Microvascular Dysfunction: Impact Ischemia-Reperfusion Vascular Cell Interaction

微血管功能障碍：影响缺血再灌注血管细胞相互作用

• 批准号: 7918618
• 负责人: RONALD JOHN KORTHUIS
• 金额: $ 36.22万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-22 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7918618
• 关键词: Address; Adherence; Adhesions; Adhesives; Angiotensin II; Angiotensins; Animal Model; Animals; Arteries; Blood Vessels; Blood flow; Brain; Caliber; Cause of Death; Cell Adhesion Molecules; Cell Communication; Cell Degranulation; Cells; Chymase; Coupling; Development; Dilator; Emigrations; Endothelial Cells; Endothelium; Event; Extracellular Matrix; Functional disorder; Gelatinase B; Generations; Goals; Heart; Integrins; Intestines; Ischemia; Ischemic Bowel Disease; Kidney; Leukocyte Rolling; Leukocytes; Link; Lymph; Mediating; Microscopic; Modeling; Molecular; Mus; Oxidants; Oxidases; Pathogenesis; Pathway interactions; Peptide Hydrolases; Play; Production; Rattus; Reaction; Reactive Oxygen Species; Reagent; Reperfusion Therapy; Role; Signal Transduction; Site; Source; Superoxides; Tissues; Transgenic Animals; Vascular blood supply; Vasodilation; Work; arteriole; design; disability; interstitial; knockout gene; mast cell; neutrophil; novel; novel therapeutic intervention; postcapillary venule; prevent; response

Ischemia/reperfusion (I/R) induces leukoeyte/endothelial cell adhesive interactions (LECA) in postcapillary venules and impaired endothelium-dependent, NO-mediated vasodllatory responses (EDD) in upstream arterioles. Even though leukocytes do not roll along, adhere to, or emigrate across arteriolar endothelium in postischemic intestine, recent work indicates that l/R-induced venular LECA is causally linked to EDD in arterioles. However, the mechanisms coupling l/R-induced postcapillary venular LECA and EDD in upstream arterioles are unknown. Our overall hypothesis is that l/R-induced EDD in arterioles occurs by a mechanism that is triggered by LECA in postcapillary venules and involves the formation of signals in the interstitium elicited by the proteolytic activity of emigrated leukocytes which exposes matricryptic sites in the extracellular matrix (ECM) that interact with the integrin avp3 to induce mast cell-dependent formation of angiotensin II (Ang II). Subsequent activation of NAD(P)H oxidase promotes eNOS uncoupling in the vascular wall and leads to the formation of oxidants which inactivate NO, resulting in arteriolar EDD. Our Specific Aims are to determine: Aim A) whether venular LECA play an obligatory role in the development of EDD in upstream arterioles; Aim B) the contribution of leukocyte-derived proteases to the development of arteriolar EDD; Aim C) the role of avp3 integrin in initiating chymase-dependent formafion of Ang II; and Aim D) the role of Ang ll-dependent, NAD(P)H oxidase- and uncoupled eNOS-mediated oxidant production in arteriolar EDD. Intravital microscopic approaches will be used to examine arteriolar EDD, venular LECA, and mast cell responses to I/R. Arterioles will be isolated from non-ischemic intesfine and exposed to posfischemic lymph, as a means to examine interstitial signals that are generated by the proteolytic acfivity of extravasated leukocytes. A novel three-dimensional ECM model engrafted with isolated cannulated arterioles and seeded with mast cells in the presence and absence of neutrophils will also be used to to further explore our hypothesis. Isolated arterioles obtained from a number of gene knockout and transgenic animal models will be used to further explore the mechanisms of arteriolar EDD. Collectively, these aims address a novel mechanism to explain the profound disturbance in arteriolar vasoregulatory funcfion in postischemic tissues. Significance: This work will identify new links between LECA in postcapillary venules, signals generated in the interstitium by emigrated leukocytes, and EDD in arterioles. Given the importance of the endothelium in regulating vascular tone, these fundamentally important findings have enormous implications for our understanding of blood flow dysregulation in conditions characterized by I/R.

缺血/再灌注（I/R）诱导白细胞/内皮细胞粘合剂相互作用（LECA） 上游的静脉和内皮依赖性，无介导的血管结构反应（EDD） 小动脉。即使白细胞不会沿着动脉内皮沿着动脉内皮移民或移民 牙齿后肠，最近的工作表明L/R诱导的静脉LECA与EDD有因果关系 小动脉。但是，在上游中耦合l/r诱导的后毛细血管静脉LECA和EDD的机制 小动脉是未知的。我们的总体假设是，A动脉中L/R诱导的EDD是由A发生的 LECA在后毛细血管上触发的机制，涉及在信号中形成 由迁移的白细胞的蛋白水解活性引起的间质，该白细胞暴露了母系位点 与整合素AVP3相互作用以诱导肥大细胞依赖性形成的细胞外基质（ECM） 血管紧张素II（ANG II）。随后的NAD（P）H氧化酶的激活促进了在eNOS中的解偶联 血管壁并导致氧化剂的形成，这些氧化剂会使NO失活，从而导致小动脉EDD。我们的 具体目的是确定：目标a）静脉LECA在发展中是否起着强制性的作用 EDD在上游动脉中；目标b）白细胞衍生的蛋白酶对发展的贡献 小动脉EDD;目标c）AVP3整联蛋白在启动Chymase依赖性形式II中的作用；和目标 d）ANG LL依赖性，NAD（P）H氧化酶和未偶联的eNOS介导的氧化剂在中的作用 小动脉EDD。插入式微观方法将用于检查小动脉EDD，Venular Leca， 和肥大细胞对I/R的响应。小动脉将从非缺血性直肠分离，并暴露于 Posfischemic淋巴，作为检查由蛋白水解产生的间隙信号的一种手段 奢侈的白细胞。一种新型的三维ECM模型，该模型植入了孤立的插管 在存在和不存在嗜中性粒细胞的情况下，小动脉并用肥大细胞接种，也将用于进一步探索我们的假设。从许多基因敲除和转基因动物模型获得的分离小动脉将用于进一步探索小动脉EDD的机理。总的来说，这些目的介绍了一种新的机制，以解释缺血后组织中动脉血管调节功能的深刻干扰。意义：这项工作将确定后毛细血管静脉静脉内的LECA之间的新联系，由移民白细胞在间质中产生的信号和小动脉中的EDD。鉴于内皮在调节血管张力方面的重要性，这些根本重要的发现具有巨大 我们对以I/R为特征的条件下对血流失调的理解的影响。