HB-EGF Therapy for Necrotizing Entercolitis

HB-EGF 治疗坏死性小肠结肠炎

• 批准号: 7474014
• 负责人: GAIL E BESNER
• 金额: $ 28.93万
• 依托单位: RESEARCH INST NATIONWIDE CHILDREN'S HOSP
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7474014
• 关键词: Actins; Acute; Adhesions; Affect; Anti-Inflammatory Agents; Bacterial Translocation; Biological Preservation; Cause of Death; Cells; Chemicals; Clinical; Clinical Protocols; Complex; Development; Dextrans; Disease; E-Cadherin; EGF gene; Electrical Resistance; End Point; Enteral; Enterocolitis; Epithelial Cells; Evaluation; Exposure to; Family; Fiber; Focal Adhesions; Gastrointestinal Diseases; Goals; Hand; Hemorrhagic Shock; Histologic; Histology; Hour; Human; Hypoxia; Immunohistochemistry; In Vitro; Infiltration; Injury; Integrins; Intestinal Mucosa; Intestines; Ischemic Bowel Disease; Knock-out; Knockout Mice; Label; Lead; Left; Lesion; Measures; Mediator of activation protein; Modeling; Molecular; Morbidity - disease rate; Mucous Membrane; Mus; Myosin ATPase; Necrotizing Enterocolitis; Neonatal; Newborn Infant; Nitrogen; PTK2 gene; Permeability; Predisposition; Premature Infant; Process; Production; Proteins; Public Health; Pulmonary Valve Insufficiency; Rattus; Reperfusion Injury; Research; Research Personnel; Resistance; Resuscitation; Reverse Transcriptase Polymerase Chain Reaction; Role; Small Interfering RNA; Specimen; Testing; Therapeutic; Time; Tissues; Transgenic Mice; Transgenic Organisms; Treatment Protocols; Western Blotting; Work; Wound Healing; absorption; base; day; dextran; feeding; fluorescein isothiocyanate dextran; free radical oxygen; gain of function; heparin-binding EGF-like growth factor; in vivo; inhibitor/antagonist; injured; loss of function; mRNA Expression; macrophage; member; migration; mortality; mouse model; natural hypothermia; neonate; neutrophil; novel strategies; paxillin; prevent; programs; pup; receptor; rho

DESCRIPTION (provided by applicant): Necrotizing enterocolitis (NEC) is the most common gastrointestinal disease of newborns, and is anticipated to replace pulmonary insufficiency as the leading cause of death in premature babies. We have accumulated multiple lines of evidence supporting a role for heparin-binding EGF-like growth factor (HB-EGF) in protection of the intestines from injury via preservation of the intestinal mucosa. The long term goal of our work is based on the premise that protection of the intestinal mucosa from injury represents a logical target for the development of novel strategies to prevent the disease, and involves the clinical administration of HB- EGF, both therapeutically and prophylactically, to protect neonates from NEC. Recently, we have shown that HB-EGF decreases histologic injury and mortality in a rat model of NEC whereby rat pups are exposed to repeated cycles of hypoxia/hypothermia, hypertonic feedings and exposure to LPS (HHHTF+LPS), leading to intestinal lesions indistinguishable from those of human NEC. Our central hypothesis is that tissues afflicted with NEC have a local deficiency of HB-EGF which leaves a portion of the intestine susceptible to injury, and that administration of exogenous HB-EGF protects the intestine from injury via promotion of intestinal restitution, thereby preserving intestinal permeability. Towards our goal, we have proposed three specific aims that will allow a better understanding of the mechanistic basis of HB-EGF function in injured intestine, as a prerequisite to developing therapeutic clinical protocols: Aim [1] To test the hypothesis that HB-EGF gain-of-function will lead to resistance to NEC whereas HB-EGF loss-of-function will lead to increased susceptibility to NEC. We will subject neonatal HB-EGF transgenic and knockout mice to experimental NEC by exposing them to HHHTF, with evaluation of gut barrier function by systemic absorption of enteral FICT- dextran, Ussing chamber ex vivo studies and determination of bacterial translocation; intestinal histology; and mortality. Aim [2] To test the hypothesis that HB-EGF protects the intestine in vivo by inducing mediators of intestinal restitution during HHHTF-induced NEC. The mouse model of NEC will be used in HB- EGF TG, HB-EGF KO and WT mice, with measured endpoints including mRNA expression and protein production of mediators of restitution (integrins, FAK, paxillin, Rho). Ex vivo Ussing chamber studies will also be performed to further examine the mechanisms by which HB-EGF promotes intestinal restitution. Aim [3] To test the hypothesis that HB-EGF promotes restitution by affecting epithelial cell-matrix interactions. The in vitro scrape-wounding model of restitution will be utilized to examine the molecular mechanisms utilized by HB-EGF to promote restitution. The relevance of this research to public health is that it will provide a better understanding of the mechanisms utilized by HB-EGF in protection of the intestines from NEC, as a prerequisite for the development of HB-EGF-based therapeutic regimens.

描述（由申请人提供）：坏死性小肠结肠炎（NEC）是新生儿最常见的胃肠道疾病，预计将取代肺功能不全成为早产儿死亡的主要原因。我们已经积累了多种证据，支持肝素结合 EGF 样生长因子 (HB-EGF) 通过保护肠粘膜来保护肠道免受损伤。我们工作的长期目标是基于以下前提：保护肠粘膜免受损伤是制定预防该疾病的新策略的合理目标，并涉及 HB-EGF 的临床施用，无论是治疗性还是预防性，以保护新生儿免受 NEC。最近，我们发现 HB-EGF 可降低 NEC 大鼠模型的组织学损伤和死亡率，在该模型中，幼鼠暴露于缺氧/低温、高渗喂养和暴露于 LPS (HHHTF+LPS) 的重复循环中，导致与人类 NEC 难以区分的肠道损伤。我们的中心假设是，患有 NEC 的组织局部存在 HB-EGF 缺乏，这使得肠道的一部分容易受到损伤，而外源性 HB-EGF 的施用可以通过促进肠道恢复来保护肠道免受损伤，从而保持肠道通透性。为了实现我们的目标，我们提出了三个具体目标，这将有助于更好地了解 HB-EGF 在受损肠道中的功能机制基础，作为制定治疗临床方案的先决条件： 目标 [1] 检验 HB-EGF 功能获得将导致对 NEC 耐药而 HB-EGF 功能丧失将导致对 NEC 易感性增加的假设。我们将对新生 HB-EGF 转基因和基因敲除小鼠进行 NEC 实验，将其暴露于 HHHTF，通过肠内 FICT-葡聚糖的全身吸收来评估肠道屏障功能，使用室离体研究和细菌易位的测定；肠道组织学；和死亡率。目的 [2] 检验 HB-EGF 在 HHHTF 诱导的 NEC 过程中通过诱导肠道恢复介质来保护体内肠道的假设。 NEC的小鼠模型将用于HB-EGF TG、HB-EGF KO和WT小鼠，测量的终点包括恢复介质（整合素、FAK、桩蛋白、Rho）的mRNA表达和蛋白质产生。还将进行离体使用室研究，以进一步检查 HB-EGF 促进肠道恢复的机制。目的 [3] 检验 HB-EGF 通过影响上皮细胞-基质相互作用促进恢复的假设。体外刮伤恢复模型将用于检查 HB-EGF 促进恢复的分子机制。这项研究与公共卫生的相关性在于，它将提供对 HB-EGF 保护肠道免受 NEC 侵害的机制的更好理解，这是开发基于 HB-EGF 的治疗方案的先决条件。