Expression of apoptosis stimulating protein two of p53 in acute kidney injury induced by carbon tetrachloride in mice

Objective To investigate the expression of apoptosis stimulating protein two of p53 (ASPP2) in acute kidney injury (AKI) induced by carbon tetrachloride (CCl4) in mice. Methods Thirty-two male Balb/c mice were randomly divided into olive oil control group (control group, 8 mice) and CCl4 experimental group (experimental group, 24 mice). A mouse model of AKI was induced by a single high-dose abdominal injection of CCl4. The mice in the experimental group were sacrificed at 12 h, 24 h and 48 h after CCl4 injection. The mice in the control group were sacrificed 24 h after treatment. The serum and kidney tissue samples were collected. Serum biochemical indicators [serum creatinine (Scr) and urea nitrogen (BUN)] were measured by automatic biochemical analyzer. The pathological damage of kidney tissue was observed by hematoxylin-eosin (HE) staining and Periodate-Schiff (PAS) staining. ASPP2 positioning and expression level were observed by immunohistochemistry. The apoptosis of mouse kidney tissue was detected by in situ apoptosis. The expression of ASPP2 protein and ASPP2 mRNA in renal tissue were detected by Western blotting and quantitative real-time PCR. Results Compared with the control group, the levels of Scr and BUN were significantly increased in the experimental group (P＜0.01). Histopathology showed partial renal tubular brush margin detachment, renal tubular epithelial cell necrosis and nuclear disintegration in the experimental group. TUNEL staining showed that the apoptosis rate of renal tissue cells increased significantly in the experimental group (P＜0.01). Compared with the control group, the expression of ASPP2 in the experimental group increased at the early period and then decreased with the prolongation of injury time. The mRNA expression was consistent with the protein expression, and all reached the peak after 24 hours injury (P＜0.01). Immunohistochemistry showed that ASPP2 was mainly localized in the cytoplasm of renal tubular epithelial cells. Conclusions A single high-dose injection of CCl4 in the abdominal cavity can induce AKI in mice. The expression of ASPP2 is consistent with the degree of renal tissue damage. As the damage of renal tissue is aggravated, the expression of ASPP2 is gradually increased, which indicates that ASPP2 may be a damage factor.