NKX6.3 通过下调β-淀粉样蛋白的产生来保护胃黏膜萎缩。
NKX6.3 protects against gastric mucosal atrophy by downregulating β-amyloid production.
机构信息
Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul 06591, South Korea.
Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul 06591, South Korea.
出版信息
World J Gastroenterol. 2019 Jan 21;25(3):330-345. doi: 10.3748/wjg.v25.i3.330.
BACKGROUND
Atrophic gastritis is characterized by loss of appropriate glands and reduction in gastric secretory function due to chronic inflammatory processes in gastric mucosa. Moreover, atrophic gastritis is considered as a precancerous condition of gastric cancer. However, little is known about the molecular mechanism underlying gastric mucosal atrophy and its contribution to gastric carcinogenesis. Thus, we hypothesized that transcription factor NKX6.3 might be involved in maintaining gastric epithelial homeostasis by regulating amyloid β (Aβ) production.
AIM
To determine whether NKX6.3 might protect against gastric mucosal atrophy by regulating Aβ production.
METHODS
We identified NKX6.3 depletion induced cell death by cell count and Western blot assay. Production and mechanism of Aβ oligomer were analyzed by enzyme-linked immunosorbent assay, Western blot, immunoprecipitation, real-time quantitative polymerase chain reaction and immunofluorescence analysis. We further validated the correlation between expression of NKX6.3, CagA, Aβ oligomer, apolipoprotein E (ApoE), and β-secretase 1 (Bace1) in 55 gastric mucosae.
RESULTS
NKX6.3 depletion increased both adherent and floating cell populations in HFE-145 cells. Expression levels of cleaved caspase-3, -9, and poly ADP ribose polymerase were elevated in floating HFE-145 cells. NKX6.3 depletion produced Aβ peptide oligomers, and increased expression of ApoE, amyloid precursor protein, Aβ, Bace1, low-density lipoprotein receptor, nicastrin, high mobility group box1, and receptor for advanced glycosylation end product proteins. In immunoprecipitation assay, γ-secretase complex was stably formed only in HFE-145 cells. In gastric mucosae with atrophy, expression of Aβ peptide oligomer, , and was detected and inversely correlated with NKX6.3 expression. Treatment with recombinant Aβ 1-42 produced Aβ oligomeric forms and decreased cell viability in HFE-145 cells. Additionally, NKX6.3 depletion increased expression of inflammatory cytokines and cyclooxygenase-2.
CONCLUSION
NKX6.3 inhibits gastric mucosal atrophy by regulating Aβ accumulation and inflammatory reaction in gastric epithelial cells.
背景
萎缩性胃炎的特征是由于胃黏膜的慢性炎症过程，适当的腺体丧失和胃分泌功能降低。此外，萎缩性胃炎被认为是胃癌的癌前状态。然而，对于胃黏膜萎缩的分子机制及其对胃癌发生的贡献知之甚少。因此，我们假设转录因子 NKX6.3 可能通过调节淀粉样 β（Aβ）的产生来参与维持胃上皮细胞的稳态。
目的
确定 NKX6.3 是否通过调节 Aβ 的产生来防止胃黏膜萎缩。
方法
我们通过细胞计数和 Western blot 分析确定了 NKX6.3 耗竭诱导的细胞死亡。通过酶联免疫吸附试验、Western blot、免疫沉淀、实时定量聚合酶链反应和免疫荧光分析分析了 Aβ 寡聚体的产生和机制。我们进一步验证了 NKX6.3、CagA、Aβ 寡聚体、载脂蛋白 E（ApoE）和β-分泌酶 1（Bace1）在 55 个胃黏膜中的表达之间的相关性。
结果
NKX6.3 耗竭增加了 HFE-145 细胞中的贴壁和漂浮细胞群体。漂浮的 HFE-145 细胞中 cleaved caspase-3、-9 和多聚 ADP 核糖聚合酶的表达水平升高。NKX6.3 耗竭产生 Aβ 肽寡聚体，并增加 ApoE、淀粉样前体蛋白、Aβ、Bace1、低密度脂蛋白受体、尼克酰胺嘌呤二核苷酸转移酶、高迁移率族框 1 和晚期糖基化终产物受体蛋白的表达。在免疫沉淀分析中，γ-分泌酶复合物仅在 HFE-145 细胞中稳定形成。在有萎缩的胃黏膜中，检测到 Aβ 肽寡聚体的表达，并与 NKX6.3 的表达呈负相关。用重组 Aβ 1-42 处理会产生 Aβ 寡聚形式，并降低 HFE-145 细胞的细胞活力。此外，NKX6.3 耗竭增加了炎症细胞因子和环氧化酶-2 的表达。
结论
NKX6.3 通过调节胃上皮细胞中 Aβ 的积累和炎症反应抑制胃黏膜萎缩。
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