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Modulation of lipid metabolism is a well-established cancer hallmark, and SCD1 has been recognized as a key enzyme in promoting cancer cell growth, including in glioblastoma (GBM), the deadliest brain tumor and a paradigm of cancer resistance. The central goal of this work was to identify, by MS, the phospholipidome alterations resulting from the silencing of SCD1 in human GBM cells, in order to implement an innovative therapy to fight GBM cell resistance. With this purpose, RNAi technology was employed, and low serum-containing medium was used to mimic nutrient deficiency conditions, at which SCD1 is overexpressed. Besides the expected increase in the saturated to unsaturated fatty acid ratio in SCD1 silenced-GBM cells, a striking increase in polyunsaturated chains, particularly in phosphatidylethanolamine and cardiolipin species, was noticed and tentatively correlated with an increase in autophagy (evidenced by the increase in LC3BII/I ratio). The contribution of autophagy to mitigate the impact of SCD1 silencing on GBM cell viability and growth, whose modest inhibition could be correlated with the maintenance of energetically associated mitochondria, was evidenced by using autophagy inhibitors. In conclusion, SCD1 silencing could constitute an important tool to halt GBM resistance to the available treatments, especially when coupled with a mitochondria disrupter chemotherapeutic.

The polyphenol resveratrol activates the deacetylase Sirt1, resulting in various antioxidant, chemoprotectant, neuroprotective, cardioprotective, and anti-inflammatory properties. We found that at high concentrations of resveratrol, human CD4 + T cells showed defective antigen receptor signaling and arrest at the G 1 stage of the cell cycle, whereas at low concentrations, cells were readily activated and exhibited enhanced Sirt1 deacetylase activity. Nevertheless, low-dose resveratrol rapidly stimulated genotoxic stress in the T cells, which resulted in engagement of a DNA damage response pathway that depended on the kinase ATR [ataxia telangiectasia-mutated (ATM) and Rad3-related], but not ATM, and subsequently in premitotic cell cycle arrest. The concomitant activation of p53 was coupled to the expression of gene products that regulate cell metabolism, leading to a metabolic reprogramming that was characterized by decreased glycolysis, increased glutamine consumption, and a shift to oxidative phosphorylation. These alterations in the bioenergetic homeostasis of CD4 + T cells resulted in enhanced effector function, with both naïve and memory CD4 + T cells secreting increased amounts of the inflammatory cytokine interferon-γ. Thus, our data highlight the wide range of metabolic adaptations that CD4 + T lymphocytes undergo in response to genomic stress., (Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The use of particulate adjuvants offers an interesting possibility to enhance and modulate the immune responses elicited by vaccines. Aluminium salts have been extensively used as vaccine adjuvants, but they lack the capacity to induce a strong cellular and mucosal immune response. Taking this into consideration, in this study we designed a new antigen delivery system combining aluminium salts with chitosan. Chitosan-aluminium nanoparticles (CH-Al NPs) exhibited a mean diameter of 280nm and a positive surface charge. The newly developed CH-Al NPs are more stable at physiological environment than classical CH NPs, showing no cytotoxic effects and revealing potential as a delivery system for a wide range of model antigens. In vivo studies showed that mice immunized with hepatitis B surface antigen (HBsAg)-containing CH NPs display high anti-HBsAg IgG titers in the serum, as well as the highest antigen-specific IgG on vaginal washes. Furthermore, in contrast to mice receiving antigen alone, mice immunized with the particulate adjuvant were able to elicit IgG2c antibody titers and exhibited higher antigen-specific IFN-γ levels in splenocytes. In conclusion, we established that CH-Al NPs, combining two immunostimulants to enhance both humoral and cellular immune responses, are a safe and promising system for antigen delivery. Our findings point towards their potential in future vaccination approaches., (Copyright © 2017 Elsevier B.V. All rights reserved.)