Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada.
Cardiovascular and Respiratory Sciences graduate program, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
BMC Med Genomics. 2019 Jan 31;12(1):29. doi: 10.1186/s12920-018-0467-2.
Glucocorticoids act on the glucocorticoid receptor (GR; NR3C1) to resolve inflammation and, as inhaled corticosteroids (ICS), are the cornerstone of treatment for asthma. However, reduced efficacy in severe disease or exacerbations indicates a need to improve ICS actions.
Glucocorticoid-driven transcriptomes were compared using PrimeView microarrays between primary human bronchial epithelial (HBE) cells and the model cell lines, pulmonary type II A549 and bronchial epithelial BEAS-2B cells.
In BEAS-2B cells, budesonide induced (≥2-fold, P ≤ 0.05) or, in a more delayed fashion, repressed (≤0.5-fold, P ≤ 0.05) the expression of 63, 133, 240, and 257 or 15, 56, 236, and 344 mRNAs at 1, 2, 6, and 18 h, respectively. Within the early-induced mRNAs were multiple transcriptional activators and repressors, thereby providing mechanisms for the subsequent modulation of gene expression. Using the above criteria, 17 (BCL6, BIRC3, CEBPD, ERRFI1, FBXL16, FKBP5, GADD45B, IRS2, KLF9, PDK4, PER1, RGCC, RGS2, SEC14L2, SLC16A12, TFCP2L1, TSC22D3) induced and 8 (ARL4C, FLRT2, IER3, IL11, PLAUR, SEMA3A, SLC4A7, SOX9) repressed mRNAs were common between A549, BEAS-2B and HBE cells at 6 h. As absolute gene expression change showed greater commonality, lowering the cut-off (≥1.25 or ≤ 0.8-fold) within these groups produced 93 induced and 82 repressed genes in common. Since large changes in few mRNAs and/or small changes in many mRNAs may drive function, gene ontology (GO)/pathway analyses were performed using both stringency criteria. Budesonide-induced genes showed GO term enrichment for positive and negative regulation of transcription, signaling, proliferation, apoptosis, and movement, as well as FOXO and PI3K-Akt signaling pathways. Repressed genes were enriched for inflammatory signaling pathways (TNF, NF-κB) and GO terms for cytokine activity, chemotaxis and cell signaling. Reduced growth factor expression and effects on proliferation and apoptosis were highlighted.
While glucocorticoids repress mRNAs associated with inflammation, prior induction of transcriptional activators and repressors may explain longer-term responses to these agents. Furthermore, positive and negative effects on signaling, proliferation, migration and apoptosis were revealed. Since many such gene expression changes occurred in human airways post-ICS inhalation, the effects observed in cell lines and primary HBE cells in vitro may be relevant to ICS in vivo.
糖皮质激素通过糖皮质激素受体（GR；NR3C1）发挥作用，以解决炎症问题，作为吸入性皮质类固醇（ICS），是治疗哮喘的基石。然而，在严重疾病或恶化时疗效降低表明需要改善 ICS 的作用。
使用 PrimeView 微阵列在原代人支气管上皮（HBE）细胞和模型细胞系，肺 II 型 A549 和支气管上皮 BEAS-2B 细胞之间比较糖皮质激素驱动的转录组。
在 BEAS-2B 细胞中，布地奈德诱导（≥2 倍，P≤0.05）或在更延迟的时间内（≤0.5 倍，P≤0.05）分别在 1、2、6 和 18 小时时，分别表达 63、133、240 和 257 或 15、56、236 和 344 个 mRNA。在早期诱导的 mRNA 中，有多个转录激活因子和抑制因子，从而为随后的基因表达调控提供了机制。使用上述标准，在 A549、BEAS-2B 和 HBE 细胞中，有 17 个（BCL6、BIRC3、CEBPD、ERRFI1、FBXL16、FKBP5、GADD45B、IRS2、KLF9、PDK4、PER1、RGCC、RGS2、SEC14L2、SLC16A12、TFCP2L1、TSC22D3）诱导和 8 个（ARL4C、FLRT2、IER3、IL11、PLAUR、SEMA3A、SLC4A7、SOX9）抑制的 mRNAs 在 6 小时时是共同的。由于绝对基因表达变化具有更大的共性，因此在这些组中降低（≥1.25 或≤0.8 倍）的截止值会产生 93 个共同诱导和 82 个共同抑制的基因。由于少数 mRNA 的大量变化和/或许多 mRNA 的微小变化可能会驱动功能，因此使用两种严格标准进行了基因本体论（GO）/途径分析。布地奈德诱导的基因显示 GO 术语富集，包括转录、信号、增殖、凋亡和运动的正调控和负调控，以及 FOXO 和 PI3K-Akt 信号通路。抑制的基因富含 TNF、NF-κB 等炎症信号通路和细胞因子活性、趋化性和细胞信号等 GO 术语。突出了生长因子表达减少以及对增殖和凋亡的影响。
虽然糖皮质激素抑制与炎症相关的 mRNA，但转录激活因子和抑制因子的预先诱导可能解释了对这些药物的长期反应。此外，还揭示了对信号、增殖、迁移和凋亡的积极和消极影响。由于许多此类基因表达变化在 ICS 吸入后出现在人类气道中，因此在细胞系和原代 HBE 细胞中观察到的体外效应可能与体内 ICS 相关。
