BMP9 Secretome of hHiPC LC-MS/MS

To investigate BMP9/ALK1 signaling in human highly proliferative cells (hHiPC), we selected one primary population of hHiPC from 3 individuals and studied the secretome responses to BMP9 treatment. Proteins were collected in hHiPC treated conditioned media (CM) for mass spectrometry analysis. Proteomic analysis of the hHiPC secretome following BMP9 treatment demonstrates that the secreted proteins, sclerostin (SOST), meflin/immunoglobulin superfamily containing leucine rich repeat (ISLR), and insulin-like growth factor binding protein-3 (IGFBP3), are novel downstream targets of BMP9/ALK1-mediated signaling. Consistent with this hypothesis, lentiviral shRNA and pharmacological inhibition of ALK1 in hHiPCs suppressed secretion of SOST, ISLR, and IGFBP3 following BMP9 treatment as measured by secretome LC-MS/MS.