Validation of IKKβ as therapeutic target in airway inflammatory disease by adenoviral‐mediated delivery of dominant‐negative IKKβ to pulmonary epithelial cells

• Published in: British journal of pharmacology Vol. 145; no. 1; pp. 114 - 122
• Main Authors: Catley, Matthew C, Chivers, Joanna E, Holden, Neil S, Barnes, Peter J, Newton, Robert
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-05-2005; Nature Publishing
• Subjects: Adenoviridae; Apoptosis; Asthma - metabolism; Biological and medical sciences; Cell Line; cytokines; Epithelial Cells - metabolism; Gene Transfer Techniques; Genetic Vectors; GM‐CSF; Humans; I kappa B kinase; IL‐8; inflammation; Medical sciences; NF-kappa B - metabolism; NF‐kappa B; Pharmacology. Drug treatments; prostaglandin GH synthase; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - physiology; pulmonary epithelium; Respiratory Mucosa - cytology; Respiratory Mucosa - metabolism; signal transduction; Transcription, Genetic - drug effects; Transcription, Genetic - physiology; I kappa B kinase; Prostaglandin-endoperoxide synthase; prostaglandin GH synthase; Lung; Respiratory system; Inflammatory disease; Respiratory tract; Signal transduction; pulmonary epithelium; Target; NF-kappa B; GM-CSF; cytokines; Interleukin 8; Enzyme; Transferases; Cytokine; Inflammation; IL-8; Treatment; Kinase; Cell death; Epithelial cell; Oxidoreductases; Granulocyte macrophage colony stimulating factor; Apoptosis
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0706170

1
Asthma is an inflammatory disease of the lungs and the transcription factor NF‐κB regulates the production of numerous inflammatory mediators that may have a role in the pathogenesis of asthma. Hence, the signalling pathways leading to NF‐κB activation are considered prime targets for novel anti‐inflammatory therapies. The prevention of NF‐κB activity in mice, through the knockout of IKKβ or p65, causes fatal liver degeneration in utero making it difficult to determine the full implications of inhibiting NF‐κB activity in tissues physiologically relevant to human diseases.
2
This study used adenovirus delivery of a dominant inhibitor of NF‐κB (IκBαΔN) and dominant‐negative IKKα (IKKα(KM)) and IKKβ (IKKβ(KA)) to investigate the role of the individual IKKs in NF‐κB activation and inflammatory gene transcription by human pulmonary A549 cells.
3
Overexpression of IKKβ(KA) or IκBαΔN prevented NF‐κB‐dependent transcription and DNA binding. IKKβ(KA) also prevented IκBα kinase activity. Similarly, IKKβ(KA) and IκBαΔN overexpression also inhibited IL‐1β‐ and TNFα‐dependent increases in ICAM‐1, IL‐8 and GM‐CSF in addition to IL‐1β‐mediated increases in cyclooxygenase‐2 expression, whereas IKKα(KM) overexpression had little effect on these outputs.
4
IKKβ(KA) also reduced cell viability and induced caspase‐3 and PARP cleavage regardless of the stimuli, indicating the induction of apoptosis. This effect seemed to be directly related to IKKβ kinase activity since IκBαΔN only induced PARP cleavage in TNFα‐treated cells.
5
These results demonstrate that inhibition of IKKβ and NF‐κB suppresses inflammatory mediator production and reduces A549 cell viability. Thus, novel therapies that target IKKβ could have potent anti‐inflammatory effects and may be beneficial in the treatment of certain cancers.
British Journal of Pharmacology (2005) 145, 114–122. doi:10.1038/sj.bjp.0706170