The Notch signaling plays a predominant role in maintaining immunomodulatory activities of hUC-MSCs.

Abstract

<p>A. Western blotting shows that Bortezomib alone does not affect the IFN-γ-induced IDO1 expression, does not induce apoptosis as no PARP cleavage was induced, but elevates Mcl-1 protein level. B. Western blotting shows that siNotch1 transfection can silence approximately 50% of IDO1 protein expression, but does not induce apoptosis. C. Western blotting shows that treatment with 5 nM Bortezomib does not further enhance the effect of siNotch1 transfection on IDO1 reduction. In addition, Bortezomib and siNotch1 together do not induce apoptosis as no PARP cleavage is observed. D. The flow cytometry assay shows that siNotch1 transfection alone can significantly reduce the inhibitory effect of hUC-MSCs on Th1 lymphocyte proliferation. Bortezomib alone shows no such effect and does not enhance the effect of siNotch1 either. The * indicates statistical significance with <i>p</i><0.05.</p