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IL‐34 and macrophage colony‐stimulating factor are overexpressed in hepatitis C virus fibrosis and induce profibrotic macrophages that promote collagen synthesis by hepatic stellate cells
Author(s) -
Preisser Laurence,
Miot Charline,
GuillouGuillemette Hélène,
Beaumont Elodie,
Foucher Etienne D,
Garo Erwan,
Blanchard Simon,
Frémaux Isabelle,
Croué Anne,
Fouchard Isabelle,
LunelFabiani Françoise,
Boursier Jérôme,
Roingeard Philippe,
Calès Paul,
Delneste Yves,
Jeannin Pascale
Publication year - 2014
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.27328
Subject(s) - hepatic stellate cell , chemokine , fibrosis , hepatic fibrosis , monocyte , macrophage colony stimulating factor , biology , hepatitis c virus , immunology , macrophage , inflammation , medicine , endocrinology , virus , in vitro , biochemistry
Chronic hepatitis C virus (HCV) infection is characterized by progressive hepatic fibrosis, a process dependent on monocyte recruitment and accumulation into the liver. The mediators expressed in chronically injured liver that control the differentiation of human monocytes into profibrotic macrophages (Mφ) remain poorly defined. We report that chronically HCV‐infected patients with high fibrosis stages have higher serum levels of macrophage colony‐stimulating factor (M‐CSF) and interleukin (IL)−34 than HCV‐infected patients with lower fibrosis stages and healthy subjects. Immunohistochemistry reveals an intense expression of IL‐34 and M‐CSF by hepatocytes around liver lesions. In addition, HCV infection and inflammatory cytokines enhance the in vitro production of IL‐34 and M‐CSF by hepatocytes. We next analyzed the acquisition of profibrotic properties by Mφ generated with M‐CSF (M‐CSF‐Mφ) or IL‐34 (IL‐34‐Mφ). M‐CSF and IL‐34 up‐regulate the expression, by differentiating monocytes, of chemokine (C‐C motif) ligand (CCL)2, CCL4, C‐C chemokine receptor (CCR)1, and CCR5, which are involved in monocyte recruitment/Mφ accumulation in liver lesions. M‐CSF‐Mφ and IL‐34‐Mφ also express the hepatic stellate cell (HSC) activators, platelet‐derived growth factor, transforming growth factor beta, and galectin‐3. IL‐34‐Mφ and M‐CSF‐Mφ induce type I collagen synthesis by HSCs, the main collagen‐producing cells in liver fibrosis. IL‐13, whose expression correlates with the fibrosis stage in HCV‐infected patients, decreases the expression of the collagenase, matrix metalloproteinase 1, by IL‐34‐Mφ and M‐CSF‐Mφ, thereby enhancing collagen synthesis. By inhibiting the production of interferon‐gamma (IFN‐γ) by activated natural killer cells, IL‐34‐Mφ and M‐CSF‐Mφ prevent the IFN‐γ‐induced killing of HSCs. Conclusion : These results identify M‐CSF and IL‐34 as potent profibrotic factors in HCV liver fibrosis. (H epatology 2014;60:1878–1889)