Effect of chronic alcohol on ischemic injury and endothelial cells

描述（由申请人提供）：动物研究已经证实，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），进而参与损伤组织的血管修复。我们和其他人已经证明，补充e2增加了卵巢切除（OVX）小鼠对乙醇的消耗。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相竞争，目前尚不清楚。我们提出的研究的前提是基于以下已发表的和初步的观察结果：a)与接受安慰剂的小鼠相比，接受E2 （17b-雌二醇）补充剂的OVX小鼠消耗的乙醇明显更多；b)尽管补充了E2，但在摄入乙醇的小鼠中，E2介导的脱脱颈动脉再内皮化和E2介导的缺血后肢新血管形成和血流恢复均被减弱；c)在小鼠急性心肌梗死（AMI）模型中，补充e2后乙醇消耗量增加，减少EPC动员和eNOS和MMP9依赖的缺血组织归巢，抑制生理和解剖组织修复，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EPCs和成熟内皮细胞（EC）的增殖、小管形成和存活；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转换为诱导促凋亡信号。因此，我们的中心假设是，增加的乙醇消耗通过否定E2对EPC功能和信号传导的保护作用，与E2介导的梗死后心肌修复相竞争。当前提案中描述的实验旨在通过根据以下3个具体目标测试一系列假设来扩展这些发现：1)确定个体雌激素受体（ER）在乙醇介导的BM-EPC动员抑制和ami后心肌修复中的作用；2)明确eNOS和MMP9在乙醇抑制e2诱导的BM-EPC动员和ami后心肌修复中的作用；3)阐明乙醇介导的e2诱导的EPC细胞存活信号通路中参与的分子信号。

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.