RESUMO
ObjectiveTo explore the mechanism of Dihuang Yinzi in improving astrocyte injury and glycolysis in Alzheimer's disease （AD） mice via regulating the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway， thereby improving the cognitive function of AD mice. MethodForty male APP/PS1 transgenic mice aged four months were randomly divided into a model group and a model + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. Forty C57BL/6J mice with the same background and same age were randomly divided into a control group and a control + Dihuang Yinzi （0.25 g·kg-1） group， with 20 mice in each group. The mice in the control + Dihuang Yinzi group and the model + Dihuang Yinzi group were administered with Dihuang Yinzi by gavage， and those in the control group and the model group received an equal volume of sterilized normal saline， once a day for 150 days. Morris water maze test was performed to test the ability of navigation and space exploration of mice. The protein expression of p-PI3K， PI3K， p-Akt， Akt， phosphofructokinase-1 （PFK-1）， and aldehyde dehydrogenase 3 family member B2 （ALDH3B2） in mouse brain tissues was measured by Western blot. An immunofluorescence assay was performed to detect astrocyte morphology and the expression level of ALDH3B2. ResultAs compared with the control group， the model group showed prolonged escape latency during the 2nd to 5th days of the location-based navigation （P<0.05， P<0.01）， reduced number of times crossing the target area of the platform， shortened residence time in the target quadrant （P<0.05， P<0.01）， prolonged residence time in the opposite quadrant （P<0.05）， increased surface area of the cell body and total length of cell protrusions of astrocytes （P<0.05， P<0.01）， and down-regulated protein expression of p-PI3K， p-Akt， ALDH3B2， and PFK-1 （P<0.01）， while the above experimental indexes were not significantly different in the control + Dihuang Yinzi group. Compared with the model group， the model + Dihuang Yinzi group showed shortened escape latency of APP/PS1 mice during the 2nd to 5th days of the location-based navigation （P<0.05， P<0.01）， increased number of times crossing the platform， prolonged target quadrant residence time （P<0.05， P<0.01）， shortened residence time in the opposite quadrant （P<0.05）， reduced surface area of the cell body and total length of cell protrusions of astrocytes （P<0.05）， and up-regulated protein expression of p-PI3K， p-Akt， ALDH3B2， and PFK-1 （P<0.01）. ConclusionDihuang Yinzi can improve the learning and memory ability of AD mice by activating the PI3K/Akt signaling pathway and up-regulating the protein expression of PFK-1 and ALDH3B2 to protect against astrocyte injury in brain tissues and improve glycolysis.
RESUMO
Astrocytes are important nerve cells in the central nervous system （CNS）， which mainly play a key role in nutrition and support. Astrocytes and neurons undergo close energy coupling and substance coupling， which are closely related and interact with each other. In recent years， many studies have shown that the astrocyte-neuron coupling imbalance plays a central role in the occurrence and progression of Alzheimer's disease （AD） and serves as an important therapeutic target receiving increasing attention. According to traditional Chinese medicine （TCM） theory， the main pathogenesis of AD is kidney deficiency and marrow inadequacy， and in clinical medication， kidney-tonifying and marrow-filling TCM prescriptions are often employed with satisfactory results achieved. As reported， many kidney-tonifying and marrow-filling prescriptions exhibit regulatory and protective effects on the imbalance of astrocyte-neuron coupling， suggesting that the effect of kidney-tonifying and marrow-filling prescriptions in treating AD may have some internal relationship with its regulation of the imbalance of astrocyte-neuron coupling. This article reviewed the underlying internal relationship between the imbalance of astrocyte-neuron coupling and the pathogenesis of kidney deficiency and marrow inadequacy in AD and the research progress in the intervention mechanism of TCM for tonifying the kidney and filling the marrow.