Multiplexed Single-Cell Proteomic and Transcriptomic Analysis of Embryonic Stem Cells

While immunofluorescent labeling of ESC surface receptors can suggest a signal dependence on the cognate ligand for those receptors, it provides limited insight as to whether this pathway is autocrine or paracrine in nature. Bulk analysis of media conditioned by ESCs and feeders have been profiled with proteomic studies, but the distinct molecules within a heterogenous mixture cannot be traced back to the secretory cell of origin. We use a single-cell platform uniquely enables the high thoroughput, quantitative profiling of candidate signaling proteins secreted by a single ESC or ESC-derivative. The ability to simultaneously assay a multiplex of secreted proteins can define and classify subpopulations of cells with distinct secretomes, several of which may be characteristic of pluripotent cells. In addition, this novel diagnostic tool will also be useful in the field of regenerative medicine, particularly in studies related to the generation and application of induced pluripotent stem cell (iPSC) technology. The reprogramming of a somatic cell to a pluripotent cell is highly inefficient, and the mechanism underlying this process remains largely unknown. Probing the signaling aspects of a single cell undergoing the reprogramming process will yield novel insights into molecular mechanisms and thereby enhance the efficiency of the process.