[Effect of moxibustion-induced deqi on hippocampal autophagy function in APPswe/PSEN1dE9 transgenic Alzheimer's disease mice].

OBJECTIVE

To investigate the effect of moxibustion on autophagy regulation under deqi (arrival of qi ) versus non-deqi moxibustion, using APPswe/PSEN1dE9 transgenic Alzheimer's disease (AD) model mice.

METHODS

Forty SPF-grade male APPswe/PSEN1dE9 transgenic mice were randomly divided into a model group (n=10) and a moxibustion group (n=30) at a ratio of 1∶3. Ten SPF-grade male C57BL/6 mice served as the control group. In the moxibustion group,gentle moxibustion was operated at the site around 3 cm far from "Dazhui" (GV14), 40 min each intervention, once daily and for 28 consecutive days. The deqi group (the mean tail temperature increase [TTI]>1 ℃ within 7 days, n=20) and non-deqi group (the mean TTI≤1 ℃, n=10) were subdivided according to the change of tail temperature within 7 days after intervention with moxibustion. After intervention completion, Morris water maze was performed to determine cognitive behavior of mice, HE staining was to observe hippocampal morphology, transmission electron microscopy (TEM) was to observe hippocampal autophagy-related ultrastructure; Western blot analysis was to detect the expression of hippocampal β-amyloid protein (Aβ) and autophagy-related proteins (microtubule-associated protein light chain 3 [LC3]Ⅱ、LC3Ⅰ,benzochlorine 1 [Beclin-1], ubiquitin-binding protein [p62], lysosome-associated membrane protein 1 [LAMP1]).

RESULTS

Compared with the control group, in the model group, the escape latency was prolonged in the hidden platform test for 5 consecutive days (P<0.001), and the number of platform crossings was reduced in spatial probe test (P<0.000 1). The hippocampal neuronal arrangement was disorganized, cell morphology was abnormal, and the number of autophagolysosome complexes reduced, and a large number of insoluble cellular components were visible within them. The ratio of LC3Ⅱ/LC3Ⅰand the protein expression of Aβ, p62 and LAMP1 increased (P<0.001, P<0.000 1, P<0.05), while the protein expression of Beclin-1 decreased (P<0.000 1). When compared with the model group, the escape latency was shortened during the last 2 days of hidden platform test in the non-deqi group (P<0.05), and it was shortened for 5 consecutive days in the deqi group (P<0.05, P<0.01); in the deqi group and the non-deqi group, the hippocampal neuronal morphology was improved, a large number of autophagosomes increased in size, and the number of lysosomes rose. Besides, the hippocampal protein expression of A β was reduced in both the deqi group and the non-deqi group (P<0.01, P<0.001), the hippocampal protein expression of Beclin-1 was elevated (P<0.01) and that of p62 was reduced (P<0.01) in the deqi group. When compared with the non-deqi group, in the deqi group, the escape latency was shortened during the last 3 days of the hidden platform test(P<0.05), the number of autophagolysosome complexes increased markedly, the amount of insoluble cellular components inside was significantly reduced; the protein expression of hippocampal Beclin-1 increased (P<0.05) and that of p62 decreased (P<0.05). The differences in the other indexes were not significant statistically between the two groups (P>0.05).

CONCLUSION

Moxibustion with deqi obviously improves autophagic function and cognitive behavioral performance in AD model, versus moxibustion without deqi.