ABSTRACT
Objective::To observe the effect of icariin on damaged neurons from the perspective of endoplasmic reticulum stress, in order to explore some mechanisms for repairing damaged neurons. Method::PC12 cells were induced by nerve growth factor (NGF) to differentiate into neurons, and the positive rate of microtubule associated protein-2 (MAP2) and neuron-specific enolase (NSE) expressions was determined by flow cytometry. The experiment was divided into 4 groups, blank control group: PC12 induced differentiation into neuronal cells, solvent control group: PC12 induced differentiation into neurons+ 0.1% dimethyl sulfoxide (DMSO), thapsigargin group: PC12 induced differentiation into nerves Yuan+ 2 μmol·L-1 thapsigargin, and icariin group: PC12 induced differentiation into neurons+ 2 μmol·L-1 thapsigargin+ 0.1 μmol·L-1 icariin. The proliferation of the cells was detected by using cell counting kit-8(CCK-8) method, the apoptosis of the cells was detected by flow cytometry, the protein expressions of CCAAT/enhace-binding protein homologous protein(CHOP) and glucoseregulated protein 78(Grp78) were detected by Western blot, and the mRNA expressions of CHOP and Grp78 were detected by real-time quantitative PCR (Real-time PCR). Result::Compared with the solvent control group, the thapsigargin group inhibited the proliferation of neuron-like PC12 cells induced by NGF, promoted apoptosis, and up-regulated the expressions of CHOP and Grp78 (P<0.05, P<0.01). Compared with the thapsigargin group, the icariin group can alleviate the inhibition of neurotrophic activity by thapsigargin, reduce neuronal apoptosis, and down-regulate the expressions of CHOP and Grp78 (P<0.05, P<0.01). Conclusion::Icariin can inhibit endoplasmic reticulum stress by down-regulating the expressions of CHOP and Grp78 and promote the repair of damaged neurons.
ABSTRACT
BACKGROUND: Osthol has been reported to promote osteogenesis by increasing osteoblast proliferation, but the anti-osteoporosis mechanism underlying osthol is poorly understood.OBJECTIVE:To observe the effect of osthol on the proliferation and differentiation of rat osteoblasts in vitro and to explore its mechanism of anti-osteoporosis effect. METHODS: Rat osteoblasts were isolated by secondary enzyme digestion and identified by alkaline phosphatase staining and mineralized nodule staining. There were five groups: blank control, solvent control, β-estradiol as well as low-, medium- and high-dose osthol groups. Cell proliferation was detected by cell counting kit-8 assay, and cell differentiation was evaluated by detection of alkaline phosphatase and mineralized nodule staining. The expression levels of GRP78, PDI and CHOP were detected by western blot assay. RESULTS AND CONCLUSION: Osthol at the concentrations of 1x10-4and 1x10-5mol/L could inhibit osteoblast proliferation. 1x10-4mol/L osthol could increase the activity of alkaline phosphatase in osteoblasts and enhance osteoblastic mineralization. Meanwhile, 1x10-4mol/L osthol was able to down-regulate the expression level of GRP78 and up-regulate the expression levels of PDI and CHOP. To conclude, osthol can promote osteoblast differentiation and inhibit osteoblast proliferation probably by endoplasmic reticulum stress.