Quantitative protein profiling of conditioned medium cultured with various mesenchymal stem/stromal cells (MSCs)

To compare the proteins secreted by human primary cultured MSCs and human iPSC-derived MSCs in the medium, each MSCs and human dermal fibroblasts were cultured in PRIME-XV MSC Expansion XSFM medium for 48 hours, and the cultured media were collected. Albumin and immunoglobulin were removed from the cultured media using High select top14 abundant protein depletion mini spin columns. The depleted media were precipitated by acetone and subjected to trypsin digestion followed by desalting. Samples were labeled with mTRAQ reagent. Tryptic peptides were fractionated through SCX-HILIC mix mode and analyzed by nLC-Orbitrap in DDA mode. MS data were searched against UniProt using Mascot.