Mechanisms involved in male-female differences in cardioprotection

男女心脏保护差异的机制

• 批准号: 8939767
• 负责人: Elizabeth Murphy
• 金额: $ 32.92万
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 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/8939767
• 关键词: 1-Phosphatidylinositol 3-Kinase; Acute; Animal Model; Animals; Binding; Biopsy; Biotin; Calcium; Cancer Cell Growth; Cardiomyopathies; Cardiovascular Diseases; Cardiovascular system; Cell membrane; Clinical Trials; Data; Dendrimers; Estradiol; Estrogen Nuclear Receptor; Estrogen Receptor alpha; Estrogen Receptor beta; Estrogens; Female; Gender; Genes; Goals; Growth; Heart; Heart Diseases; Heart failure; Heat shock proteins; Hormone replacement therapy; Human; Incidence; Infarction; Injury; Ischemia; Location; Maleimides; Measures; Mediating; Menopause; Methods; Mitochondria; Mitochondrial Proteins; Modeling; Mus; Nitric Oxide; Nitric Oxide Synthase; Outcome; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Phosphotransferases; Plant Resins; Play; Post-Translational Protein Processing; Postmenopause; Premenopause; Primary idiopathic dilated cardiomyopathy; Protein S; Proteins; Receptor Signaling; Recovery of Function; Reperfusion Injury; Reperfusion Therapy; Reporting; Role; Selective Estrogen Receptor Modulators; Sex Characteristics; Sex Functioning; Signal Pathway; Signal Transduction; Testing; Transcriptional Regulation; Uterine Cancer; Woman; Women' s Health; cardiovascular disorder risk; gel electrophoresis; human female; improved; male; malignant breast neoplasm; non-genomic; oxidation; response

Although gender disparities in cardiac disease are recognized, the mechanisms through which pre-menopausal females are protected have not been fully elucidated. Cardiac disease incidence in females increases post-menopause, suggesting a role for estrogen in pre-menopausal cardioprotection. However, clinical trials found no beneficial cardiovascular outcomes from hormone replacement therapy, indicating a better mechanistic understanding is needed. Thus the goal of this study is to understand the mechanism responsible for the male-female differences in ischemia-reperfusion injury and cardioprotection. Classical estrogen-induced transcription regulation is mediated by nuclear estrogen receptors (ER) ER-alpha and ER-beta. However, ER-alpha and ER-beta are also localized to the plasma membrane and can elicit effects through kinase signaling, leading to an increase in S-nitrosylation (SNO), a post-translational modification associated with cardioprotection. We hypothesized that estrogen-related cardioprotection is at least partially mediated by non-nuclear ER signaling leading to an increase in SNO. We tested this using an estrogen-dendrimer conjugate (EDC), which has been demonstrated in mice to be a non-nuclear selective ER modulator (SERM) that does not promote uterine or breast cancer growth. We treated ovariectomized C57BL/6J mice with EDC, dendrimer control, 17-beta-estradiol, or vehicle for two weeks. Isolated hearts were perfused in the Langendorff model and subjected to 30 minutes ischemia and 90 minutes reperfusion. As previously reported, estradiol-treated hearts had decreased infarct size (40.4 2.5% vs. 62.9 5.8%) and increased functional recovery (44.7 4.0% vs. 27.0 2.7%) compared to vehicle-treated hearts. Similar to estradiol, EDC decreased infarct size (40.9 3.6% vs. 63.8 4.7% total ventricle) and improved functional recovery (48.8 3.0% vs. 28.6 2.5%) compared to dendrimer control. Similar protection was seen when mice were treated with EDC for five days (42.1 4.7% vs. 63.8 6.4% infarct and 38.9 2.9% vs. 22.8 2.4% functional recovery for EDC vs. dendrimer). 2-D Difference Gel Electrophoresis showed an increase in protein SNO from hearts treated with EDC for 5 days and 2 weeks compared to dendrimer treatment. Many of the identified proteins have increased SNO in other models of cardioprotection. These results indicate that EDC is as effective as estradiol in providing cardioprotection during ischemia-reperfusion injury in mice, possibly due to increased protein SNO. They further suggest that non-nuclear ER actions play a major role in the protection afforded by estrogen. Thus, EDC and non-nuclear ER signaling pathways could be utilized clinically to provide cardiovascular benefit without promoting cancer cell growth. Dilated idiopathic cardiomyopathy (DCM) is one of the most common types of cardiomyopathy. It has been proposed that an increase in oxidative stress in heart failure leads to a decrease in nitric oxide signaling, leading to impaired nitroso-redox signaling. To test this hypothesis we investigated the occurrence of protein S-nitrosylation (SNO) and protein oxidation in biopsies from explanted DCM and non-failing donor male and female human hearts. A modified biotin switch method using DyLight-maleimide sulfhydryl-reactive fluors was used to identify the SNO proteins and a resin-assisted capture Ox-RAC was used to measure protein oxidation. We found that oxidative stress rises in DCM human biopsies in comparison with healthy donors. DyLight-maleimide gel electrophoresis showed that females have an increase in protein SNO compared with males at baseline. Interestingly many of the proteins that showed an increase in SNO in females are mitochondrial proteins. Because there are sex differences in SNO at baseline, we examined changes in SNO in heart failure as a function of sex and found sex differences in this response.

尽管人们认识到心脏病中的性别差异，但绝经前女性受到保护的机制尚未完全阐明。绝经后女性心脏病发病率增加，表明雌激素在绝经前心脏保护中发挥作用。然而，临床试验发现激素替代疗法没有有益的心血管结局，这表明需要更好的机制理解。因此，本研究的目的是了解男女在缺血再灌注损伤和心脏保护方面存在差异的机制。 经典雌激素诱导的转录调节是由核雌激素受体 (ER) ER-α 和 ER-β 介导的。然而，ER-α 和 ER-β 也定位于质膜，可以通过激酶信号传导引发效应，导致 S-亚硝基化 (SNO) 增加，这是一种与心脏保护相关的翻译后修饰。我们假设雌激素相关的心脏保护作用至少部分是由导致 SNO 增加的非核 ER 信号介导的。我们使用雌激素-树枝状大分子缀合物 (EDC) 对此进行了测试，该缀合物已在小鼠中被证明是一种非核选择性 ER 调节剂 (SERM)，不会促进子宫癌或乳腺癌的生长。我们用 EDC、树枝状聚合物对照、17-β-雌二醇或载体治疗卵巢切除的 C57BL/6J 小鼠两周。离体心脏在 Langendorff 模型中进行灌注，并进行 30 分钟缺血和 90 分钟再灌注。正如之前报道的，与载体治疗的心脏相比，雌二醇治疗的心脏梗塞面积减小（40.4±2.5% vs. 62.9±5.8%），功能恢复增加（44.7±4.0% vs. 27.0±2.7%）。与雌二醇类似，与树枝状聚合物对照相比，EDC 减少了梗塞面积（40.9±3.6% vs. 63.8±4.7%），并改善了功能恢复（48.8±3.0% vs. 28.6±2.5%）。当小鼠用 EDC 治疗五天时，也观察到了类似的保护作用（EDC 与树枝状聚合物相比，梗塞程度为 42.1±4.7% vs. 63.8±6.4%，功能恢复为 38.9±2.9% vs. 22.8±2.4%）。二维差异凝胶电泳显示，与树枝状聚合物处理相比，用 EDC 处理 5 天和 2 周的心脏的蛋白质 SNO 有所增加。许多已鉴定的蛋白质在其他心脏保护模型中增加了 SN​​O。这些结果表明，EDC 在小鼠缺血再灌注损伤期间提供与雌二醇一样有效的心脏保护作用，这可能是由于蛋白质 SNO 增加所致。他们进一步表明，非核内质网作用在雌激素提供的保护中发挥着重要作用。因此，EDC 和非核 ER 信号传导途径可在临床上用于提供心血管益处，而不促进癌细胞生长。 扩张型特发性心肌病（DCM）是最常见的心肌病类型之一。有人提出，心力衰竭时氧化应激的增加会导致一氧化氮信号传导减少，从而导致亚硝基氧化还原信号传导受损。为了检验这一假设，我们研究了外植 DCM 和非衰竭供体男性和女性人类心脏活检中蛋白质 S-亚硝基化 (SNO) 和蛋白质氧化的发生情况。使用 DyLight-马来酰亚胺硫氢基反应性荧光体的改良生物素开关方法来鉴定 SNO 蛋白质，并使用树脂辅助捕获 Ox-RAC 来测量蛋白质氧化。我们发现，与健康捐献者相比，DCM 人体活检中的氧化应激有所增加。 DyLight-马来酰亚胺凝胶电泳显示，与基线时的男性相比，女性的蛋白质 SNO 有所增加。有趣的是，许多显示女性 SNO 增加的蛋白质都是线粒体蛋白质。 由于基线时 SNO 存在性别差异，因此我们检查了心力衰竭中 SNO 随性别变化的变化，并发现这种反应存在性别差异。