A Novel Cytoprotective Peptide for GI Epithelial Cell

一种新型胃肠道上皮细胞细胞保护肽

• 批准号: 6881136
• 负责人: FREDERICK Gary TOBACK
• 金额: $ 15.25万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881136
• 关键词: Pseudomonas aeruginosa; actins; confocal scanning microscopy; cytoprotection; gastrointestinal agents; gastrointestinal epithelium; gastrointestinal infection; heat shock proteins; inflammatory bowel diseases; laboratory mouse; nonhuman therapy evaluation; peptides; protein structure function; septicemia; tight junctions; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Disruption of intestinal barrier function may be a common pathogenetic mechanism that mediates morbidity and mortality in subjects with inflammatory bowel disease (IBD) and gut-derived sepsis (GDS). If so, a therapeutic strategy that protects mucosal barrier function and structure by increasing accumulation of tight and adhesion junction proteins that connect mucosal epithelial cells could be used to treat these conditions. We recently characterized a novel 18-kDa protein called AMP-18, that is synthesized in epithelial cells of the gastric antrum mucosa of humans and 6 other mammals, and has mitogenic and motogenic properties. A 21-mer peptide derived from the central domain of the protein was found to be cytoprotective in human colonic epithelial cell (Caco-2/bbe) cultures subjected to injury by an oxidant, indomethacin, or dextran sulfate sodium (DSS) used to induce colitis in mice, Studies in cell culture indicate that this AMP peptide activates p38 MAP kinase, increases accumulation of specific tight junction proteins (occludin, ZO-1, claudin-5), an adherens junction protein (E-cadherin), and heat shock proteins (hsp25, hsp72), and protects the actin microfilament network in cells exposed to cytochalasin D. When given to mice, AMP peptide increases the content of hyperphosphorylated occludin in the colonic mucosa. To determine if these biological effects of AMP peptide confer colonic cytoprotection in vivo, its effectiveness was tested in two important animal models of barrier compromise, IBD and GDS. Pretreatment of mice with AMP peptide delayed the onset of bloody diarrhea and reduced weight loss in animals given DSS to induce colitis. The peptide also prevented the death of mice given intracecal Pseudomonas aeruginosa following the surgical stress of partial hepatectomy and post-operative food deprivation in a model GDS. Our objective is to obtain additional support in cell culture and in vivo models of IBD and GDS to demonstrate that AMP peptide, by increasing accumulation of tight junction proteins such as occludin, protects colonic mucosal barrier structure and function. Studies that confirm and extend the cytoprotective, mitogenic, and motogenic effects of AMP peptide would lend further support to developing this molecule as a therapeutic agent to treat not only IBD and GDS, but other GI diseases mediated by disruption of intestinal tight junctions and the subsequent increase in mucosal permeability to bacteria and their products.

描述（由申请人提供）：肠道屏障功能的破坏可能是一种常见的致病机制，可介导炎症性肠病（IBD）和肠源性败血症（GDS）的受试者中的发病率和死亡率。如果是这样，可以通过增加连接粘膜上皮细胞的紧密和粘附连接蛋白的积累来保护粘膜屏障功能和结构的治疗策略。我们最近表征了一种新型的18-kDa蛋白，称为AMP-18，该蛋白在人类和其他6种哺乳动物的胃胃粘膜上皮细胞中合成，具有有丝分裂和MOTENIC特性。发现在蛋白质的中心结构域中衍生的21-Mer肽在人类结肠上皮细胞（CACO-2/BBE）培养物中受到细胞保护作用 tight junction proteins (occludin, ZO-1, claudin-5), an adherens junction protein (E-cadherin), and heat shock proteins (hsp25, hsp72), and protects the actin microfilament network in cells exposed to cytochalasin D. When given to mice, AMP peptide increases the content of hyperphosphorylated occludin in the colonic mucosa.为了确定AMP肽会赋予体内结肠细胞保护作用的这些生物学作用，在两个重要的屏障折衷动物模型IBD和GDS中测试了其有效性。用AMP肽对小鼠进行预处理延迟了血腥腹泻的发作，并且给定DSS的动物体重减轻降低以诱导结肠炎。该肽还阻止了在模型GDS中部分肝切除术和术后食物剥夺后的手术应激后，给予铜绿假单胞菌的小鼠死亡。我们的目标是在细胞培养和IBD和GD的体内模型中获得额外的支持，以证明AMP肽通过增加紧密连接蛋白的积累（如闭塞蛋白）保护结肠粘膜屏障结构和功能。确认和扩展AMP肽的细胞保护，有丝分裂和动作效应的研究将为发展该分子作为一种治疗剂提供进一步的支持，不仅可以治疗IBD和GDS，还可以治疗其他GI疾病，而是通过破坏肠道紧密连接的破坏来介导的GI疾病，并随后增加了粘膜渗透性疾病，并增加了粘膜渗透性疾病。