Department of Biomedical Laboratory Science, College of Life and Health Sciences, Hoseo University, Asan, 31499, Republic of Korea.
Department of Integrated Biomedical and Life Sciences, Graduate School, Korea University, Seoul, 02841, Republic of Korea.
Food Chem Toxicol. 2018 Aug;118:880-888. doi: 10.1016/j.fct.2018.06.039. Epub 2018 Jun 20.
The intestinal mucus layer plays an important role in the management of inflammatory bowel disease. The aim of this study was to investigate the effects of oxyresveratrol (OXY), an antioxidant, on the stimulation of mucin production in human LS 174T goblet cells and the underlying mechanism thereof. OXY increased MUC2 expression at both the mRNA and protein levels. By performing two-dimensional gel electrophoresis, we found that the expression of nicotinic acid phosphoribosyltransferase1 (NaPRT1) in OXY-treated LS 174T cells was greatly increased compared with that in negative control cells. In addition, the NAD/NADH ratio was increased in proportion to OXY in LS 174T cells. The expression of NAD-synthesis enzymes, NaPRT1, nicotinamide riboside kinase1 (NRK1) and nicotinamide mononucleotide adenylyltransferase1 (Nmnat1) was significantly increased at both the mRNA and protein levels in OXY-treated LS 174T cells. The inhibition of NaPRT1 and NRK1 did not decrease MUC2 expression after inhibiting by small interfering RNA (siRNA)-NaPRT1 and siRNA-NRK1, respectively; however, inhibition of Nmnat by an Nmnat inhibitor decreased MUC2 expression in a dose-dependent manner. In conclusion, OXY increases NAD levels, resulting in the stimulation of MUC2 expression in LS 174T cells. These findings present a novel role for NAD in stimulation of MUC2 expression.
肠黏液层在炎症性肠病的管理中起着重要作用。本研究旨在探讨抗氧化剂氧代白藜芦醇（OXY）对人 LS 174T 杯状细胞黏蛋白产生的刺激作用及其潜在机制。OXY 可在 mRNA 和蛋白水平上增加 MUC2 的表达。通过二维凝胶电泳，我们发现与阴性对照组细胞相比，OXY 处理的 LS 174T 细胞中烟酰胺磷酸核糖转移酶 1（NaPRT1）的表达大大增加。此外，LS 174T 细胞中的 NAD/NADH 比值与 OXY 呈比例增加。OXY 处理的 LS 174T 细胞中 NAD 合成酶 NaPRT1、烟酰胺核苷激酶 1（NRK1）和烟酰胺单核苷酸腺苷转移酶 1（Nmnat1）的表达在 mRNA 和蛋白水平上均显著增加。用小干扰 RNA（siRNA）-NaPRT1 和 siRNA-NRK1 分别抑制 NaPRT1 和 NRK1 的表达后，并不降低 MUC2 的表达；然而，Nmnat 抑制剂抑制 Nmnat 以剂量依赖的方式降低 MUC2 的表达。总之，OXY 增加 NAD 水平，从而刺激 LS 174T 细胞中 MUC2 的表达。这些发现为 NAD 在刺激 MUC2 表达中的作用提供了新的认识。
