Department of Pediatric Surgery, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
Shanghai Institute of Pediatric Research, Shanghai, People's Republic of China.
JPEN J Parenter Enteral Nutr. 2019 Jan;43(1):96-106. doi: 10.1002/jpen.1173. Epub 2018 May 15.
The objectives of this study were to address the role of autophagy in the pathogenesis of parenteral nutrition (PN)-associated liver disease (PNALD) and its possible mechanism in vivo.
Five-week-old male Sprague Dawley rats were fed Shoobree chow (Xietong Organism, Jiangsu, China) and administered intravenous 0.9% saline (sham group), PN (PN group), PN plus rapamycin (1 mg/kg; PN + Rapa group), or rapamycin (Rapa group) for 7 days. Before and after study, body weight, biochemical indicators, hepatic histology, level of autophagy, hepatocyte apoptosis, reactive oxygen species (ROS), and endoplasmic reticulum (ER) stress indicators including binding immunoglobulin protein (BIP), spliced X-box-binding protein-1 (sXBP1), and CCAAT-enhancer-binding protein homologous protein (CHOP) were measured.
Autophagy was suppressed in the PNALD model, which was demonstrated by less light chain 3 fluorescence (LC3) puncta and lower LC3II expression. Rapamycin effectively induced hepatic autophagy in PN rats. The PN + Rapa group presented improved hepatic function, decreased pathology scores, and less steatosis than the PN group. In addition, rapamycin treatment decreased terminal deoxynucleotidyl transferase dUTP nick end labeling and cleaved-caspase 3 expression, indicating a lower level of hepatocyte apoptosis. Compared with the PN group, the PN + Rapa group had lower levels of ROS and reduced expression of ER stress-related protein markers, such as BIP, sXBP1 and CHOP.
Autophagy was suppressed in the PNALD model. Rapamycin treatment induced autophagy and protected against PNALD, possibly by suppressing ROS-induced ER stress.
本研究旨在探讨自噬在肠外营养（PN）相关肝病（PNALD）发病机制中的作用及其在体内的可能机制。
5 周龄雄性 Sprague Dawley 大鼠给予 Xietong 生物 Shoobree 饲料（江苏协通生物，江苏），并连续 7 天静脉注射 0.9%生理盐水（假手术组）、PN（PN 组）、PN 加雷帕霉素（1mg/kg；PN+Rapa 组）或雷帕霉素（Rapa 组）。研究前后，测量体重、生化指标、肝组织学、自噬水平、肝细胞凋亡、活性氧（ROS）和内质网（ER）应激指标，包括结合免疫球蛋白蛋白（BIP）、剪接 X 盒结合蛋白 1（sXBP1）和 CCAAT 增强子结合蛋白同源蛋白（CHOP）。
PNALD 模型中自噬受到抑制，表现为 LC3 荧光（LC3）斑点减少和 LC3II 表达降低。雷帕霉素有效诱导 PN 大鼠肝内自噬。与 PN 组相比，PN+Rapa 组肝功能改善，病理评分降低，脂肪变性减少。此外，雷帕霉素治疗降低了末端脱氧核苷酸转移酶 dUTP 缺口末端标记和裂解 caspase 3 的表达，表明肝细胞凋亡水平降低。与 PN 组相比，PN+Rapa 组 ROS 水平较低，ER 应激相关蛋白标志物 BIP、sXBP1 和 CHOP 的表达降低。
PNALD 模型中自噬受到抑制。雷帕霉素治疗诱导自噬并预防 PNALD，可能通过抑制 ROS 诱导的 ER 应激。
