Sphingosine-1-Phosphate Enhance Osteogenic Activity of Multipotent Stromal Cells Cultured in Biodegradable 3D Alginate Hydrogels

Sphingolipids represent an important class of bioactive signaling lipids that regulates many processes in vertebrate development, physiology, and pathology. Sphingosine-1-phosphate is a pleiotropic signaling molecule belonging to the chemoattractant proteins, which play key roles in numerous cellular processes, including circulating stem cells' recruitment. This study aimed to evaluate whether sphingosine-1-phosphate can also enhance the osteogenic properties of multipotent stromal stem cells cultured in alginate hydrogels and improve the process of ECM deposition. We focused on mesenchymal stem cells of bone marrow origin and used immunohistochemistry and protein expression analysis combined with advanced scanning electron microscopy techniques to describe influence of sphingosine-1-phosphate on cultured cells. In addition, architecture of extracellular matrix including the distribution of hydroxyapatite-like particles involved in biomineralization in the alginate hydrogels were investigated. Based on results obtained in this study, we postulate that alginate hydrogel doped with sphingosine-1-phosphate significantly enhanced osteogenic differentiation potential of bone marrow mesenchymal stem cells and influenced the distribution of ECM. Thus, the data presented here might provide an important information, concerning the application of sphingolipids in alginate based hydrogels designed for bone tissue engineering.