Interferon-stimulated Genes Research Articles

Neutrophil Heterogeneity Is Modified during Acute Lung Inflammation in Apoa1-/- Mice.

Neutrophils play important roles in inflammatory airway diseases. In this study, we assessed whether apolipoprotein A-I modifies neutrophil heterogeneity as part of the mechanism by which it attenuates acute airway inflammation. Neutrophilic airway inflammation was induced by daily intranasal administration of LPS plus house dust mite (LPS+HDM) to Apoa1-/- and Apoa1+/+ mice for 3 d. Single-cell RNA sequencing was performed on cells recovered from bronchoalveolar lavage fluid on day 4. Unsupervised profiling identified 10 clusters of neutrophils in bronchoalveolar lavage fluid from Apoa1-/- and Apoa1+/+ mice. LPS+HDM-challenged Apoa1-/- mice had an increased proportion of the Neu4 neutrophil cluster that expressed S100a8, S100a9, and Mmp8 and had high maturation, aggregation, and TLR4 binding scores. There was also an increase in the Neu6 cluster of immature neutrophils, whereas neutrophil clusters expressing IFN-stimulated genes were decreased. An unsupervised trajectory analysis showed that Neu4 represented a distinct lineage in Apoa1-/- mice. LPS+HDM-challenged Apoa1-/- mice also had an increased proportion of recruited airspace macrophages, which was associated with a reciprocal reduction in resident airspace macrophages. Increased expression of a common set of proinflammatory genes, S100a8, S100a9, and Lcn2, was present in all neutrophils and airspace macrophages from LPS+HDM-challenged Apoa1-/- mice. These findings show that Apoa1-/- mice have increases in specific neutrophil and macrophage clusters in the lung during acute inflammation mediated by LPS+HDM, as well as enhanced expression of a common set of proinflammatory genes. This suggests that modifications in neutrophil and macrophage heterogeneity contribute to the mechanism by which apolipoprotein A-I attenuates acute airway inflammation.

Interferon-stimulated gene 56 positively regulates Toll-like receptor 3-mediated CXCL10 expression in human renal proximal tubular epithelial cells.

Viral infections in tubular epithelial cells lead to the production of inflammatory cytokines by innate immunity, causing tubulointerstitial nephritis. TLR3 recognizes viral infections and acts via the activation of interferon (IFN)/IFN-stimulated genes (ISGs). This study investigates the role of ISG56, a representative ISG, in TLR3 signaling in cultured human renal proximal tubular epithelial cells (hRPTECs). To this end, hRPTECs were stimulated by a synthetic TLR3 ligand, polyinosinic-polycytidylic acid (poly IC), recombinant human interferon-β [r(h)IFN-β] or Japanese encephalitis virus (JEV) infection and assayed for inflammatory cytokine mRNA expression by RT-qPCR, and protein expression via western blotting or ELISA. ISG56 was expressed by poly IC or r(h)IFN-β and IFN-β knockdown reduced poly IC-induced expression of ISG56 and CXCL10. Moreover, ISG56 knockdown reduced poly IC- or r(h)IFN-β-induced expression of CXCL10 at the same time as increasing JEV growth and reducing CXCL10 expression induced by JEV infection. Overall, TLR3 signaling induced IFN-β-dependent expression of ISG56 and CXCL10. We show that ISG56 possibly plays a critical role in antiviral immunity of hRPTECs by positive regulation of IFN-β-mediated CXCL10 expression downstream of TLR3.

Viral modulation of type II interferon increases T cell adhesion and virus spread

During primary varicella zoster virus (VZV) infection, infected lymphocytes drive primary viremia, causing systemic dissemination throughout the host, including the skin. This results in cytokine expression, including interferons (IFNs), which partly limit infection. VZV also spreads from skin keratinocytes to lymphocytes prior to secondary viremia. It is not clear how VZV achieves this while evading the cytokine response. Here, we show that VZV glycoprotein C (gC) binds IFN-γ and modifies its activity, increasing the expression of a subset of IFN-stimulated genes (ISGs), including intercellular adhesion molecule 1 (ICAM1), chemokines and immunomodulatory genes. The higher ICAM1 protein level at the plasma membrane of keratinocytes facilitates lymphocyte function-associated antigen 1-dependent T cell adhesion and expression of gC during infection increases VZV spread to peripheral blood mononuclear cells. This constitutes the discovery of a strategy to modulate IFN-γ activity, upregulating a subset of ISGs, promoting enhanced lymphocyte adhesion and virus spread.

A bi-adjuvant nanovaccine amplifying STING activation for cancer immunotherapy

The insufficient immune activation and immunosuppressive microenvironment restrict the therapeutic efficacy of cancer vaccines. Herein, we exploited a bi-adjuvant nanovaccine to amplify the activation of the stimulator of interferon genes (STING) for potent and durable anti-tumor immunity. STING agonist (MnO2 nanoparticles), toll-like receptor 9 agonist (CpG), and antigenic proteins or peptides were strategically formulated into nanovaccines (MnC NVs) by a one-step biomineralization method. The nanovaccine efficiently targeted dendritic cells of draining lymph nodes, in which CpG-mediated the stimulation of nuclear factor-kappa B pathway augmented STING signaling. RNA sequencing analysis validated the enhanced expression of relevant genes of type-I interferon signaling pathways. The priming of antigen-specific CD8+ T cells and humoral immune responses led to potent tumor growth inhibition and prolonged survival time in melanoma and human papilloma virus-derived tumor models. MnC NVs were able to synergize with immune checkpoint blockade therapy, with 80 % survival over 40 days in TC-1 tumor model. Moreover, rechallenging of tumor-free mice with homotypic cells resulted in complete tumor growth inhibition, suggesting the generation of a long-term memory effect. The simplified nanovaccine platform provides a safe and robust strategy to boost STING-mediated anti-tumor immunity for personalized cancer immunotherapy, showing significant potential for clinical translation.

A new gene signature for endothelial senescence identifies self-RNA sensing by retinoic acid-inducible gene I as a molecular facilitator of vascular aging.

The number of senescent vascular endothelial cells increases during aging and their dysfunctional phenotype contributes to age-related cardiovascular disease. Identification of senescent cells is challenging as molecular changes are often tissue specific and occur amongst clusters of normal cells. Here, we established, benchmarked, and validated a new gene signature called EndoSEN that pinpoints senescent endothelial cells. The EndoSEN signature was enriched for interferon-stimulated genes (ISG) and correlated with the senescence-associated secretory phenotype (SASP). SASP establishment is classically attributed to DNA damage and cyclic GMP-AMP synthase activation, but our results revealed a pivotal role for RNA accumulation and sensing in senescent endothelial cells. Mechanistically, we showed that endothelial cell senescence hallmarks include self-RNA accumulation, RNA sensor RIG-I upregulation, and an ISG signature. Moreover, a virtual model of RIG-I knockout in endothelial cells underscored senescence as a key pathway regulated by this sensor. We tested and confirmed that RIG-I knockdown was sufficient to extend the lifespan and decrease the SASP in endothelial cells. Taken together, our evidence suggests that targeting RNA sensing is a potential strategy to delay vascular aging.

SARS-CoV-2 inflammation durably imprints memory CD4 T cells.

Memory CD4 T cells are critical to human immunity, yet it is unclear whether viral inflammation during memory formation has long-term consequences. Here, we compared transcriptional and epigenetic landscapes of Spike (S)-specific memory CD4 T cells in 24 individuals whose first exposure to S was via SARS-CoV-2 infection or mRNA vaccination. Nearly 2 years after memory formation, S-specific CD4 T cells established by infection remained enriched for transcripts related to cytotoxicity and for interferon-stimulated genes, likely because of a chromatin accessibility landscape altered by inflammation. Moreover, S-specific CD4 T cells primed by infection had reduced proliferative capacity in vitro relative to vaccine-primed cells. Furthermore, the transcriptional state of S-specific memory CD4 T cells was minimally altered by booster immunization and/or breakthrough infection. Thus, infection-associated inflammation durably imprints CD4 T cell memory, which affects the function of these cells and may have consequences for long-term immunity.

Bacterial c-di-GMP triggers metamorphosis of mussel larvae through a STING receptor

Bacteria induced metamorphosis observed in nearly all marine invertebrates. However, the mechanism of bacteria regulating the larvae-juvenile metamorphosis remains unknown. Here, we test the hypothesis that c-di-GMP, a ubiquitous bacterial second-messenger molecule, directly triggers the mollusc Mytilus coruscus larval metamorphosis via the stimulator of interferon genes (STING) receptor. We determined that the deletion of c-di-GMP synthesis genes resulted in reduced c-di-GMP levels and biofilm-inducing activity on larval metamorphosis, accompanied by alterations in extracellular polymeric substances. Additionally, c-di-GMP extracted from tested varying marine bacteria all exhibited inducing activity on larval metamorphosis. Simultaneously, through pharmacological and molecular experiments, we demonstrated that M. coruscus STING (McSTING) participates in larval metamorphosis by binding with c-di-GMP. Our findings reveal that new role of bacterial c-di-GMP that triggers mussel larval metamorphosis transition, and extend knowledge in the interaction of bacteria and host development in marine ecosystems.

A dicoumarol-graphene oxide quantum dot polymer inhibits porcine reproductive and respiratory syndrome virus through the JAK-STAT signaling pathway.

Porcine reproductive and respiratory syndrome virus (PRRSV) causes substantial economic losses in the global swine industry. The current vaccine options offer limited protection against PRRSV transmission, and there are no effective commercial antivirals available. Therefore, there is an urgent need to develop new antiviral strategies that slow global PRRSV transmission. In this study, we synthesized a dicoumarol-graphene oxide quantum dot (DIC-GQD) polymer with excellent biocompatibility. This polymer was synthesized via an electrostatic adsorption method using the natural drug DIC and GQDs as raw materials. Our findings demonstrated that DIC exhibits high anti-PRRSV activity by inhibiting the PRRSV replication stage. The transcriptome sequencing analysis revealed that DIC treatment stimulates genes associated with the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway. In porcine alveolar macrophages (PAMs), DIC-GQDs induce TYK2, JAK1, STAT1, and STAT2 phosphorylation, leading to the upregulation of JAK1, STAT1, STAT2, interferon-β (IFN-β) and interferon-stimulated genes (ISGs). Animal challenge experiments further confirmed that DIC-GQDs effectively alleviated clinical symptoms and pathological reactions in the lungs, spleen, and lymph nodes of PRRSV-infected pigs. These findings suggest that DIC-GQDs significantly inhibits PRRSV proliferation by activating the JAK/STAT signalling pathway. Therefore, DIC-GQDs hold promise as an alternative treatment for PRRSV infection.

T Cell-Derived Apoptotic Extracellular Vesicles Hydrolyze cGAMP to Alleviate Radiation Enteritis via Surface Enzyme ENPP1.

Radiation enteritis is the most common complication of pelvic radiotherapy, but there is no effective prevention or treatment drug. Apoptotic T cells and their products play an important role in regulating inflammation and maintaining physiological immune homeostasis. Here it is shown that systemically infused T cell-derived apoptotic extracellular vesicles (ApoEVs) can target mice irradiated intestines and alleviate radiation enteritis. Mechanistically, radiation elevates the synthesis of intestinal 2'3' cyclic GMP-AMP (cGAMP) and activates cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) proinflammatory pathway. After systemic infusion of ApoEVs, the ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) enriches on the surface of ApoEVs hydrolyze extracellular cGAMP, resulting in inhibition of the cGAS-STING pathway activated by irradiation. Furthermore, after ApoEVs are phagocytosed by phagocytes, ENPP1 on ApoEVs hydrolyzed intracellular cGAMP, which serves as an intracellular cGAMP hydrolyzation mode, thereby alleviating radiation enteritis. The findings shed light on the intracellular and extracellular hydrolysis capacity of ApoEVs and their role in inflammation regulation.

The interferon-induced protein, IFIT2, requires RNA-binding activity and neuronal expression to protect mice from intranasal vesicular stomatitis virus infection.

The interferon (IFN) system protects mammals from diseases caused by virus infections. IFN synthesis is induced by pattern recognition receptor signaling pathways activated by virus infection. IFN is secreted from the infected cells and acts upon neighboring cells by binding cell surface receptors and triggering induction of hundreds of IFN-stimulated genes and proteins, many of which block different steps of virus replication. The IFN-induced tetratricopeptide repeat proteins (IFIT) are a family of RNA-binding proteins. We and others have previously reported that IFIT2 protects mice from many neurotropic RNA viruses; indeed, Ifit2-/- mice are very susceptible to intranasal or subcutaneous infections with vesicular stomatitis virus (VSV). Here, using a newly generated conditional knockout mouse, we report that ablation of Ifit2 expression only in neuronal cells was sufficient to render mice susceptible to neuropathogenesis caused by intranasal, but not subcutaneous, infection of VSV. Another genetically modified mouse line, expressing a mutant IFIT2 that cannot bind RNA, was as susceptible to VSV infection as Ifit2-/- mice. These results demonstrated that IFIT2 RNA-binding activity is essential for protecting mice against neurological diseases caused by intranasal infection of VSV.IMPORTANCEInterferon's (IFN's) antiviral effects are mediated by the proteins encoded by the interferon-stimulated genes. IFN-stimulated genes (IFIT2) is one such protein, which inhibits replication of many RNA viruses in the mouse brain and the resultant neuropathology. Our study sheds light on how IFIT2 works. By ablating Ifit2 expression only in neuronal cells, using a newly generated conditional knockout mouse line, we showed that Ifit2 induction in the neurons of the infected mouse was necessary for antiviral function of interferon. IFIT2 has no known enzyme activity; instead, it functions by binding to cellular or viral proteins or RNAs. We engineered a new mouse line that expressed a mutant IFIT2 that cannot bind RNA. These mice were very susceptible to infection with vesicular stomatitis virus indicating that the RNA-binding property of IFIT2 was essential for its antiviral function in vivo.

Manganese-enriched prussian blue nanohybrids with smaller electrode potential and lower charge transfer resistance to enhance combination therapy

Prussian blue (PB) is authenticated in clinical treatment, while it generally exhibits unfavorable chemodynamic therapy (CDT) performance. Herein, we developed manganese-doped prussian blue (PBM) nanoparticles to significantly enhance both CDT and photothermal therapy (PTT) effect. The lower redox potential of Mn3+/2+ (0.088 V) in PBM against that of Fe2+/3+ (0.192 V) in PB leads to favorable electron transfer of PBM with respect to PB. Besides, PBM has a lower charge-transfer resistance (Rct) of 2.98 Ω than 4.83 Ω of PB. Once PBM entering the tumor microenvironment (TME), Mn3+ may be readily reduced by glutathione (GSH) and therein to enhance intracellular oxidative stress. Meanwhile, the superoxide dismutase (SOD)-like activity of PBM facilitates the conversion of endogenous superoxide (O2•−) into H2O2. Mn2+ subsequently catalyzes H2O2 to generate toxic hydroxyl radicals (•OH). Notably, the PBM plus laser irradiation can effectively trigger a robust immunogenic cell death (ICD) due to the combination therapy of CDT and PTT. Additionally, the mice treated by PBM followed by laser irradiation efficiently avoided splenomegaly and lung metastasis, along with significant up-regulation of the Stimulator of Interferon Genes (STING) expression. Overall, PBM significantly inhibits tumor growth and metastasis, making it a promising multifunctional nanoplatform for cancer treatment.

Polydatin attenuates diabetic renal inflammatory fibrosis via the inhibition of STING pathway

Diabetic nephropathy (DN) is a complication of diabetes and is mainly characterized by renal fibrosis, which could be attributed to chronic kidney inflammation. Stimulator of interferon genes (STING), a linker between immunity and metabolism, could ameliorate various metabolic and inflammatory diseases. However, the regulatory role of STING in DN remains largely unexplored. In this study, knockdown of STING decreased extracellular matrix (ECM), pro-inflammatory, and fibrotic factors in high glucose (HG)-induced glomerular mesangial cells (GMCs), whereas overexpression of STING triggered the inflammatory fibrosis process, suggesting that STING was a potential target for DN. Polydatin (PD) is a glucoside of resveratrol and has been reported to ameliorate DN by inhibiting inflammatory responses. Nevertheless, whether PD improved DN via STING remains unclear. Here, transcriptomic profiling implied that the STING/NF-κB pathway might be an important target for PD. We further found that PD decreased the protein expression of STING, and subsequently suppressed the activation of downstream targets including TBK1 phosphorylation and NF-κB nuclear translocation, and eventually inhibited the production of ECM, pro-inflammatory and fibrotic factors in HG-induced GMCs. Notably, results of molecular docking, molecular dynamic simulations, surface plasmon resonance, cellular thermal shift assay and Co-immunoprecipitation assay indicated that PD directly bound to STING and restored the declined proteasome-mediated degradation of STING induced by HG. In diabetic mice, PD also inhibited the STING pathway and improved the pathological changes of renal inflammatory fibrosis. Our study elucidated the regulatory role of STING in DN, and the novel mechanism of PD treating DN via inhibiting STING expression.

STING orchestrates the neuronal inflammatory stress response in multiple sclerosis

Inflammation-induced neurodegeneration is a defining feature of multiple sclerosis (MS), yet the underlying mechanisms remain unclear. By dissecting the neuronal inflammatory stress response, we discovered that neurons in MS and its mouse model induce the stimulator of interferon genes (STING). However, activation of neuronal STING requires its detachment from the stromal interaction molecule 1 (STIM1), a process triggered by glutamate excitotoxicity. This detachment initiates non-canonical STING signaling, which leads to autophagic degradation of glutathione peroxidase 4 (GPX4), essential for neuronal redox homeostasis and thereby inducing ferroptosis. Both genetic and pharmacological interventions that target STING in neurons protect against inflammation-induced neurodegeneration. Our findings position STING as a central regulator of the detrimental neuronal inflammatory stress response, integrating inflammation with glutamate signaling to cause neuronal cell death, and present it as a tractable target for treating neurodegeneration in MS.

DiABZI and poly(I:C) inhibit osteoclastic bone resorption by inducing IRF7 and IFIT3.

Type I interferons (IFN-I) are pleiotropic factors endowed with multiple activities that play important roles in innate and adaptive immunity. Although many studies indicate that IFN-I inducers exert favorable effects on broad-spectrum antivirus, immunomodulation, and anti-tumor activities by inducing endogenous IFN-I and IFN-stimulated genes, their function in bone homeostasis still needs further exploration. Here, our study demonstrates 2 distinct IFN-I inducers, diABZI and poly(I:C), as potential therapeutics to alleviate osteolysis and osteoporosis. First, IFN-I inducers suppress the genes that control osteoclast (OC) differentiation and activity in vitro. Moreover, diABZI alleviates bone loss in Ti particle-induced osteolysis and ovariectomized -induced osteoporosis in vivo by inhibiting OC differentiation and function. In addition, the inhibitory effects of IFN-I inducers on OC differentiation are not observed in macrophages derived from Ifnar1-/-mice, which indicate that the suppressive effect of IFN-I inducers on OC is IFNAR-dependent. Mechanistically, RNAi-mediated silencing of IRF7 and IFIT3 in OC precursors impairs the suppressive effect of the IFN-I inducers on OC differentiation. Taken together, these results demonstrate that IFN-I inducers play a protective role in bone turnover by limiting osteoclastogenesis and bone resorption through the induction of OC-specific mediators via the IFN-I signaling pathway.

FASN regulates STING palmitoylation via malonyl-CoA in macrophages to alleviate sepsis-induced liver injury

STING (stimulator of interferon genes) is a critical immunoregulatory protein in sepsis and is regulated by various mechanisms, especially palmitoylation. FASN (fatty acid synthase) is the rate-limiting enzyme to generate cellular palmitic acid (PA) via acetyl-CoA and malonyl-CoA and participates in protein palmitoylation. However, the mechanisms underlying the interaction between STING and FASN have not been completely understood. In this study, STING-knockout mice were used to confirm the pivotal role of STING in sepsis-induced liver injury. Metabolomics confirmed the dyslipidemia in septic mice and patients. The compounds library was screened, revealing that FASN inhibitors exerted a significant inhibitory effect on the STING pathway. Mechanically, the regulatory effect of FASN on the STING pathway was dependent on palmitoylation. Further experiments indicated that the upstream of FASN, malonyl-CoA inhibited STING pathway possibly due to C91 (palmitoylated residue) of STING. Overall, this study reveals a novel paradigm of STING regulation and provides a new perspective on immunity and metabolism.

BRG1 Deficiency Promotes Cardiomyocyte Inflammation and Apoptosis by Activating the cGAS-STING Signaling in Diabetic Cardiomyopathy.

Brahma-related gene 1 (BRG1) has been implicated in the repair of DNA double-strand breaks (DSBs). Downregulation of BRG1 impairs DSBs repair leading to accumulation of double-stranded DNA (dsDNA). Currently, the role of BRG1 in diabetic cardiomyopathy (DCM) has not been clarified. In this study, we aimed to explore the function and molecular by which BRG1 regulates DCM using mice and cell models. We found that BRG1 was downregulated in the cardiac tissues of DCM mice and in cardiomyocytes cultured with high glucose and palmitic acid (HG/PA), which was accompanied by accumulation of dsDNA and activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. shRNA-mediated Brg1 knockdown aggravated DCM mice cardiac functions, enhanced dsDNA accumulation, cGAS-STING signaling activation, which induced inflammation and apoptosis. In addition, the results were further verified in HG/PA-treated primary neonatal rat cardiomyocytes (NRCMs). Overexpression of BRG1 in NRCMs yielded opposite results. Furthermore, a selective cGAS inhibitor RU.521 or STING inhibitor C-176 partially reversed the BRG1 knockdown-induced inflammation and apoptosis in vitro. In conclusion, our results demonstrate that BRG1 is downregulated during DCM in vivo and in vitro, resulting in cardiomyocyte inflammation and apoptosis due to dsDNA accumulation and cGAS-STING signaling activation. Therefore, targeting the BRG1-cGAS-STING pathway may represent a novel therapeutic strategy for improving cardiac function of patients with DCM.

Interferon-tau infusion into the ovine corpus luteum delays luteolysis†.

Conceptus-derived interferon-tau (IFNT) initiates maternal recognition of pregnancy in ewes by paracrine actions on the endometrium and endocrine action on the corpus luteum (CL). To examine the effect of IFNT on the CL without inducing IFN-stimulated genes (ISGs) in the endometrium, recombinant ovine IFNT (roIFNT) or bovine serum albumin was delivered directly into CLs via osmotic pumps at a rate of 10, 50, or 100ng/h from days 9 to 12 of the estrous cycle. Endometrial and CL samples were collected on day 12. 50 ng/h of roIFNT induced ISG15 in the CL on day 12 without affecting endometrial ISG15 concentrations. In a second experiment, roIFNT (50ng/h) was infused into the CL from days 10 to 17 of the estrous cycle and serum samples were collected daily. Serum progesterone concentrations were significantly higher from days 15 to 17 in roIFNT-infused ewes compared to controls. Levels of LHCGR, STAR, CYP11A1, HSL, OPA1, and protein kinase A mRNA and proteins were higher in the roIFNT-infused CLs compared to the controls. Levels of ISG15 and MX1 mRNA increased in the CLs of roIFNT-infused ewes but not in the endometrium. Endometrial ESR1 mRNA and protein concentrations were higher in the controls compared to roIFNT-infused ewes. In conclusion, intra-luteal delivery of roIFNT induced ISGs, stabilized steroidogenesis in the CL, and delayed luteolysis without inducing endometrial IFN-stimulated genes. Inhibition of ESR1 in the endometrium of roIFNT-infused ewes was observed suggesting that direct delivery of IFNT to the CL has an additional anti-luteolytic effect on the endometrium.

Reovirus infection induces transcriptome-wide unique A-to-I editing changes in the murine fibroblasts.

The conversion of Adenosine (A) to Inosine (I), by Adenosine Deaminases Acting on RNA or ADARs, is an essential post-transcriptional modification that contributes to proteome diversity and regulation in metazoans including humans. In addition to its transcriptome-regulating role, ADARs also play a major part in immune response to viral infection, where an interferon response activates interferon-stimulated genes, such as ADARp150, in turn dynamically regulating host-virus interactions. A previous report has shown that infection from reoviruses, despite strong activation of ADARp150, does not influence the editing of some of the major known editing targets, while likely editing others, suggesting a potentially nuanced editing pattern that may depend on different factors. However, the results were based on a handful of selected editing sites and did not cover the entire transcriptome. Thus, to determine whether and how reovirus infection specifically affects host ADAR editing patterns, we analyzed a publicly available deep-sequenced RNA-seq dataset, from murine fibroblasts infected with wild-type and mutant reovirus strains that allowed us to examine changes in editing patterns on a transcriptome-wide scale. To the best of our knowledge, this is the first transcriptome-wide report on host editing changes after reovirus infection. Our results demonstrate that reovirus infection induces unique nuanced editing changes in the host, including introducing sites uniquely edited in infected samples. Genes with edited sites are overrepresented in pathways related to immune regulation, cellular signaling, metabolism, and growth. Moreover, a shift in editing targets has also been observed, where the same genes are edited in infection and control conditions but at different sites, or where the editing rate is increased for some and decreased for other differential targets, supporting the hypothesis of dynamic and condition-specific editing by ADARs.

STING Contributes to Pulmonary Hypertension by Targeting IFN and BMPR2 Signaling through Regulating of F2RL3.

Pulmonary hypertension (PH) is an incurable disease characterized by pulmonary vascular remodeling. Endothelial injury and inflammation are the key triggers of disease initiation. Recent findings suggest that STING (stimulator of IFN genes) activation plays a critical role in endothelial dysfunction and IFN signaling. Here, we investigated the involvement of STING in the pathogenesis of PH. Patients with PH and rodent PH model samples, a Sugen 5416/hypoxia PH model, and pulmonary artery endothelial cells (PAECs) were used to evaluate the hypothesis. We found that the cyclic guanosine monophosphate-AMP synthase-STING signaling pathway was activated in lung tissues from rodent PH models and patients with PH and in TNF-α-induced PAECs invitro. Specifically, STING expression was significantly elevated in the endothelial cells in PH disease settings. In the Sugen 5416/hypoxia mouse model, genetic knockout or pharmacological inhibition of STING prevented the progression of PH. Functionally, knockdown of STING reduced the proliferation and migration of PAECs. Mechanistically, STING transcriptionally regulates its binding partner F2RL3 (F2R-like thrombin or trypsin receptor 3) through the STING-NF-κB axis, which activated IFN signaling and repressed BMPR2 (bone morphogenetic protein receptor 2) signaling both invitro and invivo. Further analysis revealed that F2RL3 expression was increased in PH settings and identified negative feedback regulation of F2RL3/BMPR2 signaling. Accordingly, a positive correlation of expression amounts between STING and F2RL3/IFN-stimulated genes was observed invivo. Our findings suggest that STING activation in PAECs plays a critical role in the pathobiology of PH. Targeting STING may be a promising therapeutic strategy for preventing the development of PH.

Type I interferon exacerbates Mycobacterium tuberculosis induced human macrophage death

Type I interferons (IFN-I) are implicated in exacerbation of tuberculosis (TB), but the mechanisms are unclear. Mouse macrophages infected with Mycobacterium tuberculosis (Mtb) produce IFN-I, which contributes to their death. Here we investigate whether the same is true for human monocyte-derived macrophages (MDM). MDM prepared by a conventional method markedly upregulate interferon-stimulated genes (ISGs) upon Mtb infection, while MDM prepared to better restrict Mtb do so much less. A mixture of antibodies inhibiting IFN-I signaling prevents ISG induction. Surprisingly, secreted IFN-I are undetectable until nearly two days after ISG induction. These same antibodies do not diminish Mtb-infected MDM death. MDM induce ISGs in response to picogram/mL levels of exogenous IFN-I while depleting similar quantities from the medium. Exogenous IFN-I increase the proportion of dead MDM. We speculate that Mtb-infected MDM produce and respond to minute levels of IFN-I, and that only some of the resultant signaling is susceptible to neutralizing antibodies. Many types of cells may secrete IFN-I in patients with TB, where IFN-I is likely to promote the death of infected macrophages.