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β肾上腺素能受体（β-adrenergic receptors, βAR）刺激可通过表皮生长因子受体（epidermal growth factor receptor, EGFR）的反式激活促进生存信号通路，但长期暴露会逐渐改变心脏结构与收缩功能，其部分机制为细胞因子信号通路的增强。本研究提出假设：慢性儿茶酚胺信号通路在体内可对心脏转录组表达产生时间依赖性影响，尤其是细胞因子类转录本，且EGFR反式激活在此过程中发挥关键作用。实验中，C57BL/6小鼠分别接受溶剂、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，处理时长为1周或2周。结果显示，异丙肾上腺素处理2周后，小鼠心脏收缩功能出现下降；而在两个处理时间点均观察到心脏肥厚、纤维化与细胞凋亡程度升高。联合吉非替尼处理可在2周时维持心脏收缩功能、阻断异丙肾上腺素诱导的细胞凋亡，并阻止心脏肥厚，但单独使用吉非替尼则会引发心肌纤维化。RNA测序（RNAseq）分析显示，在每个时间点均有数百个心脏转录本受异丙肾上腺素调控；后续实时定量逆转录聚合酶链反应（RT-qPCR）验证证实了转录调控的独特时间模式，涉及心脏重构、生存信号通路以及大量细胞因子相关转录本。单独使用吉非替尼并不会显著改变细胞因子表达，但可抵消绝大多数受βAR调控的细胞因子的异丙肾上腺素介导的表达变化，包括CCL2与肿瘤坏死因子-α（TNF-α）。此外，本研究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两类细胞中。总体而言，伴随心脏结构与收缩功能的改变，βAR刺激会随时间动态调控心脏转录组表达，其中包括大量通过EGFR依赖信号通路调控的细胞因子。