正常角膜与圆锥角膜中的Ⅰ型、Ⅵ型胶原与金属蛋白酶-2

Collagen type Ⅰ 、Ⅵ and Matrix Metalloproteinase-2 in Normal and Keratoconus Corneas

目的对比正常角膜与圆锥角膜中的Ⅰ型，Ⅵ型胶原及金属蛋白酶－２的定位与含量。方法应用酶免疫组化及间接免疫荧光技术检测正常与圆锥角膜中Ⅰ型、Ⅵ型胶原及金属蛋白酶－２（ＭＭＰ毛）的定位。阳性结果应用图像分析系统进行定量分析。结果免疫组化结果显示所有角膜中Ⅰ型胶原存在于前弹力层和基质中；Ⅵ型胶原存在于上皮基底膜、前弹力层、基质、后弹力层；ＭＭＰ－２存在于上皮、基质、内皮中。同正常角膜比，圆锥角膜中Ⅰ型、Ⅵ型胶原的含量无差别而 ＭＭＰ－２的含量明显增多，差异有显著性。结论圆锥角膜的ＭＭＰ－２含量增多，其所导致的胶原降解异常可能是圆锥角膜发病的关键。

Objective To compare the levels and locations of metalloprotionase-2 (MMP-2), collagen types Ⅰ and Ⅵ in keratoconus and normal human corneas. Methods An immunoperoxidase and indirect immunofluorescent technique were used to visualize the presence of collagen types Ⅰ, Ⅵ and MMP-2. The immunohistochemical staining was further analyzed and the intensity of reaction products was measured with an Image-processing system. Results Collagen type Ⅰ was demonstrated immunohistochemicall and indirect immunonuorescent technique in the bowman and stroma layers; collagen type Ⅵ was in epithelium basement, bowman, stroma and descement layers; MMP-2 was in epithelium ， stroma and endothelium of all comeal sections. Compared with normal control specimens, the staining intensity of collagen types Ⅰ and Ⅵ was similar, while MMP-2 was markly increased. Conclusions Keratoconus contained an increased level of MMP-2 and similar of collagen levels. These results lead further support to the hypothesis that degradation processes may be aberrant in keratoconus.