From the Molecular Cardiology and Angiogenesis Laboratory, Department of Surgery, University of Connecticut School of Medicine, Farmington, CT (Pradeep, Lim, Thirunavukkarasu, Joshi, Cernuda, Maulik).
Department of Surgery, Saint Mary's Hospital, Waterbury, CT (Lim, Joshi, Palesty).
J Am Coll Surg. 2022 Aug 1;235(2):240-254. doi: 10.1097/XCS.0000000000000241. Epub 2022 Apr 21.
Our earlier studies showed that inhibiting prolyl-4-hydroxylase enzymes (PHD-1 and PHD-3) improves angiogenesis, heart function, and limb perfusion in mouse models via stabilizing hypoxia-inducible transcription factor-alpha (HIF-1α). The present study explored the effects of the prolyl-4-hydroxylase enzyme, PHD-2, on ischemic heart failure using cardiac-specific PHD-2 gene knockout (KO) mice (PHD2 -/- ).
Adult wild-type (WT) and PHD2 -/- mice, 8-12 weeks old, were subjected to myocardial infarction (MI) by irreversibly ligating the left anterior descending (LAD) coronary artery. All sham group mice underwent surgery without LAD ligation. Animals were divided into 4 groups: (1) wild-type sham (WTS); (2) wild-type myocardial infarction (WTMI); (3) PHD2KO sham (PHD2 -/- S); (4) PHD2KO myocardial infarction (PHD2 -/- MI). Left ventricular tissue samples collected at various time points after surgery were used for microRNA expression profiling, Western blotting, and immunohistochemical analysis.
Volcano plot analysis revealed 19 differentially-expressed miRNAs in the PHD2 -/- MI group compared with the WTMI group. Target analysis using Ingenuity Pathway Analysis showed several differentially regulated miRNAs targeting key signaling pathways such as Akt, VEGF, Ang-1, PTEN, apoptosis, and hypoxia pathways. Western blot analysis showed increased HIF-1α, VEGF, phospho-AKT, β-catenin expression and reduced Bax expression for the PHD2 -/- MI group compared with the WTMI group. Echocardiographic analysis showed preserved heart functions, and picrosirius red staining revealed decreased fibrosis in PHD2 -/- MI compared with the WTMI group.
PHD2 inhibition showed preserved heart function, enhanced angiogenic factor expression, and decreased apoptotic markers after MI. Overall, cardiac PHD2 gene inhibition is a promising candidate for managing cardiovascular diseases.
我们之前的研究表明，抑制脯氨酰-4-羟化酶（PHD-1 和 PHD-3）可通过稳定缺氧诱导因子-α（HIF-1α）来改善小鼠模型中的血管生成、心脏功能和肢体灌注。本研究使用心脏特异性 PHD-2 基因敲除（KO）小鼠（PHD2 -/- ）探索脯氨酰-4-羟化酶 PHD-2 对缺血性心力衰竭的影响。
成年野生型（WT）和 PHD2 -/- 小鼠（8-12 周龄）通过不可逆结扎左前降支（LAD）冠状动脉造成心肌梗死（MI）。所有假手术组小鼠仅接受手术而不结扎 LAD。动物分为 4 组：（1）野生型假手术（WTS）；（2）野生型心肌梗死（WTMI）；（3）PHD2KO 假手术（PHD2 -/- S）；（4）PHD2KO 心肌梗死（PHD2 -/- MI）。手术后不同时间点采集左心室组织样本进行 microRNA 表达谱分析、Western blot 和免疫组织化学分析。
火山图分析显示，与 WTMI 组相比，PHD2 -/- MI 组有 19 个差异表达的 miRNA。Ingenuity 通路分析的靶标分析显示，一些差异调节的 miRNA 靶向 Akt、VEGF、Ang-1、PTEN、凋亡和缺氧通路等关键信号通路。Western blot 分析显示，与 WTMI 组相比，PHD2 -/- MI 组的 HIF-1α、VEGF、磷酸化-AKT、β-连环蛋白表达增加，Bax 表达减少。超声心动图分析显示，PHD2 -/- MI 组心脏功能得到保存，picrosirius 红染色显示 PH2 -/- MI 组纤维化减少。
与 WTMI 组相比，PHD2 抑制后 MI 后心脏功能得到保存，血管生成因子表达增强，凋亡标志物减少。总之，心脏 PHD2 基因抑制是治疗心血管疾病的一种有前途的候选方法。
