Umbilical cord blood mesenchymal stem cells protect amyloid-β42 neurotoxicity via paracrine

AIM: To understand the neuroprotective mechanism of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) against amyloid-β42 (Aβ42) exposed rat primary neurons. METHODS: To evaluate the neuroprotective effect of hUCB-MSCs, the cells were co-cultured with Aβ42-exposed rat primary neuronal cells in a Transwell apparatus. To assess the involvement of soluble factors released from hUCB-MSCs in neuroprotection, an antibody-based array using co-cultured media was conducted. The neuroprotective roles of the identified hUCB-MSC proteins was assessed by treating recombinant proteins or specific small interfering RNAs (siRNAs) for each candidate protein in a co-culture system. RESULTS: The hUCB-MSCs secreted elevated levels of decorin and progranulin when co-cultured with rat primary neuronal cells exposed to Aβ42. Treatment with recombinant decorin and progranulin protected from Aβ42-neurotoxicity in vitro. In addition, siRNA-mediated knock-down of decorin and progranulin production in hUCB-MSCs reduced the anti-apoptotic effects of hUCB-MSC in the co-culture system. CONCLUSION: Decorin and progranulin may be involved in anti-apoptotic activity of hUCB-MSCs exposed to Aβ42.