ABSTRACT
BACKGROUND:Chitosan biological materials can induce bone marrow mesenchymal stem cells to differentiate toward neurons. As a derivative of chitosan, carboxymethyl chitosan has a series of excelent properties. However, whether carboxymethyl chitosan can induce the neuronal differentiation of bone marrow mesenchymal stem cells remains unclear.OBJECTIVE:To investigate the effect of carboxymethyl chitosan thermosensitive hydrogel on the differentiation of bone marrow mesenchymal stem cells into neurons and the possible mechanism.METHODS:Passage 3 bone marrow mesenchymal stem cells from rats were selected and cultured in carboxymethyl chitosan thermosensitive hydrogel extracts in different concentrations (0, 50, 100, 150, 200, 500 g/L). Control cells were cultured in culture medium with no addition of carboxymethyl chitosan thermosensitive hydrogel extracts. MTT assay was performed to investigate the effects of different concentrations of carboxymethyl chitosan thermosensitive hydrogel extracts on bone marrow mesenchymal stem cell proliferation. Western blot assay was used to explore the effect of 150 g/L carboxymethyl chitosan thermosensitive hydrogel extracts on the expression of neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, β3-tubulin, Notch1 and Jag1 protein.RESULTS AND CONCLUSION:MTT assay showed that carboxymethyl chitosan thermosensitive hydrogel promoted the cell proliferation, and the proliferation rate reached the peak at the concentration of 150 g/L. Western blot assay showed that the cells induced by 150 g/L carboxymethyl chitosan thermosensitive hydrogel extract had significant increases in neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, and β3-tubulin protein expression, and obvious decreases in Notch1 and Jag1 protein expression in comparison with the control group. These results indicate that the carboxymethyl chitosan thermosensitive hydrogel induces rat bone marrow mesenchymal stem cells to differentiate toward neurons, and suppresses the activity of Notch signal pathway in the process of differentiation.