bims-stacyt 2019-01-13 papers

bims-stacyt

Biomed News

on Metabolism and the paracrine crosstalk between cancer and the organism

Issue of 2019–01–13
seven papers selected by
Cristina Muñoz Pinedo, L’Institut d’Investigació Biomèdica de Bellvitge

NLRP3 Inflammasome: A Possible Link Between Obesity-Associated Low-Grade Chronic Inflammation and Colorectal Cancer Development.
Reciprocal activation of cancer-associated fibroblasts and oral squamous carcinoma cells through CXCL1.
The Sweet Surrender: How Myeloid Cell Metabolic Plasticity Shapes the Tumor Microenvironment.
Loss of X-box binding protein 1 in Müller cells augments retinal inflammation in a mouse model of diabetes.
Glucose transporter 1 critically controls microglial activation through facilitating glycolysis.
Endoplasmic Reticulum Stress Responses in Intratumoral Immune Cells: Implications for Cancer Immunotherapy.
AP-1 (Activated Protein-1) Transcription Factor JunD Regulates Ischemia/Reperfusion Brain Damage via IL (Interleukin)-1β.

Front Immunol. 2018 ;9 2918

NLRP3 Inflammasome: A Possible Link Between Obesity-Associated Low-Grade Chronic Inflammation and Colorectal Cancer Development.

Patricia Ahechu, Gabriel Zozaya, Pablo Martí, José Luis Hernández-Lizoáin, Jorge Baixauli, Xabier Unamuno, Gema Frühbeck, Victoria Catalán.

  Emerging evidence reveals that adipose tissue-associated inflammation is a main mechanism whereby obesity promotes colorectal cancer risk and progression. Increased inflammasome activity in adipose tissue has been proposed as an important mediator of obesity-induced inflammation and insulin resistance development. Chronic inflammation in tumor microenvironments has a great impact on tumor development and immunity, representing a key factor in the response to therapy. In this context, the inflammasomes, main components of the innate immune system, play an important role in cancer development showing tumor promoting or tumor suppressive actions depending on the type of tumor, the specific inflammasome involved, and the downstream effector molecules. The inflammasomes are large multiprotein complexes with the capacity to regulate the activation of caspase-1. In turn, caspase-1 enhances the proteolytic cleavage and the secretion of the inflammatory cytokines interleukin (IL)-1β and IL-18, leading to infiltration of more immune cells and resulting in the generation and maintenance of an inflammatory microenvironment surrounding cancer cells. The inflammasomes also regulate pyroptosis, a rapid and inflammation-associated form of cell death. Recent studies indicate that the inflammasomes can be activated by fatty acids and high glucose levels linking metabolic danger signals to the activation of inflammation and cancer development. These data suggest that activation of the inflammasomes may represent a crucial step in the obesity-associated cancer development. This review will also focus on the potential of inflammasome-activated pathways to develop new therapeutic strategies for the prevention and treatment of obesity-associated colorectal cancer development.

Keywords:  NLRP3; adipose tissue; colon cancer; immunity; inflammasome; inflammation; obesity

DOI:  https://doi.org/10.3389/fimmu.2018.02918
Oral Oncol. 2019 Jan;pii: S1368-8375(18)30413-5. [Epub ahead of print]88 115-123

Reciprocal activation of cancer-associated fibroblasts and oral squamous carcinoma cells through CXCL1.

Ling-Ying Wei, Jang-Jaer Lee, Chiou-Yueh Yeh, Chia-Ju Yang, Sang-Heng Kok, Jenq-Yuh Ko, Feng-Chiao Tsai, Jean-San Chia.

   OBJECTIVES: Crosstalk between cancer cells and carcinoma-associated fibroblasts (CAFs) is known to be involved in various aspects of tumor biology, including during invasion. Using oral squamous cell carcinoma (OSCC) cells as a model, we examined whether and how CAFs respond to inflammatory signals to influence cancer cell migration and invasion.
MATERIALS AND METHODS: Chemokine signatures within the human HNSCC datasets from The Cancer Genome Atlas (TCGA) were analyzed together with tissue assessment using immunohistochemical staining (IHC) and real-time PCR. A co-culture system was used to identify reciprocal effects exerted by CAFs and cancer cells upon one another. Recombinant CXCL1, CXCL1 neutralizing antibodies, and CXCR2 antagonist were used to confirm CXCL1/CXCR2 axis-mediated cell behaviors.
RESULTS: Analysis of the TCGA dataset revealed that CXCL1 is associated with poor survival, and IHC demonstrated CXCL1 is highly expressed in OSCC stromal cells. Moreover, real-time PCR showed that in addition to CXCL1, IL-1β and CXCR2 are also highly expressed in OSCC and IL-1β mRNA levels positively correlate with CXCL1 expression. Furthermore, CAFs co-cultured with SAS, a poorly differentiated OSCC cell line, or stimulated with IL-1β exhibit increased CXCL1 secretion in an NF-κB-dependent manner. Treatment of SAS cells with CAF-conditioned medium or CXCL1 increased their invasion and migration capabilities, indicating a reciprocal activation between CAFs and cancer cells. Moreover, CXCL-1 upregulated matrix metalloprotease-1 (MMP-1) expression and activity in CAFs.
CONCLUSION: The induction of IL-1β following CXCL1 stimulation of CAFs mediates cancer cell invasion, and there is a reciprocal dependency between CAFs and cancer cells in the OSCC microenvironment.

Keywords:  CXCL1; Cancer-associated fibroblasts; IL-1β; Matrix metalloproteinase 1; Neoplasm invasiveness; Oral squamous cell carcinoma; Survival rate

DOI:  https://doi.org/10.1016/j.oraloncology.2018.11.002
Front Cell Dev Biol. 2018 ;6 168

The Sweet Surrender: How Myeloid Cell Metabolic Plasticity Shapes the Tumor Microenvironment.

Je Lin Sieow, Sin Yee Gun, Siew Cheng Wong.

  Immune cells are one of the most versatile cell types, as they can tailor their metabolic activity according to their required function. In response to diverse environmental cues, immune cells undergo metabolic reprogramming to support their differentiation, proliferation and pro-inflammatory effector functions. To meet a dramatic surge in energetic demand, immune cells rewire their metabolism to utilize aerobic glycolysis. This preferential use of glycolysis even under aerobic conditions is well established in tumor cells, and is known as the "Warburg effect." Tumor cells avidly use glucose for aerobic glycolysis, thereby creating a nutrient-starved microenvironment, outcompeting T cells for glucose, and directly inhibiting T-cell anti-tumoral effector function. Given that both immune and tumor cells use similar modes of metabolism in the tumor stroma, it is imperative to identify a therapeutic window in which immune-cell and tumor-cell glycolysis can be specifically targeted. In this review, we focus on the Warburg metabolism as well as other metabolic pathways of myeloid cells, which comprise a notable niche in the tumor environment and promote the growth and metastasis of malignant tumors. We examine how differential immune-cell activation triggers metabolic fate, and detail how this forbidding microenvironment succeeds in shutting down the vigorous anti-tumoral response. Finally, we highlight emerging therapeutic concepts that aim to target immune-cell metabolism. Improving our understanding of immunometabolism and immune-cell commitment to specific metabolic fates will help identify alternative therapeutic approaches to battle this intractable disease.

Keywords:  glycolysis; immunometabolism; immunotharapy; macrophages; myeloid derived suppressor cell (MDSC); tumor immunology

DOI:  https://doi.org/10.3389/fcell.2018.00168
Diabetologia. 2019 Jan 06.

Loss of X-box binding protein 1 in Müller cells augments retinal inflammation in a mouse model of diabetes.

Jing Yang, Chen Chen, Todd McLaughlin, Yaqin Wang, Yun-Zheng Le, Joshua J Wang, Sarah X Zhang.

   AIMS/HYPOTHESIS: Müller glia (MG) are major sources of retinal cytokines, and their activation is closely linked to retinal inflammation and vascular leakage in diabetic retinopathy. Previously, we demonstrated that X-box binding protein 1 (XBP1), a transcription factor activated by endoplasmic reticulum (ER) stress in diabetic retinopathy, is involved in regulation of inflammation in retinal endothelial cells. Now, we have explored the role of XBP1 and ER stress in the regulation of MG-derived proinflammatory factors, and their influence on vascular permeability in diabetic retinopathy.
METHODS: MG-specific conditional Xbp1 knockout (Xbp1Müller-/-) mice were generated by crossing Xbp1 flox/flox mice with Müller-Cre transgenic mice. Diabetes was modelled by induction with streptozotocin, and retinal vascular permeability was measured with FITC-conjugated dextran 2 months after induction. Primary Müller cells were isolated from Xbp1Müller-/- and Xbp1Müller+/+ mice and exposed to hypoxia and high levels of glucose. Levels of ER-stress and inflammatory factors were examined by real-time PCR, western blotting or immunohistochemistry.
RESULTS: Xbp1Müller-/- mice exhibited normal retinal development and retinal function and expressed similar levels of ER-stress and inflammatory genes to Xbp1Müller+/+ littermates. In diabetes-inducing conditions, compared with Xbp1Müller+/+ mice, Xbp1Müller-/- mice had higher mRNA levels of retinal Vegf (also known as Vegfa) and Tnf-α (also known as Tnf) and ER-stress marker genes Grp78 (also known as Hspa5), Atf4, Chop (also known as Ddit3) and Atf6 and higher protein levels of vascular endothelial growth factor (VEGF), TNF-α, phospho-c-Jun N-terminal kinase (JNK), 78 kDa glucose-regulated protein (GRP78), phospho-eukaryotic translation initiation factor (eIF)2α and activating transcription factor (ATF)6. Retinal vascular permeability was significantly higher in diabetic Xbp1Müller-/- mice than in diabetic Xbp1Müller+/+ mice (p < 0.01). Results obtained in vitro with primary Müller cells isolated from Xbp1Müller-/- mice confirmed higher expression levels of inflammatory and ER-stress markers (but not GRP78) than in cells from Xbp1Müller+/+ mice. Moreover, XBP1-deficient Müller cells were more susceptible to high-glucose- or hypoxia-induced ER stress and inflammation than cells from Xbp1Müller+/+ mice. Inhibition of ER stress with chemical chaperones suppressed hypoxia-induced VEGF and TNF-α production in XBP1-deficient Müller cells.
CONCLUSIONS/INTERPRETATION: Our results have revealed an important role of XBP1 and ER stress in MG-driven retinal inflammation, and suggest that targeting ER stress may represent a promising approach for the prevention and treatment of diabetic retinopathy.

Keywords:  Diabetic retinopathy; ER stress; Inflammation; Müller cell; X-box binding protein 1

DOI:  https://doi.org/10.1007/s00125-018-4776-y
Mol Neurodegener. 2019 Jan 11. 14(1): 2

Glucose transporter 1 critically controls microglial activation through facilitating glycolysis.

Luxi Wang, Sofia Pavlou, Xuan Du, Mohajeet Bhuckory, Heping Xu, Mei Chen.

   BACKGROUND: Uncontrolled microglial activation contributes to the pathogenesis of various neurodegenerative diseases. Previous studies have shown that proinflammatory microglia are powered by glycolysis, which relays on high levels of glucose uptake. This study aimed to understand how glucose uptake is facilitated in active microglia and whether microglial activation can be controlled by restricting glucose uptake.
METHODS: Primary murine brain microglia, BV2 cells and the newly established microglial cell line B6M7 were treated with LPS (100 ng/ml) + IFNγ (100 ng/ml) or IL-4 (20 ng/ml) for 24 h. The expression of glucose transporters (GLUTs) was examined by PCR and Western blot. Glucose uptake by microglia was inhibited using the GLUT1-specific inhibitor STF31. The metabolic profiles were tested using the Glycolysis Stress Test and Mito Stress Test Kits using the Seahorse XFe96 Analyser. Inflammatory gene expression was examined by real-time RT-PCR and protein secretion by cytokine beads array. The effect of STF31 on microglial activation and neurodegeneraion was further tested in a mouse model of light-induced retinal degeneration.
RESULTS: The mRNA and protein of GLUT1, 3, 4, 5, 6, 8, 9, 10, 12, and 13 were detected in microglia. The expression level of GLUT1 was the highest among all GLUTs detected. LPS + IFNγ treatment further increased GLUT1 expression. STF31 dose-dependently reduced glucose uptake and suppressed Extracellular Acidification Rate (ECAR) in naïve, M(LPS + IFNγ) and M(IL-4) microglia. The treatment also prevented the upregulation of inflammatory cytokines including TNFα, IL-1β, IL-6, and CCL2 in M(LPS + IFNγ) microglia. Interestingly, the Oxygen Consumption Rates (OCR) was increased in M(LPS + IFNγ) microglia but reduced in M(IL-4) microglia by STF31 treatment. Intraperitoneal injection of STF31 reduced light-induced microglial activation and retinal degeneration.
CONCLUSION: Glucose uptake in microglia is facilitated predominately by GLUT1, particularly under inflammatory conditions. Targeting GLUT1 could be an effective approach to control neuroinflammation.

Keywords:  Glucose metabolism; Microglia; Neuroinflammation; Retinal degeneration

DOI:  https://doi.org/10.1186/s13024-019-0305-9
Trends Immunol. 2019 Jan 03. pii: S1471-4906(18)30227-8. [Epub ahead of print]

Endoplasmic Reticulum Stress Responses in Intratumoral Immune Cells: Implications for Cancer Immunotherapy.

Minkyung Song, Juan R Cubillos-Ruiz.

  Protective anti-tumor immune responses are mediated by effector molecules that enable successful elimination of malignant cells. As the site where transmembrane and secreted proteins are generated, the endoplasmic reticulum (ER) of immune cells plays a key role in this process. Recent studies have indicated that adverse conditions within tumors perturb ER homeostasis in infiltrating immune cells, which can impede the development of effective anti-cancer immunity. Here, we describe how the tumor microenvironment induces ER stress in immune cells, and discuss the detrimental consequences of persistent ER stress responses in intratumoral immune populations. We also explore the concept of targeting ER stress responses to reinvigorate endogenous anti-tumor immunity and enhance the efficacy of various forms of cancer immunotherapy.

Keywords:  ER stress; cancer; immune cells; immunotherapy; tumor microenvironment; unfolded protein response

DOI:  https://doi.org/10.1016/j.it.2018.12.001
Stroke. 2019 Jan 10. STROKEAHA118023739

AP-1 (Activated Protein-1) Transcription Factor JunD Regulates Ischemia/Reperfusion Brain Damage via IL (Interleukin)-1β.

Candela Diaz-Cañestro, Martin F Reiner, Nicole R Bonetti, Luca Liberale, Mario Merlini, Patricia Wüst, Heidi Amstalden, Sylvie Briand-Schumacher, Aurora Semerano, Giacomo Giacalone, Maria Sessa, Jürg H Beer, Alexander Akhmedov, Thomas F Lüscher, Giovanni G Camici.

  Background and Purpose- Inflammation is a major pathogenic component of ischemia/reperfusion brain injury, and as such, interventions aimed at inhibiting inflammatory mediators promise to be effective strategies in stroke therapy. JunD-a member of the AP-1 (activated protein-1) family of transcription factors-was recently shown to regulate inflammation by targeting IL (interleukin)-1β synthesis and macrophage activation. The purpose of the present study was to assess the role of JunD in ischemia/reperfusion-induced brain injury. Methods- WT (wild type) mice randomly treated with either JunD or scramble (control) siRNA were subjected to 45 minutes of transient middle cerebral artery occlusion followed by 24 hours of reperfusion. Stroke size, neurological deficit, plasma/brain cytokines, and oxidative stress determined by 4-hydroxynonenal immunofluorescence staining were evaluated 24 hours after reperfusion. Additionally, the role of IL-1β was investigated by treating JunD siRNA mice with an anti-IL-1β monoclonal antibody on reperfusion. Finally, JunD expression was assessed in peripheral blood monocytes isolated from patients with acute ischemic stroke. Results- In vivo JunD knockdown resulted in increased stroke size, reduced neurological function, and increased systemic inflammation, as confirmed by higher neutrophil count and lymphopenia. Brain tissue IL-1β levels were augmented in JunD siRNA mice as compared with scramble siRNA, whereas no difference was detected in IL-6, TNF-α (tumor necrosis factor-α), and 4-hydroxynonenal levels. The deleterious effects of silencing of JunD were rescued by treating mice with an anti-IL-1β antibody. In addition, JunD expression was decreased in peripheral blood monocytes of patients with acute ischemic stroke at 6 and 24 hours after onset of stroke symptoms compared with sex- and age-matched healthy controls. Conclusions- JunD blunts ischemia/reperfusion-induced brain injury via suppression of IL-1β.

Keywords:  animals; humans; inflammation; mice; monocytes; stroke

DOI:  https://doi.org/10.1161/STROKEAHA.118.023739