糖尿病大鼠视网膜中内质网应激蛋白、HIF-1α和血管内皮生长因子的表达

Expressions of endoplasmic reticulumstress related protein,hypoxia-inducible factor-1α and vascular endothelial growth factor in the retina of diabetic rats

目的:探索糖尿病大鼠视网膜中内质网应激相关BIP(蛋白重链结合蛋白)、HIF-1α(低氧诱导因子-1α)和VEGF(血管内皮生长因子)的表达及意义。方法:72只雄性SD大鼠,随机分为6组:正常2月对照组(C2m),糖尿病2月组(D2m),正常4月对照组(C4m),糖尿病4月组(D4m),正常6月对照组(C6m),糖尿病6月组(D6m),每组各12只。实验组给予一次性腹腔注射65mg/kg STZ建立糖尿病模型。ELISA法检测BIP、HIF-1α和VEGF表达水平,免疫组化法观察大鼠BIP、HIF-1α和VEGF视网膜内定位情况。结果:BIP表达随DM病程的延长而增加(P<0.05),且DM各组与对照组相比,其差异均有统计学意义(P<0.01)。HIF-1α在DM组中表达较对照组增加,其差异有统计学意义(P<0.05),但DM组各组间差异无统计学意义。VEGF蛋白在D2m组与对照组间差别无统计学意义,但D4m、D6m与对照组间差别有统计学意义(P<0.05),且D4m和D6m两组间差别有统计学意义。免疫组化:BIP在对照组视网膜神经节细胞层中少量表达,DM组主要分布于视网膜内核层和神经节细胞层;HIF-1α在对照组基本不表达,DM组各层均有表达;VEGF在对照组大鼠中视网膜各层中少量表达,而DM组大鼠的内核层、外核层及视网膜血管、神经节细胞层中VEGF阳性表达。结论:糖尿病大鼠视网膜组织中的BIP、HIF-1α、VEGF均较对照组增加且随糖尿病病程进展而增加,内质网应激和低氧诱导因子途径均可能在糖尿病视网膜病变的进展中起重要作用。

AIM： To evaluate the expressions and significances of endoplasmic reticulum stress related protein （ BlP ） , hypoxia-inducible factor-1α （ HlF-1α） and vascular endothelial growth factor （ VEGF） in the retina of diabetic rats. METHODS：Seventy-two male Sprague-Dawley （ SD） rats were chosen and divided randomly into 6 groups：normal control 2mo （C2m, n = 12）, diabetes mellitus 2mo （D2m, n=12）, normal control 4mo （C4m, n=12）, diabetes mellitus 4mo （D4m, n = 12）, normal control 6mo （C6m, n=12） and diabetes mellitus 6mo （D6m, n=12 ） . The diabetes mellitus mouse were induced by intraperitoneal injection of 0. 1mol/L streptozotocin （STZ, 65mg/kg）. The expression of BlP, HlF-1α and VEGF in the retina were detected by enzyme- linked immuno sorbent assay. The location of BlP, HlF-1α and VEGF in epiretinal membranes were investigated by immunohistochemistry staining. RESULTS： BlP were significantly increase than control groups in all DM groups with the course of diabetes （ P〈0. 01）. HlF-1α were detected higher than control groups in all DM groups （P〈 0. 05）, but there was no statistical significance among treatment groups. VEGF in D4m and D6m groups were higher than control groups （P〈0. 05）, and there was statistical significance between D4m and D6m groups. BlP can be detected in control groups a little, mainly in the inner limiting membrane and ganglion cell layers. HlF - 1α cannot be detected in control groups, meanwhile it can be detected in all layers in DM. VEGF can be detected in control groups a little, it mainly be detected in inner nuclear layer, outer nuclear layer, around retinal vessel and ganglion cell layers in DM groups. CONCLUSION：The expressions of BlP, HlF-1α and VEGF increase in the retina of diabetic rats than control groups with progressive of diabetes mellitus, both endoplasmic reticulum stress and HlF-1α signal path play important role in the progress of diabetic retinopathy.