Constitutive DAMPs in CNS injury: From preclinical insights to clinical perspectives.

Damage-associated molecular patterns (DAMPs) are endogenous molecules released in tissues upon cellular damage and necrosis, acting to initiate sterile inflammation. Constitutive DAMPs (cDAMPs) have the particularity to be present within the intracellular compartments of healthy cells, where they exert diverse functions such as regulation of gene expression and cellular homeostasis. However, after injury to the central nervous system (CNS), cDAMPs are rapidly released by stressed, damaged or dying neuronal, glial and endothelial cells, and can trigger inflammation without undergoing structural modifications. Several cDAMPs have been described in the injured CNS, such as interleukin (IL)-1α, IL-33, nucleotides (e.g. ATP), and high-mobility group box protein 1. Once in the extracellular milieu, these molecules are recognized by the remaining surviving cells through specific DAMP-sensing receptors, thereby inducing a cascade of molecular events leading to the production and release of proinflammatory cytokines and chemokines, as well as cell adhesion molecules. The ensuing immune response is necessary to eliminate cellular debris caused by the injury, allowing for damage containment. However, seeing as some molecules associated with the inflammatory response are toxic to surviving resident CNS cells, secondary damage occurs, aggravating injury and exacerbating neurological and behavioral deficits. Thus, a better understanding of these cDAMPs, as well as their receptors and downstream signaling pathways, could lead to identification of novel therapeutic targets for treating CNS injuries such as SCI, TBI, and stroke. In this review, we summarize the recent literature on cDAMPs, their specific functions, and the therapeutic potential of interfering with cDAMPs or their signaling pathways.

Novel Treatments in Refractory Recurrent Pericarditis.

Refractory recurrent pericarditis is a troublesome condition that severely impairs the quality of life of affected patients and significantly increases healthcare spending. Until recently, therapeutic options included only a few medications and most of the patients resorted to chronic glucocorticoid treatment with steroid dependence. In the most recent decade, the introduction of interleukin-1 blockers in clinical practice has revolutionized the treatment of glucocorticoid-dependent and colchicine-resistant recurrent pericarditis due to their excellent efficacy and good safety profile. The rationale for the introduction of this class of medications in clinical practice is the autoinflammatory nature of recurrent pericarditis in a substantial rate of cases, with interleukin-1 being the main pro-inflammatory cytokine involved in this context. This review aims to discuss the contemporary available evidence from original research and real-world data on interleukin-1 blocker use in refractory recurrent pericarditis, in terms of indications, mechanism of action, efficacy, side effects, and recommended treatment protocols. Moreover, novel treatment proposals, such as hydroxychloroquine, beta blockers, and cannabidiol, which showed encouraging preliminary results, are addressed. Finally, gaps in knowledge, unmet needs, and future perspectives related to recurrent pericarditis are thoroughly discussed.

Bacillus coagulans BACO-17 ameliorates in vitro and in vivo progression of Rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that causes persistent inflammation involving the joints, cartilage, and synovium. In individuals with RA, alterations in the composition of intestinal bacteria suggest the vital role of gut microbiota in immune dysfunction. Multiple therapies commonly used to treat RA can also alter the diversity of gut microbiota, further suggesting the modulation of gut microbiota as a prevention or treatment for RA. Therefore, a better understanding of the changes in the gut microbiota that accompany RA should facilitate the development of novel therapeutic approaches. In this study, B. coagulans BACO-17 not only significantly reduced paw swelling, arthritis scores, and hind paw and forepaw thicknesses but also protected articular cartilage and the synovium against RA degeneration, with a corresponding downregulation of TNF-α expression. The inhibition or even reversing of RA progression highlights B. coagulans BACO-17 as a novel therapeutic for RA worth investigating.

IL1RL2 is related to the expression and prognosis of bladder cancer.

IL1RL2 has been reported to be highly expressed in a variety of tumor types whereas its role in bladder cancer (BLCA) remains unclear. The aim of the present study was to explore the prognostic value of Il1RL2 in BLCA and its relationship with clinical pathological features. The Cancer Genome Atlas (TCGA) database was used to assess the levels of IL1RL2 expression in BLCA tissues and cells, which were validated by reverse transcription-quantitative polymerase chain reaction and western blotting. Immunohistochemistry was employed to analyze expression of the IL1RL2 gene in 17 pairs of tumor and normal specimens, as well as 112 samples with different stages and grades of tumors. To investigate the biological functions of Il1RL2 in BLCA, co-expression networks and functional enrichment analyses were conducted. A protein-protein interaction network was constructed using interaction gene search tools. IL1RL2 was revealed to be clearly expressed in BLCA cells and tissues. The area under the curve for amplification of IL1RL2 distinguishing between tumor and normal tissues was 0.700 (95% CI: 0.579-0.821) in the TCGA database and 0.647 (95% CI: 0.497-0.797) in Miyun chart database, respectively. Furthermore, in our database, both univariate and multivariate analyses indicated that IL1RL2 expression was an independent risk factor for overall survival (OS). Kaplan-Meier survival analysis revealed an association between high IL1RL2 expression and low OS. Pathway enrichment analysis suggested that IL1RL2 is involved in the regulation of tumor progression through the MAPK signaling pathway. The expression level of IL1RL2 was associated with the stage, grade, lymph node album and prognosis of BLCA.

Structural characterization of TIR-domain signalosomes through a combination of structural biology approaches.

The TIR (Toll/interleukin-1 receptor) domain represents a vital structural element shared by proteins with roles in immunity signalling pathways across phyla (from humans and plants to bacteria). Decades of research have finally led to identifying the key features of the molecular basis of signalling by these domains, including the formation of open-ended (filamentous) assemblies (responsible for the signalling by cooperative assembly formation mechanism, SCAF) and enzymatic activities involving the cleavage of nucleotides. We present a historical perspective of the research that led to this understanding, highlighting the roles that different structural methods played in this process: X-ray crystallography (including serial crystallography), microED (micro-crystal electron diffraction), NMR (nuclear magnetic resonance) spectroscopy and cryo-EM (cryogenic electron microscopy) involving helical reconstruction and single-particle analysis. This perspective emphasizes the complementarity of different structural approaches.

Interleukin-1α inhibitor bermekimab in patients with atopic dermatitis: randomized and nonrandomized studies.

Bermekimab is a human-derived recombinant monoclonal antibody that exhibits immunoregulatory activity by specifically blocking interleukin-1α activity. Four phase 2 studies evaluated efficacy and safety of bermekimab in patients with moderate-to-severe atopic dermatitis (AD). In addition, a novel human skin explant model was developed to assess bermekimab pharmacokinetics/pharmacodynamics and proteomic/transcriptomic effects. Study 1 (NCT03496974, N = 38) was an open-label, dose escalation study of subcutaneous bermekimab (200 mg or 400 mg). Study 2 (NCT04021862, N = 87) was a double-blind, placebo-controlled, randomized (1:1:1) study of subcutaneous bermekimab (400 mg every week (qw) or every 2 weeks) or placebo. GENESIS (NCT04791319, N = 198) was a double-blind, placebo- and active-comparator-controlled, randomized (1:1:2:2) study of placebo, subcutaneous bermekimab (350 mg or 700 mg qw), or dupilumab. LUNA (NCT04990440, N = 6) was a double-blind, placebo-controlled, randomized (4:1) study of intravenous bermekimab 800 mg qw or placebo. A novel human ex vivo skin pharmacodynamic assay supported phase 0 (NCT03953196) and phase 1 (NCT04544813) studies. In Study 1, 400 mg subcutaneous bermekimab showed improvement in efficacy assessments (e.g., ≥ 75% improvement of EASI over baseline, IGA 0/1, and worst itch); however, efficacy was not confirmed in Study 2 or GENESIS. Consequently, GENESIS and LUNA were terminated early. The novel human ex vivo skin pharmacodynamic assay demonstrated that bermekimab reduced downstream skin injury responses. Although bermekimab showed potential as an AD treatment in preclinical and early open-label trials, larger controlled studies (Study 2 and GENESIS) did not confirm those initial results.

Spirulina platensis shields the submandibular gland from cadmium toxicity by bolstering antioxidant defenses and maintaining its structural integrity.

Cadmium (Cd), an element categorized as a non-essential transitional metal, has potential hazards to the health of both human beings and animals. Spirulina platensis (SP), a type of blue-green algae, possesses a high concentration of essential antioxidants. The present study aimed to explore the possible defensive role of SP against Cd-induced submandibular gland injury in rats by assessment of biomarkers related to both oxidative stress and inflammatory processes, which were further explored through histopathological examination of submandibular gland tissue. Consequently, the study included 32 mature rats, subdivided into four different groups as follows: control, SP, Cadmium chloride (CdCl2), and CdCl2/SP. The duration of the study was 24days. The results revealed that CdCl2 induced submandibular gland injury as shown by the oxidant/antioxidant imbalance and increased inflammatory reactions, in addition to, histopathological changes and overexpression of BAX immunostaining. Concurrent SP administration to CdCl2-treated rats significantly improved all these effects. We concluded that concurrent SP supplement improved the submandibular gland injury provoked by CdCl2.

Interleukin-1α inhibits transforming growth factor-ß1 and ß2-induced extracellular matrix production, remodeling and signaling in human lung fibroblasts: Master regulator in lung mucosal repair.

BACKGROUND: Lung fibroblasts play a central role in maintaining lung homeostasis and facilitating repair through the synthesis and organization of the extracellular matrix (ECM). This study investigated the cross-talk between interleukin-1 alpha (IL-1α) and transforming growth factor-ß (TGF-ß) signaling, two key regulators in tissue repair and fibrosis, in the context of lung fibroblast repair in the healthy lung. RESULTS: Stimulation of lung fibroblasts with TGF-ß1 and TGF-ß2 induced collagen-I and fibronectin protein expression (p < 0.05), a response inhibited with co-treatment with IL-1α (p < 0.05). Additionally, TGF-ß1 and TGF-ß2 induced myofibroblast differentiation, and collagen-I gel contraction, which were both suppressed by IL-1α (p < 0.05). In contrast, interleukin (IL)-6, IL-8 and thymic stromal lymphopoietin induced by IL-1α, were unaffected by TGF-ß1 or TGF-ß2. Mechanistically, IL-1α administration led to the suppression of TGF-ß1 and TGF-ß2 signaling, through downregulation of mRNA and protein for TGF-ß receptor II and the downstream adaptor protein TRAF6, but not through miR-146a that is known to be induced by IL-1α. DISCUSSION: IL-1α acts as a master regulator, modulating TGF-ß1 and TGF-ß2-induced ECM production, remodeling, and myofibroblast differentiation in human lung fibroblasts, playing a vital role in balancing tissue repair versus fibrosis. Further research is required to understand the dysregulated cross-talk between IL-1α and TGF-ß signaling in chronic lung diseases and the exploration of therapeutic opportunities. METHODS: Primary human lung fibroblasts (PHLF) were treated with media control, or 1 ng/ml IL-1α with or without 50 ng/ml TGF-ß1 or TGF-ß2 for 1, 6 and 72 h. Cell lysates were assessed for the expression of ECM proteins and signaling molecules by western blot, miRNA by qPCR, mRNA by RNA sequencing and cell supernatants for cytokine production by ELISA. PHLFs were also seeded in non-tethered collagen-I gels to measure contraction, and myofibroblast differentiation using confocal microscopy.

Citrus Flavanone Effects on the Nrf2-Keap1/GSK3/NF-κB/NLRP3 Regulation and Corticotroph-Stress Hormone Loop in the Old Pituitary.

Oxidative stress and inflammation are significant causes of aging. At the same time, citrus flavanones, naringenin (NAR), and hesperetin (HES) are bioactives with proven antioxidant and anti-inflammatory properties. Nevertheless, there are still no data about flavanone's influence and its potential effects on the healthy aging process and improving pituitary functioning. Thus, using qPCR, immunoblot, histological techniques, and biochemical assays, our study aimed to elucidate how citrus flavanones (15 mg/kg b.m. per os) affect antioxidant defense, inflammation, and stress hormone output in the old rat model. Our results showed that HES restores the redox environment in the pituitary by down-regulating the nuclear factor erythroid 2-related factor 2 (Nrf2) protein while increasing kelch-like ECH-associated protein 1 (Keap1), thioredoxin reductase (TrxR1), and superoxide dismutase 2 (SOD2) protein expression. Immunofluorescent analysis confirmed Nrf2 and Keap1 down- and up-regulation, respectively. Supplementation with NAR increased Keap1, Trxr1, glutathione peroxidase (Gpx), and glutathione reductase (Gr) mRNA expression. Decreased oxidative stress aligned with NLRP3 decrement after both flavanones and glycogen synthase kinase-3 (GSK3) only after HES. The signal intensity of adrenocorticotropic hormone (ACTH) cells did not change, while corticosterone levels in serum decreased after both flavanones. HES showed higher potential than NAR in affecting a redox environment without increasing the inflammatory response, while a decrease in corticosterone level has a solid link to longevity. Our findings suggest that HES could improve and facilitate redox and inflammatory dysregulation in the rat's old pituitary.

Correlation of brain tissue volume loss with inflammatory biomarkers IL1ß, P-tau, T-tau, and NLPR3 in the aging cognitively impaired population.

Background: Blood inflammatory biomarkers have emerged as important tools for diagnosing, assessing treatment responses, and predicting neurodegenerative diseases. This study evaluated the associations between blood inflammatory biomarkers and brain tissue volume loss in elderly people. Methods: This study included 111 participants (age 67.86 ± 8.29 years; 32 men and 79 women). A battery of the following blood inflammatory biomarkers was measured, including interleukin 1-beta (IL1ß), NACHT, LRR, and PYD domains-containing protein 3 (NLRP3), monomer Aß42 (mAß), oligomeric Aß42 (oAß), miR155, neurite outgrowth inhibitor A (nogo-A), phosphorylated tau (P-tau), and total tau (T-tau). Three-dimensional T1-weight images (3D T1WI) of all participants were prospectively obtained and segmented into gray matter and white matter to measure the gray matter volume (GMV), white matter volume (WMV), and gray-white matter boundary tissue volume (gwBTV). The association between blood biomarkers and tissue volumes was assessed using voxel-based and region-of-interest analyses. Results: GMV and gwBTV significantly decreased as the levels of IL1ß and T-tau increased, while no significant association was found between the level of P-tau and the three brain tissue volumes. Three brain tissue volumes were negatively correlated with the levels of IL1ß, P-tau, and T-tau in the hippocampus. Specifically, IL1ß and T-tau levels showed a distinct negative association with the three brain tissue volume losses in the hippocampus. In addition, gwBTV was negatively associated with the level of NLRP3. Conclusion: The observed association between brain tissue volume loss and elevated levels of IL1ß and T-tau suggests that these biomarkers in the blood may serve as potential biomarkers of cognitive impairment in elderly people. Thus, IL1ß and T-tau could be used to assess disease severity and monitor treatment response after diagnosis in elderly people who are at risk of cognitive decline.

Cytokine Storm Syndrome Associated with Systemic Juvenile Idiopathic Arthritis.

The cytokine storm syndrome (CSS) associated with systemic juvenile idiopathic arthritis (sJIA) has widely been referred to as macrophage activation syndrome (MAS). In this chapter, we use the term sJIA-associated CSS (sJIA-CSS) when referring to this syndrome and use the term MAS when referencing publications that specifically report on sJIA-associated MAS.

Anti-Interferon-γ Therapy for Cytokine Storm Syndromes.

A vast body of evidence provides support to a central role of exaggerated production of interferon-γ (IFN-γ) in causing hypercytokinemia and signs and symptoms of hemophagocytic lymphohistiocytosis (HLH). In this chapter, we will describe briefly the roles of IFN-γ in innate and adaptive immunity and in host defense, summarize results from animal models of primary HLH and secondary HLH with particular emphasis on targeted therapeutic approaches, review data on biomarkers associated with activation of the IFN-γ pathway, and discuss initial efficacy and safety results of IFN-γ neutralization in humans.

IL-1 Family Blockade in Cytokine Storm Syndromes.

Interleukin-1 is a prototypic proinflammatory cytokine that is elevated in cytokine storm syndromes (CSSs), such as secondary hemophagocytic lymphohistiocytosis (sHLH) and macrophage activation syndrome (MAS). IL-1 has many pleotropic and redundant roles in both innate and adaptive immune responses. Blockade of IL-1 with recombinant human interleukin-1 receptor antagonist has shown efficacy in treating CSS. Recently, an IL-1 family member, IL-18, has been demonstrated to be contributory to CSS in autoinflammatory conditions, such as in inflammasomopathies (e.g., NLRC4 mutations). Anecdotally, recombinant IL-18 binding protein can be of benefit in treating IL-18-driven CSS. Lastly, another IL-1 family member, IL-33, has been postulated to contribute to CSS in an animal model of disease. Targeting of IL-1 and related cytokines holds promise in treating a variety of CSS.

Methylation of Interleukin-1 receptor-associated kinase-3 and the risk of multiple sclerosis relapse/activity.

This study retrospectively investigated the impact of interleukin-1 receptor-associated kinase-3 (IRAK-3/IRAK-M) silencing by methylation on the likelihood of multiple sclerosis (MS) activity. This cross-sectional study included 90 patients with MS: 45 with active disease (Group 1), 45 in remission (Group 2), and 45 healthy controls. The study included quantitation of IRAK-3 methylation index (MI%), IRAK-3 mRNA, and myeloid differentiation factor88 (MyD88) and assessment of NF-κB activity. IRAK-3 MI% was significantly higher in group 1 compared to group 2, accompanied by lower IRAK-3 mRNA expression, elevated circulating MyD88, and increased NF-κB activity. IRAK-3 MI% correlated negatively with its transcript and positively with MyD88 and NF-κB activity. A logistic regression model was created to predict active demyelination. The C-index was 0.924, which indicates a very strong prediction model. Within the limitations of current work, IRAK-3 methylation level seems to be a promising candidate biomarker for identifying MS patients at risk of relapse.

IL-1ß Induces LDL Transcytosis by a Novel Pathway Involving LDLR and Rab27a.

BACKGROUND: In early atherosclerosis, circulating LDLs (low-density lipoproteins) traverse individual endothelial cells by an active process termed transcytosis. The CANTOS trial (Canakinumab Antiinflammatory Thrombosis Outcome Study) treated advanced atherosclerosis using a blocking antibody for IL-1ß (interleukin-1ß); this significantly reduced cardiovascular events. However, whether IL-1ß regulates early disease, particularly LDL transcytosis, remains unknown. METHODS: We used total internal reflection fluorescence microscopy to quantify transcytosis by human coronary artery endothelial cells exposed to IL-1ß. To investigate transcytosis in vivo, we injected wild-type and knockout mice with IL-1ß and LDL to visualize acute LDL deposition in the aortic arch. RESULTS: Exposure to picomolar concentrations of IL-1ß induced transcytosis of LDL but not of albumin by human coronary artery endothelial cells. Surprisingly, expression of the 2 known receptors for LDL transcytosis, ALK-1 (activin receptor-like kinase-1) and SR-BI (scavenger receptor BI), was unchanged or decreased. Instead, IL-1ß increased the expression of the LDLR (LDL receptor); this was unexpected because LDLR is not required for LDL transcytosis. Overexpression of LDLR had no effect on basal LDL transcytosis. However, knockdown of LDLR abrogated the effect of IL-1ß on transcytosis rates while the depletion of Cav-1 (caveolin-1) did not. Since LDLR was necessary but overexpression had no effect, we reasoned that another player must be involved. Using public RNA sequencing data to curate a list of Rab (Ras-associated binding) GTPases affected by IL-1ß, we identified Rab27a. Overexpression of Rab27a alone had no effect on basal transcytosis, but its knockdown prevented induction by IL-1ß. This was phenocopied by depletion of the Rab27a effector JFC1 (synaptotagmin-like protein 1). In vivo, IL-1ß increased LDL transcytosis in the aortic arch of wild-type but not Ldlr-/- or Rab27a-deficient mice. The JFC1 inhibitor nexinhib20 also blocked IL-1ß-induced LDL accumulation in the aorta. CONCLUSIONS: IL-1ß induces LDL transcytosis by a distinct pathway requiring LDLR and Rab27a; this route differs from basal transcytosis. We speculate that induction of transcytosis by IL-1ß may contribute to the acceleration of early disease.

Innate immune memory after brain injury drives inflammatory cardiac dysfunction.

The medical burden of stroke extends beyond the brain injury itself and is largely determined by chronic comorbidities that develop secondarily. We hypothesized that these comorbidities might share a common immunological cause, yet chronic effects post-stroke on systemic immunity are underexplored. Here, we identify myeloid innate immune memory as a cause of remote organ dysfunction after stroke. Single-cell sequencing revealed persistent pro-inflammatory changes in monocytes/macrophages in multiple organs up to 3 months after brain injury, notably in the heart, leading to cardiac fibrosis and dysfunction in both mice and stroke patients. IL-1ß was identified as a key driver of epigenetic changes in innate immune memory. These changes could be transplanted to naive mice, inducing cardiac dysfunction. By neutralizing post-stroke IL-1ß or blocking pro-inflammatory monocyte trafficking with a CCR2/5 inhibitor, we prevented post-stroke cardiac dysfunction. Such immune-targeted therapies could potentially prevent various IL-1ß-mediated comorbidities, offering a framework for secondary prevention immunotherapy.

SIGIRR suppresses hepatitis B virus X protein-induced chronic inflammation in hepatocytes.

Although antiviral drugs can effectively inhibit hepatitis B virus (HBV) replication, the maintenance of chronic inflammation in the liver is still considered to be an important cause for the progression of HBV-related liver disease to liver fibrosis and advanced liver disease. As an endogenous inhibitory receptor of IL-1R and TLR signaling pathways, single immunoglobulin interleukin-1-related receptor (SIGIRR) has been proven to reduce inflammation in tissues to maintain system homeostasis. However, the relationship between SIGIRR expression and HBV replication and inflammatory pathway activation in hepatocytes remains unclear. In this study, hepatitis B virus X protein (HBx) upregulated MyD88 in liver cells, promoting NF-κB signaling and inflammatory factor production with LPS treatment, and the cell supernatant accelerated the activation and collagen secretion of hepatic stellate cells. However, SIGIRR overexpression suppressed HBx-mediated MyD88/NF-κB inflammatory signaling activation and inflammatory cytokine production induced by LPS in hepatocytes and HBV replication hepatocytes. Although we did not find any effect of SIGIRR on HBV replication in vitro, this study investigated the role of SIGIRR in blocking the proinflammatory function of HBx, which may provide a new idea for the treatment of chronic hepatitis B.

Canakinumab in Yao Syndrome: Insights From a Comprehensive Case Report and Literature Review .

Yao syndrome, a rare autoinflammatory disorder linked to mutations in the nucleotide-binding oligomerization domain-containing protein-2 (NOD2) gene, manifests through periodic fever, polyarthritis, dermatitis, gastrointestinal disturbances, and sicca-like symptoms. The therapeutic landscape is limited, primarily encompassing glucocorticoids, interleukin-1 (IL-1), and IL-6 inhibitors. This report details the case of a teenager with periodic fevers, arthritis, livedo reticularis, and NOD2 gene mutations R702W and IVS8+158C consistent with Yao syndrome. The individual demonstrated significant improvement with canakinumab therapy. This case report aims to enhance recognition and understanding of Yao syndrome's clinical spectrum and management options.

Inflammatory response of leptomeninges to a single cortical spreading depolarization.

BACKGROUND: Neurogenic meningeal inflammation is regarded as a key driver of migraine headache. Multiple evidence show importance of inflammatory processes in the dura mater for pain generation but contribution of the leptomeninges is less clear. We assessed effects of cortical spreading depolarization (CSD), the pathophysiological mechanism of migraine aura, on expression of inflammatory mediators in the leptomeninges. METHODS: A single CSD event was produced by a focal unilateral microdamage of the cortex in freely behaving rats. Three hours later intact cortical leptomeninges and parenchyma of ipsi-lesional (invaded by CSD) and sham-treated contra-lesional (unaffected by CSD) hemispheres were collected and mRNA levels of genes associated with inflammation (Il1b, Tnf, Ccl2; Cx3cl1, Zc3h12a) and endocannabinoid CB2 receptors (Cnr2) were measured using qPCR. RESULTS: Three hours after a single unilateral CSD, most inflammatory factors changed their expression levels in the leptomeninges, mainly on the side of CSD. The meninges overlying affected cortex increased mRNA expression of all proinflammatory cytokines (Il1b, Tnf, Ccl2) and anti-inflammatory factors Zc3h12a and Cx3cl1. Upregulation of proinflammatory cytokines was found in both meninges and parenchyma while anti-inflammatory markers increased only meningeal expression. CONCLUSION: A single CSD is sufficient to produce pronounced leptomeningeal inflammation that lasts for at least three hours and involves mostly meninges overlying the cortex affected by CSD. The prolonged post-CSD inflammation of the leptomeninges can contribute to mechanisms of headache generation following aura phase of migraine attack.

Construction of IRAK4 inhibitor activity prediction model based on machine learning.

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a crucial serine/threonine protein kinase that belongs to the IRAK family and plays a pivotal role in Toll-like receptor (TLR) and Interleukin-1 receptor (IL-1R) signaling pathways. Due to IRAK4's significant role in immunity, inflammation, and malignancies, it has become an intriguing target for discovering and developing potent small-molecule inhibitors. Consequently, there is a pressing need for rapid and accurate prediction of IRAK4 inhibitor activity. Leveraging a comprehensive dataset encompassing activity data for 1628 IRAK4 inhibitors, we constructed a prediction model using the LightGBM algorithm and molecular fingerprints. This model achieved an R2 of 0.829, an MAE of 0.317, and an RMSE of 0.460 in independent testing. To further validate the model's generalization ability, we tested it on 90 IRAK4 inhibitors collected in 2023. Subsequently, we applied the model to predict the activity of 13,268 compounds with docking scores less than - 9.503 kcal/mol. These compounds were initially screened from a pool of 1.6 million molecules in the chemdiv database through high-throughput molecular docking. Among these, 259 compounds with predicted pIC50 values greater than or equal to 8.00 were identified. We then performed ADMET predictions on these selected compounds. Finally, through a rigorous screening process, we identified 34 compounds that adhere to the four complementary drug-likeness rules, making them promising candidates for further investigation. Additionally, molecular dynamics simulations confirmed the stable binding of the screened compounds to the IRAK4 protein. Overall, this work presents a machine learning model for accurate prediction of IRAK4 inhibitor activity and offers new insights for subsequent structure-guided design of novel IRAK4 inhibitors.