MBD2 regulates TH17 differentiation and experimental autoimmune encephalomyelitis by controlling the homeostasis of T-bet/Hlx axis

miR-146a-3p as a potential novel therapeutic by targeting MBD2 to mediate Th17 differentiation in Th17 predominant neutrophilic severe asthma

Th17 (T-helper 17) cells subtype of non-T2 (non-type 2) asthma is related to neutrophilic infiltration and resistance to inhaled corticosteroids (ICS), so is also known as severe asthma. Methyl-CpG binding domain protein 2 (MBD2) regulates the differentiation of the Th17 cells, tending to show a therapeutic target in severe asthma. miR-146a-3p is associated with anti-inflammatory characteristics and immunity. Moreover, bioinformatic analysis showed that MBD2 may be a target gene of miR-146a-3p. However, the role of miR-146a-3p in the differentiation of Th17 cells via MBD2 in severe asthma remains unknown. Here, we aimed to explore how miR-146a-3p interacts with MBD2 and affects the differentiation of Th17 cells in severe asthma. First, we recruited 30 eligible healthy people and 30 patients with severe asthma to detect the expression of miR-146a-3p in peripheral blood mononuclear cells (PBMCs) by qRT-PCR. Then, we established a HDM/LPS (house dust mite/lipopolysaccharide) exposure model of bronchial epithelial cells (BECs) to evaluate the expression of miR-146a-3p, the interaction between miR-146a-3p and MBD2 using western blot and luciferase reporter analysis and the effect of miR-146a-3p regulated Th17 cells differentiation by flow cytometry in BECs in vitro. Finally, we constructed a mouse model of Th17 predominant neutrophilic severe asthma to assess the therapeutic potential of miR-146a-3p in severe asthma and the effect of miR-146a-3p regulated Th17 cells differentiation via MBD2 in vivo. Decreased miR-146a-3p expression was noted in severe asthma patients, in the BECs and in the animal severe asthma models. Moreover, we demonstrated that miR-146a-3p suppressed Th17 cells differentiation by targeting the MBD2. miR-146a-3p overexpression significantly reduced airway hyperresponsiveness, airway inflammation and airway mucus secretion, while also inhibiting Th17 cells response in vivo, which relieved severe asthma. By targeting MBD2 to suppress Th17 cells differentiation, miR-146a-3p provides a potential novel therapeutic for Th17 predominant neutrophilic severe asthma.

Molecular Characterization and Clinical Characteristics of m5C-Based RNA Methylation in Spinal Cord Injury: Validated by qPCR

Aberrant patterns of 5-methylcytosine (m5C)-based ribonucleic acid (RNA) methylation have critical roles in various human diseases, but their importance in spinal cord injury (SCI) is largely unknown. We explore the expression patterns and potential roles of m5C-based regulators of RNA modification after SCI. We analyzed 16 m5C-based regulators of RNA modification in tissues with SCI and normal rats from the Gene Expression Omnibus database. We constructed a "gene signature" of m5C-based regulators of RNA modification to predict the prognosis of SCI using least absolute shrinkage and selection operator regression and random-forest strategy. We found that the m5C-related genes, deoxyribonucleic acid (DNA) methyltransferase1 (Dnmt1), methyl-CpG binding domain protein 2 (Mbd2), ubiquitin-like with PHD and ring finger domains 1 (Uhrf1), uracil-N-glycosylase (Ung), and zinc finger and BTB(brica-brac, tramtrack, and broad) domain containing 38 (Zbtb38) had high expression, and zinc finger and BTB domain containing 4 (Zbtb4) had low expression in SCI. Analysis of the correlation between the gene sets of m5C-based regulators of RNA modification and immune-cell infiltration and immune response revealed Dnmt1, DNA methyltransferases 3A (Dnmt3a), Mbd2, and Ung to be positive regulators of the immune microenvironment, and Zbtb4 may negatively regulate the immune environment. Then, two molecular subtypes were identified based on 16 m5C-regulated genes. Functional-enrichment analysis of differentially expressed genes between different patterns of m5C-based modification was undertaken. Through the creation of a protein-protein interaction network, we screened 11 hub genes. We demonstrated their importance between SCI group and sham group using real-time reverse transcription-quantitative polymerase chain reaction in rat model. Expression of hub genes did not correlate with mitophagy but was positively correlated with endoplasmic reticulum stress (ERS), which suggested that there may be differences in ERS between different patterns of m5C-based modification. This present study explored and discovered the close link between m5C regulators-related genes and SCI. We also hope our findings may contribute to further mechanistic and therapeutic research on the role of key m5C regulators after SCI.

MBD2 mediates Th17 cell differentiation by regulating MINK1 in Th17-dominant asthma

Objectives: .Asthma is a highly heterogeneous disease, and T-helper cell type 17 (Th17) cells play a pathogenic role in the development of non-T2 severe asthma. Misshapen like kinase 1 (MINK1) is involved in the regulation of Th17 cell differentiation, but its effect on severe asthma remains unclear. Our previous studies showed that methyl-CpG binding domain protein 2 (MBD2) expression was significantly increased in patients with Th17 severe asthma and could regulate Th17 cell differentiation. The aim of this study was to investigate how MBD2 interacts with MINK1 to regulate Th17 cell differentiation in Th17-dominant asthma.

Materials and methods: Female C57BL/6 mice and bronchial epithelial cells (BECs) were used to establish mouse and cell models of Th17-dominant asthma, respectively. Flow cytometry was used to detect Th17 cell differentiation, and the level of IL-17 was detected by enzyme-linked immunosorbent assay (ELISA). Western blot and quantitative real-time PCR (qRT-PCR) were used to detect MBD2 and MINK1 expression. To investigate the role of MBD2 and MINK1 in Th17 cell differentiation in Th17-dominant asthma, the MBD2 and MINK1 genes were silenced or overexpressed by small interfering RNA and plasmid transfection.

Results: Mouse and BEC models of Th17-dominant asthma were established successfully. The main manifestations were increased neutrophils in BALF, airway hyperresponsiveness (AHR), activated Th17 cell differentiation, and high IL-17 levels. The expression of MBD2 in lung tissues and BECs from the Th17-dominant asthma group was significantly increased, while the corresponding expression of MINK1 was significantly impaired. Through overexpression or silencing of MBD2 and MINK1 genes, we have concluded that MBD2 and MINK1 regulate Th17 cell differentiation and IL-17 release. Interestingly, MBD2 was also found to negatively regulate the expression of MINK1.

Conclusion: Our findings have revealed new roles for MBD2 and MINK1, and provide new insights into epigenetic regulation of Th17-dominant asthma, which is dominated by neutrophils and Th17 cells. This study could lead to new therapeutic targets for patients with Th17-dominant asthma.

Blockade of Mbd2 by siRNA-loaded liposomes protects mice against OVA-induced allergic airway inflammation via repressing M2 macrophage production

Objective

To address the role of methyl-CpG-binding domain 2 (MBD2) in the pathogenesis of asthma and its potential as a target for the asthmatic therapy.

Methods

Studies were conducted in asthmatic patients and macrophage-specific Mbd2 knockout mice to dissect the role of MBD2 in asthma pathogenesis. Additionally, RNAi-based therapy with Mbd2 siRNA-loaded liposomes was conducted in an ovalbumin (OVA)-induced allergic airway inflammation mouse model.

Results

Asthmatic patients and mice challenged with OVA exhibited upregulated MBD2 expression in macrophages, especially in alternatively activated (M2) macrophages. In particular, macrophage-specific knockout of Mbd2 protected mice from OVA-induced allergic airway inflammation and suppressed the M2 program. Notably, intratracheal administration of liposomes carrying Mbd2 siRNA decreased the expression of Mbd2 and prevented OVA-induced allergic airway inflammation in mice, as indicated by the attenuated airway inflammation and mucus production.

Conclusions

The above data indicate that Mbd2 implicates in the pathogenesis of asthma predominantly by regulating the polarization of M2 macrophages, which supports that Mbd2 could be a viable target for treatment of asthma in clinical settings.

Aloperine Ameliorates IMQ-Induced Psoriasis by Attenuating Th17 Differentiation and Facilitating Their Conversion to Treg

Aloperine is an anti-inflammatory compound isolated from the Chinese herb Sophora alopecuroides L. Previously, our group has reported that the generation of induced Treg was promoted by aloperine treatment in a mouse colitis model. However, the effect of aloperine on effector T cell subsets remains unclear. We therefore carefully examined the effect of aloperine on the differentiation of major subsets of T helper cells. Based on our results, psoriasis, a Th17 dominant skin disease, is selected to explore the potential therapeutic effect of aloperine in vivo. Herein, we demonstrated that topical application of aloperine suppressed epidermal proliferation, erythema, and infiltration of inflammatory cells in skin lesions. Mechanistic studies revealed that aloperine suppressed the differentiation of Th17 cells directly through inhibiting the phosphorylation of STAT3 or indirectly through impairing the secretion of Th17-promoting cytokines by dendritic cells. Moreover, aloperine enhanced the conversion of Th17 into Treg via altering the pSTAT3/pSTAT5 ratio. Collectively, our study supported that aloperine possesses the capacity to affect Th17 differentiation and modulates Th17/Treg balance, thereby alleviating imiquimod (IMQ)-induced psoriasis in mice.

Methyl-CpG-binding domain protein 2 contributes to renal fibrosis through promoting polarized M1 macrophages

Recent studies reported that Methyl-CpG–binding domain protein 2 (MBD2) promoted M2 macrophages accumulation to increase bleomycin-induced pulmonary fibrosis. However, the role and mechanism of action of MBD2 in macrophages differentiation and renal fibrosis remain largely unknown. In the current study, MBD2 not only promoted the differentiation of resting M0 macrophages to polarized M2 macrophages, but also induced them to polarized M1 macrophages and the transition of M2 to M1 macrophages. ChIP analysis demonstrated that MBD2 physically interacted with the promoter region of the CpG islands of G0S2 genes, and then activated their expression by inducing hypomethylation of the promoter region. Interestingly, the data demonstrated that the role of G0S2 in macrophages differentiation is consistent with MBD2. Furthermore, Co-culture of activated M1 macrophages and murine embryonic NIH 3T3 fibroblasts indicated that MBD2 mediated the M1-induction of ECM production by embryonic NIH 3T3 fibroblasts via promotion of G0S2. In addition, we also found that inhibition of MBD2 suppressed LPS induced the expression of p53 as well as activation and expression of stat3 in RAW264.7 macrophages. In vivo, MBD2 LysM^cre attenuated unilateral ureteral obstruction (UUO) and ischemia/reperfusion (I/R)-induced renal fibrosis via downregulation of G0S2, which was demonstrated by the downregulation of fibronectin (FN), collagen I and IV, α-SMA, G0S2. These data collectively demonstrated that MBD2 in macrophages contributed to UUO and I/R-induced renal fibrosis through the upregulation of G0S2, which could be a target for treatment for chronic kidney disease.

The methyl-CpG-binding domain 2 facilitates pulmonary fibrosis by orchestrating fibroblast to myofibroblast differentiation

Although DNA methylation has been recognized in the pathogenesis of idiopathic pulmonary fibrosis (IPF), the exact mechanisms, however, are yet to be fully addressed. Herein, we demonstrated that lungs originated from IPF patients and mice after bleomycin (BLM)-induced pulmonary fibrosis are characterized by the altered DNA methylation along with overexpression of methyl-CpG-binding domain 2 (MBD2) in myofibroblasts, a reader responsible for interpreting DNA methylome-encoded information. Specifically, depletion of Mbd2 in fibroblasts or myofibroblasts protected mice from BLM-induced pulmonary fibrosis coupled with a significant reduction of fibroblast differentiation. Mechanistically, TGF-β1 induced a positive feedback regulatory loop between transforming growth factor-β receptor I (TβRI), Smad3 and Mbd2, and erythroid differentiation regulator 1 (Erdr1). TGF-β1 induced fibroblasts to undergo a global DNA hypermethylation along with Mbd2 overexpression in a TβRI/Smad3 dependent manner, and Mbd2 selectively bound to the methylated CpG DNA within the Erdr1 promoter to repress its expression, through which it enhances TGF-β/Smads signaling to promote fibroblast differentiating into myofibroblast and exacerbate pulmonary fibrosis. Therefore, enhancing Erdr1 expression strikingly reversed established pulmonary fibrosis. Collectively, our data support that strategies aimed at silencing Mbd2 or increasing Erdr1 could be viable therapeutic approaches for prevention and treatment of pulmonary fibrosis in clinical settings.

MBD2 acts as a repressor to maintain the homeostasis of the Th1 program in type 1 diabetes by regulating the STAT1-IFN-γ axis

The methyl-CpG-binding domain 2 (MBD2) interprets DNA methylome-encoded information through binding to the methylated CpG DNA, by which it regulates target gene expression at the transcriptional level. Although derailed DNA methylation has long been recognized to trigger or promote autoimmune responses in type 1 diabetes (T1D), the exact role of MBD2 in T1D pathogenesis, however, remains poorly defined. Herein, we generated an Mbd2 knockout model in the NOD background and found that Mbd2 deficiency exacerbated the development of spontaneous T1D in NOD mice. Adoptive transfer of Mbd2^-/- CD4 T cells into NOD.scid mice further confirmed the observation. Mechanistically, Th1 stimulation rendered the Stat1 promoter to undergo a DNA methylation turnover featured by the changes of DNA methylation levels or patterns along with the induction of MBD2 expression, which then bound to the methylated CpG DNA within the Stat1 promoter, by which MBD2 maintains the homeostasis of Th1 program to prevent autoimmunity. As a result, ectopic MBD2 expression alleviated CD4 T cell diabetogenicity following their adoptive transfer into NOD.scid mice. Collectively, our data suggest that MBD2 could be a viable target to develop epigenetic-based therapeutics against T1D in clinical settings.

Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma

Sex hormone has become a “hot topic” to evaluate the hormonal therapeutic potential in severe asthma. Th17 cell is one of the main influencing factors involved in the pathogenesis of severe asthma, hence also called as kernel of severe asthma, and Th17 subtype of non-T2 asthma is less responsive (resistance) to inhaled corticosteroid (ICS), so severe in nature. Methyl-CpG binding domain protein 2 (MBD2) is overexpressed and regulates the Th17 differentiation, showing the possibility of therapeutic target in treating Th17 mediated severe asthma. Sex hormone fluctuates at the different physiobiological conditions of the human body and affects the asthma pathobiology showing its role in asthma prevalence, severity, remission, and therapy. This review briefly overviews the sex hormones, their influence in asthma at the different physiobiological conditions of human body, and MBD2 severe asthma connection with the possible therapeutic potential of sex steroids in MBD2 mediated Th17 predominant severe asthma. Male sex hormone tends to show a beneficial effect and possibly downregulates the expression of Th17 cells via regulating MBD2 through a mechanism distinct from corticosteroid treatment and guides us towards discovery of new therapeutic agent, reduces the asthma-related complications, and promotes long-term survival by lowering the risk of therapy-resistant issues of old age severe asthma.

MBD2 as a Potential Novel Biomarker for Identifying Severe Asthma With Different Endotypes

Background: Studies have shown that methyl-CpG binding domain protein 2 (MBD2) expression is significantly elevated in a neutrophil-dominant severe asthma mouse model. It also regulates Th17 cell differentiation. The objective of this study was to investigate the relationship between serum MBD2 levels in patients with severe asthma with different endotypes.

Methods: Eligible adults with confirmed asthma (n = 63) underwent a clinical assessment, asthma control test and pulmonary function test and were classified as having mild, moderate or severe asthma. Severe asthma endotypes were defined according to the percentage of Th2 and Th17 cells in the peripheral blood and by the type of inflammation. The percentage of Th2 and Th17 cells in the peripheral blood was determined by flow cytometry. Serum MBD2, eosinophilic cationic protein and myeloperoxidase were measured by enzyme-linked immunosorbent assay. Correlations of MBD2 expression with clinical parameters were evaluated using Spearman's rank correlation analysis.

Results: Serum MBD2 levels were upregulated in patients with severe asthma compared to healthy controls and patients with mild to moderate asthma. MBD2 was also significantly increased in patients with Th17 severe asthma compared to patients with type 2 severe asthma. Furthermore, MBD2 was positively correlated with MPO and Th17 cells but negatively correlated with ECP and Th2 cells in patients with severe asthma.

Conclusions: These findings suggest that serum MBD2 may be a potential new biomarker for identifying severe asthma, Th17 severe asthma and the type of airway inflammation. However, these findings are still preliminary and need to be further investigated.

MBD2 serves as a viable target against pulmonary fibrosis by inhibiting macrophage M2 program

Despite past extensive studies, the mechanisms underlying pulmonary fibrosis (PF) still remain poorly understood. Here, we demonstrated that lungs originating from different types of patients with PF, including coronavirus disease 2019, systemic sclerosis-associated interstitial lung disease, and idiopathic PF, and from mice following bleomycin (BLM)-induced PF are characterized by the altered methyl-CpG-binding domain 2 (MBD2) expression in macrophages. Depletion of Mbd2 in macrophages protected mice against BLM-induced PF. Mbd2 deficiency significantly attenuated transforming growth factor-β1 (TGF-β1) production and reduced M2 macrophage accumulation in the lung following BLM induction. Mechanistically, Mbd2 selectively bound to the Ship promoter in macrophages, by which it repressed Ship expression and enhanced PI3K/Akt signaling to promote the macrophage M2 program. Therefore, intratracheal administration of liposomes loaded with Mbd2 siRNA protected mice from BLM-induced lung injuries and fibrosis. Together, our data support the possibility that MBD2 could be a viable target against PF in clinical settings.

Loss of MBD2 affects early T cell development by inhibiting the WNT signaling pathway

DNA methylation alters the expression of certain genes without any alteration to the DNA sequence and is a dynamic process during normal hematopoietic differentiation. As an epigenetic regulator, methyl-CpG-binding domain protein 2 (MBD2) is an important member of the MBD protein family and is acknowledged as a "reader" of DNA methylation. We used a mouse model to study the effects of MBD2 on the early development of T cells. Here, we found that MBD2 deficiency led to retardation of T cell differentiation at the DN3 stage. Meanwhile, decreased proliferative capacity and increased apoptosis were detected in Mbd2^-/- DN thymocytes. Furthermore, we found the WNT pathway was significantly down-regulated in Mbd2^-/- DN thymocytes: DKK1 (Dickkopf-1) expression was significantly increased, while TCF7 (transcription factor 7) and c-MYC were down-regulated. Thus, these findings established that MBD2 acted as a dominant regulator to imprint DN T cell development via the WNT pathway.

Mechanisms by Which the MBD2/miR-301a-5p/CXCL12/CXCR4 Pathway Regulates Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible expiratory airflow obstruction, and its chronic course is worsened by recurrent acute exacerbations. Our previous microarray assay identified microRNA (miR)-301a-5p as being associated with progression of acute exacerbation of COPD (AE-COPD); however, the mechanism underlying COPD pathogenesis remains unknown.

Methods

Samples of serum and peripheral blood mononuclear cells (PBMCs) were isolated from healthy control subjects and patients with stable COPD (R-COPD) or with an acute exacerbation of COPD (AE-COPD). Human HULEC-5a and human bronchial epithelial (HBE) cells were transfected with methyl-CpG-binding domain protein 2 (MBD2), sh-MBD2, miR-301a-5p mimics or an inhibitor, and then stimulated with cigarette smoke extract (CSE). Conditioned medium co-culture assays were performed by adding the supernatant of medium derived from HULEC-5a cells transfected with miR-301a-5p mimics or inhibitor into wells containing si-c-x-c motif chemokine receptor 4 (CXCR4)-transfected-lung fibroblasts or human leukemic THP-1 cell line macrophages. Transwell assays were performed to analyze cell migration.

Results

Our analysis of clinical samples showed that decreased miR-301a-5p levels in patients with AE-COPD were positively correlated with levels of MBD2 expression, but negatively correlated with levels of chemokine ligand C-X-C motif chemokine ligand 12 (CXCL12) expression. MBD2 overexpression significantly promoted miR-301a-5p production, but suppressed CXCL12 production in HULEC-5a and HBE cells. CXCL12 was confirmed to be a direct target of miR-301a-5p. CXCR4 knockdown significantly enhanced the suppressive effect of miR-301a-5p mimics and attenuated the promotional effects of the miR-301a-5p inhibitor on the migration of circulating fibroblasts and macrophages, as well as the expression levels of phospho-mitogen-activated protein kinase (p-MEK) and phospho-protein kinase B (p-AKT).

Conclusion

In summary, the MBD2/miR-301a-5p/CXCL12/CXCR4 pathway was shown to affect the migration of lung fibroblasts and monocyte-derived macrophages, which may play an important role during COPD exacerbations.

Circulating Exosomes Control CD4+ T Cell Immunometabolic Functions via the Transfer of miR-142 as a Novel Mediator in Myocarditis

CD4⁺ T cells undergo immunometabolic activation to mount an immunogenic response during experimental autoimmune myocarditis (EAM). Exosomes are considered key messengers mediating multiple T cell functions in autoimmune responses. However, the role of circulating exosomes in EAM immunopathogenesis and CD4⁺ T cell dysfunction remains elusive. Our objective was to elucidate the mechanism of action for circulating exosomes in EAM pathogenesis. We found that serum exosomes harvested from EAM mice induced CD4⁺ T cell immunometabolic dysfunction. Treatment with the exosome inhibitor GW4869 protected mice from developing EAM, underlying that exosomes are indispensable for the pathogenesis of EAM. Furthermore, by transfer of EAM exosomes, we confirmed that circulating exosomes initiate the T cell pathological immune response, driving the EAM pathological process. Mechanistically, EAM-circulating exosomes selectively loaded abundant microRNA (miR)-142. We confirmed methyl-CpG binding domain protein 2 (MBD2) and suppressor of cytokine signaling 1 (SOCS1) as functional target genes of miR-142. The miR-142/MBD2/MYC and miR-142/SOCS1 communication axes are critical to exosome-mediated immunometabolic turbulence. Moreover, the in vivo injection of the miR-142 inhibitor alleviated cardiac injury in EAM mice. This effect was abrogated by pretreatment with EAM exosomes. Collectively, our results indicate a newly endogenous mechanism whereby circulating exosomes regulate CD4⁺ T cell immunometabolic dysfunction and EAM pathogenesis via cargo miR-142.

Loss of ubiquitin-conjugating enzyme E2 (Ubc9) in macrophages exacerbates multiple low-dose streptozotocin-induced diabetes by attenuating M2 macrophage polarization

Type 1 diabetes (T1D) is characterized by the selective autoimmune destruction of the islet β cells, and macrophages play a significant role in this process. Small ubiquitin-like modification (SUMOylation) is an important posttranslational modification involved in T1D pathogenesis, but its function in macrophages remains unexplored. We presently developed and used macrophage-specific ubiquitin-conjugating enzyme E2 (Ubc9) knockout (LyzM-Cre-Ubc9^fl/fl, KO) mice to address the impact of SUMOylation on macrophage function in a T1D model. We observed that blocking Ubc9 in macrophages exacerbated multiple-low dose streptozotocin (MLD-STZ)-induced diabetes. Specifically, after STZ treatment, blood glucose levels were consistently elevated in the KO mice. The KO mice exhibited a higher diabetes incidence than WT controls (85% vs. 55%, P < 0.01) along with a higher insulitis severity. The loss of Ubc9 impaired macrophage energy metabolism and attenuated macrophage M2 program, thereby enhancing T cell activation. Pancreas-resident macrophages, rather than migrant macrophages, played a predominant role in MLD-STZ-induced diabetes. Mechanistically, Ubc9-mediated SUMOylation of interferon regulator factor 4 (IRF4) enhanced its nuclear localization and stability, thereby transcribing IL-4 and arginase 1 (Arg1) to promote the macrophage M2 program. Ubc9-mediated SUMOylation modulates T1D risk at least in part by regulating macrophage function. Modulation of disturbed SUMOylation process in macrophages, either through cell adoptive transfer or targeted drug-delivery, could help to establish a tolerant pancreatic microenvironment and promote inflammation resolution in early insulitis stage, thus hindering T1D progression.

Increased HERV-E clone 4-1 expression contributes to DNA hypomethylation and IL-17 release from CD4+ T cells via miR-302d/MBD2 in systemic lupus erythematosus

Background

Increased human endogenous retroviruses E clone 4–1 (HERV-E clone 4–1) mRNA expression is observed in systemic lupus erythematosus (SLE) patients and associates with the disease activity. In this study, we want to further investigate the mechanism of HERV-E clone 4–1 mRNA upregulation and its roles in SLE progression.

Methods

CD4⁺ T cells were isolated from venous blood of SLE patients or healthy controls and qRT-PCR was used to detect HERV-E clone 4–1 mRNA expression. We then investigated the regulation of Nuclear factor of activated T cells 1 (NFAT1) and Estrogen receptor-α (ER-α) on HERV-E clone 4–1 transcription and the functions of HERV-E clone 4–1 3′ long terminal repeat (LTR) on DNA hypomethylation and IL-17 release.

Results

We found HERV-E clone 4–1 mRNA expression was upregulated in CD4⁺ T cells from SLE patients and positively correlated with SLE disease activity. This is associated with the activation of Ca²⁺/calcineurin (CaN)/NFAT1 and E2/ER-α signaling pathway and DNA hypomethylation of HERV-E clone 4–1 5’LTR. HERV-E clone 4–1 also takes part in disease pathogenesis of SLE through miR-302d/Methyl-CpG binding domain protein 2 (MBD2)/DNA hypomethylation and IL-17 signaling via its 3’LTR.

Conclusions

HERV-E clone 4–1 mRNA upregulation is due to the abnormal inflammation/immune/methylation status of SLE and it could act as a potential biomarker for diagnosis of SLE. HERV-E clone 4–1 also takes part in disease pathogenesis of SLE via its 3’LTR and the signaling pathways it involved in may be potential therapeutic targets of SLE.

Electronic supplementary material

The online version of this article (10.1186/s12964-019-0416-5) contains supplementary material, which is available to authorized users.

MBD2-mediated Th17 differentiation in severe asthma is associated with impaired SOCS3 expression

T helper 17 (Th17) cells has proven to be crucial in the pathogenesis of severe asthma. Although it is known that Suppressor of cytokine signaling 3 (SOCS3) is involved in differentiation of Th17 cells but, how it affects severe asthma is uncertain. Since previous studies indicated that Methtyl-CpG binding domain protein 2 (MBD2) null mice was deficient in Th17 cell differentiation, the aim of the present study was to understand how MBD2 interacts with SOCS3 to regulate Th17 cell differentiation in severe asthma. Here, we show that SOCS3 expression was significantly decreased in Th17-mediated severe asthmatic mice, accompanied by elevated STAT3 phosphorylation and RORγt expression. Knock-down of SOCS3 promoted the differentiation of naïve T cells into Th17 cells through STAT3/RORγt pathway. Meanwhile, MBD2 was overexpressed in Th17-mediated severe asthmatic mice. Intervention of MBD2 expression lead to a negative change of SOCS3 expression, whereas the differentiation of Th17 cells showed positive change. In addition, MBD2 knockout (MBD2-KO) mice displayed increased SOCS3 expression and decreased Th17 differentiation after severe asthma modeling. Taken together, our results suggest that MBD2 might facilitate Th17 cell differentiation via down-regulating SOCS3 expression in severe asthma. These findings uncover new roles for SOCS3 and MBD2, and provide a potential target for treatment of severe asthma.

Mbd2 enables tumourigenesis within the intestine while preventing tumour-promoting inflammation

Epigenetic regulation plays a key role in the link between inflammation and cancer. Here we examine Mbd2, which mediates epigenetic transcriptional silencing by binding to methylated DNA. In separate studies the Mbd2-/- mouse has been shown (1) to be resistant to intestinal tumourigenesis and (2) to have an enhanced inflammatory/immune response, observations that are inconsistent with the links between inflammation and cancer. To clarify its role in tumourigenesis and inflammation, we used constitutive and conditional models of Mbd2 deletion to explore its epithelial and non-epithelial roles in the intestine. Using a conditional model, we found that suppression of intestinal tumourigenesis is due primarily to the absence of Mbd2 within the epithelia. Next, we demonstrated, using the DSS colitis model, that non-epithelial roles of Mbd2 are key in preventing the transition from acute to tumour-promoting chronic inflammation. Combining models revealed that prior to inflammation the altered Mbd2-/- immune response plays a role in intestinal tumour suppression. However, following inflammation the intestine converts from tumour suppressive to tumour promoting. To summarise, in the intestine the normal function of Mbd2 is exploited by cancer cells to enable tumourigenesis, while in the immune system it plays a key role in preventing tumour-enabling inflammation. Which role is dominant depends on the inflammation status of the intestine. As environmental interactions within the intestine can alter DNA methylation patterns, we propose that Mbd2 plays a key role in determining whether these interactions are anti- or pro-tumourigenic and this makes it a useful new epigenetic model for inflammation-associated carcinogenesis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Aloperine Protects Mice against Bleomycin-induced Pulmonary Fibrosis by Attenuating Fibroblast Proliferation and Differentiation

Aloperine is a quinolizidine alkaloid extracted from Sophora alopecuroides. It has been proven to alleviate oxidative stress and effectively promote tumor cell apoptosis in mice. Herein, we investigated whether aloperine could also mediate its protective effects on bleomycin (BLM)-induced pulmonary fibrosis. Pathological staining, western blot, RT-PCR and flow cytometry were used to evaluate the impact of aloperine on the development of pulmonary fibrosis. The effect of aloperine on fibroblast proliferation, differentiation and related signaling pathways were next investigated to demonstrate the underlying mechanisms. In the present report, we showed that aloperine provided protection for mice against BLM-induced pulmonary fibrosis as manifested by the attenuated lung injury and reduced fibrosis along with alleviated fibroblast proliferation and differentiation. Additionally, we provided in vitro evidence revealing that aloperine inhibited cellular proliferation in PDGF-BB-stimulated mouse lung fibroblasts by repressed PI3K/AKT/mTOR signaling and fibroblast to myofibroblast differentiation by repressed TGF-β/Smad signaling. Overall, our data showed that aloperine could protect the mice against BLM-induced pulmonary fibrosis by attenuated fibroblast proliferation and differentiation, which indicated that aloperine may be therapeutically beneficial for IPF patients.

Reduced MBD2 expression enhances airway inflammation in bronchial epithelium in COPD

Background

Chronic obstructive pulmonary disease (COPD) is a common inflammatory lung disease characterized by inflammatory cells activation and production of inflammatory mediators. Methyl-CpG-binding domain protein 2 (MBD2) plays an important role in diverse immunological disorders by regulating immune cell functions, such as differentiation and mediator secretion. However, the role of MBD2 in COPD remains unknown.

Methods

MBD2 protein expression in lung tissues of patients with COPD and cigarette smoke (CS)-exposed mice were evaluated by Western blot and immunohistochemistry. The role of MBD2 in cigarette smoke extract (CSE)-induction of inflammatory mediator expression in the human bronchial epithelial (HBE) cell line was assessed by silencing MBD2 expression in vitro. The involvement of signaling pathways in mediation of inflammation was tested with signaling inhibitors.

Results

Compared with controls, MBD2 expression was distinctly reduced in the bronchial epithelium of both patients with COPD and CS-exposed mice. Moreover, MBD2 expression was decreased in HBE after CSE stimulation in vitro. Moreover, MBD2 knockdown enhanced interleukin (IL)-6 and IL-8 expression in HBE in the presence and absence of CSE treatment by the ERK signaling pathway.

Conclusion

MBD2 protein expression was reduced in the airway epithelium of COPD. In HBE, this reduced expression was associated with increased levels of IL-6 and IL-8 mediated by the ERK pathway. These results suggest that MBD2 could contribute to chronic airway inflammation in COPD.

MBD2 Regulates Th17 Cell Differentiation and Experimental Severe Asthma by Affecting IRF4 Expression

Th17 cells and IL-17 participate in airway neutrophil infiltration characteristics in the pathogenesis of severe asthma. Methyl-CpG binding domain protein 2 (MBD2) expression increased in CD4⁺ T cells in peripheral blood samples of asthma patients. However, little is known about that epigenetic regulation of MBD2 in both immunological pathogenesis of experimental severe asthma and CD4⁺ T cell differentiation. Here, we established a neutrophil-predominant severe asthma model, which was characterized by airway hyperresponsiveness (AHR), BALF neutrophil granulocyte (NEU) increase, higher NEU and IL-17 protein levels, and more Th17 cell differentiation. In the model, MBD2 and IRF4 protein expression increased in the lung and spleen cells. Under overexpression or silencing of the MBD2 and IRF4 gene, the differentiation of Th17 cells and IL-17 secretion showed positive changes. IRF4 protein expression showed a positive change with overexpression or silencing of the MBD2 gene, whereas there was no significant difference in the expression of MBD2 under overexpression or silencing of the IRF4 gene. These data provide novel insights into epigenetic regulation of severe asthma.

An Unbiased Linkage Approach Reveals That the p53 Pathway Is Coupled to NK Cell Maturation

Natural killer cells constitute potent innate lymphoid cells that play a major role in both tumor immunosurveillance and viral clearance via their effector functions. A four-stage model of NK cell functional maturation has been established according to the expression of CD11b and CD27, separating mature NK (mNK) cells into distinct populations that exhibit specific phenotypic and functional properties. To identify genetic factors involved in the regulation of NK cell functional maturation, we performed a linkage analysis on F₂ (B6.Rag1^-/- × NOD.Rag1^-/- intercross) mice. We identified six loci on chromosomes 2, 4, 7, 10, 11, and 18 that were linked to one or more mNK cell subsets. Subsequently, we performed an in silico analysis exploiting mNK cell subset microarray data, highlighting various genes and microRNAs as potential regulators of the functional maturation of NK cells. Together, the combination of our unbiased genetic linkage study and the in silico analysis positions genes known to affect NK cell biology along the specific stages of NK cell functional maturation. Moreover, this approach allowed us to uncover a novel candidate gene in the regulation of NK cell maturation, namely Trp53 Using mice deficient for Trp53, we confirm that this tumor suppressor regulates NK cell functional maturation. Additional candidate genes revealed in this study may eventually serve as targets for the modulation of NK cell functional maturation to potentiate both tumor immunosurveillance and viral clearance.

Role of C/EBP homologous protein and endoplasmic reticulum stress in asthma exacerbation by regulating the IL-4/signal transducer and activator of transcription 6/transcription factor EC/IL-4 receptor α positive feedback loop in M2 macrophages

BACKGROUND

C/EBP homologous protein (Chop), a marker of endoplasmic reticulum (ER) stress, exhibits aberrant expression patterns during asthma development. However, its exact role in asthma pathogenesis is not fully understood.

OBJECTIVES

We aimed to determine the function and mechanism of Chop in the pathogenesis of allergic asthma in patients and animals.

METHODS

Studies were conducted in asthmatic patients and Chop^-/- mice to dissect the role of Chop and ER stress in asthma pathogenesis. An ovalbumin (OVA)-induced allergic airway inflammation model was used to address the effect of Chop deficiency on asthma development. Next, the effect of Chop deficiency on macrophage polarization and related signaling pathways was investigated to demonstrate the underlying mechanisms.

RESULTS

Asthmatic patients and mice after OVA induction exhibited aberrant Chop expression along with ER stress. Specifically, Chop was noted to be specifically overexpressed in macrophages, and mice deficient in Chop were protected from OVA-induced allergic airway inflammation, as manifested by attenuated airway inflammation, remodeling, and hyperresponsiveness. Chop was found to exacerbate allergic airway inflammation by enhancing M2 programming in macrophages. Mechanistic studies characterized an IL-4/signal transducer and activator of transcription 6/transcription factor EC (Tfec)/IL-4 receptor α positive feedback regulatory loop, in which IL-4 induces Chop expression, which then promotes signal transducer and activator of transcription 6 signaling to transcribe Tfec expression. Finally, Tfec transcribes IL-4 receptor α expression to promote M2 programming in macrophages.

CONCLUSIONS

Chop and ER stress are implicated in asthma pathogenesis, which involves regulation of M2 programming in macrophages.

Loss of Mbd2 Protects Mice Against High-Fat Diet-Induced Obesity and Insulin Resistance by Regulating the Homeostasis of Energy Storage and Expenditure

Previous studies including ours demonstrated that methyl-CpG-binding domain 2 (MBD2) acts as a reader to decipher DNA methylome-encoded information. We thus in the current study used Mbd2^-/- mice as a model to dissect the impact of high-fat diet (HFD) on DNA methylome relevant to the pathoetiology of obesity. It was interestingly noted that mice deficient in Mbd2 were protected from HFD-induced obesity and insulin resistance. Mechanistic study revealed that HFD rendered epididymal adipose tissues to undergo a DNA methylation turnover as evidenced by the changes of methylation levels and patterns. Specifically, HFD was noted with higher potency to induce DNA hypomethylation in genes relevant to energy storage than that in genes associated with energy expenditure. As a result, arrays of genes were subjected to expression changes, which led to an altered homeostasis for energy storage and expenditure in favor of obesity development. Loss of Mbd2 resulted in impaired implementation of above DNA methylation changes associated with altered energy homeostasis, which then protected mice from HFD-induced obesity and insulin resistance. Those data would provide novel insight into the understanding of the pathoetiology underlying obesity with potential for developing effective therapies against obesity in clinical settings.

Autoimmunity in 2014

Our PubMed search for peer-reviewed articles published in the 2014 solar year retrieved a significantly higher number of hits compared to 2013 with a net 28 % increase. Importantly, full articles related to autoimmunity constitute approximately 5 % of immunology articles. We confirm that our understanding of autoimmunity is becoming a translational paradigm with pathogenetic elements rapidly followed by new treatment options. Furthermore, numerous clinical and pathogenetic elements and features are shared among autoimmune diseases, and this is well illustrated in the recent literature. More specifically, the past year witnessed critical revisions of our understanding and management of antiphospholipid syndrome with new exciting data on the pathogenicity of the serum anti-beta2 glycoprotein autoantibody, a better understanding of the current and new treatments for rheumatoid arthritis, and new position papers on important clinical questions such as vaccinations in patients with autoimmune disease, comorbidities, or new classification criteria. Furthermore, data confirming the important connections between innate immunity and autoimmunity via toll-like receptors or the critical role of T regulatory cells in tolerance breakdown and autoimmunity perpetuation were also reported. Lastly, genetic and epigenetic data were provided to confirm that the mosaic of autoimmunity warrants a susceptible individual background which may be geographically determined and contribute to the geoepidemiology of diseases. The 2014 literature in the autoimmunity world should be cumulatively regarded as part of an annus mirabilis in which, on a different level, the 2014 Annual Meeting of the American College of Rheumatology in Boston was attended by over 16,000 participants with over selected 3000 abstracts.

DNA Methylation: a New Player in Multiple Sclerosis

Multiple sclerosis (MS) is a neurological and chronic inflammatory disease that is mediated by demyelination and axonal degeneration in the central nervous system (CNS). Studies have shown that immune system components such as CD4+, CD8+, CD44+ T cells, B lymphatic cells, and inflammatory cytokines play a critical role in inflammatory processes and myelin damage associated with MS. Nevertheless, the pathogenesis of MS remains poorly defined. DNA methylation, a significant epigenetic modification, is reported to be extensively involved in MS pathogenesis through the regulation of gene expression. This review focuses on DNA methylation involved in MS pathogenesis. Evidence showed the hypermethylation of human leukocyte antigen-DRB1 (HLA-DRB1) in CD4+ T cells, the genome-wide DNA methylation in CD8+ T cells, the hypermethylation of interleukin-4 (IL-4)/forkhead winged helix transcription factor 3 (Foxp3), and the demethylation of interferon-γ (IFN-γ)/IL-17a in CD44+ encephalitogenic T cells. Studies also showed the hypermethylation of SH2-containing protein tyrosine phosphatase-1 (SHP-1) in peripheral blood mononuclear cells (PBMCs) and methylated changes of genes regulating oligodendrocyte and neuronal function in normal-appearing white matter. Clarifying the mechanism of aberrant methylation on MS may explain part of the pathology and will lead to the development of a new therapeutic target for the treatment of MS in the future.

Emerging Molecular and Biological Functions of MBD2, a Reader of DNA Methylation

DNA methylation is an epigenetic mark that is essential for many biological processes and is linked to diseases such as cancer. Methylation is usually associated with transcriptional silencing, but new research has challenged this model. Both transcriptional activation and repression have recently been found to be associated with DNA methylation in a context-specific manner. How DNA methylation patterns are interpreted into different functional output remains poorly understood. One mechanism involves the protein ‘readers’ of methylation, which includes the methyl-CpG binding domain (MBD) family of proteins. This review examines the molecular and biological functions of MBD2, which binds to CpG methylation and is an integral part of the nucleosome remodeling and histone deacetylation (NuRD) complex. MBD2 has been linked to immune system function and tumorigenesis, yet little is known about its functions in vivo. Recent studies have found the MBD2 protein is ubiquitously expressed, with relatively high levels in the lung, liver, and colon. Mbd2 null mice surprisingly show relatively mild phenotypes compared to mice with loss of function of other MBD proteins. This evidence has previously been interpreted as functional redundancy between the MBD proteins. Here, we examine and contextualize research that suggests MBD2 has unique properties and functions among the MBD proteins. These functions translate to recently described roles in the development and differentiation of multiple cell lineages, including pluripotent stem cells and various cell types of the immune system, as well as in tumorigenesis. We also consider possible models for the dynamic interactions between MBD2 and NuRD in different tissues in vivo. The functions of MBD2 may have direct therapeutic implications for several areas of human disease, including autoimmune conditions and cancer, in addition to providing insights into the actions of NuRD and chromatin regulation.

Tagging methyl-CpG-binding domain proteins reveals different spatiotemporal expression and supports distinct functions

AIM

DNA methylation is recognized by methyl-CpG-binding domain (MBD) proteins. Multiple MBDs are linked to neurodevelopmental disorders in humans and mice. However, the functions of MBD2 are poorly understood. We characterized Mbd2 knockout mice and determined spatiotemporal expression of MBDs and MBD2-NuRD (nucleosome remodeling deacetylase) interactions.

EXPERIMENTAL PROCEDURES

We analyzed behavioral phenotypes, generated biotin-tagged MBD1 and MBD2 knockin mice, and performed biochemical studies of MBD2-NuRD.

RESULTS

Most behavioral measures are minimally affected in Mbd2 knockout mice. In contrast to other MBDs, MBD2 shows distinct expression patterns.

CONCLUSION

Unlike most MBDs, MBD2 is ubiquitously expressed in all tissues examined and appears dispensable for brain functions measured in this study. We provide novel genetic tools and reveal new directions to investigate MBD2 functions in vivo.

CCL2-CCR2 signaling promotes hepatic ischemia/reperfusion injury

BACKGROUND

Liver ischemia/reperfusion (I/R) injury is a type of uncontrolled inflammatory cascade in which neutrophils, an early infiltrating immune cell population, elicit significant tissue damage. However, the precise mechanism for neutrophil recruitment and infiltration remains to be fully characterized.

METHODS

A hepatic partial I/R model was reproduced in wild-type, CCL2(-/-) and CCR2(-/-) mice. Tissue damage was evaluated by serum enzyme analysis, hematoxylin-eosin staining, and cytokine production measurement. Mobilization of neutrophils from the bone marrow and subsequent infiltration into the liver were measured by flow cytometry. C-C motif chemokine receptor 2 (CCR2) expression on neutrophils and C-C motif chemokine ligand 2 (CCL2) chemotaxis were measured using flow cytometry. The cellular source of CCL2 in the liver was determined by deleting specific cell groups and performing intracellular staining.

RESULTS

Liver damage was ameliorated, and neutrophil recruitment and accumulation were decreased in both CCL2(-/-) and CCR2(-/-) mice compared with wild-type mice. Neutrophils displayed upregulated expression of CCR2 during I/R, and these cells were required for CCL2-induced chemotaxis. Depletion of Kupffer cells protected the liver from I/R injury. Furthermore, genetic ablation of CCL2 reduced liver injury, as demonstrated by decreases in the levels of alanine aminotransferase and aspartate aminotransferase and subsequent reductions in neutrophil recruitment and accumulation.

CONCLUSIONS

Kupffer cells secrete CCL2 to promote CCR2-expressing neutrophil recruitment from the bone marrow and subsequent infiltration into the liver during I/R. These findings reveal a novel pro-inflammatory role of cell-mediated CCL2-CCR2 interactions during this sterile insult.

Chop Deficiency Protects Mice Against Bleomycin-induced Pulmonary Fibrosis by Attenuating M2 Macrophage Production

C/EBP homologous protein (Chop) has been shown to have altered expression in patients with idiopathic pulmonary fibrosis (IPF), but its exact role in IPF pathoaetiology has not been fully addressed. Studies conducted in patients with IPF and Chop(-/-) mice have dissected the role of Chop and endoplasmic reticulum (ER) stress in pulmonary fibrosis pathogenesis. The effect of Chop deficiency on macrophage polarization and related signalling pathways were investigated to identify the underlying mechanisms. Patients with IPF and mice with bleomycin (BLM)-induced pulmonary fibrosis were affected by the altered Chop expression and ER stress. In particular, Chop deficiency protected mice against BLM-induced lung injury and fibrosis. Loss of Chop significantly attenuated transforming growth factor β (TGF-β) production and reduced M2 macrophage infiltration in the lung following BLM induction. Mechanistic studies showed that Chop deficiency repressed the M2 program in macrophages, which then attenuated TGF-β secretion. Specifically, loss of Chop promoted the expression of suppressors of cytokine signaling 1 and suppressors of cytokine signaling 3, and through which Chop deficiency repressed signal transducer and activator of transcription 6/peroxisome proliferator-activated receptor gamma signaling, the essential pathway for the M2 program in macrophages. Together, our data support the idea that Chop and ER stress are implicated in IPF pathoaetiology, involving at least the induction and differentiation of M2 macrophages.

Aloperine Protects Mice against Ischemia-Reperfusion (IR)-Induced Renal Injury by Regulating PI3K/AKT/mTOR Signaling and AP-1 Activity

Aloperine is a quinolizidine alkaloid extracted from the leaves of Sophora plants. It has been recognized with the potential to treat inflammatory and allergic diseases as well as tumors. In this report, we demonstrate that pretreatment with aloperine provided protection for mice against ischemia-reperfusion (IR)-induced acute renal injury as manifested by the attenuated inflammatory infiltration, reduced tubular apoptosis, and well-preserved renal function. Mechanistic studies revealed that aloperine selectively repressed IL-1β and IFN-γ expression by regulating PI3K/Akt/mTOR signaling and NF-κB transcriptional activity. However, aloperine did not show a perceptible impact on IL-6 and TGF-β expression and the related Jak2/Stat3 signaling. It was also noted that aloperine regulates AP-1 activity, through which it not only enhances SOD expression to increase reactive oxygen species (ROS) detoxification but also promotes the expression of antiapoptotic Bcl-2, thereby preventing tubular cells from IR-induced apoptosis. Collectively, our data suggest that administration of aloperine prior to IR insults, such as renal transplantation, could be a viable approach to prevent IR-induced injuries.

Chop deficiency prevents UUO-induced renal fibrosis by attenuating fibrotic signals originated from Hmgb1/TLR4/NFκB/IL-1β signaling

Renal fibrosis, particularly tubulointerstitial fibrosis is considered to be the final manifestation of almost all chronic kidney diseases (CKDs). Herein we demonstrated evidence that CHOP-related ER stress is associated with the development of renal fibrosis in both CKD patients and unilateral ureteral obstruction (UUO)-induced animals, and specifically, mice deficient in Chop were protected from UUO-induced renal fibrosis. Mechanistic studies revealed that loss of Chop protected tubular cells from UUO-induced apoptosis and secondary necrosis along with attenuated Hmgb1 passive release and active secretion. As a result, Chop deficiency suppressed Hmgb1/TLR4/NFκB signaling, which then repressed UUO-induced IL-1β production. Consequently, the IL-1β downstream Erk1/2 activity and its related c-Jun transcriptional activity were reduced, leading to attenuated production of TGF-β1 following UUO insult. It was further noted that reduced IL-1β production also inhibited UUO-induced PI3K/AKT signaling, and both of which ultimately protected mice from UUO-induced renal fibrosis. Together, our data support that suppression of CHOP expression could be a viable therapeutic strategy to prevent renal fibrosis in patients with CKDs.

Cx3cr1 deficiency in mice attenuates hepatic granuloma formation during acute schistosomiasis by enhancing the M2-type polarization of macrophages

Acute schistosomiasis is characterized by pro-inflammatory responses against tissue- or organ-trapped parasite eggs along with granuloma formation. Here, we describe studies in Cx3cr1^−/− mice and demonstrate the role of Cx3cr1 in the pathoetiology of granuloma formation during acute schistosomiasis. Mice deficient in Cx3cr1 were protected from granuloma formation and hepatic injury induced by Schistosoma japonicum eggs, as manifested by reduced body weight loss and attenuated hepatomegaly along with preserved liver function. Notably, S. japonicum infection induced high levels of hepatic Cx3cr1 expression, which was predominantly expressed by infiltrating macrophages. Loss of Cx3cr1 rendered macrophages preferentially towards M2 polarization, which then led to a characteristic switch of the host immune defense from a conventional Th1 to a typical Th2 response during acute schistosomiasis. This immune switch caused by Cx3cr1 deficiency was probably associated with enhanced STAT6/PPAR-γ signaling and increased expression of indoleamine 2,3-dioxygenase (IDO), an enzyme that promotes M2 polarization of macrophages. Taken together, our data provide evidence suggesting that CX3CR1 could be a viable therapeutic target for treatment of acute schistosomiasis.

Highlighted Article: A reduction in CX3CR1 signaling provides protection for mice against pro-inflammatory responses and hepatic granuloma formation during acute schistosomiasis.