Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O stain...Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β（1L-1β）-induced mRNA and protein changes of low-density lipoprotein receptor （LDLR） and ATP-binding cassette transporter Al （ABCAl） were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin （mTOR）, including mTOR-WT （wild type）, mTOR-RR （rapamycin resistant, with kinase activity）, and mTOR-RR-KD （rapamycin resistant, without kinase activity）, were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR.展开更多
Complex research is devoted to basic non-specific stress-reactions caused by abiotic factors such as drought and salinity in vivo and in vitro. A comparative physiological, biochemical and cytogenetic analysis was per...Complex research is devoted to basic non-specific stress-reactions caused by abiotic factors such as drought and salinity in vivo and in vitro. A comparative physiological, biochemical and cytogenetic analysis was performed and showed the peculiarities of growth and viability on various （cellular, tissular, organismic） levels of plants structural arrangement at stress conditions. Determined the parameters of the growth, ion balance, the content of free proline, superoxide dismutase activity and conducted the cytological studies. The commonness of cytological reactions of plant cells to abiotic stress was revealed. The considerable positive correlation relationships between growth of callus biomass and increases of primary roots number under abiotic stressess, between growth of callus biomass and capacity for survival of seedlings under osmotic stress were registered. Such correlation tells about comparability of stress tolerance valuation at different levels of plants structural arrangement. The considerable negative correlation between K~/Na~ ions relations and percent increase of free proline in calluses were showed. Physiological and biochemical indicators of abiotic stresses impact on plants cells and tissues, such as SOD activity and K^＋/Na^＋ ions correlation were noted. These indicators are effective as metabolic markers in the course of testing and selection of stress-resistant cereals in vivo and in vitro.展开更多
For attaining the optimized locomotory performance of swimming fishes,both the passive visco-elastic properties of the fish body and the mechanical behavior of the active muscles should coordinate with the fish body’...For attaining the optimized locomotory performance of swimming fishes,both the passive visco-elastic properties of the fish body and the mechanical behavior of the active muscles should coordinate with the fish body’s undulatory motion pattern.However,it is difficult to directly measure the visco-elastic constitutive relation and the muscular mechanical performance in vivo.In the present paper,a new approach based on the continuous beam model for steady swimming fish is proposed to predict the fish body’s visco-elastic properties and the related muscle mechanical behavior in vivo.Given the lateral travelling-wave-like movement as the input condition,the required muscle force and the energy consumption are functions of the fish body’s visco-elastic parameters,i.e.the Young’s modulus E and the viscosity coefficient in the Kelvin model.After investigating the variations of the propagating speed of the required muscle force with the fish body’s visco-elastic parameters,we analyze the impacts of the visco-elastic properties on the energy efficiencies,including the energy utilization ratios of each element of the kinematic chain in fish swimming and the overall efficiency.Under the constraints of reasonable wave speed of muscle activation and the physiological feasibility,the optimal design of the passive visco-elastic properties can be predicted aiming at maximizing the overall efficiency.The analysis is based on the small-amplitude steady swimming of the carangiform swimmer,with typical Reynolds number varying from 2.5×104to 2.5×105,and the present results show that the non-dimensional Young’s modulus is 112±34,and the non-dimensional viscosity coefficient is 13 approximately.In the present estimated ranges,the overall efficiency of the swimming fish is insensitive to the viscosity,and its magnitude is about 0.11±0.02,in the predicted range given by previous study.展开更多
文摘Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β（1L-1β）-induced mRNA and protein changes of low-density lipoprotein receptor （LDLR） and ATP-binding cassette transporter Al （ABCAl） were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin （mTOR）, including mTOR-WT （wild type）, mTOR-RR （rapamycin resistant, with kinase activity）, and mTOR-RR-KD （rapamycin resistant, without kinase activity）, were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR.
文摘Complex research is devoted to basic non-specific stress-reactions caused by abiotic factors such as drought and salinity in vivo and in vitro. A comparative physiological, biochemical and cytogenetic analysis was performed and showed the peculiarities of growth and viability on various （cellular, tissular, organismic） levels of plants structural arrangement at stress conditions. Determined the parameters of the growth, ion balance, the content of free proline, superoxide dismutase activity and conducted the cytological studies. The commonness of cytological reactions of plant cells to abiotic stress was revealed. The considerable positive correlation relationships between growth of callus biomass and increases of primary roots number under abiotic stressess, between growth of callus biomass and capacity for survival of seedlings under osmotic stress were registered. Such correlation tells about comparability of stress tolerance valuation at different levels of plants structural arrangement. The considerable negative correlation between K~/Na~ ions relations and percent increase of free proline in calluses were showed. Physiological and biochemical indicators of abiotic stresses impact on plants cells and tissues, such as SOD activity and K^＋/Na^＋ ions correlation were noted. These indicators are effective as metabolic markers in the course of testing and selection of stress-resistant cereals in vivo and in vitro.
基金supported by the National Natural Science Foundation of China(Grants No.10832010)the Innovation Project of the Chinese Academy of Sciences(Grant No.KJCX2-YW-L05)
文摘For attaining the optimized locomotory performance of swimming fishes,both the passive visco-elastic properties of the fish body and the mechanical behavior of the active muscles should coordinate with the fish body’s undulatory motion pattern.However,it is difficult to directly measure the visco-elastic constitutive relation and the muscular mechanical performance in vivo.In the present paper,a new approach based on the continuous beam model for steady swimming fish is proposed to predict the fish body’s visco-elastic properties and the related muscle mechanical behavior in vivo.Given the lateral travelling-wave-like movement as the input condition,the required muscle force and the energy consumption are functions of the fish body’s visco-elastic parameters,i.e.the Young’s modulus E and the viscosity coefficient in the Kelvin model.After investigating the variations of the propagating speed of the required muscle force with the fish body’s visco-elastic parameters,we analyze the impacts of the visco-elastic properties on the energy efficiencies,including the energy utilization ratios of each element of the kinematic chain in fish swimming and the overall efficiency.Under the constraints of reasonable wave speed of muscle activation and the physiological feasibility,the optimal design of the passive visco-elastic properties can be predicted aiming at maximizing the overall efficiency.The analysis is based on the small-amplitude steady swimming of the carangiform swimmer,with typical Reynolds number varying from 2.5×104to 2.5×105,and the present results show that the non-dimensional Young’s modulus is 112±34,and the non-dimensional viscosity coefficient is 13 approximately.In the present estimated ranges,the overall efficiency of the swimming fish is insensitive to the viscosity,and its magnitude is about 0.11±0.02,in the predicted range given by previous study.
