Role of E-selectin in cell apoptosis induced by allogeneic blood perfusion in isolated mouse lung.
BACKGROUND
In a model of mouse isolated lung, we have recently demonstrated that E-selectin is involved in the activation of endothelial cells induced by allogeneic blood perfusion. In the present study, we explored the signaling pathway of apoptosis induced by E-selectin triggering.


METHODS
Lungs were perfused for 3 hours with fresh blood in the absence or presence of an anti-E-selectin monoclonal antibody, or a protein kinase C (PKC), protein tyrosine phosphatase (PTP), or protein tyrosine kinase (PTK) inhibitor. The number of apoptotic cells in lung sections was determined by a TUNEL method. mRNAs for Fas, FasL and caspase-8, and for Bad, Bax, Bcl-w, Bcl-xL and caspase-9, for the FasL and the mitochondrial cytochrome-c pathways of apoptosis, respectively, and mRNA for the effector caspase-3 were quantified in lung tissues by RT-PCR. PTP and Src-PTK activities were also measured.


RESULTS
After 3 hours of allogeneic perfusion, we observed a significant increase in: 1) the number of apoptotic cells in lung sections, 2) mRNA levels of FasL, Bcl-xL, caspase-8 and caspase-3, and 3) PTP activity (P < 0.05 compared with isogeneic perfusion). Surprisingly, mRNA levels of the proapoptotic genes Bad and Bax were significantly decreased (P < 0.05). PTK activity and caspase-9 mRNA level were not affected. Blocking anti-E-selectin mAbs and inhibitors for PKC, PTP, and PTK resulted in a significant reduction of apoptosis.


CONCLUSIONS
In our model, the engagement of E-selectin induced by endothelial cell allogeneic activation appeared to be a prerequisite for lung apoptosis, which involved FasL and increase of PTP activity. Blockade of apoptosis with selective inhibitors may be a promising approach to the treatment/prevention of lung graft injury.
Joucher
Franck
F
CNRS UMR 8078, IPSC, Université Paris-Sud 11, Centre Chirurgical Marie-Lannelongue, Le Plessis Robinson, France.
Mazmanian
Guy-Michel
GM
German-Fattal
Michele
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D020169:Caspases / Q000235:genetics; D019040:E-Selectin / Q000276:immunology / Q000378:metabolism*; D004727:Endothelium / Q000378:metabolism / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D053222:Fas Ligand Protein; D005260:Female; D020287:In Situ Nick-End Labeling; D008168:Lung / Q000378:metabolism* / Q000473:pathology*; D016040:Lung Transplantation; D008562:Membrane Glycoproteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D010477:Perfusion; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014184:Transplantation, Homologous; D048069:Tumor Necrosis Factors / Q000235:genetics; D051028:bcl-2-Associated X Protein / Q000235:genetics; D051025:bcl-Associated Death Protein / Q000235:genetics; D051020:bcl-X Protein / Q000235:genetics; D019014:fas Receptor / Q000235:genetics
D000911:Antibodies, Monoclonal; D051017:Apoptosis Regulatory Proteins; C101155:Bcl2l2 protein, mouse; D019040:E-Selectin; D004791:Enzyme Inhibitors; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D011506:Proteins; D012333:RNA, Messenger; D048069:Tumor Necrosis Factors; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein; D019014:fas Receptor; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D017027:Protein Tyrosine Phosphatases; D020169:Caspases