Differences in activity and phosphorylation of MAPK enzymes in esophageal squamous cells of GERD patients with and without Barrett's esophagus
Differences in activity and phosphorylation of MAPK enzymes in esophageal squamous cells of GERD patients with and without Barrett's esophagus
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DOI：
10.1152/ajpgi.90262.2008
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发表时间：
2008-09-01
影响因子：
4.5
通讯作者：
Souza, Rhonda F.
中科院分区：
文献类型：
--
作者：
Zhang, Hui Ying;Zhang, Xi;Souza, Rhonda F.
我们假设，在食管鳞状上皮细胞中，酸反流激活的信号转导通路可能是巴雷特食管发展的基础，个体之间存在差异。为了探讨这一假设，我们永生化的非肿瘤性，食管鳞状细胞从胃食管反流病（GERD）患者（NES-B3 T）和没有（NES-G2 T）巴雷特食管，并使用这些细胞来研究酸对MAPK蛋白的影响。在GERD患者的内镜检查中，无论有无Barrett食管，我们从远端鳞状食管取活检标本，研究0.1 N HCl食管灌注前后的MAPK蛋白。我们使用免疫印迹和蛋白质印迹法研究MEK 1/ 2在两个激活位点（丝氨酸217/221）的磷酸化，MEK 1在抑制位点（苏氨酸286）的磷酸化，和MEK 1/ 2活性。酸暴露后，两种细胞系均表现出活化位点的MEK 1/2磷酸化增加; NES-B3 T细胞在抑制位点具有更高水平的MEK 1磷酸化，然而，只有NES-G2 T细胞表现出酸诱导的MEK 1/ 2活性增加。同样，在伴有和不伴有Barrett食管的GERD患者的鳞状上皮中，酸灌注增加了两组患者激活部位的MEK 1/ 2磷酸化;然而，Barrett患者在抑制部位的MEK 1磷酸化水平较高，只有不伴有Barrett食管的患者表现出酸诱导的ERK 1/ 2磷酸化增加。在食管鳞状细胞系和活检的患者与胃食管反流病与巴瑞特食管，我们已经发现的差异MAPK途径激活酸暴露。我们推测这些差异可能是巴雷特化生发展的基础。
We hypothesized that, in esophageal squamous epithelial cells, there are differences among individuals in the signal transduction pathways activated by acid reflux that might underlie the development of Barrett's esophagus. To explore that hypothesis, we immortalized nonneoplastic, esophageal squamous cells from patients with gastroesophageal reflux disease (GERD) with (NES-B3T) and without (NES-G2T) Barrett's esophagus and used those cells to study acid effects on MAPK proteins. During endoscopy in patients with GERD with and without Barrett's esophagus, we took biopsy specimens from the distal squamous esophagus to study MAPK proteins before and after esophageal perfusion with 0.1 N HCl. We used immunoblotting and Western blotting to study MEK1/ 2 phosphorylation at two activating sites (serines 217/221), MEK1 phosphorylation at an inhibitory site (threonine 286), and MEK1/ 2 activity. After acid exposure, both cell lines exhibited increased MEK1/2 phosphorylation at the activating sites; the NES-B3T cells had higher levels of MEK1 phosphorylation at the inhibitory site, however, and only the NES-G2T cells showed an acid-induced increase in MEK1/ 2 activity. Similarly, in the squamous epithelium of patients with GERD with and without Barrett's esophagus, acid perfusion increased MEK1/ 2 phosphorylation at the activating sites in both patient groups; the Barrett's patients had higher levels of MEK1 phosphorylation at the inhibitory site, however, and only the patients without Barrett's demonstrated an acid-induced increase in ERK1/ 2 phosphorylation. In esophageal squamous cell lines and biopsies from patients with GERD with and without Barrett's esophagus, we have found differences in MAPK pathways activated by acid exposure. We speculate that these differences might underlie the development of Barrett's metaplasia.