Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
Section of Nephrology, Boston University Medical Center, Boston, Massachusetts, United States of America.
PLoS One. 2021 Jan 22;16(1):e0245614. doi: 10.1371/journal.pone.0245614. eCollection 2021.
αKlotho is primarily known to express as a transmembrane protein. Proteolytic cleavage results in shedding of the extracellular domain which enters systemic circulation. A truncated form of αKlotho resulting from alternative splicing of the αKLOTHO transcript exists and is believed to be secreted, thereby also entering systemic circulation. Existing ELISA methods fail to distinguish between the two circulating isoforms resulting in inconsistencies in assessing circulating αKlotho levels. We have exploited a unique 15aa peptide sequence present in the alternatively spliced secreted isoform to generate an antibody and show that it is able to specifically detect only the secreted Klotho isoform in human plasma. This finding will facilitate in distinguishing the levels of different circulating Klotho isoforms in health and disease and enhance their potential to serve as a biomarker for CKD and other conditions.
αKlotho 主要表达为跨膜蛋白。蛋白水解切割导致细胞外结构域脱落，进入体循环。αKlotho 转录本的选择性剪接产生了一种截断形式的 αKlotho，据信该形式被分泌并因此也进入体循环。现有的 ELISA 方法无法区分两种循环同工型，导致在评估循环 αKlotho 水平时存在不一致性。我们利用了在选择性剪接的分泌同工型中存在的独特的 15 个氨基酸肽序列来产生抗体，并表明它能够特异性地仅检测人血浆中的分泌型 Klotho 同工型。这一发现将有助于区分健康和疾病状态下不同循环 Klotho 同工型的水平，并增强它们作为 CKD 和其他疾病的生物标志物的潜力。
