title: Reduced microtubule acetylation in cystic fibrosis epithelial cells.
abstract: Dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) leads to many cellular consequences, including perinuclear accumulation of free cholesterol due to impaired endosomal transport. The hypothesis being tested is that CF-related perinuclear cholesterol accumulation due to disrupted endocytic trafficking occurs as a result of reduced microtubule (MT) acetylation. Here, it is identified that acetylated-α-tubulin (Ac-tub) content is reduced by ∼40% compared with respective wild-type controls in both cultured CF cell models (IB3) and primary Cftr-/- mouse nasal epithelial tissue. Histone deacetylase 6 (HDAC6) has been shown to regulate MT acetylation, which provides reasonable grounds to test its impact on reduced Ac-tub content on CF cellular phenotypes. Inhibition of HDAC6, either through tubastatin treatment or HDAC6 knockdown in CF cells, increases Ac-tub content and results in redistributed free cholesterol and reduced stimulation of NF-κB activity. Mechanistically, endoplasmic reticulum stress, which is widely reported in CF and leads to aggresome formation, is identified as a regulator of MT acetylation. F508del CFTR correction with C18 in primary airway epithelial cells restores MT acetylation and cholesterol transport. A significant role for phosphatidyl inositol-3 kinase p110α is also identified as a regulator of MT acetylation.
authors.affiliation: Dept. of Pediatrics, Case Western Reserve Univ., 833 BRB, 10900 Euclid Ave., Cleveland, OH 44106-4948. Thomas.kelley@case.edu.
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Rymut
authors.forename: Alyssa
authors.initials: A
authors.lastname: Harker
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Corey
authors.forename: James D
authors.initials: JD
authors.lastname: Burgess
authors.forename: Hongtao
authors.initials: H
authors.lastname: Sun
authors.forename: John P
authors.initials: JP
authors.lastname: Clancy
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Kelley
mesh_terms: D000107:Acetylation; D000818:Animals; D002784:Cholesterol / Q000378:metabolism; D058534:Class I Phosphatidylinositol 3-Kinases; D003550:Cystic Fibrosis / Q000503:physiopathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000502:physiology*; D059865:Endoplasmic Reticulum Stress / Q000502:physiology; D011992:Endosomes / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009297:Nasal Mucosa / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014404:Tubulin / Q000378:metabolism
chemical_list: D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007211:Indoles; D016328:NF-kappa B; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014404:Tubulin; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; C553587:tubastatin A; D002784:Cholesterol; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D006655:Histone Deacetylases
keywords: cholesterol; cystic fibrosis; histone deacetylase 6; microtubule; phosphatidyl inositol-3 kinase p110α