Analyte heterogeneity analysis as a possible potency parameter for MSC

Mesenchymal stem/stromal cells (MSC) have been transplanted for therapeutic purposes with inconsistent results. MSC preparations are heterogeneous, and this person-to-person heterogeneity may account for the variable clinical outcomes. Additionally, the mechanisms of therapeutic action for MSC are unclear which confounds attempts to understand and identify factors that may account for variable clinical results. Here, we report our analysis of MSC preparations for the expression levels of molecules that have been hypothesized to mediate MSC function. Although most of the analytes assessed demonstrated little divergent expression, several molecules were found with enhanced heterogeneity both within individual MSC preparations and among MSC preparations from the sample of multiple sclerosis patients. The variable expression of these molecules may relate to the therapeutic heterogeneity of MSC. Additionally, we found a novel set of molecules that were highly intercorrelated in MSC. The tight association of this group of molecules may represent an invariant molecular organization that is integral to MSC activity. The precise analysis of molecular expression levels in MSC has the potential to answer concerns about variable therapeutic effects of MSC transplantation as well as to understand the mechanism of clinical effects.