Laboratory of Liver Disease, Department of Infectious Disease, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Alcohol Clin Exp Res. 2022 May;46(5):724-735. doi: 10.1111/acer.14815. Epub 2022 Apr 8.
Alcoholic liver disease (ALD) is associated with high morbidity and mortality worldwide. The pathogenesis of ALD is not completely understood. Although accumulating evidence suggests an important role of glial cell line-derived neurotrophic factor (GDNF) in several diseases, there are no data concerning its role in ALD. This study compared patients with ALD with control subjects and used a mouse model and a cell culture model to investigate the function of GDNF in ALD and its mechanism of action in hepatocyte injury.
Serum levels of GDNF were measured in 25 patients with ALD and 25 healthy control subjects. A 4-week Lieber-DeCarli ethanol (EtOH) liquid diet combined with the Gao-Binge model was used in the mouse study. Mouse primary hepatocytes and Huh-7 cells were used for cell experiments. The parameters of liver injury, inflammatory cytokines, and lipid metabolism were measured.
Patients with alcoholic hepatitis had higher serum GDNF than control subjects. Expression of GDNF mRNA and protein was markedly increased in mice in the chronic-plus-binge ALD mouse model. The level of GDNF mRNA was upregulated in primary hepatic stellate cells isolated from ethanol-fed mouse liver. Ethanol induced GDNF expression in LX2 cells. The levels of inflammatory cytokines (tumor necrosis factor α, interleukin 1β, and monocyte chemotactic protein 1) were significantly increased after GDNF stimulation in primary hepatocytes and Huh-7 cells. After GDNF stimulation, levels of both p-AKT and p-NF-κB were significantly increased in primary hepatocytes and Huh-7 cells. The NF-κB activity induced by GDNF was significantly decreased by an NF-κB inhibitor, which limited hepatocyte injury and inflammation.
The concentration of GDNF is increased in the circulation of ALD patients. GDNF promotes alcohol-induced liver injury and inflammation via the activation of NF-κB, which mediates hepatocyte injury and inflammatory cytokine expression. Based on these findings, GDNF is a potential therapeutic target for preventing or ameliorating liver injury in ALD.
酒精性肝病（ALD）在全球范围内与高发病率和高死亡率相关。ALD 的发病机制尚不完全清楚。尽管越来越多的证据表明胶质细胞源性神经营养因子（GDNF）在多种疾病中具有重要作用，但尚无关于其在 ALD 中作用的数据。本研究比较了 ALD 患者与对照组，并使用小鼠模型和细胞培养模型研究了 GDNF 在 ALD 中的功能及其在肝细胞损伤中的作用机制。
检测了 25 例 ALD 患者和 25 例健康对照者的血清 GDNF 水平。在小鼠研究中使用了为期 4 周的 Lieber-DeCarli 乙醇（EtOH）液体饮食联合 Gao-Binge 模型。使用小鼠原代肝细胞和 Huh-7 细胞进行细胞实验。测定肝损伤、炎症细胞因子和脂质代谢的参数。
酒精性肝炎患者的血清 GDNF 水平高于对照组。在慢性加 binge 型 ALD 小鼠模型中，小鼠的 GDNF mRNA 和蛋白表达明显增加。从乙醇喂养的小鼠肝中分离的原代肝星状细胞中，GDNF mRNA 水平上调。乙醇诱导 LX2 细胞表达 GDNF。在原代肝细胞和 Huh-7 细胞中，GDNF 刺激后炎症细胞因子（肿瘤坏死因子-α、白细胞介素 1β 和单核细胞趋化蛋白 1）水平显著升高。在原代肝细胞和 Huh-7 细胞中，GDNF 刺激后 p-AKT 和 p-NF-κB 水平均显著升高。NF-κB 抑制剂显著降低了 GDNF 诱导的 NF-κB 活性，从而限制了肝细胞损伤和炎症。
ALD 患者循环中的 GDNF 浓度增加。GDNF 通过激活 NF-κB 促进酒精诱导的肝损伤和炎症，NF-κB 介导肝细胞损伤和炎症细胞因子表达。基于这些发现，GDNF 是预防或改善 ALD 肝损伤的潜在治疗靶点。
