Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic strok...Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury.展开更多
Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expr...Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expression and enzyme activity of CYPs are variable between individuals,which subsequently leads to different patterns of susceptibility to carcinogenesis by genotoxic xenobiotics,as well as differences in the efficacy and toxicity of clinically used drugs.This research aimed to examine the presence of the CYP2B6*9 polymorphism and its possible association with the incidence of B-CLL in Egyptian patients,as well as the clinical outcome after receiving cyclophosphamide chemotherapy.DNA was isolated from whole blood samples of 100 de novo B-CLL cases and also from 100 sex-and age-matched healthy individuals.The presence of the CYP2B6*9(G516T)polymorphism was examined by PCR-based allele specific amplification(ASA).Patients were further indicated for receiving chemotherapy,and then they were followed up.The CYP2B6*9 variant indicated a statistically significant higher risk of B-CLL under different genetic models,comprising allelic(T-allele vs.G-allele,OR=4.8,p<0.001)and dominant(GT+TT vs.GG,OR=5.4,p<0.001)models.Following cyclophosphamide chemotherapy,we found that the patients with variant genotypes(GT+TT)were less likely to achieve remission compared to those with the wild-type genotype(GG),with a response percentage of(37.5%vs.83%,respectively).In conclusion,our findings showed that the CYP2B6*9(G516T)polymorphism is associated with B-CLL susceptibility among Egyptian patients.This variant greatly affected the clinical outcome and can serve as a good therapeutic marker in predicting response to cyclophosphamide treatment.展开更多
The in vitro inhibitory effects of chrysophanol and physcion on CYP1B1 were explored,utilizing ethoxyresorufin as the substrate.The inhibition kinetics of CYP1B1 by these compounds were assessed with escalating doses ...The in vitro inhibitory effects of chrysophanol and physcion on CYP1B1 were explored,utilizing ethoxyresorufin as the substrate.The inhibition kinetics of CYP1B1 by these compounds were assessed with escalating doses of ethoxyresorufin.Both chrysophanol(IC_(50)(0.47±0.01)μmol·L^(-1))and physcion(IC_(50)(0.35±0.02)μmol·L^(-1))significantly reduce the catalytic efficiency of CYP1B1.The V_(max)and K_(m)values are determined to be(51.9912±10.0547)pmol·μg^(-1)(protein)·min^(-1) and(0.9663±0.2987)nmol·L^(-1)for chrysophanol,and(45.4227±1.9978)pmol·μg^(-1)(protein)·min^(-1) and(0.4367±0.0386)nmol·L^(-1)for physcion,respectively.Kinetic analysis reveals that chrysophanol and physcion exert mixed inhibitory effects on CYP1B1.This mixed inhibition is primarily characterized by the compounds’ability to competitively bind to the active sites of CYP1B1,as well as potentially through non-competitive mechanisms,thereby reducing the enzyme’s catalytic efficiency.Molecular docking studies are conducted to elucidate the interaction between anthraquinone derivatives and CYP1B1,indicating that these compounds may inhibit CYP1B1 activity by binding to their active sites.The demonstrated capacity of chrysophanol and physcion to inhibit CYP1B1 enzymatic function unveils a potential anticancer mechanism,advancing our comprehension of how the structure of anthraquinone derivatives correlates with CYP1B1 inhibition and paving the way for developing innovative cancer treatments.展开更多
基金supported by the National Natural Science Foundation of China,No.81771250(to XC)the Natural Science Foundation of Fujian Province,Nos.2020J011059(to XC),2020R1011004(to YW),2021J01374(to XZ)+1 种基金Medical Innovation Project of Fujian Province,No.2021 CXB002(to XC)Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare(to XC)。
文摘Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain barrier.However,the potential links between them following ischemic stroke remain largely unknown.The present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin pathway.Meanwhile,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia rats.Moreove r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and migration.Overexpression ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,respectively.In addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/reoxygenation.Thus,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury.
文摘Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expression and enzyme activity of CYPs are variable between individuals,which subsequently leads to different patterns of susceptibility to carcinogenesis by genotoxic xenobiotics,as well as differences in the efficacy and toxicity of clinically used drugs.This research aimed to examine the presence of the CYP2B6*9 polymorphism and its possible association with the incidence of B-CLL in Egyptian patients,as well as the clinical outcome after receiving cyclophosphamide chemotherapy.DNA was isolated from whole blood samples of 100 de novo B-CLL cases and also from 100 sex-and age-matched healthy individuals.The presence of the CYP2B6*9(G516T)polymorphism was examined by PCR-based allele specific amplification(ASA).Patients were further indicated for receiving chemotherapy,and then they were followed up.The CYP2B6*9 variant indicated a statistically significant higher risk of B-CLL under different genetic models,comprising allelic(T-allele vs.G-allele,OR=4.8,p<0.001)and dominant(GT+TT vs.GG,OR=5.4,p<0.001)models.Following cyclophosphamide chemotherapy,we found that the patients with variant genotypes(GT+TT)were less likely to achieve remission compared to those with the wild-type genotype(GG),with a response percentage of(37.5%vs.83%,respectively).In conclusion,our findings showed that the CYP2B6*9(G516T)polymorphism is associated with B-CLL susceptibility among Egyptian patients.This variant greatly affected the clinical outcome and can serve as a good therapeutic marker in predicting response to cyclophosphamide treatment.
基金Supported by the Heilongjiang Administration of Traditional Chinese Medicine(ZHY2020-078)the Education Department of Heilongjiang Province(SJGY20210830)。
文摘The in vitro inhibitory effects of chrysophanol and physcion on CYP1B1 were explored,utilizing ethoxyresorufin as the substrate.The inhibition kinetics of CYP1B1 by these compounds were assessed with escalating doses of ethoxyresorufin.Both chrysophanol(IC_(50)(0.47±0.01)μmol·L^(-1))and physcion(IC_(50)(0.35±0.02)μmol·L^(-1))significantly reduce the catalytic efficiency of CYP1B1.The V_(max)and K_(m)values are determined to be(51.9912±10.0547)pmol·μg^(-1)(protein)·min^(-1) and(0.9663±0.2987)nmol·L^(-1)for chrysophanol,and(45.4227±1.9978)pmol·μg^(-1)(protein)·min^(-1) and(0.4367±0.0386)nmol·L^(-1)for physcion,respectively.Kinetic analysis reveals that chrysophanol and physcion exert mixed inhibitory effects on CYP1B1.This mixed inhibition is primarily characterized by the compounds’ability to competitively bind to the active sites of CYP1B1,as well as potentially through non-competitive mechanisms,thereby reducing the enzyme’s catalytic efficiency.Molecular docking studies are conducted to elucidate the interaction between anthraquinone derivatives and CYP1B1,indicating that these compounds may inhibit CYP1B1 activity by binding to their active sites.The demonstrated capacity of chrysophanol and physcion to inhibit CYP1B1 enzymatic function unveils a potential anticancer mechanism,advancing our comprehension of how the structure of anthraquinone derivatives correlates with CYP1B1 inhibition and paving the way for developing innovative cancer treatments.
