Correlation between sKL and Nrf2 plasma levels and calcium oxalate urolithiasis.

OBJECTIVE: To investigate the relationship between plasma levels of sKL and Nrf2 and calcium oxalate calculi. METHODS: The clinical data of 135 patients with calcium oxalate calculi treated in the Department of Urology of the second affiliated Hospital of Xinjiang Medical University from February 2019 to December 2022, and 125 healthy persons who underwent physical examination in the same period were collected and divided into healthy group and stone group. The levels of sKL and Nrf2 were measured by ELISA. Correlation test was used to analyze the risk factors of calcium oxalate stones, logistic regression analysis was used to analyze the risk factors of calcium oxalate stones, and ROC curve was used to evaluate the sensitivity and specificity of sKL and Nrf2 in predicting urinary calculi. RESULTS: Compared with the healthy group, the plasma sKL level in the stone group decreased (111.53 ± 27.89 vs 130.68 ± 32.51), while the plasma Nrf2 level increased (300.74 ± 114.31 vs 246.74 ± 108.22). There was no significant difference in the distribution of age and sex between the healthy group and the stone group, but there were significant differences in plasma levels of WBC, NEUT, CRP, BUN, BUA, SCr, BMI, and eating habits. The results of correlation test showed that the level of plasma Nrf2 was positively correlated with SCr (r = 0.181, P < 0.05) and NEUT (r = 0.144 P < 0.05). Plasma sKL was not significantly correlated with Nrf2 (r = 0.047, P > 0.05), WBC (r = 0.108, P > 0.05), CRP (r = - 0.022, P > 0.05), BUN (r = - 0.115, P > 0.05), BUA (r = - 0.139, P > 0.05), SCr (r = 0.049, P > 0.05), and NEUT (r = 0.027, P > 0.05). Plasma Nrf2 was not significantly correlated with WBC (r = 0.097, P > 0.05), CRP (r = 0.045, P > 0.05), BUN (r = 0.122, P > 0.05), and BUA (r = 0.122, P > 0.05); (r = 0.078, P > 0.05) had no significant correlation. Logistic regression showed that elevated plasma sKL (OR 0.978, 95% CI 0.969 ~ 0.988, P < 0.05) was a protective factor for the occurrence of calcium oxalate stones, BMI (OR 1.122, 95% CI 1.045 ~ 1.206, P < 0.05), dietary habit score (OR 1.571, 95% CI 1.221 ~ 2.020, P < 0.05), and WBC (OR 1.551, 95% CI 1.423 ~ 1.424, P < 0.05). Increased NEUT (OR 1.539, 95% CI 1.391 ~ 1.395, P < 0.05) and CRP (OR 1.118, 95% CI: 1.066 ~ 1.098, P < 0.05) are risk factors for the occurrence of calcium oxalate stones. CONCLUSION: Plasma sKL level decreased and Nrf2 level increased in patients with calcium oxalate calculi. Plasma sKL may play an antioxidant role in the pathogenesis of calcium oxalate stones through Nrf2 antioxidant pathway.

Effect of Klotho protein on renal oxidative stress in rat with calcium oxalate nephrolithiasis / 中华泌尿外科杂志

Objective To investigate the protective effect and mechanism of Klotho protein on oxidative stress in renal tubular epithelial cells of experimental rat nodels of renal calcium oxalate stone.Methods The 30 SD rats,6-8 weeks old,were randomly divided into 3 groups (10 of each),normal control group(group A),calcium oxalate model group(group B),drug plus calcium oxalate model group (group C).Group A was established with physiological saline by garage each day,group B was established with 1％ ethylene glycol in drinking water + 2％ ammonium chloride by garage (2 ml/d),group C was established with Fosinopril 2.5mg + Valsartan 15mg aqueous solution 2 ml by gavage on the basis of group B (2 ml/d).4 weeks later,the level of malondialdehyde (MDA),superoxide dismutase (SOD),catalase (CAT) and glutathione peroxidase (GSH) in the kidney homogenate were measured by double antibody sandwich enzyme-linked immunosorbent assay (ELISA),Polymerase chain reaction (RT-PCR) was used to measure expression of Klotho and Nrf2 mRNA,and Western Blot was used to measure the expression of Klotho and Nrf2 protein.Results The level of MDA in group B [(12.43 ± 0.43) μmol/mg] was significantly increased compared to group A[(8.67 ±0.84) μmol/mg,P ＜0.05] and group C [(7.97 ±0.81) μmol/mg,P＜0.05],while group A was close to group C (P ＞0.05).In group A,B,and C,the levels of SOD were (247.89 ± 2.45),(109.54 ± 4.21),and (189.74 ± 10.47) U/mg,respectively;the levels of GSH were (38.98 ± 4.55),(26.87 ± 3.92),and (31.29± 2.54) μmol/mg,respectively;CAT were (138.47 ± 8.74),(119.87 ± 8.45),and (127.46 ± 7.45) U/mg,respectively.The levels of SOD,GSH,CAT in group B were significantly lower than that in group A and C,while those in group B were close to group A (P ＞ 0.05).The expression of Klotho and Nrf2 mRNA in group B [(0.208 ± 0.036) and (0.499 ± 0.086)] were significantly lower than group A (1.011 ± 0.174 and 1.023 ± 0.139,P ＜ 0.05)and group C(1.123 ±0.248 and 1.023 ±0.139,P ＜0.05).The expression of Klotho and Nrf2 protien were also significantly lower than that in group A and C (P ＜0.05).Conclusions Valsartan and Fosinopril could prevent the formation of renal CaOx stones by upregulating expression of low level Klotho gene induced by ethylene glycol.This effect may be involved with activation of Keapl-Nrf2-ARE signaling pathway.