Figure 1.

Molecular pathogenesis of initial systemic sclerosis. In early SSc vascular damage activates endothelial cells, leading to the expression of adhesion molecules, chemokine production, endothelin-1 release, and activation of coagulation cascade. Chemokines attract macrophages, while DAMPs activate dendritic cells. Activated T cells release IL-6, IL-4, and IL-13, stimulating B cells to produce autoantibodies. Fibroblasts, driven by TGF-beta, IL-13, and IL-6, generate ROS and become myofibroblasts, which secrete growth factors and extracellular matrix molecules, leading to fibrosis.

Abbreviations: SSc, systemic sclerosis; DAMP, damage-associated molecular patterns; TGF, transforming growth factor ; IL, interleukin; ROS, reactive oxygen species.