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Aims Atherosclerosis-related deaths from heart attacks and strokes remain leading causes of global mortality, despite the use of lipid-lowering statins. Thus, there is an urgent need to develop additional therapies. Methods and results Reports that NKT cells promote atherosclerosis and an NKT cell CD1d-dependent lipid antagonist (DPPE-PEG350, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N[methoxy(polyethyleneglycol)-350]) reduces allergeninduced inflammation led us to investigate its therapeutic potential in preventing the development and progression of experimental atherosclerosis. DPPE-PEG350 was administered to hyperlipidaemic ApoE-/- mice with/without established atherosclerosis. Atherosclerosis and immune cells were assessed in the aortic sinus lesions. Lesion expression of monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion protein-1 (VCAM-1) responsible for inflammatory immune cell recruitment as well as mRNA expression of IFNγ and its plasma levels were investigated. Necrotic cores and lesion smooth muscle and collagen contents important in plaque stability were determined as were plasma lipid levels. DPPE-PEG350 reduced atherosclerosis development and delayed progression of established atherosclerosis without affecting plasma lipids. CD4 and CD8 T cells and B cells in atherosclerotic lesions were decreased in DPPE-PEG350-treated mice. Lesion MCP-1 and VCAM-1 protein expression and necrotic core size were reduced without affecting lesion smooth muscle and collagen content. IFNγ and lymphocytes were unaffected by the treatment. Conclusion The attenuation of progression of established atherosclerosis together with reduced development of atherosclerosis in hyperlipidaemic mice by the NKT antagonist, without affecting NKT cell or other lymphocyte numbers, suggests that targeting lesion inflammation via CD1d-dependent activation of NKT cells using DPPE-PEG350 has a therapeutic potential in treating atherosclerosis. [ABSTRACT FROM AUTHOR]

Oncogenic KRAS mutations are major drivers of lung adenocarcinoma (LAC), yet the direct therapeutic targeting of KRAS has been problematic. Here, we reveal an obligate requirement by oncogenic KRAS for the ADAM17 protease in LAC. In genetically engineered and xenograft (human cell line and patient‐derived) KrasG12D‐driven LAC models, the specific blockade of ADAM17, including with a non‐toxic prodomain inhibitor, suppressed tumor burden by reducing cellular proliferation. The pro‐tumorigenic activity of ADAM17 was dependent upon its threonine phosphorylation by p38 MAPK, along with the preferential shedding of the ADAM17 substrate, IL‐6R, to release soluble IL‐6R that drives IL‐6 trans‐signaling via the ERK1/2 MAPK pathway. The requirement for ADAM17 in KrasG12D‐driven LAC was independent of bone marrow‐derived immune cells. Furthermore, in KRAS mutant human LAC, there was a significant positive correlation between augmented phospho‐ADAM17 levels, observed primarily in epithelial rather than immune cells, and activation of ERK and p38 MAPK pathways. Collectively, these findings identify ADAM17 as a druggable target for oncogenic KRAS‐driven LAC and provide the rationale to employ ADAM17‐based therapeutic strategies for targeting KRAS mutant cancers. Synopsis: Oncogenic KRAS mutations are associated with one‐third of lung adenocarcinoma (LAC) cases, yet the downstream molecular events that facilitate KRAS‐mediated tumorigenesis in the lung remain unresolved. This study reveals an obligate requirement by oncogenic KRAS for the ADAM17 protease in LAC. The specific genetic and therapeutic targeting of ADAM17, the latter with a non‐toxic prodomain inhibitor, suppressed tumour burden by reducing cellular proliferation in genetically‐engineered and xenograft mutant KRAS‐driven LAC models.The pro‐tumorigenic activity of ADAM17 in LAC was dependent upon its threonine phosphorylation by p38 MAPK.ADAM17 preferentially shed the substrate, IL‐6R, during LAC to release soluble IL‐6R that drives IL‐6 trans‐signaling via the ERK1/2 MAPK pathway.The requirement for ADAM17 in mutant KRAS‐driven LAC was independent of bone marrow‐derived hematopoietic immune cells.In KRAS mutant human LAC, augmented phospho‐ADAM17 levels were observed primarily in epithelial rather than immune cells, and significantly and positively correlated with activated p38 and ERK1/2 MAPK pathways. Oncogenic KRAS mutations are associated with one‐third of lung adenocarcinoma (LAC) cases, yet the downstream molecular events that facilitate KRAS‐mediated tumorigenesis in the lung remain unresolved. This study reveals an obligate requirement by oncogenic KRAS for the ADAM17 protease in LAC. [ABSTRACT FROM AUTHOR]

Gastric cancer (GC) is the third most lethal cancer worldwide, and like many other types of cancers, it is associated with precursory chronic inflammatory responses. In the context of many inflammation-associated cancers such as GC, activation of the innate immune response by infectious microbes and/or host-derived molecules is often characterized by production of the cytokines interleukin (IL)-1β and IL-18, which can often have divergent and opposing (i.e., pro or anti) roles in inflammation and oncogenesis. The processing of these mature bioactive cytokines from their inactive precursor polypeptides is dependent upon the enzyme Caspase-1, which is part of multiprotein complexes called "inflammasomes." Considering the recent mounting evidence for the role of IL-18 in the pathogenesis of GC, here, we describe a Western blotting technique used on genetic mouse models for GC to detect and characterize both pro-Il-18 and mature IL-18 proteins.

Rationale: CD4(+) natural killer T (NKT) cells augment atherosclerosis in apolipoprotein E-deficient (ApoE)(-/-) mice but their mechanisms of action are unknown., Objectives: We investigated the roles of bystander T, B, and NK cells; NKT cell-derived interferon-γ, interleukin (IL)-4, and IL-21 cytokines; and NKT cell-derived perforin and granzyme B cytotoxins in promoting CD4(+) NKT cell atherogenicity., Methods and Results: Transfer of CD4(+) NKT cells into T- and B-cell-deficient ApoE(-/-)Rag2(-/-) mice augmented aortic root atherosclerosis by ≈75% that was ≈30% of lesions in ApoE(-/-) mice; macrophage accumulation similarly increased. Transferred NKT cells were identified in the liver and atherosclerotic lesions of recipient mice. Transfer of CD4(+) NKT cells into T-, B-cell-deficient, and NK cell-deficient ApoE(-/-)Rag2(-/-)γC(-/-) mice also augmented atherosclerosis. These data indicate that CD4(+) NKT cells can exert proatherogenic effects independent of other lymphocytes. To investigate the role of NKT cell-derived interferon-γ, IL-4, and IL-21 cytokines and perforin and granzyme B cytotoxins, CD4(+) NKT cells from mice deficient in these molecules were transferred into NKT cell-deficient ApoE(-/-)Jα18(-/-) mice. CD4(+) NKT cells deficient in IL-4, interferon-γ, or IL-21 augmented atherosclerosis in ApoE(-/-)Jα18(-/-) mice by ≈95%, ≈80%, and ≈70%, respectively. Transfer of CD4(+) NKT cells deficient in perforin or granzyme B failed to augment atherosclerosis. Apoptotic cells, necrotic cores, and proinflammatory VCAM-1 (vascular cell adhesion molecule) and MCP-1 (monocyte chemotactic protein) were reduced in mice receiving perforin-deficient NKT cells. CD4(+) NKT cells are twice as potent as CD4(+) T cells in promoting atherosclerosis., Conclusions: CD4(+) NKT cells potently promote atherosclerosis by perforin and granzyme B-dependent apoptosis that increases postapoptotic necrosis and inflammation., (© 2014 American Heart Association, Inc.)

Objective: Bcl-x is the most abundantly expressed member of the Bcl-2 gene family in macrophages, but its role in macrophage apoptosis during atherogenesis is unknown., Methods and Results: We previously reported dual pro- and antiatherogenic effects of macrophage survival in early versus advanced atherosclerotic lesions, respectively, potentially reflecting growing impairment of efferocytosis during plaque progression. Here, we specifically inactivated Bcl-x in macrophages and evaluated its impact on atherosclerotic lesion formation in Apoe(-/-) mice at various stages of the disease. Bcl-x deficiency in macrophages increased their susceptibility to apoptosis, resulting in the depletion of tissue macrophages in vivo, including its major pool, Küppfer cells in the liver. We also observed increased cholesterol levels that were, however, not associated with any acceleration of early atherosclerotic plaque progression. This observation suggests that the atheroprotective effect of macrophage apoptosis at that stage of disease was counterbalanced by enhanced cholesterol levels. Bcl-x KO(mac)/Apoe(-/-) mice exhibited significantly larger advanced lesions than control mice. These lesions showed vulnerable traits. Such enhanced lesion size may occur as a result not only of apoptotic cell accumulation but also of elevated cholesterol levels., Conclusions: Modulation of macrophage resistance to apoptosis through targeted deletion of Bcl-x has a major impact on the entire macrophage cell population in the body, including Küpffer cells. Macrophage survival may, therefore, not only influence atherosclerotic plaque development and vulnerability but also cholesterol metabolism.