| BackgroundAlzheimer Disease is a chronic neurodegeneration. Due to its insidious onset, slow progression of symptom, causing disabilities and hard to cure, AD has become the second thread to the aged people. Coming with the aggravate ageing problem, the morbidity of AD has gradually increased. Thus, the humanity is facing a great problem on how to cure AD. Until now, the pathological mechanism of AD is still unclear, while support and symptomatic treatments remain to be the main therapies of AD.4 of 5 drugs which the US FDA permitted to treat AD are cholinesterase inhibitors. These drug only could function in mild to moderate. So it's very important to find a new way to treat AD and make a difference.Aetyl choline, as the first neurotransmitter to be found plays an important role in AD pathological mechanism. Endogenous Aetyl choline plays an important part in memory acquiring, encoding, consolidating, eliminating and recovery. In the pathogenesis of AD, the main character of AD is the loss of cholinergic neurons. However, in the early stage of AD, there are no loss of cholinergic neurons, instead these neurons shrink and cause the loss of itsmarkers, and the decrease in dendrites. Therefore if the changes in cholinergic neurons would stop in the early stage of AD, there might rescue the abnormality in behavior and memory caused by the loss of cholinergic neurons.DAPK1 belonged to CA2+/calcium protein. The protein could be activated where the ischemic infusion injury happened in the brain, and guide to programmed cell death. Meanwhile it also participates in Tau protein over phosphorylation in neurodegeneration disease. However, whether DAPK1 take part in cell death progress and Tau over phosphorylation remains unknown.ObjectiveTo observe whether DAPK1 participates in neurogenesis in the pathogenesis in ADMethods3 Month old C57BL/6J mice, ChAT-IRES-CreER+/+DAPK1KDloxp/loxp+/+ were used in the following experiment. Immunofluorence were use to detect the expression of cre, Open field test, elevated plus maze, Morris water maze were performed twice. AD models were made by injecting A? into mice side ventricles of the brain. And inject PBS as sham control. The amplitude and frequency of the mice brain section and LTP was recorded. Tau and relevant protein was detected by western blot. At last the morphology and number of spine was observed and calculated in Golgi.ResultsThe mice were sacrificed after 10 days tamoxinfen induction and 15 days rest. The immunofluorences shows that the cre has already expressed in cholinergic neurons. And open field, elevated plus maze and Morris water maze was performed among every group. And the results showed no difference. Then we injected A? into mice side ventricles of the brain. And we used DAB and detected that there were some accumulation of A? in the hippocampus. Then we use open field, elevated plus maze and Morris water maze to test mice behavior. The A? injected mice moved shorter than the control mice and those with DAPK1 KD deletion in the open field test. And they stayed longer in the closed arm in elevated plus maze. Even in the Morris water maze, there is an increased in latency. While DAPK1 deletion mice could reverse these change. These results indicating the space learning and memory could be rescue by the DAPK1 deletion. We tested the LTP of every group. The western blot shows the total tau protein expression didn't change, while the phosphorylation of tau has changed in the A? injected mice. The DAPK1 KD deletion didn't change the expression of Tau phosphrylation. At last we used Golgi staining to observe the morphology of spine and calculate the spine number. The spine morphology has changed and the number of spine has decreased. Compared with those treated with PBS ones and treated with A? and DAPK1 KD deletion ones.ConclusionThe deletion of DAPK1 KD cloud rescue the neurodegenertion caused by A? and cloud sustain the secretion of ACH, protect the function of LTP and prevent the injury of space learning and memory.BackgroundStroke happens when the blood flow occluded in the brain, which will lead to neuronal dysfunction. The high morbidity, mortality and disability in stroke is a huge threat to human health and life. Thus, it's very important to develop drugs to heal the disease. Part of post-stroke patient has cognition decline, however, there is no efficient drugs to deal with the cognition dysfunction. At present we still use heteropathy, the improvement of circulation and rehabilitation training to treat the disease. So to develop drugs to improve post-stroke cognition dysfunction is very meaningful.Cholinergic neurons play an important role in learning and memory processions. Most neurodegeneration would related to cholinergic system. Resent studies shows the neurodegeneration and the injury of vascular are the main cause of post-stroke cognition decline. Therefore, the therapy and intervention in the early stage of stroke may decrease of prevent the cognition decline in post-stroke.DAPK1 is a Ca2+/calmodulin regulated serine/threonine kinase, which is activated after stroke, causing vast Ca2+flow into cell and leading to apoptosis. We discuss the function of cholinergic neurons in post-stroke. Then we specifically deleted the DAPK1 KD in cholinergic neurons and studied whether the knockout had any impact after ischemia reperfusion injury.MethodMonth old C57BL/6J mice, ChAT-IRES-CreER+/+DAPK1KDloxp/loxp+/+ were used in the following experiment. We performed MCAO and use TTC to stain the mice brain 1,3,7 days after the surgery. Then we stained brain section with FJ-C and ChAT and observed cholinergic neurons in the infraction border.ResultsCompared with DAPK1 KD knockout in cholinergic neurons mice, the infraction zone didn't change. The morphology and number of cholinergic neurons has change in the DAPK1 KD knockout in cholinergic neurons mice.ConclusionThe DAPK1 KD deletion in cholinergic neurons mice could protect the cholinergic neurons from ischemia reperfusion injury but didn't change infraction volum. |
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