Department of Clinical Laboratory, Jinan City People's Hospital, Jinan People's Hospital Affiliated to Shandong First Medical University, Jinan, China.
Eur Rev Med Pharmacol Sci. 2020 Oct;24(20):10745-10752. doi: 10.26355/eurrev_202010_23435.
To investigate the influences of adiponectin (APN) on the liver injury in sepsis rats and to explore whether it exerts a therapeutic effect through the adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway.
A rat model of sepsis was established through cecal ligation and puncture (CLP) (CLP group), and APN treatment group (APN group) and control group were also set. The changes in the liver function-related indicators, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were determined by automatic biochemistry analyzer, and the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1, and IL-6 were measured via enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was employed to detect liver tissue injury, and the hepatocyte apoptosis and necrosis after intervention with APN were evaluated using in situ fluorescence staining. Moreover, the mRNA expression of APN in liver tissues was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR), and the expression levels of phosphorylated AMPK and mTOR proteins in liver tissue samples were determined using Western blotting.
In terms of changes in liver function-related indicators, the concentrations of ALT and AST were substantially raised in the CLP group, and compared with those in the control group, the concentrations of the two indicators significantly declined in the APN group, showing statistically significant differences (p<0.05). CLP and APN group had evidently higher levels of inflammatory factors than the control group, but their levels in APN group were notably lower than those in the CLP group (p<0.05). It was found through the HE staining that the sepsis rats in CLP group had massive inflammatory cell infiltration, and that the inflammatory cells were remarkably decreased in the APN group after APN treatment. According to the in-situ fluorescence staining detection results, CLP group exhibited a notable increase in the cell apoptosis rate, and APN group had substantially reduced apoptotic cells (p<0.05). The determination results of APN expression revealed that CLP group had a lowered level of APN, and that the level of APN in APN group was markedly higher than that in the control group. Based on the results of Western blotting, the level of phosphorylated AMPK was remarkably elevated, and that of phosphorylated mTOR was lowered in the CLP group compared with those in the control group, while in comparison with CLP group, APN group showed a considerable elevation of phosphorylated AMPK level and a distinct decline in the phosphorylated mTOR level.
APN can activate the AMPK/mTOR pathway and reduce hepatocyte apoptosis to alleviate liver injury in sepsis rats.
探讨脂联素（APN）对脓毒症大鼠肝损伤的影响，并探讨其是否通过腺苷酸活化蛋白激酶（AMPK）/哺乳动物雷帕霉素靶蛋白（mTOR）通路发挥治疗作用。
采用盲肠结扎穿孔（CLP）法建立大鼠脓毒症模型（CLP 组），并设置 APN 治疗组（APN 组）和对照组。采用自动生化分析仪测定肝功能相关指标血清丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）的变化，酶联免疫吸附试验（ELISA）法测定肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-1 和 IL-6 的水平。采用苏木精-伊红（HE）染色观察肝组织损伤情况，采用原位荧光染色法评价 APN 干预后肝细胞凋亡和坏死情况。此外，采用实时荧光定量逆转录聚合酶链反应（qRT-PCR）检测肝组织中 APN 的 mRNA 表达，采用 Western blot 法检测肝组织中磷酸化 AMPK 和 mTOR 蛋白的表达水平。
在肝功能相关指标变化方面，CLP 组 ALT 和 AST 浓度明显升高，与对照组相比，APN 组浓度明显降低，差异有统计学意义（p<0.05）。CLP 组和 APN 组炎症因子水平明显高于对照组，但 APN 组明显低于 CLP 组（p<0.05）。HE 染色发现，CLP 组大量炎性细胞浸润，APN 治疗后 APN 组炎性细胞明显减少。原位荧光染色检测结果显示，CLP 组细胞凋亡率明显升高，APN 组凋亡细胞明显减少（p<0.05）。APN 表达测定结果显示，CLP 组 APN 水平降低，APN 组 APN 水平明显高于对照组。Western blot 结果显示，CLP 组磷酸化 AMPK 水平显著升高，磷酸化 mTOR 水平降低，与对照组相比，APN 组磷酸化 AMPK 水平显著升高，磷酸化 mTOR 水平明显降低。
APN 可激活 AMPK/mTOR 通路，减少肝细胞凋亡，从而减轻脓毒症大鼠肝损伤。
