【摘要】 目的探讨米诺环素对碱烧伤大鼠角膜新生血管生成的影响及其作用机制。方法选取SPF级健康SD大鼠72只（取右眼为实验眼）,从中随机选取24只（24眼）作为空白对照组（不做任何干预）,其余48只采用1 mol·L^-1 NaOH浸润过的实验滤纸建立角膜碱烧伤模型,然后随机分为溶剂对照组和米诺环素组,每组24只（24眼）。溶剂对照组在大鼠角膜碱烧伤后给予9 g·L^-1 NaCl溶液(10 mL·kg^-1)腹腔注射,米诺环素组在大鼠角膜碱烧伤后给予米诺环素溶液(45 mg·kg^-1)腹腔注射。各组于角膜碱烧伤后1 d、4 d、7 d、14 d随机抽取6只大鼠,在裂隙灯下观察眼前节情况,并测量各时间点大鼠角膜新生血管长度及面积。采用HE染色对角膜炎症细胞计数,实时荧光定量PCR检测角膜组织中一氧化氮合酶（iNOS）和精氨酸酶-1（Arg-1）mRNA的相对表达量,免疫组织化学染色法分析角膜组织中肿瘤坏死因子-α（TNF-α）、CD206的表达,对所得数据进行统计学分析。结果整个实验过程中,空白对照组大鼠角膜透明,无角膜新生血管。碱烧伤后4 d、7 d、14 d,米诺环素组及溶剂对照组均可见角膜新生血管长出,但米诺环素组角膜新生血管长度及面积均小于溶剂对照组,差异均有统计学意义（均为P<0.01）。HE染色发现,空白对照组角膜结构清晰,上皮细胞排列整齐,无血管结构。碱烧伤后4 d、7 d、14 d,溶剂对照组与米诺环素组每个视野（×200）炎症细胞数分别为（119.83±7.28）个、（81.83±8.30）个,（92.50±7.34）个、（42.33±9.11）个,（48.33±7.76）个、（16.67±4.93）个,各时间点两组间比较差异均有统计学意义（均为P<0.01）。与空白对照组相比,碱烧伤后1 d、4 d、7 d、14 d,溶剂对照组iNOS、Arg-1 mRNA相对表达量均升高（均为P<0.05）;与溶剂对照组相比,碱烧伤后4 d、 7 d,米诺环素组iNOS mRNA相对表达量均明显减少（均为P<0.05）,而在碱烧伤后1 d、14 d,两组间差异均无统计学意义（均为P>0.05）;与溶剂对照组相比,米诺环素组Arg-1 mRNA相对表达量在碱烧伤后14 d显著减少（P<0.01）,而在碱烧伤后1 d、4 d、7 d,两组间差异均无统计学意义（均为P>0.05）。溶剂对照组碱烧伤后4 d、7 d、14 d,Arg-1和iNOS mRNA相对表达量比值分别为0.73±0.14、0.82±0.90、1.71±0.21,与空白对照组相比差异均有统计学意义（均为P<0.01）。溶剂对照组Arg-1 mRNA相对表达量与角膜新生血管长度和面积之间均呈显著正相关,相关系数分别为0.898（P=0.000）、0.781（P=0.000）。碱烧伤后7 d、14 d,溶剂对照组TNF-α、CD206蛋白表达的累积光密度值均高于米诺环素组（均为P<0.05）。结论巨噬细胞极化调控角膜碱烧伤后新生血管的生成,米诺环素可能通过调控巨噬细胞极化,减轻碱烧伤后角膜新生血管生成。更多还原

【Abstract】 Objective To investigate the effect of minocycline and its mechanism on corneal neovascularization after alkali burns.Methods Totally 72 healthy SD rats with SPF grade were selected（right eyes were selected as the experimental ones）. Twenty-four ones among of 72 rats were selected randomly as the control group（they got not treatment）, and the remaining 48 ones were burned by filter paper infiltrated 1 mol·L^-1 NaOH to create the model of cornea with alkali burn, then were divided into solvent group and minocycline group, and each group had 24 rats（24 eyes）. The rats of the solvent group were given intraperitoneal injection with 9 g·L^-1 saline solution(10 mL·kg^-1) and the ones of the minocycline group were given intraperitoneal injection with minocycline solution(45 mg·kg^-1). Afterwards 6 rats were randomly selected from each group on day 1, 4, 7 and 14 after alkali burns successively, and the anterior segments of their eyes were observed by slit lamp, then the lengths and growth area sizes of corneal neovascularization were calculated at each time point. The inflammation of cornea was detected by Hematoxylin and Eosin（HE） staining. The mRNA relative expressions of inducible Nitric Oxide Synthase（iNOS） and Argininase-1（Arg-1） in corneal tissue were detected by real-time fluorescence quantitative PCR. The expressions of tumor necrosis factor-α（TNF-α） and CD206 in corneal tissue were analyzed by immunohistochemical staining. All data were statistically analyzed.Results During the whole experiment, the rats in the control group had clear cornea and no corneal neovascularization. On day 4, 7 and 14 after alkali burns, corneal neovascularization could be observed in both minocycline group and solvent group, and the lengths and the area sizes of corneal neovascularizationin the minocycline group were less than that in solvent group, and the differences were statistically significant（all P<0.01）. HE staining showed that the rats in the control group had clear corneal structure, orderly epithelial cells and no vascular structure. On the 4 th, 7 th and 14 th day after alkali burns, the number of inflammatory cells in each visual field（×200） of the solvent group compared with minocycline group were（119.83±7.28） cells vs.（81.83±8.30） cells,（92.50±7.34） cells vs.（42.33±9.11） cells, and（48.33±7.76） cells vs.（16.67±4.93） cells, and the differences between the two groups at each time point were statistically significant（all P<0.01）. Compared with the control group, the relative expression levels of iNOS and Arg-1 mRNA in the solvent group increased on day 1, 4, 7 and 14 day after alkali burns（all P<0.05）. Compared with the solvent group, the relative expression of iNOS mRNA in the minocycline group significantly decreased on the 4 th and 7 th day after alkali burns（all P<0.05）, while there was no statistically significant difference between the two groups on the 1 st and 14 th day after alkali burns（both P>0.05）. Compared with the solvent group, the relative expression of Arg-1 mRNA in the minocycline group significantly decreased on the 14 th day after alkali burns（P<0.01）, while there was no significant difference between the two groups on the 1 st, 4 th, and 7 th day after alkali burns（all P>0.05）. The relative expression ratios of Arg-1 and iNOS mRNA in the solvent group were 0.73±0.14, 0.82±0.90 and 1.71±0.21 on the 4 th, 7 th and 14 th days after alkali burns, respectively, which was statistically significant compared with that of the control group（all P<0.01）. The relative expression of Arg-1 was positively correlated to the length and area size of corneal neovascularization in the solvent group, and the correlation coefficient were 0.898（P=0.000） and 0.781（P=0.000）. The cumulative optical density values of TNF-α and CD206 protein expression in solvent group were higher than those in minocycline group on the 7 th and 14 th day after alkali burns（all P<0.05）.Conclusion The polarization of macrophages regulates the formation of corneal neovascularization after alkali burns, and minocycline can reduce corneal neovascularization after alkali burns by regulating the polarization of macrophages.更多还原