In order to explore the effect of manganese on DNA-protein crosslinks （DPC） of testicle in chicken. 500, 800, 1 700 mg·kg^-1 MnC12 were added to forage to establish the model of the sub-chronic manganese poison...In order to explore the effect of manganese on DNA-protein crosslinks （DPC） of testicle in chicken. 500, 800, 1 700 mg·kg^-1 MnC12 were added to forage to establish the model of the sub-chronic manganese poisoning. After 30, 60 and 90 d, testicles were taken out to detect hydroxyl radical inhibiting capacity and DPC content. The results showed that compared with control group, hydroxyl radical inhibiting capacity significantly decreased and DPC content notably increased, and there was a time-dose relationship. It demonstrated that manganese could decrease the inhibitng capacity of hydroxyl radical, increase the content of hydroxyl and DPC, and induce DNA damage.展开更多
DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleter...DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleterious and understudied forms of DNA damage, posing as steric blockades to transcription and replication. If not properly repaired, these lesions can lead to mutations, genomic instability, and cell death. DPCs can be induced endogenously or through environmental carcinogens and chemotherapeutic agents. Endogenously, DPCs are commonly derived through reactions with aldehydes, as well as through trapping of various enzymatic intermediates onto the DNA. Proteolytic cleavage of the protein moiety of a DPC is a general strategy for removing the lesion. This can be accomplished through a DPC-specific protease and and/or proteasome-mediated degradation.Nucleotide excision repair and homologous recombination are each involved in repairing DPCs, with their respective roles likely dependent on the nature and size of the adduct. The Fanconi anemia pathway may also have a role in processing DPC repair intermediates. In this review, we discuss how these lesions are formed, strategies and mechanisms for their removal, and diseases associated with defective DPC repair.展开更多
Effects of mineral nutrient imbalance,DNA lesion and DNA-protein crosslink on growth of Vicia faba L.seedlings hydroponically cultivated in concentrations of extraneous lanthanum（La） for 20 days were investigated in...Effects of mineral nutrient imbalance,DNA lesion and DNA-protein crosslink on growth of Vicia faba L.seedlings hydroponically cultivated in concentrations of extraneous lanthanum（La） for 20 days were investigated in the present experiment.The results showed that contents of La,Cu or K elements in roots generally changed synchronously with those in leaves,while Ca,Fe,Zn,Mg,Mn or P in the roots altered inversely to those in the leaves.Thus,the extraneous La led to redistribution and imbalance of mineral nutrient elements in the roots and leaves.DNA lesion and DNA-protein crosslink were investigated by single cell gel electrophoresis（SCGE） and sodium dodecyl sulfate/potassium（SDS/K＋） precipitation methods,respectively.The results demonstrated that the increasing La induced DNA break and DNA-protein crosslinks（DPCs） in the seedlings.These results suggested that mineral nutrient imbalance,DNA lesion and DNA-protein crosslink were involved in the growth retardation and growth alteration of the seedlings,which may help to understand the mechanisms of rare earth elements（REEs） on plant growth.展开更多
To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In...To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In this study, detection of a series of biomarkers, including reactive oxygen species （ROS）, glutathione （GSH）, 8-hydroxy-2＇- deoxyguanosine （8-OHdG）, in addition to DNA and protein crosslink （DPC） and MTT assay, were conducted to evaluate the cytotoxicity. It is indicated that compared with the control group, there was no significant difference in the induced cytotoxicity at concentrations lower than 50 μg/mL for both nanosized and microsized tellurium powders. While there appears a significant difference in the induced cytotoxicity for nanosized tellurium powders when the concentration is higher than 100 μg/mL as well as for microsized tellurium powders when the concentration is higher than 200 μg/mL. Moreover, it is found that the cytotoxicity induced on HeLa cells exhibits a certain dose-effect relationship with the concentration of tellurium powders. A conclusion has been reached that the toxicity on HeLa cells can be induced by both nanosized and microsized tellurium powders, and the toxicity of the nanosized tellurium powders is significantly greater than the microsized one.展开更多
文摘In order to explore the effect of manganese on DNA-protein crosslinks （DPC） of testicle in chicken. 500, 800, 1 700 mg·kg^-1 MnC12 were added to forage to establish the model of the sub-chronic manganese poisoning. After 30, 60 and 90 d, testicles were taken out to detect hydroxyl radical inhibiting capacity and DPC content. The results showed that compared with control group, hydroxyl radical inhibiting capacity significantly decreased and DPC content notably increased, and there was a time-dose relationship. It demonstrated that manganese could decrease the inhibitng capacity of hydroxyl radical, increase the content of hydroxyl and DPC, and induce DNA damage.
基金supported by the National Institutes of Health (CA179441, CA193124-Project 3 to Lei Li)
文摘DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleterious and understudied forms of DNA damage, posing as steric blockades to transcription and replication. If not properly repaired, these lesions can lead to mutations, genomic instability, and cell death. DPCs can be induced endogenously or through environmental carcinogens and chemotherapeutic agents. Endogenously, DPCs are commonly derived through reactions with aldehydes, as well as through trapping of various enzymatic intermediates onto the DNA. Proteolytic cleavage of the protein moiety of a DPC is a general strategy for removing the lesion. This can be accomplished through a DPC-specific protease and and/or proteasome-mediated degradation.Nucleotide excision repair and homologous recombination are each involved in repairing DPCs, with their respective roles likely dependent on the nature and size of the adduct. The Fanconi anemia pathway may also have a role in processing DPC repair intermediates. In this review, we discuss how these lesions are formed, strategies and mechanisms for their removal, and diseases associated with defective DPC repair.
基金supported by the National Natural Science Foundation of China (No. 20877032)the Foundation of State Key Laboratory of Pollution Control and Resources Reuse of China (No. PCRRF10020)
文摘Effects of mineral nutrient imbalance,DNA lesion and DNA-protein crosslink on growth of Vicia faba L.seedlings hydroponically cultivated in concentrations of extraneous lanthanum（La） for 20 days were investigated in the present experiment.The results showed that contents of La,Cu or K elements in roots generally changed synchronously with those in leaves,while Ca,Fe,Zn,Mg,Mn or P in the roots altered inversely to those in the leaves.Thus,the extraneous La led to redistribution and imbalance of mineral nutrient elements in the roots and leaves.DNA lesion and DNA-protein crosslink were investigated by single cell gel electrophoresis（SCGE） and sodium dodecyl sulfate/potassium（SDS/K＋） precipitation methods,respectively.The results demonstrated that the increasing La induced DNA break and DNA-protein crosslinks（DPCs） in the seedlings.These results suggested that mineral nutrient imbalance,DNA lesion and DNA-protein crosslink were involved in the growth retardation and growth alteration of the seedlings,which may help to understand the mechanisms of rare earth elements（REEs） on plant growth.
文摘To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In this study, detection of a series of biomarkers, including reactive oxygen species （ROS）, glutathione （GSH）, 8-hydroxy-2＇- deoxyguanosine （8-OHdG）, in addition to DNA and protein crosslink （DPC） and MTT assay, were conducted to evaluate the cytotoxicity. It is indicated that compared with the control group, there was no significant difference in the induced cytotoxicity at concentrations lower than 50 μg/mL for both nanosized and microsized tellurium powders. While there appears a significant difference in the induced cytotoxicity for nanosized tellurium powders when the concentration is higher than 100 μg/mL as well as for microsized tellurium powders when the concentration is higher than 200 μg/mL. Moreover, it is found that the cytotoxicity induced on HeLa cells exhibits a certain dose-effect relationship with the concentration of tellurium powders. A conclusion has been reached that the toxicity on HeLa cells can be induced by both nanosized and microsized tellurium powders, and the toxicity of the nanosized tellurium powders is significantly greater than the microsized one.
