Sun Xiao-Fei, Gu Lei, Deng Wen-Sheng, Xu Qing
Xiao-Fei Sun, Lei Gu, Wen-Sheng Deng, Qing Xu, Department of General Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
World J Gastroenterol. 2014 Feb 28;20(8):2062-70. doi: 10.3748/wjg.v20.i8.2062.
To investigate the effect of T helper (Th) 17/T regulatory (Treg) cells on hepatic fibrosis in mice and its possible mechanism.
Hepatic fibrosis was induced by intraperitoneal injection of carbon tetrachloride. Hepatic pathological changes were observed by hematoxylin and eosin staining; the protein levels of interleukin (IL)-6, transforming growth factor (TGF)-β and α-smooth muscle actin (SMA) in liver tissue were determined by Western blotting; and the frequency of Th17 and Treg cells in the liver was estimated by flow cytometry. In addition, hepatic stellate cells were isolated from healthy mouse liver and co-cultured with Th17 or Treg cells. Immunofluorescence staining and Western blotting were performed to determine the change in HSC activation.
In the model group, there were different degrees of fibroplasia, degeneration and necrosis. The protein levels of IL-6, TGF-β and α-SMA in liver tissue were significantly higher than those in the control group at 12 wk (P < 0.05). Compared with the control group, the frequency of Th17 cells in the model group was increased but the frequency of Treg cells decreased gradually. Furthermore, at 4, 8 and 12 wk, there were significant differences in the number of Th17 cells (0.52% ± 0.16%, 1.46% ± 0.24%, and 2.60% ± 0.41%, respectively, P < 0.05) and Treg cells (2.99% ± 0.40%, 2.16% ± 0.50%, and 1.49% ± 0.34%, respectively, P < 0.05). In vitro, Th17 cells promoted, whereas Treg cells inhibited the expression of α-SMA, both in a dose-dependent manner, compared with the control group.
Th17/Treg imbalance exists in mice with liver fibrosis, which potentially promotes liver fibrosis via HSC activation.
探讨辅助性T细胞（Th）17/调节性T细胞（Treg）对小鼠肝纤维化的影响及其可能机制。
通过腹腔注射四氯化碳诱导肝纤维化。采用苏木精-伊红染色观察肝脏病理变化；用蛋白质免疫印迹法检测肝组织中白细胞介素（IL）-6、转化生长因子（TGF）-β和α-平滑肌肌动蛋白（SMA）的蛋白水平；用流式细胞术评估肝脏中Th17和Treg细胞的频率。此外，从健康小鼠肝脏中分离肝星状细胞，并与Th17或Treg细胞共培养。采用免疫荧光染色和蛋白质免疫印迹法检测肝星状细胞激活的变化。
模型组出现不同程度的纤维组织增生、变性和坏死。在第12周时，模型组肝组织中IL-6、TGF-β和α-SMA的蛋白水平显著高于对照组（P<0.05）。与对照组相比，模型组Th17细胞频率增加而Treg细胞频率逐渐降低。此外，在第4、8和12周时，Th17细胞数量（分别为0.52%±0.16%、1.46%±0.24%和2.60%±0.41%，P<0.05）和Treg细胞数量（分别为2.99%±0.40%、2.16%±0.50%和1.49%±0.34%，P<0.05）存在显著差异。在体外，与对照组相比，Th17细胞以剂量依赖的方式促进α-SMA的表达，而Treg细胞则抑制α-SMA的表达。
肝纤维化小鼠存在Th17/Treg失衡，可能通过激活肝星状细胞促进肝纤维化。
