IBR1: A Novel Endogenous dsRNA Binding to the Helicase Domain of IFIH1 and Its Role in LPS-induced IFIH1 Activation and Macrophage M1 Polarization in ARDS
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ORGANISM(S): Mus musculus
PROVIDER: GSE247177 | GEO | 2024/09/05
REPOSITORIES: GEO
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Project description:Uncontrolled inflammatory responses driven by macrophages and monocytes play a crucial role in perpetuating lung injury and the severity of acute respiratory distress syndrome (ARDS). Previous studies have identified IFIH1 as a key regulator of macrophage M1 polarization in pneumonia-induced ARDS. IFIH1 is a cytosolic receptor responsible for recognizing viral double-stranded RNA (dsRNA) and activating inflammatory and antiviral signaling pathways. Interestingly, our observations indicate that IFIH1 can also be activated by lipopolysaccharide (LPS), a component of bacterial cell walls. However, the precise molecular mechanism underlying LPS-induced IFIH1 activation remains unclear. In our preliminary investigations, we have discovered a novel transcript, named IFIH1-binding RNA1 (IBR1), which is upregulated by LPS and gram-negative bacilli in monocytes and macrophages. We have confirmed that IBR1 interacts with the IFIH1 protein, forming a complex. Further experiments have revealed that IBR1, acting as an endogenous dsRNA, binds to the helicase domain of IFIH1 due to its local double-stranded structure. This specific interaction serves as the underlying molecular mechanism responsible for LPS-induced IFIH1 activation and subsequent macrophage M1 polarization in ARDS. Importantly, our observations indicate a significant upregulation of IBR1 expression in ARDS patients with gram-negative bacilli-induced pneumonia. Understanding the molecular mechanisms driving IFIH1 activation and macrophage M1 polarization in ARDS is of great importance for developing new therapeutic strategies to alleviate lung inflammation and improve patient outcomes. Further research is warranted to elucidate the precise roles of IBR1 and its potential as a therapeutic target in the management of ARDS.
2024-09-05 | GSE247176 | GEO
Project description:Uncontrolled inflammatory responses driven by macrophages and monocytes play a crucial role in perpetuating lung injury and the severity of acute respiratory distress syndrome (ARDS). Previous studies have identified IFIH1 as a key regulator of macrophage M1 polarization in pneumonia-induced ARDS. IFIH1 is a cytosolic receptor responsible for recognizing viral double-stranded RNA (dsRNA) and activating inflammatory and antiviral signaling pathways. Interestingly, our observations indicate that IFIH1 can also be activated by lipopolysaccharide (LPS), a component of bacterial cell walls. However, the precise molecular mechanism underlying LPS-induced IFIH1 activation remains unclear. In our preliminary investigations, we have discovered a novel transcript, named IFIH1-binding RNA1 (IBR1), which is upregulated by LPS and gram-negative bacilli in monocytes and macrophages. We have confirmed that IBR1 interacts with the IFIH1 protein, forming a complex. Further experiments have revealed that IBR1, acting as an endogenous dsRNA, binds to the helicase domain of IFIH1 due to its local double-stranded structure. This specific interaction serves as the underlying molecular mechanism responsible for LPS-induced IFIH1 activation and subsequent macrophage M1 polarization in ARDS. Importantly, our observations indicate a significant upregulation of IBR1 expression in ARDS patients with gram-negative bacilli-induced pneumonia. Understanding the molecular mechanisms driving IFIH1 activation and macrophage M1 polarization in ARDS is of great importance for developing new therapeutic strategies to alleviate lung inflammation and improve patient outcomes. Further research is warranted to elucidate the precise roles of IBR1 and its potential as a therapeutic target in the management of ARDS.
2024-09-05 | GSE244502 | GEO
Project description:Accumulated evidence has demonstrated that the macrophage phenotypic switch from M0 to M1 is crucial in the initiation of the inflammatory process of acute respiratory distress syndrome (ARDS). Better insight into the molecular control of M1 macrophages in ARDS may identify potential therapeutic targets. In the current study, 36 candidate genes associated with the severity of ARDS and simultaneously involved in M1-polarized macrophages were first screened through a weighted network algorithm on all gene expression profiles from the 26 ARDS patients and empirical Bayes analysis on the gene expression profiles of macrophages. STAT1, IFIH1, GBP1, IFIT3, and IRF1 were subsequently identified as hub genes according to connectivity degree analysis and multiple external validations. Among these candidate genes, IFIH1 had the strongest connection with ARDS through the RobustRankAggreg algorithm. It was selected as a crucial gene for further investigation. For in vitro validation, the RAW264.7 cell line and BMDMs were transfected with shIFIH1 lentivirus and plasmid expression vectors of IFIH1. Cellular experimental studies further confirmed that IFIH1 was a novel regulator for promoting M1 macrophage polarization. Moreover, gene set enrichment analysis (GSEA) and in vitro validations indicated that IFIH1 regulated M1 polarization by activating IRF3. In addition, previous studies demonstrated that activation of IFIH1-IRF3 was stimulated by viral RNAs or RNA mimics. Surprisingly, the current study found that LPS could also induce IFIH1-IRF3 activation via a MyD88-dependent mechanism. We also found that only IFIH1 expression without LPS or RNA mimic stimulation could not affect IRF3 activation and M1 macrophage polarization. These findings were validated on two types of macrophages, RAW264.7 cells and BMDMs, which expanded the knowledge on the inflammatory roles of IFIH1 and IRF3, suggesting IFIH1 as a potential target for ARDS treatment.
| S-EPMC7841399 | biostudies-literature
Project description:IBR1: A Novel Endogenous dsRNA Binding to the Helicase Domain of IFIH1 and Its Role in LPS-induced IFIH1 Activation and Macrophage M1 Polarization in ARDS
| PRJNA1036576 | ENA
Project description:IBR1: A Novel Endogenous dsRNA Binding to the Helicase Domain of IFIH1 and Its Role in LPS-induced IFIH1 Activation and Macrophage M1 Polarization in ARDS [RNA-seq]
| PRJNA1023280 | ENA
Project description:IBR1: A Novel Endogenous dsRNA Binding to the Helicase Domain of IFIH1 and Its Role in LPS-induced IFIH1 Activation and Macrophage M1 Polarization in ARDS [ATAC, ChIP]
| PRJNA1036578 | ENA
Project description:Acute respiratory distress syndrome (ARDS) is independently associated with a poor prognosis in patients with sepsis. Macrophage M1 polarization plays an instrumental role in this process. Therefore, the exploration of key molecules affecting acute lung injury and macrophage M1 polarization may provide therapeutic targets for the treatment of septic ARDS. Here, we identified that elevated levels of Ankyrin repeat domain-containing protein 22 (ANKRD22) were associated with poor prognosis and more pronounced M1 macrophage polarization in septic patients by analyzing high-throughput data. ANKRD22 expression was also significantly upregulated in the alveolar lavage fluid, peripheral blood, and lung tissue of septic ARDS model mice. Knockdown of ANKRD22 significantly attenuated acute lung injury in mice with sepsis-induced ARDS and reduced the M1 polarization of lung macrophages. Furthermore, deletion of ANKRD22 in macrophages inhibited M1 macrophage polarization and reduced levels of phosphorylated IRF3 and intracellular interferon regulatory factor 3 (IRF3) expression, while re-expression of ANKRD22 reversed these changes. Further experiments revealed that ANKRD22 promotes IRF3 activation by binding to mitochondrial antiviral-signaling protein (MAVS). In conclusion, these findings suggest that ANKRD22 promotes the M1 polarization of lung macrophages and exacerbates sepsis-induced ARDS.
| S-EPMC10788270 | biostudies-literature
Project description:BackgroundA growing body of research has shown that the phenotypic change in macrophages from M0 to M1 is essential for the start of the inflammatory process in septic acute respiratory distress syndrome (ARDS). Potential treatment targets might be identified with more knowledge of the molecular regulation of M1 macrophages in septic ARDS.MethodsA multi-microarray interrelated analysis of high-throughput experiments from ARDS patients and macrophage polarization was conducted to identify the hub genes associated with macrophage M1 polarization and septic ARDS. Lipopolysaccharide (LPS) and Poly (I:C) were utilized to stimulate bone marrow-derived macrophages (BMDMs) for M1-polarized macrophage model construction. Knock down of the hub genes on BMDMs via shRNAs was used to screen the genes regulating macrophage M1 polarization in vitro. The cecal ligation and puncture (CLP) mouse model was constructed in knockout (KO) mice and wild-type (WT) mice to explore whether the screened genes regulate macrophage M1 polarization in septic ARDS in vivo. ChIP-seq and further experiments on BMDMs were performed to investigate the molecular mechanism.ResultsThe bioinformatics analysis of gene expression profiles from a clinical cohort of 26 ARDS patients and macrophage polarization found that the 5 hub genes (IFIH1, IRF1, STAT1, IFIT3, GBP1) may have a synergistic effect on macrophage M1 polarization in septic ARDS. Further in vivo investigations indicated that IFIH1, STAT1 and IRF1 contribute to macrophage M1 polarization. The histological evaluation and immunohistochemistry of the lungs from the IRF1-/- and WT mice indicated that knockout of IRF1 markedly alleviated CLP-induced lung injury and M1-polarized infiltration. Moreover, the molecular mechanism investigations indicated that knockdown of IFIH1 markedly promoted IRF1 translocation into the nucleus. Knockout of IRF1 significantly decreases the expression of STAT1. ChIP-seq and PCR further confirmed that IRF1, as a transcription factor of STAT1, binds to the promoter region of STAT1.ConclusionIRF1 was identified as the key molecule that regulates macrophage M1polarization and septic ARDS development in vivo and in vitro. Moreover, as the adaptor in response to infection mimics irritants, IFIH1 promotes IRF1 (transcription factor) translocation into the nucleus to initiate STAT1 transcription.
| S-EPMC9709523 | biostudies-literature
Project description:Macrophages are found in tissues, body cavities, and mucosal surfaces. Most tissue macrophages are seeded in the early embryo before definitive hematopoiesis is established. Others are derived from blood monocytes. The macrophage lineage diversification and plasticity are key aspects of their functionality. Macrophages can also be generated from monocytes in vitro and undergo classical (LPS+IFN-γ) or alternative (IL-4) activation. In vivo, macrophages with different polarization and different activation markers coexist in tissues. Certain mouse strains preferentially promote T-helper-1 (Th1) responses and others Th2 responses. Their macrophages preferentially induce iNOS or arginase and have been called M1 and M2, respectively. In many publications, M1 and classically activated and M2 and alternatively activated are used interchangeably. We tested whether this is justified by comparing the gene lists positively [M1(=LPS+)] or negatively [M2(=LPS-)] correlated with the ratio of IL-12 and arginase 1 in transcriptomes of LPS-treated peritoneal macrophages with in vitro classically (LPS, IFN-γ) vs. alternatively activated (IL-4) bone marrow derived macrophages, both from published datasets. Although there is some overlap between in vivo M1(=LPS+) and in vitro classically activated (LPS+IFN-γ) and in vivo M2(=LPS-) and in vitro alternatively activated macrophages, many more genes are regulated in opposite or unrelated ways. Thus, M1(=LPS+) macrophages are not equivalent to classically activated, and M2(=LPS-) macrophages are not equivalent to alternatively activated macrophages. This fundamental discrepancy explains why most surface markers identified on in vitro generated macrophages do not translate to the in vivo situation. Valid in vivo M1/M2 surface markers remain to be discovered.
| S-EPMC6543837 | biostudies-literature
Project description:BackgroundCircadian rhythm is an important player for reproduction. Rev-erbα, a significant clock gene, is involved in regulating cell differentiation, inflammation and metabolism. Macrophage polarization plays crucial roles in immune tolerance at the maternal-fetus interface, which also modulates the initiation and resolution of inflammation. Alteration of macrophage polarization induces adverse pregnancy outcomes such as infertility, recurrent spontaneous abortion and preterm labor.ResultsDecidual macrophages from LPS-induced mice abortion model displayed M1-like bias, accompanied by decreased expression of Rev-erbα. SR9009, an agonist of Rev-erbα, may reduce lipopolysaccharide (LPS)-induced M1 polarization of macrophages via activation of PI3K but not NF-κB signaling pathway. Furthermore, SR9009 could reduce M1-like polarization of decidual macrophages induced by LPS and attenuate LPS-induced resorption rates in mice model.ConclusionsBoth in vivo and in vitro experiments demonstrated that the pharmacological activation of Rev-erbα using SR9009 could attenuate the effect of LPS on macrophage polarization and protect pregnancy. This study may provide a potential therapeutic strategy for miscarriage induced by inflammation.
| S-EPMC8369701 | biostudies-literature