University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America.
PLoS One. 2013 May 28;8(5):e63368. doi: 10.1371/journal.pone.0063368. Print 2013.
The analysis of protein biomarkers in urine is expected to lead to advances in a variety of clinical settings. Several characteristics of urine including a low-protein matrix, ease of testing and a demonstrated proteomic stability offer distinct advantages over current widely used biofluids, serum and plasma. Improvements in our understanding of the urine proteome and in methods used in its evaluation will facilitate the clinical development of urinary protein biomarkers. Multiplexed bead-based immunoassays were utilized to evaluate 211 proteins in urines from 103 healthy donors. An additional 25 healthy donors provided serial urine samples over the course of two days in order to assess temporal variation in selected biomarkers. Nearly one-third of the evaluated biomarkers were detected in urine at levels greater than 1 ng/ml, representing a diverse panel of proteins with respect to structure, function and biological role. The presence of several biomarkers in urine was confirmed by western blot. Several methods of data normalization were employed to assess impact on biomarker variability. A complex pattern of correlations with urine creatinine, albumin and beta-2-microglobulin was observed indicating the presence of highly specific mechanisms of renal filtration. Further investigation of the urinary protein biomarkers identified in this preliminary study along with a consideration of the underlying proteomic trends suggested by these findings should lead to an improved capability to identify candidate biomarkers for clinical development.
尿液中蛋白质生物标志物的分析有望在多种临床环境中取得进展。尿液具有多种特性，包括低蛋白基质、易于检测和已证明的蛋白质组稳定性，与当前广泛使用的生物体液（血清和血浆）相比具有明显优势。对尿液蛋白质组的理解的提高以及用于评估尿液蛋白质组的方法的改进将促进尿液蛋白质生物标志物的临床开发。利用多重珠基免疫测定法评估了 103 名健康供体尿液中的 211 种蛋白质。另外 25 名健康供体在两天的时间内提供了连续的尿液样本，以评估选定生物标志物的时间变化。评估的生物标志物中近三分之一以大于 1ng/ml 的水平存在于尿液中，代表了具有不同结构、功能和生物学作用的蛋白质的多样化组合。通过 Western blot 证实了尿液中存在几种生物标志物。采用了几种数据归一化方法来评估对生物标志物变异性的影响。观察到与尿肌酐、白蛋白和β-2-微球蛋白的复杂相关性模式，表明存在高度特异性的肾脏滤过机制。对本初步研究中鉴定的尿液蛋白质生物标志物的进一步研究以及对这些发现所提示的潜在蛋白质组趋势的考虑，应能提高识别候选生物标志物以进行临床开发的能力。
