Tumor necrosis factor-alpha induces fractalkine expression preferentially in arterial endothelial cells and mithramycin A suppresses TNF-alpha-induced fractalkine expression.
Fractalkine is an unusual tumor necrosis factor (TNF)-alpha-induced chemokine. The molecule is tethered to cells that express it and produces strong and direct adhesion to leukocytes expressing fractalkine receptor. However, the potential mechanism and significance of TNF-alpha-induced fractalkine expression in vascular endothelial cells are poorly understood. Here we show that in primary cultured endothelial cells TNF-alpha-induced fractalkine mRNA expression is mediated mainly through phosphatidylinositol 3'-kinase activation and nuclear factor (NF)-kappaB mediated transcriptional activation, along with GC-rich DNA-binding protein-mediated transcription. Interestingly, GC-rich DNA-binding protein inhibitors, mithramycin A and chromomycin A3, strongly suppressed TNF-alpha-induced fractalkine mRNA expression, possibly through inhibition of transcriptional activities by NF-kappaB and Sp1. In fact, direct inhibition of NF-kappaB and Sp1 bindings by decoy oligonucleotides suppressed TNF-alpha-induced fractalkine expression. Histologically, TNF-alpha-induced fractalkine expression was observed markedly in arterial and capillary endothelial cells, endocardium, and endothelium of intestinal villi, and slightly in venous endothelial cells, but not at all in lymphatic endothelial cells of intestine. Mithramycin A markedly suppressed TNF-alpha-induced fractalkine expression in vivo. These results indicate that TNF-alpha-stimulated fractalkine expression could act as part of arterial endothelial adhesion to leukocytes and monocytes during inflammation and atherosclerosis. NF-kappaB and Sp1 inhibitors such as mithramycin A may provide a pharmacological approach to suppressing these processes.
Ahn
So Young
SY
Biomedical Research Center and Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
Cho
Chung-Hyun
CH
Park
Keun-Gyu
KG
Lee
Hyuek Jong
HJ
Lee
Sik
S
Park
Sung Kwang
SK
Lee
In-Kyu
IK
Koh
Gou Young
GY
D000818:Animals; D001158:Arteries / Q000378:metabolism*; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C / Q000096:biosynthesis*; D003720:Densitometry; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis*; D009206:Myocardium / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism; D009841:Oligonucleotides / Q000737:chemistry; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D008926:Plicamycin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012260:Ribonucleases / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D013997:Time Factors; D015533:Transcriptional Activation; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
C515538:CX3CL1 protein, human; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C; C515540:Cx3cl1 protein, rat; D008565:Membrane Proteins; D016328:NF-kappa B; D009841:Oligonucleotides; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D014409:Tumor Necrosis Factor-alpha; C066851:mithramycin A; D019869:Phosphatidylinositol 3-Kinases; D012260:Ribonucleases; D008926:Plicamycin