Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510089, China.
School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China.
Dig Dis Sci. 2018 Jan;63(1):81-91. doi: 10.1007/s10620-017-4801-x. Epub 2017 Oct 23.
To date, mechanisms of sepsis-induced intestinal epithelial injury are not well known. P2X7 receptor (P2X7R) regulates pyroptosis of lymphocytes, and propofol is usually used for sedation in septic patients.
We aimed to determine the occurrence of enterocyte pyroptosis mediated by P2X7R and to explore the effects of propofol on pyroptosis and intestinal epithelial injury after lipopolysaccharide (LPS) challenge.
A novel regimen of LPS challenge was applied in vitro and in vivo. Inhibitors of P2X7R (A438079) and NLRP3 inflammasome (MCC950), and different doses of propofol were administered. The caspase-1 expression, caspase-3 expression, caspase-11 expression, P2X7R expression and NLRP3 expression, extracellular ATP concentration and YO-PRO-1 uptake, and cytotoxicity and HMGB1 concentration were detected to evaluate enterocyte pyroptosis in cultured cells and intestinal epithelial tissues. Chiu's score, diamine oxidase and villus length were used to evaluate intestinal epithelial injury. Moreover, survival analysis was performed.
LPS challenge activated caspase-11 expression and P2X7R expression, enhanced ATP concentration and YO-PRO-1 uptake, and led to increased cytotoxicity and HMGB1 concentration. Subsequently, LPS resulted in intestinal epithelial damage, as evidenced by increased levels of Chiu's score and diamine oxidase, and shorter villus length and high mortality of animals. A438079, but not MCC950, significantly relieved LPS-induced enterocyte pyroptosis and intestinal epithelial injury. Importantly, propofol did not confer the protective effects on enterocyte pyroptosis and intestinal epithelia although it markedly decreased P2X7R expression.
LPS attack leads to activation of caspase-11/P2X7R and pyroptosis of enterocytes. Propofol does not reduce LPS-induced pyroptosis and intestinal epithelial injury, although it inhibits P2X7R upregulation.
迄今为止，关于脓毒症诱导的肠上皮损伤的机制尚不清楚。P2X7 受体 (P2X7R) 调节淋巴细胞的细胞焦亡，而异丙酚通常用于脓毒症患者的镇静。
本研究旨在确定 P2X7R 介导的肠上皮细胞焦亡的发生，并探讨异丙酚对脂多糖 (LPS) 刺激后细胞焦亡和肠上皮损伤的影响。
本研究采用体外和体内的新型 LPS 刺激方案，并应用 P2X7R 抑制剂 (A438079) 和 NLRP3 炎性体抑制剂 (MCC950) 以及不同剂量的异丙酚。检测细胞培养物和肠上皮组织中 caspase-1 表达、caspase-3 表达、caspase-11 表达、P2X7R 表达和 NLRP3 表达、细胞外 ATP 浓度和 YO-PRO-1 摄取、细胞毒性和 HMGB1 浓度，以评估肠上皮细胞的焦亡情况。采用 Chiu 评分、二胺氧化酶和绒毛长度评估肠上皮损伤。此外，还进行了生存分析。
LPS 刺激可激活 caspase-11 表达和 P2X7R 表达，增加 ATP 浓度和 YO-PRO-1 摄取，导致细胞毒性和 HMGB1 浓度增加，从而导致肠上皮损伤。随后，LPS 导致肠上皮损伤，表现为 Chiu 评分、二胺氧化酶水平升高，绒毛长度缩短，动物死亡率升高。A438079 而非 MCC950 显著减轻 LPS 诱导的肠上皮细胞焦亡和损伤。重要的是，尽管异丙酚显著降低了 P2X7R 的表达，但它对肠上皮细胞的焦亡和上皮细胞没有保护作用。
LPS 攻击导致 caspase-11/P2X7R 激活和肠上皮细胞焦亡。尽管异丙酚抑制了 P2X7R 的上调，但它并不能减轻 LPS 诱导的细胞焦亡和肠上皮损伤。
