Ion Channels and Pumps: The Machinery of Electric Signaling at Corneal Wounds

描述（由申请人提供）：角膜上皮细胞迁移和增殖;重要的是，它们定向迁移和增殖以愈合伤口。生长因子和细胞因子在伤口愈合中起关键作用，可能是角膜伤口治疗的潜在靶点。我们发现了一个非常不同的因素，即角膜伤口处自然产生的电场（EF）也会激活细胞内通路。更重要的是，由于EF具有内在的方向性，因此它们定向激活信号通路，为细胞提供方向性提示，并引导细胞沿伤口方向迁移和分裂，以促进愈合。我们的研究表明，EFs覆盖其他公认的方向线索，如接触抑制释放，伤口空隙，人口压力和趋化性，以引导细胞迁移在一个确定的方向。内源性EF如何产生和调节尚不清楚。在链脲佐菌素（STZ）诱导的1型糖尿病大鼠和Pax 6 +/-突变小鼠，有缺陷的角膜伤口愈合，我们观察到显着降低内源性伤口EF。我们能否提高内源性伤口EF以促进伤口愈合，尤其是难治性和慢性伤口？我们的长期目标是阐明电信号可以用来加速伤口愈合的机制。我们最近观察到，伤口EFs逐渐增加损伤后，和Cl-或Na+的替代在浴液显着改变内源性EFs。因此，我们假设角膜损伤诱导主动调节的伤口电场，这是由特定离子（如Cl-）的流量，由Cl-通道和运输分子控制形成的;操纵Cl-流量可能会增强内源性电场和伤口愈合。我们将用以下具体目标来检验这一假设：目标1。确认伤口电场是对损伤的主动反应。目标2.确定角膜伤口内源性EFs的离子机制。目标3：阐明创伤电场的分子机制。本申请的结果将定义角膜伤口愈合中的主动电信号，提供伤口愈合中电信号的离子和分子机制，并可能导致利用电信号改善伤口愈合的新疗法。 公共卫生相关性：持续性角膜上皮缺损是一个重要的医学问题。我们最近在角膜伤口处发现了一种新的信号传导机制，即自然发生的电场，其对上皮细胞愈合伤口具有深刻的指导作用。该项目旨在确定控制角膜伤口处离子通量的离子和分子机制。通过该项目获得的科学知识，即细胞如何调节这一基本信号，将为治疗延迟和不愈合的角膜伤口以及一般伤口开辟一条新途径。

DESCRIPTION (provided by applicant): Corneal epithelial cells migrate and proliferate; importantly they do so directionally, to heal wounds. Growth factors and cytokines play pivotal roles in wound healing and may be potential targets for corneal wound therapies. We have discovered a very different factor, namely naturally-occurring electric fields (EFs) at corneal wounds that also activate intracellular pathways. More significantly, because EFs are intrinsically directional, they activate signaling pathways directionally, giving cells a directional cue and guiding cells to migrate and divide in the direction of the wound to facilitate healing. Our studies have shown that EFs override other well-accepted directional cues such as contact inhibition release, wound void, population pressure and chemotaxis to guide cell migration in a defined direction. How the endogenous EFs are generated and regulated is not known. In streptozotocin (STZ)- induced type 1 diabetes mellitus rats and Pax6+/- mutant mice that have defective corneal wound healing, we observed significantly reduced endogenous wound EFs. Can we enhance the endogenous wound EFs to enhance wound healing, especially in refractory and chronic wounds? Our long-term goal is to elucidate the mechanisms through which electric signals can be exploited to accelerate wound healing. We recently observed that wound EFs increase gradually following injury, and substitution of Cl- or Na+ in the bathing solution significantly alters the endogenous EFs. We thus hypothesize that injury to the cornea induces actively-regulated wound electric fields, which are formed by fluxes of specific ions (e.g. Cl-) that are controlled by Cl- channels and transport molecules; manipulating Cl- flux may enhance endogenous electric fields and wound healing. We will test this hypothesis with the following Specific Aims: Aim 1. To confirm that wound electric fields are an active response to injury. Aim 2. To determine the ionic mechanisms of endogenous EFs at corneal wounds. Aim 3. To elucidate the molecular mechanisms of wound electric fields. The results from this application will define the active electric signaling in corneal wound healing, provide ionic and molecular mechanisms of electric signaling in wound healing, and may lead to novel therapies to improve wound healing exploiting electric signaling. PUBLIC HEALTH RELEVANCE: Persistent corneal epithelial defects pose an important medical problem. We recently discovered a novel signaling mechanism at corneal wounds, namely naturally-occurring electric fields that have profound guidance effects on epithelial cells to heal wounds. This project seeks to determine the ionic and molecular mechanisms controlling ionic fluxes at corneal wounds. The scientific knowledge to be acquired through this project, i.e. how cells regulate this fundamental signal, will open a new avenue to treat delayed and non-healing corneal wounds, and wounds in general.