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Updated: Oct 3, 2025
Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-β Signaling
Published on: August 3, 2018
NADPH-derived ROS generation drives fibrosis and endothelial-to-mesenchymal transition in systemic sclerosis:
Anna Maria Posadino1, Gian Luca Erre2, Annalisa Cossu1
1Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy.
Abstract:
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.
Insights
Systemic sclerosis sera promote fibrosis and vascular changes by increasing reactive oxygen species (ROS) and endothelial to mesenchymal transition (EndMT). Specific microRNAs (miRNAs) in SSc sera may drive these fibrotic and vascular alterations.
Area of Science:
- Immunology
- Vascular Biology
- Fibrosis Research
Background:
- Systemic sclerosis (SSc) is an immune disorder with unknown causes, involving fibrosis and vascular issues.
- Endothelial damage and oxidative stress are suspected contributors to SSc.
- Current understanding of SSc pathogenesis, particularly vascular involvement, requires further elucidation.
Purpose of the Study:
- To investigate the impact of SSc sera on human pulmonary microvascular endothelial cells (HPMECs).
- To explore the role of reactive oxygen species (ROS) and endothelial to mesenchymal transition (EndMT) in SSc.
- To identify potential microRNA (miRNA) biomarkers associated with SSc-related fibrosis and vascular changes.
Main Methods:
- Incubation of HPMECs with sera from SSc patients and healthy donors.
- Measurement of ROS production, collagen synthesis, and cell proliferation.
- Assessment of EndMT markers (vWF, alpha-smooth muscle actin).
- Inhibition of NADPH oxidase to evaluate ROS's role.
- Analysis of fibrosis/EndMT-associated miRNA expression in sera.
Main Results:
- SSc sera significantly increased ROS production, collagen synthesis, and HPMEC proliferation.
- SSc sera induced EndMT, evidenced by decreased vWF and increased alpha-smooth muscle actin.
- NADPH oxidase inhibition prevented SSc-induced fibroproliferative effects, confirming ROS's role.
- Specific miRNAs (miR-21, miR-92a, miR-24, miR-27b, miR-125b, miR-29c, miR-181b) were upregulated in SSc sera, while miR-29b was downregulated.
Conclusions:
- NADPH oxidase-driven EndMT is a potential mechanism underlying fibrosis in SSc.
- Fibrosis-associated miRNAs in SSc sera may initiate and sustain vascular alterations.
- Targeting ROS and specific miRNAs could offer therapeutic strategies for SSc.
