Synergism between apolipoprotein E Ɛ4 allele and paraoxonase (PON1) 55-M allele is associated with risk of systemic lupus erythematosus

Intricating connections: the role of ferroptosis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease with multiple tissue damage. However, the pathology remains elusive, and effective treatments are lacking. Multiple types of programmed cell death (PCD) implicated in SLE progression have recently been identified. Although ferroptosis, an iron-dependent form of cell death, has numerous pathophysiological features similar to those of SLE, such as intracellular iron accumulation, mitochondrial dysfunction, lipid metabolism disorders and concentration of damage associated-molecular patterns (DAMPs), only a few reports have demonstrated that ferroptosis is involved in SLE progression and that the role of ferroptosis in SLE pathogenesis continues to be neglected. Therefore, this review elucidates the potential intricate relationship between SLE and ferroptosis to provide a reliable theoretical basis for further research on ferroptosis in the pathogenesis of SLE.

Systemic lupus erythematosus and epilepsy: A Mendelian randomization study

OBJECTIVE

Numerous observational studies have found a relationship between systemic lupus erythematosus (SLE) and epilepsy; however, their causal relationship remains unclear. This study aimed to investigate the causal role of SLE in epilepsy or any of its subtypes using a two-sample Mendelian randomization (MR) analysis.

METHODS

Single nucleotide polymorphisms (SNPs) linked to SLE were utilized as instrumental variables in MR analysis to assess their causal impact on epilepsy. The primary MR findings were derived using the inverse variance weighted (IVW) method, which was further supported by the weighted median and MR-Egger regression techniques. Additionally, sensitivity analyses, including Cochran's Q test and pleiotropy tests, were conducted to evaluate the influence of these SNPs on epilepsy, particularly looking for signs of horizontal pleiotropy and heterogeneity.

RESULTS

We selected 43 SNPs that reached genome-wide significance from genome-wide association studies (GWASs) on SLE to serve as instrumental variables in this study. The IVW method showed no evidence to support a causal association between SLE and epilepsy (all epilepsy: odds ratio (OR) = 1.006, 95% confidence interval (CI) = 0.994-1.018; focal epilepsy: OR = 1.006, 95% CI = 0.994-1.019; generalized epilepsy: OR = 1.015, 95% CI = 0.996-1.035). Other MR complementary methods revealed consistent results. Furthermore, there was no evidence indicating heterogeneity or horizontal pleiotropy.

SIGNIFICANCE

The findings of MR analysis did not support a genetically predicted causal relationship between SLE and epilepsy, but emphasized the need for further research on shared pathophysiological mechanisms, particularly the role of immune system abnormalities and potential influences such as chronic inflammation and therapeutic interventions.

PLAIN LANGUAGE SUMMARY

The etiology of epilepsy is complex and diverse, including immune factors. Through a Mendelian randomization analysis, we did not find evidence of a genetic causal relationship between systemic lupus erythematosus and epilepsy. However, this does not invalidate epidemiological evidence, and further exploration is needed to investigate factors influencing the relationship between the two.

Plasma/Serum Oxidant Parameters in Systemic Lupus Erythematosus Patients: A Systematic Review and Meta-Analysis

Most published results have revealed variations in the association of serum/plasma levels of malondialdehyde (MDA), apolipoprotein B (ApoB), and oxidized low-density lipoprotein (OxLDL) and systemic lupus erythematosus (SLE). This study was performed to establish MDA, ApoB, and OxLDL levels in systemic lupus erythematosus (SLE) patients. Electronic databases were searched for the included articles up to 27th February 2023. The meta-analysis included 48 articles with 2358 SLE patients and 2126 healthy controls considered for MDA, ApoB, and OxLDL levels. There were significantly higher MDA, ApoB, and OxLDL levels in SLE patients than those in the control groups. Subgroup analysis indicated that European/American SLE patients and patients of both ages <36 and ≥36 exhibited higher MDA, ApoB, and OxLDL levels. Arab and Asian SLE patients had higher ApoB and MDA/OxLDL levels. African SLE patients recorded higher OxLDL levels than the control groups. SLE patients with a body mass index (BMI) of ≥23 and a disease duration of <10 recorded significantly higher MDA, ApoB, and OxLDL levels. Patients with systemic lupus erythematosus disease activity index (SLEDAI) ≥8 of SLE had higher MDA and ApoB levels, whereas SLE patients with SLEDAI <8 showed significantly higher ApoB levels. Patients with BMI <23 of SLE had higher MDA and OxLDL levels. This study established significantly higher MDA, ApoB, and OxLDL levels in SLE patients, suggesting a possible role of MDA, ApoB, and OxLDL in the disease.

Association of angiotensin-converting enzyme (ACE) I/D variation with biochemical parameters and oxidative stress markers in systemic lupus erythematosus patients in west of Iran

PURPOSE

We aimed to study insertion/deletion (I/D) variation (rs4646994) of ACE gene in a group of SLE patients in west of Iran and its possible relationship with oxidative stress.

METHOD AND RESULTS

Genotypes and allele frequencies related to ACE (I/D) variation were determined in 108 SLE patients and 110 gender and age-matched healthy controls using PCR. Neopterin, malondialdehyde (MDA), and serum lipid concentrations were determined by HPLC and enzyme assay respectively. The overall distribution of ACE I/D genotypes in SLE patients was different from that of the control group (P = 0.005). DD genotype compared to ID genotype increased the risk of SLE (OR = 2.57, 95% CI 1.4-4.8, P = 0.003). ID genotype compared to the II genotype decreased the risk of disease (OR = 0.45, 95% CI 0.2-0.99, p = 0.042). SLE patients with DD, ID, and II genotypes had lower paraoxonase (PON) activity and higher serum levels of MDA and neopterin versus control patients. We also detected a significant protective effect against SLE in presence of ACE I alleles and lack of angiotensin II receptor, type 1 (AGTR1) A1166C (NCBI reference SNP id: rs5186), C alleles in this study (OR = 0.31, 95% CI 0.14-0.68, P = 0.002).

CONCLUSIONS

Carriers of the DD genotype of ACE gene with higher serum concentrations of neopterin and MDA, and lower PON activity had a high risk to develop SLE, while ID genotype decreased the risk of disease development by 2.22 times compared to II genotype.

A systematic review and meta-analysis of neopterin in rheumatic diseases

Introduction

Novel biomarkers of inflammation and oxidative stress might enhance the early recognition, management, and clinical outcomes of patients with rheumatic diseases (RDs). We assessed the available evidence regarding the pathophysiological role of neopterin, the oxidation product of 7,8-dihydroneopterin, a pteridine generated in macrophages activated by interferon-γ, by conducting a systematic review and meta-analysis of studies reporting its concentrations in biological fluids in RD patients and healthy controls.

Methods

We searched electronic databases for relevant articles published between inception and 31 August 2023. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development and Evaluation Working Group system, respectively.

Results

In 37 studies, when compared to healthy controls, RD patients had significantly higher concentrations of neopterin both in plasma or serum (standard mean difference, SMD=1.31, 95% CI 1.01 to 1.61; p<0.001; moderate certainty of evidence) and in the urine (SMD=1.65, 95% CI 0.86 to 2.43, p<0.001; I2 = 94.2%, p<0.001; low certainty of evidence). The results were stable in sensitivity analysis. There were non-significant associations in meta-regression and subgroup analysis between the effect size and age, male to female ratio, year of publication, sample size, RD duration, C-reactive protein, erythrocyte sedimentation rate, specific type of RD, presence of connective tissue disease, analytical method used, or biological matrix investigated (plasma vs. serum). By contrast, the effect size was significantly associated with the geographical area in studies assessing serum or plasma and with the type of RD in studies assessing urine.

Discussion

Pending additional studies that also focus on early forms of disease, our systematic review and meta-analysis supports the proposition that neopterin, a biomarker of inflammation and oxidative stress, can be useful for the identification of RDs. (PROSPERO registration number: CRD42023450209).

Systematic review registration

PROSPERO, identifier CRD42023450209.

The genetic link between systemic autoimmune disorders and temporal lobe epilepsy: A bioinformatics study

OBJECTIVE

We aimed to explore the underlying pathomechanisms of the comorbidity between three common systemic autoimmune disorders (SADs) [i.e., insulin-dependent diabetes mellitus (IDDM), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA)] and temporal lobe epilepsy (TLE), using bioinformatics tools. We hypothesized that there are shared genetic variations among these four conditions.

METHODS

Different databases (DisGeNET, Harmonizome, and Enrichr) were searched to find TLE-associated genes with variants; their single nucleotide polymorphisms (SNPs) were gathered from the literature. We also did a separate literature search using PubMed with the following keywords for original articles: "TLE" or "Temporal lobe epilepsy" AND "genetic variation," "single nucleotide polymorphism," "SNP," or "genetic polymorphism." In the next step, the SNPs associated with TLE were searched in the LitVar database to find the shared gene variations with RA, SLE, and IDDM.

RESULTS

Ninety unique SNPs were identified to be associated with TLE. LitVar search identified two SNPs that were shared between TLE and all three SADs (i.e., IDDM, SLE, and RA). The first SNP was rs16944 on the Interleukin-1β (IL-1β) gene. The second genetic variation was ε4 variation of apolipoprotein E (APOE) gene.

SIGNIFICANCE

The shared genetic variations (i.e., rs16944 on the IL-1β gene and ε4 variation of the APOE gene) may explain the underlying pathomechanisms of the comorbidity between three common SADs (i.e., IDDM, SLE, and RA) and TLE. Exploring such shared genetic variations may help find targeted therapies for patients with TLE, especially those with drug-resistant seizures who also have comorbid SADs.

Exosomes as Crucial Players in Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that affects multiple systems. Its clinical manifestation varies across patients, from skin mucosa to multiorgan damage to severe central nervous system involvement. The exosome has been shown to play an important role in the pathogenesis of autoimmune diseases, including SLE. We review the recent knowledge of exosomes, including their biology, functions, mechanism, and standardized extraction and purification methods in SLE, to highlight potential therapeutic targets for SLE.

Homozygous variant p. Arg90His in NCF1 is associated with early-onset Interferonopathy: a case report

BACKGROUND

Biallelic loss-of-function variants in NCF1 lead to reactive oxygen species deficiency and chronic granulomatous disease (CGD). Heterozygosity for the p.Arg90His variant in NCF1 has been associated with susceptibility to systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome in adult patients. This study demonstrates the association of the homozygous p.Arg90His variant with interferonopathy with features of autoinflammation and autoimmunity in a pediatric patient.

CASE PRESENTATION

A 5-year old female of Indian ancestry with early-onset recurrent fever and headache, and persistently elevated antinuclear, anti-Ro, and anti-La antibodies was found to carry the homozygous p.Arg90His variant in NCF1 through exome sequencing. Her unaffected parents and three other siblings were carriers for the mutant allele. Because the presence of two NCF1 pseudogenes, this variant was confirmed by independent genotyping methods. Her intracellular neutrophil oxidative burst and NCF1 expression levels were normal, and no clinical features of CGD were apparent. Gene expression analysis in peripheral blood detected an interferon gene expression signature, which was further supported by cytokine analyses of supernatants of cultured patient's cells. These findings suggested that her inflammatory disease is at least in part mediated by type I interferons. While her fever episodes responded well to systemic steroids, treatment with the JAK inhibitor tofacitinib resulted in decreased serum ferritin levels and reduced frequency of fevers.

CONCLUSION

Homozygosity for p.Arg90His in NCF1 should be considered contributory in young patients with an atypical systemic inflammatory antecedent phenotype that may evolve into autoimmunity later in life. The complex genomic organization of NCF1 poses a difficulty for high-throughput genotyping techniques and variants in this gene should be carefully evaluated when using the next generation and Sanger sequencing technologies. The p.Arg90His variant is found at a variable allele frequency in different populations, and is higher in people of South East Asian ancestry. In complex genetic diseases such as SLE, other rare and common susceptibility alleles might be necessary for the full disease expressivity.

Genetic and molecular biology of systemic lupus erythematosus among Iranian patients: an overview

BACKGROUND

Systemic lupus erythematosus (SLE) is a clinicopathologically heterogeneous chronic autoimmune disorder affecting different organs and tissues. It has been reported that there is an increasing rate of SLE incidence among Iranian population. Moreover, the Iranian SLE patients have more severe clinical manifestations compared with other countries. Therefore, it is required to introduce novel methods for the early detection of SLE in this population. Various environmental and genetic factors are involved in SLE progression.

MAIN BODY

In present review we have summarized all of the reported genes which have been associated with clinicopathological features of SLE among Iranian patients.

CONCLUSIONS

Apart from the reported cytokines and chemokines, it was interestingly observed that the apoptosis related genes and non-coding RNAs were the most reported genetic abnormalities associated with SLE progression among Iranians. This review clarifies the genetics and molecular biology of SLE progression among Iranian cases. Moreover, this review paves the way of introducing an efficient panel of genetic markers for the early detection and better management of SLE in this population.

Paraoxonases Activities and Polymorphisms in Elderly and Old-Age Diseases: An Overview

Aging is defined as the accumulation of progressive organ dysfunction. There is much evidence linking the involvement of oxidative stress in the pathogenesis of aging. With increasing age, susceptibility to the development of diseases related to lipid peroxidation and tissue injury increases, due to chronic inflammatory processes, and production of reactive oxygen species (ROS) and free radicals. The paraoxonase (PON) gene family is composed of three members (PON1, PON2, PON3) that share considerable structural homology and are located adjacently on chromosome 7 in humans. The most studied member product is PON1, a protein associated with high-density lipoprotein with paraoxonase/esterase activity. Nevertheless, all the three proteins prevent oxidative stress. The major aim of this review is to highlight the importance of the role of PON enzymes in the aging process, and in the development of the main diseases present in the elderly: cardiovascular disease, diabetes mellitus, neurodegenerative diseases, and cancer.

Chemerin rs17173608 and vaspin rs2236242 gene variants on the risk of end stage renal disease (ESRD) and correlation with plasma malondialdehyde (MDA) level

Introduction: End-stage renal disease (ESRD) is associated with critical kidney illness that seriously affects the lifespan. Genetic factors and oxidative stress could play critical role in the development of ESRD. We assessed the association between chemerin rs17173608 T/G and vaspin rs2236242 T/A genes variants with the risk of ESRD and their correlation with plasma malondialdehyde (MDA) level.

Materials and methods: In a case-control study, 131 gender and age-matched unrelated healthy controls and 110 ESRD patients were enrolled. The chemerin rs17173608 T/G and vaspin rs2236242 T/A were detected by Tetra primer-amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). The MDA concentration was determined by HPLC.

Results: Our findings for the first time revealed that in codominant genetic model (T/G vs. T/T genotype), the T/G genotype of chemerin gene significantly had a protective role against ESRD susceptibility. Also, in the presence of chemerin G allele, the risk of ESRD decreased by 0.79-fold (p = .048) in Kurdish population of Iran. The MDA serum levels in ESRD patients carrying the chemerin T/G + G/G genotype of rs17173608 T/G and also in carriers of A/A + T/A genotype of vaspin rs2236242 T/A were significantly higher compared to those in control subjects. The overall distribution of vaspin rs2236242 T/A genotypes and alleles comparing ESRD patients and healthy subjects were not statistically significant.

Conclusion: We found that the G allele of chemerin rs17173608 compared to T allele decreased the risk of ESRD, and there was a significant association between chemerin and vaspin variants with plasma MDA level in a sample of the Iranian population.