Protection Of Electroacupuncture Against AD-like Neurotoxicity Induced By Isoflurane

ObjectiveInvestigate the protection mechanism of electroacupuncture against AD-like neurotoxicity induced by isoflurane.MethodsThe Alzheimer’s disease APPswe/PS1dE9double transgenic mice and littermate wild-type mice were assigned randomly into the control group, isoflurane group and electroacupuncture group. Electroacupuncture treatment was implemented before isoflurane exposure:selected Baihui and Yongquan xue,15minutes one day for3days, while the control group and isoflurane group was only fixed15minutes one time. Isoflurane exposure:the isoflurane group and electroacupuncture group were placed in a case containing1.2%isoflurane which was delivered by30%oxygen and70%nitrogen for4hours and the control group was put in a same case which was full of the mixed gas composed of containing30%oxygen and70%nitrogen. Morris water maze test was proceeded before electroacupuncture treatment and after isoflurane exposure, including hidden platform test and space exploration test.Morris water maze test was applied to study the changes of learning and memory ability of mouse(n=8). The neuronal apoptosis in hippocampus was detected by TUNEL staining (n=8), and cleaved caspase-3、A βin hippocampus was detected by immunohistochemistry in each group (n=8). Western blot was used to analyze the APP-C83and APP-C99of hippocampus.Results1. Water maze test(1)Comparison of learning and memory abilities between AD and wild mice: the escape latency of AD mice was shorter than the wild mice, the number of target crossing and the percentage of residence time in the first quadrant were higher than the wild mice, and the difference was statistically significant (P<0.05).(2)The AD mice:comparison of escape latency:T-Con<T-EA<T-Iso. There was a significant difference between the T-Iso and T-Con(P<0.05), while between the T-EA and T-Iso(P<0.05).Comparison of the percentage of residence time in the first quadrant: T-Con>T-EA>T-Iso. There was a significant difference between T-Iso and T-Con (P<0.05), the same with T-EA and T-Iso.Comparison of the number of target crossing in60s:T-Con>T-EA>T-Iso. The T-EA and T-Iso were statistically significant compared with the T-Con (P<0.05).(3) The wild mice:comparison of escape latency:W-Con<W-EA<W-Iso. There was a significant difference between the W-Iso and W-Con and between W-EA and W-Iso(P<0.05).Comparisons of the percentage of residence time in the first quadrant and the number of target crossing in60s:W-Con> W-EA>W-Iso. There was no significant difference between the three groups (P>0.05).2. Expression of cleaved caspase-3and neuronal apoptosis(1)The Alzheimer’s disease APPswe/PS1dE9double transgenic mice: Comparison of cleaved caspase-3’s number in the hippocampus:T-Con<T-EA<T-Iso, and T-Iso was statistically significant compared with the T-Con and T-EA(P<0.05). The expression of neuronal apoptosis was consistent with cleaved caspase-3.(2)The Wild mice:Comparison of cleaved caspase-3’s number in hippocampal CA1region:W-Con<W-EA<W-Iso, but there was no obvious difference between the three groups (P>0.05). The expression of neuronal apoptosis was consistent with cleaved caspase-3.3. The expression of APP-C83, APP-C99and Aβ(1)The expression of APP-C83and APP-C99detected by western blot:APP-C83/GAPDH:APP-C83’s expression of T-Iso was lower than T-Con and W-Con(P<0.05), and there was statistical significance between the T-EA and T-Iso(P<0.05). APP-C99/GAPDH:APP-C99’s expression of T-Iso was significantly higher than T-Con and W-Con (P<0.05), but the expression of T-EA was lower than T-Iso(P<0.05).(2)The expression of Aβ detected by Immunohistochemistry:The expression of Aβ in T-Iso and T-EA was higher than T-Con(P<0.05). Aβ’s expression of T-EA was lower than T-Iso group, but there was no statistical significance(P>0.05).Conelusion1. The learning and memory abilities of AD6-month-old mouse has a serious decline compared with wild-type mouse2. Electric acupuncture can alleviate the cognitive impairment of AD mouse induced by isoflurane.3. Electric acupuncture can alleviate isoflurane-induced neuronal damage of AD mouse through inhibiting the overexpressing of activated caspase-3of hippocampus and reducing the neuronal apoptosis4. Electric acupuncture could inhibit the overexpression of APP-C99induced by isoflurane, and reduce Aβ’s generation and aggregation to some extent.