APRIL and BAFF Proteins Increase Proliferation of Human Adipose-Derived Stem Cells Through Activation of Erk1/2 MAP Kinase

Human adipose-derived stem cells (hASC) are mesenchymal stem cells with reduced immunogenicity and the ability to modulate immune responses. APRIL and BAFF proteins are overexpressed in inflammatory and autoimmune diseases for which allogeneic hASC therapy is currently under clinical investigation. Modification of hASC properties by the tissue microenvironment could be a critical factor in patient outcome and is still not well understood. Our aim was to characterize the APRIL/BAFF system in hASC by analyzing the ligand and receptor expression patterns, the effects mediated by APRIL and BAFF on hASC, and the underlying signaling. We found that hASC express the tumor necrosis factor proteins APRIL (a proliferation-inducing ligand) and BAFF (B cell-activator factor) as well as their receptors TACI (transmembrane activator and calcium-modulator and cyclophilin ligand interactor), BCMA (B cell maturation antigen) and the BAFF-specific receptor (BAFF-R). APRIL and BAFF secretion was differentially enhanced by C...