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A PI3Kγ mimetic peptide triggers CFTR gating, bronchodilation, and reduced inflammation in obstructive airway diseases
- Source :
- Sci Transl Med
- Publication Year :
- 2022
-
Abstract
- Cyclic adenosine 3′,5′-monophosphate (cAMP)–elevating agents, such as β 2 -adrenergic receptor (β 2 -AR) agonists and phosphodiesterase (PDE) inhibitors, remain a mainstay in the treatment of obstructive respiratory diseases, conditions characterized by airway constriction, inflammation, and mucus hypersecretion. However, their clinical use is limited by unwanted side effects because of unrestricted cAMP elevation in the airways and in distant organs. Here, we identified the A-kinase anchoring protein phosphoinositide 3-kinase γ (PI3Kγ) as a critical regulator of a discrete cAMP signaling microdomain activated by β 2 -ARs in airway structural and inflammatory cells. Displacement of the PI3Kγ-anchored pool of protein kinase A (PKA) by an inhaled, cell-permeable, PI3Kγ mimetic peptide (PI3Kγ MP) inhibited a pool of subcortical PDE4B and PDE4D and safely increased cAMP in the lungs, leading to airway smooth muscle relaxation and reduced neutrophil infiltration in a murine model of asthma. In human bronchial epithelial cells, PI3Kγ MP induced unexpected cAMP and PKA elevations restricted to the vicinity of the cystic fibrosis transmembrane conductance regulator (CFTR), the ion channel controlling mucus hydration that is mutated in cystic fibrosis (CF). PI3Kγ MP promoted the phosphorylation of wild-type CFTR on serine-737, triggering channel gating, and rescued the function of F508del-CFTR, the most prevalent CF mutant, by enhancing the effects of existing CFTR modulators. These results unveil PI3Kγ as the regulator of a β 2 -AR/cAMP microdomain central to smooth muscle contraction, immune cell activation, and epithelial fluid secretion in the airways, suggesting the use of a PI3Kγ MP for compartment-restricted, therapeutic cAMP elevation in chronic obstructive respiratory diseases.
- Subjects :
- Inflammation
Animal
Cystic Fibrosis Transmembrane Conductance Regulator
bronchus
General Medicine
PI3K
Article
lung
Mice
Phosphatidylinositol 3-Kinases
CFTR, PI3K, cAMP, PKA, inflammation, lung, bronchus, airways
cAMP
Peptide
Animals
Class Ib Phosphatidylinositol 3-Kinase
Humans
PKA
CFTR
Phosphatidylinositol 3-Kinase
airways
Peptides
Human
Subjects
Details
- ISSN :
- 19466242
- Volume :
- 14
- Issue :
- 638
- Database :
- OpenAIRE
- Journal :
- Science translational medicine
- Accession number :
- edsair.doi.dedup.....4d7206a5f43dd3588b77ae179d94c0d7