IL-1 Receptor Accessory Protein Research Articles

IL1RAP regulated by PRPRD promotes gliomas progression via inducing neuronal synapse development and neuron differentiation in vitro

BackgroundGlioma is a common fatal brain tumor that affects the central nervous system of the brain and spinal cord. MethodsThis is an original research. The morphology of M059 J cells and U373 cells were detected by microscope, cell neurite outgrowth was observed by immunofluorescence, and the expression of PRPRD and its downstream genes in HMC3 cells, M059 J cells and U373 cells were evaluated and compared with flow cytometry, immunofluorescence and Western blotting assay. ResultsHere we show that the expression of FBP17 on the surface of glioma cells M059 J and U373 cells is more than normal cells. Overexpression of protein tyrosine phosphatase receptor-δ (PTPRD) in M059 J and U373 cells resulted in a significant increase in the S phase of the cells, while the G2 phase of the cells decreased significantly after interference with PTPRD. And PTPRD protein is mainly distributed in HMC3 cells, M059 J and U373 cytoplasm. Moreover, overexpression of PTPRD resulted in a significant increase in the expression of interleukin 1 receptor accessory protein (IL1RAP), PPFIA1 and SLITRK2, and these genes were significantly suppressed after interference with PTPRD. ConclusionThis study shows that PRPRD can be used as a potential biomarker for glioma treatment. These results indicate that the PRPRD protein affects the development of neuronal synapses and neuronal differentiation by regulating IL1RAP, thereby promoting the progression of gliomas, indicating that PRPRD can be used as a potential biomarker for the treatment of gliomas.

OSA as a probable risk factor for severe COVID-19.

Citation:McSharry D, Lam MT, Malhotra AT. OSA as a probable risk factor for severe COVID-19. J Clin Sleep Med. 2020;16(9):1649.

Serum proteome profiles revealed dysregulated proteins and mechanisms associated with fibromyalgia syndrome in women

Fibromyalgia syndrome (FM) is a multifactorial disorder whose pathogenesis and diagnosis are poorly understood. This study investigated differential serum proteome profiles in patients with FM and healthy pain-free controls and explored the association between serum proteome and clinical profiles in patients with FM. Twenty patients with FM (according to the American College of Rheumatology criteria, 2010) and 20 healthy pain-free controls were recruited for optimized quantitative serum proteomics analysis. The levels of pain, pressure pain threshold, sleep, anxiety, depression, and functional status were evaluated for patients with FM. We identified 22 proteins differentially expressed in FM when compared with healthy pain-free controls and propose a panel of methyltransferase-like 18 (METTL18), immunoglobulin lambda variable 3–25 (IGLV3–25), interleukin-1 receptor accessory protein (IL1RAP), and IGHV1OR21-1 for differentiating FM from controls by using a decision tree model (accuracy: 0.97). In addition, we noted several proteins involved in coagulation and inflammation pathways with distinct expression patterns in patients with FM. Novel proteins were also observed to be correlated with the levels of pain, depression, and dysautonomia in patients with FM. We suggest that upregulated inflammation can play a major role in the pathomechanism of FM. The differentially expressed proteins identified may serve as useful biomarkers for diagnosis and evaluation of FM in the future.

The role of the IL-1 system in pregnancy and the use of IL-1 system markers to identify women at risk for pregnancy complications†.

The interleukin (IL)-1 system plays a major role in immune responses and inflammation. The IL-1 system components include IL-1α, IL-1β, IL-1 receptor type 1 and IL-1 receptor type 2 (decoy receptor), IL-1 receptor accessory protein, and IL-1 receptor antagonist (IL-1Ra). These components have been shown to play a role in pregnancy, specifically in embryo-maternal communication for implantation, placenta development, and protection against infections. As gestation advances, maternal tissues experience increasing fetal demand and physical stress and IL-1β is induced. Dependent on the levels of IL-1Ra, which regulates IL-1β activity, a pro-inflammatory response may or may not occur. If there is an inflammatory response, prostaglandins are synthesized that may lead to myometrial contractions and the initiation of labor. Many studies have examined the role of the IL-1 system in pregnancy by independently measuring plasma, cervical, and amniotic fluid IL-1β or IL-1Ra levels. Other studies have tested for polymorphisms in IL-1β and IL-1Ra genes in women experiencing pregnancy complications such as early pregnancy loss, in vitro fertilization failure, pre-eclampsia and preterm delivery. Data from those studies suggest a definite role for the IL-1 system in successful pregnancy outcomes. However, as anticipated, the results varied among different experimental models, ethnicities, and disease states. Here, we review the current literature and propose that measurement of IL-1Ra in relation to IL-1 may be useful in predicting the risk of poor pregnancy outcomes.

Dickkopf-related protein 3 is a novel biomarker for chronic GVHD after allogeneic hematopoietic cell transplantation

AbstractTo identify plasma biomarkers associated with fibrotic mechanisms of chronic graft-versus-host disease (GVHD), we used multiplex mass spectrometry with pooled samples for biomarker discovery in comparing proteomic profiles between patients with newly diagnosed sclerotic chronic GVHD (n = 21), those with newly diagnosed nonsclerotic chronic GVHD (n = 33), and those without chronic GVHD (n = 20). Immunoassay was used to measure protein concentrations of individual discovery samples and 186 independent verification samples. The discovery mass spectrometry analysis identified 2 candidate proteins with at least 1.5-fold difference in sclerotic GVHD: Dickkopf-related protein 3 (DKK3) and interleukin-1 receptor accessory protein (IL1RAP). Analysis of individual discovery samples by immunoassay showed that DKK3, a modulator of the Wnt signaling pathway, was a biomarker for both sclerotic and nonsclerotic chronic GVHD. Verification analysis of 186 patients confirmed that elevated plasma DKK3 concentrations were associated with chronic GVHD, regardless of the presence or absence of sclerosis, and that the area under the receiver operating characteristic curve was 0.85 for association of DKK3 concentrations with chronic GVHD. Multiple linear regression analysis showed that chronic GVHD with or without steroid treatment and patient age were independently associated with DKK3 concentrations. Patients with high DKK3 concentrations had a higher nonrelapse mortality than those with low concentrations. The lower IL1RAP concentrations in patients with sclerotic GVHD compared with other conditions in the discovery cohort were not confirmed in the verification cohort. DKK3 is a novel biomarker for chronic GVHD. Further studies are needed to determine the biological functions of DKK3 in the pathogenesis of chronic GVHD.

Splice-dependent trans-synaptic PTPδ-IL1RAPL1 interaction regulates synapse formation and non-REM sleep.

Alternative splicing regulates trans‐synaptic adhesions and synapse development, but supporting in vivo evidence is limited. PTPδ, a receptor tyrosine phosphatase adhering to multiple synaptic adhesion molecules, is associated with various neuropsychiatric disorders; however, its in vivo functions remain unclear. Here, we show that PTPδ is mainly present at excitatory presynaptic sites by endogenous PTPδ tagging. Global PTPδ deletion in mice leads to input‐specific decreases in excitatory synapse development and strength. This involves tyrosine dephosphorylation and synaptic loss of IL1RAPL1, a postsynaptic partner of PTPδ requiring the PTPδ‐meA splice insert for binding. Importantly, PTPδ‐mutant mice lacking the PTPδ‐meA insert, and thus lacking the PTPδ interaction with IL1RAPL1 but not other postsynaptic partners, recapitulate biochemical and synaptic phenotypes of global PTPδ‐mutant mice. Behaviorally, both global and meA‐specific PTPδ‐mutant mice display abnormal sleep behavior and non‐REM rhythms. Therefore, alternative splicing in PTPδ regulates excitatory synapse development and sleep by modulating a specific trans‐synaptic adhesion.

Sleep- and time of day-linked RNA transcript expression in wild-type and IL1 receptor accessory protein-null mice.

Sleep regulation involves interleukin-1β (IL1) family members, TNF, and circadian clock genes. Previously, we characterized spontaneous sleep and sleep after 8 h of sleep deprivation (SD) ending at zeitgeber time (ZT)4 and ZT16 in wild-type (WT) and IL1 receptor accessory protein (AcP)- and brain-specific AcP (AcPb)-knockout (KO) mice. Here, we applied quantitative reverse transcriptase polymerase chain reaction and Spearman gene pair expression correlation methods to characterize IL1, IL1 receptor 1 (IL1R1), AcP, AcPb, Period 1 (Per1), Clock, adenosine deaminase (Ada), peptidoglycan recognition protein 1 (Pglyrp1), and TNF mRNA expressions under conditions with distinct sleep phenotypes. In WT mice, IL1, IL1R1, AcP, Ada, and Clock mRNAs were higher at ZT4 (mid-sleep period) than at ZT16. mRNA expressions differed substantially in AcP and AcPb KO mice at those times. After SD ending at ZT4, only WT mice had a non-rapid eye movement sleep (NREMS) rebound, and AcPb and IL1R1 mRNA increases were unique to WT mice. In AcPb KO mice, which have spontaneous high EEG slow wave power, AcP and Pglyrp1 mRNAs were elevated relative to WT mice at ZT4. At ZT4, the AcPb KO - WT Spearman correlation difference networks showed high positive correlations between IL1R1 and IL1, Per1, and Clock and high negative correlations between TNF and Pglyrp1 and Ada. At ZT16, the WT mice gene pair expression network was mostly negative, whereas in AcP KO mice, which have substantially more rapid eye movement sleep than WT mice, it was all positive. We conclude that gene pair expression correlations depend on the presence of AcP and AcPb.NEW & NOTEWORTHY Spearman gene pair expression correlations depend upon the presence or absence of interleukin-1 receptor accessory protein and upon sleep phenotype.

From CANTOS to CIRT to COLCOT to Clinic: Will All Atherosclerosis Patients Soon Be Treated With Combination Lipid-Lowering and Inflammation-Inhibiting Agents?

From CANTOS to CIRT to COLCOT to Clinic: Will All Atherosclerosis Patients Soon Be Treated With Combination Lipid-Lowering and Inflammation-Inhibiting Agents?

Increased interleukin 18 activity in adolescents with early-onset psychosis is associated with cortisol and depressive symptoms

ObjectiveEvidence indicates that the pathophysiology of adult psychosis involves immune dysregulation, but its associations with stress are often not considered. The inflammatory cytokine interleukin (IL)-18, which is elevated in adult schizophrenia, is suggested to be sensitive to stress. We compared the associations of IL-18 with cortisol and clinical variables in adolescents with early-onset psychosis (EOP) aged 12–18 years and age-matched healthy controls (HC). MethodWe measured serum IL-18, IL-18 binding protein (IL-18BP), IL-18 receptor accessory protein (IL-18RAP), IL-18 receptor 1 (IL-18R1) and cortisol, and calculated the IL-18/IL-18BP ratio in patients (n = 31) and HC (n = 60). Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale and depressive symptoms by the Mood and Feelings Questionnaire-Child version (MFQ-C). Bivariate correlation analysis was used to explore relationships between IL-18/IL-18BP ratio and cortisol, depression and other clinical characteristics. Hierarchical multiple linear regression analysis was used to assess their individual contributions to the variance of the IL-18/IL-18BP ratio. ResultsPatients had significantly higher IL-18 levels and IL-18/IL-18BP ratios than HC, but similar IL-18BP, IL-18RAP and IL-18R1. Both cortisol (R2 change = 0.05) and the MFQ-C score (R2 change = 0.09) contributed significantly to the variance in IL-18/IL-18BP ratios after controlling for confounders. ConclusionWe found increased IL-18 system activity in adolescents with EOP. Cortisol and depressive symptoms each contributed to the variance in the IL-18/IL-18BP ratio. Our findings support activation of inflammatory pathways in adolescent psychosis and suggest interactions between stress, inflammation and depressive symptoms in EOP.

The Clinical Association and Prognostic Impact of IL1RAP Expression in Patients with De Novo Acute Myeloid Leukemia

Introduction One of the contributing factors to the relapse of acute myeloid leukemia (AML) is the presence of leukemia stem cells (LSCs). Interleukin 1 receptor accessory protein (IL1RAP) was reported to be one of the LSC markers. Most studies regarding clinical implications of IL1RAP expression in AML focused on small and selected patient groups. Besides, its correlation with other molecular alterations has not been reported yet in literature. In this study, we aimed to elucidate the relationship between bone marrow IL1RAP expression level and clinical and biological features in patients with de novo non-M3 AML. Furthermore, we would like to explore its prognostic impact and potential underlying mechanism. Method We enrolled 275 newly diagnosed de novo non-M3 AML patients. Among them, 187 (68%) patients received standard induction chemotherapy and 2-4 courses of high-dose cytarabine based post-remission therapy. Analyses of 54 gene mutations were performed by next generation sequencing. The global gene expressions were profiled with the Affymetrix GeneChip Human Transcriptome Array 2.0. Result We used the median as the cut-off value to define the higher and lower IL1RAP expression groups. The patients with higher IL1RAP expression had significantly higher white blood cell counts at diagnosis, higher peripheral blast counts, and higher lactate dehydrogenase levels. Higher IL1RAP expression was closely associated with t(8;21), favorable-risk cytogenetics based on the refined MRC classification, but inversely with unfavorable-risk cytogenetics. Compared with low-expression patients, the high-expression patients had significantly more FLT3/ITD and KIT mutations, but less mutations in U2AF1, TP53, or CEBPA. Among the 187 patients receiving standard intensive chemotherapy, those with lower IL1RAP expression had significantly longer overall survival (OS) than those with higher expression (P=0.047) after a median follow-up time of 91.1 months, but disease-free survival (DFS) was not significantly different between the two groups (P=0.311). Among the 77 patients who relapsed after first complete remission (CR), the second CR rate was similar between the two groups (P=0.649), but the second DFS was significantly longer in the low-expression patients than the high-expression patients (P=0.028) which was also reflected in a significantly longer survival after first relapse in the former group than the latter group (P=0.014). The prognostic impact of IL1RAP expression on OS could be externally validated in the TCGA cohort (P=0.038). Its prognostic implication remained significant in the subgroup of our cohort with intermediate-risk cytogenetics (P=0.006) and those with normal karyotype (P=0.025). In multivariate analysis incorporating age, transplantation status, 2017 ELN risk-stratification and IL1RAP expression as covariates, the higher IL1RAP expression was an independent poor prognostic factor for OS (HR=1.555, P=0.025). The Gene Set Enrichment Analysis revealed significant up-regulation of LSC related genes in the higher IL1RAP expressed patients (Figure 1 and 2). We further profiled genome-wide RNA expression with 70,523 probes to survey the potential molecular mechanisms underlying the IL1RAP expression signature. Totally, 313 differentially expressed genes were identified (>1.5-fold change and Student t-test P<0.0001, Figure 3). We used Ingenuity Pathway Analysis (Qiagen) to analyze the possible underlying mechanism and found that the top upstream regulators were transcription factors, such as GATA1/GATA2 (P=1.39*10-11 and 1.61*10-10, respectively), and ABCB6 (P=3.84*10-8), one of the ATP-Binding Cassette transporter superfamily. The hub genes in the regulation network included ELAVL1 and NFκB, in addition to GATA1 and GATA2. Conclusion Higher IL1RAP expression is associated with distinct clinical and genetic alterations. It is an independent prognostic factor for OS irrespective of the risk category based on the ELN classification. Transcription factors, such as GATA1 and GATA2, ABCB6, ELAVL1 and NFκB might be involved in the underlying mechanism. Further prospective large cohort is warrant to validate our findings. Disclosures Tien: Novartis: Other: Travel Grant. Hou:Celgene: Research Funding; Abbvie, Astellas, BMS, Celgene, Chugai, Daiichi Sankyo, IQVIA, Johnson & Johnson, Kirin, Merck Sharp & Dohme, Novartis, Pfizer, PharmaEssential, Roche, Takeda: Honoraria. Tien:Daiichi Sankyo: Honoraria; Roche: Honoraria; Abbvie: Honoraria; Alexion: Honoraria; Celgene: Honoraria; Johnson &Johnson: Honoraria; Novartis: Honoraria; Celgene: Research Funding; BMS: Honoraria; Pfizer: Honoraria; Roche: Research Funding.

Helicobacter pylori Induces IL-33 Production and Recruits ST-2 to Lipid Rafts to Exacerbate Inflammation.

Helicobacter pylori colonizes human gastric epithelial cells and contributes to the development of several gastrointestinal disorders. Interleukin (IL)-33 is involved in various immune responses, with reported proinflammatory and anti-inflammatory effects, which may be associated with colitis and colitis-associated cancer. IL-33 induces the inflammatory cascade through its receptor, suppression of tumorigenicity-2 (ST-2). Binding of IL-33 to membrane-bound ST-2 (mST-2) recruits the IL-1 receptor accessory protein (IL-1RAcP) and activates intracellular signaling pathways. However, whether IL-33/ST-2 is triggered by H. pylori infection and whether this interaction occurs in lipid rafts remain unclear. Our study showed that both IL-33 and ST-2 expression levels were significantly elevated in H. pylori-infected cells. Confocal microscopy showed that ST-2 mobilized into the membrane lipid rafts during infection. Depletion of membrane cholesterol dampened H. pylori-induced IL-33 and IL-8 production. Furthermore, in vivo studies revealed IL-33/ST-2 upregulation, and severe leukocyte infiltration was observed in gastric tissues infected with H. pylori. Together, these results demonstrate that ST-2 recruitment into the lipid rafts serves as a platform for IL-33-dependent H. pylori infection, which aggravates inflammation in the stomach.

Interleukin-36 in Infectious and Inflammatory Skin Diseases.

Interleukin-36 (IL-36) comprises to a cytokine family consisting of four isoforms IL-36α, IL-36β, IL-36γ, and IL-36 receptor antagonist (IL-36 Ra). These IL-36 cytokines, in turn, belong to the IL-1 superfamily. The IL-36 receptor (IL-1R6) is functional as a heterodimer formed of IL-1R6 and IL-1 receptor accessory protein (IL-1RAcP). IL-36α, IL-36β, and IL-36γ are regarded as pro-inflammatory ligands and IL-36 Ra as well as IL-38 as anti-inflammatory ligands of IL-1R6. IL-36 cytokines are mainly expressed on the barrier sites of the body e.g., bronchial, intestinal, and dermal epithelium. One of their most important biological functions is the bridging of innate and adaptive immune responses. A disturbed balance between pro-inflammatory and anti-inflammatory branches easily leads to inflammation of the corresponding tissue. The most prominent example for an altered IL-36 expression is the spectrum of psoriasis. In addition to inflammatory dermatoses, IL-36 also seems to play a role in infectious dermatoses. Microbial triggers, especially Staphylococcus aureus infection, increase the production of pro-inflammatory IL-36 cytokines and initiate/promote the inflammation of skin lesions. Due to the discovery of IL-36 as an important immune mediator, it has already been possible to develop important diagnostic tools for dermatitis. Not only in the field of inflammatory skin diseases, but also in pulmonary and intestinal inflammation, there is evidence that IL-36 cytokines might have diagnostic and/or therapeutic relevance.

Methamphetamine-associated cognitive decline is attenuated by neutralizing IL-1 signaling

Methamphetamine (METH) abusers are prone to develop a variety of comorbidities, including cognitive disabilities, and the immunological responses have been recognized as an important component involved in the toxicity of this drug. Cytokines are among the key mediators between systemic inflammatory status and tissue responses. One of these, interleukin 1 (IL-1), has been hypothesized to be involved in cognitive functions and also appears to play a pivotal role among inflammatory molecules. In the present study, we demonstrate that exposure of mice to METH markedly increased the protein level of IL-1β in hippocampal tissue. Additionally, METH administration induced a decline in spatial learning as determined by the Morris water maze test. We next evaluated the hypothesis that blocking IL-1β signaling can protect against METH-induced loss of cognitive functioning. The results indicated that METH-induced impaired spatial learning abilities were attenuated by co-administration of mouse IL-1 Trap, a dimeric fusion protein that incorporates the extracellular domains of both of the IL-1 receptor components required for IL-1 signaling (IL-1 receptor type 1 and IL-1 receptor accessory protein), linked to the Fc portion of murine IgG2a. This effect was associated with a decrease in hippocampal IL-1β level. The current study indicates for the first time that the loss of METH-related cognitive decline can be attenuated by neutralizing IL-1 signaling. Our findings suggest a potential new therapeutic pathway for treatment of altered cognitive abilities that occur in METH abusing individuals.

IL-33trap is a novel IL-33–neutralizing biologic that inhibits allergic airway inflammation

The emergence of IL-33 as a key molecular player in the development and propagation of widespread inflammatory diseases, including asthma and atopic dermatitis, has established the need for effective IL-33-neutralizing biologics. Here we describe the development and validation of a new antagonist of IL-33, termed IL-33trap, which combines the extracellular domains of the IL-33 receptor (ST2) and its coreceptor, IL-1 receptor accessory protein, into a single fusion protein. We produced and purified recombinant IL-33trap from human cells and analyzed its IL-33-binding affinity and IL-33 antagonistic activity in cultured cells and mice. IL-33trap activity was also benchmarked with a recombinant soluble ST2 corresponding to the naturally occurring IL-33 decoy receptor. Finally, we studied the effect of IL-33trap in the Alternaria alternata mouse model of allergic airway inflammation. Invitro IL-33trap binds IL-33 and inhibits IL-33 activity to a much stronger degree than soluble ST2. Furthermore, IL-33trap inhibits eosinophil infiltration, splenomegaly, and production of signature cytokines in splenic lymphocytes and lung tissue on IL-33 injection. Finally, administration of IL-33trap at the time of allergen challenge inhibits inflammatory responses in a preclinical mouse model of acute allergic airway inflammation. IL-33trap is a novel IL-33 antagonist that outperforms the natural IL-33 decoy receptor and shows anti-inflammatory activities in a preclinical mouse model of acute allergic airway inflammation when administered at the time of allergen challenge.

Ginsenoside Rd inhibits IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.

Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1β, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1β by suppressing the increase in IL-1β, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1β-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1β to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.

The neuron-specific interleukin-1 receptor accessory protein alters emergent network state properties in Vitro

Small in vitro neuronal/glial networks exhibit sleep-like states. Sleep regulatory substance interleukin-1β (IL1) signals via its type I receptor and a receptor accessory protein (AcP). AcP has a neuron-specific isoform called AcPb. After sleep deprivation, AcPb, but not AcP, upregulates in brain, and mice lacking AcPb lack sleep rebound. Herein we used action potentials (APs), AP burstiness, synchronization of electrical activity (SYN), and delta wave (0.5–3.75 Hz) power to characterize cortical culture network state. Homologous parameters are used in vivo to characterize sleep. Cortical cells from 1–2-day-old pups from AcP knockout (KO, lacking both AcP and AcPb), AcPb KO (lacking only AcPb), and wild type (WT) mice were cultured separately on multi-electrode arrays. Recordings of spontaneous activity were taken each day during days 4–14 in vitro. In addition, cultures were treated with IL1, or in separate experiments, stimulated electrically to determine evoked response potentials (ERPs). In AcP KO cells, the maturation of network properties accelerated compared to those from cells lacking only AcPb. In contrast, the lack of AcPb delayed spontaneous network emergence of sleep-linked properties. The addition of IL1 enhanced delta wave power in WT cells but not in AcP KO or AcPb KO cells. The ontology of electrically-induced ERPs was delayed in AcP KO cells. We conclude IL1 signaling has a critical role in the emergence of sleep-linked network behavior with AcP playing a dominant role in the slowing of development while AcPb enhances development rates of sleep-linked emergent network properties.

The Synaptic and Neuronal Functions of the X-Linked Intellectual Disability Protein Interleukin-1 Receptor Accessory Protein Like 1 (IL1RAPL1).

Since the first observation that described a patient with a mutation in IL1RAPL1 gene associated with intellectual disability in 1999, the function of IL1RAPL1 has been extensively studied by a number of laboratories. In this review, we summarize all the major data describing the synaptic and neuronal functions of IL1RAPL1 and recapitulate most of the genetic deletion identified in humans and associated to intellectual disability (ID) and autism spectrum disorders (ASD). All the data clearly demonstrate that IL1RAPL1 is a synaptic adhesion molecule localized at the postsynaptic membrane. Mutations in IL1RAPL1 gene cause either the absence of the protein or the production of a dysfunctional protein. More recently it has been demonstrated that IL1RAPL1 regulated dendrite formation and mediates the activity of IL-1β on dendrite morphology. All these data will possibly contribute to identifying therapies for patients carrying mutations in IL1RAPL1 gene.

Upregulation of Tissue Factor May Contribute to Thrombosis in Polycythemia Vera and Essential Thrombocythemia

Thrombosis is a major cause of morbidity and mortality in polycythemia vera (PV) and essential thrombocythemia (ET). The mechanistic basis of thrombosis in PV/ET, however, is unknown. To better understand the pathophysiology of thrombosis in PV and ET, we first studied transcript levels of selected thrombotic, inflammatory and hypoxia- inducible factor (HIF) pathway genes in granulocytes and platelets of PV and ET patients with and without thrombosis. Genes selected for the study included: tissue factor (F3); P-selectin (SELP); serpin peptidase inhibitor clade E member 1 (SERPINE1, encoding plasminogen activator inhibitor I, PAI1); thrombospondin 1 (THBS1); interleukin 1 receptor associated kinase 1 (IRAK1); interleukin 1 receptor accessory protein (IL1RAP) and HIF-regulated genes: vascular endothelial growth factor A (VEGFA) and solute carrier family 2 (SLC2A1, encoding glucose transporter 1). We have previously reported at this meeting that PV and ET patients with a history of thrombosis had higher transcripts of F3, SERPINE1, IL1RAP, VEGFA and SLC2A1 compared to those without thrombosis. We also performed unbiased total RNA sequencing of platelets and granulocytes (Gangaraju R et al Blood, 2016;128:3143).Tissue factor (TF) is the principal initiator of coagulation in vivo. The presence of TF transcript in leukocytes and platelets may or may not reflect the translated protein level. Furthermore, TF functional activity is modulated by encryption. Therefore, we proceeded to evaluate the functional activity of microvesicle-associated TF (MVTF) in the plasma of 10 ET and 33 PV patients considered to have high thrombotic risk (Tefferi A, Barbui T Am J Hematol. 2017;92(1):94-108). TF activity was measured in MVs collected by centrifugation of patient plasma to 20,200 xg by a two-step FXa generation assay with and without an inhibitory TF antibody to determine the contribution of TF to FXa generation (Owens 3d et al. Circ Res. 2011;108(10):1284-97). We found significantly increased levels of MVTF activity in PV and ET compared to normal controls (Figure 1). However, MVTF levels in PV and ET patients with and without thrombosis were comparable (Figure 1).In the vasculature, leukocytes can synthesize TF (upon stimulation) and it has been shown that monocytes, not neutrophils, are the principal source of TF under normal conditions (Osterud B, Thromb Res. 2010;25 Suppl 1:S31-4). MPN granulocytes, in contrast to normal granulocytes, had increased levels of TF transcripts, a novel and important finding of as yet undetermined significance (Figure 2).Since TF synthesis is regulated by hypoxia-inducing factor-1 (HIF-1) (Rolfs et al. J Biol Chem. 1997;272(32):20055-62), we also examined MVTF activity in the plasma of Chuvash polycythemia (CP) patients. These patients have a germline VHLC598T mutation in the negative regulator of HIFs, the von Hippel Lindau gene (VHLC598T), and as a result they have increased levels of HIF-1, HIF-2 and transcripts of a vast array of HIF-regulated genes. CP subjects have an even higher propensity for arterial and venous thrombosis than PV. As predicted, some CP plasmas also demonstrated elevated levels of MVTF activity (Figure 1). In conclusion, hypoxia-induced increased levels of plasma MVTF activity may play a role in the increased thrombotic risk of PV and ET. TF joins TSP-1 (Sergeueva et al. Haematologica. 2017;102(5):e166-e169) and protein S (Pilly et al. Blood 2018;132(4):452-455) as a potential HIF-regulated mechanism of thrombotic risk in patients with PV/ET and CP. Granulocytes may also be a source of hypoxia-induced TF in these patients. The hypoxia-mediated upregulation of thrombotic risk is further underscored by the observation that PV patients living in moderate hypoxia at Salt Lake City have a higher risk of thrombosis than those living at sea level (Baltimore MD) in multivariate analysis (Zangari et al, Blood Coagul Fibrinolysis 2013; 24(3):311-316). The data described here may facilitate identification of novel targets and their therapies including the use of HIF-1 inhibitors such as digoxin to prevent thrombosis in these patients (Zhang et al. PNAS 2008;105(50):19579-86). [Display omitted] DisclosuresKey:UniQure BV: Research Funding.

Interleukin-33 in Systemic Sclerosis: Expression and Pathogenesis

Interleukin-33 (IL-33), a member of the IL-1 superfamily, functions as a traditional cytokine and nuclear factor. It is proposed to have an “alarmin” role. IL-33 mediates biological effects by interacting with the ST2 receptor and IL-1 receptor accessory protein, particularly in innate immune cells and T helper 2 cells. Recent articles have described IL-33 as an emerging pro-fibrotic cytokine in the immune system as well as a novel potential target for systemic sclerosis. Here, we review the available information and focus on the pleiotropic expression and pathogenesis of IL-33 in systemic sclerosis, as well as the feasibility of using IL-33 in clinical applications.

1172P - A first-in-class, first-in-human phase I/IIa trial of CAN04, targeting interleukin-1 receptor accessory protein (IL1RAP), in patients with solid tumors

1172P - A first-in-class, first-in-human phase I/IIa trial of CAN04, targeting interleukin-1 receptor accessory protein (IL1RAP), in patients with solid tumors