低酯果胶对小鼠急性胰腺炎及相关肠屏障损伤的保护作用

发布时间：2018-08-08 14:02

【摘要】：急性胰腺炎(Acute pacreatitis,AP)是一种常见的临床急性腹部疾病,近年来发病率持续升高,但市场上尚未有治疗AP的特效药。与AP相关的肠道损伤将反过来加重的病情恶化。此研究旨在探究一种提取自柠檬的低酯果胶(Low-methoxyl pectin,LMP)是否可以减轻AP严重程度及其相关肠黏膜屏障损伤。本研究将BALB/c小鼠随机分成正常对照组、急性胰腺炎模型组、低酯果胶组,通过雨蛙素(Caerulein,CAE)过度刺激诱导AP模型,收取血清、胰腺、结肠、回肠等样品。通过测定小鼠血清淀粉酶水平、血清脂肪酶水平、胰腺髓过氧化物酶活力、胰腺水肿程度研究低酯果胶是否能够减轻急性胰腺炎严重程度;通过测定血清及胰腺中TNF-α、IL-1β及IL-6的水平研究低酯果胶是否可以降低AP病程中炎症因子的分泌;通过测定血清内毒素含量,肠道中紧密连接蛋白ZO-1及Occuldin和抗菌肽DEFB1及CRAMP的表达水平,小鼠粪便中短链脂肪酸水平研究低酯果胶是否可以保障AP小鼠肠道屏障功能;通过测定肠道中TNF-α、IL-1β及IL-6的水平研究低酯果胶是否可以减轻AP小鼠肠道炎症反应。实验结果发现膳食补充低酯果胶后,小鼠的AP严重程度降低,表现为血清淀粉酶及脂肪酶水平,胰腺水肿程度及髓过氧化物酶活性的降低。胰腺组织病理切片的组织学检查也证实了低酯果胶的保护作用。膳食补充低酯果胶还可以抑制胰腺中促炎细胞因子的分泌,包括TNF-α,IL-1β和IL-6。此外,膳食补充低酯果胶恢复了AP相关肠道屏障的损伤,如上调了肠道紧密连接蛋白Occludin及ZO-1和抗菌肽DEFB1及Cramp的表达,增加了小鼠肠道短链脂肪酸的产量。并且,与CAE组相比,膳食补充了低酯果胶的AP小鼠表现出肠道炎症反应被抑制,结肠及回肠的促炎细胞因子分泌减少。综上,低酯果胶可以通过保障肠道屏障功能从而减轻小鼠AP的严重程度。本研究的实验结果表明,低酯果胶可作为有效的营养干预手段减轻AP的严重程度及相关肠道屏障损伤。该保护作用的机制可能跟低酯果胶的炎症抑制与肠道黏膜屏障功能的保护作用有关。低酯果胶作为一种安全健康的可溶性膳食纤维,或许可将其开发成AP相关功能性食品,以更好地预防、缓解AP。
[Abstract]:Acute pancreatitis (AP) is a common clinical acute abdominal disease, the incidence of which has been increasing in recent years, but there is no specific drug to treat AP in the market. Intestinal injury associated with AP will in turn worsen the condition. The aim of this study was to investigate whether a Low-methoxyl pectin extracted from lemon can reduce the severity of AP and its associated intestinal mucosal barrier damage. In this study, BALB/c mice were randomly divided into normal control group, acute pancreatitis model group and low-ester pectin group. AP model was induced by excessive stimulation of Caerulein (CAE). Serum, pancreas, colon and ileum were collected. The levels of serum amylase, serum lipase, the activity of pancreatic myeloperoxidase and the degree of pancreatic edema were measured to study whether low ester pectin could reduce the severity of acute pancreatitis. To study whether low ester pectin can reduce the secretion of inflammatory factors in the course of AP, to determine the levels of TNF- 伪 -IL-1 尾 and IL-6 in serum and pancreas, and to determine the expression of ZO-1, Occuldin, DEFB1 and CRAMP in intestinal tract by measuring the content of endotoxin in serum. Effects of low Ester Pectin on intestinal Barrier function in AP mice and the effects of low Ester Pectin on intestinal inflammation in AP mice were studied by measuring the levels of TNF- 伪 -TNF- 伪 -IL-1 尾 and IL-6. The results showed that the severity of AP in mice decreased after dietary supplementation of low ester pectin, including the decrease of serum amylase and lipase levels, pancreatic edema and myeloperoxidase activity. Histological examination of pancreatic histopathological sections also confirmed the protective effect of low-ester pectin. Dietary supplementation of low ester pectin also inhibited the secretion of pro-inflammatory cytokines, including TNF- 伪, IL-1 尾 and IL-6. In addition, dietary supplementation of low-ester pectin restored the injury of the intestinal barrier associated with AP, such as up-regulating the expression of Occludin and ZO-1, DEFB1 and Cramp, and increasing the production of short-chain fatty acids in the intestinal tract of mice. In addition, compared with CAE group, AP mice fed with low-ester pectin diet showed inhibition of intestinal inflammatory response and decreased secretion of inflammatory cytokines in colon and ileum. In conclusion, low-ester pectin can reduce the severity of AP by protecting intestinal barrier function in mice. The results showed that low ester pectin could be used as an effective nutritional intervention to alleviate the severity of AP and related intestinal barrier damage. The protective mechanism may be related to the inflammatory inhibition of low-ester pectin and the protective effect of intestinal mucosal barrier function. As a safe and healthy soluble dietary fiber, low ester pectin may be developed into AP related functional food for better prevention and relief of APs.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R576;TS201.4

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