Amelioration of cognitive ability in senescence-accelerated mouse prone 8 (SAMP8) by intra-bone marrow-bone marrow transplantation

Bone marrow cells (BMCs) can increase the number of activated microglias, which play a central role in the inflammatory response in Alzheimer's disease (AD). Senescence-accelerated mouse (SAM) prone 8 (SAMP8) are widely used in various experiments because of cognitive deficits observed with age. In the present study, 4-month-old SAMP8 were reconstituted with BMCs of C57BL/6 mice by intra-bone marrow-bone marrow transplantation (IBM-BMT), which can reconstitute both donor-derived hemopoietic stem cells and mesenchymal stem cells. Three months after IBM-BMT, the impairment of spatial memory in SAMP8 was found to be ameliorated after analyzing the results of the water maze test. Although IL-1β, IL-6 and iNOS increased and TGF-β decreased in 7 M SAMP8, IL-1β, IL-6 and iNOS decreased while TGF-β increased after IBM-BMT by RT-PCR. Moreover, oxidative stress-related heme oxygenase-1 (HO-1) increased in 7 M SAMP8, but significantly decreased after IBM-BMT. In conclusion, this is the first report suggesting that the impaired cognitive ability of SAMP8 is ameliorated by IBM-BMT. It seems likely that decreases in IL-1β, IL-6, iNOS and HO-1 are a result of the development of donor-derived BMCs.