Reduced microtubule acetylation in cystic fibrosis epithelial cells
Reduced microtubule acetylation in cystic fibrosis epithelial cells
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DOI：
10.1152/ajplung.00411.2012
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发表时间：
2013-09-01
影响因子：
4.9
通讯作者：
Kelley, Thomas J.
中科院分区：
文献类型：
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作者：
Rymut, Sharon M.;Harker, Alyssa;Kelley, Thomas J.
囊性纤维化跨膜传导调节因子（CFTR）功能失调会导致许多细胞后果，包括由于内体转运受损而导致的游离胆固醇核周积聚。正在测试的假设是，CF相关的核周胆固醇积累，由于破坏内吞运输发生作为一个结果，减少微管（MT）乙酰化。在此，确定了在培养的CF细胞模型（IB 3）和原代Cftr-/-小鼠鼻上皮组织中，与相应的野生型对照相比，乙酰化-α-微管蛋白（Ac-tub）含量降低了类似于40%。组蛋白去乙酰化酶6（HDAC 6）已被证明调节MT乙酰化，这为测试其对CF细胞表型上减少的Ac-tub含量的影响提供了合理的依据。通过tubastatin处理或CF细胞中的HDAC 6敲低来抑制HDAC 6，增加Ac-tub含量并导致游离胆固醇的重新分布和NF-κ B活性的刺激降低。机制上，内质网应激，这是广泛报道的CF，并导致侵略形成，被确定为MT乙酰化的调节剂。在原代气道上皮细胞中用C18校正F508 del CFTR恢复MT乙酰化和胆固醇转运。磷脂酰肌醇-3激酶p110 α的重要作用也被确定为MT乙酰化的调节剂。
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-alpha-tubulin (Ac-tub) content is reduced by similar to 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-kappa B 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 p110 alpha is also identified as a regulator of MT acetylation.