bims-stacyt 2022-04-03 papers

Food Chem Toxicol. 2022 Mar 26. pii: S0278-6915(22)00167-3. [Epub ahead of print] 112969

Nicotinamide N-methyltransferase protects against deoxynivalenol-induced growth inhibition by suppressing pro-inflammatory cytokine expression.

Aimei Liu, Mingyue Guo, Lixuan He, María-Aránzazu Martínez, Marta Martínez, Bernardo Lopez-Torres, María-Rosa Martínez-Larrañaga, Xu Wang, Arturo Anadón, Irma Ares.

Deoxynivalenol (DON) is an inevitable contaminant in cereals for infants. Indeed, children's growth retardation caused by widespread DON pollution has become a global problem that cannot be ignored. Accumulating evidence has shown that DON stunts growth in children through pro-inflammatory cytokines. An exogenous increase of methylnicotinamide, a metabolite produced by nicotinamide N-methyltransferase (NNMT), has anti-inflammatory effects, but it is not clear whether NNMT has the same effect, and the role of NNMT in DON-induced inflammation and growth impairment remains indistinct. The present research reports that NNMT is an inflammatory self-protective factor in DON-exposed L02 cells. DON promoted the production of pro-inflammatory cytokines. Furthermore, DON increased NNMT to reduce pro-inflammatory cytokines, including interleukin (IL)-1β, IL-11 and IL-6, and thus increased IGF-1 and cell viability, alleviating the cell growth inhibition induced by DON. Interestingly, NNMT negatively regulated the expression of IL-1β through Sirtuin type 1 (SIRT1). Collectively, these findings provide new mechanistic insights into the toxicity of DON-induced growth retardation and inflammatory responses in children.

Keywords: Deoxynivalenol; Growth inhibition; IL-1β; Nicotinamide N-Methyltransferase; SIRT1

DOI: https://doi.org/10.1016/j.fct.2022.112969

Front Immunol. 2022 ;13 812822

IDO1 Inhibition Reduces Immune Cell Exclusion Through Inducing Cell Migration While PD-1 Blockage Increases IL-6 and -8 Secretion From T Cells in Head and Neck Cancer.

Meri Sieviläinen, Jordan Saavalainen, Shady Adnan-Awad, Tuula Salo, Ahmed Al-Samadi.

Background: Immune checkpoint inhibitors (ICIs), primarily anti-PD-1, are currently used to treat patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). However, only a minority of patients benefit from these costly therapies. Therefore, there is an unmet need to better understand the effect of ICIs on immune effector cells. This study aimed to investigate the effect of a PD-1 antibody and an IDO1 inhibitor on different lymphocyte populations (NK, CD4+, and CD8+ T cells) in term of migration, cytotoxicity, and cytokine release in the presence of HNSCC cells.Methods: Using a microfluidic chip, we injected HSC-3 cells (an oral tongue squamous cell carcinoma cell line) embedded in a human tumor-derived matrix "myogel/fibrin" together with NK, CD4+, and CD8+ T cells in separate channels. The two channels were connected with microchannels. The PD-1 antibody nivolumab and IDO1 inhibitor epacadostat were added to the microfluidic chips. Lymphocyte migration and cytotoxicity were examined under fluorescent microscopy and cytokine release was measured using a FirePlex Human Discovery Cytokines Immunoassay.
Results: Epacadostat significantly increased the migration and infiltration of NK and CD4+ T cells, but not CD8+ T cells, towards the cancer cells. Nivolumab did not exhibit a similar effect. While CD8+ T cells alone showed near to no migration, adding CD4+ T cells enhanced migration towards the cancer cells. There was a mild nonsignificant increase in apoptosis of HSC-3 cells after adding epacadostat to lymphocytes. In contrast, HSC-3 proliferation was not affected by lymphocytes regardless of ICIs. Nivolumab significantly increased release of MIP1-α, IL-6, and IL-8 from NK, CD4+, and CD8+ T cells, respectively.
Conclusions: This study revealed that each subpopulation of lymphocytes respond differently to ICIs. We also revealed the subpopulation of lymphocytes responsible for the increases in specific serum cytokines after ICI treatment.

Keywords: IDO1; PD-1; PD-L1; head and neck squamous cell carcinoma; immune checkpoint inhibitors; immunotherapy; microfluidic chip

DOI: https://doi.org/10.3389/fimmu.2022.812822

Exp Cell Res. 2022 Mar 25. pii: S0014-4827(22)00105-7. [Epub ahead of print]415(1): 113112

IL-6 promotes chemoresistance via upregulating CD36 mediated fatty acids uptake in acute myeloid leukemia.

Yanjie Zhang, Hezhou Guo, Zhaoli Zhang, Wei Lu, Jiang Zhu, Jun Shi.

Chemoresistance contributes to poor survival and high relapse risk in acute myeloid leukemia (AML). As a pro-inflammatory cytokine, interleukin-6 (IL-6) plays a vital role in the chemoresistance of malignancies. However, the underlying mechanisms of chemoresistance in AML have not been widely studied. Lipid metabolism, which contributes to chemoresistance in AML, is enhanced by IL-6 in skeletal muscle cells. We hypothesized that IL-6 promotes the chemoresistance of AML by promoting lipid metabolism. Based on the positive correlation between IL-6 receptor expression and the cellular response to exogenous IL-6, we performed Gene Ontology analysis of a dataset consisting the information of 151 AML patients from The Cancer Genome Atlas. We found that lipid transport-associated genes were upregulated in the high IL-6 receptor expression group. Additionally, IL-6 promoted fatty acid (FA) uptake in both AML cell lines and primary AML cells. Inhibition of FA uptake by sulfo-N-succinimidyl oleate repressed IL-6-induced chemoresistance. Western blotting, quantitative polymerase chain reaction, and chromatin immunoprecipitation assays indicated that IL-6 promoted CD36 expression at both the mRNA and protein levels through stat3 signaling. Knockout of CD36 or stat3 repressed IL-6-induced FA uptake and chemoresistance. Furthermore, in five human AML samples, we validated that compared to CD36-cells, CD36+ primary AML cells were less sensitive to cytosine arabinoside (Ara-c) and that blockade of CD36 re-sensitized CD36+ AML cells to Ara-c. Mice injected with CD36 knockout cells followed by treatment with Ara-c showed markedly decreased leukemia burden and prolonged survival in vivo. Finally, treatment with the CD36 antibody in combination with Ara-c exhibited synergistic effects in vivo. In conclusion, IL-6 promotes chemoresistance in AML through the stat3/CD36-mediated FA uptake. Blockade of CD36 improved the effect of Ara-c, representing a promising strategy for AML therapy.

Keywords: Acute myeloid leukemia; CD36; Chemoresistance; Fatty acid uptake; Interleukin-6

DOI: https://doi.org/10.1016/j.yexcr.2022.113112