Johansson Maria E, Fagerberg Björn, Bergström Göran
Department of Molecular and Clinical Medicine/Clinical Physiology, The Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
J Renin Angiotensin Aldosterone Syst. 2008 Mar;9(1):17-21. doi: 10.3317/jraas.2008.005.
Expression of the angiotensin type 2 receptor (AT2-receptor) occurs in many animal models of atherosclerosis. However, its expression in human plaques and its functional role remains undetermined. This study examined AT2-receptor expression in human atherosclerotic plaque and also explored its potentially important functional role in atherosclerosis.
We analysed carotid atherosclerotic plaques obtained from 14 Caucasian patients who had previously undergone endarterectomy for symptomatic carotid artery stenosis. Half of all subjects received treatment with an angiotensin receptor blocker (ARB) (n=7); the remaining subjects received no intervention in the renin-angiotensin system (n=7). Immunohistochemistry measured tissue expression of smooth muscle cells (a-actin), macrophages (CD68 antibody), collagen (picro-sirius), and AT2-receptor (AT2-receptor antibody).
AT2-receptor expression occurred consistently in all specimens. Although cellular localisation varied, AT2-receptor expression levels correlated with macrophage levels (p<0.01). Compared to conventional treatment, ongoing ARB treatment affected neither AT2-receptor levels nor plaque composition.
AT2-receptor is expressed in human atherosclerotic plaque. Furthermore, we detected no functionally important role of AT2-receptor expression and found no evidence that ARB treatment regulates AT2-receptor expression.
血管紧张素2型受体（AT2受体）在许多动脉粥样硬化动物模型中均有表达。然而，其在人类斑块中的表达及其功能作用仍未明确。本研究检测了人类动脉粥样硬化斑块中AT2受体的表达，并探讨了其在动脉粥样硬化中潜在的重要功能作用。
我们分析了14例因有症状性颈动脉狭窄而接受过颈动脉内膜切除术的白种人患者的颈动脉粥样硬化斑块。所有受试者中有一半接受了血管紧张素受体阻滞剂（ARB）治疗（n = 7）；其余受试者在肾素 - 血管紧张素系统方面未接受干预（n = 7）。免疫组织化学法检测了平滑肌细胞（α - 肌动蛋白）、巨噬细胞（CD68抗体）、胶原蛋白（苦味酸天狼星）和AT2受体（AT2受体抗体）的组织表达情况。
所有标本中均持续出现AT2受体表达。尽管细胞定位有所不同，但AT2受体表达水平与巨噬细胞水平相关（p < 0.01）。与传统治疗相比，持续的ARB治疗既不影响AT2受体水平，也不影响斑块成分。
AT2受体在人类动脉粥样硬化斑块中表达。此外，我们未检测到AT2受体表达的重要功能作用，也未发现ARB治疗调节AT2受体表达的证据。
