The on-off action of Forkhead protein O3a in endotoxin tolerance of Kupffer cells depends on the PI3K/AKT pathway
The on-off action of Forkhead protein O3a in endotoxin tolerance of Kupffer cells depends on the PI3K/AKT pathway
复制标题
Forkhead 蛋白 O3a 在 Kupffer 细胞内毒素耐受中的开关作用取决于 PI3K/AKT 通路
DOI：
10.1016/j.intimp.2020.106342
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发表时间：
2020
影响因子：
5.6
通讯作者：
Zhang W
中科院分区：
文献类型：
--
作者：
Mu D;Miao C;Cheng Y;Li P;Gong J;Zhang W
库普弗细胞（KCs）的内毒素耐受（ET）是限制内毒素休克的重要保护机制。叉头蛋白O3a （Foxo3a）作为一种关键的抗炎分子，在KCs ET中的作用和机制尚不清楚。方法建立体外和体内非内毒素耐受（NET） KCs模型。采用酶联免疫吸附试验（ELISA）检测细胞因子水平。western blotting （WB）检测蛋白表达和磷酸化水平。免疫荧光法检测核因子κB （NF-κB）和Foxo3a在KCs中的定位变化。分别用流式细胞术和自动计数仪检测KCs的凋亡和存活率。结果ET组NF-κB活性、p-Foxo3a、肿瘤坏死因子（TNF-α）水平显著低于NET组，而Foxo3a、白细胞介素10 （IL-10）水平显著高于NET组。过表达Foxo3a或使用磷脂酰肌醇-3-羟基激酶（PI3K）抑制剂，通过抑制PI3K/AKT活性，降低p-Foxo3a水平，从而抑制NF-κB的活化，从而提高KCs和小鼠对内毒素的耐受性。相反，沉默Foxo3a或使用PI3K激动剂会降低KCs和小鼠对内毒素的耐受性。PI3K激动剂抵消了Foxo3a过表达对NF-κB的抑制作用，损害了KCs对内毒素的耐受性。结论Foxo3a在KCs ET中的开关作用依赖于PI3K/AKT通路。
BackgroundThe endotoxin tolerance (ET) of Kupffer cells (KCs) is an important protective mechanism for limiting endotoxin shock. As a key anti-inflammatory molecule, the roles and mechanism of Forkhead protein O3a (Foxo3a) in ET of KCs are not yet well understood.MethodsET and nonendotoxin tolerance (NET) KCs models were establishedin vitroandin vivo. The levels of cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The protein expression and phosphorylation levels were detected by western blotting (WB). Changes in the localization of nuclear factor kappa B (NF-κB) and Foxo3a in KCs were detected by immunofluorescence assays. KCs apoptosis and survival rates were detected by flow cytometry and an automatic cell counter, respectively.ResultsThe activity of NF-κB and the levels of p-Foxo3a and tumor necrosis factor (TNF-α) in the ET group were significantly lower than those in the NET group, while the levels of Foxo3a and interleukin 10 (IL-10) in the ET group were significantly higher than those in the NET group. Overexpression of Foxo3a or the use of a phosphatidylinositol-3-hydroxykinase (PI3K) inhibitor suppressed the activation of NF-κB by decreasing the levels of p-Foxo3a by inhibiting the activity of PI3K/AKT, which improved the tolerance of KCs and mice to endotoxin. In contrast, silencing Foxo3a or the use of a PI3K agonist reduced the tolerance of KCs and mice to endotoxin. The PI3K agonist counteracted the inhibitory effects of Foxo3a overexpression on NF-κB, impairing the tolerance of KCs to endotoxin.ConclusionsThe on-off action of Foxo3a in the ET of KCs depends on the PI3K/AKT pathway.