Tripathi R C, Li J, Borisuth N S, Tripathi B J
Department of Ophthalmology and Visual Science, University of Chicago, IL 60637.
Invest Ophthalmol Vis Sci. 1993 Jul;34(8):2562-9.
To determine whether trabecular tissue in vivo and cultured trabecular cells have the messenger RNA transcript for transforming growth factor-beta 1 (TGF-beta 1), and to examine whether these cells synthesize and secrete TGF-beta 1 in vitro.
Total RNA was isolated from the trabecular meshwork, iris, and ciliary body freshly excised from porcine eyes as well as from cultured trabecular cells, and the reverse transcriptase-polymerase chain reaction and Southern hybridization were used for detection of TGF-beta 1 messenger RNA. The amount of TGF-beta 1 secreted by trabecular cells in culture was determined by radioimmunoassay.
Excised whole trabecular tissue, iris, and ciliary body, as well as cultured trabecular cells expressed messenger RNA transcripts for TGF-beta 1. On the ethidium bromide-stained agarose gel, two PCR-amplified products (161 and 400 base pairs) were found in the total RNA isolated from cultured trabecular cells. The oligonucleotide probe specific for TGF-beta 1 detected only one band with the expected length of 161 base pairs. The secretion of TGF-beta 1 into conditioned medium was at the level of 16.7-20 pg/ml per 2 million trabecular cells during a 24-hr period.
These investigations show that the trabecular meshwork, iris, and ciliary body in vivo express the messenger RNA transcript for TGF-beta 1, and that trabecular cells in vitro synthesize and secrete this cytokine. The TGF-beta 1 present in normal aqueous humor may be derived locally, at least in part, from the cells of the trabecular meshwork, iris, and ciliary body. Abnormal synthesis, secretion, activation, and clearance of TGF-beta 1 may contribute to the pathogenesis of many ocular disorders, including primary open-angle glaucoma.
确定体内小梁组织和培养的小梁细胞是否有转化生长因子-β1（TGF-β1）的信使核糖核酸转录物，并检测这些细胞在体外是否合成和分泌TGF-β1。
从猪眼新鲜切除的小梁网、虹膜和睫状体以及培养的小梁细胞中分离总RNA，采用逆转录-聚合酶链反应和Southern杂交检测TGF-β1信使核糖核酸。通过放射免疫测定法测定培养的小梁细胞分泌的TGF-β1量。
切除的整个小梁组织、虹膜和睫状体以及培养的小梁细胞均表达TGF-β1的信使核糖核酸转录物。在溴化乙锭染色的琼脂糖凝胶上，从培养的小梁细胞分离的总RNA中发现了两种聚合酶链反应扩增产物（161和400个碱基对）。对TGF-β1特异的寡核苷酸探针仅检测到一条预期长度为161个碱基对的条带。在24小时内，每200万个小梁细胞分泌到条件培养基中的TGF-β1水平为16.7 - 20 pg/ml。
这些研究表明，体内小梁网、虹膜和睫状体表达TGF-β1的信使核糖核酸转录物，体外小梁细胞合成并分泌这种细胞因子。正常房水中存在的TGF-β1可能至少部分来源于小梁网、虹膜和睫状体的细胞。TGF-β1的异常合成、分泌、激活和清除可能导致包括原发性开角型青光眼在内的许多眼部疾病的发病机制。
