Erickson A C, Couchman J R
Department of Cell Biology and Cell Adhesion and Matrix Biology Research Center, University of Alabama at Birmingham, 1670 University Blvd, VH 201C, Birmingham, AL 35294-0019, USA.
Matrix Biol. 2001 Jan;19(8):769-78. doi: 10.1016/s0945-053x(00)00126-8.
Multiple proteoglycans (PGs) are present in all basement membranes (BM) and may contribute to their structure and function, but their effects on cell behavior are not well understood. Their postulated functions include: a structural role in maintaining tissue histoarchitecture, or aid in selective filtration processes; sequestration of growth factors; and regulation of cellular differentiation. Furthermore, expression PGs has been found to vary in several disease states. In order to elucidate the role of PGs in the BM, a well-characterized model of polarized epithelium, Madin-Darby canine kidney (MDCK) cells has been utilized. Proteoglycans were prepared from conditioned medium by DEAE anion exchange chromatography. The eluted PGs were treated with heparitinase or chondroitinase ABC (cABC), separately or combined, followed by SDS-PAGE. Western blot analysis, using antibodies specific for various PG core proteins or CS stubs generated by cABC treatment, revealed that both basement membrane and interstitial PGs are secreted by MDCK cells. HSPGs expressed by MDCK cells are perlecan, agrin, and collagen XVIII. Various CSPG core proteins are made by MDCK cells and have been identified as biglycan, bamacan, and versican (PG-M). These PGs are also associated with mammalian kidney tubules in vivo.
多种蛋白聚糖（PGs）存在于所有基底膜（BM）中，可能对其结构和功能有贡献，但其对细胞行为的影响尚未完全了解。它们假定的功能包括：在维持组织结构中起结构作用，或有助于选择性过滤过程；隔离生长因子；以及调节细胞分化。此外，已发现PGs的表达在几种疾病状态下有所不同。为了阐明PGs在基底膜中的作用，使用了一种特征明确的极化上皮模型，即Madin-Darby犬肾（MDCK）细胞。通过DEAE阴离子交换色谱法从条件培养基中制备蛋白聚糖。洗脱的PGs分别或联合用肝素酶或软骨素酶ABC（cABC）处理，然后进行SDS-PAGE。使用针对各种PG核心蛋白或由cABC处理产生的CS残基的特异性抗体进行蛋白质印迹分析，结果显示基底膜和间质PGs均由MDCK细胞分泌。MDCK细胞表达的HSPGs是基底膜蛋白聚糖、集聚蛋白和胶原蛋白XVIII。MDCK细胞产生各种CSPG核心蛋白，已鉴定为双糖链蛋白聚糖、基底膜硫酸软骨素蛋白聚糖和多功能蛋白聚糖（PG-M）。这些PGs在体内也与哺乳动物肾小管相关。
