摘要
背景糖尿病视网膜病变（DR）是一种慢性炎症性疾病，并伴有微血管病变。研究证实丝胶具有抗炎和抗氧化功能，但其是否对DR早期的微血管结构和功能有保护作用目前仍不十分清楚。目的观察丝胶对糖尿病大鼠视网膜中细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）、Cx43表达的影响，探讨其对糖尿病大鼠视网膜微血管病变的防护作用。方法将48只SPF级健康雄性SD大鼠按计算机数字随机分配法分为正常对照组、糖尿病模型组、丝胶治疗组和羟苯磺酸钙阳性对照组，每组12只。糖尿病模型组、丝胶治疗组、羟苯磺酸钙阳性对照组大鼠均采用链脲佐菌素（STZ）连续腹腔内注射3d并给予高脂饲料饮食法制备糖尿病大鼠模型，成模后分别用生理盐水、2．4g／（kg·d）丝胶溶液和0．2s／（kg·d）羟苯磺酸钙灌胃3个月。采用过量麻醉法处死大鼠并制备视网膜标本，采用苏木精-伊红染色法观察各组大鼠视网膜组织的形态学变化。分别采用Western blot法和逆转录PCR技术检测大鼠视网膜中ICAM-1、VCAM-1和Cx43蛋白及其mRNA的相对表达量，并对各组检测结果进行比较。结果正常对照组大鼠视网膜组织结构正常，糖尿病模型组视网膜可见内界膜肿胀或断裂，偶见突出于内界膜的毛细血管内皮细胞，视网膜神经节细胞（RGCs）数量减少，丝胶治疗组和羟苯磺酸钙阳性对照组大鼠视网膜内界膜轻度增厚，内外核层细胞排列稍欠规则。糖尿病模型组、丝胶治疗组和羟苯磺酸钙组阳性对照大鼠视网膜中ICAM-1和VCAM-1蛋白相对表达量较正常对照组大鼠均明显升高，而Cx43相对表达量均明显下降，差异均有统计学意义（均P〈0．05）。与糖尿病模型组比较，丝胶治疗组大鼠视网膜中ICAM-1和VCAM-1蛋白相对表达量均明显降低（0．8343±0．0321与0．9189±0．0424、0．7264±0．0112与1．2350±0．0789），而Cx43相对表达量明显升高（0．1331±0．0153与0．0392＋0．0020），差异均有统计学意义（均P〈0．05）。与正常对照组比较，糖尿病组大鼠视网膜中ICAM-1mRNA和VCAM-1mRNA相对表达量明显升高，而Cx43mRNA表达明显下降，差异均有统计学意义（均P〈0．05）；与糖尿病模型组大鼠比较，丝胶治疗组大鼠视网膜中ICAM-1mRNA和VCAM-1mRNA相对表达量明显下降（0．7163±0．0086与0．9568±O．0125；0．3937±0．0350与0．4779±0．0206），而Cx43mRNA表达明显升高（0．6768±0．0648与0．4308±0，1113），差异均有统计学意义（均P〈0．05），各组ICAM-1mRNA、VCAM-1mRNA和Cx43mRNA相对表达量的变化趋势与其蛋白表达相同。结论丝胶能够减轻糖尿病大鼠早期视网膜的微血管病变，从而对DR的发生和发展发挥防护作用，其机制可能是下调视网膜中ICAM-1和VCAM-1的表达以及上调Cx43的表达。
Background Diabetic retinopathy （DR） is a chronic inflammatory disease, with pathological changes of retinal microvessels. Studies demonstrated that sericin has anti-inflammation and anti-oxidation effects, inferring that sericin might play a protective effect on diabetic microangiopathy. Objective This study was to investigate the effects of sericin on intercellular adhesion molecule-1 （ ICAM-1 ） , vascular cell adhesion molecule-I （ VCAM-1 ） and Cx43 expressions in retina and explore the protection of sericin to retinal microangiopathy in diabetic rats. Methods Forty-eight specific pathogen free male SD rats were randomly divided into normal control group, diabetic model group, sericin-treated group and calcium dobesilate-treated group, with 12 rats for each group. The diabetic models were established by intraperitoneal injection of streptozotocin （STZ） for 3 consecutive days and feeding up with high lipid foods. Normal saline solution,2.4 g/（kg · d） sericin solution and 0.2 g/（ kg · d） calcium dobesilate were used by gavage administration in the rats of the diabetic model group, sericin-treated group and calcium dobesilate-treated for 3 months group, respectively. The rats were sacrificed and retinal sections were prepared, and the retinal morphology was examined by hematoxylin-eosin staining. The expressions of ICAM-1 ,VCAM-1 and Cx43 proteins and mRNA in retinas were detected by Western blot assay and reverse transcription PCR. The use and care of the rats complied with Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission and ARVO statement. Results The retinal structure was normal in the normal control group. The swell and rupture of inter limiting membrane （ILM） , scatter vascular endothelial cell nuclei breakthrough ILM and decrease of retinal ganglion cells （RGCs） were displayed in the diabetic model group;while in the sericin-treated group and calcium dobesilate-treated group,the mild thickening of ILM and disorder of retinal ceils were obtained. The relative expression levels of ICAM-1 and VCAM-1 were significantly raised and those of Cx43 were reduced in the diabetic model group, sericin-treated group and calcium dobesilate-treated group when compared with the normal control group （all at P〈0. 05）. Compared with the diabetic model group, the expressions of ICAM-1 and VCAM-1 proteins and mRNA in the sericin-treated group were significantly reduced （ICAM-1 protein ：0. 834 3±0. 032 1 vs. 0. 918 9±0. 042 4;VCAM-1 protein：0. 726 4±0. 011 2 vs. 1. 235 0±0. 078 9;ICAM-1 mRNA：0. 716 3±0. 008 6 vs. 0. 956 8±0. 012 5 ;VCAM-1 mRNA：0. 393 7±0. 035 0 vs. 0. 477 9±0. 020 6） and those of Cx43 protein and mRNA were evidently elevated （Cx43 protein：0. 133 1±0. 015 3 vs.0. 039 2±0. 002 0;Cx43 mRNA：0. 676 8±0. 064 8 vs. 0. 430 8±0. 111 3） （ all at P〈0.05）. Conclusions Seriein can relieve retinal microangiopathy and protect retina against the patbogenesis and development of DR by down-regulating the expressions of ICAM-1, VCAM-1 and upregulating the expression of Cx43 in retinas of diabetic rats.
出处
《中华实验眼科杂志》
CAS
CSCD
北大核心
2017年第1期32-37,共6页
Chinese Journal Of Experimental Ophthalmology
