Nilsson David, Gustafsson Lotta, Wackenfors Angelica, Gesslein Bodil, Edvinsson Lars, Paulsson Per, Ingemansson Richard, Malmsjö Malin
Department of Medicine, Lund University Hospital, Sweden.
BMC Cardiovasc Disord. 2008 Sep 8;8:21. doi: 10.1186/1471-2261-8-21.
Up-regulation of vascular endothelin type B (ETB) receptors is implicated in the pathogenesis of cardiovascular disease. Culture of intact arteries has been shown to induce similar receptor alterations and has therefore been suggested as a suitable method for, ex vivo, in detail delineation of the regulation of endothelin receptors. We hypothesize that mitogen-activated kinases (MAPK) and protein kinase C (PKC) are involved in the regulation of endothelin ETB receptors in human internal mammary arteries.
Human internal mammary arteries were obtained during coronary artery bypass graft surgery and were studied before and after 24 hours of organ culture, using in vitro pharmacology, real time PCR and Western blot techniques. Sarafotoxin 6c and endothelin-1 were used to examine the endothelin ETA and ETB receptor effects, respectively. The involvement of PKC and MAPK in the endothelin receptor regulation was examined by culture in the presence of antagonists.
The endothelin-1-induced contraction (after endothelin ETB receptor desensitization) and the endothelin ETA receptor mRNA expression levels were not altered by culture. The sarafotoxin 6c contraction, endothelin ETB receptor protein and mRNA expression levels were increased after organ culture. This increase was antagonized by; (1) PKC inhibitors (10 microM bisindolylmaleimide I and 10 microM Ro-32-0432), and (2) inhibitors of the p38, extracellular signal related kinases 1 and 2 (ERK1/2) and C-jun terminal kinase (JNK) MAPK pathways (10 microM SB203580, 10 microM PD98059 and 10 microM SP600125, respectively).
In conclusion, PKC and MAPK seem to be involved in the up-regulation of endothelin ETB receptor expression in human internal mammary arteries. Inhibiting these intracellular signal transduction pathways may provide a future therapeutic target for hindering the development of vascular endothelin ETB receptor changes in cardiovascular disease.
血管内皮素B型（ETB）受体上调与心血管疾病的发病机制有关。完整动脉的培养已被证明可诱导类似的受体改变，因此被认为是一种适合于离体详细描述内皮素受体调节的方法。我们假设丝裂原活化蛋白激酶（MAPK）和蛋白激酶C（PKC）参与人乳内动脉内皮素ETB受体的调节。
在冠状动脉搭桥手术期间获取人乳内动脉，并在器官培养24小时前后进行研究，采用体外药理学、实时PCR和蛋白质印迹技术。分别使用沙拉毒素6c和内皮素-1来检测内皮素ETA和ETB受体效应。通过在拮抗剂存在下培养来检测PKC和MAPK在内皮素受体调节中的作用。
内皮素-1诱导的收缩（在内皮素ETB受体脱敏后）和内皮素ETA受体mRNA表达水平未因培养而改变。器官培养后，沙拉毒素6c收缩、内皮素ETB受体蛋白和mRNA表达水平增加。这种增加被以下物质拮抗：（1）PKC抑制剂（10微摩尔双吲哚马来酰亚胺I和10微摩尔Ro-32-0432），以及（2）p38、细胞外信号相关激酶1和2（ERK1/2）以及C- Jun末端激酶（JNK）MAPK途径的抑制剂（分别为10微摩尔SB203580、10微摩尔PD98059和10微摩尔SP600125）。
总之，PKC和MAPK似乎参与人乳内动脉内皮素ETB受体表达的上调。抑制这些细胞内信号转导途径可能为阻碍心血管疾病中血管内皮素ETB受体变化的发展提供未来的治疗靶点。
