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Divalent metal ions such as magnesium (Mg 2+ ), manganese (Mn 2+ ), and zinc (Zn 2+ ) play important roles in regulating innate immune responses. Lipopolysaccharide stimulation led to increased intracellular Mn and Zn in macrophages. However, the effect of those metal ions in regulating lipopolysaccharide-induced innate immune responses remains unclear. Here, we uncovered that both Mn 2+ and Zn 2+ have immunostimulatory effects, which could potentiate the lipopolysaccharide-induced expression of interferon-stimulated genes (ISGs), cytokines and pro-inflammatory genes in a dose-dependent manner. Enhancement of lipopolysaccharide-induced innate immune gene expression by Mn 2+ varies between 10 % and 900 %. Conversely, the chelating of Mn 2+ almost totally diminished Mn 2+ -enhanced lipopolysaccharide-induced gene expression. In addition, Mn 2+ exerted its ability to potentiate LPS-induced innate immune gene expression regardless of slight pH changes. Importantly, we found that Mn 2+ potentiates lipopolysaccharide-induced immune responses independent of TLR4 but partially relies on cGAS-STING pathway. Further in vivo study showed that colloidal Mn 2+ salt (Mn jelly [MnJ]) pretreatment exacerbated lipopolysaccharide-induced septic shock and mice death. In conclusion, we demonstrated that Mn 2+ plays an essential role in boosting lipopolysaccharide-induced innate immune responses. These findings greatly expand the current understanding of the immunomodulatory potential of divalent metal Mn 2+ and may provide a potential therapeutic target to prevent excessive immune responses., Competing Interests: Declaration of interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Signaling initiated by type I interferon (IFN) results in the induction of hundreds of IFN-stimulated genes (ISGs). The type I IFN response is important for antiviral restriction, but aberrant activation of this response can lead to inflammation and autoimmunity. Regulation of this response is incompletely understood. We previously reported that the mRNA modification m 6 A and its deposition enzymes, METTL3 and METTL14 (METTL3/14), promote the type I IFN response by directly modifying the mRNA of a subset of ISGs to enhance their translation. Here, we determined the role of the RNA demethylase fat mass and obesity-associated protein (FTO) in the type I IFN response. FTO, which can remove either m 6 A or cap-adjacent m 6 Am RNA modifications, has previously been associated with obesity and body mass index, type 2 diabetes, cardiovascular disease, and inflammation. We found that FTO suppresses the transcription of a distinct set of ISGs, including many known pro-inflammatory genes, and that this regulation requires its catalytic activity but is not through the actions of FTO on m 6 Am. Interestingly, depletion of FTO led to activation of the transcription factor STAT3, whose role in the type I IFN response is not well understood. This activation of STAT3 increased the expression of a subset of ISGs. Importantly, this increased ISG induction resulting from FTO depletion was partially ablated by depletion of STAT3. Together, these results reveal that FTO negatively regulates STAT3-mediated signaling that induces proinflammatory ISGs during the IFN response, highlighting an important role for FTO in suppression of inflammatory genes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Next-generation sequencing has provided a more complete picture of the composition of the human transcriptome indicating that much of the "blueprint" is a vastness of poorly understood non-protein-coding transcripts. This includes a newly identified class of genes called long noncoding RNAs (lncRNAs). The lack of sequence conservation for lncRNAs across species meant that their biological importance was initially met with some skepticism. LncRNAs mediate their functions through interactions with proteins, RNA, DNA, or a combination of these. Their functions can often be dictated by their localization, sequence, and/or secondary structure. Here we provide a review of the approaches typically adopted to study the complexity of these genes with an emphasis on recent discoveries within the innate immune field. Finally, we discuss the challenges, as well as the emergence of new technologies that will continue to move this field forward and provide greater insight into the biological importance of this class of genes. This article is part of a Special Issue entitled: ncRNA in control of gene expression edited by Kotb Abdelmohsen., (Copyright © 2019 Elsevier B.V. All rights reserved.)