Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then...Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then their influence on senescence of harvested Peach fruits was studied. The results showed that low temperature （5℃） strongly inhibited the reduction of firmness and the increase in respiration rate. During storage at ambient temperature （20℃）, ROS had a cumulative process while malondialdehye （MDA） content continued to increase in associated with enhanced membrane lipid peroxidation. Lipoxygenase （LOX） activity was strongly inhibited under the low temperature condition. The activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, and Ca^2＋-ATPase declined to a certain extent at ambient temperature, while they showed higher activities at low temperature, which may be related to lower membrane lipid peroxidation at low temperature. Higher Ca^2＋ content at ambient temperature may be responsible for impairment of mitochondrial function, thus, leading to fruit senescence. The results showed that under low temperature condition, the low accumulation of ROS and the low level of membrane lipid peroxidation could maintain the function of mitochondria that would help to delay the senescence of peach fruits. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration. It can be inferred that the low temperature helps to delay senescence of peach fruits via suppression of ROS and related enzymes, maintain better homeostasis of Ca^2＋ in mitochondria and thus better mitochondrial functions.展开更多
The fruits of peach cultivar Yuhua 3 were used as materials to investigate the changes of active oxygen and related enzymes in mitochondria respiratory metabolism during ripening of peach fruit, involving their influe...The fruits of peach cultivar Yuhua 3 were used as materials to investigate the changes of active oxygen and related enzymes in mitochondria respiratory metabolism during ripening of peach fruit, involving their influence on the proceeding of peach fruit senescence. The results showed that the large decrease in firmness occurred between maturity II and IV. The decrease in firmness coincided with an increase in respiratory intensity. Obvious peaks of respiratory intensity lagging to the rapid change of fruit firmness could be shown during peach ripening. Reactive oxygen species （ROS） had a cumulative process and positively correlated with respiratory intensity. During peach ripening, the content of Ca^2＋ increased, the activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, H＋-ATPase, and Ca^2＋-ATPase decreased varying in different degree at the later step of ripening. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration, namely, both ROS metabolism and mitochondrial respiration probably played important roles in ripening and senescing of peach fruit.展开更多
AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (D...AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.展开更多
BACKGROUND： During the cellular aging process, the number of mitochondria, generation of adenosine triphosphate （ATP）, activity of respiratory chain enzyme complex 1 and 4, and oxidation decrease. OBJECTIVE： To ob...BACKGROUND： During the cellular aging process, the number of mitochondria, generation of adenosine triphosphate （ATP）, activity of respiratory chain enzyme complex 1 and 4, and oxidation decrease. OBJECTIVE： To observe the effects of aqueous and spirituous extract, as well as polysaccharides from Fructus schizandrae （Magnolia Vine） on energy metabolism and mitochondrial anti-oxidation in cranial nerve cells of a D-gal-induced aging mouse model. DESIGN, TIME AND SETTING： A randomized, controlled, animal study. The experiment was conducted at the Department of Biochemistry, Qiqihar Medical College between March and July 2006. MATERIALS： Fifty healthy, Kunming mice of both sexes, aged 2 3 months old and weighing 18 22 g, were used for the present study. Fructus schizandrae was purchased from the Medical College of Jiamusi University. Aqueous extracts, spirituous extracts, and polysaccharides from Fructus schizandrae were prepared. D-galactose （D-gal） is a product of the Second Reagent Factory, Shanghai City, China. Mn-superoxide dismutase （Mn-SOD） kit, malonaldehyde （MDA） kit, protein quantification kit, and inorganic phosphorus testing kit were purchased from Jian Cheng Bioeng. Co., China. METHODS： Fifty mice were randomly divided into five groups, with 10 mice in each group： young control, aging model, aqueous Fructus schizandrae extract, spirituous Fructus schizandrae extract, and Fructus schizandrae polysaccharides. Over a course of 30 days, mice in aging model, aqueous Fructus schizandrae extract, spirituous Fructus schizandrae extract, and Fructus schizandrae polysaccharides groups were injected subcutaneously with D-gal （100 mg/kg） into the nape of the neck daily, and administered intragastrically with an equal volume of sterile, warm water （aging model）, aqueous Fructus schizandrae extract （2 g/kg）, spirituous Fructus schizandrae extract （2 g/kg）, or Fructus schizandrae polysaccharides （0.2 g/kg）, respectively. Mice in the young control group were injected into the nape of the neck with physiological saline and administered intragastrically with sterile, warm water. MAIN OUTCOME MEASURES： Respiratory chain complex I and H^＋-ATP enzyme activities, as well as Mn-SOD and MDA levels, were determined by the Coomassie brilliant blue method. RESULTS： All fifty mice were included in the final analysis. In mitochondria fiom cranial nerve cells of the aging mouse group MDA levels were significantly increased, compared with young control group （P 〈 0.01）; however, Mn-SOD levels, as well as respiratory chain complex I and H＋-ATP enzyme activity, were remarkably decreased （P 〈 0.01 ）. In each Fructus schizandrae group, Mn-SOD levels, as well as respiratory chain complex I and H＋-ATP enzyme activity was enhanced to various extents （P 〈 0.05, P 〈 0.01）, and MDA levels were decreased （P 〈 0.01）, compared with the aging model group. CONCLUSION： Aqueous and spirituous Fructus schizandrae extracts, as well as Fructus schizandrae polysaccharides delayed changes in mitochondrial energy metabolism, increased Mn-SOD levels, and decreased MDA levels in cranial nerve cell mitochondria of an aging mouse model. Fructus schizandrae polysaccharides were particularly capable of protecting mitochondria from oxidative injury.展开更多
It is a well-known fact that a mature seed can survive losing most of its water, yet how seeds acquire desiccation- tolerance is not well understood. Through sampling maize embryos of different developmental stages an...It is a well-known fact that a mature seed can survive losing most of its water, yet how seeds acquire desiccation- tolerance is not well understood. Through sampling maize embryos of different developmental stages and comparatively studying the integrity, oxygen consumption rate and activities of antioxidant enzymes in the mitochondria, the main origin site of reactive oxygen species （ROS） production in seed cells, we found that before an embryo achieves desiccation-tolerance, its mitochondria shows a more active metabolism, and might produce more ROS and therefore need a more effective ROS scavenging system. However, embryo dehydration in this developmental stage declined the activities of most main antioxidant enzymes and accumulated thiobarbituric acid-reactive products in mitochondria, and then destroyed the structure and functional integrity of mitochondria. In physiologically-matured embryos （dehydration- tolerant）, mitochondria showed lower metabolism levels, and no decline in ROS scavenging enzyme activities and less accumulation of thiobarbituric acid-reactive products after embryo dehydration. These data indicate that seed desiccation- tolerance acquisition might be associated with down-adjustment of the metabolism level in the late development stage, resulting in less ROS production, and ROS scavenging enzymes becoming desiccation-tolerant and then ensuring the structure and functional integrity of mitochondria.展开更多
Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic ac...Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications.展开更多
基金funded by the National Natural Science Fundation of China (30840016)the Natural Science Fundation of Jiangsu Province, China (BK 2010310)the Natural Science Fundation for Colleges and Universities in Jiangsu Province, China (10KJB550004)
文摘Peach fruits [Prumus persica （L.） Batsch, cv. Yuhuasanhao] were used as materials to investigate the changes of reactive oxygen species （ROS） and related enzymes in mitochondria respiration during storage and then their influence on senescence of harvested Peach fruits was studied. The results showed that low temperature （5℃） strongly inhibited the reduction of firmness and the increase in respiration rate. During storage at ambient temperature （20℃）, ROS had a cumulative process while malondialdehye （MDA） content continued to increase in associated with enhanced membrane lipid peroxidation. Lipoxygenase （LOX） activity was strongly inhibited under the low temperature condition. The activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, and Ca^2＋-ATPase declined to a certain extent at ambient temperature, while they showed higher activities at low temperature, which may be related to lower membrane lipid peroxidation at low temperature. Higher Ca^2＋ content at ambient temperature may be responsible for impairment of mitochondrial function, thus, leading to fruit senescence. The results showed that under low temperature condition, the low accumulation of ROS and the low level of membrane lipid peroxidation could maintain the function of mitochondria that would help to delay the senescence of peach fruits. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration. It can be inferred that the low temperature helps to delay senescence of peach fruits via suppression of ROS and related enzymes, maintain better homeostasis of Ca^2＋ in mitochondria and thus better mitochondrial functions.
基金supported by the National Natural Science Fundation of China (30840016,30570134)the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD22B01)the Natural Science Fundation of Jiangsu Province,China(BK 2007076)
文摘The fruits of peach cultivar Yuhua 3 were used as materials to investigate the changes of active oxygen and related enzymes in mitochondria respiratory metabolism during ripening of peach fruit, involving their influence on the proceeding of peach fruit senescence. The results showed that the large decrease in firmness occurred between maturity II and IV. The decrease in firmness coincided with an increase in respiratory intensity. Obvious peaks of respiratory intensity lagging to the rapid change of fruit firmness could be shown during peach ripening. Reactive oxygen species （ROS） had a cumulative process and positively correlated with respiratory intensity. During peach ripening, the content of Ca^2＋ increased, the activities of succinic dehydrogenase （SDH）, cytochrome C oxidase （CCO）, H＋-ATPase, and Ca^2＋-ATPase decreased varying in different degree at the later step of ripening. These suggested a close relationship existed between ROS metabolism and mitochondrial respiration, namely, both ROS metabolism and mitochondrial respiration probably played important roles in ripening and senescing of peach fruit.
基金National Natural Science Foundation of China,No.39770300,30070873the Overseas Chinese Affairs Office of the State Council Foundation,No.98-33
文摘AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.
文摘BACKGROUND： During the cellular aging process, the number of mitochondria, generation of adenosine triphosphate （ATP）, activity of respiratory chain enzyme complex 1 and 4, and oxidation decrease. OBJECTIVE： To observe the effects of aqueous and spirituous extract, as well as polysaccharides from Fructus schizandrae （Magnolia Vine） on energy metabolism and mitochondrial anti-oxidation in cranial nerve cells of a D-gal-induced aging mouse model. DESIGN, TIME AND SETTING： A randomized, controlled, animal study. The experiment was conducted at the Department of Biochemistry, Qiqihar Medical College between March and July 2006. MATERIALS： Fifty healthy, Kunming mice of both sexes, aged 2 3 months old and weighing 18 22 g, were used for the present study. Fructus schizandrae was purchased from the Medical College of Jiamusi University. Aqueous extracts, spirituous extracts, and polysaccharides from Fructus schizandrae were prepared. D-galactose （D-gal） is a product of the Second Reagent Factory, Shanghai City, China. Mn-superoxide dismutase （Mn-SOD） kit, malonaldehyde （MDA） kit, protein quantification kit, and inorganic phosphorus testing kit were purchased from Jian Cheng Bioeng. Co., China. METHODS： Fifty mice were randomly divided into five groups, with 10 mice in each group： young control, aging model, aqueous Fructus schizandrae extract, spirituous Fructus schizandrae extract, and Fructus schizandrae polysaccharides. Over a course of 30 days, mice in aging model, aqueous Fructus schizandrae extract, spirituous Fructus schizandrae extract, and Fructus schizandrae polysaccharides groups were injected subcutaneously with D-gal （100 mg/kg） into the nape of the neck daily, and administered intragastrically with an equal volume of sterile, warm water （aging model）, aqueous Fructus schizandrae extract （2 g/kg）, spirituous Fructus schizandrae extract （2 g/kg）, or Fructus schizandrae polysaccharides （0.2 g/kg）, respectively. Mice in the young control group were injected into the nape of the neck with physiological saline and administered intragastrically with sterile, warm water. MAIN OUTCOME MEASURES： Respiratory chain complex I and H^＋-ATP enzyme activities, as well as Mn-SOD and MDA levels, were determined by the Coomassie brilliant blue method. RESULTS： All fifty mice were included in the final analysis. In mitochondria fiom cranial nerve cells of the aging mouse group MDA levels were significantly increased, compared with young control group （P 〈 0.01）; however, Mn-SOD levels, as well as respiratory chain complex I and H＋-ATP enzyme activity, were remarkably decreased （P 〈 0.01 ）. In each Fructus schizandrae group, Mn-SOD levels, as well as respiratory chain complex I and H＋-ATP enzyme activity was enhanced to various extents （P 〈 0.05, P 〈 0.01）, and MDA levels were decreased （P 〈 0.01）, compared with the aging model group. CONCLUSION： Aqueous and spirituous Fructus schizandrae extracts, as well as Fructus schizandrae polysaccharides delayed changes in mitochondrial energy metabolism, increased Mn-SOD levels, and decreased MDA levels in cranial nerve cell mitochondria of an aging mouse model. Fructus schizandrae polysaccharides were particularly capable of protecting mitochondria from oxidative injury.
基金Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-YW-Z-058)the National Natural Science Foundation of China (3047018330870223)
文摘It is a well-known fact that a mature seed can survive losing most of its water, yet how seeds acquire desiccation- tolerance is not well understood. Through sampling maize embryos of different developmental stages and comparatively studying the integrity, oxygen consumption rate and activities of antioxidant enzymes in the mitochondria, the main origin site of reactive oxygen species （ROS） production in seed cells, we found that before an embryo achieves desiccation-tolerance, its mitochondria shows a more active metabolism, and might produce more ROS and therefore need a more effective ROS scavenging system. However, embryo dehydration in this developmental stage declined the activities of most main antioxidant enzymes and accumulated thiobarbituric acid-reactive products in mitochondria, and then destroyed the structure and functional integrity of mitochondria. In physiologically-matured embryos （dehydration- tolerant）, mitochondria showed lower metabolism levels, and no decline in ROS scavenging enzyme activities and less accumulation of thiobarbituric acid-reactive products after embryo dehydration. These data indicate that seed desiccation- tolerance acquisition might be associated with down-adjustment of the metabolism level in the late development stage, resulting in less ROS production, and ROS scavenging enzymes becoming desiccation-tolerant and then ensuring the structure and functional integrity of mitochondria.
基金financially supported by National Natural Science Foundation of China(81700524)Natural Science Foundation of Fujian Province(2022J01866)from Fujian Provincial Department of Science and Technology+1 种基金Key Project of Fujian University of Traditional Chinese Medicine(X2021019)Collaborative Innovation and Platform Establishment Project of Department of Science and Technology of Guangdong Province(2019A050520003)。
文摘Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications.
