Steroid resistance in asthma: mechanisms and treatment options.
Glucocorticoid insensitivity presents a profound management problem in patients with asthma because conventional therapies are not effective. Glucocorticoids, acting through the glucocorticoid receptor (GR), are able to selectively repress inflammatory gene expression by utilizing several distinct mechanisms targeting nuclear factor-varphiB and activator protein-1 activation complexes and by effects on mitogen-activated protein kinases. Different model systems often activate distinct sets of signaling molecules and different glucocorticoid responsiveness may result from differences in concentrations and timing of steroid treatment of cells, GR expression levels, and the precise inflammatory stimulus used. Thus, abnormal activation of many signaling pathways may affect corticosteroid responsiveness in patients with corticosteroid-resistant asthma. Understanding the molecular mechanisms of GR action and inaction may lead to the development of new anti-inflammatory drugs or enable clinicians to reverse the relative steroid-insensitivity that is characteristic of some patients with severe asthma.
Adcock
Ian M
IM
Cell and Molecular Biology, Airways Disease Section, National Heart and Lung Institute, Imperial College London, London SW3 6LY, UK. ian.adcock@imperial.ac.uk
Ford
Paul A
PA
Bhavsar
Pank
P
Ahmad
Tehireem
T
Chung
Kian Fan
KF
D018927:Anti-Asthmatic Agents / Q000494:pharmacology*; D001249:Asthma / Q000188:drug therapy* / Q000235:genetics; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D020022:Genetic Predisposition to Disease; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D011965:Receptors, Glucocorticoid; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D018927:Anti-Asthmatic Agents; D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D014409:Tumor Necrosis Factor-alpha