S100 Proteins As an Important Regulator of Macrophage Inflammation

The S100 proteins, a family of calcium-binding cytosolic proteins, have a broad range of intracellularand extracellularfunctions through regulating calcium balance, cell apoptosis, migration, proliferation, differentiation, energy metabolism, and inflammation. The intracellularfunctions of S100 proteinsinvolve interaction with intracellular receptors, membrane protein recruitment/transportation, transcriptional regulation and integrating with enzymes or nucleic acids and DNA repair. The S100 proteinscould also be released from the cytoplasm, induced by tissue/ cell damageand cellular stress. The extracellular S100 proteins, serving as a danger signal, are crucial in regulating immune homeostasis, post-traumatic injury, and inflammation. Extracellular S100 proteinsare also considered biomarkers for some specific diseases. In this review, we will discuss the multi-functional roles of S100 proteins, especially their potential roles associated with cell migration, differentiation, tissue repair and inflammation.