Doi K, Itoh H, Ikeda T, Hosoda K, Ogawa Y, Igaki T, Yamashita J, Chun T H, Inoue M, Masatsugu K, Matsuda K, Ohmori K, Nakao K
Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Japan.
Biochem Biophys Res Commun. 1997 Oct 29;239(3):889-94. doi: 10.1006/bbrc.1997.7576.
We have proposed the "vascular natriuretic peptide system", in which C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, can control vascular tone and growth as an endothelium-derived relaxing peptide. We aimed at overexpression of CNP gene in vascular smooth muscle cells (SMCs) by adenovirus-mediated gene transfer to examine the growth characteristics of SMCs via the augmentation of cGMP production. Rat aortic SMCs infected with Ad.CNP, a replication-deficient adenovirus driving rat CNP cDNA, produced 162 +/- 55 fmol/mL of CNP, which was 4,000 times higher than that produced by endothelial cells. cGMP production was also augmented in Ad.CNP-infected SMCs (2200 +/- 270 fmol/10(4) cells). Accordingly, significant growth inhibition was observed in SMCs infected with Ad.CNP. The flow cytometry analysis revealed that the population of the S and G2 + M phases was reduced by 60% of the control in Ad.CNP-infected SMCs. The gene expression of ANP-B receptor, which is expressed abundantly in SMCs with the synthetic phenotype, was suppressed in Ad.CNP-infected SMCs, while the gene expression of ANP-A receptor, which is expressed predominantly in SMCs with the contractile phenotype, became detectable in Ad.CNP-infected SMCs. In addition, the gene expression of smooth muscle myosin heavy chain-2 (SM-2), which is the molecular marker of highly-differentiated SMCs, was also induced in Ad.CNP-treated SMCs. These results suggest that cGMP cascade activation induces re-differentiation of SMCs. The present study demonstrated that overexpression of CNP induced growth inhibition of SMCs at the G1 phase with possible alteration of the phenotype.
我们提出了“血管利钠肽系统”，其中利钠肽家族的第三个成员C型利钠肽（CNP）可作为一种内皮源性舒张肽来控制血管张力和生长。我们旨在通过腺病毒介导的基因转移使血管平滑肌细胞（SMC）中CNP基因过表达，以通过增强环磷酸鸟苷（cGMP）生成来研究SMC的生长特性。用Ad.CNP（一种驱动大鼠CNP cDNA的复制缺陷型腺病毒）感染大鼠主动脉SMC后，其产生的CNP为162±55 fmol/mL，这比内皮细胞产生的CNP高4000倍。在Ad.CNP感染的SMC中，cGMP生成也有所增加（2200±270 fmol/10⁴个细胞）。因此，在Ad.CNP感染的SMC中观察到明显的生长抑制。流式细胞术分析显示，在Ad.CNP感染的SMC中，S期和G2 + M期细胞群体比对照减少了60%。在具有合成表型的SMC中大量表达的心房钠尿肽B受体（ANP-B受体）的基因表达在Ad.CNP感染的SMC中受到抑制，而主要在具有收缩表型的SMC中表达的心房钠尿肽A受体（ANP-A受体）的基因表达在Ad.CNP感染的SMC中变得可检测到。此外，在Ad.CNP处理的SMC中还诱导了平滑肌肌球蛋白重链2（SM-2）的基因表达，SM-2是高度分化的SMC的分子标志物。这些结果表明，cGMP级联激活诱导SMC重新分化。本研究表明，CNP过表达诱导SMC在G1期生长抑制，并可能改变其表型。
