基质金属蛋白酶-3、层粘连蛋白及Ⅲ型胶原在人眼翼状胬肉组织中的表达及意义

目的检测人眼翼状胬肉组织中基质金属蛋白酶-3(MMP-3)、层粘连蛋白(LN)、Ⅲ型胶原(col Ⅲ)及胶原纤维和弹力纤维的表达。方法应用S-P免疫组织化学染色方法检测15例翼状胬肉组织及8例正常球结膜组织中MMP-3、LN、col Ⅲ的免疫学定位及表达情况，用Masson及VG染色法检测各标本中胶原纤维及弹力纤维的分布情况。结果HE染色：翼状胬肉组织上皮下基质中存在结缔组织的增生和血管形成；基质浅层存在一无定形物质透明区及粗糙的颗粒样嗜酸性物质，在翼状胬肉体部深层基质中存在粗糙的纤维组织；正常球结膜组织细胞排列整齐；基质为疏松结缔组织，胶原纤维平行排列，其间可见成纤维细胞，散在少量中性粒细胞、毛细血管；Masson染色：翼状胬肉浅层基质中存在致密的胶原纤维染色，深层基质中的胶原纤维存在变性样改变；VG染色：翼状胬肉组织深层基质中存在大量变性的胶原纤维，其间夹杂黑色的弹性纤维；免疫组化染色法：MMP-3在翼状胬肉上皮细胞中呈强表达，成纤维细胞中呈中等强度表达，血管内皮细胞中未见表达；LN在血管壁中呈强表达，在上皮细胞基底膜中呈中等强度表达，在整个基质中未见明显表达；col Ⅲ在整个翼状胬肉基质中呈强表达。结论翼状胬肉组织中ECM的成分较正常球结膜发生改变，有大量的弹性纤维变性、胶原纤维增生及新生血管形成；col Ⅲ在翼状胬肉组织中表达增加，LN及胶原纤维可能对翼状胬肉中血管形成、细胞粘附和迁移及ECM重建起作用；MMP-3在翼状胬肉组织中表达增加，其对ECM成分的降解作用可能有助于翼状胬肉的形成和向角膜中央侵袭。

Expression of matrix metalloproteinases-3, laminin and collagen Ⅲ in the human pterygium

o study the expression and the immunohistochemical location of matrix metalloproteinases-3 (MMP-3), laminin (LN) and collagen Ⅲ(col Ⅲ) in the human pterygium. MethodsPrimary nasal pterygial tissues(15 eyes) and normal human conjunctival tissues(8 eyes) were determined by immunohistochemical staining, using monoclonal and polyconal antibodies specifically against MMP-3, LN and col Ⅲ. The intensity of reaction on individual sections was semi quantitatively graded. Special staining methods, such as Masson and the Van Gieson staining were used to study the distribution of collogen fibers and elastic fibers. ResultsBy HE staining, the sub epithelial connective tissues and vessels in the pterygium were more prominent than normal conjunctival tissues. An amorphous sub epithelial superficial hyalinized zone and coarse eosinophilic granular materials were observed in the pterygia, but they were not found in normal conjunctival specimens. Coarse fibers were visible only in the deeper subepithelial connective tissues of pterygial samples. With Masson′s staining, the dense staining of collagen fibers was also more prominent in the pterygium than in the subepithelial connective tissues of normal conjunctiva. Abnormal collagen fibers were visible in the deeper sub-epithelial connective tissues of pterygial samples. With Van Gieson staining, abnormal collagen fibers were visible in the deeper subepithelial connective tissues. Dark coarse elastic fibers were found in the abnormal fibers only in the subepithelial deep connective tissues of pinguecula in the pterygia but not in the conjunctiva. With immunohistochemistry staining, MMP-3 was strong in the pterygial epithelium, moderate in fibroblast　and absent from pterygial vascular walls. LN was strongly expressed in the blood vessel wall, moderately in the epithelial basement membrane and absent from the entire stroma. Antibodies against col Ⅲ reacted strongly in the entire pterygial stroma. Conclusions Components of ECM are changed in the pterygium: the sub-epithelial connective tissues and vessels are more prominent in the pterygia than in normal conjunctiva tissues, and abnormal fibers are visible only in the deeper subepithelial connective tissues. This study documents the over expression of LN and col Ⅲ. They may play roles in cellular adherency, migration and angiogenesis. Also this study documents the over expression of MMP 3 which may degrade ECM in the pathogenesis of the pterygium.