Randell S H, Liu J Y, Ferriola P C, Kaartinen L, Doherty M M, Davis C W, Nettesheim P
Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, NC 27599, USA.
Am J Respir Cell Mol Biol. 1996 Feb;14(2):146-54. doi: 10.1165/ajrcmb.14.2.8630264.
An airway epithelial mucous goblet cell line would be useful towards understanding mechanisms underlying the common problem of respiratory mucus hypersecretion. SPOC1 is a novel rat tracheal epithelial (RTE) cell line that developed cytologic features suggestive of mucous goblet cells when grown in tracheal grafts in vivo (Am. J. Respir. Cell Mol. Biol. 1995; 12:385-395). Our aims were to determine whether SPOC1 cells were capable of mucin synthesis and to directly compare mucin production by SPOC1 cells and RTE cells. Towards this end, we validated the use of monoclonal antibody (mAb) RTE11 (Exp. Lung Res. 1992; 18:323-342) as an immunologic probe for rat airway secretory mucin. Our results strongly suggest that mAb RTE11 detects a carbohydrate antigen that is a sensitive and specific marker for rat tracheobronchial secretory mucin. SPOC1 cells in tracheal grafts in vivo contained granules with ultrastructural features similar to mucous granules in normal rat airway goblet cells and they were strongly stained by mAb RTE11. Retinoic acid (RA) and culture on porous supports are known to profoundly modify airway epithelial cell phenotype in vitro. Expression of several retinoid-responsive proteins was similar in cultured SPOC1 and primary RTE cells, but major differences in mucin production were noted. Primary RTE cells in vitro only made mucin when grown on porous supports in the presence of RA, whereas SPOC1 cells produced mucin when grown on plastic or glass surfaces and even in the absence of RA. Interestingly, RA enhanced mucin secretion by SPOC1 cells during the early plateau stage of culture but there were no differences due to RA late in the culture period. SPOC1 cells are capable of mucin production and will be a useful tool for studying select aspects of airway secretory cell differentiation and function.
气道上皮黏液杯状细胞系对于理解呼吸道黏液分泌过多这一常见问题的潜在机制将非常有用。SPOC1是一种新型大鼠气管上皮（RTE）细胞系，当在体内气管移植物中生长时，它会呈现出提示黏液杯状细胞的细胞学特征（《美国呼吸与细胞分子生物学杂志》1995年；12:385 - 395）。我们的目的是确定SPOC1细胞是否能够合成黏蛋白，并直接比较SPOC1细胞和RTE细胞的黏蛋白产生情况。为此，我们验证了单克隆抗体（mAb）RTE11（《实验肺研究》1992年；18:323 - 342）作为大鼠气道分泌性黏蛋白免疫探针的用途。我们的结果强烈表明，mAb RTE11检测到一种碳水化合物抗原，它是大鼠气管支气管分泌性黏蛋白的敏感且特异的标志物。体内气管移植物中的SPOC1细胞含有具有超微结构特征的颗粒，类似于正常大鼠气道杯状细胞中的黏液颗粒，并且它们被mAb RTE11强烈染色。已知视黄酸（RA）和在多孔支持物上培养会在体外深刻改变气道上皮细胞表型。在培养的SPOC1细胞和原代RTE细胞中，几种视黄酸反应性蛋白的表达相似，但在黏蛋白产生方面存在主要差异。体外原代RTE细胞仅在存在RA的情况下在多孔支持物上生长时才产生黏蛋白，而SPOC1细胞在塑料或玻璃表面生长时甚至在没有RA的情况下也能产生黏蛋白。有趣的是，RA在培养的早期平稳阶段增强了SPOC1细胞的黏蛋白分泌，但在培养后期由于RA没有差异。SPOC1细胞能够产生黏蛋白，将成为研究气道分泌细胞分化和功能特定方面的有用工具。
