Remodeling of Neurotransmission, Chemokine, and PI3K-AKT Signaling Genomic Fabrics in Neuropsychiatric Systemic Lupus Erythematosus.

Cognitive dysfunction and mood changes are prevalent and especially taxing issues for patients with systemic lupus erythematosus (SLE). Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its cognate receptor Fn14 have been shown to play an important role in neurocognitive dysfunction in murine lupus. We profiled and compared gene expression in the cortices of MRL/+, MRL/lpr (that manifest lupus-like phenotype) and MRL/lpr-Fn14 knockout (Fn14ko) adult female mice to determine the transcriptomic impact of TWEAK/Fn14 on cortical gene expression in lupus. We found that the TWEAK/Fn14 pathway strongly affects the expression level, variability and coordination of the genomic fabrics responsible for neurotransmission and chemokine signaling. Dysregulation of the Phosphoinositide 3-kinase (PI3K)-AKT pathway in the MRL/lpr lupus strain compared with the MRL/+ control and Fn14ko mice was particularly prominent and, therefore, promising as a potential therapeutic target, although the complexity of the transcriptomic fabric highlights important considerations in in vivo experimental models.

A Novel Microglia-Specific Transcriptional Signature Correlates With Behavioral Deficits in Neuropsychiatric Lupus.

Neuropsychiatric symptoms of systemic lupus erythematosus (NP-SLE) affect over one-half of SLE patients, yet underlying mechanisms remain largely unknown. We demonstrate that SLE-prone mice (CReCOM) develop NP-SLE, including behavioral deficits prior to systemic autoimmunity, reduced brain volumes, decreased vascular integrity, and brain-infiltrating leukocytes. NP-SLE microglia exhibit numerical expansion, increased synaptic uptake, and a more metabolically active phenotype. Microglia from multiple SLE-prone models express a "NP-SLE signature" unrelated to type I interferon. Rather, the signature is associated with lipid metabolism, scavenger receptor activity and downregulation of inflammatory and chemotaxis processes, suggesting a more regulatory, anti-inflammatory profile. NP-SLE microglia also express genes associated with disease-associated microglia (DAM), a subset of microglia thought to be instrumental in neurodegenerative diseases. Further, expression of "NP-SLE" and "DAM" signatures correlate with the severity of behavioral deficits in young SLE-prone mice prior to overt systemic disease. Our data are the first to demonstrate the predictive value of our newly identified microglia-specific "NP-SLE" and "DAM" signatures as a surrogate for NP-SLE clinical outcomes and suggests that microglia-intrinsic defects precede contributions from systemic SLE for neuropsychiatric manifestations.

A De Novo Frameshift Mutation in TNFAIP3 Impairs A20 Deubiquitination Function to Cause Neuropsychiatric Systemic Lupus Erythematosus.

PURPOSE: Genome-wide association study of systemic lupus erythematosus (SLE) revealed tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20) as a susceptibility gene. Here, we report a de novo mutation in TNFAIP3 in a Chinese patient with neuropsychiatric SLE (NPSLE). METHODS: Whole exome sequencing was performed for the patient and healthy members from the family. Suspected pathogenic variants were further analyzed and co-segregation was confirmed by Sanger sequencing. Real-time PCR and western blot were performed with peripheral blood mononuclear cells (PBMCs) and patient-derived T cells. Transfected HEK293T cells, human umbilical vein endothelial cells, normal human astrocytes, and microglia were used for in vitro studies. RESULTS: A de novo frameshift mutation in TNFAIP3 was found in the NPSLE patient. Western blot analysis showed activated NF-κB and mitogen-activated protein kinase pathways. Real-time PCR revealed elevated expression of pro-inflammatory cytokines. On immunoprecipitation assay, the mutant A20 altered the K63-linked ubiquitin level of TRAF6 via its ubiquitin-editing function. CONCLUSIONS: The mutant A20 may play a role in weakening the tight junction of the blood-brain barrier to cause neurologic symptoms. We report a rare variant of TNFAIP3 in a patient with NPSLE and reveal its autoimmune disease-causing mechanism in both peripheral tissues and the central nervous system.

Vascular endothelial growth factor G1612A (rs10434) gene polymorphism and neuropsychiatric manifestations in systemic lupus erythematosus patients / Polimorfismo genético do fator de crescimento vascular endotelial G1612A (rs10434) e manifestações neuropsiquiátricas em pacientes com lúpus eritematoso sistêmico

Abstract Aim: To investigate the relation between vascular endothelial growth factor (VEGF) gene polymorphism in systemic lupus erythematosus (SLE) patients and lupus related neuropsychiatric manifestations. Patients and methods: Sixty adult SLE patients recruited from the Rheumatology and Neurology departments of Cairo University hospitals were classified into two groups; Group A: 30 patients with neuropsychiatric manifestations (NPSLE) and Group B: 30 patients without. For both groups the SNP G1612A (rs10434) of the VEGF gene was genotyped by real time polymerase chain reaction (RT-PCR). Results: Statistically significant difference was found in genotype and allele frequencies between both groups (AA [70% vs 13.3%, p < 0.001] and GG [10% vs 66.7%, p < 0.001]). Conclusion: Polymorphism in the gene coding for VEGF may be associated with increased incidence of neuropsychiatric lupus in SLE patients.

Resumo Objetivo: Investigar a relação entre o polimorfismo genético do fator de crescimento vascular endotelial (VEGF) em pacientes com lúpus eritematoso sistêmico (LES) e manifestações neuropsiquiátricas relacionadas com o lúpus. Pacientes e métodos: Foram recrutados 60 pacientes adultos com LES nos departamentos de Reumatologia e Neurologia de hospitais universitários do Cairo e classificados em dois grupos; grupo A: 30 pacientes com manifestações neuropsiquiátricas (LESNP) e grupo B: 30 pacientes sem manifestações neuropsiquiátricas. Genotipou-se o SNP G1612A (rs10434) do gene VEGF em ambos os grupos por reação em cadeia da polimerase em tempo real (RT-PCR). Resultados: Foi encontrada diferença estatisticamente significativa nas frequências genotípicas e alélicas entre os dois grupos (AA [70% vs. 13,3%, p < 0,001] e GG [10% vs. 66,7%, p < 0,001]). Conclusão: O polimorfismo no gene que codifica o VEGF pode estar associado ao aumento na incidência de lúpus neuropsiquiátrico em pacientes com LES.

Vascular endothelial growth factor G1612A (rs10434) gene polymorphism and neuropsychiatric manifestations in systemic lupus erythematosus patients.

AIM: To investigate the relation between vascular endothelial growth factor (VEGF) gene polymorphism in systemic lupus erythematosus (SLE) patients and lupus related neuropsychiatric manifestations. PATIENTS AND METHODS: Sixty adult SLE patients recruited from the Rheumatology and Neurology departments of Cairo University hospitals were classified into two groups; Group A: 30 patients with neuropsychiatric manifestations (NPSLE) and Group B: 30 patients without. For both groups the SNP G1612A (rs10434) of the VEGF gene was genotyped by real time polymerase chain reaction (RT-PCR). RESULTS: Statistically significant difference was found in genotype and allele frequencies between both groups (AA [70% vs 13.3%, p<0.001] and GG [10% vs 66.7%, p<0.001]). CONCLUSION: Polymorphism in the gene coding for VEGF may be associated with increased incidence of neuropsychiatric lupus in SLE patients.

Genetic Variants That Are Associated with Neuropsychiatric Systemic Lupus Erythematosus.

OBJECTIVE: While genetic risks have been implicated in systemic lupus erythematosus (SLE), the involvement of various genotypes in neuropsychiatric SLE (NPSLE) remains uncertain. The present metaanalysis aimed to combine data from different studies and evaluate the association between each genotype and the risk of developing NPSLE. METHODS: Studies were searched and retrieved from online databases (PubMed, EMBASE, BIOSIS, and ScienceDirect). Case-control studies were chosen if they reported genotype frequencies of the γ Fc region (FCγR) receptors II-A, III-A, and III-B; tumor necrosis factor-α (TNF-α); mannan-binding lectin (MBL); integrin alpha M (ITGAM); interleukin (IL) 1, IL-1ß, and IL-6; IL-10 promoter; and vitamin D genes. The OR were used to assess the strength of this association between patients with NPSLE and SLE. RESULTS: A total of 33 studies were considered in this metaanalysis. The results suggest that these genotypes demonstrated a significant association with NPSLE: the homozygous FCγR IIIa 158 FF genotype (OR 1.89, p = 0.03 for FF vs VV + FV), heterozygous FCγR IIIb NA1/2 genotype (OR 2.14, p = 0.03 for NA1/2 vs NA1/1; OR 1.81, p = 0.04 for NA1/2 vs NA1/1 + NA2/2), and homozygous ITGAM rs1143679 HH genotype (OR 3.39, p = 0.04 for HH vs RH; OR 3.11, p = 0.048 for HH vs RR + RH). Polymorphisms of the TNF-α, MBL2, IL-1, IL-1ß, IL-6, IL-10 promoter, and vitamin D receptor genes did not show a statistically significant association with the risk of developing NPSLE (p > 0.05). CONCLUSION: This metaanalysis indicates that polymorphisms in the pathways of immune complex clearance, such as the FcγRIIIa, FcγRIIIb, and ITGAM genotypes, are potential susceptibility genes for NPSLE.

Nephritogenic anti-DNA antibodies regulate gene expression in MRL/lpr mouse glomerular mesangial cells.

OBJECTIVE: Lupus-associated IgG anti-double-stranded DNA antibodies are thought to be pathogenic in the kidney due to cross-reaction with glomerular antigens, leading subsequently to immune complex formation in situ and complement activation. We undertook this study to determine if pathogenic anti-DNA antibodies may also contribute to renal damage by directly influencing mesangial gene expression. METHODS: Complementary DNA microarray gene profiling was performed in primary mesangial cells (derived from lupus-prone MRL/lpr mice) treated with pathogenic, noncomplexed anti-DNA antibodies. Significant gene up-regulation induced by anti-DNA antibodies as determined by microarray analysis was further investigated by real-time polymerase chain reaction and methods to detect the relevant proteins. Induction of proinflammatory genes by pathogenic antibodies was confirmed by comparing gene expression in glomeruli of old versus young MRL/lpr mice, and by antibody injection in vivo. RESULTS: Pathogenic, but not nonpathogenic, antibodies significantly induced a number of transcripts, including CXCL1/KC, LCN2, iNOS, CX3CL1/fractalkine, SERPINA3G, and IkappaBalpha ("marker genes"). Blocking of Fcgamma receptors or using Fcgamma chain-knockout mesangial cells had no effect on the gene regulation effect of the pathogenic antibody R4A, indicating a non-Fc-dependent mechanism. The glomerular expression of these marker genes increased over time with the development of glomerular antibody deposition and active nephritis in MRL/lpr mice. Moreover, injection of R4A into SCID mice in vivo significantly up-regulated glomerular marker gene expression. CONCLUSION: These findings indicate that the renal pathogenicity of anti-DNA antibodies may be attributed in part to their ability to directly modulate gene expression in kidney mesangial cells through both Fc-dependent and non-Fc-dependent mechanisms.

Relationship of tumour necrosis factor alpha gene polymorphisms and neuropsychiatric lupus.

Systemic lupus erythematosus (SLE) is a multisystem disorder which appears to be influenced by genetic make-up. In this study we determine allele frequency and genotype distribution of TNFalpha polymorphisms in two populations of SLE patients (with and without neuropsychiatric manifestations) in order to determine whether the rare allele (TNF2) confers susceptibility for neuropsychiatric disease in SLE. Patients with SLE were retrospectively reviewed to determine presence (n = 17) or absence (n = 47) of documented neuropsychiatric manifestations attributable to SLE. The DNA from these patients was extracted from peripheral blood mononuclear cells, and PCR amplification, NcoI enzyme digestion and 10% polyacrylamide gel electrophoresis were performed to define the different TNFalpha alleles. Two alleles were demonstrated, TNF1 (wild-type) and TNF2 (rare type), with three possible genotypes, TNF1,1, TNF1,2 and TNF2,2. A frequency of 24% was found for the TNF2 patients with neuropsychiatric involvement and was not statistically different to a frequency of 28% found in SLE patients without neuropsychiatric manifestations. The TNF-2 allele does not confer susceptibility for neuropsychiatric manifestations in SLE patients.