Zhao Pin, Kuai Jianke, Gao Jinjian, Sun Li, Wang Yan, Yao Linong
Department of Anesthesiology, Third Hospital of Xi'an, 10 Fengcheng Three Road, Xi'an, Shanxi 710018, China.
Department of Orthopaedics, Tangdu Hospital, The Fourth Military Medical University, 569 Xinsi Road, Xi'an, Shanxi 710038, China.
Biochem Biophys Res Commun. 2017 Oct 7;492(1):140-146. doi: 10.1016/j.bbrc.2017.06.029. Epub 2017 Jun 21.
Previous studies have described the protective effects of DADLE on myocardial injury in sepsis. Recently, autophagy has been shown to be an innate defense mechanism in sepsis-related myocardial injury. However, whether DADLE has an pro-autophagic effect is yet to be elucidated. The present study aimed to investigate the effect of DADLE on the regulation of autophagy during sepsis.
Male mice were subjected to LPS or vehicle intraperitoneal injection. After LPS injection, mice received either DADLE, Naltrindole or vehicle. ELISA and JC-1 were used to evaluate the level cTnI and Mitochondrial membrane potential. Cardiac ultrastructural and autophagosomes were visualized by transmission electron microscopy. The relative protein levels were analyzed by Western blot.
The results showed that treatment with DADLE both immediately or 4 h after LPS intraperitoneal injection could improve the survival rate of mice with endotoxemic. DADLE could ease myocardium ultrastructure injury induced by LPS, this cardioprotective effect was also seen in increased MMP levels, and decreased cTnI levels. Through observation of transmission electron microscopy and Western blot we have discovered that the amount of autophagosome and the expression of autophagy related protein LC3II, Beclin1 were significantly increased with DADLE treatment. DADLE promoted LPS-induced autophagosome maturation as indicated by the increased LAMP-1 protein level and decreased SQSTM1/p62 protein level. The selective δ-opioid receptor antagonist Naltrindole play an opposite effects.
DADLE could improve the survival and protect myocardial dysfunction in mice with LPS-induced endotoxemia. This effect was related to the increase of autophagy.
先前的研究已经描述了DADLE对脓毒症心肌损伤的保护作用。最近，自噬已被证明是脓毒症相关心肌损伤中的一种固有防御机制。然而，DADLE是否具有促自噬作用尚待阐明。本研究旨在探讨DADLE在脓毒症期间对自噬调节的影响。
雄性小鼠腹腔注射脂多糖（LPS）或赋形剂。注射LPS后，小鼠接受DADLE、纳曲吲哚或赋形剂。采用酶联免疫吸附测定（ELISA）和JC-1法评估心肌肌钙蛋白I（cTnI）水平和线粒体膜电位。通过透射电子显微镜观察心脏超微结构和自噬体。采用蛋白质免疫印迹法分析相关蛋白水平。
结果显示，腹腔注射LPS后立即或4小时给予DADLE治疗可提高内毒素血症小鼠的存活率。DADLE可减轻LPS诱导的心肌超微结构损伤，这种心脏保护作用还表现为线粒体膜电位（MMP）水平升高和cTnI水平降低。通过透射电子显微镜观察和蛋白质免疫印迹法，我们发现DADLE治疗后自噬体数量以及自噬相关蛋白微管相关蛋白轻链3-II（LC3II）、Beclin1的表达显著增加。LAMP-1蛋白水平升高和Sequestosome1/p62（SQSTM1/p62）蛋白水平降低表明DADLE促进了LPS诱导的自噬体成熟。选择性δ-阿片受体拮抗剂纳曲吲哚则发挥相反作用。
DADLE可提高LPS诱导的内毒素血症小鼠的存活率并保护其心肌功能障碍。这种作用与自噬增加有关。
