Cell Surface Sialylation and Fucosylation Are Regulated by L1 via Phospholipase Cγ and Cooperate to Modulate Neurite Outgrowth, Cell Survival and Migration

BACKGROUND: Cell surface glycosylation patterns are markers of cell type and status. However, the mechanisms regulating surface glycosylation patterns remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using a panel of carbohydrate surface markers, we have shown that cell surface sialylation and fucosylation were downregulated in L1(-/y) neurons versus L1(+/y) neurons. Consistently, mRNA levels of sialyltransferase ST6Gal1, and fucosyltransferase FUT9 were significantly reduced in L1(-/y) neurons. Moreover, treatment of L1(+/y) neurons with L1 antibodies, triggering signal transduction downstream of L1, led to an increase in cell surface sialylation and fucosylation compared to rat IgG-treated cells. ShRNAs for both ST6Gal1 and FUT9 blocked L1 antibody-mediated enhancement of neurite outgrowth, cell survival and migration. A phospholipase Cgamma (PLCgamma) inhibitor and shRNA, as well as an Erk inhibitor, reduced ST6Gal1 and FUT9 mRNA levels and inhibited effects of L1 on neurite outgrowth and cell survival. CONCLUSIONS: Neuronal surface sialylation and fucosylation are regulated via PLCgamma by L1, modulating neurite outgrowth, cell survival and migration

Metabolomics of Human Amniotic Fluid and Maternal Plasma during Normal Pregnancy - Fig 2

<p><b>The PCA results obtained using quantified metabolites (signal areas) for amniotic fluid (A) and plasma (B).</b> Pregnancy stages. Yellow inverted triangles– 2^nd trimester (T2), red triangles– 3^rd trimester (T3), blue squares–delivery (TD) and green circles–prolonged pregnancy (PP).</p

The characterization of the amniotic fluid and plasma samples.

<p>The characterization of the amniotic fluid and plasma samples.</p

Differences of metabolites (expressed as percentage) between the four gestational age periods.

<p>Differences of metabolites (expressed as percentage) between the four gestational age periods.</p