Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoA...Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of ScYbr159p.展开更多
Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug ...Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug delivery system(FA-LP-CaAs)was fabricated using the reverse microemulsion method.Methods A Malvern particle size analyzer and a transmission electron microscope were employed to determine the particle size,distribution,zeta potential and morphology of FA-LP-CaAs.Further,inductively coupled plasma emission spectrometry was employed to determine the drug loading capacity,entrapment efficiency,and in vitro release behavior of FA-LP-CaAs.To determine its toxicity in human hepatoma cells(HepG2)and human normal hepatocytes(LO2)and its effect on HepG2 cell cycle and apoptosis,the MTT method was used.Laser confocal and flow cytometry were also employed to determine the uptake of FA-LP-CaAs by cells.After establishing a mouse liver cancer model,the in vivo distribution of the drug included in the formulation was investigated using in vivo fluorescence.To evaluate the liver cancer targeting and anti-tumor effects of FALP-CaAs in vivo,the distribution of ATO in tissues and changes in tumor volume and body weight after liposomal administration were investigated using hematoxylin-eosin(HE)-stained tumor sections.Results The particle size,zeta potential and PDI of FA-LP-CaAs were(122.67±2.18)nm,(12.81±0.75)mV and 0.22±0.01,respectively,while its drug loading capacity was 18.49%±1.14%.In vitro experimental results revealed that FA-LP-CaAs had a strong killing effect on HepG2 cells.Further,the cell uptake capacity of this formulation was found to improve.Based on in vivo assessments,FA-LP-CaAs could significantly increase the distribution of ATO in tumor sites and inhibit tumor growth.Conclusions Herein,an FA-LP-CaAs formulation was successfully fabricated.This liposomal drug delivery system had a round appearance,uniform particle size,good polydispersity coefficient,evident“core-shell”structure,high drug loading capacity and pH response,tumor targeted drug delivery and sustained drug release.These findings support further research and the application of ATO as an anti-liver cancer prodrug and provide a new method for the treatment of liver cancer.展开更多
Heavy metals pose a potential threat to aquatic organisms. In this study, a static-renewal acute toxicity test was conducted to investigate the effects of cadmium on the antioxidant defense systems （both enzymatic an...Heavy metals pose a potential threat to aquatic organisms. In this study, a static-renewal acute toxicity test was conducted to investigate the effects of cadmium on the antioxidant defense systems （both enzymatic and non-enzymatic） and lipid peroxidaton in liver and gill tissues of juvenile GIFT tilapia Oreochromis niloticus. After 8 days of exposure to Cd （0, 0.016, 0.08, 0.4 and 2 mg/L）, livers accumulated significantly more Cd than gills. Catalase （CAT）, superoxide dismutase （SOD） and glutathione S-transferase （GST） activities were stimulated only at the highest concentration tested （2 mg/L）. Glutathione peroxidase （GPx） activity was stimulated in the gill while inhibited in the liver, these alternations in gill and liver showed a strong relationship with Cd levels in these tissues. This may indicate either a tissue-specific response of GPx to Cd or, most probably, a hormetic effect of Cd on GPx. Cd increased GSH levels and decreased the ratio GSSG/GSH in fish livers at 2 mg/L. Cd exposure resulted in an elevated level of MDA in the livers of fish at 2 mg/L, indicating that Cd caused lipid peroxidation. Taken together, the results demonstrated that Cd altered the enzymatic and non-enzymatic defensive systems and caused lipid peroxidation in O. niloticus at relatively high concentrations （compared to environmentally relevant concentrations）. In addition, the results implied that O. niloticus could tolerate high level of Cd in sites polluted by Cd.展开更多
Based on current research, there are three technologies during the test of bacterial endotoxin of liposomes：（1） extraction of bacterial endotoxin from liposomes;（2） addition of bacterial endotoxin in the process ...Based on current research, there are three technologies during the test of bacterial endotoxin of liposomes：（1） extraction of bacterial endotoxin from liposomes;（2） addition of bacterial endotoxin in the process of recovery test; and（3） elimination of the interference factors from drugs and excipients. In the present study, we pointed out that the key technologies to test bacterial endotoxin from paclitaxel liposome included following steps： extraction of bacterial endotoxins from ethanol-dissolved liposomes; preparation of positive control of recovery solution by adding 0.01 m L standard endotoxins in 1 m L liposome ethanol solution; and the use of 0.5% human albumin to eliminate the interference from detection, and accurate detection of the bacterial endotoxin of liposomes.展开更多
基金supported by grants from China Na-tional Basic Research Program (NO. 2004CB117302)National Natural Science Foundation of China (No.30470171)the Sigrid Jusélius Foundation Finland and the Academy of Finland
文摘Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of ScYbr159p.
基金funding support from the National Natural Science Foundation of China (No. 81873014)。
文摘Objective To reduce the toxicity and side effects of arsenic trioxide(ATO)and provide a new approach for the treatment of primary liver cancer,a folic acid-modified calcium arsenite liposomal“target-controlled”drug delivery system(FA-LP-CaAs)was fabricated using the reverse microemulsion method.Methods A Malvern particle size analyzer and a transmission electron microscope were employed to determine the particle size,distribution,zeta potential and morphology of FA-LP-CaAs.Further,inductively coupled plasma emission spectrometry was employed to determine the drug loading capacity,entrapment efficiency,and in vitro release behavior of FA-LP-CaAs.To determine its toxicity in human hepatoma cells(HepG2)and human normal hepatocytes(LO2)and its effect on HepG2 cell cycle and apoptosis,the MTT method was used.Laser confocal and flow cytometry were also employed to determine the uptake of FA-LP-CaAs by cells.After establishing a mouse liver cancer model,the in vivo distribution of the drug included in the formulation was investigated using in vivo fluorescence.To evaluate the liver cancer targeting and anti-tumor effects of FALP-CaAs in vivo,the distribution of ATO in tissues and changes in tumor volume and body weight after liposomal administration were investigated using hematoxylin-eosin(HE)-stained tumor sections.Results The particle size,zeta potential and PDI of FA-LP-CaAs were(122.67±2.18)nm,(12.81±0.75)mV and 0.22±0.01,respectively,while its drug loading capacity was 18.49%±1.14%.In vitro experimental results revealed that FA-LP-CaAs had a strong killing effect on HepG2 cells.Further,the cell uptake capacity of this formulation was found to improve.Based on in vivo assessments,FA-LP-CaAs could significantly increase the distribution of ATO in tumor sites and inhibit tumor growth.Conclusions Herein,an FA-LP-CaAs formulation was successfully fabricated.This liposomal drug delivery system had a round appearance,uniform particle size,good polydispersity coefficient,evident“core-shell”structure,high drug loading capacity and pH response,tumor targeted drug delivery and sustained drug release.These findings support further research and the application of ATO as an anti-liver cancer prodrug and provide a new method for the treatment of liver cancer.
文摘Heavy metals pose a potential threat to aquatic organisms. In this study, a static-renewal acute toxicity test was conducted to investigate the effects of cadmium on the antioxidant defense systems （both enzymatic and non-enzymatic） and lipid peroxidaton in liver and gill tissues of juvenile GIFT tilapia Oreochromis niloticus. After 8 days of exposure to Cd （0, 0.016, 0.08, 0.4 and 2 mg/L）, livers accumulated significantly more Cd than gills. Catalase （CAT）, superoxide dismutase （SOD） and glutathione S-transferase （GST） activities were stimulated only at the highest concentration tested （2 mg/L）. Glutathione peroxidase （GPx） activity was stimulated in the gill while inhibited in the liver, these alternations in gill and liver showed a strong relationship with Cd levels in these tissues. This may indicate either a tissue-specific response of GPx to Cd or, most probably, a hormetic effect of Cd on GPx. Cd increased GSH levels and decreased the ratio GSSG/GSH in fish livers at 2 mg/L. Cd exposure resulted in an elevated level of MDA in the livers of fish at 2 mg/L, indicating that Cd caused lipid peroxidation. Taken together, the results demonstrated that Cd altered the enzymatic and non-enzymatic defensive systems and caused lipid peroxidation in O. niloticus at relatively high concentrations （compared to environmentally relevant concentrations）. In addition, the results implied that O. niloticus could tolerate high level of Cd in sites polluted by Cd.
基金The National Major Scientific and Technological Special Project for"Significant New Drugs Development"of China(Grant No.2015ZX09303001)Sub-task"study on methods for detection and evaluation of pyrogen substances in new preparations"(Grant No.2015ZX093030012002)
文摘Based on current research, there are three technologies during the test of bacterial endotoxin of liposomes：（1） extraction of bacterial endotoxin from liposomes;（2） addition of bacterial endotoxin in the process of recovery test; and（3） elimination of the interference factors from drugs and excipients. In the present study, we pointed out that the key technologies to test bacterial endotoxin from paclitaxel liposome included following steps： extraction of bacterial endotoxins from ethanol-dissolved liposomes; preparation of positive control of recovery solution by adding 0.01 m L standard endotoxins in 1 m L liposome ethanol solution; and the use of 0.5% human albumin to eliminate the interference from detection, and accurate detection of the bacterial endotoxin of liposomes.
