[Effects of Interleukin-6 Gene Knockout on β-amyloid Deposition and Cognition in 5×FAD Mouse Model of Alzheimer's Disease].

Objective To explore the effects of interleukin-6 (IL-6) gene knockout on the cognitive function and pathological changes in 5×FAD transgenic mice of Alzheimer's disease.Methods IL-6 mice were crossed with 5×FAD mice to establish the 5×FAD;IL-6 mouse model,and 3-month-old and 10-month-old mice were selected for experiments.The cognitive function of mice was detected by behavioral tests,and HE staining and β-amyloid (Aβ) immunohistochemical staining were performed to detect the pathological changes of mouse brain tissue.Results The number of 5×FAD;IL-6 model mice (3 months old,=20;10 months old,=5) and 5×FAD littermate control (3 months old,=26;10 months old,=24) conformed to the Mendel's law.Compared with that of the 5×FAD mice at the same age,the discrimination ratio of 3-month-old 5×FAD;IL-6 mice increased in the novel object recognition test (=3.890,=0.002).Morris water maze test results showed that the 3-month-old 5×FAD;IL-6 mice had longer time spent in target quadrant (=3.797,=0.012) and more times of crossing platform (=2.505,=0.017) than the 5×FAD mice at the same age.The results of immunohistochemical staining showed that IL-6 knockout reduced the Aβ deposition in the hippocampus (=13.490,=0.002;=45.680,<0.001) and cortex (=16.830,=0.001;=14.180,=0.001) of 5×FAD mice.Conclusion IL-6 gene knockout can significantly improve the spatial memory and reduce the Aβ deposition in the brain of 5×FAD mice.