Amphiregulin inhibits TNF-α-induced alveolar epithelial cell death through EGFR signaling pathway
Amphiregulin inhibits TNF-α-induced alveolar epithelial cell death through EGFR signaling pathway
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双调蛋白通过EGFR信号通路抑制TNF-α诱导的肺泡上皮细胞死亡
DOI：
10.1016/j.biopha.2020.109995
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发表时间：
2020-05-01
影响因子：
7.5
通讯作者：
Wang, Xianyu
中科院分区：
文献类型：
--
作者：
Meng, Chen;Wang, Silu;Wang, Xianyu
背景：我们之前观察到，双调节蛋白（Areg），上皮生长因子受体（EGFR）的配体，主要通过经典活化（M1）肺泡巨噬细胞（AMs）在脂多糖（LPS）诱导的急性肺损伤（ALI）肺组织中高表达。Areg还在lps诱导的肺组织和肺泡上皮细胞（AECs）损伤中发挥保护作用。然而，Areg是否在ALI肺组织中与肿瘤坏死因子(TNF)- α共表达，并能直接抑制TNF- α诱导的AEC损伤尚不清楚。方法：首先检测lps刺激肺组织和M1 am中Areg和tnf - α的动态表达，然后确定外源性重组Areg （rmAreg）在损伤肺组织中的作用。采用末端脱氧核苷酸转移酶dUTP缺口末端标记法观察Areg对tnf - α诱导的AECs MLE-12细胞凋亡的影响。Western blotting检测EGFR-AKT通路和caspase-3、-8、-9的激活情况。通过小干扰RNA敲低EGFR来评估EGFR在Areg功能中的作用。结果：在M1 am和ALI肺组织中，Areg的产生与tnf - α的表达密切相关，并且rmAreg减轻了lps诱导的小鼠ALI。tnf - α刺激诱导MLE-12细胞显著凋亡，但rmAreg抑制了这种凋亡。此外，rmAreg增强了EGFR和AKT的激活，降低了ALI肺组织和tnf - α挑战的MLE-12细胞中cleaved caspase-3、-8和-9的表达。然而，EGFR敲低显著抑制areg诱导的细胞凋亡改善、EGFR和AKT活化增强、cleaved - caspase-3、-8和-9表达减少。结论：ALI肺组织和M1 am同步产生Areg和tnf - α， Areg通过EGFR途径直接抑制tnf诱导的aec细胞凋亡和caspase死亡信号的转导。
Background: We previously observed that amphiregulin (Areg), a ligand of epithelial growth factor receptor (EGFR), was highly expressed in lipopolysaccharide (LPS)-induced acute lung injury (ALI) lung tissues mainly by the classically activated (M1) alveolar macrophages (AMs). Areg also plays a protective role in LPS-induced injury in lung tissues and alveolar epithelial cells (AECs). However, whether Areg is co-expressed with tumor necrosis factor (TNF)-alpha in ALI lung tissues, and can directly inhibit TNF-alpha-induced AEC injury remains unclear.Methods: We first detected the kinetic expressions of Areg and TNF-alpha in LPS-stimulated lung tissues and M1 AMs and then identified the role of exogenous recombinant Areg (rmAreg) in the injured lung tissues. The effect of Areg on TNF-alpha-induced apoptosis in MLE-12 cells, a kind of AECs, was examined by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The activation of the EGFR-AKT pathway and caspase-3, -8, and -9 were detected by Western blotting. The EGFR knockdown by small interfering RNA was used to assess the role of EGFR in Areg functions.Results: Areg production occurred in close parallel with TNF-alpha expression in M1 AMs and ALI lung tissues, and rmAreg attenuated LPS-induced ALI in mice. TNF-alpha stimulation induced significant apoptosis in MLE-12 cells, but this apoptosis was inhibited under rmAreg treatment. Moreover, rmAreg enhanced the activation of EGFR and AKT, and reduced the expressions of cleaved caspase-3, -8, and -9 in ALI lung tissues and TNF-alpha-challenged MLE-12 cells. However, the EGFR knockdown significantly inhibited the Areg-induced improvement in apoptosis, enhancement of EGFR and AKT activation, and reduction of cleaved caspase-3, -8, and -9 expressions.Conclusions: Areg and TNF-alpha were synchronously produced by ALI lung tissues and M1 AMs, and Areg directly inhibited the TNF-induced apoptosis and transduction of caspase death signals in AECs via the EGFR pathway.