Search

Both norepinephrine (NE) and connective tissue growth factor (CTGF) contribute to vascular fibrosis during hypertension. Recent studies indicate that farnesyl pyrophosphate synthase (FPPS) plays an important role in cardiac remodeling in hypertension. However, the role of FPPS in NE-induced fibrotic responses and related molecular mechanisms is unknown. Vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were stimulated with NE. The fibrotic responses were assessed by measuring CTGF, hydroxyproline (hyp), and α-1 procollagen I levels using Western blot, a hydroxyproline test kit, and real-time quantitative PCR assays, respectively. Ras activity was determined by a pull-down assay using a Ras activation assay kit and detected by Western blot. NE dose-dependently increased fibrosis in SHR-VSMCs, and this increase was significantly reduced by ibandronate, an inhibitor of FPPS. The addition of farnesol, but not geranylgeraniol, partially reversed the inhibitory effects of ibandronate. Furthermore, the anti-fibrotic effects of ibandronate could be mimicked by FTI-276 but not by GGTI-286. A pull-down assay showed that ibandronate reduced the NE-induced Ras activation. Moreover, ibandronate inhibited the NE-induced activation of p38, JNK, and ERK1/2. Only SB203580 (specific inhibitor of p38) diminished the NE-induced CTGF production. These results demonstrated that inhibiting FPPS prevents NE-induced fibrotic responses in SHR-VSMCs and that the Ras kinase and p38 pathways were the underlying mechanisms involved in this process.

Aim: To investigate the effect of tricyclodecane-9-yl-xanthogenate (D609) on cell differentiation in vascular endothelial cells (VECs) and marrow stromal cells (MSCs)., Methods: Morphological changes were observed under phase contrast microscope. Electron microscope and immunostaining were used for VECs identification. The expressions of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry., Results: After 6 h of induction with D609, some VECs showed morphological changes characteristic of neurones. 9 h later, more VECs became neuron-like cells. About 30.8% of VECs displayed positive NSE (P<0.01), while the expression of GFAP was negative. When MSCs were exposed to D609, the cells displayed neuronal morphologies, such as pyramidal cell bodies and processes formed extensive networks at 3 h. 6 h later, almost all of the cells exhibited a typical neuronal appearance, and 85.6% of MSCs displayed intensive positive NSE, but GFAP did not express., Conclusion: D609 induces VECs and MSCs differentiation into neuron-like cells.

Aim: To investigate effect of safrole oxide on cell growth and apoptosis induced by deprivation of survival factors (fibroblast growth factors, aFGF and bFGF) in vascular endothelial cells (VEC)., Methods: Morphological changes were observed by light microscopy. Cell growth was determined by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium) method. DNA fragmentation was analyzed by agarose gel electrophoresis and fluorescence microscopy. Cell cycle distribution was analyzed by flow cytometry (FCM)., Results: The cells deprived of FGF were exposed to safrole oxide 5-25 mg/L for 24 h. Cells spreading and growth were promoted (P<0.01), detachment and DNA fragmentation of these cells were suppressed (P<0.01), safrole oxide 10 mg/L had no obvious effect on cell cycle distribution (P>0.05). When the cells were treated with safrole oxide 50-100 mg/L, detachment and DNA fragmentation of VEC were promoted (P<0.01). The cell cycle was blocked at G2-M phase by safrole oxide 100 mg/L., Conclusion: Safrole oxide 10 mg/L inhibited, but 100 mg/L promoted apoptosis of VEC. Safrole oxide might be an important compound that affects VEC growth and apoptosis.