Piao Nanzhe, Ikejima Kenichi, Kon Kazuyoshi, Aoyama Tomonori, Osada Taro, Takei Yoshiyuki, Sato Nobuhiro, Watanabe Sumio
Department of Gastroenterology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan.
Life Sci. 2009 Oct 21;85(17-18):617-24. doi: 10.1016/j.lfs.2009.07.013. Epub 2009 Aug 7.
In this study, we investigated the effect of synthetic triglyceride containing an arachidonic acid branch (8A8) on lipopolysaccharide (LPS)-induced production of tumor necrosis factor (TNF)-alpha and nitric oxide (NO) in macrophages, and LPS-induced liver injury in the rat.
RAW264.7 macrophages were co-incubated with 8A8 and LPS (100ng/ml), and TNF-alpha mRNA/protein levels, nuclear factor (NF)-kappaB DNA binding activity, expression of inducible-type NO synthase (NOS2), and NO(2) production were measured. Male Wistar rats were given a single intraperitoneal injection of 8A8 prior to an intravenous injection of LPS (5mg/kg), and liver histology, apoptotic cell death, serum TNF-alpha levels, and hepatic TNF-alpha mRNA were then evaluated.
LPS-induced increases in TNF-alpha production in RAW264.7 macrophages were blunted by 8A8 in a dose-dependent manner, with 40% inhibition at 100ppm. Further, 8A8 dose-dependently prevented LPS-induced increases in TNF-alpha mRNA levels, as well as NF-kappaB DNA binding activities, in RAW264.7 macrophages. LPS-induction of NOS2 and NO(2) release from these cells was also decreased by 8A8 in a dose-dependent manner. In vivo, LPS-induced liver injury, including hepatocyte apoptosis, was largely prevented when 8A8 (100microl/kg) was given 30min prior to LPS. Indeed, 8A8 blunted increases in both serum TNF-alpha and hepatic TNF-alpha mRNA levels significantly.
LPS-induced liver injury was prevented by 8A8 most likely through the inhibition of TNF-alpha and NO production from hepatic macrophages, suggesting a potential usefulness of 8A8 as an immuno-modulating nutrient for prevention/treatment of endotoxin-related organ injuries including alcoholic liver disease and non-alcoholic steatohepatitis (NASH).
在本研究中，我们探究了含有花生四烯酸分支的合成甘油三酯（8A8）对脂多糖（LPS）诱导的巨噬细胞中肿瘤坏死因子（TNF）-α和一氧化氮（NO）生成以及对LPS诱导的大鼠肝损伤的影响。
将RAW264.7巨噬细胞与8A8和LPS（100ng/ml）共同孵育，然后检测TNF-α mRNA/蛋白水平、核因子（NF）-κB DNA结合活性、诱导型一氧化氮合酶（NOS2）的表达以及NO₂生成。雄性Wistar大鼠在静脉注射LPS（5mg/kg）前腹腔注射一次8A8，随后评估肝脏组织学、凋亡细胞死亡、血清TNF-α水平以及肝脏TNF-α mRNA。
8A8以剂量依赖的方式抑制LPS诱导的RAW264.7巨噬细胞中TNF-α生成增加，在100ppm时抑制率达40%。此外，8A8还以剂量依赖的方式阻止LPS诱导的RAW264.7巨噬细胞中TNF-α mRNA水平以及NF-κB DNA结合活性增加。8A8也以剂量依赖的方式降低LPS诱导的这些细胞中NOS2和NO₂释放。在体内，在LPS注射前30分钟给予8A8（100μl/kg）可很大程度上预防LPS诱导的肝损伤，包括肝细胞凋亡。实际上，8A8显著抑制血清TNF-α和肝脏TNF-α mRNA水平升高。
8A8很可能通过抑制肝巨噬细胞产生TNF-α和NO来预防LPS诱导的肝损伤，这表明8A8作为一种免疫调节营养素在预防/治疗包括酒精性肝病和非酒精性脂肪性肝炎（NASH）在内的内毒素相关器官损伤方面具有潜在用途。
