Department of Pediatrics, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America.
PLoS One. 2018 Jul 10;13(7):e0199206. doi: 10.1371/journal.pone.0199206. eCollection 2018.
Although the accumulation of amyloidogenic proteins in neuroinflammatory conditions is generally considered pathologic, in a murine model of multiple sclerosis, amyloid-forming fibrils, comprised of hexapeptides, are anti-inflammatory. Whether these molecules modulate systemic inflammatory conditions remains unknown. We hypothesized that an amylin hexapeptide that forms fibrils can attenuate the systemic inflammatory response in a murine model of sepsis. To test this hypothesis, mice were pre-treated with either vehicle or amylin hexapeptide (20 μg) at 12 hours and 6 hours prior to intraperitoneal (i.p.) lipopolysaccharide (LPS, 20 mg/kg) administration. Illness severity and survival were monitored every 6 hours for 3 days. Levels of pro- (IL-6, TNF-α, IFN-γ) and anti-inflammatory (IL-10) cytokines were measured via ELISA at 1, 3, 6, 12, and 24 hours after LPS (i.p.). As a metric of lung injury, pulmonary artery endothelial cell (PAEC) barrier function was tested 24 hours after LPS administration by comparing lung wet-to-dry ratios, Evan's blue dye (EBD) extravasation, lung histology and caspase-3 activity. Compared to controls, pretreatment with amylin hexapeptide significantly reduced mortality (p<0.05 at 72 h), illness severity (p<0.05), and pro-inflammatory cytokine levels, while IL-10 levels were elevated (p<0.05). Amylin pretreatment attenuated LPS-induced lung injury, as demonstrated by decreased lung water and caspase-3 activity (p<0.05, versus PBS). Hence, in a murine model of systemic inflammation, pretreatment with amylin hexapeptide reduced mortality, disease severity, and preserved lung barrier function. Amylin hexapeptide may represent a novel therapeutic tool to mitigate sepsis severity and lung injury.
尽管在神经炎症条件下，淀粉样蛋白原性蛋白的积累通常被认为是病理性的，但在多发性硬化症的小鼠模型中，由六肽组成的淀粉样蛋白形成纤维具有抗炎作用。这些分子是否调节全身炎症状态尚不清楚。我们假设，形成纤维的淀粉样蛋白六肽可以减轻脓毒症小鼠模型中的全身炎症反应。为了验证这一假设，在腹腔内（i.p.）给予脂多糖（LPS，20mg/kg）前 12 小时和 6 小时，用载体或淀粉样蛋白六肽（20μg）预处理小鼠。在接下来的 3 天中，每 6 小时监测一次疾病严重程度和存活率。在 LPS（i.p.）后 1、3、6、12 和 24 小时通过 ELISA 测量促炎（IL-6、TNF-α、IFN-γ）和抗炎（IL-10）细胞因子的水平。作为肺损伤的度量标准，在 LPS 给药后 24 小时通过比较肺湿重/干重比、伊文思蓝染料（EBD）渗出、肺组织学和 caspase-3 活性来测试肺动脉内皮细胞（PAEC）屏障功能。与对照组相比，淀粉样蛋白六肽预处理显著降低死亡率（p<0.05 在 72 小时）、疾病严重程度（p<0.05）和促炎细胞因子水平，而 IL-10 水平升高（p<0.05）。淀粉样蛋白预处理减轻了 LPS 诱导的肺损伤，如肺水和 caspase-3 活性降低（p<0.05，与 PBS 相比）。因此，在全身炎症的小鼠模型中，淀粉样蛋白六肽预处理降低了死亡率、疾病严重程度并保护了肺屏障功能。淀粉样蛋白六肽可能代表一种减轻脓毒症严重程度和肺损伤的新型治疗工具。
