Previous studies have shown that patients with Guillain-Barré syndrome express autoantibodies against ganglioside GM1 (GM1), although its pathogenic significance for the development of the disease remains to be elucidated.

nSMase2 is the best characterized neutral sphingomyelinase (nSMase) found in neuronal cells. Activation of this enzyme leads to ceramide production, which is a known second messenger of the cell-death program in neuronal cells.

We have explored the effects of anti-GM1 antibodies on sphingomyelin metabolism of PC12 cells stably transfected with human trk cDNA (PCtrk cells) by determining their effects on nSMase2 activity. The data we present here strongly suggest that anti-GM1 caused a significant change in sphingomyelin content of the membrane fraction in PCtrk cells. Both nSMase2 activity and the level of nSMase2 protein were significantly decreased by anti-GM1 treatment of PCtrk cells, while acidic SMase activities remained unchanged.

Our results indicate, for the first time, that anti-GM1 may produce profound impacts on lipid metabolism in neuronal cell membranes.

先前的研究表明，患有Guillain-Barré综合征的患者表达针对神经节苷脂GM1（GM1）的自身抗体，尽管其对于疾病发展的致病意义尚待阐明。

nSMase2是在神经元细胞中发现的最具特征的中性鞘磷脂酶（nSMase）。该酶的激活导致神经酰胺的产生，这是神经元细胞中细胞死亡程序的第二种信使。

我们已经通过确定抗GM1抗体对nSMase2活性的影响，探讨了抗GM1抗体对稳定转染了人类trk cDNA的PC12细胞（PCtrk细胞）的鞘磷脂代谢的影响。我们在此提供的数据有力地表明，抗GM1引起PCtrk细胞膜级分中鞘磷脂含量的显着变化。通过抗GM1处理PCtrk细胞，nSMase2活性和nSMase2蛋白水平均显着降低，而酸性SMase活性保持不变。

我们的结果首次表明，抗GM1可能会对神经元细胞膜中的脂质代谢产生深远的影响。