CYP2D6 Expression Research Articles

The influence of concentration of micro-rna hsa-mir-370-3p and CYP2D6*4 on equilibrium concentration of mirtazapine in patients with major depressive disorder

IntroductionMirtazapine is commonly prescribed to patients diagnosed with major depressive disorder.Some proportion of these patients do not show adequate response to treatment regimen containing mirtazapine, whereas many of them experience dose-dependent adverse drug reactions.ObjectivesThe objective of our study was to investigate the influence of 1846G>A polymorphism of the CYP2D6 gene on the concentration/dose indicator of mirtazapine, using findings on enzymatic activity of CYP2D6 and on CYP2D6 expression level obtained by measuring the hsa-miR-370-3p plasma levels in patients suffering from recurrent depressive disorder.MethodsOur study included 192 patients with major depressive disorder. Treatment efficacy was evaluated using the international psychometric scales. For genotyping and estimation of the microRNA plasma levels we performed the real-time polymerase chain reaction. The activity of CYP2D6 was assessed with HPLC-MS/MS method by the content of the endogenous substrate of given isoenzyme and its metabolite in urine. Therapeutic drug monitoring has been performed using HPLC-MS/MS.ResultsWe didn’t reveal a statistical significance for concentration/dose indicator of mirtazapine in patients with different genotypes: (GG) 0.229 [0.158; 0.468] and (GA) 0.290 [0.174; 0.526], p = 0.196). We revealed the relationship between the CYP2D6 enzymatic activity and the hsa-miR-370-3p plasma concentration: rs = -0.32, p < 0.001. At the same time, correlation analysis revealed a statistically significant relationship between the mirtazapine concentration and the hsa-miR-370-3p plasma concentration: rs = 0.31, p<0.001.ConclusionsThus, the effect of genetic polymorphism of the CYP2D6 gene on the efficacy and safety profiles of mirtazapine was demonstrated in a group of 192 patients with recurrent depressive disorder.Conflict of interestAuthors do not have any conflict of interests.

CYP2D6 rs35742686 and rs3892097 Gene Polymorphisms and Childhood Acute Lymphoblastic Leukemia: Relation to Disease Susceptibility in Kashmiri Children.

CYP2D6 is one of the most widely investigated CYPs in relation to gene polymorphism. This study analyzed the relationship between CYP2D6 rs35742686 and rs3892097 single-nucleotide polymorphisms (SNPs) and potential risk factors in the development of acute lymphoblastic leukemia (ALL) in Kashmiri children. We recruited 300 cases and 600 controls for genotyping and risk factors assessment. Genotypes of rs35742686 and rs3892097 were analyzed by polymerase chain reaction-restriction fragment length polymorphism method. CYP2D6 expression analysis was done by quantitative reverse transcription polymerase chain reaction in ALL cases. Conditional logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI). High risk of ALL was observed in cases who carried the mutant genotypes of rs35742686 (OR = 18.15; 95% CI = 4.13-79.66, p < 0.0001) or rs3892097 (OR = 24.06; 95% CI = 10.23-56.53, p < 0.0001). Significant interaction was observed between rs35742686 and rs3892097 SNPs (P interaction = 0.001). The risk associated with the variant genotypes of rs35742686 and rs3892097 was retained in the cases whose fathers were smokers or had maternal X-ray exposure ( p < 0.001). Relative messenger ribonucleic acid expression across genotypes was significantly decreased in cases carrying rs35742686 3 (*3/*3) ( n -fold = 0.37 ± 0.156, p < 0.0079) and rs3892097 SNPs (*4/*4) ( n -fold = 0.02 ± 0.0075, p < 0.0001) suggesting these two events are independent in ALL cases. The study concluded that rs35742686 and rs3892097 SNPs are significantly associated with ALL risk in Kashmiri children.

Dimethoxycurcumin reduces proliferation and induces apoptosis in renal tumor cells more efficiently than demethoxycurcumin and curcumin

Curcumin (Cur), is a pigment with antiproliferative activity but has some pharmacokinetic limitations, which led researchers to look for more effective structure analogs. This work investigated the effects of Cur and compared them with the two analogs, demethoxycurcumin (DeMC) and dimethoxycurcumin (DiMC), to elucidate their mechanisms of action. The cytotoxic, antiproliferative, and genotoxic effects these compounds were correlated based on gene expression analysis in the human renal adenocarcinoma cells (786-O). Cur decreased CYP2D6 expression and exhibited cytotoxic effects, such as inducing monopolar spindle formation and mitotic arrest mediated by the increase in CDKN1A (p21) mRNA. This dysregulation induced cell death through a caspase-independent pathway but was mediated by decrease in MTOR and BCL2 mRNA expression, suggesting that apoptosis occurred by autophagy. DeMC and DiMC had similar effects in that they induced monopolar spindle and mitotic arrest, were genotoxic, and activated GADD45A, an important molecule in repair mechanisms, and CDKN1A. However, the induction of apoptosis by DeMC was delayed and regulated by the decrease of antiapoptotic mRNA BCL.XL and subsequent activation of caspase 9 and caspase 3/7. DiMC treatment increased the expression of CYP1A2, CYP2C19, and CYP3A4 and exhibited higher cytotoxicity compared with other compounds. It induced apoptosis by increasing mRNA expression of BBC3, MYC, and CASP7 and activation of caspase 9 and caspase 3/7. These data revealed that different gene regulation processes are involved in cell death induced by Cur, DeMC, and DiMC. All three can be considered as promising chemotherapy candidates, with DiMC showing the greatest potency.

CYP2D6 EXPRESSION IS CUMULATIVELY UP REGULATED IN MULTIDRUG TREATED HEPATOMA CELLS: A PREDECTIVE PHARMACOGENETICS IN VITRO MODEL

Cancer and many other diseases require concomitant treatments with combinations of many drugs.Debrisoquine 4-Hydroxylayase (CYP2D6) is microsomal enzyme involved in phase I metabolism of a long list of drugs. Also, it is a marker of inter-individual variability in drug responsiveness. This study was designated to explore the regulation of CYP2D6 in hepatoma cells exposed to combinations of anticancer and epigenetic modifying drugs. HepG2 cell were treated with combinations of anticancer drug (Taxol), glucocorticoid (dexamethasone, DEX) and epigenetic modifiers: Trichostatin A (TSA) and 5 aza-deoxycytidine (5 aza-dC). The expression of CYP2D6 was determined by quantitative RT-PCR and compared to other CYPs and the corresponding cumulative apoptotic effect was determined by flow cytometry. The obtained results revealed thatUnder non-induced conditions, CYP2D6 was stably expressed and sub micromolar concentration of DEX mildly increased its expression. Individual treatments as DEX, Taxol, TSA and 5-azadC induced 2-6-fold increase in the transcript level, where the TSA was the most potent inducer. Combinations of 2 drugs as (Taxol+DEX), (Taxol+TSA), (Taxol+5-aza-dC) and (TSA+5-aza-dC). led to 3-10-fold increase (average 6.2), whereas cocktails of 3 drugs as (Taxol+DEX+5-aza-dC), (Taxol+DEX+TSA) and (Taxol+TSA+5-aza-dC) led to further up regulatory effect (11-27-fold). The highest increment (28-fold) was observed when cells were treated with 4 drugs as (Taxol+TSA+5-aza-dC+DEX). The progressive induction of CYP2D6 was correlated with the cumulative apoptotic effect (r=0.79). Conclusively, the data suggest, for the first time, that anticancer, epigenetic regulatory factors and dexamethasone cumulatively enhanced the baseline expression of CYP2D6

Effects of Saikosaponin D on CYP1A2 and CYP2D6 in HepaRG Cells.

BackgroundBupleurum is one of the most important traditional Chinese medicines and an ingredient in many compound preparations. It is widely used together with other drugs in clinical practice, and thus there is great potential for drug–drug interactions. Saikosaponin D (SsD) is a major bioactive triterpenoid saponin extracted from Bupleurum with anti-inflammatory, anticancer, antioxidative, and antihepatic fibrosis effects. Effects of the main components of Bupleurum on cytochromes P450 (CYPs) need to be clarified in the clinical application of combination therapies of formulations containing SsD or Bupleurum.PurposeThis study aimed to investigate the effects of SsD on the CYP1A2 and CYP2D6 mRNAs, protein expression, and relative enzyme activities in HepaRG cells.MethodsHepaRG cells were cultured with SsD at concentrations of 0.5, 1, 5 and 10 μM for 72 hours. mRNA and protein expression of CYP1A2 and CYP2D6 were analyzed with real-time PCR and Western blot analysis. Relative enzyme activities were analyzed with HPLC based on consumption of the specific probe substrate.ResultsSsD significantly induced expression of mRNA and increased relative activity of CYP1A2 in HepaRG cells after the cells had been treated with SsD at concentrations of 1, 5 and 10 μM. SsD also induced protein expression of CYP1A2 at concentrations of 5 and 10 μM. SsD exhibited an inductive effect on CYP2D6 mRNA and protein expression, while increasing the relative activity of CYP2D6 at concentrations of 5 and 10 μM.ConclusionThis study is the first to investigate the effect of SsD on CYP1A2 and CYP2D6 in HepaRG cells, and the results may provide some useful information on potential drug–drug interactions related to clinical preparations containing SsD or Bupleurum.

Human CYP2D6 in the Brain Is Protective Against Harmine-Induced Neurotoxicity: Evidence from Humanized CYP2D6 Transgenic Mice.

CYP2D6 metabolically inactivates several neurotoxins, including beta-carbolines, which are implicated in neurodegenerative diseases. Variation in CYP2D6 within the brain may alter local inactivation of neurotoxic beta-carbolines, thereby influencing neurotoxicity. The beta-carboline harmine, which induces hypothermia and tremor, is metabolized by CYP2D6 to the non-hypothermic/non-tremorgenic harmol. Transgenic mice (TG), expressing human CYP2D6 in addition to their endogenous mouse CYP2D, experience less harmine-induced hypothermia and tremor compared with wild-type mice (WT). We first sought to elucidate the role of CYP2D in general within the brain in harmine-induced hypothermia and tremor severity. A 4-h intracerebroventricular (ICV) pretreatment with the CYP2D inhibitor propranolol increased harmine-induced hypothermia and tremor in TG and increased harmine-induced hypothermia in WT. We next sought to specifically demonstrate that human CYP2D6 expressed in TG brain altered harmine response severity. A 24-h ICV propranolol pretreatment, which selectively and irreversibly inhibits human CYP2D6 in TG brain, increased harmine-induced hypothermia. This 24-h pretreatment had no impact on harmine response in WT, as propranolol is not an irreversible inhibitor of mouse CYP2D in the brain, thus confirming no off-target effects of ICV propranolol pretreatment. Human CYP2D6 activity in TG brain was sufficient in vivo to mitigate harmine-induced neurotoxicity. These findings suggest that human CYP2D6 in the brain is protective against beta-carboline-induced neurotoxicity and that the extensive interindividual variability in CYP2D6 expression in human brain may contribute to variation in susceptibility to certain neurotoxin-associated neurodegenerative disorders.

Cytochrome P450 expression-associated multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD) in HepG2 cells

Purpose: To establish a free fatty acid (FFA)-induced non-alcoholic fatty liver disease (NAFLD) model in HepG2 cells.Methods: HepG2 cells were incubated with 0.1, 1, or 5 mM oleic acid (OA) or palmitic acid (PA) for 24 h. Histological features were examined by oil-red-O staining. Expression levels of metabolic genes (peroxisome proliferator activated receptors α/γ, sterol regulatory element binding proteins 1a/1c, acetyl-CoA carboxylase, acyl-CoA oxidase, and fatty acid synthase), antioxidative genes (catalase and superoxide dismutases 1/2), and cytochrome P450 genes (CYP1A2, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP4A11) were determined by reverse transcription-real time polymerase chain reaction (RT-qPCR).Results: Intracellular lipid storage was observed in cells treated with 1 mM OA or PA while cell shrinkage was present at 5 mM concentrations of both. Expression of all metabolic genes were elevated by 1 mM PA and 5 mM OA and PA. Expression of all antioxidative genes were diminished by 5 mM OA whereas 5 mM PA only reduced superoxide dismutase-2 expression. Expression of CYP1A2, CYP2D6, and CYP3A4 genes were down-regulated by both FFAs, CYP2C19 was induced by PA, while CYP2E1 and CYP4A11 were up-regulated in a concentration-dependent manner.Conclusion: PA was the more potent steatogenic agent in an OA- or PA- induced NAFLD model in HepG2 cells. Increase in intracellular hepatic lipid and expression of metabolic genes, suppression of antioxidative genes, suppression of CYP1A2, CYP2D6, and CYP3A4, and induction of CYP2E1 andCYP4A11 correlated with the multiple-hit pathogenesis model of NAFLD. These findings suggest that PA-induced NAFLD model in HepG2 cells is a suitable in vitro model for studying novel therapeutic approaches to NAFLD treatment.&#x0D; Keywords: NAFLD, Multiple-hit pathogenesis, Free fatty acid, Oleic acid, Palmitic acid

Silybin enhances the blood concentration of brexpiprazole in rats by downregulating expression of CYP3A4 and CYP2D6.

In this study, we investigated the effect of silybin on the pharmacokinetics of brexpiprazole and the underlying mechanism in rats. Two groups of animals received silybin at different doses (50 mg/kg, 25 mg/kg) for 2 weeks, while another group was given vehicle alone. After that, rats were intragastrically administrated with 2 mg/kg brexpiprazole. Then, the tail blood and liver tissues were collected from each rat at different time points. Brexpiprazole in serum was determined by an established UPLC-MS/MS assay. Finally, pharmacokinetic parameters of animals in each group were figured out. The results show that silybin remarkably changed the pharmacokinetic properties of brexpiprazole, especially at the highest dose. AUC and Cmax in the combination group with 50 mg/kg silybin were enhanced approximately 4 times as much as after a single dose of brexpiprazole, p < 0.05. Meanwhile, total liver protein of each sample was extracted, and was subjected to immunoblotting assay for probing CYP3A4 and CYP2D6. Therein CYP3A4 was significantly downregulated compared to the control group. Overall, silybin can increase blood concentration of brexpiprazole in rat by downregulating its main metabolic enzyme CYP3A4. Therefore, the maintenance dose of brexpiprazole should be decreased while co-treating with silybin.

Sex steroid hormones differentially regulate CYP2D in female wild-type and CYP2D6-humanized mice.

The CYP2D subfamily catalyses the metabolism of about 25% of prescribed drugs, including the majority of antidepressants and antipsychotics. At present, the mechanism of hepatic CYP2D regulation remains largely unknown. This study investigated the role of sex steroid hormones in CYP2D regulation. For this purpose, Cyp2d22 expression was assessed in the distinct phases of the estrous cycle of normocyclic C57BL/6J (WT) female mice. Cyp2d22 was also evaluated in ovariectomised WT and CYP2D6-humanized (hCYP2D6) mice that received hormonal supplementation with either 17β-estradiol (E2) and/or progesterone. Comparisons were also made to male mice. The data revealed that hepatic Cyp2d22 mRNA, protein and activity levels were higher at estrous compared to the other phases of the estrous cycle and that ovariectomy repressed Cyp2d22 expression in WT mice. Tamoxifen, an anti-estrogenic compound, also repressed hepatic Cyp2d22 via activation of GH/STAT5b and PI3k/AKT signaling pathways. Both hormones prevented the ovariectomy-mediated Cyp2d22 repression. In case of progesterone, this may be mediated by inhibition of the PI3k/AKT/FOX01 pathway. Notably, Cyp2d22 mRNA levels in WT males were similar to those in ovariectomised mice and were markedly lower compared to females at estrous, a differentiation potentially regulated by the GH/STAT5b pathway. Sex steroid hormone-related alterations in Cyp2d22 mRNA expression were highly correlated with Hnf1a mRNA. Interestingly, fluctuations in Cyp2d22 in hippocampus and cerebellum followed those in liver. In contrast to WT mice, ovariectomy induced hepatic CYP2D6 expression in hCYP2D6 mice, whereas E2 and/or progesterone prevented this induction. Apparently, sex steroid hormones display a significant gender- and species-specific role in the regulation of CYP2D.

`Cadmium induced cardiac inflammation in chicken (Gallus gallus) via modulating cytochrome P450 systems and Nrf2 mediated antioxidant defense

Cadmium (Cd) has been implicated in the pathogenesis of inflammation, myocardial infarction, angiocardiopathy, even cancers. However, it is unknown that Cd-induced cardiac toxicity through Nrf2-mediate antioxidant defense and Cytochrome P450 (CYP450) system. To ascertain the chemoprevention of Cd-induced cardiac toxicity, total 60 newborn chicks were fed with different doses of Cd (0 mg/kg, 35 mg/kg and 70 mg/kg) for a period of 90 days feed administration. Results indicated Cd exposure caused cardiac histopathology changed and functions abnormal, induced NOS activities raised and cardiac inflammation, triggering inflammation factors (IL-6, IL-8, TNF-α, and NF-κb) upregulation and inhabitation of IL-10. Cd caused increase of total CYP450 and Cytochrome b5 (Cyt b5) contents, while erythromycin N-demethylase (ERND), aminopyrin N-demethylase (APND), aniline-4-hydeoxylase (AH) and NADPH-cytochrome c reductase (NCR) indicated opposite situations with different degrees of reduction in microsomes. The mRNA level of most CYP450s isoforms (CYP1A1, CYP1A2, CYP1A5, CYP1B1, CYP2C18, CYP2C45, CYP3A4, CYP3A7 and CYP3A9) were significantly increase but CYP2D6 expression level changed not obvious. Furthermore, Cd treatment caused increased the peroxidation product (MDA) and H2O2 over accumulation, the decreased of T-AOC accompanied by decreased activity of antioxidant enzymes (T-SOD, GST and GPX). Over accumulation of Cd lead to oxidative stress and activated Nrf2 signal pathway through upregulating pivotal target genes (HO-1, NQO1, GCLC, GCLM and SOD). These findings suggested Cd exposure caused cardiotoxicity through CYP450s enzymes homeostasis disturbance and Nrf2-mediated oxidative stress signal pathways defense. These results may provide new evidence on molecular mechanism of Cd-induced cardiac toxicity.

Assessment of the impact of the steady state level of microRNA hsa-miR-370-3p concentration on the efficacy and safety profile of fluvoxamine in patients with depressive disorders disorder comorbid with alcohol use disorders

Fluvoxamine is used in therapy for patients with depressive spectrum disorders comorbid with alcohol addiction. At the same time, a large proportion of such patients do not respond properly to fluvoxamine therapy and many of them show dose-dependent adverse reactions. Previous studies have demonstrated that CYP2D6 participates in the fluvoxamine biotransformation and its activity depends on polymorphism of the encoding gene. The purpose of this study was to evaluate the effect of CYP2D6 genetic polymorphism on the efficacy and safety of fluvoxamine using data on CYP2D6 activity evaluated by the 6M-THBC/pinoline metabolic ratio, as well as data on CYP2D6 expression level obtained by measuring plasma concentration of hsa-miR-370-3p in patients with depressive disorders comorbid with alcohol use disorder. A group of 83 patients with depressive spectrum disorders comorbid with alcohol addiction demonstrated the effect of the 1846G &gt; A polymorphism of the CYP2D6 gene (rs3892097) on the efficacy and safety of fluvoxamine. Unfortunately, hsa-miR-370-3p turned out to be not a valid marker for assessing the level of CYP2D6 expression, since its plasma concentration did not differ in carriers of different genotypes by 1846G &gt; A polymorphic marker.

The Influence of Concentration of micro-RNA hsa-miR-370-3p and CYP2D6*4 on Equilibrium Concentration of Sertraline in Patients Diagnosed with Depressive Disorders Comorbid with Alcohol Use Disroder

Introduction: Sertralineis commonly administered topatients with depressive disorders comorbid with alcohol use disroder. Some part of such patients do not respond adequately to treatment regimen containing sertraline, whereas many of them experience type A adverse drug reactions (type A ADRs). Previous studies have shown that CYP2D6 is involved in the metabolism of sertraline, the activity of which is considerablydependent on the polymorphism of the gene encoding it. Objective: The objective of the study was to investigate the impact of 1846G>A polymorphism of the CYP2D6 gene on the concentration/dose indicator of sertralinepatients diagnosed with depressive disorders comorbid with alcoholism, using findings on activity of CYP2D6 (as evaluated by the 6M-THBC/pinoline ratio measurement) and on CYP2D6 expression level obtained by measuring the hsa-miR-370-3p plasma concentration levels patients suffering from depressive disorders comorbid with alcoholism. Material and Methods: The study included 120 patients with depressive disorders comorbid with alcoholism (age - 40.5±14.7 years). Therapy included sertraline in an average daily dose of 88.8±35.6 mg per day. Treatment efficacy was assessed using the validated psychometric scales. Therapy safety was assessed using the UKU Side-Effect Rating Scale. For genotyping and estimation of the microRNA (miRNA) plasma levels we performed the real-time polymerase chain reaction (PCR Real-time). The activity of CYP2D6 was assessed with HPLC-MS/MS method by the content of the endogenous substrate of given isoenzyme and its metabolite in urine (6M-THBC/pinoline). Theraputic drug monitoring (TDM) has been performed using HPLC-MS/MS. Results: Our study revealed the statistically significant results in terms of the treatment efficacy evaluation (HAMD scores at the end of the treatment course): (GG) 1.0 [1.0; 2.0] and (GA) 4.0 [3.0; 5.0], p < 0.001; at the same time, the statistical significance in the safety profile was obtained (the UKU scores): (GG) 3.0 [2.0; 3.0] and (GA) 3.0 [3.0; 3.0], p = 0.018. We didn't reveal a statistical significance for concentration/dose indicator of sertraline in patients with different genotypes: (GG) 0.749 [0.593; 1.277] and (GA) 1.030 [0.829; 1.257], p = 0.052). Analysis of the results of the pharmacotranscriptomic part of the study didn’t show the statistically significant difference in the hsa-miR-370-3p plasma levels in patients with different genotypes: (GG) 23.4 [16.3; 29.3], (GA) 26.1 [16.5; 28.9], p = 0.945. At the same time, correlation analysis didn't reveal a statistically significant relationship between the sertraline efficacy profile evaluated by changes in HAMD scale scores and the hsa-miR-370-3p plasma concentration: rs = -0.05, p = 0.592. Also, we didn't reveal the correlation between the miRNA concentration and safety profile: rs = 0.07, p = 0.421. Also we revealed the relationship between the CYP2D6 enzymatic activity (as evaluated by 6M-THBC/pinoline ratio measurement) and the hsa-miR-370-3p plasma concentration: rs = -0.25, p = 0.005. At the same time, correlation analysis revealed a statistically significant relationship between the sertraline concentration and the hsa-miR-370-3p plasma concentration: rs = 0.30, p < 0.001. Conclusion: Thus, the effect of genetic polymorphism of the CYP2D6 gene on the efficacy and safety profiles of sertraline was demonstrated in a group of 120 patients with depressive disorders comorbid with alcoholism. At the same time, hsa-miR-370-3p remains a promising biomarker for assessing the level of CYP2D6 expression, because it correlates with encoded isoenzyme activity. Funding Statement: This work was supported by the grant of the Russian Science Foundation (project No. 18- 75-10073). This work was financially supported by the project 16-15-00227 entitled “Fundamental research and exploratory research in priority areas of research” of the Russian Science Foundation. Declaration of Interests: The authors declare that there is no conflict of interest regarding the publication of this article. Ethics Approval Statement: The local ethical committee of the Russian Medical Academy of Continuous Professional Education of the Ministry of Health of the Russian Federation approved the research (The protocol No. 6 from 5/16/2017).

Long-term culture and characterization of patient-derived primary hepatocytes using conditional reprogramming.

Cultivation of primary human hepatocytes (PHHs) often faces obstacles including failure of long-term in vitro culture, weak proliferation ability, rapid loss of liver-specific function and morphology, and tendency of fibrosis. Previous research focused on immortalization methods, such as telomerase and viral, to culture immortalized primary human hepatocytes, which may lose some of the normal properties. However, non-immortalized PHHs often fail to maintain long-term viability and functionality. These highlight the urgent need for developing new culture strategy for PHHs. In the present study, we isolated PHHs from fresh human liver tissues representing different liver diseases and age groups. We used conditional reprogramming, without permanent immortalization, for long-term in vitro primary human hepatocytes cultivation and characterization. For functional characterization, we assessed CYP3A4, 1A1 and 2C9 activities and measured the mRNA expression of albumin, s100a4, krt8, krt18, cyp1a1, cyp3a4, cyp2b6, cyp2c8, cyp2c9, and cyp2d6. Additionally, we compared the DNA fingerprint of the cells against their original liver tissues using short tandem repeat (STR) analysis. We found that PHHs-derived from young patients can survive for more than three months, while the lifespan of primary human hepatocytes derived from adult patients ranges from two to three months, which is longer than most commercial primary hepatocytes. Importantly, the cells at early passages retain strong CYP3A4, 1A1 and 2C9 activities and the DNA fingerprints are identical with their original tissues. Through conditional programming, we achieved, for the first time, a high level of success rate in the long-term in vitro cultivation of primary human hepatocytes-derived patients representing diverse liver disease. Moreover, the conditional programming cell culture technology reported in this paper requires neither co-culture with additive cells, nor complex and expensive components, such as collagen sandwich or spheroid culture. We thus believe that the patient-derived PHHs cultivation using conditional programming may provide a viable and valuable cell model to study liver disease-related mechanisms. Impact statement Commercially available primary human hepatocytes rapidly lose their proliferative ability and liver-specific functions over a few cultivation days. The demand for pharmaceutical toxicity screening and liver disease research requires the development of long-term primary hepatocyte culture methods. This manuscript addresses this challenge by introducing for the first time successful long-term in vitro cultivation of primary human hepatocytes from a range of liver transplantation patients using conditional reprogramming technique. The beauty of this technique is that it is not a permanent immortalization and does not require co-culture with additive cells. The primary human hepatocytes retain proliferative capacity, genetic stability, and hepatocyte-specific functions at early passages. In view of these, we believe that scientists and researchers will benefit from using these highly valuable cell models to study diverse liver diseases.

CYP2D6 haplotypes with enhancer single-nucleotide polymorphism rs5758550 and rs16947 (*2 allele): implications for CYP2D6 genotyping panels.

CYP2D6 metabolizes ∼25% of all clinically used drugs, with numerous genetic polymorphisms affecting enzyme activity and drug response. Clinical utility of current CYP2D6 genotyping is partially compromised the unresolved complex haplotype structure of the CYP2D6 locus. We have identified a distal enhancer single-nucleotide polymorphism rs5758550 that robustly increases CYP2D6 expression, whereas rs16947 (CYP2D6*2), previously considered inert, reduces correct mRNA splicing and expression, thereby affecting presumed activity of other alleles on the *2 haplotype. This study aims to determine the structure and frequency of haplotypes containing either rs5758550 or rs16947, or both, together with other relevant CYP2D6 alleles, assigning predictive enzyme activity scores to each, and addressing ambiguities in estimating diplotypes in different populations. The structure and frequency of haplotypes containing rs5758550 and/or rs16947 in different populations were determined by using phased genotype data from 'The 1000 Genomes Project'. The assigned haplotype-phenotype relationship was tested by associating assigned CYP2D6 activity score with CYP2D6 enzyme activity in a cohort of 122 human liver microsomes. Addition of enhancer single-nucleotide polymorphism rs5758550 and *2 to a CYP2D6 panel improves prediction of CYP2D6 activity. Moreover, the haplotype containing rs5758550 and rs16947 predict extensive CYP2D6 activity more accurately than CYP2D6*2A, a surrogate marker for extensive activity. With further studies, the results support possible incorporation of rs5758550 and rs16947 into CYP2D6 biomarker panels for more accurate prediction of CYP2D6 metabolizer status.

Expression of clinically relevant drug-metabolizing enzymes along the human intestine and their correlation to drug transporters and nuclear receptors: An intra-subject analysis.

The oral bioavailability of many drugs is highly influenced not only by hepatic but also by intestinal biotransformation. To estimate the impact of intestinal phase I and II metabolism on oral drug absorption, knowledge on the expression levels of the respective enzymes is an essential prerequisite. In addition, the potential interplay of metabolism and transport contributes to drug disposition. Both mechanisms may be subjected to coordinative regulation by nuclear receptors, leading to unwanted drug-drug interactions due to induction of intestinal metabolism and transport. Thus, it was the aim of this study to comprehensively analyse the regional expression of clinically relevant phase I and II enzymes along the entire human intestine and to correlate these data to expression data of drug transporters and nuclear receptors of pharmacokinetic relevance. Gene expression of 11 drug-metabolizing enzymes (CYP2B6, 2C8, 2C9, 2C19, 2D6, 3A4, 3A5, SULT1A, UGT1A, UGT2B7, UGT2B15) was studied in duodenum, jejunum, ileum and colon from six organ donors by real-time RT-PCR. Enzyme expression was correlated with expression data of the nuclear receptors PXR, CAR and FXR as well as drug transporters observed in the same cohort. Intestinal expression of all studied metabolizing enzymes was significantly higher in the small intestine compared to colonic tissue. CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, SULT1A, UGT1A and UGT2B7 expression increased from the duodenum to jejunum but was markedly lower in the ileum. In the small intestine, that is, the predominant site of drug absorption, the highest expression has been observed for CYP3A4, CYP2C9, SULT1A and UGT1A. In addition, significant correlations were found between several enzymes and PXR as well as ABC transporters in the small intestine. In conclusion, the observed substantial site-dependent intestinal expression of several enzymes may explain regional differences in intestinal drug absorption. The detected correlations between intestinal enzymes, transporters and nuclear receptors provide indirect evidence for their coordinative expression, regulation and function in the human small intestine.

Effects and Mechanism of Nano-Copper Exposure on Hepatic Cytochrome P450 Enzymes in Rats.

Although nano-copper is currently used extensively, the adverse effects on liver cytochrome P450 (CYP450) enzymes after oral exposure are not clear. In this study, we determined the effects and mechanisms of action of nano- and micro-copper on the expression and activity of CYP450 enzymes in rat liver. Rats were orally exposed to micro-copper (400 mg/kg), Cu ion (100 mg/kg), or nano-copper (100, 200 and 400 mg/kg) daily for seven consecutive days. Histopathological, inflammatory and oxidative stress were measured in the livers of all rats. The mRNA levels and activity of CYP450 enzymes, as well as the mRNA levels of select nuclear receptors, were determined. Exposure to nano-copper (400 mg/kg) induced significant oxidative stress and inflammation relative to the controls, indicated by increased levels of interleukin (IL)-2, IL-6, interferon (IFN)-γ, macrophage inflammatory protein (MIP-1), total antioxidant capacity (T-AOC), malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) after exposure. The levels of mRNA expression of pregnane X receptor (PXR), constitutive androstane receptor (CAR) and aryl hydrocarbon receptor (AHR) were significantly decreased in 400 mg/kg nano-copper treated rats. Nano-copper activated the expression of the NF-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT)3 signaling pathways. Nano-copper decreased the mRNA expression and activity of CYP 1A2, 2C11, 2D6, 2E1 and 3A4 in a dose-dependent manner. The adverse effects of micro-copper are less severe than those of nano-copper on the CYP450 enzymes of rats after oral exposure. Ingestion of large amounts of nano-copper in animals severely affects the drug metabolism of the liver by inhibiting the expression of various CYP450 enzymes, which increases the risk of drug-drug interactions in animals.

CYP2D6 Protein Level Is the Major Contributor to Interindividual Variability in CYP2D6-Mediated Drug Metabolism in Healthy Human Liver Tissue.

CYP2D6 genetic polymorphisms are considered a major contributor to the large interindividual variability in CYP2D6-mediated drug metabolism, but fail to explain a significant portion of the variability. The aim of this study was to assess the ability of the CYP2D6 activity score (AS) estimated from CYP2D6 genotype to predict CYP2D6 expression and enzyme activity. The CYP2D6 gene region was sequenced in 115 healthy human liver tissue samples to determine their CYP2D6 AS. Additionally, CYP2D6 enzyme activity, protein, and mRNA levels were estimated. CYP2D6 AS explained 23% of the interindividual variability in CYP2D6 activity, but only 7.5% in tissues assigned AS 1-2. The CYP2D6 protein level was found to be the major determinant of CYP2D6 activity, explaining 59% of variability. These findings suggest that while CYP2D6 AS is a good predictor of poor metabolizer phenotype, additional nongenetic factors may govern the rate of CYP2D6-mediated metabolism in those without the poor metabolizer phenotype.

High-Fat Diet Feeding Alters Expression of Hepatic Drug-Metabolizing Enzymes in Mice.

Medical conditions accompanying obesity often require drug therapy, but whether and how obesity alters the expression of drug-metabolizing enzymes and thus drug pharmacokinetics is poorly defined. Previous studies have shown that high-fat diet (HFD) feeding and subsequent obesity in mice lead to altered expression of transcriptional regulators for cytochrome P450 CYP2D6, including hepatocyte nuclear factor 4α (HNF4α, a transcriptional activator of CYP2D6) and small heterodimer partner (SHP, a transcriptional repressor of CYP2D6). The objective of this study was to examine whether diet-induced obesity alters CYP2D6 expression by modulating HNF4α and SHP expression. Male CYP2D6-humanized transgenic (Tg-CYP2D6) mice were fed with HFD or matching control diet for 18 weeks. Hepatic mRNA expression of CYP2D6 decreased to a small extent in the HFD group (by 31%), but the differences in CYP2D6 protein and activity levels in hepatic S9 fractions were found insignificant between the groups. Although hepatic SHP expression did not differ between the groups, HNF4α mRNA and protein levels decreased by ∼30% in the HFD group. Among major mouse endogenous cytochrome P450 genes, Cyp1a2 and Cyp2c37 showed significant decreases in the HFD group, whereas Cyp2e1 expression did not differ between groups. Cyp2b10 and Cyp3a11 expression was higher in the HFD group, with corresponding 2.9-fold increases in hepatic CYP3A activities in HFD-fed mice. Together, these results suggest that obesity has minimal effects on CYP2D6-mediated drug metabolism, although it modulates the expression of mouse endogenous P450s in a gene-specific manner.

Antifibrotic Effects of Carvedilol and Impact of Liver Fibrosis on Carvedilol Pharmacokinetics in a Rat model.

Carvedilol is a drug of choice in treatment of portal hypertension. The present study was designed to elucidate the potential role of antifibrotic effects of carvedilol in improving hepatic efficiency and the carvedilol oral pharmacokinetic changes during induction of liver fibrosis. Rats were given CCl4 (1ml/kg, intraperitoneal) twice weekly for 6weeks and/or co-treated with carvedilol (10mg/kg, orally) three times weekly on alternating days. Indocyanine green (ICG) clearance test was used as a modality for the measurement of hepatic blood flow. In addition, assessment of serum albumin as a marker of synthetic capacity and immunohistochemical staining of P-glycoprotein (P-gp) expression as a marker of metabolic capacity were done. Furthermore, hydroxyproline and TGF-β1 were detected as markers of liver fibrosis. The area under plasma concentration-time curve of a single dose of carvedilol was significantly increased, associated with decreased the clearance in rats intoxicated with CCl4 compared to control group. Carvedilol co-treatment in CCl4-intoxicated rats for 6weeks significantly counteracted the changes in hepatotoxicity markers and histopathological lesions induced by CCl4. In addition, there were no significant alterations in carvedilol pharmacokinetics between control and CCl4-intoxicated rats. Furthermore, carvedilol treatment restored liver efficiency, including synthetic and metabolic capacity as well as hepatic blood flow. The present study provides evidence underlying the antifibrotic effects of carvedilol and enhancement of hepatic efficiency. In addition, the pharmacokinetic parameters of a single dose of carvedilol are altered in liver fibrosis, manifested as delayed clearance. This was attributed to the reduction of both hepatic blood flow and CYP2D6 expression in the liver. Carvedilol co-treatment in CCl4-intoxicated rats for 6weeks recovered its pharmacokinetic profile, which is mainly attributed to the impact of pharmacodynamic antifibrotic effects of carvedilol on its own kinetics.

Characterization of human cytochrome P450 mediated bioactivation of amodiaquine and its major metabolite N-desethylamodiaquine.

Oxidative bioactivation of amodiaquine (AQ) by cytochrome P450s to a reactive quinoneimine is considered as an important mechanism underlying its idiosyncratic hepatotoxicity. However, because internal exposure to its major metabolite N-desethylamodiaquine (DEAQ) is up to 240-fold higher than AQ, bioactivation of DEAQ might significantly contribute to covalent binding. The aim of the present study was to compare the kinetics of bioactivation of AQ and DEAQ by human liver microsomes (HLM) and to characterize the CYPs involved in bioactivation of AQ and DEAQ. Glutathione was used to trap reactive metabolites formed in incubations of AQ and DEAQ with HLM and recombinant human cytochrome P450s (hCYPs). Kinetics of bioactivation of AQ and DEAQ in HLM and involvement of hCYPs were characterized by measuring corresponding glutathione conjugates (AQ-SG and DEAQ-SG) using a high-performance liquid chromatography method. Bioactivation of AQ and DEAQ in HLM both exhibited Michaelis-Menten kinetics. For AQ bioactivation, enzyme kinetical parameters were Km , 11.5±2.0μmoll-1 , Vmax , 59.2±3.2pmolmin-1 mg-1 and CLint , 5.15μlmin-1 mg-1 . For DEAQ, parameters for bioactivation were Km , 6.1±1.3μmoll-1 , Vmax , 5.5±0.4pmolmin-1 mg-1 and CLint 0.90μlmin-1 mg-1 . Recombinant hCYPs and inhibition studies with HLM showed involvement of CYP3A4, CYP2C8, CYP2C9 and CYP2D6 in bioactivation. The major metabolite DEAQ is likely to be quantitatively more important than AQ with respect to hepatic exposure to reactive metabolites in vivo. High expression of CYP3A4, CYP2C8, CYP2C9, and CYP2D6 may be risk factors for hepatotoxicity caused by AQ-therapy.