AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cel...AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC 50 ) and reversal index (IC 50 in experimental group/IC 50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC 50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/ OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.展开更多
AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARP...AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.展开更多
AIM： To investigate the role of CCR7/p-ERKI/2/VEGF signaling in the mouse model of oxygen-induced retinopathy （OIR）. METHODS： Neonatal C57BL/6J mice were evenly randomized into four groups： normoxia, OIR, OIR co...AIM： To investigate the role of CCR7/p-ERKI/2/VEGF signaling in the mouse model of oxygen-induced retinopathy （OIR）. METHODS： Neonatal C57BL/6J mice were evenly randomized into four groups： normoxia, OIR, OIR control （treated with scramble siRNA）, and OIR treated （treated with CCR7 siRNA）. Normoxia group was not specially handled. Postnatal day 7 （P7） mice in the OIR group were exposed to 75%±5% oxygen for 5d （P7-P12） and then maintained under normoxic conditions for 5d （P12-P17）. Mice in the OIR control and OIR treated groups were given injections of scramble or CCR7 siRNA plasmid on P12 before returning to normoxic conditions for 5d （P12-P17）. Retina samples were collected from all mice on P17, stained with adenosine diphosphatase （ADPase）, and retinal neovascularization （RNV） was assessed. Retinas were also stained with hematoxylin and eosin （H＆E） for RNV quantitation. The distribution and expression of CCR7, p-ERKI/2 and vas- cular endothelial growth factor （VEGF） were assessed via immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction （qRT-PCR）. RESULTS： High oxygen promoted retinal neovascularization （P〈0.05） and increased the number of endothelial nuclei in new vessels extending from the retina to the vitreous body; CCR7 promoted this process （P〈0.05）. CCR7 and VEGF mRNA were expressed at higher levels in the OIR and OIR control groups than in the normoxia and OIR treated groups. CCR7, p-ERK1/2, and VEGF protein were expressed in the retinas of mice in the OIR and OIR control groups. Intravitreal injection of CCR7 siRNA significantly reduced CCR7, p-ERKI/2, and VEGF expression in the OIR mouse model （all P〈0.05）. CCR7 significantly enhancedthe neovascularization and non-perfusion areas in the OIR group （P〈0,05）, CCR7 siRNA significantly reduced levels of p-ERK1/2 and VEGF as compared to OIR controls （P〈0.05）. CONCLUSION： These results suggest that CCR7/p-ERK I/2NEGF signaling plays an important role in OIR, CCR7 may be a potential target for the prevention and treatment of retinopathy of prematurity.展开更多
Objective:To investigate the regulation of the epidermal growth factor receptor(EGFR)pathway by visfatin and its effect on cardiac hypertrophy.Methods:60 Wistar male rats were randomly divided into control group,visfa...Objective:To investigate the regulation of the epidermal growth factor receptor(EGFR)pathway by visfatin and its effect on cardiac hypertrophy.Methods:60 Wistar male rats were randomly divided into control group,visfatin group and visfatin+AG1478 group,with 20 rats in each group.The cardiac mass index,left ventricular mass index and cardiomyocyte volume of rats in each group were calculated.The total protein content of each group of cardiomyocytes was detected by coomassie bright blue staining,and the protein expression was detected by Western blotting.Results:Compared with the control group,the cardiac mass index,left ventricular mass index,cardiomyocyte volume,protein content,and relative expressions of ANP and BNP were significantly increased in the visfatin group(P<0.05).The relative expression levels of EGFR,p-AKT,p-ERK1/2,p-STAT3,ANP and BNP in cardiac myocytes in the visfatin group were significantly higher than those in the control group and the visfatin+AG1478 group(P<0.05).Conclusion:Visfatin induces hypertrophy in cardiomyocytes by activating the EGFR signaling pathway.展开更多
Accumulating evidence indicates that endostatin inhibits fibrosis. However, the mechanism is yet to be clarified. The aim of this study is to evaluate the effect of endostatin on platelet-derived growth factor-BB （PD...Accumulating evidence indicates that endostatin inhibits fibrosis. However, the mechanism is yet to be clarified. The aim of this study is to evaluate the effect of endostatin on platelet-derived growth factor-BB （PDGF-BB）- or transforming growth factor β1 （TGF-β1）-induced fibrosis in cultured human skin fibroblasts, and to further examine the molecular mechanisms involved. Human dermal flbroblasts were cultured in Dulbecco＇s modified Eagle＇s medium （DMEM） and serum-starved for 48 h before treatment. Cells were grouped as follows： ＂PDGF-BB＂, ＂PDGF-BB＋ endostatin＂, ＂TGF-β1＂, ＂TGF-β1＋endostatin＂, ＂endostatin＂, and ＂blank control＂. The fibroblasts were stimulated with either TGF-β1 or PDGF-BB for 72 h in order to set up the fibrosis model in vitro. The cells were co-cultured with either TGF-β1 or PDGF-BB and endostatin and were used to check the inhibiting effect of endostatin. A blank control group and an endostatin group were used as negative control groups. The biomarkers of fibrosis, including the expression of collagen I, hydrroxyproline, and α-smooth muscle actin （a-SMA）, were evaluated using an enzyme-linked immune- sorbent assay （ELISA） and Western blot. The expression of phosphorylated PDGF receptor β （p-PDGFRβ）, PDGFRβ, phosphorylated extracellular signal-regulated kinase （p-ERK）, and ERK was detected using Western blot and im- munofiuorescent staining was used to explore the mechanisms. Both PDGF-BB and TGF-β1 significantly up-regulated the expression of collagen I, hydroxyproline, and a-SMA. Endostatin significantly attenuated both the PDGF-BB- and TGF-β1-induced over-expression of collagen I, hydroxyproline, and a-SMA. PDGF-BB and TGF-β1 both promoted the expression of PDGFR, ERK, and p-ERK. Endostatin inhibited the expression of PDGFR and p-ERK but did not affect the expression of total ERK. Endostatin inhibited hypertrophic scar by modulating the PDGFRI3/ERK pathway. En- dostatin could be a promising multi-target drug in future fibrosis therapy.展开更多
基金Supported by National Natural Sciences Foundation of China,No. 81001067the Ministry of Science and Technology International Cooperation Project, No. 2010DFA31870the AstraZeneca Special Research Foundation for Targeted Therapy of the Wu Jieping Medical Foundation, No. 320.6700.09068
文摘AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC 50 ) and reversal index (IC 50 in experimental group/IC 50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC 50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/ OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.
基金Supported by Shandong Provincial Natural Science Foundation,China(No.ZR2012HQ004)the Research Fund for Fundamental Research Project of Qingdao(No.13-1-4-180-jch)+1 种基金the Scientific Research Fund of Huangdao District of Qingdao City(No.2014-1-74)the Young People Scientific Research Fund of Affiliated Hospital,Qingdao University(No.QDFY134)
文摘AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.
基金Supported by the Science and Technology Planning Foundation of Liaoning Province(No.2010225034)
文摘AIM： To investigate the role of CCR7/p-ERKI/2/VEGF signaling in the mouse model of oxygen-induced retinopathy （OIR）. METHODS： Neonatal C57BL/6J mice were evenly randomized into four groups： normoxia, OIR, OIR control （treated with scramble siRNA）, and OIR treated （treated with CCR7 siRNA）. Normoxia group was not specially handled. Postnatal day 7 （P7） mice in the OIR group were exposed to 75%±5% oxygen for 5d （P7-P12） and then maintained under normoxic conditions for 5d （P12-P17）. Mice in the OIR control and OIR treated groups were given injections of scramble or CCR7 siRNA plasmid on P12 before returning to normoxic conditions for 5d （P12-P17）. Retina samples were collected from all mice on P17, stained with adenosine diphosphatase （ADPase）, and retinal neovascularization （RNV） was assessed. Retinas were also stained with hematoxylin and eosin （H＆E） for RNV quantitation. The distribution and expression of CCR7, p-ERKI/2 and vas- cular endothelial growth factor （VEGF） were assessed via immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction （qRT-PCR）. RESULTS： High oxygen promoted retinal neovascularization （P〈0.05） and increased the number of endothelial nuclei in new vessels extending from the retina to the vitreous body; CCR7 promoted this process （P〈0.05）. CCR7 and VEGF mRNA were expressed at higher levels in the OIR and OIR control groups than in the normoxia and OIR treated groups. CCR7, p-ERK1/2, and VEGF protein were expressed in the retinas of mice in the OIR and OIR control groups. Intravitreal injection of CCR7 siRNA significantly reduced CCR7, p-ERKI/2, and VEGF expression in the OIR mouse model （all P〈0.05）. CCR7 significantly enhancedthe neovascularization and non-perfusion areas in the OIR group （P〈0,05）, CCR7 siRNA significantly reduced levels of p-ERK1/2 and VEGF as compared to OIR controls （P〈0.05）. CONCLUSION： These results suggest that CCR7/p-ERK I/2NEGF signaling plays an important role in OIR, CCR7 may be a potential target for the prevention and treatment of retinopathy of prematurity.
基金Hebei province science and technology support plan project(No.132777186)。
文摘Objective:To investigate the regulation of the epidermal growth factor receptor(EGFR)pathway by visfatin and its effect on cardiac hypertrophy.Methods:60 Wistar male rats were randomly divided into control group,visfatin group and visfatin+AG1478 group,with 20 rats in each group.The cardiac mass index,left ventricular mass index and cardiomyocyte volume of rats in each group were calculated.The total protein content of each group of cardiomyocytes was detected by coomassie bright blue staining,and the protein expression was detected by Western blotting.Results:Compared with the control group,the cardiac mass index,left ventricular mass index,cardiomyocyte volume,protein content,and relative expressions of ANP and BNP were significantly increased in the visfatin group(P<0.05).The relative expression levels of EGFR,p-AKT,p-ERK1/2,p-STAT3,ANP and BNP in cardiac myocytes in the visfatin group were significantly higher than those in the control group and the visfatin+AG1478 group(P<0.05).Conclusion:Visfatin induces hypertrophy in cardiomyocytes by activating the EGFR signaling pathway.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY15H150004)the Teaching Department of the Zhejiang Province(No.Y201330073),China
文摘Accumulating evidence indicates that endostatin inhibits fibrosis. However, the mechanism is yet to be clarified. The aim of this study is to evaluate the effect of endostatin on platelet-derived growth factor-BB （PDGF-BB）- or transforming growth factor β1 （TGF-β1）-induced fibrosis in cultured human skin fibroblasts, and to further examine the molecular mechanisms involved. Human dermal flbroblasts were cultured in Dulbecco＇s modified Eagle＇s medium （DMEM） and serum-starved for 48 h before treatment. Cells were grouped as follows： ＂PDGF-BB＂, ＂PDGF-BB＋ endostatin＂, ＂TGF-β1＂, ＂TGF-β1＋endostatin＂, ＂endostatin＂, and ＂blank control＂. The fibroblasts were stimulated with either TGF-β1 or PDGF-BB for 72 h in order to set up the fibrosis model in vitro. The cells were co-cultured with either TGF-β1 or PDGF-BB and endostatin and were used to check the inhibiting effect of endostatin. A blank control group and an endostatin group were used as negative control groups. The biomarkers of fibrosis, including the expression of collagen I, hydrroxyproline, and α-smooth muscle actin （a-SMA）, were evaluated using an enzyme-linked immune- sorbent assay （ELISA） and Western blot. The expression of phosphorylated PDGF receptor β （p-PDGFRβ）, PDGFRβ, phosphorylated extracellular signal-regulated kinase （p-ERK）, and ERK was detected using Western blot and im- munofiuorescent staining was used to explore the mechanisms. Both PDGF-BB and TGF-β1 significantly up-regulated the expression of collagen I, hydroxyproline, and a-SMA. Endostatin significantly attenuated both the PDGF-BB- and TGF-β1-induced over-expression of collagen I, hydroxyproline, and a-SMA. PDGF-BB and TGF-β1 both promoted the expression of PDGFR, ERK, and p-ERK. Endostatin inhibited the expression of PDGFR and p-ERK but did not affect the expression of total ERK. Endostatin inhibited hypertrophic scar by modulating the PDGFRI3/ERK pathway. En- dostatin could be a promising multi-target drug in future fibrosis therapy.
