The suppression of hepatic cytochrome P4504A mRNA mediated by the interferon inducer polyinosinic acid- poly cytidylic acid

doi:10.1016/0006-2952(92)90458-U

Biochemical Pharmacology

Volume 44, Issue 3, 4 August 1992, Pages 604-608

https://doi.org/10.1016/0006-2952(92)90458-U Get rights and content

Abstract

Interferon and interferon inducers are well known to depress the cytochrome P450-dependent hepatic mixed-function oxidase system and cause a decrease in the capacity of the liver to metabolize drugs and xenobiotics. In this study we have shown that the interferon-mediated changes in an induced form of hepatic cytochrome P450 (CYP4A) are mediated via a depression in the levels of mRNA as assessed by Northern blot and slot blot analyses using a 20-base synthetic oligodeoxyribonucleotide hybridization probe. Rats were pretreated with clofibrate to maximize CYP4A mRNA levels prior to the administration of polyinosinic acid-polycytidylic acid (poly 1C), an α/β interferon inducer. Hepatic CYP4A mRNA levels were decreased by 49 and 30% at 6 and 24 hr, respectively, following poly IC administration. In hepatic microsomes cytochome P450 and functional CYP4A as measured by lauric acid hydroxylation, were not affected at 6hr, but were depressed by 39 and 27%, respectively, 24 hr following poly IC administration. These results suggest that interferon depresses induced levels of hepatic drug metabolism by lowering the level of cytochrome P450 mRNAs and subsequent synthesis of cytochrome P450 apoproteins.

References (28)

KW Renton et al.
Depression of hepatic cytochrome P-450-dependent monooxygenase systems with administered interferon inducing agents
Biochem Biophys Res Commun
(1976)
G Singh et al.
Homogeneous interferon from E. coli depresses hepatic cytochrome P-450 and drug biotransformation
Biochem Biophys Res Commun
(1982)
KW Renton et al.
Relationship between the antiviral effects of interferons and their abilities to depress cytochrome P-450
Biochem Pharmacol
(1984)
PI Craig et al.
Rat but not human interferons suppress hepatic oxidative drug metabolism in rats
Gastroenterology
(1989)
S Moochhala et al.
The effect of IFN-α-CON₁] on hepatic cytochrome P-450 and protein synthesis and degradation in hepatic microsomes
Int J Immunopharmacol
(1991)
JP Hardwick et al.
Isolation, complementary DNA sequence, and regulation of rat hepatic lauric acid (ω-hydroxylase (cytochrome P-450LA ω): Identification of a new cytochrome P-450 gene family
J Biol Chem
(1987)
OH Lowry et al.
Protein measurement with the Folin phenol reagent
J Biol Chem
(1951)
T Omura et al.
The carbon monoxide-binding pigment of liver microsomes. I. Evidence for its hemoprotein nature
J Biol Chem
(1964)
AM Maxam et al.
Sequencing end-labeled DNA with base-specific chemical cleavages
Methods Enzymol
(1980)
CB Harley
Hybridization of oligo(dT) to RNA on nitrocellulose
Gene Anal Tech
(1987)

ET Morgan

Suppression of P450IIC12 gene expression and elevation of actin messenger ribonucleic acid levels in the livers of female rats after injection of the interferon inducer poly rI·poly rC

Biochem Pharmacol

(1991)

LA Stanley et al.

Differential effects of recombinant interferon α on constitutive and inducible cytochrome P450 isozymes in mouse liver

Biochem Pharmacol

(1991)

JF Williams et al.

Effect of interleukin 6 on phenobarbital induction of cytochrome P450IIB in cultured rat hepatocytes

Biochem Biophys Res Commun

(1991)

KW Renton et al.

Depression of the hepatic cytochrome P-450 mono-oxygenase system by administered tilorone {2,7-bis[2-(diethylamino)ethoxy] fluoren-9-one dihydrochloride}

Drug Metab Dispos

(1976)

Cited by (29)

Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances
2010, Research in Autism Spectrum Disorders
Worldwide, approximately 2 billion people are chronically infected with Toxoplasma gondii with largely yet unknown consequences. Patients with autism spectrum disorders (ASD) similarly as mice with chronic toxoplasmosis have persistent neuroinflammation, hypercytokinemia with hypermetabolism associated with enhanced lipid peroxidation, and extreme changes in the weight resulting in obesity or wasting. Data presented in this review suggest that environmental triggering factors such as pregnancy, viral/bacterial infections, vaccinations, medications, and other substances caused reactivation of latent cerebral toxoplasmosis because of changes in intensity of latent central nervous system T. gondii infection/inflammation and finally resulted in development of ASD. Examples of such environmental factors together with their respective biomarker abnormalities are: pregnancy (increased NO, IL-1β, TNF-α, IL-6, IL-10, prolactin; decreased IFN-γ, IL-12), neuroborreliosis (increased IL-1β, sIL-1R2, TNF-α, IFN-γ, IL-6, IL-10, IL-12, IL-18, transforming growth factor-β1 (TGF-β1)), viral infections (increased IL-1β, IL-6, IL-8, TNF-α, IFN-γ/α/β, TGF-β1), thimerosal (increased IL-5, IL-13; decreased IFN-γ, TNF-α, IL-6, IL-12p70, NOS), and valproic acid (increased NO, reactive oxygen species; decreased TNF-α, IL-6, IFN-γ). The imbalances in pro- and antiinflammatory processes could markedly hinder host defense mechanisms important for immune control of the parasite, such as the production of NO, cytokines, and reactive oxygen/nitrogen species, tryptophan degradation by indoleamine 2,3-dioxygenase and/or tryptophan 2,3-dioxygenase, limitation of the availability of intracellular iron to T. gondii, and the mechanisms mediated by an IFN-γ responsive gene family. These fluctuations could result in a recurrent profuse multiplication of T. gondii in the brain associated with persistent neuroinflammation, chronic overproduction of pro- and antiinflammatory cytokines, and NO causing increased oxidative stress, and significantly depressed activity of several enzymes including cytochrome P450 monooxygenase family responsible for metabolism of physiological substrates and xenobiotics, such as steroids, fatty acids, prostaglandins, drugs, pollutants, and carcinogens, finally leading to development of ASD. This reasoning may be supported by such abnormal metabolic events as: (1) patients with ASD have significantly decreased melatonin levels caused by marked deficit in acetylserotonin methyltransferase activity, possibly resulting from maternal and/or fetal/postnatal overproduction of NO, characteristic for this clinical entity; (2) thimerosal inhibited both insulin-like growth factor-1- and dopamine-stimulated methylation reactions, and depressed methionine synthase activity, the metabolic events important for promoting normal neurodevelopment; (3) valproic acid, a strong histone deacetylase inhibitor, have potent anti-T. gondii activity. Thus, patients with ASD should be tested for T. gondii infection.
Chapter 4 Mechanisms of immunotoxic effects
2004, Immunotoxicology of Drugs and Chemicals: an Experimental and Clinical Approach
The immunotoxic effects of drugs and other chemicals are extremely varied and have been shown to affect almost every organ or tissue of the body. This chapter provides an overview of the mechanisms of immunotoxic effects. Overlapping mechanisms can result in diverse adverse effects. The immunotoxic effects are best divided into immunosuppression, immunostimulation, hypersensitivity, and autoimmunity. Although similar immunotoxic mechanisms may impact on the normal immunity to induce a shift toward hyperimmunity and result in either hypersensitivity, autoimmunity, or immunostimulation, the three latter categories are sufficiently different both mechanistically and clinically to justify their individualization as different categories of immunotoxic effects. Over the past 30 years, immunotoxicologists have focused most of their efforts on developing animal models and assay that can be reliable to predict immunotoxicity in nonclinical studies. Despite extensive research to understand the mechanisms involved in the immunotoxicity of a few drugs and chemicals, relatively limited knowledge is available on the mechanisms of immunotoxic effects in general.
P450 isoforms in a murine macrophage cell line, RAW264.7, and changes in the levels of P450 isoforms by treatment of cells with lipopolysaccharide and interferon-γ
1998, Biochimica et Biophysica Acta - Protein Structure and Molecular Enzymology
The presence of P450 in a murine macrophage cell line, RAW264.7, was investigated to clarify the biological role and regulation of P450. Microsomes of RAW264.7 cells were isolated and subjected to immunoblotting with anti-rat CYP2A1, 2B1, and 4A2 antibodies. The microsomes gave staining bands with all these antibodies, suggesting the presence of mouse Cyp2a, 2b, and 4a isoforms in RAW264.7. RAW264.7 cells were treated with typical inducers of P450 (phenobarbital, clofibrate, β-naphthoflavone and 3-methylcholanthrene). None of these chemicals induced these P450s. Stimulation of RAW264.7 cells with lipopolysaccharide (LPS) and interferon-γ (INF-γ) which increase inducible nitric oxide synthase (iNOS) and cytokines in cells decreased Cyp4a protein but not Cyp2a and 2b proteins. To identify P450 isoforms in RAW264.7, we used polymerase chain reaction (PCR) primers for mouse Cyp2a4, 2a12, 2b9/10, 4a10, and 4a12. Total RNA was isolated from these cells and converted to cDNA by reverse transcriptase. PCR was done with these primers and the amplified nucleotides were analyzed by a DNA sequencer. Only Cyp2b9/10 and 4a12 primers gave clear bands, although all primers gave clear bands from liver total RNA. Nucleotide sequences of these products amplified by PCR were identical with Cyp2b9 and 4a12. These findings indicate that Cyp2b9 and 4a12 were present in a macrophage cell line, RAW264.7, and the regulation of P450 by inducers and cytokine differed from that in liver.
Regulation of CYP4A1 and peroxisome proliferator-activated receptor alpha expression by interleukin-1β, interleukin-6, and dexamethasone in cultured fetal rat hepatocytes
1997, Biochemical Pharmacology
The CYP4A1 isoenzyme induced in rodents by peroxisome proliferators is known to be repressed at a pretranslational level by interferon. Interleukin'lβ (IL-1β) also reduces CYP4A1-related 12-laurate hydroxylase activity in cultured fetal rat hepatocytes after induction by clofibric acid. In this fetal hepatocyte model, IL-lβ and interleukin-6 (IL-6) were tested for their ability to reduce 12-laurate hydroxylase activity, CYP4A1 apoprotein content, and the CYP4A1 mRNA level. IL-1β and IL-6 strongly diminished CYP4A1 activity and apoprotein and mRNA levels in a dose- and time-dependent manner. CYP4A1 expression is thus down-regulated at a pretranslational level by these cytokines. As it has been shown that the peroxisome proliferator-activated receptor alpha (PPARa) mediates the induction of the CYP4A1 gene by a peroxisome proliferator, the capacity of IL-1β or IL-6 to modulate the PPARa mRNA level was tested. It was found that IL-1β and IL-6 both repress the induction of PPARa expression exerted by the combined action of clofibric acid and dexamethasone. However, even at the highest concentration (10 ng/mL) tested for both cytokines, IL-lβ as well as IL-6 failed to abolish the induction of CYP4A1 by dexamethasone. The mechanism of the protective effect of the synthetic glucocorticoid on CYP4A1 repression by interleukins is discussed.
The role of nitric oxide generation in interferon-evoked cytochrome P450 down-regulation
1995, International Journal of Immunopharmacology
The down-regulation of cytochrome P450 during host defence involves one or more mediators of unknown source and identity. Owing to striking similarities in the features that are involved in the production of NO and the features involved in the down-regulation of cytochrome P450 we hypothesized that NO could be a mediator in the interferon-evoked loss of cytochrome P450. In these experiments the nitric oxide synthase inhibitor l-nitroarginine (5 mg/kg) failed to protect mice from the down-regulation of cytochrome P450, ethoxyresorufin dealkylase and para-nitrophenol hydroxylase in the liver following administration of the interferon inducer polyinosinic.polycytidylic acid. A higher dose of L-nitroarginine (30 mg/kg) given every 12 h for 3 days also did not protect against cytochrome P450 losses. In addition, no down-regulation of the enzyme was observed in animals treated with multiple doses of the NO-generating drugs glyceryl trinitrate (16 and 80 mg/kg given every 4 h for 16 h) and nitroprusside (20 and 100 mg/kg given every 4 h for 16 h). These results indicate that the down-regulation of cytochrome P450 by interferon or its inducers probably does not involve NO as a required intermediary.
Differential effect of cytokines on the phenobarbital or 3-methylcholanthrene induction of P450 mediated monooxygenase activity in cultured rat hepatocytes
1995, Biochemical Pharmacology
Cultured rat hepatocytes have been used to compare the relative activities of cytokines to inhibit the phenobarbital (PB) or 3-methylcholanthrene (MC) induction of cytochrome P4502B1 and 2B2 (P4502B1/2) or P4501A1 and 1A2 (P4501A1/2), respectively. Recombinant cytokines tested were human interleukin-6 (IL-6), interleukin-1α and -β (IL-1α and IL-1β, respectively), and rat γ-interferon (INFγ). Hepatocytes were cultured in the presence of 2mM PB or 1 μg MC/mL culture medium for 24 hr with or without the cytokines. Benzyloxyresorufin and ethoxyresorufin O-dealkylase (BROD and EROD, respectively) activities were determined as indices of P4502B1/2 and P4501A1/2, respectively. All cytokines produced a concentration-dependent inhibition of the PB induction of BROD activity. IL-1β and IL-6 were approximately equipotent with IC₅₀ values of 1–2 U/mL, causing greater than 90% inhibition of PB induction of BROD activity at a concentration of 50 U/mL culture medium. IL-1α tended to be less active. PB induction of BROD activity was also inhibited by INFγ, but higher concentrations (62.5 to 500 U/mL culture medium) were required. All cytokines were less effective in inhibiting the MC induction of EROD activity than the PB induction of BROD activity. IL-1β and IL-6, at 50 U/mL culture medium, inhibited EROD induction by only 35% compared with the greater than 90% inhibitory effect on the PB induction of BROD activity. INFγ was ineffective in inhibiting EROD activity at the concentrations studied. Western immunoblot analysis indicated that the cytokines prevented the ability of the inducers to increase the expression of P4502B1/2 and P4501A1/2 immunoreactive proteins, and this effect correlated with their inhibitory effect on induction of enzyme activity. The results suggest that inducible isoforms of cytochrome P450 differ in their susceptibility to regulation by the cytokines, and that cytokines possess differential activity to inhibit the induction of P450 isoforms, with IL-1β and IL-6 being the most effective.

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Biochemical Pharmacology

Abstract

References (28)

Depression of hepatic cytochrome P-450-dependent monooxygenase systems with administered interferon inducing agents

Biochem Biophys Res Commun

Homogeneous interferon from E. coli depresses hepatic cytochrome P-450 and drug biotransformation

Biochem Biophys Res Commun

Relationship between the antiviral effects of interferons and their abilities to depress cytochrome P-450

Biochem Pharmacol

Rat but not human interferons suppress hepatic oxidative drug metabolism in rats

Gastroenterology

The effect of IFN-α-CON₁] on hepatic cytochrome P-450 and protein synthesis and degradation in hepatic microsomes

Int J Immunopharmacol

Isolation, complementary DNA sequence, and regulation of rat hepatic lauric acid (ω-hydroxylase (cytochrome P-450LA ω): Identification of a new cytochrome P-450 gene family

J Biol Chem

Protein measurement with the Folin phenol reagent

J Biol Chem

The carbon monoxide-binding pigment of liver microsomes. I. Evidence for its hemoprotein nature

J Biol Chem

Sequencing end-labeled DNA with base-specific chemical cleavages

Methods Enzymol

Hybridization of oligo(dT) to RNA on nitrocellulose

Gene Anal Tech

Suppression of P450IIC12 gene expression and elevation of actin messenger ribonucleic acid levels in the livers of female rats after injection of the interferon inducer poly rI·poly rC

Biochem Pharmacol

Differential effects of recombinant interferon α on constitutive and inducible cytochrome P450 isozymes in mouse liver

Biochem Pharmacol

Effect of interleukin 6 on phenobarbital induction of cytochrome P450IIB in cultured rat hepatocytes

Biochem Biophys Res Commun

Depression of the hepatic cytochrome P-450 mono-oxygenase system by administered tilorone {2,7-bis[2-(diethylamino)ethoxy] fluoren-9-one dihydrochloride}

Drug Metab Dispos

Cited by (29)

Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances

Chapter 4 Mechanisms of immunotoxic effects

P450 isoforms in a murine macrophage cell line, RAW264.7, and changes in the levels of P450 isoforms by treatment of cells with lipopolysaccharide and interferon-γ

Regulation of CYP4A1 and peroxisome proliferator-activated receptor alpha expression by interleukin-1β, interleukin-6, and dexamethasone in cultured fetal rat hepatocytes

The role of nitric oxide generation in interferon-evoked cytochrome P450 down-regulation

Differential effect of cytokines on the phenobarbital or 3-methylcholanthrene induction of P450 mediated monooxygenase activity in cultured rat hepatocytes

Short communicationThe suppression of hepatic cytochrome P4504A mRNA mediated by the interferon inducer polyinosinic acid- poly cytidylic acid

Abstract

Biochem Biophys Res Commun

Biochem Biophys Res Commun

Biochem Pharmacol

Gastroenterology

Int J Immunopharmacol

J Biol Chem

J Biol Chem

J Biol Chem

Methods Enzymol

Gene Anal Tech

Biochem Pharmacol

Biochem Pharmacol

Biochem Biophys Res Commun

Depression of the hepatic cytochrome P-450 mono-oxygenase system by administered tilorone {2,7-bis[2-(diethylamino)ethoxy] fluoren-9-one dihydrochloride}

Drug Metab Dispos

Short communication
The suppression of hepatic cytochrome P4504A mRNA mediated by the interferon inducer polyinosinic acid- poly cytidylic acid