Effect of TAT-XIAP fusion protein on learning and memory impairment rats and its mechanism

Abstract

Objective To investigate the TAT-XIAP fusion protein on learning and memory impairment in rats and its relationship with the brain hippocampus neuron apoptosis, and to provide experimental evidence for the in-depth study of learning and memory. Methods Using genetic engineering technology to prepare biologically active fusion protein TAT-XIAP, D-galactose (D-Gal) by intraperitoneal injection and Aβ1-42 by hippocampal injection, rat model was established by injection of learning and memory impairment.The rats were randomly divided into TAT-XIAP groups (left lateral cerebral ventricle injection of TAT-XIAP fusion protein, 80 mg/kg per day, 3 days) and model group (lateral cerebral ventricle injection of an equal volume of PBS), each group 30 rats.Learning and memory of rats were measured by water maze, and rat hippocampal neuronal apoptosis were measured by TUNEL assay. Results The time was significantly shorter into the water to climb up platform in each quadrant of TAT-XIAP rats, with an average of (48.31±9.44)s, and it was significantly lower than the model group((87.80±10.32)s, P<0.05). The number through the platform, target quadrant swim away a percentage and time in the target quadrant percentage were significantly increased in TAT-XIAP group rats(respectively, 4.78±0.93, (47.39±5.84)%, (48.43±5.75)%). It was significant difference with the model group comparison(P<0.05). Apoptosis of neuron reduced significantly in hippocampus of TAT-XIAP group rats, apoptosis of neuron count was 16.37±3.15 pieces per square millimeter, and model group was 54.66±7.20 pieces per square millimeter.It was significant difference compared by statistical analysis(P<0.05). Conclusion TAT-XIAP fusion protein can significantly improve learning and memory function of learning and memory impairment in rats, which may be related to decreasing neurons apoptosis in hippocampus. Key words: Learning and memory impairment; X-linked inhibitor of apoptosis protein; Hippocampus; Neuron apoptosis; Trans-activator of transcription