Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density li...Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density lipoprotein receptor - deficient mice. This study was to investigate the molecular mechanism of antiatherogenic effects of SAL. Method Six-week old apoE-/- male mice were fed a high-fat diet for 8 weeks and then were ad- ministered with SAL for another 8 weeks. Atherosclerotic lesion and vascular function were analyzed. Primary cul- tured human umbilical vein endothelial cells （HUVECs） were prepared. Superoxide anion （O2^-）, NO produc- tion, mitochondrial membrane potential （△ψm） and intracellular ATP and AMP levels were measured. Expression of eNOS and AMPK were analyzed by Western blot. Result SAL significantly improved endothelial function asso- ciated with increasing eNOS activation thus reduced the atherosclerotic lesion area. SAL increased eNOS-Serl177 phosphorylation and decreased eNOS-Thr495 phosphorylation. SAL significantly activated AMP-activated protein ki- nase （AMPK）. Both AMPK inhibitor and AMPK small interfering RNA （siRNA） abolished SAL-induced Akt- Ser473 and eNOS-Serl177 phosphorylation. In contrast, LY294002, the PI3k/Akt pathway inhibitor, abolished SAL-induced phosphorylation and expression of eNOS. SAL decreased cellular ATP content and increased the cel- lular AMP/ATP ratio, which was associated with the activation of AMPK. SAL was found to decrease A^m, which is likely consequence of reduced ATP production. Conclusion The action of SAL to reduce atherosclerotic lesion formation may at least be attributed to its effect on improving endothelial function by promoting nitric oxide （NO） production, which was associated with mitochondria depolarization and subsequent activation of the AMPK/PI3 IC/ Akt/eNOS pathway. Taken together, our data described the effects of SAL on mitochondria, which played critical roles in improving endothelial function in atherosclerosis.展开更多
AIM:To explore the influence of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate(TPOL)on cell apoptosis and its potential mechanism.METHODS:HEK293T cells sensitive to TPOL were treated with different concentrations of T...AIM:To explore the influence of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate(TPOL)on cell apoptosis and its potential mechanism.METHODS:HEK293T cells sensitive to TPOL were treated with different concentrations of TPOL with or without exposure to light radiation,before treatment with various inhibitors,N-acetyl-Lcysteine(NAC),pifithrin-αand Z-DVED-FMK.Cell viability was measured by CCK-8 assay.Annexin V/propidium iodide staining was used to count the number of apoptotic cells.DCFH-DA staining was used to detect reactive oxygen species(ROS)levels,and JC-1 staining was used to assess mitochondrial membrane potential by flow cytometry.The expression of apoptosis-related proteins and cell cycle-regulated molecules was measured by Western blot.RESULTS:TPOL enhanced the apoptosis of HEK293T cells in a dose-dependent manner(P<0.05),with a decrease in Bcl-2 and increases in Bax and cytochrome C(Cyto C),followed by up-regulation of activated caspase-9 and caspase-3,and the cleavage of PARP(P<0.05).The TPOL-enhanced cleavage of caspase-3 and PARP was rescued by Z-DVED-FMK(P<0.01).TPOL also led to a rapid increase in ROS,a reduction in mitochondrial membrane potential,and the release of Cyto C(P<0.01),all of which could be reversed by the ROS scavenger NAC.Moreover,the TPOL-caused alterations in p21,p27,Rb,and CDK2 were also recovered by the p53 inhibitor pifithrin-α(P<0.05).The TPOL-induced changes in Bax,Bcl-2,cleaved caspase-9,activated caspase-3,and cleaved PARP were subsequently rescued by pretreatment with pifithrin-α(P<0.05).CONCLUSION:TPOL can induce cellular apoptosis with ROS-mediated mitochondrial membrane damage through the activation of a ROS-dependent p53/p21/p27/Rb/Bax/Cyto C/caspase-mediated signal axis.展开更多
The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied t...The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied to compare sources of copper(CuSO_4 versus Cu-Met) and 4 levels of dietary Cu (11,110,220 and 330 mg/kg).Day-old broilers(Cobb 500,Gallus domesticus,n=288) were randomly divided into 8 groups of 36 each and fed diets as follows:Controls(Cu 11 mg/kg) and high copper(Cu 110, 220,and 330 mg/kg),for 60 days under normal conditions.Sample collections were made at 12,36 and 60 days of age to investigate the changes in H_2O_2 generation by mitochondria from hepatocytes.Compared with those of the control diets,H_2O_2 generation by mitochondria in the high copper groups(110 to 330 mg/kg) of the two copper sources were increased(P<0.05 or P<0.01);At days 36 and 60,H_2O_2 generation by hepatic mitochondria from Cu-Met supplementation exceeded that from birds supplemented with CuSO_4 (P<0.05 or P<0.01).In addition,H_2O_2 generation by mitochondria from broilers fed with high dietary copper appeared to be associated with altered function of mitochondrial complexⅣ.The results indicated that dietary supplementation with copper induced oxidative stress damage in liver.At each level of copper supplementation,the organic Cu-Met led to more rapid H_2O_2 generation than did inorganic CuSO_4.The results also suggest that mitochondrial complexⅣmay be targeted under conditions of high dietary copper supplementation.展开更多
OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) us...OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) using wild type and CSE knockout mouse models.METHODS Continuous subcutaneous injection isoprenaline(7.5 mg·kg^(-1) per day),once a day for 4 weeks to induce heart failure in male C57BL/6(6-8 weeks old) mice and CSE-/-mice.150 μmol·L^(-1) H_2O_2 was used to induce oxidative stress in H9c2 cells.Echocardiograph was used to detect cardiac parameters.H&E stain and Masson stain was to observation histopathological changes.Western blot was used to detect protein expression and activity.The si RNA was used to silence protein expression.HPLC was used to detect H_2S level.Biotin assay was used to detect the level of S-sulfhydration protein.RESULTS Treatment with S-propyl-L-cysteine(SPRC) or sodium hydrosulfide(Na HS),modulators of blood H_2S levels,attenuated the development of heart failure in animals,reduced lipid peroxidation,and preserved mitochondrial function.The inhibition Ca MKⅡ phosphorylation by SPRC and Na HS as demonstrated using both in vivo and in vitro models corresponded with the cardioprotective effects of these compounds.Interestingly,Ca MKⅡ activity was found to be elevated in CSE-/-mice as compared to wild type animals and the phosphorylation status of Ca MK Ⅱ appeared to relate to the severity of heart failure.Importantly,in wild type mice SPRC was found to promote S-sulfhydration of Ca MKⅡ leading to reduced activity of this protein however,in CSE-/-mice S-sulfhydration was abolished following SPRC treatment.CONCLUSION A novel mechanism depicting a role of S-sulfhydration in the regulation of Ca MKⅡ is presented.SPRC mediated S-sulfhydration of Ca MKⅡ was found to inhibit Ca MKⅡ activity and to preserve cardiovascular homeostasis.展开更多
文摘Aim Salidroside （SAL） is a phenylpropanoid glycoside isolated from the medicinal plant Rhodiola rosea. A recent study has reported that SAL can efficiently decrease atherosclerotic plaque formation in low-density lipoprotein receptor - deficient mice. This study was to investigate the molecular mechanism of antiatherogenic effects of SAL. Method Six-week old apoE-/- male mice were fed a high-fat diet for 8 weeks and then were ad- ministered with SAL for another 8 weeks. Atherosclerotic lesion and vascular function were analyzed. Primary cul- tured human umbilical vein endothelial cells （HUVECs） were prepared. Superoxide anion （O2^-）, NO produc- tion, mitochondrial membrane potential （△ψm） and intracellular ATP and AMP levels were measured. Expression of eNOS and AMPK were analyzed by Western blot. Result SAL significantly improved endothelial function asso- ciated with increasing eNOS activation thus reduced the atherosclerotic lesion area. SAL increased eNOS-Serl177 phosphorylation and decreased eNOS-Thr495 phosphorylation. SAL significantly activated AMP-activated protein ki- nase （AMPK）. Both AMPK inhibitor and AMPK small interfering RNA （siRNA） abolished SAL-induced Akt- Ser473 and eNOS-Serl177 phosphorylation. In contrast, LY294002, the PI3k/Akt pathway inhibitor, abolished SAL-induced phosphorylation and expression of eNOS. SAL decreased cellular ATP content and increased the cel- lular AMP/ATP ratio, which was associated with the activation of AMPK. SAL was found to decrease A^m, which is likely consequence of reduced ATP production. Conclusion The action of SAL to reduce atherosclerotic lesion formation may at least be attributed to its effect on improving endothelial function by promoting nitric oxide （NO） production, which was associated with mitochondria depolarization and subsequent activation of the AMPK/PI3 IC/ Akt/eNOS pathway. Taken together, our data described the effects of SAL on mitochondria, which played critical roles in improving endothelial function in atherosclerosis.
基金Supported by the National Natural Science Foundation of China(No.81172824)。
文摘AIM:To explore the influence of ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate(TPOL)on cell apoptosis and its potential mechanism.METHODS:HEK293T cells sensitive to TPOL were treated with different concentrations of TPOL with or without exposure to light radiation,before treatment with various inhibitors,N-acetyl-Lcysteine(NAC),pifithrin-αand Z-DVED-FMK.Cell viability was measured by CCK-8 assay.Annexin V/propidium iodide staining was used to count the number of apoptotic cells.DCFH-DA staining was used to detect reactive oxygen species(ROS)levels,and JC-1 staining was used to assess mitochondrial membrane potential by flow cytometry.The expression of apoptosis-related proteins and cell cycle-regulated molecules was measured by Western blot.RESULTS:TPOL enhanced the apoptosis of HEK293T cells in a dose-dependent manner(P<0.05),with a decrease in Bcl-2 and increases in Bax and cytochrome C(Cyto C),followed by up-regulation of activated caspase-9 and caspase-3,and the cleavage of PARP(P<0.05).The TPOL-enhanced cleavage of caspase-3 and PARP was rescued by Z-DVED-FMK(P<0.01).TPOL also led to a rapid increase in ROS,a reduction in mitochondrial membrane potential,and the release of Cyto C(P<0.01),all of which could be reversed by the ROS scavenger NAC.Moreover,the TPOL-caused alterations in p21,p27,Rb,and CDK2 were also recovered by the p53 inhibitor pifithrin-α(P<0.05).The TPOL-induced changes in Bax,Bcl-2,cleaved caspase-9,activated caspase-3,and cleaved PARP were subsequently rescued by pretreatment with pifithrin-α(P<0.05).CONCLUSION:TPOL can induce cellular apoptosis with ROS-mediated mitochondrial membrane damage through the activation of a ROS-dependent p53/p21/p27/Rb/Bax/Cyto C/caspase-mediated signal axis.
基金supported by the National Natural Science Foundation of China(NSFC) awarded to Tang Zhao-xin(grant number:30671550)
文摘The present experiment was performed with the objective of examining the effects of copper sources and levels on hydrogen peroxide(H_2O_2) generation by mitochondria from broiler hepatocytes. Treatments were applied to compare sources of copper(CuSO_4 versus Cu-Met) and 4 levels of dietary Cu (11,110,220 and 330 mg/kg).Day-old broilers(Cobb 500,Gallus domesticus,n=288) were randomly divided into 8 groups of 36 each and fed diets as follows:Controls(Cu 11 mg/kg) and high copper(Cu 110, 220,and 330 mg/kg),for 60 days under normal conditions.Sample collections were made at 12,36 and 60 days of age to investigate the changes in H_2O_2 generation by mitochondria from hepatocytes.Compared with those of the control diets,H_2O_2 generation by mitochondria in the high copper groups(110 to 330 mg/kg) of the two copper sources were increased(P<0.05 or P<0.01);At days 36 and 60,H_2O_2 generation by hepatic mitochondria from Cu-Met supplementation exceeded that from birds supplemented with CuSO_4 (P<0.05 or P<0.01).In addition,H_2O_2 generation by mitochondria from broilers fed with high dietary copper appeared to be associated with altered function of mitochondrial complexⅣ.The results indicated that dietary supplementation with copper induced oxidative stress damage in liver.At each level of copper supplementation,the organic Cu-Met led to more rapid H_2O_2 generation than did inorganic CuSO_4.The results also suggest that mitochondrial complexⅣmay be targeted under conditions of high dietary copper supplementation.
文摘OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) using wild type and CSE knockout mouse models.METHODS Continuous subcutaneous injection isoprenaline(7.5 mg·kg^(-1) per day),once a day for 4 weeks to induce heart failure in male C57BL/6(6-8 weeks old) mice and CSE-/-mice.150 μmol·L^(-1) H_2O_2 was used to induce oxidative stress in H9c2 cells.Echocardiograph was used to detect cardiac parameters.H&E stain and Masson stain was to observation histopathological changes.Western blot was used to detect protein expression and activity.The si RNA was used to silence protein expression.HPLC was used to detect H_2S level.Biotin assay was used to detect the level of S-sulfhydration protein.RESULTS Treatment with S-propyl-L-cysteine(SPRC) or sodium hydrosulfide(Na HS),modulators of blood H_2S levels,attenuated the development of heart failure in animals,reduced lipid peroxidation,and preserved mitochondrial function.The inhibition Ca MKⅡ phosphorylation by SPRC and Na HS as demonstrated using both in vivo and in vitro models corresponded with the cardioprotective effects of these compounds.Interestingly,Ca MKⅡ activity was found to be elevated in CSE-/-mice as compared to wild type animals and the phosphorylation status of Ca MK Ⅱ appeared to relate to the severity of heart failure.Importantly,in wild type mice SPRC was found to promote S-sulfhydration of Ca MKⅡ leading to reduced activity of this protein however,in CSE-/-mice S-sulfhydration was abolished following SPRC treatment.CONCLUSION A novel mechanism depicting a role of S-sulfhydration in the regulation of Ca MKⅡ is presented.SPRC mediated S-sulfhydration of Ca MKⅡ was found to inhibit Ca MKⅡ activity and to preserve cardiovascular homeostasis.
