Klinkspoor J H, Mok K S, Van Klinken B J, Tytgat G N, Lee S P, Groen A K
Departments of Gastroenterology, and Pediatric Gastroenterology and Nutrition, University of Amsterdam, Academic Medical Center, Amsterdam, The Netherlands.
Glycobiology. 1999 Jan;9(1):13-9. doi: 10.1093/glycob/9.1.13.
We recently reported that bile salts play a role in the regulation of mucin secretion by cultured dog gallbladder epithelial cells. In this study we have examined whether bile salts also influence mucin secretion by the human epithelial colon cell line LS174T. Solutions of bile salts were applied to monolayers of LS174T cells. Mucin secretion was quantified by measuring the secretion of [3H]GlcNAc labeled glycoproteins. Both unconjugated bile salts as well as taurine conjugated bile salts stimulated mucin secretion by the colon cells in a dose-dependent fashion. Hydrophobic bile salts were more potent stimulators than hydrophilic bile salts. Free (unconjugated) bile salts were more stimulatory compared with their taurine conjugated counterparts. Stimulation of mucin secretion by LS174T cells was found to occur at much lower bile salt concentrations than in the experiments with the dog gallbladder epithelial cells. The protein kinase C activators PMA and PDB had no stimulatory effect on mucin secretion. We conclude that mucin secretion by the human colon epithelial cell line LS174T is regulated by bile salts. We suggest that regulation of mucin secretion by bile salts might be a common mechanism, by which different epithelia protect themselves against the detergent action of bile salts, to which they are exposed throughout the gastrointestinal tract.
我们最近报道，胆盐在培养的犬胆囊上皮细胞粘蛋白分泌的调节中起作用。在本研究中，我们检测了胆盐是否也影响人结肠上皮细胞系LS174T的粘蛋白分泌。将胆盐溶液应用于LS174T细胞单层。通过测量[3H]GlcNAc标记糖蛋白的分泌来定量粘蛋白分泌。未结合胆盐以及牛磺酸结合胆盐均以剂量依赖性方式刺激结肠细胞的粘蛋白分泌。疏水性胆盐比亲水性胆盐是更强效的刺激剂。游离（未结合）胆盐与其牛磺酸结合对应物相比更具刺激性。发现LS174T细胞粘蛋白分泌的刺激发生在比犬胆囊上皮细胞实验中低得多的胆盐浓度下。蛋白激酶C激活剂PMA和PDB对粘蛋白分泌没有刺激作用。我们得出结论，人结肠上皮细胞系LS174T的粘蛋白分泌受胆盐调节。我们认为胆盐对粘蛋白分泌的调节可能是一种常见机制，通过该机制不同上皮细胞保护自身免受整个胃肠道中所接触胆盐的去污剂作用。
