Expression of cytochromes P450 4F4 and 4F5 in infection and injury models of inflammation

Fragrances as a trigger of immune responses in different environments

Fragrances can cause allergic skin reactions, expressed as allergic contact dermatitis and reactions in the respiratory tract that range from acute temporary upper airway irritation to obstructive lung disease. These adverse health effects may result from the stimulation of a specific (adaptive) immune response. Th1 cells, which essentially produce interleukin-2 (IL-2) and interferon-γ (IFN-γ), play a key role in allergic contact dermatitis and also on allergic sensitization to common allergens (e.g., nickel and fragrance). It has been shown that fragrance allergy leads to Th2/Th22 production of IL-4, IL-5 and IL-13, controlling the development of IgE and mediating hypersensitivity reactions in the lung, such as asthma. Cytokines released during immune response modulate the expression of cytochrome P450 (CYPs) proteins, which can result in alterations of the pharmacological effects of substances in inflammatory diseases. The mechanisms linking environment and immunity are still not completely understood but it is known that aryl hydrocarbon receptor (AhR) is a sensor with conserved ligand-activated transcription factor, highly expressed in cells that controls complex transcriptional programs which are ligand and cell type specific, with CYPs as targeted genes. This review focuses on these important aspects of immune responses of the skin and respiratory tract cells, describing some in vitro models applied to evaluate the mechanisms involved in fragrance-induced allergy.

Effect of inflammation on cytochrome P450-mediated arachidonic acid metabolism and the consequences on cardiac hypertrophy

The incidence of heart failure (HF) is generally preceded by cardiac hypertrophy (CH), which is the enlargement of cardiac myocytes in response to stress. During CH, the metabolism of arachidonic acid (AA), which is present in the cell membrane phospholipids, is modulated. Metabolism of AA gives rise to hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acids (EETs) via cytochrome P450 (CYP) ω-hydroxylases and CYP epoxygenases, respectively. A plethora of studies demonstrated the involvement of CYP-mediated AA metabolites in the pathogenesis of CH. Also, inflammation is known to be a characteristic hallmark of CH. In this review, our aim is to highlight the impact of inflammation on CYP-derived AA metabolites and CH. Inflammation is shown to modulate the expression of various CYP ω-hydroxylases and CYP epoxygenases and their respective metabolites in the heart. In general, HETEs such as 20-HETE and mid-chain HETEs are pro-inflammatory, while EETs are characterized by their anti-inflammatory and cardioprotective properties. Several mechanisms are implicated in inflammation-induced CH, including the modulation of NF-κB and MAPK. This review demonstrated the inflammatory modulation of cardiac CYPs and their metabolites in the context of CH and the anti-inflammatory strategies that can be employed in the treatment of CH and HF.

Transcriptomic Analyses Reveal 2 and 4 Family Members of Cytochromes P450 (CYP) Involved in LPS Inflammatory Response in Pharynx of Ciona robusta

Cytochromes P450 (CYP) are enzymes responsible for the biotransformation of most endogenous and exogenous agents. The expression of each CYP is influenced by a unique combination of mechanisms and factors including genetic polymorphisms, induction by xenobiotics, and regulation by cytokines and hormones. In recent years, Ciona robusta, one of the closest living relatives of vertebrates, has become a model in various fields of biology, in particular for studying inflammatory response. Using an in vivo LPS exposure strategy, next-generation sequencing (NGS) and qRT-PCR combined with bioinformatics and in silico analyses, compared whole pharynx transcripts from naïve and LPS-exposed C. robusta, and we provide the first view of cytochrome genes expression and miRNA regulation in the inflammatory response induced by LPS in a hematopoietic organ. In C. robusta, cytochromes belonging to 2B,2C, 2J, 2U, 4B and 4F subfamilies were deregulated and miRNA network interactions suggest that different conserved and species-specific miRNAs are involved in post-transcriptional regulation of cytochrome genes and that there could be an interplay between specific miRNAs regulating both inflammation and cytochrome molecules in the inflammatory response in C. robusta.

The Functions of Cytochrome P450 ω-hydroxylases and the Associated Eicosanoids in Inflammation-Related Diseases

The cytochrome P450 (CYP) ω-hydroxylases are a subfamily of CYP enzymes. While CYPs are the main metabolic enzymes that mediate the oxidation reactions of many endogenous and exogenous compounds in the human body, CYP ω-hydroxylases mediate the metabolism of multiple fatty acids and their metabolites via the addition of a hydroxyl group to the ω- or (ω-1)-C atom of the substrates. The substrates of CYP ω-hydroxylases include but not limited to arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, epoxyeicosatrienoic acids, leukotrienes, and prostaglandins. The CYP ω-hydroxylases-mediated metabolites, such as 20-hyroxyleicosatrienoic acid (20-HETE), 19-HETE, 20-hydroxyl leukotriene B4 (20-OH-LTB₄), and many ω-hydroxylated prostaglandins, have pleiotropic effects in inflammation and many inflammation-associated diseases. Here we reviewed the classification, tissue distribution of CYP ω-hydroxylases and the role of their hydroxylated metabolites in inflammation-associated diseases. We described up-regulation of CYP ω-hydroxylases may be a pathogenic mechanism of many inflammation-associated diseases and thus CYP ω-hydroxylases may be a therapeutic target for these diseases. CYP ω-hydroxylases-mediated eicosanods play important roles in inflammation as pro-inflammatory or anti-inflammatory mediators, participating in the process stimulated by cytokines and/or the process stimulating the production of multiple cytokines. However, most previous studies focused on 20-HETE,and further studies are needed for the function and mechanisms of other CYP ω-hydroxylases-mediated eicosanoids. We believe that our studies of CYP ω-hydroxylases and their associated eicosanoids will advance the translational and clinal use of CYP ω-hydroxylases inhibitors and activators in many diseases.

Postnatal distribution of ZnO nanoparticles to the breast milk through oral route and their risk assessment for breastfed rat offsprings

Various studies in rodents have shown that nanoparticles are transferred to the breast milk. Under the present study, lactating Wistar rats were repetitively gavaged 5, 25, and 50 mg/kg bw of zinc oxide nanoparticles (ZnO-NPs) and 50 mg kg^-1 bw of bulk zinc oxide (bZnO) for 19 days after parturition. The results showed that ZnO-NPs were absorbed in the small intestine of dams and distributed to the liver. Furthermore, ZnO-NPs were distributed to the intestine and liver of rat pups through dam's milk. No significant change in body weight was observed in the dams treated with ZnO-NPs or bZnO and their offsprings as compared to the control group. The spleen weight significantly increased in the rat dams treated with 50 mg kg^-1 of ZnO-NPs. ZnO-NPs were mostly excreted through feces. The levels of liver cytochrome P450 reductase and serum total antioxidant capacity significantly decreased in the rat dams treated with ZnO-NPs (50 mg kg^-1) and their offsprings. The levels of serum cytokines (tumor necrosis factor-alpha and interleukin-1 beta) and liver injury marker enzymes (alanine aminotransferase and aspartate aminotransferase) significantly increased in the rat dams treated with ZnO-NPs (25 and 50 mg kg^-1) and their offsprings. The level of immunoglobulin A secretion in the intestinal fluid of rat dams and their offsprings is significantly increased by increasing the dose of ZnO-NPs. Histopathology of intestine and liver of offsprings whose rat dams were treated with ZnO-NPs (50 mg kg^-1) showed gross pathological changes. These results provide information for the safety evaluation of ZnO-NPs use during lactation. In conclusion, a dose-dependent postnatal transfer of ZnO-NPs is hazardous to the breastfed offsprings.

The Role of Cytochromes P450 in Infection

Cytochromes are expressed in many different tissues of the human body. They are found mostly in intestinal and hepatic tissues. Cytochromes P450 (CYPs) are enzymes that oxidize substances using iron and are able to metabolize a large variety of xenobiotic substances. CYP enzymes are linked to a wide array of reactions including and O-dealkylation, S-oxidation, epoxidation, and hydroxylation. The activity of the typical P450 cytochrome is influenced by a variety of factors, such as genus, environment, disease state, herbicide, alcohol, and herbal medications. However, diet seems to play a major role. The mechanisms of action of dietary chemicals, macro- and micronutrients on specific CYP isoenzymes have been extensively studied. Dietary modulation has effects upon the metabolism of xenobiotics. Cytochromes harbor intra- or interindividual and intra- or interethnic genetic polymorphisms. Bacteria were shown to express CYP-like genes. The tremendous metabolic activity of the microbiota is associated to its abundant pool of CYP enzymes, which catalyze phase I and II reactions in drug metabolism. Disease states, intestinal disturbances, aging, environmental toxic effects, chemical exposures or nutrition modulate the microbial metabolism of a drug before absorption. A plethora of effects exhibited by most of CYP enzymes can resemble those of proinflammatory cytokines and IFNs. Moreover, they are involved in the initiation and persistence of pathologic pain by directly activating sensory neurons and inflammatory cytokines.

Interplay between pro-inflammatory cytokines and brain oxidative stress biomarkers: evidence of parallels between butyl paraben intoxication and the valproic acid brain physiopathology in autism rat model

Butyl paraben is a preservative used in food, drugs and cosmetics. Neurotoxic effect was reported recently beside the potential estrogenic activity of parabens. There is controversy as to the potential harmful effects of butyl parabens, which are suspected to contribute to autism and learning disabilities. The purpose of this study was to examine the similarities between paraben intoxication signs in the rat brain and brain markers in an autistic like rat model. This study provides evidence of many parallels between the two, including (1) oxidative stress, (2) decreased reduced glutathione levels and elevated oxidised glutathione, (3) mitochondrial dysfunction, and (4) neuroinflammation and increased pro-inflammatory cytokine levels in the brain (tumour necrosis factor-alpha, interleukin-1-beta, and interleukin-6). (5) Increased protein oxidation reported by a significant increase in 3-nitrotyrosine (3-NT)/tyrosine ratio. (6) A marked disturbance was found in the production of energy carriers (AMP, ATP and AMP/ATP ratio) in comparison with the control. The evidence suggests that paraben may, to some extent, either cause or contribute to the brain physiopathology in ASDs or pathogens that produce the brain pathology observed in the diagnosed rat model of ASD.

The cytochrome P450 genes of channel catfish: their involvement in disease defense responses as revealed by meta-analysis of RNA-Seq data sets

BACKGROUND

Cytochrome P450s (CYPs) encode one of the most diverse enzyme superfamily in nature. They catalyze oxidative reactions of endogenous molecules and exogenous chemicals.

METHODS

We identified CYPs genes through in silico analysis using EST, RNA-Seq and genome databases of channel catfish. Phylogenetic analyses and conserved syntenic analyses were conducted to determine their identities and orthologies. Meta-analysis of RNA-Seq databases was conducted to analyze expression profile of CYP genes following bacterial infection.

RESULTS

A full set of 61 CYP genes was identified and characterized in channel catfish. Phylogenetic tree and conserved synteny provided strong evidence of their identities and orthorlogy. Lineage-specific gene duplication was evident in a number of clans in channel catfish. CYP46A1 is missing in the catfish genome as observed with syntenic analysis and RT-PCR analysis. Thirty CYPs were found up- or down-regulated in liver, while seven and eight CYPs were observed regulated in intestine and gill following bacterial infection.

CONCLUSION

We systematically identified and characterized a full set of 61 CYP genes in channel catfish and studied their expression profiles after bacterial infection. While bacterial challenge altered the expression of large numbers of CYP genes, the mechanisms and significance of these changes are not known.

GENERAL SIGNIFICANCE

This work provides an example to systematically study CYP genes in non-model species. Moreover, it provides a basis for further toxicological and physiological studies in channel catfish.

Serum IL-6: a candidate biomarker for intracranial pressure elevation following isolated traumatic brain injury

Background

Increased intracranial pressure (ICP) is a serious, life-threatening, secondary event following traumatic brain injury (TBI). In many cases, ICP rises in a delayed fashion, reaching a maximal level 48-96 hours after the initial insult. While pressure catheters can be implanted to monitor ICP, there is no clinically proven method for determining a patient's risk for developing this pathology.

Methods

In the present study, we employed antibody array and Luminex-based screening methods to interrogate the levels of inflammatory cytokines in the serum of healthy volunteers and in severe TBI patients (GCS≤8) with or without incidence of elevated intracranial pressure (ICP). De-identified samples and ELISAs were used to confirm the sensitivity and specificity of IL-6 as a prognostic marker of elevated ICP in both isolated TBI patients, and polytrauma patients with TBI.

Results

Consistent with previous reports, we observed sustained increases in IL-6 levels in TBI patients irrespective of their ICP status. However, the group of patients who subsequently experienced ICP ≥ 25 mm Hg had significantly higher IL-6 levels within the first 17 hours of injury as compared to the patients whose ICP remained ≤20 mm Hg. When blinded samples (n = 22) were assessed, a serum IL-6 cut-off of <5 pg/ml correctly identified 100% of all the healthy volunteers, a cut-off of >128 pg/ml correctly identified 85% of isolated TBI patients who subsequently developed elevated ICP, and values between these cut-off values correctly identified 75% of all patients whose ICP remained ≤20 mm Hg throughout the study period. In contrast, the marker had no prognostic value in predicting elevated ICP in polytrauma patients with TBI. When the levels of serum IL-6 were assessed in patients with orthopedic injury (n = 7) in the absence of TBI, a significant increase was found in these patients compared to healthy volunteers, albeit lower than that observed in TBI patients.

Conclusions

Our results suggest that serum IL-6 can be used for the differential diagnosis of elevated ICP in isolated TBI.

CYP4Fs expression in rat brain correlates with changes in LTB4 levels after traumatic brain injury

Cytochrome P450 (CYP) 4Fs constitute a subgroup of the cytochrome P450 superfamily and are involved in cellular protection and metabolism of numerous molecules, including drugs, toxins, and eicosanoids. CYP4Fs are widely distributed in rat brain with each isoform having a unique distribution pattern throughout different brain regions. The present study shows that traumatic brain injury (TBI) triggers inflammation and elicits changes in mRNA expression of CYP4Fs in the frontal and occipital lobes and the hippocampus. At 24 h post-injury, almost all CYP4F mRNA expression is suppressed compared with sham control throughout these three regions, while at 2 weeks post-injury, all CYP4F mRNAs increase, reaching levels higher than those at 24 h post-injury or uninjured controls. These changes in CYP4F levels inversely correlate with levels of leukotriene B4 (LTB4) levels in the brain following injury at the same time points. TBI also causes changes in CYP4F protein expression and localization around the injury site. CYP4F1 and CYP4F6 immunoreactivity increases in surrounding astrocytes, while CYP4F4 immunoreactivity shifts from endothelia of cerebral vessels to astrocytes.

Altered eicosanoid metabolism in the cystic fibrosis mouse small intestine

OBJECTIVES

Imbalances in essential fatty acid levels have been reported in cystic fibrosis (CF), which may relate to elevated proinflammatory eicosanoid generation. The aim of this work was to better define eicosanoid metabolism in the CF intestine.

MATERIALS AND METHODS

We used the small intestine of the cystic fibrosis transmembrane conductance regulator knockout mouse (CF mouse) to measure eicosanoid metabolic gene expression by quantitative reverse transcription polymerase chain reaction and Western blot, and eicosanoid levels by enzyme immunoassay, as compared with wild-type (WT) littermates.

RESULTS

In the CF small intestine, expression of the secretory phospholipase A2 Pla2g5 mRNA was upregulated to 980% of WT levels. The following were downregulated: leukotriene C4 synthase Ltc4s (mRNA 55% of WT); omega-hydroxylase cytochrome P450s Cyp2c40 (mRNA 54% of WT), and Cyp4a10 (mRNA 4% of WT); and the major prostaglandin degradative enzymes prostaglandin dehydrogenase Hpgd (mRNA 27% of WT) and leukotriene B4 12-hydroxydehydrogenase/15-oxo-prostaglandin 13-reductase Ltb4dh (mRNA 64% and protein 30% of WT). The prostaglandins PGE2 and PGF2alpha were increased to 400% to 600% of WT levels in the CF mouse intestine, and the hydroxyeicosatetraenoic acids (HETEs) 12-, 15-, and 20-HETE were decreased to 3% to 20% of WT levels.

CONCLUSIONS

There are changes in eicosanoid metabolic gene expression that are accompanied by significant changes in specific eicosanoid levels. These changes are expected to play important roles in the pathophysiology of CF in the intestine.

Evidence for impairment of hepatic energy homeostasis in head-injured rat

Traumatic brain injury (TBI) is known to induce a metabolic adaptation characterized by a nitrogen transfer from the periphery to the liver. However, the consequences of TBI on liver energy status are poorly documented. We evaluated the consequences of TBI on liver energy homeostasis in rats. In a first set of experiments, rats were randomized into two groups: a TBI group traumatized by fluid percussion, and an ad libitum fed group (AL) of healthy rats. The rats were sacrificed at 2, 3, or 4 days (D2, D3, and D4, respectively to determine the kinetic of hepatic energy changes). Since TBI leads to a profound anorexia, in a second set of experiments TBI rats received enteral nutrition (TBI-EN group) for 4 days to specifically assess the role of anorexia in the hepatic disturbances. TBI led to a decrease in hepatic glycogen (D2: TBI 3.9 +/- 1.9 vs. AL 18.9 +/- 2.6 mg/g, p < 0.05) and ATP (D2: TBI 540 +/- 57 vs. AL 850 +/- 44 nmol/g, p < 0.05) contents. These effects were not linked to anorexia, since they were observed when rats were fed using continuous enteral nutrition. Interestingly, there was no adaptation of the mitochondrial oxidative capacity to compensate for the increase in energy requirements (cytochrome C oxidase activity: AL, 82 +/- 5; TBI, 82 +/- 4; and TBI-EN, 87 +/- 3 micromol/min/g, NS). These findings demonstrate that TBI is responsible for an impairment of liver energy homeostasis. Moreover, these alterations are related neither to anorexia nor to decreased mitochondrial oxidative capacity.

Genomic structure and regulation of the rat hepatic CYP4F1 gene by peroxisome proliferators

The rat hepatic gene CYP4F1 encodes a fatty acid omega hydroxylase P450 that metabolizes proinflammatory eicosanoids and long-chain fatty acids. We have completely sequenced the CYP4F1 gene (Accession Nos. AF200361 and AF181083), identified multiple transcription start sites, and characterized a strong core promoter region, -760/116, induced by retinoic acids and peroxisome proliferators in rat hepatoma McA-RH7777 cells. Three peroxisome proliferator responsive elements (PPRE) bind both PPARalpha/RXRalpha and HNF4alpha. Co-transfection of McA-RH7777 cells with the -760/116 reporter construct and PPARalpha/RXRalpha or HNF4alpha showed that HNF4alpha activated while PPARalpha/RXRalpha inhibited CYP4F1 promoter activity. Treating cells with Wy14,643 reversed all initial effects, indicating co-regulation of CYP4F1 gene transcription by PPARalpha/RXRalpha and HNF4alpha. Chromatin immunoprecipitation analysis of cells treated with Wy14,643 showed association of PPARalpha/RXRalpha with the active transcription of the CYP4F1 gene while in clofibrate treated rats HNF4alpha binds during gene repression, suggesting differential regulation of the CYP4F1 gene in vivo and in cell lines.

Inflammation resolved by retinoid X receptor-mediated inactivation of leukotriene signaling pathways

Leukotrienes are implicated in the pathogenesis of diverse, inflammation-driven diseases. Metabolic inactivation of leukotriene signaling is an innate response to resolve inflammation, yet little is known of mechanisms regulating disposition of leukotrienes in peripheral tissues afflicted in common inflammatory diseases. We studied leukotriene hydroxylases (CYP4F gene products) in human skin, a common target of inflammation and adverse drug reactions. Epidermal keratinocytes express at least six CYP4F enzymes; the most highly expressed and highly regulated is CYP4F3A-the main neutrophil leukotriene hydroxylase. Differentiation-specific factors and retinoids are positive CYP4F regulators in vitro, effecting increased leukotriene B4 hydroxylation (inactivation). CYP4F expression is up-regulated in situ in hyperproliferative dermatoses-an innate mechanism to repair and restore epidermal barrier competency-and after retinoid therapy. Enhanced CYP4F-mediated inactivation of leukotriene signaling is a previously unrecognized antiinflammatory property of therapeutic retinoids mediated by preferential interactions between retinoid X receptors and CYP4F promoter elements in epidermal cells.

Global gene expression analysis of the mouse colonic mucosa treated with azoxymethane and dextran sodium sulfate

BACKGROUND

Chronic inflammation is well known to be a risk factor for colon cancer. Previously we established a novel mouse model of inflammation-related colon carcinogenesis, which is useful to examine the involvement of inflammation in colon carcinogenesis. To shed light on the alterations in global gene expression in the background of inflammation-related colon cancer and gain further insights into the molecular mechanisms underlying inflammation-related colon carcinogenesis, we conducted a comprehensive DNA microarray analysis using our model.

METHODS

Male ICR mice were given a single ip injection of azoxymethane (AOM, 10 mg/kg body weight), followed by the addition of 2% (w/v) dextran sodium sulfate (DSS) to their drinking water for 7 days, starting 1 week after the AOM injection. We performed DNA microarray analysis (Affymetrix GeneChip) on non-tumorous mucosa obtained from mice that received AOM/DSS, AOM alone, and DSS alone, and untreated mice at wks 5 and 10.

RESULTS

Markedly up-regulated genes in the colonic mucosa given AOM/DSS at wk 5 or 10 included Wnt inhibitory factor 1 (Wif1, 48.5-fold increase at wk 5 and 5.7-fold increase at wk 10) and plasminogen activator, tissue (Plat, 48.5-fold increase at wk 5), myelocytomatosis oncogene (Myc, 3.0-fold increase at wk 5), and phospholipase A2, group IIA (platelets, synovial fluid) (Plscr2, 8.0-fold increase at wk 10). The notable down-regulated genes in the colonic mucosa of mice treated with AOM/DSS were the peroxisome proliferator activated receptor binding protein (Pparbp, 0.06-fold decrease at wk 10) and the transforming growth factor, beta 3 (Tgfb3, 0.14-fold decrease at wk 10). The inflammation-related gene, peroxisome proliferator activated receptor gamma (Ppargamma 0.38-fold decrease at wk 5), was also down-regulated in the colonic mucosa of mice that received AOM/DSS.

CONCLUSION

This is the first report describing global gene expression analysis of an AOM/DSS-induced mouse colon carcinogenesis model, and our findings provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies against carcinogenesis.

Brain trauma leads to enhanced lung inflammation and injury: evidence for role of P4504Fs in resolution

Traumatic brain injury is known to cause several secondary effects, which lead to multiple organ dysfunction syndrome. An acute systemic inflammatory response seems to play an integral role in the development of such complications providing the potential for massive secondary injury. We show that a contusion injury to the rat brain causes large migration of inflammatory cells (especially macrophages and neutrophils) in the major airways and alveolar spaces at 24 h post-injury, which is associated with enhanced pulmonary leukotriene B4 (LTB4) production within the lung. However, by 2 weeks after injury, a temporal switch occurs and the resolution of inflammation is underway. We provide evidence that 5-lipoxygenase and Cytochrome P450 4Fs (CYP4Fs), the respective enzymes responsible for LTB4 synthesis and breakdown, play crucial roles in setting the cellular concentration of LTB4. Activation of LTB4 breakdown via induction of CYP4Fs, predominantly in the lung tissue, serves as an endogenous signal to ameliorate further secondary damage. In addition, we show that CYP4Fs are localized primarily in the airways and pulmonary endothelium. Given the fact that adherence to the microvascular endothelium is an initial step in neutrophil diapedesis, the temporally regulated LTB4 clearance in the endothelium presents a novel focus for treatment of pulmonary inflammation after injury.

Broad up-regulation of innate defense factors during acute cholera

We used a whole-genome microarray screening system (Affymetrix human GeneChips covering 47,000 different transcripts) to examine the gene expression in duodenal mucosa during acute cholera. Biopsies were taken from the duodenal mucosa of seven cholera patients 2 and 30 days after the onset of diarrhea, and the gene expression patterns in the acute- and convalescent-phase samples were compared pairwise. Of about 21,000 transcripts expressed in the intestinal epithelium, 29 were defined as transcripts that were up-regulated and 33 were defined as transcripts that were down-regulated during acute cholera. The majority of the up-regulated genes characterized were found to have an established or possible role in the innate defense against infections; these genes included the LPLUNC1, LF, VCC1, TCN1, CD55, SERPINA3, MMP1, MMP3, IL1B, LCN2, SOCS3, GDF15, SLPI, CXCL13, and MUC1 genes. The results of confirmative PCR correlated well with the microarray data. An immunohistochemical analysis revealed increased expression of lactoferrin in lamina propria cells and increased expression of CD55 in epithelial cells, whereas increased expression of the SERPINA3 protein (alpha1-antichymotrypsin) was detected in both lamina propria and epithelial cells during acute cholera. The expression pattern of CD55 and SERPINA3 in cholera toxin (CT)-stimulated Caco-2 cells was the same as the pattern found in the intestinal mucosa during acute cholera, indicating that the activation of the CD55 and SERPINA3 genes in intestinal epithelium was induced by CT. In conclusion, during acute cholera infection, innate defense mechanisms are switched on to an extent not described previously. Both direct effects of CT on the epithelial cells and changes in the lamina propria cells contribute to this up-regulation.

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

The expression of the mouse Cyp family and key inflammatory mediators were examined in a model of ovalbumin (OVA)-induced allergic airway disease. The expression of IL-4, IL-13 and Ccl11 increased during the acute phase of allergic inflammation and decreased with its resolution. Interestingly, the expression of Ccl20 was increased during the resolution phase. The response of the Cyp gene family to the development of allergic inflammation was differential and correlated with the evolution of the inflammatory response. During the acute inflammatory phase the mRNA levels of Cyp2e1, Cyp2f2, Cyp2j6, Cyp4b1, Cyp8a1 and Cypor were decreased while the mRNA levels of Cyp4f18, Cyp5a1 and Cyp7b1 were elevated. With resolution of the inflammation the expression patterns returned to normal. These changes suggest that the Cyp family may play a role in the allergic inflammation by modulating the metabolism of xenobiotics and endogenous compounds such as LTB4, TXA1, PGI2 and native anti-glucocorticoids.

Cytochrome P450 4F subfamily: at the crossroads of eicosanoid and drug metabolism

The cytochrome P450 4F (CYP4F) subfamily has over the last few years come to be recognized for its dual role in modulating the concentrations of eicosanoids during inflammation as well as in the metabolism of clinically significant drugs. The first CYP4F was identified because it catalyzed the hydroxylation of leukotriene B(4) (LTB(4)) and since then many additional members of this subfamily have been documented for their distinct catalytic roles and functional significance. Recent evidence emerging in relation to the temporal change of CYP4F expression in response to injury and infection supports an important function for these isozymes in curtailing inflammation. Their tissue-dependent expression, isoform-based catalytic competence and unique response to the external stimuli imply a critical role for them to regulate organ-specific functions. From this standpoint variations in relative CYP4F levels in humans may have direct influence on the metabolic outcome through their ability to generate and/or degrade bioactive eicosanoids or therapeutic agents. This review covers the enzymatic characteristics and regulatory properties of human and rodent CYP4F isoforms and their physiological relevance to major pathways in eicosanoid and drug metabolism.

Alternative splicing within the human cytochrome P450 superfamily with an emphasis on the brain: the convolution continues

The human cytochrome P450 (CYP) superfamily of enzymes regulate hepatic phase 1 drug metabolism and subsequently play a significant role in pharmacokinetics, drug discovery and drug development. Alternative splicing of the cytochrome CYP gene transcripts enhances gene diversity and may play a role in transcriptional regulation of certain CYP proteins. Tissue-specific alternative splicing of CYPs is significant for its potential to add greater dimension to differential drug metabolism in hepatic and extrahepatic tissues, such as the brain, and to our understanding of the CYP family. This review provides an overview of tissue-specific splicing patterns, splicing types, regulation and the functional diversities between liver and splice variant CYP proteins and further explores the relevance of tissue-specific alternative splicing of CYPs in the nervous system.

Regulation of neuronal type genes in congestive heart failure rats

AIM

After myocardial infarction (MI), complex changes in the heart occur during progression into congestive heart failure (CHF). This study sought to identify regulated genes that could have a functional role in some of the changes seen in CHF.

METHODS

Myocardial infarction was induced by ligation of the left anterior descending coronary artery (LAD) in Wistar rats. Gene expression changes in 1- and 7-day MI left ventricular myocardium was analysed using complementary DNA (cDNA) filter arrays. Regulated genes were identified by repeated measurements and a ranked ratio analysis method.

RESULTS

A total of 135 genes were identified as differentially expressed. A few genes were robustly regulated at 1-day MI. In 7-day CHF hearts, changes in the expression of neuronal type genes was prominent (32%, n = 28). Eleven of these genes with no described association with CHF were selected for validation. One gene failed the validation. In CHF hearts, the expression of the muscarinic m4 (Chrm4) and nicotinic alpha4 (Chrna4) acetylcholin receptors, the ATP receptor P2rx4, nerve growth factor receptor (Ngfr), discoidin domain receptor 1 (Ddr1), neuronal pentraxin receptor (Nptxr), peripheral myelin protein Pmp-22, leukocyte type 12-lipoxygenase (Alox15), cytochrome P450 4F5 (Cyp4F5) and cardiac Kcne1 were all increased (range 1.6-6.0-fold, P < 0.01 for all genes). The lack of significant regulation of these genes at 1-day post-MI, suggests that the induction of these genes at 7-day post-MI is not a short-term response induced by the infarct itself.

CONCLUSION

These neuronal type genes may participate in underlying processes that affect contractility, intracardiac nerve function and development of arrhythmias in CHF hearts.

Monitoring Expression of Cytochrome P450 Genes During Postischemic Rat Liver Reperfusion Using DNA Microarrays

We investigated the expression of 50 cytochrome P450 (CYP) genes in the postischemic reperfused rat liver using a DNA microarray. Thirteen CYPs showed absent expression in all experiments and 2 CYPs were induced by pentobarbital, which was used as an anesthetic. Eight of the remaining 35 CYPs showed significantly decreased expression following ischemia-reperfusion. Monitoring CYP expression may be a powerful approach for elucidation of pathways regulating drug metabolism that may be involved in postischemic reperfusion liver injury.

Inflammation of the cystic fibrosis mouse small intestine

The CFTR null mouse [cystic fibrosis (CF) mouse] has a severe intestinal phenotype that serves as a model for CF-related growth deficiency, meconium ileus, and distal intestinal obstructive syndrome. DNA microarray analysis was used to investigate gene expression in the CF mouse small intestine. Sixty-one genes exhibited a statistically significant twofold or greater increase in expression, and 98 genes were downregulated twofold or greater. Of the upregulated genes, most were associated with inflammation and included markers for cells of the innate immune system (mast cells and neutrophils) and for acute-phase genes (serum amyloid A and complement factors). The downregulated genes include 10 cytochrome P-450 genes; several are involved in lipid metabolism, and several are involved in various transport processes. Confirmation by quantitative RT-PCR showed gene expression was significantly increased for mast cell protease 2 (27-fold), hematopoietic cell transcript 1 (17-fold), serum amyloid A3 (2.9-fold), suppressor of cytokine signaling 3 (2.0-fold), leucine-rich alpha(2)-glycoprotein (21-fold), resistin-like molecule-beta (49-fold), and Muclin (2.5-fold) and was significantly decreased for cytochrome P-450 4a10 (28-fold) and cubilin (114-fold). Immune cell infiltration was confirmed histologically by staining for mast cells and neutrophils. These data demonstrate that the CF intestine exhibits an inflammatory state with upregulation of components of the innate immune system.

Differential effects of traumatic brain injury on the cytochrome p450 system: a perspective into hepatic and renal drug metabolism

Traumatic brain injury is known to cause several secondary effects, one of which is altered drug clearance. Given the fact that patients who sustain TBI are subsequently treated with a variety of pharmacological agents for the purpose of either neuroprotection or physiological support, it is imperative to clarify changes in expression and/or activities of enzymes involved in clearing drugs. The mixed function oxidase system, which consists of cytochrome P450 and cytochrome P450 reductase, plays a vital role in phase I drug metabolism. This paper addresses the issue as to what extent TBI affects the levels and activity of various rat CYP450 subfamilies. Our results show that TBI induces tissue-specific and time-dependent alterations. Total hepatic CYP450 content showed a biphasic response with a decrease seen at 24 h followed by an increase at 2 weeks. CYP450 reductase, in contrast, showed an opposite temporal profile. Immunoblot analyses and marker substrate metabolism demonstrated a clear decrease in hepatic CYP1A levels while a significant increase in kidney was seen at both 24 h and 2 weeks. A dramatic induction of CYP3A was evident at 2 weeks in liver, while no changes were noticed in CYP2B or CYP2D subfamilies. CYP4F subfamily showed induction in kidney only. Collectively, the data reveal the differential effects of TBI on hepatic and renal drug metabolism.

Inflammatory prompts produce isoform-specific changes in the expression of leukotriene B(4) omega-hydroxylases in rat liver and kidney

Cytochrome p450 (CYP) 4Fs metabolize leukotriene B(4) and other inflammatory mediators in the arachidonic acid cascade. Here we show that lipopolysaccharide (LPS) treatment suppresses CYP4F4 and up-regulates CYP4F5 mRNA expression in rat liver whereas renal CYP4Fs are essentially unchanged. BaSO(4) treatment, in contrast, increases both hepatic and renal CYP4F expression levels. Thus, distinct regulatory mechanisms in CYP4F expression might operate under different inflammatory prompts. To examine hepatic totipotency, primary hepatocytes were treated with varying doses of LPS resulting in decrease in all the CYP4F isoforms. Treatment of hepatocytes with 5 ng/ml of interleukin-1beta mimics the in vivo effects of LPS on CYP4F expression.

Lipopolysaccharide induces CYP2E1 in astrocytes through MAP kinase kinase-3 and C/EBPbeta and -delta

Cytochrome P450 2E1 (CYP2E1) is highly inducible in a subset of astrocytes in vivo following ischemic or mechanical injury and in vitro by lipopolysaccharide (LPS) or interleukin-1beta. We have studied the mechanism of induction, and found that transcriptional activation of CYP2E1 occurred within 3 h, and CYP2E1 dependent catalytic activity was induced more than 4-fold within 5 h. The induction was sensitive to several tyrosine kinase inhibitors, and was further modulated by inhibitors of p38 MAP kinase. MAP kinase kinase-3 (MKK3) was phosphorylated in response to LPS, and expression of constitutively active MKK3, but not the MAP kinase kinases MEKK1 or MKK1, activated CYP2E1. Transcriptional activation was mediated through a C/EBPbeta and -delta binding element situated at -486/-474, and appeared to involve activation of prebound factors as well as recruitment of newly synthesized C/EBPbeta and -delta. It is thus suggested that LPS induces MKK3 activation in astrocytes, which in turn stimulates a C/EBPbeta and -delta binding element to mediate transcriptional activation of CYP2E1.