Hepatic Stellate Cells Orchestrate Clearance of Necrotic Cells in a Hypoxia-Inducible Factor-1α–Dependent Manner by Modulating Macrophage Phenotype in Mice
| Autor: | Cheryl E. Rockwell, Ryan Albee, Kate M. O’Brien, Keara Towery, Akie Mochizuki, Aaron Pace, Aaron K. Chow, Kara Kelly, Bryan L. Copple, Katherine Roth, James P. Luyendyk |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 192:3847-3857 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.1303195 |
| Popis: | Hypoxia-inducible factor-1α (HIF-1α) is activated in hepatic stellate cells (HSCs) by hypoxia and regulates genes important for tissue repair. Whether HIF-1α is activated in HSCs after acute injury and contributes to liver regeneration, however, is not known. To investigate this, mice were generated with reduced levels of HIF-1α in HSCs by crossing HIF-1α floxed mice with mice that express Cre recombinase under control of the glial fibrillary acidic protein (GFAP) promoter (i.e., HIF-1α-GFAP Cre+ mice). These mice and control mice (i.e., HIF-1α-GFAP Cre− mice) were treated with a single dose of carbon tetrachloride, and liver injury and repair were assessed. After carbon tetrachloride, HIF-1α was activated in HSCs. Although liver injury was not different between the two strains of mice, during resolution of injury, clearance of necrotic cells was decreased in HIF-1α-GFAP Cre+ mice. In these mice, the persistence of necrotic cells stimulated a fibrotic response characterized by extensive collagen deposition. Hepatic accumulation of macrophages, which clear necrotic cells from the liver after carbon tetrachloride, was not affected by HIF-1α deletion in HSCs. Conversion of macrophages to M1-like, proinflammatory macrophages, which have increased phagocytic activity, however, was reduced in HIF-1α-GFAP Cre+ mice as indicated by a decrease in proinflammatory cytokines and a decrease in the percentage of Gr1hi macrophages. Collectively, these studies have identified a novel function for HSCs and HIF-1α in orchestrating the clearance of necrotic cells from the liver and demonstrated a key role for HSCs in modulating macrophage phenotype during acute liver injury. |
| Databáze: | OpenAIRE |
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