Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
Department of Hematology, The First Affiliated Hospital of Jishou University, Jishou, Hunan 416000, P.R. China.
Int J Mol Med. 2018 Sep;42(3):1756-1764. doi: 10.3892/ijmm.2018.3747. Epub 2018 Jun 27.
Growth differentiation factor‑15 (GDF‑15) is a transforming growth factor (TGF)‑β superfamily member with a poorly characterized biological activity, speculated to be implicated in several diseases. The present study aimed to determine whether GDF‑15 participates in sepsis‑induced acute liver injury in mice. Lipopolysaccharide (LPS) and D‑galactosamine (D‑GalN) were administered to mice to induce acute liver injury. Survival of mice, histological changes in liver tissue, and levels of inflammatory biomarkers in serum and liver tissue were evaluated following treatment with GDF‑15. The underlying mechanism was investigated by western blotting, ELISA, flow cytometry, and reverse transcription‑quantitative polymerase chain reaction using Kupffer cells. The results demonstrated that GDF‑15 prevented LPS/D‑GalN‑induced death, increase in inflammatory cell infiltration and serum alanine aminotransferase and aspartate aminotransferase activities. In addition, GDF‑15 treatment reduced the production of hepatic malondialdehyde and myeloperoxidase, and attenuated the increase of interleukin (IL)‑6, tumor necrosis factor (TNF)‑α, and IL‑1β expression in serum and liver tissue, accompanied by inducible nitric oxide synthase (iNOS) inactivation in the liver. Similar changes in the expression of inflammatory cytokines, IL‑6, TNF‑α and IL‑1β, and iNOS activation were observed in the Kupffer cells. Further mechanistic experiments revealed that GDF‑15 effectively protected against LPS‑induced nuclear factor (NF)‑κB pathway activation by regulating TGFβ‑activated kinase 1 (TAK1) phosphorylation in Kupffer cells. In conclusion, GDF‑15 reduced the activation of pro‑inflammatory factors, and prevented LPS‑induced liver injury, most likely by disrupting TAK1 phosphorylation, and consequently inhibiting the activation of the NF‑κB pathway in the liver.
生长分化因子 15(GDF-15)是转化生长因子(TGF)-β超家族成员,其生物学活性特征描述不佳,据推测与多种疾病有关。本研究旨在确定 GDF-15 是否参与了小鼠脓毒症诱导的急性肝损伤。采用脂多糖(LPS)和 D-半乳糖胺(D-GalN)处理小鼠以诱导急性肝损伤。用 GDF-15 处理后,评估小鼠的存活率、肝组织的组织学变化以及血清和肝组织中炎症生物标志物的水平。使用枯否细胞通过 Western blot、ELISA、流式细胞术和逆转录-定量聚合酶链反应来研究潜在的机制。结果表明,GDF-15 可预防 LPS/D-GalN 诱导的死亡、炎症细胞浸润增加以及血清丙氨酸氨基转移酶和天冬氨酸氨基转移酶活性升高。此外,GDF-15 治疗可减少肝丙二醛和髓过氧化物酶的产生,并减弱血清和肝组织中白细胞介素(IL)-6、肿瘤坏死因子(TNF)-α和 IL-1β表达的增加,同时肝脏中诱导型一氧化氮合酶(iNOS)失活。在枯否细胞中观察到炎症细胞因子、IL-6、TNF-α和 IL-1β以及 iNOS 激活的表达也发生了类似的变化。进一步的机制实验表明,GDF-15 通过调节枯否细胞中 TGFβ-激活激酶 1(TAK1)磷酸化,有效防止 LPS 诱导的核因子(NF)-κB 途径激活。总之,GDF-15 通过破坏 TAK1 磷酸化,从而抑制 NF-κB 通路在肝脏中的激活,减少促炎因子的激活,并防止 LPS 诱导的肝损伤。