α-Klotho is unstable in human urine
α-Klotho is unstable in human urine
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DOI：
10.1038/ki.2015.238
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发表时间：
2015-12-01
影响因子：
19.6
通讯作者：
Heijboer, Annemieke C.
中科院分区：
文献类型：
--
作者：
Adema, Aaltje Y.;Vervloet, Marc G.;Heijboer, Annemieke C.
α - klotho是肾脏和心血管疾病中一种有趣的新生物标志物。由于α - klotho主要在肾上皮组织中表达，许多论文报道了尿中a-Klotho的浓度。由于这些研究没有解决尿α - klotho测量的可靠性，并且已知尿液是一个复杂的环境，我们研究了α - klotho在新鲜导管和新鲜空尿中的稳定性。a-Klotho在这些新鲜尿液样本和其他几种条件下的相同样本中进行了测量。在37℃下储存新鲜导管尿3小时，与在膀胱中储存相当，导致a- klotho浓度下降82%。与新鲜尿相比，- 80℃和- 20℃储存后，α - klotho浓度分别平均下降45%和82%。额外的冻融循环进一步降低了α - klotho浓度。添加蛋白酶抑制剂或0.1%白蛋白部分阻止了新鲜尿中的降解。因此，alpha-Klotho在尿液中是高度不稳定的。未来显示尿α - klotho结果的研究应该提到保存条件，并证明α - klotho测量的可靠性。
alpha-Klotho is an interesting new biomarker in kidney and cardiovascular disease. As alpha-Klotho is primarily expressed in renal epithelial tissue, various papers have reported a-Klotho concentrations in urine. As these studies did not address the reliability of urinary alpha-Klotho measurements and as urine is known to be a complex milieu, we investigated the stability of alpha-Klotho in both fresh catheter and fresh voided urine. a-Klotho was measured in these fresh urine samples and in the same samples under several other conditions. Storage of fresh catheter urine for 3 h at 37 degrees C, comparable to storage in the bladder, led to a 82% decrease in a-Klotho concentrations. Compared with fresh voided urine, alpha-Klotho concentrations decreased on an average of 45 and 82% after storage at - 80 degrees C and - 20 degrees C, respectively. An additional freeze-thaw cycle further decreased alpha-Klotho concentrations. The addition of a protease inhibitor or 0.1% albumin partly prevented degradation in fresh voided urine. Thus, alpha-Klotho is highly unstable in urine. Future studies showing results of urinary alpha-Klotho should mention conservation conditions and prove the reliability of the alpha-Klotho measurements.