Promoting effect of botulinum neurotoxin serotype A heavy chain on neu-ritogenesis in cultured Neuro-2a cells / 中国病理生理杂志

ABSTRACT

AIM:To observe the neuritogenic actions of botulinum neurotoxin serotype A heavy chain ( BoNT/A HC) on cultured Neuro-2a cells and to investigate the related signaling mechanisms for the effect of BoNT /A HC. METHODS:Neuro-2a cells were treated with different doses of BoNT/A HC (0.01, 0.1, 1 and 10 nmol/L), and then the cells were harvested at 24 h, 48 h and 72 h of BoNT/A HC exposure for detecting the neurite length and the percen-tage of the cells with neuronal processes by immunofluorescence staining .The most efficient dose of BoNT/A HC was cho-sen for exposure to Neuro-2a cells as the above.Whole cell protein was harvested at different time points for detecting the protein levels of phosphorylated ERK 1/2 ( p-ERK1/2 ) and phosphorylated Akt ( p-Akt ) by Western blot .RESULTS:Low doses of BoNT/A HC stimulated the neurite outgrowth , and increased the percentage of the cells with neurites com-pared with the negative controls (P<0.05), especially in the group with 1 nmol/L of BoNT/A HC treatment.Meanwhile, the phosphorylation of ERK 1/2 and Akt was increased after treated with BoNT/A HC.There was an increasing tendency for the phosphorylation of ERK1/2 after the exposure of the cells to BoNT/A HC.The obvious increase in p-ERK1/2 was seen from 60 min to 5 h with 1 nmol/L of BoNT/A HC treatment ( P<0.05 ) , and the increased protein level of p-Akt was mainly observed at 15 min and 60 min ( P<0.05 ) .CONCLUSION: BoNT/A HC stimulates the neuritogenesis .The neuritogenic mechanism of BoNT/A HC on Neuro-2a cells might be realized by activation of the phosphorylation of ERK 1/2 and Akt.