Revealing an association between HPV and systemic lupus erythematosus: A bidirectional two-sample Mendelian randomization study.

BACKGROUND: An increasing number of studies have focused on the association between Human papillomavirus (HPV) infection and systemic lupus erythematosus (SLE). However, current evidence is largely based on retrospective studies, which are susceptible to confounding factors and cannot establish causation. METHODS: A bidirectional two-sample Mendelian randomization (MR) design was used to evaluate the causal relationship between HPV and SLE. Mononucleoside polymers (SNPS) with strong evidence for genome-wide association studies (GWAS) were selected from the HPV exposure dataset and used as an instrumental variable (IV) for this study. For the MR Analysis results, the MR-Egger intercept P test, MR-Presso global test, CochranQ test and leave-one test were used for sensitivity analysis. RESULTS: Based on the evidence of MR Analysis, this study finally determined that there was no causal association between HPV16 and HPV18 and SLE. CONCLUSIONS: Possible regulation of HPV infection is not significantly associated with regulation of SLE. These findings provide new insights into the underlying mechanisms of HPV and SLE and need to be validated by further studies.

Identification of ENTPD1 as a novel biomarker linking allergic rhinitis and systemic lupus erythematosus.

Several studies reveal that allergic rhinitis (AR) is a significant risk factor of systemic lupus erythematosus (SLE). However, studies investigating the common pathogenesis linking AR and SLE are lacking. Our study aims to search for the shared biomarkers and mechanisms that may provide new therapeutic targets for preventing AR from developing SLE. GSE50223 for AR and GSE103760 for SLE were downloaded from the Gene Expression Omnibus (GEO) database to screen differentially expressed genes (DEGs). The Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed to explore the functions of shared DEGs. Hub genes were screened by cytoHubba (a plugin of Cytoscape) and validated in another two datasets. Gene set enrichment analysis (GSEA) and single-sample Gene set enrichment analysis (ssGSEA) algorithm were applied to understand the functions of hub gene. ENTPD1 was validated as a hub gene between AR and SLE. GSEA results revealed that ENTPD1 was associated with KRAS_SIGNALING_UP pathway in AR and related to HYPOXIA, TGF_BETA_SIGNALING and TNFA_SIGNALING_VIA_NFKB pathways in SLE. The expression of ENTPD1 was positively correlated with activated CD8 T cell in both diseases. Thus, ENTPD1 may be a novel therapeutic target for preventing AR from developing SLE.

High-throughput identification of functional regulatory SNPs in systemic lupus erythematosus.

Genome-wide association studies implicate multiple loci in risk for systemic lupus erythematosus (SLE), but few contain exonic variants, rendering systematic identification of non-coding variants essential to decoding SLE genetics. We utilized SNP-seq and bioinformatic enrichment to interrogate 2180 single-nucleotide polymorphisms (SNPs) from 87 SLE risk loci for potential binding of transcription factors and related proteins from B cells. 52 SNPs that passed initial screening were tested by electrophoretic mobility shift and luciferase reporter assays. To validate the approach, we studied rs2297550 in detail, finding that the risk allele enhanced binding to the transcription factor Ikaros (encoded by IKZF1), thereby modulating expression of IKBKE. Correspondingly, primary cells from genotyped healthy donors bearing the risk allele expressed higher levels of the interferon / NF-κB regulator IKKε. Together, these findings define a set of likely functional non-coding lupus risk variants and identify a regulatory pathway involving rs2297550, Ikaros, and IKKε implicated by human genetics in risk for SLE.

Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations in conjunction with systemic lupus erythematosus: Missed diagnosis or misdiagnosis?

BACKGROUND: Retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations (RVCL-S) is a rare autosomal dominant systemic microvascular disorder attributed to TREX1 (three-prime repair exonuclease-1) gene mutations, often proned to misdiagnosed. METHODS: We reported a case of RVCL-S coexisting with systemic lupus erythematosus due to a mutation in the TREX1 gene. This study provided a summary and discussion of previously documented cases related to TREX1 mutations or RVCL-S. RESULTS: A 39-year-old female patient visited the clinic due to progressive memory loss and speech difficulties. Magnetic resonance imaging results showed corpus callosum atrophy and multiple subcortical calcifications in both brain hemispheres. Genetic testing revealed a TREX1 gene mutation (c.294dupA). Treatment with immunosuppressive therapy for 2 months led to improvements in communication and mobility. We also summarized previously reported cases providing an overview of TREX1 gene mutation or RCVL-S. CONCLUSION: Our case establishes a compelling foundation for future RVCL-S diagnosis and treatment paradigms. Notably, conducting systemic immunity screening in patients with RVCL-S emerges as a strategic approach to prevent potential diagnostic oversights.

Panel miRNAs are potential diagnostic markers for chronic kidney diseases: a systematic review and meta-analysis.

BACKGROUND: Accurate detection of kidney damage is key to preventing renal failure, and identifying biomarkers is essential for this purpose. We aimed to assess the accuracy of miRNAs as diagnostic tools for chronic kidney disease (CKD). METHODS: We thoroughly searched five databases (MEDLINE, Web of Science, Embase, Scopus, and CENTRAL) and performed a meta-analysis using R software. We assessed the overall diagnostic potential using the pooled area under the curve (pAUC), sensitivity (SEN), and specificity (SPE) values and the risk of bias by using the QUADAS-2 tool. The study protocol was registered on PROSPERO (CRD42021282785). RESULTS: We analyzed data from 8351 CKD patients, 2989 healthy individuals, and 4331 people with chronic diseases. Among the single miRNAs, the pooled SEN was 0.82, and the SPE was 0.81 for diabetic nephropathy (DN) vs. diabetes mellitus (DM). The SEN and SPE were 0.91 and 0.89 for DN and healthy controls, respectively. miR-192 was the most frequently reported miRNA in DN patients, with a pAUC of 0.91 and SEN and SPE of 0.89 and 0.89, respectively, compared to those in healthy controls. The panel of miRNAs outperformed the single miRNAs (pAUC of 0.86 vs. 0.79, p < 0.05). The SEN and SPE of the panel miRNAs were 0.89 and 0.73, respectively, for DN vs. DM. In the lupus nephritis (LN) vs. systemic lupus erythematosus (SLE) cohorts, the SEN and SPE were 0.84 and 0.81, respectively. Urinary miRNAs tended to be more effective than blood miRNAs (p = 0.06). CONCLUSION: MiRNAs show promise as effective diagnostic markers for CKD. The detection of miRNAs in urine and the use of a panel of miRNAs allows more accurate diagnosis.

Interferon subverts an AHR-JUN axis to promote CXCL13+ T cells in lupus.

Systemic lupus erythematosus (SLE) is prototypical autoimmune disease driven by pathological T cell-B cell interactions1,2. Expansion of T follicular helper (TFH) and T peripheral helper (TPH) cells, two T cell populations that provide help to B cells, is a prominent feature of SLE3,4. Human TFH and TPH cells characteristically produce high levels of the B cell chemoattractant CXCL13 (refs. 5,6), yet regulation of T cell CXCL13 production and the relationship between CXCL13+ T cells and other T cell states remains unclear. Here, we identify an imbalance in CD4+ T cell phenotypes in patients with SLE, with expansion of PD-1+/ICOS+ CXCL13+ T cells and reduction of CD96hi IL-22+ T cells. Using CRISPR screens, we identify the aryl hydrocarbon receptor (AHR) as a potent negative regulator of CXCL13 production by human CD4+ T cells. Transcriptomic, epigenetic and functional studies demonstrate that AHR coordinates with AP-1 family member JUN to prevent CXCL13+ TPH/TFH cell differentiation and promote an IL-22+ phenotype. Type I interferon, a pathogenic driver of SLE7, opposes AHR and JUN to promote T cell production of CXCL13. These results place CXCL13+ TPH/TFH cells on a polarization axis opposite from T helper 22 (TH22) cells and reveal AHR, JUN and interferon as key regulators of these divergent T cell states.

Functional analysis of a panel of molecular markers for diagnosis of systemic lupus erythematosus in rats.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a diverse autoimmune disease that arises from a combination of complex genetic factors and environmental influences. While circRNAs and miRNAs have recently been identified as promising biomarkers for disease diagnosis, their specific expression patterns, and clinical implications in SLE are not yet fully understood. AIM OF THE WORK: The aim of the present study was to determine the role of a panel of noncoding-RNAs specifically circRNAs (circ-TubD1, circ-CDC27, and circ-Med14), along with miRNA (rno-miR-146a-5p) and mRNA (TRAF6), as novel minimally invasive diagnostic biomarkers for experimentally induced SLE. Additionally, the study involved an insilico bioinformatics analysis to explore potential pathways involved in the pathogenesis of SLE, aiming to enhance our understanding of the disease, enable early diagnosis, and facilitate improved treatment strategies. MATERIALS AND METHODS: SLE was induced in rats using single IP injection of incomplete Freund's adjuvant (IFA). The Induction was confirmed by assessing the ANA and anti-ds DNA levels using ELSA technique. qPCR analysis was conducted to assess the expression of selected RNAs in sera collected from a group of 10 rats with induced SLE and a control group of 10 rats. In addition, bioinformatics and functional analysis were used to construct a circRNA-miRNA-mRNA network and to determine the potential function of these differentially expressed circRNAs. RESULTS: SLE rats demonstrated significantly higher expression levels of circ-CDC27, circ-Med14, and rno-miR-146a-5p as well as TRAF6, with lower expression level of circ-TubD1 in sera of SLE rats relative to controls. ROC curve analysis indicated that all the selected non-coding RNAs could serve as potential early diagnostic markers for SLE. In addition, the expression level of circ-TubD1 was negatively correlated with rno-miR-146a-5p, however, rno-miR-146a-5p was positively correlated with TRAF6. Bioinformatic analysis revealed the incorporation of the circRNAs targeted genes in various immune system and neurodegeneration pathways. CONCLUSIONS: Therefore, circRNAs; circ-TubD1, circ-CDC27, and circ-Med14, in addition to the miRNA (rno-miR-146a-5p) and mRNA (TRAF6) may be involved in the development of SLE and may have promising roles for future diagnosis and targeted therapy.

[Rare Autoimmune Diseases Role of Genetics - Example of Systemic Lupus Erythematosus]. / Maladies auto-immunes rares : place de la génétique, exemple du lupus systémique.

Systemic lupus erythematosus (SLE) presents a complex clinical landscape with diverse manifestations, suggesting a multifactorial etiology. However, the identification of rare monogenic forms of the disease has shed light on specific genetic defects underlying SLE pathogenesis, offering valuable insights into its underlying mechanisms and clinical heterogeneity. By categorizing these monogenic forms based on the implicated signaling pathways, such as apoptotic body clearance, type I interferon signaling, JAK-STAT pathway dysregulation, innate immune receptor dysfunction and lymphocytic abnormalities, a more nuanced understanding of SLE's molecular basis emerges. Particularly in pediatric populations, where monogenic forms are more prevalent, routine genetic testing becomes increasingly important, with a diagnostic yield of approximately 10% depending on the demographic and methodological factors involved. This approach not only enhances diagnostic accuracy but also informs personalized treatment strategies tailored to the specific molecular defects driving the disease phenotype.

Title: Maladies auto-immunes rares : place de la génétique, exemple du lupus systémique. Abstract: Le lupus érythémateux systémique (LES) est une maladie auto-immune chronique caractérisée par une grande hétérogénéité clinique. Certaines formes rares de LES sont causées par des mutations génétiques spécifiques, contrairement à la nature multifactorielle généralement associée à la maladie. Ces formes monogéniques ont été décrites particulièrement dans les cas de LES à début pédiatrique. Leur découverte a permis une meilleure compréhension de la physiopathologie du LES, mettant en lumière la grande complexité des présentations cliniques. Nous proposons ici une classification basée sur les voies de signalisation sous-jacentes, impliquant la clairance des corps apoptotiques et des complexes immuns, les interférons de type I, les voies JAK-STAT, les récepteurs de l'immunité innée et les fonctions lymphocytaires. Dans les formes pédiatriques, un test génétique devrait être proposé systématiquement avec un rendement diagnostique autour de 10 % selon la population et les approches utilisées.

tRF-His-GTG-1 enhances NETs formation and interferon-α production in lupus by extracellular vesicle.

BACKGROUND: Hyperactive neutrophil extracellular traps (NETs) formation plays a crucial role in active severe systemic lupus erythematosus (SLE). However, what triggers the imbalance in dysregulated NETs formation in SLE is elusive. Transfer RNA-derived small RNAs (tsRNAs) are novel non-coding RNAs, which participate in various cellular processes. We explore the role of tsRNAs on NETs formation in SLE. METHODS: We analyzed the levels of NETs DNA and platelet-derived extracellular vesicles (pEVs) from 50 SLE patients and 20 healthy control subjects. The effects of pEVs on NETs formation were evaluated by using immunofluorescence assay and myeloperoxidase-DNA PicoGreen assay. The regulatory mechanism of pEVs on NETs formation and inflammatory cytokines production were investigated using an in vitro cell-based assay. RESULTS: Increased circulating NETs DNA and pEVs were shown in SLE patients and were associated with disease activity (P < 0.005). We demonstrated that SLE patient-derived immune complexes (ICs) induced platelet activation, followed by pEVs release. ICs-triggered NETs formation was significantly enhanced in the presence of pEVs through Toll-like receptor (TLR) 8 activation. Increased levels of tRF-His-GTG-1 in pEVs and neutrophils of SLE patients were associated with disease activity. tRF-His-GTG-1 interacted with TLR8 to prime p47phox phosphorylation in neutrophils, resulting in reactive oxygen species production and NETs formation. Additionally, tRF-His-GTG-1 modulated NF-κB and IRF7 activation in neutrophils upon TLR8 engagement, resulting IL-1ß, IL-8, and interferon-α upregulation, respectively. CONCLUSIONS: The level of tRF-His-GTG-1 was positively correlated with NETs formation in SLE patients; tRF-His-GTG-1 inhibitor could efficiently suppress ICs-triggered NETs formation/hyperactivation, which may become a potential therapeutic target.

Neutrophils and platelets are key members in the immunopathogenesis of SLE. EVs play a key role in intercellular communication. Abnormal NETs formation promotes vascular complications and organ damage in SLE patients. tsRNA is a novel regulatory small non-coding RNA and participates in diverse pathological processes. Herein, we showed that SLE patient-derived ICs activates platelets directly, followed by intracellular tRF-His-GTG-1 upregulation, which is loaded into pEVs. The pEV-carried tRF-His-GTG-1 could interact with TLR8 in neutrophils, followed by activation of the downstream signaling pathway, including p47phox-NOX2-ROS, which causes NETs enhancement, while IRF7 promotes the expression of IFN-α. The tRF-His-GTG-1 inhibitor could suppress efficiently SLE ICs-induced NETs formation and pEVs primed NETs enhancement. This study offers new molecular machinery to explain the association between the platelets-derived tsRNAs, pEVs, and hyperactive NETs formation in lupus. tRF-His-GTG-1 may serve as a potential therapeutic target and help to advance our understanding of tsRNAs in SLE pathogenesis.

Potential association of rheumatic diseases with bone mineral density and fractures: a bi-directional mendelian randomization study.

BACKGROUND: Previous studies have implicated rheumatoid arthritis as an independent risk factor for bone density loss. However, whether there is a causal relationship between rheumatic diseases and bone mineral density (BMD) and fractures is still controversial. We employed a bidirectional Mendelian analysis to explore the causal relationship between rheumatic diseases and BMD or fractures. METHODS: The rheumatic diseases instrumental variables (IVs) were obtained from a large Genome-wide association study (GWAS) meta-analysis dataset of European descent. Analyses were performed for the three rheumatic diseases: ankylosing spondylitis (AS) (n = 22,647 cases, 99,962 single nucleotide polymorphisms [SNPs]), rheumatoid arthritis (RA) (n = 58,284 cases, 13,108,512 SNPs), and systemic lupus erythematosus (SLE) (n = 14,267 cases, 7,071,163 SNPs). Two-sample Mendelian randomization (MR) analyses were carried out by using R language TwoSampleMR version 0.5.7. The inverse-variance weighted (IVW), MR-Egger, and weighted median methods were used to analyze the causal relationship between rheumatic diseases and BMD or fracture. RESULTS: The MR results revealed that there was absence of evidence for causal effect of AS on BMD or fracture. However, there is a positive causal relationship of RA with fracture of femur (95% CI = 1.0001 to 1.077, p = 0.046), and RA and fracture of forearm (95% CI = 1.015 to 1.064, p = 0.001). SLE had positive causal links for fracture of forearm (95% CI = 1.004 to 1.051, p = 0.020). Additionally, increasing in heel bone mineral density (Heel-BMD) and total bone mineral density (Total-BMD) can lead to a reduced risk of AS without heterogeneity or pleiotropic effects. The results were stable and reliable. There was absence of evidence for causal effect of fracture on RA (95% CI = 0.929 to 1.106, p = 0.759), and fracture on SLE (95% CI = 0.793 to 1.589, p = 0.516). CONCLUSIONS: RA and SLE are risk factors for fractures. On the other hand, BMD increasing can reduce risk of AS. Our results indicate that rheumatic diseases may lead to an increased risk of fractures, while increased BMD may lead to a reduced risk of rheumatic diseases. These findings provide insight into the risk of BMD and AS, identifying a potential predictor of AS risk as a reduction in BMD.

Imbalance of programmed cell death patterns mediated by dendritic cell subsets in systemic lupus erythematosus and lupus nephritis. / æ ‘çªçŠ¶ç»†èƒžäºšç¾¤ä»‹å¯¼ç³»ç»Ÿæ€§çº¢æ–‘ç‹¼ç–®å’Œç‹¼ç–®è‚¾ç‚Žçš„ç¨‹åºæ€§ç»†èƒžæ­»äº¡æ¨¡å¼å¤±è¡¡ï¼ˆè‹±æ–‡ï¼‰.

OBJECTIVES: Abnormal programmed cell death in immune cells is associated with autoimmune diseases, but the patterns of programmed cell death in systemic lupus erythematosus (SLE) and especially lupus nephritis (LN) remain unclear. This study aims to explore the association between SLE, LN, and immune cell death patterns. METHODS: Bulk RNA sequencing (bulk RNA-seq) and single-cell RNA sequencing (scRNA-seq) data were downloaded from the Gene Expression Omnibus (GEO) database. Bioinformatic analysis was conducted to explore the expression levels of genes related to 3 cell death patterns in peripheral blood mononuclear cells of SLE patients. Key cell subsets involved in the imbalance of cell death patterns were identified through scRNA-seq. Immunofluorescence was used to detect the expression levels of receptor interacting serine/threonine kinase 3 (RIPK3), mixed-lineage kinase domain-like protein (MLKL), phosphorylated MLKL (pMLKL), caspase 1 (CASP1), CD1c molecule (CD1C), C-type lectin domain containing 9A (CLEC9A), and X-C motif chemokine receptor 1 (XCR1) in dendritic cells (DC). scRNA-seq was performed on kidney tissues collected from LN patients and healthy controls (HC) at the Third Xiangya Hospital of Central South University, followed by bioinformatic analysis to identify key cell subsets involved in the imbalance of cell death patterns. Pseudotime analysis and ligand-receptor analysis were used to explore the differentiation direction and cell communication of different DC subsets. Transient transfection was used to transfect RAW264.7 cells with empty plasmid, empty plasmid+dsDNA (HSV-DNA), empty plasmid+200 µmol/L tert-butyl hydroperoxide (TBHP), stimulator of interferon genes (STING) shRNA plasmid, STING shRNA plasmid+dsDNA (HSV-DNA), and STING shRNA plasmid+200 µmol/L TBHP. Annexin V-mCherry and SYTOX Green staining were used to detect cell death in each group. Western blotting was used to detect the activation of CASP1, gasdermin D (GSDMD), RIPK3, and MLKL in each group. RESULTS: Bioinformatic analysis showed an imbalance in 3 cell death patterns in SLE and LN patients: Pro-inflammatory pyroptosis and necroptosis were activated, while anti-inflammatory apoptosis was inhibited. The key cell subsets involved were DC subsets, particularly focusing on CLEC9A+cDC1. Immunofluorescence results showed that the expression levels of RIPK3, MLKL, and CASP1 in DCs were higher in the SLE group compared to the HC group. pMLKL and CASP1 expression levels in renal cDC1 marked by CLEC9A and XCR1 were higher in the LN group than in the HC group. Pseudotime analysis and ligand-receptor analysis suggested that the CLEC9A+cDC1 subset in LN kidney tissues originated from peripheral circulation. Annexin V-mCherry and SYTOX Green staining results showed that the number of dead cells decreased in the STING shRNA transfection group compared to the empty plasmid group in RAW264.7 cells. Western blotting results showed that the activation of CASP1, GSDMD, RIPK3, and MLKL was decreased in the STING shRNA transfection group compared to the empty plasmid group. CONCLUSIONS: This study provides novel insights into the role of CLEC9A+cDC1 in the imbalance of cell death patterns in SLE and LN.

Identifying the genetic association between common rheumatic diseases and vitiligo.

BACKGROUND: Although observational studies have suggested a correlation between vitiligo and rheumatic diseases, conclusive evidence supporting a causal relationship is still lacking. Therefore, this study aims to explore the potential causal relationship between vitiligo and rheumatic diseases. METHODS: Using genome-wide association studies, we performed a two-sample Mendelian randomization (MR) analysis. In our analysis, the random-effects inverse variance weighted (IVW) method was predominantly employed, followed by several sensitivity analyses, which include heterogeneity, horizontal pleiotropy, outliers, and "leave-one-out" analyses. RESULTS: The genetically predicted vitiligo was associated with an increased risk of rheumatoid arthritis (RA) (OR, 1.47; 95% confidence interval [CI], 1.29-1.68; p < 0.001), and systemic lupus erythematosus (SLE) (OR, 1.22; 95% CI, 1.06-1.39; p = 0.005). The causal associations were supported by sensitivity analyses. In Sjögren's syndrome and ankylosing spondylitis, no causal relationship with vitiligo was found in the study. CONCLUSION: Our MR results support the causal effect that vitiligo leads to a higher risk of RA and SLE. Individuals with vitiligo should be vigilant for the potential development of RA and SLE. Managing and addressing this potential requires regular monitoring.

DNA methylation and whole-genome transcription analysis in CD4+ T cells from systemic lupus erythematosus patients with or without renal damage.

BACKGROUND: Lupus nephritis (LN) is the most common cause of kidney injury in systemic lupus erythematosus (SLE) patients and is associated with increased mortality. DNA methylation, one of the most important epigenetic modifications, has been reported as a key player in the pathogenesis of SLE. Hence, our article aimed to explore DNA methylation in CD4+ T cells from LNs to identify additional potential biomarkers and pathogenic genes involved in the progression of LN. METHODS: Our study enrolled 46 SLE patients with or without kidney injury and 23 healthy controls from 2019 to 2022. CD4+ T cells were sorted for DNA methylation genotyping and RNA-seq. Through bioinformatics analysis, we identified the significant differentially methylated CpG positions (DMPs) only in the LN group and validated them by Bisulfite PCR. Integration analysis was used to screen for differentially methylated and expressed genes that might be involved in the progression of LN, and the results were analyzed via cell experiments and flow cytometry. RESULTS: We identified 243 hypomethylated sites and 778 hypermethylated sites only in the LN cohort. Three of these DMPs, cg08332381, cg03297029, and cg16797344, were validated by Bisulfite PCR and could be potential biomarkers for LN. Integrated analysis revealed that the expression of BCL2L14 and IFI27 was regulated by DNA methylation, which was validated by azacytidine (5-aza) treatment. The overexpression of BCL2L14 in CD4+ T cells might induce renal fibrosis and inflammation by regulating the differentiation and function of Tfh cells. CONCLUSION: Our study identified novel aberrant DMPs in CD4+ T cells only in LN patients and DNA methylation-regulated genes that could be potential LN biomarkers. BCL2L14 is likely involved in the progression of LN and might be a treatment target.

Identification of novel biomarkers for childhood-onset systemic lupus erythematosus using machine learning algorithms and immune infiltration analysis.

BACKGROUND: Childhood-onset systemic lupus erythematosus (cSLE) is a chronic autoimmune disease that is often more severe than adult-onset SLE and is challenging to diagnose due to its variable presentation and lack of specific diagnostic tests. OBJECTIVES: This study aimed to identify potential diagnostic biomarkers for cSLE by analyzing differentially expressed genes (DEGs) using machine learning algorithms. METHODS: In this study, we utilized the Gene Expression Omnibus database to investigate the DEGs between cSLE and normal samples, conducting a functional enrichment analysis on DEGs. Subsequently, we employed machine learning algorithms, including Least Absolute Shrinkage and Selection Operator regression and Support Vector Machine-Recursive Feature Elimination, to identify hub DEGs, which serve as crucial biomarkers. We delved into the role of these hub DEGs in the pathogenesis of the disease and the correlation between these hub DEGs and immune infiltration by comprehensive immune infiltration analysis using the CIBERSORT algorithm. RESULTS: We identified 110 DEGs in cSLE, including 95 upregulated and 15 downregulated genes. Functional annotation revealed that these DEGs were involved in immune response processes, viral defense mechanisms, and regulation of interferon responses. Machine learning algorithms identified CCR1 and SAMD9L as hub DEGs, which were validated in multiple datasets and demonstrated high diagnostic value for cSLE. Mechanistic exploration suggested that CCR1 and SAMD9L are involved in immune response modulation, particularly in interferon signaling and the innate immune system. Assessment of immune cell infiltration revealed significant differences in immune cell composition between cSLE patients and healthy controls, with cSLE patients exhibiting a higher proportion of neutrophils. Moreover, CCR1 and SAMD9L expression levels showed positive correlations with neutrophil infiltration and other immune cell types. CONCLUSION: CCR1 and SAMD9L were identified as potential diagnostic biomarkers for cSLE using machine learning and were validated in multiple datasets. These findings provide novel insights into the biological underpinnings of cSLE.

Genetic polymorphisms in genes involved in the type I interferon system (STAT4 and IRF5): association with Asian SLE patients.

Systemic lupus erythematosus (SLE) is a common autoimmune disease with a polymorphic clinical presentation involving multisystem damages with significant differences in prevalence and disease severity among different ethnic groups. Although genetic, hormonal, and environmental factors have been demonstrated to contribute a lot to SLE, the pathogenesis of SLE is still unknown. Numerous evidence revealed that gene variants within the type I interferons (IFN) signaling pathway performed the great genetic associations with autoimmune diseases including SLE. To date, through genome-wide association studies (GWAS), genetic association studies showed that more than 100 susceptibility genes have been linked to the pathogenesis of SLE, among which TYK2, STAT1, STAT4, and IRF5 are important molecules directly connected to the type I interferon signaling system. The review summarized the genetic associations and the detailed risk loci of STAT4 and IRF5 with Asian SLE patients, explored the genotype distributions associated with the main clinical manifestations of SLE, and sorted out the potential reasons for the differences in susceptibility in Asia and Europe. Moreover, the therapies targeting STAT4 and IRF5 were also evaluated in order to propose more personalized and targeted treatment plans in SLE.

Deletion of the Mitochondrial Membrane Protein Fam210b Is Associated with the Development of Systemic Lupus Erythematosus.

Mitochondrial dysfunction has been increasingly recognized as a trigger for systemic lupus erythematosus (SLE). Recent bioinformatics studies have suggested Fam210b as a significant candidate for the classification and therapeutic targeting of SLE. To experimentally prove the role of Fam210b in SLE, we constructed Fam210b knockout (Fam210b-/-) mice using the CRISPR-Cas9 method. We found that approximately 15.68% of Fam210b-/- mice spontaneously developed lupus-like autoimmunity, which was characterized by skin ulcerations, splenomegaly, and an increase in anti-double-stranded DNA (anti-dsDNA) IgG antibodies and anti-nuclear antibodies(ANA). Single-cell sequencing showed that Fam210b was mainly expressed in erythroid cells. Critically, the knockout of Fam210b resulted in abnormal erythrocyte differentiation and development in the spleens of mice. Concurrently, the spleens exhibited an increased number of CD71+ erythroid cells, along with elevated levels of reactive oxygen species (ROS) in the erythrocytes. The co-culture of CD71+ erythroid cells and lymphocytes resulted in lymphocyte activation and promoted dsDNA and IgG production. In summary, Fam210b knockout leads to a low probability of lupus-like symptoms in mice through the overproduction of ROS in CD71+ erythroid cells. Thus, Fam210b reduction may serve as a novel key marker that triggers the development of SLE.

Haploinsufficiency in PTPN2 leads to early-onset systemic autoimmunity from Evans syndrome to lupus.

An exome sequencing strategy employed to identify pathogenic variants in patients with pediatric-onset systemic lupus or Evans syndrome resulted in the discovery of six novel monoallelic mutations in PTPN2. PTPN2 is a phosphatase that acts as an essential negative regulator of the JAK/STAT pathways. All mutations led to a loss of PTPN2 regulatory function as evidenced by in vitro assays and by hyperproliferation of patients' T cells. Furthermore, patients exhibited high serum levels of inflammatory cytokines, mimicking the profile observed in individuals with gain-of-function mutations in STAT factors. Flow cytometry analysis of patients' blood cells revealed typical alterations associated with autoimmunity and all patients presented with autoantibodies. These findings further supported the notion that a loss of function in negative regulators of cytokine pathways can lead to a broad spectrum of autoimmune manifestations and that PTPN2 along with SOCS1 haploinsufficiency constitute a new group of monogenic autoimmune diseases that can benefit from targeted therapy.

The dualistic role of Lyn tyrosine kinase in immune cell signaling: implications for systemic lupus erythematosus.

Systemic lupus erythematosus (SLE, lupus) is a debilitating, multisystem autoimmune disease that can affect any organ in the body. The disease is characterized by circulating autoantibodies that accumulate in organs and tissues, which triggers an inflammatory response that can cause permanent damage leading to significant morbidity and mortality. Lyn, a member of the Src family of non-receptor protein tyrosine kinases, is highly implicated in SLE as remarkably both mice lacking Lyn or expressing a gain-of-function mutation in Lyn develop spontaneous lupus-like disease due to altered signaling in B lymphocytes and myeloid cells, suggesting its expression or activation state plays a critical role in maintaining tolerance. The past 30 years of research has begun to elucidate the role of Lyn in a duplicitous signaling network of activating and inhibitory immunoreceptors and related targets, including interactions with the interferon regulatory factor family in the toll-like receptor pathway. Gain-of-function mutations in Lyn have now been identified in human cases and like mouse models, cause severe systemic autoinflammation. Studies of Lyn in SLE patients have presented mixed findings, which may reflect the heterogeneity of disease processes in SLE, with impairment or enhancement in Lyn function affecting subsets of SLE patients that may be a means of stratification. In this review, we present an overview of the phosphorylation and protein-binding targets of Lyn in B lymphocytes and myeloid cells, highlighting the structural domains of the protein that are involved in its function, and provide an update on studies of Lyn in SLE patients.

Association of education attainment and risk of connective tissue diseases.

OBJECTIVE: We employed two-sample Mendelian randomization (MR) to assess the genetic causal relationship between educational attainment (EA) and risk of five common connective tissue diseases (CTDs). METHODS: Educational attainment (self-reported at age ≥30 years) was obtained from a meta-analysis of years of schooling in 766 345 participants of European ancestry from genome-wide association studies (GWAS). A total of 1265 signals associated with EA were identified. Genetic data for five CTDs [rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM), and dermatomyositis (DM)] were obtained from the FinnGen consortium. Two-sample MR analyses were performed separately for EA and the five CTDs. RESULTS: We found a negative causal relationship between EA and RA (ORIVW = 0.627, 95% CI = 0.537-0.732, p < .001), and SLE (ORIVW = 0.341, 95% CI = 0.123-0.944, p = .038). There were no genetic causal association between EA and SSc (ORIVW = 0.647, 95% CI = 0.351-1.195, p = .164), PM (ORIVW = 0.938, 95% CI = 0.320-2.746, p = .907), or DM (ORIVW = 0.754, 95% CI = 0.351-1.619, p = .468). None of the analyses revealed any horizontal pleiotropy or heterogeneity. CONCLUSION: Our findings indicated a potential causal association between EA and RA, SLE, emphasizing the need for further investigation and potential integration of EA into clinical practice to enhance treatment strategies.

Genetic variants in UNC93B1 predispose to childhood-onset systemic lupus erythematosus.

Rare genetic variants in toll-like receptor 7 (TLR7) are known to cause lupus in humans and mice. UNC93B1 is a transmembrane protein that regulates TLR7 localization into endosomes. In the present study, we identify two new variants in UNC93B1 (T314A, located proximally to the TLR7 transmembrane domain, and V117L) in a cohort of east Asian patients with childhood-onset systemic lupus erythematosus. The V117L variant was associated with increased expression of type I interferons and NF-κB-dependent cytokines in patient plasma and immortalized B cells. THP-1 cells expressing the variant UNC93B1 alleles exhibited exaggerated responses to stimulation of TLR7/-8, but not TLR3 or TLR9, which could be inhibited by targeting the downstream signaling molecules, IRAK1/-4. Heterozygous mice expressing the orthologous Unc93b1V117L variant developed a spontaneous lupus-like disease that was more severe in homozygotes and again hyperresponsive to TLR7 stimulation. Together, this work formally identifies genetic variants in UNC93B1 that can predispose to childhood-onset systemic lupus erythematosus.