Involvement of Creatine Kinase B in Cigarette Smoke-Induced Bronchial Epithelial Cell Senescence
Involvement of Creatine Kinase B in Cigarette Smoke-Induced Bronchial Epithelial Cell Senescence
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DOI：
10.1165/rcmb.2011-0214oc
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发表时间：
2012-03-01
影响因子：
6.4
通讯作者：
Kuwano, Kazuyoshi
中科院分区：
文献类型：
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作者：
Hara, Hiromichi;Araya, Jun;Kuwano, Kazuyoshi
香烟烟雾通过氧化应激诱导蛋白质和细胞器的损伤，导致肺中上皮细胞加速衰老，这与慢性阻塞性肺疾病（COPD）发病机制有关。虽然详细的分子机制还不完全清楚，但细胞能量状态是细胞衰老的最关键决定因素之一。肌酸激酶（CK）是一种组成性酶，在细胞能量平衡中起调节作用。在两种同工酶中，脑型CK（CKB）是肺组织中的优势CK。在这项研究中，我们研究了CKB在香烟烟雾提取物（CSE）诱导的人支气管上皮细胞（HBEC）细胞衰老中的作用。使用原代HBEC和Beas 2B细胞。蛋白质羰基化被评价为氧化蛋白质损伤的标志物。通过衰老相关β-半乳糖苷酶染色评价细胞衰老。用小干扰RNA和环肌酸检测CKB抑制。通过ELISA测量IL-8的分泌，这是衰老相关的分泌表型的标志。与非吸烟者的HBEC相比，COPD患者的HBEC中CKB表达水平降低。CSE诱导CKB的羰基化，随后降低CKB蛋白水平，这被蛋白酶体抑制剂逆转。CKB抑制单独诱导细胞衰老，并进一步增强CSE诱导的细胞衰老和IL-8分泌。CSE诱导的CKB氧化是蛋白酶体降解的触发因素。伴随的调节能量稳态的酶活性的丧失可能导致支气管上皮细胞衰老的加速，这与COPD的发病机制有关。
Cigarette smoke induces damage to proteins and organelles by oxidative stress, resulting in accelerated epithelial cell senescence in the lung, which is implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. Although the detailed molecular mechanisms are not fully understood, cellular energy status is one of the most crucial determinants for cell senescence. Creatine kinase (CK) is a constitutive enzyme, playing regulatory roles in energy homeostasis of cells. Among two isozymes, brain-type CK (CKB) is the predominant CK in lung tissue. In this study, we investigated the role of CKB in cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBECs). Primary HBECs and Beas2B cells were used. Protein carbonylation was evaluated as a marker of oxidative protein damage. Cellular senescence was evaluated by senescence-associated beta-galactosidase staining. CKB inhibition was examined by small interfering RNA and cyclocreatine. Secretion of IL-8, a hallmark of senescence-associated secretary phenotype, was measured by ELISA. CKB expression levels were reduced in HBECs from patients with COPD compared with that of HBECs from nonsmokers. CSE induced carbonylation of CKB and subsequently decreased CKB protein levels, which was reversed by a proteasome inhibitor. CKB inhibition alone induced cell senescence, and further enhanced CSE-induced cell senescence and IL-8 secretion. CSE-induced oxidation of CKB is a trigger for proteasomal degradation. Concomitant loss of enzymatic activity regulating energy homeostasis may lead to the acceleration of bronchial epithelial cell senescence, which is implicated in the pathogenesis of COPD.