Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
Department of Cardiology and Angiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
J Mol Med (Berl). 2019 Oct;97(10):1427-1438. doi: 10.1007/s00109-019-01817-6. Epub 2019 Jul 23.
Alveolar and myocardial hypoxia may be causes or sequelae of pulmonary hypertension (PH) and heart failure. We hypothesized that hypoxia initiates specific epigenetic and transcriptional, pro-inflammatory programs in the right ventricle (RV) and left ventricle (LV). We performed an expression screen of 750 miRNAs by qPCR arrays in the murine RV and LV in normoxia (Nx) and hypoxia (Hx; 10% O for 18 h, 48 h, and 5d). Additional validation included single qPCR analysis of miRNA and pro-inflammatory transcripts in murine and human RV/LV, and neonatal rat cardiomyocytes (NRCMs). Differential qPCR-analysis (Hx vs. Nx in RV, Hx vs. Nx in LV, and RV vs. LV in Hx) identified nine hypoxia-regulated miRNAs: let-7e-5p, miR-29c-3p, miR-127-3p, miR-130a-3p, miR-146b-5p, miR-197-3p, miR-214-3p, miR-223-3p, and miR-451. Hypoxia downregulated miR-146b in the RV (p < 0.01) and, less so, in the LV (trend; p = 0.28). In silico alignment showed significant binding affinity of miR-146b-5p sequence with the 3'UTR of TRAF6 known to be upstream of pro-inflammatory NF-kB. Consistently, hypoxia induced TRAF6, IL-6, CCL2(MCP-1) in the mouse RV and LV. Incubating neonatal rat cardiomyocytes with pre-miR-146b led to a downregulation of TRAF6, IL-6, and CCL2(MCP-1). TRAF6 mRNA expression was also increased by 3-fold in the RV and LV of end-stage idiopathic pulmonary arterial hypertension (PAH) patients vs. non-PAH controls. We identified hypoxia-regulated, ventricle-specific miRNA expression profiles in the adult mouse heart in vivo. Hypoxia suppresses miR-146b, thus de-repressing TRAF6, and inducing pro-inflammatory IL-6 and CCL2(MCP-1). This novel hypoxia-induced miR-146b-TRAF6-IL-6/CCL2(MCP-1) axis likely drives cardiac fibrosis and dysfunction, and may lead to heart failure. KEY MESSAGES: Chouvarine P, Legchenko E, Geldner J, Riehle C, Hansmann G. Hypoxia drives cardiac miRNAs and inflammation in the right and left ventricle. • Hypoxia drives ventricle-specific miRNA profiles, regulating cardiac inflammation. • miR-146b-5p downregulates TRAF6, known to act upstream of pro-inflammatory NF-κB. • Hypoxia downregulates miR-146b and induces TRAF6, IL-6, CCL2 (MCP-1) in the murine RV and LV. • The inhibitory regulatory effects of miR-146b are confirmed in primary rat cardiomyocytes (pre-miR, anti-miR) and human explant heart tissue (endstage pulmonary arterial hypertension). • A novel miR-146b-TRAF6-IL-6/CCL2(MCP-1) axis likely drives cardiac inflammation, fibrosis and ventricular dysfunction.
肺泡和心肌缺氧可能是肺动脉高压 (PH) 和心力衰竭的原因或后果。我们假设缺氧会在右心室 (RV) 和左心室 (LV) 中引发特定的表观遗传和转录、促炎程序。我们通过 qPCR 阵列对正常氧 (Nx) 和缺氧 (Hx; 18 小时、48 小时和 5 天 10% O2) 条件下的小鼠 RV 和 LV 中的 750 个 miRNA 进行了表达筛选。额外的验证包括对小鼠和人类 RV/LV 以及新生大鼠心肌细胞 (NRCMs) 的 miRNA 和促炎转录物的单个 qPCR 分析。差异 qPCR 分析 (RV 中的 Hx 与 Nx，LV 中的 Hx 与 Nx，以及 Hx 中的 RV 与 LV) 确定了 9 个受缺氧调节的 miRNA：let-7e-5p、miR-29c-3p、miR-127-3p、miR-130a-3p、miR-146b-5p、miR-197-3p、miR-214-3p、miR-223-3p 和 miR-451。缺氧下调了 RV 中的 miR-146b (p < 0.01)，在 LV 中下调程度较小 (趋势;p = 0.28)。计算机分析表明，miR-146b-5p 序列与 TRAF6 的 3'UTR 具有显著的结合亲和力，而 TRAF6 是促炎 NF-kB 的上游。一致地，缺氧诱导了小鼠 RV 和 LV 中的 TRAF6、IL-6 和 CCL2(MCP-1)。用 pre-miR-146b 孵育新生大鼠心肌细胞导致 TRAF6、IL-6 和 CCL2(MCP-1)下调。TRAF6 mRNA 表达在特发性肺动脉高压 (PAH) 患者与非 PAH 对照的 RV 和 LV 中也增加了 3 倍。我们在体内鉴定了成年小鼠心脏中受缺氧调节的心室特异性 miRNA 表达谱。缺氧抑制 miR-146b，从而解除 TRAF6 的抑制，并诱导促炎的 IL-6 和 CCL2(MCP-1)。这种新的缺氧诱导的 miR-146b-TRAF6-IL-6/CCL2(MCP-1)轴可能导致心脏纤维化和功能障碍，并可能导致心力衰竭。关键信息：Chouvarine P、Legchenko E、Geldner J、Riehle C、Hansmann G. 缺氧驱动右心室和左心室的心脏 miRNAs 和炎症。 • 缺氧驱动心室特异性 miRNA 谱，调节心脏炎症。 • miR-146b-5p 下调 TRAF6，已知 TRAF6 在前炎症 NF-κB 上游起作用。 • 缺氧下调 miR-146b 并诱导小鼠 RV 和 LV 中的 TRAF6、IL-6、CCL2 (MCP-1)。 • 在原代大鼠心肌细胞 (pre-miR、anti-miR) 和人离体心脏组织 (终末期肺动脉高压) 中证实了 miR-146b 的抑制调节作用。 • 一种新的 miR-146b-TRAF6-IL-6/CCL2(MCP-1) 轴可能驱动心脏炎症、纤维化和心室功能障碍。
