title: S100B protein in tissue development, repair and regeneration.
abstract: The Ca(2+)-binding protein of the EF-hand type, S100B, exerts both intracellular and extracellular regulatory activities. As an intracellular regulator, S100B is involved in the regulation of energy metabolism, transcription, protein phosphorylation, cell proliferation, survival, differentiation and motility, and Ca(2+) homeostasis, by interacting with a wide array of proteins (i.e., enzymes, enzyme substrates, cytoskeletal subunits, scaffold/adaptor proteins, transcription factors, ubiquitin E3 ligases, ion channels) in a restricted number of cell types. As an extracellular signal, S100B engages the pattern recognition receptor, receptor for advanced glycation end-products (RAGE), on immune cells as well as on neuronal, astrocytic and microglial cells, vascular smooth muscle cells, skeletal myoblasts and cardiomyocytes. However, RAGE may not be the sole receptor activated by S100B, the protein being able to enhance bFGF-FGFR1 signaling by interacting with FGFR1-bound bFGF in particular cell types. Moreover, extracellular effects of S100B vary depending on its local concentration. Increasing evidence suggests that at the concentration found in extracellular fluids in normal physiological conditions and locally upon acute tissue injury, which is up to a few nM levels, S100B exerts trophic effects in the central and peripheral nervous system and in skeletal muscle tissue thus participating in tissue homeostasis. The present commentary summarizes results implicating intracellular and extracellular S100B in tissue development, repair and regeneration.
authors.affiliation: Guglielmo Sorci, Francesca Riuzzi, Cataldo Arcuri, Claudia Tubaro, Roberta Bianchi, Ileana Giambanco, Rosario Donato, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, 06122 Perugia, Italy.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Sorci
authors.forename: Francesca
authors.initials: F
authors.lastname: Riuzzi
authors.forename: Cataldo
authors.initials: C
authors.lastname: Arcuri
authors.forename: Claudia
authors.initials: C
authors.lastname: Tubaro
authors.forename: Roberta
authors.initials: R
authors.lastname: Bianchi
authors.forename: Ileana
authors.initials: I
authors.lastname: Giambanco
authors.forename: Rosario
authors.initials: R
authors.lastname: Donato
keywords: Cell differentiation; Cell motility; Cell proliferation; Cell survival; Development; S100B; Tissue homeostasis; Tissue regeneration; Tissue repair