Abstract
The regulation of microtubule dynamics in cystic fibrosis (CF) epithelial cells and the consequences of reduced rates of microtubule polymerization on downstream CF cellular events, such as cholesterol accumulation, a marker of impaired intracellular transport, are explored here. It is identified that microtubules in both CF cell models and in primary CF nasal epithelial cells repolymerize at a slower rate compared with respective controls. Previous studies suggest a role forcAMPin modulating organelle transport in CF cells, implicating a role for exchange protein activated by cAMP (EPAC) 1, a regulator of microtubule elongation, as a potential mechanism. EPAC1 activity is reduced in CF cell models and in Cftr2/2 mouse lung compared with respective non-CF controls. Stimulation of EPAC1 activity with the selective EPAC1 agonist, 8-cpt-2-O-MecAMP, stimulates microtubule repolymerization to wild-type rates in CF cells. EPAC1 activation also alleviates cholesterol accumulation in CF cells, suggesting a direct link between microtubule regulation and intracellular transport. To verify the relationship between transport and microtubule regulation, expression of the protein, tubulin polymerization-promoting protein, was knocked down in non-CF human tracheal (9/HTEo2) cells to mimic the microtubule dysregulation in CF cells. Transduced cells with short hairpin RNA targeting tubulin polymerization-promoting protein exhibit CF-like perinuclear cholesterol accumulation and other cellular manifestations of CF cells, thus supporting a role for microtubule regulation as a mechanism linking CFTR function to downstream cellular manifestation.
Original language | English (US) |
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Pages (from-to) | 853-862 |
Number of pages | 10 |
Journal | American journal of respiratory cell and molecular biology |
Volume | 53 |
Issue number | 6 |
DOIs | |
State | Published - Dec 2015 |
Keywords
- Cholesterol
- Cystic fibrosis
- Exchange protein activated by camp 1
- Microtubules
- Rap1
ASJC Scopus subject areas
- Molecular Biology
- Pulmonary and Respiratory Medicine
- Clinical Biochemistry
- Cell Biology