1 Veterans Affairs San Diego Healthcare System, San Diego, California; RWTH Aachen, Aachen, Germany.
2 Department of Medicine, University of California San Diego, San Diego, California; RWTH Aachen, Aachen, Germany.
Hum Gene Ther. 2019 Jan;30(1):10-20. doi: 10.1089/hum.2018.103. Epub 2018 Oct 2.
Peptide infusions of peptides the corticotropin releasing factor family, including urocortin 2, stresscopin, and urocortin 3 (UCn3), have favorable acute effects in clinical heart failure (HF), but their short half-lives make them unsuitable for chronic therapy. This study asked whether UCn3 gene transfer, which provides sustained elevation of plasma UCn3 levels, increases the function of the failing heart. HF was induced by transmural left ventricular (LV) cryoinjury in mice. LV function was assessed 3 weeks later by echocardiography. Those with ejection fractions (EF) <40% received intravenous saline or intravenous adeno-associated virus type-8 encoding murine UCn3 (AAV8.mUCn3; 1.9 × 10 genome copies/kg). Five weeks after randomization, repeat echocardiography, assessment of LV function (+dP/dt, -dP/dt), and quantification of Ca transients and sarcomere shortening in isolated cardiac myocytes were conducted, and assessment of LV Ca handling and stress proteins was performed. Three weeks after myocardial infarction, prior to treatment, EFs were reduced (mean 31%, from 63% in sham-operated animals). Mice randomized to receive UCn3 gene transfer showed increased plasma UCn3 (from 0.1 ± 0.01 ng/mL in the saline group to 5.6 ± 1.1 ng/mL; n = 12 each group; p < 0.0001). Compared to mice that received saline, UCn3 gene transfer was associated with higher values for EF (p = 0.0006); LV +dP/dt (p < 0.0001), and LV -dP/dt (p < 0.0001). Cardiac myocytes from mice that received UCn3 gene transfer showed higher peak Ca transients (p = 0.0005), lower time constant of cytosolic Ca decline (tau, p < 0.0001), and higher rates of sarcomere shortening (+dL/dt, p = 0.03) and lengthening (-dL/dt, p = 0.04). LV samples from mice that received UCn3 gene transfer contained higher levels of SERCA2a (p = 0.0004 vs. HF) and increased amounts of phosphorylated troponin I (p = 0.04 vs. HF). UCn3 gene transfer is associated with improved Ca handling and LV function in mice with HF and reduced EF.
肽类物质家族中的促肾上腺皮质激素释放因子，包括 Ucn3 等，在临床心力衰竭（HF）中有良好的急性作用，但半衰期短，不适合慢性治疗。本研究旨在探讨 Ucn3 基因转移是否能增加衰竭心脏的功能，因为 Ucn3 基因转移可以持续升高血浆 Ucn3 水平。通过透壁性左心室（LV）冷冻损伤诱导 HF 模型，3 周后行超声心动图评估 LV 功能，EF<40%的小鼠给予静脉注射生理盐水或腺相关病毒 8 型编码的小鼠 Ucn3（AAV8.mUCn3；1.9×10 基因组拷贝/千克）。随机分组 5 周后，重复行超声心动图、LV 功能（+dP/dt、-dP/dt）评估、分离心肌细胞的 Ca 瞬变和肌节缩短定量分析，以及 LV Ca 处理和应激蛋白评估。心肌梗死后 3 周，在治疗前，EF 降低（平均 31%，来自于假手术组的 63%）。给予 Ucn3 基因转移的小鼠，血浆 Ucn3 水平升高（从生理盐水组的 0.1±0.01ng/mL 升高至 5.6±1.1ng/mL；每组各 12 只；p<0.0001）。与接受生理盐水的小鼠相比，Ucn3 基因转移与更高的 EF 值相关（p=0.0006）；LV +dP/dt（p<0.0001）和 LV -dP/dt（p<0.0001）。接受 Ucn3 基因转移的小鼠心肌细胞的 Ca 峰瞬变更高（p=0.0005），胞浆 Ca 下降的时标（tau）更低（p<0.0001），肌节缩短（+dL/dt）和延长（-dL/dt）速度更快（p=0.03 和 p=0.04）。接受 Ucn3 基因转移的 LV 样本中 SERCA2a 水平更高（p=0.0004 与 HF 相比），磷酸化肌钙蛋白 I 含量增加（p=0.04 与 HF 相比）。Ucn3 基因转移与 HF 合并 EF 降低的小鼠的 Ca 处理和 LV 功能改善相关。
