scholarly journals Advanced oxidation protein products downregulate CYP1A2 and CYP3A4 expression and activity via the NF-κB-mediated signaling pathway in vitro and in vivo

2021 ◽  
Author(s):  
Tianrong Xun ◽  
Zhufen Lin ◽  
Xiaokang Wang ◽  
Xia Zhan ◽  
Haixing Feng ◽  
...  
Keyword(s):  
Liver Microsomes ◽  
Advanced Oxidation ◽  
Uremic Toxins ◽  
Uremic Toxin ◽  
Dependent Manner ◽  
Advanced Oxidation Protein Products ◽  
Protein Levels ◽  
Cyp3a4 Expression

AbstractUremic toxin accumulation is one possible reason for alterations in hepatic drug metabolism in patients with chronic kidney disease (CKD). However, the types of uremic toxins and underlying mechanisms are poorly understood. In this study, we report the role of advanced oxidation protein products (AOPPs), a modified protein uremic toxin, in the downregulation of cytochromes P450 1A2 (CYP1A2) and P450 3A4 (CYP3A4) expression levels and activities. We found that AOPP accumulation in plasma in a rat CKD model was associated with decreased protein levels of CYP1A2 and CYP3A4. CYP1A2 and CYP3A4 metabolites (acetaminophen and 6β-hydroxytestosterone, respectively,) in liver microsomes were also significantly decreased. In human hepatocytes, AOPPs significantly decreased CYP1A2 and CYP3A4 protein levels in a dose- and time-dependent manner and downregulated their activities; however, bovine serum albumin (BSA), a synthetic precursor of AOPPs, had no effect on these parameters. The effect of AOPPs was associated with upregulation of p-IKKα/β, p-IκBα, p-NF-κB, and inflammatory cytokines protein levels and increases in p-IKKα/β/IKKα, p-IκBα/IκBα, and p-NF-κB/NF-κB phosphorylation ratios. Further, NF-kB pathway inhibitors BAY-117082 and PDTC abolished the downregulatory effects of AOPPs. These findings suggest that AOPPs downregulate CYP1A2 and CYP3A4 expression and activities by increasing inflammatory cytokine production and stimulating NF-κB-mediated signaling. Protein uremic toxins, such as AOPPs, may modify the nonrenal clearance of drugs in patients with CKD by influencing metabolic enzymes.

scholarly journals Mn Inhibits GSH Synthesis via Downregulation of Neuronal EAAC1 and Astrocytic xCT to Cause Oxidative Damage in the Striatum of Mice

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xinxin Yang ◽  
Haibo Yang ◽  
Fengdi Wu ◽  
Zhipeng Qi ◽  
Jiashuo Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Dependent Manner ◽  
Protein Levels ◽  
Key Factor ◽  
Protein Sulfhydryl ◽  
Mrna And Protein Expression ◽  
The Brain

Excessive manganese (Mn) can accumulate in the striatum of the brain following overexposure. Oxidative stress is a well-recognized mechanism in Mn-induced neurotoxicity. It has been proven that glutathione (GSH) depletion is a key factor in oxidative damage during Mn exposure. However, no study has focused on the dysfunction of GSH synthesis-induced oxidative stress in the brain during Mn exposure. The objective of the present study was to explore the mechanism of Mn disruption of GSH synthesis via EAAC1 and xCT in vitro and in vivo. Primary neurons and astrocytes were cultured and treated with different doses of Mn to observe the state of cells and levels of GSH and reactive oxygen species (ROS) and measure mRNA and protein expression of EAAC1 and xCT. Mice were randomly divided into seven groups, which received saline, 12.5, 25, and 50 mg/kg MnCl2, 500 mg/kg AAH (EAAC1 inhibitor) + 50 mg/kg MnCl2, 75 mg/kg SSZ (xCT inhibitor) + 50 mg/kg MnCl2, and 100 mg/kg NAC (GSH rescuer) + 50 mg/kg MnCl2 once daily for two weeks. Then, levels of EAAC1, xCT, ROS, GSH, malondialdehyde (MDA), protein sulfhydryl, carbonyl, 8-hydroxy-2-deoxyguanosine (8-OHdG), and morphological and ultrastructural features in the striatum of mice were measured. Mn reduced protein levels, mRNA expression, and immunofluorescence intensity of EAAC1 and xCT. Mn also decreased the level of GSH, sulfhydryl, and increased ROS, MDA, 8-OHdG, and carbonyl in a dose-dependent manner. Injury-related pathological and ultrastructure changes in the striatum of mice were significantly present. In conclusion, excessive exposure to Mn disrupts GSH synthesis through inhibition of EAAC1 and xCT to trigger oxidative damage in the striatum.

scholarly journals In vitro inhibitory effect of obtusofolin on the activity of CYP3A4, 2C9, and 2E1

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Liu ◽  
Ping Chen ◽  
Xiaojun Du ◽  
Junxia Sun ◽  
Shasha Han
Keyword(s):  
Human Liver ◽  
Competitive Inhibition ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cytochrome P450 Enzymes ◽  
Inhibition Model ◽  
Dose Dependent

Abstract Background Obtusofolin is the major active ingredient of Catsia tora L., which possesses the activity of improving eyesight and protecting the optic nerve. Investigation on the interaction of obtusofolin with cytochrome P450 enzymes (CYP450s) could provide a reference for the clinical application of obtusofolin. Methods The effect of obtusofolin on the activity of CYP450s was investigated in the presence of 100 μM obtusofolin in pooled human liver microsomes (HLMs) and fitted with the Lineweaver–Burk plots to characterize the specific inhibition model and kinetic parameters. Results Obtusofolin was found to significantly inhibited the activity of CYP3A4, 2C9, and 2E1. In the presence of 0, 2.5, 5, 10, 25, 50, and 100 μM obtusofolin, the inhibition of these CYP450s showed a dose-dependent manner with the IC50 values of 17.1 ± 0.25, 10.8 ± 0.13, and 15.5 ± 0.16 μM, respectively. The inhibition of CYP3A4 was best fitted with the non-competitive inhibition model with the Ki value of 8.82 μM. While the inhibition of CYP2C9 and 2E1 was competitive with the Ki values of 5.54 and 7.79 μM, respectively. After incubating for 0, 5, 10, 15, and 30 min, the inhibition of CYP3A4 was revealed to be time-dependent with the KI value of 4.87 μM− 1 and the Kinact value of 0.0515 min− 1. Conclusions The in vitro inhibitory effect of obtusofolin implying the potential drug-drug interaction between obtusofolin and corresponding substrates, which needs further in vivo validations.

scholarly journals A Bifunctional Adsorber Particle for the Removal of Hydrophobic Uremic Toxins from Whole Blood of Renal Failure Patients

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 389 ◽  
Author(s):  
Marieke Sternkopf ◽  
Sven Thoröe-Boveleth ◽  
Tobias Beck ◽  
Kirsten Oleschko ◽  
Ansgar Erlenkötter ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Binding Affinity ◽  
Whole Blood ◽  
Uremic Toxins ◽  
In Vivo Studies ◽  
Uremic Toxin ◽  
High Binding ◽  
High Binding Affinity

Hydrophobic uremic toxins accumulate in patients with chronic kidney disease, contributing to a highly increased cardiovascular risk. The clearance of these uremic toxins using current hemodialysis techniques is limited due to their hydrophobicity and their high binding affinity to plasma proteins. Adsorber techniques may be an appropriate alternative to increase hydrophobic uremic toxin removal. We developed an extracorporeal, whole-blood bifunctional adsorber particle consisting of a porous, activated charcoal core with a hydrophilic polyvinylpyrrolidone surface coating. The adsorption capacity was quantified using analytical chromatography after perfusion of the particles with an albumin solution or blood, each containing mixtures of hydrophobic uremic toxins. A time-dependent increase in hydrophobic uremic toxin adsorption was depicted and all toxins showed a high binding affinity to the adsorber particles. Further, the particle showed a sufficient hemocompatibility without significant effects on complement component 5a, thrombin-antithrombin III complex, or thrombocyte concentration in blood in vitro, although leukocyte counts were slightly reduced. In conclusion, the bifunctional adsorber particle with cross-linked polyvinylpyrrolidone coating showed a high adsorption capacity without adverse effects on hemocompatibility in vitro. Thus, it may be an interesting candidate for further in vivo studies with the aim to increase the efficiency of conventional dialysis techniques.

scholarly journals Prebiotics Inhibit Proteolysis by Gut Bacteria in a Host Diet-Dependent Manner: a Three-Stage Continuous In Vitro Gut Model Experiment

2020 ◽  
Vol 86 (10) ◽  
Author(s):  
Xuedan Wang ◽  
Glenn R. Gibson ◽  
Manuela Sailer ◽  
Stephan Theis ◽  
Robert A. Rastall
Keyword(s):  
Dietary Protein ◽  
Health Benefit ◽  
Distal Colon ◽  
High Protein ◽  
Model Systems ◽  
Dependent Manner ◽  
Bacterial Fermentation ◽  
Protein Levels

ABSTRACT Dietary protein residue can result in microbial generation of various toxic metabolites in the gut, such as ammonia. A prebiotic is “a substrate that is selectively utilised by host microorganisms conferring a health benefit” (G. R. Gibson, R. Hutkins, M. E. Sanders, S. L. Prescott, et al., Nat Rev Gastroenterol Hepatol 14:491–502, 2017, https://doi.org/10.1038/nrgastro.2017.75). Prebiotics are carbohydrates that may have the potential to reverse the harmful effects of gut bacterial protein fermentation. Three-stage continuous colonic model systems were inoculated with fecal samples from omnivore and vegetarian volunteers. Casein (equivalent to 105 g protein consumption per day) was used within the systems as a protein source. Two different doses of inulin-type fructans (Synergy1) were later added (equivalent to 10 g per day in vivo and 15 g per day) to assess whether this influenced protein fermentation. Bacteria were enumerated by fluorescence in situ hybridization with flow cytometry. Metabolites from bacterial fermentation (short-chain fatty acid [SCFA], ammonia, phenol, indole, and p-cresol) were monitored to further analyze proteolysis and the prebiotic effect. A significantly higher number of bifidobacteria was observed with the addition of inulin together with reduction of Desulfovibrio spp. Furthermore, metabolites from protein fermentation, such as branched-chain fatty acids (BCFA) and ammonia, were significantly lowered with Synergy1. Production of p-cresol varied among donors, as we recognized four high producing models and two low producing models. Prebiotic addition reduced its production only in vegetarian high p-cresol producers. IMPORTANCE Dietary protein levels are generally higher in Western populations than in the world average. We challenged three-stage continuous colonic model systems containing high protein levels and confirmed the production of potentially harmful metabolites from proteolysis, especially replicates of the transverse and distal colon. Fermentations of proteins with a prebiotic supplementation resulted in a change in the human gut microbiota and inhibited the production of some proteolytic metabolites. Moreover, we observed both bacterial and metabolic differences between fecal bacteria from omnivore donors and vegetarian donors. Proteins with prebiotic supplementation showed higher Bacteroides spp. and inhibited Clostridium cluster IX in omnivore models, while in vegetarian modes, Clostridium cluster IX was higher and Bacteroides spp. lower with high protein plus prebiotic supplementation. Synergy1 addition inhibited p-cresol production in vegetarian high p-cresol-producing models while the inhibitory effect was not seen in omnivore models.

Acetylation of GATA-1 Is Required for Chromatin Occupancy.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1179-1179 ◽  
Author(s):  
Janine M. Lamonica ◽  
Christopher R. Vakoc ◽  
Gerd A. Blobel
Keyword(s):  
Protein Interactions ◽  
Dependent Manner ◽  
Protein Levels ◽  
Defective Mutant ◽  
Cellular Target ◽  
Stable Association ◽  
Peptide Affinity

Abstract All three hematopoietic GATA transcription factors GATA-1, GATA-2, and GATA-3 are acetylated, although the in vivo role of this modification remains unclear. It has been proposed that acetylation of GATA-1 increases its affinity for DNA in vitro, although this finding has not been observed by others. To study the role of GATA-1 acetylation, we examined the functions of an acetylation-defective mutant of GATA-1 in maturing erythroid cells. We found that removal of the acetylation sites in GATA-1 largely abrogates its biological activity but does not impair its nuclear localization, steady state protein levels, or its ability to bind naked GATA elements in vitro. However, chromatin immunoprecipitation (ChIP) experiments revealed that mutant GATA-1 was dramatically impaired in binding to its cellular target sites in vivo, including genes that are normally activated (α- and β-globin, EKLF, FOG-1, Band3, and AHSP) and repressed (GATA-2 and c-kit) by GATA-1. Together, these results suggest that acetylation is required for GATA-1 chromatin occupancy. These findings point to a novel function for transcription factor acetylation, perhaps by facilitating protein interactions required for stable association with chromatin templates in vivo. To identify proteins that interact with acetylated GATA-1, we performed peptide affinity chromatography using acetylated GATA-1 peptides. Using this technique coupled with mass spectrometry, several proteins that bind to GATA-1 peptides in an acetylation-dependent manner were identified. The identified proteins contain known acetyl-lysine binding modules (bromodomains) consistent with their binding properties. The in vivo role of these proteins with regard to GATA-1 function is being examined and will be discussed.

scholarly journals Vasculopathy in the setting of cardiorenal syndrome: roles of protein-bound uremic toxins

2017 ◽  
Vol 313 (1) ◽  
pp. H1-H13 ◽  
Author(s):  
Jingbin Guo ◽  
Lu Lu ◽  
Yue Hua ◽  
Kevin Huang ◽  
Ian Wang ◽  
...  
Keyword(s):  
Vascular System ◽  
Current Knowledge ◽  
Cardiorenal Syndrome ◽  
Left Ventricular ◽  
Uremic Toxins ◽  
Uremic Toxin ◽  
Contributing Factors ◽  
Clinical Observations

Chronic kidney disease (CKD) often leads to and accelerates the progression of cardiovascular disease (CVD), while CVD also causes kidney dysfunction. This bidirectional interaction leads to the development of a complex syndrome known as cardiorenal syndrome (CRS). CRS not only involves both the heart and the kidney but also the vascular system through a vast array of contributing factors. In addition to hemodynamic, neurohormonal, mechanical, and biochemical factors, nondialyzable protein-bound uremic toxins (PBUTs) are also key contributing factors that have been demonstrated through in vitro, in vivo, and clinical observations. PBUTs are ineffectively removed by hemodialysis because their complexes with albumins are larger than the pores of the dialysis membranes. PBUTs such as indoxyl sulfate and p-cresyl sulfate are key determinate and predictive factors for the progression of CVD in CKD patients. In CRS, both vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) exhibit significant dysfunction that is associated with the progression of CVD. PBUTs influence proliferation, calcification, senescence, migration, inflammation, and oxidative stress in VSMCs and ECs through various mechanisms. These pathological changes lead to arterial remodeling, stiffness, and atherosclerosis and thus reduce heart perfusion and impair left ventricular function, aggravating CRS. There is limited literature about the effect of PBUT on the vascular system and their contribution to CRS. This review summarizes current knowledge on how PBUTs influence vasculature, clarifies the relationship between uremic toxin-related vascular disease and CRS, and highlights the potential therapeutic strategies of uremic vasculopathy in the setting of CRS.

scholarly journals Glycyrrhetinic acid might increase the nephrotoxicity of bakuchiol by inhibiting cytochrome P450 isoenzymes

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2723 ◽  
Author(s):  
Aifang Li ◽  
Nana Ma ◽  
Zijing Zhao ◽  
Mei Yuan ◽  
Hua Li ◽  
...  
Keyword(s):  
Oral Dose ◽  
Single Oral Dose ◽  
Liver Microsomes ◽  
Glycyrrhetinic Acid ◽  
Internal Exposure ◽  
Functional Markers ◽  
Dependent Manner ◽  
Cyp Isoforms

BackgroundLicorice, a popular traditional Chinese medicine (TCM), is widely used to moderate the effects (detoxification) of other herbs in TCM and often combined withFructus Psoraleae. However, the classical TCM book states thatFructus Psoraleaeis incompatible with licorice; the mechanism underlying this incompatibility has not been identified. Glycyrrhetinic acid (GA), the active metabolite of licorice, may increase the toxicity of bakuchiol (BAK), the main chemical ingredient inPsoralea corylifolia, by inhibiting its detoxification enzymes CYP450s.MethodsThe effect of concomitant GA administration on BAK-induced nephrotoxicity was investigated, and the metabolic interaction between BAK and GA was further studied in vitro and in vivo. The cytotoxicity was assessed using an MTT assay in a co-culture model of HK-2 cell and human liver microsomes (HLMs). The effect of GA on the metabolism of BAK, and on the activities of CYP isoforms were investigated in HLMs. The toxicokinetics and tissue exposure of BAK as well as the renal and hepatic functional markers were measured after the administration of a single oral dose in rats.ResultsIn vitrostudies showed that the metabolic detoxification of BAK was significantly reduced by GA, and BAK was toxic to HK-2 cells, as indicated by 25∼40% decreases in viability when combined with GA. Further investigation revealed that GA significantly inhibited the metabolism of BAK in HLMs in a dose-dependent manner. GA strongly inhibits CYP3A4 and weakly inhibits CYP2C9 and CYP1A2; these CYP isoforms are involved in the metabolism of BAK.In vivoexperiment found that a single oral dose of BAK combined with GA or in the presence of 1-aminobenzotriazole (ABT), altered the toxicokinetics of BAK in rats, increased the internal exposure, suppressed the elimination of BAK prototype, and therefore may have enhanced the renal toxicity.ConclusionThe present study demonstrated that GA inhibits CYP isoforms and subsequently may increase the nephrotoxicity of BAK, which underlie one of the possible mechanisms responsible for the incompatibility of Licorice withFructus Psoraleae.

scholarly journals Herb-Drug Interaction Between Xiyanping Injection and Lopinavir/Ritonavir, Two Agents Used in COVID-19 Pharmacotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Linhu Ye ◽  
Lei Cheng ◽  
Yan Deng ◽  
Hong Liu ◽  
Xinyu Wu ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Liver Microsomes ◽  
Pharmacokinetic Parameters ◽  
Dependent Manner ◽  
Epidemic Outbreak ◽  
Global Epidemic ◽  
Incubation Study ◽  
Oral Pharmacokinetics

The global epidemic outbreak of the coronavirus disease 2019 (COVID-19), which exhibits high infectivity, resulted in thousands of deaths due to the lack of specific drugs. Certain traditional Chinese medicines (TCMs), such as Xiyanping injection (XYPI), have exhibited remarkable benefits against COVID-19. Although TCM combined with Western medicine is considered an effective approach for the treatment of COVID-19, the combination may result in potential herb-drug interactions in the clinical setting. The present study aims to verify the effect of XYPI on the oral pharmacokinetics of lopinavir (LPV)/ritonavir (RTV) using an in vivo rat model and in vitro incubation model of human liver microsomes. After being pretreated with an intravenous dose of XYPI (52.5 mg/kg) for one day and for seven consecutive days, the rats received an oral dose of LPV/RTV (42:10.5 mg/kg). Except for the t1/2 of LPV is significantly prolonged from 4.66 to 7.18 h (p < 0.05) after seven consecutive days pretreatment, the pretreatment resulted in only a slight change in the other pharmacokinetic parameters of LPV. However, the pharmacokinetic parameters of RTV were significantly changed after pretreatment with XYPI, particularly in treatment for seven consecutive days, the AUC0-∞ of RTV was significantly shifted from 0.69 to 2.72 h μg/mL (p < 0.05) and the CL exhibited a tendency to decrease from 2.71 L/h to 0.94 L/h (p < 0.05), and the t1/2 of RTV prolonged from 3.70 to 5.51 h (p < 0.05), in comparison with the corresponding parameters in untreated rats. After administration of XYPI, the expression of Cyp3a1 protein was no significant changed in rats. The in vitro incubation study showed XYPI noncompetitively inhibited human CYP3A4 with an apparent Ki value of 0.54 mg/ml in a time-dependent manner. Our study demonstrated that XYPI affects the pharmacokinetics of LPV/RTV by inhibiting CYP3A4 activity. On the basis of this data, patients and clinicians can take precautions to avoid potential drug-interaction risks in COVID-19 treatment.

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