IL-33/IL-31 Axis: A Potential Inflammatory Pathway

The IL-31/CysLT2R axis is associated with itching in patients with allergic rhinitis

BACKGROUND

Itching is a troublesome symptom that disturbs patients with allergic rhinitis (AR). The molecular mechanisms underlying itching in AR need to be further illuminated. The aim of this study was to investigate the role of epithelial cell-derived interleukin-31 (IL-31) in nasal itching in AR.

METHODS

A total of 33 patients and 20 healthy control subjects were enrolled in this prospective study. The disease severity of patients with AR was assessed by the total visual analog scale score. The levels of IL-31, cysteinyl leukotriene receptor 1 (CysLT1R), and CysLT2R in the nasal brush specimens from the enrolled subjects were measured by quantitative real-time polymerase chain reaction (RT-PCR) and immunohistochemical staining. The expression of CysLT2R in a human nasal epithelial cell line (HNEpC) was assessed by immunofluorescence staining.

RESULTS

Compared with the control subjects, the protein and mRNA levels of IL-31 and CysLT2R were significantly increased in patients with AR. Higher levels of IL-31 and CysLT2R in nasal epithelial cells were associated with itching but not nasal congestion, rhinorrhea, or sneezing in AR. A significant relationship was found between IL-31 and CysLT2R in nasal epithelial cells, with a correlation coefficient of 0.93. Furthermore, RT-PCR and immunofluorescence staining revealed that IL-31 directly induced CysLT2R expression in HNEpCs. Nasal steroid treatment inhibited IL-31 and CysLT2R expression in 13 patients with AR in vivo.

CONCLUSIONS

Nasal epithelial cell-derived IL-31 might be associated with itching symptoms via CysLT2R in AR.

The relationship and clinical significance of serum cytokine expression level and skin pruritus in patients with Hodgkin lymphoma and angioimmunoblastic T-cell lymphoma

Pruritus of lymphoma is commonly associated with both Hodgkin lymphoma (HL) and angioimmunoblastic T cell lymphoma (AITL) and critically affects the life quality of patient. Recent evidence suggests that the pruritogenic cytokines seem to play a significant role in the genesis of chronic. This study aims to investigate the cytokines associated with itching in lymphoma patients and provide the basis for potential therapeutic targets. Serum samples were collected from 60 lymphoma patients, including 47 with Hodgkin lymphoma (HL) and 13 with angioimmunoblastic T-cell lymphoma (AITL), serving as the observation group (lymphoma group, LP group, n = 60). Additionally, serum samples from 8 healthy donors (HD group, n = 8) were collected for comparison. Within the lymphoma group, patients were stratified into those with pruritus (LWP group, n = 30) and those without pruritus (LWOP group, n = 30) based on the presence of skin pruritus symptoms. Elevated levels of multiple cytokines were significantly observed in the LP group in comparison to the HD group (p < 0.01). Patients in LWP group exhibited higher serum levels of IL-31 (p < 0.001), IL-1β (P = 0.039), and IL-1α (P = 0.037) compared to LWOP group. Notably, serum IL-31 levels were higher in advanced AITL patients (stage IV) than in early AITL patients (stage I-Ⅲ, P < 0.05). In subgroup analysis, patients with pruritus in the AITL group exhibited higher serum levels of MIG and CTACK compared to HL group, whereas PDGF-BB levels were significantly lower (p < 0.05). Elevated serum levels of IL-31, IL-1β, and IL-1α are linked to lymphoma-associated pruritus. Differences in serum cytokine profiles between HL and AITL subgroups are also highlighted. These findings offer valuable insights for clinical intervention in managing lymphoma-related pruritus.

Increased tissue expression of IL-31 in patients with psoriasis

Psoriasis is a chronic inflammatory skin disease, and its pathogenesis remains unclear. Although many studies have demonstrated the role of serum interleukin-31 (IL-31) in psoriasis, only one study has examined histopathological expression in lesional skin. This study aimed to investigate the expression of IL-31 in skin biopsy specimens of psoriasis patients compared to healthy subjects and identify its possible correlation to disease severity and itch intensity. Psoriasis patients and healthy volunteers were recruited. Four-millimeter punch biopsy was performed at the lesional skin of psoriasis patients and normal skin of healthy subjects. Expression of IL-31 was measured by immunohistochemistry. Baseline characteristics, disease activity, itch intensity, and related laboratory results were collected. Twenty-six biopsy specimens of psoriasis patients and 10 tissue samples of healthy subjects were evaluated. Epidermal and dermal psoriasis lesions had significantly higher IL-31 expression compared to the healthy skin (P < 0.001). However, there was no significant difference in lesional expression of IL-31 by disease severity or itch intensity. Increased IL-31 expression in the lesions of psoriasis patients suggests the involvement of IL-31 in the pathogenesis of psoriasis.

Serum IL-31 is related to the severity and 3-month prognosis of patients with Intracerebral hemorrhage

Interleukin (IL)-31/IL-33 axis has been proved to play an important role in the regulation of inflammation, and serum IL-33 was found to be a novel serum prognostic marker of intracerebral hemorrhage (ICH), while the value of serum IL-31 levels on prognosis in patients with ICH remains unknown. The present study was designed to study the value of serum IL-31 levels on prognosis in ICH patients. A total of 200 ICH patients and 50 healthy people were included in this study. We collected clinical data such as demographic data, laboratory data, admission disease scores and medical histories of these participants. We measured serum IL-31 levels using enzyme-linked immunosorbent assay, and assessed the prognosis of ICH patients 3 months after onset by mRS scale, and mRS > 2 was defined as a 3-month poor outcome. The level of IL-31 in ICH patients were significantly higher than that in healthy control people (211.91 ± 61.61 vs 167.64 ± 27.45 pg/mL, P < .001), and levels of IL-31 in ICH patients with 3-month good outcome were significantly lower than that in ICH patients with 3-month poor outcome (196.09 ± 50.84 vs 248.05 ± 41.41 pg/mL, P < .001). Results of correlation analysis suggested that the level of serum IL-31 was positively related to admission NIHSS score (r = 0.627, P < .001), hematoma volume (r = 0.352, P < .001), mRS score (r = 0.515, P < .001), high-density lipoprotein-cholesterol (r = 0.177, P = .012), serum C-reactive protein levels (r = 0.483, P < .001), and serum tumor necrosis factor α levels (r = 0.389, P < .001) in ICH patients, while the level of serum IL-31 was negatively related to the admission GCS score (r = -0.518, P < .001) and triglycerides (r = -0.147, P = .038). Results of multivariate regression analysis shows that serum IL-31 levels are an independent risk factor affecting NIHSS scores (OR = 1.023, 95% CI = 1.010-2.036) and 3-month prognosis (OR = 1.023, 95% CI = 0.982-1.747) in ICH patients. The receiver operating characteristic curve analysis showed that the sensitivity and specificity of serum IL-31 level in evaluating the prognosis of ICH were 85.2% and 76.7%, respectively. A cutoff value of serum IL-31 level > 185.30 pg/mL may indicate a poor prognosis for ICH. Serum IL-31 levels on admission in ICH patients are associated with patient prognosis, and higher serum IL-31 levels are associated with a higher risk of poor prognosis in ICH patients.

Interleukin (IL)-23, IL-31, and IL-33 Play a Role in the Course of Autoimmune Endocrine Diseases

BACKGROUND

Interleukins (IL)-23, 31, and 33 are involved in the regulation of T helper 17 (Th17)/regulatory T (Treg) cells balance. The role of IL-23, 31 and 33 in non-endocrine autoimmune diseases has been confirmed. Data on the involvement of these cytokines in endocrine autoimmune diseases are limited.

OBJECTIVE

This study aimed to determine the involvement of cytokines regulating the T helper 17 (Th17)/regulatory T (Treg) cells axis in the course of autoimmune endocrine diseases.

METHODS

A total number of 80 participants were divided into 4 groups: the autoimmune polyendocrine syndrome (APS) group consisting of APS type 2 (APS-2) and type 3 (APS-3) subgroups, the Hashimoto's thyroiditis (HT) group, the Graves' disease (GD) group and the control (C) group. Fifteen cytokines related to Th17 and Treg lymphocytes were determined in the serum of all participants.

RESULTS

Higher levels of IL-23 and IL-31 were found in the APS, GD, and HT groups compared to the C group. Higher levels of IL-23 and IL-31 were also observed in the APS-2 group, in contrast to the APS-3 group. Correlation analysis of variables in the groups showed a statistically significant correlation between the cytokines IL-23, IL-31, and IL-33 in the APS and APS-2 groups, but no correlation in the APS-3 and C groups.

CONCLUSION

IL-23 and IL-31 are independent factors in the course of HT, GD, and APS-2, in contrast to APS-3. The positive correlation between IL-23 and IL-31, IL-23 and IL-33, and between IL-31 and IL-33 in the APS, APS-2 groups, but the lack of correlation in the APS-3 and C groups may further suggest the involvement of these cytokines in the course of Addison's disease.

Juvenile idiopathic arthritis and its associated uveitis

INTRODUCTION

Juvenile idiopathic arthritis is the most common chronic rheumatologic disease in children. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition.

AREAS COVERED

In this review article, we discussed epidemiology, risk factors, clinical presentation, supportive laboratory tests, treatment options, and complications of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis associated uveitis. We covered conventional immunomodulatory therapy and biologic response modifiers agents for different types of Juvenile idiopathic arthritis and their associated uveitis. Finally, we discussed the course of disease, functional outcome, and the quality of life of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis-associated uveitis.

EXPERT OPINION

Although clinical outcomes of Juvenile idiopathic arthritis and its associated uveitis have been improved over the past three decades by biologic response modifier agents, a significant proportion of patients require active treatment into adult life therefore screening and monitoring of these patients is required during the patient's entire life. The limited number of food and drug administration approved biologic response modifier agents for the treatment of Juvenile idiopathic arthritis associated uveitis justify more randomized clinical trials with new medications in this field.

Bone marrow mesenchymal stem cell-derived exosomes alleviate skin fibrosis in systemic sclerosis by inhibiting the IL-33/ST2 axis via the delivery of microRNA-214

Interleukin (IL)- 33 is a tissue-derive proinflammatory cytokine that promotes fibrosis in systemic sclerosis (SSc). microRNA (miR)- 214 expression has been elaborated to be downregulated in SSc patients and exert anti-fibrotic and anti-inflammatory effects. This study elucidates the role of bone marrow mesenchymal stem cell-derived exosome (BMSC-Exos)-delivered miR-214 in SSc and the relationship between this miR and IL-33/ST2 axis. SSc clinical samples were obtained to evaluate levels of miR-214, IL-33, and ST2. Primary fibroblasts and BMSC-Exos were extracted, followed by the co-culture of PKH6-labeled BMSC-Exos and fibroblasts. Subsequently, Exos extracted from miR-214 inhibitor-transfected BMSCs were co-cultured with TGF-β1-stimulated fibroblasts, after which the expression of fibrotic markers, miR-214, IL-33, and ST2, as well as fibroblast proliferation and migration, was determined. A skin fibrosis mouse model was induced with bleomycin (BLM) and treated with BMSC-Exos. Collagen fiber accumulation, collagen content, α-SMA expression, and IL-33 and ST2 levels were examined in BLM-treated or IL-33-knockout mice. IL-33 and ST2 were upregulated and miR-214 was downregulated in SSc patients. Mechanistically, miR-214 targeted IL-33 and blocked the IL-33/ST2 axis. BMSC-Exos delivering miR-214 inhibitor augmented proliferation, migration, and fibrotic gene expression in TGF-β1-stimulated fibroblasts. Similarly, IL-33 induced migration, proliferation, and fibrotic gene expression in fibroblasts via ST2. In BLM-treated mice, IL-33 knockout suppressed skin fibrosis, and BMSC-Exos delivered miR-214 to suppress the IL-33/ST2 axis, thus mitigating skin fibrosis. Conclusively, BMSC-Exos alleviate skin fibrosis through the blockade of the IL-33/ST2 axis by delivering miR-214.

Endogenous IL-33 Accelerates Metacestode Growth during Late-Stage Alveolar Echinococcosis

During the course of the infectious disease alveolar echinococcosis (AE), the larval stage of Echinococcus multilocularis develops in the liver, where an initial Th1/Th17 immune response may allow its elimination in resistant individuals. In patients susceptible to infection and disease, the Th2 response initiates later, inducing tolerance to the parasite. The role of interleukin 33 (IL-33), an alarmin released during necrosis and known to drive a Th2 immune response, has not yet been described during AE. Wild-type (WT) and IL-33-/- C57BL/6J mice were infected by peritoneal inoculation with E. multilocularis metacestodes and euthanized 4 months later, and their immune response were analyzed. Immunofluorescence staining and IL-33 enzyme-linked immunosorbent assay (ELISA) were also performed on liver samples from human patients with AE. Overall, metacestode lesions were smaller in IL-33-/- mice than in WT mice. IL-33 was detected in periparasitic tissues, but not in mouse or human serum. In infected mice, endogenous IL-33 modified peritoneal macrophage polarization and cytokine profiles. Th2 cytokine concentrations were positively correlated with parasite mass in WT mice, but not in IL-33-/- mice. In human AE patients, IL-33 concentrations were higher in parasitic tissues than in distant liver parenchyma. The main sources of IL-33 were CD31+ endothelial cells of the neovasculature, present within lymphoid periparasitic infiltrates together with FOXP3+ Tregs. In the murine model, periparasitic IL-33 correlated with accelerated parasite growth putatively through the polarization of M2-like macrophages and release of immunosuppressive cytokines IL-10 and transforming growth factor β1 (TGF-β1). We concluded that IL-33 is a key alarmin in AE that contributes to the tolerogenic effect of systemic Th2 cytokines. IMPORTANCE Infection with the metacestode stage of Echinococcus multilocularis, known as alveolar echinococcosis, is the most severe cestodosis worldwide. However, less than 1% of exposed individuals, in which the immune system is unable to control the parasite, develop the disease. The factors responsible for this interindividual variability are not fully understood. In this in vivo study comparing wild-type and IL-33-/- infected mice, together with data from human clinical samples, we determined that IL-33, an alarmin released following tissue injury and involved in the pathogenesis of cancer and asthma, accelerates the progression of the disease by modulating the periparasitic microenvironment. This suggests that targeting IL-33 could be of interest for the management of patients with AE, and that IL-33 polymorphisms could be responsible for increased susceptibility to AE.

CD19+CD24highCD27+ B cell and interleukin 35 as potential biomarkers of disease activity in systemic lupus erythematosus patients

BACKGROUND

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that associates with aberrant activation of B lymphocytes and excessive autoantibodies. Interleukin 10 (IL-10)/interleukin 35 (IL-35) and IL-10/IL-35-producing regulatory B cells have been demonstrated to possess immunosuppressive functions during systemic lupus erythematosus. Here, we detected the proportion of CD19⁺CD24^highCD27⁺ B cells as well as IL-10 and IL-35 levels in peripheral blood of SLE patients and healthy individuals, and investigated their relations with clinical features of SLE.

METHODS

41 SLE patients and 25 healthy controls were recruited. The patients were divided into groups based on SLEDAI score, anti-dsDNA antibody, rash, nephritis and hematological disorder. Flow cytometry was used to detect the proportion of CD24^hiCD27⁺ B cells. ELISA was used to detect serum levels of IL-10 and IL-35.

RESULTS

Our results showed that the CD19⁺CD24^highCD27⁺ B population was decreased in active SLE patients, and anti-correlated with the disease activity. Of note, we found significant increase of IL-10 and decrease of IL-35 in SLE patients with disease activity score > 4, lupus nephritis or hematological disorders compared to those without related clinical features.

CONCLUSIONS

Reduced CD19⁺CD24^highCD27⁺ B cells expression may be involved in the pathogenesis of SLE. Moreover, we supposed that IL-35 instead of IL-10 played a crucial role in immune regulation during SLE disease.

JAK-STAT signaling pathway in the pathogenesis of atopic dermatitis: An updated review

Atopic dermatitis (AD) is a chronic, inflammatory, pruritic form of dermatosis with heterogeneous manifestations that can substantially affect patients' quality of life. AD has a complex pathogenesis, making treatment challenging for dermatologists. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a central role in modulating multiple immune axes involved in the immunopathogenesis of AD. In particular, Th2 cytokines, including interleukin (IL)-4, IL-5, IL-13, IL-31, and thymic stromal lymphopoietin, which contribute to the symptoms of chronic inflammation and pruritus in AD, are mediated by JAK-STAT signal transduction. Furthermore, JAK-STAT is involved in the regulation of the epidermal barrier and the modulation of peripheral nerves related to the transduction of pruritus. Targeting the JAK-STAT pathway may attenuate these signals and show clinical efficacy through the suppression of various immune pathways associated with AD. Topical and oral JAK inhibitors with variable selectivity have emerged as promising therapeutic options for AD. Notably, topical ruxolitinib, oral upadacitinib, and oral abrocitinib were approved by the U.S. Food and Drug Administration for treating patients with AD. Accordingly, the present study reviewed the role of JAK-STAT pathways in the pathogenesis of AD and explored updated applications of JAK inhibitors in treating AD.

Multiplex array analysis of serum cytokines offers minimal predictive value for cognitive function in the subacute phase after stroke

OBJECTIVE

The effects of inflammation on post-stroke cognitive function are still unclear. This study investigated the correlation between the Th17-related cytokines in peripheral blood and post-stroke cognitive function after ischemic stroke in the subacute phase.

DESIGN

A retrospective cohort study.

SETTING

Academic acute inpatient rehabilitation facility.

PARTICIPANTS

One hundred and fourteen patients with first ischemic stroke were categorized as the poor cognitive recovery group (n = 58) or good cognitive recovery group (n = 56) based on their cognitive MRFS efficiency.

INTERVENTIONS

All subjects received routine physical, occupational, and speech-language pathology therapy.

MAIN OUTCOME MEASURES

Serum cytokines/chemokine (IL-1 β, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p70, IL-13, IL-15, IL-17A, IL-17E, IL-17F, IL-21, IL-22, IL-23, IL-27, IL-28A, IL-31, IL-33, GM-CSF, IFN-γ, MIP-3 α, TNF-α, and TNF-β) levels were measured in duplicate using Human Th17 magnetic bead panel and multiplex array analysis (Luminex-200 system). The primary functional outcome was a gain in functional independence measure (FIM) cognitive subscore at discharge. The secondary outcome measures were FIM total score at discharge, length of stay in the hospital, and discharge destination. Cognitive Montebello Rehabilitation Factor Score (MRFS) and cognitive MRFS efficiency were calculated. Demographic and clinical characteristics were obtained from the medical record.

RESULTS

The good cognitive recovery group had an interesting trend of higher IL-13 than the poor cognitive recovery group (good cognitive recovery group 257.82 ± 268.76 vs. poor cognitive recovery group 191.67 ± 201.82, p = 0.049, unit: pg/ml). However, Pearson's correlation analysis showed no significant correlation between cytokine levels and gain of cognition, cognitive MRFS, or cognitive MRFS efficiency. Receiver operating characteristic (ROC) analysis of cytokines also suggested a low accuracy of prediction as a predictor for post-stroke cognitive recovery improvement.

CONCLUSION

Our preliminary findings suggested that the level of serum cytokines had minimal predictive value for the recovery of cognitive function during the subacute inpatient rehabilitation after stroke.

Interrelationship and Sequencing of Interleukins4, 13, 31, and 33 - An Integrated Systematic Review: Dermatological and Multidisciplinary Perspectives

The interrelations and sequencing of interleukins are complex (inter)actions where each interleukin can stimulate the secretion of its preceding interleukin. In this paper, we attempt to summarize the currently known roles of IL-4, IL-13, IL-31, and IL-33 from a multi-disciplinary perspective. In order to conduct a comprehensive review of the current literature, a search was conducted using PubMed, Google Scholar, Medscape, UpToDate, and Key Elsevier for keywords. The results were compiled from case reports, case series, letters, and literature review papers, and analyzed by a panel of multi-disciplinary specialist physicians for relevance. Based on 173 results, we compiled the following review of interleukin signaling and its clinical significance across a multitude of medical specialties. Interleukins are at the bed rock of a multitude of pathologies across different organ systems and understanding their role will likely lead to novel treatments and better outcomes for our patients. New interleukins are being described, and the role of this inflammatory cascade is still coming to light. We hope this multi-discipline review on the role interleukins play in current pathology assists in this scope.

Clinical implications of interleukins-31, 32, and 33 in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignancies in China with a high morbidity and mortality.

AIM

To determine whether interleukin (IL)-31, IL-32, and IL-33 can be used as biomarkers for the detection of GC, via evaluating the correlations between their expression and clinicopathological parameters of GC patients.

METHODS

Tissue array (n = 180) gastric specimens were utilised. IL-31, IL-32, and IL-33 expression in GC and non-GC tissues was detected immunohistochemically. The correlations between IL-31, IL-32, and IL-33 expression in GC and severity of clinicopathological parameters were evaluated. Survival curves were plotted using the Kaplan-Meier method/Cox regression. Circulating IL-31, IL-32, and IL-33 were detected by ELISA.

RESULTS

We found that the expression levels of IL-31, IL-32, and IL-33 were all lower in GC than in adjacent non-GC gastric tissues (P < 0.05). IL-33 in peripheral blood of GC patients was significantly lower than that of healthy individuals (1.50 ± 1.11 vs 9.61 ± 8.00 ng/mL, P <0.05). Decreased IL-31, IL-32, and IL-33 in GC were observed in younger patients (< 60 years), and IL-32 and IL-33 were lower in female patients (P < 0.05). Higher IL-32 correlated with a longer survival in two GC subgroups: T4 invasion depth and TNM I-II stage. Univariate/multivariate analysis revealed that IL-32 was an independent prognostic factor for GC in the T4 stage subgroup. Circulating IL-33 was significantly lower in GC patients at TNM stage IV than in healthy people (P < 0.05).

CONCLUSION

Our findings may provide new insights into the roles of IL-31, IL-32, and IL-33 in the carcinogenesis of GC and demonstrate their relative usefulness as prognostic markers for GC. The underlying mechanism of IL-31, IL-32, and IL-33 actions in GC should be further explored.

Pre-Activated Granulocytes from an Autoimmune Uveitis Model Show Divergent Pathway Activation Profiles upon IL8 Stimulation In Vitro

In the pathophysiology of autoimmune-mediated uveitis, granulocytes have emerged as possible disease mediators and were shown to be pre-activated in equine recurrent uveitis (ERU), a spontaneous disease model. We therefore used granulocytes from ERU horses to identify early molecular mechanisms involved in this dysregulated innate immune response. Primary granulocytes from healthy and ERU horses were stimulated with IL8, and cellular response was analyzed with differential proteomics, which revealed significant differences in protein abundance of 170 proteins in ERU. Subsequent ingenuity pathway analysis identified three activated canonical pathways “PKA signaling”, “PTEN signaling” and “leukocyte extravasation”. Clustered to the leukocyte extravasation pathway, we found the membrane-type GPI-anchored protease MMP25, which was increased in IL8 stimulated ERU granulocytes. These findings point to MMP25 as a possible regulator of granulocyte extravasation in uveitis and a role of this molecule in the impaired integrity of the blood-retina-barrier. In conclusion, our analyses show a clearly divergent reaction profile of pre-activated granulocytes upon IL8 stimulation and provide basic information for further in-depth studies on early granulocyte activation in non-infectious ocular diseases. This may be of interest for the development of new approaches in uveitis diagnostics and therapy. Raw data are available via ProteomeXchange with identifier PXD013648.

Increased IL-31 expression in serum and tissue protein in prurigo nodularis

Background:

Prurigo nodularis (PN) is a chronic pruritic skin disease which can greatly impact patients’ quality of life. Moreover, the pathogenesis remains unclear, making it a difficult-to-treat condition.

Aims:

To investigate the expression of interleukin-31 (IL-31) in serum and skin biopsy specimens of PN patients and healthy subjects and identify its possible correlation to disease severity and itch intensity.

Methods:

Patients with PN and healthy volunteers were recruited for the study. Expression levels of IL-31 were measured by enzyme-linked immunosorbent assay and immunohistochemistry. Baseline characteristics, disease activity, itch intensity, and related laboratory results were collected.

Results:

Forty-three PN patients and 31 healthy subjects participated in our study. The PN patients had significantly higher mean serum IL-31 levels than the healthy subjects (52.9 ± 18.2 versus 36.3 ± 10.7 pg/ml, p < 0.001). Epidermal and dermal PN lesions also exhibited significantly higher IL-31 expression compared with the healthy skin (p < 0.001 and p = 0.01, respectively). However, there was no significant difference in serum or lesional expression of IL-31 by disease severity or itch intensity.

Conclusion:

Increased IL-31 expression in serum and PN lesions suggests that IL-31 has a potential role in the pathogenesis of PN.

IL-31 expression in HIV-infected patients with different routes of disease transmission

Acquired immunodeficiency syndrome (AIDS) is caused by the human immunodeficiency virus (HIV). AIDS is characterized by an impaired immune system and low cellular immunity. The main manifestation of AIDS is a reduction in the number of CD4+ T cells and alteration in cytokine concentration. The present work aimed to explore the expression of IL-31 in HIV infection and disease progression.Serum samples were collected from HIV-infected patients with different routes of disease transmission. The subjects included 24 patients who were infected with HIV upon blood transmission and 36 patients who had acquired the disease through sexual transmission (21 cases of homosexual transmission and 15 cases of heterosexual transmission). In addition, 20 normal healthy individuals were included to serve as the control group. The levels of IL-31 in the collected serum samples were estimated using the human IL-31 Platinum ELISA kit.The serum analysis results revealed that the concentration of IL-31 in the serum samples for the blood transmission, sexually transmission, and normal group patients was 4.07 ± 1.63 pg/L, 7.43 ± 1.15 pg/L, and 2.87 ± 1.04 pg/L, respectively. The statistical analysis revealed that the concentration of IL-31 in HIV-1 infection was higher than that in the normal control. In addition, the expression of IL-31 was significantly higher in the sexual transmission group compared to the blood transmission group (P < .05).IL-31 could have an important role in HIV infection, although the role of IL-31 in disease progression in HIV-infected individuals requires further research.

Atopic dermatitis: pathomechanisms and lessons learned from novel systemic therapeutic options

Atopic dermatitis (AD) is a chronic, heterogenous, inflammatory skin disorder associated with a high skin-related health burden, typically starting in childhood and often persisting into adulthood. AD is characterized by a wide range of clinical phenotypes, reflecting multiple underlying pathophysiological mechanisms and interactions between genetics, immune system dysregulation, and environmental factors. In this review, we describe the diverse cellular and molecular mechanisms involved in AD, including the critical role of T cell-driven inflammation, primarily via T helper (Th) 2- and Th17-derived cytokines, many of which are mediated by the Janus kinase (JAK) signaling pathway. These local inflammatory processes interact with sensory neuronal pathways, contributing to the clinical manifestations of AD, including itch, pain, and sleep disturbance. The recent elucidation of the molecular pathways involved in AD has allowed treatment strategies to evolve from broad-acting systemic immunosuppressive therapies to more targeted agents, including JAK inhibitors and cytokine-specific biologic agents. Evidence from the clinical development of these targeted therapies has reinforced and expanded our understanding of the pathophysiological mechanisms underlying AD and holds promise for individualized treatment strategies tailored to specific AD subtypes.

Interleukin-33/ Suppression of Tumorigenicity 2 in Renal Fibrosis: Emerging Roles in Prognosis and Treatment

Chronic kidney disease (CKD) is a major public health problem that affects more than 10% of the population worldwide and has a high mortality rate. Therefore, it is necessary to identify novel treatment strategies for CKD. Incidentally, renal fibrosis plays a central role in the progression of CKD to end-stage renal disease (ESRD). The activation of inflammatory pathways leads to the development of renal fibrosis. In fact, interleukin-33 (IL-33), a newly discovered member of the interleukin 1 (IL-1) cytokine family, is a crucial regulator of the inflammatory process. It exerts pro-inflammatory and pro-fibrotic effects via the suppression of tumorigenicity 2 (ST2) receptor, which, in turn, activates other inflammatory pathways. Although the role of this pathway in cardiac, pulmonary, and hepatic fibrotic diseases has been extensively studied, its precise role in renal fibrosis has not yet been completely elucidated. Recent studies have shown that a sustained activation of IL-33/ST2 pathway promotes the development of renal fibrosis. However, with prolonged research in this field, it is expected that the IL-33/ST2 pathway will be used as a diagnostic and prognostic tool for renal diseases. In addition, the IL-33/ST2 pathway seems to be a new target for the future treatment of CKD. Here, we review the mechanisms and potential applications of the IL-33/ST2 pathway in renal fibrosis; such that it can help clinicians and researchers to explore effective treatment options and develop novel medicines for CKD patients.

HMGB-1 in Psoriasis

Psoriasis is a multifactorial pathology linked to systemic inflammation. Enhanced keratinocytes proliferation and a minor maturation state of the cells are typical features. Perivascular T cells, dendritic cells, macrophages, and neutrophilic granulocytes are part of the scenario completed by apoptosis dysregulation. Several proinflammatory mediators, alarmins and growth factors are increased too, both in the skin and the patients’ blood. HMGB1 is important as an alarmin in several inflammatory conditions. Released after cellular damage, HMGB1 acts as a danger signal. Several studies have considered its role in psoriasis pathogenesis. We evaluated its level in psoriasis and the potential of the alarmin blockade through standard therapies, biological treatments and using monoclonal antibodies. PV patients were shown to have significantly increased levels of HMGB1 both in lesional skin and in serum, which were linked, in some cases, to other pro-inflammatory markers and alarmins. In most cases these parameters were correlated with PASI score. Data demonstrated that blocking HMGB1 is effective in ameliorating psoriasis. Focusing on this approach could be valuable in terms of a therapeutic option for counteracting immune-related diseases in a way unthinkable until few years ago.

The Role of Serum Th1, Th2, and Th17 Cytokines in Patients with Alopecia Areata: Clinical Implications

Alopecia areata is a type of non-scarring hair loss. The dysregulation of numerous systemic Th1 (IL-2, IFN-γ, TNF, IL-12, and IL-18), Th2 (IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17E, IL-31 and IL-33) and Th17 (IL-17, IL-17F, IL-21, IL-22, IL-23 and TGF-β) cytokines was observed in patients with alopecia areata. Positive correlations between the severity of alopecia areata and an increased serum level of various cytokines including IL-2, TNF, IL-12, IL-17, and IL-17E were reported in the literature. An increased serum level of numerous cytokines, such as IL-2, IL-6, TNF, IL-12, IL-17E, and IL-22, was described as positively correlated with the duration of the disease. Moreover, it was shown that increased pre-treatment serum level of IL-12 was a positive, while increased serum levels of IL-4 and IL-13 were negative prognostic markers for the efficacy of diphenylcyclopropenone. In conclusion, alopecia areata is associated with the dysregulation of systemic Th1, Th2 and Th17 cytokines with their role in the pathogenesis, clinical manifestations and prognosis of the disease. Available data indicate the most significant role of serum IL-2, TNF, IL-12, IL-17, and IL-17E as markers of disease activity. The serum levels IL-4, IL-12 and IL-13 may be useful as potential predictors of diphenylcyclopropenone efficacy.

Alarmins, COVID-19 and comorbidities

The coronavirus SARS-CoV-2, the aetiological agent of COVID-19 disease, is representing a worldwide threat for the medical community and the society at large so that it is being defined as "the twenty-first-century disease". Often associated with a severe cytokine storm, leading to more severe cases, it is mandatory to block such occurrence early in the disease course, to prevent the patients from having more severe, sometimes fatal, outcomes. In this framework, early detection of "danger signals", possibly represented by alarmins, can represent one of the most promising strategies to effectively tailor the disease and to better understand the underlying mechanisms eventually leading to death or severe consequences. In light of such considerations, the present article aims at evaluating the role of alarmins in patients affected by COVID-19 disease and the relationship of such compounds with the most commonly reported comorbidities. The conducted researches demonstrated yet poor literature on this specific topic, however preliminarily confirming a role for danger signals in the amplification of the inflammatory reaction associated with SARS-CoV-2 infection. As such, a number of chronic conditions, including metabolic syndrome, gastrointestinal and respiratory diseases, in turn, associated with higher levels of alarmins, both foster the infection and predispose to a worse prognosis. According to these preliminary data, prompt detection of high levels of alarmins in patients with COVID-19 and co-morbidities could suggest an immediate intense anti-inflammatory treatment.Key messageAlarmins have a role in the amplification of the inflammatory reaction associated with SARS-CoV-2 infectiona prompt detection of high levels of alarmins in patients with COVID-19 could suggest an immediate intense anti-inflammatory treatment.

IL-33 genetics and epigenetics in immune-related diseases

Interleukin-33 (IL-33) is a 30KDa protein, which belongs to the Interleukin-1 cytokine family. It is a crucial regulator of innate and adaptive immune responses. This interleukin is additionally involved in the inflammatory reaction versus helminthic infections. Interleukin 33 acts on group 2 innate lymphoid cells and mast cells macrophages, dendritic cells and CD4 + Th2 cells eliciting a type 2 immune response. Moreover, the cytokine can activate the ST2 of Tregs, demonstrating its ability to downregulate inflammation. IL-33 has also an intracellular function by regulating transcription. The active IL-33 doesn’t have a signal peptide, so it’s not released across a normal secretory pathway; the interleukin is released when the cells are damages and acts like an “alarmin”. Its influence on immune activation could be slightly adjusted via fine epigenetic interactions involving cascade pathways and immune genes. Due to the diverse data emerged from different experimental research, we decided span literature to clarify, as much as possible, how IL-33 is influenced by and influence gene expression. The authors reported how its balance is influenced, according to the tissue considered. Fundamental for immune-related diseases, IL-33 has a key role in controlling inflammation. The understanding of the cytokine switch will be fundamental in a near future in order to block or activate some immune pathways. In fact, we could control interleukins effects not only by monoclonal antibodies but also by using siRNA or miRNAs for silencing or expressing key genes.

Baricitinib for the treatment of atopic dermatitis

Atopic dermatitis is a common, chronic and recurrent inflammatory skin disease, which often appears in childhood but can last into adulthood. It negatively impacts patients, their families and society in general. There is a therapeutic unmet need, with patients requiring new drugs that are safe and effective. The increasing knowledge of the pathophysiology of AD and the role of the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway in the development and maintenance of AD, has led to the development of agents blocking this intracellular signaling pathway, the JAK inhibitors. Baricitinib shows high selectivity for JAK1 and JAK2, making it appealing for the treatment of this condition. Phase II and phase III trials evaluated the efficacy and safety of baricitinib in the treatment of AD, and the results have been encouraging, showing a good efficacy and a favorable safety and tolerability profile. At the end of 2020, EMA approved baricitinib for the treatment of adult patients with moderate-to-severe atopic dermatitis who are candidates for systemic therapy, increasing the therapeutic option for this debilitating disease.

Involvement of Alarmins in the Pathogenesis and Progression of Multiple Myeloma

OBJECTIVE

Multiple Myeloma (MM) is a haematological disease resulting from the neoplastic transformation of plasma cells. The uncontrolled growth of plasma cells in the bone marrow and the delivery of several cytokines causes bone erosion that often does not regress, even in the event of disease remission. MM is characterised by a multi-step evolutionary path, which starts with an early asymptomatic stage defined as monoclonal gammopathy of undetermined significance (MGUS) evolving to overt disease.

DATA SOURCES AND STUDY SELECTION

We have selected scientific publications on the specific topics "alarmis, MGUS, and MM", drawing from PubMed. The keywords we used were alarmines, MGUS, MM, and immune system.

RESULTS

The analysis confirms the pivotal role of molecules such as high-mobility group box-1, heat shock proteins, and S100 proteins in the induction of neoangiogenesis, which represents a milestone in the negative evolution of MM as well as other haematological and non-haematological tumours.

CONCLUSIONS

Modulation of the host immune system and the inhibition of neoangiogenesis may represent the therapeutic target for the treatment of MM that is capable of promoting better survival and reducing the risk of RRMM.

Eosinophils, a Jack of All Trades in Immunity: Therapeutic Approaches for Correcting Their Functional Disorders

BACKGROUND AND OBJECTIVE

Eosinophils are primitive myeloid cells derived from bonemarrow precursors and require the intervention of interleukin (IL)-5 for their survival and persistence in blood and tissues. Under steady-state conditions, they contribute to immune regulation and homeostasis. Under pathological circumstances, eosinophils are involved in host protection against parasites and participate in allergy and inflammation.

DISCUSSION

Mostly, in asthma, eosinophils provoke airway damage via the release of granule contents and IL-13 with mucus hypersecretion and differentiation of goblet cells. Then, tissue remodeling follows with the secretion of transforming growth factor-β. Eosinophils are able to kill helminth larvae acting as antigen-presenting cells with the involvement of T helper (h)-2 cells and subsequent antibody response. However, they also exert pro-worm activity with the production of suppressive cytokine (IL- 10 and IL-4) and inhibition of nitric oxide. Eosinophils may play a pathogenic role in the course of chronic and autoimmune disease, e.g., inflammatory bowel disease and eosinophilic gastroenteritis, regulating Th2 responses and promoting a profibrotic effect. In atopic dermatitis, eosinophils are commonly detected and may be associated with disease severity. In cutaneous spontaneous urticaria, eosinophils participate in the formation of wheals, tissue remodeling and modifications of vascular permeability. With regard to tumor growth, it seems that IgE can exert anti-neoplastic surveillance via mast cell and eosinophil-mediated cytotoxicity, the so-called allergo-oncology. From a therapeutic point of view, monoclonal antibodies directed against IL-5 or the IL-5 receptors have been shown to be very effective in patients with severe asthma. Finally, as an alternative treatment, polyphenols for their anti-inflammatory and anti-allergic activities seem to be effective in reducing serum IgE and eosinophil count in bronchoalveolar lavage in murine asthma.

CONCLUSION

Eosinophils are cells endowed with multiple functions and their modulation with monoclonal antibodies and nutraceuticals may be effective in the treatment of chronic disease.

IL-31, itch and hematological malignancies

Pruritus is one of the most common symptoms experienced by neoplastic patients. The pathogenesis of neoplastic itch is complex and multifactorial and could be due to an unbalanced production of humoral mediators by altered immune effector cells. IL-31 is a pro-inflammatory cytokine produced by CD4 + T helper cells. The aim of this review was to evaluate the role of this Th2 cytokine and its receptor IL-31RA, in the onset of neoplastic pruritus. We analysed scientific literature looking for the most relevant original articles linking IL-31to itch in oncologic diseases. Interleukin-31 seems to be a main itch mediator in several hematologic disease such as Cutaneous T cells lymphomas. In these patients IL-31 was positively linked to itch level, and IL-31 matched with disease stage. IL-31 seems to play an important role in the signalling pathway involved in pruritus, but it is also suggested to play a proinflammatory and immunomodulatory role which could play a part in the progression of the neoplastic disease. Further studies will be fundamental in facing pruritus in oncologic patients, since this problem compromise their quality of life worsening an already critic picture.

Comprehensive microRNA and transcriptomic profiling of rheumatoid arthritis monocytes: role of microRNA-146b in proinflammatory progression

OBJECTIVE

To explore global miRNA and transcriptomic profiling of monocytes from rheumatoid arthritis (RA) patients compared with healthy controls (HC) to predict which aberrantly expressed microRNA (miRNA) can negatively modulate inflammatory molecules.

METHODS

Using next generation sequencing (NGS), we have performed simultaneous global analysis of miRNA (miRNA-seq) and transcriptome (RNA-seq) of monocytes from RA patients, HC. Global analysis of miRNA of systemic sclerosis (SSc) monocytes was also performed. Following differential analysis and negative correlation, miRNA-RNA pairs were selected.

RESULTS

We found that 20 specific miRNA candidates are predicted to silence inflammatory mediators, out of 191 significantly changed miRNAs in RA monocytes. Based on the highest scoring in terms of negative correlation (r=-0.97, p= 1.75e-07, FDR = 0.04) and the number of seeds in miRNA responsible for negative regulation, we selected miRNA-146b and its target gene anti-inflammatory retinoic acid receptor alpha (RARA). Similarly, to NGS, qPCR analysis also confirmed negative correlation between miRNA-146b and RARA expression (r= -0.45, p= 0.04,). Additionally, miRNA-146b expression in RA monocytes significantly correlated with clinical parameters including disease activity score-28 for RA with c-reactive protein (DAS28-CRP) and erythrocyte sedimentation rate (DAS28-ESR). Whereas overexpression of miRNA-146b was able to functionally reduce RARA expression in THP-1 monocytic cell line. Finally, circulating miRNA-146b expression in sera and synovial fluids was significantly elevated in RA patients.

CONCLUSIONS

Overall, in this study we have identified a new miRNA-146b candidate which is predicted to negatively regulate anti-inflammatory RARA transcript, whereas circulating miRNA-146b level can be used as a biomarker predicting proinflammatory RA progression and disease activity.

Advancing of Cellular Signaling Pathways in Respiratory Diseases Using Nanocarrier Based Drug Delivery Systems

Cell Signaling pathways form an integral part of our existence that allows the cells to comprehend a stimulus and respond back. Such reactions to external cues from the environment are required and are essential to regulate the normal functioning of our body. Abnormalities in the system arise when there are errors developed in these signals, resulting in a complication or a disease. Presently, respiratory diseases contribute to being the third leading cause of morbidity worldwide. According to the current statistics, over 339 million people are asthmatic, 65 million are suffering from COPD, 2.3 million are lung cancer patients and 10 million are tuberculosis patients. This toll of statistics with chronic respiratory diseases leaves a heavy burden on society and the nation's annual health expenditure. Hence, a better understanding of the processes governing these cellular pathways will enable us to treat and manage these deadly respiratory diseases effectively. Moreover, it is important to comprehend the synergy and interplay of the cellular signaling pathways in respiratory diseases, which will enable us to explore and develop suitable strategies for targeted drug delivery. This review, in particular, focuses on the major respiratory diseases and further provides an in-depth discussion on the various cell signaling pathways that are involved in the pathophysiology of respiratory diseases. Moreover, the review also analyses the defining concepts about advanced nano-drug delivery systems involving various nanocarriers and propose newer prospects to minimize the current challenges faced by researchers and formulation scientists.

Biologics in food allergy: up-to-date

Introduction: In recent years, the advent of immunotherapy has remarkably improved the management of IgE-mediated food allergy. However, some barriers still exist. Therefore, the effort of researchers aims to investigate new perspectives in the field of non-allergen specific therapy, also based on the current knowledge of the pathogenesis of this disease.Areas covered: This review aims to focus on the role of biologics as a treatment option in patients with IgE-mediated food allergy. These agents are characterized by their ability to inactivate the Th2 pro-inflammatory pathways. Biologics can be used both alone and in association with immunotherapy. Monoclonal antibodies targeting IgE, the IL-4/IL-13 axis, IL-5, and alarmins have been proposed and investigated for treating food allergy.Expert opinion: The clinical efficacy and safety of biologics have been demonstrated in several preclinical studies and randomized controlled trials. Future studies are still required to address current unmet needs, including the identification of the optimal dose to be used by ensuring the effectiveness of therapy.

A potential inflammatory role of IL-31 in psoriatic arthritis: A correlation with Th17 cytokine profile

The goals of our study were to determine the possible association of interleukin (IL)-31 with Th17 cytokine profile in serum and to quantify retinoic acid-related orphan receptor C (RORC) mRNA expression in psoriatic arthritis (PsA) patients. This cross-sectional study was conducted in 50 patients with PsA and 30 control subjects (CS) matched by age and gender. The cytokine serum levels were quantified by magnetic bead–based assay using the Bio-Plex MAGPIX system, and RORC mRNA expression was determined by quantitative polymerase chain reaction (qPCR). As a result, significant differences in IL-31 were observed between study groups (77.23 pg/mL in PsA vs 64.4 pg/mL in CS, P < 0.001) and Th17 cytokine profile serum levels (IL-17A: 6.36 pg/mL in PsA vs 2.97 pg/mL in CS, P = 0.02; IL-17F: 44.15 pg/mL in PsA vs 23.36 pg/mL in PsA, P = 0.01; IL-17E: 3.03 pg/mL in PsA vs 0.82 pg/mL in CS, P < 0.001; IL-21: 36.45 pg/mL in PsA vs 12.44 pg/mL in CS, P = 0.02); however, significant differences were not observed for IL-23 (31.2 pg/mL in PsA vs 53.26 pg/mL in CS, P = 0.58). Furthermore, positive correlations between IL-31 and Th17 cytokine profile serum levels were found (IL-17A: r_s = 0.64, P < 0.001; IL-17F: r_s = 0.73, P < 0.001; IL-17E: r_s = 0.70, P < 0.001; IL-21: r_s = 0.54, P = 0.002; IL-23: r_s = 0.5, P < 0.01). Regarding RORC gene expression, the PsA group showed an increase of 6.85-fold compared to the CS group. We did not find any association between the serum levels of cytokines and RORC gene expression. In conclusion, in PsA, there are increased serum levels of IL-31, IL-17A, IL-17F, IL-17E, and IL-21, but not IL-23. Moreover, there was a positive correlation of IL-31 with the Th17 cytokine profile and a high RORC gene expression. Altogether, these findings suggest a proinflammatory contribution of IL-31 in close association with the Th17 cytokine profile in PsA.

IL-33/Vitamin D Crosstalk in Psoriasis-Associated Osteoporosis

Patients with psoriasis (Pso) and, in particular, psoriatic arthritis (PsoA) have an increased risk of developing osteoporosis (OP). It has been shown that OP is among the more common pathologies associated with Pso, mainly due to the well-known osteopenizing conditions coexisting in these patients. Pso and OP share common risk factors, such as vitamin D deficiency and chronic inflammation. Interestingly, the interleukin (IL)-33/ST2 axis, together with vitamin D, is closely related to both Pso and OP. Vitamin D and the IL-33/ST2 signaling pathways are closely involved in bone remodeling, as well as in skin barrier pathophysiology. The production of anti-osteoclastogenic cytokines, e.g., IL-4 and IL-10, is promoted by IL-33 and vitamin D, which are stimulators of both regulatory and Th2 cells. IL-33, together with other Th2 cytokines, shifts osteoclast precursor differentiation towards macrophage and dendritic cells and inhibits receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis by regulating the expression of anti-osteoclastic genes. However, while the vitamin D protective functions in OP and Pso have been definitively ascertained, the overall effect of IL-33 on bone and skin homeostasis, because of its pleiotropic action, is still controversial. Emerging evidence suggests a functional link between vitamin D and the IL-33/ST2 axis, which acts through hormonal influences and immune-mediated effects, as well as cellular and metabolic functions. Based on the actions of vitamin D and IL-33 in Pso and OP, here, we hypothesize the role of their crosstalk in the pathogenesis of both these pathologies.

The Impact of Immunological Checkpoint Inhibitors and Targeted Therapy on Chronic Pruritus in Cancer Patients

Although pruritus may sometimes be a consequential situation to neoplasms, it more frequently emerges after commencing chemotherapy. In this review, we present our analysis of the chemotherapy treatments that most often induce skin changes and itching. After discussing conventional chemotherapies capable of inducing pruritus, we present our evaluation of new drugs such as immunological checkpoint inhibitors (ICIs), tyrosine kinase inhibitors, and monoclonal antibodies. Although ICIs and targeted therapy are thought to damage tumor cells, these therapies can modify homeostatic events of the epidermis and dermis, causing the occurrence of cutaneous toxicities in treated subjects. In the face of greater efficacy, greater skin toxicity has been reported for most of these drugs. A remarkable aspect of some reports is the presence of a probable correlation between cutaneous toxicity and treatment effectiveness in tumor patients who were treated with novel drugs such as nivolumab or pembrolizumab. Findings from these experiments demonstrate that the occurrence of any grade of skin side effects can be considered as a predictor of a better outcome. In the near future, studies on the relationship between the onset of skin alterations and outcomes could open new perspectives on the treatment of neoplasms through specific target therapy.

Aberrant expression of USF2 in refractory rheumatoid arthritis and its regulation of proinflammatory cytokines in Th17 cells

IL-17-producing Th17 cells are implicated in the pathogenesis of rheumatoid arthritis (RA) and TNF-α, a proinflammatory cytokine in the rheumatoid joint, facilitates Th17 differentiation. Anti-TNF therapy ameliorates disease in many patients with rheumatoid arthritis (RA). However, a significant proportion of patients do not respond to this therapy. The impact of anti-TNF therapy on Th17 responses in RA is not well understood. We conducted high-throughput gene expression analysis of Th17-enriched CCR6+CXCR3-CD45RA- CD4+ T (CCR6+ T) cells isolated from anti-TNF-treated RA patients classified as responders or nonresponders to therapy. CCR6+ T cells from responders and nonresponders had distinct gene expression profiles. Proinflammatory signaling was elevated in the CCR6+ T cells of nonresponders, and pathogenic Th17 signature genes were up-regulated in these cells. Gene set enrichment analysis on these signature genes identified transcription factor USF2 as their upstream regulator, which was also increased in nonresponders. Importantly, short hairpin RNA targeting USF2 in pathogenic Th17 cells led to reduced expression of proinflammatory cytokines IL-17A, IFN-γ, IL-22, and granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as transcription factor T-bet. Together, our results revealed inadequate suppression of Th17 responses by anti-TNF in nonresponders, and direct targeting of the USF2-signaling pathway may be a potential therapeutic approach in the anti-TNF refractory RA.

Increased serum IL-31 levels in chronic spontaneous urticaria and psoriasis with pruritic symptoms

Background

Chronic spontaneous urticaria (CSU) is a common pruritic skin condition, the pathogenesis of which remains unclear. Interleukin-31 (IL-31) is a major pruritogenic cytokine that plays a role in inducing pruritus in various skin diseases.

Aim.

To 1) compare serum IL-31 levels among CSU patients, psoriasis patients with pruritic symptoms, and healthy subjects, 2) examine the correlations between serum IL-31 levels and disease severity, and 3) compare IL-31 levels in patients with and without CSU-associated auto-antibodies.

Methods

Patients with CSU, psoriasis with pruritic symptoms, and healthy volunteers were recruited in the study. Serum IL-31 levels were measured with commercial kits. Baseline characteristics, urticaria activity score, psoriasis area severity index, pruritic intensity score, and related laboratory results were collected.

Results

Sixty-five CSU patients, 30 psoriasis patients who had pruritus, and 31 healthy subjects participated in our study. The CSU patients had significantly higher mean serum IL-31 levels than the psoriasis patients (252.4 ± 115.5 vs 121.4 ± 16.6 pg/mL, P < 0.001). Both CSU and psoriasis patients also had significantly higher mean serum IL-31 when compared with the healthy subjects. Serum IL-31 levels of CSU and psoriasis patients did not differ significantly according to disease or itching severity. Thyroid antibodies and antinuclear antibodies were positive in 22 (33.8%) and 28 (43.1%) CSU patients, respectively. The CSU patients with ANA titers ≥1:160 had significantly higher mean serum IL-31 levels than in those who were negative for ANA and those with titers of 1:80 (P < 0.003 and P < 0.008, respectively).

Conclusion

Higher serum IL-31 levels were found in patients with CSU and psoriasis with pruritic symptoms. This suggests that IL-31 has a possible role in the pathogenesis of CSU and psoriasis with pruritic symptoms.

Correlation between IL-31 and sCD40L plasma levels in Fingolimod-treated patients with Relapsing-Remitting Multiple Sclerosis (RRMS)

INTRODUCTION

Multiple Sclerosis (MS) is a chronic, autoimmune, demyelinating disease of the central nervous system (CNS). Currently, several protocols are described for the different phases of MS. In this longitudinal study, we aim to quantify the concentration of plasma cytokines of MS patients treated with Fingolimod alone or after Glatiramer Acetate (GA) or Interferon-beta (IFN-β), in order to compeer both treatments and describes if it is possible to use them as biomarkers.

OBJECTIVE

Compare the two different types of drug treatment and describes possible immune biomarkers in RRMS patients treated with Fingolimod alone or after GA or IFN-β.

MATERIALS AND METHODS

This is a controlled, non-randomized clinical trial. Plasma concentrations of IL-31, sCD40L and nine others cytokines were evaluated in two groups of patients with a one-year follow-up. Group 1 (n = 12): RRMS patients treated with GA or IFN-β for at least six months before the study who changed therapy to Fingolimod after six months, and Group 2 (n = 12): naïve RRMS patients who started treatment with Fingolimod. We used ANOVA two-way to analyze the cytokines and Spearman coefficient to evaluate the correlation.

RESULTS

Although Group 2 started with a greater number of relapses per disease duration, Fingolimod treatment was effective in decreasing this parameter, as well as EDSS over 12 months. However, the treatment with GA or IFN-β on Group 1 showed a tendency to increase the number of relapses after 6 months of follow-up, which decrease when the therapy was changed to Fingolimod. After the evaluation of 11 cytokines in one year, we found that IL-31 and sCD40L were the biomarkers that demonstrated a more difference when compared to the classical ones, following the clinical pattern over the treatment period.

CONCLUSIONS

Our study describes the existence of two promising plasmatic biomarkers (IL-31 and sCD40L), which reduced plasmatic levels in RRMS patients followed the treatment time of Fingolimod, despite that more studies are needed to prove their efficiency.

Characterization of immune responses and the lung transcriptome in a murine model of IL-33 challenge

IL-33 induces airway inflammation and hyper-responsiveness in respiratory diseases. Although defined as a therapeutic target, there are limited studies that have comprehensively investigated IL-33-mediated responses in the lungs in vivo. In this study, we characterized immunological and physiological responses induced by intranasal IL-33 challenge, in a mouse model. We identified specific cytokines, IL-4, IL-5, IL-6, IL-10, IP-10 and MIP1-α, that are increased in bronchoalveolar lavage and lung tissues by IL-33. Using transcriptomics (RNA-Seq) we demonstrated that 2279 transcripts were up-regulated and 1378 downregulated (≥ 2-fold, p < 0.01) in lung tissues, in response to IL-33. Bioinformatic interrogation of the RNA-Seq data was used to predict biological pathways and upstream regulators involved in IL-33-mediated responses. We showed that the mRNA and protein of STAT4, a predicted upstream regulator of IL-33-induced transcripts, was significantly enhanced in the lungs following IL-33 challenge. Overall, this study provides specific IL-33-induced molecular targets and endpoints that can be used as a resource for in vivo studies, e.g. in preclinical murine models examining novel interventions to target downstream effects of IL-33.

Review of Prominent Cytokines as Superior Therapeutic Targets for Moderate-to-Severe Atopic Dermatitis

Cytokines predominate the inflammatory pathways in diseases like rhinitis, asthma, and atopic dermatitis. Corticosteroids and immunosuppressants are presently the mainstays of treatment for patients with moderate-to-severe disease, but often accompany a poor side effect profile. In this review, we attempt to consolidate current data on various interleukins (IL) that participate in the pathogenesis of atopic dermatitis (AD) to further improve therapeutic strategies. For now, dupilumab is the most accepted biologic to be registered for treatment for moderate-to-severe disease. Recently, IL-37, IL-13, IL-26, IL-17 & IL-31/33 axis as well as proteins like thymic stromal lymphopoietin (TSLP) show promising results as future therapeutic targets because of their important role in the pathogenesis of AD. However, further studies are required to clarify the safety and efficacy of these interventions compared to current treatment modalities but it is worthwhile to pursue research into biologics as a more successful treatment option for moderate-to-severe AD.

Interleukin-31 and Chronic Pruritus of Unknown Origin

Chronic pruritus of unknown origin (CPUO) is a refractory condition. The expression of Interleukin-31 (IL-31), a major pruritogenic cytokine, in CPUO patients has not been investigated. This study aimed to investigate the potential association of IL-31 with CPUO. This was a cross-sectional, analytical study. Patients diagnosed with CPUO and healthy subjects were included at a ratio of 1:2. Serum IL-31 levels were measured in both groups and compared. There were 10 CPUO and 20 healthy subjects who participated in this study. The median IL-31 level in the CPUO group was significantly higher than in the healthy group (127.3 vs 34.4 pg/mL; P < .001). The presence of CPUO was independently associated with IL-31 levels with a coefficient of 89.678 (P < .001). The serum IL-31 cutoff point for CPUO was 56.8 pg/mL, with an area under the receiver operating characteristic curve (ROC) of 100%. Chronic pruritus of unknown origin was significantly and independently associated with higher IL-31 levels. Further clinical trials of IL-31-related treatment may be justified in CPUO patients.

Implication of Increased Serum IL-31 for Primary Biliary Cholangitis

Interleukin-31 (IL-31) has diverse biological functions. Increased IL-31 has been found in some skin and autoimmune diseases. There has been no study reporting the association between IL-31 and primary biliary cholangitis (PBC). This study was designed to determine serum IL-31 level and to explore its diagnostic value for PBC as well as the association of IL-31 with inflammatory and fibrotic progression. 60 PBC patients, 32 age- and sex-matched patients with chronic hepatitis B (CHB) and 30 age- and sex-matched healthy controls (HC) were recruited. The sera were detected for IL-31, IL-4, interferon gamma (IFN-γ), IL-17 and other laboratory indicators. Serum IL-31 levels were significantly higher in PBC patients (median, IQR, 20.6, 16.7-26.2, pg/ml) than CHB patients (median, IQR, 11.3, 8.0-13.0, pg/ml) and HC (median, IQR, 11.0, 10.0-12.2 pg/ml) (P < .001). Serum IL-31 performed well for identifying PBC, especially for antimitochondrial antibodies (AMA)-negative PBC with AUC of 0.900, optimal cutoff value of 13.6 pg/ml, sensitivity of 87.5% and specificity of 83.9%. Serum IL-31 was positively correlated with platelet count (r = 0.368, P = .004), but negatively with FIB4 (r = -0.307, P = .017) and histological stages (r = -0.364, P = .004) in PBC patients. It was also significantly correlated with IFN-γ (r = 0.404, P = .001) and IL-4 (r = 0.291, P = .026), but not with IL-17 (r = 0.151, P = .259) in PBC patients. Serum IL-31 is increased in and may be a useful marker for PBC, in particular, for AMA-negative PBC. Furthermore, it is inversely associated with fibrotic progression of PBC.

The Effect of Statins through Mast Cells in the Pathophysiology of Atherosclerosis: a Review

PURPOSE OF REVIEW

In this review, we discuss the evidence supporting the effects of statins on mast cells (MCs) in atherosclerosis and their molecular mechanism of action.

RECENT FINDINGS

Statins or HMG-CoA reductase inhibitors are known for their lipid-lowering properties and are widely used in the prevention and treatment of cardiovascular diseases. There is growing evidence that statins have an inhibitory effect on MCs, which contributes to the pleiotropic effect of statins in various diseases. MCs are one of the crucial effectors of the immune system which play an essential role in the pathogenesis of multiple disorders. Recent studies have shown that MCs are involved in the development of atherosclerotic plaques. MCs secrete various inflammatory cytokines (IL-6, IL4, TNF-α, and IFNγ) and inflammatory mediators (histamine, tryptase, proteoglycans) after activation by various stimulants. This, in turn, will exacerbate atherosclerosis. Statins suppress the activation of MCs via IgE inhibition which leads to inhibition of inflammatory mediators and cytokines which are involved in the development and progression of atherosclerosis. In keeping with this evidence presented here, MCs can be considered as one of the therapeutic targets for statins in the treatment of atherosclerosis.

A Phytocomplex Consisting of Tropaeolum majus L. and Salvia officinalis L. Extracts Alleviates the Inflammatory Response of Dermal Fibroblasts to Bacterial Lipopolysaccharides

Background

The antimicrobial activity and effects of a phytocomplex consisting of Tropaeolum flos (T) and Salviae folium (S) extracts on the cytokine levels and transcription factors on dermal fibroblast BJ exposed to bacterial lipopolysaccharides were examined.

Methods

In order to select the most optimal combination ratio of the two extracts for using in vitro, the physicochemical characterization of vegetal extract mixtures was performed and the antioxidant and antibacterial activities were evaluated on five different formulations of T : S, namely, 1 : 1, 1 : 2, 2 : 1, 3 : 1, and 1 : 3. The best combination of bioactive compounds with regard to antioxidant and antibacterial activities (T : S 1 : 2) was selected for in vitro evaluation of the anti-inflammatory effect. Human dermal fibroblast BJ cells were treated with two doses of the extract mixture and then exposed to bacterial lipopolysaccharides (LPS). The levels of the cytokines involved in inflammatory response, namely, interleukin- (IL-) 6, tumor necrosis factor- (TNF-) α, IL-31, and IL-33, were quantified by ELISA, and the expression of transcription factors, namely, signal transducer and activator of transcription (STAT) 3, nuclear factor kappa B (NFκB), and phosphorylated NFκB (pNFκB), were evaluated by western blot analysis.

Results

The results have shown that the mixture of T : S 1 : 2 exhibited significant antibacterial effects on Staphylococcus aureus ATCC 25923. LPS exposure increased the cytokine levels in BJ cells and enhanced the NFκB expression. The pretreatment of BF cells exposed to LPS with the two doses of the extract mixture markedly inhibited the increase of IL-33 and TNF-α levels and amplified the NFκB expression and its activation, especially with the high dose. The low doses of the extract reduced NFκB expression but increased its activation.

Conclusions

These experimental findings suggest that the mixture of T : S 1 : 2 can exert some protection against bacterial infections and inflammation induced by LPS in BJ cells being a good therapeutic option in related conditions associated with inflammation.

Interleukin-31 interaction with inflammasome: A promising diagnostic and prognostic panel for early sepsis identification in critically ill patients

PURPOSE

This case-control study aimed to evaluate the ability to use a panel of IL-31, IL-1ß and NLRP3 to differentiate sepsis from systemic inflammatory response syndrome (SIRS) and to predict septic shock.

METHODS

Serum levels of IL-31, IL-1ß and NLRP3 were measured by ELISA in 149 participants; 38 with sepsis, 51 with SIRS, 30 with septic shock and 30 healthy controls.

RESULTS

Lower levels of IL-31 were found in sepsis (10.21 ± 4.34 pg/ml) compared to SIRS (16.74 ± 3.18 pg/ml) and to controls with the lowest levels detected in septic shock (6.26 ± 2.72 pg/ml). IL-1ß and NLRP3 levels were higher in sepsis (54.99 ± 14.11 pg/ml and 9.93 ± 2.38 ng/ml) compared to SIRS (27.8 ± 6.94 pg/ml and 4.86 ± 1.33 ng/ml) with the highest levels seen in septic shock (125.1 ± 32.79 pg/ml and 19.43 ± 6.48 ng/ml) respectively. IL-31 discriminated sepsis in patients showing SIRS with 80% sensitivity and 70% specificity and, identified septic shock with 78.6% sensitivity and 60.3% specificity. IL-1ß identified sepsis from SIRS with 93.3% and 83.3% specificity. NLRP3 discriminated sepsis from SIRS with 94.5% sensitivity and 93.3% specificity. And, with sensitivity 99.1% and 90.1% and specificity 98.9% and 80% IL-1ß and NLRP3 could respectively define septic shock. A panel of combined markers provided 100% sensitivity and specificity. The three biomarkers proved to be independent prognostic biomarkers. At 95% CI, IL-31 hazard ratio (HR) was 0.716, p = 0.001; IL-1β HR was 1.023, p ≤ 0.001; and NLRP3 HR was 1.114, p ≤ 0.001. Additionally, IL-1ß proved to be an independent predictor of septic shock (β = 0.355; p = 0.035).

CONCLUSION

The cross-relation between IL-31, IL-1ß and NLRP3 in sepsis can provide a promising diagnostic and prognostic panel.

Effect of Luteolin and Apigenin on the Production of Il-31 and Il-33 in Lipopolysaccharides-Activated Microglia Cells and Their Mechanism of Action

Microglia cells are resident cells of the central nervous system (CNS) charged with modulating inflammation in the CNS. Overstimulation of microglia cells continuously releases inflammatory mediators that contribute to neurodegenerative diseases. Apigenin and Luteolin are flavonoids with reported anti-inflammatory activities. However, their effects on IL-31 and IL-33 production in microglial cells are unknown. Here, we investigated the effects of apigenin and luteolin on the production of IL-31 and IL-33 by microglia cells. SIM-A9 microglial cells were pre-treated with apigenin or luteolin and stimulated with lipopolysaccharides to evaluate the production of IL-31 and IL-33. The study revealed that apigenin and luteolin inhibited the production of IL-31 and IL-33 at the gene and protein expressions and the secretion levels. Using potent inhibitors of MAPK, NF-κB, and STAT3 signaling pathways, we demonstrated that apigenin and luteolin’s suppression of ERK and JNK contributed to the inhibition of IL-31 and IL-33 in the MAPK pathway. Luteolin’s suppression of NF-κB and STAT3 also contributed to the inhibition of IL-31 and IL-33. Further analysis revealed that both compounds prevented nuclear translocation of activated NF-κB and STAT3, an act that subsequently prevented their DNA binding activities. Collectively, the study suggested that apigenin and luteolin’s regulation of signaling pathways contributed to the inhibition of IL-31 and IL-33, thus suggesting its importance for the improvement of neurodegenerative diseases involving these two cytokines.

IL-33/IL-31 Axis in Osteoporosis

The study of the immunoskeletal interface has led to the discovery of numerous cytokines involved in the regulation of bone remodeling, providing valuable information on the pathogenesis of osteoporosis. The role of inflammatory cytokines of the Th1 and Th17 profile in osteoporosis is well known. Here we focus on two newly discovered Th2 cytokines, IL-31 and IL-33, whose implications in osteoporosis are recently emerging. Clinical and experimental observations suggest an important role of the IL-33/IL-31 axis in osteoporosis. IL-33 induces IL-31 secretion by Th2 cells and inhibits RANKL-dependent osteoclastogenesis, thus counteracting bone loss. IL-31 influences Th1/Th17 osteoclastogenetic inflammation and limits Th2 osteoprotective processes, thus favoring osteoporosis. Better knowledge of the role of IL-31 and IL-33 and their receptor complexes in osteoporosis could provide an interesting perspective for the development of new and more effective therapies, possibly with less side effects.

Keratinocyte-specific ablation of Mcpip1 impairs skin integrity and promotes local and systemic inflammation

MCPIP1 (Regnase-1, encoded by the ZC3H12A gene) regulates the mRNA stability of several inflammatory cytokines. Due to the critical role of this RNA endonuclease in the suppression of inflammation, Mcpip1 deficiency in mice leads to the development of postnatal multiorgan inflammation and premature death. Here, we generated mice with conditional deletion of Mcpip1 in the epidermis (Mcpip1^EKO). Mcpip1 loss in keratinocytes resulted in the upregulated expression of transcripts encoding factors related to inflammation and keratinocyte differentiation, such as IL-36α/γ cytokines, S100a8/a9 antibacterial peptides, and Sprr2d/2h proteins. Upon aging, the Mcpip1^EKO mice showed impaired skin integrity that led to the progressive development of spontaneous skin pathology and systemic inflammation. Furthermore, we found that the lack of epidermal Mcpip1 expression impaired the balance of keratinocyte proliferation and differentiation. Overall, we provide evidence that keratinocyte-specific Mcpip1 activity is crucial for the maintenance of skin integrity as well as for the prevention of excessive local and systemic inflammation. KEY MESSAGES: Loss of murine epidermal Mcpip1 upregulates transcripts related to inflammation and keratinocyte differentiation. Keratinocyte Mcpip1 function is essential to maintain the integrity of skin in adult mice. Ablation of Mcpip1 in mouse epidermis leads to the development of local and systemic inflammation.

IL-33/IL-31 Axis in Immune-Mediated and Allergic Diseases

Several allergic and immunologic diseases including asthma, food allergy (FA), chronic spontaneous urticaria (CSU), atopic dermatitis (AD), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA), and Behçet's disease (BD) are characterized by the involvement of Th2 immunity. Several mediators lead to immunoglobulin (Ig)E production, thus including key cytokines such as interleukin (IL)-4, IL-5, and IL-13. Among them, IL-31 and IL-33 have been recently studied as novel biomarkers and future therapeutic targets for allergic and immunological disorders. IL-31 is a proinflammatory cytokine-it regulates cell proliferation and is involved in tissue remodeling. IL-33, acting through its receptor suppression of tumorigenity (ST2L), is an alarmin cytokine from the IL-1 family, whose expression is mediated by tissue damage. The latter has a pleiotropic effect, as it may modulate specific and innate immune cells functions. To date, several researchers have investigated the involvement of IL-31 and IL-33 in several allergic and immune-mediated diseases. Further studies are needed to understand the future applications of these molecules as novel therapeutic agents. This paper aims to give the readers a complete and updated review of IL-31 and IL-33 involvement among the most common autoimmune and allergic disorders.

Possible Roles of IL-33 in the Innate-Adaptive Immune Crosstalk of Psoriasis Pathogenesis

Background

IL-33 belongs to the IL-1 family, playing a role in several biologic processes as well as in the pathogenesis of different diseases, including skin pathologies. It acts as an alarmin, released by damaged cells. Binding to a ST2 receptor, it stimulates many immune cells such as ILC2 and Th2 cells. IL-33/ST2 axis seems to be involved in Th17 response. According to this, a review was performed to analyze if IL-33 even interplay in the onset of psoriasis, a Th1/Th17 inflammatory disease.

Methods

Data obtained from the included articles are study author name, publication date, group studied, clinical and biological variables, laboratory tests, and outcome of interest of the study.

Results

Data are obtained from the 19 studies identified, which assessed the association between IL-33 and psoriasis.

Discussion

It seems to promote the innate-adaptive immune crosstalk: it could induce mast cells and neutrophil response after being released by injured keratinocytes and after stimulation by some cytokines, in particular TNFα, INFγ, and IL-17A. In addition, it seems to be involved from the onset of disease to the development of comorbidities, as psoriatic arthritis.

Conclusion

The core of the future research on psoriasis could be to fully understand the role of this complex cytokine, in order also to find a new therapeutic approach.