促红细胞生成素对腹膜间皮细胞凋亡的保护作用

Protective Effect of Erythropoietin on Apoptosis of Peritoneal Mesothelial Cells

目的:观察重组人促红细胞生成素(recombinant human erythropoietin,rHuEPO)对腹膜间皮细胞(PMCs)的抗凋亡作用及其机制。方法:体外分离小鼠PMCs并给予rHuEPO干预,观察起对JAK2,STAT5,ERK1/2和P38磷酸化的影响。体内试验采用5000U/kg的rHuEPO预处理后再予以4.25%的腹透液腹腔内注射后4小时,取小鼠脏层腹膜组织检测活性凋亡蛋白酶-3表达。结果:小鼠PMCs上表达EPO受体mRNA和蛋白,5U/mL的rHuEPO可诱导PMCs的JAK2,STAT5和ERK1/2磷酸化上调。rHuEPO预处理1小时后再予腹透液处理的PMCs较单独予腹透液处理的PMCs,凋亡蛋白酶-3活化降低,DNA碎裂减少。rHuEPO干预可提高ERK1/2磷酸化水平而抑制腹透液诱导的P38磷酸化。特异性的ERK活化抑制剂PD98059可完全阻断rHuEPO的保护作用。通过检测凋亡蛋白酶-3证实rHuEPO可在小鼠体内降低腹透液引起的PMCs凋亡水平。结论:本研究为rHuEPO在腹透临床治疗中的临床应用开辟了新途径,rHuEPO可通过ERK1/2依赖途径减少PMCs的凋亡发挥保护性作用。rHuEPO及其衍生物可能成为维护腹膜完整性的新治疗手段。

Objective： To investigate the antiapoptotic effect of recombinant human erythropoietin （rHuEPO） in peritoneal mesothelial cells （PMCs） and to unclaim related mechanism. Methods： Isolated mice PMCs were used for in vitro characterization of rHuEPO effects on JAK2, STAT5, ERK1/2 and P38 phosphrylation. For in rive observation, active caspase-3 was analyzed in imprints of liver visceral peritoneum of mice pretreated overnight with rHuEPO （5000 U/kg intraperitoneally） and exposed to PDF （Dianeal 4.25%; Baxter Healthcare, Deerfield, Illinois, USA） for 4 hours. Results： EPO-receptor mRNA and protein were expressed in mouse PMCs. Exposure to rHuEPO （5 U/mL） induced phosphorylation of JAK2, STATS, and ERK1/2. PMCs pretreated for 1 hour with rHuEPO showed reduced PDF-induced caspase-3 activation and DNA fragmentation in comparison to cells treated by PDF alone （p 〈0.05）. rHuE- PO intervention induced an increase in ERK1/2 phosphorylation and reduced levels of PDF-induced phospho-P38. PD98059, a specific inhibitor of ERK activation, fully blocked the protective effect of rHuEPO. In mice, rHuEPO reduced the apoptotic effect of PDF, as as- sessed by the level of active caspase-3. Conclusions： Our study sheds new light on clinical use of rHuEPO in the setting of PD. rHuEPO could provide ERK1/2-dependent protection to PMCs from PDF-induced apoptosis. The use of rHuEPO, or its new derivatives, should be considered for novel peritoneal integrity maintaining strategy.