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

Deciphering Autoimmune Diseases: Unveiling the Diagnostic, Therapeutic, and Prognostic Potential of Immune Repertoire Sequencing

Autoimmune diseases (AIDs) are immune system disorders where the body exhibits an immune response to its own antigens, causing damage to its own tissues and organs. The pathogenesis of AIDs is incompletely understood. However, recent advances in immune repertoire sequencing (IR-seq) technology have opened-up a new avenue to study the IR. These studies have revealed the prevalence in IR alterations, potentially inducing AIDs by disrupting immune tolerance and thereby contributing to our comprehension of AIDs. IR-seq harbors significant potential for the clinical diagnosis, personalized treatment, and prognosis of AIDs. This article reviews the application and progress of IR-seq in diseases, such as multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and type 1 diabetes, to enhance our understanding of the pathogenesis of AIDs and offer valuable references for the diagnosis and treatment of AIDs.

Subclinical choroidal involvement in Systemic Lupus Erythematosus

PURPOSE

To assess the choroidal status of Systemic Lupus Erythematosus (SLE) patients using Optical Coherence Tomography (OCT) and OCT-Angiography.

METHODS

SLE patients with disease duration < 10 years, no disease activity and no ocular involvement were recruited and cross-sectionally evaluated. A demographically similar cohort of healthy subjects was used for comparison. The main outcome is choroidal vascularity index (CVI). As secondary outcomes, choriocapillaris parameters and choroidal thickness (CT) were evaluated.

RESULTS

Forty eyes of 40 subjects (20 SLE patients and 20 healthy subjects) were studied with a mean ± SD age of 36.7 ± 9.9 years. In the SLE group, the mean ± SD duration of disease was 7.35 ± 2.21 years. Increased CVI was found in the SLE group (p = 0.022). Considering the choriocapillaris, SLE patients presented a lower number (p = 0.037) and a smaller total area (p = 0.041) of signal voids. No differences between groups were found in CT. For SLE patients, CT at subfoveal, temporal and inferior locations presented a negative moderate correlation with disease duration. A strong correlation between choriocapillaris parameters and age was demonstrated for both groups.

CONCLUSIONS

This study provides evidence of subclinical choroidal changes in adult SLE patients with inactive disease and no overt ocular manifestation. Increased CVI and fewer and smaller flow voids in choriocapillaris with normal CT suggest increased choroidal vascularity in SLE.

Risks and outcomes of pregnancy in neuromyelitis optica spectrum disorder: A comprehensive review

Neuromyelitis optica spectrum disorder (NMOSD) is a rare central nervous system autoimmune disease. Aquaporin-4 antibody (AQP4-IgG) is present in over 75% of cases and criteria also exist for the diagnosis of seronegative NMOSD. AQP4-IgG NMOSD has a strong female predominance (9:1 ratio), with a median onset age of 40 years. Pregnancy in those with NMOSD is therefore an important topic. Fecundity in NMOSD is likely impaired, and for females who conceive, obstetric complications including miscarriages and pre-eclampsia are significantly higher in NMOSD compared to the general population and in related conditions such as multiple sclerosis (MS). In contrast to MS, NMOSD disease activity does not subside during pregnancy. Also, relapse risk substantially rises above pre-pregnancy rates in the early postpartum period. In view of the evolving landscape of NMOSD, we provide a contemporary update of the impacts of pregnancy in NMOSD.

TLR7 activation by imiquimod worsens glycemic control in female FVB/N mice consuming a high-fat diet

Toll-like receptor-7 (TLR7) activation promotes autoimmunity, and metabolic syndrome (MetS) is a common comorbidity in patients with autoimmune disease. We previously demonstrated hyperinsulinemia in TLR7 agonist imiquimod (IMQ)-treated, high-fat diet (HFD)-fed female C57BL/6 mice. Since mouse strains differ in susceptibility to MetS and target organ damage, this study investigated whether 12 weeks of exposure to HFD and IMQ promoted MetS, autoimmunity, and target organ damage in female FVB/N mice. Supporting early-stage autoimmunity, spleen-to-tibia ratio, and anti-nuclear antibodies (ANA) were significantly increased by IMQ. No significant effect of IMQ on urinary albumin excretion or left ventricular hypertrophy was observed. HFD increased liver-to-tibia ratio, which was further exacerbated by IMQ. HFD increased fasting blood glucose levels at the end of 12 weeks, but there was no significant effect of IMQ treatment on fasting blood glucose levels at 6 or 12 weeks of treatment. However, oral glucose tolerance testing at 12 weeks revealed impaired glucose tolerance in HFD-fed mice compared to control diet mice together with IMQ treatment exacerbating the impairment. Accordingly, these data suggest TLR7 activation also exacerbates HFD-induced dysregulation of glucose handling FVB/N mice, supporting the possibility that endogenous TLR7 activation may contribute to dysglycemia in patients with autoimmune disease.

Identification of biomarkers associated with immune scores in diabetic retinopathy

Background

Diabetic retinopathy (DR) causes irreversible visual impairment in diabetes mellitus (DM) patients. Immunity played a crucial role in DR. Nevertheless, the triggering mechanism of DR was not yet thorough enough. Herein, we aim to identify the immune-associated genes as biomarkers associated with immune scores that can distinguish early DR from DM without DR.

Methods

In this study, total RNA of peripheral blood mononuclear cell (PBMC) samples from 15 non-proliferative DR patients and 15 DM patients without DR were collected and the transcriptome sequencing data were extracted. Firstly, the target genes were obtained by intersecting the differentially expressed genes (DEGs), which were screened by "limma", and the module genes (related to immune scores), which were screened by "WGCNA". In order to screen for the crucial genes, three machine learning algorithms were implemented, and a receiver operating characteristic (ROC) curve was used to obtain the diagnostic genes. Moreover, the gene set enrichment analysis (GSEA) was performed to understand the function of diagnostic genes, and analysis of the proportions of immune cells and their association with diagnostic genes was performed to analyze the pathogenesis of DR. Furthermore, the regulatory network of TF-mRNA-miRNA was built to reveal the possible regulation of diagnostic genes. Finally, the quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the mRNA level of diagnostic genes.

Results

A total of three immune-associated diagnostic genes, namely, FAM209B, POM121L1P, and PTGES, were obtained, and their expression was increased in PBMC samples of DR, and qRT-PCR results confirmed these results. Moreover, the functions of these genes were associated with immune response. The expression of POM121L1P and PTGES was significantly negatively associated with naive B cells, and the expression of FAM209B was significantly negatively associated with immature dendritic cells. Moreover, ESR1 could regulate both FAM209B and PTGES.

Conclusion

This study identified three immune-associated diagnostic genes, FAM209B, POM121L1P, and PTGES, as biomarkers associated with immune scores in DR for the first time. This finding might proffer a novel perspective of the triggering mechanism of DR, and help to understand the role of immune-associated genes in the molecular mechanism of DR more deeply.

Gender Disparities in Hospitalization Outcomes and Healthcare Utilization Among Patients with Systemic Lupus Erythematosus in the United States

Background Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by various clinical manifestations. Despite efforts to improve outcomes, mortality rates remain high, and certain disparities, including gender, may influence prognosis and mortality rates in SLE. This study aims to examine the gender disparities in outcomes of SLE hospitalizations in the US. Methods We conducted a retrospective analysis of the Nationwide Inpatient Sample (NIS) database between 2016 and 2020. The NIS database is the largest publicly available all-payer database for inpatient care in the United States, representing approximately 20% of all hospitalizations nationwide. We selected every other year during the study period and included hospitalizations of adult patients (≥18 years old) with a primary or secondary diagnosis of SLE using International Classification of Diseases, Tenth Revision (ICD-10) codes. The control population consisted of all adult hospitalizations. Multivariate logistic regression was used to estimate the strength of the association between gender and primary and secondary outcomes. The regression models were adjusted for various factors, including age, race, median household income based on patients' zip codes, Charlson comorbidity index score, insurance status, hospital location, region, bed size, and teaching status. To ensure comparability across the years, revised trend weights were applied as the healthcare cost and use project website recommends. Stata version 17 (StataCorp LLC, TX, USA) was used for the statistical analyses, and a two-sided P-value of less than 0.05 was considered statistically significant. Results Among the 42,875 SLE hospitalizations analyzed, women accounted for a significantly higher proportion (86.4%) compared to men (13.6%). The age distribution varied, with the majority of female admissions falling within the 30- to 60-year age range, while most male admissions fell within the 15- to 30-year age category. Racial composition showed a slightly higher percentage of White Americans in the male cohort compared to the female cohort. Notably, more Black females were admitted for SLE compared to Black males. Male SLE patients had a higher burden of comorbidities and were more likely to have Medicare and private insurance, while a higher percentage of women were uninsured. The mortality rate during the index hospitalization was slightly higher for men (1.3%) compared to women (1.1%), but after adjusting for various factors, there was no statistically significant gender disparity in the likelihood of mortality (adjusted odds ratio (aOR): 1.027; 95% confidence interval (CI): 0.570-1.852; P=0.929). Men had longer hospital stays and incurred higher average hospital costs compared to women (mean length of stay (LOS): seven days vs. six days; $79,751 ± $5,954 vs. $70,405 ± $1,618 respectively). Female SLE hospitalizations were associated with a higher likelihood of delirium, psychosis, and seizures while showing lower odds of hematological and renal diseases compared to men. Conclusion While women constitute the majority of SLE hospitalizations, men with SLE tend to have a higher burden of comorbidities and are more likely to have Medicare and private insurance. Additionally, men had longer hospital stays and incurred higher average hospital costs. However, there was no significant gender disparity in the likelihood of mortality after accounting for various factors.

Estradiol in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune polymorphous disease that primarily affects women of reproductive age. This gender disparity has suggested the importance of investigating the role of reproductive hormones in the pathogenesis of the disease. Estradiol, the most potent form of estrogen, plays a key role in shaping the immune system including the production of lymphocytes, the peripheral differentiation of regulatory T cells (T-regs), antibody production, and the complement and interferon systems, and has been studied in the pathogenesis of systemic lupus erythematosus (SLE). It operates by binding to estrogen receptors (ERs) α and β, initiating cellular responses including alterations in gene expression. Regulatory T cells are instrumental in preserving immunological self-tolerance and moderating immune responses. Estradiol's serum levels correlate with the expansion of CD4+CD25+ and FoxP3+ in healthy females. However, this response is reduced in lupus patients. Estradiol also interacts with microRNAs (miRNAs) in gene regulation. Hsa-miR-10b-5p, a miRNA targeting SRSF1, is overexpressed in SLE patients and its levels increase with exposure to estrogens. Other miRNAs also show correlation with plasma Estradiol levels. The precise role of Estradiol in the pathogenesis of SLE remains complex and multifaceted and is a topic for further research.

Clinical characteristics, management, and quality of life of psoriasis patients with coexistent lupus erythematosus: Data from the Malaysian Psoriasis Registry

OBJECTIVE

To describe the clinical characteristics, management and quality of life of psoriasis patients with and without coexistent lupus erythematosus (LE).

METHODS

This retrospective cross-sectional study uses data from the Malaysian Psoriasis Registry (MPR) from January 2007 to December 2018.

RESULTS

Of 21 735 psoriasis patients, 34 (0.16%) had coexistent LE. The male to female ratio among psoriasis patients with coexistent LE was 1:5.8 versus 1.3:1 in patients with psoriasis but without LE. Nearly 70% presented with LE preceding psoriasis. Psoriasis patients with LE had an earlier age of psoriasis onset (27.56 ± 11.51 versus 33.31 ± 16.94 years, P = 0.006), a higher rate of psoriatic arthropathy (26.5% versus 13.0%, P = 0.02), and a significantly greater impairment of quality of life (Dermatology Quality of Life Index >10; 57.6% versus 40.3%, P = 0.04) compared with psoriasis patients without LE. The majority (87.5%) had systemic LE. The incidences of lupus nephritis (72.7% versus 40%) and hematological abnormalities (50% versus 20%) were higher among patients with LE preceding psoriasis compared with those with psoriasis preceding LE. Antinuclear antibody and double-stranded DNA were positive in 59.4% and 28.1% of psoriasis patients with LE, respectively. Hydroxychloroquine triggered the onset of psoriasis in 7 (24.1%) patients. Patients with LE were more likely to receive systemic treatment for psoriasis compared with those without LE (30.3% versus 14.2%, P = 0.008).

CONCLUSIONS

Psoriasis patients with coexistent LE were uncommon, displayed a female preponderance, were more likely to have joint involvement, and had greater quality of life impairment than those without LE. LE preceded psoriasis in most of these patients, and systemic LE was the most common subtype.

Renal TLR-7/TNF-α pathway as a potential female-specific mechanism in the pathogenesis of autoimmune-induced hypertension

Hypertension is prevalent in patients with systemic lupus erythematosus (SLE). The goal of the current study is to track the pathogenesis of hypertension and renal injury in SLE, identify contributory mechanisms, and highlight differences in disease development among sexes. Mean arterial pressure was measured in conscious male and female SLE (NZBWF1) and control (NZW) mice at 34-35 wk of age using indwelling arterial catheters. Measures of renal injury, renal inflammation, and renal hemodynamics were used to monitor the potential contributors to latent sex differences. Both male and female SLE mice were hypertensive at 35 wk of age, and the hypertension was linked to renal injury in females, but not in males. A known contributor of renal pathology in SLE, Toll-like receptor (TLR)-7, and its downstream effector, the proinflammatory cytokine tumor necrosis factor (TNF)-α, were lower in male SLE mice than in females. Male SLE mice also had higher glomerular filtration rate (GFR) and lower renal vascular resistance (RVR) than females. Our data suggest that although hypertension in female SLE mice is associated with renal mechanisms, hypertension in male SLE mice may develop independent of renal changes. Future studies will continue to dissect sex-specific factors that should be considered when treating patients with hypertension with underlying chronic inflammation and/or autoimmunity.NEW & NOTEWORTHY There is a high prevalence of hypertension in male and female SLE; however, male SLE mice are hypertensive without renal involvement. The development of hypertension in female SLE mice is renocentric and strongly associated with injurious renal mechanisms like the TLR-7→TNF-α pathway. This clear difference in the pathogenesis among the sexes could have a significant impact on how we treat patients with hypertension with underlying chronic autoimmune/inflammatory diseases.

The aberrant expression of CD45 isoforms and levels of sex hormones in systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a common autoimmune disease with significant gender bias in women, and sex hormones are considered to play an important role in the regulation of immune activity. The CD45 isoforms generated through alternative splicing of mRNA identify different functional status of lymphocytes and also are suggested as a biomarker for assessing the progression of SLE, while the modulation of CD45 expression in SLE patients is not clear.

METHODS

In this study, the peripheral blood sera of 46 SLE patients and 15 health individuals were collected for detecting the levels of sex hormones and immune associated factors. The expression of CD45 isoforms and the status of CD45 DNA methylation of the peripheral mononuclear blood cells were detected by flow cytometry and bisulfite sequencing PCR, respectively.

RESULTS

The levels of complement C3 and IgA decreased, especially decline of the serum IgA to the level of selective immunoglobulin A deficiency, and the C-reactive protein increased in SLE patients when compared with healthy controls, which manifested the abnormal immune activity of the SLE patients. Sex hormones detection showed a decreased testosterone and increased prolactin in SLE. An accelerated expression of CD45RO, reduced CD45RA and CD45RB, and a relative hypermethylation of CD45 DNA in SLE were also identified that provided a clue to explain the possible regulatory mechanism for the immune function in SLE.

CONCLUSION

The results indicated that the aberrant CD45 isoforms, DNA methylation and hormone levels might be correlated with the imbalanced immune activity of SLE patients. Key Points • Selective immunoglobulin A deficiency was significantly higher in SLE than in healthy individuals. • SLE patients had decreased testosterone and increased prolactin in the sera. • An aberrant expression of CD45 isoforms and CD45 DNA methylation were identified in SLE.

Update on Management of Cardiovascular Diseases in Women

Cardiovascular diseases (CVD) have a lower prevalence in women than men; although, a higher mortality rate and a poorer prognosis are more common in women. However, there is a misperception of CVD female risk since women have commonly been considered more protected so that the real threat is vastly underestimated. Consequently, female patients are more likely to be treated less aggressively, and a lower rate of diagnostic and interventional procedures is performed in women than in men. In addition, there are substantial sex differences in CVD, so different strategies are needed. This review aims to evaluate the main gender-specific approaches in CVD.

Long Non-coding RNAs in Rheumatology

The last decade has seen an enormous increase in long non-coding RNA (lncRNA) research within rheumatology. LncRNAs are arbitrarily classed as non-protein encoding RNA transcripts that exceed 200 nucleotides in length. These transcripts have tissue and cell specific patterns of expression and are implicated in a variety of biological processes. Unsurprisingly, numerous lncRNAs are dysregulated in rheumatoid conditions, correlating with disease activity and cited as potential biomarkers and targets for therapeutic intervention. In this chapter, following an introduction into each condition, we discuss the lncRNAs involved in rheumatoid arthritis, osteoarthritis and systemic lupus erythematosus. These inflammatory joint conditions share several inflammatory signalling pathways and therefore not surprisingly many commonly dysregulated lncRNAs are shared across these conditions. In the interest of translational research only those lncRNAs which are strongly conserved have been addressed. The lncRNAs discussed here have diverse roles in regulating inflammation, proliferation, migration, invasion and apoptosis. Understanding the molecular basis of lncRNA function in rheumatology will be crucial in fully determining the inflammatory mechanisms that drive these conditions.

Gut Microbiota Dysbiosis in Systemic Lupus Erythematosus: Novel Insights into Mechanisms and Promising Therapeutic Strategies

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that was traditionally thought to be closely related to genetic and environmental risk factors. Although treatment options for SLE with hormones, immunosuppressants, and biologic drugs are now available, the rates of clinical response and functional remission of these drugs are still not satisfactory. Currently, emerging evidence suggests that gut microbiota dysbiosis may play crucial roles in the occurrence and development of SLE, and manipulation of targeting the gut microbiota holds great promises for the successful treatment of SLE. The possible mechanisms of gut microbiota dysbiosis in SLE have not yet been well identified to date, although they may include molecular mimicry, impaired intestinal barrier function and leaky gut, bacterial biofilms, intestinal specific pathogen infection, gender bias, intestinal epithelial cells autophagy, and extracellular vesicles and microRNAs. Potential therapies for modulating gut microbiota in SLE include oral antibiotic therapy, fecal microbiota transplantation, glucocorticoid therapy, regulation of intestinal epithelial cells autophagy, extracellular vesicle-derived miRNA therapy, mesenchymal stem cell therapy, and vaccination. This review summarizes novel insights into the mechanisms of microbiota dysbiosis in SLE and promising therapeutic strategies, which may help improve our understanding of the pathogenesis of SLE and provide novel therapies for SLE.

Post-translational modifications in T cells in systemic erythematosus lupus

Systemic erythematosus lupus (SLE) is a classic autoimmune disease characterized by multiple autoantibodies and immune-mediated tissue damage. The aetiology of this disease is still unclear. A new drug, belimumab, which acts against the B-lymphocyte stimulator (BLyS), can effectively improve the condition of SLE patients, but it cannot resolve all SLE symptoms. The discovery of novel, precise therapeutic targets is urgently needed. It is well known that abnormal T-cell function is one of the most crucial factors contributing to the pathogenesis of SLE. Protein post-translational modifications (PTMs), including phosphorylation, glycosylation, acetylation, methylation, ubiquitination and SUMOylation have been emphasized for their roles in activating protein activity, maintaining structural stability, regulating protein-protein interactions and mediating signalling pathways, in addition to other biological functions. Summarizing the latest data in this area, this review focuses on the potential roles of diverse PTMs in regulating T-cell function and signalling pathways in SLE pathogenesis, with the goal of identifying new targets for SLE therapy.

Estrogen-induced hsa-miR-10b-5p is elevated in T cells from patients with systemic lupus erythematosus and downregulates splicing factor SRSF1

Objective

Autoimmune diseases affect women disproportionately more than men. Estrogen is implicated in immune cell dysfunction, yet its precise molecular roles are not fully known. We recently identified new roles for serine/arginine‐rich splicing factor 1 (SRSF1) in T cell function and autoimmunity. SRSF1 levels are decreased in T cells from patients with systemic lupus erythematosus (SLE) and are associated with active disease and comorbidity. However, the molecular mechanisms that control SRSF1 expression are unknown. Srsf1 messenger RNA (mRNA) has a long 3′‐untranslated region (3′‐UTR), suggesting posttranscriptional control. This study was undertaken to investigate the role of estrogen and posttranscriptional mechanisms of SRSF1 regulation in T cells and SLE.

Methods

In silico bioinformatics analysis of Srsf1–3′‐UTR revealed multiple microRNA (miRNA; miR)–binding sites. Additional screening and literature searches narrowed down hsa‐miR‐10b‐5p for further study. Peripheral blood T cells from healthy individuals and SLE patients were evaluated for mRNA and miRNA expression by quantitative reverse transcription–polymerase chain reaction, and SRSF1 protein levels were assessed by immunoblotting. T cells were cultured with β‐estradiol, and transient transfections were used to overexpress miRNAs. Luciferase assays were used to measure 3′‐UTR activity.

Results

We demonstrated that estrogen increased hsa‐miR‐10b‐5p expression in human T cells, and hsa‐miR‐10b‐5p down‐regulated SRSF1 protein expression. Mechanistically, hsa‐mir‐10b‐5p regulated SRSF1 posttranscriptionally via control of its 3′‐UTR activity. Importantly, hsa‐miR‐10b‐5p expression levels were elevated in T cells from healthy women compared to healthy men and also elevated in T cells from SLE patients.

Conclusion

We identified a previously unrecognized molecular link between estrogen and gene regulation in immune cells, with potential relevance to systemic autoimmune disease.

Phase 2, Randomized, Placebo-Controlled Trial of Dapirolizumab Pegol in Patients with Moderate-to-Severe Active Systemic Lupus Erythematosus

Objective

To evaluate the dose–response, efficacy and safety of dapirolizumab pegol (DZP) in patients with SLE.

Methods

Adults with moderately to severely active SLE (SLEDAI-2K score ≥6 and ≥1 BILAG A or ≥2 BILAG B domain scores), receiving stable CS (≤40 mg/day prednisone-equivalent), antimalarial or immunosuppressant drugs were included. Patients with stable LN (proteinuria ≤2 g/day) not receiving high-dose CS or CYC were permitted entry. Randomized patients received placebo or i.v. DZP (6/24/45 mg/kg) and standard-of-care (SOC) treatment every 4 weeks to week 24, after which patients received only SOC to week 48. The primary objective was to establish a dose–response relationship based on week 24 BILAG-Based Composite Lupus Assessment (BICLA) responder rates.

Results

All DZP groups exhibited improvements in clinical and immunological outcomes vs placebo at week 24; however, BICLA responder rates did not fit pre-specified dose–response models [best-fitting model (E_max): P = 0.07]. Incidences of serious treatment-emergent adverse events across DZP groups were low and similar to placebo. Following DZP withdrawal, SLEDAI-2K, physician’s global assessment (PGA), BILAG, and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) scores stabilized; BICLA and SLE Responder Index (SRI-4) responder rates declined (likely due to interventions with disallowed escape medications), BILAG flares increased, and immunologic parameters returned towards baseline.

Conclusions

Although the primary objective was not met, DZP appeared to be well tolerated, and patients exhibited improvements across multiple clinical and immunological measures of disease activity after 24 weeks relative to placebo. The potential clinical benefit of DZP warrants further investigation.

Sex Hormones and Gender Influence the Expression of Markers of Regulatory T Cells in SLE Patients

Regulatory T cells have been implicated in the regulation and maintenance of immune homeostasis. Whether gender and sex hormones differentially influence the expression and function of regulatory T cell phenotype and their influence on FoxP3 expression remains obscure. We provide evidence in this study that the number and percent of human regulatory T cells (T_regs) expressing CD4⁺ and CD8⁺ are significantly reduced in healthy females compared to healthy males. In addition, both CD4⁺CD25^+hi and CD8⁺CD25^+hi subsets in healthy males have a 2-3 fold increase in FoxP3 mRNA expression compared to healthy females. Female SLE patients, compared to healthy women, have elevated plasma levels of estradiol and decreased levels of testosterone. Higher levels of testosterone correlate with higher expression of FoxP3 in CD4⁺CD25^hiCD127^low putative T_regs in women with SLE. Incubation of CD4⁺ regulatory T cells with 17β-estradiol at physiological levels generally decreased FoxP3 expression in females with SLE. These data suggest that females may be more susceptible than males to SLE and other autoimmune diseases in part because they have fewer T_regs and reduced FoxP3 expression within those cells due to normal E2 levels which suppress FoxP3 expression. In addition, low levels of plasma testosterone in women may further reduce the ability of the T_regs to express FoxP3. These data suggest that gender and sex hormones can influence susceptibility to SLE via effects on regulatory T cells and FoxP3 expression.

Splicing factor SRSF1 controls T cell homeostasis and its decreased levels are linked to lymphopenia in systemic lupus erythematosus

OBJECTIVE

Lymphopenia is a frequent clinical manifestation and risk factor for infections in SLE, but the underlying mechanisms are not fully understood. We previously identified novel roles for the RNA-binding protein serine arginine-rich splicing factor 1 (SRSF1) in the control of genes involved in signalling and cytokine production in human T cells. SRSF1 is decreased in T cells from patients with SLE and associates with severe disease. Because SRSF1 controls the expression of apoptosis-related genes, we hypothesized that SRSF1 controls T cell homeostasis and, when reduced, leads to lymphopenia.

METHODS

We evaluated SRSF1 expression in T cells from SLE patients by immunoblots and analysed its correlation with clinical parameters. T cell conditional Srsf1 knockout mice were used to evaluate lymphoid cells and apoptosis by flow cytometry. Quantitative PCR and immunoblots were used to assess Bcl-xL mRNA and protein expression. SRSF1 overexpression was performed by transient transfections by electroporation.

RESULTS

We found that low SRSF1 levels correlated with lymphopenia in SLE patients. Selective deletion of Srsf1 in T cells in mice led to T cell lymphopenia, with increased apoptosis and decreased expression of the anti-apoptotic Bcl-xL. Lower SRSF1 expression correlated with low Bcl-xL levels in T cells and lower Bcl-xL levels associated with lymphopenia in SLE patients. Importantly, overexpression of SRSF1 rescued survival of T cells from patients with SLE.

CONCLUSION

Our studies uncovered a previously unrecognized role for SRSF1 in the control of T cell homeostasis and its reduced expression as a molecular defect that contributes to lymphopenia in systemic autoimmunity.

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.

Time Course of Metabolic Alterations Associated with the Progression of Systemic Lupus Erythematosus in MRL/lpr Mice Based on GC/MS

Exploring the dynamic changes of metabolites and metabolic pathways during the development of the disease can help to further understand the etiology and pathogenesis of systemic lupus erythematosus (SLE). In this study, serum metabolomics based on gas chromatography/mass spectrometry (GC/MS) was employed to investigate the metabolic alterations at different stages of SLE using lupus-prone mice (MRL/lpr) of 9, 11, and 13 weeks of age. Multivariate statistical analysis was performed to view the alterations of metabolic profiles between MRL/lpr mice and age-matched C57BL/6 mice, and t-test and fold change criteria were used to identify differential metabolites at each stage. 11 changed metabolites were found in MRL/lpr mice at 9 weeks of age, which were mainly involved in the tricarboxylic acid (TCA) cycle, glycolysis, and butanoate metabolism; with the increase of week age, the TCA cycle was still disturbed, and the biosynthesis of fatty acids was significantly upregulated since 11 weeks of age; in addition, urea, urate, and indole-3-lactate were increased at 13 weeks of age. We found a time course of metabolic alterations in MRL/lpr mice, which may be related to the progression of SLE. These findings could provide a reference for studying the mechanism of SLE and judging the pathological stage and severity of the disease. The MS data have been deposited in Mendeley (https://www.mendeley.com/).

Leveraging Heterogeneity in Systemic Lupus Erythematosus for New Therapies

Systemic lupus erythematosus (SLE) is a multisystem, chronic autoimmune disease where treatment varies by patient and disease activity. Strong preclinical results and clinical correlates have motivated development of many drugs, but many of these have failed to achieve efficacy in clinical trials. FDA approval of belimumab in 2011 was the first successful SLE drug in nearly six decades. In this article, we review insights into the molecular and clinical heterogeneity of SLE from transcriptomics studies and detail their potential impact on drug development and clinical practices. We critically examine the pipeline of SLE drugs, including past failures and their associated lessons and current promising approaches. Finally, we identify opportunities for integrating these findings and drug development with new multidisciplinary advances to enhance future SLE treatment.

Relapsing and progressive MS: the sex-specific perspective

Background:

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease whose aetiology is not fully understood. The female sex is clearly predominant, with a sex ratio between 2 and 3. In primary progressive MS the sex ratio almost balances out. Since the age at onset is higher for patients with progressive onset (POMS) than for relapsing onset (ROMS), it can be hypothesized that the age at onset is a decisive factor for the sex ratio.

Methods:

To address this aspect, we compare clinical and demographic data between females and males for the different disease courses within the population of the German MS Register by the German MS Society. Only patients with complete details in mandatory data items and a follow-up visit since 01. Jan 2018 were included.

Results:

A total of 18,728 patients were included in our analyses, revealing a female-to-male ratio of 2.6 (2.7 for patients with ROMS and 1.3 for POMS). The age at diagnosis is higher in patients with POMS (43.3 and 42.3 years for females and males versus 32.1 and 33.2 years, respectively). Females irrespective of disease course are statistically significantly more often affected by cognitive impairment (POMS: p = 0.013, ROMS: p = 0.001) and depression (POMS: p = 0.002, ROMS: 0.001) and suffer more often from pain (POMS and ROMS: p < 0.001). Fatigue is significantly more often seen in females with ROMS (p < 0.001) but not in POMS. Females with ROMS retire significantly (p < 0.001) earlier (42.8 versus 44.2 years) and to a greater extent than males (28 versus 24%). Disease progression was similar for women and men.

Conclusion:

Our analysis shows that clinical and demographic data differ more between disease courses than between men and women. For pain, depression and cognitive impairment the female sex is the decisive factor. Whether these factors are responsible for the earlier retirement of females with ROMS is not clear. Appropriate measures for optimization of symptomatic treatment as well as to promote employment should be taken.

Epigenetic Mechanisms and Posttranslational Modifications in Systemic Lupus Erythematosus

The complex physiology of eukaryotic cells is regulated through numerous mechanisms, including epigenetic changes and posttranslational modifications. The wide-ranging diversity of these mechanisms constitutes a way of dynamic regulation of the functionality of proteins, their activity, and their subcellular localization as well as modulation of the differential expression of genes in response to external and internal stimuli that allow an organism to respond or adapt to accordingly. However, alterations in these mechanisms have been evidenced in several autoimmune diseases, including systemic lupus erythematosus (SLE). The present review aims to provide an approach to the current knowledge of the implications of these mechanisms in SLE pathophysiology.

Autoimmune Disease in Women: Endocrine Transition and Risk Across the Lifespan

Women have a higher incidence and prevalence of autoimmune diseases than men, and 85% or more patients of multiple autoimmune diseases are female. Women undergo sweeping endocrinological changes at least twice during their lifetime, puberty and menopause, with many women undergoing an additional transition: pregnancy, which may or may not be accompanied by breastfeeding. These endocrinological transitions exert significant effects on the immune system due to interactions between the hormonal milieu, innate, and adaptive immune systems as well as pro- and anti-inflammatory cytokines, and thereby modulate the susceptibility of women to autoimmune diseases. Conversely, pre-existing autoimmune diseases themselves impact endocrine transitions. Concentration-dependent effects of estrogen on the immune system; the role of progesterone, androgens, leptin, oxytocin, and prolactin; and the interplay between Th1 and Th2 immune responses together maintain a delicate balance between host defense, immunological tolerance and autoimmunity. In this review, multiple autoimmune diseases have been analyzed in the context of each of the three endocrinological transitions in women. We provide evidence from human epidemiological data and animal studies that endocrine transitions exert profound impact on the development of autoimmune diseases in women through complex mechanisms. Greater understanding of endocrine transitions and their role in autoimmune diseases could aid in prediction, prevention, and cures of these debilitating diseases in women.

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.