Exosomes in Wound Healing

摘要 伤口，手术或创伤的起源，是一个主要的医疗保健负担，当它持续存在。之一 不愈合的慢性糖尿病（D）伤口的常见并发症是停滞的炎症。 因此，调节这种脱轨的免疫应答的机制是特别感兴趣的。 该建议基于我们的新观察，即伤口边缘组织的角质形成细胞（K） 通过携带遗传信息的K-起源的外泌体与来访的巨噬细胞进行交流 巨噬细胞（免疫细胞）在一个高度组织和定向的方式。外来体可以 被视为生物纳米载体，由活细胞释放，并已涉及许多 炎症性疾病，包括败血症。exomotif基因选择他们为exosomal 包装.我们认为miR-21是一种这样的非编码基因，其前体， miR-21被包装在K-来源的外泌体中，并被递送至伤口巨噬细胞以溶解 及时消炎。这种串扰过程在D中被折衷。我们观察到 外泌体的表面蛋白质化学，即甘露糖的存在，靶向其递送至 伤口巨噬细胞D修饰这种表面蛋白质化学，产生甘露糖 这些修饰损害了伤口巨噬细胞对这些外来体的摄取。添加 临床意义的拟议工作，我们寻求研究外泌体表面甘露糖 与非D患者相比，在控制不良、控制良好的D患者中， 伤口因此，提出了以下三个具体目标：目标1：确定K- 巨噬细胞串扰在D伤口边缘组织中受损。1.1吸收钾源 在D. 1.2 D伤口中受损的K-巨噬细胞串扰导致 炎症目的2：测试是否K-衍生的外来体的表面糖蛋白来自于 伤口部位在D损害巨噬细胞靶向的条件下被糖基化。2.1伤口- 边缘K衍生的外泌体（κ-GFPEXO）在D. 2.2伤口部位κ-GFPEXO表面上的甘露糖在D 使得巨噬细胞靶向受损。目的3：从D和非D人中分离外泌体 慢性伤口流体来表征外泌体亚群及其表面甘露糖修饰。 这一来自早期研究者的建议旨在为实验室奠定基础 这将致力于研究外泌体在外科和创伤性损伤中的作用机制 和修复。这些努力很可能有助于我们在理解 伤口修复和提供新的治疗方法。

ABSTRACT Wounds, surgical or trauma in origin, is a major healthcare burden when it persists. One of the common complications of non-healing chronic diabetic (D) wounds is stalled inflammation. Mechanisms regulating such derailed immune response is therefore of extraordinary interest. This proposal rests on our novel observation that keratinocytes (K) of the wound-edge tissue cross-talk with visiting macrophages via K-originating exosomes which carry genetic information to macrophages (immune cells) in a highly organized and directed manner. Exosomes may be viewed as biology nanocarriers, released by live cells, and have been implicated in numerous inflammatory conditions including sepsis. Exomotif in genes select them for exosomal packaging. We propose that miR-21 is one such non-coding gene the precursor of which, pre- miR-21, is packaged in K-originating exosomes and delivered to wound macrophages to resolve inflammation in a timely manner. This process of cross-talk is compromised in D. We observed that surface protein chemistry of exosomes, i.e. presence of mannose, targets it for delivery to wound macrophages. D modifies this surface protein chemistry resulting in mannose modifications which compromises uptake of these exosomes by wound macrophages. To add clinical significance to the proposed work we seek to study exosome surface mannose modifications in poorly controlled, well controlled D compared to non-D patients with chronic wounds. The following three specific aims are thus proposed: Aim 1: Determine whether K- macrophage cross-talk is compromised in D wound-edge tissue. 1.1 Uptake of K-originating exosomes by wound-site macrophages (wmφ) is compromised under conditions of D. 1.2 Compromised K-macrophage cross-talk in D wound causes impairment in resolution of inflammation. Aim 2: Test whether surface glycoproteins of K-derived exosomes from the wound-site are glycosylated under conditions of D impairing macrophage targeting. 2.1 Wound- edge K-derived exosomes (κ-GFPEXO) undergoes mannose isomerization under conditions of D. 2.2 Mannose on the surface of κ-GFPEXO at the wound-site is glycated under conditions of D such that macrophage targeting is impaired. Aim 3: Isolate exosomes from D and non-D human chronic wound fluid to characterize exosomal subsets and their surface mannose modifications. This proposal from an early stage investigator is aimed at laying the foundation of a laboratory that would be dedicated to the study of exosomal mechanisms in surgical and traumatic injury and repair. Such efforts are likely to contribute to seminal advances in our understanding of wound repair and inform novel therapies.