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 fac-tors 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 recombi-nant proteins or specific small interfering RNAs(siRNAs) for each candidate protein in a co-culture system.RESULTS:The hUCB-MSCs secreted elevated levels ofdecorin and progranulin when co-cultured with rat pri-mary neuronal cells exposed to Aβ42.Treatment with recombinant decorin and progranulin protected from Aβ42-neurotoxicity in vitro.In addition,siRNA-mediat-ed 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.