Vimentin is important in the neural differentiation of PC12 cells promoted by sialylation

Sialic acid modification is a kind of post-translational modification. To investigate the regulation effect of sialic acid on neural differentiation, we used CycloManN propanyl perac (CycloManN pro), a metabolic precursor of sialic acid, to treat PC12 cells. We noted that CycloManN pro indeed robustly promoted global sialylation detected by MAL II lectin blot in PC12 cells. Simultaneously, we interestingly found that the neurite outgrowth of PC12 cells was significantly promoted by the CycloManN pro treatment. The profile analysis of sialylated proteins showed that a protein band at 55KD was greatly enhanced especially in PC12L cells after CycloManN pro treatment. After enrichment with lectin MAL II, the proteins in this band were analyzed by mass spectrometry. The results showed that 23 proteins were in the band, but the score of vimentin was the highest among them. To investigate further the role of vimentin in the process of neurite differentiation, vimentin construct was transfected into PC12 cells. We interestingly observed that ectopic expression of vimentin significantly enhanced the neurite outgrowth induced by CycloManN pro. However, after three potential glycosylation sites (Ser-7, Thr-33, Ser-34:) of vimentin were mutated to alanine, overexpression of the mutated vimentin completely lost the enhancement activity for the neural differentiation even in the presence of CycloManN pro. Taken together, our study demonstrated that vimentin was important in the induction of neural differentiation by CycloManN pro.