Division of Gastroenterology, Department of Medicine, School of Medicine, Kurume University, Kurume, Fukuoka 830‑0011, Japan.
Int J Mol Med. 2020 Jul;46(1):427-438. doi: 10.3892/ijmm.2020.4594. Epub 2020 May 5.
The cytokine transforming growth factor‑β (TGF‑β) serves a key role in hepatic fibrosis and has cytostatic effects on hepatocytes. The present study investigated the anti‑fibrogenic and regenerative effects of the TGF‑β receptor type I kinase inhibitor galunisertib (LY2157299) in mice with carbon tetrachloride (CCl4)‑induced liver cirrhosis and in vitro. Mice were intraperitoneally treated with CCl4 for 8 weeks. At week 5, the mice were divided randomly into four treatment groups: Vehicle‑treated; and treated with low‑; middle‑; and high‑dose galunisertib, which was administered from weeks 5‑8. The mice were sacrificed after 8 weeks of CCl4 treatment. Liver fibrosis, as evaluated by histology and determination of hydroxyproline content, progressed during week 4‑8 of CCl4 treatment in the vehicle‑treated mice. Galunisertib treatment dose‑dependently prevented liver fibrosis, as demonstrated by the direct inhibition of α‑smooth muscle actin‑positive activated hepatic stellate cells (HSCs) after 8 weeks of CCl4 treatment. The levels of active matrix metalloproteinase (MMP)‑9 in galunisertib‑treated livers were significantly increased compared with the vehicle‑treated livers. In the high‑dose group, the number of PCNA‑positive hepatocytes and endothelial cells markedly increased compared with the vehicle group. Reverse transcription‑quantitative PCR analysis verified that interleukin‑6 and epiregulin expression levels were significantly increased in livers from the group treated with high‑dose galunisertib compared with the vehicle‑treated group. Galunisertib inhibited the proliferation of activated HSCs and collagen synthesis in addition to restoring MMP activity. Moreover, galunisertib promoted liver remodeling by proliferating hepatocytes and vascular endothelial cells, while significantly increasing liver weight. These results are consistent with the cytostatic action of TGF‑β that negatively regulates liver regeneration, and demonstrated that galunisertib inhibited TGF‑β signaling, halted liver fibrosis progression and promoted hepatic regeneration. The results of the present study suggest that galunisertib may be an effective treatment for liver cirrhosis.
细胞因子转化生长因子-β（TGF-β）在肝纤维化中起关键作用，并对肝细胞具有细胞抑制作用。本研究旨在探讨 TGF-β受体 I 型激酶抑制剂 galunisertib（LY2157299）在四氯化碳（CCl4）诱导的肝纤维化小鼠模型和体外的抗纤维化和再生作用。小鼠经腹腔注射 CCl4 8 周。第 5 周时，将小鼠随机分为 4 组：对照组；低、中、高剂量 galunisertib 组，从第 5 周到第 8 周给药。8 周 CCl4 处理后处死小鼠。通过组织学和羟脯氨酸含量测定评估肝纤维化，结果显示在对照组小鼠 CCl4 处理的第 4-8 周，肝纤维化进展。Galunisertib 治疗呈剂量依赖性地预防肝纤维化，这可通过第 8 周 CCl4 处理后直接抑制α-平滑肌肌动蛋白阳性激活的肝星状细胞（HSCs）来证明。与对照组相比，Galunisertib 处理的肝脏中活性基质金属蛋白酶（MMP）-9 水平显著增加。在高剂量组中，与对照组相比，PCNA 阳性的肝细胞和内皮细胞数量明显增加。逆转录-定量 PCR 分析证实，与对照组相比，高剂量 galunisertib 治疗组的白细胞介素-6 和表皮调节素表达水平显著增加。Galunisertib 除了恢复 MMP 活性外，还抑制激活的 HSCs 增殖和胶原合成。此外，Galunisertib 通过增殖肝细胞和血管内皮细胞促进肝重塑，同时显著增加肝重。这些结果与 TGF-β 的细胞抑制作用一致，后者负性调节肝再生，并表明 galunisertib 抑制 TGF-β 信号转导，阻止肝纤维化进展并促进肝再生。本研究结果表明，Galunisertib 可能是治疗肝硬化的有效方法。
