Reduced expression of flice-inhibitory protein (FLIP) and NFkappaB is associated with death receptor-induced cell death in human aortic endothelial cells (HAECs).
We investigated the effects of TNF receptor 1 (TNFR1) and 2 (TNFR2) modulation on the death of human aortic endothelial cells (HAECs) resistant to TNF-alpha-induced cell death. Alteration of the transcription of anti-apoptotic proteins, including inhibitor of apoptosis protein 1, 2 (cIAP1, 2), TNF receptor-associated factor 1 (TRAF1), nuclear factor kappa B1 protein (NFkappaB1), and FLICE-inhibitory protein (FLIP) was assessed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). TNF-alpha (200 ng/ml) or actinomycin D (ActD) (5 ng/ml) did not kill cells, while 5 ng/ml of TNF-alpha and 5 ng/ml of ActD increased expression of Fas (CD95) and FasL (CD95L), and 45% of cells died. TNFR2 blockade suppressed NFkappaB1 and FLIP expression and increased cell death. TNFR1 blockade enhanced FLIP expression and decreased cell death. Cells insensitive to TNF-alpha may respond to TNF-alpha through TNFR that induces transcription of NFkappaB1 and FLIP. Down-regulation of these proteins may facilitate death of cells insensitive to TNF-alpha-induced cell death.
Okada
Y
Y
Department of Pediatrics, Gunma University School of Medicine, Maebashi, Gunma 371-8511, Japan.
Kato
M
M
Minakami
H
H
Inoue
Y
Y
Morikawa
A
A
Otsuki
K
K
Kimura
H
H
D001011:Aorta; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003609:Dactinomycin / Q000378:metabolism / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D053222:Fas Ligand Protein; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D044767:Ubiquitin-Protein Ligases; D019014:fas Receptor / Q000378:metabolism*
D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D002352:Carrier Proteins; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D051034:Inhibitor of Apoptosis Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011506:Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D003609:Dactinomycin; C494833:BIRC2 protein, human; D044767:Ubiquitin-Protein Ligases