Interleukin-38 alleviates cardiac remodelling after myocardial infarction

Runt-related transcription factors: from pathogenesis to therapeutic targets in multiple-organ fibrosis

Fibrosis is a partially manageable process that leads to scarring and tissue hardening by prompting myofibroblasts to deposit significant amounts of extracellular matrix (ECM) following injury. It results in detrimental consequences and pathological characteristics, which hinder the functioning of associated organs and increase mortality rates. Runt-related transcription factors (RUNX) are part of a highly conserved family of heterodimer transcription factors, comprising RUNX1, RUNX2, and RUNX3. They are involved in several biological processes and undergo various forms of post-translational modification. RUNX regulates multiple targets and pathways to impact fibrosis, indicating promise for clinical application. Therefore, its significance in the fibrosis process should not be disregarded. The review begins with an objective description of the structure, transcriptional mechanism, and biological function of RUNX1, RUNX2, and RUNX3. A subsequent analysis is made of their physiological relationship with heart, lung, kidney, and liver, followed by a focus on the signaling mechanism of RUNX in regulating fibrosis of these organs. Furthermore, potential agents or drugs targeting RUNX for treating organ fibrosis are summarized, along with an evaluation of the therapeutic prospects and potential value of RUNX in fibrosis. Further research into RUNX could contribute to the development of novel therapeutic approaches for fibrosis.

The complex roles of IL-36 and IL-38 in cancer: friends or foes?

The interleukin-36 (IL-36) family comprises of three pro-inflammatory receptor agonists (IL-36α, IL-36β and IL-36γ), two anti-inflammatory receptor antagonists (IL-36RA and IL-38) along with the IL-36 receptor (IL-36R). Part of the IL-1 cytokine superfamily, the IL-36 family was discovered in the early 2000s due to the homology of its member sequences to the IL-1 cytokines. As pro- and anti-inflammatory cytokines, respectively, IL-36α, IL-36β, IL-36γ and IL-38 aid in maintaining homoeostasis by reciprocally regulating the body's response to damage and disease through IL-36R-associated signalling. With the significant roles of IL-36α, IL-36β and IL-36γ in regulating the immune response realised, interest has grown in investigating their roles in cancer. While initial studies indicated solely tumour-suppressing roles, more recent work has identified tumour-promoting roles in cancer, suggesting a more complex dual functionality of the IL-36 cytokines. The activity of IL-38 in cancer is similarly complex, with the receptor antagonist displaying distinct tumour-suppressive roles, particularly in colorectal cancer (CRC), in addition to broad tumour-promoting roles in various other malignancies. This review provides a comprehensive overview of the IL-36 and IL-38 cytokines, their activation and IL-36R signalling, the physiological functions of these cytokines, and their activity in cancer.

The role of IL-1 family cytokines in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is the primary cause of heart failure in patients with diabetes and is characterised by contractile dysfunction and left ventricular hypertrophy. The complex pathological and physiological mechanisms underlying DCM have contributed to a limited number of available treatment options. A substantial body of evidence has established that DCM is a low-grade inflammatory cardiovascular disorder, with the interleukin-1 (IL-1) family of cytokines playing crucial roles in initiating inflammatory responses and shaping innate and adaptive immunity. In this review, we aim to provide an overview of the underlying mechanisms of the IL-1 family and their relevance in DCM of various aetiologies. Furthermore, we highlighted potential therapeutic targets within the IL-1 family for the management of DCM.

Interleukin-38 as a potential diagnostic biomarker for heart failure

OBJECTIVE

Interleukin-38 (IL-38) attenuates inflammation, myocardial injury, and ventricular remodeling after myocardial infarction, which potentially reduces the incidence of heart failure (HF). This study aimed to evaluate the diagnostic value of IL-38 for HF.

METHODS

IL-38 was detected via enzyme-linked immunosorbent assay in the serum samples of 238 hF patients and 30 healthy controls when enrollment.

RESULTS

IL-38 was elevated in HF patients compared with controls (p = 0.002). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of IL-38 for predicting HF risk was 0.676 (95% confidence interval = 0.594-0.758). The Youden index of IL-38 for diagnosing HF peaked at 0.329 when the cutoff value of IL-38 was set as 6 ng/mL, with sensitivity and specificity of 0.833 and 0.496, respectively. Before (odds ratio = 1.493, p = 0.002) and after (odds ratio = 1.500, p = 0.007) adjustment of age and gender by multivariable regression analysis, IL-38 was associated with a higher HF risk. Moreover, the combination of IL-38 with age and gender possessed a good value for predicting HF risk (AUC = 0.796, 95% confidence interval = 0.706-0.885).

CONCLUSION

IL-38 is increased in HF patients compared with controls, and its combination with age and gender shows a good value for the diagnosis of HF.

Interleukin-38 ameliorates myocardial Ischemia-Reperfusion injury via inhibition of NLRP3 inflammasome activation in fibroblasts through the IL-1R8/SYK axis

OBJECTIVE

Although IL-38 is recognized for its regulatory role in a spectrum of chronic inflammatory diseases, investigations into its cardiac physiological and pathophysiological functions are nascent. Our aim was to delineate the biological impact of IL-38 in the context of myocardial ischemia-reperfusion injury (MIRI) and to uncover the mechanisms through which it exerts its effects.

METHODS AND RESULTS

In this study, we used an MIRI mouse model, LPS/ATP stimulation, and a hypoxia/reoxygenation cell model to determine the regulatory influence of IL-38 on MIRI. We observed that the administration of recombinant IL-38 to mice led to a reduction in infarct size, an enhancement in cardiac function, and a suppression of NLRP3 inflammasome activation. In contrast, genetic deletion of IL-38 was associated with an increase in infarct size, worsening of cardiac function, and upregulation of NLRP3 inflammasome activity. The detrimental effects associated with the absence of IL-38 were mitigated by the administration of a specific NLRP3 inhibitor, suggesting that the inhibition of NLRP3 is a critical component of the protective effect mediated by IL-38 in MIRI. In vitro assays revealed that IL-38 inhibited NLRP3 inflammasome activation in cardiac fibroblasts through the engagement of IL-1R8 and the modulation of SYK phosphorylation. Silencing of IL-1R8 negated the suppressive effect of IL-38 on the NLRP3 inflammasome.

CONCLUSION

IL-38 acts as a potent negative regulator of inflammasome activation after MIRI. It achieves this regulatory effect within cardiac fibroblasts by inhibiting SYK phosphorylation, a process mediated by IL-1R8.

Interleukin-38-overexpressing adenovirus infection in dendritic cell-based treatment enhances immunotherapy for allergic asthma via inducing Foxp3+ regulatory T cells

Allergic asthma is a chronic disease tied to unusual immune reactions involving type 2 T helper (Th2) cells specific to allergens. Dendritic cells (DCs) play a crucial role in guiding T-cell responses. Regulatory T (Treg) cells have the ability to suppress effector T-cell responses, and interleukin (IL)-38 is involved in Treg cell differentiation. In this study, we explored impacts of IL-38 on the activation and function of DCs, and we then developed an IL-38-overexpressing adenovirus (Ad-IL38) to evaluate its effectiveness in treating allergic asthma in mice through the adaptive transfer of Ad-IL38-infected DCs (IL38-DCs). Treating lipopolysaccharide (LPS)-activated bone marrow-derived DCs with recombinant IL-38 reduced cluster of differentiation 80 (CD80), CD86, and major histocompatibility complex (MHC) II expressions and decreased IL-1β, IL-6, and tumor necrosis factor (TNF)-α while increasing IL-10 secretion. The simultaneous culture of these semi-mature DCs with allogeneic CD4+ T cells facilitated the production of Forkhead box protein P3-positive (Foxp3+) Treg cells. A transcriptomic analysis revealed downregulation of the Chil3, Inhba, and Ctgf genes that are crucial for regulating inflammatory responses and cytokine-mediated signaling pathways in IL-38-treated DCs. In an animal model of asthma, IL38-DC treatment effectively decreased levels of an ovalbumin (OVA)-specific immunoglobulin E (IgE) antibody in serum, attenuated the severity of airway hyperresponsiveness, reduced the production of Th2-type cytokines (IL-4, IL-5, and IL-13) and proinflammatory cytokines (IL-6 and TNF-α) in bronchoalveolar lavage fluid, lowered expressions of the Th2-related cytokines IL-25 and thymic stromal-derived lymphopoietin (TSLP) by lung epithelial cells, and mitigated airway inflammation. Notably, enhanced expression of Foxp3+ Treg cells was linked to increased mRNA levels of transforming growth factor (TGF)-β production in vivo. In conclusion, we comprehensively clarified the immunomodulatory effects of IL-38 on DCs and provide a new treatment with IL-38 genetically modified DCs for alleviating Th2-mediated allergic diseases.

Inflammation as the nexus: exploring the link between acute myocardial infarction and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), particularly following acute exacerbations (AE-COPD), significantly heightens the risks and mortality associated with acute myocardial infarction (AMI). The intersection of COPD and AMI is characterised by a considerable overlap in inflammatory mechanisms, which play a crucial role in the development of both conditions. Although extensive research has been conducted on individual inflammatory pathways in AMI and COPD, the understanding of thrombo-inflammatory crosstalk in comorbid settings remains limited. The effectiveness of various inflammatory components in reducing AMI infarct size or slowing COPD progression has shown promise, yet their efficacy in the context of comorbidity with COPD and AMI is not established. This review focuses on the critical importance of both local and systemic inflammation, highlighting it as a key pathophysiological connection between AMI and COPD/AE-COPD.

Emerging functions and therapeutic targets of IL-38 in central nervous system diseases

Interleukin (IL)-38 is a newly discovered cytokine of the IL-1 family, which binds various receptors (i.e., IL-36R, IL-1 receptor accessory protein-like 1, and IL-1R1) in the central nervous system (CNS). The hallmark physiological function of IL-38 is competitive binding to IL-36R, as does the IL-36R antagonist. Emerging research has shown that IL-38 is abnormally expressed in the serum and brain tissue of patients with ischemic stroke (IS) and autism spectrum disorder (ASD), suggesting that IL-38 may play an important role in neurological diseases. Important advances include that IL-38 alleviates neuromyelitis optica disorder (NMOD) by inhibiting Th17 expression, improves IS by protecting against atherosclerosis via regulating immune cells and inflammation, and reduces IL-1β and CXCL8 release through inhibiting human microglial activity post-ASD. In contrast, IL-38 mRNA is markedly increased and is mainly expressed in phagocytes in spinal cord injury (SCI). IL-38 ablation attenuated SCI by reducing immune cell infiltration. However, the effect and underlying mechanism of IL-38 in CNS diseases remain inadequately characterized. In this review, we summarize the biological characteristics, pathophysiological role, and potential mechanisms of IL-38 in CNS diseases (e.g., NMOD, Alzheimer's disease, ASD, IS, TBI, and SCI), aiming to explore the therapeutic potential of IL-38 in the prevention and treatment of CNS diseases.

IL-38 alleviates airway remodeling in chronic asthma via blocking the profibrotic effect of IL-36γ

Airway remodeling is a major feature of asthma. Interleukin (IL)-36γ is significantly upregulated and promotes airway hyper-responsiveness (AHR) in asthma, but its role in airway remodeling is unknown. Here, we aimed to investigate the role of IL-36γ in airway remodeling, and whether IL-38 can alleviate airway remodeling in chronic asthma by blocking the effects of IL-36γ. IL-36γ was quantified in mice inhaled with house dust mite (HDM). Extracellular matrix (ECM) deposition in lung tissues and AHR were assessed following IL-36γ administration to mice. Airway inflammation, AHR, and remodeling were evaluated after IL-38 or blocking IL-36 receptor (IL-36R) treatment in asthmatic mice. The effects of lung fibroblasts stimulated with IL-36γ and IL-38 were quantified in vitro. Increased expression of IL-36γ was detected in lung tissues of HDM-induced asthmatic mice. The intratracheal instillation of IL-36γ to mice significantly enhanced the ECM deposition, AHR, and the number of activated lung fibroblasts around the airways. IL-38 or blocking IL-36R treated asthmatic mice showed a significant alleviation in the airway inflammation, AHR, airway remodeling, and number of activated fibroblasts around airways as compared with the HDM group. In vitro, IL-36γ promoted the activation and migration of human lung fibroblasts (HFL-1). The administration of IL-38 can counteract these biological processes induced by IL-36γ in HFL-1cells. The results indicated that IL-38 can mitigate airway remodeling by blocking the profibrotic effects of IL-36γ in chronic asthma. IL-36γ may be a new therapeutic target, and IL-38 is a potential candidate agent for inhibiting airway remodeling in asthma.

The emerging role of IL-38 in diseases: A comprehensive review

INTRODUCTION

Interleukin-38 (IL-38) is a new type of anti-inflammatory cytokine, which is mainly expressed in the immunity-related organs and is involved in various diseases including cardiovascular and cerebrovascular diseases, lung diseases, viral infectious diseases and autoimmune diseases.

AIM

This review aims to detail the biological function, receptors and signaling of IL-38, which highlights its therapeutic potential in related diseases.

CONCLUSION

This article provides a comprehensive review of the association between interleukin-38 and related diseases, using interleukin-38 as a keyword and searching the relevant literature through Pubmed and Web of science up to July 2023.

Serum IL-38 Level Was Associated with Incidence of MACE in the STEMI Patients

Background

The relationship between serum IL-38 and major adverse cardiovascular events (MACE) in patients with ST elevation myocardial infarction (STEMI) remains unclear.

Methods

In the present study, 589 STEMI patients were included, the serum level of IL-38 was measured. The median follow-up time was 720 days, the STEMI patients were divided into high IL-38 (IL-38>6.49ng/mL) and low IL-38 groups (IL-38≤6.49ng/mL) to compare the probability of MACE.

Results

Plasma IL-38 levels were significantly lower in STEMI patients than in SAP patients (4.0±2.2 vs 6.9±3.2 ng/mL, P < 0.001). Ninety-three STEMI patients met the defined MACE study endpoint. The incidence of MACE was significantly lower in patients with high IL-38 group than in patients with low IL-38 group (7.8% vs 23.7%, P < 0.001). Low plasma IL-38 levels were independently associated with the occurrence of MACE (OR = 0.90, P < 0.001).

Conclusion

We get a conclusion that low plasma levels of IL-38 are independently associated with the occurrence of MACE.

IL-38 attenuates myocardial ischemia-reperfusion injury by inhibiting macrophage inflammation

BACKGROUND

Reperfusion therapy is the most effective approach to resolve coronary occlusion, but myocardial injury caused by excessive inflammation during myocardial ischemia-reperfusion will also pose a new threat to health. Our prior study revealed the expression pattern of interleukin-38 (IL-38) in the peripheral blood serum of patients with ischemic cardiomyopathy and the role of IL-38 in acute myocardial infarction in mice. However, its role and potential mechanisms in myocardial ischemia/reperfusion injury (MIRI) remain to be determined.

METHODS AND RESULTS

The left anterior descending artery of C57BL/6 mice was transiently ligated to induce the MIRI model. We found that MIRI induced the expression of endogenous IL-38, which was mainly produced by locally infiltrating macrophages. Overexpression of IL-38 in C57BL/6 mice attenuated inflammatory injury and decreased myocardial apoptosis after myocardial ischemia-reperfusion. Furthermore, IL-38 inhibited lipopolysaccharide-induced macrophage inflammation in vitro. Cardiomyocytes cocultured with the supernatant of IL-38- and troponin I-treated macrophages showed a lower rate of apoptosis than controls.

CONCLUSIONS

IL-38 attenuates MIRI by inhibiting macrophage inflammation. This inhibitory effect may be partially achieved by inhibiting the activation of NOD-like receptor pyrin domain-related protein 3 inflammasome, resulting in decreased expression of inflammatory factors and reduced cardiomyocyte apoptosis.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

Theroleofinterleukin-1familyinfibroticdiseases

Fibrosis refers to the phenomenon that fibrous connective tissues are increased and parenchymal cells are decreased in organs or tissues such as lung, heart, liver, kidney, skin and so on. It usually occurs at the late stage of repair of chronic or recurrent tissue damage. Fibrotic disease is the main factor for the morbidity and mortality of all tissues and organ systems. Long-term fibrosis can lead to organ and tissue dysfunction and even failure. Interleukin -1 family cytokines are a series of classical inflammatory factors and involved in the occurrence and development process of multiple fibrotic diseases, its biological function, relationship with diseases and application are more and more favored by scientists from various countries. So far, 11 cytokines and 10 receptors of IL-1 family have been identified. In this paper, the cytokines, receptors, signaling pathways and biological functions of IL-1 family are summarized, and the correlation with fibrosis diseases is analyzed.

The Pathogenic Role of Oxidative Stress, Cytokine Expression, and Impaired Hematological Indices in Diabetic Cardiovascular Diseases

A simultaneous increase in the prevalence of diabetes mellitus (DM), a risk factor for cardiovascular diseases (CVDs), has contributed to the escalation of CVD related mortalities. To date, oxidative stress and inflammation are increasingly recognized as significant drivers of cardiovascular complications in patients with diabetes. Therefore, this study aims to explore the correlation between oxidative stress, inflammation, and hematological indices in diabetic patients with CVDs. Patients were allocated into five groups: healthy controls; nondiabetic patients with myocardial infarction; diabetic patients with myocardial infarction; nondiabetic patients with heart failure; and diabetic patients with heart failure. The results revealed that the malondialdehyde levels were increased; whereas superoxide dismutase enzyme activities were markedly reduced in all CVD groups compared with those of healthy controls. Although the mRNA expression levels of interleukin (IL)-6, IL-18, and IL-38 were significantly increased, those of the anti-inflammatory cytokine, IL-35, have been reduced in all CVD groups compared with healthy controls. Regarding hematological indices, hematocrit, red blood cell distribution width, mean platelet (PLT) volume, plateletcrit, PLT distribution width, leukocyte count, and PLT-to-lymphocyte and neutrophil-to-lymphocyte ratios were markedly increased in the diabetic and nondiabetic CVD groups compared with those of the healthy controls. Oxidative stress and cytokine biomarkers may play a significant role in the complications of diabetic cardiomyopathy. Moreover, hematological indices are particularly sensitive to systemic inflammatory changes and are novel markers for the early detection of diabetic cardiomyopathy.

Interleukin-38 suppresses abdominal aortic aneurysm formation in mice by regulating macrophages in an IL1RL2-p38 pathway-dependent manner

Macrophages play crucial roles in abdominal aortic aneurysm (AAA) formation through the inflammatory response and extracellular matrix degradation; therefore, regulating macrophages may suppress AAA formation. Interleukin-38 (IL-38) is a member of the IL-1 family, which binds to IL-36 receptor (IL1RL2) and has an anti-inflammation effect. Because macrophages express IL1RL2, we hypothesized that IL-38 suppresses AAA formation by controlling macrophages. We assessed a C57BL6/J mouse angiotensin II-induced AAA model with or without IL-38 treatment. RAW 264.7 cells were cultured with tumor necrosis factor-α and treated with or without IL-38. Because p38 has important roles in inflammation, we assessed p38 phosphorylation in vitro and in vivo. To clarify whether the IL-38 effect depends on the p38 pathway, we used SB203580 to inhibit p38 phosphorylation. IL1RL2+ macrophage accumulation along with matrix metalloproteinase (MMP)-2 and -9 expression was observed in mouse AAA. IL-38 reduced the incidence of AAA formation along with reduced M1 macrophage accumulation and MMP-2 and -9 expression in the AAA wall. Macrophage activities including inducible nitric oxide, MMP-2, and MMP-9 production and spindle-shaped changes were significantly suppressed by IL-38. Furthermore, we revealed that inhibition of p38 phosphorylation diminished the effects of IL-38 on regulating macrophages to reduce AAA incidence, indicating the protective effects of IL-38 depend on the p38 pathway. IL-38 plays protective roles against AAA formation through regulation of macrophage accumulation in the aortic wall and modulating the inflammatory phenotype. Using IL-38 may be a novel therapy for AAA patients.

Interleukin-38 in atherosclerosis

Chronic inflammation caused by immune cells and their mediators is a characteristic of atherosclerosis. Interleukin-38 (IL-38), a member of the IL-1 family, exerts multiple anti-inflammatory effects via specific ligand-receptor interactions. Upon recognizing a specific receptor, IL-38 restrains mitogen-activated protein kinase (MAPK), nuclear factor kappa B (NK-κB), or other inflammation-related signaling pathways in inflammatory disease. Further research has shown that IL-38 also displays anti-atherosclerotic effects and reduces the occurrence and risk of cardiovascular events. On the one hand, IL-38 can regulate innate and adaptive immunity to inhibit inflammation, reduce pathological neovascularization, and inhibit apoptosis. On the other hand, it can curb obesity, reduce hyperlipidemia, and restrain insulin resistance to reduce cardiovascular disease risk. Therefore, this article expounds on the vital function of IL-38 in the development of atherosclerosis to provide a theoretical basis for further in-depth studies of IL-38 and insights on the prophylaxis and treatment of atherosclerosis.

Clinical relevance and therapeutic potential of IL-38 in immune and non-immune-related disorders

Interleukin-38 (IL-38) is the most recent member of the IL-1 family that acts as a natural inflammatory inhibitor by binding to cognate receptors, particularly the IL-36 receptor. In vitro, animal and human studies on autoimmune, metabolic, cardiovascular and allergic diseases, as well sepsis and respiratory viral infections, have shown that IL-38 exerts an anti-inflammatory activity by modulating the generation and function of inflammatory cytokines (e.g. IL-6, IL-8, IL-17 and IL-36) and regulating dendritic cells, M2 macrophages and regulatory T cells (Tregs). Accordingly, IL-38 may possess therapeutic potential for these types of diseases. IL-38 down-regulates CCR3+ eosinophil cells, CRTH2+ Th2 cells, Th17 cells, and innate lymphoid type 2 cells (ILC2), but up-regulates Tregs, and this has influenced the design of immunotherapeutic strategies based on regulatory cells/cytokines for allergic asthma in future studies. In auto-inflammatory diseases, IL-38 alleviates skin inflammation by regulating γδ T cells and limiting the production of IL-17. Due to its ability to suppress IL-1β, IL-6 and IL-36, this cytokine could reduce COVID-19 severity, and might be employed as a therapeutic tool. IL-38 may also influence host immunity and/or the components of the cancer microenvironment, and has been shown to improve the outcome of colorectal cancer, and may participate in tumour progression in lung cancer possibly by modulating CD8 tumour infiltrating T cells and PD-L1 expression. In this review, we first briefly present the biological and immunological functions of IL-38, and then discuss the important roles of IL-38 in various types of diseases, and finally highlight its use in therapeutic strategies.

Serum VCAM-1 and ICAM-1 measurement assists for MACE risk estimation in ST-segment elevation myocardial infarction patients

Background

Vascular cell adhesion molecule‐1 (VCAM‐1) and intercellular adhesion molecule‐1 (ICAM‐1) modulate atherosclerosis by promoting leukocyte infiltration, neutrophil recruitment, endothelial cell proliferation, etc., which may directly or indirectly facilitate the occurrence of major adverse cardiac events (MACE). This study intended to investigate the value of VCAM‐1 and ICAM‐1 for predicting MACE in ST‐segment elevation myocardial infarction (STEMI) patients.

Methods

Totally, 373 STEMI patients receiving the percutaneous coronary intervention and 50 health controls (HCs) were included. Serum VCAM‐1 and ICAM‐1 were detected by ELISA. Meanwhile, MACE was recorded during a median follow‐up of 18 (range: 1–46) months in STEMI patients.

Results

Vascular cell adhesion molecule‐1 and ICAM‐1 were raised in STEMI patients compared with HCs (both p < 0.001). VCAM‐1 (p = 0.002) and ICAM‐1 (p = 0.012) high were linked with raised accumulating MACE rate in STEMI patients. Notably, VCAM‐1 high (hazard ratio [HR] = 2.339, p = 0.031), age ≥ 65 years (HR = 2.019, p = 0.039), history of diabetes mellitus (DM) (HR = 2.395, p = 0.011), C‐reactive protein (CRP) ≥ 5 mg/L (HR = 2.550, p = 0.012), multivessel disease (HR = 2.561, p = 0.007) independently predicted MACE risk in STEMI patients. Furthermore, a nomogram‐based prediction model combining these factors was established, exhibiting an acceptable value for estimating 1, 2, and 3‐year MACE risk, with AUC of 0.764, 0.716, and 0.778, respectively, in STEMI patients.

Conclusion

This study confirms the value of VCAM‐1 and ICAM‐1 measurement in predicting MACE risk in STEMI patients. Moreover, VCAM‐1 plus other traditional prognostic factors (such as age, history of DM, CRP, and multivessel disease) cloud further improve the predictive accuracy of MACE risk in STEMI patients.

Interleukin-38 promotes skin tumorigenesis in an IL-1Rrp2-dependent manner

Interleukin-38 (IL-38) is strongly associated with chronic inflammatory diseases; however, its role in tumorigenesis is poorly understood. We demonstrated that expression of IL-38, which exhibits high expression in the skin, is downregulated in human cutaneous squamous cell carcinoma and 7,12-dimethylbenzanthracene/12-O-tetradecanoyl phorbol-13-acetate-induced mouse skin tumorigenesis. IL-38 keratinocyte-specific knockout mice displayed suppressed skin tumor formation and malignant progression. Keratinocyte-specific deletion of IL-38 was associated with reduced expression of inflammatory cytokines, leading to reduced myeloid cell infiltration into the local tumor microenvironment. IL-38 is dispensable for epidermal mutagenesis, but IL-38 keratinocyte-specific deletion reduces proliferative gene expression along with epidermal cell proliferation and hyperplasia. Mechanistically, we first demonstrated that IL-38 activates the c-Jun N-terminal kinase (JNK)/activator protein 1 signal transduction pathway to promote the expression of cancer-related inflammatory cytokines and proliferation and migration of tumor cells in an IL-1 receptor-related protein 2 (IL-1Rrp2)-dependent manner. Our findings highlight the role of IL-38 in the regulation of epidermal cell hyperplasia and pro-tumorigenic microenvironment through IL-1Rrp2/JNK and suggest IL-38/IL-1Rrp2 as a preventive and potential therapeutic target in skin cancer.

IL-38 in modulating hyperlipidemia and its related cardiovascular diseases

Hyperlipidemia is confirmed to be associated with several health problems that include the combination of diabetes mellitus, obesity, and hypertension, ie, metabolic syndrome. Although the lipid-lowering therapy is an effective treatment in hyperlipidemia and its related cardiovascular diseases (CVDs), the persistence of high atherosclerotic risk is notable which could not be simply explained as a phenomenon of hyperlipidemia. Concerning on this notion, it is imperative to identify novel biomarkers which could monitor treatment and predict adverse cardiovascular events. It is demonstrated that the chronic inflammatory response caused by immune cells is a characteristic of hyperlipidemia and atherosclerosis. Notably, among several inflammatory related cytokines, interleukin 38 (IL-38), as a member of the IL-1 family, plays an important role in anti-inflammatory response by binding with its receptor which inhibits the downstream signaling pathways. In addition, IL-38 suppresses the expression of inflammatory factors mainly through the mitogen-activated protein kinase (MAPK). At the cellular level, IL-38 could inhibit the CD4 positive T lymphocyte into T-helper 17 (Th-17) lymphocyte which further enhances the immunosuppressive activity of the T-regulatory lymphocyte (T-reg) to inhibit the inflammatory response. Consistently, IL-38 is shown to be strongly correlated to development of hyperlipidemic related CVDs. In this review, the roles of IL-38 in the development of hyperlipidemia are fully summarized. Furthermore, a theoretical basis for further in-depth research of IL-38 for treatment of hyperlipidemia is also provided.

Effects of IL-38 on Macrophages and Myocardial Ischemic Injury

Macrophages play an important role in clearing necrotic myocardial tissues, myocardial ischemia-reperfusion injury, and ventricular remodeling after myocardial infarction. M1 macrophages not only participate in the inflammatory response in myocardial tissues after infarction, which causes heart damage, but also exert a protective effect on the heart during ischemia. In contrast, M2 macrophages exhibit anti-inflammatory and tissue repair properties by inducing the production of high levels of anti-inflammatory cytokines and fibro-progenitor cells. Interleukin (IL)-38, a new member of the IL-1 family, has been reported to modulate the IL-36 signaling pathway by playing a role similar to that of the IL-36 receptor antagonist, which also affects the production and secretion of macrophage-related inflammatory factors that play an anti-inflammatory role. IL-38 can relieve myocardial ischemia-reperfusion injury by promoting the differentiation of M1 macrophages into M2 macrophages, inhibit the activation of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome, and increase the secretion of anti-inflammatory cytokines, such as IL-10 and transforming growth factor-β. The intact recombinant IL-38 can also bind to interleukin 1 receptor accessory protein-like 1 (IL-1RAPL1) to activate the c-jun N-terminal kinase/activator protein 1 (JNK/AP1) pathway and increase the production of IL-6. In addition, IL-38 regulates dendritic cell-induced cardiac regulatory T cells, thereby regulating macrophage polarization and improving ventricular remodeling after myocardial infarction. Accordingly, we speculated that IL-38 and macrophage regulation may be therapeutic targets for ameliorating myocardial ischemic injury and ventricular remodeling after myocardial infarction. However, the specific mechanism of the IL-38 action warrants further investigation.

Leukocyte-Mediated Cardiac Repair after Myocardial Infarction in Non-Regenerative vs. Regenerative Systems

Innate and adaptive leukocytes rapidly mobilize to ischemic tissues after myocardial infarction in response to damage signals released from necrotic cells. Leukocytes play important roles in cardiac repair and regeneration such as inflammation initiation and resolution; the removal of dead cells and debris; the deposition of the extracellular matrix and granulation tissue; supporting angiogenesis and cardiomyocyte proliferation; and fibrotic scar generation and resolution. By organizing and comparing the present knowledge of leukocyte recruitment and function after cardiac injury in non-regenerative to regenerative systems, we propose that the leukocyte response to cardiac injury differs in non-regenerative adult mammals such as humans and mice in comparison to cardiac regenerative models such as neonatal mice and adult zebrafish. Specifically, extensive neutrophil, macrophage, and T-cell persistence contributes to a lengthy inflammatory period in non-regenerative systems for adverse cardiac remodeling and heart failure development, whereas their quick removal supports inflammation resolution in regenerative systems for new contractile tissue formation and coronary revascularization. Surprisingly, other leukocytes have not been examined in regenerative model systems. With this review, we aim to encourage the development of improved immune cell markers and tools in cardiac regenerative models for the identification of new immune targets in non-regenerative systems to develop new therapies.

Immunobiological Properties and Clinical Applications of Interleukin-38 for Immune-Mediated Disorders: A Systematic Review Study

Exponential growth in the usage of "cytokines" (as seroimmunobiomarkers) has facilitated more accurate prognosis, early diagnosis, novel, and efficient immunotherapeutics. Numerous studies have reported immunopathophysiological and immunopathological processes of interleukin-38 (IL-38). Therefore, in this systematic review article, the authors aimed to present an updated comprehensive overview on the immunobiological mechanisms, diagnostic, and immune gene-based therapeutic potentials of IL-38. According to our inclusion and exclusion criteria, a total of 216 articles were collected from several search engines and databases from the January 2012 to July 2021 time interval by using six main keywords. Physiologic or pathologic microenvironments, optimal dosage, and involved receptors affect the functionalities of IL-38. Alterations in serum levels of IL-38 play a major role in the immunopathogenesis of a wide array of immune-mediated disorders. IL-38 shows anti-inflammatory activities by reduction or inhibition of pro-inflammatory cytokines, supporting the therapeutic aspects of IL-38 in inflammatory autoimmune diseases. According to the importance of pre-clinical studies, it seems that manipulation of the immune system by immunomodulatory properties of IL-38 can increase the accuracy of diagnosis, and decipher optimal clinical outcomes. To promote our knowledge, more collaboration is highly recommended among laboratory scientists, internal/infectious diseases specialists, oncologists, immunologists, diseases-specific biomarkers scientists, and basic medical researchers.

Neutralization of interleukin-38 exacerbates coxsackievirus B3-induced acute myocarditis in mice

Background

Interleukin (IL)-38, a novel member of the IL-1 family, has been reported to be involved in several diseases associated with viral infection. However, the expression and functional role of IL-38 in acute viral myocarditis (AVMC) have not been investigated.

Methods

Male BALB/c mice were treated with intraperitoneal (i.p.) injection of coxsackievirus B3 (CVB3) for establishing AVMC models. On day 7 post-injection, the expression of IL-38 and IL-36R (IL-36 receptor) were measured. Mice were then treated with i.p. injection of mouse Anti-IL-38 Antibodies (Abs) for neutralization of IL-38. The survival, bodyweight loss, cardiac function, and myocarditis severity of mice were recorded. The percentages of splenic Th1 and Th17 cells, the expression levels of Th1/Th17-related master transcription factors (T-bet and RORγt) and cytokines were determined by flow cytometry, RT-qPCR, and ELISA, respectively. Cardiac viral replication was further detected.

Results

The mRNA and protein expression levels of IL-38 in myocardium and serum, as well as cardiac IL-36R mRNA levels were significantly elevated in mice with AVMC. Increased IL-38 levels were negatively correlated with the severity of AVMC. Neutralization of IL-38 exacerbated CVB3-induced AVMC, as verified by the lower survival rate, impaired cardiac function, continuous bodyweight loss, and higher values of HW/BW and cardiac pathological scores. In addition, neutralization of IL-38 suppressed Th1 cells differentiation while promoted Th17 cells differentiation, accompanied by decreased T-bet mRNA expression and increased RORγt expression. Down-regulation of IFN-γ and up-regulation of IL-17, TNF-α, and IL-6 mRNA and protein expression levels in myocardium and serum were also observed in the IL-38 neutralization group. Furthermore, neutralization of IL-38 markedly promoted cardiac viral replication.

Conclusions

Neutralization of IL-38 exacerbates CVB3-induced AVMC in mice, which may be attributable to the imbalance of Th1/Th17 cells and increased CVB3 replication. Thus, IL-38 can be considered as a potential therapeutic target for AVMC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01687-w.

IL-36 in chronic inflammation and fibrosis - bridging the gap?

IL-36 is a member of the IL-1 superfamily and consists of three agonists and one receptor antagonist (IL-36Ra). The three endogenous agonists, IL-36α, -β, and -γ, act primarily as proinflammatory cytokines, and their signaling through the IL-36 receptor (IL-36R) promotes immune cell infiltration and secretion of inflammatory and chemotactic molecules. However, IL-36 signaling also fosters secretion of profibrotic soluble mediators, suggesting a role in fibrotic disorders. IL-36 isoforms and IL-36 have been implicated in inflammatory diseases including psoriasis, arthritis, inflammatory bowel diseases, and allergic rhinitis. Moreover, IL-36 has been connected to fibrotic disorders affecting the kidney, lung, and intestines. This review summarizes the expression, cellular source, and function of IL-36 in inflammation and fibrosis in various organs, and proposes that IL-36 modulation may prove valuable in preventing or treating inflammatory and fibrotic diseases and may reveal a mechanistic link between inflammation and fibrosis.

IL-38 Exerts Anti-Inflammatory and Antifibrotic Effects in Thyroid-Associated Ophthalmopathy

CONTEXT

Thyroid-associated ophthalmopathy (TAO) is an organ-specific autoimmune disease closely associated with Graves' disease. IL-38, a novel cytokine in the IL-1 superfamily, has been reported to be involved in the pathogenesis of various autoimmune diseases.

OBJECTIVE

We aimed to evaluate the relationship between IL-38 and TAO disease activity and its role in inflammation and fibrosis in TAO.

METHODS

Blood samples and orbital connective tissues were collected from TAO patients and controls. Orbital fibroblasts were isolated from patients with TAO. Enzyme-linked immunosorbent assay, immunohistochemistry, flow cytometry, immunofluorescence, quantitative real-time PCR and Western blot analysis were performed.

RESULTS

Here, we demonstrated that IL-38 levels decreased in the circulation and orbital connective tissues of patients with TAO compared with the controls, and levels were negatively correlated with the clinical activity score. In vitro, potent anti-inflammatory and antifibrotic effects of IL-38 were observed. Furthermore, we revealed that IL-38 can counteract the phosphorylation of star molecules in multiple classical pathways.

CONCLUSION

IL-38 plays a protective role in TAO and is associated with its pathogenesis. Our data suggest that IL-38 may be a promising marker of TAO disease activity and a potential target for TAO therapy.

Biology of interleukin-38 and its role in chronic inflammatory diseases

Interleukin (IL)-38 is the tenth member of the IL-1 cytokine family. IL-38 shares high similarity with IL-36Ra and IL-1Ra and can bind to their receptors, thus exerting an anti-inflammatory effect. Despite the lack of a signal peptide, IL-38 can be released from several cell types, but its maturation process remains obscure. The role of IL-38 in numerous inflammatory diseases, especially in autoimmune diseases, has been extensively studied. In this review, we discuss the characteristics, biological functions and pathways of IL-38, as well as its role in several chronic inflammatory diseases. Better understanding the role of IL-38 will pave the way for clinical treatments in the near future.

Human recombinant interleukin-38 suppresses inflammation in mouse models of local and systemic disease

Interleukin (IL)-38 belongs to the IL-1 family and is part of the IL-36 subfamily due to its binding to the IL-36 Receptor (IL-1R6). In the current study, we assessed the anti-inflammatory properties of IL-38 in murine models of arthritis and systemic inflammation. First, the anti-inflammatory properties of mouse and human IL-38 precursors were compared to forms with a truncated N-terminus. In mouse bone marrow derived dendritic cells (BMDC), human and mouse IL-38 precursors with a truncation of the two N-terminal amino acids (3-152) suppressed LPS-induced IL-6. Recombinant human IL-38 (3-152) was further investigated for its immunomodulatory potential using four murine models of inflammatory disease: streptococcal cell wall (SCW)-induced arthritis, monosodium urate (MSU) crystal-induced arthritis, MSU crystal-induced peritonitis, and systemic endotoxemia. In each of these models IL-38 significantly reduced inflammation. In SCW and MSU crystal-induced arthritis, joint swelling, inflammatory cell influx, and synovial levels of IL-1β, IL-6, and KC were reduced by 50% or greater. These suppressive properties of IL-38 in SCW-induced arthritis were independent of the anti-inflammatory co-receptor IL-1R8, as IL-38 reduced arthritis equally in IL-1R8 deficient and WT mice. In MSU crystal-induced peritonitis, IL-38 reduced hypothermia, while plasma IL-6 and KC and peritoneal KC levels were reduced by 65-70%. In the LPS endotoxemia model, IL-38 pretreatment reduced systemic IL-6, TNFα and KC. Furthermore, in ex vivo cultured bone marrow, LPS-induced IL-6, TNFα and KC were reduced by 75-90%. Overall, IL-38 exhibits broad anti-inflammatory properties in models of systemic and local inflammation and therefore may be an effective cytokine therapy.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Interleukin-36 Cytokine/Receptor Signaling: A New Target for Tissue Fibrosis

Tissue fibrosis is a major unresolved medical problem, which impairs the function of various systems. The molecular mechanisms involved are poorly understood, which hinders the development of effective therapeutic strategies. Emerging evidence from recent studies indicates that interleukin 36 (IL-36) and the corresponding receptor (IL-36R), a newly-characterized cytokine/receptor signaling complex involved in immune-inflammation, play an important role in the pathogenesis of fibrosis in multiple tissues. This review focuses on recent experimental findings, which implicate IL-36R and its associated cytokines in different forms of organ fibrosis. Specifically, it outlines the molecular basis and biological function of IL-36R in normal cells and sums up the pathological role in the development of fibrosis in the lung, kidney, heart, intestine, and pancreas. We also summarize the new progress in the IL-36/IL-36R-related mechanisms involved in tissue fibrosis and enclose the potential of IL-36R inhibition as a therapeutic strategy to combat pro-fibrotic pathologies. Given its high association with disease, gaining new insight into the immuno-mechanisms that contribute to tissue fibrosis could have a significant impact on human health.

Interleukin-38 inhibits adipogenesis and inflammatory cytokine production in 3T3-L1 preadipocytes

Interleukin-38 (IL-38) is a novel member of the IL-1 cytokine family with anti-inflammatory activity. However, its effect on adipogenesis and inflammatory cytokines secretion of adipocytes in vitro has not been reported. To address whether IL-38 inhibits adipogenesis and inflammation in vitro, adipose precursor 3T3-L1 cells were cultured with or without IL-38. The morphology and size of lipid droplets in 3T3-L1 cells were measured by Oil red O staining. The mRNA expression levels of GATA-binding protein-3 (GATA-3), glucose transporter type 4 (GLUT4), peroxisome proliferator-associated receptor γ2, IL-1β, IL-6, and monocyte chemoattractant protein-1 (MCP-1) in 3T3-L1 cells were detected by real-time PCR, The contents of IL-6, IL-1β, and MCP-1 in 3T3-L1 cell medium supernatants were determined by enzyme-linked immunosorbent assay. IL-38 significantly decreased the number of lipid droplets in 3T3-L1 cells. IL-38 also increased GATA-3 and GLUT4 mRNA expression and inhibited IL-1β, IL-6, and MCP-1 secretion by 3T3-L1 cells. It is concluded that IL-38 can inhibit the differentiation of human adipocytes and inflammatory cytokine production by 3T3-L1 cells.

Interleukin-1 and the Inflammasome as Therapeutic Targets in Cardiovascular Disease

The intracellular sensing protein termed NLRP3 (for NACHT, LRR, and PYD domains-containing protein 3) forms a macromolecular structure called the NLRP3 inflammasome. The NLRP3 inflammasome plays a major role in inflammation, particularly in the production of IL (interleukin)-1β. IL-1β is the most studied of the IL-1 family of cytokines, including 11 members, among which are IL-1α and IL-18. Here, we summarize preclinical and clinical findings supporting the key pathogenetic role of the NLRP3 inflammasome and IL-1 cytokines in the formation, progression, and complications of atherosclerosis, in ischemic (acute myocardial infarction), and nonischemic injury to the myocardium (myocarditis) and the progression to heart failure. We also review the clinically available IL-1 inhibitors, although not currently approved for cardiovascular indications, and discuss other IL-1 inhibitors, not currently approved, as well as oral NLRP3 inflammasome inhibitors currently in clinical development. Canakinumab, IL-1β antibody, prevented the recurrence of ischemic events in patients with prior acute myocardial infarction in a large phase III clinical trial, including 10 061 patients world-wide. Phase II clinical trials show promising data with anakinra, recombinant IL-1 receptor antagonist, in patients with ST-segment-elevation acute myocardial infarction or heart failure with reduced ejection fraction. Anakinra also improved outcomes in patients with pericarditis, and it is now considered standard of care as second-line treatment for patients with recurrent/refractory pericarditis. Rilonacept, a soluble IL-1 receptor chimeric fusion protein neutralizing IL-1α and IL-1β, has also shown promising results in a phase II study in recurrent/refractory pericarditis. In conclusion, there is overwhelming evidence linking the NLRP3 inflammasome and the IL-1 cytokines with the pathogenesis of cardiovascular diseases. The future will likely include targeted inhibitors to block the IL-1 isoforms, and possibly oral NLRP3 inflammasome inhibitors, across a wide spectrum of cardiovascular diseases.

Interleukin-38 alleviates cardiac remodelling after myocardial infarction

Excessive immune‐mediated inflammatory reaction plays a deleterious role in ventricular remodelling after myocardial infarction (MI). Interleukin (IL)‐38 is a newly characterized cytokine of the IL‐1 family and has been reported to exert a protective effect in some autoimmune diseases. However, its role in cardiac remodelling post‐MI remains unknown. In this study, we found that the expression of IL‐38 was increased in infarcted heart after MI induced in C57BL/6 mice by permanent ligation of the left anterior descending artery. In addition, our data showed that ventricular remodelling after MI was significantly ameliorated after recombinant IL‐38 injection in mice. This amelioration was demonstrated by better cardiac function, restricted inflammatory response, attenuated myocardial injury and decreased myocardial fibrosis. Our results in vitro revealed that IL‐38 affects the phenotype of dendritic cells (DCs) and IL‐38 plus troponin I (TNI)‐treated tolerogenic DCs dampened adaptive immune response when co‐cultured with CD4⁺T cells. In conclusion, IL‐38 plays a protective effect in ventricular remodelling post‐MI, one possibility by influencing DCs to attenuate inflammatory response. Therefore, targeting IL‐38 may hold a new therapeutic potential in treating MI.