2023, Vol. 27 ›› Issue (8): 1172-1178

Expression of mitochondrial sirtuin 3 in mice with acute renal ischemia-reperfusion injury

Jia Shengqi, Luo Wenlong, Tian Dingyuan, Zhang Xinhui, Cui Qian, Wang Chao, Pei Hanjun   

Abstract: BACKGROUND: Contrast-induced nephropathy has become one of the main causes of hospital-acquired acute kidney injury and its essence is acute renal ischemia-reperfusion injury. However, the role of sirtuin 3 in it is still unclear.
OBJECTIVE: To probe the dynamical changes of sirtuin 3 after different duration of renal ischemia and to establish the relationship of sirtuin3 expression with mitochondrial injury-related parameters.
METHODS: The mouse model of acute renal ischemia-reperfusion injury was established by ischemia for different time (15, 20, 25, 30 minutes) followed by 48 hours of reperfusion in C57BL/6 mice. According to the ischemic time, all animals were divided into six groups (n=8 per group): control group, sham group, 15-, 20-, 25- and 30-minute ischemia groups. Forty-eight hours after modeling, the serum levels of creatinine and blood urea nitrogen were measured. The apoptosis of renal tissue cells was monitored by TUNEL. Adenosine triphosphate content in the kidney was measured by luciferase luminescence method. Hematoxylin-eosin staining was used to observe pathological changes of the kidney. Mitochondrial changes were observed under a transmission electron microscope. The expression of mitochondrial dynamin related protein 1, mitofusion 1, and sirtuin 3 was determined by western blot.
RESULTS AND CONCLUSION: After ischemia, serum ccreatinine, blood urea nitrogen, histopathological score and apoptotic index increased gradually after ischemia; the injury of mitochondrial structure of the kidney gradually aggravated and the mitochondrial adenosine triphosphate content decreased in general. The sirtuin 3 expression showed no significant difference among control, sham and 15-minute ischemia groups. The expression of sirtuin 3 was higher at 20 minutes of ischemia than at 15 minutes of ischemia (P < 0.05), further increased significantly at 25 minutes of ischemia (P < 0.05), and reached a peak at 30 minutes of ischemia (P < 0.05). Mitofusion 1 expression significantly increased in the 15- and 20-minute ischemia groups compared with the sham group (P < 0.05) and further increased significantly in the 25- and 30-minute ischemia groups compared with the 15-minute ischemia group (P < 0.05). The expression of mitochondrial dynamin related protein 1 increased to the peak value at 15 minutes (P < 0.05) and then decreased at 20 and 25 minutes. Relationship study showed that the content of adenosine triphosphate was negatively correlated with the expression of sirtuin 3 (r=-0.77, P < 0.05). The expression of sirtuin 3 was negatively correlated with the expression of mitochondrial dynamin related protein 1 (r=-0.52, P < 0.05). The expression of sirtuin 3 was positively correlated with the expression of mitofusion 1 (r=0.72, P < 0.05). To conclude, during renal ischemia-reperfusion injury, the decreased adenosine triphosphate level time-dependently stimulates the expression of sirtuin 3. The over expression of sirtuin3 enhances mitochondrial fusion and inhibit its fission, then protect the mitochondria and maintain energy metabolism. All these findings indicate that sirtuin3 may be a potential target for reducing renal ischemia-reperfusion injury.
Key words: mitochondria, sirtuin 3, kidney, ischemia-reperfusion injury, adenosine triphosphate, mitochondrial dynamin related protein 1, mitofusion 1, C57BL/6J mouse