title: Nuclear Factor-kappaB-Mediated Endothelin Receptor Up-Regulation Increases Renal Artery Contractility in Rats.
abstract: Increased renal artery contractility leads to renal vasospasm and ischaemia as well as kidney damage. This study was designed to examine the hypothesis that organ culture of renal arteries induces transcriptional up-regulation of endothelin type A (ETA ) and type B2 (ETB2 ) receptors in the smooth muscle cells via activation of nuclear factor-kappaB (NF-κB) and subsequently increases renal artery contractility. Rat renal artery segments were organ-cultured for 6 or 24 hr to increase endothelin receptor-mediated contraction. To dissect molecular mechanisms involved in this process, inhibitors for NF-κB signalling pathway (MG-132 and BMS345541), transcription (actinomycin D) and translation (cycloheximide) were used during organ culture. Endothelin receptors were studied using a sensitive myograph (functional contractility), real-time PCR (mRNA analysis) and immunohistochemistry (protein localization). Compared with fresh segments, contractile responses to endothelin-1 (non-selective endothelin receptor agonist) and sarafotoxin 6c (selective ETB receptor agonist) were significantly increased in the segments after 24 hr of organ culture; ETB2 receptor-mediated maximal contraction increased from 2.7 ± 0.5 to 135.3 ± 5.1 (p < 0.001), and potency (pEC50 ) of ETA receptor agonist increased from 8.20 ± 0.04 to 8.72 ± 0.07 (p < 0.001). This was in parallel with increased corresponding mRNA and protein expression for ETA and ETB2 receptors. BMS345541, MG-132, actinomycin D or cyclohexamide, respectively, suppressed the up-regulation of ETA and ETB2 receptors. Immunostaining performed with specific antibody showed that IκB was phosphorylated during organ culture. In conclusion, activation of NF-κB mediates up-regulation of ETA and ETB2 receptors and subsequently increases renal artery contractility, which may contribute to renal vasospasm and ischaemia as well as kidney damage.
authors.affiliation: Institute of Materia Medica, School of Pharmacy, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Xie
authors.affiliation: Institute of Materia Medica, School of Pharmacy, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Si-Wang
authors.initials: SW
authors.lastname: Wang
authors.affiliation: Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Edvinsson
authors.affiliation: Institute of Basic and Translational Medicine, Xi'an Medical University, Xi'an, Shaanxi, China.|Division of Experimental Vascular Research, Institute of Clinical Science in Lund, Lund University, Lund, Sweden.
authors.forename: Cang-Bao
authors.initials: CB
authors.lastname: Xu
mesh_terms: D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D016328:NF-kappa B / Q000502:physiology*; D009924:Organ Culture Techniques; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D044022:Receptor, Endothelin A / Q000187:drug effects / Q000502:physiology*; D044023:Receptor, Endothelin B / Q000187:drug effects / Q000502:physiology*; D012077:Renal Artery / Q000187:drug effects* / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology; D014757:Viper Venoms / Q000494:pharmacology
chemical_list: C471109:4(2'-aminoethyl)amino-1,8-dimethylimidazo(1,2-a)quinoxaline; D007093:Imidazoles; D007976:Leupeptins; D016328:NF-kappa B; D011810:Quinoxalines; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D014757:Viper Venoms; C057354:sarafotoxins s6; D003609:Dactinomycin; D003513:Cycloheximide; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde