IL-32, a Novel Proinflammatory Cytokine in Chronic Obstructive Pulmonary Disease

A lactobacilli-based inhaled live biotherapeutic product attenuates pulmonary neutrophilic inflammation

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity. Exposure to noxious stimuli such as hyperoxia, volutrauma, and infection in infancy can have long-reaching impacts on lung health and predispose towards the development of conditions such as chronic obstructive pulmonary disease (COPD) in adulthood. BPD and COPD are both marked by lung tissue degradation, neutrophil influx, and decreased lung function. Both diseases also express a change in microbial signature characterized by firmicute depletion. However, the relationship between pulmonary bacteria and the mechanisms of downstream disease development has yet to be elucidated. We hypothesized that murine models of BPD would show heightened acetylated proline-glycine-proline (Ac-PGP) pathway and neutrophil activity, and through gain- and loss-of-function studies we show that Ac-PGP plays a critical role in driving BPD development. We further test a inhaled live biotherapeutic (LBP) using active Lactobacillus strains in in vitro and in vivo models of BPD and COPD. The Lactobacillus-based LBP is effective in improving lung structure and function, mitigating neutrophil influx, and reducing a broad swath of pro-inflammatory markers in these models of chronic pulmonary disease via the MMP-9/PGP (matrix metalloproteinase/proline-glycine-proline) pathway. Inhaled LBPs show promise in addressing common pathways of disease progression that in the future can be targeted in a variety of chronic lung diseases.

Transgenic mice applications in the study of endometriosis pathogenesis

Endometriosis (EM), characterized by ectopic growth of endometrial tissues and recurrent pelvic pain, is a common disease with severe negative impacts on the life quality of patients. Conventional uterine tissue transplantation-based models have been broadly used to investigate the pathogenic mechanism(s) of EM. Transgenic mice with whole body or uterine/pelvic tissue-specific labelling by the expression of GFP, β-gal or other light-emitting or chromogenic markers enable investigators to analyze the contribution to endometriotic lesions by the donor or recipient side after uterine tissue transplantation. Moreover, when coupled to uterine tissue transplantation, transgenic mice with a specific EM-related gene knocked out or overexpressed make it possible to determine the gene's in vivo role(s) for EM pathogenesis. Furthermore, observations on the rise of de novo endometriotic lesions as well as structural/functional changes in the eutopic endometrium or pelvic tissues after gene manipulation will directly relate the cognate gene to the onset of EM. A major advantage of transgenic EM models is their efficiency for analyzing gene interactions with hormonal, dietetic and/or environmental factors. This review summarizes the features/sources/backgrounds of transgenic mice and their applications to EM studies concerning hormonal regulation, angiogenesis and inflammation. Findings from these studies, the advantages/disadvantages of transgenic EM models, and future expectations are also discussed.

Stimulated Human Umbilical Cord Mesenchymal Stem Cells Enhance the Osteogenesis and Cranial Bone Regeneration through IL-32 Mediated P38 Signaling Pathway

Objective

Our previous study found that it could significantly increase the expression of IL32 after stimulating the human umbilical cord mesenchymal stem cells (S-HuMSCs). However, its role on the osteogenesis and cranial bone regeneration is still largely unknown. Here, we investigated the possible mechanism of this effect. Material and Methods. A series of experiments, including single-cell sequencing, flow cytometry, quantitative real-time polymerase chain reaction, and western blotting, were carried out to evaluate the characteristic and adipogenic-osteogenic differentiation potential of IL-32 overexpression HuMSCs (IL-32highHuMSCs) through mediating the P38 signaling pathway. Moreover, a rat skull bone defect model was established and treated by directly injecting the IL-32highHuMSCs to conduct its role on the cranial bone regeneration.

Results

In total, it found that compared to HuMSCs, IL32 was significantly increased and promoted the osteogenic differentiation (lower expressions of PPARγ, Adiponectin, and C/EBPα, and increased expressions of RUNX2, ALP, BMP2, OPN, SP7, OCN, and DLX5) in the S-HuMSCs (P < 0.05). Meanwhile, the enhanced osteogenic differentiation of HuMSCs was recovered by IL-32 overexpression (IL-32highHuMSCs) through activating the P38 signaling pathway, like as the S-HuMSCs (P < 0.05). However, the osteogenic differentiation potential of IL-32highHuMSCs was significantly reversed by the P38 signaling pathway inhibitor SB203580 (P < 0.05). Additionally, the HuMSCs, S-HuMSCs, and IL-32highHuMSCs all presented adipogenic-osteogenic differentiation potential, with higher levels of CD73, CD90, and CD105, and lower CD14, CD34, and CD45 (P > 0.05). Furthermore, these findings were confirmed by the rat skull bone defect model, in which the cranial bone regeneration was more pronounced in the IL-32highHuMSCs treated group compared to those in the HuMSCs group, with higher expressions of RUNX2, ALP, BMP2, and DLX5 (P < 0.05).

Conclusion

We have confirmed that S-HuMSCs can enhance the osteogenesis and cranial bone regeneration through promoting IL-32-mediated P38 signaling pathway, which is proved that IL-32 may be a therapeutic target, or a biomarker for the treatment of cranial bone injuries.

Exploring the importance of m5c in the diagnosis and subtype classification of COPD using the GEO database

BACKGROUND

5-Methylcytosine (m5C) is an mRNA modifier that is associated with the occurrence and development of viral infection, pulmonary fibrosis, lung cancer, and other diseases. However, the role of m5C regulators in chronic obstructive pulmonary disease (COPD) remains unknown.

METHODS

In this study, by analysing the GSE42057 dataset, the differential expression of m5c regulators in the COPD group and control group was obtained, and a correlation analysis was conducted. The random forest model and support vector machine model were used to predict the occurrence of COPD. A nomogram model was also constructed to predict the prevalence of COPD. The COPD patients were divided into subtypes by consistent cluster analysis based on m5c methylation regulators. Immune cell infiltration was performed on the m5c methylation subtypes. Differentially expressed genes (DEGs) between m5c methylation subtypes were screened, and the DEGs were analysed by Gene Ontology (GO) Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, we verified the expression of several m5C regulators and related pathways using a COPD cell model.

RESULTS

Seven m5c methylation regulators were differentially expressed. The random forest model based on the above genes was the most accurate for predicting the occurrence of COPD. A nomogram model based on the above genes could also accurately predict the prevalence of COPD, and the implementation of these models could benefit COPD patients. The consistent cluster analysis divided the COPD patients into two subtypes (Cluster A and Cluster B). The main component analysis algorithm determined the m5c methylation subtypes and found that patients in Cluster A had a higher m5c score than those in Cluster B. GO analysis of the DEGs between the m5c methylation COPD patient subtypes revealed that DEGS were mainly enriched in leukocyte-mediated immunity and regulation of T-cell activation. KEGG analysis revealed that DEGS were mainly enriched in Th1 and Th2 cell differentiation, neutrophil extracellular trap formation, and the NF-κB signalling pathway. Immunocyte correlation analysis revealed that Cluster B was associated with neutrophil- and macrophage-mediated immunity, while Cluster A was associated with CD4 + T-cell- and CD8 + T-cell-mediated immunity. Cell experiments have also verified some of the above research results.

CONCLUSION

The diagnosis and subtype classification of COPD patients based on m5c regulators may provide a new strategy for the diagnosis and treatment of COPD.

Differential Impact of IL-32 Isoforms on the Functions of Coronary Artery Endothelial Cells: A Potential Link with Arterial Stiffness and Atherosclerosis

Chronic inflammation is associated with higher risk of cardiovascular disease (CVD) in people living with HIV (PLWH). We have previously shown that interleukin-32 (IL-32), a multi-isoform proinflammatory cytokine, is chronically upregulated in PLWH and is linked with CVD. However, the mechanistic roles of the different IL-32 isoforms in CVD are yet to be identified. In this study, we aimed to investigate the potential impact of IL-32 isoforms on coronary artery endothelial cells (CAEC), whose dysfunction represents a major factor for atherosclerosis. Our results demonstrated that the predominantly expressed IL-32 isoforms (IL-32β and IL-32γ) have a selective impact on the production of the proinflammatory cytokine IL-6 by CAEC. Furthermore, these two isoforms induced endothelial cell dysfunction by upregulating the expression of the adhesion molecules ICAM-I and VCAM-I and the chemoattractants CCL-2, CXCL-8 and CXCL-1. IL-32-mediated expression of these chemokines was sufficient to drive monocyte transmigration in vitro. Finally, we demonstrate that IL-32 expression in both PLWH and controls correlates with the carotid artery stiffness, measured by the cumulated lateral translation. These results suggest a role for IL-32-mediated endothelial cell dysfunction in dysregulation of the blood vessel wall and that IL-32 may represent a therapeutic target to prevent CVD in PLWH.

Interleukin-32 as a biomarker in rheumatic diseases: A narrative review

Interleukin-32 (IL-32) is an important cytokine involved in the innate and adaptive immune responses. The role of IL-32 has been studied in the context of various diseases. A growing body of research has investigated the role of IL-32 in rheumatic diseases including inflammatory arthritides (rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis) and connective tissue diseases (systemic lupus erythematosus, systemic sclerosis, granulomatosis and polyangiitis, and giant cell arteritis). IL-32 has been shown to play different roles according to the type of rheumatic diseases. Hence, the putative role of IL-32 as a biomarker is also different in each rheumatic disease: IL-32 could serve as a biomarker for disease activity in some diseases, whereas in other diseases it could be a biomarker for certain disease manifestations. In this narrative review, we summarize the associations between IL-32 and various rheumatic diseases and discuss the putative role of IL-32 as a biomarker in each disease.

LncRNA HCG18 loaded by polymorphonuclear neutrophil-secreted exosomes aggravates sepsis acute lung injury by regulating macrophage polarization

Polymorphonuclear neutrophils (PMNs) exert significant roles in septic acute lung injury (ALI). Accumulating evidence suggests that PMN-derived exosomes (PMN-exo) are a novel subcellular entity that is the fundamental link between PMN-driven inflammation and tissue damage. However, the role of PMN-exo in septic ALI and the underlying mechanisms remain unclear. Tumor necrosis factor-α (TNF-α), a key regulator of innate immunity in septic ALI, was used to induce PMN activation in vitro. Using an in vitro co-culture system, the rat alveolar macrophage cell line NR8383 was co-cultured with TNF-α-stimulated PMN-released exosomes (TNF-α-exo) to further confirm the results of the in vitro studies and explore the underlying mechanisms involved. A septic lung injury model was established by cecal ligation and puncture surgery, and PMN-exo were injected into septic mice through the tail vein, and then lung injury, inflammatory release, macrophage polarization, and apoptosis were examined. The results reported that TNF-α-exo promoted the activation of M1 macrophages after i.p. injection in vivo or co-culture in vitro. Furthermore, TNF-α-exo affected alveolar macrophage polarization by delivering HCG18. Mechanistic studies indicated that HCG18 mediated the function of TNF-α-exo by targeting IL-32 in macrophages. In addition, tail vein injection of si-HCG18 in septic mice significantly reduced TNF-α-exo-induced M1 macrophage activation and lung macrophage death, as well as histological lesions. In conclusion, TNF-α-exo-loaded HCG18 contributes to septic ALI by regulating macrophage polarization. These findings may provide new insights into novel mechanisms of PMN-macrophage polarization interactions in septic ALI and may provide new therapeutic strategies for patients with sepsis.

Genetic Association between Polymorphisms of Interleukin-32 and Dilated Cardiomyopathy in Chinese Han Population

Background

Dilated cardiomyopathy is a primary myocardial disease and one of the critical causes of heart failure. It is the most common indication for heart transplantation worldwide, and most idiopathic dilated cardiomyopathies are sporadic and multifactorial. Evidence has supported that several inflammatory cytokines and immune responses are involved in its pathological process. Interleukin-32 is a proinflammatory cytokine and is elevated during the worsening cardiac function. Herein, we evaluated the correlation between interleukin-32 gene polymorphisms (rs12934561 and rs28372698) and the susceptibility to dilated cardiomyopathy.

Methods

We enrolled 418 dilated cardiomyopathy patients and 437 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping the two single-nucleotide polymorphisms (SNPs), and SPSS software was used for statistical analyses.

Results

The C allele and CC genotype frequencies of rs12934561 were remarkably elevated in dilated cardiomyopathy patients compared to controls (both P < 0.001). The A allele and AA genotype frequencies of rs28372698 significantly decreased in dilated cardiomyopathy patients (P = 0.004 and P = 0.02, respectively). Compared to TT/TC genotype carriers of rs12934561, CC homozygotes presented an increased risk of dilated cardiomyopathy when the left ventricular ejection fraction no more than 30% (P = 0.02).

Conclusions

The IL-32 gene polymorphisms might implicate in DCM risk in the Chinese Han population, and rs12934561 could be a potential forecasting factor for screening high-risk population for DCM.

Novel Applications of Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an important health problem and an increasing cause of morbidity and mortality worldwide. Currently, COPD is considered a multisystem disease. Although it primarily affects the lungs, structural and functional changes occur in other organs due to systemic inflammation. It is stated that in patients with COPD, airway and systemic inflammatory markers are increased and that these markers are high are associated with a faster decline in lung functions. In recent years, numerous articles have been published on the discovery and evaluation of biomarkers in COPD. Many markers have also been studied to accurately assess COPD exacerbations and provide effective treatment. However, based on the evidence from published studies, a single molecule has not been adequately validated for broad clinical use.

Comparison of the Seven Interleukin-32 Isoforms’ Biological Activities: IL-32θ Possesses the Most Dominant Biological Activity

Cytokines are significantly associated with the homeostasis of immune responses in health and disease. Interleukin-32 (IL-32) is a cytokine originally discovered in natural killer cell transcript 4. IL-32 with different disorders has been described in terms of pathogenesis and the progression of diseases. Clinical studies have investigated IL-32 under various conditions, such as viral infection, autoimmune diseases, inflammatory diseases, certain types of cancer, vascular disease, and pulmonary diseases. The high expression of IL-32 was identified in different tissues with various diseases and found to have multiple transcripts of up to seven isoforms. However, the purification and biological activities of these isoforms have not been investigated yet. Therefore, in this study, we purified and compared the biological activity of recombinant IL-32 (rIL-32) isoforms. This is the first time for seven rIL-32 isoforms (α, β, δ, γ, ϵ, ζ, and θ) to be cloned and purified using an Escherichia coli expression system. Next, we evaluate the biological activities of these seven rIL-32 isoforms, which were used to treat different types of cells by assessing the levels of inflammatory cytokine production. The results revealed that rIL-32θ possessed the most dominant biological activity in both immune and non-immune cells.

The Role of Interleukins in the Pathogenesis of Dermatological Immune-Mediated Diseases

Autoimmune inflammatory diseases are primarily characterized by deregulated expression of cytokines, which drive pathogenesis of these diseases. A number of approved and experimental therapies utilize monoclonal antibodies against cytokine proteins. Cytokines can be classified into different families including the interleukins, which are secreted and act on leukocytes, the tumor necrosis factor (TNF) family, as well as chemokine proteins. In this review article, we focus on the interleukin family of cytokines, of which 39 members have been identified to this date. We outline the role of each of these interleukins in the immune system, and various dermatological inflammatory diseases with a focused discussion on the pathogenesis of psoriasis and atopic dermatitis. In addition, we describe the roles of various interleukins in psychiatric, cardiovascular, and gastrointestinal comorbidities. Finally, we review clinical efficacy and safety data from emerging late-phase anti-interleukin therapies under development for psoriasis and atopic dermatitis. Collectively, additional fundamental and clinical research remains necessary to fully elucidate the roles of various interleukin proteins in the pathogenesis of inflammatory dermatologic diseases, and treatment outcomes in patients.

Tanimilast, A Novel Inhaled Pde4 Inhibitor for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases are the third leading cause of death, behind cardiovascular diseases and cancer, affecting approximately 550 million of people all over the world. Most of the chronic respiratory diseases are attributable to asthma and chronic obstructive pulmonary disease (COPD) with this latter being the major cause of deaths. Despite differences in etiology and symptoms, a common feature of asthma and COPD is an underlying degree of airways inflammation. The nature and severity of this inflammation might differ between and within different respiratory conditions and pharmacological anti-inflammatory treatments are unlikely to be effective in all patients. A precision medicine approach is needed to selectively target patients to increase the chance of therapeutic success. Inhibitors of the phosphodiesterase 4 (PDE4) enzyme like the oral PDE4 inhibitor roflumilast have shown a potential to reduce inflammatory-mediated processes and the frequency of exacerbations in certain groups of COPD patients with a chronic bronchitis phenotype. However, roflumilast use is dampened by class related side effects as nausea, diarrhea, weight loss and abdominal pain, resulting in both substantial treatment discontinuation in clinical practice and withdrawal from clinical trials. This has prompted the search for PDE4 inhibitors to be given by inhalation to reduce the systemic exposure (and thus optimize the systemic safety) and maximize the therapeutic effect in the lung. Tanimilast (international non-proprietary name of CHF6001) is a novel highly potent and selective inhaled PDE4 inhibitor with proven anti-inflammatory properties in various inflammatory cells, including leukocytes derived from asthma and COPD patients, as well as in experimental rodent models of pulmonary inflammation. Inhaled tanimilast has reached phase III clinical development by showing promising pharmacodynamic results associated with a good tolerability and safety profile, with no evidence of PDE4 inhibitors class-related side effects. In this review we will discuss the main outcomes of preclinical and clinical studies conducted during tanimilast development, with particular emphasis on the characterization of the pharmacodynamic profile that led to the identification of target populations with increased therapeutic potential in inflammatory respiratory diseases.

Brief Report: Subclinical Carotid Artery Atherosclerosis Is Associated With Increased Expression of Peripheral Blood IL-32 Isoforms Among Women Living With HIV

BACKGROUND

Persistent inflammation in HIV infection is associated with elevated cardiovascular disease (CVD) risk, even with viral suppression. Identification of novel surrogate biomarkers can enhance CVD risk stratification and suggest novel therapies. We investigated the potential of interleukin 32 (IL-32), a proinflammatory multi-isoform cytokine, as a biomarker for subclinical carotid artery atherosclerosis in virologically suppressed women living with HIV (WLWH).

METHODS AND RESULTS

Nested within the Women's Interagency HIV Study, we conducted a cross-sectional comparison of IL-32 between 399 WLWH and 100 women without HIV, followed by a case-control study of 72 WLWH (36 carotid artery plaque cases vs. 36 age-matched controls without plaque). Plasma IL-32 protein was measured by ELISA, and mRNA of IL-32 isoforms (IL-32α, β, γ, D, ε, and θ) was quantified by reverse transcription polymerase chain reaction from peripheral blood mononuclear cells. Plasma IL-32 protein levels were higher in WLWH compared with women without HIV (P = 0.02). Among WLWH, although plasma IL-32 levels did not differ significantly between plaque cases and controls, expression of IL-32 isoforms α, β, and ε mRNA was significantly higher in peripheral blood mononuclear cells from cases (P = 0.01, P = 0.005, and P = 0.018, respectively). Upregulation of IL-32β and IL-32ε among WLWH with carotid artery plaque persisted after adjustment for age, race/ethnicity, smoking, systolic blood pressure, body mass index, and history of hepatitis C virus (P = 0.04 and P = 0.045); the adjusted association for IL-32α was marginally significant (P = 0.07).

CONCLUSIONS

IL-32 isoforms should be studied further as potential CVD biomarkers. This is of particular interest in WLWH by virtue of altered IL-32 levels in this population.

Interleukin-32 in Pathogenesis of Atopic Diseases: Proinflammatory or Anti-Inflammatory Role?

Atopic diseases, such as atopic dermatitis (AD), allergic asthma (AA), and allergic rhinitis (AR), are increasingly becoming a worldwide issue. This atopic triad originates at an early age and on a multifactorial basis, causing significant discomfort to susceptible individuals. The global case number is now reaching new highs, so exploring immune system regulation and its components is becoming critical. One cytokine, interleukin-32 (IL-32), is involved in inflammation and regulation of the immune system. It has nine isoforms that show varying degrees of expression, both intracellularly and extracellularly. IL-32 is secreted by immune cells, such as monocytes, macrophages, natural killer cells, and T cells, and by nonimmune cells, including fibroblasts, keratinocytes, and endothelial cells. Its production is regulated and augmented by microorganisms, mitogens, and other cytokines. Early studies demonstrated that IL-32 was an immune regulator that functioned to protect against inflammatory diseases, including AD, AA, and AR, and proposed a proinflammatory role for IL-32 in immune regulation and symptom exacerbation. However, several later reports suggested that IL-32 is downregulated in inflammatory diseases and exerts an anti-inflammatory effect. This review article focuses on recent findings regarding the detrimental and protective roles of IL-32 in development and management of inflammatory diseases. The exact role of IL-32 in AD, AA, and AR still remains to be elucidated. Future research should explore new avenues of IL-32 functionality in human inflammatory diseases.

Naïve CD4+ cell counts significantly decay and high HIV RNA levels contribute to immunological progression in long-term non-progressors infected with HIV by blood products: a cohort study

BACKGROUND

Some long-term non-progressors (LTNPs) have decreasing CD4⁺ T cell counts and progress to AIDS. Exploring which subsets of CD4⁺ T cell decreasing and the determinants associated with the decay in these patients will improve disease progression surveillance and provide further understanding of HIV pathogenesis.

METHODS

Twenty-five LTNPs infected with HIV by blood products were classified as decreased (DG) if their CD4⁺ cell count dropped to < 400 cells/μL during follow-up or as non-decreased (non-DG) if their CD4⁺ cell count was ≥400 cells/μL. Laboratory and clinical assessments were conducted at 6 consecutive visits to identify DG characteristics.

RESULTS

The LTNPs were infected with HIV for 12 (IQR: 11.5-14) years, and 23 were classified as the B' subtype. Six individuals lost LTNP status 14.5 (IQR: 12.5-17.5) years after infection (DG), and the CD4⁺ T cell count decreased to 237 (IQR: 213-320) cells/μL at the latest visit. The naïve CD4⁺ T cell count decrease was greater than that of memory CD4⁺ T cells [- 128 (IQR: - 196, - 107) vs - 64 (IQR: - 182, - 25) cells/μL)]. Nineteen individuals retained LTNP status (non-DG). At enrolment, the viral load (VL) level (p = 0.03) and CD8⁺CD38⁺ percentage (p = 0.03) were higher in DG than non-DG individuals. During follow-up, viral load and CD8⁺CD38⁺ percentage were significantly increased and negatively associated with CD4⁺ cell count [(r = - 0.529, p = 0.008), (r = - 0.476, p = 0.019), respectively]. However, the CD8⁺CD28⁺ percentage and B cell count dropped in DG and were positively correlated with CD4⁺ T cell count [(r = 0.448, p = 0.028), (r = 0.785, p < 0.001)].

CONCLUSION

Immunological progression was mainly characterized by the decrease of naïve CD4⁺ T cell in LTNPs infected with HIV by blood products and it may be associated with high HIV RNA levels.

IL32: The multifaceted and unconventional cytokine

Interleukin 32 is a unique intracellular cytokine which affects many cellular and physiological functions like cell death and survival, inflammation and response to pathogens. With numerous transcripts, more than one biologically active isoforms, IL32 drives its effect in diverse cellular functions. A cytokine restricted to higher mammals, it is known to fine tune multiple pathways involved in metabolic processes or infection. It modulates the immune response against diverse pathogens like Leishmania, Mycobacterium and HIV. IL32 has been associated with cancers of inflammatory nature too. It also plays an important role in chronic inflammatory diseases like RA, lung and airway disease like COPD. In this review we have discussed about identification and characterization of this non classical cytokine IL32, its structure and function at gene as well as at protein level, isoforms and their diverse functions. Role of IL32 in multiple diseases and particularly mycobacterial disease has been highlighted here. We have also summarised the genetic variants present in the IL32 gene and it's promoter region. Association of these variants, with cellular phenotype, patho-physiological conditions in different disease have also been discussed here.

Associations between Interleukin-32 Gene Polymorphisms rs12934561 and rs28372698 and Susceptibilities to Bladder Cancer and the Prognosis in Chinese Han Population

The proinflammatory chemokine interleukin-32 is related to various diseases, including cancer. However, it has never been associated with bladder cancer (BC). To detect whether there is a relationship between the IL-32 gene polymorphisms (rs12934561 C/T and rs28372698 T/A) and BC, the study enrolled 170 non-muscle-invasive bladder cancer (NMIBC) patients, 151 muscle-invasive bladder cancer (MIBC) patients, and 437 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for the IL-32 single-nucleotide polymorphism (SNP) genotyping. Statistical analysis was performed using SNPstats online analysis software and SPSS software. Our data revealed that the CC homozygous genotype of rs12934561 in BC patients was significantly higher than that in controls (P = 0.03, OR = 1.47, 95%CI = 1.04‐2.08), and the percentage of TC genotype carriers was relatively less than that of controls (P = 0.001, OR = 0.61, 95%CI = 0.45‐0.82). Furthermore, the TT homozygous genotype of rs28372698 was associated with a significantly lower overall survival rate in MIBC patients (P = 0.028, OR = 2.77, 95%CI = 1.11‐6.90). The IL-32 gene polymorphism rs12934561 might be associated with increased BC risk, and the rs28372698 might participate in the prognosis of BC patients. Therefore, they could be potential forecasting factors for the prognosis of MIBC patients.

Correlation between serum IL-32 concentration and clinical parameters of stable COPD: a retrospective clinical analysis

This study was to investigate the association between serum interleukin 32 (IL-32) concentration and clinical parameters in patients with stable chronic obstructive pulmonary disease (COPD). One hundred and sixteen patients with stable COPD and 70 healthy subjects were included in the study. The serum concentration of IL-32 was detected by enzyme-linked immunosorbent assay. The correlation between serum IL-32 and clinical parameters of patients with COPD was analyzed by T-test, one-way analysis of variance, multiple linear regression and receiver operating characteristic curve. The serum concentration of IL-32 in patients with stable COPD was higher than that in healthy control group (p < 0.001) and increased serum IL-32 was positively correlated with GOLD grading (p = 0.026), mMRC score (p = 0.004) and clinical medical history (p = 0.005), but negatively related to FEV1/FVC (p = 0.001) and FEV1% predicted (p = 0.001). Patient's COPD grading (p = 0.001), clinical medical history (p < 0.001) and FEV1/FVC (p = 0.001) exerted a significant impact on serum IL-32. The sensitivity and specificity of serum IL-32 for discerning COPD patients from healthy individuals were 85.34% and 64.29%, and the area under the curve was 0.808 (p < 0.001). Increased IL-32 is involved in the chronic disease progression of COPD, suggesting that IL-32 may be a molecular biomarker that reflects the severity of COPD and contributes to the disease diagnosis.

Therapeutic RNA Strategies for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation with persistent respiratory symptoms. Current therapeutics for COPD are largely borrowed from the drug armamentarium for the treatment of asthma, which has different pathophysiological mechanisms from COPD. COPD has been linked to dysregulated expression of mRNAs and noncoding (nc)RNAs including miRNAs, PIWI-interacting (pi)RNAs, long noncoding (lnc)RNAs, and circular (circ)RNAs. This review highlights and discusses some recent advances towards development of RNA therapeutics for COPD.

Sputum and blood transcriptomics characterisation of the inhaled PDE4 inhibitor CHF6001 on top of triple therapy in patients with chronic bronchitis

Background

Although phosphodiesterase-4 (PDE4) inhibitors have been shown to reduce COPD exacerbation rate, their biological mechanism of action is not completely elucidated at the molecular level. We aimed to characterise the whole genome gene expression profile of the inhaled PDE4-inhibitor CHF6001 on top of triple therapy in sputum cells and whole blood of patients with COPD and chronic bronchitis.

Methods

Whole genome gene expression analysis was carried out by microarray in 54 patients before and after 32 days treatment with CHF6001 800 and 1600 μg and placebo twice daily (BID) in a randomised crossover study.

Results

CHF6001 had a strong effect in sputum, with 1471 and 2598 significantly differentially-expressed probe-sets relative to placebo (p-adjusted for False Discovery Rate < 0.05) with 800 and 1600 μg BID, respectively. Functional enrichment analysis showed significant modulation of key inflammatory pathways involved in cytokine activity, pathogen-associated-pattern-recognition activity, oxidative stress and vitamin D with associated inhibition of downstream inflammatory effectors. A large number of pro-inflammatory genes coding for cytokines and matrix-metalloproteinases were significantly differentially expressed for both doses; the majority (> 87%) were downregulated, including macrophage inflammatory protein-1-alpha and 1-beta, interleukin-27-beta, interleukin-12-beta, interleukin-32, tumour necrosis factor-alpha-induced-protein-8, ligand-superfamily-member-15, and matrix-metalloproteinases-7,12 and 14. The effect in blood was not significant.

Conclusions

Inhaled PDE4 inhibition by CHF6001 on top of triple therapy in patients with COPD and chronic bronchitis significantly modulated key inflammatory targets and pathways in the lung but not in blood. Mechanistically these findings support a targeted effect in the lung while minimising unwanted systemic class-effects.

Trial registration

ClinicalTrial.gov, EudraCT, 2015–005550-35. Registered 15 July 2016.

Interleukin-32 in Infection, Inflammation and Cancer Biology

Cytokines are small pleiotropic polypeptids secreted dominantly by the cells of the immune system. These polypeptids are main mediators of innate and acquired immunity, responsible for clonal expansion and differentiation of immune cells, initiation of immune response and enhancing of effector functions of leukocytes. Cytokine-related effects are most studied in the fields of inflammation, immunology, and cancer biology. In this review we discuss one of the most intriguing, recently discovered proinflammatory cytokine, interleukin 32.

[Immunology of chronic rhinosinusitis with nasal polyps as a basis for treatment with biologicals]

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous and multifactorial inflammation of the nasal and paranasal mucosa. Until now, no internationally standardized classification could be developed. In most cases, CRS is phenotypically classified according to chronic rhinosinusitis with (CRScNP) and without nasal polyps (CRSsNP). However, recent studies could show that there are numerous endotypes within these phenotypes based on different inflammatory mechanisms. This review describes the important immunological mechanisms of CRScNP and highlights modern treatment options with biologicals directly addressing particular immunological processes.

METHODS

Current knowledge on immunological and molecular processes of CRS, particularly CRScNP, was extracted from Medline, PubMed, national and international study- and guideline-registers, and the Cochrane library by a systematic review of the literature.

RESULTS

Based on current literature, various immunological mechanisms for CRS and CRScNP could be identified. Relevant studies for the treatment of eosinophilic conditions such as asthma or CRScNP are presented and, if available, results of these studies are discussed.

CONCLUSION

The growing insight into the underlying immunological mechanisms of CRScNP could pave the way for new personalized treatment options such as biologicals in the future.

Elevated serum interleukin-32 levels in patients with endometriosis: A cross-sectional study

PROBLEM

Recently, interleukin (IL)-32 has been suggested to be involved in the pathogenesis of endometriosis. The aim of this study was to investigate whether serum IL-32 level might be used as a biomarker for diagnosis of endometriosis.

METHOD OF STUDY

We recruited the serum samples of 50 patients with histologically confirmed endometriosis and 35 controls. Enzyme-linked immunosorbent assay was used to analyze the serum IL-32, IL-6, IL-10, tumour necrosis factor (TNF)-α, IL-1β, and CA-125 levels in patients with and without the disease and the diagnostic potentials of the cytokines were assessed using receiver operating characteristic curve and the area under the curve (AUC).

RESULTS

Among evaluated cytokines, only serum IL-32 levels showed significant differences between patients with and without endometriosis (1111.24 ± 149.59 vs 631.10 ± 120.23 ng/mL, P = 0.018, respectively). When the diagnostic power of serum IL-32 was evaluated, the AUC was 0.638 (95% confidence interval (CI): 0.521-0.766, P = 0.031). When serum IL-32 levels were combined with serum CA-125 levels, the AUC was increased to 0.749 (95% CI: 0.640-0.858, P < 0.001) with sensitivity and specificity of 60.0% and 82.9% at cutoff value of 0.640, which led to detect 25 more cases of endometriosis than the use of serum CA 125 with the cutoff value of 35 IU/mL (36/50 vs 11/50, P < 0.001) without sacrificing the specificity of the marker.

CONCLUSION

Serum IL-32 levels are elevated in patients with endometriosis, and with combination of serum CA-125 levels, it may serve as a potential biomarker for endometriosis.

Structural Characteristics of Seven IL-32 Variants

IL-32 exists as seven mRNA transcripts that can translate into distinct individual IL-32 variants with specific protein domains. These translated protein domains of IL-32 variants code for specific functions that allow for interaction with different molecules intracellularly or extracellularly. The longest variant is IL-32γ possessing 234 amino acid residues with all 11 protein domains, while the shortest variant is IL-32α possessing 131 amino acid residues with three of the protein domains. The first domain exists in 6 variants except IL-32δ variant, which has a distinct translation initiation codon due to mRNA splicing. The last eleventh domain is common domain for all seven IL-32 variants. Numerous studies in different fields, such as inflammation, autoimmunity, pathogen infection, and cancer biology, have claimed the specific biological activity of individual IL-32 variant despite the absence of sufficient data. There are 4 additional IL-32 variants without proper transcripts. In this review, the structural characteristics of seven IL-32 transcripts are described based on the specific protein domains.

Asian Sand Dust Regulates IL-32 Production in Airway Epithelial Cells: Inhibitory Effect of Glucocorticoids

Purpose

Epidemiologic studies have reported that Asian sand dust (ASD) is associated with chronic inflammatory diseases of the respiratory system. Glucocorticoids (GCs) have potent anti-inflammatory properties. The aims of this study were to evaluate the effects of GCs on ASD-induced interleukin-32 (IL-32) expression and to identify the underlying signaling pathways in airway epithelial cells.

Methods

A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate cytotoxicity in A549 and human primary nasal epithelial cells. Expression levels of IL-32 messenger RNA and protein were measured by Western blot, real-time polymerase chain reaction, ELISA, and immunofluorescence staining. Signaling pathways were analyzed using specific inhibitors of Akt, MAPK, or NF- κB. The effects of GCs on the expression of ASD-induced IL-32 were confirmed with ex vivo organ cultures of the nasal interior turbinate.

Results

ASD (0–400 ng/mL) had no significant cytotoxic effects in A549 cells and human primary nasal epithelial cells. Expression levels of IL-32 were dose-dependently upregulated by ASD treatment in A549 cells. ASD induced phosphorylation of Akt, MAPK, and NF-κB, whereas GCs and specific inhibitors of Akt, MAPK, and NF-κB downregulated these activations and the expression of IL-32. These findings were further confirmed in human primary nasal epithelial cells and ex vivo organ cultures of the nasal interior turbinate.

Conclusions

GCs have an inhibitory effect on ASD-induced IL-32 expression via the Akt, MAPK, and NF- κB signaling pathways in airway epithelial cells.

Establishing a generalized polyepigenetic biomarker for tobacco smoking

Large-scale epigenome-wide association meta-analyses have identified multiple 'signatures'' of smoking. Drawing on these findings, we describe the construction of a polyepigenetic DNA methylation score that indexes smoking behavior and that can be utilized for multiple purposes in population health research. To validate the score, we use data from two birth cohort studies: The Dunedin Longitudinal Study, followed to age-38 years, and the Environmental Risk Study, followed to age-18 years. Longitudinal data show that changes in DNA methylation accumulate with increased exposure to tobacco smoking and attenuate with quitting. Data from twins discordant for smoking behavior show that smoking influences DNA methylation independently of genetic and environmental risk factors. Physiological data show that changes in DNA methylation track smoking-related changes in lung function and gum health over time. Moreover, DNA methylation changes predict corresponding changes in gene expression in pathways related to inflammation, immune response, and cellular trafficking. Finally, we present prospective data about the link between adverse childhood experiences (ACEs) and epigenetic modifications; these findings document the importance of controlling for smoking-related DNA methylation changes when studying biological embedding of stress in life-course research. We introduce the polyepigenetic DNA methylation score as a tool both for discovery and theory-guided research in epigenetic epidemiology.

Role of interleukin-32 in the pathogenesis of endometriosis: in vitro, human and transgenic mouse data

STUDY QUESTION

Does interleukin-32 (IL-32) play a role in the pathogenesis of endometriosis?

SUMMARY ANSWER

IL-32 might be involved in the pathogenesis of endometriosis through increased viability, proliferation and invasion of endometrial cells.

WHAT IS KNOWN ALREADY

Endometriosis is characterized as a chronic inflammatory disease and several proinflammatory cytokines are suggested to be involved in its pathogenesis and pathophysiology. IL-32, recognized as a new proinflammatory cytokine and a strong inducer of other proinflammatory cytokines, has been shown to serve as a key modulator in several chronic inflammatory diseases.

STUDY DESIGN, SIZE, DURATION

This study included comparison of IL-32 levels in the peritoneal fluids between women with and without endometriosis, in-vitro experiments using Ishikawa cells and endometrial stromal cells (ESCs), and experiments on IL-32 transgenic mice and wild-type mice with induced endometriosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

IL-32 levels in the peritoneal fluids were measured using enzyme-linked immunosorbent assays. Cell viability, expression of proliferating cell nuclear antigen (PCNA), and cellular invasiveness were analyzed following in-vitro treatment of Ishikawa cells and ESCs with recombinant IL-32 alpha (α) and gamma (γ). Ectopic endometriotic lesions were compared between IL-32 transgenic mice and wild-type mice after autologous endometrial transplantation with immunohistochemistry for Ki-67 antigen and PCNA.

MAIN RESULTS AND THE ROLE OF CHANCE

The peritoneal fluid concentration of IL-32 was significantly higher in patients with advanced stage endometriosis compared with the controls. In-vitro treatment with IL-32 α and γ caused significant increases in cellular viability, PCNA expression, and invasiveness in Ishikawa cells and ESCs. The IL-32 transgenic mice had a significantly larger size of the ectopic endometrial lesions with higher expression of Ki-67 antigen and PCNA compared with wild-type mice.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

It is still unclear whether IL-32 is a main regulator, or one of several downstream proinflammatory cytokines, causing establishment and/or progression of endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

Further investigation on IL-32 signaling pathways may contribute to development a more effective treatment of endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (Grant number: HI16C1682). None of the authors has anything to disclose.

Multiple myeloma cell-derived IL-32γ increases the immunosuppressive function of macrophages by promoting indoleamine 2,3-dioxygenase (IDO) expression

The interaction of multiple myeloma (MM) cells with macrophages (MΦs) contributes to the pathophysiology of MM. We previously showed that IL-32 is overexpressed in MM patients. The present study was designed to explore the clinical significance of IL-32 in MM and to further elucidate the mechanisms underlying the IL-32-mediated immune function of MΦs. Our results showed that high IL-32 expression in MM patients was associated with more advanced clinical stage. RNA-sequencing revealed that IL-32γ significantly induced the production of the immunosuppressive molecule indoleamine 2,3-dioxygenase (IDO) in MΦs, and this effect was verified by qRT-PCR, western blotting, and immunofluorescence. Furthermore, MM cells with IL-32-knockdown showed a reduced ability to promote IDO expression. As a binding protein for IL-32, proteinase 3 (PR3) was universally expressed on the surfaces of MΦs, and knockdown of PR3 or inhibition of the STAT3 and NF-κB pathways hindered the IL-32γ-mediated stimulation of IDO expression. Finally, IDO-positive IL-32γ-educated MΦs inhibited CD4⁺ T cell proliferation and IL-2, IFN-γ, and TNF-α production. Taken together, our results indicate that IL-32γ derived from MM cells promotes the immunosuppressive function of MΦs and is a potential target for MM treatment.

The Biology and Role of Interleukin-32 in Tuberculosis

Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading cause of morbidity and mortality globally, with nearly 10.4 million new cases of incidence and over 1.7 million deaths annually. Drug-resistant M. tuberculosis strains, especially multidrug-resistant or extensively drug-resistant strains, have further intensified the problem associated with tuberculosis control. Host-directed therapy is a promising alternative for tuberculosis control. IL-32 is increasingly recognized as an important host molecule against tuberculosis. In this review, we highlight the proinflammatory properties of IL-32 and the mode of action of IL-32 in mycobacterial infections to inspire the development of novel immunity-based countermeasures and host-directed therapies against tuberculosis.

IL-32γ attenuates airway fibrosis by modulating the integrin-FAK signaling pathway in fibroblasts

Background

Fibrosis in severe asthma often leads to irreversible organ dysfunction. However, the mechanism that regulates fibrosis remains poorly understood. Interleukin (IL)-32 plays a role in several chronic inflammatory diseases, including severe asthma. In this study, we investigated whether IL-32 is involved in fibrosis progression in the lungs.

Methods

Murine models of chronic airway inflammation induced by ovalbumin and Aspergillus melleus protease and bleomycin-induced pulmonary fibrosis were employed. We evaluated the degree of tissue fibrosis after treatment with recombinant IL-32γ (rIL-32γ). Expression of fibronectin and α-smooth muscle actin (α-SMA) was examined and the transforming growth factor (TGF)-β-related signaling pathways was evaluated in activated human lung fibroblasts (MRC-5 cells) treated with rIL-32γ.

Results

rIL-32γ significantly attenuated collagen deposition and α-SMA production in both mouse models. rIL-32γ inhibited the production of fibronectin and α-SMA in MRC-5 cells stimulated with TGF-β. Additionally, rIL-32γ suppressed activation of the integrin-FAK-paxillin signaling axis but had no effect on the Smad and non-Smad signaling pathways. rIL-32γ localized outside of MRC-5 cells and inhibited the interaction between integrins and the extracellular matrix without directly binding to intracellular FAK and paxillin.

Conclusions

These results demonstrate that IL-32γ has anti-fibrotic effects and is a novel target for preventing fibrosis.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0863-3) contains supplementary material, which is available to authorized users.

Proteinase 3; a potential target in chronic obstructive pulmonary disease and other chronic inflammatory diseases

Chronic Obstructive Pulmonary Disease (COPD) is a common, multifactorial lung disease which results in significant impairment of patients' health and a large impact on society and health care burden. It is believed to be the result of prolonged, destructive neutrophilic inflammation which results in progressive damage to lung structures. During this process, large quantities of neutrophil serine proteinases (NSPs) are released which initiate the damage and contribute towards driving a persistent inflammatory state.Neutrophil elastase has long been considered the key NSP involved in the pathophysiology of COPD. However, in recent years, a significant role for Proteinase 3 (PR3) in disease development has emerged, both in COPD and other chronic inflammatory conditions. Therefore, there is a need to investigate the importance of PR3 in disease development and hence its potential as a therapeutic target. Research into PR3 has largely been confined to its role as an autoantigen, but PR3 is involved in triggering inflammatory pathways, disrupting cellular signalling, degrading key structural proteins, and pathogen response.This review summarises what is presently known about PR3, explores its involvement particularly in the development of COPD, and indicates areas requiring further investigation.

Interleukin-32: its role in asthma and potential as a therapeutic agent

Interleukin (IL)-32, also named natural killer cell transcript 4 (NK4), has increasingly been described as an immunoregulator that controls cell differentiation and cell death and is involved in the stimulation of anti−/pro-inflammatory cytokines. Abnormal presence of IL-32 has been repeatedly noticed during the pathogenesis of allergic, infectious, cancerous, and inflammatory diseases. Of particular note was the observation of the anti-inflammatory property of IL-32 in a murine ovalbumin model of allergic asthma. Compared to wild-type mice, IL-32γ transgenic mice show decreased levels of inflammatory cells, recruited eosinophils, and lymphocytes in bronchoalveolar lavage fluid in a mouse model of acute asthma. To date, the molecular mechanism underlying the role of IL-32 in asthma remains to be elucidated. This review aims to summarize recent advances in the pathophysiology of asthma and describe the links to IL-32. The possibilities of using IL-32 as an airway inflammation biomarker and an asthma therapeutic agent are also evaluated.

Role of interleukin-32 in cancer biology

Interleukin-32 (IL-32), a novel proinflammatory cytokine, is highly expressed in various cancer tissues and in established cancer cell lines. IL-32 has been revealed to serve a crucial role in human cancer development, including tumour initiation, proliferation and maintenance. The expression of IL-32 is regulated by numerous factors, including genetic variations, hypoxia and acidosis in the tumour microenvironment. Understanding the underlying mechanisms of IL-32 expression and its function are critical for the discovery of novel therapeutic strategies that target IL-32. This is a review of the current literature on the regulation and function of IL-32 in cancer progression, focusing on the molecular pathways linking IL-32 and tumour development.

Role of IL-32 Gamma on Bone Metabolism in Autoimmune Arthritis

IL-32 acts as a pro-inflammatory cytokine by inducing the synthesis of inflammatory molecules as well as promoting the morphological changes involved in the transformation of monocytes into osteoclasts (OCs). Evaluation of the functions of IL-32 has mainly focused on its inflammatory properties, such as involvement in the pathogenesis of various autoimmune diseases. Recently, IL-32 was shown to be involved in bone metabolism, in which it promotes the differentiation and activation of OCs and plays a key role in bone resorption in inflammatory conditions. IL-32γ also regulates bone formation in conditions such as ankylosing spondylitis and osteoporosis. In this review, we summarize the results of recent studies on the role of IL-32γ in bone metabolism in inflammatory arthritis.

Interleukin-32: An endogenous danger signal or master regulator of intracellular pathogen infections-Focus on leishmaniases

Interleukin 32 (IL-32) is an intracellular cytokine produced by immune and non immune cells after different stimuli. It contributes to inflammation and control of intracellular pathogens mainly by inducing proinflammatory cytokines and microbicidal molecules. Evidence is rising showing that IL-32 can be considered an endogenous danger signal after tissue injury, amplifying the inflammatory process and acquired immune responses. It seems to be a master regulator of intracellular infectious diseases. In this review, first the general properties of IL-32 are described followed by its role in the immunopathogenesis of inflammatory and infectious diseases. Roles of IL-32 in the control of infectious diseases caused by intracellular pathogens are reported, and later a focus on IL-32 in leishmaniases, diseases caused by an intracellular protozoan, is presented.

Subtyping of polyposis nasi: phenotypes, endotypes and comorbidities

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous, multifactorial inflammatory disease of the nasal and paranasal mucosa. It has not been possible to date to develop an internationally standardized, uniform classification for this disorder. A phenotype classification according to CRS with (CRSwNP) and without polyposis (CRSsNP) is usually made. However, a large number of studies have shown that there are also different endotypes of CRS within these phenotypes, with different pathophysiologies of chronic inflammation of the nasal mucosa. This review describes the central immunological processes in nasal polyps, as well as the impact of related diseases on the inflammatory profile of nasal polyps.

MATERIALS AND METHODS

The current knowledge on the immunological and molecular processes of CRS, in particular CRSwNP and its classification into specific endotypes, was put together by means of a structured literature search in Medline, PubMed, the national and international guideline registers, and the Cochrane Library.

RESULTS

Based on the current literature, the different immunological processes in CRS and nasal polyps were elaborated and a graphical representation in the form of an immunological network developed. In addition, different inflammatory profiles can be found in CRSwNP depending on related diseases, such as bronchial asthma, cystic fibrosis (CF), or NASID-Exacerbated Respiratory Disease (N‑ERD).

CONCLUSION

The identification of different endotypes of CRSwNP may help to improve diagnostics and develop novel individual treatment approaches in CRSwNP.

Exploring the Role of IL-32 in HIV-Related Kaposi Sarcoma

The intracellular proinflammatory mediator IL-32 is associated with tumor progression; however, the mechanisms remain unknown. We studied IL-32 mRNA expression as well as expression of other proinflammatory cytokines and mediators, including IL-1α, IL-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, the proangiogenic and antiapoptotic enzyme cyclooxygenase-2, the IL-8 receptor C-X-C chemokine receptor (CXCR) 1, and the intracellular kinase focal adhesion kinase-1. The interaction of IL-32 expression with expression of IL-6, TNF-α, IL-8, and cyclooxygenase-2 was also investigated. Biopsy specimens of 11 HIV-related, 7 non-HIV-related Kaposi sarcoma (KS), and 7 normal skin tissues (NSTs) of Dutch origin were analyzed. RNA was isolated from the paraffin material, and gene expression levels of IL-32 α, β, and γ isoforms, IL1a, IL1b, IL6, IL8, TNFA, PTGS2, CXCR1, and PTK2 were determined using real-time quantitative PCR. Significantly higher expression of IL-32β and IL-32γ isoforms was observed in HIV-related KS biopsy specimens compared with non-HIV-related KS and NST. The splicing ratio of the IL-32 isoforms showed IL-32γ as the highest expressed isoform, followed by IL-32β, in HIV-related KS cases compared with non-HIV-related KS and NST. Our data suggest a possible survival mechanism by the splicing of IL-32γ to IL-32β and also IL-6, IL-8, and CXCR1 signaling pathways to reverse the proapoptotic effect of the IL-32γ isoform, leading to tumor cell survival and thus favoring tumor progression.

Effects of leukotriene B4 on interleukin-32, interferon-γ and chemokines in rats with rheumatoid arthritis

The objective of this study was to investigate the effects of leukotriene B4 (LTB4) on the expression of interleukin-32 (IL-32) interferon-γ (IFN-γ) and chemokine monocyte chemoattractant protein (MCP-1) and macrophage inhibitory protein (MIP-1α) in rheumatoid arthritis (RA). The rat model of RA collagen induced-arthritis (CIA) was established. The levels of LTB4, interleukin-32, IFN-γ and chemokines MCP-1 and MIP-1α in CIA rats were detected by ELISA. After the rat synovial cells were isolated and treated with different concentrations of LTB4, the effect of LTB4 the expression of IL-32, IFN-γ and chemokines MCP-1 and MIP-1α mRNA in synovial cells was detected by real-time quantitative PCR, the effect of LTB4 on protein expression was detected by immunoblotting. The effects of different concentrations of LTB4 on the viability and apoptosis of synovial cells were detected by LDH and cell proliferation reagent WST-1. Compared with the control group, the levels of LTB4, IL-32, IFN-γ and chemokines MCP-1 and MIP-1α were significantly increased in the serum of the CIA group. After treatment of CIA rat synovial cells with different concentrations of LTB4, the expression of IL-32, IFN-γ and chemokines MCP-1 and MIP-1α mRNA and protein were increased with significant differences among groups. WST-1 and flow cytometry showed that LTB4 had significant toxic effects on synovial cells and promoted apoptosis. In conclusion, LTB4 promotes the expression of interleukin-32, IFN-γ and chemokines MCP-1 and MIP-1α in synovial cells and facilitates apoptosis of synovial cells.

Unveil the mysterious mask of cytokine-based immunotherapy for melanoma

Melanoma is the leading cause of death among all skin cancers and its incidence continues to rise rapidly worldwide in the past decades. The available treatment options for melanoma remain limited despite extensive clinical research. Melanoma is an immunogenic tumor and great advances in immunology in recent decades allow for the development of immunotherapeutic agents against melanoma. In recent years, immunotherapy utilizing cytokines has been particularly successful in certain cancers and holds promise for patients with advanced melanoma. In this review, an overview of the current status and emerging perspectives on cytokine immunotherapy for melanoma are discussed in details. Such a study will be helpful to unveil the mysterious mask of cytokine-based immunotherapy for melanoma.

Interleukin 32, inflammation and cancer

Interleukin-32 (IL-32) is a novel cytokine involved in inflammation and cancer development. IL-32 gene consists of eight small exons, and IL-32 mRNA has nine alternative spliced isoforms, and was thought to be secreted because it contains an internal signal sequence and lacks a transmembrane region. IL-32 is initially expressed selectively in activated T cells by mitogen and activated NK cells and their expression is strongly augmented by microbes, mitogens, and other cytokines. The IL-32 is induced mainly by pathogens and pro-inflammatory cytokines, but IL-32 is more prominent in immune cells than in non-immune tissues. The IL-32 transcript is expressed in various human tissues and organs such as the spleen, thymus, leukocyte, lung, small intestine, colon, prostate, heart, placenta, liver, muscle, kidney, pancreas, and brain. Cytokines are critical components of cell signaling pathways that are involved in the regulation of cell growth, metabolism, hormone signaling, immune regulation and a variety of other physiological functions. Earlier studies have demonstrated that IL-32 regulates cell growth, metabolism and immune regulation and is therefore involved in the pathologic regulator or protectant of inflammatory diseases. Previous studies defined that IL-32 is upregulated in the patients with several inflammatory diseases, and is induced by inflammatory responses. However, several reports suggested that IL-32 is downregulated in several inflammatory diseases including asthma, HIV infection disease, neuronal diseases, metabolic disorders, experimental colitis and metabolic disorders. IL-32 is also involved in various cancer malignancies including renal cancer, esophageal cancer and hepatocellular carcinoma, lung cancer, gastric cancer, breast cancer, pancreatic cancer, lymphoma, osteosarcoma, breast cancer, colon cancer and thyroid carcinoma. Other studies suggested that IL-32 decreases tumor development including cervical cancer, colon cancer and prostate cancer, melanoma, pancreatic cancer, liver cancer and chronic myeloid leukemia. Nevertheless, review articles that discuss the roles and its mechanism of IL-32 isoforms focusing on the therapeutic approaches have not yet been reported. In this review article, we will discuss recent findings regarding IL-32 in the development of diseases and further discuss therapeutic approaches targeting IL-32. Moreover, we will suggest that IL-32 could be the target of several diseases and the therapeutic agents for targeting IL-32 may have potential beneficial effects for the treatment of inflammatory diseases and cancers. Future research should open new avenues for the design of novel therapeutic approaches targeting IL-32.

Activating transcription factor 3 represses cigarette smoke-induced IL6 and IL8 expression via suppressing NF-κB activation

Airway and lung inflammation is a fundamental hallmark of chronic obstructive pulmonary disease (COPD). Activating transcription factor 3 (ATF3) has been reported to negatively regulate many pro-inflammatory cytokines and chemokines. However, little is known about the impact of ATF3 on the inflammatory response of COPD. Since cigarette smoke (CS) is considered to be the most important risk factor in the etiology of COPD, we attempted to investigate the effects and molecular mechanisms of ATF3 in CS-induced inflammation. We observed an increase in the expression of ATF3 in the lung tissues of CS-exposed mice and CS extract (CSE)-treated human bronchial epithelial (HBE) cells. In vitro results indicated that ATF3 inhibition significantly increased the expression of proinflammatory cytokines interleukin 6 (IL6) and interleukin 8 (IL8) in CSE-stimulated HBE cells. Furthermore, in vivo data verified that CS induced inflammatory cell recruitment around the bronchus. In addition, neutrophil infiltration in bronchoalveolar lavage fluid (BALF) of CS-exposed Atf3^-/- mice was markedly higher than in stimulated WT mice. Finally, ATF3 deficiency increased the in vitro and in vivo expression and phosphorylation of nuclear factor-κB (NF-κB), a positive mediator of inflammation. Thus, this study shows that ATF3 plays an important role in the negative regulation of CS-induced pro-inflammatory gene expression through downregulating NF-κB phosphorylation.

Interleukin-32 Gamma Stimulates Bone Formation by Increasing miR-29a in Osteoblastic Cells and Prevents the Development of Osteoporosis

Interleukin-32 gamma (IL-32γ) is a recently discovered cytokine that is elevated in inflamed tissues and contributes to pathogenic features of bone in human inflammatory rheumatic diseases. Nevertheless, the role of IL-32γ and its direct involvement in bone metabolism is unclear. We investigated the molecular mechanism of IL-32γ in bone remodeling and the hypothetical correlation between IL-32γ and disease activity in osteoporosis patients. Transgenic (TG) mice overexpressing human IL-32γ showed reduced bone loss with advancing age, increased bone formation, and high osteogenic capacity of osteoblast compared to wild-type (WT) mice through the upregulation of miR-29a, which caused a reduction of Dickkopf-1 (DKK1) expression. IL-32γ TG mice were protected against ovariectomy (OVX)induced osteoporosis compared with WT mice. Decreased plasma IL-32γ levels were associated with bone mineral density (BMD) in human patients linked to increased DKK1 levels. These results indicate that IL-32γ plays a protective role for bone loss, providing clinical evidence of a negative correlation between IL-32γ and DKK1 as bone metabolic markers.

The Role of Mitochondria and Oxidative/Antioxidative Imbalance in Pathobiology of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable disease, characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. The major risk factor of COPD, which has been proven in many studies, is the exposure to cigarette smoke. However, it is 15-20% of all smokers who develop COPD. This is why we should recognize the pathobiology of COPD as involving a complex interaction between several factors, including genetic vulnerability. Oxidant-antioxidant imbalance is recognized as one of the significant factors in COPD pathogenesis. Numerous exogenous and endogenous sources of ROS are present in pathobiology of COPD. One of endogenous sources of ROS is mitochondria. Although leakage of electrons from electron transport chain and forming of ROS are the effect of physiological functioning of mitochondria, there are various intra- and extracellular factors which may increase this amount and significantly contribute to oxidative-antioxidative imbalance. With the coexistence with impaired antioxidant defence, all these issues lead to oxidative and carbonyl stress. Both of these states play a significant role in pathobiology of COPD and may account for development of major comorbidities of this disease.