目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和...目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和对离子通道的作用。(2)使用过表达电压门控性钾(voltage-gated potassium channel,Kv)通道2.1亚型(Kv2.1)的慢病毒转染中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞构建CHO-Kv2.1细胞系,使用膜片钳技术观察替米沙坦对Kv2.1通道的直接作用。结果缬沙坦和厄贝沙坦无类似替米沙坦的高糖浓度下促胰岛素分泌、升高β细胞内Ca^(2+)浓度和抑制β细胞的Kv通道等作用。过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)阻断剂GW9662亦未阻断替米沙坦的上述作用。而替米沙坦可以浓度依赖性地抑制CHO-Kv2.1细胞的Kv2.1通道电流。结论替米沙坦的促胰岛素分泌作用可能与血管紧张素Ⅱ-1型(angiotensin II type 1,AT-1)受体和PPARγ无关,但至少与对Kv2.1通道的直接抑制作用有关。展开更多
OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like g...OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like growth factor-binding protein-3(IGFBP-3)suppresses HCC cell proliferation in both IGF-dependent and independent manners.The present study is to investigate whether treatment with exogenous IGFBP-3 inhibits bF GF and PDGF production and the cell proliferation of HCC cells.METHODS Cell Counting Kit 8 assay were designed to detect HCC cell proliferation,transcription factor early growth response-1(EGR1)involving in IGFBP-3 regulation of b FGF and PDGF were detected by RT-PCR and Western blot assays.Western blot assay was adopted to detect the IGFBP-3 regulating insulin-like growth factor 1 receptor(IGF-1R)signaling pathway.RESULTS The present study demonstrates that IGFBP-3 suppressed IGF-1-induced b FGF and PDGF expression while it does not affect their expression in the absence of IGF-1.To delineate the underlying mechanism,Western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1(EGR1)is involved in IGFBP-3 regulation of b FGF and PDGF.IGFBP-3 inhibition of type 1 insulin-like growth factor receptor(IGF1R),ERK and AKT activation is IGF-1-dependent.Furthermore,transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1,b FGF and PDGF expression.CONCLUSION In conclusion,these findings suggest that IGFBP-3suppresses transcription of EGR1 and its target genes b FGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation.It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation,suggesting that IGFBP-3 could be a target for the treatment of HCC.展开更多
文摘目的研究替米沙坦促进大鼠胰岛素分泌作用相关的信号通路。方法(1)分离成年Wistar大鼠胰腺获得胰岛和胰岛细胞,通过胰岛素分泌实验观察药物对胰岛素分泌的影响,通过钙成像实验和全细胞膜片钳技术观察药物对β细胞内Ca^(2+)浓度的变化和对离子通道的作用。(2)使用过表达电压门控性钾(voltage-gated potassium channel,Kv)通道2.1亚型(Kv2.1)的慢病毒转染中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞构建CHO-Kv2.1细胞系,使用膜片钳技术观察替米沙坦对Kv2.1通道的直接作用。结果缬沙坦和厄贝沙坦无类似替米沙坦的高糖浓度下促胰岛素分泌、升高β细胞内Ca^(2+)浓度和抑制β细胞的Kv通道等作用。过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)阻断剂GW9662亦未阻断替米沙坦的上述作用。而替米沙坦可以浓度依赖性地抑制CHO-Kv2.1细胞的Kv2.1通道电流。结论替米沙坦的促胰岛素分泌作用可能与血管紧张素Ⅱ-1型(angiotensin II type 1,AT-1)受体和PPARγ无关,但至少与对Kv2.1通道的直接抑制作用有关。
基金supported by National Natural Science Foundation of China(81502123 and81330081)Natural Science Foundation of Anhui Province(1308085QH130)Anhui Province Nature Science Foundation in University(KJ2014A119)
文摘OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like growth factor-binding protein-3(IGFBP-3)suppresses HCC cell proliferation in both IGF-dependent and independent manners.The present study is to investigate whether treatment with exogenous IGFBP-3 inhibits bF GF and PDGF production and the cell proliferation of HCC cells.METHODS Cell Counting Kit 8 assay were designed to detect HCC cell proliferation,transcription factor early growth response-1(EGR1)involving in IGFBP-3 regulation of b FGF and PDGF were detected by RT-PCR and Western blot assays.Western blot assay was adopted to detect the IGFBP-3 regulating insulin-like growth factor 1 receptor(IGF-1R)signaling pathway.RESULTS The present study demonstrates that IGFBP-3 suppressed IGF-1-induced b FGF and PDGF expression while it does not affect their expression in the absence of IGF-1.To delineate the underlying mechanism,Western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1(EGR1)is involved in IGFBP-3 regulation of b FGF and PDGF.IGFBP-3 inhibition of type 1 insulin-like growth factor receptor(IGF1R),ERK and AKT activation is IGF-1-dependent.Furthermore,transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1,b FGF and PDGF expression.CONCLUSION In conclusion,these findings suggest that IGFBP-3suppresses transcription of EGR1 and its target genes b FGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation.It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation,suggesting that IGFBP-3 could be a target for the treatment of HCC.
