Functional Requirement of the Hypoxia-responsive Element in the Activation of the Inducible Nitric Oxide Synthase Promoter by the Iron Chelator Desferrioxamine

Melillo, Giovanni; Taylor, Lynn S.; Brooks, Alan D.; Musso, Tiziana; Cox, George W.; Varesio, Luigi

doi:10.1074/jbc.272.18.12236

Cited by 191 publications

(156 citation statements)

References 47 publications

Supporting

Mentioning

146

Contrasting

Unclassified

Order By: Relevance

“…15,18 We investigated whether IFNg produced endogenously by HRE-IFN-Mf could act synergistically with the costimulatory agents. HRE-IFN-Mf were cultured for different time points in the presence of PA or DFX and then tested for iNOS mRNA expression (Figure 7a), nitric oxide (NO) production ( Figure 7b) and TNFa secretion ( Figure 7c).…”

Section: Resultsmentioning

confidence: 99%

“…15,21,22 To investigate the role of iron chelation on the response of HRE-IFN-Mf to PA and DFX, cells were stimulated for 24 h with PA or DFX, alone or in the presence of different doses of Fe 2 SO 4 , and the expression of IFNg mRNA was analyzed. One representative experiment out of three performed is depicted in Figure 8a.…”

Section: Resultsmentioning

confidence: 99%

“…7,8 PA and DFX share the property of chelating divalent cations, including iron and zinc, and evidence exists that their biological activities involve iron chelation. 15,18,21 We demonstrated that the addition of iron can block the activation of HRE-IFN-Mf by PA and DFX. These results suggest that local changes in iron concentration can modulate the sensitivity of HRE-IFN-Mf to PA and DFX.…”

Section: Activation Of Macrophage Vectors S Pastorino Et Almentioning

confidence: 86%

“…The Mf vector system described in this paper was designed to generate activated macrophages (Mf), because the therapeutic gene (IFNg) is an Mf activator and is expressed in an inducible manner in response to molecules, PA or DFX, which have costimulatory activities on Mf. The inducibility by hypoxia of HREcontaining synthetic promoters was previously characterized in vivo 23,24 in vitro, 9,15,25,11,26 and also in Mf. 12,11 New perspectives in the use of hypoxia-sensitive Mf vectors stem from the observation that stimuli other than hypoxia can activate HRE.…”

Section: Activation Of Macrophage Vectors S Pastorino Et Almentioning

confidence: 99%

“…Therefore, it is important to develop strategies allowing the expression of the hypoxia-driven therapeutic gene under normoxic conditions utilizing stimuli or drugs, other than hypoxia, which can be delivered in a controlled manner. One group of these compounds is represented by metal chelators including desferrioxamine (DFX), 15,16 a drug used to treat iron overload, and picolinic acid (PA), 9 a metabolite of tryptophan. The Mf-activating properties of PA have been studied extensively.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Picolinic acid- or desferrioxamine-inducible autocrine activation of macrophages engineered to produce IFNγ: an approach for gene therapy

et al. 2004

View full text Add to dashboard Cite

Macrophage (Mf)-based vectors are highly mobile cellular shuttles designed to deliver therapeutic genes within the tissues. We engineered a mouse Mf cell line to express the murine interferon-g (IFNg) under the control of an inducible promoter containing the hypoxia-responsive element, which can be triggered by hypoxia and other stimuli. We show that this Mf vector can be induced to produce IFNg under normoxic conditions by stimulation with picolinic acid (PA), a catabolite of tryptophan, or desferrioxamine (DFX), an ironchelating drug. The Mf vector responds to IFNg with the induction of IRF-1 and of other IFNg-inducible genes, the expression of Ia antigens and induction of phagocytic activity.Inducible nitric oxygen synthase gene expression, nitric oxide production, as well as TNFa secretion were enhanced by PA or DFX as the sole stimuli. None of the above responses could be triggered individually by PA or DFX in control, normal Mf, indicating that the Mf vector overcame the need for costimulatory molecules derived from the immune system for its full activation. Furthermore, we demonstrate that extracellular iron can downregulate such response, thereby identifying an additional tool for the fine tuning of the Mf vector response to stimulation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Activation Of Macrophage Vectors S Pastorino Et Almentioning

confidence: 86%

Section: Activation Of Macrophage Vectors S Pastorino Et Almentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Picolinic acid- or desferrioxamine-inducible autocrine activation of macrophages engineered to produce IFNγ: an approach for gene therapy

et al. 2004

View full text Add to dashboard Cite

show abstract

Hypoxia‐inducible factor 1α is involved in the prostaglandin metabolism of osteoarthritic cartilage through up‐regulation of microsomal prostaglandin E synthase 1 in articular chondrocytes

Grimmer¹,

Pfander²,

Swoboda³

et al. 2007

Arthritis & Rheumatism

View full text Add to dashboard Cite

Objective. To investigate crosslinks between catabolic and anabolic pathways in articular cartilage by examining the synthesis and distribution pattern of microsomal prostaglandin E synthase 1 (mPGES-1) in healthy and osteoarthritic (OA) cartilage and analyzing its functional relationship to hypoxia-inducible factor 1␣ (HIF-1␣) in primary articular chondrocytes.Methods. Normal cartilage and OA cartilage were subjected to immunohistochemical staining for mPGES-1 and HIF-1␣. Isolated chondrocytes were cultivated under 21% or 1% O 2 . Microarray analysis and quantitative reverse transcriptase-polymerase chain reaction were used to detect genes differentially expressed in chondrocytes cultured under normoxic compared with hypoxic conditions. Immunoblotting was conducted to evaluate intracellular protein levels of mPGES and nuclear accumulation of HIF-1␣ under different oxygen tension levels and with different stimulatory or inhibitory chemical agents.Results. We found enhanced levels of expression of the mPGES-1 gene and an increased number of OA chondrocytes showing staining for mPGES-1 in OA cartilage. Microarray analysis demonstrated that mPGES-1 was among the genes that were up-regulated to the greatest degree in primary chondrocytes exposed to 1% O 2 . In vitro, hypoxia led to an enhanced synthesis of mPGES-1, coinciding with a nuclear accumulation of the transcription factor HIF-1␣. In chondrocyte culture, stimulation with dimethyloxaloylglycine promoted the expression of mPGES-1, phosphoglycerate kinase 1, and cyclooxygenase 2 (COX-2) by stabilizing HIF-1␣ protein levels. A reduction of mPGES-1 synthesis was detected after treatment with 2-methoxyestradiol, correlating with lower HIF-1␣ activity. In contrast, synthesis of mPGES-1 was not influenced by treatment with the specific COX-2 inhibitor NS398.Conclusion. These findings suggest that the transcription factor HIF-1␣ is involved in the up-regulation of mPGES-1 and may therefore play an important role in the metabolism of OA cartilage.The regulation of the metabolism of articular cartilage involves a complex network of a multitude of signaling pathways. In osteoarthritis (OA), the usually well-regulated maintenance between extracellular matrix synthesis and degradation is greatly disturbed. Inflammatory cytokines promote catabolism by inducing expression of matrix-degrading enzymes, which lead to the breakdown of the collagen network and the release of cartilage proteoglycans (1). The biologic effects of interleukin-1␤ (IL-1␤), one of the key agents in the pathophysiology of OA, are mediated by signaling pathways involving NF-B, JNK, p38, or ERK, by nitric oxide, and by cytokines as well as by prostaglandins (2). Prostaglandin E 2 (PGE 2 ), the most abundant prostaglandin in the skeletal system (3), induces a number of matrix-degrading enzymes, thus stimulating the cataboSupported by the Interdisciplinary Center of Clinical Research Erlangen (Project C2) and the DFG (PF 383/4-1).

show abstract

Interferon‐γ limits the availability of iron for intramacrophage Salmonella typhimurium

et al. 2008

View full text Add to dashboard Cite

In stimulating effector functions of mononuclear phagocytes, IFN-c is of pivotal importance in host defense against intramacrophage pathogens including salmonellae. As the activity of IFN-c is modulated by iron and since a sufficient availability of iron is essential for the growth of pathogens, we investigated the regulatory effects of IFN-c on iron homeostasis and immune function in murine macrophages infected with Salmonella typhimurium. In Salmonella-infected phagocytes, IFN-c caused a significant reduction of iron uptake via transferrin receptor 1 and resulted in an increased iron efflux caused by an enhanced expression of the iron exporter ferroportin 1. Moreover, the expression of haem oxygenase 1 and of the siderophore-capturing antimicrobial peptide lipocalin 2 was markedly elevated following bacterial invasion, with IFN-c exerting a super-inducing effect. This observed regulatory impact of IFN-c reduced the intracellular iron pools within infected phagocytes, thus restricting the acquisition of iron by engulfed Salmonella typhimurium while concomitantly promoting NO and TNF-a production. Our data suggest that the modulation of crucial pathways of macrophage iron metabolism in response to IFN-c concordantly aims at withdrawing iron from intracellular Salmonella and at strengthening macrophage immune response functions. These regulations are thus consistent with the principles of nutritional immunity. IntroductionHost defense against intracellular microbes such as salmonellae or mycobacteria strongly depends on cell-mediated immunity, a major component of which is characterized by interactions between Th1 cells and macrophages [1]. By secreting Th1 cytokines, particularly IFN-c, antigen-specific Th1 cells activate a plethora of microbicidal mechanisms in infected macrophages. Specifically, in mononuclear phagocytes infected with Salmonella enterica serovar typhimurium (S. typhimurium), IFN-c promotes the internalization of bacteria and stimulates their elimination by various mechanisms including reactive oxygen and nitrogen species (ROS and RNS), generated via NADPH phagocyte oxidase and iNOS, respectively [2][3][4][5]. In Salmonella-infected mice, treatment with recombinant IFN-c increases host survival and decreases bacterial numbers in liver and spleen [6]. Conversely, neutralization of murine IFN-c functions with specific antibodies results in reduced host survival and increased bacterial counts [7]. Eur. J. Immunol. 2008. 38: 1923-1936 Immunity to infection In humans, the central importance of IFN-c for immune response against salmonellae is highlighted by the fact that patients with genetic defects in the IL-12-induced production of IFN-c or in the IFN-c receptor 1 selectively suffer from infections with salmonellae and otherwise weakly pathogenic mycobacteria since their phagocytes fail to eliminate these microbes [8,9]. Iron serves as an essential nutrient for nearly all pathogenic microorganisms, and the expression of iron acquisition systems by infectious agents is associated with their virule...

show abstract

Functional Requirement of the Hypoxia-responsive Element in the Activation of the Inducible Nitric Oxide Synthase Promoter by the Iron Chelator Desferrioxamine

Cited by 191 publications

References 47 publications

Picolinic acid- or desferrioxamine-inducible autocrine activation of macrophages engineered to produce IFNγ: an approach for gene therapy

Picolinic acid- or desferrioxamine-inducible autocrine activation of macrophages engineered to produce IFNγ: an approach for gene therapy

Hypoxia‐inducible factor 1α is involved in the prostaglandin metabolism of osteoarthritic cartilage through up‐regulation of microsomal prostaglandin E synthase 1 in articular chondrocytes

Interferon‐γ limits the availability of iron for intramacrophage Salmonella typhimurium

Contact Info

Product

Resources

About