Electroacupuncture promotes neurogenesis in the dentate gyrus and improves pattern separation in an early Alzheimer's disease mouse model.

BACKGROUND: Impaired pattern separation occurs in the early stage of Alzheimer's disease (AD), and hippocampal dentate gyrus (DG) neurogenesis participates in pattern separation. Here, we investigated whether spatial memory discrimination impairment can be improved by promoting the hippocampal DG granule cell neogenesis-mediated pattern separation in the early stage of AD by electroacupuncture (EA). METHODS: Five familial AD mutations (5 × FAD) mice received EA treatment at Baihui and Shenting points for 4 weeks. During EA, mice were intraperitoneally injected with BrdU (50 mg/kg) twice a day. rAAV containing Wnt5a shRNA was injected into the bilateral DG region, and the viral efficiency was evaluated by detecting Wnt5a mRNA levels. Cognitive behavior tests were conducted to assess the impact of EA treatment on cognitive function. The hippocampal DG area Aß deposition level was detected by immunohistochemistry after the intervention; The number of BrdU+/CaR+ cells and the gene expression level of calretinin (CaR) and prospero homeobox 1(Prox1) in the DG area of the hippocampus was detected to assess neurogenesis by immunofluorescence and western blotting after the intervention; The gene expression levels of FZD2, Wnt5a, DVL2, p-DVL2, CaMKII, and p-CaMKII in the Wnt signaling pathway were detected by Western blotting after the intervention. RESULTS: Cognitive behavioral tests showed that 5 × FAD mice had impaired pattern separation (P < 0.001), which could be improved by EA (P < 0.01). Immunofluorescence and Western blot showed that the expression of Wnt5a in the hippocampus was decreased (P < 0.001), and the neurogenesis in the DG was impaired (P < 0.001) in 5 × FAD mice. EA could increase the expression level of Wnt5a (P < 0.05) and promote the neurogenesis of immature granule cells (P < 0.05) and the development of neuronal dendritic spines (P < 0.05). Interference of Wnt5a expression aggravated the damage of neurogenesis (P < 0.05), weakened the memory discrimination ability (P < 0.05), and inhibited the beneficial effect of EA (P < 0.05) in AD mice. The expression level of Wnt pathway related proteins such as FZD2, DVL2, p-DVL2, CAMKII, p-CAMKII increased after EA, but the effect of EA was inhibited after Wnt5a was knocked down. In addition, EA could reduce the deposition of Aß plaques in the DG without any impact on Wnt5a. CONCLUSION: EA can promote hippocampal DG immature granule cell neogenesis-mediated pattern separation to improve spatial memory discrimination impairment by regulating Wnt5a in 5 × FAD mice.

Electroacupuncture protective effects after cerebral ischemia are mediated through miR-219a inhibition.

BACKGROUND: Electroacupuncture (EA) is a complementary and alternative therapy which has shown protective effects on vascular cognitive impairment (VCI). However, the underlying mechanisms are not entirely understood. METHODS: Rat models of VCI were established with cerebral ischemia using occlusion of the middle cerebral artery or bilateral common carotid artery. The brain structure and function imaging were measured through animal MRI. miRNA expression was detected by chip and qPCR. Synaptic functional plasticity was detected using electrophysiological techniques. RESULTS: This study demonstrated the enhancement of Regional Homogeneity (ReHo) activity of blood oxygen level-dependent (BOLD) signal in the entorhinal cortical (EC) and hippocampus (HIP) in response to EA treatment. miR-219a was selected and confirmed to be elevated in HIP and EC in VCI but decreased after EA. N-methyl-D-aspartic acid receptor1 (NMDAR1) was identified as the target gene of miR-219a. miR-219a regulated NMDAR-mediated autaptic currents, spontaneous excitatory postsynaptic currents (sEPSC), and long-term potentiation (LTP) of the EC-HIP CA1 circuit influencing synaptic plasticity. EA was able to inhibit miR-219a, enhancing synaptic plasticity of the EC-HIP CA1 circuit and increasing expression of NMDAR1 while promoting the phosphorylation of downstream calcium/calmodulin-dependent protein kinase II (CaMKII), improving overall learning and memory in VCI rat models. CONCLUSION: Inhibition of miR-219a ameliorates VCI by regulating NMDAR-mediated synaptic plasticity in animal models of cerebral ischemia.

Bufadienolides from Venenum Bufonis Inhibit mTOR-Mediated Cyclin D1 and Retinoblastoma Protein Leading to Arrest of Cell Cycle in Cancer Cells.

OBJECTIVE: Bufadienolides, the main components in Venenum Bufonis secreted from toads, have been proved to be with significant anticancer activity aside from the positive inotropic action as cardenolides. Here an underlying anticancer mechanism was further elucidated for an injection made from Venenum Bufonis containing nine bufadienolides. METHODS: One solution reagent and cell cycle analyses were for determining effect of bufadienolides on cancer cells. Western blotting was used for protein expression. RESULTS: Bufadienolides inhibit cell proliferation and arrest cells in G1 phase. Bufadienolides also inhibit the mammalian target of rapamycin (mTOR) signaling pathway, which is evidenced by the data that bufadienolides inhibit type I insulin-like growth factor- (IGF-1-) activated phosphorylation of mTOR by a concentration- and time-dependent way, as well as phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4E-BP1). Subsequent results indicated that cyclin D1 expression and phosphorylation of retinoblastoma protein (Rb)-two characterized regulators in cell cycle of G1-are also inhibited and the process is dependent on mTOR pathway. CONCLUSION: Bufadienolides inhibit proliferation partially due to arresting cell cycle in G1 phase, which is mediated by inhibiting mTOR-cyclin D1/Rb signal pathway.