AIM: To determine whether the PI3K/AKT/mTOR pathway is activated in proliferative vitreoretinopathy (PVR) in homo-sapiens. METHODS: The retina of controls and patients with PVR were collected and their levels of PI3K,...AIM: To determine whether the PI3K/AKT/mTOR pathway is activated in proliferative vitreoretinopathy (PVR) in homo-sapiens. METHODS: The retina of controls and patients with PVR were collected and their levels of PI3K, phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP-1 were determined by Western blot. The cultured human retinal pigment epithelial cell line D407 was treated with a specific mTOR inhibitor, rapamycin (RAPA) or a PI3K inhibitor, LY294002, of various concentrations and durations. Cell morphology was observed by phase contrast microscopy and the proliferation and apoptosis of treated cells were determined by MTT assay and flow cytometry. RESULTS: Levels of PI3K, phospho-AKT, phospho-mTOR, phospho-P70S6K and phospho-4EBP1 was increased in the retina in PVR (P <0.05). In D407 cells, both RAPA and LY294002 significantly inhibited cell proliferation and cell cycle progression, and promoted apoptosis (P <0.05); morphologically, the cells became smaller. Both RAPA and LY294002 reduced levels of phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP1 expression (P <0.05). RAPA, but not LY294002, had no significant effect on PI3K expression. CONCLUSION: PI3K/AKT/mTOR signaling pathway is highly activated in the retinal pigment epithelial cells of PVR. The inhibitors of PI3K/AKT/mTOR signaling pathway, RAPA and LY294002, could inhibited the PI3K/AKT/mTOR signaling pathway by reducing the levels of phosphorylation of mTOR pathway components.展开更多
This study was designed to determine the impact of chrysoeriol on proliferation and cell cycle progression in the human multiple myeloma cell lines RPMI 8226 and KM3,and its related molecular mechanisms.Chryseoriol wa...This study was designed to determine the impact of chrysoeriol on proliferation and cell cycle progression in the human multiple myeloma cell lines RPMI 8226 and KM3,and its related molecular mechanisms.Chryseoriol was identified by using the phosphorylated AKT-specific cytoblot high throughput assay.CCK-8 assay was employed to examine the growth inhibition rate and IC 50 (48 h) in peripheral blood mononuclear cells (PBMNCs),RPMI 8226 and KM3 cells treated with chrysoeriol at various concentrations.Cells were labeled with 5-6-carboxyfluorescein diacetate succinimidyl ester (CFSE),and the proliferation dynamics was detected by flow cytometry and analyzed with ModFit software.The cell cycles of RPMI 8226 and KM3 cells were measured by flow cytometry when the IC 50 concentration of chrysoeriol was adopted.The alterations in cell-cycle related proteins (Cyclin B1,Cyclin D1,p21) and proteins in PI3K-AKT-mTOR pathway were determined by Western blot analysis.The results showed the proliferation of multiple myeloma cells was significantly inhibited by chrysoeriol,resulting in cell cycle arrest in G 2 /M phase.Chrysoeriol could significantly reduce the expression of p-AKT (s473) and p-4eBP1 (t37/46) protein,meanwhile enhanced Cyclin B1 and p21 protein expression.Similar effects were not observed in PBMNCs from normal donors.It was concluded that chrysoeriol was a selective PI3K-AKT-mTOR pathway inhibitor.It restrained the proliferation of human multiple myeloma cells,but didn’t affect proliferation of PBMNCs from normal donors.It might exhibit the cell cycle regulatory effect via the inhibition of PI3K-AKT-mTOR signal pathway.展开更多
基金Scientific Research Project of Education Department of Liaoning Province, China (No.L2010676)Project of Science and Technology Commission of Shenyang City,China(No.F10-149-9-58)Doctoral Foundation of Ministry of Education of China (No.20102104120027)
文摘AIM: To determine whether the PI3K/AKT/mTOR pathway is activated in proliferative vitreoretinopathy (PVR) in homo-sapiens. METHODS: The retina of controls and patients with PVR were collected and their levels of PI3K, phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP-1 were determined by Western blot. The cultured human retinal pigment epithelial cell line D407 was treated with a specific mTOR inhibitor, rapamycin (RAPA) or a PI3K inhibitor, LY294002, of various concentrations and durations. Cell morphology was observed by phase contrast microscopy and the proliferation and apoptosis of treated cells were determined by MTT assay and flow cytometry. RESULTS: Levels of PI3K, phospho-AKT, phospho-mTOR, phospho-P70S6K and phospho-4EBP1 was increased in the retina in PVR (P <0.05). In D407 cells, both RAPA and LY294002 significantly inhibited cell proliferation and cell cycle progression, and promoted apoptosis (P <0.05); morphologically, the cells became smaller. Both RAPA and LY294002 reduced levels of phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP1 expression (P <0.05). RAPA, but not LY294002, had no significant effect on PI3K expression. CONCLUSION: PI3K/AKT/mTOR signaling pathway is highly activated in the retinal pigment epithelial cells of PVR. The inhibitors of PI3K/AKT/mTOR signaling pathway, RAPA and LY294002, could inhibited the PI3K/AKT/mTOR signaling pathway by reducing the levels of phosphorylation of mTOR pathway components.
基金supported by grants from the National Natural Sciences Foundation of China(No.30770914No.30901587)China State Key Basic Research Program(No.2002CB513100)
文摘This study was designed to determine the impact of chrysoeriol on proliferation and cell cycle progression in the human multiple myeloma cell lines RPMI 8226 and KM3,and its related molecular mechanisms.Chryseoriol was identified by using the phosphorylated AKT-specific cytoblot high throughput assay.CCK-8 assay was employed to examine the growth inhibition rate and IC 50 (48 h) in peripheral blood mononuclear cells (PBMNCs),RPMI 8226 and KM3 cells treated with chrysoeriol at various concentrations.Cells were labeled with 5-6-carboxyfluorescein diacetate succinimidyl ester (CFSE),and the proliferation dynamics was detected by flow cytometry and analyzed with ModFit software.The cell cycles of RPMI 8226 and KM3 cells were measured by flow cytometry when the IC 50 concentration of chrysoeriol was adopted.The alterations in cell-cycle related proteins (Cyclin B1,Cyclin D1,p21) and proteins in PI3K-AKT-mTOR pathway were determined by Western blot analysis.The results showed the proliferation of multiple myeloma cells was significantly inhibited by chrysoeriol,resulting in cell cycle arrest in G 2 /M phase.Chrysoeriol could significantly reduce the expression of p-AKT (s473) and p-4eBP1 (t37/46) protein,meanwhile enhanced Cyclin B1 and p21 protein expression.Similar effects were not observed in PBMNCs from normal donors.It was concluded that chrysoeriol was a selective PI3K-AKT-mTOR pathway inhibitor.It restrained the proliferation of human multiple myeloma cells,but didn’t affect proliferation of PBMNCs from normal donors.It might exhibit the cell cycle regulatory effect via the inhibition of PI3K-AKT-mTOR signal pathway.
