Different Therapeutic Approaches forTreatment of Chronic Heart Failure

慢性心力衰竭的不同治疗方法

• 批准号: 8335936
• 负责人: Mark Talan
• 金额: $ 43.53万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8335936
• 关键词: 7,7' -dimethoxy-(4,4' -bi-1,3-benzodioxole)-5,5' -dicarboxylic acid dimethyl ester; Adrenergic Agents; Adrenergic Agonists; Adrenergic Antagonists; Adrenergic Receptor; Agonist; Angiotensin-Converting Enzyme Inhibitors; Animal Experiments; Animal Model; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Antioxidants; Apoptotic; Asthma; Attenuated; Cardiac; Cardiac Myocytes; Chronic; Collaborations; Consensus; Control Groups; Coronary; Coronary Occlusions; Coronary artery; Cyclic AMP-Dependent Protein Kinases; Data; Developed Countries; Development; Dilated Cardiomyopathy; EFRAC; Echocardiography; Effectiveness; Elderly; Engineering; Erythropoiesis; Erythropoietin; Exhibits; Experimental Designs; Experimental Models; Fenoterol; GTP-Binding Proteins; Heart failure; Hematocrit procedure; Injection of therapeutic agent; Isomerism; Left; Left Ventricular Remodeling; Ligation; Mediating; Mitogen-Activated Protein Kinases; Modality; Modeling; Morbidity - disease rate; Muscle Cells; Myocardial; Myocardial Infarction; Myocardial Ischemia; Peptides; Pertussis Toxin; Pharmaceutical Preparations; Phosphorylation; Photoaffinity Labels; Property; Proteins; Publishing; Pyroglutamate; Rattus; Receptor Activation; Receptors, Adrenergic, beta-1; Reporting; Research; Research Personnel; Rodent; Role; Saline; Series; Severities; Signal Transduction; Stereoisomer; Surface; Testing; Therapeutic; Therapeutic Effect; Time; Tissues; adrenergic; attenuation; base; beta-2 Adrenergic Receptors; beta-adrenergic receptor; comparative efficacy; drinking water; enantiomer; functional decline; improved; mortality; novel therapeutic intervention; pre-clinical; prevent; primary outcome; programs; receptor; receptor binding; receptor coupling; research study; secondary outcome; stereochemistry; success; therapeutic effectiveness; translational study

The broad objective of this program is to perform preclinical experimentation on animal models of myocardial ischemia and subsequent chronic heart failure (CHF) to elucidate the mechanisms of its development and to evaluate the potential of different therapeutic modalities to limit the extent of myocardial damage and to prevent or attenuate the development of CHF. I. Beta-2 adrenergic receptors in treatment of CHF. The role of beta-adrenergic receptors (AR) subtype signaling in development of CHF is clearly important. It is widely accepted now that beta-1 AR activation is associated with development of CHF. Recent data indicate that stimulation of beta-1 AR is proapoptotic, thus, the use of beta-1 AR antagonists became a recommended therapy for HF. The possible role of beta-2 AR agonists remains debatable; however, the consensus is that similar to beta-1 AR, activation of beta-2 AR during CHF is harmful. Recent research in LCS using single myocytes indicated that beta-2 AR agonist, fenoterol, possesses a unique cardioprotective property, and, in fact, is antiapoptotic. In several previously published studies we have reported the positive therapeutic effect of chronic treatment with combination of the beta-2 AR agonist, fenoterol and beta-1 AR blocker, metaprolol in the rat model of post MI dilated cardiomyopathy. Proposed treatment was equal to a currently standard therapy for chronic heart failure (combination of beta-1 AR blocker and ACE-inhibitor) with respect to mortality and exceeded the standard therapy with respect to cardiac remodeling. Fenoterol exists as four stereoisomers. II. Combination of two of enantiomers, RR and SS are a racemic mixture, which represents an actual drug that had been used clinically for treatment of asthma and for our experiments cited above. In order to refine the therapeutic effectiveness of fenoterol in the CHF model researchers in LCS in collaboration with BDD, NIA (Dr. Wainer) have synthesized a series of stereoisomers of fenoterol and its derivatives and characterized their receptor binding and pharmacological properties. The hypothesis had been tested that the stereochemistry of an agonist determines selectivity of receptor coupling to different G protein(s). The R,R-isomers of fenoterol and methoxyfenoterol exhibited more potent effects to increase cardiomyocyte contraction than their S,R-isomers. Importantly, while R,R-fenoterol and R,R-methoxyfenoterol preferentially activate Gs signaling, their S,R-isomers were able to activate both Gs and Gi proteins as evidenced by the robust pertussis toxin-sensitivities of their effects on cardiomyocyte contraction and on phosphorylation of extracellular signal-regulated kinase 1/2. The differential G protein selectivities of the fenoterol stereoisomers were further confirmed by photoaffinity labeling studies on Gs, Gi2 and Gi3 proteins. The inefficient Gi signaling with the R,R-isomers is not caused by the inability of the R,R-isomers to trigger the PKA-mediated phosphorylation of the beta2-AR, since the R,R-isomers also markedly increased phosphorylation of the receptor at serine262 by PKA. It also has been reported that in experiments in isolated rat cardiomyocytes the R-enantiomer of fenoterol exhibits more potent effects on cardiomyocyte contractility and better Gs protein selectivity than other stereoisomers, and had been proposed as a promising new drug. We used the rat experimental model of post MI DCM to compare the efficacy of the R- and L-enantiomers of fenoterol with its racemic mixture, whose efficacy had been demonstrated in our previous experiments. Racemic mixture of fenoterol (F) and one of its enantiomers, right (RF) or left (LF) were given to rats in drinking water as described above, starting 2 weeks after induction of MI. The LV remodeling and function were assessed during the next 5 months via serial echocardiograaphy. All the effects of fenoterol described above, attenuation of LV remodeling and functional decline and arrest of MI expansion were replicated in the present experiment, including the loss of effectiveness after 3 months as a monotherapy. Both groups treated with right or left enantiomers of fenoterol were undistinguishable from the untreated group. Thus, the therapeutic potential of the R-enantiomer of fenoterolreported on the basis of experiment on single cardiomyocyte level was not confirmed in our whole animal experiments. III. Non-erythropoietic derivatives of Erythropoietin. A pyroglutamate helix B surface peptide (pHBP) had been engineered on the basis of erythropoietin molecule to effect tissue protection without erythropoiesis. In experiments in the rat model of MI induced by a permanent ligation of a coronary artery we demonstrated strong cardioprotective effect of pHBP. Taking advantage of the fact that multiple injections of pHBP do not result in the elevation of hematocrit, we tested the idea that repeated injections of pHBP can attenuate the post MI LV remodeling. Experiment was conducted using our usual experimental design: Two weeks after coronary ligation early remodeling was evaluated by echocardiography and rats divided into experimental and control groups of similar average MI size. pHBP (60 g/kg) or saline (1 mL/kg) were injected twice a week for 6 weeks. Reduction of ejection fraction and expansion of MI size observed in control rats were arrested in pHBP treated animals. Since relatively short-term treatment with pHBP showed beneficial effects on post-MI LV remodeling in the rat model of permanent coronary occlusion. We initiated a year-long experiment injecting post-MI rats twice a week with 60 g of pHBP. Progression of LV remodeling, LV function and MI expansion is assessed via serial echocardiography. Primary outcome of treatment is mortality. Secondary outcome is a cardiac remodeling. At the time of composing this report the experiment is half-way through and preliminary results are very encouraging survival of pHBP treated rats was significantly improved in comparison with untreated animals.

该项目的主要目标是在心肌缺血和随后的慢性心力衰竭（CHF）动物模型上进行临床前实验，以阐明其发展机制，并评估不同治疗方式限制心肌损伤程度和预防或减弱 CHF 发展的潜力。 I. Beta-2 肾上腺素受体治疗 CHF​​。 β-肾上腺素能受体 (AR) 亚型信号传导在 CHF 发展中的作用显然很重要。现在人们普遍认为 beta-1 AR 激活与 CHF 的发生有关。最近的数据表明，刺激 beta-1 AR 可以促进细胞凋亡，因此，使用 beta-1 AR 拮抗剂成为心力衰竭的推荐治疗方法。 beta-2 AR 激动剂的可能作用仍存在争议。然而，一致认为与 beta-1 AR 类似，CHF 期间 beta-2 AR 的激活是有害的。最近使用单肌细胞进行 LCS 的研究表明，β-2 AR 激动剂非诺特罗具有独特的心脏保护特性，而且实际上具有抗细胞凋亡作用。 在之前发表的几项研究中，我们报道了联合使用 β-2 AR 激动剂非诺特罗和 β-1 AR 阻滞剂美普洛尔进行长期治疗对 MI 后扩张型心肌病大鼠模型的积极治疗效果。就死亡率而言，拟议的治疗方法相当于目前慢性心力衰竭的标准疗法（β1 AR 阻滞剂和 ACE 抑制剂的组合），而在心脏重塑方面则超过了标准疗法。 非诺特罗以四种立体异构体存在。 二.两种对映体 RR 和 SS 的组合是外消旋混合物，它代表了临床上用于治疗哮喘和我们上面引用的实验的实际药物。 为了完善非诺特罗在 CHF 模型中的治疗效果，LCS 的研究人员与 BDD 合作，合成了一系列非诺特罗及其衍生物的立体异构体，并表征了它们的受体结合和药理学特性。已经测试了激动剂的立体化学决定受体与不同 G 蛋白偶联的选择性的假设。非诺特罗和甲氧基非诺特罗的 R,R-异构体比其 S,R-异构体表现出更有效的增强心肌细胞收缩的作用。重要的是，虽然 R,R-非诺特罗和 R,R-甲氧基非诺特罗优先激活 Gs 信号传导，但它们的 S,R-异构体能够激活 Gs 和 Gi 蛋白，如它们对心肌细胞收缩和细胞外信号调节激酶 1/2 磷酸化的强大百日咳毒素敏感性所证明的那样。通过对 Gs、Gi2 和 Gi3 蛋白的光亲和标记研究进一步证实了非诺特罗立体异构体的差异 G 蛋白选择性。 R,R-异构体的低效Gi信号传导并不是由于R,R-异构体无法触发PKA介导的β2-AR磷酸化引起的，因为R,R-异构体还显着增加了PKA对受体丝氨酸262的磷酸化。据报道，在离体大鼠心肌细胞实验中，非诺特罗的R-对映异构体比其他立体异构体对心肌细胞收缩力表现出更有效的作用和更好的Gs蛋白选择性，并被提议作为一种有前途的新药。 我们使用MI后DCM的大鼠实验模型来比较非诺特罗的R-和L-对映体与其外消旋混合物的功效，其功效已在我们之前的实验中得到证实。在诱导 MI 后 2 周开始，如上所述，将非诺特罗 (F) 及其一种对映体右旋 (RF) 或左旋 (LF) 的外消旋混合物置于饮用水中给予大鼠。在接下来的 5 个月内，通过系列超声心动图评估左室重塑和功能。上述非诺特罗的所有作用、左室重构的减弱和功能下降以及心肌梗塞扩张的阻止在本实验中均得到了重复，包括作为单一疗法 3 个月后有效性的丧失。用非诺特罗右对映体或左对映体治疗的两组与未治疗组没有区别。因此，基于单心肌细胞水平的实验报告的非诺特罗R-对映体的治疗潜力在我们的整个动物实验中并未得到证实。 三．促红细胞生成素的非促红细胞生成衍生物。 在促红细胞生成素分子的基础上设计了焦谷氨酸螺旋 B 表面肽 (pHBP)，可在不产生红细胞生成的情况下实现组织保护。在由冠状动脉永久结扎诱导的心肌梗死大鼠模型的实验中，我们证明了 pHBP 具有强大的心脏保护作用。利用多次注射 pHBP 不会导致血细胞比容升高的事实，我们测试了重复注射 pHBP 可以减弱 MI 后左心室重塑的想法。实验采用我们通常的实验设计进行：冠状动脉结扎两周后，通过超声心动图评估早期重构，并将大鼠分为平均心肌梗死大小相似的实验组和对照组。 pHBP (60 g/kg) 或盐水 (1 mL/kg) 每周注射两次，持续 6 周。在对照大鼠中观察到的射血分数降低和 MI 大小扩大在 pHBP 处理的动物中被抑制。 因为在永久性冠状动脉闭塞的大鼠模型中，相对短期的 pHBP 治疗显示出对 MI 后左心室重塑的有益作用。我们发起了一项为期一年的实验，每周两次向 MI 后大鼠注射 60 克 pHBP。通过连续超声心动图评估左室重构、左室功能和心肌梗死扩张的进展。治疗的主要结果是死亡率。次要结果是心脏重塑。在撰写本报告时，实验已完成一半，初步结果非常令人鼓舞，与未治疗的动物相比，经过 pHBP 治疗的大鼠的存活率显着提高。