Effect of chronic alcohol on ischemic injury and endothelial cells

描述（由申请人提供）：动物研究已经确定雌激素（E2）是一种已知的心脏保护激素，有助于在受损心脏中招募骨髓来源的内皮祖细胞/干细胞（EPC），进而参与受损组织的血管修复。我们和其他人已经表明，E2补充剂增加了卵巢切除（OVX）小鼠的乙醇消耗。然而，酒精/雌激素的相互作用是否会改变EPCs的生物学特性，或者微环境（酒精）的变化是否会与E2对EPCs介导的心肌修复的已知有益作用竞争，目前尚不清楚。我们提出的研究的前提是基于我们以下已发表的和初步的观察：a）OVX小鼠接受E2 B）在消耗乙醇的小鼠中，尽管补充了E2，但裸露的颈动脉中E2介导的再内皮化和缺血后肢中E2介导的新血管形成和血流恢复是迟钝的; c）在急性心肌梗死（AMI）的小鼠模型中，补充E2后增加的乙醇消耗以eNOS和MMP 9依赖性方式减少EPC动员和归巢到缺血组织，抑制生理和解剖组织修复并抑制新血管生成; d）在体外，乙醇剂量依赖性地减弱E2诱导的EPC和成熟内皮细胞（EC）的增殖、小管生成和存活;干扰雌激素受体的基因组和非基因组功能，并将E2介导的细胞存活信号传导转换为诱导促凋亡信号传导。因此，我们的中心假设是，增加乙醇消耗与E2介导的梗死后心肌修复的竞争，通过否定E2对EPC功能和信号的保护作用。本提案中描述的实验旨在通过测试根据以下3个具体目标分组的一系列假设来扩展这些发现：1）确定单个雌激素受体（ER）对乙醇介导的BM-EPC动员和AMI后心肌修复的抑制的作用，2）确定eNOS和MMP 9在乙醇抑制E2诱导的BM-EPC动员和AMI后心肌修复功能中的作用，3）阐明乙醇诱导的BM-EPC动员和功能中的分子信号传导。E2介导的抑制EPC中E2诱导的细胞存活信号通路。 公共卫生相关性：某些疾病，如心肌梗死（MI）是绝经后妇女死亡的主要原因。雌激素是一种已知的心脏保护激素，有助于在受损心脏中招募骨髓来源的内皮祖细胞/干细胞（EPC），用于受损组织修复。然而，雌激素治疗也会增加酒精的消耗，这可能会与雌激素对祖细胞的益处相竞争。这项提案将测试酒精消费可能掩盖雌激素的心脏保护作用的机制，特别是雌激素/酒精相互作用可能会影响实验性心脏损伤期间EPC的生物学。

DESCRIPTION (provided by applicant): Animal studies have established that estrogen (E2) is a known cardio-protective hormone that helps recruit bone-marrow derived endothelial progenitor/stem cells (EPC) in the injured heart which, in turn, participate in the vascular repair of injured tissue. We and others have shown that E2-supplementation enhances the consumption of ethanol in ovariectomized (OVX) mice. However, whether alcohol/estrogen interactions alter the biology of EPCs or whether change in the microenvironment (alcohol) competes with the known beneficial effects of E2 on EPC-mediated myocardial repair is not known. The premise of our proposed research is based on our following published and preliminary observations: a) OVX mice receiving E2 (17b-estradiol) supplementation consume significantly more ethanol compared to those receiving placebo; b) E2-mediated re-endothelialization in denuded carotid arteries and E2-mediated neo-vascularization and blood flow recovery in ischemic hind limbs is blunted in mice consuming ethanol, despite E2 supplementation; c) in a mouse model of acute myocardial infarction (AMI) increased ethanol consumption following E2-supplementation reduces EPC mobilization and homing to ischemic tissues in eNOS and MMP9 dependent manner, depresses physiological and anatomical tissue repair and represses neo-vasculogenesis; d) in vitro, ethanol dose-dependently attenuates E2-induced proliferation, tubulogenesis and survival of both EPCs and mature endothelial cells (EC); interferes with genomic and non-genomic functions of estrogen receptors and switches the E2-mediated cell survival signaling to the induction of pro-apoptotic signaling. Our central hypothesis, therefore, is that increased ethanol consumption competes with E2-mediated post-infarct myocardial repair by negating the protective effects of E2 on EPC function and signaling. The experiments described in the current proposal are designed to extend these findings by testing a series of hypotheses grouped according to the following 3 specific aims: 1) Determine the role of individual estrogen receptors (ER) on ethanol-mediated repression of BM-EPC mobilization and post-AMI myocardial repair, 2) Define the role of eNOS and MMP9 in ethanol repression of E2-induced BM-EPC mobilization and function in post-AMI myocardial repair and 3) Elucidate molecular signaling involved in the ethanol-mediated suppression of E2-induced cell survival signaling pathways in EPC. PUBLIC HEALTH RELEVANCE: Certain diseases like myocardial infarction (MI) are the major cause of mortality in post- menopausal women. Estrogen is a known cardio-protective hormone helps recruit bone-marrow derived endothelial progenitor/stem cells (EPC) in the injured heart for injured tissue repair. However, estrogen therapy also increases alcohol consumption which may compete with the benefits provided by estrogen on progenitor cells. This proposal will test mechanisms by which alcohol consumption may mask the cardio-protective effects of estrogen, specifically as estrogen/alcohol interactions may affect the biology of EPC during experimental heart injury.