Expression of tumor necrosis factor-α induced protein 8 like-1 in cisplatin-induced acute kidney injury models / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the expression and role of the tumor necrosis factor-α (TNF-α) induced protein 8 like-1 (TIPE1) in acute kidney injury (AKI) induced by cisplatin in animal model and cells.Methods:Twelve male C57BL/6 mice aged 6-8 weeks were randomly divided into the control group and the model group. Mice in the model group received a single intraperitoneal injection of 20 mg/kg of cisplatin (20 mg/kg saline in the control group). All mice were euthanized after 5 days. Meanwhile, serum and kidney samples were collected. The levels of serum creatinine (Scr) and blood urea nitrogen (BUN) were detected by biochemical kits. Renal histopathological changes in mice were observed by HE staining. The expression of TIPE1 in kidney was examined using immunohistochemistry. qRT-PCR was used for testing the relative expression of TIPE1 mRNA in mice kidney. Western blotting was used for testing TIPE1 and NGAL protein relative expression in mice kidney. Human kidney proximal tubular cells (HK-2) were stimulated with 20 μmol/L cisplatin for 0, 6, 12 and 24 h to establish cisplatin-induced AKI cell model. The expressions of TIPE1 mRNA and protein were detected by qRT-PCR and Western blotting in HK-2 cells. The expression of TIPE1 gene in HK-2 cells was silenced by lentivirus containing TIPE1 siRNA sequence. Then, TIPE1 stable knockout HK-2 cell strains were treated with 20 μmol/L of cisplatin for 24 hours. The protein expression of tubular damage marker neutrophil gelatinase-associated lipocalin (NGAL), microtubule-associated protein 1 light chain 3 (LC3) and Beclin1 in HK-2 cells were detected by Western blotting. Results:Compared with the control group, the expressions of TIPE1 mRNA and protein were up-regulated and NGAL protein expression was increased significantly in renal tissue of the model group (all P<0.05). The expressions of TIPE1 mRNA and protein were remarkably increased with the prolongation of cisplatin treatment in HK-2 cells (both P<0.05). Compared with the scramble siRNA group, the protein expressions of NGAL, LC3-Ⅱ and Beclin1 were increased significantly in the TIPE1 siRNA group after lentivirus interfered with the expression of TIPE1 gene in HK-2 cells (all P<0.05). Conclusions:The mRNA and protein expressions of TIPE1 are increased in acute kidney injury models. Gene silencing of TIPE1 can promote the expressions of early renal tubular damage marker and autophagy-related proteins, which indicates the excessive autophagy aggravates renal tubular injury. It is suggested that TIPE1 may be involved in the pathogenesis of acute kidney injury.