靶向转染色素上皮源性因子治疗大鼠子宫内膜异位症的研究

目的:探索免疫纳米脂质体介导色素上皮源性因子(PEDF)质粒转染对子宫内膜异位症大鼠模型的治疗效果。方法:将新生血管内皮细胞表面高表达的VEGFR-2作为靶向位点,用其特异性配体寡肽ATWLPPR修饰纳米脂质体,反向装载PEDF表达质粒,制备一种新型免疫纳米脂质体载药系统ATWLPPR-IML-PEDF。以子宫内膜片异位移植法建立EM大鼠模型,随机分为对照组(n=6,移植内膜数为32)和脂质体转染组(n=6,移植内膜数为33),于造模后次日分别给予生理盐水0.1ml或ATWLPPR-IML-PEDF脂质体溶液(含PEDF质粒5mg/kg体重)0.1ml尾静脉注射。造模后3周测量病灶大小。检测病灶中PEDF融合蛋白水平,并以qRT-PCR及Western blot法检测VEGF mRNA及蛋白表达量。结果:体外实验表明,ATWLPPR-IML-PEDF能高效转染VEGFR-2阳性细胞,转染率达(91.80±0.03)%。动物实验表明,ATWLPPR-IML-PEDF一次尾静脉给药即可显著抑制子宫内膜片的异位生长,异位内膜萎缩消失率为18.18%(6/33),其余EM病灶平均体积显著低于对照组(18.92±0.88)mm3vs(78.40±1.93)mm3,P0.001]。脂质体转染组PEDF蛋白表达量增高的同时,EM病灶中VEGF mRNA及蛋白的表达量亦显著降低(P0.001)。结论:载药免疫纳米脂质体ATWLPPR-IML-PEDF可有效抑制大鼠EM病灶生长,为EM的抗新生血管治疗提供了一种简便、特异、高效的新手段。

Targeting therapy of endometriotic lesions in rat models using a novel PEGF gene delivery system

Objective: To evaluate the therapeutic effects of immuno-nanoliposomal-induced transfection of PEDF( pigment epithelium-derived factor) expression plasmid on endometriotic lesions in S-D rat models.Methods: A novel immuno-nanoliposomal PEDF plasmid delivery system,named ATWLPPR-IML-PEDF,was established by modifying nanoliposomes with the oligo-peptide ATWLPPR which specifically targets VEGFR-2 on neovascular endothelial cells,and reversely encapsulating PEDF plasmid. Endometriosis was induced by transplanting the endometrial pieces onto the peritoneum of rats. The EM rat models were randomly injected with either 0.1ml saline solution( control group,n = 6,total lesions = 32) or 0.1ml ATWLPPRIML-PEDF solution( 5mg / kg body weight of PEDF)( therapy group,n = 6,total lesions = 33)via vena caudalis on postoperative day 1. Three weeks after grafting,the rats were sacrificed to measure the sizes of lesions,to detect the levels of PEDF protein,as well as the levels of vascular epithelium growth factor( VEGF) mRNA and protein in EM tissues. Results: ATWLPPRIML-PEDF could efficiently transfect VEGFR-2 positive target cells in vitro,with a transfection rate of 91.80±0.03%.It was also observed that one shot of ATWLPPR-IML-PEDF was sufficient to significantly inhibit the growth of EM lesions.18.18%( 6 / 33) of transplanted endometrial tissues failed to develop into EM lesions.In the therapy group,the average size of lesions was significantly smaller than that in the control group( 18.92±0.88) mm3vs( 78.40±1.93) mm3]( P<0.001).The over-expression of EYFP-PEDF fusion protein was observed in each EM lesion in the therapy group. In contrast,the levels of VEGF mRNA and protein were significantly decreased after ATWLPPR-IML-PEDF treatment( P<0.001). Conclusion: ATWLPPR-IML-PEDF can efficiently inhibit the development and growth of endometriotic lesions in rat models,representing a novel treatment for endometriosis.