Interleukin-1 Receptor-associated Kinase Research Articles

Preventive effect of total flavonoids of Trollius altaicus on a chronic obstructive pulmonary disease rat model based on the TLR4/NF-κB pathway.

BackgroundChronic obstructive pulmonary disease (COPD) is diagnosed based on the clinical symptoms, risk factors, and pulmonary function tests. Exposure to cigarette smoke (CS), microbial infection stimulates monocytes and macrophages to rapidly synthesise and release inflammatory factors. A previous study of Trollius altaicus (TAF) revealed that it had significant anti-inflammatory and anti-oxidation effects on a pneumonia disease. Based on recent studies of the inflammatory pathway of toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB), we will explore the influence of TAF on COPD.MethodsWistar rats were randomly divided into blank control group, Model Group, low-dose TAF + model group, middle-dose TAF + model group, high-dose TAF + model group, positive control + model group. Except for the blank control group, COPD inflammation models were established in all groups by CS poisoning and LPS. Prior to the daily poisoning, 125 mg/kg, 250 mg/kg, and 500 mg/kg of TAF were administered by gavage in the low-, middle-, and high-dose groups, respectively, and dexamethasone solution (1 mg/kg, once daily) was administered continuously in the positive control group on the last 5 days of modelling. General signs, lung function indices, lung imaging results, complete blood count, lung histopathological changes, inflammatory factors in the alveolar lavage fluid, relative expressions of TLR4, IκB kinase α (IKKα), p65, as well as IL-1β proteins and their mRNA relative expressions were measured and compared between each group.ResultsCompared with the blank control group, TAF effectively reduced pulmonary parenchymal oedema (wet-to-dry ratio) and respiratory secretions. It also significantly delayed lung function injury. Lung X-ray imaging and haematoxylin and eosin staining. Blood routine examination results showed that TAF effectively inhibited the increase of white blood cell, lymphocyte, and eosinophil counts, decreased the release of inflammatory cytokines [IL-1β, IL-6, IL-8, TNF-α, and transforming growth factor-1β (TGF-1β)] and promoted the release of IL-10. It also inhibited the relative expressions of TLR4, IKKα, p65, IL-1β proteins, as well as IL-1 receptor-associated kinase (IRAK-1), IKKɑ, p65, and IL-1β mRNA.ConclusionsEarly intervention of TAF can reduce the occurrence of COPD, reduce the development of inflammation via TLR/NF-κB pathway, and provide reference for further study of the medicinal value of TAF.

Loss of NLRP3 increases bacterial cystitis via IRAKM.

BackgroundWe attempted to characterize the molecular mechanisms that underpin urinary tract infections using a mouse model of cystitis induced by bacterial infection in a background of NOD-, LRR- and PYD domains-containing protein (NLRP3) deficiency.MethodsMale NLRP3 knockout (NLRP3−/−) and control mice (12 weeks old) were intraurethrally inoculated with 2×108 Escherichia coli (E. coli) and euthanized 1, 3, and 7 days later to assess the degree of bladder infection. Immunohistochemical detection of NLRP3 and interleukin-1 receptor-associated kinase M (IRAKM) was performed. Quantitative PCR analysis was performed to analyze the expression of interleukin (IL)-1β and tumor necrosis factor (TNF)-α.ResultsBladder infection was observed in control mice 1 day after inoculation with E. coli. The infection had disappeared by day 7. IL-1β and TNF-α levels were lower 1 day after injection but higher on days 3 and 7 in the NLRP3−/− group compared with the control mice (P<0.05). Expression of NLRP3 and IRAKM in wild-type (WT) group were significantly decreased 1 day post infection, and by day 7 were increased back to similar level on day 0. On the contrary, in the NLRP3−/− group, IRAKM was significantly lower than WT mice on day 0 and were significantly decreased by day 7.ConclusionsDeficiency of NLRP3 expression in NLRP3−/− mice contributes to the pathogenesis of chronic inflammation associated with cystitis through IRAKM.

The constitutive activation of TLR4-IRAK1- NFκB axis is involved in the early NLRP3 inflammasome response in peripheral blood mononuclear cells of Rett syndrome patients

Rett syndrome (RTT), a devastating neurodevelopmental disorder, is caused in 95% of the cases by mutations in the X-chromosome-localized MECP2 gene. To date, RTT is considered a broad-spectrum disease, due to multisystem disturbances affecting patients, associated with mitochondrial dysfunctions, subclinical inflammation and an overall OxInflammatory status.Inflammasomes are multi-protein complexes crucially involved in innate immune responses against pathogens and oxidative stress mediators. The assembly of NLRP3:ASC inflammasome lead to pro-caspase 1 activation, maturation of interleukins (IL)-1β and 18 and proteolytic cleavage of Gasdermin D leading eventually to pyroptosis and systemic inflammation.The possible de-regulation of this system, in parallel with upstream nuclear factor (NF)-κB p65 pathway, were analyzed in peripheral blood mononuclear cells (PBMCs) and plasma isolated from RTT patients and matching controls.RTT PBMCs showed a constitutive activation of the axis TLR4 (Toll-like receptor 4)-IRAK1 (interleukin-1 receptor associated kinase 1)-NF-κB p65, together with augmented ROS generation and enhanced IL-18 mRNA levels and NLRP3:ASC co-localization. The deregulation of inflammasome components was even found in THP-1 cells silenced for MECP2 and importantly, in plasma compartment of RTT subjects, from the earliest stages of the pathology or in correlation with the severity of MeCP2 mutations.Taken together, these data provide new insights into the mechanisms involved in RTT sub-clinical inflammatory status present in RTT patients, thus helping to reveal new targets for future therapeutic approaches.

C-Myc participates in high glucose-mediated endothelial inflammation via upregulation of IRAK1 expression in diabetic nephropathy

Diabetic nephropathy (DN) is a common vascular complication of diabetes. Endothelial adhesion molecules are involved in physiopathology of DN. Interleukin-1 receptor-associated kinase 1 (IRAK1) and c-Myc participate in inflammation in DN. We hypothesized c-Myc modulates IRAK1 expression, contributing to hyperglycemia-mediated endothelial inflammation. The expression of endothelial adhesion molecules and IRAK1 were increased in glomerular endothelium of DN patients and rats. Our cellular experiments indicated high glucose-induced endothelial cell inflammation was inhibited by si-IRAK1. Additionally, high glucose increased c-Myc expression. si-c-Myc inhibited high glucose-mediated increase of IRAK1 levels and endothelial cell inflammation. c-Myc overexpression-mediated endothelial cell inflammation was counteracted by si-IRAK1. c-Myc also interacted with lysine methyltransferase 5A (KMT5A). Furthermore, high glucose decreased KMT5A expression and histone H4 lysine 20 methylation (H4K20me1). KMT5A upregulation decreased high glucose-mediated increase of IRAK1 levels as well as endothelial inflammation. KMT5A silencing-mediated endothelial inflammation was reversed by si-IRAK1. Mechanistic research indicated that c-Myc and H4K20me1 occupied IRAK1 promoter region. KMT5A silencing augmented the active action of c-Myc on IRAK1 levels. Our in vivo experiments represented KMT5A is downregulated and c-Myc is upregulated in DN patients and rats. KMT5A interacts with c-Myc to modulate IRAK1 expression, thus contributing to hyperglycemia-mediated endothelial inflammation in DN.

Eliminating chronic myeloid leukemia stem cells by IRAK1/4 inhibitors

Leukemia stem cells (LSCs) in chronic myeloid leukemia (CML) are quiescent, insensitive to BCR-ABL1 tyrosine kinase inhibitors (TKIs) and responsible for CML relapse. Therefore, eradicating quiescent CML LSCs is a major goal in CML therapy. Here, using a G0 marker (G0M), we narrow down CML LSCs as G0M- and CD27- double positive cells among the conventional CML LSCs. Whole transcriptome analysis reveals NF-κB activation via inflammatory signals in imatinib-insensitive quiescent CML LSCs. Blocking NF-κB signals by inhibitors of interleukin-1 receptor-associated kinase 1/4 (IRAK1/4 inhibitors) together with imatinib eliminates mouse and human CML LSCs. Intriguingly, IRAK1/4 inhibitors attenuate PD-L1 expression on CML LSCs, and blocking PD-L1 together with imatinib also effectively eliminates CML LSCs in the presence of T cell immunity. Thus, IRAK1/4 inhibitors can eliminate CML LSCs through inhibiting NF-κB activity and reducing PD-L1 expression. Collectively, the combination of TKIs and IRAK1/4 inhibitors is an attractive strategy to achieve a radical cure of CML.

Extracellular HSP90α Induces MyD88-IRAK Complex-Associated IKKα/β−NF-κB/IRF3 and JAK2/TYK2−STAT-3 Signaling in Macrophages for Tumor-Promoting M2-Polarization

M2-polarization and the tumoricidal to tumor-promoting transition are commonly observed with tumor-infiltrating macrophages after interplay with cancer cells or/and other stroma cells. Our previous study indicated that macrophage M2-polarization can be induced by extracellular HSP90α (eHSP90α) secreted from endothelial-to-mesenchymal transition-derived cancer-associated fibroblasts. To extend the finding, we herein validated that eHSP90α-induced M2-polarized macrophages exhibited a tumor-promoting activity and the promoted tumor tissues had significant increases in microvascular density but decreases in CD4+ T-cell level. We further investigated the signaling pathways occurring in eHSP90α-stimulated macrophages. When macrophages were exposed to eHSP90α, CD91 and toll-like receptor 4 (TLR4) functioned as the receptor/co-receptor for eHSP90α binding to recruit interleukin (IL)-1 receptor-associated kinases (IRAKs) and myeloid differentiation factor 88 (MyD88), and next elicited a canonical CD91/MyD88–IRAK1/4–IκB kinase α/β (IKKα/β)–nuclear factor-κB (NF-κB)/interferon regulatory factor 3 (IRF3) signaling pathway. Despite TLR4-MyD88 complex-associated activations of IKKα/β, NF-κB and IRF3 being well-known as involved in macrophage M1-activation, our results demonstrated that the CD91-TLR4-MyD88 complex-associated IRAK1/4−IKKα/β−NF-κB/IRF3 pathway was not only directly involved in M2-associated CD163, CD204, and IL-10 gene expressions but also required for downregulation of M1 inflammatory cytokines. Additionally, Janus kinase 2 (JAK2) and tyrosine kinase 2 (TYK2) were recruited onto MyD88 to induce the phosphorylation and activation of the transcription factor signal transducer and activator of transcription-3 (STAT-3). The JAK2/TYK2−STAT-3 signaling is known to associate with tumor promotion. In this study, the MyD88−JAK2/TYK2−STAT-3 pathway was demonstrated to contribute to eHSP90α-induced macrophage M2-polarization by regulating the expressions of M1- and M2-related genes, proangiogenic protein vascular endothelial growth factor, and phagocytosis-interfering factor Sec22b.

Long non-coding RNA lncC11orf54-1 modulates neuroinflammatory responses by activating NF-\u03baB signaling during meningitic Escherichia coli infection

Escherichia coli is the most common gram-negative pathogenic bacterium causing meningitis. It penetrates the blood–brain barrier (BBB) and activates nuclear factor kappa B (NF-κB) signaling, which are vital events leading to the development of meningitis. Long non-coding RNAs (lncRNAs) have been implicated in regulating neuroinflammatory signaling, and our previous study showed that E. coli can induce differential expression of lncRNAs, including lncC11orf54-1, in human brain microvascular endothelial cells (hBMECs). The hBMECs constitute the structural and functional basis for the BBB, however, it is unclear whether lncRNAs are involved in the regulation of inflammatory responses of hBMECs during meningitic E. coli infection. In this study, we characterized an abundantly expressed lncRNA, lncC11orf54-1, which was degraded by translocated coilin to produce mgU2-19 and mgU2-30 in hBMECs during E. coli infection. Functionally, lncC11orf54-1-originated non-coding RNA mgU2-30 interacted with interleukin-1 receptor-associated kinase 1 (IRAK1) to induce its oligomerization and autophosphorylation, thus promoting the activation of NF-κB signaling and facilitating the production of pro-inflammatory cytokines. In summary, our study uncovers the involvement of lncC11orf54-1 in IRAK1–NF-κB signaling, and it functions as a positive regulator of inflammatory responses in meningitic E. coli-induced neuroinflammation, which may be a valuable therapeutic and diagnostic target for bacterial meningitis.

Tripeptides from Allium subhirsitum L. extracts: Pharmacokinetics properties, toxicity prediction and in silico study against SARS-CoV-2 enzymes and pro-inflammatory proteins.

Developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities is urgently needed to combat emerging human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since no available clinically antiviral drugs have been approved to eradicate COVID-19 as of the writing of this report, this study aimed to investigate bioactive short peptides from Allium subhirsutum L. (Hairy garlic) extracts identified through HR-LC/MS analysis that could potentially hinder the multiplication cycle of SARS-CoV-2 via molecular docking study. The obtained promising results showed that the peptides (Asn-Asn-Asn) possess the highest binding affinities of -8.4 kcal/mol against S protein, (His-Phe-Gln) of -9.8 kcal/mol and (Gln-His-Phe) of -9.7 kcal/mol towards hACE2, (Thr-Leu-Trp) of -10.3 kcal/mol and (Gln-Phe-Tyr) of -9.8 kcal/mol against furin. Additionally, the identified peptides show strong interactions with the targeted and pro-inflammatory ranging from -8.1 to -10.5 kcal/mol for NF-κB-inducing kinase (NIK), from -8.2 to -10 kcal/mol for phospholipase A2 (PLA2), from -8.0 to -10.7 kcal/mol for interleukin-1 receptor-associated kinase 4 (IRAK-4), and from -8.6 to -11.6 kcal/mol for the cyclooxygenase 2 (COX2) with Gln-Phe-Tyr model seems to be the most prominent. Results from pharmacophore, drug-likeness and ADMET prediction analyses clearly evidenced the usability of the peptides to be developed as an effective drug, beneficial for COVID-19 treatment.

Elucidation of the hepatoprotective effect and mechanism of Melastoma dodecandrum Lour. based on network pharmacology and experimental validation

To systematically explore the effect and mechanism of melastomatis dodecandri herba ( Melastoma dodecandrum Lour.) in the treatment of hepatitis based on network pharmacology. We evaluated the hepatoprotective effects of M. dodecandrum in concanavalin A (Con A)-induced hepatitis in mice by assessing survival rate, histological analysis, serum transaminases, and related cytokines. Then the mechanism of action was predicted by a network pharmacology-based strategy. Based on the results, we measured the hepatic expression of related genes at mRNA level and proteins related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and nuclear factor-kappa B (NF-кB) pathways. Our study results clearly demonstrated that M. dodecandrum pretreatment significantly alleviated liver injury. This was demonstrated by an increase in survival rate, decreased severity of liver damage, and reduced serum transaminase levels compared with those in the Con A group. Moreover, M. dodecandrum significantly reduced the serum levels of tumor necrosis factor-α, interleukin-6, and interferon-γ and increased the liver levels of superoxide dismutase, which indicated that M. dodecandrum exhibits anti-inflammatory and antioxidant activities. On the basis of network pharmacology, 50 nodes were selected as major hubs based on their topological importance. Pathway enrichment analyses indicated that the putative targets of M. dodecandrum mostly participate in various pathways associated with the anti-inflammation response, which implies the underlying mechanism by which M. dodecandrum acts on hepatitis. Real-time fluorescent quantitative PCR analysis showed that M. dodecandrum downregulates the mRNA expression of interleukin-6, Toll-like receptor 7, interleukin-1 receptor-associated kinase-4, NF-кB and tumor necrosis factor-α in liver tissues. Western blotting showed that M. dodecandrum pretreatment protected against inflammation through activating the PI3K-Akt pathway by upregulating phosphorylated Akt (p-Akt) expression and suppressing NF-кB activation by inhibiting the phosphorylation of IKK, IκBα, and p65. The present work demonstrated the hepatoprotective effects of M. dodecandrum by regulating the PI3K/Akt and NF-кB pathways in Con A-induced mice, which provide insights into the treatment of hepatitis using M. dodecandrum .

Interleukin-1 receptor-associated kinase 4 (IRAK4) in the nucleus accumbens regulates opioid-seeking behavior in male rats

Opioid addiction remains a severe health problem. While substantial insights underlying opioid addiction have been yielded from neuron-centric studies, the contribution of non-neuronal mechanisms to opioid-related behavioral adaptations has begun to be recognized. Toll-like receptor 4 (TLR4), a pattern recognition receptor, has been widely suggested in opioid-related behaviors. Interleukin-1 receptor-associated kinase 4 (IRAK4) is a kinase essential for TLR4 responses, However, the potential role of IRAK4 in opioid-related responses has not been examined. Here, we explored the role of IRAK4 in cue-induced opioid-seeking behavior in male rats. We found that morphine self-administration increased the phosphorylation level of IRAK4 in the nucleus accumbens (NAc) in rats; the IRAK4 signaling remained activated after morphine extinction and cue-induced reinstatement test. Both systemic and local inhibition of IRAK4 in the NAc core attenuated cue-induced morphine-seeking behavior without affecting the locomotor activity and cue-induced sucrose-seeking. In addition, inhibition of IRAK4 also reduced the cue-induced reinstatement of fentanyl-seeking. Our findings suggest an important role of IRAK4 in opioid relapse-like behaviors and provide novel evidence in the association between innate immunity and drug addiction.

Creating Awareness for Primary Immunodeficiencies in Japan.

Primary immunodeficiency (PID) is primarily characterized by susceptibility to infectious diseases. In addition, patients with some type of PID are prone to develop autoimmune, autoinflammatory, or malignant diseases. Therefore, the term, inborn errors of immunity (IEI), has been more used rather than PID. In recent years, the number of diseases which belong to PID has been increasing. There were approximately 110 diseases in the report of International Union of Immunological Societies in 1999. Since then, the number increased to 430 diseases in the latest IUIS report in 2019. We conducted PID nationwide survey in Japan for 3 times in the last 15 years. These studies were focused on incidence and complications of PID, the clinical course of viral infection, and methods to prevent infectious diseases in PID patients. For the awareness of PID, it is essential to know the general and fundamental information of PID patients. Needless to say, we need it to offer appropriate medical services for PID patients. Moreover, chances to provide answers to the questionnaires and seeing the results of the analysis should contribute to the awareness of PID among doctors. In this review, I am going to summarize the results of 3 nationwide survey in Japan, and pick up interleukin-1 receptor-associated kinase 4 (IRAK4) deficiency as an example for creating awareness for its appropriate management.

Inhibition of IL-1 Receptor-Associated Kinase 1 Decreases Murine Acute Graft-versus-Host Disease While Preserving the Graft-versus-Lymphoma Effect

Activation of antigen-presenting cells (APCs) is crucial in initiating inflammation and alloreaction during acute graft-versus-host disease (aGVHD), a common life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT). IL-1 receptor-associated kinase 1 (IRAK1) regulates the activation of APCs in inflammatory settings, and inhibition of IRAK1 might decrease APC activation and aGVHD. This study was conducted to explore the impact of IRAK1 inhibition on APC activation and aGVHD in mice. We administered a selective IRAK1 inhibitor, Jh-X-119-01, to recipient mice undergoing allo-HCT or co-challenged by A20 lymphoma cells. We assessed aGVHD and the graft-versus-lymphoma (GVL) effect. T cell and APC activations were analyzed as well. Jh-X-119-01 was associated with increased survival and decreased aGVHD of recipients. Jh-X-119-01 decreased the proportions of Th1 cells and Tc1 cells in the aGVHD model and in the in vitro mixed lymphocyte reaction. The IRAK1 inhibitor reduced production of TNFα and IFNγ in macrophages of recipient mice. In in vitro cultured bone marrow dendritic cells (BMDCs), Jh-X-119-01 decreased productions of inflammatory cytokines, reduced expression levels of CD80 and CD86, and decreased protein levels of antiapoptotic Bcl2 and phosphorylated NF-κB p65. RNA-seq analysis showed that Jh-X-119-01 had an impact on several pathophysiologic processes of BMDCs, including reduction of GVHD-related genes and regulation of helper T cell differentiation. Importantly, IRAK1 inhibition did not impair cytotoxic function of T cells or the allo-HCT-related GVL effect against A20 lymphoma cells. In addition, the IRAK1 inhibitor did not retard recovery of hematopoietic cells in blood or bone marrow. Our findings show that selective IRAK1 inhibition ameliorates murine aGVHD but preserves the GVL effect. Our findings may have implications for the use of an IRAK1 inhibitor in allo-HCT.

Polygonatum sibiricum polysaccharides (PSP) improve the palmitic acid (PA)-induced inhibition of survival, inflammation, and glucose uptake in skeletal muscle cells

ABSTRACT Polygonatum sibiricum polysaccharides (PSP) can decrease the levels of fasting blood glucose, total cholesterol, and triglyceride (TG) in hyperlipidemic and diabetic animals. It can also reduce inflammatory cytokines and promote glucose uptake in adipocytes. However, the underlying molecular mechanisms of PSP in improving insulin resistance (IR) in skeletal muscle remain unclear. In this study, palmitic acid (PA) induced an IR model in L6 myotubes. After treatment, cell proliferation was measured using the CCK8. miR-340-3p, glucose transporter 4 (GLUT-4), and interleukin-1 receptor-associated kinase 3 (IRAK3) expression was measured by qRT-PCR. IRAK3 protein levels were measured by Western blotting. Glucose in the cell supernatant, TG concentration in L6 myotubes, and the levels of IL-1β, IL-6, and TNF-α were measured by an ELISA. We found that cell survival, glucose uptake, and GLUT-4 expression in L6 myotubes were significantly suppressed, while lipid accumulation and inflammatory factor levels were enhanced by PA stimulation. Furthermore, PSP treatment markedly alleviated these effects. Interestingly, PSP also significantly reduced the upregulated expression of miR-340-3p in the L6 myotube model of IR. Furthermore, overexpression of miR-340-3p reversed the beneficial effects of PSP in the same IR model. miR-340-3p can bind to the 3′-untranslated regions of IRAK3. Additionally, PA treatment inhibited IRAK3 expression, whereas PSP treatment enhanced IRAK3 expression in L6 myotubes. Additionally, miR-340-3p also inhibited IRAK3 expression in L6 myotubes. Taken together, PSP improved inflammation and glucose uptake in PA-treated L6 myotubes by regulating miR-340-3p/IRAK3, suggesting that PSP may be suitable as a novel therapeutic agent for IR.

IRAK1-regulated IFN-\u03b3 signaling induces MDSC to facilitate immune evasion in FGFR1-driven hematological malignancies

BackgroundStem Cell leukemia/lymphoma syndrome (SCLL) presents as a myeloproliferative disease which can progress to acute myeloid leukemia and is associated with the coincident development of B-cell and T-cell lymphomas. SCLL is driven by the constitutive activation of fibroblast growth factor receptor-1 (FGFR1) as a result of chromosome translocations with poor outcome. Mouse models have been developed which faithfully recapitulate the human disease and have been used to characterize the molecular genetic events that are associated with development and progression of the disease.MethodsCRISPR/Cas9 approaches were used to generate SCLL cells null for Interleukin receptor associated kinase 1 (IRAK1) and interferon gamma (IFNG) which were introduced into syngeneic hosts through tail vein injection. Development of the disease and changes in immune cell composition and activity were monitored using flow cytometry. Bead-based immunoassays were used to compare the cytokine and chemokine profiles of control and knock out (KO) cells. Antibody mediated, targeted depletion of T cell and MDSCs were performed to evaluate their role in antitumor immune responses.ResultsIn SCLL, FGFR1 activation silences miR-146b-5p through DNMT1-mediated promoter methylation, which derepresses the downstream target IRAK1. IRAK1 KO SCLL cells were xenografted into immunocompetent syngeneic mice where the typical rapid progression of disease was lost and the mice remained disease free. IRAK1 in this system has no effect on cell cycle progression or apoptosis and robust growth of the KO cells in immunodeficient mice suggested an effect on immune surveillance. Depletion of T-cells in immunocompetent mice restored leukemogenesis of the KO cells, and tumor killing assays confirmed the role of T cells in tumor clearance. Analysis of the immune cell profile in mice transplanted with the IRAK1 expressing mock control (MC) cells shows that there is an increase in levels of myeloid-derived suppressor cells (MDSCs) with a concomitant decrease in CD4+/CD8+ T-cell levels. MDSC suppression assays and depletion experiments showed that these MDSCs were responsible for suppression of the T cell mediated leukemia cell elimination. Immuno-profiling of a panel of secreted cytokines and chemokines showed that activation of IFN-γ is specifically impaired in the KO cells. In vitro and in vivo expression assays and engraftment with interferon gamma receptor-1 (IFNGR1) null mice and IFNG KO SCLL cells, showed the leukemia cells produced IFN-γ directly participating in the induction of MDSCs to establish immune evasion. Inhibition of IRAK1 using pacritinib suppresses leukemogenesis with impaired induction of MDSCs and attenuated suppression of CD4+/CD8+ T-cells.ConclusionsIRAK1 orchestrates a previously unknown FGFR1-directed immune escape mechanism in SCLL, through induction of MDSCs via regulation of IFN-γ signaling from leukemia cells, and targeting IRAK1 may provide a means of suppressing tumor growth in this syndrome by restoring immune surveillance.

Effects of adenovirus-mediated knockdown of IRAK4 on synovitis in the osteoarthritis rabbit model

BackgroundThe use of interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor as a treatment for the inflammatory joint disease is a promising method. However, its underlying mechanism in osteoarthritis (OA) remains unclear. The purpose of this study is to look into the effects of adenovirus-mediated knockdown of IRAK4 on synovitis in the OA rabbit model.MethodsAd-shIRAK4 was injected two weeks after anterior cruciate ligament resection. Six weeks later, the rabbits were killed. The expression of IRAK4, TNFR-associated factor 6(TRAF6), TGF-activated kinase 1(TAK1), p-IKB kinase (p-IKK), p-nuclear factor kappa-B (p-NFκB), p38, and p-p38 in the synovial membrane was detected by western blot, qRT-PCR, and immunohistochemistry analysis. Immunohistochemistry was to detect the expression of IRAK4 proteins in articular cartilage. H&E staining was to assess the pathological changes of synovium and cartilage. The levels of interleukin (IL)-1β, tumor necrosis factor-α(TNF-α), and MMP-13 in the synovial fluid were measured by ELISA. X-ray and micro-computerized tomography (μCT) scans were used to assess knee joint conditions and microstructure of subchondral bone.ResultsIRAK4 expression levels in synovial tissues of the OA model group exhibited a significant upward trend. Ad-shIRAK4 significantly reduced IRAK4 mRNA expression in synovium tissues. Notably, Ad-shIRAK4 suppressed the Toll-like receptor/interleukin-1 receptor (TLR/IL-1R) signaling. In addition, in the Ad-shIRAK4 treatment group, we can see less inflammatory cell infiltration and reduced hyperplasia and angiogenesis. The levels of IL-1β, TNF-α, and MMP-13 in the synovial fluid in the OA model group were significantly higher than that in the control group, which were reduced by Ad-shIRAK4 treatment. Finally, Results of HE stains, immunohistochemistry, and μCT showed that Ad-shIRAK4 treatment has a protective effect on cartilage damage.ConclusionsIRAK4 is significantly upregulated in the synovium from the osteoarthritis rabbit model. In addition, Ad-shIRAK4 reduced the expression of IRAK4 and suppressed TLR/IL-1R signaling in the synovium from the osteoarthritis rabbit model. Ad-shIRAK4 could alleviate synovitis and cartilage degradation in the osteoarthritis rabbit model, and thus alleviate the symptoms of OA and prevent the progression of OA.Graphical abstract

Toll-like Receptor Signaling Inhibitory Peptide Improves Inflammation in Animal Model and Human Systemic Lupus Erythematosus.

Toll-like receptors (TLRs) play a major role in the innate immune system. Several studies have shown the regulatory effects of TLR-mediated pathways on immune and inflammatory diseases. Dysregulated functions of TLRs within the endosomal compartment, including TLR7/9 trafficking, may cause systemic lupus erythematosus (SLE). TLR signaling pathways are fine-tuned by Toll/interleukin-1 receptor (TIR) domain-containing adapters, leading to interferon (IFN)-α production. This study describes a TLR inhibitor peptide 1 (TIP1) that primarily suppresses the downstream signaling mediated by TIR domain-containing adapters in an animal model of lupus and patients with SLE. The expression of most downstream proteins of the TLR7/9/myeloid differentiation factor 88 (MyD88)/IFN regulatory factor 7 signaling was downregulated in major tissues such as the kidney, spleen, and lymph nodes of treated mice. Furthermore, the pathological analysis of the kidney tissue confirmed that TIP1 could improve inflammation in MRL/lpr mice. TIP1 treatment downregulated many downstream proteins associated with TLR signaling, such as MyD88, interleukin-1 receptor-associated kinase, tumor necrosis factor receptor-associated factor 6, and IFN-α, in the peripheral blood mononuclear cells of patients with SLE. In conclusion, our data suggest that TIP1 can serve as a potential candidate for the treatment of SLE.

Proteomic analysis of differential expression of lung proteins in response to highly pathogenic avian influenza virus infection in chickens

Elucidation of the molecular pathogenesis underlying virus-host interactions is important for the development of new diagnostic and therapeutic strategies against highly pathogenic avian influenza (HPAI) virus infection in chickens. However, the pathogenesis of HPAI virus in chickens is not completely understood. To identify the intracellular signaling pathways and critical host proteins associated with influenza pathogenesis, we analyzed the lung proteome of a chicken infected with HPAI H5N1 virus (A/duck/India/02CA10/2011/Agartala). Mass spectrometry data sets were searched against the chicken UniProt reference database. At the local false discovery rate level of 5%, a total of 3313 proteins with the presence of at least one unique peptide were identified in the chicken lung proteome datasets. Differential expression analysis of these proteins showed that 247 and 1754 proteins were downregulated at 12 h and 48 h postinfection, respectively. We observed expression of proteins of the predominant signaling pathways, including Toll-like receptors (TLRs), retinoic acid-inducible gene I-like receptors (RLRs), NOD-like receptors (NLRs), and JAK-STAT signaling. Activation of these pathways is associated with the cytokine storm effect and thus may be the cause of the severity of HPAI H5N1 infection in chickens. We also observed the expression of myeloid differentiation primary response protein (MyD88), inhibitor of nuclear factor kappa B kinase subunit beta (IKBKB), interleukin 1 receptor associated kinase 4 (IRAK4), RELA proto-oncogene NF-κB subunit (RELA), and mitochondrial antiviral signaling protein (MAVS), which are involved in critical signaling pathways, as well as other, less-commonly identified proteins such as hepatocyte nuclear factor 4 alpha (HNF4A), ELAV-like RNA binding protein 1 (ELAVL1), fibronectin 1 (FN1), COP9 signalosome subunit 5 (COPS5), cullin 1 (CUL1), breast cancer type 1 susceptibility protein (BRCA1), and the FYN proto-oncogene Src family tyrosine kinase (FYN) as main hub proteins that might play important roles in influenza pathogenesis in chickens. In summary, we identified the signaling pathways and the proteomic determinants associated with disease pathogenesis in chickens infected with HPAI H5N1 virus.

MiR-539-5p inhibits the inflammatory injury in septic H9c2 cells by regulating IRAK3

BackgroundMicroRNAs (miRNAs) have been confirmed to play a potential role in sepsis, but little is known about their role in sepsis-induced cardiomyopathy (SIC).MethodsThe model of septic cardiomyopathy was constructed with H9c2 cells induced by lipopolysaccharide (LPS), and the expression of miR-539-5p was detected by qRT-PCR assay. ELISA, CCK-8, EdU TUNEL analysis were performed to evaluate the role of miR-539-5p in inflammation response, viability, proliferation and apoptosis of LPS-treated H9c2 cells. Moreover, miRWalk and TargetScan prediction, and dual-luciferase reporter gene assays were carried out to predict and confirm the target of miR-539-5p. Furthermore, the effects of target on inflammation response, proliferation and apoptosis of LPS-induced H9c2 cells mediated by miR-539-5p was further explored.ResultsThe expression of miR-539-5p was obviously down-regulated in LPS-induced H9c2 cells. In addition, over-expression of miR-539-5p significantly inhibited the inflammation response, promoted viability and proliferation, and suppressed apoptosis of LPS-treated H9c2 cells. Moreover, interleukin-1 receptor-associated kinase 3 (IRAK3) was verified as a target of miR-539-5p by dual-luciferase reporter gene assay. Besides, IRAK3 was highly expressed in H9c2 cells transfected with miR-539-5p inhibitor detected with qRT-PCR and western blot assays. Furthermore, over-expression of IRAK3 partially weakened the effects of miR-539-5p mimic on the inflammation response, proliferation and apoptosis of LPS-induced H9c2 cells.ConclusionsMiR-539-5p potentially plays an important role in the pathogenesis of LPS-induced sepsis by targeting IRAK3, suggesting that miR-539-5p may be a potential new target for the treatment of LPS-induced sepsis.

Preclinical Activity of the Clinical Stage Protein Arginine Methyltransferase 5 (PRMT5) Inhibitor PRT543 in Splicing Mutant Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML)

MDS and AML are generally incurable malignancies that need newer therapeutic options, as the disease-initiating stem cells are not eliminated by conventional therapies. Splicing factor mutations account for approximately 50% of mutations in MDS. Among those are SF3B1 and U2AF1 mutations, which are related to pathogenesis of disease by overactivation of oncogenic pathways, such as Interleukin-1 Receptor-Associated Kinase 4 (IRAK4) signaling. Via activation of IRAK4 and other pathways, spliceosome mutations can lead to a block in differentiation and malignant proliferation. PRMT5 is an enzyme involved in spliceosome complex formation and fidelity and is over-expressed in patients with MDS/AML. The inhibition of PRMT5 may contribute to stem/progenitor cell differentiation rather than aberrant proliferation in an undifferentiated immature state. The objective of this study is to determine the activity of a clinical stage PRMT5 inhibitor, PRT543, in subtypes of MDS/AML using cell lines and primary samples. In preclinical studies PRT543 showed broad antitumor activity in vitro and in vivo (Bhagwat AACR 2020) and is currently under investigation in a Phase I clinical trial in patients with myeloid malignancies.We used a K562 cell line with CRISPR-introduced SF3B1 K700E mutation and isogenic control (K700K) in proliferation and myeloid differentiation assays with PRT543. The SF3B1 K700E mutant cells showed myeloid differentiation after treatment with the PRT543 PRMT5 inhibitor, as assessed by single cell colony assays and flow cytometry, while no substantial effects were observed in controls (K700K). We next evaluated PRMT5 expression in a large set of MDS CD34+ cells and observed substantial overexpression in SF3B1 mutant samples. Primary MDS/AML progenitors were cultured in methylcellulose colony forming unit (CFU) assays and treated with PRT543 at multiple concentrations versus vehicle controls. A majority of the SF3B1 patient samples showed a substantial increase in erythroid differentiation as assessed by colony formation and flow cytometry in the presence of 1nM and 5nM PRT543. In non-SF3B1 mutated patient samples, there was no clear difference in differentiation in the presence of PRT543.We next evaluated whether PRMT5 inhibition led to inhibition of oncogenic IRAK4 pathways. Retention of exon 4 of IRAK4 occurs in splicing mutant MDS and leads to production of an active long IRAK4 isoform. As measured by RNA-seq, PRMT5 inhibition led to decreased retention of exon 4 in IRAK4 transcripts. This decrease in the IRAK4 long form in response to PRT543 treatment was confirmed by immunoblotting, demonstrating reduction of this oncogenic signaling pathway.In summary, PRMT5 inhibition with PRT543 can release a differentiation block in MDS/AML, specifically in splicing mutant samples. PRMT5 inhibition decreases IRAK4-long isoform expression providing a potential mechanism for its activity in splicing factor mutant cases. DisclosuresRuggeri: Prelude Therapeutics: Current Employment, Current equity holder in publicly-traded company. Heiser: Prelude Therapeutics: Current Employment, Current equity holder in publicly-traded company. Scherle: Prelude Therapeutics: Current Employment, Current equity holder in publicly-traded company. Starczynowski: kurome Inc: Consultancy. Verma: Throws Exception: Current equity holder in publicly-traded company; Stelexis: Current equity holder in publicly-traded company; Celgene: Consultancy; Acceleron: Consultancy; Novartis: Consultancy; Stelexis: Consultancy, Current equity holder in publicly-traded company; Eli Lilly: Research Funding; Curis: Research Funding; Medpacto: Research Funding; Incyte: Research Funding; GSK: Research Funding; BMS: Research Funding.

IRAK1 and IRAK4 as emerging therapeutic targets in hematologic malignancies.

Purpose of reviewCell intrinsic and extrinsic perturbations to inflammatory signaling pathways are a hallmark of development and progression of hematologic malignancies. The interleukin 1 receptor-associated kinases (IRAKs) are a family of related signaling intermediates (IRAK1, IRAK2, IRAK3, IRAK4) that operate at the nexus of multiple inflammatory pathways implicated in the hematologic malignancies. In this review, we explicate the oncogenic role of these kinases and review recent therapeutic advances in the dawning era of IRAK-targeted therapy.Recent findingsEmerging evidence places IRAK signaling at the confluence of adaptive resistance and oncogenesis in the hematologic malignancies and solid tissue tumors. Preclinical investigations nominate the IRAK kinases as targetable molecular dependencies in diverse cancers.SummaryIRAK-targeted therapies that have matriculated to early phase trials are yielding promising preliminary results. However, studies of IRAK kinase signaling continue to defy conventional signaling models and raise questions as to the design of optimal treatment strategies. Efforts to refine IRAK signaling mechanisms in the malignant context will inspire deliberate IRAK-targeted drug development and informed combination therapy.