RESUMO
Bone marrow-derived mesenchymal stem cells (BMSCs) are a promising source for cell-based treatment of brain injury, but the therapy of BMSCs is restricted by low cell survival. We examined whether nerve growth factor (NGF) improve BMSCs viability in the brain with Fimbria-Fornix lesion (FF). After transduction of NGF gene via recombinant retroviral vectors, the rat BMSCs were transformed into the NGF-GFP positive BMSCs, nearly 100% of cells expressed NGF. After transplanted into basal forebrain of rat with FF, the NGF-GFP positive BMSCs expressed the exogenous NGF gene in the host brain, and interesting, the survival number of BMSCs in the NGF group was significant more than that of the void plasmid group. Furthermore, the number of choline acetyltransferase (ChAT) immunoreactive neurons of NGF group was also significant higher than those of the void plasmid group (p<0.05) or the PBS group (p<0.01). Performance in the water maze test was improved in these rats in NGF group. These results indicate that NGF increased BMSCs survival in brain with FF, which results in better improvement of brain function than injected with BMSCs alone.
RESUMO
AIM: To explore the production of anti-Abeta42 antibody after immunization with Abeta42 and its subunit peptide vaccines. METHODS: Seventy five male BALB/c with the age of 6 weeks were randomly divided into 5 groups, namely, control group, Abeta42 group, Abeta(36-42) group, Abeta(1-15)group and F Abeta(1-15) group. The BALB/c mice were immunized four times with PBS+MF59 adjuvant, Abeta42+MF59, Abeta(36-42)+heptalysine (MAP)+MF59, Abeta(1-15)+MAP+MF59 and Abeta(1-15)+MAP+Freud's adjuvant, respectively. The titers of specific antibodies in sera and supernatants of brain tissue homogenates from the immunized mice in every group were detected by indirect ELISA. After Abeta42, Abeta(36-42), Abeta(1-15) and F Abeta(1-15) were co-cultured together with cultured PC12 cells for 7 days, the cytotoxicity of the 3 antigen peptides to PC12 cells were determined by MTT colorimetry. In addition, after immune sera from each group were added to culture medium containing 20 mg/L Abeta42 and co-cultured with PC12 cells for 7 days, the survival rate of PC12 cells were examined by MTT assay. RESULTS: The production of anti-Abeta42 antibodies was detected in sera of each experimental group after the second time immunization, and the titer of antibody rose with the increase of immunizing times. In addition, the anti-Abeta42 antibody with low titer was also detected in supernatants of brain tissue homogenates. The Abeta42 could reduce the survival rate of PC12 cells, whereas Abeta(36-42) and Abeta(1-15) had no obvious effect on survival rate of PC12 cells. After immune sera from 4 experimental groups and Abeta42 were co-cultured with PC12 cells, their survival rate was found improved. CONCLUSION: Combination of Abeta42 and its subunit (Abeta(36-42) and Abeta(1-15)) vaccines with MF59 adjuvant can induce BALB/c mice to produce anti-Abeta42 antibody. The antibody may neutralize the cytotoxicity of Abeta42.