The cytochromes P450 (CYP) response to allergic inflammation of the lung

Cyp2e1 protects against OVA-induced allergic rhinitis through the inhibition of Th2 cell activation and differentiation: Mediated by MAFB

Allergic rhinitis (AR) is a common allergic disease. Cytochrome P450, family 2, subfamily e, polypeptide 1 (Cyp2e1) is a member of the cytochrome P450 family of enzymes, while its role in AR is still unveiled. In AR mice, T cell-specific overexpression of Cyp2e1 relieved the AR symptoms. Overexpressed-Cyp2e1 restrained the infiltration of eosinophils and mast cells in the nasal mucosa of mice, and the inflammatory cells in nasal lavage fluid (NALF). Cyp2e1 overexpressed mice exhibited decreased goblet cell hyperplasia and mucus secretion as well as decreased MUC5AC expression in nasal mucosa. The epithelial permeability and integrity of nasal mucosa were improved upon Cyp2e1 overexpression in AR mice, as evidenced by decreased fluorescein isothiocyanate-dextran 4 content in serum, increased expression of IL-25, IL-33, and TSLP in NALF, and increased expression of ZO-1 and occluding in nasal mucosa. Cyp2e1 inhibited Th2 immune response by decreasing the expression and secretion of IL-4, IL-5, and IL-13 as well as the expression of GATA-3 in NALF or nasal mucosa. We proved that Cyp2e1 inhibited the differentiation of naïve CD4+ T cells toward the Th2 subtype, which was regulated by MAFB by binding to Cyp2e1 promoter to activate its transcription. Overall, these results show the potential role of Cyp2e1 in alleviating AR symptoms by restraining CD4+ T cells to Th2 cell differentiation. Our findings provide further insight into the AR mechanism.

Asthma and Post-Asthmatic Fibrosis: A Search for New Promising Molecular Markers of Transition from Acute Inflammation to Pulmonary Fibrosis

Asthma is a heterogeneous pulmonary disorder, the progression and chronization of which leads to airway remodeling and fibrogenesis. To understand the molecular mechanisms of pulmonary fibrosis development, key genes forming the asthma-specific regulome and involved in lung fibrosis formation were revealed using a comprehensive bioinformatics analysis. The bioinformatics data were validated using a murine model of ovalbumin (OVA)-induced asthma and post-asthmatic fibrosis. The performed analysis revealed a range of well-known pro-fibrotic markers (Cat, Ccl2, Ccl4, Ccr2, Col1a1, Cxcl12, Igf1, Muc5ac/Muc5b, Spp1, Timp1) and a set of novel genes (C3, C3ar1, Col4a1, Col4a2, Cyp2e1, Fn1, Thbs1, Tyrobp) mediating fibrotic changes in lungs already at the stage of acute/subacute asthma-driven inflammation. The validation of genes related to non-allergic bleomycin-induced pulmonary fibrosis on asthmatic/fibrotic lungs allowed us to identify new universal genes (Col4a1 and Col4a2) associated with the development of lung fibrosis regardless of its etiology. The similarities revealed in the expression profiles of nodal fibrotic genes between asthma-driven fibrosis in mice and nascent idiopathic pulmonary fibrosis in humans suggest a tight association of identified genes with the early stages of airway remodeling and can be considered as promising predictors and early markers of pulmonary fibrosis.

Porphyromonas gingivalis W83 Membrane Components Induce Distinct Profiles of Metabolic Genes in Oral Squamous Carcinoma Cells

Periodontitis, a chronic inflammatory disease is caused by a bacterial biofilm, affecting all periodontal tissues and structures. This chronic disease seems to be associated with cancer since, in general, inflammation intensifies the risk for carcinoma development and progression. Interactions between periodontal pathogens and the host immune response induce the onset of periodontitis and are responsible for its progression, among them Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic rod, capable of expressing a variety of virulence factors that is considered a keystone pathogen in periodontal biofilms. The aim of this study was to investigate the genome-wide impact of P. gingivalis W83 membranes on RNA expression of oral squamous carcinoma cells by transcriptome analysis. Human squamous cell carcinoma cells (SCC-25) were infected for 4 and 24 h with extracts from P. gingivalis W83 membrane, harvested, and RNA was extracted. RNA sequencing was performed, and differential gene expression and enrichment were analyzed using GO, KEGG, and REACTOME. The results of transcriptome analysis were validated using quantitative real-time PCR with selected genes. Differential gene expression analysis resulted in the upregulation of 15 genes and downregulation of 1 gene after 4 h. After 24 h, 61 genes were upregulated and 278 downregulated. GO, KEGG, and REACTONE enrichment analysis revealed a strong metabolic transcriptomic response signature, demonstrating altered gene expressions after 4 h and 24 h that mainly belong to cell metabolic pathways and replication. Real-time PCR of selected genes belonging to immune response, signaling, and metabolism revealed upregulated expression of CCL20, CXCL8, NFkBIA, TNFAIP3, TRAF5, CYP1A1, and NOD2. This work sheds light on the RNA transcriptome of human oral squamous carcinoma cells following stimulation with P. gingivalis membranes and identifies a strong metabolic gene expression response to this periodontal pathogen. The data provide a base for future studies of molecular and cellular interactions between P. gingivalis and oral epithelium to elucidate the basic mechanisms of periodontitis and the development of cancer.

Multiple Targets for Oxysterols in Their Regulation of the Immune System

Oxysterols, or cholesterol oxidation products, are naturally occurring lipids which regulate the physiology of cells, including those of the immune system. In contrast to effects that are mediated through nuclear receptors or by epigenetic mechanism, which take tens of minutes to occur, changes in the activities of cell-surface receptors caused by oxysterols can be extremely rapid, often taking place within subsecond timescales. Such cell-surface receptor effects of oxysterols allow for the regulation of fast cellular processes, such as motility, secretion and endocytosis. These cellular processes play critical roles in both the innate and adaptive immune systems. This review will survey the two broad classes of cell-surface receptors for oxysterols (G-protein coupled receptors (GPCRs) and ion channels), the mechanisms by which cholesterol oxidation products act on them, and their presence and functions in the different cell types of the immune system. Overall, this review will highlight the potential of oxysterols, synthetic derivatives and their receptors for physiological and therapeutic modulation of the immune system.

A stepwise integrated multi-system to screen quality markers of Chinese classic prescription Qingzao Jiufei decoction on the treatment of acute lung injury by combining 'network pharmacology-metabolomics-PK/PD modeling'

BACKGROUND

Previously, we have investigated the therapeutic mechanism of Qingzao Jiufei Decoction (QZJFD), a Chinese classic prescription, on acute lung injury (ALI), however, which remained to be further clarified together with the underlying efficacy related compounds for quality markers (Q-markers).

HYPOTHESIS/PURPOSE

To explore Q-markers of QZJFD on ALI by integrating a stepwise multi-system with 'network pharmacology-metabolomics- pharmacokinetic (PK)/ pharmacodynamic (PD) modeling'.

METHODS

First, based on in vitro and in vivo component analysis, a network pharmacology strategy was developed to identify active components and potential action mechanism of QZJFD on ALI. Next, studies of poly-pharmacology and non-targeted metabolomics were used to elaborate efficacy and verify network pharmacology results. Then, a comparative PK study on active components in network pharmacology was developed to profile their dynamic laws in vivo under ALI, suggesting Q-marker candidates. Next, quantified analytes with marked PK variations after modeling were fitted with characteristic endogenous metabolites along drug concentration-efficacy-time curve in a PK-PD modeling to verify and select primary effective compounds. Finally, Q-markers were further chosen based on representativeness among analytes through validity analysis of PK quantitation of primary effective compounds.

RESULTS

In virtue of 121 and 33 compounds identified in vitro and in vivo, respectively, 33 absorbed prototype compounds were selected to construct a ternary network of '20 components-47 targets-113 pathways' related to anti-ALI of QZJFD. Predicted mechanism (leukocytes infiltration, cytokines, endogenous metabolism) were successively verified by poly-pharmacology and metabolomics. Next, 18 measurable components were retained from 20 analytes by PK comparison under ALI. Then, 15 primary effective compounds from 18 PK markers were further selected by PK-PD analysis. Finally, 9 representative Q-markers from 15 primary effective compounds attributed to principal (chlorogenic acid), ministerial (methylophiopogonanone A, methylophiopogonanone B), adjuvant (sesamin, ursolic acid, amygdalin), conductant drugs (liquiritin apioside, liquiritigenin and isoliquiritin) in QZJFD, were recognized by substitutability and relevance of plasmatic concentration at various time points.

CONCLUSION

9 Q-markers for QZJFD on ALI were identified by a stepwise integration strategy, moreover, which was a powerful tool for screening Q-makers involved with the therapeutic action of traditional Chinese medicine (TCM) prescription and promoting the process of TCM modernization and scientification.

The incidence of ALK inhibitor-related pneumonitis in advanced non-small-cell lung cancer patients: A systematic review and meta-analysis

INTRODUCTION

We evaluated the incidence of pneumonitis in clinical trials of anaplastic lymphoma kinase (ALK) inhibitors in patients with advanced non-small cell lung cancer (NSCLC) and compared the incidence among different cohorts, in order to identify possible predisposing factors for ALK inhibitor-related pneumonitis.

METHODS

MEDLINE and EMBASE search up to 1/30/18 using the keywords, "alectinib", "ceritinib", "crizotinib", "brigatinib", and "lung cancer", resulting in a total of 20 eligible cohorts with 2261 patients treated with ALK inhibitor monotherapy for advanced NSCLC. The pooled incidences of all-grade, high-grade, and grade 5 pneumonitis were calculated. Subgroup analyses were conducted with meta-regression using study-level covariates.

RESULTS

The overall pooled incidence of pneumonitis was 2.14% (95% CI: 1.37-3.34) for all grade, 1.33% (95% CI: 0.80-2.21) for high grade, and 0.22% (95% CI: 0.09-0.52) for grade 5 pneumonitis. The incidence was significantly higher in studies from Japan compared to studies of non-Japan origin, for all-grade (6.25% vs 1.14%, p < 0.001) and high-grade pneumonitis (3.31% vs 0.39%, p < 0.001). Multivariate meta-regression demonstrated the cohorts from Japanese studies had significantly higher odds of pneumonitis for all-grade (odds ratio [OR]: 4.329 [95% CI: 1.918, 9.770], p < 0.001) compared to those of non-Japan origin, after adjusting for types of ALK inhibitors.

CONCLUSIONS

The overall incidence of ALK inhibitor pneumonitis was 2.14% in patients with advanced NSCLS. The patients from Japanese cohorts had a higher incidence of ALK-inhibitor pneumonitis, which indicates the need for increased awareness and caution for pneumonitis in Japanese patients treated with ALK inhibitors.

Acetaminophen Attenuates House Dust Mite-Induced Allergic Airway Disease in Mice

Epidemiologic evidence suggests that N-acetyl-para-aminophenol (APAP) may play a role in the pathogenesis of asthma, likely through pro-oxidant mechanisms. However, no studies have investigated the direct effects of APAP on the development of allergic inflammation. To determine the likelihood of a causal relationship between APAP and asthma pathogenesis, we explored the effects of APAP on inflammatory responses in a murine house dust mite (HDM) model of allergic airway disease. We hypothesized that APAP would enhance the development of HDM-induced allergic inflammation. The HDM model consisted of once daily intranasal instillations for up to 2 weeks with APAP or vehicle administration 1 hour prior to HDM during either week 1 or 2. Primary assessment of inflammation included bronchoalveolar lavage (BAL), cytokine expression in lung tissue, and histopathology. Contrary to our hypothesis, the effects of HDM treatment were substantially diminished in APAP-treated groups compared with controls. APAP-treated groups had markedly reduced airway inflammation: including decreased inflammatory cells in the BAL fluid, lower cytokine expression in lung tissue, and less perivascular and peribronchiolar immune cell infiltration. The anti-inflammatory effect of APAP was not abrogated by an inhibitor of cytochrome P450 (P450) metabolism, suggesting that the effect was due to the parent compound or a non-P450 generated metabolite. Taken together, our studies do not support the biologic plausibility of the APAP hypothesis that APAP use may contribute to the causation of asthma. Importantly, we suggest the mechanism by which APAP modulates airway inflammation may provide novel therapeutic targets for asthma.

Cytochrome P450 ω-Hydroxylases in Inflammation and Cancer

Cytochrome P450-dependent ω-hydroxylation is a prototypic metabolic reaction of CYP4 family members that is important for the elimination and bioactivation of not only therapeutic drugs, but also endogenous compounds, principally fatty acids. Eicosanoids, derived from arachidonic acid, are key substrates in the latter category. Human CYP4 enzymes, mainly CYP4A11, CYP4F2, and CYP4F3B, hydroxylate arachidonic acid at the omega position to form 20-HETE, which has important effects in tumor progression and on angiogenesis and blood pressure regulation in the vasculature and kidney. CYP4F3A in myeloid tissue catalyzes the ω-hydroxylation of leukotriene B4 to 20-hydroxy leukotriene B4, an inactivation process that is critical for the regulation of the inflammatory response. Here, we review the enzymology, tissue distribution, and substrate selectivity of human CYP4 ω-hydroxylases and their roles as catalysts for the formation and termination of the biological effects of key eicosanoid metabolites in inflammation and cancer progression.

CYP7B1 Enzyme Deletion Impairs Reproductive Behaviors in Male Mice

In addition to androgenic properties mediated via androgen receptors, dihydrotestosterone (DHT) also regulates estrogenic functions via an alternate pathway. These estrogenic functions of DHT are mediated by its metabolite 5α-androstane-3β, 17β-diol (3β-diol) binding to estrogen receptor β (ERβ). CYP7B1 enzyme converts 3β-diol to inactive 6α- or 7α-triols and plays an important role as a regulator of estrogenic functions mediated by 3β-diol. Using a mutant mouse carrying a null mutation for the CYP7B1 gene (CYP7B1KO), we examined the contribution of CYP7B1 on physiology and behavior. Male, gonadectomized (GDX) CYP7B1KO and their wild type (WT) littermates were assessed for their behavioral phenotype, anxiety-related behavioral measures, and hypothalamic pituitary adrenal axis reactivity. No significant effects of genotype were evident in anxiety-like behaviors in open field (OFA), light-dark (L/D) exploration, and elevated plus maze (EPM). T significantly reduced open arm time on the EPM while not affecting L/D exploratory and OFA behaviors in CYP7B1KO and WT littermates. T also attenuated the corticosterone response to EPM in both genotypes. In GDX animals, T was able to reinstate male-specific reproductive behaviors (latencies and number of mounts, intromission, and ejaculations) in the WT but not in the CYP7B1KO mice. The male reproductive behavior defect in CYP7B1KO seems to be due to their inability to distinguish olfactory cues from a behavioral estrus female. CYP7B1KO mice also showed a reduction in androgen receptor mRNA expression in the olfactory bulb. Our findings suggest a novel role for the CYP7B1 enzyme in the regulation of male reproductive behaviors.

RNA expression analysis of passive transfer myasthenia supports extraocular muscle as a unique immunological environment

PURPOSE

Myasthenia gravis demonstrates a distinct predilection for involvement of the extraocular muscles (EOM), and we have hypothesized that this may be due to a unique immunological environment. To assess this hypothesis, we took an unbiased approach to analyze RNA expression profiles in EOM, diaphragm, and extensor digitorum longus (EDL) in rats with experimentally acquired myasthenia gravis (EAMG).

METHODS

Experimentally acquired myasthenia gravis was induced in rats by intraperitoneal injection of antibody directed against the acetylcholine receptor (AChR), whereas control rats received antibody known to bind the AChR but not induce disease. After 48 hours, animals were killed and muscles analyzed by RNA expression profiling. Profiling results were validated using qPCR and immunohistochemical analysis.

RESULTS

Sixty-two genes common among all muscle groups were increased in expression. These fell into four major categories: 12.8% stress response, 10.5% immune response, 10.5% metabolism, and 9.0% transcription factors. EOM expressed 212 genes at higher levels, not shared by the other two muscles, and a preponderance of EOM gene changes fell into the immune response category. EOM had the most uniquely reduced genes (126) compared with diaphragm (26) and EDL (50). Only 18 downregulated genes were shared by the three muscles. Histological evaluation and disease load index (sum of fold changes for all genes) demonstrated that EOM had the greatest degree of pathology.

CONCLUSIONS

Our studies demonstrated that consistent with human myasthenia gravis, EOM demonstrates a distinct RNA expression signature from EDL and diaphragm, which is based on differences in the degree of muscle injury and inflammatory response.

Genome-wide association mapping of acute lung injury in neonatal inbred mice

Reactive oxygen species (ROS) contribute to the pathogenesis of many acute and chronic pulmonary disorders, including bronchopulmonary dysplasia (BPD), a respiratory condition that affects preterm infants. However, the mechanisms of susceptibility to oxidant stress in neonatal lungs are not completely understood. We evaluated the role of genetic background in response to oxidant stress in the neonatal lung by exposing mice from 36 inbred strains to hyperoxia (95% O2) for 72 h after birth. Hyperoxia-induced lung injury was evaluated by using bronchoalveolar lavage fluid (BALF) analysis and pathology. Statistically significant interstrain variation was found for BALF inflammatory cells and protein (heritability estimates range: 33.6-55.7%). Genome-wide association mapping using injury phenotypes identified quantitative trait loci (QTLs) on chromosomes 1, 2, 4, 6, and 7. Comparative mapping of the chromosome 6 QTLs identified Chrm2 (cholinergic receptor, muscarinic 2, cardiac) as a candidate susceptibility gene, and mouse strains with a nonsynonymous coding single-nucleotide polymorphism (SNP) in Chrm2 that causes an amino acid substitution (P265L) had significantly reduced hyperoxia-induced inflammation compared to strains without the SNP. Further, hyperoxia-induced lung injury was significantly reduced in neonatal mice with targeted deletion of Chrm2, relative to wild-type controls. This study has important implications for understanding the mechanisms of oxidative lung injury in neonates.

Transcriptional suppression of CYP2A13 expression by lipopolysaccharide in cultured human lung cells and the lungs of a CYP2A13-humanized mouse model

CYP2A13, a human P450 enzyme preferentially expressed in the respiratory tract, is highly efficient in the metabolic activation of tobacco-specific nitrosamines. The aim of this study was to test the hypothesis that inflammation suppresses CYP2A13 expression in the lung, thus explaining the large interindividual differences in CYP2A13 levels previously found in human lung biopsy samples. We first demonstrated that the bacterial endotoxin lipopolysaccharide (LPS) and the proinflammatory cytokine IL-6 can suppress CYP2A13 messenger RNA (mRNA) expression in the NCI-H441 human lung cell line. We then report that an ip injection of LPS (1mg/kg), which induces systemic and lung inflammation, caused substantial reductions in CYP2A13 mRNA (~50%) and protein levels (~80%) in the lungs of a newly generated CYP2A13-humanized mouse model. We further identified two critical CYP2A13 promoter regions, one (major) between -484 and -1008bp and the other (minor) between -134 and -216bp, for the response to LPS, through reporter gene assays in H441 cells. The potential involvement of the nuclear factor NF-κB in LPS-induced CYP2A13 downregulation was suggested by identification of putative NF-κB binding sites within the LPS response regions and effects of an NF-κB inhibitor (pyrrolidine dithiocarbamate) on CYP2A13 expression in H441 cells. Results from gel shift assays further confirmed binding of NF-κB-like nuclear proteins of H441 cells to the major LPS response region of the CYP2A13 promoter. Thus, our findings strongly support the hypothesis that CYP2A13 levels in human lung can be suppressed by inflammation associated with disease status in tissue donors, causing underestimation of CYP2A13 levels in healthy lung.

Interleukin 13 exposure enhances vitamin D-mediated expression of the human cathelicidin antimicrobial peptide 18/LL-37 in bronchial epithelial cells

Vitamin D is an important regulator of the expression of antimicrobial peptides, and vitamin D deficiency is associated with respiratory infections. Regulating expression of antimicrobial peptides, such as the human cathelicidin antimicrobial peptide 18 (hCAP18)/LL-37, by vitamin D in bronchial epithelial cells requires local conversion of 25(OH)-vitamin D(3) (25D(3)) into its bioactive metabolite, 1,25(OH)(2)-vitamin D(3) (1,25D(3)), by CYP27B1. Low circulating vitamin D levels in childhood asthma are associated with more-severe exacerbations, which are often associated with infections. Atopic asthma is accompanied by Th2-driven inflammation mediated by cytokines such as interleukin 4 (IL-4) and IL-13, and the effect of these cytokines on vitamin D metabolism and hCAP18/LL-37 expression is unknown. Therefore, we investigated this with well-differentiated bronchial epithelial cells. To this end, cells were treated with IL-13 with and without 25D(3), and expression of hCAP18/LL-37, CYP27B1, the 1,25D(3)-inactivating enzyme CYP24A1, and vitamin D receptor was assessed by quantitative PCR. We show that IL-13 enhances the ability of 25D(3) to increase expression of hCAP18/LL-37 and CYP24A1. In addition, exposure to IL-13 resulted in increased CYP27B1 expression, whereas vitamin D receptor (VDR) expression was not significantly affected. The enhancing effect of IL-13 on 25D(3)-mediated expression of hCAP18/LL-37 was further confirmed using SDS-PAGE Western blotting and immunofluorescence staining. In conclusion, we demonstrate that IL-13 induces vitamin D-dependent hCAP18/LL-37 expression, most likely by increasing CYP27B1. These data suggest that Th2 cytokines regulate the vitamin D metabolic pathway in bronchial epithelial cells.

Multicohort genomewide association study reveals a new signal of protection against HIV-1 acquisition

BACKGROUND

To date, only mutations in CCR5 have been shown to confer resistance to human immunodeficiency virus type 1 (HIV-1) infection, and these explain only a small fraction of the observed variability in HIV susceptibility.

METHODS

We performed a meta-analysis between 2 independent European genomewide association studies, each comparing HIV-1 seropositive cases with normal population controls known to be HIV uninfected, to identify single-nucleotide polymorphisms (SNPs) associated with the HIV-1 acquisition phenotype. SNPs exhibiting P < 10(-5) in this first stage underwent second-stage analysis in 2 independent US cohorts of European descent.

RESULTS

After the first stage, a single highly significant association was revealed for the chromosome 8 rs6996198 with HIV-1 acquisition and was replicated in both second-stage cohorts. Across the 4 groups, the rs6996198-T allele was consistently associated with a significant reduced risk of HIV-1 infection, and the global meta-analysis reached genomewide significance: P(combined) = 7.76 × 10(-8).

CONCLUSIONS

We provide strong evidence of association for a common variant with HIV-1 acquisition in populations of European ancestry. This protective signal against HIV-1 infection is the first identified outside the CCR5 nexus. First clues point to a potential functional role for a nearby candidate gene, CYP7B1, but this locus warrants further investigation.

CYP7B1: one cytochrome P450, two human genetic diseases, and multiple physiological functions

The CYP7B1 cytochrome P450 enzyme hydroxylates carbons 6 and 7 of the B ring of oxysterols and steroids. Hydroxylation reduces the biological activity of these substrates and facilitates their conversion to end products that are readily excreted from the body. CYP7B1 is expressed in the liver, reproductive tract, and brain and performs different physiological functions in each tissue. Hepatic CYP7B1 activity is crucial for the inactivation of oxysterols and their subsequent conversion into bile salts. Loss of CYP7B1 activity is associated with liver failure in children. In the reproductive tract, the enzyme metabolizes androgens that antagonize estrogen action; mice without CYP7B1 have abnormal prostates and ovaries. The role of CYP7B1 in brain is under investigation; recent studies show that spastic paraplegia type 5, a progressive neuropathy, is caused by loss-of-function mutations in the human gene.

Coordinate regulation of metabolic enzymes and transporters by nuclear transcription factors in human liver disease

BACKGROUND

It has been hypothesised, mainly from studies with animal models of liver disease, that the transport of substrates for metabolic enzymes and their subsequent metabolism and elimination in hepatic bile or blood is co-ordinated, but there is little information on this process in diseased human liver.

METHODS

In this study we have measured by reverse transcription polymerase chain reaction (RT-PCR) major genes involved in drug metabolism from UDP-glucuronosyltransferases (UGT1A1, UGT1A6, UGT1A9, and UGT2B4) and cytochrome P450 (CYP) families (CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4), transport (OATP-C, MRP2, MRP3, and MDR1) and major transcription factors (PXR, CAR, HNF1alpha, HNF4alpha, RXR, and AHR) involved in their regulation. Liver biopsy tissue from patients with viral hepatitis was scored for inflammation and fibrosis by the METAVIR system, and separated into groups with mild (A0-1; F0-1, n = 20) or severe (A2-3; F3-4, n = 19) liver disease. Correlation analysis (Spearman rank-test, P < 0.05) was used to identify metabolic enzymes and transporters which shared significant correlation with transcription factors.

RESULTS

Our results show an extensive correlation between transcription factors, transporters, and metabolic enzymes. An unexpected finding was that this was substantially greater in the severely diseased liver. Cross-talk between transcription factors was markedly increased in tissue from patients with severe liver disease, particularly between CAR, HNF4alpha, and PXR.

CONCLUSION

Our results support the hypothesis of co-ordinate regulation of metabolic enzymes and transporters in diseased human liver, as part of a widespread co-ordinated process under the control of nuclear receptor transcription factors.

Increased CYP4B1 mRNA is associated with the inhibition of dextran sulfate sodium-induced colitis by caffeic acid in mice

Susceptibility to inflammatory bowel diseases depends upon interactions between the genetics of the individual and induction of chronic mucosal inflammation. We hypothesized that administration of dietary phenolics, caffeic acid and rutin, would suppress upregulation of inflammatory markers and intestinal damage in a mouse model of colitis. Colitis was induced in C3H/ HeOuJ mice (8 weeks old, 6 male/6 female per treatment) with 1.25% dextran sulfate sodium (DSS) for 6 d in their drinking water. Rutin (1.0 mmol (524 mg)/kg in diet), caffeic acid (1.0 mmol (179 mg)/kg in diet), and hypoxoside extract (15 mg/d, an anticolitic phenolic control) were fed to the mice for 7 d before and during DSS treatment, as well as without DSS treatment. Body weight loss was prevented by rutin and caffeic acid during DSS treatment. Colon lengths in mice fed caffeic acid and hypoxoside during DSS treatment were similar to DSS-negative control. Food intake was improved and myeloperoxidase (MPO) was decreased with each phenolic treatment in DSS-treated mice compared with DSS treatment alone. Colonic mRNA expression of IL-17 and iNOS were inhibited when IL-4 was increased by each phenolic treatment combined with DSS, whereas CYP4B1 mRNA was increased only by caffeic acid in DSS-treated mice, compared with DSS treatment alone. Colonic and cecal histopathology scores of DSS-treated mice were significantly more severe (P < 0.01) than in mice fed caffeic acid before and during DSS treatment, based on mucosal height, necrosis, edema, erosion, and inflammatory cell infiltration. Although both rutin and caffeic acid suppressed the expression of selected inflammatory markers, only caffeic acid protected against DSS-induced colitis, in association with normalization of CYP4B1 expression. The inhibition of DSS-induced colitic pathology by caffeic acid was mediated by mechanisms in addition to anti-inflammatory effects that deserve further study.

20-Hydroxylation is the CYP-dependent and retinoid-inducible leukotriene B4 inactivation pathway in human and mouse skin cells

Metabolic inactivation of leukotriene B4 (LTB4) is an innate mechanism to resolve tissue inflammation. We studied the nine Cyp4f genes in the mouse genome, measuring cutaneous transcript levels by real-time polymerase chain reaction, and LTB4 metabolism in mouse and human skin. Transcripts arising from Cyp4f13 and 4f16 ranked most abundant, Cyp4f14, 4f17, and 4f37 ranked least abundant, and Cyp4f18 and 4f39 ranked intermediate. Those from Cyp4f15 and Cyp4f40 were highly variable or too low to measure in some animals. Retinoic acid exposure induced microsomal LTB4 hydroxylation activities in mouse and human skin cells. Two NADPH-dependent LTB4 metabolites eluted identically with 20-OH and 20-COOH LTB4 reference standards. Collision induced dissociation of the precursor ion m/z 351 confirmed that LTB4 products from CYP4F3A and human epidermal keratinocytes are identical structurally to 20-OH LTB4. We conclude 20-hydroxylation is the major CYP-dependent LTB4 inactivation pathway in skin; this retinoid-inducible metabolic pathway has capacity to modulate tissue levels of pro-inflammatory lipids.