Altered protein expression levels of Fas/CD95 and Fas ligand in differentially vulnerable brain areas in rats after global cerebral ischemia.
To assess the role of the apoptosis-inducing death receptor Fas/CD95 and Fas Ligand (FasL) after global cerebral ischemia, expression of these proteins was investigated in differentially, i.e. selectively vulnerable brain areas. Following experimentally induced cardiac arrest of 6 min duration, rats were resuscitated. After 3, 6, and 24 h of reperfusion, the thalamus and hippocampus of one hemisphere were analyzed for Fas/CD95 and FasL by immunoblotting and semiquantitative densitometry. Corresponding hemispheres were examined by immunohistochemistry. No significant changes in hippocampal Fas/CD95 expression were revealed in comparison to sham operated animals. In the thalamus, a significant reduction in Fas/CD95 expression was observed after 24 h of reperfusion. FasL expression in the hippocampus had declined after 3 and 6 h, as compared with control animals. In contrast, in the thalamus a significant induction of FasL expression was observed after 3 h. Immunohistochemistry revealed a predominantly neuronal expression of the two proteins. In light of the observed increased expression of FasL in the thalamus, such an induction may lead to significant activation of the Fas/CD95 signaling cascade. Our results suggest for the first time a possible role of the Fas/CD95-FasL system after global cerebral ischemia.
Padosch
S A
SA
Department of Anaesthesiology, University of Heidelberg, Im Neuenheimer Feld 110, D-69120, Heidelberg, Germany.
Popp
E
E
Vogel
P
P
Böttiger
B W
BW
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002545:Brain Ischemia / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D003720:Densitometry; D053222:Fas Ligand Protein; D006323:Heart Arrest / Q000150:complications; D015151:Immunoblotting; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D051381:Rats; D015424:Reperfusion; D013997:Time Factors; D019014:fas Receptor / Q000096:biosynthesis*
D053222:Fas Ligand Protein; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D019014:fas Receptor