BaCKgRoUND aND aIMS: Acetaminophen (APAP) overdose represents the most frequent cause of acute liver failure, resulting in death or liver transplantation in more than one third of patients in the United States. The effectiveness of the only antidote, N-acetylcysteine, declines rapidly after APAP ingestion, long before patients are admitted to the clinic with symptoms of severe liver injury. The direct hepatotoxicity of APAP triggers a cascade of innate immune responses that may exacerbate or limit the progression of tissue damage. A better understanding of this complex mechanism will help uncover targets for therapeutic interventions. appRoaCH aND ReSUltS: We observed that APAP challenge caused stabilization of hypoxia-inducible factors (HIFs) in the liver and hepatic macrophages (MΦs), particularly HIF-2α. Genetic deletion of the HIF-2α gene in myeloid cells (HIF-2α mye/− ) markedly exacerbated APAP-induced liver injury (AILI) without affecting APAP bioactivation and detoxification. In contrast, hepatic and serum levels of the hepatoprotective cytokine interleukin 6 (IL-6), its downstream signal transducer and transcription factor 3 activation in hepatocytes, as well as hepatic MΦ IL-6 expression were markedly reduced in HIF-2α mye/− mice compared to wildtype mice post-APAP challenge. In vitro experiments revealed that hypoxia induced IL-6 production in hepatic MΦs and that such induction was abolished in HIF-2α-deleted hepatic MΦs. Restoration of IL-6 by administration of exogenous IL-6 ameliorated AILI in HIF-2α mye/− mice. Finally, IL-6-mediated hepatoprotection against AILI was abolished in hepatocyte-specific IL-6 receptor knockout mice. CoNClUSIoNS:The data demonstrate that APAP treatment leads to HIF-2α stabilization in hepatic MΦs and that HIF-2α subsequently reprograms hepatic MΦs to produce the hepatoprotective cytokine IL-6, thereby ameliorating AILI.

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Serum myoglobin is one of the earliest markers for the diagnosis of acute myocardial infarction. It is, therefore, critical to develop a point-of-care testing technology for myoglobin detection. In this work, we reported a sensitive plasmonic immunoassay-based on enzyme-mediated localized surface plasmon resonance change of gold nanorods for the point-of-care testing detection of myoglobin. In addition, we developed a novel plasmonic immunoassay reader using the ambient light sensor of smart phone to increase the accessibility and utility of the plasmonic immunoassay. The linear detection range of gold nanorods-based plasmonic immunoassay for myoglobin detection was 0.1–1000 ng mL−1 and the limit of detection was 0.057 ng mL−1. Myoglobin in serum samples was also analyzed by the plasmonic immunoassay. The results were significantly correlated with those of conventional enzyme-linked immunosorbent assay. The plasmonic immunoassay, coupled with smart phone-based reader, could be widely used for point-of-care testing application of acute myocardial infarction, especially in the regions with limited technological resources.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2806-9) contains supplementary material, which is available to authorized users.

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Macrophages are divided into two subpopulations: classically activated macrophages (M1) and alternatively activated macrophages (M2). BCG (Bacilli Calmette-Guérin) activates disabled naïve macrophages to M1 macrophages, which act as inflammatory, microbicidal and tumoricidal cells through cell-cell contact and/or the release of soluble factors. Various transcription factors and signaling pathways are involved in the regulation of macrophage activation and polarization. We discovered that BCG-activated macrophages (BAM) expressed a new molecule, and we named it Novel Macrophage Activated Associated Protein 1 (NMAAP1).The current study found that the overexpression of NMAAP1 in macrophages results in M1 polarization with increased expression levels of M1 genes, such as inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), Interleukin 6 (IL-6), Interleukin 12 (IL-12), Monocyte chemoattractant protein-1 (MCP-1) and Interleukin-1 beta (IL-1β), and decreased expression of some M2 genes, such as Kruppel-like factor 4 (KLF4) and suppressor of cytokine signaling 1 (SOCS1), but not other M2 genes, including arginase-1 (Arg-1), Interleukin (IL-10), transforming growth factor beta (TGF-β) and found in inflammatory zone 1 (Fizz1). Moreover, NMAAP1 overexpression in the RAW264.7 cell line increased cytotoxicity against MCA207 tumor cells, which depends on increased inflammatory cytokines rather than cell-cell contact. NMAAP1 also substantially enhanced the phagocytic ability of macrophages, which implies that NMAAP1 promoted macrophage adhesive and clearance activities. Our results indicate that NMAAP1 is an essential molecule that modulates macrophages phenotype and plays an important role in macrophage tumoricidal functions.

BCG-activated macrophages (BAM) could kill the tumor cells through cell-cell contact. In this process membrane proteins play an important role. However, up to date, few membrane proteins were revealed. In this study, we selected a surface molecule named Trim59, which was specifically expressed on BAM membrane (compared with the negative control). We cloned and prokaryoticly expressed the extracellular domain of Trim59, purified the recombinant protein and generated polyclonal antibodies. Immunohistochemistry showed that Trim59 abundantly expressed in spleen, stomach and ovary; intermediately expressed in brain, lung, kidney, muscle and intestine; but not in thymus, liver, heart, uterus. Using the antibodies to block Trim59 on BAM significantly reduced BAM cytotoxicity against MCA207 cells. This demonstrated that Trim59 serves as an indispensable molecule in maintaining BAM activity. Overexpression of Trim59 in Raw264.7 cell line failed to lyse target MCA207 cells, which potentiated Trim59 per se could not enhance macrophage cytotoxicity; on another hand, overexpression of Trim59 enhance the pinocytosis and Phagocytosis activity of Raw-264.7, which imply Trim59 might mediate the cell-molecule interaction. Our results indicate Trim59 might be an essential accessory molecule in mediating BAM tumoricidal functions; and Trim59 is a phagocytosis-correlated molecule.

Liver fibrosis represents a severe stage of liver damage, with hallmarks of inflammation, hepatic stellate cell activation, and extracellular matrix accumulation. Although previous studies demonstrated γδ T cells are involved in liver fibrosis, the precise role and mechanisms of γδ T cells migrating to fibrotic liver have not been elucidated. Here, we aim to investigate the functional subsets of γδ T cells in hepatic fibrosis and to further explore the underlying causes and drivers of migration. In this study, we observed that γδ T cells accumulate in fibrotic liver. Adoptive transfer of γδ T, especially Vγ4 γδ T subset, can significantly alleviate liver fibrosis. In addition, CCl4 treatment also leads to activation of mTOR signaling in γδ T cells. Genetic deletion of the Rictor gene, but not Raptor, in γδ T cells markedly exacerbated liver fibrosis. Mechanistically, CCl4-induced liver injury causes macrophage accumulation in the liver, and IL-1β produced by macrophages promotes mTORC2 signaling activation in γδ T cells, which upregulates T-bet expression and eventually promotes CXCR3 transcription to drive γδ T cell migration. Moreover, hepatic γδ T cells ameliorated liver fibrosis by cytotoxicity against activated hepatic stellate cells in FasL-dependent manner, and secrete IFN-γ to inhibit the differentiation of pro-fibrotic Th17 cells. Thus, IL-1β-activated mTORC2 signaling in γδ T cells upregulates CXCR3 expression, which is critical for IFN-γ+ γδ T cells migration into the liver and amelioration of liver fibrosis. Our findings indicate that targeting the mTORC2 or CXCR3 in γδ T cells could be considered as a promising approach for γδ T cell immunotherapy against liver fibrosis.