Estrogen receptor alpha promotes lupus in (NZB×NZW)F1 mice in a B cell intrinsic manner

The molecular underpinnings of female predominance in lupus

Most people affected by systemic lupus erythematosus (SLE) are women. Although the role of sex hormones has been appreciated, we discuss emerging evidence that links X-linked genes escaping from dosage compensation to female predisposition to lupus. This is exemplified by TLR7 and CXorf21 whose female-biased expression may converge to enhance interferon responses and promote autoantibody-producing B cells, which are hallmarks of SLE. Notably, autosomal transcription factors with female overexpression may regulate molecular programs in the skin that are sufficient to induce lupus. These findings indicate a multifactorial basis for female vulnerability; however, several areas remain elusive, including the epigenetic landscape of X-chromosome inactivation (XCI) in SLE, the interplay with environmental factors, and the role of male-specific factors such as Y-linked genes.

A humanized mouse that mounts mature class-switched, hypermutated and neutralizing antibody responses

Humanized mice are limited in terms of modeling human immunity, particularly with regards to antibody responses. Here we constructed a humanized (THX) mouse by grafting non-γ-irradiated, genetically myeloablated KitW-41J mutant immunodeficient pups with human cord blood CD34+ cells, followed by 17β-estradiol conditioning to promote immune cell differentiation. THX mice reconstitute a human lymphoid and myeloid immune system, including marginal zone B cells, germinal center B cells, follicular helper T cells and neutrophils, and develop well-formed lymph nodes and intestinal lymphoid tissue, including Peyer's patches, and human thymic epithelial cells. These mice have diverse human B cell and T cell antigen receptor repertoires and can mount mature T cell-dependent and T cell-independent antibody responses, entailing somatic hypermutation, class-switch recombination, and plasma cell and memory B cell differentiation. Upon flagellin or a Pfizer-BioNTech coronavirus disease 2019 (COVID-19) mRNA vaccination, THX mice mount neutralizing antibody responses to Salmonella or severe acute respiratory syndrome coronavirus 2 Spike S1 receptor-binding domain, with blood incretion of human cytokines, including APRIL, BAFF, TGF-β, IL-4 and IFN-γ, all at physiological levels. These mice can also develop lupus autoimmunity after pristane injection. By leveraging estrogen activity to support human immune cell differentiation and maturation of antibody responses, THX mice provide a platform to study the human immune system and to develop human vaccines and therapeutics.

Lupus progression deteriorates oogenesis quality in MRL/lpr mice

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the activation of the immune response against self antigens. Numerous reproductive complications, including reduced birth rate and complications for the mother and the fetus during pregnancy, have been observed in women with SLE. In the present study, we aimed to investigate the effect of SLE development on oocyte meiosis in lupus-prone mice. Lupus-prone MRL/lpr mice were used for the experiments: disease-free (4 weeks of age) and sick (20 weeks of age, virgin and postpartum). The immune response was monitored by flow cytometry, ELISpot, ELISA, and histology. Oocytes were analyzed by fluorescence microscopy based on chromatin, tubulin, and actin structures. The lupus-prone MRL/lpr mice developed age-dependent symptoms of SLE with increased levels of various autoantibodies, proteinuria, and renal infiltrates and a tendency for the immune response to worsen with changes in cell populations and the cytokine profile. The number and quality of oocytes were also affected, and the successful pregnancy rate of MRL/lpr mice was limited to only 60%. Isolated oocytes showed severe structural changes in all studied groups. Systemic alterations in immune homeostasis in SLE affect the quality of developing oocytes, which is evident from a young age. The data obtained is in line with the trend of reduced fertility in lupus-prone MRL/lpr mice. The phenomenon can be explained by changes in the microenvironment of the relevant organs and close connection between ovulation and inflammatory processes.

The conneXion between sex and immune responses

There are notable sex-based differences in immune responses to pathogens and self-antigens, with female individuals exhibiting increased susceptibility to various autoimmune diseases, and male individuals displaying preferential susceptibility to some viral, bacterial, parasitic and fungal infections. Although sex hormones clearly contribute to sex differences in immune cell composition and function, the presence of two X chromosomes in female individuals suggests that differential gene expression of numerous X chromosome-linked immune-related genes may also influence sex-biased innate and adaptive immune cell function in health and disease. Here, we review the sex differences in immune system composition and function, examining how hormones and genetics influence the immune system. We focus on the genetic and epigenetic contributions responsible for altered X chromosome-linked gene expression, and how this impacts sex-biased immune responses in the context of pathogen infection and systemic autoimmunity.

Investigating the therapeutic mechanism of Jiedu-Quyu-Ziyin Fang on systemic lupus erythematosus through the ERα-miRNA-TLR7 immune axis

Jiedu-Quyu-Ziyin Fang (JQZF) is a formula that has been empirically used for the treatment of SLE in clinical practice. JQZF has become an approved hospital prescription in China. Fifteen MRL/lpr mice were randomly divided into three groups: Model, JQZF, and JQZF + GC, with five mice in each group. Five MRL/MPJ mice were used as the Blank group. After 8 weeks of administration, peripheral blood serum was collected to detect anti-dsDNA antibodies and complement C3 levels. Spleen B cells were collected to detect the expression of TLR7 and NF-κBp65 mRNA, and correlation analysis was performed. Transcriptome sequencing analysis was also performed on spleen B cells. Further, key miRNA and key gene mRNA expression were detected by RT-qPCR, and key protein expression levels were detected by Western blot method. Bioinformatics methods predicted that ESR1 is a key target of JQZF action on SLE, hsa-miR-146a-5p is one of the key miRNAs, and KEGG pathway analysis showed that NF-κB signaling pathway is its key signaling pathway. Transcriptome sequencing of MRL/lpr mouse spleen B cells revealed that the differential genes between the JQZF and Model groups were enriched in Toll-like receptor signaling pathway, NF-κB signaling pathway, Estrogen signaling pathway, etc. Animal studies show that JQZF treatment significantly boosts serum C3 and lowers anti-dsDNA antibodies (P < 0.01). On the molecular level, JQZF suppresses TLR7 and NF-κBp65 mRNA in spleen B cells, with TLR7 mRNA positively linked to anti-dsDNA titers and negatively to serum C3. Further cellular work demonstrates that JQZF reverses the increased IRAK1 and TRAF6 expression seen after miR146a inhibition. Additionally, post-ERα inhibition, JQZF continues to upregulate miR146a and more significantly reduces TLR7 mRNA expression (P < 0.01), pointing to ERα's pivotal role in the miR146a-TLR7 axis. These results indicate JQZF alleviates SLE by adjusting the ERα-miR146a-TLR7 loop, showcasing its mechanism and therapeutic potential for SLE.

Construction of competing endogenous RNA networks in systemic lupus erythematosus by integrated analysis

Objective

Systemic lupus erythematosus (SLE) is a disease characterised by immune inflammation and damage to multiple organs. Recent investigations have linked competing endogenous RNAs (ceRNAs) to lupus. However, the exact mechanism through which the ceRNAs network affects SLE is still unclear. This study aims to investigate the regulatory functions of the ceRNAs network, which are important pathways that control the pathophysiological processes of SLE.

Methods

CircRNA microarray for our tested assays were derived from bone marrow samples from three healthy individuals and three SLE patients in our hospital. The other sequencing data of circRNA, miRNA and mRNA were obtained from Gene Expression Omnibus (GEO) datasets. Using the limma package of R program, the differential expression of mRNA and miRNA in the GEO database was discovered. Then predicted miRNA-mRNA and circRNA-miRNA were established using miRMap, miRanda, miRDB, TargetScan, and miTarBase. CircRNA-miRNA-mRNA ceRNA network was constructed using Cytoscape, and hub genes were screened using a protein-protein interaction network. Immune infiltration analysis of the hub gene was also performed by CIBERSORT and GSEA.

Results

230 overlapped circRNAs, 86 DEmiRNAs and 2083 DEmRNAs were identified in SLE patients as compared to healthy controls. We constructed a circRNA-miRNA-mRNA ceRNAs network contained 11 overlapped circRNAs, 9 miRNAs and 51 mRNAs. ESR1 and SIRT1 were the most frequently associated protein-protein interactions in the PPI network. KEGG analysis showed that DEGs was enriched in FoxO signaling pathway as well as lipids and atherosclerosis. We constructed a novel circRNA-miRNA-mRNA ceRNA network (HSA circ 0000345- HSA miR-22-3-P-ESR1/SIRT1) that may have a major impact on SLE.

Conclusion

Through this bioinformatics and integrated analysis, we suggest a regulatory role for ceRNA network in the pathogenesis and treatment of SLE.

Renal tubular and glomerular estrogen receptor ß levels are lower in lupus nephritis than in familial Mediterranean fever-associated renal amyloidosis

BACKGROUND

Estrogen has been thought to play an essential role in the disease pathogenesis of systemic lupus erythematosus, which is 9-10 times more prevalent in the female population. It has been shown that irregular estrogen/estrogen receptor signaling pathways may contribute to the pathophysiology of various renal diseases. In this study, we compared renal estrogen receptors between lupus nephritis, familial Mediterranean fever-associated renal amyloidosis, ANCA-associated nephritis, and intact kidney to investigate their role in the pathophysiology of renal diseases.

METHODS

This study was designed as a retrospective cohort study. Thirty systemic lupus erythematosus patients with lupus nephritis, 12 familial Mediterranean fever amyloidosis and 10 ANCA-associated glomerulonephrites, and 14 individuals with normal renal histology were included in the study.

RESULTS

Tubular estrogen receptor ß expression score was found to be significantly higher in the familial Mediterranean fever [5 (1-8)] group than in the lupus nephritis [0 (0-1)] (B = 1.385, OR = 3.996, CI %95 = 1.805-8.846, p = .001) and ANCA [4 (1-6.5)] (B = -1.431, OR = 0.239, CI 95% = 0.093-0.614, p = .003) groups. A significant correlation was found between serum creatinine values and tubular estrogen receptor ß expression score (OR = 0.565, CI 95% = 0.622-1.402, p < .0001). In ANCA-associated glomerulonephritis, a significant relationship was found between fibro cellular crescents in renal biopsy and glomerular estrogen receptor ß expression score (OR = 0.247, CI 95% = 0.11-0.999, p = .045) and tubular estrogen receptor ß expression score (OR = 0.282, CI 95% = -0.180-2.812, p = .026).

CONCLUSIONS

This study showed that tubular estrogen receptor ß expression score was elevated in familial Mediterranean fever amyloidosis and correlated with serum creatinine levels and renal crescents.

Lupus and recurrent pregnancy loss: the role of female sex hormones and B cells

Systemic lupus erythematosus is a debilitating autoimmune disease characterized by uncontrolled activation of adaptive immunity, particularly B cells, which predominantly affects women in a 9 to 1 ratio compared to men. This stark sex disparity strongly suggests a role for female sex hormones in the disease's onset and progression. Indeed, it is widely recognized that estradiol not only enhances the survival of autoreactive B cells but also stimulates the production of autoantibodies associated with systemic lupus erythematosus, such as anti-nuclear antibodies and anti-dsDNA antibodies. Clinical manifestations of systemic lupus erythematosus typically emerge after puberty and persist throughout reproductive life. Furthermore, symptoms often exacerbate during the premenstrual period and pregnancy, as increased levels of estradiol can contribute to disease flares. Despite being fertile, women with lupus face a heightened risk of pregnancy-related complications, including pregnancy loss and stillbirth, which significantly surpass the rates observed in the healthy population. Therefore, this review aims to summarize and discuss the existing literature on the influence of female sex hormones on B-cell activation in patients with systemic lupus erythematosus, with a particular emphasis on their impact on pregnancy loss.

Cardiac and vascular complications in lupus: Is there a role for sex?

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disorder and is characterized by autoantibody formation and subsequent immune complex deposition into target organs. SLE affects nearly nine women to every one man worldwide. Patients with SLE are at an enhanced risk for cardiovascular disease (CVD) morbidity and mortality. CVD is the leading cause of death worldwide and includes heart and blood vessel disorders, cerebrovascular disease, and rheumatic heart disease. Specific mechanisms by which cardiac and vascular pathophysiology develops in patients with SLE are still not fully known. Not only do we not understand this correlation between SLE and CVD, but there is also a critical gap in scientific knowledge on the contribution of sex. In this review, we will discuss the cardiac and vascular pathological disease states that are present in some patients with SLE. More importantly, we will discuss the potential mechanisms for the role of sex and sex hormones in the development of CVD with SLE.

The Influence of Sex Hormones and X Chromosome in Immune Responses

Males and females differ in their susceptibility to develop autoimmunity and allergy but also in their capacity to cope with infections and cancers. Cellular targets and molecular pathways underlying sexual dimorphism in immunity have started to emerge and appeared multifactorial. It became increasingly clear that sex-linked biological factors have important impact on the development, tissue maintenance and effector function acquisition of distinct immune cell populations, thereby regulating multiple layers of innate or adaptive immunity through distinct mechanisms. This review discusses the recent development in our understanding of the cell-intrinsic actions of biological factors linked to sex, sex hormones and sex chromosome complement, on immune cells, which may account for the sex differences in susceptibility to autoimmune diseases and allergies, and the sex-biased responses in natural immunity and cancer.

The effectiveness and safety of total glucosides of paeony in systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

To evaluate the efficacy and safety of total glucosides of paeony in the treatment of systemic lupus erythematosus (SLE).

METHODS

From the creation of the database to July 2021, multiple databases were searched for randomized controlled trials of treating SLE with total glucosides of paeony (TGP) combining chemical medicine. After screening, quality evaluation and data extraction, the included studies were analyzed by Revman5.3 software.

RESULTS

A total of 11 studies were included, including 836 patients (treatment group 417, control group 419). Meta analysis showed that on the basis of routine treatment, TGP could further improve the treatment effective rate (OR = 4.19, 95% CI: 2.21 to 7.95, Z = 4.38, P < .0001), reduced SLE Disease Activity Index (SLEDAI) (MD = -1.70, 95%CI: -2.51 to -0.89, Z = 4.11, P < .0001) and erythrocyte sedimentation rate (MD = -7.04, 95%CI: -8.48 to -5.59, Z = 9.53, P < .00001), reduced the level of immunoglobulin A (IgA) (MD = -0.60, 95%CI: -0.82 to -0.37, Z = 5.24, P < .00001), immunoglobulin G (IgG) (MD = -2.97, 95%CI: -3.72 to -2.23, Z = 7.82, P < .00001), and immunoglobulin M (IgM) (MD = -0.36, 95%CI: -0.45 to -0.27, Z = 7.54, P < .00001), increased the level of complement C3 (MD = 0.34, 95%CI: 0.30 to 0.39, Z = 14.40, P < .00001) and complement C4 (MD = 0.07, 95%CI: 0.06 to 0.08, Z = 10.08, P < .00001), and decreased the recurrence (OR = 0.31, 95%CI: 0.16 to 0.61, Z = 3.39, P = .0007), and there was no significant difference in the incidence of adverse reactions (OR = 0.93, 95%CI: 0.45 to 1.91, Z = 0.20, P = .84).

CONCLUSION

On the basis of conventional treatment, the combined use of TGP can enhance the clinical efficacy of SLE without increasing the incidence of adverse effects.

Sex hormones affect the pathogenesis and clinical characteristics of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) affects women more frequently than men, similar to the female predilection for other autoimmune diseases. Moreover, male patients with SLE exhibit different clinical features than female patients. Sex-associated differences in SLE required special considerations for disease management such as during pregnancy or hormone replacement therapy (HRT). Sex hormones, namely, estrogen and testosterone, are known to affect immune responses and autoimmunity. While estrogen and progesterone promote type I immune response, and testosterone enhances T-helper 1 response. Sex hormones also influence Toll-like receptor pathways, and estrogen receptor signaling is involved in the activation and tolerance of immune cells. Further, the clinical features of SLE vary according to hormonal changes in female patients. Alterations in sex hormones during pregnancy can alter the disease activity of SLE, which is associated with pregnancy outcomes. Additionally, HRT may change SLE status. Sex hormones affect the pathogenesis, clinical features, and management of SLE; thus, understanding the occurrence and exacerbation of disease caused by sex hormones is necessary to improve its management.

How does age determine the development of human immune-mediated arthritis?

Does age substantially affect the emergence of human immune-mediated arthritis? Children do not usually develop immune-mediated articular inflammation during their first year of life. In patients with juvenile idiopathic arthritis, this apparent ‘immune privilege’ disintegrates, and chronic inflammation is associated with variable autoantibody signatures and patterns of disease that resemble adult arthritis phenotypes. Numerous mechanisms might be involved in this shift, including genetic and epigenetic predisposing factors, maturation of the immune system with a progressive modulation of putative tolerogenic controls, parallel development of microbial dysbiosis, accumulation of a pro-inflammatory burden driven by environmental exposures (the exposome) and comorbidity-related drivers. By exploring these mechanisms, we expand the discussion of three (not mutually exclusive) hypotheses on how these factors can contribute to the differences and similarities between the loss of immune tolerance in children and the development of established immune-mediated arthritis in adults. These three hypotheses relate to a critical window in genetics and epigenetics, immune maturation, and the accumulation of burden. The varied manifestation of the underlying mechanisms among individuals is only beginning to be clarified, but the establishment of a framework can facilitate the development of an integrated understanding of the pathogenesis of arthritis across all ages.

In this Review, the authors discuss age-related arthropathy and the similarities and differences between childhood loss of immune tolerance and adult development of immune-mediated arthritis, and develop three hypotheses describing age-related mechanisms that contribute to the onset of arthritis.

The arthritis-free ‘immune privilege’ of early childhood is overridden by multiple mechanisms, progressively and age-dependently, generating recognizable patterns of chronic inflammatory arthritis.

The emergence of arthritis involves interconnected mechanisms related to immune priming, to a situational susceptibility and to the accumulation of an inflammatory burden.

The accumulation of epigenetic drift may contribute to differences across ages.

The exposome is expected to contribute to arthritis emergence in adults as well as in children.

Sex bias in systemic lupus erythematosus: a molecular insight

Acknowledging sex differences in immune response is particularly important when we consider the differences between men and women in the incidence of disease. For example, over 80% of autoimmune disease occurs in women, whereas men have a higher incidence of solid tumors compared to women. In general women have stronger innate and adaptive immune responses than men, explaining their ability to clear viral and bacterial infections faster, but also contributing to their increased susceptibility to autoimmune disease. The autoimmune disease systemic lupus erythematosus (SLE) is the archetypical sexually dimorphic disease, with 90% of patients being women. Various mechanisms have been suggested to account for the female prevalence of SLE, including sex hormones, X-linked genes, and epigenetic regulation of gene expression. Here, we will discuss how these mechanisms contribute to pathobiology of SLE and how type I interferons work with them to augment sex specific disease pathogenesis in SLE.

Altered Phenotype and Enhanced Antibody-Producing Ability of Peripheral B Cells in Mice with Cd19-Driven Cre Expression

Given the importance of B lymphocytes in inflammation and immune defense against pathogens, mice transgenic for Cre under the control of Cd19 promoter (Cd19^Cre/+ mice) have been widely used to specifically investigate the role of loxP-flanked genes in B cell development/function. However, impacts of expression/insertion of the Cre transgene on the phenotype and function of B cells have not been carefully studied. Here, we show that the number of marginal zone B and B1a cells was selectively reduced in Cd19^Cre/+ mice, while B cell development in the bone marrow and total numbers of peripheral B cells were comparable between Cd19^Cre/+ and wild type C57BL/6 mice. Notably, humoral responses to both T cell-dependent and independent antigens were significantly increased in Cd19^Cre/+ mice. We speculate that these differences are mainly attributable to reduced surface CD19 levels caused by integration of the Cre-expressing cassette that inactivates one Cd19 allele. Moreover, our literature survey showed that expression of Cd19^Cre/+ alone may affect the development/progression of inflammatory and anti-infectious responses. Thus, our results have important implications for the design and interpretation of results on gene functions specifically targeted in B cells in the Cd19^Cre/+ mouse strain, for instance, in the context of (auto) inflammatory/infectious diseases.

Estrogen and estrogen receptors in kidney diseases

Acute kidney injury (AKI) and chronic kidney disease (CKD) are posing great threats to global health within this century. Studies have suggested that estrogen and estrogen receptors (ERs) play important roles in many physiological processes in the kidney. For instance, they are crucial in maintaining mitochondrial homeostasis and modulating endothelin-1 (ET-1) system in the kidney. Estrogen takes part in the kidney repair and regeneration via its receptors. Estrogen also participates in the regulation of phosphorus homeostasis via its receptors in the proximal tubule. The ERα polymorphisms have been associated with the susceptibilities and outcomes of several renal diseases. As a consequence, the altered or dysregulated estrogen/ERs signaling pathways may contribute to a variety of kidney diseases, including various causes-induced AKI, diabetic kidney disease (DKD), lupus nephritis (LN), IgA nephropathy (IgAN), CKD complications, etc. Experimental and clinical studies have shown that targeting estrogen/ERs signaling pathways might have protective effects against certain renal disorders. However, many unsolved problems still exist in knowledge regarding the roles of estrogen and ERs in distinct kidney diseases. Further research is needed to shed light on this area and to enable the discovery of pathway-specific therapies for kidney diseases.

Estrogen Receptor Alpha Signaling Is Responsible for the Female Sex Bias in the Loss of Tolerance and Immune Cell Activation Induced by the Lupus Susceptibility Locus Sle1b

The dramatic female sex bias observed in human lupus is thought to be due, at least in part, to estrogens. Using mouse models, we have shown that estrogens, acting through estrogen receptor alpha (ERα) promote lupus development and contribute significantly to the female sex bias observed in this disease. C57Bl/6 (B6) mice carrying the lupus susceptibility locus Sle1 locus exhibit immune cell hyperactivation and loss of tolerance, and the action of Sle1 displays a strong female sex bias. Previously, we showed that disruption of ERα completely eliminates the female sex bias in the effects of Sle1. Here we report that ERα signaling selectively modulates the action of Sle1b, one of the three subloci that together constitute Sle1. We observed that disruption of ERα signaling attenuated T cell hyperactivation, formation of spontaneous germinal centers, loss of tolerance, and the development of anti-chromatin autoantibodies in B6.Sle1b female mice, but had no impact on these phenotypes in B6.Sle1b male mice. In fact, disruption of ERα completely abolished the female sex bias that is seen in each of these phenotypes in B6.Sle1b mice. Strikingly, Sle1b-induced B cell hyperactivation, a female sex-specific manifestation of Sle1b, was completely abrogated by disruption of ERα in B6.Sle1b females. Altogether, these results demonstrate that ERα signaling is responsible for the female sex bias in the actions of Sle1b, and is absolutely required for the female-specific B cell hyperactivation phenotype associated with this lupus susceptibility locus. By contrast, we found that ERα signaling had no impact on Sle1a, the other Sle1 sublocus that exerts effects that show a female sex bias.

Increased estrogen to androgen ratio enhances immunoglobulin levels and impairs B cell function in male mice

Sex steroids, such as estrogens and androgens, are important regulators of the humoral immune response. Studies in female mice have demonstrated that alteration of circulating estrogen concentration regulates antibody-mediated immunity. As males have normally little endogenous estrogen, we hypothesized that in males high estrogens and low androgens affect the immune system and enhance the allergic inflammatory response. Here, we studied transgenic male mice expressing human aromatase (AROM+). These animals have a high circulating estrogen to androgen ratio (E/A), causing female traits such as gynecomastia. We found that AROM+ male mice had significantly higher plasma immunoglobulin levels, particularly IgE. Flow cytometry analyses of splenocytes revealed changes in mature/immature B cell ratio together with a transcriptional upregulation of the Igh locus. Furthermore, higher proliferation rate and increased IgE synthesis after IgE class-switching was found. Subsequently, we utilized an ovalbumin airway challenge model to test the allergic response in AROM+ male mice. In line with above observations, an increase in IgE levels was measured, albeit no impact on immune cell infiltration into the lungs was detected. Together, our findings suggest that high circulating E/A in males significantly alters B cell function without any significant enhancement in allergic inflammation.

Klinefelter's syndrome with systemic lupus erythematosus and atrial fibrillation

We describe a 65-year-old man who presented with arthralgia, reduced body hair and gynecomastia. He showed severe pancytopaenia. Laboratory examination revealed high follicle-stimulating hormone, low testosterone and oestradiol, elevated antinuclear antibodies, anti-dsDNA and ESR levels, as well as low complement levels. An electrocardiogram showed atrial fibrillation. Computed tomography and dual-energy x-ray absorptiometry showed pleural effusion and osteoporosis. Chromosome analysis revealed 47, XXY karyotype. The unifying diagnosis was therefore Klinefelter's syndrome (KS) with systemic lupus erythematosus (SLE), with manifestations of pancytopaenia, atrial fibrillation, serositis and osteoporosis. After immunosuppressive therapy, his physical condition and pancytopaenia improved. Sex hormones and gene escape from X chromosome inactivation may contribute to the pathogenesis of SLE. Clinicians should consider autoimmune processes when patients with KS present with pancytopaenia or additional features of a systemic autoimmune disorder.

DNA methylation was involved in total glucosides of paeony regulating ERα for the treatment of female systemic lupus erythematosus mice

Total glucosides of paeony (TGP) is a bioactive compound extracted from paeony roots and has been used in therapy for autoimmune diseases. However the molecular mechanism of TGP in the therapy of autoimmune diseases remains unclear. ERα has a pro-inflammatory role in SLE disease. In this study, we found that TGP treatment significantly decreased the expression of ERα by up-regulating ERα promoter methylation levels. Further investigation revealed that treatment with TGP increased the expression of DNMT in lupus mice. We also used DNA methyltransferase inhibitors to verify whether DNA methylation was involved in these process. HE staining results showed that TGP can reduce renal injury in SLE mice. Moreover, cytokines including IFN-γ, IL6 and IL12 expression and dsDNA levels in serum were inhibited by TGP treatment. These findings indicate that TGP inhibits autoimmunity in SLE mice possibly by downregulate ERα expression, which may in turn be due to its ability to regulate the methylation status of the ERα promoter.

Updated advances of linking psychosocial factors and sex hormones with systemic lupus erythematosus susceptibility and development

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that primarily affects women, especially those of reproductive age. Genetics, environment, and gene-environment interactions play key roles in the development of SLE. Despite the numerous susceptibility genes of SLE identified to date, gene therapy is far from a clinical reality. Thus, more attention should be paid to the risk factors and underlying mechanisms of SLE. Currently, it is reported that psychosocial factors and sex hormones play vital roles in patients with SLE, which still need further investigated. The purpose of this review is to update the roles and mechanisms of psychosocial factors and sex hormones in the susceptibility and development of SLE. Based on review articles and reports in reputable peer-reviewed journals and government websites, this paper summarized psychosocial factors (e.g., alexithymia, depression, anxiety, negative emotions, and perceived stress) and sex hormones (e.g., estrogens, progesterone, androgens, and prolactin) involved in SLE. We further explore the mechanisms linking these factors with SLE susceptibility and development, which can guide the establishment of practical measures to benefit SLE patients and offer new ideas for therapeutic strategies.

Association of oestrogen receptor alpha gene polymorphisms with systemic lupus erythematosus risk: An updated meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease, and oestrogen is considered to be a predisposing factor for SLE. Although some studies are conducted to explore the association between oestrogen receptor alpha (ERα) gene polymorphisms and SLE susceptibility, their results are inconsistent.

METHODS

Meta-analysis was conducted to confirm whether ERα gene polymorphisms were associated with SLE susceptibility, and the strength of association was anticipated by pooled ORs with 95% CIs. Stata software package version 12.0 was used to calculate all the statistical analyses.

RESULTS

Twelve studies included 2494 cases and 4176 controls were incorporated in our meta-analysis. A significant association was found for ERα PvuII polymorphism in the overall population (CC+CT vs TT: OR = 1.334, 95% CI = 1.195-1.490, P < 0.001; CC vs TT: OR = 1.401, 95% CI = 1.096-1.791, P = 0.007; CT vs TT: OR = 1.284, 95% CI = 1.141-1.444, P < 0.001; C vs T: OR = 1.221, 95% CI = 1.084-1.375, P = 0.001), while there was no significant association for ERα XbaI polymorphism. Besides, in stratification analyses by ethnicity, the PvuII polymorphism was associated with an increased risk of SLE in Asians (CC+CT vs TT: OR = 1.379, 95% CI = 1.203-1.581, P < 0.001; CT vs TT: OR = 1.308, 95% CI = 1.130-1.515, P < 0.001; C vs T: OR = 1.240, 95% CI = 1.052-1.462, P = 0.010), while for ESR1 XbaI polymorphism, a significantly increased risk of SLE susceptibility was found in Asians (GA vs AA: OR = 1.271, 95% CI = 1.101-1.467, P = 0.001).

CONCLUSION

Our meta-analysis indicated that the ERα PvuII polymorphism was significantly associated with SLE susceptibility in the overall and Asian populations, while the ERα XbaI GA genotype only played a key role in SLE susceptibility in Asian populations.

Sex Hormones in Acquired Immunity and Autoimmune Disease

Women have stronger immune responses to infections and vaccination than men. Paradoxically, the stronger immune response comes at a steep price, which is the high incidence of autoimmune diseases in women. The reasons why women have stronger immunity and higher incidence of autoimmunity are not clear. Besides gender, sex hormones contribute to the development and activity of the immune system, accounting for differences in gender-related immune responses. Both innate and adaptive immune systems bear receptors for sex hormones and respond to hormonal cues. This review focuses on the role of sex hormones particularly estrogen, in the adaptive immune response, in health, and autoimmune disease with an emphasis on systemic lupus erythematosus.

Female predisposition to TLR7-driven autoimmunity: gene dosage and the escape from X chromosome inactivation

Women develop stronger immune responses than men, with positive effects on the resistance to viral or bacterial infections but magnifying also the susceptibility to autoimmune diseases like systemic lupus erythematosus (SLE). In SLE, the dosage of the endosomal Toll-like receptor 7 (TLR7) is crucial. Murine models have shown that TLR7 overexpression suffices to induce spontaneous lupus-like disease. Conversely, suppressing TLR7 in lupus-prone mice abolishes SLE development. TLR7 is encoded by a gene on the X chromosome gene, denoted TLR7 in humans and Tlr7 in the mouse, and expressed in plasmacytoid dendritic cells (pDC), monocytes/macrophages, and B cells. The receptor recognizes single-stranded RNA, and its engagement promotes B cell maturation and the production of pro-inflammatory cytokines and antibodies. In female mammals, each cell randomly inactivates one of its two X chromosomes to equalize gene dosage with XY males. However, 15 to 23% of X-linked human genes escape X chromosome inactivation so that both alleles can be expressed simultaneously. It has been hypothesized that biallelic expression of X-linked genes could occur in female immune cells, hence fostering harmful autoreactive and inflammatory responses. We review here the current knowledge of the role of TLR7 in SLE, and recent evidence demonstrating that TLR7 escapes from X chromosome inactivation in pDCs, monocytes, and B lymphocytes from women and Klinefelter syndrome men. Female B cells where TLR7 is thus biallelically expressed display higher TLR7-driven functional responses, connecting the presence of two X chromosomes with the enhanced immunity of women and their increased susceptibility to TLR7-dependent autoimmune syndromes.

Gender Bias in Human Systemic Lupus Erythematosus: A Problem of Steroid Receptor Action?

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease resulting from abnormal interactions between T and B cells. The acquisition of SLE is linked to genetic susceptibility, and diverse environmental agents can trigger disease onset in genetically susceptible individuals. However, the strongest risk factor for developing SLE is being female (9:1 female to male ratio). The female sex steroid, estradiol, working through its receptors, contributes to the gender bias in SLE although the mechanisms remain enigmatic. In a small clinical trial, monthly administration of the estrogen receptor (ERα) antagonist, ICI182,780 (fulvestrant), significantly reduced disease indicators in SLE patients. In order to identify changes that could account for improved disease status, the present study utilized fulvestrant (Faslodex) to block ERα action in cultured SLE T cells that were purified from blood samples collected from SLE patients (n = 18, median age 42 years) and healthy control females (n = 25, median age 46 years). The effects of ERα antagonism on estradiol-dependent gene expression and canonical signaling pathways were analyzed. Pathways that were significantly altered by addition of Faslodex included T helper (Th) cell differentiation, steroid receptor signaling [glucocorticoid receptor (GR), ESR1 (ERα)], ubiquitination, and sumoylation pathways. ERα protein expression was significantly lower (p < 0.018) in freshly isolated, resting SLE T cells suggesting ERα turnover is inherently faster in SLE T cells. In contrast, ERα/ERβ mRNA and ERβ protein levels were not significantly different between SLE and normal control T cell samples. Plasma estradiol levels did not differ (p > 0.05) between SLE patients and controls. A previously undetected interaction between GR and ERα signaling pathways suggests posttranslational modification of steroid receptors in SLE T cells may alter ERα/GR actions and contribute to the strong gender bias of this autoimmune disorder.

Pathogenesis of Human Systemic Lupus Erythematosus: A Cellular Perspective

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease affecting multiple organs. A complex interaction of genetics, environment, and hormones leads to immune dysregulation and breakdown of tolerance to self-antigens, resulting in autoantibody production, inflammation, and destruction of end-organs. Emerging evidence on the role of these factors has increased our knowledge of this complex disease, guiding therapeutic strategies and identifying putative biomarkers. Recent findings include the characterization of genetic/epigenetic factors linked to SLE, as well as cellular effectors. Novel observations have provided an improved understanding of the contribution of tissue-specific factors and associated damage, T and B lymphocytes, as well as innate immune cell subsets and their corresponding abnormalities. The intricate web of involved factors and pathways dictates the adoption of tailored therapeutic approaches to conquer this disease.