冬虫夏草对自发性高血压大鼠肾脏Klotho表达和肾小管上皮细胞凋亡的影响

目的 观察自发性高血压大鼠（SHR）肾脏Klotho表达和肾小管上皮细胞的凋亡情况以及冬虫夏草对其的影响，探讨冬虫夏草在高血压肾损伤肾小管上皮细胞凋亡中的保护作用机制。 方法 按随机数字表法将20只22周龄雄性SHR分为模型组（SHR）、冬虫夏草组、氯沙坦组、冬虫夏草＋氯沙坦组，以5只22周龄雄性Wistar-Kyoto（WKY）大鼠为对照组。测定尿蛋白量（24 h）、NAG、Scr、BUN水平，并观察肾脏病理改变；RT-PCR法观察肾组织Klotho、p53和p21 mRNA表达；Western印迹法检测肾组织Klotho、p53、p21和活性caspase-3蛋白表达；原位缺口末端标记法（TUNEL）检测肾小管上皮细胞凋亡。 结果 与SHR组相比，冬虫夏草组、氯沙坦组、冬虫夏草＋氯沙坦组尿蛋白量（24 h）（52.16±29.3） mg、（49.97±32.5） mg、（54.67±30.09） mg比（96.52±36.94） mg]、尿NAG(44.13±9.11)、(42.75±8.33)、（41.96±7.88） U/L比（54.07±6.57） U/L]、Scr（45.25±9.55）、（43.76±8.65）、（45.18±7.28） μmol/L比（53.84±10.21） μmol/L]和BUN（8.25±1.03）、（8.40±1.58）、（8.32±0.98） mmol/L比（8.91±1.24） mmol/L]均显著减少（均P ＜ 0.05），肾脏病理损害减轻，同时肾脏Klotho表达显著上调（P ＜ 0.01），而p53、p21及活性caspase-3表达均显著下调（均P ＜ 0.01），肾小管上皮细胞凋亡显著减少（分别为7.56%±0.52％、7.93%±0.37％、7.37%±0.36％比13.32%±0.64％，均P ＜ 0.01），各药物干预组间差异无统计学意义（P ＞ 0.05）。 结论 冬虫夏草可能通过上调Klotho表达，抑制p53、p21的表达和caspase-3的活化，减少肾小管上皮细胞凋亡，从而对高血压肾损伤起一定的保护作用。

Effects of cordyceps sinensis on Klotho expression in kidneys and apoptosis in renal tubular epithelial cells of spontaneously hypertensive rats

Objective To observe the Klotho expression in kidneys and renal tubular epithelial cells apoptosis in spontaneously hypertensive rats (SHRs) and the effects of cordyceps sinensis (CS), in order to study the mechanism of protective effects of CS on renal tubular cells apoptosis in hypertensive renal damage. Methods Twenty 22-week-old male SHRs were control group. After 8 weeks, the levels of 24 hours urinary protein (Upre), urinary N-acetyl-β-D-glucosaminidase (NAG), serum creatinine (Scr), blood urea nitrogen (BUN) and renal pathological changes were detected; the mRNA expression of Klotho, 053 and 021 was detected by RT-PCR; the protein expression of Klotho, 053, 021 and cleaved-caspase-3 was tested by Western blotting. TUNEL assay was applied to evaluate the renal tubular cell apoptosis. Results As compared to SHR group, the levels of 24 h urinary protein content (52.16±29.3) mg, (49.97±32.5) mg, (54.67±30.09) mg vs (96.52±36.94) mg], urinary NAG (44.13±9.11), (42.75±8.33), (41.96±7.88) U/L vs (54.07±6.57) U/L], Sct (45.25±9.55), (43.76±8.65), (45.18±7.28) μmol/L vs (53.84±10.21) μmol/L]and BUN (8.25±1.03), (8.40±1.58), (8.32±0.98) mmol/L vs (8.91±1.24) mmol/L]were decreased (all P<0.05), renal pathological changes were relieved, the levels of Klotho expression were up-regulated and the levels of p53 and p21 expression and cleaved-caspase-3 protein expression were down-regulated (all P<0.01), tubular cell apoptosis was decreased 7.56%±0.52%, 7.93%±0.37%, 7.37%±0.36% vs 13.32%±0.64%, P<0.01] in CS, Los and CS+Los group. Conclusions Klotho, p53 and p21 play important roles in renal tubular cells apoptosis in hypertensive renal damage. CS can up-regulate Klotho expression, down-regulate p53 and p21 expression and decrease the cleaved-caspase-3 expression and tubular cell apoptosis to ameliorate the hypertensive renal damage.