OBJECTIVE Cytochrome P450(CYP)3A accounts for nearly 30%of total CYP enzymes in human liver and participates in the metabolism of over 50%of clinical drugs.CYP3A also plays an important role in the chemical metabolism...OBJECTIVE Cytochrome P450(CYP)3A accounts for nearly 30%of total CYP enzymes in human liver and participates in the metabolism of over 50%of clinical drugs.CYP3A also plays an important role in the chemical metabolism,toxicity,and carcinogenicity.New animal models are needed to investigate CYP3A functions.METHODS The CRISPR-Cas9 technology was used to generate Cyp3a1/2 double knockout rat model.The absence of Cyp3a1/2 expression was evaluated through PCR and immunostaining.Metabolic studies of the CYP3A substrates midazolam and nifedipine both in vitro and in vivo were conducted to verify that CYP3A1/2 was functional y inactive in KO rats.In addition,compensatory up-regulation of other P450 genes in Cyp3a1/2 KO rats was detected.RESULTS The Cyp3a1/2 double KO rats were viable and fertile,and had no obvious physiological abnormities.Compared with the wild-type(WT)rat,Cyp3a1/2 expression was completely absent in the liver of the KO rat.In vitro and in vivo metabolic studies of the CYP3A1/2 substrates indicated that CYP3A1/2 was functionally inactive in double KO rats.CONCLUSION The Cyp3a1/2 double KO rat model was successfully generated and characterized.The Cyp3a1/2 KO rats as a novel rodent animal model will be a valuable tool for the study of the physiological and pharmacological roles of CYP3A,and determining whether the absence of CYP3A results in non-CYP mediated metabolism or metabolism by other CYP isoforms.展开更多
OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new ...OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new inhibitor of CYP2J2 from natural compounds and evaluate its potential to inhibit hepatoma carcinoma cells.METHODS Total fifty natural products were screened for the inhibitory potency against the activity of CYP2J2-mediated astemizole O-demethylation via LCMS/MS analysis.Enzyme kinetic and molecular docking studies were also carried out.RESULTS Our data found that plumbagin potently inhibited CYP2J2 with IC50value at 3.42,3.37 and 1.17μmol·L-1in rat liver microsomes,human liver microsomes(HLMs)and recombinant CYP2J2(rC YP2J2),respectively.Further enzyme kinetic studies showed that plumbagin was a mixed-type inhibitor of CYP2J2 in HLMs and r CYP2J2 with Kivalues of 1.88and 0.92μmol·L-1,respectively.Docking data presented that plumbagin interacted with CYP2J2 mainly through GLU222 and ALA223,which were crucial residues for substrates binding.At the same time,plumbagin showed cytotoxicity effects on hepatic carcinoma cell lines,such as HepG 2 and SMMC-7721,with IC50values at 11.55±1.06and(13.15±1.11)μmol·L-1,respectively.CONCLUSION These results indicated that plumbagin was a potent CYP2J2 inhibitor and potential anticancer agent.Further studies are needed to cover the mechanism of its antitumor activity.展开更多
基金The project supported by National Natural Science Foundation of China(81301908)the Science and Technology Commission of Shanghai Municipality(15140904700,13ZR1412600,14DZ2270100)
文摘OBJECTIVE Cytochrome P450(CYP)3A accounts for nearly 30%of total CYP enzymes in human liver and participates in the metabolism of over 50%of clinical drugs.CYP3A also plays an important role in the chemical metabolism,toxicity,and carcinogenicity.New animal models are needed to investigate CYP3A functions.METHODS The CRISPR-Cas9 technology was used to generate Cyp3a1/2 double knockout rat model.The absence of Cyp3a1/2 expression was evaluated through PCR and immunostaining.Metabolic studies of the CYP3A substrates midazolam and nifedipine both in vitro and in vivo were conducted to verify that CYP3A1/2 was functional y inactive in KO rats.In addition,compensatory up-regulation of other P450 genes in Cyp3a1/2 KO rats was detected.RESULTS The Cyp3a1/2 double KO rats were viable and fertile,and had no obvious physiological abnormities.Compared with the wild-type(WT)rat,Cyp3a1/2 expression was completely absent in the liver of the KO rat.In vitro and in vivo metabolic studies of the CYP3A1/2 substrates indicated that CYP3A1/2 was functionally inactive in double KO rats.CONCLUSION The Cyp3a1/2 double KO rat model was successfully generated and characterized.The Cyp3a1/2 KO rats as a novel rodent animal model will be a valuable tool for the study of the physiological and pharmacological roles of CYP3A,and determining whether the absence of CYP3A results in non-CYP mediated metabolism or metabolism by other CYP isoforms.
基金The project supported by National Natural Science Foundation of China(81301908)the Science and Technology Commission of Shanghai Municipality(15140904700,13ZR1412600 and 14DZ2270100)
文摘OBJECTIVE Cytochrome P450(CYP)2J2 is highly expressed in many kinds of human tumors and promotes tumor cell growth via regulating the metabolism of arachidonic acids.The purposes of this study were toidentify the new inhibitor of CYP2J2 from natural compounds and evaluate its potential to inhibit hepatoma carcinoma cells.METHODS Total fifty natural products were screened for the inhibitory potency against the activity of CYP2J2-mediated astemizole O-demethylation via LCMS/MS analysis.Enzyme kinetic and molecular docking studies were also carried out.RESULTS Our data found that plumbagin potently inhibited CYP2J2 with IC50value at 3.42,3.37 and 1.17μmol·L-1in rat liver microsomes,human liver microsomes(HLMs)and recombinant CYP2J2(rC YP2J2),respectively.Further enzyme kinetic studies showed that plumbagin was a mixed-type inhibitor of CYP2J2 in HLMs and r CYP2J2 with Kivalues of 1.88and 0.92μmol·L-1,respectively.Docking data presented that plumbagin interacted with CYP2J2 mainly through GLU222 and ALA223,which were crucial residues for substrates binding.At the same time,plumbagin showed cytotoxicity effects on hepatic carcinoma cell lines,such as HepG 2 and SMMC-7721,with IC50values at 11.55±1.06and(13.15±1.11)μmol·L-1,respectively.CONCLUSION These results indicated that plumbagin was a potent CYP2J2 inhibitor and potential anticancer agent.Further studies are needed to cover the mechanism of its antitumor activity.
