Protective effect of Klotho protein on acute renal injury and fibrosis in rats with ischemia-reperfusion

doi:10.11958/20221063

Abstract

Abstract:

Objective To investigate the role of Klotho protein in acute renal injury and fibrosis induced by ischemia-reperfusion (I/R) in rats. Methods Sixty healthy SD rats were randomly divided into the sham operation group (sham group), the renal ischemia-reperfusion group (I/R group) and the Klotho protein intervention group (I/R+Kl group), with 20 rats in each group. In the I/R group, the acute renal injury model of I/R was established by clamping the right renal pedicle for 40 min. In the sham group, the right renal artery was dissociated, but the right renal pedicle was not clamped. After exposure for 40 minutes, the abdominal cavity was sutured. The operation method of the I/R+Kl group was the same as that of the I/R group. Kiotho protein (0.01 mg/kg) was injected intraperitoneally. The blood and renal tissue samples were collected on the 1st, 7th, 14th and 28th days after successful modeling in the three groups, and blood creatinine (Scr) and blood urea nitrogen (BUN) were measured respectively. HE staining was used to observe the damage of renal tissue. Masson staining was used to observe the renal fibrosis. ELISA was used to detect levels of Klotho protein in blood and renal tissue. Western blot assay was used to detect the expression of Klotho protein in renal tissue. Results Compared with the sham group, levels of SCR and BUN were increased in the I/R group and the I/R+Kl group (P<0.05). Compared with the I/R+Kl group, serum levels of SCR and BUN were increased in different time points in the I/R group (P<0.05). HE staining showed extensive acute necrosis of renal tubules in the I/R group, and the injury was mild in the I/R+Kl group. Masson staining showed that mild fibrosis occurred in the I/R group on the 14th day, and the degree of fibrosis was more significant on the 28th day, while the degree of fibrosis was very mild in the I/R+Kl group (P < 0.05). ELISA results showed that compared with the Sham group at day 1, 14 and 28, levels of Klotho in blood and renal tissue decreased significantly in the I/R+Kl group and the I/R group, and the level of Klotho decreased in the I/R group than that of the I/R+Kl group (P<0.05). Western blot results showed that compared with the Sham group, Klotho levels were decreased at all time points in the I/R group and the I/R+Kl group. while Klotho levels were higher in the I/R+Kl group than those in the I/R group (P<0.05). Conclusion Klotho expression is down-regulated during renal I/R injury. Exogenous supplementation of Klotho protein can alleviate acute renal injury and fibrosis in rats with renal I/R injury and play a role in renal protection.

Key words: acute kidney injury, reperfusion injury, fibrosis, kidney diseases, Klotho protein

CLC Number:

R726.92

Figures/Tables 8

Fig.1 Comparison of serum creatinine levels between the three groups

Fig.2 Comparison of serum urea nitrogen levels between the three groups of rats

Fig.3 Renal histomorphological changes of rats in each group after ischemia-reperfusion injury (HE staining, ×400)

Fig.4 Changes of renal fibrosis in rats after ischemia-reperfusion injury (Masson staining, ×400)

Fig.5 Renal fibrosis injury score of rats in each group after ischemia-reperfusion injury

Fig.6 Comparison of Klotho protein levels in renal tissue of rats between the three groups

Fig.7 Comparison of serum Klotho protein levels of rats between the three groups

Fig.8 The expression levels of Klotho protein in renal tissue of rats detected by Western blot assay

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