Objective: To study the pathogenetic role of tissue factor (TF) in endothelial-injury in GVHD.
Methods: Gene and protein expressions of TF in the organs of allogenic hematopoietic stem cell transplantation (allo-HSCT) and autologous HSCT (auto-HSCT) mice were determined by real-time PCR and Western blot. The effect of allogeneic T lymphocytes on the expression of TF and other cytokines and activation of MAPKs in human umbilical vein endothelial cells (HUVECs) was detected by flow cytometry, real-time PCR or Western blot. The influence of TF antibodies (SB203580 and SP600125) on allogeneic T lymphocytes-induced cytokines expression was also tested.
Results: (1) TF gene and protein expression in the liver, skin, small intestine and stomach of allo-HSCT mice was significantly elevated about 15.1+/-2.1, 5.5+/-1.4, 9.7+/-2.3, 14.2+/-2.9 folds and 13.5+/-2.7, 6.2+/-0.9, 7.9+/-1.6, 15.3+/-3.2 folds respectively compared with that of auto-HSCT mice. (2) Allogeneic CD4+ CD8+ T lymphocytes significantly enhanced TF, VCAM-1, TNF-alpha, IFN-gamma and IL-6 expression in TNF-alpha prestimulated HUVECs. (3) Allogeneic T lymphocytes enhanced p38MAPK and JNK phosphorylation in HUVECs, but did not affect ERK phosphorylation. p38 MAPK JNK inhibitors SB203580 and SP600125 reduced allogeneic T lymphocytes-induced TF expression in HUVECs. (4) SB203580 and SP600125 down-regulated allogeneic T lymphocytes-induced VCAM-1, TNF-alpha, IFN-gamma, IL-6 expression in HUVECs.
Conclusion: TF mediates vascular endothelial-injury and activation in GVHD via phosphorylation of p38MAPK and JNK.