Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Anam Hospital, Korea University, 73, Inchon-ro, Seongbuk-gu, Seoul, South Korea.
College of Medicine, Neuroscience Research Institute, Korea University, Seoul, Republic of Korea.
J Mol Med (Berl). 2022 Feb;100(2):313-322. doi: 10.1007/s00109-021-02166-z. Epub 2022 Jan 1.
Laryngopharyngeal reflux disease (LPRD) is caused by pharyngeal mucosal damage due to the reflux of gastric contents, including acid, pepsin, and bile juice. Our previous study has demonstrated that LPRD is associated with the cleavage of E-cadherin, which is facilitated by the acid-activated matrix metalloproteinase-7 (MMP-7); however, the mechanism by which the acid activates MMP-7 remains unclear. The purpose of this study was to investigate the mechanism by which MMP-7 is activated in the pharyngeal epithelial cells that are exposed to acid. The levels of reactive oxygen species (ROS) were measured in the epithelial cells exposed to acid. To investigate the signaling mechanism of ROS in the expression of MMP-7, the mechanism of action of the mitogen-activated protein kinase was examined. The expression of various signaling factors was determined, according to the presence or absence of each inhibitor in the acid-exposed pharyngeal epithelial cells. To identify changes in the cleavage of E-cadherin, the integrity of the mucosal membrane was assessed using a transepithelial permeability test. We found that acid exposure increased the levels of ROS, phosphorylated-extracellular signal-regulated kinase (p-ERK) 1/2, and phosphorylated-c-Jun (p-c-Jun) in pharyngeal epithelial cells. The ROS inhibitor reduced the expression of p-ERK and MMP-7, while the ERK inhibitor reduced the expression of p-c-Jun and MMP-7. Moreover, the c-Jun inhibitor reduced the expression of MMP-7 and blocked the degradation of E-cadherin. In addition, decrease in the levels of immunostained E-cadherin and increase in transepithelial permeability after acid exposure were collectively alleviated by the inhibitors of ROS, ERK, and c-Jun. The degradation of E-cadherin that occurs after human mucosal cells are exposed to acid appears to be caused by an increase in the expression of MMP-7 via the ROS/ERK/c-Jun pathway, which is thought to be an important mechanism associated with the development of LPRD. KEY MESSAGES: • ROS is triggered when reflux occurs. • ROS regulates the transcription factor c-Jun via the ERK pathway. • The increase in MMP-7 that induces LPRD is induced via the ROS/ERK/c-Jun pathway. • This study revealed for the first time the expression mechanism of MMP-7, which is one of the causes of LPRD.
咽胃反流病（LPRD）是由胃内容物反流引起的咽黏膜损伤引起的，其中包括酸、胃蛋白酶和胆汁。我们之前的研究表明，LPRD 与 E-钙黏蛋白的裂解有关，这是由酸激活的基质金属蛋白酶-7（MMP-7）介导的；然而，酸激活 MMP-7 的机制尚不清楚。本研究旨在探讨暴露于酸的咽上皮细胞中 MMP-7 激活的机制。测量暴露于酸的上皮细胞中的活性氧（ROS）水平。为了研究 ROS 在 MMP-7 表达中的信号转导机制，研究了丝裂原活化蛋白激酶的作用机制。根据酸暴露的咽上皮细胞中每种抑制剂的存在或不存在，确定各种信号转导因子的表达。为了确定 E-钙黏蛋白裂解的变化，使用跨上皮通透性试验评估粘膜膜的完整性。我们发现酸暴露会增加咽上皮细胞中 ROS、磷酸化细胞外信号调节激酶（p-ERK）1/2 和磷酸化 c-Jun（p-c-Jun）的水平。ROS 抑制剂降低了 p-ERK 和 MMP-7 的表达，而 ERK 抑制剂降低了 p-c-Jun 和 MMP-7 的表达。此外，c-Jun 抑制剂降低了 MMP-7 的表达并阻断了 E-钙黏蛋白的降解。此外，酸暴露后免疫染色 E-钙黏蛋白水平降低和跨上皮通透性增加可通过 ROS、ERK 和 c-Jun 的抑制剂共同缓解。酸暴露后人类粘膜细胞中 E-钙黏蛋白的降解似乎是通过 ROS/ERK/c-Jun 途径增加 MMP-7 的表达引起的，这被认为是与 LPRD 发展相关的重要机制。 主要信息： • 反流时触发 ROS。 • ROS 通过 ERK 途径调节转录因子 c-Jun。 • 诱导 LPRD 的 MMP-7 增加是通过 ROS/ERK/c-Jun 途径诱导的。 • 本研究首次揭示了 MMP-7 的表达机制，MMP-7 是 LPRD 的原因之一。
