ABSTRACT
Objective: To investigate the neuroprotective effect and mechanism of tetrahydroxy stilbene glucoside (TSG) on β-amyloid protein 25-35 (Aβ25-35)-induced neuron synapses damage. Method: Primary neurons were isolated and purified from cerebral cortex of suckling mouse. Then neurons were divided into control group, model group (incubation with Aβ25-35) and TSG groups (after incubation with Aβ25-35, add 6.25, 12.5, 25, 50, 100 μmol·L-1 TSG). Cell counting kit-8 (CCK-8) and Lactate dehydrogenase (LDH) methods were used to observe the viability of neuron, immunocytochemical staining was performed to determine the expressions of synapsin-1 (SYN-1), and the concentration of postsynaptic density-95 (PSD-95) and synaptophysin (SYP) were detected by enzyme-linked immunosorbent assay (ELISA) method. The level of cyclic adenosine monophosphate response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) mRNA were determined by reverse transcription-polymerase chain reaction (RT-PCR) and the level of CREB, Phosphorylated CREB (p-CREB) and BDNF proteins were determined by immunocytochemical staining or Western blot (WB). Result: Compared with normal group, the cell survival rate of model group was significantly reduced, LDH release was significantly increased (PPPPPPP-1,25 μmol·L-1 TSG can significantly enhance the expression of SYN-1(PPPPConclusion: TSG possesses the neuroprotective effect on Aβ25-35-induced neuron synapses, the mechanism may be associated with the activation of CREB/BDNF signaling pathway.
ABSTRACT
AIM:To investigate the effects of curcumin on the viability ,the lactate dehydrogenase(LDH)re-lease,the apoptosis,and the activity and the expression levels of caspase-3,caspase-8 and caspase-9 of rat adrenal pheo-chromocytoma PC12 cells induced by β-amyloid protein 25-35(Aβ25-35 ).METHODS:The PC12 cells were treated with Aβ25-35.The viability and LDH release rates were measured by MTT assay and LDH kit ,respectively.The cells were ran-domly divided into blank control group ,model group,curcumin 10μmol/L group and curcumin 20μmol/L group.The ap-optotic rates were evaluated by flow cytometry with Annexin V-FITC/PI staining.The activities and expression levels of caspase-3,caspase-8 and caspase-9 were detected by colorimetric method and Western blot analysis.RESULTS:Com-pared with model group ,curcumin significantly increased the viability ,and decreased the LDH release rates and the apop-totic rates of the PC12 cells treated with Aβ25-35(P<0.01).Compared with model group,curcumin significantly decreased the activity and expression levels of caspase-3,caspase-8 and caspase-9(P<0.05 or P<0.01).CONCLUSION:Cur-cumin inhibits Aβ25-35-induced apoptosis of PC12 cells by inhibiting the expression of caspase-3,caspase-8 and caspase-9.
ABSTRACT
Objective: To investigate the protective effect of human lipoxin A4 (LXA4) on N2a cell damage induced by β-amyloid protein 25-35 (Aβ25-35) and the underlying mechanism. Methods: Aβ25-35 was used to treat N2a cells to establish Alzheimer's disease (AD) cell injury model. Meanwhile, LXA4 was added to the experimental group at different concentrations (50, 100 and 200 nmol·L-1 ). MTT assay was used to detect the activity of N2a cells. The apoptosis was detected by Hoechst 33258-PI staining, the expression of P62 and TRAF6 mRNA was detected by RT-PCR, and the expression of P62 and TRAF6 protein was detected by Western blot. Results: Compared with that of the model group, the cell survival rate of LXA4 protective group (50,100 and 200 nmol·L-1 ) increased (P <0. 01) and the apoptosis of N2a cells induced by Aβ25-35 was reduced by LXA4 (100 and 200 nmol·L-1 ) . Compared with that of the model group, the expression of P62-mRNA and protein-P62 of N2a cells treated with Aβ25-35 increased (P <0. 05 or P <0. 01) and the expression of TRAF6-mRNA and protein-TRAF6 of N2a cells treated with Aβ25-35 were reduced (P <0. 05 or P <0. 01). Conclusion: LXA4 has protective effect on N2a cell damage induced by Aβ25-35 , and its mechanism may be related to the up-regulation of P62 gene and down-regulation of TRAF6 gene.