S1P receptor signalling and RGS proteins; expression and function in vascular smooth muscle cells and transfected CHO cells
S1P receptor signalling and RGS proteins; expression and function in vascular smooth muscle cells and transfected CHO cells
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DOI：
10.1016/j.ejphar.2008.09.041
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发表时间：
2008-12-14
影响因子：
5
通讯作者：
Alewijnse, Astrid E.
中科院分区：
文献类型：
--
作者：
Hendriks-Balk, Marielle C.;van Loenen, Pieter B.;Alewijnse, Astrid E.
鞘氨醇-1-磷酸（SIP）信号通过C蛋白偶联受体在调节细胞功能和分化中起重要作用。G蛋白信号传导（RGS）蛋白的特异性调节因子在包括血管平滑肌细胞（VSMCs）在内的许多细胞类型中调节这些受体的功能。因此，我们研究了RGS蛋白表达水平改变在VSMCs和转染CHO细胞中SIP受体功能中的作用。在培养诱导的表型调节过程中，VSMCs中SI P、受体、RGS4和RGS16的mRNA表达量下调，而RGS2、RGS3、S1P(2)和S1P(3)受体的mRNA表达量不变。有趣的是，RGS5的表达水平瞬间上调。尽管RGS水平发生了重大变化，但s1p诱导的VSMCs钙升高并未发生改变。将RGS2、RGS3、RGS4、RGS5和RCS16共转染到稳定表达S1P(2)或S1P(3)受体的cho - flip -in细胞中，在很大程度上没有改变S1P诱导的cAMP积累抑制。选择性S1P(1)受体激动剂SEW2871也获得了类似的结果。然而，与RGS5共转染后，激动剂FrY720-P通过SIP受体对cAMP积累的抑制作用显著降低。这些结果表明，在表型调节过程中，SIP、受体、RGS4、RGS5和RGS16的mRNA受到差异调控。然而，RGS蛋白表达的重大改变对SI - P受体功能的影响有限。(c) 2008 Elsevier B.V.版权所有
Sphingosine-1-phosphate (SIP) signalling via C protein-coupled receptors is important for the regulation of cell function and differentiation. Specific Regulators of G protein Signalling (RGS) proteins modulate the function of these receptors in many cell types including vascular smooth muscle cells (VSMCs). Therefore, we investigated the role of altered expression levels of RGS proteins in SIP receptor function in VSMCs and transfected CHO cells. The mRNA expression of the SI P, receptor, RGS4 and RGS16 were down-regulated in VSMCs during phenotypic modulation induced by culturing, whereas mRNA levels of RGS2, RGS3, S1P(2) and S1P(3) receptors were unchanged. Interestingly, the expression level of RGS5 was transiently up-regulated. Despite major alterations in RGS levels, S1P-induced calcium elevation in VSMCs was not altered. Co-transfection of RGS2, RGS3, RGS4, RGS5 and RCS16 into CHO-Flp-In cells stably expressing the S1P(2) or S1P(3) receptor did not modify S1P-induced inhibition of cAMP accumulation to a major extent. Similar results were obtained with SEW2871, a selective S1P(1) receptor agonist. However, the inhibition of cAMP accumulation by the agonist FrY720-P via the SIP, receptor was significantly decreased by co-transfection with RGS5. These results indicate that mRNA of the SIP, receptor, RGS4, RGS5 and RGS16 is differentially regulated during phenotypic modulation. However, major alterations in RGS protein expression have only limited effect on SI P receptor function. (c) 2008 Elsevier B.V. All rights reserved.