Jianlan Chang1, Tian Lan2, Changzheng Li2, Xiaoqian Ji2, Lingyun Zheng2, Hongju Gou3, Yitao Ou2, Teng Wu2, Cuiling Qi2, Qianqian Zhang2, Jiangchao Li2, Quliang Gu2, Dingwen Wen2, Liu Cao4, Liang Qiao5, Yanqing Ding6, Lijing Wang7. 1. Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Department of Oncology, Affiliated Heping Hospital of Changzhi Medical College, Changzhi, China. 2. Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou 510006, China. 3. Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China. 4. Department of Developmental Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China. 5. Storr Liver Centre, the Westmead Millennium Institute for Medical Research, the University of Sydney, NSW 2145, Australia. Electronic address: liang.qiao@sydney.edu.au. 6. Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China. Electronic address: dyq@fimmu.com. 7. Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou 510006, China. Electronic address: wanglijing62@163.com.
Abstract
BACKGROUND & AIMS: The secretory protein Slit2 and its receptor Robo1 are believed to regulate cell growth and migration. Here, we aimed to determine whether Slit2-Robo1 signaling mediates the pathogenesis of liver fibrosis. METHODS: Serum levels of Slit2 in patients with liver fibrosis were determined by ELISA. Liver fibrosis was induced in wild-type (WT), Slit2 transgenic (Slit2-Tg) and Robo1(+/-)Robo2(+/-) double heterozygotes (Robo1/2(+/-)) mice by carbon tetrachloride (CCl4). The functional contributions of Slit2-Robo1 signaling in liver fibrosis and activation of hepatic stellate cells (HSCs) were investigated using primary mouse HSCs and human HSC cell line LX-2. RESULTS: Significantly increased serum Slit2 levels and hepatic expression of Slit2 and Robo1 were observed in patients with liver fibrosis. Compared to WT mice, Slit2-Tg mice were much more vulnerable to CCl4-induced liver injury and more readily develop liver fibrosis. Development of hepatic fibrosis in Slit2-Tg mice was associated with a stronger hepatic expression of collagen I and α-smooth muscle actin (α-SMA). However, liver injury and hepatic expression of collagen I and α-SMA were attenuated in CCl4-treated Robo1/2(+/-) mice in response to CCl4 exposure. In vitro, Robo1 neutralizing antibody R5 and Robo1 siRNA downregulated phosphorylation of Smad2, Smad3, PI3K, and AKT in HSCs independent of TGF-β1. R5 and Robo1 siRNA also inhibited the expression of α-SMA by HSCs. Finally, the protective effect of R5 on the CCl4-induced liver injury and fibrosis was further verified in mice. CONCLUSIONS: Slit2-Robo1 signaling promotes liver injury and fibrosis through activation of HSCs.
BACKGROUND & AIMS: The secretory protein Slit2 and its receptor Robo1 are believed to regulate cell growth and migration. Here, we aimed to determine whether Slit2-Robo1 signaling mediates the pathogenesis of liver fibrosis. METHODS: Serum levels of Slit2 in patients with liver fibrosis were determined by ELISA. Liver fibrosis was induced in wild-type (WT), Slit2 transgenic (Slit2-Tg) and Robo1(+/-)Robo2(+/-) double heterozygotes (Robo1/2(+/-)) mice by carbon tetrachloride (CCl4). The functional contributions of Slit2-Robo1 signaling in liver fibrosis and activation of hepatic stellate cells (HSCs) were investigated using primary mouse HSCs and human HSC cell line LX-2. RESULTS: Significantly increased serum Slit2 levels and hepatic expression of Slit2 and Robo1 were observed in patients with liver fibrosis. Compared to WT mice, Slit2-Tg mice were much more vulnerable to CCl4-induced liver injury and more readily develop liver fibrosis. Development of hepatic fibrosis in Slit2-Tg mice was associated with a stronger hepatic expression of collagen I and α-smooth muscle actin (α-SMA). However, liver injury and hepatic expression of collagen I and α-SMA were attenuated in CCl4-treated Robo1/2(+/-) mice in response to CCl4 exposure. In vitro, Robo1 neutralizing antibody R5 and Robo1 siRNA downregulated phosphorylation of Smad2, Smad3, PI3K, and AKT in HSCs independent of TGF-β1. R5 and Robo1 siRNA also inhibited the expression of α-SMA by HSCs. Finally, the protective effect of R5 on the CCl4-induced liver injury and fibrosis was further verified in mice. CONCLUSIONS:Slit2-Robo1 signaling promotes liver injury and fibrosis through activation of HSCs.
Authors: Kathleen E Tumelty; Nathan Higginson-Scott; Xueping Fan; Piyush Bajaj; Kelly M Knowlton; Michael Shamashkin; Anthony J Coyle; Weining Lu; Stephen P Berasi Journal: J Biol Chem Date: 2018-01-09 Impact factor: 5.157
Authors: Filipa Franquinho; Joana Nogueira-Rodrigues; Joana M Duarte; Sofia S Esteves; Christin Carter-Su; Anthony P Monaco; Zoltán Molnár; Antonio Velayos-Baeza; Pedro Brites; Mónica M Sousa Journal: Cereb Cortex Date: 2017-03-01 Impact factor: 4.861