bims-stacyt 2019-04-14 papers

Transl Res. 2019 Mar 15. pii: S1931-5244(19)30054-4. [Epub ahead of print]

Immunomodulatory roles of nitric oxide in cancer: tumor microenvironment says "NO" to antitumor immune response.

Jon Peñarando, Enrique Aranda, Antonio Rodríguez-Ariza.

In recent years, an increasing number of studies have shown that there is an important connection between nitric oxide (NO) and the pathology of malignant diseases, but we are far from a complete comprehension of how this simple diatomic molecule contributes to tumorigenesis. The emerging identification of immune-mediated mechanisms regulated by NO may help to unravel the intricate and complex relationships between NO and cancer. Therefore, this review provides a summary of recent advances in our understanding of the immunomodulatory role of NO in cancer, and in particular the role of this pleiotropic signaling molecule as an immunosuppressive mediator in the tumor microenvironment. We will discuss the participation of NO in the different strategies used by tumors to escape from immune system-mediated recognition, including the acquisition of stem cell like capacities by tumor cells and the metabolic reprogramming of tumor infiltrating immune cells. Finally, we will also discuss different therapeutic strategies directed against NO for abating the immunosuppressive tumor microenvironment and to increase the efficacy of immunotherapy in cancer.

DOI: https://doi.org/10.1016/j.trsl.2019.03.003

Nat Immunol. 2019 Apr 08.

SUCNR1 controls an anti-inflammatory program in macrophages to regulate the metabolic response to obesity.

Noelia Keiran, Victoria Ceperuelo-Mallafré, Enrique Calvo, Maria Isabel Hernández-Alvarez, Miriam Ejarque, Catalina Núñez-Roa, Daniel Horrillo, Elsa Maymó-Masip, M Mar Rodríguez, Rosa Fradera, Juan Vladimir de la Rosa, Rosa Jorba, Ana Megia, Antonio Zorzano, Gema Medina-Gómez, Carolina Serena, Antonio Castrillo, Joan Vendrell, Sonia Fernández-Veledo.

Succinate is a signaling metabolite sensed extracellularly by succinate receptor 1 (SUNCR1). The accumulation of succinate in macrophages is known to activate a pro-inflammatory program; however, the contribution of SUCNR1 to macrophage phenotype and function has remained unclear. Here we found that activation of SUCNR1 had a critical role in the anti-inflammatory responses in macrophages. Myeloid-specific deficiency in SUCNR1 promoted a local pro-inflammatory phenotype, disrupted glucose homeostasis in mice fed a normal chow diet, exacerbated the metabolic consequences of diet-induced obesity and impaired adipose-tissue browning in response to cold exposure. Activation of SUCNR1 promoted an anti-inflammatory phenotype in macrophages and boosted the response of these cells to type 2 cytokines, including interleukin-4. Succinate decreased the expression of inflammatory markers in adipose tissue from lean human subjects but not that from obese subjects, who had lower expression of SUCNR1 in adipose-tissue-resident macrophages. Our findings highlight the importance of succinate-SUCNR1 signaling in determining macrophage polarization and assign a role to succinate in limiting inflammation.

DOI: https://doi.org/10.1038/s41590-019-0372-7

Cell Rep. 2019 Apr 09. pii: S2211-1247(19)30349-3. [Epub ahead of print]27(2): 525-536.e4

Tricarboxylic Acid Cycle Activity and Remodeling of Glycerophosphocholine Lipids Support Cytokine Induction in Response to Fungal Patterns.

Saioa Márquez, José Javier Fernández, Cristina Mancebo, Carmen Herrero-Sánchez, Sara Alonso, Tito A Sandoval, Macarena Rodríguez Prados, Juan R Cubillos-Ruiz, Olimpio Montero, Nieves Fernández, Mariano Sánchez Crespo.

Increased glycolysis parallels immune cell activation, but the role of pyruvate remains largely unexplored. We found that stimulation of dendritic cells with the fungal surrogate zymosan causes decreases of pyruvate, citrate, itaconate, and α-ketoglutarate, while increasing oxaloacetate, succinate, lactate, oxygen consumption, and pyruvate dehydrogenase activity. Expression of IL10 and IL23A (the gene encoding the p19 chain of IL-23) depended on pyruvate dehydrogenase activity. Mechanistically, pyruvate reinforced histone H3 acetylation, and acetate rescued the effect of mitochondrial pyruvate carrier inhibition, most likely because it is a substrate of the acetyl-CoA producing enzyme ACSS2. Mice lacking the receptor of the lipid mediator platelet-activating factor (PAF; 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine) showed reduced production of IL-10 and IL-23 that is explained by the requirement of acetyl-CoA for PAF biosynthesis and its ensuing autocrine function. Acetyl-CoA therefore intertwines fatty acid remodeling of glycerophospholipids and energetic metabolism during cytokine induction.

Keywords: Lands’ cycle; Warburg effect; acetyl-CoA; arachidonic acid; cytokines; fungi; glycolysis; immunometabolism; platelet-activating factor; tricarboxylic acid cycle

DOI: https://doi.org/10.1016/j.celrep.2019.03.033

J Immunol Sci. 2019 ;3(1): 4-8

A Review of Exosomes and their Role in The Tumor Microenvironment and Host-Tumor "Macroenvironment".

Kaity H Tung, Marc S Ernstoff, Cheryl Allen, Shin La Shu.

Tumor-derived exosomes (TEX) are important intercellular messengers that contribute to tumorigenesis and metastasis through a variety of mechanisms such as immunosuppression and metabolic reprogramming that generate a pre-metastatic niche favorable to tumor progression. Our lab has contributed further to the understanding of the miRNA payloads in TEX by demonstrating that human melanoma-derived exosome (HMEX) associated miRNAs contribute to the metabolic reprogramming of normal stroma. This mini-review highlights the role of TEX in the tumor microenvironment (TME) and the hypothesis that exosomes may also generate a host-tumor "macroenvironment" beyond the TME through their miRNA and protein payloads, so to speak "fertilizing the soil for cancer seeding."

Keywords: Exosomes; Fibroblasts; Immunosuppression; Metabolic reprogramming; Tumor macroenvironment; Tumor microenvironment; miRNA

DOI: https://doi.org/10.29245/2578-3009/2019/1.1165