The cGAS-STING-interferon regulatory factor 7 pathway regulates neuroinflammation in Parkinson's disease

Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report that interferon regulatory factor 7 is markedly up-regulated in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease and co-localizes with microglial cells.Both the selective cyclic guanosine monophosphate adenosine monophosphate synthase inhibitor RU.521 and the stimulator of interferon genes inhibitor H151 effectively suppressed interferon regulatory factor 7 activation in BV2 microglia exposed to 1-methyl-4-phenylpyridinium and inhibited transformation of mouse BV2 microglia into the neurotoxic M1 phenotype.In addition,si RNA-mediated knockdown of interferon regulatory factor 7 expression in BV2 microglia reduced the expression of inducible nitric oxide synthase,tumor necrosis factorα,CD16,CD32,and CD86 and increased the expression of the anti-inflammatory markers ARG1 and YM1.Taken together,our findings indicate that the cyclic guanosine monophosphate adenosine monophosphate synthase-stimulator of interferon genes-interferon regulatory factor 7 pathway plays a crucial role in the pathogenesis of Parkinson's disease.

Interferon regulatory factor 2 binding protein 2:a new player of the innate immune response for stroke recovery

Ischemic brain injury triggers an inflammatory response. tissue but can also exacerbate brain injury. Microglia are This response is necessary to clear damaged brain the innate immune cells of the brain that execute this critical function. In healthy brain, microglia perform a housekeeping function, pruning unused syn- apses between neurons. However, microglia become activated to an inflammatory phenotype upon brain injury. Interferon regulatory factors modulate microglial activation and their production of inflammatory cytokines. This review briefly discusses recent findings pertaining to these regulatory mechanisms in the context of stroke recovery.

Association of rs10954213 Polymorphisms and Haplotype Diversity in Interferon Regulatory Factor 5 with Systemic Lupus Erythematosus: A Meta-analysis

The rs10954213 polymorphism and the haplotype diversity in interferon regulatory factor 5 （1RF5） play a special role in systemic lupus erythematosus （SLE） but with inconclusive results. We conducted a meta-analysis integrating case-control and haplotype variant studies in multiple ethnic populations to clearly discern the effect of these two variants on SLE. Eleven studies on the relation between rs10954213 polymorpisms in IRF5 and SLE were included and we selected a random effect model to calculate the pooled odds ratios （ORs） and the corresponding 95% confidence interval （95% CI）. A total of 6982 cases and 8077 controls were involved in the meta-analysis. The pooled results in- dicated that A allele was significantly associated with increased risk of SLE as compared with the IRF5 rS10954213 G allele （A vs. G, P〈0.00001） in all subjects. The same pattern of the results was also ob- tained in the European, African American, and Latin American. Asian population had a much lower prevalence of the A allele （49.1%） than any other population studied, and Europeans had the highest frequency of the IRF5 rs10954213 A allele （62.1%）. The significant association of increased SLE risk and TCA haplotype was indicated in the contrast of TCA vs. TTA as the pooled OR was 2.14 （P=0.002）. The same result was also found in the contrast of TCA vs. TTG as the pooled OR was 1.45 （P=-0.004）. This meta-analysis suggests that the A allele of rs10954213 and TCA haplotype （rs2004640-rs2070197-rs10954213） in IRF5 is associated with the increased risk of SLE in different ethnic groups, and its prevalence is ethnicity dependent.

Interferon Regulatory Factor 5 and Renin-Angiotensin-Aldosterone System Polymorphisms in Coronary Artery Disease: An Overview of Experimental and Clinical Studies

Heart diseases are the main cause of mortality in Mexico, being coronary heart disease the most frequent in the country. Its high prevalence makes important the study of the pathophysiology and the search for prognostic factors. Different genes and polymorphisms promote atherogenesis and coronary artery disease, they affect inflammatory and vascular pathological processes. Interferon regulatory factor 5 (IRF5) is associated with coronary heart disease, it promotes chronic inflammation and cytokines release;it could trigger immune reactions and its activating receptors express in the vascular endothelium. Besides, polymorphisms in the renin-angiotensin-aldosterone system (RAAS) are implied with coronary disease, they are found in angiotensinogen (AGT), angiotensin II type 1 receptor (AT1R), angiotensin II type 2 receptor (AT2R), and angiotensin-converting enzyme (ACE) genes. These genetic polymorphisms are associated with a prothrombotic state, endothelial dysfunction, and immune activation. Multiple experimental studies showed that chronic activation of RAAS and chronic expression of IRF5 generates an environment prone to the development of atherosclerosis, and autoimmune and cardiovascular diseases. Studying these specific genes and their relationship with coronary heart disease will allow a better understanding of the pathological process and possibly the quest for new treatments.

Key role of interferon regulatory factor 1(IRF-1)in regulating liver disease:progress and outlook

Interferon regulatory factor 1(IRF-1)is a member of the IRF family.It is the first transcription factor to be identified that could bind to the interferon-stimulated response element(ISRE)on the target gene and displays crucial roles in the interferoninduced signals and pathways.IRF-1,as an important medium,has all of the advantages of full cell cycle regulation,cell death signaling transduction,and reinforcing immune surveillance,which are well documented.Current studies indicate that IRF-1 is of vital importance to the occurrence and evolution of multifarious liver diseases,including but not limited to inhibiting the replication of the hepatitis virus(A/B/C/E),alleviating the progression of liver fibrosis,and aggravating hepatic ischemiareperfusion injury(HIRI).The tumor suppression of IRF-1 is related to the clinical characteristics of liver cancer patients,which makes it a potential indicator for predicting the prognosis and recurrence of liver cancer;additionally,the latest studies have revealed other effects of IRF-1 such as protection against alcoholic/non-alcoholic fatty liver disease(AFLD/NAFLD),cholangiocarcinoma suppression,and uncommon traits in other liver diseases that had previously received little attention.Intriguingly,several compounds and drugs have featured a protective function in specific liver disease models in which there is significant involvement of the IRF-1 signal.In this paper,we hope to propose a prospective research basis upon which to help decipher translational medicine applications of IRF-1 in liver disease treatment.

No association between IRF3 polymorphism and susceptibility to hepatitis B virus infection in Chinese patients

AIM:To investigate the association between three tag single nucleotide polymorphisms (tagSNPs) in inter-feron regulatory factors (IRF3) and the genetic suscep-tibility to chronic hepatitis B virus (HBV) infection.METHODS:We performed a case-control study of 985 Chinese cases of chronic HBV infection and 294 self-limiting HBV-infected individuals as controls.Three tagSNPs in IRF3 (rs10415576,rs2304204,rs2304206) were genotyped with the Multiplex SNaPshot technique.The genotype and allele frequencies were calculatedand analyzed.RESULTS:The three SNPs showed no significant geno-type/allele associations with chronic HBV infection.Overall allele P values were:rs10415576,P=0.0908,odds ratio (OR) [95% confidence interval (CI)]=1.1798 (0.9740-1.4291);rs2304204,P=0.5959,OR (95% CI)=1.0597 (0.8552-1.3133);rs2304206,P=0.8372,OR (95% CI)=1.0250 (0.8097-1.2976).Overall genotype P values were:rs10415576,P=0.2106;rs2304204,P=0.8458;rs2304206,P=0.8315.There were no statisti-cally significant differences between patients with chron-ic HBV infection and controls.Haplotypes generated by these three SNPs were also not significantly different between the two groups.CONCLUSION:The three tagSNPs of IRF3 are not asso-ciated with HBV infection in the Han Chinese population.

The IKK-related kinases： from innate immunity to oncogenesis

Over the past four years, the field of the innate immune response has been highly influenced by the discovery of the IKB kinase （IKK）-related kinases, TANK Binding Kinase I （TBK1） and IKKi, which regulate the activity of interferon regulatory factor （IRF）-3/IRF-7 and NF-κB transcription factors. More recently, additional essential components of the signaling pathways that activate these IKK homologues have been discovered. These include the RNA helicases RIGi and MDA5, and the downstream mitochondrial effector known as CARDIF/MAVS/VISA/IPS-1. In addition to their essential functions in controlling the innate immune response, recent studies have highlighted a role of these kinases in cell proliferation and oncogenesis. The canonical IKKs are well recognized to be a bridge linking chronic inflammation to cancer. New findings now suggest that the IKK-related kinases TBK1 and IKKi also participate in signaling pathways that impact on cell transformation and tumor progression. This review will therefore summarize and discuss the role of TBK1 and IKKi in cellular transformation and oncogenesis by focusing on their regulation and substrate specificity.

Potential mechanisms of hepatitis B virus induced liver injury

Chronic active hepatitis(CAH) is acknowledged as an imperative risk factor for the development of liver injury and hepatocellular carcinoma.The histological end points of CAH are chronic inflammation,fibrosis and cirrhosis which are coupled with increased DNA synthesis in cirrhotic vs healthy normal livers.The potential mechanism involved in CAH includes a combination of processes leading to liver cell necrosis,inflammation and cytokine production and liver scaring(fibrosis).The severity of liver damage is regulated by Hepatitis B virus genotypes and viral components.The viral and cellular factors that contribute to liver injury are discussed in this article.Liver injury caused by the viral infection affects many cellular processes such as cell signaling,apoptosis,transcription,DNA repair which in turn induce radical effects on cell survival,growth,transformation and maintenance.The consequence of such perturbations is resulted in the alteration of bile secretion,gluconeogenesis,glycolysis,detoxification and metabolism of carbohydrates,proteins,fat and balance of nutrients.The identification and elucidation of the molecular pathways perturbed by the viral proteins are important in order to design effective strategy to minimize and/or restore the hepatocytes injury.

IRF5 regulates lung macrophages M2 polarization during severe acute pancreatitis in vitro

AIM To investigate the role of interferon regulatory factor 5(IRF5) in reversing polarization of lung macrophages during severe acute pancreatitis(SAP) in vitro.METHODS A mouse SAP model was established by intraperitoneal(ip) injections of 20 μg/kg body weight caerulein. Pathological changes in the lung were observed by hematoxylin and eosin staining. Lung macrophages were isolated from bronchoalveolar lavage fluid. The quantity and purity of lung macrophages were detectedby fluorescence-activated cell sorting and evaluated by real-time polymerase chain reaction(RT-PCR). They were treated with IL-4/IRF5 specific siR NA(IRF5 siR NA) to reverse their polarization and were evaluated by detecting markers expression of M1/M2 using RTPCR.RESULTS SAP associated acute lung injury(ALI) was induced successfully by ip injections of caerulein, which was confirmed by histopathology. Lung macrophages expressed high levels of IRF5 as M1 phenotype during the early acute pancreatitis stages. Reduction of IRF5 expression by IRF5 siR NA reversed the action of macrophages from M1 to M2 phenotype in vitro. The expressions of M1 markers, including IRF5(S + IRF5 siR NA vs S + PBS, 0.013 ± 0.01 vs 0.054 ± 0.047, P < 0.01), TNF-α(S + IRF5 siR NA vs S + PBS, 0.0003 ± 0.0002 vs 0.019 ± 0.018, P < 0.001), iN OS(S + IRF5 siR NA vs S + PBS, 0.0003 ± 0.0002 vs 0.026 ± 0.018, P < 0.001) and IL-12(S + IRF5 si RNA vs S + PBS, 0.000005 ± 0.00004 vs 0.024 ± 0.016, P < 0.001), were decreased. In contrast, the expressions of M2 markers, including IL-10(S + IRF5 siR NA vs S + PBS, 0.060 ± 0.055 vs 0.0230 ± 0.018, P < 0.01) and Arg-1(S + IRF5 siR NA vs S + PBS, 0.910 ± 0.788 vs 0.0036 ± 0.0025, P < 0.001), were increased. IRF5 si RNA could reverse the lung macrophage polarization more effectively than IL-4.CONCLUSION Treatment with IRF5 siR NA can reverse the pancreatitisinduced activation of lung macrophages from M1 phenotype to M2 phenotype in SAP associated with ALI.

Increased cGAS/STING signaling components in patients with Mooren's ulcer

AIM:To explore the expression of cGAS/STING signaling components in Mooren’s ulcer(MU).METHODS:Samples were obtained from ten MU patients,and eight residual corneal-scleral rings of healthy donor corneas for controls.Human corneal epithelial cells(HCECs)were used to evaluate the effect of cGAS/STING signaling pathway.Immunohistochemistr y(IHC)and Western blot were used to examine the expression of cGAS,STING,and phosphorylated interferon regulatory factor 3(p-IRF3)in MU tissues.The expression of interferon-β(IFN-β)and interferon-stimulated genes(ISGs)was quantified by real-time polymerase chain reaction(PCR)and enzymelinked immunosorbent assay(ELISA).RESULTS:The protein levels of cGAS and STING in MU samples were significantly elevated when compared with the healthy controls by Western blot and IHC.After stimulation with cGAMP,real-time PCR and ELISA showed a dramatic increase of IFN-βand ISGs(containing CXCL10,IFIT1,and IL-6)in HCECs.Moreover,HCECs treated with cGAMP was characterized by increased phosphorylation and more nuclear translocation of IRF3.Meanwhile,increased p-IRF3 was observed in MU samples via IHC and Western blot.CONCLUSION:The pronounced expression of cGAS/STING signaling components in the patients with MU and probably contribute to the onset and development of MU.

Interferon regulatory factor 3-CL,an isoform of IRF3,antagonizes activity of IRF3

Interferon regulatory factor 3(IRF3),one member of the IRF family,plays a central role in induction of type I interferon(IFN)and regulation of apoptosis.Controlled activity of IRF3 is essential for its functions.During reverse transcription(RT)-PCR to clone the full-length open reading frame(ORF)of IRF3,we cloned a full-length ORF encoding an isoform of IRF3,termed as IRF3-CL,and has a unique carboxyl-terminus of 125 amino acids.IRF3-CL is ubiquitously expressed in distinct cell lines.Overexpression of IRF3-CL inhibits Sendai virus(SeV)-triggered induction of IFN-β and SeV-induced and inhibitor of NF-kB kinase-e(IKKε)-mediated nuclear translocation of IRF3.When IKKε is overexpressed,IRF3-CL is associated with IRF3.These results suggest that IRF3-CL,the alternative splicing isoform of IRF-3,may function as a negative regulator of IRF3.

Variants of Interferon Regulatory Factor 5 are Associated with Neither Neuromyelitis Optica Nor Multiple Sclerosis in the Southeastern Han Chinese Population

Background： Neuromyelitis optica （NMO） and multiple sclerosis （MS） are demyelinating disorders of the central nervous system. Interferon regulatory factor 5 （IRF5） is a common susceptibility gene to different autoimmune disorders. However, the association of IRF5 variants with NMO and MS patients has not been well studied. Therefore, we aimed to evaluate whether IRF5 variants were associated with NMO and MS in the Southeastenl Han Chinese population. Methods： Four single nucleotide polymorphisnls （SNPs） were selected and genotyped by matrix-assisted laser desorption/ionization time of flight mass spectrometry in 111 NMO patients, 145 MS patients and 300 controls from Southeastern China. Results： None of these 4 SNPs was associated with NMO or MS patients. Conclusions： Our preliminary study indicates that genetic variants in IRI~ may affect neither NMO nor MS in the Southeastern Han Chinese population. Further studies with a large sample size and diverse ancestry populations are needed to clarify this isstie.

Expression and clinical significance of miRNA-146a and IRF-3 in children with infectious mononucleosis

Objective:To investigate the expression levels of interferon regulatory factor 3(IRF-3)and miRNA146a in peripheral blood of children with infectious mononucleosis and the effect of miRNA146a on IRF-3 expression.Methods:In an in vivo experiment,the expression levels of IRF-3 and miRNA146a in peripheral blood of 45 children with infectious mononucleosis and 34 healthy controls were detected by real-time PCR.The in vitro experiment was performed to examine the effect of miRNA146a on IRF-3 expression levels by transfecting miRNA146a mimics and their inhibitors.Results:There was significant difference in IRF-3 gene expression in peripheral blood between healthy controls and children with infectious mononucleosis(t=30.340,P<0.001)while miRNA146a expression was significantly increased compared with healthy controls(t=34.659,P<0.001),and there was a negative correlation between the two groups(r=-0.960,P<0.05).In HeLa cells,transfection with miRNA146a mimics significantly decreased the expression of IRF-3 mRNA(t=8.270,P<0.001)and protein(t=46.170,P<0.001),while miRNA146a inhibitor significantly up-regulated the expression of IRF-3 mRNA(t=8.582,P<0.001)and protein(t=25.891,P<0.001).Conclusion:miRNA146a may be involved in the down-regulation of IRF-3 gene expression by Epstein-Barr virus in children with infectious mononucleosis and then involved in the pathogenesis of infectious mononucleosis.

Association of Single Nucleotide Polymorphisms in IRF6 and TGFA Genes With Nonsyndromic Cleft Lip With Or Without Cleft Palate in Chinese Patients

Objective： Nonsyndromic cleft lip with or without cleft palate（NSCL/P） is a common birth defect with unclear etiology. Both genetic and environmental factors may contribute to NSCL/P. Many genes have been identified as candidate genes associated with this disease. Interferon regulatory factor 6（IRF6） gene and transforming growth factor-a（TGFA） gene seem to be crucial in the predisposition of NSCL/ P. Here we evaluated some single nucleotide polymorphisms（SNPs） loci of TGFA and IRF6 genes in Chinese nuclear families consisting of fathers, mothers and affected offspring with NSCL/P. Methods：Fifty patients of NSCL/P were confirmed by the plastic surgeons. They and their parents were included in the study, all with the informed consents. SNPs loci of TGFA and IRF6 genes were analyzed by microarray technology. Some PCR products were randomly chosen and sequenced to check microarray results. The distribution of gene type and allele frequency between patient group and parents group were compared. Then a Haplotype Relative Risk（HRR） and Transmission Disequilibrium Test（TDT） were performed. Results：The sequences of randomly selected PCR products were all consistent with the microarray results. All loci were in Hardy-Weinberg equilibrium. There were no significant differences in the distribution of genotypes and alleles between patients and their parents. Using HRR and TDT analyses the V274I of IRF6 was associated with NSCL/P, while another SNP locus oflRF6 was not. Strong evidence of linkage disequilibrium was found between the 2 SNP loci of TGFA and disease with the HRR analysis, but not with the TDT analysis. Conclusion：Our study confirms the contribution of IRF6 in the etiology of NSCL/P in populations of Asian ancestry. The association of TGFA with NSCL/P requires further research.

Zika virus non-structural protein 4B interacts with DHCR7 to facilitate viral infection

Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.

Andrographolide as An Anti-H1N1 Drug and the Mechanism Related to Retinoic Acid-Inducible Gene-I-Like Receptors Signaling Pathway

Objective： To observe the anti-virus effects of andrographolide （AD） on the retinoic acid-inducible gene-I （RIG-I）-Iike receptors （RLRs） signaling pathway when immunological cells were infected with HIN1. Methods： Leukomonocyte was obtained from umbilical cord blood by Ficoll density gradient centrifugation, and immunological cells were harvested after cytokines stimulation. Virus infected cell model was established by H1N1 co-cultured with normal human bronchial epithelial cell line （16HBE）. The optimal concentration of AD was defined by methyl-thiazolyl-tetrazolium （MTT） assay. After the virus infected cell model was established, AD was added into the medium as a treatment intervention. After 24-h co-culture, cell supernatant was collected for interferon gamma （IFN- ~, ） and interleukin-4 （IL-4） enzyme-linked immunosorbent assay （ELISA） detection while immunological cells for real-time polymerase chain reaction （RT-PCR）. Results： The optimal concentration of AD for anti-virus effect was 250 μg/mL. IL-4 and IFN-γ in the supernatant and mRNA levels in RLRs pathway increased when cells was infected by virus, RIG-I, IFN-13 promoter stimulator-1 （IPS-1）, interferon regulatory factor （IRF）-7, IRF-3 and nuclear transcription factor K B （NF- K B） mRNA levels increased significantly （P〈0.05）. When AD was added into co-culture medium, the levels of IL-4 and IFN-γ were lower than those in the non-interference groups and the mRNA expression levels decreased, RIG-I, IPS-1, IRF-7, IRF-3 and NF- K B decreased significantly in each group with significant statistic differences （P〈0.05）. Conclusions： The RLRs mediated viral recognition provided a potential molecular target for acute viral infections and andrographolide could ameliorate H1N1 virus-induced cell mortality. And the antiviral effects might be related to its inhibition of viral-induced activation of the RLRs signaling pathway.

Toll-like receptor 9 is correlated to disease activity in Chinese systemic lupus erythematosus population

Methods mRNA level of TLR9 and interferon （IFN） regulatory factor 5 （IRF5） in peripheral blood mononuclear cells （PBMCs） were determined by real-time polymerase chain reaction （PCR）. IFN-a expression was measured in the serum of the SLE patients by enzyme-linked immunosorbent assay （ELISA）. Results TLR9 expression was significantly higher in SLE patients than that in health controls （P=0.011）. SLE patients with positive anti-dsDNA antibody had significantly higher expression of TLR9 than that with negative anti-dsDNA antibody （P=0.001）. TLR9 expression was positively correlated with fever （P=0.017）, alopecia （P=0.046）, safety of estrogens in lupus erythematosus national assessment SLE disease activity index （SELENA-SLEDAI） score （rs=0.385, P=0.003）, and the level of IRF5 （rs=0.35, P=0.027） and IFN-a （rs=0.627, P=0.001） in SLE patients. Conclusion TLR9 is associated with SLE disease activity and might be involved in the IFN-a pathway of SLE.

Chaperone-and PTM-mediated activation of IRF1 tames radiation-induced cell death and the inflammatory response

The key role of structural cells in immune modulation has been revealed with the advent of single-cell multiomics,but the underlying mechanism remains poorly understood.Here,we revealed that the transcriptional activation of interferon regulatory factor 1(IRF1)in response to ionizing radiation,cytotoxic chemicals and SARS-CoV-2 viral infection determines the fate of structural cells and regulates communication between structural and immune cells.Radiation-induced leakage of mtDNA initiates the nuclear translocation of IRF1,enabling it to regulate the transcription of inflammation-and cell death-related genes.Novel posttranslational modification(PTM)sites in the nuclear localization sequence(NLS)of IRF1 were identified.Functional analysis revealed that mutation of the acetylation site and the phosphorylation sites in the NLS blocked the transcriptional activation of IRF1 and reduced cell death in response to ionizing radiation.Mechanistically,reciprocal regulation between the single-stranded DNA sensors SSBP1 and IRF1,which restrains radiation-induced and STING/p300-mediated PTMs of IRF1,was revealed.In addition,genetic deletion or pharmacological inhibition of IRF1 tempered radiation-induced inflammatory cell death,and radiation mitigators also suppressed SARS-CoV-2 NSP-10-mediated activation of IRF1.Thus,we revealed a novel cytoplasm-oriented mechanism of IRF1 activation in structural cells that promotes inflammation and highlighted the potential effectiveness of IRF1 inhibitors against immune disorders.