Rubinstein I, Gao X P, Pakhlevaniants S, Oda D
Department of Medicine, University of Illinois at Chicago, USA.
Am J Physiol. 1998 Jan;274(1):R104-11. doi: 10.1152/ajpregu.1998.274.1.R104.
The purpose of this study was to determine whether supernatants of cultured human oral keratinocytes (HOK) exposed to an aqueous extract of smokeless tobacco (STE) increase macromolecular efflux from the oral mucosa in vivo and, if so, whether bradykinin mediates in part this response. Subconfluent monolayers of HOK were incubated with STE or media, and supernatants were collected 24, 48, and 72 h thereafter. Using intravital microscopy, we found that suffusion of supernatants of STE- but not media-exposed HOK elicited significant concentration- and time-dependent increases in efflux of fluorescein isothiocyanate-labeled dextran (mol mass 70 kDa) from the in situ hamster cheek pouch (P < 0.05). These effects were significantly attenuated by HOE-140 and NPC-17647 but not by des-Arg9, [Leu8]-bradykinin. Proteolytic activity was increased in supernatants of STE- but not media-exposed HOK. However, a mixture of leupeptin, Bestatin, and DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid had no significant effects on HOK supernatant-induced responses. Collectively, these data suggest that oral keratinocytes modulate smokeless tobacco-induced increase in macromolecular efflux from the in situ oral mucosa in part by elaborating proteases that may account for local bradykinin production.
本研究的目的是确定暴露于无烟烟草水提取物（STE）的培养人口腔角质形成细胞（HOK）的上清液是否会增加体内口腔黏膜的大分子外排，如果是，缓激肽是否部分介导了这种反应。将亚汇合的HOK单层与STE或培养基一起孵育，然后在24、48和72小时后收集上清液。使用活体显微镜，我们发现灌注STE处理而非培养基处理的HOK的上清液会引起异硫氰酸荧光素标记的葡聚糖（分子量70 kDa）从原位仓鼠颊囊的外排显著增加，且呈浓度和时间依赖性（P < 0.05）。HOE - 140和NPC - 17647可显著减弱这些作用，但去精氨酸[Leu8] - 缓激肽则无此作用。STE处理而非培养基处理的HOK的上清液中的蛋白水解活性增加。然而，亮抑酶肽、贝抑素和DL - 2 - 巯基甲基 - 3 - 胍基乙基硫代丙酸的混合物对HOK上清液诱导的反应无显著影响。总体而言，这些数据表明口腔角质形成细胞部分通过分泌可能导致局部缓激肽产生的蛋白酶来调节无烟烟草诱导的原位口腔黏膜大分子外排增加。
