Department of medicine and pathology, NYU Medical Center, New York, NY, USA.
Ann Surg. 2012 Jun;255(6):1113-20. doi: 10.1097/SLA.0b013e3182512af9.
This study aimed to identify pathways and cellular processes that are modulated by exposure of normal esophageal cells to bile and acid.
Barrett's esophagus most likely develops as a response of esophageal stem cells to the abnormal reflux environment. Although insights into the underlying molecular mechanisms are slowly emerging, much of the metaplastic process remains unknown.
We performed a global analysis of gene expression in normal squamous esophageal cells in response to bile or acid exposure. Differentially expressed genes were classified into major biological functions using pathway analysis and interaction network software. Array data were verified by quantitative PCR and western blot both in vitro and in human esophageal biopsies.
Bile modulated expression of 202 genes, and acid modulated expression of 103 genes. Genes involved in squamous differentiation formed the largest functional group (n = 45) all of which were downregulated by bile exposure. This included genes such as involucrin (IVL), keratinocyte differentiation-associated protein (KRTDAP), grainyhead-like 1 (GRHL1), and desmoglein1 (DSG1) the downregulation of which was confirmed by quantitative PCR and western blot. Bile also caused expression changes in genes involved in cell adhesion, DNA repair, oxidative stress, cell cycle, Wnt signaling, and lipid metabolism. Analysis of human esophageal biopsies demonstrated greatly reduced expression of IVL, KRTDAP, DSG1, and GRHL1 in metaplastic compared to squamous epithelia.
We report for the first time that bile inhibits the squamous differentiation program of esophageal epithelial cells. This, coordinated with induction of genes driving intestinal differentiation, may be required for the development of Barrett's esophagus.
本研究旨在鉴定正常食管细胞暴露于胆汁和酸后被调控的途径和细胞过程。
巴雷特食管很可能是食管干细胞对异常反流环境的反应而发展起来的。尽管对潜在的分子机制的认识正在缓慢出现，但大部分化生过程仍然未知。
我们对正常鳞状食管细胞在胆汁或酸暴露下的基因表达进行了全局分析。通过途径分析和相互作用网络软件，将差异表达基因分类为主要生物学功能。在体外和人食管活检中，通过定量 PCR 和 Western blot 验证了阵列数据。
胆汁调节了 202 个基因的表达，而酸调节了 103 个基因的表达。参与鳞状分化的基因形成了最大的功能组（n = 45），所有这些基因都被胆汁暴露所下调。这包括 involucrin（IVL）、角蛋白细胞分化相关蛋白（KRTDAP）、粒头样蛋白 1（GRHL1）和桥粒蛋白 1（DSG1）等基因，定量 PCR 和 Western blot 证实了它们的下调。胆汁还导致参与细胞黏附、DNA 修复、氧化应激、细胞周期、Wnt 信号和脂质代谢的基因表达发生变化。对人食管活检的分析表明，与鳞状上皮相比，化生中 IVL、KRTDAP、DSG1 和 GRHL1 的表达大大降低。
我们首次报道胆汁抑制食管上皮细胞的鳞状分化程序。这与诱导驱动肠分化的基因一起，可能是巴雷特食管发展所必需的。
