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Interferon regulatory factor (IRF) 2 plays an important role in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). In this study, we explored the effects of IRF2 on apoptosis, inflammation, and oxidative stress in AKI C57BL/6 male mouse model and HEK293 cells following LPS treatment. To determine the effect of IRF2, short hairpin RNAs in mice and small interfering RNAs in cells were used to knockdown IRF2 expression. IRF2 expression, apoptosis, and severity of inflammatory and oxidative stress in mice and cells were measured. IRF2 levels were upregulated in LPS-treated mice and cells. IRF2 knockdown suppressed the levels of creatinine, blood urea nitrogen, and kidney injury molecule 1 and decreased the renal injury score in mice. Furthermore, IRF2 knockdown inhibited apoptosis and decreased the levels of inflammatory, reactive oxygen species (ROS), and malondialdehyde (MDA), but increased superoxide dismutase (SOD) levels in mice and cells. Furthermore, we found that the Janus kinase (JAK)/ signal transducer and activator of transcription pathway activated by LPS was inhibited by knockdown of IRF2, and enhanced by IRF2 overexpression. IRF2 overexpression increased cell apoptosis, inflammation, and ROS and MDA levels, and decreased SOD levels. However, the effect of IRF2 overexpression was reversed by the JAK inhibitor tofacitinib. Knockdown of IRF2 reduced LPS-induced renal tissue injury in vivo and in vitro through anti-inflammatory and antioxidant stress effects.

The transcription factor interferon regulatory factor 2 (IRF2) translates interferon signaling to regulate T cells. In this issue of Immunity, Lukhele et al. identify IRF2 in tumor-infiltrating T cells as a sensor for extrinsic signals that drives an exhaustion program.

IFN regulatory factor (IRF) 2 belongs to the IRF1 subfamily, and its functions are not yet fully understood. In this study, we showed that IRF2a was a negative regulator of the interferon (IFN) response induced by spring viremia of carp virus (SVCV). Irf2a(−/−) knockout zebrafish were less susceptible to SVCV than wild-type fish. Transcriptomic analysis reveals that differentially expressed genes (DEGs) in the irf2a(−/−) and irf2a(+/+) cells derived caudal fins were mainly involved in cytokine-cytokine receptor interaction, mitogen-activated protein kinase (MAPK) signaling pathway, and transforming growth factor-beta (TGF-beta) signaling pathway. Interestingly, the basal expression levels of interferon stimulating genes (ISGs), including pkz, mx, apol, and stat1 were higher in the irf2a(−/−) cells than irf2a(+/+) cells, suggesting that they may contribute to the increased viral resistance of the irf2a(−/−) cells. Overexpression of IRF2a inhibited the activation of ifnφ1 and ifnφ3 induced by SVCV and poly(I:C) in the epithelioma papulosum cyprini (EPC) cells. Further, it was found that SVCV phosphoprotein (SVCV-P) could interact with IRF2a to promote IRF2a nuclear translocation and protein stability via suppressing K48-linked ubiquitination of IRF2a. Both IRF2a and SVCV-P not only destabilized STAT1a but reduced its translocation into the nucleus. Our work demonstrates that IRF2a cooperates with SVCV-P to suppress host antiviral response against viral infection in zebrafish. IMPORTANCE Interferon regulatory factors (IRFs) are central in the regulation of interferon-mediated antiviral immunity. Here, we reported that IRF2a suppressed interferon response and promoted virus replication in zebrafish. The suppressive effects were enhanced by the phosphoprotein of the spring viremia of carp virus (SVCV) via inhibition of K48-linked ubiquitination of IRF2a. IRF2a and SVCV phosphoprotein cooperated to degrade STAT1 and block its nuclear translocation. Our work demonstrated that IRFs and STATs were targeted by the virus through posttranslational modifications to repress interferon-mediated antiviral response in lower vertebrates.

Background. Propofol is a widely used intravenous anesthetic drug with potential neuroprotective effect in diverse diseases of neuronal injuries such as traumatic brain injury and ischemic stroke. However, the underlying molecular mechanism remains largely unknown. Methods. Real-time qPCR, enzyme-linked immunosorbent assay, and Western blotting were used to identify the expression pattern of miR-221/222, inflammatory genes, cytokines, and IRF2. The biological roles and mechanisms of propofol in microglia activation were determined in BV2 cells and primary microglia. Bioinformatic analysis and luciferase reporter assay were used to confirm the regulatory role of miR-221/222 in Irf2 expression. Results. We found that miR-221 and miR-222 were downstream targets of propofol and were consistently upregulated in lipopolysaccharide- (LPS-) primed BV2 cells. Gain- and loss-of-function studies revealed that miR-221 and miR-222 were profoundly implicated in microglia activation. Then, interferon regulatory factor 2 (Irf2) was identified as a direct target gene of miR-221/222. IRF2 protein levels were reduced by miR-221/222 and increased by propofol treatment. Ectopic expression of IRF2 attenuated the proinflammatory roles induced by LPS in BV2 cells. More importantly, the suppressive effects of propofol on LPS-primed activation of BV2 cells or primary mouse microglia involved the inhibition of miR-221/222-IRF2 axis. Conclusions. Our study highlights the critical function of miR-221/222, which inhibited Irf2 translation, in the anti-inflammatory effects of propofol, and provides a new perspective for the molecular mechanism of propofol-mediated neuroprotective effect.

Osteosarcoma (OS) is the most frequently occurring bone cancer. Circular RNAs (circRNAs) have been shown to exert pivotal impact in modulation of gene expression, but their roles in OS are still not fully understood. In this study, we analysed the role of circ‐0000658 in OS. Thereafter, molecular techniques such as Western blot, qRT‐PCR, RNA‐binding protein immunoprecipitation and Dual‐Luciferase reporter assays were implemented to investigate the role of circ‐0000658/miR‐1227/interferon regulatory factor‐2 (IRF2) axis in OS. Eventually, the impact of circ‐0000658 on tumour growth and metastasis was observed in a xenograft mouse model. The results of this study revealed that circ‐0000658 exhibits low levels in OS tissues and cell lines. Moreover, circ‐0000658 repression promoted cell cycle, proliferation, invasion and migration but inhibited the apoptosis of OS cells. Researches have previously shown that circ‐0000658 contains a binding site for miR‐1227 and thus can abundantly sponge miR‐1227 to up‐regulate the expression of its target gene IRF2. Moreover, both inhibition of miR‐1227 and overexpression of IRF2 reversed cell proliferation and invasion, which was triggered by circ‐0000658 repression. Conclusively, circ‐0000658 modulates biological function of OS cells through the miR‐1227/IRF2 axis. Therefore, circ‐0000658 might act as a possible novel therapeutic target for the treatment of OS.

Background We reported that the pancreas of the interferon-regulatory factor (IRF) 2 knock-out (KO) mouse represents an early phase of acute pancreatitis, including defective regulatory exocytosis, intracellular activation of trypsin, and disturbance of autophagy. The significantly upregulated and downregulated genes in the IRF2 KO pancreas have been reported. The catalogue of gene transcripts included two types of calcium-binding proteins (S100 calcium binding protein G [S100g] and Annexin A10 [Anxa10]), which were highly upregulated in the IRF2 KO pancreas. As the intracellular calcium signal plays a pivotal role in regulatory exocytosis and its disturbance is related to pancreatitis, we then evaluated the role of S100g and Anxa10 in acute pancreatitis. Method We induced cerulein-pancreatitis in wild-type mice and examined the changes in the expression of these genes by qPCR and immunohistochemistry. We constructed S100g-overexpressing or Anxa10-overexpressing AR42J cells (AR42J-S100g, AR42J-Anxa10). We examined the changes in amylase secretion, intracellular calcium ([Ca2+]i), and cell viability in these cells, when incubated with cholecystokinin (CCK). Results The expression of S100g and Anxa10 was increased in cerulean-induced pancreatitis. The acini were patchily stained for S100g and the cytosol of acini was evenly but weakly stained for Anxa10. Stimulation with 100pM CCK-8, decreased amylase secretion and inhibited the [Ca2+]i increase in AR42J-S100g cells. These effects were weak in AR42J-Anxa10 cells. Cell viability was not changed by incubation with cerulein. Conclusion In cerulean pancreatitis, the expression of S100g and Anxa10 was induced in the acini. S100g may work as a Ca2+ buffer in acute pancreatitis.

De novo truncations in Interferon Regulatory Factor 2 Binding Protein Like (IRF2BPL) lead to severe childhood-onset neurodegenerative disorders. To determine how loss of IRF2BPL causes neural dysfunction, we examined its function in Drosophila and zebrafish. Overexpression of either IRF2BPL or Pits, the Drosophila ortholog, represses Wnt transcription in flies. In contrast, neuronal depletion of Pits leads to increased wingless (wg) levels in the brain and is associated with axonal loss, whereas inhibition of Wg signaling is neuroprotective. Moreover, increased neuronal expression of wg in flies is sufficient to cause age-dependent axonal loss, similar to reduction of Pits. Loss of irf2bpl in zebrafish also causes neurological defects with an associated increase in wnt1 transcription and downstream signaling. WNT1 is also increased in patient-derived astrocytes, and pharmacological inhibition of Wnt suppresses the neurological phenotypes. Last, IRF2BPL and the Wnt antagonist, CKIα, physically and genetically interact, showing that IRF2BPL and CkIα antagonize Wnt transcription and signaling., Description, Up-regulated neuronal Wnt transcription in adult brains is sufficient to cause progressive neurodegenerative phenotypes in vivo.

Interferon regulatory factor (IRF) 2 is a transcription factor belonging to the IRF family, which is essential for gasdermin D (GSDMD)-induced pyroptosis. Decreasing myocardial cell pyroptosis confers protection against heart damage and cardiac dysfunction caused by myocardial infarction (MI). The aim of the present study was to investigate the involvement of IRF2 in MI and the underlying mechanism of IRF2 in pyroptosis. To mimic MI, ligation of the left anterior descending coronary artery was performed to establish an in vivo mouse model and rat cardiomyocytes H9c2 cells were cultured under hypoxic conditions to establish an in vitro model. Transthoracic echocardiography was used to assess cardiac function. Hematoxylin and eosin staining was used to observe histopathological changes in the myocardial tissue. Immunohistochemistry and western blotting were performed to detect IRF2 expression levels. TUNEL staining and flow cytometry were used to detect apoptosis in myocardial tissue and cells. Chromatin immunoprecipitation and dual luciferase reporter assay were used to verify the effect of IRF2 on GSDMD transcription. IRF2 was upregulated in MI mice. MI induced pyroptosis, as evidenced by increased GSDMD, N-terminal GSDMD (GSDMD-N), and cleaved (c-) caspase-1 levels. MI increased IL-1β and IL-18 levels. These alterations were alleviated by IRF2 silencing. Furthermore, in hypoxia-treated H9c2 cells, IRF2 silencing significantly decreased the elevated levels of IL-1β and IL-18 and pyroptosis-associated proteins, including GSDMD, GSDMD-N and c-caspase1. Moreover, in hypoxia-treated H9c2 cells, IRF2 directly bound to the GSDMD promoter to drive GSDMD transcription and promote pyroptosis and IRF2 expression may be regulated via the hypoxia inducible factor 1 signaling pathway. In conclusion, the present results demonstrated that IRF2 is a key regulator of MI by mediating pyroptosis, which triggers GSDMD activation.

Oral squamous cell carcinoma (OSCC) is a common type of malignant tumor worldwide. Claudin-7 (CLDN7) has been reported to exhibit low expression in tissues of patients with OSCC; however, the underlying mechanisms of CLDN7 remain to be elucidated. The present study aimed to investigate the effects of CLDN7 on the progression of OSCC and identify its potential regulatory mechanisms. CLDN7 and interferon regulatory factor-2 (IRF2) expression in several OSCC cell lines were detected using reverse transcription-quantitative PCR (RT-qPCR) and western blotting. Following CLDN7 overexpression, cell proliferation, invasion and migration were determined using a Cell Counting Kit-8, colony formation, Transwell and wound healing assays, respectively. The potential binding sites of IRF2 on the CLDN7 promoter were analyzed using the PROMO and JASPAR databases, which were verified via chromatin immunoprecipitation and RT-qPCR assays. The effects of IRF2 and CLDN7 on the biological functions of OSCC cells were examined by transfection with short hairpin RNA (shRNA) against CLDN7 (sh-CLDN7), or IRF2 and CLDN7 overexpression plasmids. The results revealed that CLDN7 and IRF2 expression were significantly downregulated in OSCC cell lines, and CLDN7 overexpression reduced the proliferation, invasion and migration of OSCC cells. Additionally, IRF2 was confirmed to combine with the CLDN7 promoter. CLDN7 silencing reversed the inhibitory effects of IRF2 overexpression on the proliferation, invasion and migration of OSCC cells. Taken together, these findings demonstrated that IRF2-induced CLDN7 upregulation suppressed the proliferation, invasion and migration of OSCC cells, suggesting the possibility of CLDN7 and IRF2 as novel targets for the treatment of OSCC.

Tripartite motif‐containing 14 (TRIM14) is a mitochondrial adaptor that promotes innate immune signaling and plays important roles in antiviral defense. Expression of TRIM14 is induced by interferon (IFN)‐I. However, the mechanism by which IFN‐I induces TRIM14 production is not yet determined. In this study, we have examined the function of TRIM14 promoter and found that a GC box and an IFN‐stimulated response element (ISRE) are necessary for the basal level transcription of TRIM14. We further observed that IFN‐I activates the TRIM14 promoter through the ISRE. In particular, interferon regulatory factor (IRF)‐1 and IRF‐2 bind to the TRIM14 promoter and activate transcription of TRIM14. Moreover, knockdown of IRF‐1 reduces the stimulation of TRIM14 transcription by IFN‐α, suggesting that IRF‐1 is involved in the activation of TRIM14 by IFN‐I. IRF‐2 has little effect on IFN‐α‐induced TRIM14 transcription but is essential for the basal transcription of TRIM14.

Background Aberrant expression of microRNA-664 was involved in tumor growth and metastasis of various cancers. The specific role of miR-664 in cutaneous squamous cell carcinoma (cSCC) is yet to be elucidated. Objective The present study aimed to investigate the molecular mechanisms underpinning of cSCC development and provide translational insights for future therapeutics. Methods Human cSCC specimens were used to determine the miR-664 by in situhybridization and IRF2 by immunohistochemistry. To study the potential mechanisms in tumorigenesis, three cSCC cell lines including HSC-5, HSC-1 and A431 as well as BALB/C mouse tumor model was utilized. Results We found that miR-664 was remarkably high in cSCC patient specimens and cSCC cell lines. Overexpression of miR-664 promotes tumorigenic behaviors such as increased cell proliferation, migration and invasion capacities in vitro and enhanced tumorigenicity in xenograft mouse model. Our data further identified IRF2 as a direct downstream target of miR-664. Knockdown of IRF2 reverses pro-tumorigenesis phenotype of miR-664; whereas IRF2 over-expression inhibits miR-664 tumorigenesis in cSCC. Together, it revealed miR-664 functions as an oncogene in cSCC via suppression of IRF2. Conclusion Our data demonstrates that aberrant expression of miR-664 plays a critical role in carcinogenesis of cSCC. The discovery of novel targets such as miR-664 and IRF2 will facilitate future development of therapeutic interventions.

Innate lymphoid cells (ILCs), composed of heterogeneous populations of lymphoid cells, contribute critically to immune surveillance at mucosal surfaces. ILC subsets develop from common lymphoid progenitors through stepwise lineage specification. However, the composition and temporal regulation of the transcription factor network governing such a process remain incompletely understood. Here, we report that deletion of the transcription factor interferon regulatory factor 2 (IRF-2), known also for its importance in the maturation of conventional NK cells, resulted in an impaired generation of ILC1, ILC2 and ILC3 subsets with lymphoid tissue inducer (LTi)-like cells hardly affected. In IRF-2-deficient mice, PD-1hi ILC precursors (ILCPs) that generate these three ILCs but not LTi-like cells were present at normal frequency, while their sub-population expressing high amounts of PLZF, another marker for ILCPs, was severely reduced. Notably, these IRF-2-deficient ILCPs contained normal quantities of PLZF-encoding Zbtb16 messages, and PLZF expression in developing invariant NKT cells within the thymus was unaffected in these mutant mice. These results point to a unique, cell-type selective role for IRF-2 in ILC development, acting at a discrete step critical for the generation of functionally competent ILCPs.

UBE3A is a gene responsible for the pathogenesis of Angelman syndrome (AS), a neurodevelopmental disorder characterized by symptoms such as intellectual disability, delayed development and severe speech impairment. UBE3A encodes an E3 ubiquitin ligase, for which several targets have been identified, including synaptic molecules. Although proteolysis mainly occurs in the cytoplasm, UBE3A is localized to the cytoplasm and the nucleus. In fact, UBE3A is also known as a transcriptional regulator of the family of nuclear receptors. However, the function of UBE3A in the nucleus remains unclear. Therefore, we examined the involvement of UBE3A in transcription in the nuclei of neurons. Genome-wide transcriptome analysis revealed an enrichment of genes downstream of interferon regulatory factor (IRF) in a UBE3A-deficient AS mouse model. In vitro biochemical analyses further demonstrated that UBE3A interacted with IRF and, more importantly, that UBE3A enhanced IRF-dependent transcription. These results suggest a function for UBE3A as a transcriptional regulator of the immune system in the brain. These findings also provide informative molecular insights into the function of UBE3A in the brain and in AS pathogenesis.

Background Although interferon regulatory factor 2 (IRF2) was reported to stimulate virus replication by suppressing the type I interferon signaling pathway, because cell cycle arrest was found to promote viral replication, IRF2-regulated replication fork factor (FAM111A and RFC3) might be able to affect ZIKV replication. In this study, we aimed to investigate the function of IRF2, FAM111A and RFC3 to ZIKV replication and underlying mechanism. Methods siIRF2, siFAM111A, siRFC3 and pIRF2 in ZIKV-infected A549, 2FTGH and U5A cells were used to explore the mechanism of IRF2 to inhibit ZIKV replication. In addition, their expression was analyzed by RT-qPCR and western blots, respectively. Results In this study, we found IRF2 expression was increased in ZIKV-infected A549 cells and IRF2 inhibited ZIKV replication independent of type I IFN signaling pathway. IRF2 could activate FAM111A expression and then enhanced the host restriction effect of RFC3 to inhibit replication of ZIKV. Conclusions We speculated the type I interferon signaling pathway might not play a leading role in regulating ZIKV replication in IRF2-silenced cells. We found IRF2 was able to upregulate FAM111A expression and thus enhance the host restriction effect of RFC3 on ZIKV.

Interferon regulatory factor 8 (IRF8), also known as interferon consensus sequence-binding protein (ICSBP), is a negative regulatory factor of interferon (IFN) and plays an important role in cell differentiation and innate immunity in mammals. In recent years, some irf8 homologous genes have been cloned and confirmed to take part in innate immune response in fish, but the mechanism still remains unclear. In this paper, a grass carp (Ctenopharyngodon idella) irf8 gene (Ciirf8) was cloned and characterized. The deduced protein (CiIRF8) possesses a highly conserved N-terminal DNA binding domain but a less well-conserved C-terminal IRF association domain (IAD). Ciirf8 was widely expressed in all tested tissues of grass carp and up-regulated following poly(I:C) stimulation. Ciirf8 expression was also up-regulated in CIK cells upon treatment with poly(I:C). To explore the molecular mechanism of how fish IRF8 regulates ifn1 expression, the similarities and differences of grass carp IRF8 and IRF2 were compared and contrasted. Subcellular localization analysis showed that CiIRF8 is located both in the cytoplasm and nucleus; however, CiIRF2 is only located in the nucleus. The nuclear-cytoplasmic translocation of CiIRF8 was observed in CIK cells under stimulation with poly(I:C). The interaction of CiIRF8 and CiIRF2 was further confirmed by a co-immunoprecipitation assay in the nucleus. Dual-luciferase reporter assays showed that the promoter activity of Ciifn1 was significantly inhibited by co-transfection with CiIRF2 and CiIRF8. The transcription inhibition of Ciifn1 was alleviated by competitive binding of CiIRF2 and CiIRF8 to CiIRF1. In conclusion, CiIRF8 down-regulates Ciifn1 expression via interaction with CiIRF2 in cells.

Interferon regulatory factors (IRFs) are crucial transcription factors involved in transcriptional regulation of type I interferons (IFNs) and IFN-stimulated genes (ISGs) against viral infection. In teleost fish, eleven IRFs have been found, however, understanding of their roles in the antiviral response remains limited. In the previous study, IRF1 (LcIRF1) and IRF2 (LcIRF2) genes were cloned from large yellow croaker (Larimichthys crocea). Here, we further characterized their function in the antiviral response. LcIRF1 and LcIRF2 were constitutively expressed in primary head kidney monocytes/macrophages (PKMs), lymphocytes (PKLs), granulocytes (PKGs) and large yellow croaker head kidney (LYCK) cell line, and significantly upregulated in PKMs and LYCK cells after stimulation with poly (I:C). LcIRF1 could induce promoter activities of three large yellow croaker type I IFNs, IFNc, IFNd and IFNh, while LcIRF2 could only induce those of IFNd and IFNh, and inhibit IFNc promoter activity. Correspondingly, overexpression of LcIRF1 in LYCK cells increased expression of all three IFNs (IFNc, IFNd and IFNh), while that of LcIRF2 only upregulated the expression levels of IFNd and IFNh, and inhibited expression of IFNc, although both LcIRF1and LcIRF2 induced expression of IFN-stimulated genes (ISGs), MxA, PKR and Viperin. Additionally, both LcIRF1 and LcIRF2 inhibited the Spring Viremia of Carp Virus (SVCV) replication in epithelioma papulosum cyprinid (EPC) cells, thus showing antiviral activity. Taken together, these results indicated that both LcIRF1 and LcIRF2 play positive roles in regulating the antiviral response of large yellow croaker by induction of distinct subgroups of type I IFNs.

The physiological stresses that diminish tissue stem-cell characteristics remain largely unknown. We previously reported that type I interferon (IFN), which is essential for host antiviral responses, is a physiological stressor for hematopoietic stem cells (HSCs) and small intestinal stem cells (ISCs) and that interferon regulatory factor-2 (IRF2), which attenuates IFN signaling, maintains their stemness. Here, using a dextran sodium sulfate (DSS)-induced colitis model, we explore the role of IRF2 in maintaining colonic epithelial stem cells (CoSCs). In mice with a conditional Irf2 deletion in the intestinal epithelium (hereafter Irf2ΔIEC mice), both the number and the organoid-forming potential of CoSCs were markedly reduced. Consistent with this finding, the ability of Irf2ΔIEC mice to regenerate colon epithelium after inducing colitis was severely impaired, independently of microbial dysbiosis. Mechanistically, CoSCs differentiated prematurely into transit-amplifying (TA) cells in Irf2ΔIEC mice, which might explain their low CoSC counts. A similar phenotype was induced in wild-type mice by repeated injections of low doses of poly(I:C), which induces type I IFN. Collectively, we demonstrated that chronic IFN signaling physiologically stresses CoSCs. This study provides new insight into the development of colitis and molecular mechanisms that maintain functional CoSCs throughout life.

Chemoresistance is the leading cause of recurrence in non-small cell lung cancer (NSCLC). The long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) inhibits the tumorigenesis of various cancers. However, the regulatory function of CASC2 on the chemoresistance of NSCLC remains unclear.The levels of CASC2 and miR-18a in cisplatin (DDP)-resistant NSCLC tissues and cell lines were evaluated by quantitative Polymerase Chain Reaction (qPCR). The role of low CASC2 levels on overall survival in patients with NSCLC was tested using the log-rank test. The Chi-squared test was used to assess the relation between CASC2 expression and clinicopathological features of NSCLC patients. Cell Counting Kit-8 (CCK-8) assays tested the cell proliferation of cisplatin-resistant NSCLC cells (H226/DDP and A549/DDP). The underlying regulatory mechanism between CASC2 and miR-18a or miR-18a and interferon regulatory factor 2 (IRF-2) was predicted by bioinformatics and verified by a Dual-Luciferase reporter assay, RNA transfection, qPCR, and Western blotting. Chromatin immunoprecipitation (ChIP) assay was done to exam the relation between E74 like factor 1 (ELF1) and CASC2 gene. Mice xenografts were applied to exam the function of CASC2 on chemosensitivity of cisplatin of NSCLC cells in vivo.Low CASC2 expression is more likely to present in patients with advanced TNM stage (IV), cisplatin-resistance, and poor overall survival. The expression of CASC2 sharply decreased in cisplatin-resistant NSCLC tissues and cell lines (H226/DDP and A549/DDP). CASC2 overexpression strongly inhibited proliferation, migration, and invasion of cisplatin-resistant NSCLC cells (H226/DDP and A549/DDP) in vitro and inhibited tumor growth in vivo. Besides, CASC2 repressed miR-18a function by binding to the complementary sites of miR-18a as competing endogenous RNAs (ceRNAs). MiR-18a released by the declining expression of CASC2 reduced the protein concentration of IRF-2 in NSCLC cells. Furthermore, the transcription factor ELF1 was found to be promotor of CASC2 and increased its levels in cisplatin-resistant NSCLC cells.IRF-2 expression mediated by the ELF1/CASC2/miR-18a axis is markedly associated with the proliferation, migration, and invasion of cisplatin-resistant NSCLC, resulting in inferior survival. These findings suggest that this regulatory axis may serve as a novel therapeutic target in NSCLC.

Intestinal stem cells (ISCs) are located at the crypt base and fine-tune the balance of their self-renewal and differentiation

Fetal growth restriction (FGR) is a serious pregnancy complication associated with increased perinatal mortality and morbidity. It may lead to neurodevelopmental impairment and adulthood onset disorders. Recently, long noncoding RNAs (lncRNAs) were found to be associated with the pathogenesis of FGR. Here we report that the lncRNAH19 is significantly decreased in placentae from pregnancies with FGR. Downregulation of H19 leads to reduced proliferation and invasion of extravillous trophoblast cells. This is identified with reduced trophoblast invasion, which has been discovered in FGR. Autophagy is exaggerated in FGR. Downregulation of H19 promotes autophagy via the PI3K/AKT/mTOR and MAPK/ERK/mTOR pathways of extravillous trophoblast cells in FGR. We also found that the expression level of microRNAs miR‐18a‐5p was negatively correlated with that of H19. H19 can act as an endogenous sponge by directly binding to miR‐18a‐5p, which targets IRF2. The expression of miR‐18a‐5p was upregulated, but IRF2 expression was downregulated after the H19 knockdown. In conclusion, our study revealed that H19 downexpressed could inhibit proliferation and invasion, and promote autophagy by targeting miR‐18a‐5pin HTR8 and JEG3 cells. We propose that aberrant regulation of H19/miR‐18a‐5p‐mediated regulatory pathway may contribute to the molecular mechanism of FGR. We indicated that H19 may be a potential predictive, diagnostic, and therapeutic modality for FGR.

Long noncoding RNAs (lncRNAs), once thought to be nonfunctional, have recently been shown to participate in the multilevel regulation of transcriptional, posttranscriptional and epigenetic modifications and to play important roles in various biological processes, including immune responses. However, the expression and roles of lncRNAs in invertebrates, especially nonmodel organisms, remain poorly understood. In this study, by comparing a transcriptome to the PfIRF-2 genomic structure, we identified lncIRF-2 in the PfIRF-2 genomic intron. The results of the RNA interference (RNAi) and the nucleus grafting experiments indicated that PfIRF-2 might have a negative regulatory effect on lncIRF-2, and PfIRF-2 and lncIRF-2 may have a positive regulatory effect on PfIL-17. Additionally, lncIRF-2, PfIRF-2 and PfIL-17 were involved in responses to the nucleus graft. These results will enhance the knowledge of lncIRF-2, IRF-2, and IL-17 functions in both pearl oysters and other invertebrates.

Transforming growth factor β1 (TGF-β1) plays a promoting role in tumor growth via a mechanism associated with hyperactive Smad3 and suppressed Smad7 signaling in the tumor microenvironment. We report that retrieving the balance between Smad3 and Smad7 signaling with asiatic acid (AA, a Smad7 inducer) and naringenin (NG, a Smad3 inhibitor) effectively inhibited tumor progression in mouse models of invasive melanoma (B16F10) and lung carcinoma (LLC) by promoting natural killer (NK) cell development and cytotoxicity against cancer. Mechanistically, we found that Smad3 physically bound Id2 and IRF2 to suppress NK cell production and NK cell-mediated cytotoxicity against cancer. Treatment with AA and NG greatly inhibited Smad3 translation and phosphorylation while it restored Smad7 expression, and, therefore, it largely promoted NK cell differentiation, maturation, and cytotoxicity against cancer via Id2/IRF2-associated mechanisms. In contrast, silencing Id2 or IRF2 blunted the protective effects of AA and NG on NK cell-dependent anti-cancer activities. Thus, treatment with AA and NG produced an additive effect on inactivating TGF-β1/Smad3 signaling, and, therefore, it suppressed melanoma and lung carcinoma growth by promoting NK cell immunity against cancer via a mechanism associated with Id2 and IRF2.

Backgrounds IFN regulatory factor (IRF)-2 is one of the potential susceptibility genes for psoriasis, but how this gene influences psoriasis pathogenesis is unclear. Topical application of imiquimod (IMQ), a TLR7 ligand, induces psoriasis-like skin lesions in mice. Objective The aim of this study was to investigate whether IRF-2 gene status would influence severity of skin disease in IMQ-treated mice. Methods Imiquimod-induced psoriasis-like skin inflammation was assessed by clinical findings, histology, and cytokine expression. The effects of imiquimod or IFN on peritoneal macrophages were analyzed in vitro. Results IMQ-induced skin inflammation assessed by clinical findings and histology was more severe in IRF-2+/− mice than in wild-type mice. In inflamed skin, mRNA expression levels of tumor necrosis factor (TNF)-α, IL-12/23p40, IL-17A, and IL-22 were significantly elevated in IRF-2+/− mice compared to wild-type mice. Stimulation of peritoneal macrophages by IMQ significantly increased mRNA levels of TNF-α, IL-12/23p40, IL-23p19, IL-12p35, and IL-36. Interestingly, macrophages from IRF-2+/− mice expressed higher levels of TNF-α, IL-12/23p40, and IL-36 compared to those from wild-type mice 24 h after stimulation, while they expressed similar levels of IL-12p35 and IL-23p19. Moreover, elevated mRNA expression of inducible nitric oxide synthase was observed only in IMQ-stimulated macrophages derived from IRF-2+/− mice, which correlated with angiogenesis in IMQ-treated ears of IRF-2+/− mice. Conclusions These results suggest that IRF-2 haploinsufficiency creates heightened biologic responses to IFN-α that phenotypically lead to enhanced angiogenesis and psoriasis-like inflammation within skin.

Acute myeloid leukemia (AML) is a highly heterogeneous disease, which results in the fact that patient management has remained disappointingly uniform. Therefore, the molecular mechanism underlying AML needs to be further investigated. Here in this study, we identify the interferon-regulatory factor 2 (IRF2) as a novel regulator in human AML. We show that IRF2 knockdown inhibits growth, colony formation of OCI/AML-2, OCI/AML-3, and THP-1 cells. In addition, IRF2 knockdown induces apoptosis of AML cells by regulating the apoptotic effectors Bcl-2, Bax and Caspase 3. Further mechanism analysis shows that inositol polyphosphate-4-phosphatase, type-II (INPP4B) contributes to the effects of IRF2 on apoptosis and growth of AML cells. IRF2 binds INPP4B promoter and promotes INPP4B expression in AML cells. Restoration of the expression of INPP4B blocks the effects of IRF2 knockdown on apoptosis and colony formation in OCI/AML-2 and OCI/AML-3 cells. In conclusion, IRF2 serves as an important regulator in AML by targeting INPP4B. Therefore, IRF2 may be a potential target for AML treatment.

Interferon regulatory factors (IRFs) are transcription factors that play important roles in immune defense, stress response, hematopoietic differentiation, and cell apoptosis. IRFs of invertebrate organisms and their functions remain largely unexplored. In the present study, for the first time new IRFs (BpIRF2 and MmIRF2) were identified in the deep-sea mussel Bathymodiolus platifrons and the shallow-water mussel Modiolus modiolus. The open reading frame of BpIRF2 and MmIRF2 encoded putative proteins of 354 and 348 amino acids, respectively. Comparison and phylogenetic analysis revealed that both IRF2 proteins were new identified invertebrate IRF molecular. As transcriptional factors, both BpIRF2 and MmIRF2 could activate the interferon-stimulated response element-containing promoter and BpIRF2 could interact with itself. Moreover, both BpIRF2 and MmIRF2 were localized to the cytoplasm and nucleus. Collectively, these results demonstrated that IRF2 proteins might be crucial in the innate immunity of deep-sea and shallow-water mussels.

PRKRA (interferon-inducible double-stranded RNA-dependent protein kinase activator A) is a protective protein which regulates the adaptation of cells to ER stress and virus-stimulated signaling pathways by activating PKR. In the present study, a grass carp (Ctenopharyngodon idella) PRKRA full-length cDNA (named CiPRKRA, KT891991) was cloned and identified. The full-length cDNA is comprised of a 5′ UTR (36 bp), a 3′ UTR (350 bp) and the longest ORF (882 bp) encoding a polypeptide of 293 amino acids. The deduced amino acid sequence of CiPRKRA contains three typical dsRNA binding motifs (dsRBM). Phylogenetic tree analysis revealed a closer evolutionary relationship of CiPRKRA with other fish PRKRA, especially with Danio rerio PRKRA. qRT-PCR showed that CiPRKRA was significantly up-regulated after stimulation with tunicamycin (Tm) and Poly I:C in C. idella kidney (CIK) cells. To further study its transcriptional regulation, the partial promoter sequence of CiPRKRA (1463 bp) containing one ISRE and one CARE was cloned by Tail-PCR. Subsequently, grass carp IRF2 (CiIRF2) and ATF4 (CiATF4) were expressed in Escherichia coli BL21 and purified by affinity chromatography with the Ni-NTA His-Bind Resin. In vitro, both CiIRF2 and CiATF4 bound to CiPRKRA promoter with high affinity by gel mobility shift assays, revealing that IRF2 and ATF4 might be potential transcriptional regulatory factors for CiPRKRA. Dual-luciferase reporter assays were applied to further investigate the transcriptional regulation of CiPRKRA in vivo. Recombinant plasmid of pGL3-PRKRAPro was constructed and transiently co-transfected into CIK cells with pcDNA3.1-CiIRF2 and pcDNA3.1-CiATF4, respectively. The results showed that both CiIRF2 and CiATF4 significantly decreased the luciferase activity of pGL3-PRKRAPro, suggesting that they play a negative role in CiPRKRA transcription.

Interferon regulatory factor 2 (IRF-2) is known to play a pivotal role in the development and progression of several malignancies. As a crucial member of interferon regulatory factor family, the association between the expression of IRF-2 and clinical prognostic significance has not been fully explored in colorectal cancer (CRC). The purpose of our study was to investigate the expression profile of IRF-2 in CRC and to examine its association with clinical features. The expression levels of IRF-2 in 18 paired CRC and non-cancerous colorectal tissues were measured by quantitative real-time PCR (qRT-PCR) and those in 4 paired samples by Western blotting. The results showed a significant increase in IRF-2 mRNA expression and protein expression in CRC tissues compared to those in paired normal tissues. Besides, high expression of IRF-2 was significantly associated with distant metastasis (P = 0.041) and preoperative serum CEA level (P = 0.045). Kaplan–Meier survival analysis showed that patients with high expression of IRF-2 had a significantly worse overall survival than those with low expression of IRF-2 (P = 0.006). Further multivariate analysis indicated that IRF-2 and TNM stage were independent prognostic factors for overall survival in patients with CRC. Our study primarily suggests IRF-2 as a potential prognostic biomarker in CRC.

Cancer related inflammation (CRI) plays an important role in the development of esophageal cancer (EC), and the target gene analysis shows that miR-302b potential target genes closely correlated to CRI important signaling pathways. The present study was to evaluate the inhibition of miR-302b on CRI in EC and its mechanism. We found that the expression levels of miR-302b in EC cells were lower than that in Het-1A cells, while TE11 with the lowest expression and OE33 with the highest. Inflammatory stimuli at 48 h significantly reduced expression of miR-302b in EC cells, but had no effect in Het-1A. After up-regulation of miR-302b in TE11 and down-regulation of miR-302b in OE33, it was found that miR-302b reduced CRI key transcription factors and representative cytokines. Then, over-expressed of miR-302b significantly altered potential target genes protein expressions and there was a negative correlation between miR-302b and potential target genes protein expressions (ERBB4, IRF2 and CXCR4) in EC tissues. Then reporter gene analysis revealed that miR-302b post-transcriptionally regulated expression of target genes by specific area of 3′-UTR. Transfected by target genes shRNA plasmids together could get the same effects of miR-302b on protein expression of CRI key transcription factors. Furthermore, miR-302b was able to repress tumor growth and transcription factors protein expression in vivo. These finding suggests that miR-302b inhibits key transcription factors and cytokines by targeting ERBB4, IRF2 and CXCR4, implicating its role in the inhibition of CRI in EC.

Acute kidney injury is a common and severe complication of critical illness and cardiac surgery. Despite significant attempts at developing treatments, therapeutic advances to attenuate acute kidney injury and expedite recovery have largely failed.Identifying genetic loci associated with increased risk of acute kidney injury may reveal novel pathways for therapeutic development.We conducted an exploratory genome-wide association study to identify single-nucleotide polymorphisms associated with genetic susceptibility to in-hospital acute kidney injury.We genotyped 609,508 single-nucleotide polymorphisms and performed genotype imputation in 760 acute kidney injury cases and 669 controls. We then evaluated polymorphisms that showed the strongest association with acute kidney injury in a replication patient population containing 206 cases with 1,406 controls. We observed an association between acute kidney injury and four single-nucleotide polymorphisms at two independent loci on metaanalysis of discovery and replication populations. These include rs62341639 (metaanalysis P = 2.48 × 10Our findings reveal two genetic loci that are associated with acute kidney injury. Additional studies should be conducted to functionally evaluate these loci and to identify other common genetic variants contributing to acute kidney injury.

Interferon regulatory factors (irfs) are a family of genes that encode transcription factors with important roles in regulating the expression of Type I interferons (IFNs) and other genes associated with related pathways. irfs have multitudinous functions in growth, development and regulation of oncogenesis. In this study, three irf family members (irf2, irf7, irf9) were identified and characterized in Megalobrama amblycephala at the mRNA and amino acid levels. M. amblycephala irfs share a high sequence homology with other vertebrate irfs. Constitutive expression levels of the three genes were detected (using qPCR) in all studied tissues: low to medium in kidney, gills, heart and muscle, and high in liver, spleen, intestine and blood. qPCR was also used to analyze the dynamic expression patterns of irfs in different embryonic development stages: irf2 is not activated during the embryonic development, whereas irf9 appears to play important roles around hatching and during the larval development. Transcripts of all three studied irfs were upregulated after stimulation by Aeromonas hydrophila bacterium in liver, spleen, head kidney and trunk kidney, whereas downregulation was observed in intestine and gills. The results show that these three irfs are likely to be important factors in the blunt snout bream immune system. They also provide a foundation for studying the origin and evolution of the innate immune system in the blunt snout bream.

In fish, interferon (IFN) regulatory factor 2 (IRF2) is a regulator of the type I IFN-dependent immune response, thereby playing a crucial role in innate immunity. However, the specific mechanism by which IRF2 regulates type II IFN in fish remains unclear. In the present study, first, to analyse the potential role of golden pompano (Trachinotus ovatus) IRF2 (ToIRF2) in the immune response, the mRNA level of ToIRF2 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) after parasite infection. ToIRF2 was upregulated at early time points in both local infection sites (skin and gill) and system immune tissues (liver, spleen, and head-kidney) after stimulation with Cryptocaryon irritans. Second, to investigate the modulation effect of ToIRF2 on type II IFN (interferon gamma, IFNγ) expression, a promoter analysis was performed using progressive deletion mutations of ToIFNγ. The expression level of IFNγ-5 was highest among the five truncated mutants in response to ToIRF2, indicating that the core promoter region was located from −189 bp to +120 bp, which included the IRF2 binding sites. Mutation analyses showed that the activity of the ToIFNγ promoter dramatically decreased after the targeted mutation of the M1, M2 or M3 binding sites. Additionally, electrophoretic mobile shift assay (EMSA) confirmed that IRF2 interacted with the M1 binding site in the ToIFNγ promoter region to dominate ToIFNγ expression. Finally, overexpressing ToIRF2 in vitro notably increased ToIFNγ and the transcription of several type II IFN/IRF-based signalling pathway genes. These results suggested that ToIRF2 might be involved in the host defence against C. irritans infection and contribute to a better understanding of the transcriptional mechanisms by which ToIRF2 regulates type II IFN in fish.

The interferon-regulatory factor 2 (IRF2)-inositol polyphosphate-4-phosphatase type-II (INPP4B) axis has been shown to suppress cell apoptosis by inducing autophagy in acute myeloid leukaemia (AML) cells. T helper type 1 cell (Th1)/Th2 imbalance is involved in development of autophagy and AML. The aim of this study was to investigate whether IRF2-INPP4B axis regulates autophagy and apoptosis of AML cells via regulating Th1/Th2 cell differentiation. The frequencies of Th2 cells and Th1 cells in transfected CD4+ T cells were determined by flow cytometry. The levels of TNF-α, IFN-γ, IL-4, and IL-13 in peripheral blood and transfected CD4+ T cells from AML patients and healthy donors were examined by ELISA assay. The mRNA levels of IRF2 and INPP4B in peripheral blood mononuclear cells (PBMCs) from AML patients and healthy donors were detected by qRT-PCR. Autophagy was evaluated by green fluorescent protein (GFP)-LC3 immunofluorescence and western blot analysis of autophagy-associated proteins. AML cell apoptosis was detected by flow cytometry. In this study, elevated frequencies of Th2 cells and reduced frequencies of Th1 cells, as well as higher expression of IRF2 and INPP4B, were observed in PBMCs from AML patients relative to healthy donors. Furthermore, IRF2 inhibited Th1 cell differentiation and promoted Th2 cell differentiation through INPP4B. Moreover, we confirmed that IRF2-INPP4B-mediated regulation of Th1/Th2 differentiation promoted autophagy and inhibited apoptosis of AML cells. Collectively, IRF2-INPP4B axis regulates autophagy and apoptosis of AML cells via regulating Th1/Th2 cell differentiation. SIGNIFICANCE OF THE STUDY: In the present study, we confirmed that IRF2-INPP4B-mediated regulation of Th1/Th2 balance promoted autophagy and inhibited apoptosis of AML cells. These findings might provide clues in better understanding of the mechanisms of AML.

Rationale: Acute kidney injury is a common and severe complication of critical illness and cardiac surgery. Despite significant attempts at developing treatments, therapeutic advances to attenuate acute kidney injury and expedite recovery have largely failed.

Caspase‐4, the cytosolic LPS sensor, and gasdermin D, its downstream effector, constitute the non‐canonical inflammasome, which drives inflammatory responses during Gram‐negative bacterial infections. It remains unclear whether other proteins regulate cytosolic LPS sensing, particularly in human cells. Here, we conduct a genome‐wide CRISPR/Cas9 screen in a human monocyte cell line to identify genes controlling cytosolic LPS‐mediated pyroptosis. We find that the transcription factor, IRF2, is required for pyroptosis following cytosolic LPS delivery and functions by directly regulating caspase‐4 levels in human monocytes and iPSC‐derived monocytes. CASP4,GSDMD, and IRF2 are the only genes identified with high significance in this screen highlighting the simplicity of the non‐canonical inflammasome. Upon IFN‐γ priming, IRF1 induction compensates IRF2 deficiency, leading to robust caspase‐4 expression. Deficiency in IRF2 results in dampened inflammasome responses upon infection with Gram‐negative bacteria. This study emphasizes the central role of IRF family members as specific regulators of the non‐canonical inflammasome.

Gasdermin-D (GSDMD) is cleaved by caspase-1, caspase-4, and caspase-11 in response to canonical and noncanonical inflammasome activation. Upon cleavage, GSDMD oligomerizes and forms plasma membrane pores, resulting in interleukin-1β (IL-1β) secretion, pyroptotic cell death, and inflammatory pathologies, including periodic fever syndromes and septic shock-a plague on modern medicine. Here, we showed that IRF2, a member of the interferon regulatory factor (IRF) family of transcription factors, was essential for the transcriptional activation of

To arise and progress, cancers need to evade immune elimination. Consequently, progressing tumors are often MHC class I (MHC-I) low and express immune inhibitory molecules, such as PD-L1, which allows them to avoid the main antitumor host defense, CD8+ T cells. The molecular mechanisms that led to these alterations were incompletely understood. In this study, we identify loss of the transcription factor IRF2 as a frequent underlying mechanism that leads to a tumor immune evasion phenotype in both humans and mice. We identified IRF2 in a CRISPR-based forward genetic screen for genes that controlled MHC-I Ag presentation in HeLa cells. We then found that many primary human cancers, including lung, colon, breast, prostate, and others, frequently downregulated IRF2. Although IRF2 is generally known as a transcriptional repressor, we found that it was a transcriptional activator of many key components of the MHC-I pathway, including immunoproteasomes, TAP, and ERAP1, whose transcriptional control was previously poorly understood. Upon loss of IRF2, cytosol-to–endoplasmic reticulum peptide transport and N-terminal peptide trimming become rate limiting for Ag presentation. In addition, we found that IRF2 is a repressor of PD-L1. Thus, by downregulating a single nonessential gene, tumors become harder to see (reduced Ag presentation), more inhibitory (increased checkpoint inhibitor), and less susceptible to being killed by CD8+ T cells. Importantly, we found that the loss of Ag presentation caused by IRF2 downregulation could be reversed by IFN-stimulated induction of the transcription factor IRF1. The implication of these findings for tumor progression and immunotherapy are discussed.

Tightly interlinked feedback regulators control the dynamics of intracellular responses elicited by the activation of signal transduction pathways. Interferon alpha (IFNα) orchestrates antiviral responses in hepatocytes, yet mechanisms that define pathway sensitization in response to prestimulation with different IFNα doses remained unresolved. We establish, based on quantitative measurements obtained for the hepatoma cell line Huh7.5, an ordinary differential equation model for IFNα signal transduction that comprises the feedback regulators STAT1, STAT2, IRF9, USP18, SOCS1, SOCS3, and IRF2. The model‐based analysis shows that, mediated by the signaling proteins STAT2 and IRF9, prestimulation with a low IFNα dose hypersensitizes the pathway. In contrast, prestimulation with a high dose of IFNα leads to a dose‐dependent desensitization, mediated by the negative regulators USP18 and SOCS1 that act at the receptor. The analysis of basal protein abundance in primary human hepatocytes reveals high heterogeneity in patient‐specific amounts of STAT1, STAT2, IRF9, and USP18. The mathematical modeling approach shows that the basal amount of USP18 determines patient‐specific pathway desensitization, while the abundance of STAT2 predicts the patient‐specific IFNα signal response., Mathematical modeling based on quantitative data reveals the molecular mechanisms that cause hypersensitization of interferon alpha (IFNα) signaling by pre‐exposure with a low dose of IFNα and desensitization with a high dose of IFNα.

The biological functions and mechanisms of oncogenic KRAS(G12D) (KRAS*) in resistance to immune checkpoint blockade (ICB) therapy are not fully understood. We demonstrate that KRAS* represses the expression of interferon regulatory factor 2 (IRF2), which in turn directly represses CXCL3 expression. KRAS*-mediated repression of IRF2 results in high expression of CXCL3, which binds to CXCR2 on myeloid-derived suppressor cells (MDSCs) and promotes their migration to the tumor microenvironment. Anti-PD-1 resistance of KRAS*-expressing tumors can be overcome by enforced IRF2 expression or by the inhibition of CXCR2. Colorectal cancer (CRC) showing higher IRF2 expression exhibited increased responsiveness to anti-PD-1 therapy. The KRAS*-IRF2-CXCL3-CXCR2 axis provides a framework for patient selection and combination therapies to enhance the effectiveness of ICB therapy in CRC.

Similar to mammals, fish possess interferon (IFN) regulatory factor 2 (IRF2)-dependent type I IFN responses. Nevertheless, the detailed mechanism through which IRF2 regulates type I IFNa3 remains largely unknown. In the present study, we first identified two genes from golden pompano (Trachinotus ovatus), IRF2 (ToIRF2) and IFNa3 (ToIFNa3), in the IFN/IRF-based signalling pathway. The open reading frame (ORF) sequence of ToIRF2 encoded 335 amino acids possessing four typical characteristic domains, including a conserved DNA-binding domain (DBD), an interferon association domain 2 (IAD2), a transcriptional activation domain (TAD), and a transcriptional repression domain (TRD). Furthermore, transcripts of ToIRF2 were significantly upregulated after stimulation by polyinosinic: polycytidylic acid [poly (I:C)], lipopolysaccharide (LPS) and flagellin in immune-related tissues (blood, liver, and head-kidney). Moreover, to investigate whether ToIRF2 was a regulator of ToIFNa3, promoter analysis was performed. The results showed that the region from -896 bp to -200 bp is defined as the core promoter using progressive deletion mutations of IFNa3. Additionally, ToIRF2 overexpression led to a clear time-dependent enhancement of ToIFNa3 promoter expression in HEK293T cells. Mutation analyses indicated that the activity of the ToIFNa3 promoter significantly decreased after targeted mutation of M4/5 binding sites. Electrophoretic mobile shift assays (EMSAs) verified that IRF2 interacted with the binding site of the ToIFNa3 promoter region to regulate ToIFNa3 transcription. Last, the promoter activity of ToIFNa3-2 was more responsive to treatment with poly (I:C) than LPS and flagellin. Furthermore, overexpression of ToIRF2 in vitro obviously increased the expression of several IFN/IRF-based signalling pathway genes after poly (I:C) abduction. In conclusion, the present study provides the first evidence of the positive regulation of ToIFNa3 transcription by ToIRF2 and contributes to a better understanding of the transcriptional mechanisms of ToIRF2 in fish.

The interferon regulatory factor 2 (IRF-2) acted as a tumor suppressor. We inspected IRF-2 as a predictor of prognosis in gastric cancer (GC) patients and tried to find out the potential molecular mechanism. In this study, the association between IRF-2 expression and clinical or prognosis significance was investigated in 86 pairs of tumor and the adjacent normal gastric tissues from GC patients. After establishing the stable cell lines, the Transwell assays were deduced to evaluate the malignancy of tumor. Then, microarray assay was carried out and the GO/KEGG pathway analyses were conducted to identify IRF-2’s target gene. The relationship between IRF-2 and matrix metalloproteinases 1 (MMP-1) was also investigated by the immunohistochemistry in 15 pairs of tumor and adjacent normal gastric tissues. We found that IRF-2 expression level in GC was significantly correlated with the prognosis of the patients. Transwell assays suggested an impaired ability of invasion and migration in IRF-2-overexpressed GC cells and a progressive malignant phenotype in IRF-2-knockdown GC cells. Ninety differentially expressed genes were found between IRF-2-overexpressed GC cells and its normal control sets by microarray. We demonstrated that MMP-1 was canonical in the network of differentially expressed genes by GO and KEGG pathway analysis and its expression level was markedly decreased in IRF-2-overexpressed cells of MKN-45 and increased in IRF-2-knockdown cells of SGC-7901. The expression of MMP-1 was inversely correlated with IRF-2 in GAC TMA specimens. IRF-2 may inhibit GC progression by down-regulating MMP-1 level.

Cyclin suppresses antitumor immunity Despite the dramatic success of cancer immunotherapy, many types of cancer do not respond. Understanding why could help us to find ways to enhance the overall responsiveness of tumors to immunotherapies. Dorand et al. report that cyclin-dependent kinase 5 (Cdk5), an enzyme that is highly expressed by neurons in many brain cancers, may dampen the ability of T cells to reject tumors. In a mouse model of medulloblastoma, if tumors were Cdk5 deficient, T cells were able to remove them. This heightened antitumor immunity correlated with reduced expression of the inhibitory molecule programmed cell death ligand 1 (PD-L1), a target of current cancer immunotherapies. Science , this issue p. 399

Patients with systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS) are typically characterized by the presence of autoantibodies and an IFN-signature. The strength of the IFN-signature positively correlates with disease severity, suggesting that type I IFNs are active players in these diseases. BAFF is a cytokine critical for development and proper selection of B cells, and the targeting of BAFF has emerged as a successful treatment strategy of SLE. Previous reports have suggested that BAFF expression is directly induced by type I IFNs, but the precise mechanism for this remains unknown. In this article, we demonstrate that BAFF is a bona fide ISG and that IFN regulatory factors (IRFs) control the expression of BAFF. We identify IRF1 and IRF2 as positive regulators of BAFF transcription and IRF4 and IRF8 as potent repressors; in addition, we have mapped the precise binding site for these factors in the BAFF promoter. IFN-β injections induced BAFF expression mainly in neutrophils and monocytes, and BAFF expression in neutrophils from pSS patients strongly correlated with the strength of the IFN-signature. In summary, we show that BAFF expression is directly induced by type I IFNs via IRF1 and IRF2, whereas IRF4 and IRF8 are negative regulators of BAFF expression. These data suggest that type I IFN blockade in SLE and pSS patients will lead to downregulation of BAFF and a consequential reduction of autoreactive B cell clones and autoantibodies.

Aim This study aims to explore the role and mechanism of exosomes derived from human bone marrow mesenchymal stem cells (hBM-MSCs-Exo) in regulating proliferation and apoptosis of acute myeloid leukemia (AML) cell line THP-1. Methods hBM-MSCs-Exo was isolated by ultra-centrifugation and administered into THP-1 cells to elucidate the effects of exosomes in THP-1 cells. Cell proliferation and apoptosis were examined by CCK-8 assay and flow cytometry, respectively. The expression of miR-222-3p, IRF2, and INPP4B were measured by qRT-PCR and western blot. The interaction between miR-222-3p and IRF2 was analyzed by luciferase reporter assay. Results Lower cell viability rate, higher apoptosis ratio, higher miR-222-3p expression, and lower IRF1/INPP4B expression were observed in THP-1 cells exposed to BM-MSCs-Exo. The proliferation-inhibitory and pro-apoptotic effects of BM-MSCs-Exo on THP-1 cells were markedly compromised when miR-222-3p expression in BM-MSCs-Exo was inhibited. Furthermore, miR-222-3p directly targeted IRF2 and negatively regulated IRF2/INPP4B signaling in THP-1 cells. Moreover, overexpression of either IRF2 or INPP4B counteracted the proliferation-inhibitory and pro-apoptotic effects mediated by BM-MSCs-Exo. Conclusion BM-MSCs delivered miR-222-3p via exosomes to inhibit cell proliferation and promote cell apoptosis by targeting IRF2 and negatively regulating IRF2/INPP4B signaling in THP-1 cells.

Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are heritable risk factors for cardiovascular disease, yet the molecular mechanisms underlying the majority of blood lipid-associated genome-wide association studies signals remain elusive. One association signal is located in intron 3 of VLDLR; rs3780181-A is a risk allele associated (P ≤ 2 × 10(−9)) with increased TC and LDL-C. We investigated variants, genes and mechanisms underlying this association signal. We used a functional genetic approach to show that the intronic region spanning rs3780181 exhibited 1.6–7.6-fold enhancer activity in human HepG2 hepatocyte, THP-1 monocyte and Simpson-Golabi-Behmel Syndrome (SGBS) preadipocyte cells and that the rs3780181-A risk allele showed significantly less enhancer activity compared with the G allele, consistent with the direction of an expression quantitative trait locus in liver. In addition, rs3780181 alleles showed differential binding to multiple nuclear proteins, including stronger IRF2 binding to the rs3780181 G allele. We used a CRISPR-cas9 approach to delete 475 and 663 bp of the putative enhancer element in HEK293T kidney cells; compared to expression of mock-edited cell lines, the homozygous enhancer deletion cell lines showed 1.2-fold significantly (P

Interferon regulatory factors (IRF-1 and IRF-2) are transcription factors of IRF-family that regulate expression of genes for cytokines, chemokines and growth factors in mammalian cells. IRF-1 and IRF-2 play crucial roles in the differentiation of bone marrow cells for immune response. Bone marrow (BM) is the soft lymphoid organ that contains many types of stem cells and produces different types of cells of the blood and immune system. Genetic alterations and damage of the bone marrow cells can lead to different types of blood and immune system-related diseases including anemia and cancer. We have studied the expression of IRF-1 and IRF-2 during radiation-induced damage and regeneration of bone marrow cells after transplantation of freshly isolated bone marrow cells in the mouse. Cell cycle analysis, colony forming unit-fibroblast (CFU-F) assay and bone marrow histology showed that after radiation-induced damage, the bone marrow transplantation resulted in regeneration of the bone marrow up to 24-35% recovery. Real-time quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) for the mRNA expression showed that IRF-1 and IRF-2 were expressed at higher levels in the bone marrow cells of the irradiated (4.34× fold for IRF-1, and 3.87× fold for IRF-2) compared to control and transplanted (1.13× fold for IRF-1, and 1.12× fold IRF-2) mice and immuno-fluorescence analysis for the protein expression showed that IRF-1 and IRF-2 were expressed at higher levels in the bone marrow cells of the irradiated (2.12× fold for IRF-1 and 1.71× fold for IRF-2) compared to control and transplanted (1.73× fold for IRF-1 and 1.21× fold for IRF-2) mice. Thus, IRF-1 and IRF-2 are sensitive and responsive to radiation-induced damage in the bone marrow cells and may also be involved in the bone marrow regeneration process.

Caprine parainfluenza virus type 3 (CPIV3) is an important respiratory pathogen in the goat industry and was detected in China in 2014. Numerous studies have shown that microRNAs (miRNAs) play critical roles in viral infections, but the involvement of miRNAs during CPIV3 infection is poorly understood. In this study, we showed by deep sequencing that a panel of miRNAs, including bta-miR-222, were significantly downregulated in Madin-Darby bovine kidney (MDBK) cells infected with CPIV3 strain JS2013 compared with uninfected MDBK cells. Overexpression of bta-miR-222 significantly reduced CPIV3 replication in vitro, while inhibition of endogenous bta-miR-222 enhanced CPIV3 replication. Bta-miR-222 enhanced type I interferon expression and suppressed CPIV3 replication in MDBK cells. Moreover, we showed using luciferase reporter assays that bta-miR-222 directly targeted the 3′-untranslated region of interferon regulatory factor 2 (IRF2). Transfection of cells with bta-miR-222 mimics resulted in decreased IRF2 mRNA and protein levels, with a consequent increase in type I interferon levels and potentiation of antiviral responses. Together, these data demonstrate the important role of bta-miR-222 in restricting CPIV3 replication and suggest potential antiviral strategies against CPIV3.

Background Among the severe malaria syndromes, severe malarial anemia (SMA) is the most common, whereas cerebral malaria (CM) is the most lethal. However, the mechanisms that lead to CM and SMA are unclear. Methods We compared transcriptomic profiles of whole blood obtained from Ugandan children with acute CM (n = 17) or SMA (n = 17) and community children without Plasmodium falciparum infection (n = 12) and determined the relationships among gene expression, hematological indices, and relevant plasma biomarkers. Results Both CM and SMA demonstrated predominantly upregulated enrichment of dendritic cell activation, inflammatory/Toll-like receptor/chemokines, and monocyte modules, but downregulated enrichment of lymphocyte modules. Nuclear factor, erythroid 2 like 2 (Nrf2)-regulated genes were overexpressed in children with SMA relative to CM, with the highest expression in children with both SMA and sickle cell disease (HbSS), corresponding with elevated plasma heme oxygenase-1 in this group. Erythroid and reticulocyte-specific signatures were markedly decreased in CM relative to SMA despite higher hemoglobin levels and appropriate increases in erythropoietin. Viral sensing/interferon-regulatory factor 2 module expression and plasma interferon-inducible protein-10/CXCL10 negatively correlated with reticulocyte-specific signatures. Conclusions Compared with SMA, CM is associated with downregulation of Nrf2-related and erythropoiesis signatures by whole-blood transcriptomics. Future studies are needed to confirm these findings and assess pathways that may be amenable to interventions to ameliorate CM and SMA.

MicroRNAs (miRNAs) are small non-coding RNAs that contribute to the repertoire of host-pathogen interactions during viral infections. In the current study, miRNA analysis showed that a panel of microRNAs, including gga-miR-9*, were markedly upregulated in specific-pathogen-free (SPF) chickens upon infection with infectious bursal disease virus (IBDV); however, the biological function of gga-miR-9* during viral infection remains unknown. Using a TCID50 assay, it was found that ectopic expression of gga-miR-9* significantly promoted IBDV replication. In turn, gga-miR-9* negatively regulated IBDV-triggered type I IFN production, thus promoting IBDV replication in DF-1 cells. Bioinformatics analysis indicates that the 3' untranslated region (UTR) of interferon regulatory factor 2 (IRF2) has two putative binding sites for gga-miR-9*. Targeting of IRF2 3'UTR by gga-miR-9* was determined by luciferase assay. Functional overexpression of gga-miR-9*, using gga-miR-9* mimics, inhibited IRF2 mRNA and protein expression. Transfection of the gga-miR-9* inhibitor abolished the suppression of IRF2 protein expression. Furthermore, IRF2 knockdown mediated the enhancing effect of gga-miR-9* on the type I IFN-mediated antiviral response. These findings indicate that inducible gga-miR-9* feedback negatively regulates the host antiviral innate immune response by suppressing type I IFN production via targeting IRF2.

Interferon Regulatory Factors (IRFs) make up a family of transcription factors involved in transcriptional regulation of type I IFN and IFN-stimulated genes (ISG) in cells. In the present study, an IRF2 gene (termed CiIRF2 , JX628585) was cloned and characterized from grass carp ( Ctenopharyngodon idella ). The full-length cDNA of CiIRF2 is 1809 bp in length, with the largest open reading frame (ORF) of 981 bp encoding a putative protein of 326 amino acids. CiIRF2 contains a conserved DNA-binding domain (DBD) in N-terminal and a non-conserved C-terminal region. Protein sequence analysis revealed that CiIRF2 shares significant homology to the known IRF2 counterparts. Phylogenetic reconstruction confirmed its closer evolutionary relationship with other fish counterparts, especially with zebra fish IRF2. CiIRF2 was ubiquitously expressed at low level in all tested grass carp tissues and significantly up-regulated except in brain following poly I:C 6–12 h post stimulation. In order to understand fish innate immune and resistance to virus diseases, recombinant CiIRF2 with His-tag was over-expressed in BL21 Escherichia coli , and the expressed protein was purified by affinity chromatography with Ni-NTA His-Bind Resin. Promoter sequences of grass carp type I IFN gene ( CiIFN ) and two ISG genes ( CiPKR and CiPKZ ) were amplified and cloned. In vitro , gel mobility shift assays were employed to analyze the interaction of CiIRF2 protein with promoters of CiIFN, CiPKR and CiPKZ respectively. The results showed that CiIRF2 bound to these promoters with high affinity by means of its DBD. Afterwards, recombinant plasmids of pGL3-CiIFN, pGL3-CiPKR and pGL3-CiPKZ were constructed and transiently co-transfected with pcDNA3.1-CiIRF2 or pcDNA3.1-CiIRF1 respectively into C. idella kidney (CIK) cells. Dual-luciferase reporter assays demonstrated that CiIRF2 down-regulates the transcription activity of CiIFN, CiPKR and CiPKZ genes in CIK cells. To further understand the function of fish IRF2, expression plasmids (pcDNA3.1-IRF2 and pcDNA3.1-IRF1) were transiently co-transfected with pGL3-IFN or pGL3-CiPKZ into CIK cells, respectively. The results revealed that CiIRF2 plays an antagonistic role to CiIRF1 in transcriptional regulation of IFN and ISG genes.

MicroRNAs are small endogenous non-coding RNAs, which can frequently emerge as regulators in many cancer types. MiR-1290 was found to be abnormally elevated in non small cell lung cancer (NSCLC). However, the underlying molecular mechanism still needs to be investigated. Here, we demonstrated that miR-1290 expression levels were remarkably upregulated in NSCLC tissues compared to adjacent normal tissues. Higher miR-1290 expression levels positively associated with lymph node metastasis and advanced tumor stage. Functional assays showed that upregulated miR-1290 expression in NSCLC cells enhanced cell proliferation, cell colony formation and invasion capacities in vitro. Furthermore, we found that miR-1290 promoted cell proliferation related protein CDK2 and CDK4 expression and enhanced Epithelial-Mesenchymal Transition (EMT) process by downregulating E-cadherin expression and upregulating N-cadherin expression. Bioinformatics analysis and luciferase reporter gene assays revealed that Interferon regulatory factor 2 (IRF2) was a direct target of miR-1290. Overexpression of miR-1290 can degrade IRF2 mRNA and downregulated IRF2 protein expression in NSCLC cells. Upregulated IRF2 could partly rescue the promoting effects induced by miR-1290 overexpression on cell proliferation and invasion of NSCLC. Additionally, we confirmed that reduced miR-1290 expression could suppress tumor growth using a tumor xenograft model in vivo. Thus, we concluded that miR-1290 may serve as a potential target of NSCLC treatment.