Cytoprotection and ischemia reperfusion injury: new mechanistic aspects

Abstract# 2994 Poster Board #-Session: P412-IV 2994 Poster Board #-Session: P412-IV HO-1 PROTECTS INF-γ PRIMED ENDOTHELIAL CELLS FROM JURKAT T-CELLS ADHESION. Dunfeng Du, Sheng Chang, Bicheng Chen, Hongmin Zhou, Zhonghua Klaus. Institute of Organ Transplantation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Purpose: The heme oxygenase-1(HO-1) system is associated with ratelimiting step in the convension of heme and of the most critical role in cytoprotective mechanisms when cells undergoing processes.Our study is to investigate (1) the expression of HO-1 on the human umbilical vein endothelial cells (HUVEC);(2) its potential roles in protection of endothelial cells from Jurkat T-cells adhesion; (3) its effect on the cell cycle of Jurkat T-cells. Methods: The recombinant plasmid pcDNA3-HO-1 was transfected into endothelial cells. Indirect fluorescent staining was employed to examine the expression of HO-1 protein. Then endothelial cells primed by INF-γ were mixed cultured with Jurkat T-cells labeled by CFSE. The number of adhesive Jurkat T-cells was determined by FCM to evaluate the adhesion effect. The expressions of endothelial cells surface human leukocyte antigenDR(HLA-DR) and intercellular adhesion molecule-I(ICAM-I) were detected by immunohistochemitry. After cultured with endothelial cells, the cell cycle of Jurkat T-cells were detected by FCM. Results: The expression of HO-1 on endothelial cells conferred a significant protection against Jurkat T-cells medicated adhesions, and the rate of Jurkat T-cells adhesions was reduced to 19.06% in contrast to 31.42% in the control group (P<0.05. After using ZnPP ,the inhibitor of HO-1 , the rate of Jurkat T-cells adhesions was recovered to 29.08%. The binding activities between endothelial cells and Jurkat T-cells could bi blocked by the HO-1 expression. Compared to control group, the expression of ICAM-I in INF-γ primed endothelial cells had to no obviously change after HO-1 gene transfected. While the expression of HLA-DR in INF-γprimed endothelial cells significantly decreased after HO-1 gene transfected. The proliferation of Jurkat T-cells was inhibited after cultured with endothelial cells, which were transfected with HO-1. HO-1 blocked the cell cycle entry of T cells. Over 60% Jurkat T-cells were standstill in G0/G1 compared to 40% in control group. Conclusion: HO-1 can directly protected endothelial cells primed by INFγ from Jurkat T-cells and downregulate the expression of HLA-DR on the surface of endothelial cells. These results indicate that transgenic expression of HO-1 may be useful to prevent lymphocytes from responding to endothelial cells. Abstract# 2995 Poster Board #-Session: P413-IV 2995 Poster Board #-Session: P413-IV ISCHEMIA/REPERFUSION INDUCED OXYGEN FREE RADICAL RELEASE OF THE PANCREAS: THE ROLE OF ISCHEMIA TIME AND PERFUSATE. Hannes Neeff, Olaf Sommer, Sebastian Meyer, Moritz Scholtes, Anja Kaprolat, Oliver Drognitz, Ulrich T Hopt, Ernst von Dobschuetz. General and Digestive Surgery, University Hospital Freiburg,