Extracellular vesicles from mice with alcoholic liver disease carry adistinct protein cargo and induce macrophage activation viaHsp90

摘要

A salient feature of alcoholic liver disease (ALD) is Kupffer cell (KC) activation and recruitment of inflammatory monocytes/macrophages (Mo/MØ). These key cellular events of ALD pathogenesis may be mediated by extracellular vesicles (EVs). EVs transfer biomaterials, including proteins and miRNAs, and have recently emerged as important effectors of intercellular communication. We hypothesized that circulating EVs from mice with ALD have a protein cargo characteristic of the disease and mediate biological effects by activating immune cells. The total number of circulating EVs was increased in mice with ALD (ALD-EV) compared to pair-fed controls (control-EV). Mass spectrometry analysis of circulating EVs revealed a distinct signature for proteins involved in inflammatory responses, cellular development and cellular movement between ALD-EVs and control-EVs. We also identified uniquely important proteins in ALD-EVs that were not present in control-EVs. When ALD-EVs were injected intravenously into alcohol-naïve mice, we found evidence of uptake of ALD-EVs in recipient livers in hepatocytes and MØs. Hepatocytes isolated from mice after transfer of ALD-EVs, but not control-EVs, showed increased MCP-1 mRNA and protein expression suggesting a biologicaleffect of ALD-EVs. Compared to control-EV recipient mice, ALD-EV recipient micehad increased numbers of F4/80^hiCD11b^lo KCs and increasedpercentages of TNFα⁺IL-12/23⁺(inflammatory/M1) KCs and infiltrating monocytes(F4/80^intCD11b^hi) while the percentage ofCD206⁺CD163⁺ (anti-inflammatory/M2)KCs was decreased. In vitro, ALD-EVs increased TNFα andIL-1β production in MØ and reduced CD163 and CD206 expression.We identified Heat shock protein 90 (Hsp90) in ALD-EVs as the mediator ofALD-EV-induced MØ activation.ConclusionOur study indicates a specific protein signature of ALD-EVs anddemonstrates a functional role of circulating EVs containing Hsp90 inmediating KC/MØ activation in the liver.