Department of Nephrology and Rheumatology, University Medical Centre, Georg-August-University Goettingen, Goettingen, Germany.
Nephrol Dial Transplant. 2011 Aug;26(8):2674-83. doi: 10.1093/ndt/gfq793. Epub 2011 Feb 1.
The effect of clearance of so-called middle- and high-molecular weight proteins on clinical outcome of patients treated by peritoneal dialysis is still a matter of debate. In our present study, we investigated the impact of short-time alteration of the glucose concentration and the osmolarity of the peritoneal dialysis solution (PDS) on protein removal.
Peritoneal dialysis liquids (PDL) were collected from 19 well-characterized continuous ambulatory peritoneal dialysis (CAPD) patients treated with two types of PDS: Baxter (n = 10) and Fresenius (n = 9). The patients were treated with two different glucose concentration of each PDS in 4-h cycles. The depletion of the six interfering high-abundant proteins from the PDL samples was performed with the Multiple Affinity Removal LC Column-Human 6. The resulting protein fractions were analysed by 2D gel electrophoresis, differential in gel electrophoresis, mass spectrometry and 2D western blot.
Proteomics investigation of the PDL fractions after depletion allowed the identification of 198 polypeptides of 424 excised spots. These polypeptides equates to 48 non-redundant proteins. Comparative analyses of 2D gel electrophoresis protein pattern revealed a clear correlation between protein removal and PDS glucose concentration and osmolarity. An increase for 4 h in the PDS osmolarity (with 43-51 mosmol/L) resulted qualitatively in 18-23% more protein removal in PDL. Moreover, 2D western blot analyses of the protein glycation pattern showed that the short-time increase in PDS glucose concentration (45-50 mM) resulted in significant alteration of the advanced glycosylation end products (AGEs) pattern.
The data presented in this study demonstrate a clear correlation between the short-time changes in glucose concentration and osmolarity of the PDS, and the augmentation of the protein removal and the appearance of AGEs during CAPD.
清除所谓的中高分子量蛋白质对腹膜透析患者临床结局的影响仍存在争议。在本研究中，我们研究了短时间改变腹膜透析液（PDS）葡萄糖浓度和渗透压对蛋白质清除的影响。
从 19 名经过充分描述的持续性非卧床腹膜透析（CAPD）患者中收集腹膜透析液（PDL），这些患者接受两种类型的 PDS 治疗：Baxter（n = 10）和 Fresenius（n = 9）。患者接受两种不同葡萄糖浓度的 PDS，每 4 小时更换一次。使用多亲和去除 LC 柱-Human 6 从 PDL 样本中去除六种干扰性高丰度蛋白质。所得蛋白质级分通过 2D 凝胶电泳、差异凝胶电泳、质谱和 2D 蛋白质印迹进行分析。
经去蛋白处理后的 PDL 级分的蛋白质组学研究允许鉴定 424 个切除斑点中的 198 个多肽。这些多肽相当于 48 个非冗余蛋白质。2D 凝胶电泳蛋白图谱的比较分析表明，蛋白质清除与 PDS 葡萄糖浓度和渗透压之间存在明显的相关性。PDS 渗透压增加 4 小时（增加 43-51 mosmol/L）可使 PDL 中蛋白质清除率提高 18-23%。此外，2D 蛋白质印迹分析蛋白质糖基化模式表明，PDS 葡萄糖浓度短时间增加（45-50 mM）会导致晚期糖基化终产物（AGEs）模式发生显著改变。
本研究提供的数据表明，PDS 葡萄糖浓度和渗透压的短期变化与 CAPD 期间蛋白质清除率的增加和 AGEs 的出现之间存在明显的相关性。
