Abstract:

Objective To study the effect of Cynomorium songaricum polysaccharide（CSP）on the osteo⁃ genic differentiation of MC3T3 ⁃ E1 mouse osteoblast cell line through PI3K/Akt/GSK3β/β ⁃ catenin pathway. Methods MC3T3⁃E1 was cultured in osteogenic induction fluid with different concentrations of CSP. The cell viability was detected by MTT method on the 1st，3rd，5th，and 7th day. And then the cells were divided into Con group（0 μg/mL CSP），CSP group（100 μg/mL CSP）and CSP + BEZ group（100 μg/mL CSP and 50 μmol/L BEZ （PI3K specific inhibitor））. After 14 days of intervention，the cells in each group were stained with Alizarin Red to observe the osteogenic differentiation. Real⁃time quantitative PCR was utilized to analyze quantitatively the mRNA levels of osteogenic differentiation⁃related markers ，including Runt⁃related transcription factor 2 （Runx2）， β⁃catenin，osteocalcin，collagen I；and western blotting was used to detect the protein expression of osteogenic differentiation⁃related proteins ，including Runx2 ，collagen I ，osteocalcin ，and proteins of PI3K/Akt/GSK3 β / β ⁃catenin pathway. And the immunofluorescence was applied to detect the nuclear translocation of β ⁃catenin. Results Compared with that in the Con group，the proliferation of MC3T3⁃E1 was effectively promoted in the CSP group and CSP + BEZ group，and the effect of 100 μg/mL CSP was more significant. CSP（100 μg/mL）could effectively promote the positive rate of Alizarin Red staining in MC3T3⁃E1 cells，as well as the expression levels of osteogenic differentiation⁃related proteins and mRNA（P < 0.05），and PI3K，p⁃PI3K，Akt，P⁃Akt，GSK3β，p⁃ GSK3β，and β⁃catenin protein expression（P < 0.05）. CSP can also promote β⁃catenin into the nucleus；but this promotion effects can be reversed by BEZ. Conclusion CSP may induce osteogenic differentiation of MC3T3⁃E1cells by activating the PI3K/AKT/GSK3β/β⁃catenin pathway.

Key words:

osteoporosis； Cynomorium songaricum polysaccharide； PI3K/AKT/GSK3β/β ? catenin pathway； osteogenic differentiation ,