The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to bio...The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to biotic and abiotic stresses.However,the mechanism underlying the response of this module to cold stress and its role in flower development in wintersweet(Chimonanthus praecox)remains unclear.Through expression pattern analysis,calcium ion(Ca^(2+))concentration assays,correlation analysis,and linear regression analysis,we found that the[Ca^(2+)],along with CpCBL8 and CpCIPK9 expression levels in wintersweet flower buds(FBs),significantly decreased during the initial flowering stage when the chilling requirement reached 570 chill units(CU).Notably,there was a significant positive correlation between[Ca^(2+)]and CpCBL8 expression.Ca^(2+)increased the expression of Cp CBL8 and CpCIPK9 in FBs,causing a significant delay in the flowering of wintersweet.Furthermore,the function of CpCBL8 was studied using heterologous transformation.Overexpression of CpCBL8 significantly delayed flowering time and significantly reduced cold tolerance and altered the expression pattern of endogenous genes related to low-temperature stress and flower development in transgenic Arabidopsis thaliana.Additionally,transcriptome analysis of chilling-induced dormancy breaking and flower bud enlargement revealed that CpCBL8 and CpCIPK9 were negatively regulated by cold,and the expression pattern of endogenous genes related to flower development and cold stress in wintersweet were similar to that of in A.thaliana.Moreover,protein-protein interaction(PPI)analysis revealed that CpCBL8 and CpCIPK9 interacted in the plasma membrane and nucleus.On the basis of these findings,we speculated that the CpCBL8-CpCIPK9 module plays a crucial role in regulating responses to cold stress and flower development in wintersweet.This study elucidated molecular mechanisms through which the downregulation of the Ca^(2+)-induced CpCBL8-CpCIPK9 module results in dormancy breaking and enhances cold tolerance.This study provides valuable insights for the cultivation of new varieties of wintersweet with increased ornamental value and enhanced cold stress tolerance.展开更多
Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) an...Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.展开更多
To observe the effectof ginsenoside Re on cardiomyocyte apoptosis and Bcl- 2 / Bax gene expression after ischemia (30 m in) and reperfusion (6 h) in rats and to elucidate the possible m echanism s of ginsenoside Re ...To observe the effectof ginsenoside Re on cardiomyocyte apoptosis and Bcl- 2 / Bax gene expression after ischemia (30 m in) and reperfusion (6 h) in rats and to elucidate the possible m echanism s of ginsenoside Re on inhibition of cardiom yocyte apoptosis,the ischem ia/ reperfusion heart m odel was established by ligating the left anterior descending branch of coronary artery in Wistar rats.The apoptotic cardiom yocytes were confirmed by transm ission electron m icroscopy and counted by in situ nick end labeling(TU NEL) method and lightm icroscopy.The m RNA and protein expression of Bcl- 2 and Bax genes were studied by in situ hybridization and im munohis- tochemical staining.Mean optical density (OD) value of the positive fields of m RNA and protein expression was quantitatively exam ined by im age analysis system.The results were as follows: (1) The apoptotic cardiomyocytes were found in ischemic fields in the ischem ia/ reperfusion group and weren't observed in the sham- operation group by transmission electron microscopy;(2 ) The num bers of the apoptotic cells were134.4 5± 4 5 .6 1/ field in the ischemia/ reperfusion group,and 90 .6 6± 19.2 2 / field in the ginsenoside Re- treated group.The differences was significant between two groups(P<0 .0 1) ;(3) Gene expression of Bcl- 2 and Bax were increased significantly in the is- chemia/ reperfusion group and ginsenoside Re- treated group when compared with the sham - opera- tion group.There was no significant difference in the gene expression of Bcl- 2 between the gin- senoside Re- treated group and ischemia/ reperfusion group(P>0 .0 5 ) ,but gene expression of Bax was decreased significantly in the ginsenoside Re- treated group as compared with the ischem ia/ reperfusion group(P<0 .0 1) .The ratio of Bcl- 2 / Bax was increased significantly in the ginseno- side Re- treated group when com pared with the ischem ia/ reperfusion group and sham- operation group.These findings suggest that m yocardial ischem ia- reperfusion can induce cardiom yocyte apoptosis,and ginsenoside Re can significantly inhibit cardiom yocyte apoptosis induced by ischemi- a- reperfusion in rats.It is concluded that ginsenoside Re inhibits cardiomyocyte apoptosis by in- hibiting expression of pro- apoptotic Bax gene and raising the ratio of Bcl- 2 / Bax.展开更多
Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study, a well-described in vitro sust...Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study, a well-described in vitro sustained stretch model was employed to study mechanical stretch-induced responses in both neonatal cardiomyocytes and cardiac fibroblasts. Cardiomyocytes, but not cardiac fibroblasts, underwent mitochondria-dependent apoptosis as evidenced by cytochrome c (cyto c) and Smac/DIABLO release from mitochondria into cytosol accompanied by mitochondrial membrane potential (△ψ_m) reduction, indicative of mitochondrial permeability transition pore (PTP) opening. Cyclosporin A, an inhibitor of PTP, inhibited stretch-induced cyto c release, △ψ_m reduction and apoptosis, suggesting an important role of mitochondrial PTP in stretch-induced apoptosis. The stretch also resulted in increased expression of the pro-apoptotic Bcl-2 family proteins, including Bax and Bad, in cardiomyocytes, but not in fibroblasts. Bax was accumulated in mitochondria following stretch. Cell permeable Bid-BH3 peptide could induce and facilitate stretch-induced apoptosis and △ψ_m reduction in cardiomyocytes. These results suggest that Bcl-2 family proteins play an important role in coupling stretch signaling to mitochondrial death machinery, probably by targeting to PTP. Interestingly, the levels of p53 were increased at 12 h after stretch although we observed that Bax upregulation and apoptosis occurred as early as 1 h. Adenovirus delivered dominant negative p53 blocked Bax upregulation in cardiomyocytes but showed partial effect on preventing stretch-induced apoptosis, suggesting that p53 was only partially involved in mediating stretch-induced apoptosis. Furthermore, we showed that p21 was upregulated and cyclin B1 was downregulated only in cardiac fibroblasts, which may be associated with G_2/M accumulation in response to mechanical stretch.展开更多
Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhi...Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.展开更多
Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides...Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods: We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results: CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion: CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.展开更多
基金funded by the Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0236)Fundamental Research Funds for the Central Universities(SWU-XDJH202308)Earmarked Funds for the China Agriculture Research System(CARS-26)。
文摘The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to biotic and abiotic stresses.However,the mechanism underlying the response of this module to cold stress and its role in flower development in wintersweet(Chimonanthus praecox)remains unclear.Through expression pattern analysis,calcium ion(Ca^(2+))concentration assays,correlation analysis,and linear regression analysis,we found that the[Ca^(2+)],along with CpCBL8 and CpCIPK9 expression levels in wintersweet flower buds(FBs),significantly decreased during the initial flowering stage when the chilling requirement reached 570 chill units(CU).Notably,there was a significant positive correlation between[Ca^(2+)]and CpCBL8 expression.Ca^(2+)increased the expression of Cp CBL8 and CpCIPK9 in FBs,causing a significant delay in the flowering of wintersweet.Furthermore,the function of CpCBL8 was studied using heterologous transformation.Overexpression of CpCBL8 significantly delayed flowering time and significantly reduced cold tolerance and altered the expression pattern of endogenous genes related to low-temperature stress and flower development in transgenic Arabidopsis thaliana.Additionally,transcriptome analysis of chilling-induced dormancy breaking and flower bud enlargement revealed that CpCBL8 and CpCIPK9 were negatively regulated by cold,and the expression pattern of endogenous genes related to flower development and cold stress in wintersweet were similar to that of in A.thaliana.Moreover,protein-protein interaction(PPI)analysis revealed that CpCBL8 and CpCIPK9 interacted in the plasma membrane and nucleus.On the basis of these findings,we speculated that the CpCBL8-CpCIPK9 module plays a crucial role in regulating responses to cold stress and flower development in wintersweet.This study elucidated molecular mechanisms through which the downregulation of the Ca^(2+)-induced CpCBL8-CpCIPK9 module results in dormancy breaking and enhances cold tolerance.This study provides valuable insights for the cultivation of new varieties of wintersweet with increased ornamental value and enhanced cold stress tolerance.
文摘Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2+]) and activity of sarcoplosnic Ca2+-ATPase (SRCa2+-ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2+] was detected by fluorescent spectrophotometry and the activity of SRCa2+-ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2+-ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2+-ATPase activity in cardiomyocytes.
基金Thisprojectwassupported by a grant from the NaturalSciences Foundation of Hubei Province(No.2 0 0 0 J0 5 0 ) .
文摘To observe the effectof ginsenoside Re on cardiomyocyte apoptosis and Bcl- 2 / Bax gene expression after ischemia (30 m in) and reperfusion (6 h) in rats and to elucidate the possible m echanism s of ginsenoside Re on inhibition of cardiom yocyte apoptosis,the ischem ia/ reperfusion heart m odel was established by ligating the left anterior descending branch of coronary artery in Wistar rats.The apoptotic cardiom yocytes were confirmed by transm ission electron m icroscopy and counted by in situ nick end labeling(TU NEL) method and lightm icroscopy.The m RNA and protein expression of Bcl- 2 and Bax genes were studied by in situ hybridization and im munohis- tochemical staining.Mean optical density (OD) value of the positive fields of m RNA and protein expression was quantitatively exam ined by im age analysis system.The results were as follows: (1) The apoptotic cardiomyocytes were found in ischemic fields in the ischem ia/ reperfusion group and weren't observed in the sham- operation group by transmission electron microscopy;(2 ) The num bers of the apoptotic cells were134.4 5± 4 5 .6 1/ field in the ischemia/ reperfusion group,and 90 .6 6± 19.2 2 / field in the ginsenoside Re- treated group.The differences was significant between two groups(P<0 .0 1) ;(3) Gene expression of Bcl- 2 and Bax were increased significantly in the is- chemia/ reperfusion group and ginsenoside Re- treated group when compared with the sham - opera- tion group.There was no significant difference in the gene expression of Bcl- 2 between the gin- senoside Re- treated group and ischemia/ reperfusion group(P>0 .0 5 ) ,but gene expression of Bax was decreased significantly in the ginsenoside Re- treated group as compared with the ischem ia/ reperfusion group(P<0 .0 1) .The ratio of Bcl- 2 / Bax was increased significantly in the ginseno- side Re- treated group when com pared with the ischem ia/ reperfusion group and sham- operation group.These findings suggest that m yocardial ischem ia- reperfusion can induce cardiom yocyte apoptosis,and ginsenoside Re can significantly inhibit cardiom yocyte apoptosis induced by ischemi- a- reperfusion in rats.It is concluded that ginsenoside Re inhibits cardiomyocyte apoptosis by in- hibiting expression of pro- apoptotic Bax gene and raising the ratio of Bcl- 2 / Bax.
基金supported by Research Grants(No.30170467)Outstanding Young Scientist Award from National Natural Sciences Foundation of China(QC)+2 种基金the“Major National Basic Research Program(973 Program,No.G2000056904)”(LYC)the KIKP Projects in Chinese Academy of Sciences(QC)the Ph.D.Programs Foundation from the Ministry of Education of China(LYC).
文摘Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study, a well-described in vitro sustained stretch model was employed to study mechanical stretch-induced responses in both neonatal cardiomyocytes and cardiac fibroblasts. Cardiomyocytes, but not cardiac fibroblasts, underwent mitochondria-dependent apoptosis as evidenced by cytochrome c (cyto c) and Smac/DIABLO release from mitochondria into cytosol accompanied by mitochondrial membrane potential (△ψ_m) reduction, indicative of mitochondrial permeability transition pore (PTP) opening. Cyclosporin A, an inhibitor of PTP, inhibited stretch-induced cyto c release, △ψ_m reduction and apoptosis, suggesting an important role of mitochondrial PTP in stretch-induced apoptosis. The stretch also resulted in increased expression of the pro-apoptotic Bcl-2 family proteins, including Bax and Bad, in cardiomyocytes, but not in fibroblasts. Bax was accumulated in mitochondria following stretch. Cell permeable Bid-BH3 peptide could induce and facilitate stretch-induced apoptosis and △ψ_m reduction in cardiomyocytes. These results suggest that Bcl-2 family proteins play an important role in coupling stretch signaling to mitochondrial death machinery, probably by targeting to PTP. Interestingly, the levels of p53 were increased at 12 h after stretch although we observed that Bax upregulation and apoptosis occurred as early as 1 h. Adenovirus delivered dominant negative p53 blocked Bax upregulation in cardiomyocytes but showed partial effect on preventing stretch-induced apoptosis, suggesting that p53 was only partially involved in mediating stretch-induced apoptosis. Furthermore, we showed that p21 was upregulated and cyclin B1 was downregulated only in cardiac fibroblasts, which may be associated with G_2/M accumulation in response to mechanical stretch.
基金the financial support from the National Key Research and Development Program of China(No.2018YFC1903403)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Inhibitors are important for flotation separation of quartz and feldspar.In this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp.Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments.And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism.The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,respectively.It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity tests.The results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of collectors.In contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site.The combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.
基金supported by the National Natural Science Foundation of China(82174206)National Natural Science Foundation of China,International(Regional)Cooperation and Exchange Program(82261138556).
文摘Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods: We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results: CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion: CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.
