Signaling pathways regulating a phenotypic modulation of smooth muscle cells

调节平滑肌细胞表型调节的信号通路

• 批准号: 10670122
• 负责人: HAYASHI Ken'ichiro
• 金额: $ 1.98万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670122/
• 关键词: phenotypic modulation of smooth muscle cell; IGF-I; PDGF; signal transduction; PI3-kinase; PKB(Akt); ERK; p38MAPK; p38MAPK; 血管平滑筋細胞; 初代培養システム; MAPK; カドヘリン6B; 平滑筋細胞; 形質転換; 増殖因子; phosphatidylinositol 3-kinasc; proicin kinase B

In previous study, we found that IGF-I triggered the phosphoinositide 3-kinase (PI3-K) and protein kinase B (PKB(Akt)) in cultured gizzard SMCs and this signaling pathway played a vital role in maintaining a differentiated phenotype of SMCs. Here, we investigated the signaling pathways involved in dedifferentiation of gizzard SMCs induced by PDGF-BB, bFGF, and EGF using the primary culture system described above. In contrast to the IGF-I-triggered pathway, PDGF-BB, bFGF, and EGF coordinately activated ERK and p38MAPK pathways. Further, the forced expression of active forms of MEK1 and MKK6, which are the upstream kinases of ERK and p38MAPK, respectively, induced dedifferentiation even when SMCs were stimulated with IGF-I. Among three growth factors, PDGF-BB only triggered the PI3-K/PKB (Akt) pathway in addition to the ERK and p38MAPK pathways. When the ERK and p38MAPK pathways were simultaneously blocked by their specific inhibitors or an active form of either PI3-K or PKB (Akt) was tr … More ansfected, PDGF-BB in turn initiated to maintain the differentiated SMC phenotype. We applied these findings to vascular SMCs, and demonstrated the possibility that the same signaling pathways might be involved in regulating the vascular SMC phenotype. These results suggest that changes in the balance between the PI3-K/PKB (Akt) pathway and the ERK and p38MAPK pathways would determine phenotypes of visceral and vascular SMCs.Further, we used mRNA subtraction method to reveal the molecular mechanisms underlying the phenotypic modulation of SMCs. With this approach, we found that a 10 kb mRNA encoding a homotypic cell adhesion molecule, cadherin 6B, was strongly expressed in differentiated vascular and visceral SMCs, but not in the dedifferentiated SMCs derived from them. In vivo, cadherin 6B was expressed in vascular and visceral SMCs, in addition to brain, spinal cord, retina, and kidney, at a late stage of chicken embryonic development. These results suggest that cadherin 6B is a novel molecular marker for SMC phenotype and is involved in the late differentiation of SMCs. Less

在前期研究中，我们发现IGF-I在培养的砂囊平滑肌细胞中触发磷酸肌醇3激酶（PI3-K）和蛋白激酶B（PKB（Akt）），该信号通路在维持平滑肌细胞的分化表型中发挥着重要作用。在这里，我们使用上述原代培养系统研究了 PDGF-BB、bFGF 和 EGF 诱导的砂囊 SMC 去分化中涉及的信号通路。与 IGF-I 触发途径相反，PDGF-BB、bFGF 和 EGF 协调激活 ERK 和 p38MAPK 途径。此外，即使用IGF-I刺激SMC，MEK1和MKK6（分别是ERK和p38MAPK的上游激酶）活性形式的强制表达也会诱导去分化。在三种生长因子中，除了 ERK 和 p38MAPK 途径外，PDGF-BB 仅触发 PI3-K/PKB (Akt) 途径。当 ERK 和 p38MAPK 通路同时被其特定抑制剂阻断或 PI3-K 或 PKB (Akt) 的活性形式被感染时，PDGF-BB 反过来启动以维持分化的 SMC 表型。我们将这些发现应用于血管 SMC，并证明了相同的信号通路可能参与调节血管 SMC 表型的可能性。这些结果表明，PI3-K/PKB (Akt) 通路与 ERK 和 p38MAPK 通路之间平衡的变化将决定内脏和血管 SMC 的表型。此外，我们使用 mRNA 消减方法揭示了 SMC 表型调节的分子机制。通过这种方法，我们发现编码同型细胞粘附分子钙粘蛋白 6B 的 10 kb mRNA 在分化的血管和内脏 SMC 中强烈表达，但在源自它们的去分化 SMC 中不表达。在体内，在鸡胚胎发育的后期，钙粘蛋白 6B 在血管和内脏 SMC 以及脑、脊髓、视网膜和肾脏中表达。这些结果表明钙粘蛋白 6B 是 SMC 表型的新型分子标记，并参与 SMC 的晚期分化。较少的

项目成果

Sobue K.: "Molecular mechanism of phenotypic modulation of smooth muscle cells"Horm. Res.. 50(suppl.2). 15-24 (1998)

Sobue K.：“平滑肌细胞表型调节的分子机制”Horm。

Chinori Y.: "Phenotype-dependent expression of cadherin 6B in vascular and visceral smooth muscle cells"FEBS Lett.. (in press). (2000)

Chinori Y.：“血管和内脏平滑肌细胞中钙粘蛋白 6B 的表型依赖性表达”FEBS Lett..（出版中）。

Kimura K.: "c-Myc gene single strand binding protein-1, MSSP-1, suppresses transcription of α-smooth muscle actin gene in chicken visceral smooth muscle cells"Nucl Acids Res.. 26. 2420-2425 (1998)

Kimura K.：“c-Myc 基因单链结合蛋白-1，MSSP-1，抑制鸡内脏平滑肌细胞中 α-平滑肌肌动蛋白基因的转录”Nucl Acids Res.. 26. 2420-2425 (1998)

Sobue K.: "Expressional regulation of smooth muscle cell-specific genes in association with phenotypic modulation"Mol. Cell. Biochem.. 190. 105-118 (1999)

Sobue K.：“平滑肌细胞特异性基因的表达调节与表型调节相关”Mol。

Hayashi K.: "Changes in a balance of phosphoinositide 3-kinase/protein kinase B (Akt) and the mitogen-activated protein kinases (ERK/p38Mpk) determine the phenotype of smooth muscle cells."J. Cell Biol.. 17. 727-740 (1999)

Hayashi K.：“磷酸肌醇 3-激酶/蛋白激酶 B (Akt) 和丝裂原激活蛋白激酶 (ERK/p38Mpk) 平衡的变化决定平滑肌细胞的表型。”