Vimentin: Regulation and pathogenesis.

Vimentin, an abundant cytoplasmic intermediate filament protein, is recognized for its important role in stabilizing intracellular structure. Vimentin has been recognized for its mechanical role in cell plasticity and stress absorbers. Additionally, the functions of vimentin, similar to all other cytoplasmic intermediate filaments, are correlated to its ability to interact with cellular components responsible for signaling as well as kinases, therefore exerting control on gene regulatory networks. Moreover, several studies reveal a novel form of vimentin present at the surface of the plasma membrane or released in the extracellular environment in different physiological and pathological conditions. Based on data pertaining to vimentin's location outside of the cell, novel functions have emerged. The vimentin promoter is complex and appears to be controlled by a combination of positive and negative regulatory elements. In this review, we first present the involvement of these regulatory elements as well as epigenetic regulation of vimentin in different physiological and pathological contexts, including cell growth, cell differentiation, cancer, epithelial to mesenchymal transition and viral infection. Furthermore, this review also analyzes the secretion of vimentin, its presence at the cell surface, the role of extracellular vimentin as a specific marker, its function as a receptor for the von Willebrand factor as well as the entry of viruses, requirements for pathogen invasion, transcellular migration, and the immune response. Finally, a discussion is featured regarding the delocalization of vimentin that may contribute to diseases and disorders.