倍频激光诱导的大鼠脉络膜新生血管中CD105的表达

Expression of CD105 in laser-induced experimental choroidal neovascularization in rat

目的 观察激光诱导BN大鼠脉络膜新生血管（CNV）中CD105的表达情况.方法 532 nm倍频Nd：YAG激光诱导生成BN大鼠CNV,于光凝后7、14、21、28、56 d行荧光素眼底血管造影（FFA）检查,处死动物后摘取眼球,进行组织病理学观察.激光后7、14、28 d以免疫组织化学染色法观察CNV中CD105的表达情况.结果 激光后7 d,CNV开始形成,7～14 d为迅速增生期,此后CNV增生平稳.CD105在激光后7 d初步表达于CNV组织,于激光后14 d时表达明显.激光后28 d,新生血管形成趋于静止,CD105在CNV的表达较早期和中期明显减弱.结论 CD105在CNV形成过程中可能起重要作用,并且可以作为增生内皮细胞的一种标记物.

Objective The pathological mechanism of choroidal neovascularization （CNV） is unclear. CD105, a TGF-β receptor complex,is expressed mainly in actively proliferating endothelial cells, especially in new blood vessel. We studied the expression of CD105 in experimental laser-induced CNV in Brown-Norway rats to explore the pathogenesis of CNV. Methods Thirty eyes of 30 rats received a series of 10 multiple-frequency Nd： YAG laser（532 nm）irradiation surrounding optic disc （far from papilla 1 -2 PD）with the laser energy 180 mW, irradiation area 75 μm and duration 0. 1 s. Fluorescein fundus angiography （FFA） was performed in 7,14,21,28,56 days after laser photocoagulation to observed the CNV formation according to the Takehana grading criteria. Rats were sacrificed immediately after FFA, and the eyes were enucleated for histopathological examination. The expression of CD105 in CNV was observed by immunohistochemistry staining on days 7,14 and 28 after laser photocoagulation. The experimental data was analyzed on double-blindness design. Results The neutrophil, macrophage and migrating RPE cells were found from choroid toward inner retinal layer at the 7th day;the peak time of CNV formation was at the 14th days companied with fibrosis in the CNV lesion;red cells were seen in new blood vessels at the 21st day. On day 7 after laser photocoagulation,CD105 was firstly expressed in the CNV and markedly increased on day 14, displaying a heavy brown-yellow staining in the microvessels. Angiogenesis tended toward inactive status, and expression of CD105 was decreased 28 days later. No CD105 was expressed in normal specimen of rats. The leakage of fluorescein was seen at the 7th day and enhanced 14 days later, showing a gradually increased new blood vessels after photocoagulation. Conclusion CD105 is a marker of active proliferation of endothelial cell,it may play an important role in the process of CNV.