Riper Dee Van, Jayakumar Lalithapriya, Latchana Nicholas, Bhoiwala Dipti, Mitchell Amber N, Valenti Jonathan W, Crawford Dana R
Center for Cardiovascular Sciences, The Albany Medical College, Albany, NY 12208, USA.
Arch Biochem Biophys. 2008 Apr 1;472(1):43-50. doi: 10.1016/j.abb.2008.01.029. Epub 2008 Feb 9.
RCAN1 (Adapt78) functions mainly, if not exclusively, as a regulator of calcineurin, a phosphatase that mediates many cellular responses to calcium. Identification of this regulatory activity has led to a surge of interest in RCAN1, since calcineurin is involved in many cellular and tissue functions, and its abnormal expression is associated with multiple pathologies. Recent studies have implicated RCAN1 as a regulator of angiogenesis. To more fully investigate the role of RCAN1 in vascular function, we first extended previous studies by assessing RCAN1 response in cultured endothelial cells to various vascular agonists. Strong induction of isoform 4 but not isoform 1 was observed in human umbilical vein- and bovine pulmonary aortic-endothelial cells in response to VEGF, thrombin, and ATP but not other agonists. Inductions were both calcium and calcineurin dependent, with the relative effect of each agonist cell-type dependent. Ectopic RCAN1 expression also inhibited calcineurin signaling in the HUVEC cells. Based on these strong RCAN1 responses and a lack of RCAN1-associated vascular studies beyond angiogenesis, we investigated the potential role of RCAN1 in vascular tone using whole mounted mesenteric artery. RCAN1 knockout mice exhibited an attenuated mesenteric vasoconstriction to phenylephrine as compared with wild-type. Overall contractility was unaffected, suggesting that this component of smooth muscle action is similar in the two mouse strains. Constriction in the knockout artery appeared to be potentiated by the addition of the nitric oxide synthase (NOS) inhibitor l-NAME, suggesting that elevated nitric oxide (NO) production occurs in the knockout vasculature and contributes to the weakened vasoconstriction. Our results reveal a newly identified vascular role for RCAN1, and a potential new target for treating vascular- and calcineurin-related disorders.
RCAN1（Adapt78）主要（如果不是唯一的话）作为钙调神经磷酸酶的调节剂发挥作用，钙调神经磷酸酶是一种介导许多细胞对钙反应的磷酸酶。这种调节活性的发现引发了对RCAN1的浓厚兴趣，因为钙调神经磷酸酶参与许多细胞和组织功能，其异常表达与多种病理状况相关。最近的研究表明RCAN1是血管生成的调节剂。为了更全面地研究RCAN1在血管功能中的作用，我们首先扩展了先前的研究，评估培养的内皮细胞中RCAN1对各种血管激动剂的反应。在人脐静脉内皮细胞和牛肺动脉内皮细胞中，观察到亚型4而非亚型1对血管内皮生长因子（VEGF）、凝血酶和三磷酸腺苷（ATP）有强烈诱导反应，但对其他激动剂无反应。诱导反应均依赖于钙和钙调神经磷酸酶，每种激动剂的相对作用因细胞类型而异。异位表达RCAN1也抑制了人脐静脉内皮细胞（HUVEC）中的钙调神经磷酸酶信号传导。基于这些强烈的RCAN1反应以及除血管生成外缺乏与RCAN1相关的血管研究，我们使用肠系膜动脉整装标本研究了RCAN1在血管张力中的潜在作用。与野生型相比，RCAN1基因敲除小鼠对去氧肾上腺素的肠系膜血管收缩减弱。总体收缩性未受影响，表明平滑肌作用的这一组成部分在两种小鼠品系中相似。基因敲除动脉中的收缩似乎因添加一氧化氮合酶（NOS）抑制剂L - 精氨酸甲酯（l - NAME）而增强，表明基因敲除血管中一氧化氮（NO）生成增加并导致血管收缩减弱。我们的结果揭示了RCAN1新发现的血管作用，以及治疗血管和钙调神经磷酸酶相关疾病的潜在新靶点。
