Inosine Monophosphate Dehydrogenase 억제가 배양된 생쥐사구체 혈관간 세포에서 PDGF에 의한 Fibronectin 분비와 세포내활성산소족에 미치는 영향

Abstract

Purpose: Mesangial cell extracellular matrix (ECM) synthesis plays an important role in various renal diseases. Mycophenolic acid (MPA), which is an inhibitor of inosine monophosphate dehydrogenase (IMPDH), inhibits mesangial cell proliferation and ECM synthesis. However, the exact mechanism of MPA has not been clearly elucidated in mesangial cells. To examine the relative importance of IMPDH on the inhibitory action of MPA, we compared the effects of MPA or IMPDH2 siRNA on platelet-derived growth factor (PDGF)-induced fibronectin secretion and cellular reactive oxygen species (ROS) in mouse mesangial cells (MMC). Methods: MMC were stimulated with PDGF 10 ng/ml with or without MPA 0.1∼10μM, IMPDH2 siRNA 10∼50 nM, or N-acetylcystein (NAC). IMPDH2 siRNA was transiently transfected by lipofectamine for 24 hours. MPA 0.1∼10μM, ribavirin 10∼100μM, and NAC 5 mM were administered 1 hour before the stimulation. Cell viability was measured by methylthiazoletetrazolium (MTT) assay, fibronectin secretion by Western blot analysis, and dichlorofluorescein (DCF)-sensitive cellular ROS by flow cytometry. Results: PDGF 10 ng/ml effectively increased fibronectin secretion and cellular ROS in MMC. MPA and NAC at concentration without affecting basal level of fibronectin and cellular ROS ameliorated PDGF-induced fibronectin secretion and cellular ROS. However, IMPDH2 siRNA only partially reduced PDGF- induced fibronectin secretion and cellular ROS in MMC. Conclusion: These results suggest that MPA may inhibit PDGF-induced fibronectin secretion partly through IMPDH2 or cellular ROS in MMC, and there may be other mechanisms on the inhibitory action of MPA in mesenchymal cells.