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Objective • To investigate the role of Rho-associated coiled coil protein kinase 1 (ROCK1) in amyloid β-protein (Aβ) induced damage of rat hippocampal neurons. Methods • The rat primary neurons were treated with Aβ40 oligopeptides to establish a neurotoxicity model. Western blotting was used to detect the protein expression of ROCK1. Its activity was detected by the kit. Confocal laser scanning was used to observe the calcium signal in neurons, and apoptosis of neurons was detected by TUNEL assay. Y-27632, an inhibitor of ROCK1, was added into the culture medium in order to observe its effect on Aβ40. Results • Aβ40 (10 μmol/L) could significantly induce calcium overload, increase ROCK1 expression and activity, and promote apoptosis in primary neurons. Furthermore, ROCK1 inhibitor could decrease all the effect induced by Aβ40. Conclusion • ROCK1 is involved in both Aβ- induced neuronal calcium overload and neurotoxicity, and ROCK1 inhibitor can antagonize the toxic effects of Aβ.
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Objective To investigate the effect of electro-acupuncture on behavior alterations,the expression of amyloid precursor protein(APP),amyloid β-protein(Aβ) proteins and neuroapoptosis in the cerebral cortex in the APPswe/PS1dE9 double transgenic mice with Alzheimer's disease (AD) induced by isoflurane.Methods Sixmonth-old AD mice and wild-type mice at the same age were randomly divided into wile-type control group,AD group,isoflurane group,electro-acupuncture group (N =8).The mice were given pretreatment with electro-acupuncture at Baihui(GV20) acupoint and Yongquan(KI 1) acupoint once a day for 3 successive days,15 min each time.And then the mice in electro-acupuncture group and isoflurane group were exposed to a box full of 1.2％ isoflurane for 4 hours.Morris water maze was used to test the learning and memory abilities of the mice,Western blotting method was used to detect the expression of APP-C83,APP-C99 and Aβ,and terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end labeling(TUNEL) was used to detect neuroapoptosis in the cerebral cortex.Results The escape latency of AD group was longer than that of wild-type mice group(P＜0.05),and the latency of isoflurane group was longer than that of AD group (P ＜ 0.05),while the latency of electro-acupuncture group was shorter than that of isoflurane group(P ＜ 0.05).The percentage of retention time in the target quadrant and the times for crossing the target quadrant in isoflurane group were lower than those of AD group (P ＜ 0.05),but were higher in electro-acupuncture group than those in isoflurane group (P ＜ 0.05).APPC83 expression level in isoflurane group was significantly lower than that in AD group (P ＜ 0.05),while APP-C83 expression level in electro-acupuncture group was higher than that in isoflurane group (P ＜ 0.05).APP-C99 expression level in isoflurane group was significantly higher than that in AD group (P ＜ 0.05),and APP-C99 expression level in electro-acupuncture group was lower than that in isoflurane group (P ＜ 0.05).The cortical apoptosis index in isoflurane group was significantly higher than that in AD group (P ＜ 0.05),and the cortical apoptosis index in electro-acupuncture group was lower than that in isoflurane group (P ＜ 0.05).The expression level of Aβ in AD group,isoflurane group and electro-acupuncture group was significantly higher than wild-type control group (P ＜ 0.05).Conclusion Electro-acupuncture can relieve the AD-like neurotoxicity induced by isoflurane and inhibit the decline of learning and memory abilities of AD mice,and the mechanism is probably related with suppressing the overexpression of APP-C99 and reducing the production and accumulation of Aβ,thereby alleviating the neuroapoptosis.
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Objective: To study the effect of astragaloside (AST) on the injury induced by amyloid β-protein (Aβ) plus Dexamethasone (DEX) in rat hippocampal neurons. Methods: In vitro, the effects of AST on hippocampal neurons cell death with Aβ plus DEX were detected by MTT assay and intracellular calcium ([Ca2+]i); The effects of AST on phospho-tau (P-tau) protein were analyzed to explore the mechanisms responsible for DEX enhanced Aβ-induced cell death in hippocampal neurons. Results: AST (10, 20, and 40 μg/mL) could protect hippocampal neurons against DEX (10 μmol/L) plus Aβ25-35 (5 μmol/L) - induced hippocampal neuronal injury of felal rat in vitro (P<0.01). AST could inhibit the increased levels of [Ca2+]i and P-tau protein level induced by DEX (10 μmol/L) plus Aβ25-35 (5 μmol/L) (P < 0.05). Conclusion: AST could protect hippocampal neuron against synergistic neurotoxicity of Aβ and DEX.