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ȣ - 480652 138 |
| Effects of Exisulind and OSI461 on Vascular Smooth Muscle Cell(VSMC)s through Activation of Protein Kinase G and Downregulation of β-Catenin
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| 서울대학교병원 심혈관센터, 임상의학연구소 심혈관 연구실; 서울대학교 의과대학 내과학교실 |
| 양한모, 김주영, 강현재, 김용진, 정우영, 채인호, 김효수, 손대원, 오병희, 이명묵, 박영배, 최윤식 |
Background: After angioplasty, the arterial smooth muscle cells undergo phenotypic and proliferative changes in response to balloon injury. Some studies have demonstrated that Protein Kinase G(PKG) expression in VSMCs decreases after angioplasty and increases after neointimal formation. This result suggests that PKG occupies a central switching role in the modulation of VSMC phenotype in response to injury. In cancer cells, it is well known that Exisulind and OSI461 exert antineoplastic effects through PKG activation. Here, we examined the effects of Exisulind and OSI461 on VSMCs viability and its action mechanism.
Methods: We examined the effects of Exisulind and OSI461 on VSMCs viability and proliferation by WST-1 assay and incorporation of BrdU. Cell cycle status and apoptosis were evaluated by flow cytometry. To examine the mechanism of these actions, we performed Western blot analysis for PKG, MEKK, JNK, β-catenin. We also examined the effects of these drugs on VSMC migration. To investigate the action mechanism through β-catenin, We delivered adenoviral WT(wild type)-β-catenin to the VSMCs with Exisulind and OSI461.
Results: In WST-1 assay and cell counting, Exisulind and OSI461 reduced the viable cell numbers in a dose-dependent manner. OSI461 showed stronger effects than Exisulind. In cell cycle and apoptosis FACS, Exisulind showed less increased apoptotic VSMCs than OSI 461 and arrested the cell cycle at G1 phase. OSI461, however, arrested the cell cycle at G2 phase. In Western blot assay, Exisulind and OSI 461 increased the level of PKG, MEKK and JNK and downregulated β-catenin. Incubation with Exisulind and OSI461 reduced VSMC migration. Gene transfer of adenoviral WT-β-catenin reversed the effects of Exisulind and OSI461 on VSMCs viability and migration.
Conclusion: In this study, we demonstrated that Exisulind and OSI461 reduced VSMCs viability and migration through the activation of PKG and downregulation of β-catenin. Considering the role of PKG on phenotypic modulation of VSMCs and the effects of these drugs on PKG, our findings suggest a potential use for Exisulind and OSI461 in the prevention of restenosis after angioplasty as drug-eluting stents.
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