Endemann Michaela, Bergmeister Helga, Bidmon Bettina, Boehm Michael, Csaicsich Dagmar, Malaga-Dieguez Laura, Arbeiter Klaus, Regele Heinz, Herkner Kurt, Aufricht Christoph
Department of Pediatrics, Univ. Kinderklinik Wien, Austria.
Am J Physiol Renal Physiol. 2007 Jan;292(1):F47-56. doi: 10.1152/ajprenal.00503.2005.
Low biocompatibility of peritoneal dialysis fluid (PDF) injures mesothelial cells and activates their stress response. In this study, we investigated the role of heat shock proteins (HSP), the main cytoprotective effectors of the stress response, in cytoskeletal stabilization of mesothelial cells in experimental peritoneal dialysis. In cultured human mesothelial cells, cytoskeletal integrity was assessed by detergent extractability of marker proteins following in vitro PDF exposure. Effects of HSP on stabilization of ezrin were evaluated by a conditioning protocol (PDF pretreatment) and repair assay, based on coincubation of cytoskeletal protein fractions with recombinant HSP-72 or HSP-72 antibodies. In the rat model, detachment of mesothelial cells from their peritoneal monolayer during in vivo PDF exposure was assessed with and without overexpression of HSP-72 (by heat conditioning). In vitro, cytoskeletal disruption on sublethal PDF exposure was demonstrated by significantly altered detergent extractability of ezrin and ZO-1. Restoration was associated with significant induction and cytoskeletal redistribution of HSP during recovery. Both the conditioning protocol and in vitro repair assay provided evidence for HSP-72-mediated cytoskeletal stabilization. In the rat model, overexpression of HSP-72 following heat conditioning resulted in significantly reduced detachment of mesothelial cells on in vivo exposure to PDF. Our results establish an essential role of HSP in repair and cytoprotection of cytoskeletal integrity in mesothelial cells following acute in vitro and in vivo exposure to PDF. Repeated exposure to PDF, as is the rule in the clinical setting, may not only cause repeat injury to mesothelial cells but rather represents a kind of inadvertent conditioning treatment.
腹膜透析液（PDF）的低生物相容性会损伤间皮细胞并激活其应激反应。在本研究中，我们调查了热休克蛋白（HSP）（应激反应的主要细胞保护效应器）在实验性腹膜透析中间皮细胞细胞骨架稳定中的作用。在培养的人源间皮细胞中，通过体外暴露于PDF后标记蛋白的去污剂可提取性来评估细胞骨架的完整性。基于细胞骨架蛋白组分与重组HSP-72或HSP-72抗体的共同孵育，通过预处理方案（PDF预处理）和修复试验评估HSP对埃兹蛋白稳定的影响。在大鼠模型中，评估了在体内暴露于PDF期间，间皮细胞从腹膜单层脱离的情况，有无HSP-72过表达（通过热预处理）。在体外，亚致死剂量PDF暴露后细胞骨架的破坏表现为埃兹蛋白和ZO-1的去污剂可提取性显著改变。恢复过程与恢复期间HSP的显著诱导和细胞骨架重新分布有关。预处理方案和体外修复试验均为HSP-72介导的细胞骨架稳定提供了证据。在大鼠模型中，热预处理后HSP-72的过表达导致体内暴露于PDF时间皮细胞的脱离显著减少。我们的结果证实了HSP在体外和体内急性暴露于PDF后间皮细胞细胞骨架完整性的修复和细胞保护中起重要作用。如临床中常见的那样，反复暴露于PDF不仅可能导致间皮细胞重复损伤，反而代表了一种无意的预处理治疗。
