Exosomes and HB-EGF in Stem Cell-Mediated Therapy for Necrotizing Enterocolitis

描述（由申请人提供）：尽管经过数十年的研究，坏死性小肠结肠炎（NEC）的发病率和死亡率保持不变，这是由于我们对如何保护肠道免受这种疾病影响的理解存在根本性差距。有证据表明，不成熟的肠神经系统（ENS）可能使早产儿容易发生NEC。我们已经证明了人类和啮齿类动物NEC损伤的肠道中的长期ENS异常，这些异常在急性疾病明显恢复后持续很长时间。我们的初步数据表明，肝素结合EGF样生长因子（HB-EGF）和干细胞（SC）移植共同作用，以保护肠和ENS从实验NEC。我们工作的长期目标是确定新的预防和治疗策略，以保护新生儿免受NEC。目前更新申请的总体目标是确定HB-EGF与SC相互作用的关键要素，这些要素可用于改善肠道免受损伤的保护。我们的中心假设是HB-EGF保护SC的能力在其肠道细胞保护作用中起主要作用，并且SC的有益作用是由SC分泌的外泌体介导的。外来体是由许多细胞类型分泌的纳米囊泡，其含有反映其生产细胞的转录和/或翻译活性的微小RNA、mRNA和蛋白质的复杂混合物。我们将客观地测试我们的 通过追求以下具体目标来实现中心假设：目标1）确定哪种干细胞的生物来源在NEC期间保护肠和ENS免受损伤方面最有效。目的2）建立干细胞治疗的外泌体依赖性和外泌体HB-EGF的有益作用。目的3）确定外周血exosomes中microRNA含量是否可作为NEC的生物标志物。这项研究的意义在于，它将使我们更好地了解HB-EGF和SC对肠道和ENS的保护作用，使我们能够最好地设计潜在的临床HB-EGF和SC治疗NEC的疗法。我们研究的积极影响将是为有NEC风险的患者开发更好的治疗干预措施，以及在了解肠道中生长因子-干细胞相互作用方面取得根本性进展。拟议的研究是创新的，因为我们寻求利用新的实验疗法，旨在保护和再生的肠道和ENS通过管理肠道细胞保护生长因子与干细胞，因为它将进一步调查新的观察，HB-EGF作为促运动剂。

DESCRIPTION (provided by applicant): Despite decades of research, the morbidity and mortality of necrotizing enterocolitis (NEC) remain unchanged due to a fundamental gap in our understanding of how to protect the intestines from this disease. Evidence suggests that an immature enteric nervous system (ENS) may predispose prematures to NEC. We have demonstrated protracted ENS abnormalities in human and rodent NEC-injured intestine that persist long after apparent recovery from the acute disease. Our preliminary data demonstrate that heparin-binding EGF-like growth factor (HB-EGF) and stem cell (SC) transplantation act collectively to protect the intestines and the ENS from experimental NEC. The long-term goal of our work is to identify novel prophylactic and therapeutic strategies to protect neonates from NEC. The overall objective of the current renewal application is to identify key elements of the interaction of HB-EGF with SC that may be utilized to improve protection of the intestines from injury. Our central hypothesis is that the ability of HB-EGF to protect SC plays a major role in it intestinal cytoprotective effects, and that the beneficial effects of SC are mediated by SC-secreted exosomes. Exosomes are nanovesicles that are secreted by many cell types and which contain a complex mixture of microRNAs, mRNAs and proteins that reflect the transcriptional and/or translational activity of their producer cells. We will objectively test our central hypothesis by pursuing the following specific aims: Aim 1) to determine which biological source of stem cells is most effective in protecting the intestine and the ENS from injury during NEC. Aim 2) to establish the exosome dependency of stem cell therapy and the beneficial effects of exosomal HB-EGF. Aim 3) to determine whether the microRNA content of circulating exosomes can be used as biomarkers of NEC. The significance of the proposed research is that it will lead to a better understanding of the effects of HB- EGF and SC on protection of the intestines and the ENS, allowing us to best design potential clinical HB-EGF- and SC-based therapies to treat NEC. The positive impact of our studies will be development of improved therapeutic interventions for patients at risk of developing NEC and fundamental advances in understanding growth factor-stem cell interactions in the intestines. The proposed research is innovative because we seek to utilize novel experimental therapies designed to protect and regenerate the intestine and the ENS through administration of an intestinal cytoprotective growth factor in conjunction with stem cells, and because it will further investigate the novel observation that HB-EGF acts as a pro-motility agent.