Effects Of Receptor-mediated Transcytosis BDNF On Alzheimer's Disease Hippocampal Neurons Regeneration

ObjectiveAfter i. v. injection the molecular modified compound of human recombi-nant brain -derived neurotrophic factor, observe it's efficacy on neuronal number of the hippocampal CA1 region of Alzheimer's disease transgenic mice in vivo.Methods1. MaterialBDNF,BDNF - PEG - biotin/OX26 - SA, PEG - biotin, 0X26 - SA and the Sphacryl S300HR column were obtained from Pharmacia, Alzheimer' s disease transgenic mice were purchased form Beijing China Consonance Medical U-niversity, and all other reagents were offered by our university.2. Preparation compound of PEG - biotin/OX26 - SAAccording to the methods of W. D. et al, through avidin - biotin technology, 3.9 mg PEG - biotin and 6. 5 mg 0X26 - SA were mixed in 1 ml 0. 05 M Na2HPO4/0. 5 M NaCl (PH =7.0). The reaction was proceed at room temperature for 30 minute. The sample was applied to an Sphacryl S300HR column, followed by elution in 0.01 M Na2HPO4/0.5 M NaCl, PH =7.4/0.05% Tween -20 at 30 ml/hr, and concentrated by using a Centriprep -10 microconcentrator. It was the drug for control group.3. Experimental animals groups40 AD transgenic mice were randomly assigned into experimental group, control groups and blank group, there were 10 mice in each group. Experimental group i. v. treatment with BDNF, the. compound of BDNF - PEG - biotin/0X26 - SA, the first control group i. v. treatment with the compound of PEG -biotin/OX26 - SA, the second control group i. v. treatment with BDNF and blank group i. v. treatment with 0. 9% saline. Doses were given daily in the morning by tail vein injection for a week.4. HE - stain and hippocampal neuron quantitaionThe animals were sacrificed 24 hour after the final i. v. injection and removed brains. Coronal sections were prepared after discarding 3 mm of frontal cortex, fixed, embedded, cut, deparaffinized, and HE - stained. The neurons in the hippocampal CAl region were counted under light microscopy, and validate the efficacy of molecular modified BDNF on hippocampal neurons after peripheral administration.5. statistics analysisData were presented as the mean 卤 SEM of each group, analysis of variance were performed for the different groups.ResultsConjugated 0X26 - SA to PEG - biotin and preparation control drug PEG -biotin/OX26 - SA . Administered daily in the morning by tail vein injection for a week, hippocampal CAl neuronal number of experimental group increased. There were no significant changes in neuronal number in the hippocampus CAl region of control groups. Therapeutic results have significant differences between experimental group and control groups.ConclusionMolecular modified BDNF can transport across the BBB in vivo, and peripherally administered BDNF has protective efficacy on hippocampal neuron of AD rats.