Cellular and molecular mechanisms in the pathophysiology of systemic sclerosis

Fibrosis is characterized by disproportionate accumulation of collagens and other extracellular matrix substances, resulting in organ dysfunction and failure. In systemic sclerosis, cellular and molecular mechanisms involved in the pathophysiology of fibrosis are highly complex and yet barely understood. Anatomopathological findings showed the coexistence of patchy inflammatory cell infiltration, microvascular injuries, and fibrotic foci. One of the most commonly accepted hypotheses considers endothelial activation as the triggering phenomenon inducing inflammatory and autoimmunity activation. The resulting cytokines and autoantibodies production accelerates the proliferating rate of normal fibroblasts and their transformation into myofibroblasts, leading to diffuse fibrosis. This review aims to focus on cellular and molecular mechanisms implicated in the fibrogenesis of systemic sclerosis.