Gene expression in rat lungs during early response to paraquat-induced oxidative stress.
Gene expression in rat lungs during early response to paraquat-induced oxidative stress.
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DOI：
10.3892/ijmm.17.1.37
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发表时间：
2006
影响因子：
5.4
通讯作者：
M. Tomita;T. Okuyama;H. Katsuyama;Kazuo Hidaka;T. Otsuki;T. Ishikawa
中科院分区：
文献类型：
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作者：
M. Tomita;T. Okuyama;H. Katsuyama;Kazuo Hidaka;T. Otsuki;T. Ishikawa
百草枯(PQ)是一种著名的气体毒物，提供了一种已建立的氧化应激模型。这项研究集中在注射后早期大鼠肺内对PQ驱动的氧化应激的转录反应。分别于注射PQ后3h、2 4h和第2次注射后3h、2 4h处死大鼠。快速切除左肺，立即用于RNA制备。光镜下肺组织未见任何病理损害。用DNA阵列系统研究3h后肺组织中RNA的差异表达。15个基因的表达水平发生了1.7倍的变化，这一点通过实时荧光定量聚合酶链式反应得到了证实。与氧化应激相关的5个基因TRX、HO-1、GST-YC、NQO-1和RL/IF-1，以及一个功能未知的基因CLK3在注射PQ后表达显著增加。HO-1和NQO-1两个基因在注射后3h分别增加3倍和2倍，通过免疫组织化学定位。HO-1表达于对照肺的支气管上皮细胞、部分II型细胞和巨噬细胞，PQ处理3h后，HO-1阳性细胞尤其是支气管上皮细胞呈强阳性表达。NQO-1的免疫组织化学分析也显示PQ处理的肺切片中的支气管上皮细胞阳性染色增加。雌性肝脏特异性或显性表达的CYP2C6、2C7和2C12的表达显著降低，而雄性特异性的CYP2C13和2C11的表达增加或没有影响。这些CYP2C家族基因在PQ毒性早期的作用尚需进一步研究。这些结果表明，在PQ诱导的损伤开始时，对氧化应激的适应已经是一个高度复杂的过程，这里描述的基因可能被证明是随后肺纤维化的主要贡献者。
Paraquat (PQ) is a well-known pneumotoxicant and provides an established model of oxidative stress. This study focused on the transcriptional response to PQ-driven oxidative stress in rat lungs during an early phase post-injection. Rats were sacrificed at 3 h and 24 h after PQ injection (i.p., 20 mg/kg b.w.), and at 3 h after a second injection (i.p., 20 mg/kg b.w.). The left lungs were rapidly excised and used immediately for RNA preparation. The lung tissues did not show any pathological damage microscopically. Differential expression of RNAs in the lung at 3 h was investigated using a DNA array system. Fifteen genes showed a >1.7-fold change in expression level, which was confirmed by real-time PCR. Five genes related to oxidative stress, TRX, HO-1, GST-Yc, NQO-1, and RL/IF-1, and one gene, CLK3, whose function is unknown, showed a significant increase in their expression due to PQ injection. Two genes, HO-1 and NQO-1, that showed 3- and 2-fold increases at 3-h post-injection, were localized by immunohistochemistry. HO-1 was expressed in the bronchial epithelial cells, some type II cells and macrophages of control lungs, and the cells, especially the bronchial epithelial cells, were strongly stained 3 h following PQ treatment. Immunohistochemical analysis of NQO-1 also showed an increase in positive staining in the bronchial epithelial cells of PQ-treated lung sections. The expression of CYP2C6, 2C7, and 2C12, which are specific to or dominant in female liver, decreased markedly, while the male-specific CYP2C13 and 2C11 showed an increase or no effect. Further investigation is needed to clarify the role of these CYP2C family genes on the early phase of PQ toxicity. These results indicate that the acclimation to oxidative stress is already a highly complex process at the onset of PQ-induced damage and that the genes described herein may prove to be major contributors to the subsequent pulmonary fibrosis.