| Objective: To observed of the effect of schisandrin B(Sch B)on acute kidney injury induced by ischemia/reperfusion(I/R)and explore its possible mechanism.Methods: 1.Forty-five male C57BL/6 mice were randomly divided into 3 groups: Sham group and I/R group were intragastrically administered with olive oil,Sch B+I/R group were administrated with Sch B for 7 days before modeling.The bilateral renal arteries of the mice were clamped and then opened to establish the renal I/R model.On 1st,2nd and 7th day after renal reperfusion,5 mice were sacrificed.The blood were used to detect serum creatinine and blood urea nitrogen.HE staining and glycogen PAS staining observed the damage of kidney tissue.The expression of NGAL and Kim-1 m RNA was detected by RT-PCR.The expression levels of caspase-3,Bcl-2,Bax and LC3 proteins were detected by Western blot.TUNEL staining was detected apoptosis in tubular epithelial cells.2.Randomized renal tubular epithelial cells(HK-2)were divided into control group,hypoxia/reoxygenation(H/R)group and Sch B+H/R group.Sch B+H/R group were pre-protected with Sch B for 6h before hypoxia/reoxygenation.CCK8 detected the activity of HK-2 cells.The protein to be detected by Western blot is the same as vivo experiment,and Annexin-V/PI staining detected the apoptosis rate of HK-2 cells.Results: 1.Compared with Sham group,blood Scr and BUN levels were significantly increased in Sch B+I/R group;compared with I/R group,the levels of blood Scr and BUN were significantly lower in I/R+Sch B group.The blood Scr and BUN levels were highest on 1st day,gradually decreased on 2nd and 7th days.The HE staining showed the structure of renal tissue did not change in Sham group.In I/R group,the infiltration of a large number of inflammatory cells were observed in the renal interstitial tissue,and the damage of renal tubules were obviously aggravated.The Sch B+I/R group lesions were significantly lighter than I/R group.The glycogen PAS showed the renal tissue structure of Sham group did not change.The glomerular mesangial cells showed hyperplasia,and there was deposition of PAS positive staining material,and the non-uniformity of the blood vessels on the glomerular were thickened in I/R group.The pathological changes in Sch B+I/R group were significantly lighter than I/R group.The kidney tissues of I/R group and Sch B+I/R group were the most severely damaged on 1st day,and gradually reduced on 2nd and 7th days.On 1st and 2nd day,compared with Sham group,Kim-1 and NGAL m RNA levels were significantly increased,the expression of caspase-3 and LC3 protein were significantly increased,and Bcl-2/Bax ratio was significantly decreased in I/R+Sch B group;compared with I/R group,Kim-1 and NGAL m RNA levels were decreased,and the expression of caspase-3 protein was decreased,the Bcl-2/Bax ratio and LC3 protein were increased in Sch B+I/R group.There was no significant difference the levels of related m RNA and protein between the three groups on 7th day.The results of TUNEL staining showed the apoptotic index of I/R group and Sch B+I/R group was significantly higher than sham group on 1st and 2nd day,but I/R group was significantly higher than Sch B+I/R group.And on the 7th day there was no difference compared to Sham group.2.The cell viability of H/R group and Sch B+H/R group decreased significantly,but the cell activity of Sch B+H/R group was higher than H/R group,the cell viability was increased with the extension of reoxygenation time.Compared with control group,the expression of LC3 protein was significantly increased,Bcl-2/Bax ratio decreased significantly in H/R group and Sch B+H/R group.Compared with H/R group,the LC3 and Bcl-2/Bax ratio increased in Sch B+H/R group.The LC3 level decreased and the Bcl-2/Bax ratio increased with the extension of reoxygenation time.Compared with control group,the apoptosis rate of H/R group and Sch B+H/R group increased,the H/R group increase more significant,and the apoptosis rate was decreased with the extension of reoxygenation time.Conclusion: C57BL/6 mice can successfully induce AKI induced by I/R by clamping bilateral renal arteries for 40 min.Sch B can improve the renal function,pathological damage and apoptosis of AKI induced by ischemia-reperfusion in mice.Sch B has a protective effect on apoptosis of HK-2 cells caused by hypoxia/reoxygenation.It may be related to the regulation of apoptosis-related factors and autophagy-related factor.And the protective effect of Sch B is more significant in the early stage of AKI. |
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