ABSTRACT
The Chinese medical mechanism of Huanglian Jieduo Decoction on treating Alzheimer's disease(AD) characterized by "toxin damaging brain collateral" is still unclear. This study aims to explore the mechanism of Huanglian Jieduo Decoction on regulating triggering receptor expressed on myeloid cells 2(TREM2)/protein kinase B(Akt)/glycogen synthase kinase 3ß(GSK3ß) pathway to improve the cognitive deficit in APP/PS1 transgenic mice. APP/PS1 mice of approximately nine months old were randomly divided into the model group, the low, medium, and high(2.5, 5, and 10 g·kg~(-1)) groups of Huanglian Jiedu Decoction, and 0.75 mg·kg~(-1) donepezil hydrochloride group, and the C57BL/6J mice with the same age were taken as the normal group. After one month of continuous oral administration, a Morris water maze was performed to detect the learning and memory ability of mice. Hematoxylin-eosin(HE) staining was applied to observe the morphology of neuronal cells in the cortical area of mice. Immunofluorescence was used to detect the protein expressions of ß-amyloid(Aß_(1-42)), CD86, and arginase 1(Arg1). The mRNA levels of interleukin(IL)-1ß, IL-6, and IL-10 in the cortex of mice were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR). The protein expressions of TREM2, phosphoinositide-3 kinase(PI3K), Akt, GSK3ß, and beta-catenin(ß-catenin) in mouse cortex were determined by Western blot. The results indicated that the escape latency of the model group was significantly prolonged, and the residence time in the target quadrant and the number of crossing the platform were significantly reduced compared with the normal group. Mice in the model group had a significantly lower number of neurons in the cortex and showed nuclear pyknosis and a significant increase in the expressions of Aß_(1-42) and CD86. The mRNA levels of IL-1ß and IL-6 in tissue were significantly increased, IL-10 were increased, while Arg1 were significantly decreased. The expression of TREM2, p-PI3K(Y607), p-Akt(T308), p-GSK3ß(Ser9), and ß-catenin in the cortex were significantly down-regulated. Compared with the model group, the escape latency of the mice in the administration group was significantly shortened, and the number of crossing the platform and the residence time in the target quadrant were significantly increased. Furthermore, the number of neurons in the cortex of mice was increased, and nuclear pyknosis was improved. Aß_(1-42) deposition was decreased significantly. The mRNA levels of IL-1ß, IL-6 and CD86 were significantly decreased, while IL-10 and Arg1 levels were significantly increased. The expression of TREM2, p-PI3K(Y607), p-Akt(T308), p-GSK3ß(Ser9), and ß-catenin protein in the cortex of each administration group was significantly up-regulated compared with the model group. In conclusion, Huanglian Jiedu Decoction reduced the expression of Aß_(1-42) and neuroinflammation to a neuro-protective effect, thereby improving the learning and memory ability in APP/PS1 mice, which may be related to the TREM2/Akt/GSK3ß signaling pathway.
Subject(s)
Alzheimer Disease , Cerebral Cortex , Drugs, Chinese Herbal , Glycogen Synthase Kinase 3 beta , Membrane Glycoproteins , Mice, Inbred C57BL , Mice, Transgenic , Proto-Oncogene Proteins c-akt , Receptors, Immunologic , Animals , Glycogen Synthase Kinase 3 beta/metabolism , Glycogen Synthase Kinase 3 beta/genetics , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/administration & dosage , Mice , Cerebral Cortex/metabolism , Cerebral Cortex/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-akt/genetics , Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Alzheimer Disease/genetics , Receptors, Immunologic/genetics , Receptors, Immunologic/metabolism , Membrane Glycoproteins/metabolism , Membrane Glycoproteins/genetics , Male , Signal Transduction/drug effects , HumansABSTRACT
Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically given Buyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. In rats administered Buyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrin αvß3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days). These data suggest that Buyanghuanwu decoction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury.
