Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;howe...Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.展开更多
Ezetimibe was reported to pharmacologically defend against oxidative stress. This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprote...Ezetimibe was reported to pharmacologically defend against oxidative stress. This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprotein （oxLDL） in vitro and the underlying mechanism. Human umbilical vein endothelial cells （HUVECs） were pretreated with ezetimibe and then exposed to oxLDL for 24 h. TUNEL assay and detection for the protein levels of cleaved caspase-3, Bcl-xl and Bcl-2 were employed to assess the oxLDL-induced endothelial apoptosis. Intracellular reactive oxygen species （ROS） generation was evaluated by measuring dichlorofluorescein （DCF） fluorescence. The activities of endothelial antioxidant enzymes [superoxide dismutase （SOD） and catalase] were tested via an enzymatic assay. The mitochondrial membrane potential （MMP） was monitored by flow cytometry using JC-I staining. Phosphorylation levels of glycogen synthase kinase-3β （p-GSK-3β） and Akt （p-Akt）, as well as total GSK-3β and Akt were determined by Western blotting. The results showed that ezetimibe treatment inhibited HUVECs apoptosis, intracellular ROS production, and enhanced antioxidant enzyme activities elicited by oxLDL. HUVECs exposed to oxLDL alone had reduced mitochondrial function, while ezetimibe pre-intervention could significantly rescue the MMP. Furthermore, the protein levels of p-GSK-3β and p-Akt in ezetimibe-pretreated HUVECs were markedly increased as compared with those in oxLDL-induced HUVECs. However, no significant effect on total GSK- 3β and Akt was found in ezetimibe-pretreated HUVECs. Taken together, it was concluded that ezetimibe protects against oxLDL-induced oxidative stress through restoring the MMP, which may be mediated by Akt-dependent GSK-3β phosphorylation.展开更多
Objective To investigate whether low-dose fractionated radiation(LDFRT) could enhance cisplatin sensitivity in drug-resistant human ovarian cancer cells SKOV3/DDP, and to further explore the underlying mechanism.Metho...Objective To investigate whether low-dose fractionated radiation(LDFRT) could enhance cisplatin sensitivity in drug-resistant human ovarian cancer cells SKOV3/DDP, and to further explore the underlying mechanism.Methods SKOV3/DDP ovarian cancer cells were divided into three groups as follows: control, LDFRT, and conventional-dose radiation groups. Cells from all three groups were treated with different concentrations of cisplatin(0, 1.25, 2.5, 5, 10, and 20 μg/m L) for 48 h. The proliferation inhibition rate was investigated using the cell counting kit 8(CCK8). The rate of apoptosis was determined by flow cytometry(FCM). Protein levels of AKT, P-AKT, GSK-3β, P-GSK-3β, P21, cyclin D1, and P27 were examined by Western blotting. Results As expected, LDFRT significantly reduced the half-maximal inhibitory concentration(IC50) of cisplatin and promoted apoptosis in SKOV3/DDP cells. Moreover, in the LDFRT group, protein levels of P-AKT, P-GSK-3β, and cyclin D1 were markedly decreased, those of P21 and P27 were greatly increased, and total AKT and GSK-3β levels showed no significant difference compared to those in both the control and conventional-dose radiation groups.Conclusion LDFRT sensitizes resistant SKOV3/DDP ovarian cancer cells to cisplatin through inactivation of PI3 K/AKT/GSK-3β signaling.展开更多
In early brain injury(EBI)after subarachnoid hemorrhage(SAH),white matter(WM)axonal injury plays a key role in the prognosis of the disease.The purpose of this study was to investigate the effects of phosphatase and t...In early brain injury(EBI)after subarachnoid hemorrhage(SAH),white matter(WM)axonal injury plays a key role in the prognosis of the disease.The purpose of this study was to investigate the effects of phosphatase and tensin homolog deleted on chromosome ten(PTEN)on axonal injury and neuronal apoptosis post-SAH in rats and to find its underlying mechanism.Adeno-associated virus was injected into the lateral ventricle to suppress or promote PTEN.Neural function post-SAH in animals was determined by the modified Garcia score,beam balance,and Rotarod test,and the blood–brain barrier disruption was assessed by the brain water content.Axonal injury post-SAH was observed by TEM and determined by IF,and neuron apoptosis was measured by TUNEL staining.The mechanism was analyzed by Western blot to detect p-PTEN/PTEN,p-AKT/AKT,p-GSK-3β/GSK-3β,p-CRMP-2/CRMP-2,axonal injury markerβ-APP and pro-and anti-apoptosis proteins,including Bax and Bcl-2,expression.We found 1.After knocking down PTEN,neuronal apoptosis and axonal injury were alleviated,and nerve function and blood–brain barrier were protected;accordingly,after overexpression of PTEN,neuronal apoptosis and axon damage were aggravated,and nerve function damage and blood–brain barrier damage were increased.2.PTEN and AKT/GSK-3β/CRMP-2 pathway were jointly involved in regulating neuronal apoptosis and WM axon injury after SAH.According to our research,PTEN was a negative factor of EBI,and together with the AKT/GSK-3β/CRMP-2 signaling pathway aggravates neuronal apoptosis and WM axon damage after SAH.Inhibition of PTEN expression may become a new target for SAH treatment.展开更多
Dihydromyricetin(DHM),as a bioactive flavanonol compound,is mainly found in“Tengcha”(Ampelopsis grossedentata)cultivated in south of China.This study aimed to investigate the anti-hyperglycemic and antidyslipidemic ...Dihydromyricetin(DHM),as a bioactive flavanonol compound,is mainly found in“Tengcha”(Ampelopsis grossedentata)cultivated in south of China.This study aimed to investigate the anti-hyperglycemic and antidyslipidemic activities of DHM using type 2 diabetes mellitus(T2D)rats,which was induced by feeding with high fat and fructose diet for 42 days and intraperitoneal administration of streptozocin.Forty-eight freshlyweaned rats were randomly assigned into the negative control(Blank),low dose(100 mg/kg),medium dose(200 mg/kg),high dose(400 mg/kg),and positive(40 mg/kg,met)groups.Fasting blood glucose and body weight were measured at weekly interval.Oral glucose tolerance tests were performed on days 42.The results revealed that DHM possessed significant antihyperglycaemic and antihyperinsulinemic effects.Moreover,after the DHM treatment,p-Akt and p-AMPK expression was upregulated,and glycogen synthase kinase-3β(GSK-3β)expression was downregulated,indicating that the potential anti-diabetic mechanism of DHM might be due to the regulation of the AMPK/Akt/GSK-3βsignaling pathway.展开更多
Liver is the most common metastatic site for colorectal cancer(CRC),there is no satisfied approach to treat CRC liver metastasis(CRCLM).Here,we investigated the role of a polycomb protein BMI-1 in CRCLM.Immunohistoche...Liver is the most common metastatic site for colorectal cancer(CRC),there is no satisfied approach to treat CRC liver metastasis(CRCLM).Here,we investigated the role of a polycomb protein BMI-1 in CRCLM.Immunohistochemical analysis showed that BMI-1 expression in liver metastases was upregulated and associated with T4 stage,invasion depth and right-sided primary tumor.Knockdown BMI-1 in high metastatic HCT116 and LOVO cells repressed the migratory/invasive phenotype and reversed epithelialemesenchymal transition(EMT),while BMI-1 overexpression in low metastatic Ls174 T and DLD1 cells enhanced invasiveness and EMT.The effects of BMI-1 in CRC cells were related to upregulating snail via AKT/GSK-3βpathway.Furthermore,knockdown BMI-1 in HCT116 and LOVO cells reduced CRCLM using experimental liver metastasis mice model.Meanwhile,BMI-1 overexpression in Ls174 T and DLD1 significantly increased CRCLM.Moreover,sodium butyrate,a histone deacetylase and BMI-1 inhibitor,reduced HCT116 and LOVO liver metastasis in immunodeficient mice.Our results suggest that BMI-1 is a major regulator of CRCLM and provide a potent molecular target for CRCLM treatment.展开更多
This study investigated the specific mechanism of knockdown of neuropeptide Y(NPY) in reducing obesity-induced insulin resistance in the white adipose tissue. Adeno-associated virus(AAV)-mediated RNAi was utilized to ...This study investigated the specific mechanism of knockdown of neuropeptide Y(NPY) in reducing obesity-induced insulin resistance in the white adipose tissue. Adeno-associated virus(AAV)-mediated RNAi was utilized to downregulate NPY expression in rats fed either regular chow or high fat diet. By investigating the differences in rat body weight and food intake, we assessed the effect of knockdown of NPY expression on insulin sensitivity and β-cell proliferation. Glucose consumption and 2-[3 H]DG uptake in 3 T3-L1 adipocytes were assessed to determine the molecular mechanisms. The results showed that knockdown of NPY expression in the dorsomedial hypothalamus(DMH) reduced obesity-induced insulin resistance, increased glucose consumption, and decreased 2-[3 H]DG uptake in 3 T3-L1 adipocytes via the PI3 K/Akt/GSK-3β signaling pathways and the NPY Y5 receptor.展开更多
基金supported by National Natural Science Foundation of China(Grant No.81860873 and 81960864)the Scientific and Technological Projects of Guizhou Province(Qian Kehe Jichu(2016)1401)High-level Talents Project of Guizhou Province(GUTCM(ZQ2018005)).
文摘Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81000139） and the New Teacher Research Fund for the Doctoral Program of Higher Education （No. 200804871035）.
文摘Ezetimibe was reported to pharmacologically defend against oxidative stress. This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprotein （oxLDL） in vitro and the underlying mechanism. Human umbilical vein endothelial cells （HUVECs） were pretreated with ezetimibe and then exposed to oxLDL for 24 h. TUNEL assay and detection for the protein levels of cleaved caspase-3, Bcl-xl and Bcl-2 were employed to assess the oxLDL-induced endothelial apoptosis. Intracellular reactive oxygen species （ROS） generation was evaluated by measuring dichlorofluorescein （DCF） fluorescence. The activities of endothelial antioxidant enzymes [superoxide dismutase （SOD） and catalase] were tested via an enzymatic assay. The mitochondrial membrane potential （MMP） was monitored by flow cytometry using JC-I staining. Phosphorylation levels of glycogen synthase kinase-3β （p-GSK-3β） and Akt （p-Akt）, as well as total GSK-3β and Akt were determined by Western blotting. The results showed that ezetimibe treatment inhibited HUVECs apoptosis, intracellular ROS production, and enhanced antioxidant enzyme activities elicited by oxLDL. HUVECs exposed to oxLDL alone had reduced mitochondrial function, while ezetimibe pre-intervention could significantly rescue the MMP. Furthermore, the protein levels of p-GSK-3β and p-Akt in ezetimibe-pretreated HUVECs were markedly increased as compared with those in oxLDL-induced HUVECs. However, no significant effect on total GSK- 3β and Akt was found in ezetimibe-pretreated HUVECs. Taken together, it was concluded that ezetimibe protects against oxLDL-induced oxidative stress through restoring the MMP, which may be mediated by Akt-dependent GSK-3β phosphorylation.
文摘Objective To investigate whether low-dose fractionated radiation(LDFRT) could enhance cisplatin sensitivity in drug-resistant human ovarian cancer cells SKOV3/DDP, and to further explore the underlying mechanism.Methods SKOV3/DDP ovarian cancer cells were divided into three groups as follows: control, LDFRT, and conventional-dose radiation groups. Cells from all three groups were treated with different concentrations of cisplatin(0, 1.25, 2.5, 5, 10, and 20 μg/m L) for 48 h. The proliferation inhibition rate was investigated using the cell counting kit 8(CCK8). The rate of apoptosis was determined by flow cytometry(FCM). Protein levels of AKT, P-AKT, GSK-3β, P-GSK-3β, P21, cyclin D1, and P27 were examined by Western blotting. Results As expected, LDFRT significantly reduced the half-maximal inhibitory concentration(IC50) of cisplatin and promoted apoptosis in SKOV3/DDP cells. Moreover, in the LDFRT group, protein levels of P-AKT, P-GSK-3β, and cyclin D1 were markedly decreased, those of P21 and P27 were greatly increased, and total AKT and GSK-3β levels showed no significant difference compared to those in both the control and conventional-dose radiation groups.Conclusion LDFRT sensitizes resistant SKOV3/DDP ovarian cancer cells to cisplatin through inactivation of PI3 K/AKT/GSK-3β signaling.
基金This study was financially supported by the National Natural Science Foundation for Youth of China(No.8160051302).
文摘In early brain injury(EBI)after subarachnoid hemorrhage(SAH),white matter(WM)axonal injury plays a key role in the prognosis of the disease.The purpose of this study was to investigate the effects of phosphatase and tensin homolog deleted on chromosome ten(PTEN)on axonal injury and neuronal apoptosis post-SAH in rats and to find its underlying mechanism.Adeno-associated virus was injected into the lateral ventricle to suppress or promote PTEN.Neural function post-SAH in animals was determined by the modified Garcia score,beam balance,and Rotarod test,and the blood–brain barrier disruption was assessed by the brain water content.Axonal injury post-SAH was observed by TEM and determined by IF,and neuron apoptosis was measured by TUNEL staining.The mechanism was analyzed by Western blot to detect p-PTEN/PTEN,p-AKT/AKT,p-GSK-3β/GSK-3β,p-CRMP-2/CRMP-2,axonal injury markerβ-APP and pro-and anti-apoptosis proteins,including Bax and Bcl-2,expression.We found 1.After knocking down PTEN,neuronal apoptosis and axonal injury were alleviated,and nerve function and blood–brain barrier were protected;accordingly,after overexpression of PTEN,neuronal apoptosis and axon damage were aggravated,and nerve function damage and blood–brain barrier damage were increased.2.PTEN and AKT/GSK-3β/CRMP-2 pathway were jointly involved in regulating neuronal apoptosis and WM axon injury after SAH.According to our research,PTEN was a negative factor of EBI,and together with the AKT/GSK-3β/CRMP-2 signaling pathway aggravates neuronal apoptosis and WM axon damage after SAH.Inhibition of PTEN expression may become a new target for SAH treatment.
基金the National Natural Science Foundation of China(NSFC,Grant No.31801459,31701520)Science and Technology General Projects of Fujian Province(2019J01393)Educational research project for young and middleaged teachers in Fujian Province(JT180116).
文摘Dihydromyricetin(DHM),as a bioactive flavanonol compound,is mainly found in“Tengcha”(Ampelopsis grossedentata)cultivated in south of China.This study aimed to investigate the anti-hyperglycemic and antidyslipidemic activities of DHM using type 2 diabetes mellitus(T2D)rats,which was induced by feeding with high fat and fructose diet for 42 days and intraperitoneal administration of streptozocin.Forty-eight freshlyweaned rats were randomly assigned into the negative control(Blank),low dose(100 mg/kg),medium dose(200 mg/kg),high dose(400 mg/kg),and positive(40 mg/kg,met)groups.Fasting blood glucose and body weight were measured at weekly interval.Oral glucose tolerance tests were performed on days 42.The results revealed that DHM possessed significant antihyperglycaemic and antihyperinsulinemic effects.Moreover,after the DHM treatment,p-Akt and p-AMPK expression was upregulated,and glycogen synthase kinase-3β(GSK-3β)expression was downregulated,indicating that the potential anti-diabetic mechanism of DHM might be due to the regulation of the AMPK/Akt/GSK-3βsignaling pathway.
基金supported by the National Natural Science Foundation of China(Nos.81272493 and 81472213)the Health Commission of Zhejiang Province(Nos.2019331258 and 2019335600,China)+1 种基金Natural Sciences Foundation of Zhejiang Province(No.LY17H220001,China)the Science Technology Department of Zhejiang Province(Nos.LGF20H220001 and 2015C37112,China)。
文摘Liver is the most common metastatic site for colorectal cancer(CRC),there is no satisfied approach to treat CRC liver metastasis(CRCLM).Here,we investigated the role of a polycomb protein BMI-1 in CRCLM.Immunohistochemical analysis showed that BMI-1 expression in liver metastases was upregulated and associated with T4 stage,invasion depth and right-sided primary tumor.Knockdown BMI-1 in high metastatic HCT116 and LOVO cells repressed the migratory/invasive phenotype and reversed epithelialemesenchymal transition(EMT),while BMI-1 overexpression in low metastatic Ls174 T and DLD1 cells enhanced invasiveness and EMT.The effects of BMI-1 in CRC cells were related to upregulating snail via AKT/GSK-3βpathway.Furthermore,knockdown BMI-1 in HCT116 and LOVO cells reduced CRCLM using experimental liver metastasis mice model.Meanwhile,BMI-1 overexpression in Ls174 T and DLD1 significantly increased CRCLM.Moreover,sodium butyrate,a histone deacetylase and BMI-1 inhibitor,reduced HCT116 and LOVO liver metastasis in immunodeficient mice.Our results suggest that BMI-1 is a major regulator of CRCLM and provide a potent molecular target for CRCLM treatment.
基金Supported by the Zhengzhou Science and Technology Innovation Team Project(131PCXTD631)
文摘This study investigated the specific mechanism of knockdown of neuropeptide Y(NPY) in reducing obesity-induced insulin resistance in the white adipose tissue. Adeno-associated virus(AAV)-mediated RNAi was utilized to downregulate NPY expression in rats fed either regular chow or high fat diet. By investigating the differences in rat body weight and food intake, we assessed the effect of knockdown of NPY expression on insulin sensitivity and β-cell proliferation. Glucose consumption and 2-[3 H]DG uptake in 3 T3-L1 adipocytes were assessed to determine the molecular mechanisms. The results showed that knockdown of NPY expression in the dorsomedial hypothalamus(DMH) reduced obesity-induced insulin resistance, increased glucose consumption, and decreased 2-[3 H]DG uptake in 3 T3-L1 adipocytes via the PI3 K/Akt/GSK-3β signaling pathways and the NPY Y5 receptor.
