First Author | Baker B | Year | 2015 |
Journal | J Biol Chem | Volume | 290 |
Issue | 10 | Pages | 6670-8 |
PubMed ID | 25586187 | Mgi Jnum | J:287068 |
Mgi Id | MGI:6414677 | Doi | 10.1074/jbc.M114.611442 |
Citation | Baker B, et al. (2015) Alteration of lysosome fusion and low-grade inflammation mediated by super-low-dose endotoxin. J Biol Chem 290(10):6670-8 |
abstractText | Subclinical super-low-dose endotoxin LPS is a risk factor for the establishment of low-grade inflammation during the pathogenesis and progression of chronic diseases. However, the underlying mechanisms are not well understood. At the cellular level, a disruption of lysosome fusion with endosomes or autophagosomes may contribute to the potentiation of low-grade inflammation. In this study, we identified that subclinical super-low-dose endotoxin LPS can potently inhibit the process of endosome acidification and lysosome fusion with endosomes or autophagosomes in primary macrophages. Super-low-dose LPS induced the inhibitory phosphorylation of VPS34, thus leading to the disruption of endosome-lysosome fusion. This effect may depend upon the clearance and relocation of Tollip in macrophages by super-low-dose LPS. Consistent with this notion, Tollip-deficient macrophages had constitutively elevated levels of VPS34 inhibitory phosphorylation and constitutive disruption of endosome-lysosome fusion. By employing a skin excision wound-healing model, we observed that Tollip-deficient mice had significantly elevated levels of cell stress and reduced wound repair. This study reveals a novel mechanism responsible for the modulation of endosome-lysosome fusion and low-grade inflammation in innate macrophages. |