Wassélius Johan, Wallin Hanna, Abrahamson Magnus, Ehinger Berndt
Department of Ophthalmology, University of Lund, 221 85, Lund, Sweden.
Graefes Arch Clin Exp Ophthalmol. 2003 Nov;241(11):934-42. doi: 10.1007/s00417-003-0782-x. Epub 2003 Oct 28.
Cathepsin B is a mammalian cysteine protease. The enzyme has been suggested to participate in the patophysiological processes of keratoconus as well as in the corneal response to infectious agents. This study describes the localization of cathepsin B in the rat eye.
Cathepsin B was identified in rat ocular tissues by Western blotting and immunohistochemistry. Cathepsin B mRNA levels were analyzed in the tissues by quantitative real-time cDNA amplification (QRT-PCR).
Cathepsin B is present in the epithelium, in stromal cells and in the endothelium of the cornea. It is also present in the epithelium lining the ciliary processes, in occasional stromal cells in the iris, in the anterior subcapsular lens epithelium and in various cell types in the retina. At all locations cathepsin B is present in cytoplasmic granules, presumably lysosomes. QRT-PCR analysis detected cathepsin B mRNA in all these tissues in amounts correlating to the immunodetection results, suggesting that the enzyme detected is locally produced.
Cathepsin B is present in several tissues and cell types throughout the rat eye. It is localized to cytoplasmic granules, presumably lysosomes. Our results suggest that it is probably also produced in the same cell types.
组织蛋白酶B是一种哺乳动物半胱氨酸蛋白酶。该酶被认为参与圆锥角膜的病理生理过程以及角膜对感染因子的反应。本研究描述了组织蛋白酶B在大鼠眼中的定位。
通过蛋白质免疫印迹法和免疫组织化学法在大鼠眼组织中鉴定组织蛋白酶B。采用实时定量cDNA扩增（QRT-PCR）分析组织中组织蛋白酶B的mRNA水平。
组织蛋白酶B存在于角膜的上皮细胞、基质细胞和内皮细胞中。它也存在于睫状突内衬的上皮细胞、虹膜中偶尔的基质细胞、晶状体前囊下上皮细胞以及视网膜中的各种细胞类型中。在所有这些部位，组织蛋白酶B都存在于细胞质颗粒中，推测为溶酶体。QRT-PCR分析在所有这些组织中检测到组织蛋白酶B的mRNA，其含量与免疫检测结果相关，表明检测到的酶是在局部产生的。
组织蛋白酶B存在于大鼠眼的多种组织和细胞类型中。它定位于细胞质颗粒中，推测为溶酶体。我们的结果表明，它可能也在相同的细胞类型中产生。
