NF-kappaB signaling mediates vascular smooth muscle endothelin type B receptor expression in resistance arteries.
Vascular smooth muscle cells (SMC) endothelin type B (ET(B)) receptor upregulation results in strong vasoconstriction and reduction of local blood flow. We hypothesizes that the underlying molecular mechanisms involve transcriptional factor nuclear factor-kappaB (NF-kappaB) pathway. ET(B) receptor upregulation and activation of NF-kappaB were studied at functional contraction (in vitro myograph), mRNA (real-time PCR), and protein (Western blot and immunocytochemistry) levels during organ culture of rat mesenteric arteries. Organ culture of the artery segments induced a time-dependent strong contractile response to sarafotoxin 6c in parallel with enhanced expression of ET(B) receptor mRNA and protein in the SMC. Western blot experiments demonstrated that phosphorylation of NF-kappaB p65 was time-dependently induced during organ culture starting at 1h. In addition, cytoplasmic IkB degradation occurred in parallel with nuclear NF-kappaB accumulation following organ culture. The enhanced expression of ET(B) receptor protein was apparent at 3h in the SMC and while enhanced ET(B) receptor-mediated contractions occurred first at 12h. The specific IkappaB inhibitors, IMD-0354 (N-(3,5-Bis-trifluoromethylphenyl)-5-chloro-2-hydroxybenzamide) and Wedelolactone (7-Methoxy-5,11,12-trihydroxycoumestan), abolished the organ culture induced ET(B) receptor upregulation. The intracellular NF-kappaB pathway is involved in the process of induced expression of vascular SMC ET(B) receptors.
Zheng
Jian-Pu
JP
Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Sweden.
Zhang
Yaping
Y
Edvinsson
Lars
L
Hjalt
Tord
T
Xu
Cang-Bao
CB
D000818:Animals; D015153:Blotting, Western; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D007150:Immunohistochemistry; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009924:Organ Culture Techniques; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D044023:Receptor, Endothelin B / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D016328:NF-kappa B; D012333:RNA, Messenger; D044023:Receptor, Endothelin B; D014662:Vasoconstrictor Agents