Department of Liver Surgery, Huai'an First Hospital Affiliated to Nanjing Medical University, Huai'an, Jiangsu Province, 223300, China; Department of Liver Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, 210009, China.
Key Laboratory of Living Donor Liver Transplantation of Ministry of Public Health, Nanjing, Jiangsu Province, 210009, China; Emergency Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, 210009, China.
Chem Biol Interact. 2017 Nov 1;277:43-54. doi: 10.1016/j.cbi.2017.08.015. Epub 2017 Aug 24.
The aim of this study was to test whether endoplasmic reticulum (ER) stress suppresses hepatocyte growth factor (HGF) expression in hepatic stellate cells (HSCs) and whether ER stress plays a role in alleviating d-Galactosamine and Lipopolysaccharide (D-GalN/LPS)-induced acute liver failure (ALF) by regulating HGF expression. Rat HSCs line HSC-T6 were treated with the ER stress inducers tunicamycin or thapsigargin, and ER stress inhibitors sodium 4-phenylbutyrate (4-PBA) or salubrinal, respectively. Recombinant lentivirus containing eukaryotic translation initiation factor 2α (eIf2α), named LV-eIf2α-shRNA-GFP was produced to block eIf2α activated by ER stress. A rat ALF model was created by intraperitoneal injection of D-GalN/LPS, and 100 mg/kg 4-PBA was injected 6 h before injection as an inhibitor of ER stress. Levels of HGF, c-Met, vascular endothelial growth factor (VEGF), GRP78, eIf2α, phospho-eIF2α, ATF4 and CHOP in vitro and in vivo were measured. Our results demonstrated that ER stress stimulated VEGF but inhibited HGF expression in HSC-T6 cells. Both the stimulation of VEGF and the inhibition of HGF could be partly prevented by 4-PBA or Salubrinal. eIf2α expression was upregulated during ERS and interfering eIf2α expression proportionately down-regulated HGF expression. Inhibition of HGF and c-Met expression was also observed in the ALF rat. Treatment with 4-PBA prevented the reduction of HGF in ALF rats. ER stress regulates HGF expression in vitro and in vivo, which depends on eIf2α pathway. Reduction in liver damage of ALF by 4-PBA is associated with attenuation of ER stress and maintaining HGF production.
本研究旨在探讨内质网应激是否通过调节肝细胞生长因子（HGF）的表达来抑制肝星状细胞（HSCs）中 HGF 的表达，以及内质网应激是否通过调节 HGF 的表达在缓解 D-半乳糖胺和脂多糖（D-GalN/LPS）诱导的急性肝衰竭（ALF）中发挥作用。用内质网应激诱导剂衣霉素或他普西龙分别处理大鼠 HSCs 系 HSC-T6，并分别用内质网应激抑制剂苯丁酸钠（4-PBA）或 Salubrinal 处理。生产了含有真核翻译起始因子 2α（eIF2α）的重组慢病毒 LV-eIF2α-shRNA-GFP，用于阻断内质网应激激活的 eIF2α。通过腹腔注射 D-GalN/LPS 建立大鼠 ALF 模型，在注射前 6 h 注射 100mg/kg 4-PBA 作为内质网应激抑制剂。在体外和体内测量 HGF、c-Met、血管内皮生长因子（VEGF）、GRP78、eIF2α、磷酸化 eIF2α、ATF4 和 CHOP 的水平。我们的结果表明，内质网应激刺激 HSC-T6 细胞中 VEGF 的表达，但抑制 HGF 的表达。4-PBA 或 Salubrinal 可部分预防 VEGF 的刺激和 HGF 的抑制。内质网应激时 eIF2α 表达上调，干扰 eIF2α 表达可使 HGF 表达相应下调。在 ALF 大鼠中也观察到 HGF 和 c-Met 表达的抑制。用 4-PBA 治疗可防止 ALF 大鼠中 HGF 的减少。内质网应激在体外和体内调节 HGF 的表达，这依赖于 eIF2α 途径。4-PBA 减少 ALF 的肝损伤与减轻内质网应激和维持 HGF 产生有关。
