Aurintricarboxylic Acid Protects against Cell Death Caused by Lipopolysaccharide in Macrophages by Decreasing Inducible Nitric-Oxide Synthase Induction via IκB Kinase, Extracellular Signal-Regulated Kinase, and p38 Mitogen-Activated Protein Kinase Inhibition

Abstract

To elucidate the mechanisms involved in cell protection by aurintricarboxylic acid (ATA), an endonuclease inhibitor, high nitric oxide (NO)-induced macrophage apoptosis was studied. In RAW 264.7 macrophages, a high level of NO production accompanied by cell apoptosis was apparent with lipopolysaccharide (LPS) treatment. Direct NO donor sodium nitroprusside (SNP) also dramatically induced cell death, with an EC 50 of 1 mM. Coincubation of ATA (1-500 M) in LPS-stimulated RAW 264.7 cells resulted in a striking reduction of NO production and cell apoptosis, whereas only a partial cell protection was achieved in response to SNP. This suggests that abrogation of inducible nitric-oxide synthase (iNOS)-dependent NO production might contribute to ATA protection of LPS-treated cells. Immunoblotting and reverse transcription-polymerase chain reaction analysis revealed that ATA down-regulated iNOS protein through transcriptional inhibition of iNOS gene expression but was unrelated to iNOS protein stability. ATA not only inhibited nuclear factor-B (NF-B) activation through impairment of the targeting and degradation of IBs but also reduced LPS-induced activator protein-1 (AP-1) activation. These actions of ATA were not caused by the influence on LPS binding to macrophage membrane. Kinase assays indicated that ATA inhibited IB kinase (IKK), extracellular signal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (MAPK) activity both in vivo and in vitro, suggesting a direct interaction between ATA and these signaling molecules. Taken together, these results provide novel action targets of ATA and indicate that ATA protection of macrophages from LPS-mediated cell death is primarily the result of its inhibition of NO production, which closely relates to the inactivation of NF-B and AP-1 and inhibition of IKK, ERK and p38 MAPK.

Cell Cycle Arrest in G 2 Induces Human Immunodeficiency Virus Type 1 Transcriptional Activation through Histone Acetylation and Recruitment of CBP, NF-κB, and c-Jun to the Long Terminal Repeat Promoter

“…Aurintricarboxylic acid inhibits NF-B and AP-1 activation by blocking upstream kinases such as IB kinase, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase (31). As expected, aurintricarboxylic acid inhibited NF-B and c-Jun binding to nuc-1 (Fig.…”

Regulation of Interferon-Inducible Proteins by Doxorubicin via Interferon γ-Janus Tyrosine Kinase-Signal Transducer and Activator of Transcription Signaling in Tumor Cells

“…The discrepancy between the results obtained with ATA and AG490 could be based on different intervention in additional signaling pathways distinct from JAK-STAT signaling, which are in fact described in other cell models (Tsi et al, 2002;Kwak et al, 2008). However, the involvement of STAT1 in doxorubicin-mediated gene regulation was further evidenced by silencing STAT1 expression using a specific siRNA, resulting in a strong reduction of doxorubicin induced gene regulation.…”

Vitamin A affects the expression of antioxidant genes in bovine mammary epithelial cells with oxidative stress induced by diethylene triamine-nitric oxide

“…Therefore, the balance between the generation of free radicals and antioxidant defences is critical. In RAW 264.7 macrophages, a high level of NO production is accompanied by cell apoptosis (Tsi et al 2002). Jin et al (2014) reported that supplementation with a high dose of vitamin A (220 IU/kg BW), which is above the current NRC-recommended level in the diet, can improve the antioxidant function.…”

“…High concentrations of NO can damage proteins, lipids membranes, and DNA (Albina and Reichner 1998). Oxidative stress caused by excess NO following the generation of active nitrogen blocks signalling pathways and leads to uncontrollable systemic inflammation (Tsi et al 2002). Therefore, a complicated system is required to regulate NO production and maintain homeostasis.…”