| ObjectiveAlzheimer’s disease(AD) is a kind of degenerative disease incentral nervous system with clinical manifestation of progressivedecrease of learning and cognition ability, decline in recentmemory， thinking， perception, orientation, comprehension，calculation， judgment function and some abnormal personalitychanges. AD has become the fourth cause of death besides heartdisease，tumor and apoplexy in the aged people. The loss of advancedlabor ability, the sharp decline of self-care ability and mentalability in AD patients, caused a heavy burden to the family andsocial treatment. AD morbidity has become a serious public healthproblem because of its rapid increase tendency with nationpopulation aging. This study is designed to research on the actionmechanism of cell apoptosis mediated by JNK signal pathway intreating the rats with Alzheimer disease by moxibustion. The ADmodel was established by stereotaxis injecting agglutinated Aβ25-35into rat’s bilateral hippocampus. The rats with AD weretreated by moxibustion at the points of “Shenshu”、“Zusanli”and“Baihui”. MethodsFifty normal male SD rats with15months old, weighing400±50g were selected. Firstly they were detected with the method ofY type water maze to eliminate the rats with too clumsy or toosensitive reactions. The qualified rats were randomly divided into4groups with10cases in each group, respectively normal group,sham-operation group, model group and moxibustion group. AD modelswere established by stereotaxis injecting agglutinated Aβ25-35intorat’s bilateral hippocampus. Then AD model rats were treated bymoxibustion at the points of“Shenshu”、“Zusanli” and “Baihui”(left and right “Shenshu”,“Zusanli” respectively alternativeuse every other day)for3therapy courses，once daily with6daysa course， moxibustion for5minutes at each point, and one dayrest between two courses. The learning and memory ability wasdetected by Morris water maze test, morphological changes inhippocampal CA1region of rat neural cell structure were observedby HE staining and transmission electron microscope, the expressionchanges of p-JNK、Bcl-2、Bax、Caspase-3of hippocampus zone in ratswere observed by immunohistochemical method of SP. All data wereput into the computer and analyzed by SPSS16.0statistical package.The experiment results were expressed as mean±standard deviation（x s）.Results（1）From the Morris water maze test, we found the escape latencygradually shortened in each group as the swimming days increased,but he learning and memory ability between the groups showeddifferently. After stereotaxis injecting agglutinated Aβ25-35into rat’s bilateral hippocampus, the average escape latency of five daysand the last three days significantly lengthened, and the timesacross the platform position decreased remarkably in model group.In the Place navigation test and spatial probe test, the quadrantpercentage of swimming distance in the platform quadrant accountingfor the total swimming distance remarkably lowered in model group.There were remarkable differences compared with normal group andsham-operation group (P<0.01).The results indicated the rat’sfunction of learning and memory seriously damaged in model group.After the treatment by moxibustion, the average escape latency offive days and the last three days shortened obviously, and the timesacross the platform position significantly increased, and thequadrant percentage of swimming distance in the platform quadrantaccounting for the total swimming distance remarkably heightenedin the rats of moxibustion group. There were significantdifferences compared with model group (P<0.01). The results showedmoxibustion was effective in preventing the learning and memorydysfunction.（2）HE staining results showed that in model group, the numberof nerve cells in the hippocampus CA1zone reduced significantlycompared with normal group and sham-operation group. Nerve cellsdamaged with pyknotic nuclei, and nucleoli was not clear. Part ofthe nerve cells showed crescent type, multi tooth shaped apoptoticmorphology. After the treatment by moxibustion, nervouskaryopyknosis phenomenon was obviously improved with regular shape,and arranged more neatly. Transmission electron microscope showedsome nerve cells in the hippocampus CA1zone of the rats in modelgroup degenerated, the volume of nerve cell contracted with irregular shape. Electron density in cytoplasm and organelleobviously enhanced. Nerve cell structures were damaged anddisplayed unclearly. Mitochondrion swelled, even mitochondrialcrista was abnormal and deformed. Endoplasmic reticulum of interorganelle expanded and the deposition of lipofuscin increased.After the treatment by moxibustion, the edema of nerve cellssignificantly reduced, dilation of endoplasmic reticulum andmitochondria swelling significantly improved, golgi bodies,mitochondria, ribosomes obviously increased in comparison with themodel group. The experiment indicated that moxibustion hadsignificant effect in ameliorating the degenerative hippocampalneural cells change.（3）In model group, the number of p-JNK、Bax、Caspase-3positiveneurons in the rat hippocampus region obviously increased, and thenumber of Bcl-2positive neurons significantly decreased. Therewere remarkable differences compared with normal group andsham-operation group (P<0.01).In moxibustion group, the number ofp-JNK、Bax、Caspase-3positive neurons in the rat hippocampus regionobviously lowered, and the number of Bcl-2positive neuronssignificantly heightened. There were remarkable differencescompared with model group (P<0.01).Conclusion（1） Injecting agglutinated A β25-35into the bilateralhippocampus can activate the JNK signal pathway. The activation ofJNK leads to the increased release of Pro apoptotic protein Bax,and the decreased release of the anti apoptotic protein Bcl-2,furtherly, causing the Caspase cascade and activating the releaseof key enzyme of apoptosis Caspase-3. Then the degenerative neurons change induced in the brain of AD rats with learning and memoryimpairment.（2）The treatment by moxibustion can decrease the number ofp-JNK、Bax、Caspase-3positive neurons, and increase the number ofBcl-2positive neurons in the rat hippocampus region, so as torestrain the injury of neural cell degeneration caused by injectionof Aβ, promote the recovery of nerve cells and obviously amelioratethe degenerative hippocampal neural cells change.（3）Restraining the JNK signal pathway, relieving the releaseof Pro apoptotic protein Bax、Caspase-3, and promoting the releaseof the anti apoptotic protein Bcl-2, so as to inhibit the apoptosisof nerve cells, protect and recover the brain neurons and finallyimprove the learning and cognition ability, which may be the actionmechanism of treating AD by moxibustion. |
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