[Effect of Sim2 gene on the differentiation of PC12 cells]

To observe the effect of Sim2, a Down syndrome critical locus gene, on the differentiation of PC12 cells, and to explore the role of Sim2 in the pathogenesis of Down syndrome, PC12 cells were transfected with the pcDNA3-mSim2 plasmid. The morphology of PC12 cells was observed by phase-contrast microscopy. mRNA expression of mSim2, GAP43 and synapsin I was determined by reverse transcription-polymerase chain reaction (RT-PCR). GAP43 protein expression was detected by flow cytometry. Abundant mSim2 expression was observed in PC12 cells transfected with pcDNA3-mSim2. In these cells, there were less neurites, and their length was shorter (P<0.05). The mRNA expression of GAP43 and synapsin I was significantly decreased. Flow cytometry experiments showed that mSim2-transfected cells had significantly suppressed GAP43 protein expression (P<0.05). All the results suggest that Sim2 may play an important role in the pathogenesis of Down syndrome by influencing neurite growth and inhibiting the differentiation of neurons.