Background： The calcium clearance and reactive oxygen species （ROS） generations in the coronary artery smooth muscle cells in chronic heart failure （HF） have not been fully investigated. Therefore, we attempted t...Background： The calcium clearance and reactive oxygen species （ROS） generations in the coronary artery smooth muscle cells in chronic heart failure （HF） have not been fully investigated. Therefore, we attempted to understand the gene expressions underlying the mishandling of calcium clearance and the accumulations of ROS. Methods： We initially established an animal model of chronic HF by making the left anterior descending coronary artery ligation （CAL） in rats, and then isolated the coronary artery vascular smooth muscle cells from the ischemic and the nonischemic parts of the coronary artery vessels in 12 weeks after CAL operation. The intracellular calcium concentration and ROS level were measured using flow cytometry, and the gene expressions of sarco/endoplasmic reticulum Ca2＋-ATPase （SERCA2a）, encoding sarcoplasmic reticulum Ca2＋-ATPase 2a, encoding sodium-calcium exchanger （NCX）, andp47phox encoding a subunit of the nicotinamide adenine dinucleotide phosphate （NADPH） oxidase were examined using real-time quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Results： We found that the calcium accumulation and ROS generation in the coronary artery smooth muscle cells isolated from either the ischemic or the nonischemic part of the CAL coronary artery vessel were significantly increased irrespective of blood supply （all P 〈 0.01 ）. Moreover, these were accompanied by the increased expressions of NCX and p47phox, the decreased expression of S ERCA2a, and the increased amount of phosphorylated forms of p47phox in NADPH oxidase （all P 〈 0.05）. Conclusions： Our results demonstrated that the disordered calcium clearance and the increased ROS generation occurred in the coronary artery smooth muscle cells in rats with chronic HF produced by ligation of the left anterior descending coronary artery （CAL）, and which was found to be disassociated from blood supply, and the increased generation of ROS in the ceils was found to make concomitancy to the increased activity of NADPH oxidase in cytoplasm.展开更多
Phosphorus （P） starvation is highly notorious for limiting plant growth around the globe. To combat P-starvation, plants constantly sense the changes in their environment, and elicit an elegant myriad of plastic res...Phosphorus （P） starvation is highly notorious for limiting plant growth around the globe. To combat P-starvation, plants constantly sense the changes in their environment, and elicit an elegant myriad of plastic responses and rescue strategies to enhance P-solublization and acquisition from bound soil P-forms. Relative growth responses, P-solublization and P- acquisition ability of 14 diverse Brassica cultivars grown with sparingly soluble P-sources （Rock-P （RP） and Ca3（PO4）2 （TCP）） were evaluated in a solution culture experiment. Cultivars showed considerable genetic diversity in terms of biomass accumulation, concentration and contents of P and Ca in shoots and roots, P-stress factor （PSF） and P use efficiency. Cultivars showed variable P-stress tolerance, and cultivars depicting low PSF and high P-efficiency values were better adaptable to P-starvation. In experiment 2, after initial feeding on optimum nutrition for 12 d after transplanting （DAT）, class-I （low P-tolerant （Oscar and Con-II）） and class-II （low P-sensitive （Gold Rush and RL-18）） cultivars were exposed to P-free environment for 25 d. All of the cultivars remobilized P from above ground parts to their roots during growth in P-free environment, the magnitude of which was variable in tested cultivars. P-concentrations （[P]s） at 37 DAT were higher in developing compared with developed leaves. Translocation of absorbed P from metabolically inactive to active sites in P- stressed plants may have helped class-I cultivars to establish a better rooting system, which provided a basis for enhanced P-utilization efficiency （PUE） and tolerance against P-stress. By supplying TCP and RP spatially separated from other nutrients in split root study, class-I cultivars were still able to mobilize RP and TCP more efficiently compared with class-II cultivars. To compare the growth behavior under P-stress, cultivars were grown in pots for 41 d after sowing, using a soil low in P （NaHCO3-extractable P = 3.97 mg/kg, Mehlich-III-extractable P = 6.13 mg/kg） with （＋P=60 mg P/kg soil） or without P addition （0P） in study 4. Tested cultivars showed genetic diversity in PUE, P-efficiency （PE）, P-efficiency ratio （PER） and PSF. P-stress markedly reduced biomass and plant P contents. Cultivars that produced higher root biomass accumulated higher total P-contents （r = 0.98＊＊）, which in turn was related negatively to PSF （r = -0.95＊＊） and positively to shoot and total biomass. PER and PE showed significant correlations with shoot P-contents and biomass. Cultivars depicting high PUE and PE, and low PSF values showed better growth behavior under low soil P-environment. Systematic analysis and deployment of the plant rescue traits underlying the nutrient acquisition, assimilation, utilization and remobilization under P-starvation will bring more sparingly soluble P into cropping systems and will help to scavenge more P from plant unavailable bound P reserves.展开更多
文摘Background： The calcium clearance and reactive oxygen species （ROS） generations in the coronary artery smooth muscle cells in chronic heart failure （HF） have not been fully investigated. Therefore, we attempted to understand the gene expressions underlying the mishandling of calcium clearance and the accumulations of ROS. Methods： We initially established an animal model of chronic HF by making the left anterior descending coronary artery ligation （CAL） in rats, and then isolated the coronary artery vascular smooth muscle cells from the ischemic and the nonischemic parts of the coronary artery vessels in 12 weeks after CAL operation. The intracellular calcium concentration and ROS level were measured using flow cytometry, and the gene expressions of sarco/endoplasmic reticulum Ca2＋-ATPase （SERCA2a）, encoding sarcoplasmic reticulum Ca2＋-ATPase 2a, encoding sodium-calcium exchanger （NCX）, andp47phox encoding a subunit of the nicotinamide adenine dinucleotide phosphate （NADPH） oxidase were examined using real-time quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Results： We found that the calcium accumulation and ROS generation in the coronary artery smooth muscle cells isolated from either the ischemic or the nonischemic part of the CAL coronary artery vessel were significantly increased irrespective of blood supply （all P 〈 0.01 ）. Moreover, these were accompanied by the increased expressions of NCX and p47phox, the decreased expression of S ERCA2a, and the increased amount of phosphorylated forms of p47phox in NADPH oxidase （all P 〈 0.05）. Conclusions： Our results demonstrated that the disordered calcium clearance and the increased ROS generation occurred in the coronary artery smooth muscle cells in rats with chronic HF produced by ligation of the left anterior descending coronary artery （CAL）, and which was found to be disassociated from blood supply, and the increased generation of ROS in the ceils was found to make concomitancy to the increased activity of NADPH oxidase in cytoplasm.
基金the Japan Society for the Promotion of Science (JSPS) for financial support, which enabled him to pursue this research work
文摘Phosphorus （P） starvation is highly notorious for limiting plant growth around the globe. To combat P-starvation, plants constantly sense the changes in their environment, and elicit an elegant myriad of plastic responses and rescue strategies to enhance P-solublization and acquisition from bound soil P-forms. Relative growth responses, P-solublization and P- acquisition ability of 14 diverse Brassica cultivars grown with sparingly soluble P-sources （Rock-P （RP） and Ca3（PO4）2 （TCP）） were evaluated in a solution culture experiment. Cultivars showed considerable genetic diversity in terms of biomass accumulation, concentration and contents of P and Ca in shoots and roots, P-stress factor （PSF） and P use efficiency. Cultivars showed variable P-stress tolerance, and cultivars depicting low PSF and high P-efficiency values were better adaptable to P-starvation. In experiment 2, after initial feeding on optimum nutrition for 12 d after transplanting （DAT）, class-I （low P-tolerant （Oscar and Con-II）） and class-II （low P-sensitive （Gold Rush and RL-18）） cultivars were exposed to P-free environment for 25 d. All of the cultivars remobilized P from above ground parts to their roots during growth in P-free environment, the magnitude of which was variable in tested cultivars. P-concentrations （[P]s） at 37 DAT were higher in developing compared with developed leaves. Translocation of absorbed P from metabolically inactive to active sites in P- stressed plants may have helped class-I cultivars to establish a better rooting system, which provided a basis for enhanced P-utilization efficiency （PUE） and tolerance against P-stress. By supplying TCP and RP spatially separated from other nutrients in split root study, class-I cultivars were still able to mobilize RP and TCP more efficiently compared with class-II cultivars. To compare the growth behavior under P-stress, cultivars were grown in pots for 41 d after sowing, using a soil low in P （NaHCO3-extractable P = 3.97 mg/kg, Mehlich-III-extractable P = 6.13 mg/kg） with （＋P=60 mg P/kg soil） or without P addition （0P） in study 4. Tested cultivars showed genetic diversity in PUE, P-efficiency （PE）, P-efficiency ratio （PER） and PSF. P-stress markedly reduced biomass and plant P contents. Cultivars that produced higher root biomass accumulated higher total P-contents （r = 0.98＊＊）, which in turn was related negatively to PSF （r = -0.95＊＊） and positively to shoot and total biomass. PER and PE showed significant correlations with shoot P-contents and biomass. Cultivars depicting high PUE and PE, and low PSF values showed better growth behavior under low soil P-environment. Systematic analysis and deployment of the plant rescue traits underlying the nutrient acquisition, assimilation, utilization and remobilization under P-starvation will bring more sparingly soluble P into cropping systems and will help to scavenge more P from plant unavailable bound P reserves.
