Glutathione S-transferase genotype and risk of systemic lupus erythematosus in Koreans

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.

Glutathione S-transferase, catalase, and mitochondrial superoxide dismutase gene polymorphisms modulate redox potential in systemic lupus erythematosus patients from Manaus, Amazonas, Brazil

OBJECTIVE

To investigate the frequency of glutathione S-transferase (GST), catalase, and SOD2 genetic polymorphisms and their correlation with SLE.

METHODS

A total of 290 females (patients = 151; controls= 139) were recruited. Multiplex PCR was performed for genotyping GSTM1 and GSTT1 genes, whereas real-time qPCR was used for determination of SNPs: CAT C262T, SOD2 C47T, GSTP1 A313G and GSTP1 IVS6 -C16T.

RESULTS

Thiol levels are decreased in SLE patients (p<0.001), while MDA levels were significantly higher (p<0.001) and those carrying the polymorphisms had higher rates of oxidative stress. Patients with double null deletion GSTT1^null/GSTM1^null had a frequency almost five times higher than the controls (p<0.001, OR 4.81, CI 1.98-12.11). SLE patients had a lower wild-type frequency of SOD2^CC allele compared to controls (12.4% vs 27.3%). Statistical significances were observed on the association between the GSTT1^null and GSTM1^null with SOD2^mut (p<0.001, OR 0.15, CI 0.05-0.47), with GSTP1 A303G (p=0.012, OR 0.19, CI 0.05-0.69), and with GSTP1 IVS6 (p=0.008, OR 0.14, CI 0.03-0.63). The same was observed between SOD2 C47T with GSTP1 A303G (p=0.09, OR 0.27, CI 0.09-0.74) and GSTP1 IVS6 (p=0.036, OR 0.41, CI 0.18-0.92).

CONCLUSIONS

The deletion GSTT1^null/GSTM1^null may contribute to the increased of the oxidative stress in SLE patients. Isolated GSTP1 and CAT polymorphisms do not seem to influence the increased oxidative stress, neither SLE clinical manifestations. SOD2 47^CT/TT allele may have greater oxidative stress due to structural change in the protein and decreased H₂O₂ production. The combination of polymorphic genes may be involved in the pathogenesis of the disease. Key points • Major question of our paper: Many studies have shown that the antioxidant status levels are decreased in patients with SLE, especially in severe stages of disease. We believe that this paper will be of interest to the readership of your journal had the involvement of polymorphisms and mutations in several genes that contribute to the genetic etiology of SLE, suggesting that these may influence the mechanisms of disease. • Our results. Thiol level was significantly (p<.001) lower and MDA level significantly increased (p<.001) among SLE patients. Those carrying the polymorphisms had higher rates of oxidative stress. SLE Patients had a frequency almost five times higher of double null deletion GSTT1null/GSTM1null than the controls. SLE Patients had a lower wild type frequency of SOD2CC allele compared to controls (12.4% vs 27.3%). We believed the deletion GSTT1null/GSTM1null may contribute to the increased of the oxidative stress in SLE patients while carriers of the mutant SOD2 47CT/TT allele may have greater oxidative stress due to structural change in the protein and decreased H2O2 production. The combination of polymorphic genes may be involved in the pathogenesis of the disease. • Implications of our results: Evidence for the involvement of genetic factors in severe clinical to lupus is compelling. This manuscript shows genetic insights in pathogenic pathways that may lead to severe clinical implications to LES. Therefore, it is necessary to understand their impact on overall disease pathogenesis and prognosis in these patients. We understand from general consensus about environmental factors can modify disease, however, maybe just in individuals who have a permissive genetic background. Even that no single gene predisposes some individuals to LES, we believe the genetic factors described in this manuscript are important elements in susceptibility to severe clinical to LES.

Single-nucleotide polymorphisms (SNPs) of antioxidant enzymes SOD2 and GSTP1 genes and SLE risk and severity in an Egyptian pediatric population

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease associated with increased oxidative stress that participates in immune dysregulation, and injury resulting in loss of immune tolerance and increased auto-antibody production. This study was designed to investigate the effects of genetic polymorphisms of the antioxidant enzymes genes that code for SOD2 (rs2758332) and GSTP1 (rs1695) on SLE risk and severity in Egyptian children and adolescents cohort from Delta region.

METHODS

The frequencies of these genes polymorphic variants were compared between 100 SLE children and adolescents and 100 healthy control subjects. Single-nucleotide polymorphisms (SNPs) of the two antioxidants were determined using TaqMan SNP genotyping assay.

RESULTS

Individuals with the TT and CT genotypes of rs2758332 in the SOD2 gene were of significant risk for SLE patients (OR = 1.831, 95% CI = 1.082-3.101, P = 0.024) and (OR = 1.864, 95% CI = 1.136-3.059, P = 0.014), respectively. Cases who have combined CT + TT genotype were of significant higher risk of SLE (OR = 1.851, 95% CI = 1.156 - 2.962, P = 0.010). While, they did not show any significant association between SOD2 genotypes or alleles with SLE clinical features. In case of the SNP rs1695 in the GSTP1 gene, no significant associations of genotypes or alleles with SLE risk or with SLE clinical features were detected.

CONCLUSIONS

This study among Egyptian children and adolescents showed a strong association of the SOD2 rs2758332 not GSTP1 rs1695 polymorphism with the risk of SLE disease.

Bioinformatics Analysis of the Core Genes Related to Lupus Nephritis Through a Network and Pathway-Based Approach

In this study, we explored the genes genetically associated with lupus nephritis (LN), and their function by bioinformatics analysis. We collected genes potentially associated with LN from National Center for Biotechnology Information Center (NCBI-Gene) and Online Mendelian Inheritance in Man (OMIM) databases. The major bioinformatics analysis linked with genes was then revealed by weighted gene co-expression network analysis (WGCNA), crosstalk analysis, functional analysis, and Pivot algorithm. Two hundred twenty-three LN-related genes were obtained by intersecting NCBI-Gene and OMIM databases. Two thousand five hundred sixty-eight LN-related proteins and 23 modules were excavated by String protein interaction network and WGCNA co-expression analysis, respectively. Pivot algorithm included no coding RNA, transcription factor and drug indicated the high-count correlation-associated modules related to cancer, kidney pathophysiological changes, and kidney injury, respectively. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis based on 23 modules revealed LN-related genes mainly involved in immune response. Moreover, 19 genes that came from intersection of LN, arthritis, pleurisy, and myocarditis have close relationship with immune diseases and immune processes. Our results from this research may have important implications for understanding the genes underlying LN. Also, the framework proposed in this work can be used to research pathological molecular network and genes related to LN.

Prenatal Bisphenol-A exposure affects fetal length growth by maternal glutathione transferase polymorphisms, and neonatal exposure affects child volume growth by sex: From multiregional prospective birth cohort MOCEH study

We aimed to evaluate the effects of Bisphenol-A (BPA) exposure on fetal/child growth from the fetal period to 72months after birth. The MOCEH study is a prospective birth cohort study in Korea. A total of 788 mother-child pairs in the third trimester and 366 pairs in the neonatal period who completed BPA assessment and fetal/children growth outcomes were included. BPA assessments were conducted twice in the third trimester using maternal urines and the neonatal period using neonatal urines. Fetal femur length was measured with ultrasound, and estimated-fetal-weight was calculated. Child growth outcomes including three z-scores for age-specific length, weight-for-length (WFL) and weight were calculated. Analysis was performed according to infant sex and maternal glutathione transferases (GSTs) polymorphisms. When maternal urinary BPA concentration in the third trimester increased by 1 log-transformed unit of BPA/Cr, the third trimester femur length decreased 0.03(0.01)cm in the whole and 0.06(0.02)cm in the GSTM1/GSTT1 either null group. Then, maternal urinary BPA levels and birth outcomes were positively correlated. When the prenatal BPA concentration is increased by 1 log-transformed unit of BPA/Cr, the z-score for weight at birth increased 0.05(0.02) in whole and 0.06(0.03) in boys and the z-score for WFL at birth increased 0.05(0.02) in whole and 0.07(0.03) in girls. In linear mixed models, significant positive effects of the neonatal urinary BPA were found on WFL over the 72months period. When the neonatal BPA concentration is increased by 1 log-transformed unit of BPA concentration, the z-score for weight through 6-72months increased 0.09(0.03) in whole and 0.12(0.05) in girls. Our study suggests BPA exposure is negatively associated with intrauterine linear growth, but has a positive association with volume growth during childhood. Furthermore, intrauterine growth was affected by maternal GSTs polymorphism, and child growth was affected by sex.

Application of Various Statistical Models to Explore Gene-Gene Interactions in Folate, Xenobiotic, Toll-Like Receptor and STAT4 Pathways that Modulate Susceptibility to Systemic Lupus Erythematosus

INTRODUCTION

In view of our previous studies showing an independent association of genetic polymorphisms in folate, xenobiotic, and toll-like receptor (TLR) pathways with the risk for systemic lupus erythematosus (SLE), we have developed three statistical models to delineate complex gene-gene interactions between folate, xenobiotic, TLR, and signal transducer and activator of transcription 4 (STAT4) signaling pathways in association with the molecular pathophysiology of SLE.

METHODS

We developed additive, multifactor dimensionality reduction (MDR), and artificial neural network (ANN) models.

RESULTS

The additive model, although the simplest, suggested a moderate predictability of 30 polymorphisms of these four pathways (area under the curve [AUC] 0.66). MDR analysis revealed significant gene-gene interactions among glutathione-S-transferase (GST)T1 and STAT4 (rs3821236 and rs7574865) polymorphisms, which account for moderate predictability of SLE. The MDR model for specific auto-antibodies revealed the importance of gene-gene interactions among cytochrome P450, family1, subfamily A, polypeptide 1 (CYP1A1) m1, catechol-O-methyltransferase (COMT) H108L, solute carrier family 19 (folate transporter), member 1 (SLC19A1) G80A, estrogen receptor 1 (ESR1), TLR5, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR), thymidylate synthase (TYMS). and STAT4 polymorphisms. The ANN model for disease prediction showed reasonably good predictability of SLE risk with 30 polymorphisms (AUC 0.76). These polymorphisms contribute towards the production of SSB and anti-dsDNA antibodies to the extent of 48 and 40%, respectively, while their contribution for the production of antiRNP, SSA, and anti-cardiolipin antibodies varies between 20 and 30%.

CONCLUSION

The current study highlighted the importance of genetic polymorphisms in folate, xenobiotic, TLR, and STAT4 signaling pathways as moderate predictors of SLE risk and delineates the molecular pathophysiology associated with these single nucleotide polymorphisms (SNPs) by demonstrating their association with specific auto-antibody production.

Metabolic and redox barriers in the skin exposed to drugs and xenobiotics

INTRODUCTION

Growing exposure of human skin to environmental and occupational hazards, to numerous skin care/beauty products, and to topical drugs led to a biomedical concern regarding sustainability of cutaneous chemical defence that is essential for protection against intoxication. Since skin is the largest extra-hepatic drug/xenobiotic metabolising organ where redox-dependent metabolic pathways prevail, in this review, publications on metabolic processes leading to redox imbalance (oxidative stress) and its autocrine/endocrine impact to cutaneous drug/xenobiotic metabolism were scrutinised.

AREAS COVERED

Chemical and photo-chemical skin barriers contain metabolic and redox compartments: their protective and homeostatic functions. The review will examine the striking similarity of adaptive responses to exogenous chemical/photo-chemical stressors and endogenous toxins in cutaneous metabolic and redox system; the role(s) of xenobiotics/drugs and phase II enzymes in the endogenous antioxidant defence and maintenance of redox balance; redox regulation of interactions between metabolic and inflammatory responses in skin cells; skin diseases sharing metabolic and redox problems (contact dermatitis, lupus erythematosus, and vitiligo)

EXPERT OPINION

Due to exceptional the redox dependence of cutaneous metabolic pathways and interaction of redox active metabolites/exogenous antioxidants with drug/xenobiotic metabolism, metabolic tests of topical xenobiotics/drugs should be combined with appropriate redox analyses and performed on 3D human skin models.

The null polymorphism of the GSTM1/T1 gene is not associated with susceptibility to systemic lupus erythematosus: a meta-analysis

Previous studies have suggested that the null polymorphism of the glutathione S-transferases M1/T1 (GSTM1/T1) gene may be associated with the risk of developing systemic lupus erythematosus (SLE). We further explored this potential association using a meta-analysis. A systematic literature search was carried out in the scientific literature databases and we used odds ratios (OR) and 95 % confidence intervals (CIs) to evaluate the strength of this association. All statistical analyses were calculated using Stata software 11.0, and Bonferroni correction was used to adjust the p values. Nine eligible articles with 1,850 patients and 2,826 controls were identified. Our results showed the null polymorphism of the GSTM1 gene was associated with SLE in East Asians (OR 1.32, 95 % CI 1.04-1.69, p = 0.024), but not in Europeans and Africans. However, when Bonferroni corrections were applied (p = 0.05/2 = 0.025), we could not be sure of this association. We further analysed the associations between the GSTT1 gene null polymorphism and the risk of SLE. The results of this investigation showed that this null polymorphism was not associated with susceptibility to SLE in all included populations. In conclusion, the null polymorphism of GSTM1/T1 gene may not be associated with the risk of SLE. More studies are needed to confirm this lack of association between key oxidative defense genes and susceptibility to SLE in the future.

Chronic hydroxychloroquine improves endothelial dysfunction and protects kidney in a mouse model of systemic lupus erythematosus

Hydroxychloroquine has been shown to be efficacious in the treatment of autoimmune diseases, including systemic lupus erythematosus. Hydroxychloroquine-treated lupus patients showed a lower incidence of thromboembolic disease. Endothelial dysfunction, the earliest indicator of the development of cardiovascular disease, is present in lupus. Whether hydroxychloroquine improves endothelial function in lupus is not clear. The aim of this study was to analyze the effects of hydroxychloroquine on hypertension, endothelial dysfunction, and renal injury in a female mouse model of lupus. NZBWF1 (lupus) and NZW/LacJ (control) mice were treated with hydroxychloroquine 10 mg/kg per day by oral gavage, or with tempol and apocynin in the drinking water, for 5 weeks. Hydroxychloroquine treatment did not alter lupus disease activity (assessed by plasma double-stranded DNA autoantibodies) but prevented hypertension, cardiac and renal hypertrophy, proteinuria, and renal injury in lupus mice. Aortae from lupus mice showed reduced endothelium-dependent vasodilator responses to acetylcholine and enhanced contraction to phenylephrine, which were normalized by hydroxychloroquine or antioxidant treatments. No differences among all experimental groups were found in both the relaxant responses to acetylcholine and the contractile responses to phenylephrine in rings incubated with the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester. Vascular reactive oxygen species content and mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase subunits NOX-1 and p47(phox) were increased in lupus mice and reduced by hydroxychloroquine or antioxidants. Chronic hydroxychloroquine treatment reduced hypertension, endothelial dysfunction, and organ damage in severe lupus mice, despite the persistent elevation of anti-double-stranded DNA, suggesting the involvement of new additional mechanisms to improve cardiovascular complications.

Single-nucleotide polymorphisms and haplotype of CYP2E1 gene associated with systemic lupus erythematosus in Chinese population

Introduction

Cytochrome P-450 2E1 (CYP2E1) is an important member of the CYP superfamily, which is involved in the metabolism and activation of many low molecular weight toxic compounds. We tried to investigate the possible association of CYP2E1 tag single nucleotide polymorphisms (SNPs) with susceptibility to systemic lupus erythematosus (SLE) in a Chinese Han population.

Methods

The coding and flanking regions of the CYP2E1 gene were scanned for polymorphisms and tag SNPs were selected. A two-stage case-control study was performed to genotype a total of 876 SLE patients and 680 geographically matched healthy controls (265 cases and 288 controls in stage I and 611 cases and 392 controls in stage II). SLE associations of alleles, genotypes and haplotypes were tested by age and sex adjusted logistic regression. The gene transcription quantitation was carried out for peripheral blood mononuclear cell (PBMC) samples from 120 healthy controls.

Results

Tag SNP rs2480256 was found significantly associated with SLE in both stages of the study. The "A" allele was associated with slightly higher risk (odds ratio (OR) = 1.165, 95% confidence interval (CI) 1.073 to 1.265, P = 2.75E-4) and "A/A" genotype carriers were with even higher SLE risk (OR = 1.464 95% CI 1.259 to 1.702, P = 7.48E-7). When combined with another tag SNP rs8192772, we identified haplotype "rs8192772-rs2480256/TA" over presented in SLE patients (OR 1.407, 95% CI 1.182 to 1.675, P = 0.0001) and haplotype "TG" over presented in the controls (OR 0.771, 95% CI 0.667 to 0.890, P = 0.0004). The gene transcription quantitation analysis further proved the dominant effect of rs2480256 as the "A/A" genotype showed highest transcription.

Conclusions

Our results suggest the involvement of CYP2E1 as a susceptibility gene for SLE in the Chinese population.

Proteomic analysis for the anti-apoptotic effects of cystamine on apoptosis-prone macrophage

Increased macrophage vulnerability is associated with progression of systemic lupus erythematosus. Our previous studies have shown that cystamine, an inhibitor of transglutaminase 2 (TG2), alleviated the apoptosis of hepatocyte and brain cell in lupus-prone mice NZB/W-F1. In present study, we further investigated the effects of cystamine on apoptosis-prone macrophages (APMs) in the lupus mice. Using two-dimensional gel electrophoresis (2-DE) analysis, we found that cystamine induced a differential protein expression pattern of APM as comparing to the PBS control. The protein spots presenting differential level between cystamine and PBS treatment were then identified by peptide-mass fingerprinting (PMF). After bioinformatic analysis, these identified proteins were found involved in mitochondrial apoptotic pathway, oxidative stress, and mitogen-activated protein (MAP) kinase-mediated pathway. Further investigation revealed that cystamine significantly decreased the levels of apoptotic Bax and Apaf-1 and the activity of caspase-3, and increased the levels of anti-apoptotic Bcl-2 in APM. We also found that these apoptotic mediators were up-regulated in a correlation with the progression of lupus severity in NZB/W-F1, which were little affected in BALB/c mice. We also found that the reduced serum glutathione was restored by cystamine in NZB/W-F1. Interestingly, the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in APM and the phagocytic ability was diminished in presence of cystamine. In conclusion, our findings indicate that cystamine significantly inhibited mitochondrial pathway, induced antioxidant proteins, and diminished phosphorylation of extracellular ERK1/2, which may alleviate the apoptosis and the phagocytic ability of APM.

Association of GSTT1, GSTM1 and CYP1A1 polymorphisms with susceptibility to systemic lupus erythematosus in the Chinese population

BACKGROUND

GSTT1, GSTM1, CYP1A1 are enzymes responsible for the detoxification of the toxicant which may be involved in the development of systemic lupus erythematosus (SLE). We examined the relationship between the risk of SLE and the polymorphisms of these genes in the Chinese population.

METHODS

Samples from 298 SLE patients and 284 healthy controls were collected. Polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotypes of CYP1A1 m2 and m4, while multiplex PCR was used to analyze the genotypes of GSTT1 and GSTM1.

RESULTS

Statistically significant difference was observed in genotypes for GSTM1 (p=0.003, OR 1.66 [95% CI 1.19-2.32]), but not for GSTT1 (p=0.119, OR 0.77 [95% CI 0.56-1.07]), in the SLE patients as compared with the controls. Combinational analysis for double-null deletion of both GSTT1 and GSTM1 showed no significant difference (p=0.863, OR 1.03 [95% CI 0.70-1.52]). Significant difference was observed in the genotype frequencies (p=0.013), but not in the allele frequencies (p=0.444, OR 0.90 [95% CI 0.70-1.17]), of CYP1A1 m2. All candidates have a wild-type genotype for CYP1A1 m4.

CONCLUSIONS

Polymorphisms of GSTM1 are associated with SLE in the Chinese population.

Combination of TNF-RII, CYP1A1 and GSTM1 polymorphisms and the risk of Japanese SLE: findings from the KYSS study

OBJECTIVES

Association of the polymorphisms of the genes, TNF receptor type II gene (TNF-RII), cytochrome P4501A1 gene (CYP1A1) and glutathione S-transferase M1 gene (GSTM1), with SLE was investigated. TNF-RII mediates inflammatory and immune response, whereas CYP1A1 and GSTM1 are involved in the metabolism of xenobiotics. These three genes are involved in the generation of reactive oxygen species (ROS), which play a critical role for autoimmune diseases.

METHODS

A total of 152 SLE patients and 427 healthy individuals in a female Japanese population were enrolled in the study. Case-control studies were performed for the polymorphisms of these three genes.

RESULTS

The carriers of TNF-RII 196R were at a significantly increased risk for SLE with odds ratio (OR) of 1.59 (95% CI = 1.01, 2.52). CYP1A1 3801C homozygotes had a significantly increased risk of SLE (OR = 2.47, 95% CI = 1.28, 4.78). On the other hand, GSTM1 null genotype was not associated with SLE risk. As for combination action of two loci, CYP1A1 3801C/GSTM1 null combination was more strongly associated with an increased risk of SLE (OR = 4.35; 95% CI = 1.76, 10.73). Moreover, TNF-RII 196M/CYP1A1 3801C/GSTM1 null genotype combination was most significantly associated with SLE (OR = 5.83; 95% CI = 2, 17.04).

CONCLUSIONS

The individuals carrying two or more 'at-risk' genotypes of TNF-RII, CYP1A1 and GSTM1 had a significantly more increased risk for SLE compared with those having each 'at-risk' genotype. Combination of the risk genotypes will be important to more clearly identify the population at risk for SLE.

A proteomic study of peripheral blood mononuclear cells in systemic lupus erythematosus

Our objective was to analyze the changes in the protein expression profiles of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Peripheral blood was obtained from patients with SLE and healthy controls. 2-D gel electrophoresis was performed, and gels were silver-stained. Differentially expressed protein spots were detected, some of which were identified by MALDI-TOF spectrometry. Match rates of 71% +/- 4% and 72% +/- 4% were gotten for control and patient gels, respectively. 791 +/- 17 spots were detected for control gels and 781 +/- 17 for patient gels. Eleven protein spots were up-regulated, and 9 protein spots were down-regulated in patients with SLE. Five differentially expressed proteins were identified as immunoglobulin J chain, apolipoprotein A-IV precursor, calprotectin L1H and zinc finger protein subfamily 1A (all up-regulated) and glutathione S-transferase (down-regulated), some of which had previously been shown to play a potential role in the pathogenesis of SLE. We conclude there are significant changes in the 2-D maps of PBMCs in patients with SLE and applying this proteomic approach may be a useful way to gain novel insights into SLE.

Effect of glutathione S-transferase polymorphisms and proximity to hazardous waste sites on time to systemic lupus erythematosus diagnosis: results from the Roxbury lupus project

OBJECTIVE

The high prevalence of systemic lupus erythematosus (SLE) among African American women may be due to environmental exposures, genetic factors, or a combination of factors. Our goal was to assess association of residential proximity to hazardous waste sites and genetic variation in 3 glutathione Stransferase (GST) genes (GSTM1, GSTT1, and GSTP1) with age at diagnosis of SLE.

METHODS

Residential histories were obtained by interviewing 93 SLE patients from 3 predominantly African American neighborhoods in Boston. Residential addresses and locations of 416 hazardous waste sites in the study area were geocoded using ArcView software. Time-varying Cox models were used to study the effect of residential proximity to hazardous sites, GST genotype, and interaction between genotype and exposure in determining age at diagnosis.

RESULTS

The prevalence of SLE among African American women in these neighborhoods was 3.56 SLE cases per 1,000. Homozygosity for GSTM1-null and GSTP1 Ile105Val in combination was associated with earlier SLE diagnosis (P = 0.03), but there was no association with proximity to 416 hazardous sites. Available data on specific site contaminants suggested that, at a subset of 67 sites, there was higher potential risk for exposure to volatile organic compounds (P < 0.05 with Bonferroni correction). GST genotypes had a significant interaction with proximity (P = 0.03) in analyses limited to these sites.

CONCLUSION

There was no independent association between residential proximity to hazardous waste sites and the risk of earlier SLE diagnosis in this urban population. However, analysis of a limited number of sites indicated that the risk of earlier SLE associated with proximity to hazardous sites might be modulated by GST polymorphisms.