Insulin Stimulates Production of Glycoconjugate Layers on the Cell Surface of Gastric Surface Mucous Cell Line GSM06

Abstract

The mechanism of regulation of mucus production in the gastric mucosa remains unclear. Recently, we established a gastric surface mucous cell line GSM06, which produces periodic acid-Shiff (PAS)-positive glycoconjugate (mucus) layers on the cell surface, from transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. In this study, GSM06 cells were examined for its production of PAS-positive glycoconjugate layers to acid secretagogues and growth factors. The cells were cultured at nonpermissive temperature (39°C) for 3-18 days and stained with PAS. Insulin (1-30 μg/ml; 0.29-8.6 μM) time- and dose-dependently increased production of glycoconjugates on the cell surface. When glycoconjugate layers produced by stimulation of insulin (3-30 μg/ml; 0.86-8.6 μM) were removed from the cell surface of GSM06 cells by a mild trypsin treatment, PAS-positive materials were remarkably decreased (day 18). In addition, morphological findings indicate that a high concentration of insulin (30 μg/ml; 8.6 μM) produced thick PAS-positive glycoconjugate layers just like normal gastric surface mucosa on the cell surface on day 18. In contrast, histamine (0.1-100 μM), carbachol (0.1-100 μM), gastrin-17 (0.1-100nM), epidermal growth factor (0.01-10 ng/ ml; 1.7-1,700 pM), transforming growth factor-α (0.01-10 ng/ml; 1.8-1,800 pM), and fetal bovine serum (1-10%) did not increase glycoconjugate production. These findings suggest that insulin is a stimulator of glycoconjugate production, and stimulates production of glycoconjugate layers on the cell surface in the gastric surface mucous cell line GSM06.

Proprotein-processing endoprotease furin controls the growth and differentiation of gastric surface mucous cells.

“…3 B). However, when cells were kept confluent over 3 d, PAS-positive materials appeared as described previously (25,26). In contrast, when the cells were transferred from 33 to 39ЊC for 48 h, the cells became clearly positive for PAS staining in low or high cell density (Fig.…”

“…Morphologically, GSM06 cells are rounded or polyhedral as is typical of primary cultured gastric surface mucous cells (10,(19)(20)(21). Electron microscopy revealed that the cells contained a small number of secretory granules (26). The PAS-positive staining of the GSM06 cells appeared to be due to glycoproteins and glycolipids, but not to mucin molecules (27).…”

DNA Microarray Analysis of Differentially Expressed Genes Responsive to Bisphenol A, an Alkylphenol Derivative, in an In Vitro Mouse Sertoli Cell Model

“…The cells were cultured with DMEM supplemented with 0.5% FBS for 24 h at 33°C, followed by incubation in DMEM supplemented with 0.5% FBS and BPA for 24 h at 33°C. The cell viability was determined using a tetrazolium compound, 4-[3-(4-idophenyl)-2-(4-nitrophenyl)-2H-5-tetra-zolio]-1,3-benzene disulfonate (1a) sodium salt (WST-1), according to our previous report (8).…”

Correlation of gastric mucosal damage with sialic acid profile in rats: effect of hydrochloric acid, pepsin and hypertonic saline

“…These reports suggest that these agents induce not only acid secretion but also strengthen the gastric mucosal barrier. In contrast, Tabuchi et al 13 reported that these agents did not increase glycoconjugate production in mucous cell lines. Analysis of carbohydrates in gastric aspirates in normal subjects in response to pentagastrin, an acid-stimulating agent, revealed little difference in the sialic acid concentration either in the purified mucin or non-fractionated gastric aspirations.…”