Adhesion and Emigration of Monocyte to Vascular Endothelium were Associated with Functional Protein O-GLcNAcylation and Phosphorylation during Vascular Inflammation

Abstract: In present study， the altered levels of functional protein O-glycosylation and p38 MAPK phosphorylation in monocytes were observed during inflammation. The effects of functional protein O-glycosylation and p38 MAPK phosphorylation on monocyte adhesion through vascular endothelium and transmigration were investigated. During IFN-γ and LPS co-induced inflammation， the changes of THP-1 adhesion and migration to monolayer vascular endothelium were observed by 3D-culture， and the alteration of vascular permeability was measured by resisitance measurement as well. Furthermore， to explore the possible molecular mechanisms， p38 MAPK phosphorylation， the level of Ser(Thr)-O-linked N-acetylglucosaminlation(O-GLcNAc) and its special O-GlcNAc transferase (OGT) were observed by Western blot. As a result， IFN-γ and LPS co-treatment obviously enhanced monocytes adhesion and migration to vascular endothelium， and the permeability of vascular endothelium was also enchanced during THP-1 transmigration as well. Meanwhile， the augmented level of p38 MAPK phosphorylation was observed by western blot， and accompanied with the decreased level of OGT and O-GLcNAcylation protein in IFN-γ and LPS co-treated monocyte THP-1. To further confirm the regulation of p38 MAPK phosphorylation and O-glycosylation to THP-1 adhesion and migration to vascular endothelium， THP-1 cells were pretreated by p38 inhibitor before exposed to IFN-γ and LPS co-stimulation. Fortunately， the changes induced by IFN-γ and LPS cotreatment were mostly reversed by p38 inhibitor pretreatment. Together all， our results suggested during inflammatory reaction， monocytes adhesion and transmigration to vascular endothelium associated both with phosphorylation and glycosylation.

CSTR: 32200.14.cjcb.2012.03.0004