Objective： To explore the effects and mechanism of glycogen synthase kinase 3β （GSK-313） inhibitor （2＇Z,3＇E）-6-bromo-indirubin-3＇-oxime （BIO） on drug resistance in colon cancer cells. Methods： The colon c...Objective： To explore the effects and mechanism of glycogen synthase kinase 3β （GSK-313） inhibitor （2＇Z,3＇E）-6-bromo-indirubin-3＇-oxime （BIO） on drug resistance in colon cancer cells. Methods： The colon cancer SW480 and SW620 cells were treated with BIO, 5-fluorouracil （5-FU） and BIO/5-FU, separately. Cell cycle distribution, apoptosis level and efflux ability of rhodamine 123 （Rh123） were detected by flow cytometry. The protein expressions of P-glycoprotein （P-gp）, multidrug resistance protein 2 （MRP2）, thymidylate synthase （TS）, β-catenin, E2F-1 and βcl-2 were detected by Western blot. β-catenin and P-gp were stained with double immunofluorescence and observed under a confocal microscope. Results： BIO up-regulated β-catenin, P-gp, MRP2 and TS, enhanced the efflux ability of Rh123, decreased Bcl-2 protein and gave the opposite effect to E2F-1 protein in SW480 and SW620 ceils. Furthermore, BIO significantly inhibited cell apoptosis, increased S and G2/M phase cells, and reduced the cell apoptosis induced by 5-FU in SW480 cells, whereas the effects were slight or not obvious in SW620 cells. Conclusion： GSK-3β was involved in drug resistance regulation, and activation of β-catenin and inhibition of E2F-1 may be the most responsible for the enhancement of 5-FU chemotherapy resistance induced by GSK-β inhibitor β10 in colon cancer.展开更多
Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in hig...Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.展开更多
Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral isch...Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer＇s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries; meanwhile, fibrillar amyloid [3-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid 13-peptide could further aggravate impairments to learning and memory and neuronal cell death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 313 were significantly stronger in cerebral ischemia-reperfusion injury rats subjected to amyloid [3-peptide administration than those undergo- ing cerebral ischemia-repetfusion or amyloid 13-peptide administration alone. Conversely, the activ- ity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury following amyloid 13-peptide administration. These findings suggest that amyloid 13-peptide can potentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cognitive impairment.展开更多
Progranulin(PGRN)has recently emerged as a key player in a subset of frontotemporal dementias(FTD).Numerous mutations in the progranulin gene have been identified in patients with familial or sporadic frontotemporal l...Progranulin(PGRN)has recently emerged as a key player in a subset of frontotemporal dementias(FTD).Numerous mutations in the progranulin gene have been identified in patients with familial or sporadic frontotemporal lobar degeneration(FTLD).In order to understand the molecular mechanisms by which PGRN deficiency leads to FTLD,we examined activity of PGRN in mouse cortical and hippocampal neurons and in human neuroblastoma SH-SY5Y cells.Treatment of mouse neurons with PGRN protein resulted in an increase in neurite outgrowth,supporting the role of PGRN as a neurotrophic factor.PGRN treatment stimulated phosphorylation of glycogen synthase kinase-3 beta(GSK-3β)in cultured neurons.Knockdown of PGRN in SH-SY5Y cells impaired retinoic acid induced differentiation and reduced the level of phosphorylated GSK-3β.PGRN knockdown cells were also more sensitized to staurosporineinduced apoptosis.These results reveal an important role of PGRN in neurite outgrowth and involvement of GSK-3βin mediating PGRN activity.Identification of GSK-3βactivation as a downstream event for PGRN signaling provides a mechanistic explanation for PGRN activity in the nervous system.Our work also suggest that loss of axonal growth stimulation during neural injury repair or deficits in axonal repair may contribute to neuronal damage or axonal loss in FTLD associated with PGRN mutations.Finally,our study suggests that modulating GSK-3βor similar signaling events may provide therapeutic benefits for FTLD cases associated with PGRN mutations.展开更多
基金supported by the Sci-Tech Project Foundation of Guangdong Province(No.2009B080800023)
文摘Objective： To explore the effects and mechanism of glycogen synthase kinase 3β （GSK-313） inhibitor （2＇Z,3＇E）-6-bromo-indirubin-3＇-oxime （BIO） on drug resistance in colon cancer cells. Methods： The colon cancer SW480 and SW620 cells were treated with BIO, 5-fluorouracil （5-FU） and BIO/5-FU, separately. Cell cycle distribution, apoptosis level and efflux ability of rhodamine 123 （Rh123） were detected by flow cytometry. The protein expressions of P-glycoprotein （P-gp）, multidrug resistance protein 2 （MRP2）, thymidylate synthase （TS）, β-catenin, E2F-1 and βcl-2 were detected by Western blot. β-catenin and P-gp were stained with double immunofluorescence and observed under a confocal microscope. Results： BIO up-regulated β-catenin, P-gp, MRP2 and TS, enhanced the efflux ability of Rh123, decreased Bcl-2 protein and gave the opposite effect to E2F-1 protein in SW480 and SW620 ceils. Furthermore, BIO significantly inhibited cell apoptosis, increased S and G2/M phase cells, and reduced the cell apoptosis induced by 5-FU in SW480 cells, whereas the effects were slight or not obvious in SW620 cells. Conclusion： GSK-3β was involved in drug resistance regulation, and activation of β-catenin and inhibition of E2F-1 may be the most responsible for the enhancement of 5-FU chemotherapy resistance induced by GSK-β inhibitor β10 in colon cancer.
基金supported by National Natural Science Foundation of China(32072212)Multi-Year Research Grant of University of Macao(MYRG2018-00169-ICMS)+5 种基金Science and Technology Development Fund of Macao(FDCT)(0098/2020/A)MICINN supporting the Ramón y Cajal grant for M.A.Prieto(RYC-201722891)Jianbo Xiao(RYC2020-030365-I)Xunta de Galicia supporting the Axudas Conecta Peme,the IN852A 2018/58 Neuro Food Project,the program EXCELENCIA-ED431F 2020/12the pre-doctoral grants of P.García-Oliveira(ED481A-2019/295)to Ibero-American Program on Science and Technology(CYTED-AQUA-CIBUS,P317RT0003).
文摘Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.
基金supported by the National High Technology Research and Development Program of China("863"Program),No.2012AA020905the National Natural Science Foundation of China,No.81171143 and30971011+1 种基金National Natural Science Foundation of China(NSFC)/Research Grants Council(RGC) Joint Research Scheme,No.81161160570TsinghuaYue-Yuen Medical Sciences Fund
文摘Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer＇s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries; meanwhile, fibrillar amyloid [3-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid 13-peptide could further aggravate impairments to learning and memory and neuronal cell death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 313 were significantly stronger in cerebral ischemia-reperfusion injury rats subjected to amyloid [3-peptide administration than those undergo- ing cerebral ischemia-repetfusion or amyloid 13-peptide administration alone. Conversely, the activ- ity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury following amyloid 13-peptide administration. These findings suggest that amyloid 13-peptide can potentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cognitive impairment.
文摘Progranulin(PGRN)has recently emerged as a key player in a subset of frontotemporal dementias(FTD).Numerous mutations in the progranulin gene have been identified in patients with familial or sporadic frontotemporal lobar degeneration(FTLD).In order to understand the molecular mechanisms by which PGRN deficiency leads to FTLD,we examined activity of PGRN in mouse cortical and hippocampal neurons and in human neuroblastoma SH-SY5Y cells.Treatment of mouse neurons with PGRN protein resulted in an increase in neurite outgrowth,supporting the role of PGRN as a neurotrophic factor.PGRN treatment stimulated phosphorylation of glycogen synthase kinase-3 beta(GSK-3β)in cultured neurons.Knockdown of PGRN in SH-SY5Y cells impaired retinoic acid induced differentiation and reduced the level of phosphorylated GSK-3β.PGRN knockdown cells were also more sensitized to staurosporineinduced apoptosis.These results reveal an important role of PGRN in neurite outgrowth and involvement of GSK-3βin mediating PGRN activity.Identification of GSK-3βactivation as a downstream event for PGRN signaling provides a mechanistic explanation for PGRN activity in the nervous system.Our work also suggest that loss of axonal growth stimulation during neural injury repair or deficits in axonal repair may contribute to neuronal damage or axonal loss in FTLD associated with PGRN mutations.Finally,our study suggests that modulating GSK-3βor similar signaling events may provide therapeutic benefits for FTLD cases associated with PGRN mutations.
文摘目的研究中药降糖复方水提取物(WEJTD)对自发性2型糖尿病(T2DM)模型KK-Ay小鼠骨骼肌糖代谢PI3K/Akt信号通路的影响。方法将KK-Ay小鼠按随机数法随机分为5组:模型组、盐酸二甲双胍(MH,250 mg/kg)组和WEJTD低、中、高剂量(2、4、8 g/kg)组,C57BL/6J小鼠作为对照组,每天ig给药1次,共12周,对照组和模型组ig等体积蒸馏水。给药12周后,取小鼠血清,ELISA试剂盒法检测胰岛素水平;Trizol法提取肌肉组织中的RNA,荧光实时定量PCR(q RT-PCR)检测磷脂酰肌醇激酶-3(PI3K)、蛋白激酶B(Akt)、葡萄糖转运蛋白-4(GLUT-4)、糖原合成酶激酶-3β(GSK-3β)、糖原合成酶(GS)、胰岛素受体底物(IRS-1)m RNA水平。结果与模型组比较,WEJTD高、中剂量显著上调小鼠血清胰岛素水平、骨骼肌中IRS-1 m RNA水平(P<0.05、0.001);高、中、低剂量均显著下调骨骼肌中GSK-3βm RNA水平,显著上调PI3K、Akt、GLUT-4、GS m RNA水平(P<0.05、0.01、0.001)。结论中药降糖复方通过上调PI3K/Akt信号通路,减少糖原沉积,刺激骨骼肌中葡萄糖转运。
