Peripheral whole blood FOXP3 TSDR methylation: a potential marker in severity assessment of autoimmune diseases and chronic infections

DNA methylation in human diseases

Aberrant epigenetic modifications, particularly DNA methylation, play a critical role in the pathogenesis and progression of human diseases. The current review aims to reveal the role of aberrant DNA methylation in the pathogenesis and progression of diseases and to discuss the original data obtained from international research laboratories on this topic. In the review, we mainly summarize the studies exploring the role of aberrant DNA methylation as diagnostic and prognostic biomarkers in a broad range of human diseases, including monogenic epigenetics, autoimmunity, metabolic disorders, hematologic neoplasms, and solid tumors. The last section provides a general overview of the possibility of the DNA methylation machinery from the perspective of pharmaceutic approaches. In conclusion, the study of DNA methylation machinery is a phenomenal intersection that each of its ways can reveal the mysteries of various diseases, introduce new diagnostic and prognostic biomarkers, and propose a new patient-tailored therapeutic approach for diseases.

Psoriasis: Striving for Potential Biomarkers

Psoriasis is a chronic disease that is caused by multiple factors and is identified by itchiness, unpleasant, red, or white scaly patches on the skin, particularly on regularly chafed body regions such as the lateral areas of the limbs. Reports suggest that globally around 2%-3% of the population suffers from psoriasis. In this review, we have discussed the clinical classification of psoriasis and also the ideal characteristics of the biomarkers. An overview regarding the discovery of the biomarker and method for validating the study has been discussed. A growing body of research suggests a link to certain other systemic symptoms such as cardiovascular disorder, metabolic syndrome, and few other comorbidities such as hypertension and nonalcoholic fatty liver disease. Natural killer (NK) cells are lymphocyte cells that concentrate on the destruction of virally infected and malignant cells; these tend to produce a wide range of inflammatory cytokines, some of which are associated with the etiology of psoriasis. Detailed information on the molecular pathogenesis of psoriasis in which interleukin (IL)-17, IL-23, tumor necrosis factor-α (TNF-α), and CCL20 play a very significant role in the development of psoriasis. In this review, we have discussed an overview of the recent state of the biomarkers available for the diagnosis and treatment of psoriasis by emphasizing on the available biomarkers such as epigenomic, transcriptomic, glycomic, and metabolomic. The most recent advancements in molecular-targeted therapy utilizing biologics and oral systemic therapy (methotrexate, apremilast) enable to adequately treat the most serious psoriatic symptoms and also the studies have validated the efficacy of biologic therapy such as TNF-α antagonist (infliximab, adalimumab), IL-23 antagonist (guselkumab, risankizumab), and IL-17 antagonist (secukinumab, ixekizumab). Finally, an overview about the technological opportunities as well as various challenges has been discussed.

DNA methylation alterations in systemic lupus erythematosus: A systematic review of case-control studies

BACKGROUND

Traditionally, the diagnosis and monitoring of disease activity in systemic lupus erythematosus (SLE) are contingent upon clinical manifestations and serological markers. However, researchers are struggling to find biomarkers with higher sensitivity and specificity. DNA methylation has been the most studied epigenetic feature in SLE. So, in this study, we performed a systematic review of studies about DNA methylation alterations in SLE patients compared to healthy controls.

METHODS

By searching PubMed, Scopus, and Google Scholar up to July 2022, all case-control studies in which DNA methylation of specific genes was assessed by a non-high-throughput technique and passed the quality of bias assessment were included.

RESULTS

In total, 44 eligible studies underwent a data extraction process. In all, 3471 SLE patients and 1028 healthy individuals were included. Among the studies that reported the patients' gender (n = 2853), 89.41% were female and 10.59% were male. Forty studies have been conducted on adult patients. The number of works on fractionated and unfractionated blood cells was almost equal. In this regard, 22 studies were conducted on whole blood or peripheral blood mononuclear cells and two studies on unfractionated white blood cells. Sorted blood cells were biological sources in 20 studies. The most investigated gene was IFI44L. Sensitivity, specificity, and diagnostic power of methylation levels were only reported for IFI44L in five studies. The most employed methylation profiling method was bisulfite sequencing polymerase chain reaction. The correlation between methylation patterns and clinical parameters was explored in 22 studies, which of them 16 publications displayed a remarkable association between DNA methylation status and clinical indices.

CONCLUSIONS

The methylation status of some genes especially IFI44L, FOXP3, and MX1 has been suggested as promising SLE biomarkers. However, given the conflicting findings between studies because of potential confounders such as different sample types, methylation profiling methods, and ethnicity as well as shared DNA methylation patterns of SLE and other autoimmune diseases, DNA methylation biomarkers are currently not reliable diagnostic biomarkers and do not represent surrogate markers of SLE disease activity. Future investigations on a larger scale with the discarding of limitations of previous studies would probably lead to a consensus.

Telomere length, oxidative and epigenetic changes in blood DNA of patients with exacerbated psoriasis vulgaris

BACKGROUND

The pathogenesis of psoriasis vulgaris involves changes in DNA molecules, genomic instability, telomere attrition, and epigenetic alterations among them. These changes are also considered important mechanisms of aging in cells and tissues.

OBJECTIVE

This study dealt with oxidation damage, telomere length and methylation status in DNA originating from peripheral blood of 41 psoriatic patients and 30 healthy controls.

METHODS

Oxidative damage of serum DNA/RNA was determined immunochemically. Real-time PCR was used for the analysis of the telomere length. ELISA technique determined levels of 5-methylcytosine in blood cells' DNA.

RESULTS

Oxidative damage of serum DNA/RNA was higher in patients than in controls (median, 3758 vs. 2286pg/mL, p<0.001). A higher length of telomeres per chromosome was found in patients whole-cell DNA than in controls (3.57 vs. 3.04 kilobases, p=0.011). A negative correlation of the length of telomeres with an age of the control subjects was revealed (Spearman's rho=-0.420, p=0.028). Insignificantly different levels of 5-methylcytosine in patients and controls were observed (33.20 vs. 23.35%, p=0.234). No influences of sex, smoking, BMI, PASI score, and metabolic syndrome on the methylation status were found.

STUDY LIMITATIONS

i) A relatively small number of the participants, particularly for reliable subgroup analyses, ii) the Caucasian origin of the participants possibly influencing the results of the parameters determined, and iii) Telomerase activity was not directly measured in serum or blood cells.

CONCLUSION

The study demonstrated increased levels of oxidized DNA/RNA molecules in the serum of patients with exacerbated psoriasis vulgaris. The results were minimally influenced by sex, the presence of metabolic syndrome, or cigarette smoking. In the psoriatic blood cells' DNA, the authors observed longer telomeres compared to healthy controls, particularly in females. Insignificantly higher global DNA methylation in psoriasis cases compared to the controls indicated marginal clinical importance of this epigenetic test performed in the blood cells' DNA.

Contribution of the Environment, Epigenetic Mechanisms and Non-Coding RNAs in Psoriasis

Despite the increasing research and clinical interest in the predisposition of psoriasis, a chronic inflammatory skin disease, the multitude of genetic and environmental factors involved in its pathogenesis remain unclear. This complexity is further exacerbated by the several cell types that are implicated in Psoriasis’s progression, including keratinocytes, melanocytes and various immune cell types. The observed interactions between the genetic substrate and the environment lead to epigenetic alterations that directly or indirectly affect gene expression. Changes in DNA methylation and histone modifications that alter DNA-binding site accessibility, as well as non-coding RNAs implicated in the post-transcriptional regulation, are mechanisms of gene transcriptional activity modification and therefore affect the pathways involved in the pathogenesis of Psoriasis. In this review, we summarize the research conducted on the environmental factors contributing to the disease onset, epigenetic modifications and non-coding RNAs exhibiting deregulation in Psoriasis, and we further categorize them based on the under-study cell types. We also assess the recent literature considering therapeutic applications targeting molecules that compromise the epigenome, as a way to suppress the inflammatory cutaneous cascade.

UHRF1 shapes both the trophoblast invasion and decidual macrophage differentiation in early pregnancy

Trophoblasts play critical roles in establishment and maintenance of a normal pregnancy. Their dysfunction in early pregnancy is closely related to pregnancy-related diseases, including recurrent pregnancy loss (RPL). Epigenetic modifications dynamically change during pregnancy; however, the role of the epigenetic modifier UHRF1 in trophoblast regulation remains unknown. This is the first study to show that UHRF1 expression was localized in the cytoplasm of cytotrophoblasts, syncytiotrophoblasts, and villi columns, and decreased in the villi of patients with RPL. The invasion and cell viability in a UHRF1 knockdown trophoblast cell line were significantly decreased. In addition, the mRNA expression profiles of Swan71 cells were partially altered by UHRF1 knockdown. The altered immune-related genes were screened out and the pro-inflammatory TH1-type chemokine/cytokines CXCL2 and IL-1β were identified as the most promising targets of UHRF1 in the trophoblasts, which were significantly increased in the UHRF1 knockdown Swan71 cells, villi, and serum from patients with RPL. The macrophages treated with the supernatants of UHRF1 knockdown Swan71 cells were polarized to the M1 phenotype and secreted high levels of pro-inflammatory cytokines, which might be driven by the activated MyD88/NF-κB signaling pathway and mediated by the increased expression of CXCR2 and IL-1R1 (CXCL2 and IL-1β receptors, respectively). In addition, the supernatants of UHRF1 knockdown Swan71 cells showed stronger chemotaxis to macrophages than those from the controls. Our findings highlight the previously unknown roles of UHRF1 as one of the key regulators on the trophoblasts and their cross-talk with local immune cells, and demonstrate a potential approach for RPL intervention.

The Defect in Regulatory T Cells in Psoriasis and Therapeutic Approaches

Psoriasis is a chronic inflammatory skin disease characterized by accelerated tumor necrosis factor-α/interleukin (IL)-23/IL-17 axis. Patients with psoriasis manifest functional defects in CD4⁺CD25⁺ forkhead box protein 3 (Foxp3)⁺ regulatory T cells (Tregs), which suppress the excess immune response and mediate homeostasis. Defects in Tregs contribute to the pathogenesis of psoriasis and may attribute to enhanced inhibition and/or impaired stimulation of Tregs. IL-23 induces the conversion of Tregs into type 17 helper T (Th17) cells. IL-17A reduces transforming growth factor (TGF)-β1 production, Foxp3 expression, and suppresses Treg activity. Short-chain fatty acids (SCFAs), butyrate, propionate, and acetate are microbiota-derived fermentation products that promote Treg development and function by inducing Foxp3 expression or inducing dendritic cells or intestinal epithelial cells to produce retinoic acids or TGF-β1, respectively. The gut microbiome of patients with psoriasis revealed reduced SCFA-producing bacteria, Bacteroidetes, and Faecallibacterium, which may contribute to the defect in Tregs. Therapeutic agents currently used, viz., anti-IL-23p19 or anti-IL-17A antibodies, retinoids, vitamin D3, dimethyl fumarate, narrow-band ultraviolet B, or those under development for psoriasis, viz., signal transducer and activator of transcription 3 inhibitors, butyrate, histone deacetylase inhibitors, and probiotics/prebiotics restore the defected Tregs. Thus, restoration of Tregs is a promising therapeutic target for psoriasis.

Dysregulated epigenetic modifications in psoriasis

The observed incidence of psoriasis has been gradually increasing over time (J Am Acad Dermatol, 03, 2009, 394), but the underlying pathogenic factors have remained unclear. Recent studies suggest the importance of epigenetic modification in the pathogenesis of psoriasis. Aberrant epigenetic patterns including changes in DNA methylation, histone modifications and non-coding RNA expression are observed in psoriatic skin. Reversing these epigenetic mechanisms has showed improvement in psoriatic phenotypes, making epigenetic therapy a potential avenue for psoriasis treatment. Here, we summarize relevant evidence for epigenetic dysregulation contributing to psoriasis susceptibility and pathogenesis, and the factors responsible for epigenetic modifications, providing directions for potential future clinical avenues.

Pharmacological modulation of T cell immunity results in long-term remission of autoimmune arthritis

Chronic inflammatory diseases like rheumatoid arthritis are characterized by a deficit in fully functional regulatory T cells. DNA-methylation inhibitors have previously been shown to promote regulatory T cell responses and, in the present study, we evaluated their potential to ameliorate chronic and acute animal models of rheumatoid arthritis. Of the drugs tested, decitabine was the most effective, producing a sustained therapeutic effect that was dependent on indoleamine 2,3-dioxygenase (IDO) and was associated with expansion of induced regulatory T cells, particularly at the site of disease activity. Treatment with decitabine also caused apoptosis of Th1 and Th17 cells in active arthritis in a highly selective manner. The molecular basis for this selectivity was shown to be ENT1, a nucleoside transporter, which facilitates intracellular entry of the drug and is up-regulated on effector T cells during active arthritis. It was further shown that short-term treatment with decitabine resulted in the generation of a population of regulatory T cells that were able to suppress arthritis upon adoptive transfer. In summary, a therapeutic approach using an approved drug is described that treats active inflammatory disease effectively and generates robust regulatory T cells with the IDO-dependent capacity to maintain remission.

The DNA methylation of FOXO3 and TP53 as a blood biomarker of late-onset asthma

BACKGROUND

Late-onset asthma (LOA) is beginning to account for an increasing proportion of asthma patients, which is often underdiagnosed in the elderly. Studies on the possible relations between aging-related genes and LOA contribute to the diagnosis and treatment of LOA. Forkhead Box O3 (FOXO3) and TP53 are two classic aging-related genes. DNA methylation varies greatly with age which may play an important role in the pathogenesis of LOA. We supposed that the differentially methylated sites of FOXO3 and TP53 associated with clinical phenotypes of LOA may be useful biomarkers for the early screening of LOA.

METHODS

The mRNA expression and DNA methylation of FOXO3 and TP53 in peripheral blood of 43 LOA patients (15 mild LOA, 15 moderate LOA and 13 severe LOA) and 60 healthy controls (HCs) were determined. The association of methylated sites with age was assessed by Cox regression to control the potential confounders. Then, the correlation between differentially methylated sites (DMSs; p-value < 0.05) and clinical lung function in LOA patients was evaluated. Next, candidate DMSs combining with age were evaluated to predict LOA by receiver operating characteristic (ROC) analysis and principal components analysis (PCA). Finally, HDM-stressed asthma model was constructed, and DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-AZA) were used to determine the regulation of DNA methylation on the expression of FOXO3 and TP53.

RESULTS

Compared with HCs, the mRNA expression and DNA methylation of FOXO3 and TP53 vary significantly in LOA patients. Besides, 8 DMSs from LOA patients were identified. Two of the DMSs, chr6:108882977 (FOXO3) and chr17:7591672 (TP53), were associated with the severity of LOA. The combination of the two DMSs and age could predict LOA with high accuracy (AUC values = 0.924). In HDM-stressed asthma model, DNA demethylation increased the expression of FOXO3 and P53.

CONCLUSIONS

The mRNA expression of FOXO3 and TP53 varies significantly in peripheral blood of LOA patients, which may be due to the regulation of DNA methylation. FOXO3 and TP53 methylation is a suitable blood biomarker to predict LOA, which may be useful targets for the risk diagnosis and clinical management of LOA.

Foxp3 TSDR Hypermethylation Is Correlated with Decreased Tregs in Patients with Unexplained Recurrent Spontaneous Abortion

A decline of T regulatory cell (Treg) number and function is associated with unexplained recurrent spontaneous abortion (URSA). However, the mechanism of downregulation of Tregs in URSA patients is still unknown. This study aimed to investigate the changes of Tregs in URSA patients and the epigenetic regulation for these changes. Venous blood samples were collected from 20 patients with URSA and 20 healthy control subjects. Treg number and inhibitory capacity, and Foxp3 mRNA expression and Foxp3 TSDR methylation were compared between the 2 groups. Correlations between Treg frequency and inhibitory function and TSDR methylation status were examined by Spearman's correlation. The proportion of Tregs within the population of CD4⁺ T cells and the expression of Foxp3 mRNA was significantly lower in URSA patients than in healthy control subjects. Tregs from URSA patients and healthy controls both significantly inhibited the cytotoxic activity of natural killer (NK) cells toward K562 targets; however, the inhibitory ability of Tregs from URSA patients was significantly lower than that from healthy controls. The methylation level of the Treg-specific demethylated region (TSDR) in the Foxp3 gene was significantly greater in URSA patients than in the controls, and the level of methylation was inversely correlated with the proportion of Tregs and Foxp3 mRNA expression in the peripheral blood. However, the methylation level was not correlated with the inhibitory function of Tregs. A decrease of Treg number and function may be related to the pathogenesis of URSA, and Foxp3 hypermethylation may be associated with the decreased Treg number.

Omics-Driven Biomarkers of Psoriasis: Recent Insights, Current Challenges, and Future Prospects

Advances in omics technologies have made it possible to unravel biomarkers from different biological levels. Intensive studies have been carried out to uncover the dysregulations in psoriasis and to identify molecular signatures associated with the pathogenesis of psoriasis. In this review, we presented an overview of the current status of the omics-driven biomarker research and emphasized the transcriptomic, epigenomic, proteomic, metabolomic, and glycomic signatures proposed as psoriasis biomarkers. Furthermore, insights on the limitations and future directions of the current biomarker discovery strategies were discussed, which will continue to comprehend broader visions of psoriasis research, diagnosis, and therapy especially in the context of personalized medicine.

Homeostasis and the functional roles of CD4+ Treg cells in aging

OBJECTIVE

An upward trend in life expectancy has been observed in a majority of developed countries and leading to increasing in aging-related diseases. Aging is a risk factor for the development of widespread clinical conditions such as cardiovascular and autoimmune diseases, cancer, infections. Although studies have been very active, the problem of aging still remains one of the most obscure aspects of human biology. Regulatory T (Treg) cells with immunosuppressive properties have a pivotal role in the maintenance of immune homeostasis. Alterations in Treg cell functionality appear to be of great importance in the development of immune senescence and contribute to increased susceptibility to immune-mediated diseases with age.

DESIGN

This review highlights recent findings regarding the age-related changes in the numbers and functional activity of human Tregs. Some of the mechanisms that maintain the balance of Tregs during human aging are discussed. The possible roles of Tregs in the pathogenesis of diseases associated with advanced age are also considered.

RESULTS

Age-related systemic changes, such as thymic involution, hormonal status, and epigenetic modifications, may affect the state of the Treg population and trigger various diseases. These changes involve decline or amplification in the functional activity of Tregs, an increase in the memory Treg subset and shifting of a Th17/Treg balance.

CONCLUSION

Taken together, the reviewed data suggest equal or even increased Treg functionality with age. Thus, age-mediated Treg expansion and higher Treg activity may contribute to elevated immune suppression and increased risk of infections and cancer.

The status of FOXP3 gene methylation in pediatric systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease caused by interaction of genetic, epigenetic, and environmental factors. One of the important epigenetic factors in SLE would be methylation of immune-related genes, such as FOXP3, which plays a role in activating the regulation and also the function of T cells. To date, the relationship between levels of serum bio-markers and the susceptibility to lupus in children has not been well-understood. In this study, the involvement of etiologic factors, such as methylation of FOXP3 gene, was investigated in children with SLE.

METHOD

Twenty-four female children with SLE and 25 female healthy subjects without any history of autoimmune and inflammatory diseases were included in this study. Blood samples were obtained and DNA was extracted from the blood cells. The bisulphite method was used to convert the DNA using the MethylEdge™ Bisulfite Conversion System Kit. Then, methylation of the gene was investigated using Real Time methylation specific PCR.

RESULTS

The FOXP3 DNA methylation in patients and healthy subjects was significantly different. While the median unmethylated DNA in patients was 0.57±0.43, it was 0.97±0.83 in healthy subjects (P=0.012). The Demethylation Index in patients was 0.007±0.003, significantly lower than in controls (0.014±0.013; P=0.012).

CONCLUSIONS

The FOXP3 gene methylation in children with SLE was significantly higher than healthy subjects, which could possibly affect the level of gene expression. Therefore, one of the causes of increased immune response in SLE can be the lower expression of FOXP3 by hypermethylation of this gene.

Attenuation of canonical NF-κB signaling maintains function and stability of human Treg

Nuclear factor ‘κ‐light‐chain‐enhancer’ of activated B cells (NF‐κB) signaling is a signaling pathway used by most immune cells to promote immunostimulatory functions. Recent studies have indicated that regulatory T cells (Treg) differentially integrate TCR‐derived signals, thereby maintaining their suppressive features. However, the role of NF‐κB signaling in the activation of human peripheral blood (PB) Treg has not been fully elucidated so far. We show that the activity of the master transcription factor forkhead box protein 3 (FOXP3) attenuates p65 phosphorylation and nuclear translocation of the NF‐κB proteins p50, p65, and c‐Rel following activation in human Treg. Using pharmacological and genetic inhibition of canonical NF‐κB signaling in FOXP3‐transgenic T cells and PB Treg from healthy donors as well as Treg from a patient with a primary NFKB1 haploinsufficiency, we validate that Treg activation and suppressive capacity is independent of NF‐κB signaling. Additionally, repression of residual NF‐κB signaling in Treg further enhances interleukin‐10 (IL‐10) production. Blockade of NF‐κB signaling can be exploited for the generation of in vitro induced Treg (iTreg) with enhanced suppressive capacity and functional stability. In this respect, dual blockade of mammalian target of rapamycin (mTOR) and NF‐κB signaling was accompanied by enhanced expression of the transcription factors FOXP1 and FOXP3 and demethylation of the Treg‐specific demethylated region compared to iTreg generated under mTOR blockade alone. Thus, we provide first insights into the role of NF‐κB signaling in human Treg. These findings could lead to strategies for the selective manipulation of Treg and the generation of improved iTreg for cellular therapy.

Epigenetics of Psoriasis

Psoriasis is a chronic and recurrent inflammatory skin disease, involving the rapid proliferation and abnormal differentiation of keratinocytes and activation of T cells. It is generally accepted that the central pathogenesis of psoriasis is a T cell-dominant immune disorder affected by multiple factors including genetic susceptibility, environmental factors, innate and adaptive immune responses, etc. However, the exact etiology is largely unknown. In recent years, epigenetic involvements, such as the DNA methylation, chromatin modifications, and noncoding RNA regulation are reported to be critical for the pathogenesis of psoriasis. However, the interplay between these factors has only recently been started to be unraveled. Notably, inhibitors of enzymes that work in epigenetic modifications, such as DNA methyltransferases and histone deacetylases, are beginning to appear in the clinical setting to restore normal epigenetic patterns (Generali et al. in J Autoimmun 83:51-61, 2017), providing novel therapeutic potential as novel treatment targets for psoriasis. Indeed, medications previously used to treat autoimmune diseases have later been discovered to exert their action via epigenetic mechanisms. Herein, we review the findings on epigenetics associated with psoriasis, and discuss future perspectives in this field.

The Epigenetics of Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a life-threatening autoimmune disease that is characterized by dysregulated dendritic cells, T and B cells, and abundant autoantibodies. The pathogenesis of lupus remains unclear. However, increasing evidence has shown that environment factors, genetic susceptibilities, and epigenetic regulation contribute to abnormalities in the immune system. In the past decades, several risk gene loci have been identified, such as MHC and C1q. However, genetics cannot explain the high discordance of lupus incidence in homozygous twins. Environmental factor-induced epigenetic modifications on immune cells may provide some insight. Epigenetics refers to inheritable changes in a chromosome without altering DNA sequence. The primary mechanisms of epigenetics include DNA methylation, histone modifications, and non-coding RNA regulations. Increasing evidence has shown the importance of dysregulated epigenetic modifications in immune cells in pathogenesis of lupus, and has identified epigenetic changes as potential biomarkers and therapeutic targets. Environmental factors, such as drugs, diet, and pollution, may also be the triggers of epigenetic changes. Therefore, this chapter will summarize the up-to-date progress on epigenetics regulation in lupus, in order to broaden our understanding of lupus and discuss the potential roles of epigenetic regulations for clinical applications.

Increased levels of adipose tissue-resident Th17 cells in obesity associated with miR-326

miRNAs are important immune regulators in the control of the CD4 + T cells phenotype. miR-326 regulates the differentiation towards Th17 cells and the inhibition of miR-155 is associated with low levels of Treg cells. However, miRNAs expression and transcription factors associated with these lymphocyte subsets in obesity-induced adipose tissue inflammation is still unknown. The aim of this work was to identify Th17 cells in subcutaneous adipose tissue (SAT), proinflammatory cytokine production and their association with the miRNAs and transcription factors involved. We collected SAT samples obtained by lipoaspiration from individuals with normal weight, overweight and obesity. We obtained the stromal vascular fractions and then a Ficoll gradient was performed to obtain adipose tissue mononuclear cells (ATMC). Th17 cells were evaluated by flow cytometry and the expression of miR-326, miR-155, RORC2 and FOXP3 by qRT-PCR. We also analyzed cytokines from the supernatants of the ATMC culture and measured the FOXP3 methylation percentage by bisulfite conversion by PCR. According to the results, the frequency of Th17 cells and RORC2 expression was higher in individuals with obesity and associated with miR-326 expression. The ATMC from this group secreted a proinflammatory cytokine profile by in vitro assay. In contrast, lower levels of mRNA FOXP3 expression was detected in ATMC from individuals with obesity that correlated with methylation percentage of FOXP3 gene but no association with miR-155 was detected. Our results suggested that miR-326 participates in the polarization towards Th17 promoting the inflammatory state in the obesity-induced adipose tissue.

Therapeutic Potential of Regulatory T Cells in Preeclampsia-Opportunities and Challenges

Inflammation is a central feature and is implicated as a causal factor in preeclampsia and other hypertensive disorders of pregnancy. Inflammatory mediators and leukocytes, which are elevated in peripheral blood and gestational tissues, contribute to the uterine vascular anomalies and compromised placental function that characterize particularly the severe, early onset form of disease. Regulatory T (Treg) cells are central mediators of pregnancy tolerance and direct other immune cells to counteract inflammation and promote robust placentation. Treg cells are commonly perturbed in preeclampsia, and there is evidence Treg cell insufficiency predates onset of symptoms. A causal role is implied by mouse studies showing sufficient numbers of functionally competent Treg cells must be present in the uterus from conception, to support maternal vascular adaptation and prevent later placental inflammatory pathology. Treg cells may therefore provide a tractable target for both preventative strategies and treatment interventions in preeclampsia. Steps to boost Treg cell activity require investigation and could be incorporated into pregnancy planning and preconception care. Pharmacological interventions developed to target Treg cells in autoimmune conditions warrant consideration for evaluation, utilizing rigorous clinical trial methodology, and ensuring safety is paramount. Emerging cell therapy tools involving in vitro Treg cell generation and/or expansion may in time become relevant. The success of preventative and therapeutic approaches will depend on resolving several challenges including developing informative diagnostic tests for Treg cell activity applicable before conception or during early pregnancy, selection of relevant patient subgroups, and identification of appropriate windows of gestation for intervention.

Regulatory T cells in embryo implantation and the immune response to pregnancy

At implantation, the embryo expresses paternally derived alloantigens and evokes inflammation that can threaten reproductive success. To ensure a robust placenta and sustainable pregnancy, an active state of maternal immune tolerance mediated by CD4+ regulatory T cells (Tregs) is essential. Tregs operate to inhibit effector immunity, contain inflammation, and support maternal vascular adaptations, thereby facilitating trophoblast invasion and placental access to the maternal blood supply. Insufficient Treg numbers or inadequate functional competence are implicated in idiopathic infertility and recurrent miscarriage as well as later-onset pregnancy complications stemming from placental insufficiency, including preeclampsia and fetal growth restriction. In this Review, we summarize the mechanisms acting in the conception environment to drive the Treg response and discuss prospects for targeting the T cell compartment to alleviate immune-based reproductive disorders.

Epigenetics in SLE

Purpose of Review

Systemic lupus erythematosus is a severe autoimmune/inflammatory condition of unknown pathophysiology. Though genetic predisposition is essential for disease expression, risk alleles in single genes are usually insufficient to confer disease. Epigenetic dysregulation has been suggested as the missing link between genetic risk and the development of clinically evident disease.

Recent Findings

Over the past decade, epigenetic events moved into the focus of research targeting the molecular pathophysiology of SLE. Epigenetic alteration can be the net result of preceding infections, medication, diet, and/or other environmental influences. While altered DNA methylation and histone modifications had already been established as pathomechanisms, DNA hydroxymethylation was more recently identified as an activating epigenetic mark.

Summary

Defective epigenetic control contributes to uncontrolled cytokine and co-receptor expression, resulting in immune activation and tissue damage in SLE. Epigenetic alterations promise potential as disease biomarkers and/or future therapeutic targets in SLE and other autoimmune/inflammatory conditions.

STAT5 and TET2 Cooperate to Regulate FOXP3-TSDR Demethylation in CD4+ T Cells of Patients with Colorectal Cancer

The tumor-infiltrating Tregs are linked to colorectal cancer progression and outcome. FOXP3 is regarded as a critical developmental and functional factor for Tregs. FOXP3-TSDR demethylation is required for stable expression of FOXP3 and maintenance of Treg function. In our study, we found specific DNA hypomethylation of FOXP3-TSDR in CD4⁺ T cells from colon tumor tissues as compared with normal colonic tissues. Moreover, we also found that the expression of STAT5 and TET2 was increased in CD4⁺ T cells from colon tumor tissues, and the superfluous STAT5 and TET2 binding to FOXP3-TSDR resulted in DNA hypomethylation. In conclusion, we have demonstrated that excessive amounts of STAT5 may bind more TET2 to the FOXP3-TSDR and upregulate FOXP3 expression via DNA demethylation. Our study improved the mechanism of FOXP3-TSDR hypomethylation in tumor-infiltrating CD4⁺ T cells of CRC patients.

Analysis of Helios gene expression and Foxp3 TSDR methylation in the newly diagnosed Rheumatoid Arthritis patients

BACKGROUND

The control of auto-reactive cells is defective in rheumatoid arthritis (RA). Regulatory T (Treg) cells which play a key role in the modulation of immune responses have an impaired function in RA. Foxp3 is a master regulator of Treg cells which its expression is under the tight control of epigenetic mechanisms. In the current study, we analyzed the epigenetic modulation of the Foxp3 Treg-specific demethylated region (TSDR) and Helios gene expression to determine Treg cells alteration in RA patients.

METHODS

We have recruited 20 newly diagnosed patients with RA and 41 healthy controls in our study. The measurement of Foxp3 and Helios gene expression was performed by the real-time PCR technique and the methylation level of TSDR was analyzed by bisulfite treatment and quantitative methylation-specific PCR (Q-MSP).

RESULTS

We found that RA patients had significantly lower level of Foxp3 gene expression and TSDR demethylation compared to healthy subjects (P < 0.001 and P = 0.006, respectively). Inversely, the Helios gene expression was elevated significantly in RA patients group (P = 0.048). We also observed a significant correlation between Foxp3 and Helios gene expression (P = 0.016) as well as a significant correlation between FoxP3 expression and demethylation rate of TSDR (P = 0.010).

CONCLUSION

Our results suggested that both epigenetic modifications and Helios gene expression may have important roles in the pathogenesis of RA through their effects on Foxp3 gene expression.

Epigenetics as biomarkers in autoimmune diseases

Autoimmune diseases are immune system disorders in which immune cells cannot distinguish self-antigens from foreign ones. The current criteria for autoimmune disease diagnosis are based on clinical manifestations and laboratory tests. However, none of these markers shows both high sensitivity and specificity. In addition, some autoimmune diseases, for example, systemic lupus erythematosus (SLE), are highly heterogeneous and often exhibit various manifestations. On the other hand, certain autoimmune diseases, such as Sjogren's syndrome versus SLE, share similar symptoms and autoantibodies, which also causes difficulties in diagnosis. Therefore, biomarkers that have both high sensitivity and high specificity for diagnosis, reflect disease activity and predict drug response are necessary. An increasing number of publications have proposed the abnormal epigenetic modifications as biomarkers of autoimmune diseases. Therefore, this review will comprehensively summarize the epigenetic progress in the pathogenesis of autoimmune disorders and unearth potential biomarkers that might be appropriate for disease diagnosis and prediction.

Epigenetics and pathogenesis of systemic sclerosis; the ins and outs

The pathogenesis of many diseases is influenced by environmental factors which can affect human genome and be inherited from generation to generation. Adverse environmental stimuli are recognized through the epigenetic regulatory complex, leading to gene expression alteration, which in turn culminates in disease outcomes. Three epigenetic regulatory mechanisms modulate the manifestation of a gene, namely DNA methylation, histone changes, and microRNAs. Both epigenetics and genetics have been implicated in the pathogenesis of systemic sclerosis (SSc) disease. Genetic inheritance rate of SSc is low and the concordance rate in both monozygotic (MZ) and dizygotic (DZ) twins is little, implying other possible pathways in SSc pathogenesis scenario. Here, we provide an extensive overview of the studies regarding different epigenetic events which may offer insights into the pathology of SSc. Furthermore, epigenetic-based interventions to treat SSc patients were discussed.

Expanding Diversity and Common Goal of Regulatory T and B Cells. I: Origin, Phenotype, Mechanisms

Immunosuppressive activity of regulatory T and B cells is critical to limit autoimmunity, excessive inflammation, and pathological immune response to conventional antigens or allergens. Both types of regulatory cells are intensively investigated, however, their development and mechanisms of action are still not completely understood. Both T and B regulatory cells represent highly differentiated populations in terms of phenotypes and origin, however, they use similar mechanisms of action. The most investigated CD4+CD25+ regulatory T cells are characterized by the expression of Foxp3+ transcription factor, which is not sufficient to maintain their lineage stability and suppressive function. Currently, it is considered that specific epigenetic changes are critical for defining regulatory T cell stability in the context of their suppressive function. It is not yet known if similar epigenetic regulation determines development, lineage stability, and function of regulatory B cells. Phenotype diversity, confirmed or hypothetical developmental pathways, multiple mechanisms of action, and role of epigenetic changes in these processes are the subject of this review.

The methylation state of VDR gene in pulmonary tuberculosis patients

Background

Our previous study suggested that the methylation of vitamin D receptor (VDR) gene affected its expression and the defense against tuberculosis (TB) infection in vitro. In this study, we further investigated the methylation level of VDR gene in pulmonary TB patients.

Methods

The consecutive TB patients who were admitted into our department from January 2013 to January 2015 were recruited. The potential methylation sites analyzed in this study included 16 CpG sites. The amplification of bisulfite modified genomic DNA was ligated to pUC18-T vector and the positive clone of blue-white selection was sequenced to analyze the methylation state of VDR gene.

Results

This study had samples of 27 TB patients and 30 healthy controls. TB patients were in the hyper-methylation state compared to the healthy controls. The significant differences between TB patients and healthy controls were detected in 7 of these 16 CpG sites. The mRNA expression of AKT, GSK3βand FOXO1 decreased in TB patients compared to that of healthy controls.

Conclusions

Our study contributes to supplying more evidences that the methylation level of VDR gene affects the progression of TB.

DNA methylation in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease facilitated by aberrant immune responses directed against cells and tissues, resulting in inflammation and organ damage. In the majority of patients, genetic predisposition is accompanied by additional factors conferring disease expression. While the exact molecular mechanisms remain elusive, epigenetic alterations in immune cells have been demonstrated to play a key role in disease pathogenesis through the dysregulation of gene expression. Since epigenetic marks are dynamic, allowing cells and tissues to differentiate and adjust, they can be influenced by environmental factors and also be targeted in therapeutic interventions. Here, we summarize reports on DNA methylation patterns in SLE, underlying molecular defects and their effect on immune cell function. We discuss the potential of DNA methylation as biomarker or therapeutic target in SLE.

Epigenetic Alterations in Cellular Immunity: New Insights into Autoimmune Diseases

Epigenetic modification is an additional regulator in immune responses as the genome-wide profiling somehow fails to explain the sophisticated mechanisms in autoimmune diseases. The effect of epigenetic modifications on adaptive immunity derives from their regulations to induce a permissive or negative gene expression. Epigenetic events, such as DNA methylation, histone modifications and microRNAs (miRNAs) are often found in T cell activation, differentiation and commitment which are the major parts in cellular immunity. Recognizing the complexity of interactions between epigenetic mechanisms and immune disturbance in autoimmune diseases is essential for the exploration of efficient therapeutic targets. In this review, we summarize a list of studies that indicate the significance of dysregulated epigenetic modifications in autoimmune diseases while focusing on T cell immunity.

DNA methylation alterations in the pathogenesis of lupus

Although lupus is, by definition, associated with genetic and immunological factors, its molecular mechanisms remain unclear. The up-to-date research findings point out that various genetic and epigenetic factors, especially gene-specific and site-specific methylation, are believed to contribute to the initiation and development of systemic lupus erythematosus (SLE). This review presents and summarizes the association between abnormal DNA methylation of immune-related cells and lupus-like diseases, as well as the possible mechanisms of immune disorder caused by DNA methylation, aiming at a better understanding of the roles of aberrant DNA methylation in the initiation and development of certain forms of lupus and providing a new insight into promising therapeutic regimens in lupus-like diseases.

The critical role of epigenetics in systemic lupus erythematosus and autoimmunity

One of the major disappointments in human autoimmunity has been the relative failure on genome-wide association studies to provide "smoking genetic guns" that would explain the critical role of genetic susceptibility to loss of tolerance. It is well known that autoimmunity refers to the abnormal state that the dysregulated immune system attacks the healthy cells and tissues due to the loss of immunological tolerance to self-antigens. Its clinical outcomes are generally characterized by the presence of autoreactive immune cells and (or) the development of autoantibodies, leading to various types of autoimmune disorders. The etiology and pathogenesis of autoimmune diseases are highly complex. Both genetic predisposition and environmental factors such as nutrition, infection, and chemicals are implicated in the pathogenic process of autoimmunity, however, how much and by what mechanisms each of these factors contribute to the development of autoimmunity remain unclear. Epigenetics, which refers to potentially heritable changes in gene expression and function that do not involve alterations of the DNA sequence, has provided us with a brand new key to answer these questions. In the recent decades, increasing evidence have demonstrated the roles of epigenetic dysregulation, including DNA methylation, histone modification, and noncoding RNA, in the pathogenesis of autoimmune diseases, especially systemic lupus erythematosus (SLE), which have shed light on a new era for autoimmunity research. Notably, DNA hypomethylation and reactivation of the inactive X chromosome are two epigenetic hallmarks of SLE. We will herein discuss briefly how genetic studies fail to completely elucidate the pathogenesis of autoimmune diseases and present a comprehensive review on landmark epigenetic findings in autoimmune diseases, taking SLE as an extensively studied example. The epigenetics of other autoimmune diseases such as rheumatic arthritis, systemic sclerosis and primary biliary cirrhosis will also be summarized. Importantly we emphasize that the stochastic processes that lead to DNA modification may be the lynch pins that drive the initial break in tolerance.

Treatment of low doses curcumin could modulate Th17/Treg balance specifically on CD4+ T cell cultures of systemic lupus erythematosus patients

Introduction

The balance between T helper 17 (Th17) and regulatory T cells (Treg) is a new paradigm in the pathogenesis of systemic lupus erythematosus (SLE). Currently, there are no drugs that able to modulate Th17/Treg balance specifically in SLE. Curcumin is a bioactive agent that has a specific action against hyperproliferative cells. However, its role in modulating Th17/Treg balance in SLE is still unknown. This research aimed to investigate the role of curcumin in modulating Th17/Treg balance on CD4+ T cell cultures of SLE patients.

Material and methods

CD4+ T cells from SLE 6 untreated patients and 6 healthy subjects were collected, stimulated with Th17 differentiating factors, and curcumin 0.1 and 1 µg/ml was added on cultures. After 72 hours incubation, cells were harvested and measured for Th17 and Treg percentages using flow cytometry and interleukin-17A (IL-17A) and transforming growth factor-β1 (TGF-β1) levels using ELISA.

Results

Administration of low doses of curcumin (0.1 and 1 µg/ml) could decrease Th17 percentages (p = 0.000 and p = 0.000 compared to control), reduce IL-17A productions (p = 0.000 and p = 0.000 compared to control), increase Treg percentages (p = 0.001 and p = 0.000 compared to control), and increase TGF-β1 productions (p = 0.001 and p = 0.000 compared to control) on CD4+ T cells of SLE patients. Interestingly, these effects were not reproduced on CD4+ T cells cultures of healthy subjects.

Conclusions

These data suggest that curcumin can modulate Th17/Treg balance specifically on CD4+ T cells of SLE patients without affecting healthy subjects.

Role of miR-146a in Enforcing Effect of Specific Immunotherapy on Allergic Rhinitis

Allergic rhinitis (AR) is one of the common disorders in airway allergic inflammation. The pathogenesis of AR is unclear. It is accepted that immune deregulation is associated with the pathogenesis of AR. Recent reports suggest that a large number of micro RNAs (miR) can regulate immune functions. This study aims to investigate the role of miR-146a in an enforcing immunotherapy of AR. In this study, a mouse AR model was created. The levels of miR-146a in the mouse nasal mucosa were assessed by real time RT-PCR. A specific immunotherapy was performed in AR mice. The results showed that the AR mice had an AR-like inflammation in the nasal mucosa. Compared with naïve mice, markedly lower levels of miR-146a were detected in AR mice. The co-administration with miR-146a significantly enforced the effect of ovalbumin (OVA)-specific immunotherapy on inhibition of AR inflammation in the nasal mucosa. Further analysis showed that miR-146a induced transforming growth factor-β in dendritic cells; the latter induced naïve CD4(+) T cells to differentiate into regulatory T cells. In conclusion, miR-146a can enforce OVA-specific immunotherapy via inducing antigen-specific regulatory T cells. miR-146a may have therapeutic potential to be used in the immunotherapy of allergic diseases.