Effect of polyunsaturated fatty acid on the expression of Huntingtin associated protein 1 in hippocampus of rat model with Alzheimer' s disease

Abstract

Objective To study the effect of docosahexaenoic acid ( DHA ) and eicosapentaenoic acid (EPA) on cognition impairment and huntingtin associated protein 1 ( HAP1 ) expression in hippocampus of rat model with Alzheimer' s disease(AD). Methods Forty healthy Sprague-Dawley rats were randomly divided into control group, AD group, DHA group and EPA group on average. Alcl3 was injected intraperitoneally and D-galac tose was injected into subcutaneous to establish the model of rat with AD. ABC method of immunohistochemistry was used to observe the expression level of HAP1 in the hippocampus. Morris water maze was used to study the spatial learning and memory in rats. Results Compared with control group,the HAP1-positive neurons of hippo campus decreased and poorer performance in Morris water maze test was observed in AD group. Compared with AD group, DHA and EPA treatments significantly caused the decreases in escape latency and searching distance in the Morris water maze test. The number of HAP1- positive cells in DG region of DHA group(43.57 ±6.14) increased obviously compared with AD group( 28.56 ± 4.23 ) (P ＜ 0.05 ＝. Conclusion The immunoreactivities of HAP1 decrease in hippocampus of AD rat. The applications of DHA and EPA in AD rats significantly improve the ability of learning and memory;and the mechanisms may be related to the decrease of HAP1 expressions in hippocampus. Key words: Huntingtin associated protein 1; Hippocampus; Docosahexaenoic acid; Eicosapentaenoic acid