Li Honglin, Yan Xixin, Li Rongqin, Zhang Aili, Niu Zhiyun, Cai Zhigang, Duan Weisong, Li Xia, Zhang Huiran
Department of Respirology, The Second Hospital of Hebei Medical University, No. 215, West Heping Road, Shijiazhuang, Hebei, 050000, China.
Department of Centralab, The Second Hospital of Hebei Medical University, Shijiazhuang, China.
Inflammation. 2016 Apr;39(2):881-90. doi: 10.1007/s10753-016-0320-8.
Transmembrane protein 16A (TMEM16A) regulates a wide variety of cellular activities, including epithelial fluid secretion and maintenance of ion homeostasis. Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria, is one of the major causes of acute lung injury (ALI). In this study, we investigated the effects of LPS on the expression of TMEM16A in LA795 cells and mouse lung tissue and the potential mechanism.
We detected the expression of TMEM16A in LA795 cells and mouse lung tissue by RT-PCR, Western blot, and RNA interference techniques. TMEM16A expression was significantly increased by LPS stimulation in LA795 cells and in mouse lung tissue. Moreover, the LPS-induced TMEM16A expression enhancement in lung tissue was much more prominent in the alveolar epithelial region than in bigger airway epithelial cells. The typical TMEM16A current was recorded, and LPS treatment significantly enhances the current amplitude in LA795 cells. TMEM16A shRNA or TMEM16A inhibitor (T16Ainh-A01) did not affect alveolar fluid clearance (AFC), while co-application of T16Ainh-A01 induced a stronger AFC inhibition than LPS alone. LPS notably and synchronously enhanced Akt phosphorylation (p-Akt) and TMEM16A expression in a time-dependent manner in LA795 cells. Taken together, our results suggest that TMEM16A maybe plays an important role in pathological conditions of LPS-induced ALI as a protective protein.
跨膜蛋白16A（TMEM16A）调节多种细胞活动，包括上皮液体分泌和离子稳态的维持。脂多糖（LPS）是革兰氏阴性菌外膜成分之一，是急性肺损伤（ALI）的主要原因之一。在本研究中，我们研究了LPS对LA795细胞和小鼠肺组织中TMEM16A表达的影响及其潜在机制。
我们通过逆转录聚合酶链反应（RT-PCR）、蛋白质免疫印迹法（Western blot）和RNA干扰技术检测了LA795细胞和小鼠肺组织中TMEM16A的表达。LPS刺激显著增加了LA795细胞和小鼠肺组织中TMEM16A的表达。此外，LPS诱导的肺组织中TMEM16A表达增强在肺泡上皮区域比在较大气道上皮细胞中更为显著。记录到典型的TMEM16A电流，LPS处理显著增加了LA795细胞中的电流幅度。TMEM16A短发夹RNA（shRNA）或TMEM16A抑制剂（T16Ainh-A01）不影响肺泡液体清除率（AFC），而联合应用T16Ainh-A01比单独使用LPS诱导更强的AFC抑制。LPS显著且同步地以时间依赖性方式增强LA795细胞中蛋白激酶B（Akt）的磷酸化（p-Akt）和TMEM16A的表达。综上所述，我们的结果表明TMEM16A可能作为一种保护蛋白在LPS诱导的ALI病理状态中发挥重要作用。
