix secretion. The pro-fibrotic action of IL11 in HDFs appeared unrelated to STAT3 activity, independent of TGFβ upregulation and was not associated with phosphorylation of SMAD2/3. Inhibition of IL11 signalling using either a neutralizing antibody against IL11 or siRNA against IL11RA reduced TGFβ-induced HDF proliferation, matrix production and cell migration, which was phenocopied by pharmacological inhibition of ERK.

Conclusions

These data reveal that autocrine IL11-dependent ERK activity alone or downstream of TGFβ stimulation promotes fibrosis phenotypes in dermal fibroblasts and suggest IL11 as a potential therapeutic target in SSc.

In vitro pharmacological effects of peficitinib on lymphocyte activation: a potential treatment for systemic sclerosis with JAK inhibitors

Objectives

Peficitinib, a novel Janus kinase (JAK) inhibitor, demonstrated promising results in treating RA in phase 3 clinical trials. This in vitro study was undertaken to characterize the pharmacological properties of peficitinib and investigate the involvement of JAK and signal transducer and activator of transcription (STAT) pathways in the pathological processes of SSc, which is also an autoimmune disease.

Methods

Phosphorylation levels of STAT molecules were assessed in peripheral blood mononuclear cells collected from patients with RA or SSc and healthy subjects, and in skin specimens obtained from 19 patients with SSc. In vitro inhibition of STAT phosphorylation and cytokine/chemokine production by peficitinib, tofacitinib and baricitinib were also characterized.

Results

Higher spontaneous STAT1 or STAT3 phosphorylation was observed in peripheral T-cells and monocytes from patients with RA and SSc compared with healthy subjects. In skin sections from patients with SSc, phosphorylated STAT3–positive cells were found in almost all cases, irrespective of disease subtype or patient characteristics. Conversely, phosphorylated STAT1-positive cells were observed only in samples from untreated patients with diffuse disease of short duration. Peficitinib inhibited STAT phosphorylation induced by various cytokines, with comparable efficacy to tofacitinib and baricitinib. Peficitinib also suppressed cytokine and chemokine production by peripheral blood mononuclear cells and skin fibroblasts.

Conclusion

Our results suggest that JAK/STAT pathways are constitutively activated in SSc and RA, and that the JAK inhibitor may represent a novel therapeutic option for SSc.

Targeted delivery in scleroderma fibrosis

Systemic sclerosis (SSc) is considered one of the most challenging and difficult to treat among rheumatic disorders, due to its severity, multiorgan manifestation and different outcomes. It manifests fibrosis in different organs, mostly in skin and lungs. The skin fibrosis expression is considered the first sign of the disease and usually it is followed by internal organ fibrosis. An aberrant immune system activation seems to relate to the expression of the disease, but even environmental influences and dysregulation of many molecules signalling pathways are involved in the development of the disease. Current therapies are limited and characterized by multiple side effects: systemic route is the elective administration route, which decreases patient adherence to the therapy, as they are often already bothered by pain and disfigurement. Treatments available are organ-based, originally indicated for other conditions and there is no therapy available to reduce the fibroblast population size within existing fibrotic lesions. Disease-modifying therapies or immunomodulatory agents that are highly effective in other rheumatic diseases have shown disappointing results in SSc. There are thus no standardized and effective treatments for this disease, and there are even unanswered questions related to the insurgence of the pathology and all the mechanisms involved. An ideal approach could be considered "targeted therapy" that will be an increasingly attainable objective insofar as our understanding of the disease improves. The advantages in identifying the molecule and the signalling pathways involved in the pathology have helped to find some novel compounds for the therapy of scleroderma fibrosis or following innovative uses for already-approved drugs, corroborated by many clinical studies.

Tocilizumab and its usage for skin diseases

The monoclonal anti-IL6 receptor antibody called Tocilizumab is widely used by rheumatologists for joint diseases. Its application in dermatology has mainly concerned scleroderma and Systemic Sclerosis in the last years. The most varied skin diseases treated with tocilizumab, such as psoriasis, psoriatic arthritis, Behcet's Syndrome, Lupus, and the already mentioned scleroderma up to multi-organ syndromes with skin involvement will be discussed. At the same time, there have been several side reactions to the drug involving the skin forcing careful skin monitoring during treatment. Despite the evidence currently available in the appropriate literature, there is no formal recommendation for any of these diseases to use Tocilizumab for therapeutic purposes. The aim of this review was to collect all the main evidence on the use and involvement of the drug in dermatological practice in order to stimulate further research or hypothesize on possible therapeutic options.

Emerging drugs for the treatment of scleroderma: a review of recent phase 2 and 3 trials

INTRODUCTION

Systemic sclerosis (SSc) has the highest case-specific mortality of all connective tissue diseases. Its underlying disease mechanism affects several organs and remains incompletely understood. Ongoing work clarifying its etiopathogenesis is helping to develop targeted therapy.

AREAS COVERED

Several clinical trials have evaluated the safety and efficacy of agents targeting different mechanisms of this disease. This review article reviews those mechanisms and surveys four key recent phase II or III clinical trials that are contributing to the landscape of SSc therapy. The reported trials primarily focus on patients with systemic sclerosis in the early phase of disease.

EXPERT OPINION

Traditional therapies for SSc center on immunosuppressive and cytotoxic agents. A new cadre of therapies is borne from improved understandings of SSc pathobiology and target the inflammatory-fibrotic pathways. Scleroderma trials have entered the initial phase of personalized medicine, recognizing molecular subsets that will improve upon cohort enrichment and maximize the measurable benefit of future therapies.

Hiding in Plain Sight: Interleukin-11 Emerges as a Master Regulator of Fibrosis, Tissue Integrity, and Stromal Inflammation

Interleukin (IL)-11 is upregulated in a wide variety of fibro-inflammatory diseases such as systemic sclerosis, rheumatoid arthritis, pulmonary fibrosis, inflammatory bowel disease, kidney disease, drug-induced liver injury, and nonalcoholic steatohepatitis. IL-11 is a member of the IL-6 cytokine family and has several distinct properties that define its unique and nonredundant roles in disease. The IL-11 receptor is highly expressed on stromal, epithelial and polarized cells, where noncanonical IL-11 signaling drives the three pathologies common to all fibro-inflammatory diseases-myofibroblast activation, parenchymal cell dysfunction, and inflammation-while also inhibiting tissue regeneration. This cytokine has been little studied, and publications on IL-11 peaked in the early 1990s, when it was largely misunderstood. Here we describe recent advances in our understanding of IL-11 biology, outline how misconceptions as to its function came about, and highlight the large potential of therapies targeting IL-11 signaling for treating human disease.

Dermal fibroblasts have different extracellular matrix profiles induced by TGF-β, PDGF and IL-6 in a model for skin fibrosis

Different stimulants might induce different extracellular matrix profiles. It is essential to gain an understanding and quantification of these changes to allow for focused anti-fibrotic drug development. This study investigated the expression of extracellular matrix by dermal fibroblast mimicking fibrotic skin diseases as SSc using clinically validated biomarkers. Primary healthy human dermal fibroblasts were grown in media containing FICOLL. The cells were stimulated with PDGF-AB, TGF-β1, or IL-6. Anti-fibrotic compounds (iALK-5, Nintedanib) were added together with growth factors. Biomarkers of collagen formation and degradation together with fibronectin were evaluated by ELISAs in the collected supernatant. Immunohistochemical staining was performed to visualize fibroblasts and proteins, while selected gene expression levels were examined through qPCR. TGF-β and PDGF, and to a lesser extent IL-6, increased the metabolic activity of the fibroblasts. TGF-β primarily increased type I collagen and fibronectin protein and gene expression together with αSMA. PDGF stimulation resulted in increased type III and VI collagen formation and gene expression. IL-6 decreased fibronectin levels. iALK5 could inhibit TGF-β induced fibrosis while nintedanib could halt fibrosis induced by TGF-β or PDGF. Tocilizumab could not inhibit fibrosis induced in this model. The extent and nature of fibrosis are dependent on the stimulant. The model has potential as a pre-clinical model as the fibroblasts fibrotic phenotype could be reversed by an ALK5 inhibitor and Nintedanib.

Biomarkers as an opportunity to stratify for outcome in systemic sclerosis

Systemic sclerosis (SSc) is a highly complex disease whose heterogeneity includes multiple aspects of the condition, such as clinical presentation, progression, extent and type of organ involvement, and clinical outcomes. Thus far, these features remain not easily predictable both at the patient group level and in a given patient with regard to age at onset and clinical course. The unpredictable clinical course represents an obstacle to focusing potentially effective treatment in patients that need it the most. At the time of organ involvement and clinical diagnosis, most of the clinical manifestations are irreversible; therefore, predicting outcomes becomes crucial. This can explain the multiple attempts to identify prognostic, predictive, and monitoring-both soluble and imaging-biomarkers over the past years. They range from the currently most used biomarkers, the autoantibodies associated with disease-specific clinical features and course, to the single recently proposed skin, lung, cardiac involvement biomarkers and to the composite scores capturing multiple aspects of the disease. This review will focus on soluble and imaging biomarkers that recently showed promising evidence for outcome stratification in patients with SSc.

Genome-wide whole blood transcriptome profiling in a large European cohort of systemic sclerosis patients

OBJECTIVES

The analysis of annotated transcripts from genome-wide expression studies may help to understand the pathogenesis of complex diseases, such as systemic sclerosis (SSc). We performed a whole blood (WB) transcriptome analysis on RNA collected in the context of the European PRECISESADS project, aiming at characterising the pathways that differentiate SSc from controls and that are reproducible in geographically diverse populations.

METHODS

Samples from 162 patients and 252 controls were collected in RNA stabilisers. Cases and controls were divided into a discovery (n=79+163; Southern Europe) and validation cohort (n=83+89; Central-Western Europe). RNA sequencing was performed by an Illumina assay. Functional annotations of Reactome pathways were performed with the Functional Analysis of Individual Microarray Expression (FAIME) algorithm. In parallel, immunophenotyping of 28 circulating cell populations was performed. We tested the presence of differentially expressed genes/pathways and the correlation between absolute cell counts and RNA transcripts/FAIME scores in regression models. Results significant in both populations were considered as replicated.

RESULTS

Overall, 15 224 genes and 1277 functional pathways were available; of these, 99 and 225 were significant in both sets. Among replicated pathways, we found a deregulation in type-I interferon, Toll-like receptor cascade, tumour suppressor p53 protein function, platelet degranulation and activation. RNA transcripts or FAIME scores were jointly correlated with cell subtypes with strong geographical differences; neutrophils were the major determinant of gene expression in SSc-WB samples.

CONCLUSIONS

We discovered a set of differentially expressed genes/pathways validated in two independent sets of patients with SSc, highlighting a number of deregulated processes that have relevance for the pathogenesis of autoimmunity and SSc.

Tocilizumab in systemic sclerosis: a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

A phase 2 trial of tocilizumab showed preliminary evidence of efficacy in systemic sclerosis. We assessed skin fibrosis and systemic sclerosis-associated interstitial lung disease (SSc-ILD) in a phase 3 trial to investigate the safety and efficacy of tocilizumab, an anti-interleukin-6 receptor antibody, in the treatment of systemic sclerosis.

METHODS

In this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial, participants were recruited from 75 sites in 20 countries across Europe, North America, Latin America, and Japan. Adults with diffuse cutaneous systemic sclerosis for 60 months or less and a modified Rodnan skin score (mRSS) of 10-35 at screening were randomly assigned (1:1) with a voice-web-response system to receive subcutaneous tocilizumab 162 mg or placebo weekly for 48 weeks, stratified by IL-6 levels; participants and investigators were masked to treatment group. The primary endpoint was the difference in change from baseline to week 48 in mRSS. Percentage of predicted forced vital capacity (FVC% predicted) at week 48, time to treatment failure, and patient-reported and physician-reported outcomes were secondary endpoints. This trial is registered with ClinicalTrials.gov (number NCT02453256) and is closed to accrual.

FINDINGS

Between Nov 20, 2015, and Feb 14, 2017, 210 individuals were randomly assigned to receive tocilizumab (n=104) or placebo (n=106). In the intention-to-treat population, least squares mean [LSM] change from baseline to week 48 in mRSS was -6·14 for tocilizumab and -4·41 for placebo (adjusted difference -1·73 [95% CI -3·78 to 0·32]; p=0·10). The shift in distribution of change from baseline in FVC% predicted at week 48 favoured tocilizumab (van Elteren nominal p=0·002 vs placebo), with a difference in LSM of 4·2 (95% CI 2·0-6·4; nominal p=0·0002), as did time to treatment failure (hazard ratio 0·63 [95% CI 0·37-1·06]; nominal p=0·08). Change in LSM from baseline to week 48 in Health Assessment Questionnaire-Disability Index and in patient-global and physician-global visual analogue scale assessments did not differ between tocilizumab and placebo. In the safety set, infections were the most common adverse events (54 [52%] of 104 participants in the tocilizumab group, 53 [50%] of 106 in the placebo group). Serious adverse events were reported in 13 participants treated with tocilizumab and 18 with placebo, primarily infections (three events, eight events) and cardiac events (two events, seven events).

INTERPRETATION

The primary skin fibrosis endpoint was not met. Findings for the secondary endpoint of FVC% predicted indicate that tocilizumab might preserve lung function in people with early SSc-ILD and elevated acute-phase reactants. Safety was consistent with the known profile of tocilizumab.

FUNDING

F Hoffmann-La Roche Ltd.

CD47 prevents the elimination of diseased fibroblasts in scleroderma

Scleroderma is a devastating fibrotic autoimmune disease. Current treatments are partly effective in preventing disease progression but do not remove fibrotic tissue. Here, we evaluated whether scleroderma fibroblasts take advantage of the "don't-eat-me-signal" CD47 and whether blocking CD47 enables the body's immune system to get rid of diseased fibroblasts. To test this approach, we used a Jun-inducible scleroderma model. We first demonstrated in patient samples that scleroderma upregulated transcription factor JUN and increased promoter accessibilities of both JUN and CD47. Next, we established our scleroderma model, demonstrating that Jun mediated skin fibrosis through the hedgehog-dependent expansion of CD26+Sca1- fibroblasts in mice. In a niche-independent adaptive transfer model, JUN steered graft survival and conferred increased self-renewal to fibroblasts. In vivo, JUN enhanced the expression of CD47, and inhibiting CD47 eliminated an ectopic fibroblast graft and increased in vitro phagocytosis. In the syngeneic mouse, depleting macrophages ameliorated skin fibrosis. Therapeutically, combined CD47 and IL-6 blockade reversed skin fibrosis in mice and led to the rapid elimination of ectopically transplanted scleroderma cells. Altogether, our study demonstrates the efficiency of combining different immunotherapies in treating scleroderma and provides a rationale for combining CD47 and IL-6 inhibition in clinical trials.

The role of the oncostatin M/OSM receptor β axis in activating dermal microvascular endothelial cells in systemic sclerosis

BACKGROUND

Scleroderma (SSc) is a rare autoimmune disease characterized by vascular impairment and progressive fibrosis of the skin and other organs. Oncostatin M, a member of the IL-6 family, is elevated in SSc serum and was recognized as a significant player in various stages of fibrosis. The goal of this study was to assess the contribution of the OSM/OSMRβ pathway to endothelial cell (EC) injury and activation in SSc.

METHODS

IHC and IF were used to assess the distribution of OSM and OSMRβ in SSc (n = 14) and healthy control (n = 7) skin biopsies. Cell culture experiments were performed in human dermal microvascular endothelial cells (HDMECs) and included mRNA and protein analysis, and cell migration and proliferation assays. Ex vivo skin organoid culture was used to evaluate the effect of OSM on perivascular fibrosis.

RESULTS

OSMRβ protein was elevated in dermal ECs and in fibroblasts of SSc patients. Treatments of HDMECs with OSM or IL-6+sIL-6R have demonstrated that both cytokines similarly stimulated proinflammatory genes and genes related to endothelial to mesenchymal transition (EndMT). OSM was more effective than IL-6+sIL-6R in inducing cell migration, while both treatments similarly induced cell proliferation. The effects of OSM were mediated via OSMRβ and STAT3, while the LIFR did not contribute to these responses. Both OSM and IL-6+sIL-6R induced profibrotic gene expression in HDMECs, as well as expansion of the perivascular PDGFRβ+ cells in the ex vivo human skin culture system. Additional studies in HDMECs showed that siRNA-mediated downregulation of FLI1 and its close homolog ERG resulted in increased expression of OSMRβ in HDMECs.

CONCLUSIONS

This work provides new insights into the role of the OSM/OSMRβ axis in activation/injury of dermal ECs and supports the involvement of this pathway in SSc vascular disease.

Interleukin-6 promotes proliferative vitreoretinopathy by inducing epithelial-mesenchymal transition via the JAK1/STAT3 signaling pathway

Purpose

Interleukin-6 (IL-6) is elevated in intraocular fluid from eyes with proliferative vitreoretinopathy (PVR), but the exact role of the cytokine is still unclear. We investigated the function and mechanism of IL-6 in retinal pigment epithelium (RPE) cell biology in vitro and in a mouse model in vivo.

Methods

After treatment with various concentrations of IL-6, RPE cell proliferation was assessed with cell counting kit-8 (CCK-8) assay, and epithelial-mesenchymal transition (EMT) markers were evaluated using western blotting and immunofluorescent staining. The activation of JAK1/STAT3 signaling was determined with western blotting. Moreover, the effects of blockade of IL-6/JAK1/STAT3 signaling were investigated using pharmacological inhibitor S3I-201. For in vivo studies, the PVR model was induced with intravitreal injection of dispase/collagenase in wild-type and IL-6 knockout mice. The severity of PVR was evaluated with histological analysis. The expression of IL-6, gp130, and EMT markers was assessed with quantitative real-time PCR and western blotting.

Results

IL-6 statistically significantly induced RPE cell proliferation and EMT in a dose-dependent manner in vitro, which was accompanied by rapid phosphorylation of JAK1 and STAT3. Blockade of the IL-6/JAK1/STAT3 pathway with S3I-201 apparently inhibited RPE proliferation and EMT. Furthermore, IL-6 and gp130 overexpression, and JAK1/STAT3 signaling hyperactivation were detected in the retinas of the wild-type mice at 1, 3, and 7 days after dispase/collagenase injection. Finally, we confirmed that IL-6 deficiency markedly alleviated mouse PVR development via inhibiting EMT.

Conclusions

These findings indicate that IL-6 promotes PVR by inducing RPE proliferation and EMT via the JAK1/STAT3 signaling pathway. We provided new evidence that therapeutic strategies to block IL-6 may be beneficial for PVR.