Acrolein Inhibits Cytokine Gene Expression by Alkylating Cysteine and Arginine Residues in the NF-κB1 DNA Binding Domain

Abstract

Cigarette smoke is a potent inhibitor of pulmonary T cell responses, resulting in decreased immune surveillance and an increased incidence of respiratory tract infections. The ␣,␤-unsaturated aldehydes in cigarette smoke (acrolein and crotonaldehyde) inhibited production of interleukin-2 (IL-2), IL-10, granulocyte-macrophage colony-stimulating factor, interferon-␥, and tumor necrosis factor-␣ by human T cells but did not inhibit production of IL-8. The saturated aldehydes (acetaldehyde, propionaldehyde, and butyraldehyde) in cigarette smoke were inactive. Acrolein inhibited induction of NF-B DNA binding activity after mitogenic stimulation of T cells but had no effect on induction of NFAT or AP-1. Acrolein inhibited NF-B1 (p50) binding to the IL-2 promoter in a chromatin immunoprecipitation assay by >99%. Using purified recombinant p50 in an electrophoretic mobility shift assay, we demonstrated that acrolein was 2000-fold more potent than crotonaldehyde in blocking DNA binding to an NF-B consensus sequence. Matrix-assisted laser desorption/ionization time-offlight and tandem mass spectrometry demonstrated that acrolein alkylated two amino acids (Cys-61 and Arg-307) in the DNA binding domain. Crotonaldehyde reacted with Cys-61, but not Arg-307, whereas the saturated aldehydes in cigarette smoke did not react with p50. These experiments demonstrate that aldehydes in cigarette smoke can regulate gene expression by direct modification of a transcription factor.Cigarette smoke produces profound suppression of pulmonary immunity, resulting in an increased incidence and severity of respiratory tract infections. A recent Institute of Medicine study concluded that smoking increased the incidence of influenza and bacterial pneumonia and accounted for 19,000 smoking-related deaths per year (1). Children infected with Mycobacterium tuberculosis are five times more likely to develop pulmonary tuberculosis if exposed to cigarette smoke (2), and smoking doubles the risk of developing Pneumocystis carinii pneumonia in human immunodeficiency virus-infected individuals (3). Several studies have demonstrated that smoking suppresses T and B cell responses in the lungs without affecting cells in the peripheral blood (4 -7), but little research has been done to elucidate the underlying mechanism behind this phenomenon.We have recently identified two classes of immunosuppressive compounds in cigarette smoke. The dihydroxyphenols (hydroquinone and catechol) in the particulate phase inhibit T cell proliferation by blocking cell cycle progression in late G 1 and S phase (8 -12). In addition, the ␣,␤-unsaturated aldehydes, acrolein (CH 2 ACHCHO) and crotonaldehyde (CH 3 CHACHCHO) in the gas phase of cigarette smoke inhibit the production of several proinflammatory cytokines including IL-2, 4 tumor necrosis factor-␣, and granulocyte-macrophage colony-stimulating factor, with an IC 50 of 3 and 6 M, respectively (13). The saturated aldehydes (acetaldehyde, propionaldehyde, and butyraldehyde) have IC 50 values of Ͼ1500 M. The typical cigarett...

Acrolein: Sources, metabolism, and biomolecular interactions relevant to human health and disease

“…Because there are many tobacco smoke constituents with biological effects detrimental to human health, it is often not possible to contribute a tobacco-related effect to acrolein. The study conducted by Lambert and colleagues [95] is significant, because it identified a link between acrolein and suppression of immune responses (a well-known effect of cigarette smoke) through inhibition of the NF-κB pathway (see Section 4.3). The acrolein concentrations used in this study (low micromolar range) may be reached in lung tissue after smoking several cigarettes.…”

“…Similar to adduction of the guanidine moiety of DNA (Fig. 9), acrolein can form propano adducts with the guanidine group of arginine [95] (Fig. 10).…”

Intracellular Metabolism of α,β-Unsaturated Carbonyl Compounds, Acrolein, Crotonaldehyde and Methyl Vinyl Ketone, Active Toxicants in Cigarette Smoke: Participation of Glutathione Conjugation Ability and Aldehyde–Ketone Sensitive Reductase Activity

“…[19][20][21] These carbonyl compounds rapidly react with intracellular GSH and form their corresponding adducts, thereby depleting cellular GSH 4,22) and leading to cell damage. 4,22,23) In addition, it has been reported that a substantial amount of GSH in epithelial cells exposed to the gaseous phase of cigarette smoke is irreversibly modified to the GSH-ACR adduct (m/z 364) and GSH-CA adduct (m/z 378) by direct infusion mass spectra of the cell lysate, but the GSH-MVK adduct (m/z 378) and GSH-CA adduct are not separated.…”

Acrolein sensitizes human renal cancer Caki cells to TRAIL-induced apoptosis via ROS-mediated up-regulation of death receptor-5 (DR5) and down-regulation of Bcl-2

“…In addition, acrolein has been reported to inhibit cytokine gene expression by NF-κB inhibition [33]. In our study we investigated the effect of acrolein on TRAIL-induced cell death.…”