School of Basic Medical Sciences, Binzhou Medical University, Yantai, 264003, China.
School of Basic Medical Sciences, Binzhou Medical University, Yantai, 264003, China.
Microb Pathog. 2021 Sep;158:105054. doi: 10.1016/j.micpath.2021.105054. Epub 2021 Jun 17.
The ability of Helicobacter pylori to manipulate host autophagy is an important pathogenic mechanism. We found an inverse correlation between the expression of ILK and the autophagy marker protein LC3B in H. pylori-positive human samples, H. pylori-infected mice models and H. pylori-infected GES-1 cell lines. When the ILK-knockdown GES-1 cells were infected by H. pylori, CagA were significantly degraded, autophagosomes accumulation and autolysosomes formation were significantly increased, and LC3B protein levels and ratio of LC3BII to LC3BI were also remarkably upregulated. And chloroquine treatment increased LC3B levels in ILK-knockdown GES-1 cells. The expression levels of both Rac1 and RhoA were downregulated in GES-1 cells after H. pylori infection and were decreased in ILK-knockdown GES-1 cells. The mRNA and protein levels of PAK1, MLC, and LIMK were significantly decreased and cofilin mRNA and protein levels were significantly increased in GES-1 cells treated with the Rac1 inhibitor NSC 23766. The mRNA and protein levels of ROCK1, ROCK2, MLC, and LIMK1 were significantly reduced and cofilin mRNA and protein levels were significantly increased in GES-1 cells treated with the RhoA inhibitor CCG-1423. F-actin was significantly reduced in Rac1- or RhoA-inhibited GES-1 cells. F-actin depolymerization induced autophagosomes accumulation, autolysosomes formation, and the increase of LC3B levels in GES-1 cells. Therefore, these findings revealed that ILK could serve as a novel regulator to affect Rac1/PAK1 and RhoA/ROCKs signaling pathways, thereby influencing H. pylori-induced autophagy.
幽门螺杆菌操纵宿主自噬的能力是一种重要的致病机制。我们发现，在幽门螺杆菌阳性的人类样本、幽门螺杆菌感染的小鼠模型和幽门螺杆菌感染的 GES-1 细胞系中，ILK 的表达与自噬标志物蛋白 LC3B 呈负相关。当被幽门螺杆菌感染的 ILK 敲低 GES-1 细胞中，CagA 明显降解，自噬体积累和自溶酶体形成明显增加，LC3B 蛋白水平和 LC3BII/LC3BI 比值也明显上调。氯喹处理可增加 ILK 敲低 GES-1 细胞中的 LC3B 水平。幽门螺杆菌感染后，GES-1 细胞中 Rac1 和 RhoA 的表达水平下调，ILK 敲低的 GES-1 细胞中 Rac1 和 RhoA 的表达水平降低。PAK1、MLC 和 LIMK 的 mRNA 和蛋白水平在 GES-1 细胞中显著降低，而 cofilin 的 mRNA 和蛋白水平在 GES-1 细胞中显著升高，这些变化发生在 Rac1 抑制剂 NSC 23766 处理后。ROCK1、ROCK2、MLC 和 LIMK1 的 mRNA 和蛋白水平在 RhoA 抑制剂 CCG-1423 处理的 GES-1 细胞中显著降低，而 cofilin 的 mRNA 和蛋白水平在 GES-1 细胞中显著升高。Rac1 或 RhoA 抑制的 GES-1 细胞中 F-肌动蛋白明显减少。F-肌动蛋白解聚诱导自噬体积累、自溶酶体形成以及 GES-1 细胞中 LC3B 水平增加。因此，这些发现表明，ILK 可以作为一种新的调节剂，影响 Rac1/PAK1 和 RhoA/ROCKs 信号通路，从而影响幽门螺杆菌诱导的自噬。
