Interleukin-6: discovery of a pleiotropic cytokine

Cytokines and Their Genetic Polymorphisms Related to Periodontal Disease

Periodontal disease (PD) is a chronic inflammatory disease caused by the accumulation of bacterial plaque biofilm on the teeth and the host immune responses. PD pathogenesis is complex and includes genetic, environmental, and autoimmune factors. Numerous studies have suggested that the connection of genetic and environmental factors induces the disease process leading to a response by both T cells and B cells and the increased synthesis of pro-inflammatory mediators such as cytokines. Many studies have shown that pro-inflammatory cytokines play a significant role in the pathogenesis of PD. The studies have also indicated that single nucleotide polymorphisms (SNPs) in cytokine genes may be associated with risk and severity of PD. In this narrative review, we discuss the role of selected cytokines and their gene polymorphisms in the pathogenesis of periodontal disease.

Polystichum braunii extracts inhibit Complete Freund's adjuvant-induced arthritis via upregulation of I-κB, IL-4, and IL-10, downregulation of COX-2, PGE2, IL-1β, IL-6, NF-κB, and TNF-α, and subsiding oxidative stress

Polystichum braunii (Spenn.) Fée is a traditional remedy for rheumatoid arthritis, a chronic inflammatory disorder of polygenetic origin. The current project was intended to demonstrate the role of inflammatory and oxidative stress biomarkers in the anti-arthritic activity of the P. braunii extracts. Methanolic and aqueous extracts of the plant roots were prepared by triple maceration. The phytochemical evaluation of the plant extracts was carried out by high-performance liquid chromatography (HPLC). The plant extracts at 150, 300, and 600 mg/kg/day and piroxicam (10 mg/kg/day) were orally administered to Wistar rats for 21 days that were previously immunized with Complete Freund's adjuvant (150 µl on right hind paw) except normal and arthritic control rats. Both plant extracts mitigated the paw oedema, restored the immune organ and body weights, and ameliorated the level of blood parameters such as haemoglobin, red blood cells, platelets, white blood cells, alkaline phosphatase (ALP), C-reactive proteins, and rheumatoid factor. The evaluation of gene expression using quantitative-real-time polymerase chain reaction (qRT-PCR) revealed the substantial downregulation of tumor necrosis factor (TNF)-α, Interleukin (IL)-6, IL-1β, cyclo-oxygenase (COX)-2, nuclear factor (NF)-κB, and upregulation of IL-4, IL-10 and I-κB in polyarthritic rats treated with the plant extracts. Methanolic plant extract exhibited the maximum effect on upregulation of IL-4 (79 ± 3%), IL-10 (62.66 ± 4.93%), and I-κB (73.66 ± 3.05%) at 600 mg/kg/day. Treatment with the plant extracts also reduced the level of prostaglandin E2 and TNF-α in the serum of arthritic rats' dose dependently. It was also found that the plant extracts and piroxicam increased (p < 0.05) the activities of superoxide dismutase and catalase in the liver tissue while reduced the level of malondialdehyde in arthritic rats. Histological examination of ankle joints revealed that the plant extracts decreased the pannus formation, inflammation, and synovial hyperplasia in arthritic animals. HPLC analysis depicted that the plant extracts had contained kaempferol, quercetin, gallic acid, and other phenolic acids. It can be elucidated from the results that the extracts of P. braunii roots exhibited anti-arthritic activity in Wistar rats through modulation of inflammatory cytokines and boosting the antioxidant defense mechanism.

Structure-Based Modeling of SARS-CoV-2 Peptide/HLA-A02 Antigens

SARS-CoV-2-specific CD4 and CD8 T cells have been shown to be present in individuals with acute, mild, and asymptomatic Coronavirus disease (COVID-19). Toward the development of diagnostic and therapeutic tools to fight COVID-19, it is important to predict and characterize T cell epitopes expressed by SARS-CoV-2. Here, we use RosettaMHC, a comparative modeling approach which leverages existing structures of peptide/MHC complexes available in the Protein Data Bank, to derive accurate 3D models for putative SARS-CoV-2 CD8 epitopes. We outline an application of our method to model 8-10 residue epitopic peptides predicted to bind to the common allele HLA-A*02:01, and we make our models publicly available through an online database (https://rosettamhc.chemistry.ucsc.edu). We further compare electrostatic surfaces with models of homologous peptide/HLA-A*02:01 complexes from human common cold coronavirus strains to identify epitopes which may be recognized by a shared pool of cross-reactive TCRs. As more detailed studies on antigen-specific T cell recognition become available, RosettaMHC models can be used to understand the link between peptide/HLA complex structure and surface chemistry with immunogenicity, in the context of SARS-CoV-2 infection.

β2-Adrenergic Receptors Increase Cardiac Fibroblast Proliferation Through the Gαs/ERK1/2-Dependent Secretion of Interleukin-6

Fibroblasts are an important resident cell population in the heart involved in maintaining homeostasis and structure during normal conditions. They are also crucial in disease states for sensing signals and initiating the appropriate repair responses to maintain the structural integrity of the heart. This sentinel role of cardiac fibroblasts occurs, in part, through their ability to secrete cytokines. β-adrenergic receptors (βAR) are also critical regulators of cardiac function in the normal and diseased state and a major therapeutic target clinically. βAR are known to influence cytokine secretion in various cell types and they have been shown to be involved in cytokine production in the heart, but their role in regulating cytokine production in cardiac fibroblasts is not well understood. Thus, we hypothesized that βAR activation on cardiac fibroblasts modulates cytokine production to influence fibroblast function. Using primary fibroblast cultures from neonatal rats and adult mice, increased interleukin (IL)-6 expression and secretion occurred following β2AR activation. The use of pharmacological inhibitors and genetic manipulations showed that IL-6 elevations occurred through the Gαs-mediated activation of ERK1/2 and resulted in increased fibroblast proliferation. In vivo, a lack of β2AR resulted in increased infarct size following myocardial infarction and impaired wound closure in a murine dermal wound healing assay. These findings identify an important role for β2AR in regulating fibroblast proliferation through Gαs/ERK1/2-dependent alterations in IL-6 and may lead to the development of improved heart failure therapies through targeting fibrotic function of β2AR.

Review article: experimental therapies in autoimmune hepatitis

BACKGROUND

Current therapeutic options for autoimmune hepatitis (AIH) are limited by adverse events associated with corticosteroids and thiopurines and the limited evidence base for second- and third-line treatment options. Furthermore, current treatment approaches require long-term exposure of patients to pharmacological agents. There have been significant advances in the understanding of the mechanisms underpinning autoimmunity and an expansion in the available therapeutic agents for suppressing autoimmune responses or potentially restoring self-tolerance.

AIM

To review the mechanisms and evidence for experimental therapies that are being actively explored in the management of AIH.

METHODS

We have reviewed the literature relating to a range of novel therapeutic immunomodulatory treatment strategies and drugs.

RESULTS

Drugs which block B cell-activating factor of the tumour necrosis factor family (BAFF) and tumour necrosis factor α are currently in clinical trials for the treatment of AIH. Experimental therapies and technologies to increase immune tolerance, such as pre-implantation factor and regulatory T cell therapies, are undergoing development for application in autoimmune disorders. There is also evidence for targeting inflammatory pathways to control other autoimmune conditions, such as blockade of IL1 and IL6 and Janus-associated kinase (JAK) inhibitors.

CONCLUSIONS

With the range of tools available to clinicians and patients increasing, it is likely that the therapeutic landscape of AIH will change over the coming years and treatment approaches offering lower corticosteroid use and aiming to restore immune self-tolerance should be sought.

Safety of systemic treatments for Behçet's syndrome

INTRODUCTION

Treatment of Behçet's syndrome (BS) is aimed at controlling all symptoms of such a complex disorder, ensuring a good quality of life and preventing life-threatening complications. A better understanding of the pathogenic role of different chemokines has improved our knowledge of BS and elicited a more specific use of therapies currently available, minimizing the burden of potential side-effects related to treatment.

AREAS COVERED

This work aims to provide a detailed overview of the safety profile for current therapies available in the treatment of BS, focusing on the main side-effects, toxicity and contraindications.

EXPERT OPINION

The greatest experience in the management of BS has been achieved with the employment of monoclonal anti-tumor necrosis factor antibodies which have been advocated for BS refractory manifestations. Moreover, interleukin-1 inhibitors have proven to be effective as well as safe, despite escalation of their dosage, especially to manage the most severe and difficult-to-treat ocular manifestations. However, general treatment of BS patients remains awkward as protean clinical features may respond differently to the same treatment or even worsen. Therefore, patients' safety for therapies used in BS promotes the implementation of precision medicine, which could help targeting accurately the pathogenetic mechanisms concealed behind specific clinical phenotypes.

Prognostic and Clinical Value of Interleukin 6 and CD45+CD14+ Inflammatory Cells with PD-L1+/PD-L2+ Expression in Patients with Different Manifestation of Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest gynecological cancers. Recent studies suggest a crucial role of inflammatory immune system cells in the progression and metastasis of OC. The understanding of inflammatory mechanisms is pivotal for the selection of a biomarker that allows the differentiation between malignant and benign tumors, monitoring the progression of the disease, and identification of patients that will respond to implemented treatment. Our study is aimed at evaluating the profile of IL-6 in the plasma and peritoneal fluid (PF) of patients with various clinical manifestations of OC (n = 78). We also examined the relationship between IL-6 and PD-L1/PD-L2 positive CD45+CD14+ inflammatory cell (MO/MA) levels in three OC environments (TME): peripheral blood (PB), PF, and tumor (TT) and their clinical and prognostic relevance in OC patients. The expression of PD-L1/PD-L2 molecules was analyzed by flow cytometry. The IL-6 levels were determined by ELISA. We found an elevated level of PD-L1/PD-L2 positive MO/MA in TT compared to PB (p < 0.0001). Significantly higher (p < 0.0001) levels of IL-6 were observed in PF of the OC patients than in the benign ovarian tumor group (n = 31). Additionally, we found higher IL-6 levels in PF than in the plasma of the OC patients. Interestingly, accumulation of IL-6 was observed in PF of patients with low-differentiated OC and correlated with worse prognosis. Moreover, we observed correlations between the level of IL-6 and CD45+CD14+ cells and between CD45+CD14+PD-L1+ cells and the IL-6 level in PF. For the first time, we discovered that the higher percentage of CD45+CD14+PD-L2+ cells in PF predicts better survival of OC patients. Our study suggests that CD45+CD14+PD-L2+ cells and IL-6 may be predictive biomarkers for OC patients. Understanding how the composition of TME changes during OC development and progression is a prerequisite for projecting new therapeutic strategies. Overall, further validation research is warranted.

IL-6 Contributes to the TGF-β1-Mediated Epithelial to Mesenchymal Transition in Human Salivary Gland Epithelial Cells

To determine the role of IL-6 in bringing about the EMT, in SGEC obtained from healthy subjects. Human salivary gland (SGs) epithelial cells (SGEC) from primary Sjögren's syndrome (pSS) are able to synthesize interleukin (IL)-6, which is a critical mediator of the SGs modifications in response to chronic inflammation. Recently, a hypothetical link between epithelial-mesenchymal transition (EMT)-dependent salivary gland fibrosis and chronic inflammatory conditions has been suggested for pSS; the present study was conducted to evaluate this link. Primary cultures of human SGEC from salivary mucoceles were stimulated with increasing concentrations of IL-6 for 24-72 h. Microscopy, RT-PCR, Real-time PCR, immunoblotting and flow cytometry were used to detect morphological changes, mRNA and protein expression of the EMT markers E-Cadherin, Vimentin and Collagen type I following IL-6 stimulation. The data collected demonstrate that IL-6 can induce SGEC to undergo a morphological and phenotypical transition to a mesenchymal phenotype, in a dose-dependent manner. Decreased mRNA levels of E-Cadherin accompanied by higher mRNA levels of Vimentin and Collagen type I were observed in the IL-6-treated cells compared to control cells (all p < 0.05). This was confirmed at the protein level, demonstrating the decreased E-Cadherin expression, while Vimentin and Collagen type I expression was increased in IL-6-treated SGEC compared to controls (all p < 0.05). The results obtained corroborate the hypothesis that dysregulated cytokines IL-6 may contribute to the EMT-dependent fibrosis, offering a more complete understanding of the role of the EMT during SGs fibrosis in pSS.

Ascitic Interleukin 6 Is Associated with Poor Outcome and Spontaneous Bacterial Peritonitis: A Validation in Critically Ill Patients with Decompensated Cirrhosis

Decompensated cirrhosis predisposes to infectious diseases and acute-on-chronic liver failure (ACLF) in critically ill patients. Infections like spontaneous bacterial peritonitis (SBP) are frequently associated with multi-organ failure and increased mortality. Consequently, reliable predictors of outcome and early diagnostic markers of infection are needed to improve individualized therapy. This study evaluates the prognostic role of ascitic interleukin 6 in 64 patients with cirrhosis admitted to our intensive care unit (ICU). In addition, we analysed the diagnostic ability of ascitic interleukin 6 in a subgroup of 19 patients with SBP. Baseline ascitic interleukin 6 performed well in predicting 3-month mortality in patients with decompensated cirrhosis (area under curve (AUC) = 0.802), as well as in patients fulfilling ACLF-criteria (AUC = 0.807). Ascitic interleukin 6 showed a moderate prognostic advantage compared with common clinical scores and proinflammatory parameters. Moreover, ascitic interleukin 6 had a sufficient diagnostic ability to detect SBP (AUC = 0.901) and was well correlated with ascitic polymorphonuclear neutrophils in SBP (p = 0.002). Interestingly, ascitic interleukin 6 revealed a high predictive value to rule out apparent infections on admission to ICU (AUC = 0.904) and to identify patients with “culture-positive SBP” (AUC = 0.856). Ascitic interleukin 6 is an easily-applicable proinflammatory biomarker with high prognostic and diagnostic relevance in critically ill patients with liver cirrhosis.

A Trypsin Inhibitor from Moringa oleifera Flowers Modulates the Immune Response In Vitro of Trypanosoma cruzi-Infected Human Cells

Trypanosoma cruzi causes the lethal Chagas disease, which is endemic in Latin America. Flowers of Moringa oleifera (Moringaceae) express a trypsin inhibitor (MoFTI) whose toxicity to T. cruzi trypomastigotes was previously reported. Here, we studied the effects of MoFTI on the viability of human peripheral blood mononuclear cells (PBMCs) as well as on the production of cytokines and nitric oxide (NO) by T. cruzi-infected PBMCs. Incubation with MoFTI (trypsin inhibitory activity: 62 U/mg) led to lysis of trypomastigotes (LC₅₀ of 43.5 µg/mL) but did not affect the viability of PBMCs when tested at concentrations up to 500 µg/mL. A selectivity index > 11.48 was determined. When T. cruzi-infected PBMCs were treated with MoFTI (43.5 or 87.0 µg/mL), the release of the pro-inflammatory cytokine TNF-α and INF-γ, as well as of NO, was stimulated. The release of the anti-inflammatory cytokine IL-10 also increased. In conclusion, the toxicity to T. cruzi and the production of IL-10 by infected PBMCs treated with MoFTI suggest that this molecule may be able to control parasitemia while regulating the inflammation, preventing the progress of Chagas disease. The data reported here stimulate future investigations concerning the in vivo effects of MoFTI on immune response in Chagas disease.

Associations between IL1RAP rs4624606, IL1RL1 rs1041973, IL-6 rs1800795, and HTRA1 rs11200638 gene polymorphisms and development of optic neuritis with or without multiple sclerosis

BACKGROUND

Optic neuritis (ON) and multiple sclerosis (MS) are complex diseases with multifactorial pathogenesis. The role of genetic factors in the development of these diseases is hypothesized, and specific biochemical components involved in the pathogenesis of ON and MS are yet to be determined. The aim of our study was to determine the associations between IL1RAP rs4624606, IL1RL1 rs1041973, IL-6 rs1800795, and HTRA1 rs11200638 gene polymorphisms and development of ON with or without MS.

MATERIALS AND METHODS

The study subjects included 80 ON patients and 146 healthy controls (HCs). Genotyping of IL1RAP rs4624606, IL1RL1 rs1041973, IL-6 rs1800795, and HTRA1 rs11200638 was performed using real-time polymerase chain reaction.

RESULTS

A/C genotype of IL1RL1 rs1041973 was more frequent in ON patients than in HC subjects (p = 0.026). The IL1RL1 rs1041973 A/C genotype was associated with increased odds of ON development under the overdominant (p = 0.041) model.

CONCLUSIONS

Our study showed that IL1RAP rs4624606, IL-6 rs1800795, and HTRA1 rs11200638 are not associated with an increased risk of developing ON. However, the IL1RL1 rs1041973 A/C genotype might be associated with an increased risk of developing ON.

Treatment of Severe COVID-19 with Tocilizumab Mitigates Cytokine Storm and Averts Mechanical Ventilation During Acute Respiratory Distress: A Case Report and Literature Review

COVID-19, caused by the novel severe acute respiratory coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China, in 2019 and has resulted in the current pandemic. The disease continues to pose a major therapeutic challenge. Patient mortality is ultimately caused by acute respiratory distress syndrome (ARDS). Cytokine release syndrome (or "cytokine storm") is likely to be a contributing factor to ARDS in many patients. Because interleukin 6 (IL-6) is known to play a key role in inflammation, IL-6 receptor inhibitors such as tocilizumab may potentially treat COVID-19 by attenuating cytokine release. We present the case of a 48-year-old male with severe COVID-19, on the verge of meeting intubation requirements, who needed progressive oxygen support for respiratory distress. The patient was treated with a non-weight-based dosage of tocilizumab to prevent the onset of a cytokine storm. We chose to administer an IL-6 inhibitor because of the gradually increasing levels of acute phase reactants identified on serial blood draws, as well as his declining respiratory status. The treatment was well-tolerated in conjunction with standard drug therapies for COVID-19 (hydroxychloroquine, azithromycin, and zinc). The patient subsequently experienced marked improvements in his respiratory symptoms and overall clinical status over the following days. We believe that tocilizumab played a substantial role in his ability to avert clinical decline, particularly the need for mechanical ventilation. Ultimately, the patient was downgraded from the ICU and discharged within days. We highlight the potential of IL-6 inhibitors to prevent the progression of respiratory disease to a point requiring ventilator support. This case underscores the potential importance of early serial measurements of IL-6 and cytokine storm-associated acute phase reactants, such as ferritin, D-dimer, and C-reactive protein, in guiding clinical decision-making in the management of patients with suspected COVID-19. Conclusion: The early, proactive identification of serum acute phase reactants should be implemented in the treatment of COVID-19 in order to screen for a primary contributor to mortality-the cytokine storm. This screening, when followed by aggressive early treatment for cytokine storm, may have optimal therapeutic benefits and obviate the need for mechanical ventilation, thereby decreasing mortality. Additionally, we review current evidence regarding cytokine release syndrome in COVID-19 and the use of IL-6 receptor inhibition as a therapeutic strategy, and examine other reported cases in the literature describing IL-6 antagonist treatment for patients with COVID-19.

Anterior gradient 2 promotes tumorigenesis through upregulation of CCAAT-enhancer binding protein beta and hypoxia-inducible factor-2α and subsequent secretion of interleukin-6, interleukin-8, and vascular endothelial growth factor in the Caki-1 clear cell renal cell carcinoma cell line

It has been previously established that hypoxia leads to tumor development, treatment resistance, and a poor prognosis. Under oxygen deprivation, hypoxia-inducible factors (HIFs) are stimulated to activate the genes necessary for tumor development in a low-oxygen environment. These genes encode regulators of angiogenesis, epithelial-mesenchymal transition, and cellular metabolism. A disulfide isomerase, anterior gradient 2 (AGR2), has been shown to increase hypoxia-inducible factor 1, alpha subunit (HIF-1α) stability in breast cancer. Our goal was to determine if AGR2 affects the level of transcription factor hypoxia-inducible factor 2, alpha subunit (HIF-2α). As a model, we used the clear cell renal cell carcinoma (ccRCC) cell line Caki-1. The cells were transduced with lentiviral vector (Tet-On) encoding AGR2. After induction of AGR2 expression, cells were grown under either hypoxic (0.5% O₂ ) or normoxic (21% O₂ ) conditions. Our data showed that AGR2 upregulated both HIF-1α and HIF-2α expression in Caki-1 cells increasing the expression of HIF-activated genes (glucose transporter 1, phosphoglycerate kinase 1, vascular endothelial growth factor A, and transforming growth factor-alpha) under the hypoxic conditions. Under the normoxic conditions, AGR2 strongly activated CCAAT-enhancer binding protein beta (C/EBPβ). Upregulation of C/EBPβ correlated with increased expression and secretion of the interleukin-6 and interleukin-8, inducing angiogenesis and inflammation in Caki-1 cells. In summary, our studies revealed that AGR2 has essential functions in ccRCC progression through upregulation of C/EBPβ and HIF-2α expressions, which affects cell signaling and metabolism.

The Interplay among miRNAs, Major Cytokines, and Cancer-Related Inflammation

Inflammation is closely related with the progression of cancer and is an indispensable component that orchestrates the tumor microenvironment. Studies suggest that different mediator and cellular effectors, including cytokines (interleukins, tumor necrosis factor-α [TNF-α], transforming growth factor-β [TGF-β], and granulocyte macrophage colony-stimulating factor [GM-CSF]), chemokines, as well as some transcription factors (nuclear factor κB [NF-κB], signal transducer and activator of transcription 3 [STAT3], hypoxia-inducible factor-1α [HIF1α]), play a crucial role during cancer-related inflammation (CRI). MicroRNAs (miRNAs) are the key components of cellular physiology. They play notable roles during posttranscriptional gene regulation and, thus, might have a potential role in controlling the inflammatory cascade during cancer progression. Taking into consideration the role identified for miRNAs in relation to inflammatory cytokines, we have tried to review their participation in neoplastic progression. Additionally, the involvement of miRNAs with some important transcription factors (NF-κB, STAT3, HIF1α) and proteins (cyclooxygenase-2 [COX-2], inducible nitric oxide synthase [iNOS]) closely associated with inflammation during cancer has also been discussed. A clear insight into the responsibility of miRNAs in cytokine signaling and inflammation related to CRI could project them as new therapeutic molecules, which could lead to improved treatment of CRI in the near future.

Interleukin-6 Treatment Results in GLUT4 Translocation and AMPK Phosphorylation in Neuronal SH-SY5Y Cells

Interleukin-6 (IL-6) is a pleiotropic cytokine that can be released from the brain during prolonged exercise. In peripheral tissues, exercise induced IL-6 can result in GLUT4 translocation and increased glucose uptake through AMPK activation. GLUT4 is expressed in the brain and can be recruited to axonal plasma membranes with neuronal activity through AMPK activation. The aim of this study is to examine if IL-6 treatment: (1) results in AMPK activation in neuronal cells, (2) increases the activation of proteins involved in GLUT4 translocation, and (3) increases neuronal glucose uptake. Retinoic acid was used to differentiate SH-SY5Y neuronal cells. Treatment with 100 nM of insulin increased the phosphorylation of Akt and AS160 (p < 0.05). Treatment with 20 ng/mL of IL-6 resulted in the phosphorylation of STAT3 at Tyr705 (p ≤ 0.05) as well as AS160 (p < 0.05). Fluorescent Glut4GFP imaging revealed treatment with 20ng/mL of IL-6 resulted in a significant mobilization towards the plasma membrane after 5 min until 30 min. There was no difference in GLUT4 mobilization between the insulin and IL-6 treated groups. Importantly, IL-6 treatment increased glucose uptake. Our findings demonstrate that IL-6 and insulin can phosphorylate AS160 via different signaling pathways (AMPK and PI3K/Akt, respectively) and promote GLUT4 translocation towards the neuronal plasma membrane, resulting in increased neuronal glucose uptake in SH-SY5Y cells.

Translational Aspects of Nuclear Factor-Kappa B and Its Modulation by Thalidomide on Early and Late Radiation Sequelae in Urinary Bladder Dysfunction

PURPOSE

This preclinical study aimed to investigate the role of nuclear factor (NF)-κB in early and late radiogenic sequelae of urinary bladder dysfunction in mice. Thalidomide was applied either during the early or late response phase to determine potential effects of NF-κB inhibition on functional bladder impairment.

METHODS AND MATERIALS

After pelvic irradiation on day 0, female C3H/Neu mice were observed over a period of 360 days and radiation response was evaluated for alterations in bladder functionality and NF-κB activation. Functionality was determined in graded dose experiments (14-24 Gy) and assessed by micturition frequency analysis and transurethral cystotonometry to reveal alterations in voiding and volume. The induction of the NF-κB proteins p50 and p65 was evaluated by immunohistochemistry in response to a single dose of 23 Gy (ED₉₀). Thalidomide (100 mg/kg/d) was applied intraperitoneally in 3 treatment groups: daily from day 1 to 15, daily from day 16 to 30, and in 2-day-intervals from day 150 to 180.

RESULTS

Immunohistochemical analysis showed a biphasic activation of p50 and p65 during the early radiation cystitis phase (day 1-30). After a transient decrease, p50, but not p65, was reactivated permanently leading to increased levels, which suggests an occurrence of chronic inflammation correlated with functional impairment. Both early thalidomide treatments reduced NF-κB activation and shifted the ED₅₀ value for early radiation cystitis and late radiation sequelae to higher doses.

CONCLUSIONS

These data clearly demonstrate the involvement of NF-κB signaling in the pathogenesis of radiation-induced urinary bladder dysfunction. Additionally, this study emphasizes that biological targeting of early radiogenic processes has enormous effect on chronic symptoms. The late administration of thalidomide showed no significant effect on functionality.

Characterization of a recombinant pseudorabies virus expressing porcine parvovirus VP2 protein and porcine IL-6

Background

Porcine parvovirus (PPV) and pseudorabies virus (PRV) are the important etiological agents of swine infectious diseases, resulting in huge economic losses to the Chinese swine industry. Interleukin-6 (IL-6) has the roles to support host immune response to infections as a pleiotropic cytokine. It is essential to construct a live attenuated vaccine-based recombinant PRV that expresses PPV VP2 protein and porcine IL-6 for prevention and control of PRV and PPV.

Methods

The recombinant plasmid, pGVP2-IL6, was constructed by porcine IL-6 gene substituting for EGFP gene of the PRV transfer plasmid pGVP2-EGFP containing VP2 gene of PPV. Plasmid pGVP2-IL6 was transfected into swine testicle cells pre-infected with the virus rPRV-VP2-EGFP strain through homologous recombination and plaque purification to generate a recombinant virus rPRV-VP2-IL6. The recombinant PRV was further identified by PCR and DNA sequencing, and the expression of the VP2 protein and porcine IL-6 was analyzed by reverse transcription-PCR (RT-PCR) and Western blot. The virus titer was calculated according to Reed and Muench method. The immunogenicity of the recombinant virus was preliminarily evaluated in mice by intramuscular administration twice with the rPRV-VP2-IL6 at 4-week intervals.

Results

A recombinant virus rPRV-VP2-IL6 was successfully constructed and confirmed in this study. The properties of rPRV-VP2-IL6 were similar to the parental virus HB98 in terms of growth curve, morphogenesis and virus plaque sizes, and rPRV-VP2-IL6 was proliferated in different cell types. It induced specific antibodies against PPV as well as a strong increase of PPV-specific lymphocyte proliferation responses in mice immunized with rPRV-VP2-IL6, and provided partial protection against the virulent PPV challenge. rPRV-VP2-IL6 also induced a high level of neutralizing antibodies against PRV, and significantly reduced the mortality rate of (1 of 10) following virulent PRV challenge compared with the control (10 of 10).

Conclusions

The recombinant rPRV-VP2-IL6 might be a potential candidate vaccine against PRV and PPV infections in pigs.

Exercise as an anti-inflammatory therapy for cancer cachexia: a focus on interleukin-6 regulation

Cancer cachexia is a complicated disorder of extreme, progressive skeletal muscle wasting. It is directed by metabolic alterations and systemic inflammation dysregulation. Numerous studies have demonstrated that increased systemic inflammation promotes this type of cachexia and have suggested that cytokines are implicated in the skeletal muscle loss. Exercise is firmly established as an anti-inflammatory therapy that can attenuate or even reverse the process of muscle wasting in cancer cachexia. The interleukin IL-6 is generally considered to be a key player in the development of the microenvironment of malignancy; it promotes tumor growth and metastasis by acting as a bridge between chronic inflammation and cancerous tissue and it also induces skeletal muscle atrophy and protein breakdown. Paradoxically, a beneficial role for IL-6 has also been identified recently, and that is its status as a “founding member” of the myokine class of proteins. Skeletal muscle is an important source of circulating IL-6 in people who participate in exercise training. IL-6 acts as an anti-inflammatory myokine by inhibiting TNFα and improving glucose uptake through the stimulation of AMPK signaling. This review discusses the action of IL-6 in skeletal muscle tissue dysfunction and the role of IL-6 as an “exercise factor” that modulates the immune system. This review also sheds light on the main considerations related to the treatment of muscle wasting in cancer cachexia.

Long non-coding RNA H19 regulates endothelial cell aging via inhibition of STAT3 signalling

Aims

Long non-coding RNAs (lncRNAs) have been shown to regulate numerous processes in the human genome, but the function of these transcripts in vascular aging is largely unknown. We aim to characterize the expression of lncRNAs in endothelial aging and analyse the function of the highly conserved lncRNA H19.

Methods and results

H19 was downregulated in endothelium of aged mice. In human, atherosclerotic plaques H19 was mainly expressed by endothelial cells and H19 was significantly reduced in comparison to healthy carotid artery biopsies. Loss of H19 led to an upregulation of p16 and p21, reduced proliferation and increased senescence in vitro. Depletion of H19 in aortic rings of young mice inhibited sprouting capacity. We generated endothelial-specific inducible H19 deficient mice (H19iEC-KO), resulting in increased systolic blood pressure compared with control littermates (Ctrl). These H19iEC-KO and Ctrl mice were subjected to hindlimb ischaemia, which showed reduced capillary density in H19iEC-KO mice. Mechanistically, exon array analysis revealed an involvement of H19 in IL-6 signalling. Accordingly, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were upregulated upon H19 depletion. A luciferase reporter screen for differential transcription factor activity revealed STAT3 as being induced upon H19 depletion and repressed after H19 overexpression. Furthermore, depletion of H19 increased the phosphorylation of STAT3 at TYR705 and pharmacological inhibition of STAT3 activation abolished the effects of H19 silencing on p21 and vascular cell adhesion molecule 1 expression as well as proliferation.

Conclusion

These data reveal a pivotal role for the lncRNA H19 in controlling endothelial cell aging.

Trimethoxystilbene Reduces Nuclear Factor Kappa B, Interleukin-6, and Tumor Necrosis Factor-α Levels in Rats with Pulmonary Artery Hypertension

Pulmonary artery hypertension is a refractory disease that severely affects cardiopulmonary function, mainly resulting in irreversible pulmonary vascular remodeling. Current surgical treatment of this disease is not very effective and drug treatment is targeted at relieving symptoms, improving the quality of life of patients, and preventing disease progression. The purpose of this present study was to reveal the regulatory effects of trimethoxystilbene on the serum levels of nuclear factor kappa B, interleukin-6, and tumor necrosis factor-α in a rat model of pulmonary artery hypertension and to explore the possible underlying mechanisms. Healthy Sprague Dawley rats were randomly assigned to experimental groups and treated with monocrotaline to establish the model, and we found a significant difference in the expression levels of nuclear factor kappa B, interleukin-6, and tumor necrosis factor-α between the experimental and control groups. These results suggest that trimethoxystilbene significantly reduced the inflammatory factor levels in pulmonary hypertensive rats, providing us with new potential strategies for elucidating the mechanisms of action of trimethoxystilbene in the treatment of pulmonary artery hypertension.

The systemic inflammatory response as a source of biomarkers and therapeutic targets in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) strongly relates to inflammation, with chronic up-regulation of pro-inflammatory mediators standing as a potential unifying mechanism that underscores the origin and progression of HCC independent of aetiology. Activation of the diverse pro-inflammatory mediators either within the tumour or its microenvironment is part of an active cross-talk between the progressive HCC and the host, which is known to influence clinical outcomes including recurrence after radical treatments and long-term survival. A number of clinical biomarkers to measure the severity of cancer-related inflammation are now available, most of which emerge from routine blood parameters including neutrophil, lymphocyte, platelet counts, as well as albuminaemia and C-reactive protein levels. In this review, we summarise the body of evidence supporting the biologic qualification of inflammation-based scores in HCC and review their potential in facilitating the prognostic assessment and treatment allocation in the individual patient. We also discuss the evidence to suggest modulation of tumour-promoting inflammation may act as a source of novel therapeutic strategies in liver cancer.

Graphene Oxide in a Composite with Silver Nanoparticles Reduces the Fibroblast and Endothelial Cell Cytotoxicity of an Antibacterial Nanoplatform

Antibacterial surfaces coated with nanomaterials, including silver nanoparticles, are considered effective alternative antimicrobial agents that can be used instead of antibiotics and chemical agents. However, reports of the potential toxicity of these materials raise questions about the safety of their use in biomedical applications. The objective of this research was to reduce the human cell cytotoxicity of silver nanoparticle-coated polyurethane foils by complexing silver nanoparticles with graphene oxide. The antimicrobial activity of nanoplatforms coated with silver nanoparticles, graphene oxide and the composite of silver nanoparticles and graphene oxide was assessed with Salmonella enteritidis. Cytotoxicity was analysed by an analysis of the viability and morphology of human fibroblasts, human umbilical vein endothelial cells (HUVECs) and chicken embryo chorioallantoic membrane. Additionally, the synthesis level of inflammatory proteins was examined for fibroblasts cultured on different nanoplatforms. The nanoplatform coated with the silver nanoparticles and graphene oxide composite showed strongest antibacterial properties, although nanoplatforms coated with only silver nanoparticles or graphene oxide also resulted in decreased S. enteritidis growth. Furthermore, a nanoplatform coated with silver nanoparticles and graphene oxide composite showed limited immunological stimulation and significantly reduced cytotoxicity towards fibroblasts, HUVECs and chicken embryo chorioallantoic membrane in comparison to the nanoplatform coated only with silver nanoparticles, due to the higher stability of the nanomaterials in the nanocomposite.

Efficacy and safety of Ramucirumab and methotrexate co-therapy in rheumatoid arthritis experimental model: Involvement of angiogenic and immunomodulatory signaling

Rheumatoid arthritis (RA) is a chronic and progressive autoimmune inflammatory disease associated with irreversible joint destruction that leads to permanent motor disability and compromised quality of life. However, the main cause of RA is still unknown though stimulation of immune system and cells plays pivotal role in disease development and progression. Ramucirumab (RAM) is the monoclonal antibody against VEGF- receptor. This study aimed to investigate and evaluate the therapeutic effect of RAM with or without Methotrexate (MTX) against adjuvant-induced arthritis in rats. Complete Freund's adjuvant (CFA)-induced arthritic rats were treated for three consecutive weeks with MTX or RAM alone and MTX-RAM co-therapy. Arthritic score, gait score, ankle diameter, paw thickness, angiogenic, inflammatory cytokines, bone erosion markers, and apoptotic markers were assessed to evaluate the anti-arthritic effect. RAM monotherapy exhibited anti-inflammatory, anti-angiogenic and anti-apoptotic effects similar to MTX alone to treat RA in the current study. Furthermore, RAM alone had a protective effect on bone and cartilage health better than standard anti-rheumatic agent MTX. Interestingly, combined therapy of MTX and RAM produced significant differences in comparison with MTX or RAM monotherapy in all tested parameters. Moreover, the current study proved that MTX-RAM co-therapy has a synergistic effect.

Inflammatory cytokines in bladder cancer

The presence of inflammatory cells and their products in the tumor microenvironment plays a crucial role in the pathogenesis of a tumor. Releasing the cytokines from a host in response to infection and inflammation can inhibit tumor growth and progression. However, tumor cells can also respond to the host cytokines with increasing the growth/invasion/metastasis. Bladder cancer (BC) is one of the most common cancers in the world. The microenvironment of a bladder tumor has been indicated to be rich in growth factors/inflammatory cytokines that can induce the tumor growth/progression and also suppress the immune system. On the contrary, modulate of the cancer progression has been shown following upregulation of the cytokines-related pathways that suggested the cytokines as potential therapeutic targets. In this study, we provide a summary of cytokines that are involved in BC formation/regression with both inflammatory and anti-inflammatory properties. A more accurate understanding of tumor microenvironment creates favorable conditions for cytokines targeting to treat BC.

Discontinuation of concomitant methotrexate in Japanese patients with rheumatoid arthritis treated with tocilizumab: An interventional study

Objectives: To evaluate the efficacy and safety of methotrexate (MTX) discontinuation in Japanese rheumatoid arthritis (RA) patients with sustained low disease activity undergoing combination therapy with tocilizumab (TCZ) plus MTX.Methods: This multicenter, open-label, uncontrolled, prospective study included RA patients maintaining low disease activity (Clinical Disease Activity Index (CDAI) ≤10) for ≥12 weeks with TCZ plus MTX. Methotrexate was discontinued following 12 weeks of biweekly administration while continuing TCZ therapy. The primary endpoint was the proportion of patients maintaining low disease activity with no flare at week 36.Results: A total of 49 patients completed 36 weeks of therapy. The proportion of patients maintaining low disease activity at week 36 was 75.5%. The lower limit of the 95% confidence interval exceeded the assumed threshold response rate of 60%, demonstrating the clinical feasibility of MTX discontinuation. The prevalence of gastroesophageal reflux disease, defined as a Frequency Scale for Symptoms of Gastroesophageal reflux disease score ≥8, significantly decreased from week 0 to 12 (27.1-18.4%; p= .025).Conclusion: Discontinuation of concomitant MTX is clinically feasible for maintaining low disease activity, and may be beneficial from the perspective of reducing gastrointestinal symptoms in Japanese RA patients treated with TCZ. Trial registration number: UMIN000021247.

TERT inhibition leads to reduction of IL-6 expression induced by palmitic acid and interferes with the protective effects of tibolone in an astrocytic cell model

Although it has been shown that telomerase has neuroprotective effects, mainly as a result of its non-canonical functions in neuronal cells, its role with respect to glial cells remains unknown. There is growing evidence indicating that telomerase plays an important role with respect to inflammation, especially in the regulation of pro-inflammatory cytokine gene expression. The present study aimed to evaluate the role of telomerase in an astrocyte cell model treated with palmitic acid (PA) and tibolone. Cell death, reactive oxygen species production and interleukin-6 expression were evaluated under telomerase inhibition with the BIBR1532 compound in T98G cells treated with tibolone and PA, using fluorometry, flow cytometry, enzyme-linked immunosorbent assays and the quantitative polymerase chain reaction. The results obtained showed that telomerase protein was increased by PA after 36 hours, alone or in combination with tibolone, and that its activity was affected by PA. Telomerase inhibition reduced interleukin-6 expression and it interfered with the protective effects of tibolone on cell death. Moreover, tibolone increased Tyr707 phosphorylation in PA-treated cells. In the present study, we provide novel findings about the regulation of telomerase by PA and tibolone. Telomerase was involved in inflammation by PA and in protective effects of tibolone. Therefore, we conclude that telomerase could play a dual role in these cells.

Interleukin-6 (IL-6) mediates protection against glucose toxicity in human Müller cells via activation of VEGF-A signaling

Interleukin-6 (IL-6) has become a target of interest for drug development aiming to treat diabetic retinopathy. Since IL-6 signaling can promote beneficial as well as detrimental effects via two different signaling pathways, the objective of the present study was to investigate the effects of classical IL-6 and IL-6 trans-signaling on human Müller cells (HMC), which are important for the development of diabetic retinopathy. HMCs were cultured in normal (5 mmol/L) and high (25 mmol/L) glucose plus or minus IL-6 or IL-6/sIL-6R. IL-6 receptor expression using immunohistochemistry and flow cytometry and cytokine release using magnetic bead assays were determined. HMCs express the membrane bound form of the IL-6 receptor (mIL-6R), gp130, and can release the soluble forms sIL-6R and sgp130 demonstrating that HMCs are capable of responding to classical IL-6 and IL-6 trans-signaling. IL-6 protected HMCs from glucose toxicity via VEGF-A signaling. IL-6/sIL-6R caused only modest protection, which was not mediated by VEGF-A. Our data show for the first time that classical IL-6 signaling exerts its beneficial effects through VEGF-A action contrary to IL-6 trans-signaling, which was VEGF-A independent. These results have clinical implications for drug development targeting IL-6 since strict anti-IL-6 therapies might further decrease neuroretinal functions in the diabetic retina.

Efficacy and safety of tocilizumab in Korean patients with active rheumatoid arthritis

BACKGROUND/AIMS

To investigate the efficacy and safety of tocilizumab (TCZ) humanized anti-interleukin-6 receptor monoclonal antibody, in Korean patients with active rheumatoid arthritis (RA) refractory to conventional disease modifying anti-rheumatic drugs (DMARDs) including methotrexate (MTX).

METHODS

The main study was a 24-week, randomized, double-blind, controlled trial that was followed by a 48-week, open-labeled, extension phase. TCZ (8 mg/kg) or placebo was intravenously administered every 4 weeks.

RESULTS

Those treated with TCZ showed more favorable outcomes in terms of 20% according to the American College of Rheumatology response criteria (ACR20) and ACR50 responses, individual parameters of ACR core set, disease activity score in 28 joints (DAS28) remission, and European League Against Rheumatism (EULAR) response at week 24. These improvements were maintained or increased during the extension period. DAS28 remission at week 72 was associated with EULAR good response at week 12. The patients who experienced any adverse event (AE) were more frequent in the TCZ group compared to the placebo group. Most AEs were mild or moderate in intensity, although TCZ therapy had possible AEs including serious infection, abnormal liver function, and atherogenic lipid profile.

CONCLUSION

TCZ infusion add-on is highly efficacious and well-tolerated in Korean patients with active RA refractory to conventional DMARDs including MTX. EULAR good response at week 12 could predict DAS28 remission at week 72.

Correlation of fatigue with other disease related and psychosocial factors in patients with rheumatoid arthritis treated with tocilizumab: ACT-AXIS study

To assess the hypothesis if tocilizumab (TCZ) is effective on disease activity, and also its effect in fatigue and other clinical and psychological disease-related factors in patients with rheumatoid arthritis (RA) treated with TCZ.A 24-week, multicenter, prospective, observational study in patients with moderate to severe RA receiving TCZ after failure or intolerance to disease-modifying antirheumatic drugs or tumor necrosis factor-alpha was conducted.Of the 122 patients included, 85 were evaluable for effectiveness (85% female, 51.9 ± 12.5 years, disease duration 8.7 ± 7.4 years). Mean change in C-reactive protein level from baseline to week 12 was -11.2 ± 4.0 (P < .001). Mean Disease Activity Index score (DAS28) decreased from 5.5 ± 1.0 at baseline to 2.7 ± 1.3 (P < .001) at week 24. Mean change in Functional Assessment of Chronic Illness Therapy score was -5.4 ± 11.2 points at week 24. Multiple regression analysis showed that the improvement in DAS28, sleep, and depression explained 56% and 47% of fatigue variance at week 12 and 24, respectively.Tocilizumab is effective in reducing disease activity and results in a clinically significant improvement in fatigue, pain, swollen joint count, morning stiffness, sleepiness, depression, and DAS28; the last 3 were specifically identified as factors explaining fatigue variance with the use of TCZ in RA patients.

Role of SOCS3 in enhanced acute-phase protein genes by neonatal macrophages in response to IL-6

BACKGROUND

Interleukin 6 (IL-6) induce the inflammatory response directly related with the morbidity and mortality of neonatal. Here we aimed to explore the mechanism of IL-6 in neonatal inflammatory response by studying the IL-6/STAT3 signaling pathway.

METHODS

Cord blood samples from health term neonatal and peripheral venous blood from health volunteers were collected. The monocytes of adults and cord blood were isolated and induced into macrophages. Then the macrophages were pretreated with or without MG132 before IL-6 stimulation. Proteins were analyzed by Western blot, mRNA by real time PCR and membrane molecule by flow cytometry.

RESULTS

The acute phase protein gene expression in neonatal macrophages after stimulated with IL-6 were higher than that in adult. Significantly enhanced phosphorylation of STAT3 was seen in neonatal macrophages. Both mRNA and protein expression of SOCS3 in neonatal macrophages were lower than that in adult. After pretreated with MG132, the expression of SOCS3 protein was increased which lead to attenuate the STAT3 phosphorylation and APP gene expression.

CONCLUSION

Neonatal exhibit an enhanced expression of downstream target genes and IL-6/STAT3 signal pathway which is related with the diminished SOCS3. This provides a new sight into inflammatory responses in neonatal.

Cytokine expression in chicken embryo fibroblasts in response to infection with virulent or lentogenic avian avulavirus 1 (AAvV-1)

To investigate cytokine expression in chicken embryo fibroblast (CEF) cells, a virulent avian avulavirus 1 (AAvV-1) strain called SG10 that rapidly causes 100% mortality in its host, and a vaccine strain (La Sota) were characterized. Real-time quantitative PCR was performed on RNA samples from CEF cells, which were collected at 0, 24, 48 and 72 h post-infection. The dynamic expression patterns of ten cytokines (TNF-α, IFN-α, IFN-β, IL-1β, IL-2, IL-6, IL-10, IL-13, IL-15 and IL-18) were investigated. The results showed that infection with lentogenic La Sota induced significantly higher levels of the antiviral cytokines IFN-α and IFN-β, proinflammatory cytokines IL-2, IL-15 and IL-18, and the anti-inflammatory cytokine IL-10, than did infection with virulent SG10. Furthermore, the SG10 strain induced dramatically higher levels of the inflammatory cytokine IL-6 than those observed in cells infected with La Sota. However, the expression patterns of the other cytokines that were tested did not show any obvious trends or statistically significant differences between cells infected with the virulent and avirulent strains. These data show that infection with lentogenic La Sota induced more effective immune responses and anti-viral effects than did infection with virulent SG10 in CEFs. Our data provide distinct expression patterns of IFNs and proinflammatory and anti-inflammatory cytokines to AAvV-1 by virulence in CEF cells.

Signals from the Niche: Insights into the Role of IGF-1 and IL-6 in Modulating Skeletal Muscle Fibrosis

Muscle regeneration, characterized by the activation and proliferation of satellite cells and other precursors, is accompanied by an inflammatory response and the remodeling of the extracellular matrix (ECM), necessary to remove cellular debris and to mechanically support newly generated myofibers and activated satellite cells. Muscle repair can be considered concluded when the tissue architecture, vascularization, and innervation have been restored. Alterations in these connected mechanisms can impair muscle regeneration, leading to the replacement of functional muscle tissue with a fibrotic scar. In the present review, we will discuss the cellular mediators of fibrosis and how the altered expression and secretion of soluble mediators, such as IL-6 and IGF-1, can modulate regulatory networks involved in the altered regeneration and fibrosis during aging and diseases.

Down-regulation of the inflammatory response after short-term exposure to low levels of chemical vapours

OBJECTIVE

To investigate the relation between signs and symptoms of irritation and biomarkers of inflammatory markers in blood in healthy volunteers exposed to different chemical vapours for 2 or 4 hours in an exposure chamber.

METHODS

The investigated chemicals were: acetic acid (5 and 10 ppm), acrolein (0.05 and 0.1 ppm), 1,4-dioxane (20 ppm), n-hexanal (2 and 10 ppm), hydrogen peroxide (0.5 and 2.2 ppm), 2-propanol (150 ppm), m-xylene (50 ppm), standard and dearomatised white spirit (100 and 300 mg/m³). C reactive protein (CRP), serum amyloid A protein and interleukin 6 were measured in plasma immediately before and 2 or 4 hours after the exposures. Symptoms were rated from 0 to 100 mm in Visual Analogue Scales and covered 10 questions whereof four related to irritation: discomfort in the eyes, nose and throat and dyspnoea. The effect measurements included blink frequency by electromyography, nasal swelling by acoustic rhinometry and lung function by spirometry.

RESULTS

Logistic quantile regression analyses revealed no significant associations except a negative relation between ratings of irritation and CRP.

CONCLUSION

The results suggest a down-regulation of CRP after short-term exposure to low levels of vapours of irritating chemicals. This response might be mediated by the cholinergic anti-inflammatory pathway and further studies are recommended in order to refute or confirm this hypothesis.

Biomarkers of Atrial Fibrillation in Metabolic Syndrome

Whether the increased atrial fibrillation (AF) risk in metabolic syndrome (MetS) patients is due to the syndrome as a whole or simply the sum of the risks of its individual component parts is still obscure. These two clinical entities share many pathophysiological links and thus distinction between a casual observation and a significant association is difficult. Biomarkers associated with pathogenesis of AF in the context of MetS have the ability to refine future risk prediction. In the present review we identify circulating substances that could be regarded as potential biomarkers for prediction of incident AF, or of cardiovascular events in the setting of AF in patients with MetS. Cardiac myocyte injury and stress markers (troponin and natriuretic peptides), markers of renal function (glomeral filtration rate, cystatin-C), and inflammation markers/mediators (interleukin- 6, CRP) are promising biomarkers of patients with AF and MetS.

[Research progress on interleukin-6 in lung cancer]

As the core of cellular immunotherapy, T cells are important aspects of research and treatment of lung cancer. IL-6 is a costimulatory signal factor of T cells that is directly targeted by lung cancer stem cells. As a highly expressed cytokine in lung cancer cells, IL-6 plays an important role in variety of biological activities such as tumor occurrence, development, invasion and metastasis. This article reviews the research progress on IL-6 in lung cancer, including cancer development and progression, and the therapeutic sensitivity of lung cancer.

The relationship between 174 G/C and -572 G/C of IL-6 gene polymorphisms and susceptibility of celiac disease in the Iranian population

INTRODUCTION

Celiac disease (CD) is a chronic inflammatory intestinal disorder. Different immunological factors, including inflammatory cytokines, may play an important role in disease susceptibility.

AIM

To investigate the relationship between -174G/C and -572G/C gene polymorphisms and the serum level of interleukin 6 (IL-6) and susceptibility to CD in the Iranian population.

MATERIAL AND METHODS

In this case-control study blood samples were collected of 105 patients with CD and 106 healthy subjects randomly in 2016 and evaluated by polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) method. A sequence was also used to confirm the results of both polymorphisms. The IL-6 concentration was measured using ELISA.

RESULTS

The results showed a significant relationship between polymorphism -572G in CD patients when compared with control subjects by genotype (p = 0.001) and alleles (p = 0.022), respectively. There was no significant relationship between polymorphism 174G and frequency of genotype, but an association of this polymorphism with the frequency of alleles (p = 0.034), age (p = 0.001), and body mass index (p = 0.003) was seen. The serum level of interleukin-6 was significantly associated only with rs1800796 (p < 0.001).

CONCLUSIONS

The results confirm previous studies in different parts of the world and indicate that IL-6 (572G/C) polymorphism may play a role in susceptibility to CD in the Iranian population.

New insights and long-term safety of tocilizumab in rheumatoid arthritis

Rheumatoid arthritis is a leading musculoskeletal cause of disability in Western society. Therapeutic options have expanded rapidly with the advent of biological agents as treatment options. One of these, tocilizumab, targets the interleukin-6 receptor and has been approved since the late 2000s in many jurisdictions. This approval was based on 6-12 month trials. It is now appropriate to look at longer-term studies and what new insights they have provided into this agent. Data are based largely on observational studies with their well-known limitations as well as some further randomized trials and provide a number of important observations regarding both efficacy and safety. In conclusion, the longer-term data suggest tocilizumab efficacy increases over time for both signs and symptoms and radiographic change. It is also corticosteroid sparing. The safety data are consistent with the shorter-term trials and are largely reassuring but some questions still remain over cardiovascular safety and cancer risk.

New insights and long-term safety of tocilizumab in rheumatoid arthritis

Rheumatoid arthritis is a leading musculoskeletal cause of disability in Western society. Therapeutic options have expanded rapidly with the advent of biological agents as treatment options. One of these, tocilizumab, targets the interleukin-6 receptor and has been approved since the late 2000s in many jurisdictions. This approval was based on 6-12 month trials. It is now appropriate to look at longer-term studies and what new insights they have provided into this agent. Data are based largely on observational studies with their well-known limitations as well as some further randomized trials and provide a number of important observations regarding both efficacy and safety. In conclusion, the longer-term data suggest tocilizumab efficacy increases over time for both signs and symptoms and radiographic change. It is also corticosteroid sparing. The safety data are consistent with the shorter-term trials and are largely reassuring but some questions still remain over cardiovascular safety and cancer risk.

TH1/TH2 chemokines/cytokines profile in rats treated with tetanus toxoid and Euphorbia tirucalli

Natural products, including their purified materials, play a remarkable role in drug development. The Euphorbiaceae family, mainly Euphorbia tirucalli, is used in some traditional medicine, and has evidence that its latex comprises immunomodulatory properties and cytokine production. This study aimed to measure the in vivo production of chemokines (IL-1α, IL-1β, IL-12, and RANTES), T_H1 cytokines (IFN-γ, TNF-α, GM-CSF, and IL-2) and T_H2 cytokines (IL-4, IL-6, IL-10, and IL-13) in rats after treatments with ethanol latex extract of E. tirucalli. Vaccine treated and untreated rats were divided into seven groups to assess antimicrobial activities of the extracted components. After completion of the treatment schedule, blood was withdrawn and sera were collected. The results showed that the main component of the extract was a euphol compound. The extract showed antimicrobial activity and had the ability to modulate innate and adaptive immunity. Animals treated with extract for only 7 days before vaccination showed higher levels of antibody production. The extract showed antibacterial and antifungal activities. The extract could stimulate both adaptive and innate immunity. Pre-treatment with the extract increased immune responses in vaccinated animals, indicating the usefulness of the extract before immunization.

Dcf1 Deficiency Attenuates the Role of Activated Microglia During Neuroinflammation

Microglia serve as the principal immune cells and play crucial roles in the central nervous system, responding to neuroinflammation via migration and the execution of phagocytosis. Dendritic cell-derived factor 1 (Dcf1) is known to play an important role in neural stem cell differentiation, glioma apoptosis, dendritic spine formation, and Alzheimer’s disease (AD), nevertheless, the involvement of the Dcf1 gene in the brain immune response has not yet been reported. In the present paper, the RNA-sequencing and function enrichment analysis suggested that the majority of the down-regulated genes in Dcf1^-/- (Dcf1-KO) mice are immune-related. In vivo experiments showed that Dcf1 deletion produced profound effects on microglial function, increased the expression of microglial activation markers, such as ionized calcium binding adaptor molecule 1 (Iba1), Cluster of Differentiation 68 (CD68) and translocator protein (TSPO), as well as certain proinflammatory cytokines (Cxcl1, Ccl7, and IL17D), but decreased the migratory and phagocytic abilities of microglial cells, and reduced the expression levels of some other proinflammatory cytokines (Cox-2, IL-1β, IL-6, TNF-α, and Csf1) in the mouse hippocampus. Furthermore, in vitro experiments revealed that in the absence of lipopolysaccharide (LPS), the majority of microglia were ramified and existed in a resting state, with only approximately 10% of cells exhibiting an amoeboid-like morphology, indicative of an activated state. LPS treatment dramatically increased the ratio of activated to resting cells, and Dcf1 downregulation further increased this ratio. These data indicated that Dcf1 deletion mediates neuroinflammation and induces dysfunction of activated microglia, preventing migration and the execution of phagocytosis. These findings support further investigation into the biological mechanisms underlying microglia-related neuroinflammatory diseases, and the role of Dcf1 in the immune response.

Inflammatory biomarkers in saliva and serum of patients with rheumatoid arthritis with respect to periodontal status

OBJECTIVE

To study prospectively the association of salivary and serum matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1 and interleukin (IL)-6 with periodontal and systemic inflammation in rheumatoid arthritis (RA). We hypothesized that biomarker concentrations reflect inflammation.

METHODS

Fifty three early untreated RA (ERA) and 28 chronic RA (CRA) patients, underwent rheumatological and dental examinations at baseline and one year later after starting first conventional or biological disease modifying antirheumatic drug. We included 43 control subjects. Saliva and serum samples were analyzed for MMP-8, TIMP-1 and IL-6. Periodontal health was assessed by bleeding on probing (BOP), pocket depth (PD) and periodontal inflammatory burden index (PIBI); RA disease activity was assessed by disease activity score DAS28. Joint destruction was analyzed by the modified Sharp-van der Heijde (SHS) method.

RESULTS

Serum MMP-8 (p < .001; p < .001) and IL-6 (p < .001; p = .002) were significantly higher in CRA vs. other study groups during the study. Salivary MMP-8 (p = .010) and IL-6 (p = .010) were significantly higher in ERA vs. other study groups at baseline. Salivary MMP-8 was associated with periodontal parameters.

CONCLUSION

Elevated serum concentrations of MMP-8 and IL-6 in CRA patients reflected chronic RA, while elevated salivary concentrations of MMP-8 levels in ERA patients reflected increased periodontal inflammation. Key messages Concentrations of inflammatory biomarkers in serum and saliva were different between patients with RA and healthy controls. Concentrations of MMP-8 and of IL-6 in serum were elevated in patients with chronic RA reflecting joint inflammation and the burden of established RA. Concentrations of MMP-8 in saliva was elevated already at the early stage of RA and the level of salivary MMP-8 was associated with poor periodontal health both in patients with early and in those with chronic RA.

Interleukin-6 receptor inhibitor suppresses bone metastases in a breast cancer cell line

BACKGROUND

Interleukin-6 (IL-6) is a potent inflammatory cytokine that appears to play a key role in cancer growth and metastasis. In the present study, the effects of IL-6 receptor (IL-6R) on breast cancer aggressiveness and bone metastases were investigated.

METHODS

MDA-MB-231 (MDA-231) cells were treated in the presence or absence of anti-human IL-6 receptor (IL-6R) monoclonal antibody and examined with respect to cell survival. The expressions of signal transducer and activator of transcription 3 (Stat3), vascular endothelial growth factor (VEGF), and receptor activator of NF-κB (RANK) were analyzed by SDS-PAGE and immunoblotting. MDA-231 cells were injected into the left ventricle of mice, and then anti-human IL-6R monoclonal antibody or saline was administered intraperitoneally for 28 days. After 28 days, the incidence of bone metastases was evaluated in the hind limbs by radiography and histology.

RESULTS

Anti-human IL-6R monoclonal antibody reduced bone metastases in an animal model injected with MDA-231 cells on radiological and histomorphometric analyses. The mechanism of bone metastasis inhibition involved inhibited cell proliferation and decreased expressions of phospho-Stat3, VEGF, and RANK in MDA-231 cells.

CONCLUSIONS

The results of the present study suggest that inhibition of IL-6 signaling may become a preventive therapeutic option for breast cancer and bone metastases.

The effects of IL-10 gene polymorphism on serum, and gingival crevicular fluid levels of IL-6 and IL-10 in chronic periodontitis

OBJECTIVE

Anti-inflammatory cytokines play a crucial role in periodontitis by inhibiting synthesis of pro-inflammatory cytokines. The purpose of this study was to evaluate the effect of interleukin-10 (-597) gene polymorphism and genotype distributions on chronic periodontitis (CP) development and IL-6 and IL-10 levels in gingival crevicular fluid (GCF) and serum before and after non-surgical periodontal treatment.

MATERIAL AND METHODS

The study population consisted of 55 severe generalized CP patients as CP group and 50 healthy individuals as control group. Plaque index, gingival index, probing depth and clinical attachment level were recorded and GCF and blood samples were taken at both the baseline and the sixth week after non-surgical periodontal treatment. PCR-RFLP procedure was used for gene analyses and cytokine levels were measured via ELISA.

RESULTS

IL-10 genotype distribution was significantly different between CP and control groups (p=0.000, OR:7, 95%CI, 2.83-60.25). Clinical measurements significantly improved in the CP group after periodontal treatment (p<0.05). Periodontal treatment significantly decreased GCF IL-6 and IL-10 levels. No significant difference was found in clinical parameters between IL-10 AA and AC+CC genotypes at both the baseline and the sixth week (p>0.05). Sixth week GCF IL-10 levels were significantly lower in patients carrying IL-10 AC+CC genotype compared to the patients carrying IL-10 AA genotype (p<0.05). Serum IL-6 and IL-10 levels were lower in patients carrying the IL-10 AA genotype compared to patients with IL-10 AC+CC genotype, but the difference was not significant (p>0.05).

CONCLUSION

IL-10 AA genotype carriers had lower IL-6 and IL-6/10 levels in serum; however, GCF IL-6/10 levels were similar in both genotypes. Within the limitations of our study, a possible association between IL-10(-597) gene polymorphism and CP might be considered.

ADAM9 mediates the interleukin-6-induced Epithelial-Mesenchymal transition and metastasis through ROS production in hepatoma cells

Interleukin (IL)-6 has been implicated in the invasion and metastasis of hepatocellular carcinoma (HCC). However, the molecular events that mediate this process are poorly understood. Here, we showed that IL-6 promoted the epithelial-mesenchymal transition (EMT) in HCC cell lines, and upregulated a disintegrin and metalloprotease 9 (ADAM9) expression by activating the JNK signaling pathway. ADAM9 was upregulated in human HCCs which promoted HCC cell invasion and the EMT by interacting with NADPH oxidase 1 and inducing reactive oxygen species generation. Knockdown of ADAM9 inhibited the IL-6-induced EMT. Additionally, ADAM9 expression was positively correlated with IL-6 and Snail expression in human HCC specimens. Taken together, our results showed that ADAM9 is an important mediator of IL-6-induced HCC cell migration and invasion, and may provide a novel therapeutic target for HCC management.

Comparison of the efficacy and tolerability of tocilizumab, sarilumab, and sirukumab in patients with active rheumatoid arthritis: a Bayesian network meta-analysis of randomized controlled trials

The relative efficacy and tolerability of tocilizumab, sarilumab, and sirukumab were assessed in patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX) or tumor necrosis factor (TNF) inhibitors. We performed a Bayesian network meta-analysis to combine direct and indirect evidence from randomized controlled trials (RCTs) to examine the efficacy and safety of tocilizumab, sarilumab, and sirukumab in RA patients and an inadequate MTX or TNF inhibitor response. Fourteen RCTs, comprising 9753 patients, met the inclusion criteria. Tocilizumab 8 mg combined with MTX or as monotherapy was the most effective treatment for active RA with an inadequate MTX or TNF antagonist response, followed by sarilumab and sirukumab, regardless of MTX combination. The ranking probability based on the surface under the cumulative ranking curve (SUCRA) indicated that tocilizumab 8 mg + MTX had the highest probability of being the best treatment to achieve the ACR50 response rate, followed by tocilizumab 8 mg, sarilumab 200 mg, sarilumab 200 mg + MTX, sirukumab 100 mg, tocilizumab 4 mg + MTX, sirukumab 100 mg + MTX, sirukumab 50 mg + MTX, sarilumab 150 mg + MTX, adalimumab 40 mg, and sirukumab 50 mg, and placebo + MTX. No significant differences were observed in withdrawals owing to adverse events after treatment with tocilizumab 8 mg + MTX, sirukumab 100 mg + MTX, or sarilumab 200 mg + MTX. In RA patients with an inadequate MTX or anti-TNF therapy response, tocilizumab 8 mg as monotherapy and combined with MTX showed acceptable tolerability and the highest performance based on the ACR50 response rate, followed by sarilumab and sirukumab.