Proteomic Study Revealed a Distinction Between Human Dermal Fibroblasts and Mesenchymal Stem Cells from Different Sources.

Mesenchymal stem cells (MSCs) are an essential tool in cell-based therapies. One of the most crucial factors for efficacy in regenerative medicine is the source of MSCs. Tissue origin has long been suggested as a potential determinant of MSC properties. Human dermal fibroblasts (HDFa) share similar characteristics with MSCs, and the question of whether HDFa are functionally equivalent to MSCs remains debated. The present work used proteomic and phenotypic analyses to compare HDFa, dental pulp stem cells (DPSCs), and adipose-derived mesenchymal stem cells (AD-MSCs). We observed similarities and/or differences in morphology, cell surface markers, differentiation, and proteomic profile. Proteome was profiled by nano liquid chromatography and comprehensively quantified by mass spectrometry. In fact, HDFa and MSCs shared similar surface markers, growth kinetics, and differentiation capacity. Proteomic analysis reproducibly identified and quantified 3,051 proteins, 86 of them were differentially abundant according to strict statistical criteria. We identified a set of proteins that determined signatures for each stem cell origin. Gene Ontology (GO) term enrichment of differentially accumulated proteins, and Gene Set Enrichment Analysis (GSEA) identified signaling pathways characteristic to individual cell types. Particularly, we highlighted signaling pathways involved in cell migration, adhesion, and Wnt signaling as downregulated in HDFa compared to DPSCs. Angiogenesis and vascularization were explicitly associated with AD-MSCs. The tissue repair process requires a well-coordinated integration of complex molecular events, including cell migration and proliferation, extracellular matrix deposition, angiogenesis, and remodeling. We propose that HDFa are an alternative to MSCs, but predict their worse behavior in defect repair models compared to DPSCs. Plausibly, AD-MSCs are more suitable candidates for angiogenesis models compared to DPSCs.