Department of Respiratory Medicine, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, 510010 Guangdong, People's Republic of China.
Inflamm Res. 2013 Apr;62(4):387-97. doi: 10.1007/s00011-013-0590-7. Epub 2013 Jan 20.
Apoptosis of alveolar epithelial cells (AECs) plays a key role in acute lung injury (ALI). Understanding the underlying mechanism is conducive to the treatment of ALI. The goal of this study was to determine the possible involvement of nuclear factor-κB (NF-κB)/p65 and Bax/Bcl-2 in tumor necrosis factor-α (TNF-α)-induced apoptosis in AECs.
Type II AECs, A549, with or without NF-κB/p65 expression silenced by small interfering RNA (siRNA) were challenged with TNF-α. The levels of NF-κB/p65, Bcl-2 and Bax were detected by reverse transcription-polymerase chain reaction, Western blotting, and immunocytochemical staining. The apoptosis rate was measured by flow cytometry.
TNF-α challenge significantly increased the transcription and translation of NF-κB/p65 and Bax genes, but significantly decreased the Bcl-2 gene level. siRNA silencing of NF-κB/p65 reversed the effect of TNF-α on NF-κB/p65, Bcl-2 and Bax, and significantly decreased the TNF-α-induced apoptosis rate of AECs, as compared to the non-silenced cells.
This study indicates that NF-κB plays an important role in the process of TNF-α-induced apoptosis in AECs, via regulation of the expression of Bcl-2 and Bax.
肺泡上皮细胞 (AEC) 的凋亡在急性肺损伤 (ALI) 中起着关键作用。了解其潜在机制有助于 ALI 的治疗。本研究旨在确定核因子-κB (NF-κB)/p65 和 Bax/Bcl-2 是否参与肿瘤坏死因子-α (TNF-α) 诱导的 AEC 凋亡。
用小干扰 RNA (siRNA) 沉默 NF-κB/p65 表达或不沉默的 II 型 AEC、A549 细胞，用 TNF-α 处理。通过逆转录聚合酶链反应、Western blot 和免疫细胞化学染色检测 NF-κB/p65、Bcl-2 和 Bax 的水平。通过流式细胞术测量细胞凋亡率。
TNF-α 刺激显著增加了 NF-κB/p65 和 Bax 基因的转录和翻译，但显著降低了 Bcl-2 基因水平。NF-κB/p65 的 siRNA 沉默逆转了 TNF-α 对 NF-κB/p65、Bcl-2 和 Bax 的作用，并显著降低了 TNF-α 诱导的 AEC 凋亡率，与非沉默细胞相比。
本研究表明，NF-κB 通过调节 Bcl-2 和 Bax 的表达，在 TNF-α 诱导的 AEC 凋亡过程中发挥重要作用。
