1 Department of Surgery/Division of Pediatric Surgery, University of Alabama School of Medicine, USA.
2 Department of Pediatrics/Division of Neonatology and Center of Glial Biology in Medicine, University of Alabama School of Medicine, USA.
Innate Immun. 2018 Jul;24(5):278-284. doi: 10.1177/1753425918785715. Epub 2018 Jul 10.
Human breast milk has been shown to reduce the incidence of necrotizing enterocolitis (NEC). Breast milk has many components (immunoglobulins, proteins, fat, and, of recent interest, exosomes), but the specific component that affords protection against NEC is not known. Exosomes are small-nanometer vesicles that are rich in protein, lipid, and microRNA. Here, we hypothesized that human breast milk-derived exosomes can protect intestinal epithelial cells (IECs) from cell death. Human breast milk was collected, separated using ultracentrifugation, and quantified using NanoSight tracking analysis. Purified exosomes were added to IECs that had been treated with varying concentrations of HO. Cells were then incubated overnight with the human breast milk-derived exosomes and assessed for cell viability. Western blot analysis showed that both clathrin and CD81 were present in the purified sample. Oxidative stress using HO caused a 50% decrease in cell viability and human breast milk-derived exosomes had a protective effect in IECs. In the presence of HO, exosomes had a statistically significant protective effect. The protection seen by human breast milk-derived exosomes was not attenuated by cycloheximide. Thus, human breast milk-derived exosomes allow IECs to be protected from oxidative stress, but the mechanism is still not clear. Exosomes derived from human breast milk are an attractive treatment concept for children with intestinal injury.
人乳已被证明可降低坏死性小肠结肠炎 (NEC) 的发病率。人乳含有许多成分（免疫球蛋白、蛋白质、脂肪，以及最近受到关注的外泌体），但具有预防 NEC 作用的确切成分尚不清楚。外泌体是富含蛋白质、脂质和 microRNA 的小型纳米囊泡。在这里，我们假设人乳来源的外泌体可以保护肠上皮细胞 (IEC) 免受细胞死亡。收集人乳，使用超速离心法分离，并使用 NanoSight 跟踪分析进行定量。将纯化的外泌体添加到已用不同浓度 HO 处理的 IEC 中。然后将细胞与人乳来源的外泌体孵育过夜，并评估细胞活力。Western blot 分析显示，纯化样品中存在网格蛋白和 CD81。使用 HO 引起的氧化应激导致细胞活力降低 50%，而人乳来源的外泌体对 IEC 具有保护作用。在 HO 存在的情况下，外泌体具有统计学显著的保护作用。人乳来源的外泌体的保护作用不受环己酰亚胺的减弱。因此，人乳来源的外泌体可使 IEC 免受氧化应激的影响，但机制尚不清楚。人乳衍生的外泌体是治疗儿童肠道损伤的一种有吸引力的治疗概念。
