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。

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.