Usp9x contributes to the development of sepsis-induced acute kidney injury by promoting inflammation and apoptosis in renal tubular epithelial cells via activation of the TLR4/nf-κb pathway

• Published in: Renal failure Vol. 46; no. 2; p. 2361089
• Main Authors: Gong, Shuhao, Xiong, Huawei, Lei, Yingchao, Huang, Shipeng, Ouyang, Yingdong, Cao, Chunshui, Wang, Ying
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01-12-2024; Taylor & Francis Group
• Subjects: Acute Kidney Injury - etiology; Acute Kidney Injury - genetics; Acute Kidney Injury - pathology; Animals; Apoptosis; Cell Line; Chronic Kidney Disease and Progression; Disease Models, Animal; Epithelial Cells - metabolism; Inflammation; Kidney Tubules - cytology; Kidney Tubules - metabolism; Kidney Tubules - pathology; Lipopolysaccharides; Male; NF-kappa B - metabolism; Rats; Rats, Sprague-Dawley; Sepsis - complications; Sepsis-induced acute kidney injury; Signal Transduction; TLR4/NF-κB; Toll-Like Receptor 4 - metabolism; Ubiquitin Thiolesterase - genetics; Ubiquitin Thiolesterase - metabolism; Ubiquitination; ubiquitination modification; Usp9x; apoptosis; ubiquitination modification; Usp9x; inflammation; TLR4/NF-κB; Sepsis-induced acute kidney injury
• ISSN: 1525-6049; 0886-022X; 1525-6049
• DOI: 10.1080/0886022X.2024.2361089

As a pattern recognition receptor, Toll-like receptor 4 (TLR4) is crucial for the development and progression of acute kidney injury (AKI). This study aims to explore whether the deubiquitinase Usp9x influences the TLR4/NF-B pathway to cause sepsis-induced acute kidney injury (S-AKI). The model of AKI was established in Sprague-Dawley rats using the cecal ligation and puncture (CLP) method, while renal tubular epithelial cell NRK-52E was stimulated with lipopolysaccharide (LPS)
. All plasmids were transfected into NRK-52E cells according to the indicated group. The deubiquitinase of TLR4 was predicted by the online prediction software Ubibrowser. Subsequently, Western blot and Pearson correlation analysis identified Usp9x protein as a potential candidate. Co-IP analysis verified the interaction between TLR4 and Usp9x. Further research revealed that overexpression of Usp9x inhibited degradation of TLR4 protein by downregulating its ubiquitination modification levels. Both
and
experiments observed that interference with Usp9x effectively alleviated the inflammatory response and apoptosis of renal tubular epithelial cells (RTECs) induced by CLP or LPS, whereas overexpression of TLR4 reversed this situation. Transfection with sh-Usp9x in NRK-52E cells suppressed the expression of proteins associated with the TLR4/NF-κB pathway induced by LPS. Moreover, the overexpression of TLR4 reversed the effect of sh-Usp9x transfection. Therefore, the deubiquitinase Usp9x interacts with TLR4, leading to the upregulation of its expression through deubiquitination modification, and the activation of the TLR4/NF-κB signaling pathway, thereby promoting inflammation and apoptosis in renal tubular epithelial cells and contributing to sepsis-induced acute kidney injury.