Interleukin-1beta and tumor necrosis factor (TNF)-alpha sensitize human thyroid epithelial cells to TNF-related apoptosis-inducing ligand-induced apoptosis through increases in procaspase-7 and bid, and the down-regulation of p44/42 mitogen-activated protein kinase activity.
Primary thyroid cells are resistant to TNF-related apoptosis-inducing ligand (TRAIL). Previously we showed that the combination of IL-1beta and TNFalpha facilitated TRAIL-mediated apoptosis in these cells and enhanced cell surface expression of TRAIL receptors. The aim of this study was to further characterize the mechanism by which these cytokines sensitized primary thyroid cells to TRAIL-mediated apoptosis. IL-1beta and TNFalpha increased the concentrations of procaspase-7 and Bid. In contrast, the p44/42 MAPK (Erk) pathway was active in thyroid cells and this activity was significantly decreased after exposure to IL-1beta/TNFalpha. A MAPK kinase inhibitor (U0126) could enhance the cytokine-induced sensitization of thyroid cells to TRAIL, reinforcing the inhibitory role of Erk on TRAIL signaling. In conclusion, IL-1beta/TNFalpha treatment sensitizes human thyroid cells to TRAIL-mediated apoptosis through increased surface expression of TRAIL receptors, increased expression of procaspase-7 and Bid, and the inhibition of p44/42 MAPK (Erk) pathway.
Mezosi
Emese
E
Center for Biologic Nanotechnology, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA.
Wang
Su He
SH
Utsugi
Saho
S
Bajnok
Laszlo
L
Bretz
James D
JD
Gauger
Paul G
PG
Thompson
Norman W
NW
Baker
James R
JR
D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000166:cytology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis; D015398:Signal Transduction; D053221:TNF-Related Apoptosis-Inducing Ligand; D013961:Thyroid Gland / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D002352:Carrier Proteins; D007375:Interleukin-1; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases