Related Experiment Videos
Chemogenomic identification of Ref-1/AP-1 as a therapeutic target for asthma
Cu Nguyen1, Jia-Ling Teo, Akihisa Matsuda
1Pacific Northwest Research Institute, 720 Broadway, Seattle, WA 98122, USA.
Abstract:
Asthma is characterized by an oxidantantioxidant imbalance in the lungs leading to activation of redox-sensitive transcription factors, nuclear factor kappaB (NF-kappaB), and activator protein-1 (AP-1). To develop therapeutic strategies for asthma, we used a chemogenomics approach to screen for small molecule inhibitor(s) of AP-1 transcription. We developed a beta-strand mimetic template that acts as a reversible inhibitor (pseudosubstrate) of redox proteins. This template incorporates an enedione moiety to trap reactive cysteine nucleophiles in the active sites of redox proteins. Specificity for individual redox factors was achieved through variations in X and Y functionality by using a combinatorial library approach. A limited array (2 x 6) was constructed where X was either NHCH(3) or NHCH(2) Ph and Y was methyl, phenyl, m-cyanophenyl, m-nitrophenyl, m-acetylaniline, or m-methylbenzoate. These analogs were evaluated for their ability to inhibit transcription in transiently transfected human lung epithelial A549 cells from either an AP-1 or NF-kappaB reporter. A small-molecule inhibitor, PNRI-299, was identified that selectively inhibited AP-1 transcription (IC(50) of 20 microM) without affecting NF-kappaB transcription (up to 200 microM) or thioredoxin (up to 200 microM). The molecular target of PNRI-299 was determined to be the oxidoreductase, redox effector factor-1 by an affinity chromatography approach. The selective redox effector factor-1 inhibitor, PNRI-299, significantly reduced airway eosinophil infiltration, mucus hypersecretion, edema, and IL-4 levels in a mouse asthma model. These data validate AP-1 as an important therapeutic target in allergic airway inflammation.
Insights
Researchers identified a novel small molecule inhibitor, PNRI-299, that selectively targets activator protein-1 (AP-1) transcription. This discovery offers a new therapeutic strategy for asthma by reducing airway inflammation and mucus production.
Area of Science:
- Biochemistry
- Pharmacology
- Immunology
Background:
- Asthma involves an oxidant-antioxidant imbalance, activating redox-sensitive transcription factors like activator protein-1 (AP-1).
- Targeting AP-1 offers a potential therapeutic strategy for asthma treatment.
Purpose of the Study:
- To screen for small molecule inhibitors of AP-1 transcription using a chemogenomics approach.
- To develop novel therapeutic strategies for asthma by identifying selective AP-1 inhibitors.
Main Methods:
- A combinatorial library of beta-strand mimetic templates with enedione moieties was synthesized.
- Analogs were tested for inhibition of AP-1 and nuclear factor kappaB (NF-kappaB) transcription in human lung epithelial cells.
- Affinity chromatography was used to identify the molecular target of the inhibitor.
Main Results:
- PNRI-299 selectively inhibited AP-1 transcription (IC50 = 20 microM) without affecting NF-kappaB or thioredoxin.
- The molecular target of PNRI-299 was identified as redox effector factor-1.
- PNRI-299 significantly reduced airway inflammation, mucus, edema, and IL-4 levels in a mouse asthma model.
Conclusions:
- AP-1 is a validated therapeutic target in allergic airway inflammation.
- PNRI-299 demonstrates potential as a therapeutic agent for asthma treatment.
- Selective inhibition of redox effector factor-1 offers a promising approach for managing asthma symptoms.