Chronic alcohol ingestion modulates hepatic macrophage populations and functions in mice

M Wang, Q You, K Lor, F Chen, B Gao… - Journal of leukocyte …, 2014 - academic.oup.com
M Wang, Q You, K Lor, F Chen, B Gao, C Ju
Journal of leukocyte biology, 2014academic.oup.com
Hepatic Macs, consisting of resident KCs and infiltrating monocytes/IMs, are thought to play
an important role in the pathogenesis of ALD. Previous work has focused on KCs or studied
hepatic Macs as one cell population. The aim of the current study is to distinguish IMs from
KCs and to compare their phenotypes and functions. We show here that a 4-week ethanol
feeding of C57BL/6J mice causes recruitment of IMs into the liver. KCs and IMs can be
distinguished based on their differential expression of F4/80 and CD11b. IMs can be divided …
Abstract
Hepatic Macs, consisting of resident KCs and infiltrating monocytes/IMs, are thought to play an important role in the pathogenesis of ALD. Previous work has focused on KCs or studied hepatic Macs as one cell population. The aim of the current study is to distinguish IMs from KCs and to compare their phenotypes and functions. We show here that a 4-week ethanol feeding of C57BL/6J mice causes recruitment of IMs into the liver. KCs and IMs can be distinguished based on their differential expression of F4/80 and CD11b. IMs can be divided further into two subsets based on their differential expression of Ly6C. KCs and two subsets of IMs were separately purified by FACS. The phagocytosis abilities and the expression profiles of genes related to various functions were compared among different populations of hepatic Macs. Ly6Clow IMs exhibit an anti-inflammatory and tissue-protective phenotype; in contrast, Ly6Chi IMs exhibit a proinflammatory, tissue-damaging phenotype. The ratio of Ly6Chi/Ly6Clow increases when mice chronically fed ethanol were binged, which significantly enhanced liver injury. Moreover, upon phagocytosis of apoptotic hepatocytes, Ly6Chi IMs switch to Ly6Clow IMs. Taken together, chronic ethanol feeding induces the recruitment of two subsets of hepatic IMs, which play different or even opposite roles in regulating liver inflammation and repair. These findings may not only increase our understanding of the complex functions of Macs in the pathogenesis of ALD but also help us to identify novel therapeutic targets for the treatment of this disease.
Oxford University Press