IL-1 signaling cascade in liver cells and the involvement of a soluble form of the IL-1 receptor accessory protein

Circ_0003314 Combines with the miR-26b-5p/IL1RAP Axis to Inhibit HTR-8/SVneo Cell Proliferation, Migration, Invasion and Tube Formation and Promote Apoptosis

Preeclampsia (PE) is a pregnancy-related syndrome that can lead to a variety of pathophysiological processes, such as impaired implantation. The pathogenesis of PE involves circular RNA (circRNA). The study aims to determine the role of a novel circRNA, circ_0003314, in trophoblast cell phenotypes. Circ_0003314, microRNA-26b-5p (miR-26b-5p) and IL-1 receptor accessory protein (IL1RAP) expression were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was investigated by MTT assay and 5-Ethynyl-2'-deoxyuridine assay. Cell migration and invasion were investigated by transwell assay. Cell apoptotic rate and angiogenesis were investigated by flow cytometry analysis and tube formation assay, respectively. Protein expression was detected by western blotting. The binding relationship between miR-26b-5p and circ_0003314 or IL1RAP was identified using dual-luciferase reporter assay and RNA pull-down assay. Circ_0003314 and IL1RAP expression were significantly increased, while miR-26b-5p was decreased in placental tissues of PE patients. Circ_0003314 overexpression inhibited trophoblast cell proliferation, migration, invasion and angiogenesis and induced cell apoptosis. Additionally, circ_0003314 acted as a sponge for miR-26b-5p, and miR-26b-5p bound to IL1RAP. Introduction of miR-26b-5p or silencing of IL1RAP attenuated the effects of circ_0003314 overexpression on trophoblast cell phenotypes. Further, circ_0003314 induced IL1RAP expression through miR-26b-5p in trophoblast cells. Circ_0003314 regulated trophoblast cell phenotypes by increasing IL1RAP expression through binding to miR-26b-5p.

Engineering a modular double-transmembrane synthetic receptor system for customizing cellular programs

Implementation of designer receptors in engineered cells confers them to sense a particular physiological or disease state and respond with user-defined programs. To expand the therapeutic application scope of engineered cells, synthetic receptors realized through different strategies are in great demand. Here, we develop a synthetic receptor system that exerts dual control by incorporating two transmembrane helices for the signal chain. Together with a sensor-actuator device with minimal background signals and a positive loop circuit, this receptor system can sensitively respond to extracellular protein signals. We demonstrate that this synthetic receptor system can be readily adapted to respond to various inputs, such as interleukin-1 (IL-1), programmed death ligand 1 (PD-L1), and HER2, and release customized outputs, including fluorescence signals and the therapeutic molecule IL-2. The robust signaling ability and generality of this receptor system promise it to be a useful tool in the field of cell engineering for fundamental research and translational applications.

Signaling and functions of interleukin-33 in immune regulation and diseases

Interleukin-33 (IL-33) which belongs to the interleukin-1 (IL-1) family is an alarmin cytokine with critical roles in tissue homeostasis, pathogenic infection, inflammation, allergy and type 2 immunity. IL-33 transmits signals through its receptor IL-33R (also called ST2) which is expressed on the surface of T helper 2 (Th2) cells and group 2 innate lymphoid cells (ILC2s), thus inducing transcription of Th2-associated cytokine genes and host defense against pathogens. Moreover, the IL-33/IL-33R axis is also involved in development of multiple types of immune-related diseases. In this review, we focus on current progress on IL-33-trigggered signaling events, the important functions of IL-33/IL-33R axis in health and diseases as well as the promising therapeutic implications of these findings.

Soluble forms of cytokine and growth factor receptors: mechanisms of generation and modes of action in the regulation of local and systemic inflammation

Cytokine and growth factor receptors are usually transmembrane proteins, but they can also exist in soluble forms, either through cleavage and release of their ligand-binding extracellular domain or through the secretion of a soluble isoform. As an extension of this concept, transmembrane receptors on exosomes released into the circulation may act similarly to circulating soluble receptors. These soluble receptors add to the complexity of cytokine and growth factor signalling: they can function as decoy receptor that compete for ligand binding with their respective membrane-bound forms thereby attenuating signalling, or stabilize their ligands, or activate additional signalling events through interactions with other cell-surface proteins. Their soluble nature allows for a functional role away from the production sites, in remote cell types and organs. Accumulating evidence demonstrates that soluble receptors participate in the regulation and orchestration of various key cellular processes, particularly inflammatory responses. In this review, we will discuss release mechanisms of soluble cytokine and growth factor receptors, their mechanisms of action and strategies for targeting their pathways in disease.

The roles of interleukin-1 receptor accessory protein in certain inflammatory conditions

Interleukin-1 receptor accessory protein (IL-1RAcP) is a member of the immunoglobulin superfamily proteins consisting of soluble and membranous isoforms. IL-1RAcP plays an essential role in the signaling of the IL-1 family cytokines such as IL-1, IL-33, and IL-36, as well as tyrosine kinases FLT3 and C-Kit. IL-1RAcP generally initiate inflammatory signaling pathway through the recruitment of signaling mediators, including MYD88 and IRAK. Chronic inflammation following prolonged signaling of cytokine receptors is a critical process in the pathogenesis of many inflammatory disorders, including autoimmunity, obesity, psoriasis, type 1 diabetes, endometriosis, preeclampsia and Alzheimer's disease. Recently IL-1RAcP aberrant signaling has been considered to play a central role in the pathogenesis of these chronic inflammatory diseases. Targeting IL-1RAcP signaling pathway that was recently considered in clinical trials related to malignancies, also indicates its potential as therapeutic target for the inflammatory and autoimmune diseases. This review summarizes the molecular structure, components associated with IL-1RAcP signaling pathways, and their involvement in the pathogenesis of different inflammatory diseases. We will also discuss the effect of IL-1RAcP inhibition for treatment proposes.

Novel IL1RAP mutation associated with schizophrenia interferes with neuronal growth and related NF-κB signal pathways

Schizophrenia is a complex, severe psychiatric disorder with a high heritability that affects approximately 1% of the world's population. Numerous schizophrenia-related risk genes have been reported in large-scale studies, but the role of most genetic abnormalities in the pathogenesis of the disease is still obscure. In this study, using whole-exome sequencing, we identified a novel nonsense mutation c.1324C>T in the Interleukin 1 receptor accessory protein (IL1RAP) gene in four affected individuals with schizophrenia of a Chinese family.IL1RAP was found involved in initiating the immune responses and regulating synaptic formation. Considering that schizophrenia has been hypothesized to be neurodevelopment disorder for decades, we further explored the influence of altered expression of IL1RAP gene on neuronal growth, and assessed whether this mutation affects the function of IL1RAP protein in IL-1 signaling pathway. We used lentivirus-mediated shRNA to knockdown the IL1RAP gene expression, which suppressed the axon and dendrites growth of cultured mouse cortical neurons. These defects can be recovered by human IL1RAP wild type construct, but not the R442* mutant construct. Furthermore, this mutant even inhibited neuronal growth and IL-1β-induced JNK phosphorylation when overexpressed in cortical neurons. Although overexpression of this mutant in HePG2 cells did not change IL1RAP protein expression, it partially prohibited the IL-1β-induced nuclear translocation of transcript factor NF-κB, indicating that IL1RAP c.1324C>T is a loss-of-function mutation. Our findings show that IL1RAP plays an important role in early stages of neurodevelopment, and the mutation c.1324C>T may contribute to the pathogenesis of schizophrenia.

Soluble IL-7Rα/sCD127 in Health, Disease, and Its Potential Role as a Therapeutic Agent

Soluble cytokine receptors can influence immune responses by modulating the biological functions of their respective ligands. These effects can be either agonistic or antagonistic and a number of soluble cytokine receptors have been shown to play critical roles in both maintenance of health and disease pathogenesis. Soluble IL-7Ra (sCD127) is one such example. With its impact on the IL-7/CD127 pathway, which is fundamental for the development and homeostasis of T cells, the role of sCD127 in health and disease has been extensively studied in recent years. Within this review, the role of sCD127 in maintaining host immune function is presented. Next, by addressing genetic factors affecting sCD127 expression and the associated levels of sCD127 production, the roles of sCD127 in autoimmune disease, infections and cancer are described. Finally, advances in the field of soluble cytokine therapy and the potential for sCD127 as a biomarker and therapeutic agent are discussed.

Associations of IL6 rs1800795, BLK rs13277113, TIMP3 rs9621532, IL1RL1 rs1041973 and IL1RAP rs4624606 single gene polymorphisms with laryngeal squamous cell carcinoma

OBJECTIVE

Survival rate of laryngeal squamous cell carcinoma (LSCC) patients is not improving. To understand more complete biology of LSCC, studies focused on identification of new specific and prognostic markers are performed. The aim of current study was to evaluate the impact of five different single nucleotide polymorphisms (SNP) (IL6 rs1800795, BLK rs13277113, TIMP3 rs9621532, IL1RL1 rs1041973 and IL1RAP rs4624606) on LSCC development.

MATERIAL AND METHODS

A total of 891 subjects (353 histologically verified LSCC patients and 538 healthy controls) were involved in this study. The genotyping was carried out using the real-time-PCR.

RESULTS

Statistical analysis revealed statistically significant associations between TIMP3 rs96215332 variants and LSCC in the codominant (OR = 0.600; 95% CI: 0.390-0.922; p = 0.020), overdominant (OR = 0.599; 95% CI: 0.390-0.922; p = 0.020) and additive (OR = 0.675; 95% CI: 0.459-0.991; p = 0.045) models. Also, significant variants of IL1RAP rs4624606 were determined in the codominant (OR = 1.372; 95% CI: 1.031-1.827; p = 0.030), overdominant (OR = 1.353; 95% CI: 1.018-1.798; p = 0.037) and additive (OR = 1.337; 95% CI: 1.038-1.724; p = 0.025) models.

CONCLUSION

Results of the current study indicate significant associations between TIMP3 rs9621532 and IL1RAP rs4624606 gene polymorphisms and LSCC development.

Biological functions and therapeutic opportunities of soluble cytokine receptors

Cytokines control the immune system by regulating the proliferation, differentiation and function of immune cells. They activate their target cells through binding to specific receptors, which either are transmembrane proteins or attached to the cell-surface via a GPI-anchor. Different tissues and individual cell types have unique expression profiles of cytokine receptors, and consequently this expression pattern dictates to which cytokines a given cell can respond. Furthermore, soluble variants of several cytokine receptors exist, which are generated by different molecular mechanisms, namely differential mRNA splicing, proteolytic cleavage of the membrane-tethered precursors, and release on extracellular vesicles. These soluble receptors shape the function of cytokines in different ways: they can serve as antagonistic decoy receptors which compete with their membrane-bound counterparts for the ligand, or they can form functional receptor/cytokine complexes which act as agonists and can even activate cells that would usually not respond to the ligand alone. In this review, we focus on the IL-2 and IL-6 families of cytokines and the so-called Th2 cytokines. We summarize for each cytokine which soluble receptors exist, were they originate from, how they are generated, and what their biological functions are. Furthermore, we give an outlook on how these soluble receptors can be exploited for therapeutic purposes.

SAM68-Specific Splicing Is Required for Proper Selection of Alternative 3' UTR Isoforms in the Nervous System

Neuronal alternative splicing is a core mechanism for functional diversification. We previously found that STAR family proteins (SAM68, SLM1, SLM2) regulate spatiotemporal alternative splicing in the nervous system. However, the whole aspect of alternative splicing programs by STARs remains unclear. Here, we performed a transcriptomic analysis using SAM68 knockout and SAM68/SLM1 double-knockout midbrains. We revealed different alternative splicing activity between SAM68 and SLM1; SAM68 preferentially targets alternative 3′ UTR exons. SAM68 knockout causes a long-to-short isoform switch of a number of neuronal targets through the alteration in alternative last exon (ALE) selection or alternative polyadenylation. The altered ALE usage of a novel target, interleukin 1 receptor accessory protein (Il1rap), results in remarkable conversion from a membrane-bound type to a secreted type in Sam68^KO brains. Proper ALE selection is necessary for IL1RAP neuronal function. Thus the SAM68-specific splicing program provides a mechanism for neuronal selection of alternative 3′ UTR isoforms.

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SAM68 and the related protein SLM1 exhibit distinct alternative splicing activity

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SAM68 specifically controls 3′ UTR selection of multiple neuronal genes

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Proper 3′ UTR selection is necessary for IL1RAP neuronal function

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Neuronal expression of SAM68 requires proper 3′ UTR selection in the nervous system

The role of epigenetic changes in preeclampsia

Preeclampsia (PE) is a disorder affecting 2-10% of pregnancies and has a major role for perinatal and maternal mortality and morbidity. PE can be occurred by initiation of new hypertension combined with proteinuria after 20 weeks gestation, as well as various reasons such as inflammatory cytokines, poor trophoblast invasion can be related with PE disease. Environmental factors can cause epigenetic changes including DNA methylation, microRNAs (miRNAs), and histone modification that may be related to different diseases such as PE. Abnormal DNA methylation during placentation is the most important epigenetic factor correlated with PE. Moreover, changes in histone modification like acetylation and also the effect of overregulation or low regulation of miRNAs or long noncoding RNAs on variety signaling pathways can be resulted in PE. The aim of this review is to describe of studies about epigenetic changes in PE and its therapeutic strategies.

Expression and clinicopathological role of miR146a in thyroid follicular carcinoma

PURPOSE

Dysregulation of microRNA expression has been involved in the development and progression of follicular thyroid carcinoma (FTC). The aim of this work was to study the expression of miRNA146a in FTC and the association with clinicopathological features of the disease.

METHODS

Thirty-eight patients affected by FTC were included in the study. Twenty patients carrying follicular thyroid adenoma (FA) were also enroled as the benign counterpart of FTC. Total RNA including miRNA146a was extracted from formalin-fixed paraffin-embedded (FFPE) pairs of affected/unaffected tissue and its expression was assessed by real-time PCR. Two selected target genes, TRAF6 (tumour necrosis factor receptor-associated factor 6) and IRAK1 (Il-1 receptor-associated kinase 1/2), were also analysed.

RESULTS

miR146a expression in FTC tissue was overall not downregulated in malignant versus unaffected tissue, but its expression was inversely correlated with clinicopathological features of FTCs at diagnosis. A decreased expression of miR146a became apparent in FTC thyroid tissue of widely compared to minimally invasive tumours. However, miR146a expression differences between contralateral unaffected tissue (extra-FTC) and FTC were not observed regardless of clinicopathological features. IRAK1, a known target for miR146a, was upregulated in FTC and the increase was mainly appreciable in Hurtle FTC variant. Unexpectedly, miR146a did not correlate with TRAF6 showing an inverse trend compared to IRAK1 although both genes regulate the activity of nuclear factor- kB (NF-kB).

CONCLUSION

The results of this study indicate that downregulation of miR146a, inversely correlated with clinicopathological features of FTCs at diagnosis and suggest a possible involvement of miR146a in FTC development. IRAK1 over-expression in FTC may be related to tumour development/progression. In vitro experiments are needed to support this hypothesis.

Iranian crack induces hepatic injury through mitogen-activated protein kinase pathway in the liver of Wistar rat

Objectives

Iranian crack (IC) is a heroin-based substance manifesting various pathologic side effects. Herein, we aimed to investigate the mechanism of IC-induced liver injuries in Wistar rats.

Materials and Methods

Twenty male Wistar rats were randomly divided into two groups: control, and IC (0.9 mg/kg/day/IP, for 30 days). Mitochondrial reactive oxygen species (ROS) production was measured by DCF fluorescence staining. The expression of tumor necrosis factor-alpha (TNF-α), interleukin 1β (IL-1β), and phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (c-JNK) were assessed by immunoblotting assay. The intensity of collagen fiber in the liver was also determined by Trichrome-Masson staining. Furthermore, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activities were measured using colorimetric methods.

Results

Our results showed that ROS production, p38 MAPK, c-JNK phosphorylation levels, and expression of TNF-α and IL-1β were significantly elevated in the liver tissue of IC group as compared to the control group. Moreover, collagen fiber and ALT activity were increased in the liver tissue of IC group compared to the control group. However, there was no statistically significant difference in the levels of ALP between two groups. In addition, there was a positive correlation between the intensity of collagen fiber and the ALT activity, and the levels of TNF-α and IL-1β and liver enzymes activities including ALP, ALT, and AST.

Conclusion

Our findings revealed that IC-induced liver cells injury is partially mediated by MAPK stress kinases. Therefore, regular liver examination in substance abuse is strongly recommended.

Potential regulatory network in the PSG10P/miR-19a-3p/IL1RAP pathway is possibly involved in preeclampsia pathogenesis

Preeclampsia (PE), a pregnancy-specific disorder, is a leading cause of perinatal maternal-fetal mortality and morbidity. Impaired cell migration and invasion of trophoblastic cells and an imbalanced systemic maternal inflammatory response have been proposed as potential mechanisms of PE pathogenesis. Comparative analysis between PE placentas and normal placentas profiled differentially expressed miRNAs, lncRNAs, and mRNAs, including miR-19a-3p (miRNA), PSG10P (lncRNA), and IL1RAP (mRNA). This study was conducted to investigate their potential roles in PE pathogenesis. The expression of miR-19a-3p, PSG10P, and IL1RAP was examined in PE and normal placentas using RT-qPCR. An in vitro experiment was performed in human trophoblast HET8/SVneo and TEV-1 cells cultured in normoxic and hypoxic conditions. MiR-19a-3p targets were identified using Targetscan, miRanda, and PicTar analysis as well as luciferase reporter assays. The mouse model of PE was conducted using sFlt-1 for in vivo tests. Lower levels of miR-19a-3p, but higher levels of PSG10P and IL1RAP were observed in PE placentas and the trophoblast cells in hypoxia. Luciferase reporter assays confirmed that PSG10P and IL1RAP were both direct targets of miR-19a-3p. Exposure to hypoxia inhibited cell viability, migration, and invasion of HET8/SVneo and TEV-1 cells. Knocking out PSG10P and IL1RAP or overexpressing miR-19a-3p rescued the inhibition caused by hypoxia. In vivo experiments showed that IL1RAP promoted the expression of caspase-3, a key apoptosis enzyme, but inhibited MMP9, which is responsible for degrading the extracellular matrix, suggesting a significant role of IL1RAP in cell proliferation, migration, and invasion. miR-19a-3p, PSG10P, and IL1RAP were all found to be involved in PE pathogenesis. With a common targeting region in their sequences, a regulatory network in the PSG10P/miR-19a-3p/IL1RAP pathway may contribute to PE pathogenesis during pregnancy.

Interleukin-1 Beta-A Friend or Foe in Malignancies?

Interleukin-1 beta (IL-1β) is induced by inflammatory signals in a broad number of immune cell types. IL-1β (and IL-18) are the only cytokines which are processed by caspase-1 after inflammasome-mediated activation. This review aims to summarize current knowledge about parameters of regulation of IL-1β expression and its multi-facetted role in pathophysiological conditions. IL-1 signaling activates innate immune cells including antigen presenting cells, and drives polarization of CD4+ T cells towards T helper type (Th) 1 and Th17 cells. Therefore, IL-1β has been attributed a largely beneficial role in resolving acute inflammations, and by initiating adaptive anti-tumor responses. However, IL-1β generated in the course of chronic inflammation supports tumor development. Furthermore, IL-1β generated within the tumor microenvironment predominantly by tumor-infiltrating macrophages promotes tumor growth and metastasis via different mechanisms. These include the expression of IL-1 targets which promote neoangiogenesis and of soluble mediators in cancer-associated fibroblasts that evoke antiapoptotic signaling in tumor cells. Moreover, IL-1 promotes the propagation of myeloid-derived suppressor cells. Using genetic mouse models as well as agents for pharmacological inhibition of IL-1 signaling therapeutically applied for treatment of IL-1 associated autoimmune diseases indicate that IL-1β is a driver of tumor induction and development.

The family of the interleukin-1 receptors

The extracellular forms of the IL-1 cytokines are active through binding to specific receptors on the surface of target cells. IL-1 ligands bind to the extracellular portion of their ligand-binding receptor chain. For signaling to take place, a non-binding accessory chain is recruited into a heterotrimeric complex. The intracellular approximation of the Toll-IL-1-receptor (TIR) domains of the 2 receptor chains is the event that initiates signaling. The family of IL-1 receptors (IL-1R) includes 10 structurally related members, and the distantly related soluble protein IL-18BP that acts as inhibitor of the cytokine IL-18. Over the years the receptors of the IL-1 family have been known with many different names, with significant confusion. Thus, we will use here a recently proposed unifying nomenclature. The family includes several ligand-binding chains (IL-1R1, IL-1R2, IL-1R4, IL-1R5, and IL-1R6), 2 types of accessory chains (IL-1R3, IL-1R7), molecules that act as inhibitors of signaling (IL-1R2, IL-1R8, IL-18BP), and 2 orphan receptors (IL-1R9, IL-1R10). In this review, we will examine how the receptors of the IL-1 family regulate the inflammatory and anti-inflammatory functions of the IL-1 cytokines and are, more at large, involved in modulating defensive and pathological innate immunity and inflammation. Regulation of the IL-1/IL-1R system in the brain will be also described, as an example of the peculiarities of organ-specific modulation of inflammation.

SRSF10-mediated IL1RAP alternative splicing regulates cervical cancer oncogenesis via mIL1RAP-NF-κB-CD47 axis

High-risk human papillomavirus oncoproteins E6 and E7 are the major etiological factors of cervical cancer but are insufficient for malignant transformation of cervical cancer. Dysregulated alternative splicing, mainly ascribed to aberrant splicing factor levels and activities, contributes to most cancer hallmarks. However, do E6 and E7 regulate the expression of splicing factors? Does alternative splicing acts as an “accomplice” of E6E7 to promote cervical cancer progression? Here, we identified that the splicing factor SRSF10, which promotes tumorigenesis of cervix, was upregulated by E6E7 via E2F1 transcriptional activation. SRSF10 modulates the alternate terminator of interleukin-1 receptor accessory protein exon 13 to increase production of the membrane form of interleukin-1 receptor accessory protein. SRSF10-mediated mIL1RAP upregulates the expression of the “don’t eat me” signal CD47 to inhibit macrophage phagocytosis by promoting nuclear factor-κB activation, which is pivotal in inflammatory, immune, and tumorigenesis processes. Altogether, these data reveal a close relationship among HPV infection, alternative splicing and tumor immune evasion, and also suggests that the SRSF10-mIL1RAP-CD47 axis could be an attractive therapeutic target for the treatment of cervical cancer.

Role of the IL-33/ST2L axis in colorectal cancer progression

Interleukin-33 (IL-33) has been identified as a natural ligand of ST2L. IL-33 primarily acts as a key regulator of Th2 responses through binding to ST2L, which is antagonized by soluble ST2 (sST2). The IL-33/ST2L axis is involved in various inflammatory pathologies, including ulcerative colitis (UC). Several recent investigations have also suggested that the IL-33/ST2L axis plays a role in colorectal cancer (CRC) progression. In CRC, tumor- and stroma-derived IL-33 may activate ST2L on various cell types in an autocrine and paracrine manner. Although several findings support the hypothesis that the IL-33/ST2L axis positively regulates CRC progression, other reports do not; hence, this hypothesis remains controversial. At any rate, recent studies have provided overwhelming evidence that the IL-33/ST2L axis plays important roles in CRC progression. This review summarizes the role of the IL-33/ST2L axis in the UC and CRC microenvironments.

Overview of the IL-1 family in innate inflammation and acquired immunity

The interleukin-1 (IL-1) family of cytokines and receptors is unique in immunology because the IL-1 family and Toll-like receptor (TLR) families share similar functions. More than any other cytokine family, the IL-1 family is primarily associated with innate immunity. More than 95% of living organisms use innate immune mechanisms for survival whereas less than 5% depend on T- and B-cell functions. Innate immunity is manifested by inflammation, which can function as a mechanism of host defense but when uncontrolled is detrimental to survival. Each member of the IL-1 receptor and TLR family contains the cytoplasmic Toll-IL-1-Receptor (TIR) domain. The 50 amino acid TIR domains are highly homologous with the Toll protein in Drosophila. The TIR domain is nearly the same and present in each TLR and each IL-1 receptor family. Whereas IL-1 family cytokine members trigger innate inflammation via IL-1 family of receptors, TLRs trigger inflammation via bacteria, microbial products, viruses, nucleic acids, and damage-associated molecular patterns (DAMPs). In fact, IL-1 family member IL-1a and IL-33 also function as DAMPs. Although the inflammatory properties of the IL-1 family dominate in innate immunity, IL-1 family member can play a role in acquired immunity. This overview is a condensed update of the IL-1 family of cytokines and receptors.

Research of differential expression of sIL1RAP in low-grade gliomas between children and adults

Glioma is the most common intracranial malignant tumor. Low-grade gliomas (LGG) occupy almost 80% in all of the gliomas. The prognosis of LGG in children is much better than in adult, however, the molecular mechanism is still unclear. In our investigation, it was first found that the level of soluble IL1RAP (sIL1RAP) was significantly higher in the LGG from children than that from adult. We also revealed that sIL1RAP could induce the apoptosis of U251. In cells with overexpression of sIL-1RAP, the cell proliferation promoted by IL-1 was significantly inhibited. These decreased tumor growth ability and better prognosis of low-grade gliomas in children patients than that in adult patients. The expression level of sIL1RAP may become one of the potential indexes for determining the prognosis of low-grade gliomas.

Characterization of IL-1β and two types of IL-1 receptors in miiuy croaker and evolution analysis of IL-1 family

Interleukin (IL)-1β is a prototypical proinflammatory cytokine that belongs to the IL-1 family. This cytokine possesses two receptor types, namely, IL-1 receptor type I (IL-1RI) and IL-1 receptor type II (IL-1RII). IL-1RI, is an IL-1 receptor that plays a crucial role in immune responses and IL-1RII is a decoy receptor for IL-1β signaling inhibitors in mammals. IL-1β, together with its two types of receptors, has been characterized in mammals and implicated in immunity. However, IL-1β and IL-1 receptors in teleost species have been rarely investigated. In this study three genes, namely, IL-1β, IL-1RI, and IL-1RII, were identified and characterized from miiuy croaker. Structural and comparative analysis revealed that miiuy croaker IL-1β, IL-1RI and IL-1RII, particularly their functional domains, were conservative in most of the species. Simultaneously, synteny phylogenetic analysis indicated that IL-1β and IL-18 were widely distributed in vertebrates and hence might be the ancestors of the IL-1 family. Challenge experiment demonstrated that IL-1β, IL-1RI and IL-1RII expression in miiuy croaker was induced by LPS and poly (I:C). IL-1RI expression was also induced by the overexpressed miiuy croaker IL-1β protein which in cell supernatant, whereas IL-1RII was not induced.

Pharmacological effects of β-d-mannuronic acid (M2000) on miR-146a, IRAK1, TRAF6 and NF-κB gene expression, as target molecules in inflammatory reactions

BACKGROUND

Impaired expression and function of microRNAs (miRNAs) are involved in the pathogenesis of many autoimmune and inflammatory diseases. Moreover, there is a close relationship between TLRs and miRNAs and impairment in regulating their expression which can play a vital role in the immunopathogenesis of many inflammatory reactions. This research aimed to study the pharmaceutical effects of M2000 (β-d-mannuronic acid) on the expression of miR-146a and its two target molecules (IRAK1 and TRAF6), and the transcription factor NF-κB in the HEK-Blue hTLR2 cell line.

METHODS

The cytotoxicity of M2000 was assessed by the MTT assay, and the qRT-PCR technique was employed in the presence and absence of M2000 treatment to measure gene-expression levels of miR-146a, IRAK1, TRAF6, and NF-κB.

RESULTS

MTT assay indicated that M2000 (before the concentration of 500μg/ml) had no cytotoxic effect on HEK-Blue hTLR2 cells. Our results showed that M2000 at low and high doses (5 and 25μg/well) could significantly reduce gene expression levels of miR-146a (p<0.01). Furthermore, it was found that this medication at two different doses could considerably decrease IRAK1 and TRAF6 gene expression (p<0.001). Moreover, this study revealed that expression level of NF-κB also significantly declined at these two doses (p<0.01).

CONCLUSIONS

This study for the first time shows that M2000 as a novel NSAID with immunosuppressive properties is able to modify TLR signaling through suppressing the adaptor molecules IRAK1 and TRAF6, the transcription factor NF-κB and miR-146a as a new therapeutic approach.

Combined mesenchymal stem cell transplantation and interleukin-1 receptor antagonism after partial hepatectomy

AIM

To study the therapeutic effects of mesenchymal stem cells (MSCs) and an interleukin-1 receptor antagonist (IL-1Ra) in acute liver failure.

METHODS

Chinese experimental miniature swine (15 ± 3 kg, 5-8 mo) were obtained from the Laboratory Animal Centre of the Affiliated Drum Tower Hospital of Nanjing University Medical School. Acute liver failure was induced via 85% hepatectomy, and animals were treated by MSC transplantation combined with IL-1Ra injection. Blood samples were collected for hepatic function analysis, and the living conditions and survival time were recorded. Liver injury was histologically analyzed. Hepatic cell regeneration and apoptosis were studied by Ki67 immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. The levels of protein kinase B and nuclear factor-κB expression were analyzed by Western blotting.

RESULTS

MSCs were infected with a lentivirus for expression of green fluorescent protein (GFP) for subsequent identification; 97.3% of the MSCs were positive for GFP as assessed by flow cytometry. Additional flow cytometric analysis of cell surface marker expression demonstrated that > 90% of GFP-expressing MSCs were also positive for CD29, CD44, and CD90, indicating that most of these cells expressed typical markers of MSCs, and the population of MSCs was almost pure. Transplantation of MSCs in combination with 2 mg/kg IL-1Ra therapy significantly improved survival time compared to the acute liver failure model group (35.3 ± 6.7 d vs 17.3 ± 5.5 d, P < 0.05). Combined therapy also promoted improvement in serum inflammatory cytokines and biochemical conditions. The observed hepatic histopathologic score was significantly lower in the group with combined therapy than in the model group (3.50 ± 0.87 vs 8.17 ± 1.26, P < 0.01). In addition, liver cell apoptosis in the combined therapy group was significantly inhibited (18.1 ± 2.1% vs 70.8 ± 3.7%, P < 0.01), and hepatic cell regeneration increased. A significant increase in protein kinase B expression and decrease in nuclear factor-κB expression were observed (P < 0.01), which supports their important roles in liver regeneration.

CONCLUSION

MSCs and IL-1Ra had a synergistic effect in liver regeneration via regulation of inflammation and apoptotic signaling.

Protein and messenger RNA expression of interleukin 1 system members in bovine ovarian follicles and effects of interleukin 1β on primordial follicle activation and survival in vitro

This study aimed to investigate the expression of interleukin 1 (IL-1) system members (proteins and messenger RNA of ligands and receptors) and its distribution in ovarian follicles of cyclic cows and to evaluate the effects of IL-1β on the survival and activation of primordial follicles in vitro. The ovaries were processed for localization of IL-1 system in preantral and antral follicles by immunohistochemical, real-time polymerase chain reaction, and Western blot analysis. For in vitro studies, ovarian fragments were cultured in α-MEM(+) supplemented with IL-1β (0, 1, 10, 50, or 100 ng/mL), and after 6 d, the cultured tissues were processed for histologic analysis. Immunohistochemical results showed that the IL-1 system proteins IL-1β, IL-1RA, IL-1RI, and IL-1RII were detected in the cytoplasm of oocytes and granulosa cells from all follicular categories and theca cells of antral follicles. Variable levels of messenger RNA for the IL-1 system members were observed at different stages of development. After 6 d of culture, the presence of IL-1β (10 or 50 ng/mL) was effective in maintaining the percentage of normal follicles and in promoting primordial follicle activation. In conclusion, IL-1 system members are differentially expressed in ovarian follicles according to their stage of development. Moreover, IL-1β promotes the development of primordial follicles. These results indicate an important role of the IL-1 system in the regulation of bovine folliculogenesis.

IRAK-M regulates the inhibition of TLR-mediated macrophage immune response during late in vitro Leishmania donovani infection

Intramacrophage protozoan parasite Leishmania donovani, causative agent of visceral leishmaniasis, escapes Toll-like receptor (TLR) dependent early host immune response by inducing the deubiquitinating enzyme A20, which is sustained up to 6 h postinfection only. Therefore, Leishmania must apply other means to deactivate late host responses. Here, we elucidated the role of IL-1 receptor-associated kinase M (IRAK-M), a negative regulator of TLR signaling, in downregulating macrophage proinflammatory response during late hours of in vitro infection. Our data reveal a sharp decline in IRAK1 and IRAK4 phosphorylation at 24 h postinfection along with markedly reduced association of IRAK1-TNF receptor associated factor 6, which is mandatory for TLR activation. In contrast, IRAK-M was induced after A20 levels decreased and reached a maximum at 24 h postinfection. IRAK-M induction coincided with increased stimulation of TGF-β, a hallmark cytokine of visceral infection. TGF-β-dependent signaling-mediated induction of SMAD family of proteins, 2, 3, and 4 plays important roles in transcriptional upregulation of IRAK-M. In infected macrophages, siRNA-mediated silencing of IRAK-M displayed enhanced IRAK1 and IRAK4 phosphorylation with a concomitant increase in downstream NF-κB activity and reduced parasite survival. Taken together, the results suggest that IRAK-M may be targeted by L. donovani to inhibit TLR-mediated proinflammatory response late during in vitro infection.

The interleukin (IL)-1 cytokine family--Balance between agonists and antagonists in inflammatory diseases

The interleukin (IL)-1 family of cytokines comprises 11 members, including 7 pro-inflammatory agonists (IL-1α, IL-1β, IL-18, IL-33, IL-36α, IL-36β, IL-36γ) and 4 defined or putative antagonists (IL-1R antagonist (IL-1Ra), IL-36Ra, IL-37, and IL-38) exerting anti-inflammatory activities. Except for IL-1Ra, IL-1 cytokines do not possess a leader sequence and are secreted via an unconventional pathway. In addition, IL-1β and IL-18 are produced as biologically inert pro-peptides that require cleavage by caspase-1 in their N-terminal region to generate active proteins. N-terminal processing is also required for full activity of IL-36 cytokines. The IL-1 receptor (IL-1R) family comprises 10 members and includes cytokine-specific receptors, co-receptors and inhibitory receptors. The signaling IL-1Rs share a common structure with three extracellular immunoglobulin (Ig) domains and an intracellular Toll-like/IL-1R (TIR) domain. IL-1 cytokines bind to their specific receptor, which leads to the recruitment of a co-receptor and intracellular signaling. IL-1 cytokines induce potent inflammatory responses and their activity is tightly controlled at the level of production, protein processing and maturation, receptor binding and post-receptor signaling by naturally occurring inhibitors. Some of these inhibitors are IL-1 family antagonists, while others are IL-1R family members acting as membrane-bound or soluble decoy receptors. An imbalance between agonist and antagonist levels can lead to exaggerated inflammatory responses. Several genetic modifications or mutations associated with dysregulated IL-1 activity and autoinflammatory disorders were identified in mouse models and in patients. These findings paved the road to the successful use of IL-1 inhibitors in diseases that were previously considered as untreatable.

The role of soluble common gamma chain in autoimmune disease

The common gamma chain (γc) is the central signaling unit for a number of cytokine receptors collectively known as the γc cytokine receptor family. γc is critical for ligand binding and signaling by γc cytokines. γc cytokine signaling had been thought to be mainly regulated by cytokine-specific receptor α chain expression levels with little or no effect by γc surface levels because γc expression was presumed to remain unchanged during T-cell activation and development. The extent of γc cytokine responses is thought to be regulated by cytokine specific receptor subunits and not by the γc receptor. In contrast to this prevailing view, we have recently reported that γc itself actively regulates γc cytokine responses. Interestingly, γc exerted its regulatory effects not only as a conventional membrane receptor protein but also as a secreted protein whose expression was upregulated upon T-cell stimulation. Here we will review how a soluble form of γc, which is generated by alternative splicing, regulates γc cytokine signaling and plays a role in controlling immune activation related to autoimmune disease.

Antileishmanial effect of 18β-glycyrrhetinic acid is mediated by Toll-like receptor-dependent canonical and noncanonical p38 activation

18β-Glycyrrhetinic acid (GRA), a natural immunomodulator, greatly reduced the parasite load in experimental visceral leishmaniasis through nitric oxide (NO) upregulation, proinflammatory cytokine expression, and NF-κB activation. For the GRA-mediated effect, the primary kinase responsible was found to be p38, and analysis of phosphorylation kinetics as well as studies with dominant-negative (DN) constructs revealed mitogen-activated protein kinase kinase 3 (MKK3) and MKK6 as the immediate upstream regulators of p38. However, detection of remnant p38 kinase activity in the presence of both DN MKK3 and MKK6 suggested alternative pathways of p38 activation. That residual p38 activity was attributed to an autophosphorylation event ensured by the transforming growth factor β-activated kinase 1 (TAK1)-binding protein 1 (TAB1)-p38 interaction and was completely abolished upon pretreatment with SB203580 in DN MKK3/6 double-transfected macrophage cells. Further upstream signaling evaluation by way of phosphorylation kinetics and transfection studies with DN constructs identified TAK1, myeloid differentiation factor 88 (MyD88), interleukin 1 receptor (IL-1R)-activated kinase 1 (IRAK1), and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) as important contributors to GRA-mediated macrophage activation. Finally, gene knockdown studies revealed Toll-like receptor 2 (TLR2) and TLR4 as the membrane receptors associated with GRA-mediated antileishmanial activity. Together, the results of this study brought mechanistic insight into the antileishmanial activity of GRA, which is dependent on the TLR2/4-MyD88 signaling axis, leading to MKK3/6-mediated canonical and TAB1-mediated noncanonical p38 activation.

IL12Rβ1ΔTM is a secreted product of il12rb1 that promotes control of extrapulmonary tuberculosis

IL12RB1 is a human gene that is important for resistance to Mycobacterium tuberculosis infection. IL12RB1 is expressed by multiple leukocyte lineages, and encodes a type I transmembrane protein (IL12Rβ1) that associates with IL12p40 and promotes the development of host-protective T(H)1 cells. Recently, we observed that il12rb1—the mouse homolog of IL12RB1—is alternatively spliced by leukocytes to produce a second isoform (IL12Rβ1ΔTM) that has biological properties distinct from IL12Rβ1. Although the expression of IL12Rβ1ΔTM is elicited by M. tuberculosis in vivo, and its overexpression enhances IL12p40 responsiveness in vitro, the contribution of IL12Rβ1ΔTM to controlling M. tuberculosis infection has not been tested. Here, we demonstrate that IL12Rβ1ΔTM represents a secreted product of il12rb1 that, when absent from mice, compromises their ability to control M. tuberculosis infection in extrapulmonary organs. Furthermore, elevated M. tuberculosis burdens in IL12Rβ1ΔTM-deficient animals are associated with decreased lymph node cellularity and a decline in TH1 development. Collectively, these data support a model wherein IL12Rβ1ΔTM is a secreted product of il12rb1 that promotes resistance to M. tuberculosis infection by potentiating T(H) cells response to IL-12.

Chikungunya virus exploits miR-146a to regulate NF-κB pathway in human synovial fibroblasts

OBJECTIVES

Chikungunya virus causes chronic infection with manifestations of joint pain. Human synovial fibroblasts get infected with CHIKV and could lead to pro-inflammatory responses. MicroRNAs have potentials to regulate the gene expression of various anti-viral and pro-inflammatory genes. The study aims to investigate the role of miR-146a in modulation of inflammatory responses of human synovial fibroblasts by Chikungunya virus.

METHODS

To study the role of miR-146a in CHIKV pathogenesis in human synovial cells and underlying inflammatory manifestations, we performed CHIKV infection in primary human synovial fibroblasts. Western blotting, real-time PCR, luciferase reporter assay, overexpression and knockdown of cellular miR-146a strategies have been employed to validate the role of miR-146a in regulation of pro-inflammatory NF-κB pathway.

RESULTS

CHIKV infection induced the expression of cellular miR-146a, which resulted into down-regulation of TRAF6, IRAK1, IRAK2 and increased replication of CHIKV in human synovial fibroblasts. Exogenous expression of miR-146a in human synovial fibroblasts led to decreased expression of TRAF6, IRAK1, IRAK2 and decreased replication of CHIKV. Inhibition of cellular miR-146a by anti-miR-146a restored the expression levels of TRAF6, IRAK1 and IRAK2. Downregulation of TRAF6, IRAK1 and IRAK2 led to downstream decreased NF-κB activation through negative feedback loop.

CONCLUSION

This study demonstrated the mechanism of exploitation of cellular miR-146a by CHIKV in modulating the host antiviral immune response in primary human synovial fibroblasts.

Molecular and functional characterization of IL-1 receptor type 2 in grass carp: a potent inhibitor of IL-1β signaling in head kidney leukocytes

IL-1 receptor type 2 (IL-1R2) is known as one of natural IL-1β singling inhibitors in mammals. However, the functional role of IL-1R2 in fish remains largely unknown. In this study, grass carp (Ctenopharyngodon idellus) IL-1R2 (gcIL-1R2) was identified and functionally characterized. Similar to its fish homologs, the deduced protein of gcIL-1R2 possessed two Ig-like domains in its extracellular region but lacked an intracellular signaling domain. The involvement of gcIL-1R2 in immune response was demonstrated by investigating its expression profiles in head kidney and head kidney leukocytes (HKLs) following in vivo bacterial infection and in vitro LPS treatment, respectively. Moreover, recombinant grass carp IL-1β (rgcIL-1β) was able to stimulate gcIL-1R2 mRNA expression with a rapid kinetics. This stimulation was possibly dependent on p38, JNK, p42/44 and NF-κB pathways in grass carp HKLs, revealing a new regulatory point of IL-1β signaling at receptor level in fish. Furthermore, recombinant protein of the gcIL-1R2 extracellular region (rgcIL-1R2) was demonstrated to interact with rgcIL-1β by using ELISA, elucidating the binding specificity of gcIL-1R2. Importantly, the stimulatory effect of rgcIL-1β on its own mRNA expression was blocked by rgcIL-1R2 in a dose-dependent manner in grass carp HKLs, providing the evidence for a functional role of IL-1R2 in IL-1β signaling in teleost. These findings suggested that teleost IL-1R2 may serve as a local naturally occurring inhibitor involving in IL-1β signaling as seen in mammals.

Negative regulatory receptors of the IL-1 family

The IL-1 family of ligands and receptors has a central role in both innate and adaptive immune responses and is tightly controlled by antagonists, decoy receptors, scavengers, dominant negative molecules, miRNAs and other mechanisms, acting extracellularly or intracellularly. During evolution, the development of multiple mechanisms of negative regulation reveals the need for tight control of the biological consequences of IL-1 family ligands in order to balance local and systemic inflammation and limit immunopathology. Indeed, studies with gene targeted mice for negative regulators and genetic studies in humans provide evidence for their non-redundant role in controlling inflammation, tissue damage and adaptive responses. In addition, studies have revealed the need of negative regulation of the IL-1 family not only in disease, but also in homeostatic conditions. In this review, the negative regulation mediated by decoy receptors are presented and include IL-1R2 and IL-IL-18BP as well as atypical receptors, which include TIR8/SIGIRR, IL-1RAcPb, TIGIRR-1 and IL-1RAPL. Particular emphasis is given to IL-1R2, since its discovery is the basis for the formulation of the decoy paradigm, now considered a general strategy to counter the primary inflammatory activities of cytokines and chemokines. Emphasis is also given to TIR8, a prototypical negative regulatory receptor having non-redundant roles in limiting inflammation and adaptive responses.

IL-1 receptor 2 (IL-1R2) and its role in immune regulation

The cytokine IL-1 is critical to the pathogenesis of a variety of human conditions and diseases. Unlike most other cytokines, IL-1 is counterbalanced by two endogenous inhibitors. The functional significance of IL-1 receptor antagonist (IL-1RA) is well documented due to the clinical utilization of the recombinant human IL-1RA analog, anakinra. In contrast, much less is known about the type 2 IL-1 receptor (IL-1R2), which acts as a decoy receptor for IL-1. While IL-1R2 is structurally similar to the type 1 IL-1 receptor (IL-1R1) responsible for IL-1 signal transduction, its truncated cytoplasmic domain and lack of Toll-IL-1 receptor (TIR) region renders IL-1R2 incapable of transmembrane signaling. IL-1R2 competes with IL-1R1 for ligands and for the IL-1R1 co-receptor, IL-1 receptor accessory protein (IL-1RAP). Additionally, IL-1R2 exists in both a membrane bound and soluble form (sIL-1R2) that has biological properties similar to both a decoy receptor and a binding protein. Thus far, IL-1R2 has been implicated in arthritis, endometriosis, organ transplantation, sepsis/sickness behavior, diabetes, atherosclerosis, autoimmune inner ear disease (AIED), Alzheimer's disease and ulcerative colitis. In this review, we will detail the functional properties of IL-1R2 and examine its role in human disease.

Decoys and Regulatory "Receptors" of the IL-1/Toll-Like Receptor Superfamily

Members of the IL-1 family play a key role in innate and adaptive immunity and in the pathogenesis of diverse diseases. Members of IL-1R like receptor (ILR) family include signaling molecules and negative regulators. The latter include decoy receptors (IL-1RII; IL-18BP) and “receptors” with regulatory function (TIR8/SIGIRR; IL-1RAcPb; DIGIRR). Structural considerations suggest that also TIGIRR-1 and IL-1RAPL may have regulatory function. The presence of multiple pathways of negative regulation of members of the IL-1/IL-1R family emphasizes the need for a tight control of members of this fundamental system.

Inhibition of IL-1 Signaling by Antisense Oligonucleotide-mediated Exon Skipping of IL-1 Receptor Accessory Protein (IL-1RAcP)

The cytokine interleukin 1(IL-1) initiates a wide range of proinflammatory cascades and its inhibition has been shown to decrease inflammation in a variety of diseases. IL-1 receptor accessory protein (IL-1RAcP) is an indispensible part of the IL-1R complex that stabilizes IL-1/IL-1R interaction and plays an important role in the signal transduction of the receptor complex. The soluble form of IL-1RAcP (sIL-1RAcP) contains only the extracellular domain and serves as a natural inhibitor of IL-1 signaling. Therefore, increasing sIL-1RAcP levels might be an attractive therapeutic strategy to inhibit IL-1–driven inflammation. To achieve this we designed specific antisense oligonucleotides (AON), to redirect pre-mRNA IL-1RAcP splicing by skipping of the transmembrane domain encoding exon 9. This would give rise to a novel Δ9IL-1RAcP mRNA encoding a soluble, secreted form of IL-1RAcP, which might have similar activity as natural sIL-1RAcP. AON treatment resulted in exon 9 skipping both in vitro and in vivo. A single dose injection of 10 mg AON/kg body weight induced 90% skipping in mouse liver during at least 5 days. The truncated mRNA encoded for a secreted, soluble Δ9IL-1RAcP protein. IL-1RAcP skipping resulted in a substantial inhibition of IL-1 signaling in vitro. These results indicate that skipping of the transmembrane encoding exon 9 of IL-1RAcP using specific AONs might be a promising therapeutic strategy in a variety of chronic inflammatory diseases.

Cytokine/chemokine patterns connect host and viral characteristics with clinics during chronic hepatitis C

Background

In chronic hepatitis C virus (HCV) infection, liver tissue pathology and HCV genotype are important determinants of clinical and/or treatment-related outcome. Although consistent epidemiological and/or molecular-biological clues derived from different studies on single virus-host interactions are meanwhile published, the in vivo transcriptional responses and cellular pathways affected in >1 key aspects of the disease or treatment process are far from being understood.

Methods

Microarray analysis was performed in peripheral whole blood (PB) samples from 36 therapy-naïve HCV-infected patients with known liver histology. Linear regression analysis identified gene expression profiles significantly correlating (P < 0.015) with ≥1 out of 7 variables: sustained viral response (SVR), viral non-response (NR), end of treatment viral response (ETR), viral breakthrough (VB), HCV genotype (Gt. 1 vs. Gt. 2/3), stage of hepatic fibrosis [St. 0/1 vs. St. 2/3/4] and grade of hepatic inflammation (Gr. 0/1 vs. Gr. 2/3/4). Correlation values across all seven contrasts were considered for hierarchical clustering (HCL).

Results

A total of 1,697 genes showed ≥1 significant correlation results and genes involved in cell differentiation (183), immune response (53), and apoptosis (170) were leading fractions. HCL grouped the genes into six major clusters. Functional annotation analysis using DAVID (http://david.abcc.ncifcrf.gov) revealed that expression profiles that best linked these variables were highly enriched in cytokine/chemokine activity (Fisher-exact P < 0.0001) and specific biological module-centric algorithms finally led our focus on four out of fifty-three immune response genes: SMAD family member 3 (SMAD3), interleukin 1 receptor accessory protein (IL1RAP), tumor necrosis factor receptor superfamily member 1A (TNFRSF1A), and chemokine ‘C-C motif’ receptor 5 (CCR5). Of those, TNFRSF1A and CCR5 showed significant correlation with two out of seven variables based on microarray and/or quantitative real-time polymerase chain reaction (qRT-PCR) data.

Conclusion

We identified molecular targets of the innate and adaptive immune system and validated their transcriptional specificity in vivo suggesting significant involvement in two unique outcomes during HCV treatment.

MicroRNA profiling identifies miR-29 as a regulator of disease-associated pathways in experimental biliary atresia

Biliary atresia (BA) is a pediatric liver disease of unknown underlying etiology, in which fibroinflammatory destruction of the extrahepatic biliary system leads to obstructive cholestasis. MicroRNAs are a class of short (18-23 nucleotide), noncoding RNA molecules, which act as negative regulators of target mRNA stability and translation. The importance of these molecules in normal and diseased liver has been demonstrated, but their potential role in the pathogenesis of BA has not been addressed. We have profiled changes in liver microRNA levels in an established mouse model of the disease, identified significantly altered transcripts, and defined the spatial expression patterns of selected microRNAs. Two of these, miR-29a/29b1, are upregulated in experimental BA. Using antisense oligonucleotide-mediated inhibition in mice, we have delineated the full set of hepatic genes regulated by miR-29 and identified 2 mRNA targets of potential pathological relevance in experimental BA, Igf1 and Il1RAP. We have used reporter assays to confirm that Igf1 and Il1RAP are direct targets of miR-29.

Effect of Traumeel S on cytokine profile in a cecal ligation and puncture (CLP) sepsis model in rats

BACKGROUND

Sepsis results in significant morbidity and mortality, with current treatment options limited with respect to efficacy as well as safety. The complex homeopathic remedy Traumeel S has been shown to have both anti-inflammatory and immunostimulatory effects in the in vitro setting.

OBJECTIVES

The objective was to explore the effects of Traumeel S in an in vivo setting, using a cecal ligation and puncture (CLP) sepsis model in rats, evaluating the effects of the medication on cytokine activity.

DESIGN

Sepsis was induced in 30 rats using accepted CLP methodology. Following the procedure, rats were randomly allocated to receive an intraperitoneal injection of either Traumeel S (n=15) or normal saline (n=15). At 6 hours post-CLP, serum cytokines (interleukin [IL]-1β, tumor necrosis factor-α, IL-6, and IL-10) were evaluated.

RESULTS

IL-1β levels were significantly higher in the treatment group (p=0.03) with no significant differences found between the groups with respect to the other cytokines tested.

CONCLUSIONS

In contrast to in vitro studies, Traumeel significantly increased IL-1β levels in an in vivo model, without influencing other cytokines. IL-1β is a proinflammatory cytokine that has been shown to have a protective effect in the CLP rat model. Further research is warranted to examine this finding, as well as its clinical implications.

Cystatin cures visceral leishmaniasis by NF-κB-mediated proinflammatory response through co-ordination of TLR/MyD88 signaling with p105-Tpl2-ERK pathway

Cystatin could completely cure experimental visceral leishmaniasis by switching the differentiation of Th2 cells to Th1 type, as well as upregulating NO, and activation of NF-κB played a major role in these processes. Analysis of upstream signaling events revealed that TLR 2/4-mediated MyD88-dependent participation of IL-1R-activated kinase (IRAK)1, TNF receptor-associated factor (TRAF)6 and TGFβ-activated kinase (TAK)1 is essential to induce cystatin-mediated IκB kinase (IKK)/NF-κB activation in macrophages. Cystatin plus IFN-γ activated the IKK complex to induce phosphorylation-mediated degradation of p105, the physiological partner and inhibitor of the MEK kinase, tumor progression locus 2 (Tpl-2). Consequently, Tpl-2 was liberated from p105, thereby stimulating activation of the MEK/ERK MAPK cascade. Cystatin plus IFN-γ-induced IKK-β post-transcriptionally modified p65/RelA subunit of NF-κB by dual phosphorylation in infected phagocytic cells. IKK induced the phosphorylation of p65 directly on Ser-536 residue whereas phosphorylation on Ser 276 residue was by sequential activation of Tpl-2/MEK/ERK/MSK1. Collectively, the present study indicates that cystatin plus IFN-γ-induced MyD88 signaling may bifurcate at the level of IKK, leading to a divergent pathway regulating NF-κB activation by IκBα phosphorylation and by p65 transactivation through Tpl-2/MEK/ERK/MSK1.

MicroRNA-146a and human disease

MicroRNAs (MiRNAs) belong to a class of small non-coding regulatory RNAs that act through repression of protein expression at post-transcriptional level and emerge to play important roles in many physiological and pathophysiological processes. MiR-146a is a miRNA supposed to regulate innate immune, inflammatory response and antiviral pathway negatively. In this review, we focus on the recent progress in functional role of miR-146a in innate immune, inflammatory response, virus infection and human diseases. Together, these findings indicate that manipulation of miR-146a expression may represent a potential new therapy for several human diseases. Potential use of miR-146a as a biomarker for disease diagnosis, prevention and treatment is also discussed.