腹膜透析液诱导结缔组织生长因子在大鼠腹膜间皮细胞表达

目的 研究应用不同腹膜透析液对大鼠腹膜间皮细胞(RPMCs)结缔组织生长因子(CTGF)合成的影响。方法 分离培养的RPMC分为6组，分别以不同腹膜透析液[1.5% Dextrose(低糖组)、2.5% Dextrose(中糖组)、4.25% Dextrose(高糖组)、7.5% Icodextrin(糊精组) ]进行刺激培养，而无血清DMEM为阴性对照(对照组)， TGF-β1(2.5 ng/ml)为阳性对照(阳性对照组)。刺激培养24 h后，RT-PCR法检测RPMCs的CTGF mRNA、胶原Ⅰ mRNA、α-SMA mRNA表达。Western印迹法检测RPMCs的CTGF、胶原Ⅰ、α-SMA蛋白表达以及培养上清中的CTGF蛋白表达。结果 各组均见CTGF mRNA表达，高糖组、阳性对照组CTGF mRNA 表达水平显著高于中糖组、低糖组及对照组(P < 0.05)；中糖组与糊精组CTGF mRNA 表达亦显著上调(P < 0.05)。各组细胞均检测到CTGF蛋白质表达，为相对分子质量38 000及 25 000的2种亚型，与RT-PCR结果一致。高糖组、阳性对照组CTGF 蛋白表达水平显著高于糊精组、中糖组、低糖组及对照组(P < 0.05)。RPMCs培养上清液中检测出CTGF 38 000亚型的表达，其表达强弱趋势与CTGF在细胞中表达一致。高糖组、阳性对照组胶原I mRNA、蛋白质的表达水平显著高于对照组(P < 0.05)，其余各组间无显著性差异。各组α-SMA mRNA、蛋白质表达未见显著性差异(P > 0.05)。结论 正常培养的RPMCs表达低水平的CTGF。腹膜透析液、尤其是高浓度葡萄糖透析液，能明显上调CTGF表达的水平，这可能是导致长期腹膜透析过程中腹膜结构改变的机制之一。糊精腹膜透析液生物相容性可能优于高浓度葡萄糖透析液。

Peritoneal dialysate induces connective tissue growth factor expression in rat peritoneal mesothelial cells

Objective To investigate the effects of peritoneal dialysis fluids(PDF) on connective tissue growth factor (CTGF) synthesis in rat peritoneal mesothelial cells(RPMCs). Methods Cultured RPMCs were stimulated by 1.5% Dextrose(LG)， 2.5% Dextrose(MG)， 4.25% Dextrose(HG)， and 7.5% Icodextrin(ICO) dialysate for 24 hours. Serum free DMEM was used as negative control(Control)， TGF-β1(2.5 ng/ml) as positive control(TGF-β1). The mRNA expression levels of CTGF， α-SMA， and collagen Ⅰ were measured by RT-PCR. CTGF， α-SMA， and collagen Ⅰ protein in cell layer， secreted CTGF protein in culture supernatant were detected by Western blot. Results The CTGF mRNA could be detected in all the groups. The CTGF mRNA in HG group was significantly higher than those of other PDF groups and control group(P < 0.05). MG and ICO could also up-regulate CTGF mRNA synthesis(P < 0.05). CTGF protein expression in cell layer could be detected in all groups. The major protein species was a 38 KD， and a minor species of 25 KD. Consistent with RT-PCR reslult， HG group showed the highest level of expression(P < 0.05). In cell culture supernatant， only the species of 38 KD CTGF could be detected. The tendency was consistent with the CTGF protein expression in the cell layer. The expression levels of mRNA and protein of collagen Ⅰ in HG and TGF-β1 group were obviously increased compared with other groups， the latter had no differences. However， no significant difference was found in α-SMA mRNA and protein expression among all the groups. Conclusions There is a low level of CTGF expression in cultured RPMCs， both in mRNA and protein. Exposure to PDF， especially hypertonic glucose solution， may increase CTGF synthesis in peritoneal mesothelial cells and contribute to chronic peritoneal membrane alterations. Icodextrin may be more biocompatible than hypertonic glucose solution.