Systemic sclerosis (SSc) is a clinically heterogeneous disorder of the connective tissue characterized by vascular alterations, immune/inflammatory manifestations, and organ fibrosis. SSc pathogenesis is complex and still poorly understood. Therefore, effective therapies are lacking and remain nonspecific and limited to disease symptoms. In the last few years, many molecular and cellular mediators of SSc fibrosis have been described, providing new potential options for targeted therapies. In this review: (i) we focused on the PDGF/PDGFR pathway as key signaling molecules in the development of tissue fibrosis; (ii) we highlighted the possible role of stimulatory anti-PDGFRα autoantibodies in the pathogenesis of SSc; (iii) we reported the most promising PDGF/PDGFR targeting therapies.
Systemic sclerosis (SSc) is a systemic, immune-mediated chronic disorder characterized by small vessel alterations and progressive fibrosis of the skin and internal organs. The combination of a predisposing genetic background and triggering factors that causes a persistent activation of immune system at microvascular and tissue level is thought to be the pathogenetic driver of SSc. Endothelial alterations with subsequent myofibroblast activation, excessive extracellular matrix (ECM) deposition, and unrestrained tissue fibrosis are the pathogenetic steps responsible for the clinical manifestations of this disease, which can be highly heterogeneous according to the different entity of each pathogenic step in individual subjects. Although substantial progress has been made in the management of SSc in recent years, disease-modifying therapies are still lacking. Several molecular pathways involved in SSc pathogenesis are currently under evaluation as possible therapeutic targets in clinical trials. These include drugs targeting fibrotic and metabolic pathways (e.g., TGF-β, autotaxin/LPA, melanocortin, and mTOR), as well as molecules and cells involved in the persistent activation of the immune system (e.g., IL4/IL13, IL23, JAK/STAT, B cells, and plasma cells). In this review, we provide an overview of the most promising therapeutic targets that could improve the future clinical management of SSc.
The platelet-derived growth factor receptor (PDGFR) is a membrane tyrosine kinase receptor involved in several metabolic pathways, not only physiological but also pathological, as in tumor progression, immune-mediated diseases, and viral diseases. Considering this macromolecule as a druggable target for modulation/inhibition of these conditions, the aim of this work was to find new ligands or new information to design novel effective drugs. We performed an initial interaction screening with the human intracellular PDGFRα of about 7200 drugs and natural compounds contained in 5 independent databases/libraries implemented in the MTiOpenScreen web server. After the selection of 27 compounds, a structural analysis of the obtained complexes was performed. Three-dimensional quantitative structure–activity relationship (3D-QSAR) and absorption, distribution, metabolism, excretion, and toxicity (ADMET) analyses were also performed to understand the physicochemical properties of identified compounds to increase affinity and selectivity for PDGFRα. Among these 27 compounds, the drugs Bafetinib, Radotinib, Flumatinib, and Imatinib showed higher affinity for this tyrosine kinase receptor, lying in the nanomolar order, while the natural products included in this group, such as curcumin, luteolin, and epigallocatechin gallate (EGCG), showed sub-micromolar affinities. Although experimental studies are mandatory to fully understand the mechanisms behind PDGFRα inhibitors, the structural information obtained through this study could provide useful insight into the future development of more effective and targeted treatments for PDGFRα-related diseases, such as cancer and fibrosis.
Systemic sclerosis, also known as scleroderma or SSc, is a condition characterized by significant heterogeneity in clinical presentation, disease progression, and response to treatment. Consequently, the design of clinical trials to successfully identify effective therapeutic interventions poses a major challenge. Recent advancements in skin molecular profiling technologies and stratification techniques have enabled the identification of patient subgroups that may be relevant for personalized treatment approaches. This narrative review aims at providing an overview of the current status of skin gene expression analysis using computational biology approaches and highlights the benefits of stratifying patients upon their skin gene signatures. Such stratification has the potential to lead toward a precision medicine approach in the management of SSc.
Background: Systemic sclerosis (SSc) is characterized by endothelial dysfunction leading to progressive vascular injury and fibrosis. While microvascular involvement is well established as an early disease feature, macrovascular disease has been historically underrecognized and poorly investigated in very early disease stages. Integrated assessments across the SSc spectrum, including very early diagnosis of systemic sclerosis (VEDOSS), remain limited. Methods: In this cross-sectional observational study, patients with established SSc, VEDOSS, and primary Raynaud’s phenomenon (PRP) were prospectively enrolled between October 2023 and April 2025. Participants underwent comprehensive microvascular and macrovascular evaluation, including nailfold videocapillaroscopy, multisegmental arterial Doppler ultrasound (carotid, aortic, and lower limb districts), flow-mediated dilation, and measurement of endothelial biomarkers (vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and circulating endothelial cells (CECs)). Traditional cardiovascular risk was estimated using Systematic Coronary Risk Estimation 2 (SCORE2). Results: Sixty-two female subjects were included (34 SSc, 14 VEDOSS, and 14 PRP). Microvascular abnormalities followed the expected disease continuum, with capillaroscopic changes present in 57% of VEDOSS and 91% of SSc patients. Although SCORE2 estimates and carotid intima–media thickness were comparable across groups, macrovascular abnormalities were more frequent in SSc (52.9%) and VEDOSS (50%) compared with PRP (21.4%). VCAM-1, ICAM-1, and CEC levels were significantly increased in SSc compared with PRP, whereas no significant differences were observed between VEDOSS and PRP. Conclusions: These findings support a unified micro- and macro-vascular disease model in SSc and demonstrate that macrovascular involvement is detectable already in the VEDOSS phase. Conventional cardiovascular risk scores underestimate the true vascular burden, highlighting the need for disease-specific risk stratification tools integrating vascular imaging and endothelial biomarkers.