CYP1B1 Gene Expression Research Articles

Serotonin Availability Shapes the Effects of Phenelzine on Inflammatory Response and Gene Expression in Macrophages.

Background Serotonin (5-HT) is a neurotransmitter with extensive physiological influence in the central nervous system (CNS) and various behavioral and biological functions, including immune regulation through 5-HT receptors (5-HTRs) expressed by immune cells. A variety of serotonin-modulating drugs have been developed to treat neurological disorders. Phenelzine, a drug indicated for the management of treatment-resistant depression, is a potent, non-selectiveinhibitor of monoamine oxidase (MAO), the enzyme that metabolizes serotonin to 5-hydroxyindole acetic acid (5-HIAA). Given the emerging evidence of a bidirectional link between depression and inflammation, as well as the potential therapeutic applications of serotonin-modulating drugs in autoimmune diseases and cancer, our study investigated the pro-inflammatory and anti-inflammatory factors influenced by serotonin and phenelzine. Methodology We conducted experiments on RAW264.7 macrophages, exposing them to various combinations and concentrations of serotonin, 5-HIAA, and phenelzine. We assessed the relative gene expression of monoamine oxidase-A (MAO-A), CYP1B1, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) using real-time PCR and measured the production of IL-6, TNF-α, and IL-10 cytokines using enzyme-linked immunosorbent assays (ELISA). Results Our findings revealed that phenelzine can downregulate genes associated with the production of reactive oxygen and nitrogen species, reduce aryl hydrocarbon receptor (AHR)-related gene expression induced by serotonin, and enhance the production of inflammatory cytokines. These effects were significantly influenced by the concentration of available serotonin. Conclusions Our study demonstrates that various mechanisms, including AHR activation, modulation of reactive oxygen and nitrogen speciesproduction, and others, in addition to the increased availability of serotonin due to phenelzine treatment, can significantly influence the inflammatory state.

Polycyclic aromatic hydrocarbon (PAH) activation of AhR inhibits glutathione S-transferase (GST) activity in primary human small airway epithelial cells (hSAECs)

Background: PAH represents the organic phase of particulate matter (PM) in air pollution emitted via the incomplete combustion of various compounds (i.e. diesel fuel, wood, and plastics). It is widely regarded that PAH activation of aryl hydrocarbon receptor (AhR) plays an important role in pro-inflammatory signaling, however the mechanisms remain unknown. In contrast- endogenous AhR agonists, such as 6-Formylindolo[3,2-b]carbazole (FICZ), exert pleiotropic protective effects against inflammation, fibrosis, and oxidative stress. The objective of our research program is to delineate the differences between activation of AhR by PAH (with adverse effects) compared to its beneficial homeostatic activation by endogenous FICZ. PM may induce oxidative stress in part through inhibition of antioxidant defense mechanisms. GSTs are a superfamily of enzymes that plays an important role in protecting cells from oxidative damage (by conjugating reduced glutathione to substrates under pro-oxidizing conditions). We hypothesize that PAH activation of AhR contributes to oxidative stress via inhibition of GST activity in primary hSAECs. Methods: Primary hSAECs were subjected to varying dosages of PAH [0, 250, 500, 1000, 5000 ng/mL] to model airborne PM exposure levels, and to increasing doses of FICZ [0, 0.50, 10, 100, 1000 nM] to model normal and excessively high endogenous ligand activation of AhR. We determined the relative potencies of PAH and FICZ by measuring CYP1A1 and CYP1B1 gene expression. Oxidative stress was measured using DHE-labeling and GST activity was measured with enzymatic kits (Sigma Aldrich). AhR activity was pharmacologically inhibited using 10μM CH223191. Statistical analysis was conducted using SigmaPlot 14.0 (Systat Software). Results: PAH and FICZ maximally stimulate hSAEC CYP1A1 and CYP1B1 expression at 1000ng/mL and 100nM, respectively, and are therefore defined as equipotent concentrations used in our studies. In a representative experiment in hSAECs, PAH (1000ng/mL) significantly increased hSAEC oxidative stress vs FICZ (100nM) n=6, p<0.01), while significantly decreasing GST specific activity vs equipotent FICZ activation of AhR in primary hSAECs from a 66-year-old female without lung disease (26.6±0.874 vs 28.3±.611 nmol/mL/min); n=6 from 2 independent assays; p=0.032. Similar differential effects of PAH vs FICZ activation of AhR on GST were seen in additional experiments with male hSAECs and Calu-3 cells (male). Importantly, CH223191 inhibition of GST enzymatic activity suggests that AhR plays an important role in protecting cells from oxidative stress. Conclusions: Our studies indicate that airborne PAH exposure can have detrimental health effects on the lung via aberrant AhR signaling. Significance: Understanding activity of AhR signaling can leads to novel therapeutic options for redox disorders in the lung. Funding: VA 5I01BX001777-05 (RP) and R01HL137033 (MH). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Effects of 16-HETE Enantiomers on Hypertrophic Markers in Human Fetal Ventricular Cardiomyocytes, RL-14 Cells.

Cytochrome P450 (CYP) metabolizes arachidonic acid to produce bioactive metabolites such as EETs and HETEs: mid-chain, subterminal, and terminal HETEs. Recent studies have revealed the role of CYP1B1 and its associated cardiotoxic mid-chain HETE metabolites in developing cardiac hypertrophy and heart failure. Subterminal HETEs have also been involved in various physiological and pathophysiological processes; however, their role in cardiac hypertrophy has not been fully defined. The objective of the current study is to determine the possible effect of subterminal HETEs, R and S enantiomers of 16-HETE, on CYP1B1 expressioninvitro using human cardiomyocytes RL-14 cells. In the study, RL14 cell line was treated with vehicle and either of the 16-HETE enantiomers for 24 h. Subsequently, the following markers were assessed: cell viability, cellular size, hypertrophic markers, CYP1B1 gene expression (at mRNA, protein, and activity levels), luciferase activity, and CYP1B1 mRNA and protein half-lives. The results of the study showed that 16-HETE enantiomers significantly increased hypertrophic markers and upregulated CYP1B1 mRNA and protein expressions in RL-14 cell line. The upregulation of CYP1B1 by 16-HETE enantiomers occurs via a transcriptional mechanism as evidenced by transcriptional induction and luciferase reporter assay. Furthermore, neither post-transcriptional nor post-translational modification was involved in such modulation since there was no change in CYP1B1 mRNA and protein stabilities upon treatment with 16-HETE enantiomers. The current study provides the first evidence that 16R-HETE and 16S-HETE increase CYP1B1 gene expression through a transcriptional mechanism.

Genetic Expression of CYP2B6 Gene in Phenobarbitone Responder and Non-responder Neonates

Quantitative real-time polymerase chain reaction for identifying CYP2B6 gene expression was done on blood samples of 30 phenobarbitone responder and 30 non-responder neonates with seizures. CYP2B6 was observed to be significantly down regulated among phenobarbitone non-responders as compared to phenobarbitone responders (Mean (SD) DCt 17.97 (1.19) vs 15.40 (1.83); P<0.001).

High levels of follicular fluid testosterone could impair oocyte developmental competency via affecting aryl hydrocarbon receptor pathway in PCOS patients

BackgroundAlthough hormonal and metabolic dysfunction have been recognized as a possible cause of polycystic ovarian syndrome (PCOS), the associations between hyperandrogenism and aryl hydrocarbon receptor (Ahr) signaling pathway remains controversial. The current study aimed to investigate the effect of hyperandrogenism on oocyte developmental competency via regarding Ahr signaling downstream pathway in granulosa cells.Materials and methodsGranulosa cells were collected from 45 PCOS patients under assisted reproductive technique (ART). Gene expression of Ahr downstream pathway was evaluated based on Reverse Transcription Q-PCR assay. Moreover the correlation was investigated between gene expression and hyperandrogenism, and oocyte developmental competency in PCOS.ResultsFrom the 45 PCOS patients, 26 (64.44%) had a high level of follicular fluid testosterone (FFT). Based on the FFT level, two groups of PCOS: HFT (high level of FFT) and non-HFT, were shown significant differences in oocyte and embryo quality, and fertilization and cleavage rates. Moreover, the mean relative expressions of Ahr and Arnt genes were significantly higher in HFT –PCOS group (p < 0.01 and p < 0.01) respectively. Also, the significant positive correlations were obtained for Ahr, Arnt, Cyp1A1, and Cyp1B1 with incidence of clinical hyperandrogenism and FFT level. Besides, our results showed that Ahr, Cyp1A1, and Cyp1B1 gene expression was correlated significantly with fertilization rate.ConclusionThe present study suggested that hyperandrogenism could impair oocyte developmental competency via affecting Ahr signaling downstream pathway.

Bisphenol A is a carcinogen that induces lipid accumulation, peroxisome proliferator‑activated receptor‑γ expression and liver disease.

Bisphenol (BP) A is an exogenous endocrine disruptor that mimics hormones closely associated with health complications, e.g., obesity and cancers. The present study aimed to evaluate the effects of BPA on human liver cells and tissue. The peroxisome proliferator-activated receptor (PPAR)-γ expression profile across tumour samples and paired normal tissue was first analysed using GEPIA. Subsequently, BPA-treated liver THLE-2 cell viability was evaluated using an MTT assay. Clusterin, PPARα and PPARγ gene expression in BPA-treated THLE-2 cells was assessed using GEPIA before validating the gene expression using real-time PCR and analysing overall survival using TCGA data in GEPIA. Cytoplasmic lipid accumulation was examined in BPA-treated THLE-2 cells using Oil Red O staining, and liver tissue was examined using haematoxylin and eosin staining. Finally, cytochrome P450 (CYP) gene expression was assessed in BPA-treated THLE-2 cells using real-time PCR. PPARγ is likely the primary nuclear receptor protein involved in lipid accumulation in THLE-2 cells following BPA treatment and is associated with liver disease. THLE-2 cells exposed to BPA showed a decrease in viability and lipid accumulation after 48 h treatment. Higher PPARγ gene expression was significantly associated with survival of patients with liver cancer, with an average survival time of <80 months. Haematoxylin and eosin-stained sections showed notable disruption of the liver architecture in tissue exposed to BPA. Downregulated CYP1A1 and CYP1B1 gene expression implied that BPA-treated THLE-2 cells decreased capacity for carcinogen metabolism, while upregulated CYP2S1 gene expression exerted minimal cytotoxicity. The present study revealed that BPA served as a carcinogen, enhanced tumorigenesis susceptibility and may induce other types of liver disease.

Comparative Studies on a Standardized Subfraction of Red Onion Peel Ethanolic Extract (Plant Substance), Quercetin (Pure Compound), and Their Cell Mechanism and Metabolism on MDA-MB-231.

This study indicates the presence of quercetin in subfraction F1 and the standardized value of F1 derived from research using ultra-performance liquid chromatography (UPLC) and AlCl3 colorimetric assays, which further proved that both F1 and quercetin are potential growth inhibitors in MDA-MB-231 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In the process, staining of F1-treated cells with annexin/propidium iodide (PI) reduced cell proliferation and induced only S and G2 phases of cell cycle arrest in the treated cells by flow cytometry. Quercetin reduced cell proliferation by inducing apoptosis and S phase arrest. The 5′-bromo-2′-deoxyuridine (BrdU) incorporation of DNA synthesis in MDA-MB-231 cells was also inhibited after F1 and quercetin treatments. F1 and quercetin induced CYP1A1 and CYP1B1 gene expression, but only F1 induced CYP2S1 gene expression in the treated cells. Both F1 and quercetin inhibited the proliferation of MDA-MB-231 cells in different ways, but F1 is likely a better potential anticancer agent derived from the green approach towards breast cancer treatment.

Maternal exposure to genistein during pregnancy and oxidative DNA damage in testes of male mouse offspring.

BackgroundGenistein is a dietary supplement with phyto-estrogenic properties. Therefore, high intake of genistein during pregnancy may have adverse effects on the genetic integrity of testes and germ cells of male offspring. In this study, we examined whether maternal exposure to genistein during pregnancy induced oxidative DNA damage in the male germline at adolescence.MethodsAtm-ΔSRI mice have lower glucose-6-phosphate dehydrogenase (G6PDH) activity, which is important for maintaining levels of reduced glutathione and therefore these mice have an increased susceptibility to oxidative stress. Parental heterozygous Atm-ΔSRI mice received a genistein-rich or control diet, after which they were mated to obtain offspring. During pregnancy, mothers remained on the respective diets and after delivery all animals received control diets. Redox status and oxidative DNA damage were assessed in testes and sperm of 12 weeks old male offspring. Gene expression of Cyp1b1, Comt, and Nqo1 was assessed in testes, and DNA methylation as possible mechanism for transmission of effects to later life.ResultsIntake of genistein during pregnancy increased oxidative DNA damage in testes of offspring, especially in heterozygous Atm-ΔSRI mice. These increased DNA damage levels coincided with decreased expression of Comt and Nqo1. Heterozygous Atm-ΔSRI mice had higher levels of DNA strand breaks in sperm compared to wild type littermates, and DNA damage was further enhanced by a genistein-rich maternal diet. G6PDH activity was higher in mice with high maternal intake of genistein compared to control diets, suggesting compensation against oxidative stress. A positive correlation was observed between the levels of DNA methylation and oxidative DNA damage in testes.ConclusionThese data indicate that prenatal exposure to genistein altered gene expression and increased DNA damage in testes and sperm of adolescent male offspring. These effects of genistein on DNA damage in later life coincided with alterations in DNA methylation.

Staphylococcus aureus Activates the Aryl Hydrocarbon Receptor in Human Keratinocytes

Staphylococcus aureus is an important pathogen causing various infections, including – as most frequently isolated bacterium – cutaneous infections. Keratinocytes as the first barrier cells of the skin respond to S. aureus by the release of defense molecules such as cytokines and antimicrobial peptides. Although several pattern recognition receptors expressed in keratinocytes such as Toll-like and NOD-like receptors have been reported to detect the presence of S. aureus, the mechanisms underlying the interplay between S. aureus and keratinocytes are still emerging. Here, we report that S. aureus induced gene expression of CYP1A1 and CYP1B1, responsive genes of the aryl hydrocarbon receptor (AhR). AhR activation by S. aureus was further confirmed by AhR gene reporter assays. AhR activation was mediated by factor(s) <2 kDa secreted by S. aureus. Whole transcriptome analyses and real-time PCR analyses identified IL-24, IL-6, and IL-1beta as cytokines induced in an AhR-dependent manner in S. aureus-treated keratinocytes. AhR inhibition in a 3D organotypic skin equivalent confirmed the crucial role of the AhR in mediating the induction of IL-24, IL-6, and IL-1beta upon stimulation with living S. aureus. Taken together, we further highlight the important role of the AhR in cutaneous innate defense and identified the AhR as a novel receptor mediating the sensing of the important skin pathogen S. aureus in keratinocytes.

Bridging Sex-Specific Differences in the CAR-Mediated Hepatocarcinogenesis of Nitrapyrin Using Molecular and Apical Endpoints.

Nitrapyrin, a nitrification inhibitor, produces liver tumors in B6C3F1 mice. In a 2-year oncogenicity study, increased incidence of mice with hepatocellular tumors was observed following exposure to 125 (females only) or 250 mg/kg/day (males and females) nitrapyrin in the diet. Previous data was generated in male mice to support a mode-of-action (MoA) characterized by constitutive androstane receptor (CAR) nuclear receptor (NR) activation, increased hepatocellular proliferation, and subsequent hepatocellular foci and tumor formation. Uncertainty as to the relevance of this MoA for females remained given the increased sensitivity to tumor formation in female mice. A targeted MoA study was conducted to evaluate CAR activation and hepatic responses in female mice treated with the female carcinogenic dose of nitrapyrin for 4 days. Nitrapyrin induced a treatment-related increase in hepatocellular hypertrophy and hepatocellular proliferation. Nitrapyrin also induced a dose-related increase in the Cyp2b10/CAR-associated transcript and liver weights. Nitrapyrin-induced liver weights and Cyp2b10 gene expression for both males and females were compared to data generated from three other established CAR activators; methyl isobutyl ketone, phenobarbital, and sulfoxaflor. The response observed in female mice following exposure to nitrapyrin was within range of the degree of change observed in mice following exposure to tumorigenic doses of other CAR activators. Consistent with the liver MoA in male mice, these data support a CAR-mediated mode of action for nitrapyrin-induced liver tumors in female mice, with the understanding that a focused approach minimizing animal use can bridge male and female datasets when sex-specific carcinogenic differences are observed.

Ahr and CYP1B1 gene expression in type 2 diabetes patients in Vietnam

Type 2 diabetes is a chronic disease, which has risen dramatically in many countries in the world, including Vietnam. Recently, there is increasing evidence about the link between type 2 diabetes and the exposure to Ahr ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the experimental animal model. In the cell, after activation by the ligands, Ahr moves from the cytoplasm into the nucleus and binds to the nuclear translocator, resulting in transcription of target genes such as Cyp1b1. The development of type 2 diabetes was shown in some people who exposed to TCDD. However, the role of Ahr/Cyp1b1 genes in type 2 diabetes patients has not been elucidated. In this study, the expression of the Ahr and Cyp1b1 genes in blood samples collected from patients with type 2 diabetes and controls was studied for the first time in Vietnam. Analysis of blood glucose showed that this index in the type 2 diabetes patients was higher than that in the control group. Using real-time PCR method, the results showed that the expression of Ahr and Cyp1b1 in type 2 diabetes patients was significantly higher than that in control group. In addition, the expression of Ahr and Cyp1b1 was positively correlated with the blood glucose levels of both groups. These results are initial evidence for the link between activation of Ahr/Cyp1b1 signaling pathway and level of blood glucose so that Ahr/Cyp1b1 genes can be potential targets to treat type 2 diabetes.

Genetic variation in CYP1A1 and AHRR genes increase the risk of systemic lupus erythematosus and exacerbate disease severity in smoker patients.

Genetic variations of aryl hydrocarbon receptor (AHR) pathway genes could influence the imbalanced immune response to xenobiotics. Therefore, we aimed to investigate the polymorphism of AHR pathway genes in systemic lupus erythematosus (SLE) patients in association with smoking. Genomic DNA from patients (N = 107) and controls (N = 105) of a population from northeast of Iran was used for genotyping of CYP1A1 T>C (rs4646903) and AHRR C>G (rs2292596) variants. The SLEDAI score and smoking status of the patients were registered. The AHR activity was estimated by CYP1A1 and CYP1B1 geneexpression in peripheral blood mononuclear cells (PBMC). The C allele in rs4646903 (odds ratio [OR] = 2.67) and G allele in rs2292596 (OR = 1.79) SNPs were significantly associated with the increased risk of SLE. The AHR pathway was more active in high-risk CYP1A1/AHRR: C/G haplotype. The most severe disease was observed in smoker patients with high-risk haplotype and both smoking (Exp (β) = 9.5) and high-risk CYP1A1/AHRR (C/G) haplotype (Exp (β) = 3.7) can significantly increase the likelihood of having severe (SLEDAI ≥ 20) SLE disease activity. Our findings indicated the association of xenobiotic-metabolizing genes (CYP1A1, AHRR) polymorphisms with the susceptibility to SLE and disease severity regarding the smoking background, suggesting the interaction of gene and environmental risk factors in SLE pathogenesis.

Role of the Aryl Hydrocarbon Receptor (AhR) in Mediating the Effects of Coffee in the Colon.

This study investigates the mechanism of action and functional effects of coffee extracts in colonic cells, on intestinal stem cell growth, and inhibition of dextran sodium sulfate (DSS)-induced intestinal barrier damage in mice. Aqueous coffee extracts induced Ah receptor (AhR) -responsive CYP1A1, CYP1B1, and UGT1A1 gene expression in colon-derived Caco2 and YAMC cells. Tissue-specific AhR knockout (AhRf/f x Lgr5-GFP-CreERT2 x Villin-Cre), wild-type (Lgr5-CreERT2 x Villin-Cre) mice are sources of stem cell enriched organoids and both coffee extracts and norharman, an AhR-active component of these extracts inhibited stem cell growth. Coffee extracts also inhibit DSS-induced damage to intestinal barrier function and DSS-induced mucosal inflammatory genes such as IL-6 and TGF-β1 in wild-type (AhR+/+ ) but not AhR-/- mice. In contrast, coffee does not exhibit protective effects in intestinal-specific AhR knockout mice. Coffee extracts also enhanced overall formation of AhR-active microbial metabolites. In colon-derived cells and in the mouse intestine, coffee induced several AhR-dependent responses including gene expression, inhibition of intestinal stem cell-enriched organoid growth, and inhibition of DSS-induced intestinal barrier damage. We conclude that the anti-inflammatory effects of coffee in the intestine are due, in part, to activation of AhR signaling.

Nrf2 Antioxidative System is Involved in Cytochrome P450 Gene Expression and Activity: A Delay in Pentobarbital Metabolism in Nrf2-Deficient Mice.

NF-E2-related factor 2 (Nrf2) is a transcriptional regulator of biologic defense proteins, such as antioxidant proteins and phase II detoxification enzymes. Cytochrome P450 (P450) enzymes have been shown to regulate phase I metabolism of various drugs and are partially regulated by Nrf2; however, the influence of Nrf2 on drug pharmacokinetics is not known. Here, we showed that Nrf2 depletion prolonged the effect of pentobarbital, a sleep-promoting drug. Pretreatment with phenobarbital, a P450 inducer, shortens the sleeping time associated with pentobarbital-induced sedation in wild-type (WT) mice; however, this effect was not observed in Nrf2-/- mice. Furthermore, the blood pentobarbital concentration was higher in Nrf2-/- mice than in WT mice at 30-60 minutes, and the phenobarbital-induced enhancement of its clearance was attenuated in Nrf2-/- mice compared with WT mice. Total P450 content was decreased in Nrf2-/- mouse livers, and the phenobarbital-induced increase in P450 content was lower in Nrf2-/- mice than WT mice. Cyp1a2, Cyp2a5, Cyp2c29, and Cyp2e1 gene expression levels under physiologic conditions and Cyp1a2, Cyp2a5, and Cyp2b10 gene expression levels under phenobarbital-treated conditions were lower in Nrf2-/- mice compared with WT mice. Additionally, pentobarbital metabolism in liver microsomes was attenuated by Nrf2 depletion. Taken together, these findings suggested that Nrf2 influenced pentobarbital pharmacokinetics through the regulation of drug metabolism and P450 gene expression. Thus, Nrf2-mediated regulation of P450 may contribute to the biologic defense against increased reactive oxygen species production. SIGNIFICANCE STATEMENT: NF-E2-related factor 2 (Nrf2) plays a critical role in the cellular defense against oxidative stress. Nrf2-/- mice with reduced ability to eliminate reactive oxygen species (ROS) showed a significant delay in emergence from pentobarbital-induced sleep, which was associated with decreased P450 activities and gene expression. Our findings provide that Nrf2 dysfunction or ROS that exceed a threshold level of the eliminating ability of the Nrf2 system may reduce P450 activity.

P0517RENAL STEM CELLS (ARPCS) AS A NEPHROPROTECTIVE APPROACH DURING CISPLATIN-INDUCED ACUTE KIDNEY INJURY: A DEFENSE MECHANISM BY EXTRACELLULAR VESICLES CARRYING THE CYP1B1 GENE

Abstract Background and Aims Cisplatin, is a nonspecific cytotoxic agent that primarily interferes with cellular DNA replication and the cell cycle, nevertheless it lacks tumor selectivity and acts also in normal cells. The most serious adverse reaction of cisplatin is Acute Kidney Injury (AKI), limiting its use and efficacy in chemotherapy. Cisplatin nephrotoxicity is observed in more than 30% of older patients, however the mechanism of nephrotoxicity remains unclear and specific preventive measures are not available. Today, there is an urgent need for specific nephroprotective strategies to be used during cisplatin chemotherapy. Recently, we found that tubular stem/progenitor cells (tARPC) are able to protect the tubular epithelial (RPTEC) from cisplatin induced injury, preserving their proliferation and inhibiting apoptosis. The aim of this study was to identify the molecular mechanisms involved in tARPC-mediated resistance to cisplatin. Method Co-cultures of RPTEC cells and tARPCs were exposed to cisplatin (2.5 µM) for 6 h and then kept in culture for 96 h. Gene expression profile was obtained from tARPCs and RPTECs by Agilent SurePrint G3 Human Gene Expression Microarrays. Genespring and R software were used for the analysis. Gene expression data were validated by Real-time PCR. Extracellular vesicles were isolated from cell culture supernatant by miRCURY Exosome Cell/Urine/CSF Kit (Qiagen) and RNA contained in extracellular vesicles was purified, analyzed in quality by Bioanalyzer (RNA nano) and evaluated by qPCR. The BrdU assay and caspase 3 were used to measure proliferation and apoptosis levels. Immunohistochemical expression of activated caspase-3 was used as a marker of apoptosis in RPTECs. Results By a whole-genome gene expression analysis, we found 107 genes specifically modulated by RPTECs in response to cisplatin and, among these, 30 genes induced by ARPCs following the cisplatin damage. In particular, we found a strong upregulation of the CYP1B1 gene (false discovery rate corrected p value &amp;lt;0.05; fold change=4,1). The qPCR confirmed the increase in CYP1B1 levels in the co-cultures with respect to the respective basal conditions (p &amp;lt;0.05). Interestingly, the CYP1B1 mRNA was also enveloped in Extracellular Vesicles released in the cell co-culture media by tARPC and RPTEC after cisplatin exposition. The CYP1B1 gene encodes a member of the cytochrome P450 superfamily of enzymes and the produced enzyme metabolizes procarcinogens, such as polycyclic aromatic hydrocarbons. CYP1B1 has been shown to be active within tumors and is also capable of metabolizing a structurally diverse range of anticancer drugs. It is responsible for the resistance to docetaxel, cisplatin, tamoxifen and nucleoside analogues. CYP1B1 is involved in the detoxification of the body by various exogenous toxic agents, including cisplatin. We found that CYP1B1 gene was expressed at low levels in RPTECs and in cisplatin-damaged RPTECs. Moreover, 96 h days after 2.5 μM exposure to cisplatin, RPTECs reduced the proliferation and underwent in apoptosis, as showed by caspase 3. However, in co-culture with ARPCs, ARPC cellular and extracellular vesicles CYP1B1 gene expression significantly increased, the apoptotic process was stopped and RPTECs increased their proliferation rate. These data support the hypothesis that ARPCs are sensor of cisplatin damaged-RPTEC and confers cisplatin resistance by transferring CYP1B1 gene in extracellular vesicles. Conclusion This is the first evidence of a cisplatin-induced overexpression of CYP1b1 in renal epithelial cells as a defense mechanism against cisplatin toxicity. This is consistent with our previous data showing that renal progenitors are resistant to cisplatin. The findings may have biological and clinical significance in terms of their implications in cellular communications and potential use of CYP1B1 as biomarkers for AKI induced by cisplatin or as protective agent.

Nrf2 differentially regulates pro- and anti-inflammatory function of Th17 cells through RORγT, SOD3 and Ahr

Abstract IL-17A and IL-22 derived from CD4+ T cells are significant for both inflammatory and tissue protective responses. However, it remains unclear whether IL-17A and IL-22 can be regulated differently to achieve targeted functional outcome. Here, we showed that Nrf2 selectively regulated IL-17A and IL-22 responses in CD4+ T cells. Nrf2−/− mice challenged with Ovalbumin (Ova) + LPS displayed reduced IL-22 but enhanced IL-17A response. Interestingly, CDDO-Im, a selective Nrf2 activator, induced IL-22 but suppressed IL-17A response in CD4+ T cells polarized under Th17 cell condition. CDDO-Im-activated CD4+ T cells had lower Rorc, but increased Cybb, Sod1 and Sod3 transcript. Luciferase reporter assay showed that IL-17A promoter activity is inhibited by Nrf2 at the presence of RORγT, suggesting that inhibition of IL-17A by Nrf2 is RORγT-dependent. CDDO-Im-impaired IL-17A response was also abolished in SOD3−/−, showing that SOD3 is involved in CDDO-Im-mediated inhibition of IL-17A. Furthermore, we found that CDDO-Im induced aryl hydrocarbon receptor (Ahr) and its downstream Cyp1a1 and Cyp1b1 gene expression. Additionally, CDDO-Im induced Nqo1 expression, an Nrf2-activated gene, in WT mice but not in Ahr−/− mice. CDDO-Im-mediated induction of IL-22 production in CD4+ T cells was abrogated in Ahr−/− mice, supporting that Ahr is involved in the induction of IL-22 by Nrf2. Finally, upon the stimulation of anti-CD3 and anti-CD28, CDDO-Im also mediated the inhibition of IL-17A but induction of IL-22 production in PBMCs from relapsing-remitting multiple sclerosis patients. Collectively, our data show that Nrf2 promotes IL-22 production via Ahr, whereas RORγT and SOD3 are involved in Nrf2-mediated inhibition of IL-17A expression in Th17 cells.

Reversal of obesity and liver steatosis in mice via inhibition of aryl hydrocarbon receptor and altered gene expression of CYP1B1, PPARα, SCD1, and osteopontin.

Background/ObjectivesObesity is a global epidemic and the underlying basis for numerous comorbidities. We report that the aryl hydrocarbon receptor (AHR) plays a key role in the metabolism of obesity. The AHR is a promiscuous, ligand-activated nuclear receptor primarily known for regulating genes involved in xenobiotic metabolism and T cell polarization. The aims of the work reported here were to understand the underlying mechanism of AHR-based obesity and to determine whether inhibition of AHR activity would reverse obesity.MethodsMice were fed control (low fat) and Western (high fat) diets with and without the AHR antagonist alpha-naphthoflavone (aNF). Gene expression of identified AHR-regulated genes from liver and adipose tissue was characterized. To determine the role of the AHR in obesity reversal, selected mice in control and Western diet regimens were switched at midpoint to the respective control and Western diets containing aNF, and the identified AHR-regulated genes characterized.ResultsAHR inhibition prevented obesity in mice on a 40-week diet regimen. The likely AHR-regulated and cross-regulated downstream effectors of AHR-based obesity were shown to be CYP1B1, PPARα-target genes, SCD1, and SPP1 (osteopontin). Western diet caused an increase of mRNA and protein expression of the Cyp1b1, Scd1, and Spp1, and PPARα-target genes in the liver, and inhibition of the AHR maintained expression of these genes near control levels. The body weight of obese mice on Western diet switched to Western diet containing aNF decreased to that of mice on control diet concurrently with a reduction in the expression of liver CYP1B1, PPARα-target genes, SCD1, and SPP1. AHR inhibition prevented hypertrophy and hyperplasia in visceral adipose tissue and limited expression levels of CYP1B1 and SPP1 to that of mice on control diet.ConclusionsAHR inhibition prevents and reverses obesity by likely reducing liver expression of the Cyp1b1, Scd1, Spp1, and PPARα-target genes; and the AHR is a potentially potent therapeutic target for the treatment and prevention of obesity and linked diseases.

Synergistic induction of drug-metabolizing enzymes in co-cultures of bovine hepatocytic and sinusoidal cell lines.

Hepatocyte-derived cell lines provide useful experimental systems for studying liver metabolism. Unlike human and rodents, few hepatocyte-derived cell lines have been generated from cattle. Here, we established two immortalized bovine hepatocyte-derived cell lines (BH4 and BH5) via transfection with a SV40 large T-antigen construct. Morphological and immunocytochemical analyses revealed that BH4 and BH5 originated from hepatocytes and biliary-epithelial cells, respectively. A potent carcinogen, 3-methylcholanthrene (3-MC), upregulated gene expression of cytochrome P450 (CYP)1A1, CYP1A2, and CYP1B1 in BH4 and BH5, but only to levels less than one-fifteenth of those in primary cultured bovine hepatocytes. Phenobarbital (PB) also increased expression levels of CYP2B6, CYP2C18, and CYP3A4 in BH4 and BH, but at a lower level than 3-MC. By contrast, when BH4 or BH5 was co-cultured with previously established bovine liver sinusoidal cell lines and treated with 3-MC, the gene expression levels of CYP1A1, CYP1A2, and CYP1B1 increased by 38~290%, compared with those in BH4 or BH5 cells cultured alone. PB-treated co-cultures of BH4 or BH5 cells and liver sinusoidal cell lines also showed synergistic increases in CYP2B6 and CYP2C18 expression. Together, the results suggest that these co-cultures could provide an in vitro model for investigations into pharmacological and toxicological properties of drugs in cattle liver.

Isoflavones as Ah Receptor Agonists in Colon-Derived Cell Lines: Structure-Activity Relationships.

Many of the protective responses observed for flavonoids in the gastrointestinal track resemble aryl hydrocarbon receptor (AhR)-mediated effects. Therefore, we examined the structure-activity relationships of isoflavones and isomeric flavone and flavanones as AhR ligands on the basis of their induction of CYP1A1, CYP1B1, and UGT1A1 gene expression in colon cancer Caco2 cells and young adult mouse colonocyte (YAMC) cells. Caco2 cells were significantly more Ah-responsive than YAMC cells, and this was due, in part, to flavonoid-induced cytotoxicity in the latter cell lines. The structure-activity relationships for the flavonoids were complex and both response and cell context specific; however, there was significant variability in the AhR activities of the isomeric substituted isoflavones and flavones. For example, 4',5,7-trihydroxyisoflavone (genistein) was AhR-inactive whereas 4',5,7-trihydroxyflavone (apigenin) induced CYP1A1, CYP1B1, and UGT1A1 in Caco2 cells. In contrast, both 5,7-dihydroxy-4-methoxy substituted isoflavone (biochanin A) and flavone (acacetin) induced all three AhR-responsive genes; 4',5,7-trimethoxyisoflavone was a potent AhR agonist, and the isomeric flavone was AhR-inactive. These results coupled with simulation studies modeling flavonoid interaction within the AhR binding pocket demonstrate that the orientation of the substituted phenyl ring at C-2 (flavones) or C-3 (isoflavones) on the common 4-H-chromen-4-one ring strongly influences the activities of isoflavones and flavones as AhR agonists.

Nrf2 selectively regulates IL-22 and IL-17A production in Th17 cells

Abstract Th17 cell-derived IL-17A and IL-22 are critical for mounting both inflammatory and tissue protective responses. It remains unclear whether cytokine responses can be modified differently to achieve targeted functional outcome. A therapeutic strategy which inhibits CD4+ T cell-derived inflammatory IL-17A responses but concomitantly promotes IL-22-dependent tissue protective or regenerative response is of great clinical significance. Here, we showed that nuclear factor (erythroid-derived 2)-like 2 (Nrf2) selectively regulated IL-17A and IL-22 responses in CD4+ T cells. We found that Nrf2−/− mice had reduced IL-22 responses in Ovaalbumin (Ova) + LPS and separately concanavalin A (Con A) administered mice. Furthermore, CDDO-Im, a selective Nrf2 activator, induced IL-22 but suppressed IL-17A response in CD4+ T cells polarized under Th17 cell condition. Our qPCR data revealed that CDDO-Im-activated CD4+ T cells had lower Rorc, but increased Cybb, Sod1 and Sod3 transcript. The expression pattern of Il23r and Sod2 was unaltered. CDDO-Im-dependent IL-17A but not IL-22 response was regulated by Sod3. Interestingly, we found that CDDO-Im induced aryl hydrocarbon receptor (Ahr) and its downstream Cyp1a1 and Cyp1b1 gene expression. The luciferase reporter assay data showed that CDDO-Im regulated Ahr promoter activity in a dose-dependent manner. Additionally, CDDO-Im induced Nqo1 expression, a Nrf2-activated gene, in WT mice but not in Ahr−/− mice. Finally, we confirmed that the CDDO-Immediated induction of IL-22 production in CD4+ T cells was abrogated in Ahr−/− mice. Collectively, our data show that Nrf2 promotes IL-22 production while it inhibits IL-17A expression in Th17 cells.