Centre for Liver Disease Research, School of Medicine, The University of Queensland, Princess Alexandra Hospital, Brisbane 4102, Queensland, Australia.
World J Gastroenterol. 2012 Apr 21;18(15):1732-44. doi: 10.3748/wjg.v18.i15.1732.
To investigate the influence of macrophages on hepatocyte phenotype and function.
Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte or macrophage-conditioned medium on HepG2 mRNA and protein expression determined. The in vivo relevance of these findings was confirmed using liver biopsies from 147 patients with hepatitis C virus (HCV) infection.
Conditioned media from macrophages, but not monocytes, induced a transient morphological change in hepatocytes associated with upregulation of vimentin (7.8 ± 2.5-fold, P = 0.045) and transforming growth factor (TGF)-β1 (2.6 ± 0.2-fold, P < 0.001) and downregulation of epithelial cadherin (1.7 ± 0.02-fold, P = 0.017) mRNA expression. Microarray analysis revealed significant upregulation of lipocalin-2 (17-fold, P < 0.001) and pathways associated with inflammation, and substantial downregulation of pathways related to hepatocyte function. In patients with chronic HCV, real-time polymerase chain reaction and immunohistochemistry confirmed an increase in lipocalin-2 mRNA (F0 1.0 ± 0.3, F1 2.2 ± 0.2, F2 3.0 ± 9.3, F3/4 4.0 ± 0.8, P = 0.003) and protein expression (F1 1.0 ± 0.5, F2 1.3 ± 0.4, F3/4 3.6 ± 0.4, P = 0.014) with increasing liver injury. High performance liquid chromatography-tandem mass spectrometry analysis identified elevated levels of matrix metalloproteinase (MMP)-9 in macrophage-conditioned medium, and a chemical inhibitor of MMP-9 attenuated the change in morphology and mRNA expression of TGF-β1 (2.9 ± 0.2 vs 1.04 ± 0.1, P < 0.001) in macrophage-conditioned media treated HepG2 cells. In patients with chronic HCV infection, hepatic mRNA expression of CD163 (F0 1.0 ± 0.2, F1/2 2.8 ± 0.3, F3/4 5.3 ± 1.0, P = 0.001) and MMP-9 (F0 1.0 ± 0.4, F1/2 2.8 ± 0.3, F3/4 4.1 ± 0.8, P = 0.011) was significantly associated with increasing stage of fibrosis.
Secreted macrophage products alter the phenotype and function of hepatocytes, with increased expression of inflammatory mediators, suggesting that hepatocytes actively participate in liver injury.
研究巨噬细胞对肝细胞表型和功能的影响。
通过佛波醇肉豆蔻酸乙酯刺激将 THP-1 单核细胞分化为巨噬细胞，并确定单核细胞或巨噬细胞条件培养基对 HepG2 mRNA 和蛋白表达的影响。使用来自 147 例丙型肝炎病毒（HCV）感染患者的肝活检确认这些发现的体内相关性。
巨噬细胞而非单核细胞的条件培养基诱导肝细胞发生短暂的形态变化，伴有波形蛋白（7.8 ± 2.5 倍，P = 0.045）和转化生长因子-β1（2.6 ± 0.2 倍，P < 0.001）的上调和上皮钙黏蛋白（1.7 ± 0.02 倍，P = 0.017）mRNA 表达的下调。微阵列分析显示脂联素-2（17 倍，P < 0.001）和与炎症相关的途径显著上调，以及与肝细胞功能相关的途径显著下调。在慢性 HCV 患者中，实时聚合酶链反应和免疫组织化学证实脂联素-2 mRNA 表达增加（F0 1.0 ± 0.3、F1 2.2 ± 0.2、F2 3.0 ± 9.3、F3/4 4.0 ± 0.8，P = 0.003）和蛋白表达（F1 1.0 ± 0.5、F2 1.3 ± 0.4、F3/4 3.6 ± 0.4，P = 0.014）随着肝损伤的增加而增加。高效液相色谱-串联质谱分析鉴定出巨噬细胞条件培养基中基质金属蛋白酶（MMP）-9 水平升高，MMP-9 的化学抑制剂减弱了 TGF-β1 在巨噬细胞条件培养基处理的 HepG2 细胞中的形态和 mRNA 表达变化（2.9 ± 0.2 对 1.04 ± 0.1，P < 0.001）。在慢性 HCV 感染患者中，肝组织中 CD163（F0 1.0 ± 0.2、F1/2 2.8 ± 0.3、F3/4 5.3 ± 1.0，P = 0.001）和 MMP-9（F0 1.0 ± 0.4、F1/2 2.8 ± 0.3、F3/4 4.1 ± 0.8，P = 0.011）的 mRNA 表达与纤维化分期的增加显著相关。
分泌的巨噬细胞产物改变了肝细胞的表型和功能，炎症介质表达增加，提示肝细胞积极参与肝损伤。
