The role of protein kinase C to LPS-induced β-1,4-galactosyltransferase- I expression in endothelial cells
Objective To investigate the regulation of protein kinase C(PKC) to the expression of β-1,4-galactusyhransferase- Ⅰ ( β-1,4-GalT- Ⅰ ) and the influence on cytoskeleton and adherence ability of human umbilical vein endothelial cells(HUVECs) when stimulated by lipopolysaccharide (LPS). Methods Cultured HUVECs were pretreated by various PKC inhibitors or phorbol 12-myristate 13-acctate( PMA), an excitomotor of PKC respectively for 30 min, then stimulated by LPS for 4 h. β-1,4-GalT-Ⅰ expression were detected by RT-PCR and Western blot, expression of β-1,4-galactosylated carbohydrate chains and cytoskeleton were assayed by immumofluorescence, and adherence ability of HUVECs was observed by endothelialmonocyte cell adherence test. Results Up-regulated expression of β-1,4-GalT- Ⅰ and β-1,4-galactosylated carbohydrate chains in HUVECs stimulated by LPS were suppressed by PKC inhibitors and increased by PMA. F-actin and β-1,4-GalT- Ⅰ were partly co-localized in HUVECs. PKC inhibitor inhibited the effect of LPS on the distribution of F-actin and β-1,4-GalT- Ⅰ. Adherence ability of HUVECs enhanced by LPS was significantly suppressed by PKC inhibitor. Conclusion PKC signal transduction pathway may participate in regulating β-1,4-GalT-Ⅰ expression in endothelial cells stimulated by LPS. Furthermore, polytypes of PKC may participate in this regulating process; PKC might regulate cytoskeleton reorganization and adherence ability of EC through β-1,4-GalT-Ⅰ during inflammation. 
 
Key words: 
β-1,4-galactosyhransferase-Ⅰ ;  Protein kinase C;  Endothelial cell;  Lipopolysaccha-ride