Interaction of GATA-3/T-bet transcription factors regulates expression of sialyl Lewis X homing receptors on Th1/Th2 lymphocytes

Histone deacetylase inhibitors: targeting epigenetic regulation in the treatment of acute leukemia

Acute leukemia (AL) is a rare yet perilous malignancy. Currently, the primary treatment for AL involves combination chemotherapy as the cornerstone of comprehensive measures, alongside hematopoietic stem cell transplantation as a radical approach. However, despite these interventions, mortality rates remain high, particularly among refractory/recurrent patients or elderly individuals with a poor prognosis. Acetylation, a form of epigenetic regulation, has emerged as a promising therapeutic avenue for treating AL. Recent studies have highlighted the potential of acetylation regulation as a novel treatment pathway. Histone deacetylase inhibitors (HDACis) play a pivotal role in modulating the differentiation and development of tumor cells through diverse pathways, simultaneously impacting the maturation and function of lymphocytes. HDACis demonstrate promise in enhancing survival rates and achieving a complete response in both acute myeloid leukemia and acute T-lymphoblastic leukemia patients. This article provides a comprehensive review of the advancements in HDACi therapy for AL, shedding light on its potential implications for clinical practice.

Stability and plasticity of regulatory T cells in health and disease

The mechanisms that negatively regulate inflammation upon a pathogenic stimulus are crucial for the maintenance of tissue integrity and organ function. T regulatory cells are one of the main drivers in controlling inflammation. The ability of T regulatory cells to adapt to different inflammatory cues and suppress inflammation is one of the relevant features of T regulatory cells. During this process, T regulatory cells express different transcription factors associated with their counterparts, Th helper cells, including Tbx21, GATA-3, Bcl6, and Rorc. The acquisition of this transcription factor helps the T regulatory cells to suppress and migrate to the different inflamed tissues. Additionally, the T regulatory cells have different mechanisms that preserve stability while acquiring a particular T regulatory cell subtype. This review focuses on describing T regulatory cell subtypes and the mechanisms that maintain their identity in health and diseases.

Analysis of FOXP3 DNA Methylation Patterns to Identify Functional FOXP3+ T-Cell Subpopulations

Human regulatory CD4⁺CD25⁺FOXP3⁺ T cells (Tregs) are involved in the suppression of immune responses and play important roles in the maintenance of self-tolerance and immune homeostasis. Abnormal Treg function may result in disease states of varying severity. As FOXP3-expressing Treg cells are phenotypically and functionally heterogeneous, the success of Treg therapies depends on the ability to reliably distinguish subpopulations of T cells bearing a Treg-like phenotype. Methylation of cytosines within CpG dinucleotides is an important epigenetic mechanism involved in regulation (and suppression) of gene expression. On the other hand, demethylation of regulatory DNA sequences, such as promoters and enhancers, is essential for initiation of gene transcription. This protocol shows that bisulfite sequencing (BS) distinguishes methylated and unmethylated cytosines within DNA and reveals the methylation status of individual CpGs in cells within each population, identifying functionally different FOXP3⁺ subpopulations.

Glycome Profiling of Cancer Cell Lines Cultivated in Physiological and Commercial Media

A complex physiological culture medium (Plasmax) was introduced recently, composed of nutrients and metabolites at concentrations normally found in human plasma to mimic the in vivo environment for cell line cultivation. As glycosylation has been proved to be involved in cancer development, it is necessary to investigate the glycan expression changes in media with different nutrients. In this study, a breast cancer cell line, MDA-MB-231BR, and a brain cancer cell line, CRL-1620, were cultivated in Plasmax and commercial media to reveal cell line glycosylation discrepancies prompted by nutritional environments. Glycomics analyses of cell lines were performed using LC-MS/MS. The expressions of multiple fucosylated N-glycans, such as HexNAc₄Hex₃DeoxyHex₁ and HexNAc₅Hex₃DeoxyHex₁, derived from both cell lines exhibited a significant increase in Plasmax. Among the O-glycans, significant differences were also observed. Both cell lines cultivated in EMEM had the lowest amounts of O-glycans expressed. The original work described the development of Plasmax, which improves colony formation, and resulted in transcriptomic and metabolomic alterations of cancer cell lines, while our results indicate that Plasmax can significantly impact protein glycosylation. This study also provides information to guide the selection of media for in vitro cancer cell glycomics studies.

The TH1 cell lineage-determining transcription factor T-bet suppresses TH2 gene expression by redistributing GATA3 away from TH2 genes

Lineage-determining transcription factors (LD-TFs) drive the differentiation of progenitor cells into a specific lineage. In CD4+ T cells, T-bet dictates differentiation of the TH1 lineage, whereas GATA3 drives differentiation of the alternative TH2 lineage. However, LD-TFs, including T-bet and GATA3, are frequently co-expressed but how this affects LD-TF function is not known. By expressing T-bet and GATA3 separately or together in mouse T cells, we show that T-bet sequesters GATA3 at its target sites, thereby removing GATA3 from TH2 genes. This redistribution of GATA3 is independent of GATA3 DNA binding activity and is instead mediated by the T-bet DNA binding domain, which interacts with the GATA3 DNA binding domain and changes GATA3's sequence binding preference. This mechanism allows T-bet to drive the TH1 gene expression program in the presence of GATA3. We propose that redistribution of one LD-TF by another may be a common mechanism that could explain how specific cell fate choices can be made even in the presence of other transcription factors driving alternative differentiation pathways.

Regulation of antitumor immunity by inflammation-induced epigenetic alterations

Chronic inflammation promotes tumor development, progression, and metastatic dissemination and causes treatment resistance. The accumulation of genetic alterations and loss of normal cellular regulatory processes are not only associated with cancer growth and progression but also result in the expression of tumor-specific and tumor-associated antigens that may activate antitumor immunity. This antagonism between inflammation and immunity and the ability of cancer cells to avoid immune detection affect the course of cancer development and treatment outcomes. While inflammation, particularly acute inflammation, supports T-cell priming, activation, and infiltration into infected tissues, chronic inflammation is mostly immunosuppressive. However, the main mechanisms that dictate the outcome of the inflammation-immunity interplay are not well understood. Recent data suggest that inflammation triggers epigenetic alterations in cancer cells and components of the tumor microenvironment. These alterations can affect and modulate numerous aspects of cancer development, including tumor growth, the metabolic state, metastatic spread, immune escape, and immunosuppressive or immunosupportive leukocyte generation. In this review, we discuss the role of inflammation in initiating epigenetic alterations in immune cells, cancer-associated fibroblasts, and cancer cells and suggest how and when epigenetic interventions can be combined with immunotherapies to improve therapeutic outcomes.

Epigenetic Regulation of Glycosylation

Expression of glycosylation-related genes (or glycogenes) is strictly regulated by transcription factors and epigenetic processes, both in normal and in pathological conditions. In fact, glycosylation is an essential mechanism through which proteins and lipids are modified to perform a variety of biological events, to adapt to environment, and to interact with microorganisms.Many glycogenes with a role in normal development are epigenetically regulated. Essential studies were performed in the brain, where expression of glycogenes like MGAT5B, B4GALNT1, and ST8Sia1 are under the control of histone modifications, and in the immune system, where expression of FUT7 is regulated by both DNA methylation and histone modifications. At present, epigenetic regulation of glycosylation is still poorly described under physiological conditions, since the majority of the studies were focused on cancer. In fact, virtually all types of cancers display aberrant glycosylation, because of both genetic and epigenetic modifications on glycogenes. This is also true for many other diseases, such as inflammatory bowel disease, diabetes, systemic lupus erythematosus, IgA nephropathy, multiple sclerosis, and cardiovascular diseases.A deeper knowledge in epigenetic regulation of glycogenes is essential, since research in this field could be helpful in finding novel and personalized therapeutics.

The contributory roles of histone deacetylases (HDACs) in hematopoiesis regulation and possibilities for pharmacologic interventions in hematologic malignancies

Although the definitive role of epigenetic modulations in a wide range of hematologic malignancies, spanning from leukemia to lymphoma and multiple myeloma, has been evidenced, few articles reviewed the task. Given the high accessibility of histone deacetylase (HDACs) to necessary transcription factors involved in hematopoiesis, this review aims to outline physiologic impacts of these enzymes in normal hematopoiesis, and also to outline the original data obtained from international research laboratories on their regulatory role in the differentiation and maturation of different hematopoietic lineages. Questions on how aberrant expression of HDACs contributes to the formation of hematologic malignancies are also responded, because these classes of enzymes have a respectable share in the development, progression, and recurrence of leukemia, lymphoma, and multiple myeloma. The last section provides a special focus on the therapeutic perspectiveof HDACs inhibitors, either as single agents or in a combined-modal strategy, in these neoplasms. In conclusion, optimizing the dose and the design of more patient-tailored inhibitors, while maintaining low toxicity against normal cells, will help improve clinical outcomes of HDAC inhibitors in hematologic malignancies.

Re-Programming Autoreactive T Cells Into T-Regulatory Type 1 Cells for the Treatment of Autoimmunity

Systemic delivery of peptide-major histocompatibility complex (pMHC) class II-based nanomedicines can re-program cognate autoantigen-experienced CD4+ T cells into disease-suppressing T-regulatory type 1 (TR1)-like cells. In turn, these TR1-like cells trigger the formation of complex regulatory cell networks that can effectively suppress organ-specific autoimmunity without impairing normal immunity. In this review, we summarize our current understanding of the transcriptional, phenotypic and functional make up of TR1-like cells as described in the literature. The true identity and direct precursors of these cells remain unclear, in particular whether TR1-like cells comprise a single terminally-differentiated lymphocyte population with distinct transcriptional and epigenetic features, or a collection of phenotypically different subsets sharing key regulatory properties. We propose that detailed transcriptional and epigenetic characterization of homogeneous pools of TR1-like cells will unravel this conundrum.

Cytokines and pregnancy: Potential regulation by histone deacetylases

Cytokines are important regulators of pregnancy and parturition. Aberrant expression of proinflammatory cytokines during pregnancy contributes towards preterm labor, pre-eclampsia, and gestational diabetes mellitus. The regulation of cytokine expression in human cells is highly complex, involving interactions between environment, transcription factors, and feedback mechanisms. Recent developments in epigenetic research have made tremendous advancements in exploring histone modifications as a key epigenetic regulator of cytokine expression and the effect of their signaling molecules on various organ systems in the human body. Histone acetylation and subsequent deacetylation by histone deacetylases (HDACs) are major epigenetic regulators of protein expression in the human body. The expression of various proinflammatory cytokines, their role in normal and abnormal pregnancy, and their epigenetic regulation via HDACs will be discussed in this review.

Comments on the ambiguity of selected surface markers, signaling pathways and omics profiles hampering the identification of myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSC) are important immune-regulatory cells but their identification remains difficult. Here, we provide a critical view on selected surface markers, transcriptional and translational pathways commonly used to identify MDSC by specific, their developmental origin and new possibilities by transcriptional or proteomic profiling. Discrimination of MDSC from their non-suppressive counterparts is a prerequisite for the development of successful therapies. Understanding the switch mechanisms that direct granulocytic and monocytic development into a pro-inflammatory or anti-inflammatory direction will be crucial for therapeutic strategies. Manipulation of these myeloid checkpoints are exploited by tumors and pathogens, such as M. tuberculosis (Mtb), HIV or SARS-CoV-2, that induce MDSC for immune evasion. Thus, specific markers for MDSC identification may reveal also novel molecular candidates for therapeutic intervention at the level of MDSC.

Interplay between cofactors and transcription factors in hematopoiesis and hematological malignancies

Hematopoiesis requires finely tuned regulation of gene expression at each stage of development. The regulation of gene transcription involves not only individual transcription factors (TFs) but also transcription complexes (TCs) composed of transcription factor(s) and multisubunit cofactors. In their normal compositions, TCs orchestrate lineage-specific patterns of gene expression and ensure the production of the correct proportions of individual cell lineages during hematopoiesis. The integration of posttranslational and conformational modifications in the chromatin landscape, nucleosomes, histones and interacting components via the cofactor–TF interplay is critical to optimal TF activity. Mutations or translocations of cofactor genes are expected to alter cofactor–TF interactions, which may be causative for the pathogenesis of various hematologic disorders. Blocking TF oncogenic activity in hematologic disorders through targeting cofactors in aberrant complexes has been an exciting therapeutic strategy. In this review, we summarize the current knowledge regarding the models and functions of cofactor–TF interplay in physiological hematopoiesis and highlight their implications in the etiology of hematological malignancies. This review presents a deep insight into the physiological and pathological implications of transcription machinery in the blood system.

A case of hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome with a novel frameshift variant in GATA3, p.W10Cfs40, lacks kidney malformation

Autosomal dominant hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome are typically diagnosed by manifestations of the three features with a positive family history. Our case carried a de novo variant in causative gene, GATA3, but presenting no renal dysplasia or family history. The phenotypic heterogeneity raises a caution for diagnosis.

Commentary on: The potency of lncRNA MALAT1/miR-155 in altering asthmatic Th1/Th2 balance by modulation of CTLA4

Asthma is a common, allergic respiratory disorder affecting over 350 million people worldwide. One of the key features of asthma is skewing of CD4+ cells toward Th2 responses. This promotes the production of cytokines like IL-4 that induce IgE production resulting in the hypersecretion of mucus and airway smooth muscle contraction. Understanding the factors that favor Th2 expansion in asthma would provide important insights into the underlying pathogenesis of this disorder. Asthma research has focused on signaling pathways that control the transcription of key asthma-related genes. However, increasing evidence shows that post-transcriptional factors also determine CD4+ cell fate and the enhancement of allergic airway responses. A recent paper published by Liang et al. (Bioscience Reports (2020) 40, https://doi.org/10.1042/BSR20190397) highlights a novel role for the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in Th2 development in asthma. MALAT1 modulates several biological processes including alternative splicing, epigenetic modification and gene expression. It is one of the most highly expressed lncRNAs in normal tissues and MALAT1 levels correlate with poor clinical outcomes in cancer. The mechanisms of action of MALAT1 in tumor progression and metastasis remain unclear and even less is known about its effects in inflammatory disease states like asthma. The work of Liang et al. demonstrates heightened MALAT1 expression in asthma and further shows that this lncRNA targets miR-155 to promote Th2 differentiation in this disease. This insight sets the stage for future studies to examine how MALAT1 manipulation could deter allergic immune responses in asthmatic airways.

ARID1a Associates with Lymphoid-Restricted Transcription Factors and Has an Essential Role in T Cell Development

Maturation of lymphoid cells is controlled by the action of stage and lineage-restricted transcription factors working in concert with the general transcription and chromatin remodeling machinery to regulate gene expression. To better understand this functional interplay, we used Biotin Identification in human embryonic kidney cells to identify proximity interaction partners for GATA3, TCF7 (TCF1), SPI1, HLF, IKZF1, PAX5, ID1, and ID2. The proximity interaction partners shared among the lineage-restricted transcription factors included ARID1a, a BRG1-associated factor complex component. CUT&RUN analysis revealed that ARID1a shared binding with TCF7 and GATA3 at a substantial number of putative regulatory elements in mouse T cell progenitors. In support of an important function for ARID1a in lymphocyte development, deletion of Arid1a in early lymphoid progenitors in mice resulted in a pronounced developmental arrest in early T cell development with a reduction of CD4⁺CD8⁺ cells and a 20-fold reduction in thymic cellularity. Exploring gene expression patterns in DN3 cells from Wt and Arid1a-deficient mice suggested that the developmental block resided in the DN3a to DN3b transition, indicating a deficiency in β-selection. Our work highlights the critical importance of functional interactions between stage and lineage-restricted factors and the basic transcription machinery during lymphocyte differentiation.

Role of HDACs in normal and malignant hematopoiesis

Normal hematopoiesis requires the accurate orchestration of lineage-specific patterns of gene expression at each stage of development, and epigenetic regulators play a vital role. Disordered epigenetic regulation has emerged as a key mechanism contributing to hematological malignancies. Histone deacetylases (HDACs) are a series of key transcriptional cofactors that regulate gene expression by deacetylation of lysine residues on histone and nonhistone proteins. In normal hematopoiesis, HDACs are widely involved in the development of various lineages. Their functions involve stemness maintenance, lineage commitment determination, cell differentiation and proliferation, etc. Deregulation of HDACs by abnormal expression or activity and oncogenic HDAC-containing transcriptional complexes are involved in hematological malignancies. Currently, HDAC family members are attractive targets for drug design, and a variety of HDAC-based combination strategies have been developed for the treatment of hematological malignancies. Drug resistance and limited therapeutic efficacy are key issues that hinder the clinical applications of HDAC inhibitors (HDACis). In this review, we summarize the current knowledge of how HDACs and HDAC-containing complexes function in normal hematopoiesis and highlight the etiology of HDACs in hematological malignancies. Moreover, the implication and drug resistance of HDACis are also discussed. This review presents an overview of the physiology and pathology of HDACs in the blood system.

Sialyl Glycan Expression on T Cell Subsets in Asthma: a correlation with disease severity and blood parameters

Memory T helper (Th) and regulatory T (Treg) cells play key roles in asthma. Certain sialyl carbohydrate determinants for selectins profoundly affect the migratory properties of memory Th cells, and the suppressive function of Treg cells. Previous studies have shown that the proportion of CCR4⁺ memory Th cells expressing sialyl 6-sulfo Lewis X (Le^X) is elevated in asthma patients. We aim to investigate the roles of different sialyl glycans on T cell subsets in asthma. Using flow cytometry, we assessed the expression of three sialyl glycans, sialyl 6-sulfo Le^X, cyclic sialyl 6-sulfo Le^X, and sialyl Le^X on memory Th and Treg cells, in the peripheral blood of asthmatic children. We also assessed the relationships between glycan-expressing cell percentages and asthma clinical parameters. Compared with controls, asthmatic children showed higher proportions of memory Th cells expressing sialyl Le^X and sialyl 6-sulfo Le^X. The proportions of memory Th cells with sialyl 6-sulfo Le^X and cyclic sialyl 6-sulfo Le^X expression in asthmatic children correlated with absolute eosinophil count and IgE level, respectively. Children with moderate-to-severe asthma had lower numbers of sialyl Le^X positive Treg cells. Our study suggests that sialyl glycans on T cells may play important roles in the pathogenesis of asthma.

An evolutionarily-conserved Wnt3/β-catenin/Sp5 feedback loop restricts head organizer activity in Hydra

Polyps of the cnidarian Hydra maintain their adult anatomy through two developmental organizers, the head organizer located apically and the foot organizer basally. The head organizer is made of two antagonistic cross-reacting components, an activator, driving apical differentiation and an inhibitor, preventing ectopic head formation. Here we characterize the head inhibitor by comparing planarian genes down-regulated when β-catenin is silenced to Hydra genes displaying a graded apical-to-basal expression and an up-regulation during head regeneration. We identify Sp5 as a transcription factor that fulfills the head inhibitor properties: leading to a robust multiheaded phenotype when knocked-down in Hydra, acting as a transcriptional repressor of Wnt3 and positively regulated by Wnt/β-catenin signaling. Hydra and zebrafish Sp5 repress Wnt3 promoter activity while Hydra Sp5 also activates its own expression, likely via β-catenin/TCF interaction. This work identifies Sp5 as a potent feedback loop inhibitor of Wnt/β-catenin signaling, a function conserved across eumetazoan evolution.

Hydra regenerate various body parts on amputation by activation of the appropriate organiser, but how head formation is controlled is unclear. Here, the authors identify the transcription factor Sp5 as restricting head formation, by being activated by beta-catenin and then acting as a repressor of Wnt3.

Molecular Markers Distinguishing T Cell Subtypes With TSDR Strand-Bias Methylation

Human regulatory CD4⁺CD25⁺FOXP3⁺ T cells (Treg) play important roles in the maintenance of self-tolerance and immune homeostasis in various disease settings and are also involved in the suppression of effective immune responses. These cells are heterogeneous in phenotype and function, and the ability to reliably distinguish between various FOXP3-expressing subpopulations can affect the development of successful therapies. This study demonstrates that hypomethylated CpG sites, present in four regions of the FOXP3 locus, CAMTA1 and FUT7 gene regions, can be used to distinguish several subsets of Treg from conventional CD4⁺ T lymphocytes (Tcon) in donors of both genders. We describe a previously unreported strand-bias hemimethylation pattern in FOXP3 promoter and TSDR in donors of both genders, with the coding strand being demethylated within promoter and methylated within TSDR in all CD4⁺ lymphocyte subtypes, whereas the template strand follows the previously described pattern of methylation with both regions being more demethylated in Treg subtypes and mostly methylated in Tcon. This strand-specific approach within the TSDR may prove to be instrumental in correctly defining Treg subsets in health and in disease.

An ancient family of lytic polysaccharide monooxygenases with roles in arthropod development and biomass digestion

Thermobia domestica belongs to an ancient group of insects and has a remarkable ability to digest crystalline cellulose without microbial assistance. By investigating the digestive proteome of Thermobia, we have identified over 20 members of an uncharacterized family of lytic polysaccharide monooxygenases (LPMOs). We show that this LPMO family spans across several clades of the Tree of Life, is of ancient origin, and was recruited by early arthropods with possible roles in remodeling endogenous chitin scaffolds during development and metamorphosis. Based on our in-depth characterization of Thermobia's LPMOs, we propose that diversification of these enzymes toward cellulose digestion might have endowed ancestral insects with an effective biochemical apparatus for biomass degradation, allowing the early colonization of land during the Paleozoic Era. The vital role of LPMOs in modern agricultural pests and disease vectors offers new opportunities to help tackle global challenges in food security and the control of infectious diseases.

C/EBPδ drives interactions between human MAIT cells and endothelial cells that are important for extravasation

Many mediators and regulators of extravasation by bona fide human memory-phenotype T cells remain undefined. Mucosal-associated invariant T (MAIT) cells are innate-like, antibacterial cells that we found excelled at crossing inflamed endothelium. They displayed abundant selectin ligands, with high expression of FUT7 and ST3GAL4, and expressed CCR6, CCR5, and CCR2, which played non-redundant roles in trafficking on activated endothelial cells. MAIT cells selectively expressed CCAAT/enhancer-binding protein delta (C/EBPδ). Knockdown of C/EBPδ diminished expression of FUT7, ST3GAL4 and CCR6, decreasing MAIT cell rolling and arrest, and consequently the cells' ability to cross an endothelial monolayer in vitro and extravasate in mice. Nonetheless, knockdown of C/EBPδ did not affect CCR2, which was important for the step of transendothelial migration. Thus, MAIT cells demonstrate a program for extravasastion that includes, in part, C/EBPδ and C/EBPδ-regulated genes, and that could be used to enhance, or targeted to inhibit T cell recruitment into inflamed tissue.

BRACHYURY directs histone acetylation to target loci during mesoderm development

T-box transcription factors play essential roles in multiple aspects of vertebrate development. Here, we show that cooperative function of BRACHYURY (T) with histone-modifying enzymes is essential for mouse embryogenesis. A single point mutation (T^Y88A) results in decreased histone 3 lysine 27 acetylation (H3K27ac) at T target sites, including the T locus, suggesting that T autoregulates the maintenance of its expression and functions by recruiting permissive chromatin modifications to putative enhancers during mesoderm specification. Our data indicate that T mediates H3K27ac recruitment through a physical interaction with p300. In addition, we determine that T plays a prominent role in the specification of hematopoietic and endothelial cell types. Hematopoietic and endothelial gene expression programs are disrupted in T^Y88A mutant embryos, leading to a defect in the differentiation of hematopoietic progenitors. We show that this role of T is mediated, at least in part, through activation of a distal Lmo2 enhancer.

An integrative method to decode regulatory logics in gene transcription

Modeling of transcriptional regulatory networks (TRNs) has been increasingly used to dissect the nature of gene regulation. Inference of regulatory relationships among transcription factors (TFs) and genes, especially among multiple TFs, is still challenging. In this study, we introduced an integrative method, LogicTRN, to decode TF–TF interactions that form TF logics in regulating target genes. By combining cis-regulatory logics and transcriptional kinetics into one single model framework, LogicTRN can naturally integrate dynamic gene expression data and TF-DNA-binding signals in order to identify the TF logics and to reconstruct the underlying TRNs. We evaluated the newly developed methodology using simulation, comparison and application studies, and the results not only show their consistence with existing knowledge, but also demonstrate its ability to accurately reconstruct TRNs in biological complex systems.

Existing transcriptional regulatory networks models fall short of deciphering the cooperation between multiple transcription factors on dynamic gene expression. Here the authors develop an integrative method that combines gene expression and transcription factor-DNA binding data to decode transcription regulatory logics.

Interplay Between Inflammation and Epigenetic Changes in Cancer

Immune responses can suppress tumorigenesis, but also contribute to cancer initiation and progression suggesting a complex interaction between the immune system and cancer. Epigenetic alterations, which are heritable changes in gene expression without changes to the DNA sequence, also play a role in carcinogenesis through silencing expression of tumor suppressor genes and activating oncogenic signaling. Interestingly, epithelial cells at sites of chronic inflammation undergo DNA methylation alterations that are similar to those present in cancer cells, suggesting that inflammation may initiate cancer-specific epigenetic changes in epithelial cells. Furthermore, epigenetic changes occur during immune cell differentiation and participate in regulating the immune response, including the regulation of inflammatory cytokines. Cancer cells utilize epigenetic silencing of immune-related genes to evade the immune response. This chapter will detail the interactions between inflammation and epigenetics in tumor initiation, promotion, and immune evasion and how these connections are being leveraged in cancer prevention and treatment.

Transcription factor c-jun regulates β3Gn-T8 expression in gastric cancer cell line SGC-7901

Aberrant glycosylation, a common feature of malignant alteration, is partly due to changes in the expression of glycosyltransferases, including β1,3-N-acetyl-glucosaminyltrans-ferase 8 (β3Gn‑T8), which synthesizes poly-N-acetyllactosamine (poly-LacNAc) chains on β1,6 branched N‑glycans. Although the role of β3Gn‑T8 in tumors has been reported, the regulation of β3Gn‑T8 expression, however, is still poorly understood. In the present study, we used three online bioinformatic software tools to identify multiple c‑jun binding sites in the promoter of the β3Gn‑T8 gene. Using luciferase reporter assay, chromatin immunoprecipitation (ChIP) analysis, RT‑PCR and western blot analysis, we revealed that c‑jun could bind to and activate the β3Gn‑T8 promoter, thus upregulating β3Gn‑T8 expression. This was also confirmed by changes in β3Gn‑T8 activity as demonstrated by flow cytometry, immunofluorescence and lectin blot analysis using LEA lectin. Moreover, expression of glycoprotein HG‑CD147, the substrate of β3Gn‑T8, was also regulated by c‑jun. In addition, c‑jun and β3Gn‑T8 were more highly expressed in the gastric cancer tissues when compared to these levels in the adjacent non‑tumor gastric tissues, and β3Gn‑T8 expression was positively correlated with c‑jun expression. These results suggest that c‑jun plays a significant role in regulating the expression of β3Gn‑T8 in the SGC‑7901 cell line and may be involved in the development of malignancy via the activity of β3Gn‑T8.

Transcriptional regulator Bhlhe40 works as a cofactor of T-bet in the regulation of IFN-γ production in iNKT cells

Invariant natural killer T (iNKT) cells are a subset of innate-like T cells that act as important mediators of immune responses. In particular, iNKT cells have the ability to immediately produce large amounts of IFN-γ upon activation and thus initiate immune responses in various pathological conditions. However, molecular mechanisms that control IFN-γ production in iNKT cells are not fully understood. Here, we report that basic helix-loop-helix transcription factor family, member e40 (Bhlhe40), is an important regulator for IFN-γ production in iNKT cells. Bhlhe40 is highly expressed in stage 3 thymic iNKT cells and iNKT1 subsets, and the level of Bhlhe40 mRNA expression is correlated with Ifng mRNA expression in the resting state. Although Bhlhe40-deficient mice show normal iNKT cell development, Bhlhe40-deficient iNKT cells show significant impairment of IFN-γ production and antitumor effects. Bhlhe40 alone shows no significant effects on Ifng promoter activities but contributes to enhance T-box transcription factor Tbx21 (T-bet)-mediated Ifng promoter activation. Chromatin immunoprecipitation analysis revealed that Bhlhe40 accumulates in the T-box region of the Ifng locus and contributes to histone H3-lysine 9 acetylation of the Ifng locus, which is impaired without T-bet conditions. These results indicate that Bhlhe40 works as a cofactor of T-bet for enhancing IFN-γ production in iNKT cells.

Deletion of Smad3 improves cardiac allograft rejection in mice

T cells play a critical role in acute allograft rejection. TGF-β/Smad3 signaling is a key pathway in regulating T cell development. We report here that Smad3 is a key transcriptional factor of TGF-β signaling that differentially regulates T cell immune responses in a mouse model of cardiac allograft rejection in which donor hearts from BALB/c mice were transplanted into Smad3 knockout (KO) and wild type (WT) mice. Results showed that the cardiac allograft survival was prolonged in Smad3 KO recipients. This allograft protection was associated with a significant inhibition of proinflammatory cytokines (IL-1β, TNF-α, and MCP-1) and infiltration of neutrophils, CD3⁺ T cells, and F4/80⁺ macrophages. Importantly, deletion of Smad3 markedly suppressed T-bet and IFN-γ while enhancing GATA3 and IL-4 expression, resulting in a shift from the Th1 to Th2 immune responses. Furthermore, mice lacking Smad3 were also protected from the Th17-mediated cardiac injury, although the regulatory T cell (Treg) response was also suppressed. In conclusion, Smad3 is an immune regulator in T cell-mediated cardiac allograft rejection. Loss of Smad3 results in a shift from Th1 to Th2 but suppressing Th17 immune responses. Thus, modulation of TGF-β/Smad3 signaling may be a novel therapy for acute allograft rejection.

Identification of global regulators of T-helper cell lineage specification

Background

Activation and differentiation of T-helper (Th) cells into Th1 and Th2 types is a complex process orchestrated by distinct gene activation programs engaging a number of genes. This process is crucial for a robust immune response and an imbalance might lead to disease states such as autoimmune diseases or allergy. Therefore, identification of genes involved in this process is paramount to further understand the pathogenesis of, and design interventions for, immune-mediated diseases.

Methods

We aimed at identifying protein-coding genes and long non-coding RNAs (lncRNAs) involved in early differentiation of T-helper cells by transcriptome analysis of cord blood-derived naïve precursor, primary and polarized cells.

Results

Here, we identified lineage-specific genes involved in early differentiation of Th1 and Th2 subsets by integrating transcriptional profiling data from multiple platforms. We have obtained a high confidence list of genes as well as a list of novel genes by employing more than one profiling platform. We show that the density of lineage-specific epigenetic marks is higher around lineage-specific genes than anywhere else in the genome. Based on next-generation sequencing data we identified lineage-specific lncRNAs involved in early Th1 and Th2 differentiation and predicted their expected functions through Gene Ontology analysis. We show that there is a positive trend in the expression of the closest lineage-specific lncRNA and gene pairs. We also found out that there is an enrichment of disease SNPs around a number of lncRNAs identified, suggesting that these lncRNAs might play a role in the etiology of autoimmune diseases.

Conclusion

The results presented here show the involvement of several new actors in the early differentiation of T-helper cells and will be a valuable resource for better understanding of autoimmune processes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0237-0) contains supplementary material, which is available to authorized users.

Myeloid Zinc Finger 1 (MZF-1) Regulates Expression of the CCN2/CTGF and CCN3/NOV Genes in the Hematopoietic Compartment

Connective Tissue Growth Factor (CCN2/CTGF) and Nephroblastoma Overexpressed (CCN3/NOV) execute key functions within the hematopoietic compartment. Both are abundant in the bone marrow stroma, which is a niche for hematopoiesis and supports marrow function. Roles for 1,25-dihydroxyvitamin D3 (calcitriol) and all-trans retinoic acid in the bone marrow have also been elucidated. Interestingly, some of the annotated roles of these vitamins overlap with established functions of CCN2 and CCN3. Yet, no factor has been identified that unifies these observations. In this study, we report the regulation of the CTGF and NOV genes by Myeloid Zinc Finger-1 (MZF-1), a hematopoietic transcription factor. We show the interaction of MZF-1 with the CTGF and NOV promoters in several cell types. Up-regulation of MZF-1 via calcitriol and vitamin A induces expression of CTGF and NOV, implicating a role for these vitamins in the functions of these two genes. Lastly, knockdown of MZF1 reduces levels of CTGF and NOV. Collectively, our results argue that MZF-1 regulates the CTGF and NOV genes in the hematopoietic compartment, and may be involved in their respective functions in the stroma.

GATA-dependent transcriptional and epigenetic control of cardiac lineage specification and differentiation

Heart progenitor cells differentiate into various cell types including pacemaker and working cardiomyocytes. Cell-type specific gene expression is achieved by combinatorial interactions between tissue-specific transcription factors (TFs), co-factors, and chromatin remodelers and DNA binding elements in regulatory regions. Dysfunction of these transcriptional networks may result in congenital heart defects. Functional analysis of the regulatory DNA sequences has contributed substantially to the identification of the transcriptional network components and combinatorial interactions regulating the tissue-specific gene programs. GATA TFs have been identified as central players in these networks. In particular, GATA binding elements have emerged as a platform to recruit broadly active histone modification enzymes and cell-type-specific co-factors to drive cell-type-specific gene programs. Here, we discuss the role of GATA factors in cell fate decisions and differentiation in the developing heart.

Identification of two regulatory elements controlling Fucosyltransferase 7 transcription in murine CD4+ T cells

Fucosyltransferase VII encoded by the gene Fut7 is essential in CD4(+) T cells for the generation of E- and P-selectin ligands (E- and P-lig) which facilitate recruitment of lymphocytes into inflamed tissues and into the skin. This study aimed to identify regulatory elements controlling the inducible Fut7 expression in CD4(+) T cells that occurs upon activation and differentiation of naive T cells into effector cells. Comparative analysis of the histone modification pattern in non-hematopoetic cells and CD4(+) T cell subsets revealed a differential histone modification pattern within the Fut7 locus including a conserved non-coding sequence (CNS) identified by cross-species conservation comparison suggesting that regulatory elements are confined to this region. Cloning of the CNS located about 500 bp upstream of the Fut7 locus, into a luciferase reporter vector elicited reporter activity after transfection of the αβ-WT T cell line, but not after transfection of primary murine CD4(+) Th1 cells. As quantification of different Fut7 transcripts revealed a predominance of transcripts lacking the first exons in primary Th1 cells we searched for an alternative promoter. Cloning of an intragenic region spanning a 1kb region upstream of exon 4 into an enhancer-containing vector indeed elicited promoter activity. Interestingly, also the CNS enhanced activity of this intragenic minimal promoter in reporter assays in primary Th1 cells suggesting that both elements interact in primary CD4(+) T cells to induce Fut7 transcription.

Histone methyltransferase and histone methylation in inflammatory T-cell responses

During immune responses, T cells require tightly controlled expression of transcriptional programs to regulate the balance between beneficial and harmful immunity. These transcriptional programs are critical for the lineage specification of effector T cells, the production of effector cytokines and molecules, and the development and maintenance of memory T cells. An emerging theme is that post-translational modification of histones by methylation plays an important role in orchestrating the expression of transcriptional programs in T cells. In this article, we provide a broad overview of histone methylation signatures for effector molecules and transcription factors in T cells, and the functional importance of histone methyltransferases in regulating T-cell immune responses.

Defining the functional boundaries of the murine α1,3-fucosyltransferase Fut7 reveals a remarkably compact locus

Fut7 encodes an α1,3-fucosyltransferase critical for biosynthesis of glycan ligands for all three selectins. Consistent with this function, Fut7 expression is limited to hematopoietic cells and high endothelial cells which express selectin ligands. Mechanisms that govern Fut7 expression are poorly defined. To begin to understand the molecular genetic basis for transcriptional regulation of Fut7, a transgenic, gain-of-function, genetic complementation approach in mice was used to define the "functional boundaries" of the murine Fut7 locus, defined here as any uninterupted stretch of genomic DNA that contains all cis-acting genetic elements essential for accurate physiologic expression. A 12.7-kb contiguous genomic interval, which lies completely between the highly conserved flanking Npdc1 and Abca2 loci on chromosome 2 and which contains the complete transcriptional unit plus ∼7.4 kb upstream of the transcriptional start site and ∼2 kb downstream of the transcriptional termination and polyadenylation sites, was used as a transgene (Tg) on a Fut7 null background. Tg+ mice exhibited restoration of Fut7 gene expression and physiologic levels of selectin ligand expression and function on neutrophils, activated T cells, and high endothelial cells and corrected the functional defects in these cells found in Fut7 null mice without leading to detectable expression of Fut7 in normally non-expressing tissues. These results demonstrate that all genetic information essential for appropriate and selective expression of Fut7 in diverse cell types and in response to distinct developmental signals is contained within this comparatively small genetic region.

Transcriptional activation of Mina by Sp1/3 factors

Mina is an epigenetic gene regulatory protein known to function in multiple physiological and pathological contexts, including pulmonary inflammation, cell proliferation, cancer and immunity. We showed previously that the level of Mina gene expression is subject to natural genetic variation linked to 21 SNPs occurring in the Mina 5′ region [1]. In order to explore the mechanisms regulating Mina gene expression, we set out to molecularly characterize the Mina promoter in the region encompassing these SNPs. We used three kinds of assays – reporter, gel shift and chromatin immunoprecipitation – to analyze a 2 kb genomic fragment spanning the upstream and intron 1 regions flanking exon 1. Here we discovered a pair of Mina promoters (P1 and P2) and a P1-specific enhancer element (E1). Pharmacologic inhibition and siRNA knockdown experiments suggested that Sp1/3 transcription factors trigger Mina expression through additive activity targeted to a cluster of four Sp1/3 binding sites forming the P1 promoter. These results set the stage for comprehensive analysis of Mina gene regulation from the context of tissue specificity, the impact of inherited genetic variation and the nature of upstream signaling pathways.

Functional evaluation of activation-dependent alterations in the sialoglycan composition of T cells

Sialic acids (Sias) are often conjugated to the termini of cellular glycans and are key mediators of cellular recognition. Sias are nine-carbon acidic sugars, and, in vertebrates, the major species are N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), differing in structure at the C5 position. Previously, we described a positive feedback loop involving regulation of Neu5Gc expression in mouse B cells. In this context, Neu5Gc negatively regulated B-cell proliferation, and Neu5Gc expression was suppressed upon activation. Similarly, resting mouse T cells expressed principally Neu5Gc, and Neu5Ac was induced upon activation. In the present work, we used various probes to examine sialoglycan expression by activated T cells in terms of the Sia species expressed and the linkages of Sias to glycans. Upon T-cell activation, sialoglycan expression shifted from Neu5Gc to Neu5Ac, and the linkage shifted from α2,6 to α2,3. These changes altered the expression levels of sialic acid-binding immunoglobulin-like lectin (siglec) ligands. Expression of sialoadhesin and Siglec-F ligands increased, and that of CD22 ligands decreased. Neu5Gc exerted a negative effect on T-cell activation, both in terms of the proliferative response and in the context of activation marker expression. Suppression of Neu5Gc expression in mouse T and B cells prevented the development of nonspecific CD22-mediated T cell-B cell interactions. Our results suggest that an activation-dependent shift from Neu5Gc to Neu5Ac and replacement of α2,6 by α2,3 linkages may regulate immune cell interactions at several levels.

Human multipotent adult progenitor cells transcriptionally regulate fucosyltransferase VII

BACKGROUND AIMS

Targeted recruitment of leukocytes to sites of inflammation is a crucial event in normal host defense against pathogens, and attachment to and rolling on activated endothelial cells is a prerequisite first step for eventual leukocyte extravasation into sites of inflammation. These key events are mediated by interactions between glycosylated ligands expressed on leukocytes and selectins expressed on activated endothelium. Cell surface expression of selectin ligands on leukocytes is regulated by the rate-limiting enzyme fucosyltransferase VII (Fut7), and in its absence extravasation of leukocytes is severely inhibited. Multipotent adult progenitor cells (MAPCs) are an adherent cell population isolated from adult bone marrow. Intravenous administration of MAPCs provided functional improvement in multiple pre-clinical models of injury or disease, but the mechanisms by which these outcomes were achieved remain poorly understood.

METHODS

In vitro cell analysis studies including fluorescence-activated cell sorting, messenger RNA analysis, T-cell proliferation assays and endothelial cell binding assays were performed.

RESULTS

The in vitro cell analysis studies characterized the ability of MAPCs to secrete factors that transcriptionally attenuate expression of Fut7 in T cells, blocking the terminal fucosylation event in the biosynthesis of selectin ligands and reducing T-cell binding to endothelial cells.

CONCLUSIONS

This study presents the first example of a distinct regulatory mechanism involving transcriptional down-regulation of Fut7 by MAPCs that could modulate the trafficking behavior of T cells in vivo.

Epigenetic control of cytokine gene expression: regulation of the TNF/LT locus and T helper cell differentiation

Epigenetics encompasses transient and heritable modifications to DNA and nucleosomes in the native chromatin context. For example, enzymatic addition of chemical moieties to the N-terminal "tails" of histones, particularly acetylation and methylation of lysine residues in the histone tails of H3 and H4, plays a key role in regulation of gene transcription. The modified histones, which are physically associated with gene regulatory regions that typically occur within conserved noncoding sequences, play a functional role in active, poised, or repressed gene transcription. The "histone code" defined by these modifications, along with the chromatin-binding acetylases, deacetylases, methylases, demethylases, and other enzymes that direct modifications resulting in specific patterns of histone modification, shows considerable evolutionary conservation from yeast to humans. Direct modifications at the DNA level, such as cytosine methylation at CpG motifs that represses promoter activity, are another highly conserved epigenetic mechanism of gene regulation. Furthermore, epigenetic modifications at the nucleosome or DNA level can also be coupled with higher-order intra- or interchromosomal interactions that influence the location of regulatory elements and that can place them in an environment of specific nucleoprotein complexes associated with transcription. In the mammalian immune system, epigenetic gene regulation is a crucial mechanism for a range of physiological processes, including the innate host immune response to pathogens and T cell differentiation driven by specific patterns of cytokine gene expression. Here, we will review current findings regarding epigenetic regulation of cytokine genes important in innate and/or adaptive immune responses, with a special focus upon the tumor necrosis factor/lymphotoxin locus and cytokine-driven CD4+ T cell differentiation into the Th1, Th2, and Th17 lineages.

Genomics of lymphoid malignancies reveal major activation pathways in lymphocytes

Breakdown of tolerance leads to autoimmunity due to emergence of autoreactive T or B cell clones. Autoimmune diseases predispose to lymphoid malignancies and lymphoid malignancies, conversely, can manifest as autoimmune diseases. While it has been clear for a long time that a competitive advantage and uncontrolled growth of lymphocytes contribute to the pathogenesis of both lymphoid malignancies as well as autoimmune diseases, the overlap of the underlying mechanisms has been less well described. Next generation sequencing has led to massive expansion of the available genomic data in many diseases over the last five years. These data allow for comparison of the molecular pathogenesis between autoimmune diseases and lymphoid malignancies. Here, we review the similarities between autoimmune diseases and lymphoid malignancies: 1) Both, autoimmune diseases and lymphoid malignancies are characterized by activation of the same T and B cell signaling pathways, and dysregulation of these pathways can occur through genetic or epigenetic events. 2) In both scenarios, clonal and subclonal evolution of lymphocytes contribute to disease. 3) Development of both diseases not only depends on T or B cell intrinsic factors, such as germline or somatic mutations, but also on environmental factors. These include infections, the presence of other immune cells in the microenvironment, and the cytokine milieu. A better mechanistic understanding of the parallels between lymphomagenesis and autoimmunity may help the development of precision treatment strategies with rationally designed therapeutic agents.

Roles of repressive epigenetic machinery in lineage decision of T cells

DNA methylation and histone modifications are central to epigenetic gene regulation, which has been shown to play a crucial role in development. Epigenetics has often been discussed in the context of the maintenance of cell identity because of the heritable nature of gene expression status. Indeed, crucial roles of the epigenetic machinery in establishment and maintenance of particular lineages during early development have been well documented. However, unexpected observation of a developmental plasticity retained in mature T lymphocytes, in particular in CD4(+) T-cell subsets, by recent studies is accelerating studies that focus on roles of each epigenetic pathway in cell fate decisions of T lymphocytes. Here, we focus on the repressive epigenetic machinery, i.e. DNA methylation, histone deacetylation, H3K9 methylation and Polycomb repressive complexes, and briefly review the studies examining the role of these mechanisms during T-lymphocyte differentiation. We also discuss the current challenges faced when analysing the function of the epigenetic machinery and potential directions to overcome the problems.

Status epilepticus triggers early and late alterations in brain-derived neurotrophic factor and NMDA glutamate receptor Grin2b DNA methylation levels in the hippocampus

Status epilepticus (SE) triggers abnormal expression of genes in the hippocampus, such as glutamate receptor subunit epsilon-2 (Grin2b/Nr2b) and brain-derived neurotrophic factor (Bdnf), that is thought to occur in temporal lobe epilepsy (TLE). We examined the underlying DNA methylation mechanisms and investigated whether these mechanisms contribute to the expression of these gene targets in the epileptic hippocampus. Experimental TLE was provoked by kainic acid-induced SE. Bisulfite sequencing analysis revealed increased Grin2b/Nr2b and decreased Bdnf DNA methylation levels that corresponded to decreased Grin2b/Nr2b and increased Bdnf mRNA and protein expression in the epileptic hippocampus. Blockade of DNA methyltransferase (DNMT) activity with zebularine decreased global DNA methylation levels and reduced Grin2b/Nr2b, but not Bdnf, DNA methylation levels. Interestingly, we found that DNMT blockade further decreased Grin2b/Nr2b mRNA expression whereas GRIN2B protein expression increased in the epileptic hippocampus, suggesting that a posttranscriptional mechanism may be involved. Using chromatin immunoprecipitation analysis we found that DNMT inhibition restored the decreases in AP2alpha transcription factor levels at the Grin2b/Nr2b promoter in the epileptic hippocampus. DNMT inhibition increased field excitatory postsynaptic potential in hippocampal slices isolated from epileptic rats. Electroencephalography (EEG) monitoring confirmed that DNMT inhibition did not significantly alter the disease course, but promoted the latency to seizure onset or SE. Thus, DNA methylation may be an early event triggered by SE that persists late into the epileptic hippocampus to contribute to gene expression changes in TLE.

Aberrant histone modifications in peripheral blood mononuclear cells from patients with Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP), the most common type of leukocytoclastic vasculitis, is caused by T cell-mediated autoimmune reactions. In this study, we analyze histone modification patterns in peripheral blood mononuclear cells (PBMCs) of HSP patients, and investigate the expression levels of inflammatory cytokines (IFN-γ, IL-2, IL-4, IL-6 and IL-13), transcription factors (T-bet, GATA-3 and TIM-1) and chemokines (CXCL4 and CXCL10) in HSP patients. Our results show that histone H3 acetylation and methylation are significantly enhanced in PBMCs from HSP patients. We also demonstrate specifically that marked increases in histone H3 acetylation and H3 lysine 4 trimethylation occur at the IL-4 loci in these patients. In addition, the expression levels of IL-4, IL-6, IL-13, GATA-3, TIM-1 and CXCL4 are also increased. These findings suggest that abnormal histone modifications are present in the PBMCs of patients with HSP, possibly contributing to the activation of pathological immune responses associated with HSP.

Characterization of bovine FUT7 furthers understanding of FUT7 evolution in mammals

Background

The Sialyl-Lewis X (Sle^x) is a well-known glycan structure involved in leukocyte homing and recruitment to inflammatory sites. SLe^x is well conserved among species and is mainly synthesized by FucT-VII in vertebrates. The enzyme responsible for its biosynthesis in cattle was not known.

Results

We cloned a cDNA sequence encoding bovine α3-fucosyltransferase VII that shares 83% identity with its human counterpart. Located at the BTA 11 telomeric region, the 1029 bp open reading frame is spread over two different exons, E1 which also contains the unique 5’-untranslated region and E2 which includes the entire 3’-untranslated region. The bfut7 expression pattern is restricted to thymus and spleen. A single transcript leading to the synthesis of a 342 aa protein was identified. The encoded fucosyltransferase, produced as a recombinant enzyme in COS-1 cells, was shown to be specifically responsible for SLe^x synthesis in cattle. In addition, we showed that the gene promoter evolved from fish to mammals towards a complex system related to the immune system. But beyond the fact that the gene regulation seems to be conserved among mammals, we also identified 7 SNPs including 3 missense mutations in the coding region in a small panel of animals.

Conclusions

The FUT7 sequence was highly conserved as well as the specific activity of the encoded protein FucT-VII. In addition, our in silico promoter analysis and the high rate of polymorphism suggested that its function is evolving toward a complex system related to the immune system. Furthermore, comparing bovine to human and mouse sequences, it appeared that a decrease in gene regulation was correlated with an increase in mutation rate and wider tissue expression.

Periodic fever as the manifestation of primary Sjogren's syndrome: a case report and literature review

A 56-year-old male had periodic fever for 5 years and suffered from auditory hallucination and hearing impairment for 3 years. Xerostomia, xerophthalmia, elevated anti-SSA/Ro tilter, positive Schirmer's test, and lymphocyte infiltrate of mucoserous gland in lip biopsy of this case confirmed the diagnosis of primary Sjogren's syndrome (pSS). We review literature for fever and neuropsychiatric involvement in pSS case series. Though fever is present in 6-41 % pSS cases, periodic fever has not been reported. Auditory hallucination was rare in cases with pSS. The literature review alerts clinicians that fever and neurological manifestations were not uncommon in pSS cases.

Epigenetics mediate environment : gene effects on occupational sensitization

PURPOSE OF REVIEW

Epigenetics is the study of stable modifications of fixed genomes that direct which genes are expressed and which are silenced. Epigenetic changes are modulated by environmental exposures, making epigenetics the interface between genes and environment. This has particular relevance in understanding the effect of occupational exposures on the expression of allergic disease. The goal of this review is to describe how epigenetic changes affect transcription potential, and to examine more closely the effect of specific environmental and occupational exposures on epigenetic variations that alter allergy gene transcripts and the inflammatory milieu.

RECENT FINDINGS

Gene transcription is activated when specific CpG sites are demethylated and histones are acetylated, and, conversely, silenced when sites are methylated and histones deacetylated. The development of Th1 and Th2 phenotypes, and expression of Treg cells, are now known to be modulated by epigenetic mechanisms. Workplace exposures such as tobacco smoke, particulates, diesel exhaust, polyaromatic hydrocarbons, ozone, and endotoxin, among others, suppress Treg development, and enhance expression of inflammatory cytokines and allergic phenotypes by epigenetic means.

SUMMARY

Epigenetic manipulation to open and close transcription sites provides flexibility of gene expression in response to changing environmental cues. It may also be the window whereby allergic disease in the workplace can be reduced by targeted environmental interventions.

Induction of 6-sulfated glycans with cell adhesion activity via T-bet and GATA-3 in human helper T cells

BACKGROUND

Cell surface 6-sulfated glycans play important roles in various immunological events through cell-to-cell interactions. The 6-sulfation process is mediated by 6-sulfotransferase family isoenzymes. We previously demonstrated that GlcNAc6ST-1, one of the isoenzyme genes, is induced by GATA-3 and NF-κB in human helper T (Th) cells. However, transcriptional regulation of HEC-GlcNAc6ST, another isoenzyme important in Th cells, remains unclear.

METHODS

5'-RACE analysis, chromatin immunoprecipitation, and reporter assays were performed to reveal transcriptional regulation of HEC-GlcNAc6ST. RNA-knockdown and forced expression experiments were performed to demonstrate the contribution of HEC-GlcNAc6ST to the 6-sulfated glycan expression.

RESULTS

We identified potential binding sites of Sp1, T-bet, and GATA-3 in the HEC-GlcNAc6ST promoter. Reporter assays indicated that transfection of Sp1 enhanced the activity, whereas mithramycin A, an Sp1-specific inhibitor, repressed it. Transfection of T-bet increased the activity, which was inhibited by introducing a mutation into the potential T-bet binding site. GATA-3 alone could not elevate the activity, although co-transfection of protein kinase A, which is known to enhance IL-5 transcription in Th2 cells through phosphorylation of GATA-3, caused elevation. RNA-knockdown and forced expression of HEC-GlcNAc6ST in Jurkat cells down- and up-regulated α2,6-sialylated 6-sulfo N-acetyllactosamine, a preferential ligand for B-cell-specific CD22 antigen, respectively. From these results, we concluded that T-bet and GATA-3 as well as Sp1 control the expression of glycan with cell-adhesion activity by regulating HEC-GlcNAc6ST transcription in Th cells.

GENERAL SIGNIFICANCE

These results may provide a clue to biological regulation of Th-cell interaction with selectins and other carbohydrate-recognition molecules by T-bet and GATA-3.

Cilostazol suppression of arterial intimal hyperplasia is associated with decreased expression of sialyl Lewis X homing receptors on mononuclear cells and E-selectin in endothelial cells

BACKGROUND

An inflammatory reaction in vascular tissue is a potential factor linking restenosis after angioplasty. Although cilostazol, a selective phosphodiesterase type 3 inhibitor that is a unique antiplatelet drug and vasodilator, has been reported to be anti-inflammatory, its effect on the inflammatory action of mononuclear cells homing to endothelial cells is not clearly understood. In this study, whether cilostazol inhibits neointimal formation and improves inflammatory actions by inhibiting sialyl Lewis X (SLX) expression on mononuclear cells and E-selectin expression on endothelial cells was evaluated.

METHODS

The effect of cilostazol (1, 3, 10, 30 μM) on expression of E-selectin in human umbilical vein endothelial cells and SLX in rat mononuclear cells stimulated with lipopolysaccharide by immunofluorescence and real-time polymerase chain reaction (n = 3) was studied. Additionally, a double-balloon injury model was used on rat carotid arteries to evaluate vascular intimal hyperplasia. 0.1% cilostazol was administered 3 days before the first balloon injury, and the second balloon injury was performed 7 days after the first injury. Cilostazol administration was continued until rats were sacrificed 14 days after the second angioplasty. The expression of SLX on mononuclear cells and E-selectin on endothelial cells by immunofluorescence (n = 10) and real-time polymerase chain reaction (n = 5) were studied.

RESULTS

Cilostazol effectively inhibited the expression of SLX on mononuclear cells and E-selectin on endothelial cells. Cilostazol inhibited the migration of mononuclear cells in neointimal regions and neointimal hyperplasia after balloon injury. The numbers of macrophages and T-lymphocytes and the hyperplasia area in neointimal regions decreased from 71.06 ± 20.04, 1121 ± 244.4 cells per section, 206,400 ± 96,150 mm(2) to 29.65 ± 16.73, 374.2 ± 124.5 cells per section, and 101,900 ± 16,150 mm(2) due to the administration of cilostazol.

CONCLUSIONS

These results demonstrate that the protective effect of cilostazol against neointimal hyperplasia may be mediated by its anti-inflammatory actions of mononuclear cells homing to endothelial cells by decreasing SLX and E-selectin expression.

CLINICAL RELEVANCE

It is reported that cilostazol inhibits neointimal hyperplasia by decreasing the expression of some cell-adhesion molecules. We evaluated the effects of cilostazol for the expression of sialyl Lewis X (SLX) on mononuclear cells and E-selectin on endothelial cells, which interaction is the first step of inflammation action. Cilostazol was thought to show the anti-inflammatory actions by decreasing SLX and E-selectin expression in addition to decreasing the expression of some cell-adhesion molecules.

Stem cell gene expression in MRPS18-2-immortalized rat embryonic fibroblasts

We have recently found that primary rat embryonic fibroblasts (REFs) could be immortalized by overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2). A derived cell line, designated 18IM, expressed the embryonic stem cell markers SSEA-1 and Sox2. Upon inoculation into severe combined immunodeficiency mice, 18IM cells differentiated to express pan-keratin. They were not tumorigenic. Here we report the gene profiling of 18IM, compared with REF cells. Pathways involved in oxidative phosphorylation, ubiquinone (Coenzyme Q 10) biosynthesis, fatty acid elongation in mitochondria, PI3K/AKT signaling, a characteristic of rapidly proliferating cells, were upregulated in 18IM. Genes involved in the transcription/translation machinery and redox reactions, like elongation factors, ATP synthases, NADH dehydrogenases, mitogen activated kinases were upregulated as well. 18IM cells produced more pyruvate, indicating enhanced ATP synthesis. The expression of Oct4, Sox2, and Nanog that can contribute to the experimental induction of pluripotency in primary fibroblasts was also elevated, in contrast to Klf4 and C-myc that were downregulated. Subsequently, three new immortalized cell lines were produced by S18-2 overexpression in order to check the representativeness of 18IM. All of them showed anchorage-independent growth pattern. Two of three clones lost vimentin and smooth muscle actin, and expressed Sox2 and Oct4. We suggest that S18-2 is involved in the developmental regulation.