INTESTINAL EPITHELIAL WOUND HEALING: NSAIDS AND CALPAIN INHIBITION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 该项目的长期目标是阐明介导非甾体抗炎药（NSAID）在伤口愈合过程中对细胞迁移影响的机制，并利用所获得的知识开发治疗和预防胃肠道（GI）溃疡的新策略。NSAID在人类和其他物种中的不良GI作用包括口腔、胃、十二指肠和结肠溃疡。尽管进行了广泛的研究，但NSAID相关胃肠道损伤的机制尚未完全了解。 NSAID不仅可通过抑制粘膜环氧合酶（考克斯）和降低细胞保护性前列腺素（PG）促进溃疡形成，还可通过不利地影响肠道微生物菌群、中性粒细胞募集、表面疏水性和上皮恢复。最近的证据表明，钙蛋白酶（半胱氨酸蛋白酶）是至关重要的成纤维细胞和白细胞迁移的几个关键途径。我们的初步数据表明，溃疡性非甾体抗炎药下调钙蛋白酶基因的表达或上调的组成抑制剂，钙蛋白酶抑制素。 从全球角度来看，这使我们假设NSAID诱导的GI溃疡的形成部分是由于抑制上皮和成纤维细胞迁移，促进中性粒细胞迁移到伤口中，导致非偶联和不协调的伤口愈合反应，为慢性炎症状态奠定了基础。这里提出的实验是专门设计的，以联系NSAID抑制细胞迁移与NSAID对分化的肠上皮细胞（IEC）内钙蛋白酶功能至关重要的事件的影响。 该项目的具体目标是： 1)证明钙蛋白酶对正常IEC迁移至关重要。 2)确认钙蛋白酶是NSAID毒性和肠上皮伤口愈合中断的靶点。 3)确定NSAID对钙蛋白酶下游底物的影响，特别是肠上皮恢复过程中所需的细胞骨架和intregin元件。 该项目的结果将提供有价值的数据，不仅对希望对NSAID处方做出合理决策的医疗保健提供者有用，而且对致力于开发毒性较小的替代药物的工业科学家也有用。与塞来昔布和罗非昔布（与药物性胃病发生率最低相关的NSAID）相关的严重心血管并发症的担忧不断升级，引起了对改善NSAID诱导溃疡机制的迫切需要的关注。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term goals of this project are to elucidate mechanisms that mediate non-steroidal anti-inflammtory drugs (NSAIDs) effects on cell migration during wound healing, and use the knowledge gained to develop novel strategies for treatment and prevention of gastrointestinal (GI) ulcers. Adverse GI effects of NSAIDs in humans and other species include oral, gastric, duodenal, and colonic ulceration. Despite extensive investigation, the mechanisms responsible for NSAID-associated GI damage are not completely understood. NSAIDs may promote ulcer formation, not only by inhibiting mucosal cyclooxygenase (COX) and decreasing cytoprotective prostaglandins (PG), but also by adversely influencing intestinal microflora, neutrophil recruitment, surface hydrophobicity and epithelial restitution. Recent evidence suggests that calpains (cysteine proteases) are vital to the several key pathways of fibroblastic and WBC migration. Our preliminary data indicate that ulcerogenic NSAIDs either down-regulate calpain gene expression or up-regulate the constituent inhibitor, calpastatin. From a global perspective this has led us to hypothesyze that the formation of NSAID-induced GI ulceration is due, in part, to inhibited epithelial and fibroblastic cell migration, facilitated neutrophil migration into the wound, leading to an uncoupled and uncoordinated wound healing response setting the stage for a chronic inflammatory state. The experiments proposed here are designed specifically to link NSAID inhibition of cell migration with NSAID effects on events vital to calpain function within differentiated intestinal epithelial cells (IECs). The specific aims of this project are to: 1) Demonstrate that calpains are critical to normal IEC migration. 2)Confirm that calpains are a target for NSAID-toxicity and disruption of intestinal epithelial wound healing. 3) Determine the effects of NSAIDs on the downstream substrates of the calpains, specifically cytoskeletal and intregin elements required during intestinal epithelial restitution. The results of this project will provide valuable data immediately useful not only to the health care providers who want to make rational decisions about prescribing NSAIDs, but also to the industrial scientists who strive to develop less toxic alternatives to the drugs currently available. Escalating concerns about serious cardiovascular complications linked to celecoxib and rofecoxib, the NSAIDs associated with lowest incidence of drug-induced gastropathy, draw attention to the urgent need for improved understanding of the mechanisms that underlie NSAID-induced ulcers.