Activation of nuclear factor-κB pathway is responsible for tumor necrosis factor-α-induced up-regulation of endothelin B2 receptor expression in vascular smooth muscle cells in vitro.
The endothelin B2 (ET(B2)) receptors are induced in vascular smooth muscle cells (VSMCs) in cardiovascular diseases. We tested if in vitro short-term exposure to the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) could up-regulate ET(B2) receptors in rat mesenteric arteries, and if this effect is through activation of intracellular nuclear factor-κB (NF-κB) pathway. The mesenteric arteries were dissected from male Sprague-Dawley rats and the endothelium was removed. The arteries were co-incubated with TNF-α in serum-free Dulbecco's modified Eagle's medium. Real-time reverse transcription-PCR, Western blot and immunohistochemical staining were employed to assess the mRNA/protein expression of ET(B2) receptors and activation of NF-κB pathway. The results showed that, during organ culture, TNF-α concentration-dependently enhanced ET(B2) receptors expression at both mRNA and protein levels, paralleled with activation of NF-κB pathway in VSMC. The up-regulated ET(B2) receptor expression and NF-κB activation could be effectively suppressed by general transcriptional inhibitor actinomycin D, or either of the selective IκB kinase inhibitors wedelolactone and IMD-0354. Conclusively, the activation of intracellular NF-κB pathway is responsible for the up-regulation of ET(B2) receptors induced by short-term exposure to TNF-α. This could partly explain the toxic effects of TNF-α on VSMCs that account for cardiovascular diseases.
Xiamen Diabetes Institute, Xiamen 361003, PR China.
Wei
W
Zhang
Xue-Jun
XJ
Li
Xin
X
Zeng
Dong-Yan
DY
Shen
Chang-Qin
CQ
Liu
Hui-Jie
HJ
Zhang
Cang-Bao
CB
Xu
Xiao-Ying
XY
Li
D000818:Animals; D050197:Atherosclerosis / Q000378:metabolism*; D001549:Benzamides / Q000494:pharmacology; D003374:Coumarins / Q000494:pharmacology; D020672:I-kappa B Proteins / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009924:Organ Culture Techniques; D012313:RNA / Q000737:chemistry / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D044023:Receptor, Endothelin B / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D015854:Up-Regulation
D001549:Benzamides; D003374:Coumarins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606206:Nfkbia protein, rat; D044023:Receptor, Endothelin B; D014409:Tumor Necrosis Factor-alpha; C051122:wedelolactone; D000072000:NF-KappaB Inhibitor alpha; D012313:RNA; C492919:N-(3,5-bis(trifluoromethyl)phenyl)-5-chloro-2-hydroxybenzamide