Interferon Regulatory Factor Research Articles

Interferon Regulatory Factor 4 (IRF4)-Dependent Type 2 Conventional Dendritic Cells (cDC2s) Promote Kidney Inflammation and Injury in Ischemia-Reperfusion Injury (IRI)-Induced AKI/AKD

Interferon Regulatory Factor 4 (IRF4)-Dependent Type 2 Conventional Dendritic Cells (cDC2s) Promote Kidney Inflammation and Injury in Ischemia-Reperfusion Injury (IRI)-Induced AKI/AKD

FBXL19 in endothelial cells protects the heart from influenza A infection by enhancing antiviral immunity and reducing cellular senescence programs.

Influenza A virus (IAV) infection while primarily affecting the lungs, is often associated with cardiovascular complications. However, the mechanisms underlying this association are not fully understood. Here, we investigated the potential role of FBXL19, a member of the Skp1-Cullin-1-F-box family of E3 ubiquitin ligase, in IAV-induced cardiac inflammation. We demonstrated that FBXL19 overexpression in endothelial cells (ECs) reduced viral titers and IAV matrix protein 1 (M1) levels while increasing antiviral gene expression, including interferon (IFN)-α, -β, and -γ and RANTES (regulated on activation normal T cell expressed and secreted) in the cardiac tissue of IAV-infected mice. Moreover, EC-specific overexpression of FBXL19 attenuated the IAV infection-reduced interferon regulatory factor 3 (IRF3) level without altering its mRNA level and suppressed cardiac inflammation. Furthermore, IAV infection triggered cellular senescence programs in the heart as indicated by the upregulation of p16 and p21 mRNA levels and the downregulation of lamin-B1 levels, which were partially reversed by FBXL19 overexpression in ECs. Our findings indicate that EC-specific overexpression of FBXL19 protects against IAV-induced cardiac damage by enhancing interferon-mediated antiviral signaling, reducing cardiac inflammation, and suppressing cellular senescence programs.NEW & NOTEWORTHY Our study reveals a novel facet of IAV infection, demonstrating that it can trigger cellular senescence within the heart. Intriguingly, upregulation of endothelial FBXL19 promotes host innate immunity, reduces cardiac senescence, and diminishes inflammation. These findings highlight the therapeutic potential of targeting FBXL19 to mitigate IAV-induced cardiovascular complications.

Role of toll-like receptor 4/mutant myeloid differentiation primary response 88/nuclear factor kappa-B mediated inflammation in diabetes mellitus with Northwest dryness syndrome.

To investigate the role of toll-like receptor 4 (TLR4)/mutant myeloid differentiation primary response 88 (MyD88)/nuclear factor kappa-B (NF-κB) signaling pathway-mediated inflammation in diabetes mellitus with Northwest dryness syndrome. Rats were randomly divided into the normal control, type 2 diabetes (T2DM) model, Northwest dryness syndrome + T2DM (Northwest dryness), and simple internal dampness + T2DM (internal dampness) groups. Enzyme-linked immunosorbent assay was used to detect biochemical indexes and inflammatory factors. The histopathological observation was performed. Quantitative real-time polymerase chain reaction and Western blot analysis were used to detect the mRNA and protein expression levels, respectively. Compared with the T2DM group, the glycosylated hemoglobin A1c, insulin, glucose tolerance, the homeostasis model assessment of insulin resistance, tumor necrosis factor-α, interleukin 1β, interleukin 16, malondialdehyde, blood lipid, alanine aminotransferase, and aspartate aminotransferase were significantly elevated in the internal dampness group. Their levels were significantly elevated in the Northwest dryness group than in the T2DM and internal dampness groups. The superoxide dismutase, glutathione peroxidase, liver glycogen, and organ-to-weight ratio were significantly declined in the internal dampness group and the Northwest dryness group than in the T2DM group. However, these levels were elevated in the Northwest dryness group than in the internal dampness group. Moreover, the mRNA expression levels of interferon regulatory factor 5 and NF-κB p65, and the protein expression levels of TLR4, MyD88, and NF-κB were significantly higher in the internal dampness and the Northwest dryness groups than the T2DM group. Additionally, the mRNA and protein levels were significantly higher in the Northwest dryness group than in the internal dampness group. Northwest dryness syndrome-mediated TLR4/MyD88/NF-κB pathway and chronic inflammation might be associated with the occurrence and development of T2DM.

Programmed RNA editing with an evolved bacterial adenosine deaminase.

Programmed RNA editing presents an attractive therapeutic strategy for genetic disease. In this study, we developed bacterial deaminase-enabled recoding of RNA (DECOR), which employs an evolved Escherichia coli transfer RNA adenosine deaminase, TadA8e, to deposit adenosine-to-inosine editing to CRISPR-specified sites in the human transcriptome. DECOR functions in a variety of cell types, including human lung fibroblasts, and delivers on-target activity similar to ADAR-overexpressing RNA-editing platforms with 88% lower off-target effects. High-fidelity DECOR further reduces off-target effects to basal level. We demonstrate the clinical potential of DECOR by targeting Van der Woude syndrome-causing interferon regulatory factor 6 (IRF6) insufficiency. DECOR-mediated RNA editing removes a pathogenic upstream open reading frame (uORF) from the 5' untranslated region of IRF6 and rescues primary ORF expression from 12.3% to 36.5%, relative to healthy transcripts. DECOR expands the current portfolio of effector proteins and opens new territory in programmed RNA editing.

NOD2-mediated dual negative regulation of inflammatory responses triggered by TLRs in the gastrointestinal tract.

Loss-of-function mutations in nucleotide-binding oligomerization domain 2 (NOD2) constitute the primary risk factors for Crohn's disease. NOD2 is an intracellular sensor for muramyl dipeptide (MDP), a small molecule derived from the peptidoglycan layer of bacterial cell wall. Although NOD2 is involved in host immune responses, much attention has been paid to the involvement of NOD2 in the maintenance of intestinal homeostasis. Despite the fact that the proinflammatory cytokine and chemokine responses induced by NOD2 activation alone are weaker than those induced by toll-like receptors (TLRs), NOD2 plays a crucial role in host defense against invading pathogens and in the regulation of immune responses. Recent studies have highlighted the importance of negative regulatory functions of NOD2 in TLRs-mediated proinflammatory cytokine responses. MDP-mediated activation of NOD2 induces interferon regulatory factor 4 (IRF4) expression, thereby suppressing nuclear factor-κB-dependent colitogenic cytokine responses through the inhibition of Lys(K)63-linked polyubiquitination on receptor-interacting serine/threonine protein kinase 2. MDP-mediated activation of NOD2 also downregulates TLR9-induced type I IFN responses by inhibiting the K63-linked polyubiquitination of TNF receptor-associated factor 3 via deubiquitinating enzyme A (DUBA) expression. Thus, NOD2 exerts dual negative regulation of TLRs-mediated proinflammatory cytokine and type I IFN responses by inducing the expression of IRF4 and DUBA, respectively. In this review, we summarize the molecular mechanisms whereby NOD2 activation suppresses TLRs-mediated proinflammatory and type I IFN responses. In addition, we discuss the clinical relevance of the NOD2-mediated negative regulation of TLRs in inflammatory bowel disease.

Escape of Kdm6a from X chromosome is detrimental to ischemic brains via IRF5 signaling.

The role of chromatin biology and epigenetics in disease progression is gaining increasing recognition. Genes that escape X chromosome inactivation (XCI) can impact neuroinflammation through epigenetic mechanisms. Our prior research has suggested that the X escapee genes Kdm6a and Kdm5c are involved in microglial activation after stroke in aged mice. However, the underlying mechanisms remain unclear. We hypothesized that Kdm6a/5c demethylate H3K27Me3/H3K4Me3 in microglia respectively, and mediate the transcription of interferon regulatory factor 5 (IRF5) and IRF4, leading to microglial pro-inflammatory responses and exacerbated stroke injury. Aged (17-20 months) Kdm6a/5c microglial conditional knockout (CKO) female mice (one allele of the gene) were subjected to a 60-min middle cerebral artery occlusion (MCAO). Gene floxed females (two alleles) and males (one allele) were included as controls. Infarct volume and behavioral deficits were quantified 3 days after stroke. Immune responses including microglial activation and infiltration of peripheral leukocytes in the ischemic brain were assessed by flow cytometry. Epigenetic modification of IRF5/4 by Kdm6a/5c were analyzed by CUT&RUN assay. The demethylation of H3K27Me3 by kdm6a increased IRF5 transcription; meanwhile Kdm5c demethylated H3K4Me3 to repress IRF5. Both Kdm6a fl/fl and Kdm5c fl/fl mice had worse stroke outcomes compared to fl/y and CKO mice. Gene floxed females showed more robust expression of CD68 in microglia, elevated brain and plasma levels of IL-1β or TNF-α, after stroke. We concluded that IRF5 signaling plays a critical role in mediating the deleterious effect of Kdm6a; whereas Kdm5c's effect is independent of IRF5.

The human milk oligosaccharide 3'sialyllactose reduces low-grade inflammation and atherosclerosis development in mice.

Macrophages contribute to the induction and resolution of inflammation and play a central role in chronic low-grade inflammation in cardiovascular diseases caused by atherosclerosis. Human milk oligosaccharides (HMOs) are complex unconjugated glycans unique to human milk that benefit infant health and act as innate immune modulators. Here, we identify the HMO 3'sialyllactose (3'SL) as a natural inhibitor of Toll-Like Receptor (TLR) 4-induced low-grade inflammation in macrophages and endothelium. Transcriptome analysis in macrophages revealed that 3'SL attenuates mRNA levels of a selected set of inflammatory genes and promotes the activity of Liver X Receptor (LXR) and Sterol Regulatory Element-binding Protein-1 (SREBP). These acute anti-inflammatory effects of 3'SL were associated with reduced histone H3K27 acetylation at a subset of lipopolysaccharide (LPS)-inducible enhancers distinguished by preferential enrichment for CCCTC-binding factor (CTCF), Interferon Regulatory Factor 2 (IRF2), B-cell lymphoma 6 (BCL6), and other transcription factor recognition motifs. In a murine atherosclerosis model, both subcutaneous and oral administration of 3'SL significantly reduced atherosclerosis development and the associated inflammation. This study provides evidence that 3'SL attenuates inflammation by a transcriptional mechanism to reduce atherosclerosis development in the context of cardiovascular disease.

Etelcalcetide ameliorates bone loss in chronic kidney disease-mineral and bone disorder by activation of IRF7 and necroptosis pathways

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a multifaceted clinical syndrome characterized by mineral imbalances, abnormalities in bone metabolism, chronic inflammation and vascular calcification. Etelcalcetide, a second-generation intravenous calcimimetic agent, has been approved for treating high-turnover renal osteodystrophy, effectively targeting the pathophysiological mechanisms underlying this condition. We investigate the impacts of etelcalcetide on osteoclast (OC) differentiation and functionality in CKD-MBD via three critical mechanisms: inflammation initiated by interferon regulatory factor 7 (IRF7), receptor-interacting protein (RIP)-mediated necroptosis and apoptosis-induced cell death. The low-dose (CKD + L) or high-dose (CKD + H) of etelcalcetide groups significantly improved biochemical markers compared to the CKD control mice. Additionally, etelcalcetide-treated CKD mice significantly improved cortical and trabecular bone parameters. In an in vitro study, etelcalcetide was observed to bolster the IRF7-mediated IFNβ response in OC differentiation. Furthermore, it stimulated RIP-mediated necroptosis via RIP and MLKL activation, inhibiting bone resorption. Moreover, the drug increased levels of caspases 3 and 9, inducing cell death in OCs. These findings suggest that etelcalcetide regulates bone metabolism and reduces skeletal issues in CKD-MBD. Etelcalcetide likely enhances bone parameters in CKD-MBD mice by regulating IRF7 pathways and inhibiting OC differentiation. It also improves bone health and promotes RIP-mediated necroptosis and apoptosis pathways within OCs.

Deficiency of Tlr7 and Irf7 in mice increases the severity of COVID-19 through the reduced interferon production

Toll-like receptor 7 (Tlr7) deficiency-accelerated severe COVID-19 is associated with reduced production of interferons (IFNs). However, the underlying mechanisms remain elusive. To address these questions, we utilize Tlr7 and Irf7 deficiency mice, single-cell RNA analysis together with bone marrow transplantation approaches. We demonstrate that at the early phase of infection, SARS-CoV-2 causes the upregulation of Tlr7, Irf7, and IFN pathways in the lungs of the infected mice. The deficiency of Tlr7 and Irf7 globally and/or in immune cells in mice increases the severity of COVID-19 via impaired IFN activation in both immune and/or non-immune cells, leading to increased lung viral loads. These effects are associated with reduced IFN alpha and gamma levels in the circulation. The deficiency of Tlr7 tends to cause the reduced production and nuclear translocation of interferon regulatory factor 7 (IRF7) in the lungs of the infected mice, indicative of reduced IRF7 activation. Despite higher amounts of lung viral antigen, Tlr7 or Irf7 deficiency resulted in substantially reduced production of antibodies against SARS-CoV-2, thereby delaying the viral clearance. These results highlight the importance of the activation of TLR7 and IRF7 leading to IFN production on the development of innate and adaptive immunity against COVID-19.

Zinc-finger CCHC-type containing protein 8 promotes RNA virus replication by suppressing the type-I interferon responses.

Host cells have evolved an intricate regulatory network to fine tune the type-I interferon responses. However, the full picture of this regulatory network remains to be depicted. In this study, we found that knock out of zinc-finger CCHC-type containing protein 8 (ZCCHC8) impairs the replication of influenza A virus (IAV), Sendai virus (Sev), Japanese encephalitis virus (JEV), and vesicular stomatitis virus (VSV). Further investigation unveiled that ZCCHC8 suppresses the type-I interferon responses by targeting the interferon regulatory factor 3 (IRF3) signaling pathway. Mechanistically, ZCCHC8 associates with phosphorylated IRF3 and disrupts the interaction of IRF3 with the co-activator CREB-binding protein (CBP). Additionally, the direct binding of ZCCHC8 with the IFN-stimulated response element (ISRE) impairs the ISRE-binding of IRF3. Our study contributes to the comprehensive understanding for the negative regulatory network of the type-I interferon responses and provides valuable insights for the control of multiple viruses from a host-centric perspective.IMPORTANCEThe innate immune responses serve as the initial line of defense against invading pathogens and harmful substances. Negative regulation of the innate immune responses plays an essential role in avoiding auto-immune diseases and over-activated immune responses. Hence, the comprehensive understanding of the negative regulation network for innate immune responses could provide novel therapeutic insights for the control of viral infections and immune dysfunction. In this study, we report that ZCCHC8 negatively regulates the type-I interferon responses. We illustrate that ZCCHC8 impedes the IRF3-CBP association by interacting with phosphorylated IRF3 and competes with IRF3 for binding to ISRE. Our study demonstrates the role of ZCCHC8 in the replication of multiple RNA viruses and contributes to a deeper understanding of the negative regulation system for the type-I interferon responses.

Mycobacterial peptidyl prolyl isomerase A activates STING-TBK1-IRF3 signaling to promote IFNβ release in macrophages.

Peptidyl prolyl isomerases (PPIases) are well-conserved protein-folding enzymes that moonlight as regulators of bacterial virulence. Peptidyl prolyl isomerase A, PPiA (Rv0009) is a secretory protein of Mycobacterium tuberculosis that possesses sequence and structural similarity to eukaryotic cyclophilins. In this study, we validated the interaction of PPiA with stimulator of interferon genes (STING) using both, Escherichia coli-based and mammalian in vitro expression systems. In vitro pull-down assays confirmed that the cytosolic domain of STING interacts with PPiA, and moreover, we found that PPiA could induce dimerization of STING in macrophages. In silico docking analyses suggested that the PXXP (PDP) motif of PPiA is crucial for interaction with STING, and concordantly, mutations in the PDP domain (PPiA MUT-II) abrogated this interaction, as well as the ability of PPiA to facilitate STING dimerization. In agreement with these observations, fluorescence microscopy demonstrated that STING and wild-type PPiA, but not PPiA MUT-II, could colocalize when expressed in HEK293 cells. Highlighting the importance of the PDP domain further, PPiA, but not PPiA MUT-II could activate Tank binding kinase 1 (TBK1)-interferon regulatory factor 3 (IRF3) signaling to promote the release of interferon-beta (IFNβ). PPiA, but not PPiA MUT-II expressed in Mycobacterium smegmatis induced IFNβ release and facilitated bacterial survival in macrophages in a STING-dependent manner. The PPiA-induced release of IFNβ was c-GAS independent. We conclude that PPiA is a previously undescribed mycobacterial regulator of STING-dependent type I interferon production from macrophages.

Abstract B070: TGFB2 mRNA levels prognostically interact with Interferon-alpha receptor activation of IRF9 and IFI27, and makers for tumor-associated macrophages impacting overall survival in PDAC

Abstract Background: The treatment of pancreatic ductal adenocarcinoma (PDAC) is an unmet challenge, with the median overall survival rate remaining less than a year, even with the use of FOLFIRINOX-based therapies. Methods: In this study, we analyzed archived macrophage- associated mRNA expression using datasets deposited in the UCSC Xena web platform to compare normal pancreatic tissue and PDAC tumor samples. We also utilized TCGA datasets deposited in cBioportal (https://www.cbioportal.org/study/summary?id=paad_tcga_pan_can_atlas) and KMplotter (http://kmplot.com/analysis/index.php?p=service&cancer=pancancer_rnaseq) to relate mRNA expression levels to overall survival outcomes. The prognostic impact of TGFB2 mRNA expression levels was determined by comparing patients expressing high versus low levels of TGFB2 (50th percentile cut-off) in low macrophage TME. Results: The TGFB2 gene exhibited low mRNA expression levels in normal tissue, with less than one TPM, while, in tumor tissue, TGFB2 expression levels exhibited a 7.9-fold increase in mRNA expression relative to normal tissue (P < 0.0001). Interferon Alpha Inducible Protein 27 (IFI27), the downstream product of Interferon regulatory factor 9 (IRF9) and Signal transducer and activator of transcription 1 (STAT1) transcriptional activation by Interferon alpha/beta receptor 1 (IFNAR1) exhibited a significant 66.3-fold increase in expression in tumor tissue compared to normal tissue (P < 0.0001). The statistical contrast between the expression of IRF9 mRNA also displayed a significant (P<0.0001) 4.2-fold increase in mRNA expression levels. These increased levels of mRNA expression were found to be prognostically significant, whereby patients with high expression levels of either TGFB2, IRF9, or IFI27 showed median OS times ranging from 16 to 20 months (P<0.01 compared to 72 months for patients with low levels of expression for both TGFB2 and either IRF9 or IFI27). In TME with low macrophage levels, patients with high levels of TGFB2 mRNA exhibited significantly shorter OS outcomes than patients with low TGFB2 mRNA levels (Median OS of 72.2 versus 15.3 months, P<0.0001). Furthermore, expression of TGFB2 mRNA and TAM markers exhibited TGFB2 prognostic impact independent of 17 TAM markers suggested by multivariate Cox regression models. Conclusions: The results of our study suggest that a combination of pharmacological tools can be used in treating PDAC patients, targeting both TGFB2 and the components of the type-I interferon signaling pathway to improve OS outcomes. TGFB2 expression impacts OS independent of TAM markers, but the expression of TAM markers impacts the prognostic effect of TGFB2 mRNA expression. Citation Format: Sanjive Qazi, Wen-Han Chang, Cynthia Lee, Vuong Trieu. TGFB2 mRNA levels prognostically interact with Interferon-alpha receptor activation of IRF9 and IFI27, and makers for tumor-associated macrophages impacting overall survival in PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B070.

Abstract A039: Repeat RNA mediated disruption of cellular plasticity in pancreatic cancer

Abstract Aberrant expression of repeat RNAs in pancreatic ductal adenocarcinoma (PDAC) mimics viral-like responses with implications for tumor cell state and the surrounding microenvironment. To better understand the relationship of repeat RNAs in human PDAC, we employed the NanoString CosMx™ spatial molecular imaging (SMI) platform, which utilizes a 1,000-plex RNA panel with custom repeat RNA probes targeting long interspersed nuclear element 1 (LINE-1) retrotransposon ORF1 and ORF2, HSATII satellite (SAT) repeat, and two human endogenous retroviruses (HERV-K and HERV-H) in 46 primary tumors. This analysis revealed correlations of high repeat RNA expression with alterations in the epithelial state of PDAC cells and the myofibroblast phenotype in cancer-associated fibroblasts (CAFs). The loss of cellular identity observed with dosing of extracellular vesicles (EVs) and individual repeat RNAs in PDAC and CAF cell culture models points to cell-cell intercommunication involving these viral-like elements. Differences in the PDAC and CAF response are driven by distinct innate immune signaling pathways through interferon regulatory transcription factor 3 (IRF3). Altogether, our data indicate that cell context-specific viral-like responses driven by tumor cells have broad impacts on single-cell heterogeneity within cancer cells and the pancreatic cancer microenvironment. Citation Format: Eunae You, Patrick Danaher, Chenyue Lu, Siyu Sun, Luli Zou, Ildiko Phillips, Alexandra Rojas, Natalie Ho, Yuhui Song, Michael Raabe, Katherine Xu, Peter Richieri, Hao Li, Natalie Aston, Rebecca Porter, Bidish Patel, Linda Nieman, Nathan Schurman, Briana Hudson, Khrystyna North, Sarah Church, Vikram Deshpande, Andrew Liss, Tae Kim, Yi Cui, Youngmi Kim, Benjamin Greenbaum, Martin Aryee, David Ting. Repeat RNA mediated disruption of cellular plasticity in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A039.

IRF5 Variants Are Risk Factors for Systemic Lupus Erythematosus in Two Mexican Populations.

Interferon regulatory factor 5 ( IRF5 ) is one of the pivotal genes implicated in systemic lupus erythematosus (SLE) among diverse ethnic groups, including Europeans, Asians, Hispanics, and Africans. Notably, its significance appears particularly pronounced among Hispanic populations. Previous studies have identified several single-nucleotide variants within IRF5 , such as rs2004640G/T, rs2070197T/C, and rs10954213G/A, as associated with susceptibility to SLE among patients from Mexico City. However, the population of Yucatan, located in the Southeast of Mexico and characterized by a greater Amerindian genetic component, remains largely unexplored in this regard. Our study aimed to replicate the observed association between IRF5 variants and susceptibility to SLE among patients from Central Mexico and Yucatan. Furthermore, we investigated the impact of IRF5 rs59110799G/T, a variant that has not been previously studied in SLE individuals. Our study included 204 SLE patients and 160 controls from Central Mexico, as well as 184 SLE patients and 184 controls from Yucatan. All participants were females 18 years and older. We employed a TaqMan assay to detect the presence of the following single-nucleotide variants: rs2004640G/T, rs2070197T/C, rs10954213G/A, and rs59110799G/T. Furthermore, we utilized 2 distinct web tools and databases to predict the potential functional implications of IRF5 variants. In SLE patients from Central Mexico, several IRF5 alleles showed significant associations with the disease following adjustment by the Bonferroni test: the rs2070197C allele (odds ratio [OR], 2.08), the rs10954213A allele (OR, 1.59), and the rs59110799G allele (OR, 1.71). Conversely, among patients from Yucatan, the following alleles showed associations: rs2004640T (OR, 1.51), rs2070197C (OR, 1.62), rs10954213A (OR, 1.67), and rs59110799G (OR, 1.44). Our findings highlight genetic variations between Mexican populations and emphasize the role of IRF5 as a risk factor in SLE patients from both Central Mexico and Yucatan.

Interferon Regulatory Factor 4: An Alternative Marker for Plasma Cells in Daratumumab-Treated Patients With Multiple Myeloma.

Anti-CD38 therapeutic modalities (e.g., daratumumab) can impede classical CD38 and CD138 gating use for plasma cell (PC) detection in multiple myeloma (MM) patients with minimal residual disease (MRD). We assessed the applicability of CD229, CD269, and interferon regulatory factor (IRF-4) for PC detection in MM MRD patients. Bone marrow samples were collected from patients with MM. Through multiparameter flow cytometry, we evaluated the suitability of CD229, CD269, and IRF-4 for distinguishing PCs from other hematopoietic cells and compared their expression pattern on normal PCs (nPCs) and aberrant PCs (aPCs). We also assessed IRF-4 expression stability after sample storage under different conditions. A 10-color MRD antibody panel was used to determine whether IRF-4 is an alternative primary PC-gating marker for MM MRD assessment. IRF-4 was expressed specifically on all PCs; its mean fluorescence intensity (MFI) was highest on PCs among all hematopoietic cells. This MFI did not decrease even after sample storage at 4°C or 25°C for 72 h. In all 42 MRD assessment samples, except for samples (n = 10) with no PCs, the use of IRF-4 enabled accurate nPC (n = 12), aPC (n = 13), and nPC + aPC (n = 7) identification. Even samples from daratumumab-treated patients had high IRF-4 MFI, with no difference between pre-treatment and post-treatment (n = 7; p = 0.610). IRF-4 demonstrates high MFI on PCs, and it is not expressed on other leukocytes. In MM patients with MRD, daratumumab treatment does not affect IRF-4 expression. IRF-4 is a promising marker for PC identification in MRD assessment of MM patients undergoing anti-CD38 therapy.

Anti-inflammatory effects of Gingerenone A through modulation of toll-like receptor signaling pathways

Toll-like receptors (TLRs) play a pivotal role in initiating immune responses, particularly in the context of inflammation. However, an excessive inflammation can detrimentally affect the immune homeostasis Thus, it is important to regulate TLR signaling pathways appropriately. Gingerenone A (GIA), a bioactive compound derived from ginger, has garnered significant attention due to its potential anti-inflammatory properties. In this study, we investigate modulatory effects of GIA on TLR signaling pathways. Results showed that GIA effectively suppressed TLR-mediated inflammatory responses by modulating key signaling molecules such as nuclear factor kappa B and interferon regulatory factor 3. These results indicate that GIA is a novel regulator of TLR signaling, offering promising avenues for the development of new anti-inflammatory agents.

Geniposide attenuates influenza virus-induced pneumonia by regulating inflammatory cytokines production. Evidences to elucidate the followed pathway

BackgroundInfluenza virus-induced pneumonia (IVP) is an infectious pulmonary disease characterized by exacerbated pulmonary inflammation caused by invasion of the influenza virus. IVP continues to threaten public health due to its high morbidity and mortality rates. Geniposide is one of the major bioactive constituents of G. jasminoides, which exerts antiviral and anti-inflammatory effects on influenza A virus (IAV) infection. PurposeTo investigate therapeutic effects and comprehensive mechanisms of geniposide on IAV infection and subsequent pneumonia. MethodsICR mice were infected intranasally with H1N1 (A/FM/1/47) to detect the anti-IAV activity of geniposide. Proteomics combined with function-integrated analysis were conducted to gain insight into the comprehensive mechanisms of geniposide. Subsequently, western blot was used to detect the phosphorylation of signal transducer and activator of transcription 1 (STAT1), signal transducer and activator of transcription 2 (STAT2), Interferon regulatory factor 9 (IRF9) and Janus kinase 1 (JAK1) in Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway in lung tissue. Finally, RT-qPCR was used to detect the levels of interleukin 6 (IL-6), interleukin 17 (IL-17), interferon-γ (IFN-γ) and the STAT1 inhibitor (fludarabine) was used to verify the targeting between STAT1 and geniposide in RAW cells. ResultsGeniposide could significantly reduce the lung index, diminish lung pathology, decrease the virus loads and the inflammatory cytokines expression induced by IAV infection. A total of 411 differentially expressed proteins were identified among control, model, and geniposide-treated group in proteomic analysis. According to function-integrated analysis, 15 KEGG pathways were enriched and divided into 9 groups (modules), including influenza A, NOD-like receptor signaling, RIG-I-like receptor signaling, and so on. Among these modules, the most intensely interacting module pair was the NOD-like receptor signaling and influenza A, in which STAT1 and STAT2 acted as hubs with critical bridgeness role in the target network of geniposide. This indicated that geniposide may mitigate inflammation and alleviate IVP by JAK/STAT signaling pathways. Moreover, validation experiments confirmed that geniposide can significantly inhibit STAT1 and STAT2 phosphorylation as well as down-regulated expression of IL-6, IFN-γ and IL-17 in lung. Furthermore, when RAW cells were treated with the STAT1 inhibitor (fludarabine), the inhibitory effect of geniposide on IFN-γ and IL-6 was attenuated significantly. ConclusionsGeniposide can attenuate IAV-induced pneumonia by regulating inflammatory cytokines production through the JAK/STAT pathway.

Sulforaphane improves post-resuscitation myocardial dysfunction by inhibiting cardiomyocytes ferroptosis via the Nrf2/IRF1/GPX4 pathway

BackgroundFerroptosis is an important type of cell death contributing to myocardial dysfunction induced by whole body ischemia reperfusion following cardiac arrest (CA) and resuscitation. Sulforaphane (SFN), known as the activator of the nuclear factor E2-related factor 2 (Nrf2), has been proven to effectively alleviate regional myocardial ischemia reperfusion injury. The present study was designed to investigate whether SFN could improve post-resuscitation myocardial dysfunction by inhibiting cardiomyocytes ferroptosis and its potential regulatory mechanism. Methods and resultsAn in vivo pig model of CA and resuscitation was established. Hypoxia/reoxygenation (H/R)-stimulated AC16 cardiomyocytes was constructed as an in vitro model to simulate the process of CA and resuscitation. In vitro experiment, SFN reduced ferroptosis-related ferrous iron, lipid reactive oxygen species, and malondialdehyde, increased glutathione, and further promoted cell survival after H/R stimulation in AC16 cardiomyocytes. Mechanistically, the activation of Nrf2 with the SFN decreased interferon regulatory factor 1 (IRF1) expression, then reduced its binding to the promoter of glutathione peroxidase 4 (GPX4), and finally recovered the latter’s transcription after H/R stimulation in AC16 cardiomyocytes. In vivo experiment, SFN reversed abnormal expression of IRF1 and GPX4, inhibited cardiac ferroptosis, and improved myocardial dysfunction after CA and resuscitation in pigs. ConclusionsSFN could effectively improve myocardial dysfunction after CA and resuscitation, in which the mechanism was potentially related to the inhibition of cardiomyocytes ferroptosis through the regulation of Nrf2/IRF1/GPX4 pathway.

SGLT2 inhibitor promotes ketogenesis to improve MASH by suppressing CD8+ T cell activation

During the progression of metabolic dysfunction-associated steatohepatitis (MASH), the accumulation of auto-aggressive CD8+ Tcells significantly contributes to liver injury and inflammation. Empagliflozin (EMPA), a highly selective inhibitor of sodium-glucose co-transporter 2 (SGLT2), exhibits potential therapeutic benefits for liver steatosis; however, the underlying mechanism remains incompletely elucidated. Here, we found that EMPA significantly reduced the hepatic accumulation of auto-aggressive CD8+ Tcells and lowered granzyme B levels in mice with MASH. Mechanistically, EMPA increased β-hydroxybutyric acid by promoting the ketogenesis of CD8+ Tcells via elevating 3-hydroxybutyrate dehydrogenase 1 (Bdh1) expression. The β-hydroxybutyric acid subsequently inhibited interferon regulatory factor 4 (Irf4), which is crucial for CD8+ Tcell activation. Furthermore, the ablation of Bdh1 in Tcells aggravated the manifestation of MASH and hindered the therapeutic efficacy of EMPA. Moreover, a case-control study also showed that SGLT2 inhibitor treatment repressed CD8+ Tcell infiltration and improved liver injury in patients with MASH. In summary, our study indicates that SGLT2 inhibitors can target CD8+ Tcells and may be an effective strategy for treating MASH.

Exploring expression levels of the cGAS-STING pathway genes in peripheral blood mononuclear cells of spinal tuberculosis patients

BackgroundThis study aimed to investigate the differential expression levels of the cGAS-STING pathway in peripheral blood mononuclear cells (PBMCs) of spinal tuberculosis (TB) patients with different progression and its feasibility as a diagnostic marker.MethodsPeripheral blood and medical records of 25 patients with spinal TB and 10 healthy individuals, were prospectively collected and analyzed. PBMCs and serum were extracted from peripheral blood and the expression levels of the cGAS-STING pathway in PBMCs were measured by real-time PCR (RT-PCR) and serum interferon β (IFN-β) expression levels were measured by enzyme-linked immunosorbent assay (ELISA). The expression of Interferon regulatory Factor 3 (IRF3) in PBMCs was measured using western blot. Statistical analysis was performed using the SPSS 26.0 statistical package.ResultsThe results showed that the expression level of the TANK-binding kinase 1 (TBK1) and IRF3 was significantly higher in PBMCs (P < 0.05), in patients with active lesions than in patients with stable lesions. The serum concentration of IFN-β was significantly higher in patients with active lesions (P = 0.028). Compared with healthy individuals, the expression level of the cGAS-STING pathway was elevated in PBMCs of TB patients (P < 0.05), and the difference in the expression level of IFN-β was not statistically significant (P > 0.05), and the serum IFN-β concentration was elevated (P < 0.05). The calculated AUC values for TBK1 and IRF3 in PBMCs, IFN-β in serum and erythrocyte sedimentation rate (ESR) to distinguish between patients with active and stable lesions were 0.732, 0.714, 0.839, and 0.714 respectively.ConclusionsThe expression level of TBK1 and IRF3 in PBMCs, and IFN-β in the serum of patients with spinal TB is positively correlated with disease activity. TBK1 has higher specificity and IFN-β in serum has higher sensitivity when used to differentiate between patients with active and stable lesions.