钙敏感受体及紧密连接蛋白-14的表达对肾草酸钙结石形成的影响

Ca SR increases the expression of Claudin-14 to promote renal calcium oxalate stone formation

目的肾结石中草酸钙型结石最为常见。文中通过构建大鼠肾草酸钙结石模型,初步探讨钙敏感受体-紧密连接蛋白-14(calcium-sensing receptor-Claudin-14,Ca SR-Claudin-14)调节通路在肾草酸钙结石形成中的作用。方法 30只雄性SD大鼠随机分为对照组和结石组,每组15只。采用1%乙二醇自由饮水+2%氯化铵(2 m L)灌胃诱导大鼠肾草酸钙结石模型形成;HE染色鉴定模型;全自动生化分析仪检测各组尿生化指标;免疫组化学检测Ca SR蛋白表达;RT-PCR检测Claudin-14mRNA表达;Western blot检测Ca SR和Claudin-14蛋白表达。结果光镜下结石组有大量结石结晶形成,结石组24 h尿钙排泄量高于对照组[(9.66±1.10)mmol vs(3.26±0.60)mmol,P<0.01]、结石组24 h尿量显著高于对照组[(21.27±1.08)m L vs(13.2±0.55)m L,P<0.01],2组尿p H差异无统计学意义(P>0.05);结石组Claudin-14 mRNA相对表达量显著高于对照组[(0.150±0.004)vs(0.047±0.008),P<0.01]、结石组Claudin-14蛋白含量高于对照组[(1.526±0.089)vs 0,P<0.01];结石组Ca SR蛋白含量高于对照组[(6.697±0.051)vs(5.016±0.053),P<0.05]。结论 Ca SR可通过上调Claudin-14表达增加肾小管尿钙排泄从而参与肾草酸钙结石形成。

Objective The calcium oxalate stone is the most common type of the kidney stones.By building the rat renal calcium oxalate stone model, preliminary study the function of CaSR-Claudin14 regulating pathways on renal calcium oxalate stone for-mation model in rats. Methods 30 Male S-D rats were randomly divided into control group （n=15） and model group （n=15）. Adult male S-D rats were given ethylene glycol and ammonium chloride to induce urolithiasis.Application of full automatic biochemical analyzer to test rat renal function and the changes of urine biochemical index.Immunohistochemistry was used to detect the expression of CaSR protein;RT-PCR was used to detect the Claudin-14 mRNA expression;Western Blotting was used to detect the expression of CaSR and Claudin-14 protein respectively. Results By observing model group has large stones crystallization under light microsco-py;model group rats 24 h urine calcium are significantly higher than control group（[9.66 ±1.10]mmol vs [3.26 ±0.60]mmol, P〈0.01）; and model group 24 h urine volume are significantly higher than control group （[21.27 ±1.08]mL vs [13.2 ±0.55]mL, P〈0.01 ）; and urinary PH has no significant difference between the groups（ P 〉0.05 ） .Expression of Claudin-14 mRNA in the model group is significantly higher than normal control group（[0.150 ± 0.004] vs [0.047 ±0.008], P〈0.01）; Expression of Claudin-14 protein in the model group is significantly higher than normal control group（[1.526 ±0.089] vs 0, P〈0.01）.Expression of CaSR protein in the model group is significantly higher than normal control group（[6.697 ±0.051] vs [5.016 ±0.053], P〈0.05）. Conclusion CaSR can raise the expression of Claudin-14, increase re-nal tubular urinary calcium excretion to promote renal calcium oxalate stone formation.