Wirtz M K, Bradley J M, Xu H, Domreis J, Nobis C A, Truesdale A T, Samples J R, Van Buskirk E M, Acott T S
Department of Ophthalmology, Casey Eye Institute, Oregon Health Sciences University, Portland 97201, USA.
Curr Eye Res. 1997 May;16(5):412-21. doi: 10.1076/ceyr.16.5.412.7040.
Proteoglycans may serve important roles in trabecular meshwork structure or function. Detailed molecular characterization and identification of specific trabecular proteoglycan core proteins has been limited.
Radiolabeled proteoglycans were extracted from cultured human trabecular meshworks and subjected to ion exchange and molecular sieve chromatography. Peaks were subjected to glycosaminoglycan content analysis. Reverse transcription with polymerase chain reaction was used to identify trabecular mRNAs of several common proteoglycan core proteins. Western immunoblots of trabecular extracts were also utilized to identify these proteoglycan core proteins.
The proteoglycans elute from ion exchange columns at high salt and molecular sieve column profiles, and they exhibit broad peaks typical of the proteoglycan microheterogeneity seen in other tissues. The four common glycosaminoglycan side-chains were identified on these proteoglycans. Trabecular cells in organ or cell culture contain mRNAs coding for decorin, biglycan, versican, perlecan and a basement membrane glycoprotein, SPARC. Syndecan-1 transcripts were present at very low levels, while aggrecan transcripts were not detectable. Decorin, biglycan, versican and perlecan core proteins were also identified by immunoblots of trabecular cell extracts.
Several common proteoglycans are expressed by trabecular cells in organ explant or cell culture. Their general characteristics are not unlike those found in other tissues. These proteoglycans may serve important functions in the trabecular outflow pathway.
蛋白聚糖可能在小梁网结构或功能中发挥重要作用。但对小梁网特异性蛋白聚糖核心蛋白的详细分子特征和鉴定一直很有限。
从培养的人小梁网中提取放射性标记的蛋白聚糖，并进行离子交换和分子筛层析。对各峰进行糖胺聚糖含量分析。采用聚合酶链反应逆转录法鉴定几种常见蛋白聚糖核心蛋白的小梁网信使核糖核酸。还利用小梁网提取物的蛋白质免疫印迹法鉴定这些蛋白聚糖核心蛋白。
蛋白聚糖在高盐条件下从离子交换柱洗脱，并呈现分子筛柱图谱，且显示出在其他组织中所见的典型蛋白聚糖微异质性宽峰。在这些蛋白聚糖上鉴定出四种常见的糖胺聚糖侧链。器官或细胞培养中的小梁网细胞含有编码核心蛋白聚糖、双糖链蛋白聚糖、多功能蛋白聚糖、基底膜聚糖和一种基底膜糖蛋白（富含半胱氨酸的酸性分泌蛋白）的信使核糖核酸。Syndecan - 1转录本水平极低，而聚集蛋白聚糖转录本无法检测到。通过小梁网细胞提取物的免疫印迹也鉴定出了核心蛋白聚糖、双糖链蛋白聚糖、多功能蛋白聚糖和基底膜聚糖的核心蛋白。
器官外植体或细胞培养中的小梁网细胞表达几种常见的蛋白聚糖。它们的一般特征与其他组织中的类似。这些蛋白聚糖可能在小梁网流出途径中发挥重要作用。
