Z Gastroenterol 2011; 49 - P446
DOI: 10.1055/s-0031-1285717

CXCL9 attenuates CCl4 induced angiogenesis and liver fibrosis in vivo

H Sahin 1, C Grouls 2, MM Zaldivar 1, P Schmitz 1, E Borkham-Kamphorst 3, MJ Moeller 4, F Kiessling 5, C Trautwein 1, HE Wasmuth 1
  • 1Medizinische Klinik III (Gastroenterologie, Hepatologie und Stoffwechselerkrankungen), Aachen, Germany
  • 2Klinik für Diagnostische und Interventionelle Radiologie, Aachen, Germany
  • 3Institut für Klinische Chemie und Pathobiochemie, Aachen, Germany
  • 4Medizinische Klinik II (Nephrologie u. Klinische Immunologie), Aachen, Germany
  • 5Experimentelle Molekulare Bildgebung, Aachen, Germany

Background and aims: Previous findings indicate that the chemokine receptor CXCR3 and its ligands are crucially involved in liver fibrosis. Neoangiogenesis critically contributes to liver scarring but the specific role of ELR-negative, angiostatic chemokines in the disease process remains unclear. Here we investigate the role of neoangiogenesis in CCl4 induced liver fibrosis in Cxcr3-/- and wild-type mice. Furthermore, we assess the possibiliy of attenuation of angiogenesis and associated liver damage by therapeutic treatment with the angiostatic chemokine Cxcl9.

Methods: Liver fibrosis was induced by intraperitoneal injections of CCl4 in Cxcr3-/- and wild-type mice for six weeks. In a separate experiment, Cxcl9 (1µg) or vehicle was administered daily concomitantly with CCl4 to wild-type mice. Angiogenesis was determined by immunofluorescence staining of CD31 and by in vivo molecular imaging of VEGF receptor-2 (VEGFR-2) using fluorescence tomography. The total collagen content was measured both by quantitative analysis of Sirius red staining of liver sections and by hydroxyproline concentration. In vitro, migration (Boyden chamber) as well as proliferation (BrdU assay) of endothelial cells was dissected after stimulation with VEGF in the presence or absence of Cxcl9.

Results: The results show that fibrosis progression in Cxcr3-/- mice is strongly linked to enhanced neoangiogenesis and VEGF/Flk-1 expression compared to their wild-type littermates (both P<0.05). Functionally, the angiostatic chemokine Cxcl9 displays strong anti-proliferative and anti-migratory effects on VEGF stimulated endothelial cells (both P<0.05) via reduced ERK phosphorylation in vitro. Accordingly, systemic administration of Cxcl9 leads to a strong attenuation of neoangiogenesis and experimental liver fibrosis (both P<0.05) in vivo.

Conclusions: The results identify Cxcl9 as a critical counter-regulatory chemokine of liver fibrosis in vivo which mediates potent angiostatic and consecutive anti-fibrotic effects. The amelioration of liver damage by systemic Cxcl9 offers a potential novel strategy for treatment of chronic liver diseases.