title: Proteinase-activated receptor-1 mediates allogeneic CD8(+) T cell-induced apoptosis of vascular endothelial cells.
abstract: Vascular endothelial-cells injury plays a pivotal role in the pathogenesis of graft-versus-host disease (GVHD) and transplant-associated endothelial injury syndrome. Vascular endothelial cells are an exposed target tissue for immune-mediated injury during GVHD. Early endothelial injury syndromes share common features with acute GVHD. Chronic GVHD leads to a rarefaction of microvessels caused by the infiltration of alloreactive cytotoxic T lymphocytes. In this context, allogeneic reactive cytotoxic T cell may contribute to apoptosis of vascular endothelial cells. The involvement of proteinase-activated receptor (PAR-1) in regulation of apoptosis has been recently recognized in many cell types. We hypothesized that apoptosis of vascular endothelial cells induced by allogeneic cytotoxic T cell are mediated via the PAR-1. Allogeneic CD8(+) T cell, PAR-1 agonist peptide (SFLLRN) induced apoptosis of human umbilical vein endothelial cells (HUVECs) and human dermal microvascular endothelial cells (HDMECs) as assessed by AnnexinV-FITC labeling. To ascertain the mechanism of endothelial apoptosis, we determined that allogeneic CD8(+) T cell, SFLLRN enhanced cleavage of caspase-3 and led to p38MAPK activation as assessed by Western blot. The effects of allogeneic CD8(+) T cell and SFLLRN on apoptosis of vascular endothelial cells were largely prevented by a cleavage-blocking anti-human PAR-1-antibody (ATAP2) and a specific inhibitor of p38MAPK. In concert, these observations provide strong evidence that allogeneic CD8(+) T cell induces apoptosis of human vascular endothelial cells through PAR-1-dependent modulation of intrinsic apoptotic pathway via alterations of p38MAPK and caspase-3.
authors.affiliation: Institute of Hematology, Tong ji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China. liquan215499@163.com
authors.forename: Li
authors.initials: L
authors.lastname: Quan
authors.forename: Zhang
authors.initials: Z
authors.lastname: Jian
authors.forename: Zou
authors.initials: Z
authors.lastname: Ping
authors.forename: Li
authors.initials: L
authors.lastname: Weiming
mesh_terms: D017209:Apoptosis / Q000276:immunology*; D015153:Blotting, Western; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D053148:Caspase 3 / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D020405:Dermis / Q000166:cytology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D010446:Peptide Fragments / Q000494:pharmacology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics; D044463:Receptor, PAR-1 / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014471:Umbilical Veins / Q000166:cytology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3