目的:采用几种不同方法构建腹膜透析腹膜纤维化大鼠模型,为腹膜透析腹膜纤维化的防治提供可研究的动物模型.方法:34只SD雄性大鼠(200~250g),随机分为5组,分别是空白对照组(n=7,未予任何处理)、生理盐水组(n=7,每日腹腔内直接注射0.9%生理盐水20ml)、高糖组(n=7,每日腹腔内直接注射4.25%含糖透析液即PDF 20ml)、高糖+脂多糖(LPS)组(n=6,每日腹腔内直接注射4.25% PDF 20ml,并在第8,10,12天加入LPS 75μg)、高糖+红霉素组(n=7,每日腹腔内直接注射4.25% PDF 20ml,并在第7,14,21,28天加入乳糖酸红霉素6.25万U),观察5周.分别于第0,7,14,21,28,35天清晨,空腹状态时测量大鼠体重.5周后行2h腹膜平衡试验(PET),处死大鼠,准确测量超滤量,检测腹膜功能;观察腹膜厚度、血管数及其他组织学改变;用免疫组织化学法测定腹膜组织及肠管腹腔侧组织纤维连接蛋白(FN)表达率.结果:高糖组、高糖+脂多糖组和高糖+红霉素组皆可见腹膜间皮细胞脱落,间皮下基质及肠外纵肌层明显增厚,可见大量成纤维样细胞及单核、巨噬细胞浸润,且有纤维素样物质沉积等现象,尤以高糖+红霉素组明显;与空白对照组及生理盐水组分别比较,高糖、高糖+脂多糖及高糖+红霉素组大鼠超滤量及2h透出液葡萄糖浓度/0h透析液葡萄糖浓度(D2/D0)比值均有明显减少(P<0.05),而透析液尿素浓度/血浆尿素浓度(D/Purea)比值、大鼠腹膜组织及肠管腹腔侧组织FN表达率均有明显增加(P<0.05);与高糖组比较,高糖+红霉素组D/Purea比值、大鼠腹膜组织及肠管腹腔侧组织FN表达率均有明显增加(P<0.05);与高糖组比较,高糖+脂多糖组D/Purea比值及肠管腹腔侧组织FN表达率皆明显增加(P<0.05);而在大鼠每周体重变化、透出液中白细胞计数、超滤量、D2/D0比值等方面,高糖、高糖+红霉素和高糖+脂多糖组之间的差异无统计学意义(P>0.05).结论:采用高糖、高糖+脂多糖和
Background The peritoneum response to peritoneal dialysis can lead to fibrosis. The transforming growth factor β1 (TGF-β1 ) plays a key role in regulating tissue repair and remodelling after injury. Connective tissue growth factor (CTGF), a downstream mediator of TGF-β1 inducing fibrosis, has been implicated in peritoneal fibrosis. Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis that can hasten peritoneal fibrosis. In this study, we investigated the effect of small interfering RNA (siRNA) of CTGF by pRETRO-SUPER (PRS) retrovirus vector on the expression of CTGF and VEGF in human peritoneal mesothelial cells. Methods Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred into packaging cell line PT67 with lipofectamine, and the virus supernatant was used to infect human peritoneal mesothelial cell (HPMC). The cells were divided into seven groups: low glucose DMEM, low glucose DMEM + TGF-β1 5 ng/ml, low glucose DMEM + TGF-β1 5 ng/ml + PRS-CTGF-siRNA1-4 and low glucose DMEM + TGF-β1 5 ng/ml + PRS. The expression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot. Results Low levels of CTGF and VEGF were detected in confluent HPMCs. Following stimulation with TGF-β1 , the levels of CTGF and VEGF were significantly upregulated (P〈0.01). Introduction of PRS-CTGF-siRNA1-4 resulted in the significant reduction of CTGF mRNA and protein, and VEGF mRNA (P〈0.01), especially in groups PRS-CTGF-siRNA, and PRS-CTGF-siRNA4. The introduction of PRS void vector did not have these effects (P〉0.05). Conclusions The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level of CTGF and VEGF induced by TGF-β1 in cultured HPMCs. This study may provide potential therapeutic strategies to prevent the peritoneal fibrosis.
LIU Fu-you XIAO Li PENG You-ming DUAN Shao-bin LIU Hong LIU Ying-hong LING Gui-hui YUAN Fang CHEN Jun-xiang FU Xiao ZHU Jian-lian