Opiorphin-dependent upregulation of CD73 (a key enzyme in the adenosine signaling pathway) in corporal smooth muscle cells exposed to hypoxic conditions and in corporal tissue in pre-priapic sickle cell mice.
Opiorphin-dependent upregulation of CD73 (a key enzyme in the adenosine signaling pathway) in corporal smooth muscle cells exposed to hypoxic conditions and in corporal tissue in pre-priapic sickle cell mice.
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DOI：
10.1038/ijir.2015.5
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发表时间：
2015-07
影响因子：
2.6
通讯作者：
Davies KP
中科院分区：
文献类型：
--
作者：
Fu S;Davies KP
与镰状细胞病相关的阴茎异常勃起的确切分子机制仍有待确定。然而，越来越多的证据表明，在身体组织中的阿片肽和腺苷途径的上调活性，导致平滑肌的高度松弛，在阴茎异常勃起的发展中发挥重要作用。腺苷途径中的关键酶是CD 73，一种外-5-引物核苷酸酶（5-引物核糖核苷酸磷酸水解酶; EC 3.1.3.5），其催化腺苷单核苷酸转化为腺苷。在本研究中，我们研究了镰状细胞病和缺氧如何调节阿片肽和CD 73之间的相互作用。在镰状细胞小鼠的语料库中，我们观察到小鼠阿片肽同源物mSmr 3a（14倍）和CD 73（2.2倍）的表达相对于非镰状细胞对照在阴茎异常勃起之前的生命阶段显著升高。镰状细胞病具有明显的缺氧成分，因此我们确定了CD 73是否也在缺氧的体外躯体平滑肌（CSM）模型中被调节。缺氧显著增加CD 73蛋白和mRNA的表达，分别为1.5倍和2倍。我们以前证明，腺苷信号通路的另一个组成部分，腺苷2B受体的表达，可以调节sialorphin（大鼠阿片肽同源物），我们证明，sialorphin也调节CD 73的表达，在剂量和时间依赖性的方式。利用siRNA在体外敲低CSM细胞中sialorphin mRNA的表达，我们证明了CD 73的缺氧上调依赖于sialorphin的上调。总体而言，我们的数据提供了进一步的证据，支持阿片肽在CSM中的作用，通过激活平滑肌松弛剂途径调节细胞反应，调节对缺氧或镰状细胞病的反应。
The precise molecular mechanisms underlying priapism associated with sickle cell disease remain to be defined. However, there is increasing evidence that up-regulated activity of the opiorphin and adenosine pathways in corporal tissue, resulting in heighted relaxation of smooth muscle, play an important role in development of priapism. A key enzyme in the adenosine pathway is CD73, an ecto-5-prime-nucleotidase (5-prime-ribonucleotide phosphohydrolase; EC 3.1.3.5) which catalyzes the conversion of adenosine mononucleotides to adenosine. In the present study we investigated how sickle cell disease and hypoxia regulate the interplay between opiorphin and CD73. In the corpora of sickle cell mice we observed significantly elevated expression of both the mouse opiorphin homologue mSmr3a (14-fold) and CD73 (2.2-fold) relative to non-sickle cell controls at a life-stage prior to the exhibition of priapism. Sickle cell disease has a pronounced hypoxic component, therefore we determined if CD73 was also modulated in in vitro corporal smooth muscle (CSM) models of hypoxia. Hypoxia significantly increased CD73 protein and mRNA expression by 1.5-fold and 2-fold, respectively. We previously demonstrated that expression of another component of the adenosine signaling pathway, the adensosine 2B receptor, can be regulated by sialorphin (the rat opiorphin homolologue), and we demonstrate that sialorphin also regulates CD73 expression in a dose and time dependent fashion. Using siRNA to knock-down sialorphin mRNA expression in CSM cells in vitro, we demonstrate that the hypoxic up-regulation of CD73 is dependent on the up-regulation of sialorphin. Overall our data provides further evidence to support a role for opiorphin in CSM in regulating the cellular response regulating response to hypoxia or sickle cell disease by activating smooth muscle relaxant pathways.