Synthetic Peptide Modulators of Paracellular Conductance

描述（由申请人提供）：提出了合成肽调节上皮或内皮细胞-细胞相互作用的创新用途，用于增强基于药物或基因的治疗干预。细胞单层是将药物递送到全身选定位置的主要障碍。短暂进入这些隔间将为医生提供额外的手段来诊断和治疗衰弱和危及生命的疾病。在开发用于治疗囊性纤维化的新治疗方法时，Nacelle Therapeutics，Inc.鉴定出一小部分显示出异常活性的肽。通道形成肽的该亚组瞬时降低穿过转化的上皮细胞单层（MOCK细胞）的电阻（屏障完整性的量度）。这一观察结果超出了目标结果，但其治疗潜力立即得到认可。初步实验表明，肽诱导的细胞旁渗透性小（<10 kDa），但不是大葡聚糖。我们现在建议探索这些肽作为上皮和内皮屏障的瞬时调节剂的潜在应用。在接下来的六个月里，我们将确定适合这种调节的上皮细胞的范围。将在来自各种组织（包括气道、肠和输精管）的人和非人上皮细胞中检测体外疗效。还将检测来源于人和非人血管的内皮细胞单层，以确定这些组织中的治疗潜力范围。这些研究的结果将确定特定的靶组织，可以通过这个家族的肽治疗调节。还将研究肽引起抗性丧失的机制。将测试两种潜在的机制：一种是信号转导，受体介导的过程，其由肽与推定的受体结合触发，例如在ZOT抗性调节中所见的受体，或二种是直接氯离子电导介导的过程，其中单独通过通道形成肽诱导大的氯离子通量诱导抗性丧失。在II期申请中，将使用体外和体内系统监测药物摄取研究。

DESCRIPTION (provided by applicant): The innovative use of a synthetic peptide to modulate epithelial or endothelial cell-cell interactions is proposed for the augmentation of drug- or gene-based therapeutic interventions. Cell monolayers are a major obstacle to delivering drugs to selected locations throughout the body. Transient access to these compartments would provide physicians with an additional means to diagnose and treat debilitating and life-threatening disorders. In developing a new therapeutic approach for treating cystic fibrosis, Nacelle Therapeutics, Inc. identified a small group of peptides displaying an unusual activity. This subset of channel-forming peptides transiently reduces electrical resistance (a measure of barrier integrity) across a transformed epithelial cell monolayer (MOCK cells). This observation was outside of the targeted outcome, but its therapeutic potential was immediately recognized. Preliminary experiments indicated peptide-induced paracellular permeability to small (<10 kDa) but not large dextrans. We now propose to explore the potential applications of these peptides as transient modulators of epithelial and endothelial barriers. Over the next six months, we will identify the scope of epithelia that are amenable to such modulation. In vitro efficacy will be tested in both human and non-human epithelia from a variety of tissues including airway, intestine and vas deferens. Endothelial cell monolayers derived from both human and non-human vessels will also be tested to determine the scope of therapeutic potential in these tissues. The outcomes of these studies will identify specific target tissues that can be therapeutically modulated by this family of peptides. The mechanism by which the peptides cause the resistance loss will also be investigated. Two potential mechanisms will be tested: one, a signal transduction, receptor mediated process that is triggered by the binding of the peptide to a putative, receptor such as that seen in with ZOT resistance modulation, or two, a direct chloride conductance mediated process where the induction of large chloride fluxes by the channel forming peptides alone induce the resistance loss. In a Phase II application drug uptake studies will be monitored using both in vitro and in vivo systems.