Data from: Temporal and gefitinib-sensitive regulation of cardiac cytokine expression via chronic β-adrenergic receptor stimulation

Chronic stimulation of β-adrenergic receptors (βAR) can promote survival signaling via transactivation of epidermal growth factor receptor (EGFR), but ultimately alters cardiac structure and contractility over time, in part via enhanced cytokine signaling. We hypothesized that chronic catecholamine signaling will have a temporal impact on cardiac transcript expression in vivo, in particular cytokines, and that EGFR transactivation plays a role in this process. C57BL/6 mice underwent infusion with vehicle or isoproterenol (Iso) ± gefitinib (Gef) for 1 or 2 weeks. Cardiac contractility decreased following 2 weeks of Iso treatment, while cardiac hypertrophy, fibrosis and apoptosis were enhanced at both timepoints. Inclusion of Gef preserved contractility, blocked Iso-induced apoptosis and prevented hypertrophy at the 2 week timepoint, but caused fibrosis on its own. RNAseq analysis revealed hundreds of cardiac transcripts altered by Iso at each timepoint with subsequent RT-qPCR validation confirming distinct temporal patterns of transcript regulation, including those involved in cardiac remodeling and survival signaling, as well as numerous cytokines. While Gef infusion alone did not significantly alter cytokine expression, it abrogated the Iso-mediated changes in a majority of the βAR-sensitive cytokines, including CCL2 and TNF-α. Additionally, the impact of βAR-dependent EGFR transactivation on the acute regulation of cytokine transcript expression was assessed in isolated cardiomyocytes and in cardiac fibroblasts, where the majority of Iso-dependent, and EGFR-sensitive, changes in cytokines occurred. Overall, coincident with changes in cardiac structure and contractility, βAR stimulation dynamically alters cardiac transcript expression over time, including numerous cytokines that are regulated via EGFR-dependent signaling.

慢性刺激β肾上腺素能受体（β-adrenergic receptors, βAR）可通过表皮生长因子受体（epidermal growth factor receptor, EGFR）的反式激活促进存活信号通路，但随着时间推移最终会改变心脏结构与收缩功能，其部分机制依赖于细胞因子信号通路的激活增强。本研究假设慢性儿茶酚胺信号通路会在体内对心脏转录本表达产生时序性影响，尤其是细胞因子的表达，且EGFR反式激活在此过程中发挥关键作用。将C57BL/6小鼠分为四组，分别接受溶媒对照、异丙肾上腺素（isoproterenol, Iso）单独输注，或异丙肾上腺素联合吉非替尼（gefitinib, Gef）输注，干预时长为1周或2周。经2周异丙肾上腺素处理后，小鼠心脏收缩功能下降；而在两个干预时间点，异丙肾上腺素均会促进心脏肥大、纤维化与细胞凋亡。联合吉非替尼输注可保留心脏收缩功能，阻断异丙肾上腺素诱导的细胞凋亡，并在2周时间点阻止心脏肥大，但吉非替尼单独输注会引发心肌纤维化。RNA测序（RNA-seq）分析显示，各时间点均有数百个心脏转录本受异丙肾上腺素调控；后续实时定量聚合酶链式反应（RT-qPCR）验证证实，转录本调控存在独特的时序模式，其中包括参与心脏重构与存活信号通路的转录本，以及大量细胞因子转录本。尽管吉非替尼单独输注不会显著改变细胞因子表达，但可抵消大部分受βAR调控的细胞因子中异丙肾上腺素介导的表达变化，包括趋化因子配体2（CCL2）与肿瘤坏死因子-α（TNF-α）。此外，本研究还在分离的心肌细胞与心脏成纤维细胞中评估了βAR依赖的EGFR反式激活对细胞因子转录本表达的急性调控作用，发现大多数受异丙肾上腺素调控且对EGFR敏感的细胞因子表达变化均发生于此。总体而言，与心脏结构和收缩功能的变化相一致，βAR刺激会随时间动态改变心脏转录本表达，其中包括大量通过EGFR依赖的信号通路调控的细胞因子。