Identification of Factors Produced and Secreted by Mesenchymal Stromal Cells with the SILAC Method.

Mesenchymal stromal cells (MSCs) secrete a large variety of proteins and factors, which shape the secretome. These proteins participate in multiple cellular functions, including the promotion of regenerative processes in the damaged tissue. Secretomes derived from either undifferentiated MSCs or these cells undergoing osteogenic, chondrogenic, or adipogenic differentiation have been characterized using different liquid chromatography tandem mass spectrometry (LC-MS/MS)-based quantitative proteomic approaches. In this chapter, we describe the use of the Stable Isotope Labeling by Amino Acids in Cell culture (SILAC) strategy for the identification and relative quantification of the mesenchymal stromal cell secretome, specifically during chondrogenesis.