Trejdosiewicz L K, Southgate J, Hodges G M, Goodman S L
Exp Cell Res. 1985 Jan;156(1):153-63. doi: 10.1016/0014-4827(85)90269-1.
Using double-label techniques with fluorochrome-conjugated peanut agglutinin (PNA) and indirect immunofluorescence with rabbit species-specific anti-fibronectin antibodies and a mouse monoclonal anti-fibronectin, the extracellular matrix (ECM) of cultured human and mouse fibroblasts (Hell7 and 3T3K) and human bladder epithelial cells (T24) was studied. The antibodies and PNA co-localized extensively. However, a small but consistent degree of micro-heterogeneity was revealed insofar as both PNA-positive fibronectin-negative fibrils as well as PNA-negative fibronectin-positive fibrils were observed. Fibronectin production by T24 cells (but not fibroblasts) was influenced by the growth medium, but this did not affect the heterogeneity. Trypsin removed most cell-surface fibronectin and all PNA-binding sites, but did not account for the observed phenomenon. Intracellular fibronectin, whether present naturally or induced to accumulate by culture in presence of Monensin, was PNA-negative. These data suggest that PNA-binding sites appear on fibronectin as a consequence of incorporation into the extracellular matrix, and that the resultant heterogeneity of spatial expression of beta-galactose-like residues may offer a mechanism whereby mesenchymal cells could modulate the behaviour of overlying cell-types.
运用荧光染料偶联花生凝集素（PNA）的双标记技术以及兔种属特异性抗纤连蛋白抗体和小鼠单克隆抗纤连蛋白的间接免疫荧光法，对培养的人及小鼠成纤维细胞（Hell7和3T3K）以及人膀胱上皮细胞（T24）的细胞外基质（ECM）进行了研究。抗体与PNA广泛共定位。然而，观察到既有PNA阳性而纤连蛋白阴性的原纤维，也有PNA阴性而纤连蛋白阳性的原纤维，揭示出一种微小但一致的微观异质性程度。T24细胞（而非成纤维细胞）产生纤连蛋白受生长培养基的影响，但这并不影响异质性。胰蛋白酶去除了大部分细胞表面的纤连蛋白和所有PNA结合位点，但无法解释所观察到的现象。细胞内的纤连蛋白，无论是天然存在的还是在莫能菌素存在的情况下培养诱导积累的，都是PNA阴性的。这些数据表明，PNA结合位点是纤连蛋白整合到细胞外基质的结果而出现的，并且由此产生的β-半乳糖样残基空间表达的异质性可能提供了一种机制，间充质细胞可借此调节上层细胞类型的行为。
