Bosco D, Orci L, Meda P
Institute of Histology and Embryology, University of Geneva Medical School, Switzerland.
Exp Cell Res. 1989 Sep;184(1):72-80. doi: 10.1016/0014-4827(89)90365-0.
To assess whether and how specifically contact influences the functioning of differentiated cells, we have studied the secretion of adult pancreatic B-cells as a function of aggregation to either homologous B-cells or other heterologous endocrine islet cell types, all present in a mixed cell suspension. Using an immunological plaque assay for insulin, we have quantitated the proportion of single and aggregated B-cells inducing the formation of a hemolytic plaque (a reflection of the size of the secreting cell population) and the area of these plaques (a reflection of the hormonal output of individual cells or aggregates) after a 30-min stimulation by 16.7 mM glucose. By taking into account the number of B-cells within the aggregates, we have calculated from these data the insulin output on a per B-cell basis. We show here that the homologous contact between companion B-cells promotes the recruitment of secreting B-cells and increases their individual secretion of insulin twofold over that of single B-cells. By contrast, heterologous B- to non-B-cell contact was not effective in enhancing the recruitment of secreting B-cells and in promoting their individual secretion. These findings show that a highly differentiated cell function, such as insulin secretion, is controlled specifically by homologous cell to cell contacts.
为了评估接触是否以及如何特异性地影响分化细胞的功能，我们研究了成年胰腺β细胞的分泌情况，将其作为与同源β细胞或其他异源内分泌胰岛细胞类型聚集的函数，所有这些细胞都存在于混合细胞悬液中。使用胰岛素免疫菌斑测定法，我们定量了在16.7 mM葡萄糖刺激30分钟后，诱导溶血菌斑形成的单个和聚集β细胞的比例（反映分泌细胞群体的大小）以及这些菌斑的面积（反映单个细胞或聚集体的激素输出）。通过考虑聚集体内β细胞的数量，我们从这些数据中计算出每个β细胞的胰岛素输出量。我们在此表明，同伴β细胞之间的同源接触促进了分泌β细胞的募集，并使其胰岛素分泌量比单个β细胞增加了两倍。相比之下，异源β细胞与非β细胞的接触在增强分泌β细胞的募集和促进其个体分泌方面无效。这些发现表明，一种高度分化的细胞功能，如胰岛素分泌，是由同源细胞间接触特异性控制的。
