The role of Tumor Necrosis Factor-alpha (TNF-α) in the pathogenesis of systemic lupus erythematosus

Th1, Th2, and Th17 cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breakdown of immune tolerance leading to excessive inflammation and tissue damage. Imbalance in the levels of cytokines represents one of the multifactorial causes of SLE pathogenesis and it contributes to disease severity. Deregulated levels of T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cytokines have been associated with autoimmune inflammation. Growing evidence has shown deregulated levels of Th1, Th2, and Th17 cytokines in SLE patients compared to healthy controls associated with disease activity and severity. In this review, we describe and discuss the levels of Th1, Th2, and Th17 cytokines in SLE patients, and clinical trials involving Th1, Th2, and Th17 cytokines in SLE patients. In particular, with the exception of IL-2, IL-4, and TGF-β1, the levels of Th1, Th2, and Th17 cytokines are increased in SLE patients associated with disease severity. Current phase II or III studies involve therapeutic antibodies targeting IFN-α and type I IFN receptor, while low-dose IL-2 therapy is assessed in phase II clinical trials.

Relationship of Excess Weight with Clinical Activity and Dietary Intake Deficiencies in Systemic Lupus Erythematosus Patients

Obesity and nutrients intake deficiencies may contribute to the clinical manifestations and inflammatory processes in systemic lupus erythematosus (SLE). The aim of this study was to assess the relationship between nutritional status and dietary intake with clinical variables in Mexican-mestizo SLE patients. A cross-sectional study was conducted in 130 female SLE patients, classified by the 1997 SLE American College of Rheumatology (ACR) criteria; the clinical activity was evaluated by the Mexican-Systemic Lupus Erythematosus-Disease Activity Index (Mex-SLEDAI); body mass index (BMI) by the World Health Organization (WHO) criteria; the energy calculation and nutritional intake were performed by Nutritionist Pro Diet software. SLE patients with excess weight (BMI > 25 kg/m²) showed a higher score of clinical activity (Mex-SLEDAI = 2; p = 0.003), higher clinical activity prevalence (40.9%; p = 0.039) and a significant association for high clinical activity (odds ratio (OR) = 2.52; 95% confidence interval (CI) = 1.08-5.9; p = 0.033), in comparison with patients without excess weight (BMI < 25 kg/m²). In particular, the excess weight increased the Mex-SLEDAI score (β coefficient = 1.82; R² = 0.05; p = 0.005). Also, the SLE patients presented a high prevalence (%) of deficient consumption (cut-off point: <67% of dietary adequacy) of vitamin E (100%), iodine (96%), omega 3 (93.44%), biotin (78%), vitamin K (73.33%), iron (67%), vitamin D (63.3%), potassium (59%), folic acid (56.67%), pantothenic acid (43.3%), vitamin A (41.67%) and zinc (32%). In conclusion, in SLE patients the excess weight was associated with increased clinical activity and to the presence of deficiencies in some essential nutrients ingested.

TNF-α promoter polymorphisms (G-238A and G-308A) are associated with susceptibility to Systemic Lupus Erythematosus (SLE) and P. falciparum malaria: a study in malaria endemic area

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine associated with autoimmune and infectious diseases. Importance of TNF-α in P. falciparum malaria and systemic lupus erythematosus (SLE) have been demonstrated. However, association of functional promoter variants with SLE and malaria is lacking in malaria endemic population. A total of 204 female SLE patients and 224 age and sex matched healthy controls were enrolled in the study. Three hundred fourteen P. falciparum infected patients with different clinical phenotypes were included. TNF-α polymorphisms (G-238A & G-308A) were genotyped by PCR-RFLP. Plasma levels of TNF-α was quantified by ELISA. Heterozygous mutants and minor alleles of TNF-α (G-238A and G-308A) polymorphisms were significantly higher in SLE patients compared to healthy controls and associated with development of lupus nephritis. In addition, both promoter variants were associated with severe P. falciparum malaria. SLE patients demonstrated higher levels of plasma TNF-α compared to healthy controls. TNF-α (G-238A and G-308A) variants were associated with higher plasma TNF-α. In conclusion, TNF-α (G-238A & G-308A) variants are associated with higher plasma TNF-α levels in SLE patients residing in malaria endemic areas and could be a contributing factor in the development of SLE and susceptibility to severe P. falciparum malaria.

Novel functions of inactive rhomboid proteins in immunity and disease

iRhoms are related to a family of intramembrane serine proteinases called rhomboids but lack proteolytic activity. In mammals, there are two iRhoms, iRhom1 and iRhom2, which have similar domain structures and overlapping specificities as well as distinctive functions. These catalytically inactive rhomboids are essential regulators for the maturation and trafficking of the disintegrin metalloprotease ADAM17 from the endoplasmic reticulum to the cell surface, and are required for the cleavage and release of a variety of membrane-associated proteins, including the IL-6 receptor, l-selectin, TNF, and EGFR ligands. iRhom2-dependent regulation of ADAM17 function has been recently implicated in the development and progression of several autoimmune diseases including rheumatoid arthritis, lupus nephritis, as well as hemophilic arthropathy. In this review, we discuss our current understanding of iRhom biology, their implications in autoimmune pathologies, and their potential as therapeutic targets.

Bone turnover markers in relation to vitamin D status and disease activity in adults with systemic lupus erythematosus

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) have altered bone metabolism and are at risk of osteoporosis. The aim of this study was to examine bone turnover markers in relation to vitamin D, disease activity, and clinical risk factors in patients with established SLE.

METHODS

Clinical registry and biorepository data of 42 SLE patients were assessed. Serum samples were analyzed for osteocalcin as a marker of bone formation, C-terminal telopeptide of type 1 collagen (CTX) as a marker for bone resorption, and 25-hydroxy vitamin D.

RESULTS

Patients with a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI) score of 3 or greater had a lower median osteocalcin level ( P = 0.02) and lower 25-hydroxy vitamin D levels ( P = 0.03) than those with a score of less than 3. No significant differences in bone turnover markers were observed between patients dichotomized into subgroups using a 25-hydroxy vitamin D cut-off of 30 ng/mL or by a daily prednisone dose greater than or 5 mg or less. Osteocalcin levels were negatively correlated with SLEDAI scores ( P = 0.034), and were positively correlated with the CTX index (a ratio of measured CTX value to the upper limit of the normal value for age and gender) ( P < 0.01). No association between the CTX index and SLEDAI scores was found.

CONCLUSION

SLE disease activity may have direct effects on bone formation, but no effects on bone resorption in this cohort of established SLE patients, probably related to the inflammation-suppressing effects of glucocorticoids, thereby inhibiting cytokine-induced osteoclast activity. A fine balance exists between disease control and the use of glucocorticoids with regard to bone health.

Plasma cytokines as potential biomarkers of kidney damage in patients with systemic lupus erythematosus

Background

Systemic lupus erythematosus is a heterogeneous chronic inflammatory autoimmune disorder characterized by an exacerbated expression of cytokines and chemokines in different tissues and organs. Renal involvement is a significant contributor to the morbidity and mortality of systemic lupus erythematosus, and its diagnosis is based on renal biopsy, an invasive procedure with a high risk of complications. Therefore, the development of alternative, non-invasive diagnostic tests for kidney disease in patients with systemic lupus erythematosus is a priority.

Aim

To evaluate the plasma levels of a panel of cytokines and chemokines using multiplex xMAP technology in a cohort of Colombian patients with active and inactive systemic lupus erythematosus, and to evaluate their potential as biomarkers of renal involvement.

Results

Plasma from 40 systemic lupus erythematosus non-nephritis patients and 80 lupus nephritis patients with different levels of renal involvement were analyzed for 39 cytokines using Luminex xMAP technology. Lupus nephritis patients had significantly increased plasma eotaxin, TNF-α, interleukin-17-α, interleukin-10, and interleukin-15 as compared to the systemic lupus erythematosus non-nephritis group. Macrophage-derived chemokine, growth regulated oncogene alpha, and epidermal growth factor were significantly elevated in systemic lupus erythematosus non-nephritis patients when compared to lupus nephritis individuals. Plasma eotaxin levels allowed a discrimination between systemic lupus erythematosus non-nephritis and lupus nephritis patients, for which we performed a receiver operating characteristic curve to confirm. We observed a correlation of eotaxin levels with active nephritis (Systemic Lupus Erythematosus Disease Activity Index). Our data indicate that circulating cytokines and chemokines could be considered good predictors of renal involvement in individuals with systemic lupus erythematosus.

Cytokine production by activated plasmacytoid dendritic cells and natural killer cells is suppressed by an IRAK4 inhibitor

Background

In systemic lupus erythematosus (SLE), immune complexes (ICs) containing self-derived nucleic acids trigger the synthesis of proinflammatory cytokines by immune cells. We asked how an interleukin (IL)-1 receptor-associated kinase 4 small molecule inhibitor (IRAK4i) affects RNA-IC-induced cytokine production compared with hydroxychloroquine (HCQ).

Methods

Plasmacytoid dendritic cells (pDCs) and natural killer (NK) cells were isolated from peripheral blood mononuclear cells (PBMCs) of healthy individuals. PBMCs from SLE patients and healthy individuals were depleted of monocytes. Cells were stimulated with RNA-containing IC (RNA-IC) in the presence or absence of IRAK4i I92 or HCQ, and cytokines were measured by immunoassay or flow cytometry. Transcriptome sequencing was performed on RNA-IC-stimulated pDCs from healthy individuals to assess the effect of IRAK4i and HCQ.

Results

In healthy individuals, RNA-IC induced interferon (IFN)-α, tumor necrosis factor (TNF)-α, IL-6, IL-8, IFN-γ, macrophage inflammatory protein (MIP)1-α, and MIP1-β production in pDC and NK cell cocultures. IFN-α production was selective for pDCs, whereas both pDCs and NK cells produced TNF-α. IRAK4i reduced the pDC and NK cell-derived cytokine production by 74–95%. HCQ interfered with cytokine production in pDCs but not in NK cells. In monocyte-depleted PBMCs, IRAK4i blocked cytokine production more efficiently than HCQ. Following RNA-IC activation of pDCs, 975 differentially expressed genes were observed (false discovery rate (FDR) < 0.05), with many connected to cytokine pathways, cell regulation, and apoptosis. IRAK4i altered the expression of a larger number of RNA-IC-induced genes than did HCQ (492 versus 65 genes).

Conclusions

The IRAK4i I92 exhibits a broader inhibitory effect than HCQ on proinflammatory pathways triggered by RNA-IC, suggesting IRAK4 inhibition as a therapeutic option in SLE.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1702-0) contains supplementary material, which is available to authorized users.

Genetics of immune-mediated inflammatory diseases

Immune-mediated inflammatory diseases (IMIDs) are characterized by dysregulation of the normal immune response, which leads to inflammation. Together, they account for a high disease burden in the population, given that they are usually chronic conditions with associated co-morbidities. Examples include systemic lupus erythematosus, rheumatoid arthritis, Crohn's disease and type 1 diabetes. Since the advent of genome-wide association studies, evidence of considerable genetic overlap in the loci predisposing to a wide range of IMIDs has emerged. Understanding the genetic risk and extent of genetic overlap between IMIDs may help to determine which genes control which aspects of the different diseases; it may identify potential novel therapeutic targets for a number of these conditions, and/or it may facilitate repurposing existing therapies developed originally for different conditions. The findings show that autoantibody-mediated autoimmune diseases cluster more closely with each other than autoantibody-negative diseases such as psoriasis, psoriatic arthritis, Crohn's disease and ankylosing spondylitis which, instead, form a seronegative genetic cluster. The genetic clustering largely mirrors the known response to existing biological therapies, but apparent anomalies in treatment response are discussed.

Interleukin-6 levels in the serum and saliva of patients with oral lichen planus compared with healthy controls: a meta-analysis study

Interleukin-6 (IL-6) is a cytokine that contributes to the pathogenesis of oral lichen planus (OLP). The aim of this meta-analysis study is the evaluation of IL-6 levels in the serum and saliva of patients with OLP compared with healthy controls. We searched the studies in 5 databases: PubMed/Medline, Scopus, ScienceDirect, Web of Science, and Cochrane Library, from 1983 to Oct 31, 2016. Eleven studies were analysed for the meta-analysis study. The reviewers independently evaluated the quality of each included study using the Newcastle-Ottawa Quality Assessment Scale (NOS). A random-effects meta-analysis, using Comprehensive Meta-Analysis software version 2.0, was used to reflect the variation in studies. Heterogeneity between estimates was evaluated by the Q and I² statistics and for the Q statistic; heterogeneity was considered for p < 0.1. Eleven studies included 529 OLP patients and 333 healthy controls. The review identified two different biomaterials used for IL-6 assays: saliva and serum. The mean quality score of eleven studies was 7 (high quality). Estimates pooled from 6 studies showed significant high saliva IL-6 levels in OLP patients compared with healthy controls (the standardised difference in means (SDM) = 4.534, 95% CI = 1.915-7.153, p = 0.001). Also, estimates pooled from 7 studies showed significantly high serum IL-6 levels in OLP patients compared with healthy controls (SDM = 1.482, 95% CI = 0.524-2.439, p = 0.002). The higher levels of IL-6 in saliva compared with serum suggest that measurement of this marker in saliva may be more useful than serum for diagnostic and therapeutic aims.

Olfactory function in systemic lupus erythematosus and systemic sclerosis. A longitudinal study and review of the literature

BACKGROUND/PURPOSE

To evaluate olfactory function in systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and healthy controls over a 2-year period, and to determine the association of olfactory dysfunction with age, disease activity, disease damage, treatment, anxiety and depression symptoms and limbic structures volumes.

METHODS

Consecutive SLE and SSc patients were enrolled in this study. Clinical, laboratory disease activity and damage were assessed according to diseases specific guidelines. Olfactory functions were evaluated using the Sniffin' Sticks test (TDI). Volumetric magnetic resonance imaging (MRI) was obtained in a 3T Phillips scanner. Amygdalae and hippocampi volumes were analyzed using FreeSurfer® software.

RESULTS

We included 143 SLE, 57 SSc and 166 healthy volunteers. Olfactory dysfunction was observed in 78 (54.5%) SLE, 35 (59.3%) SSc patients and in 24 (14.45%) controls (p<0.001) at study entry. SLE and SSc patients had significantly lower mean in all three phases (TDI) of the olfactory assessment when compared with healthy volunteers. In SLE, the presence of olfactory dysfunction was associated with older age, disease activity, higher anxiety and depression symptoms score, smaller left hippocampus volume, smaller left and right amygdalae volume and the presence of anti-ribosomal P (anti-P) antibodies. In SSc the presence of olfactory impairment was associated with older age, disease activity, smaller left and right hippocampi volumes and smaller right amygdala volume. Olfactory function was repeated after a 2-year period in 90 SLE, 35 SSc and 62 controls and was stable in all three groups.

CONCLUSION

Both SLE and SSc patients with longstanding disease had significant reduction in all stages of TDI that maintained stable over a 2-year period. Olfactory dysfunction was associated with age, inflammation and hippocampi and amygdalae volumes. In SLE, additional association with anti-P, anxiety and depression symptoms was observed.

Overexpression of A20 inhibits the inflammatory response during dengue fever infection

Aim: Dengue hemorrhagic fever is a devastating disease. This study aimed to investigate the role of A20 in dengue fever infection. Materials & methods: DENV2-infected human umbilical vein endothelial cells were transfected with shRNA-A20/CD14 and A20/CD14-mimics, respectively. The expressions of inflammatory and anti-inflammatory factors, A20 and downstream proteins of the NF-κB signaling pathway were detected. Results: A20 knockdown increased the expression of IL-6, IL-10, IL-8 and CD14 during dengue virus infection, whereas overexpression of A20 had the opposite effect. FACS revealed that A20 negatively regulated the expression of CD14. Conclusion: In DENV2-infected human umbilical vein endothelial cells overexpressing A20, TNF-α stimulation inhibited NF-κB-mediated inflammatory response by negative feedback. Furthermore, A20 could affect the release of inflammatory factors via negative regulation of CD14, thus affecting the entire inflammatory response.

MIF promotes a differential Th1/Th2/Th17 inflammatory response in human primary cell cultures: Predominance of Th17 cytokine profile in PBMC from healthy subjects and increase of IL-6 and TNF-α in PBMC from active SLE patients

Macrophage migration Inhibitory Factor (MIF) is a cytokine associated with the pathogenesis of autoimmune inflammatory diseases. There is evidence that MIF functions in a positive-feedback-loop with proinflammatory cytokines and could perpetuate the inflammatory process in Systemic Lupus Erythematosus (SLE).The aim of this study was to assess the effect of recombinant-human-MIF (rhMIF) on the expression of Th1, Th2 and Th17 cytokines in Peripheral Blood Mononuclear Cells (PBMC) from Healthy Subjects (HS) and SLE patients. The PBMC were isolated from SLE patients classified according to the 1997 SLE ACR criteria and HS donors; all subjects included were women from an unrelated Mexican-Mestizo population. The PBMC isolated were stimulated with rhMIF, LPS and ISO-1 in different combinations; Th1, Th2 and Th17cytokine profiles levels were determined by MAGPIX Bio-plex assay in supernatants from cell cultures. We observed in supernatants of PBMCs from HS treated with rhMIF a predominance of Th17 cytokine profile with an increase of IL-17A, IL-17F and IL-21 versus PBMCs from SLE patients, which showed an inflammatory profile represented by increase of IL-6 cytokine. According to SLE remission/activity presented at enrollment in the study (Mex-SLEDAI index), the PBMC from active SLE patients showed higher levels of TNF-α and IL-6 versus PBMC from remission SLE patients. In conclusion, our results suggest that MIF can induce a differential inflammatory response in physiological and pathological conditions with a predominance of a Th17 cytokine profile in PBMC from HS and an increase in TNF-α and IL-6 expression in PBMC from active SLE patients.

Update on Biologic Therapies for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic multisystemic autoimmune disease driven by genetic, hormonal, and environmental factors. Despite the advances in diagnostic and therapeutic approaches in the last decades, SLE still leads to significant morbidity and increased mortality. Although a cure for SLE is still unknown, treatment is required to control acute disease exacerbation episodes (flares), decrease the frequency and severity of subsequent lupus flares, address comorbidities, and prevent end-organ damage. While conventional SLE pharmacotherapy may exhibit suboptimal efficacy and substantial toxicity, a growing knowledge of the disease pathogenesis enabled the research on novel therapeutic agents directed at specific disease-related targets. In this paper, we review the recent progress in the clinical investigation of biologic agents targeting B cells, T cells, cytokines, innate immunity, and other immunologic or inflammatory pathways. Although many investigational agents exhibited insufficient efficacy or inadequate safety in clinical trials, one of them, belimumab, fulfilled the efficacy and safety regulatory requirements and was approved for the treatment of SLE in Europe and the USA, which confirms that, despite all difficulties, advances in this field are possible.

Novel biomarkers for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex and highly heterogeneous disease. By now, no novel drug has been approved by the US FDA in the past 50 years, except Belimumab, a monoclonal antibody to inhibit B-cell activating factor. The stagnating drug development of lupus may be due to our limited understanding of disease etiopathogenesis and the extreme heterogeneity of patient population. Thus, the individualized treatment for SLE becomes necessary. Recently, biomarkers have shown potential in individualized treatment. This review comprehensively summarizes novel potential biomarkers, discusses their current status in preclinical studies and clinical use, sensitivity to treatments and correlation with the disease activity, and provides an insight into the possibility of biomarkers in the utilization of individualized treatment for SLE.

Associations of TNF-α -238 A/G and IL-10 -1082 G/A Genetic Polymorphisms With the Risk of NONFH in the Chinese Population

The study aims to explore the roles of common polymorphisms of Tumor Necrosis Factor-α (TNF-α) (-238 A/G and -308 A/G) and IL-10 (-819 T/C and -1082 G/A) genes in the risk of non-traumatic osteonecrosis of the femoral head (NONFH). One hundred and forty-seven NONFH patients and 135 healthy individuals were selected as the case and control groups. qRT-PCR and Western blotting techniques detected mRNA as well as protein expressions of TNF-α and IL-10 of each genotype in both the case and control groups. The GA genotype and the A allele of TNF-α -238 A/G were higher in the case group than in the control group. Compared with the control group, AA, GA, and AG + AA genotypes as well as the A allele of IL-10-1082 G/A were all lower in the case group. In the case groups increased levels of TNF-α as well as decreased levels of IL-10 expression when compared with the control group. TNF-α expression of TNF-α-238 GA genotype was significantly higher than that in patients with GG genotype, while the IL-10 expression of GA and AA genotypes of IL-10-1082 was significantly lower than in that of patients with the GG genotype. TNF-α protein expression in the GA genotype was significantly higher than in the GG genotype. In relation to TNF-α -238, TNF-α protein expression of GA and AA genotypes had significantly reduced more so than the GG genotype in IL-10-1082. TNF-α-238 A/G and IL-10-1082 G/A may be involved as risk factors of NONFH. J. Cell. Biochem. 118: 4872-4880, 2017. © 2017 Wiley Periodicals, Inc.

Biomarkers of systemic lupus erythematosus identified using mass spectrometry-based proteomics: a systematic review

Advances in mass spectrometry technologies have created new opportunities for discovering novel protein biomarkers in systemic lupus erythematosus (SLE). We performed a systematic review of published reports on proteomic biomarkers identified in SLE patients using mass spectrometry-based proteomics and highlight their potential disease association and clinical utility. Two electronic databases, MEDLINE and EMBASE, were systematically searched up to July 2015. The methodological quality of studies included in the review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Twenty-five studies were included in the review, identifying 241 SLE candidate proteomic biomarkers related to various aspects of the disease including disease diagnosis and activity or pinpointing specific organ involvement. Furthermore, 13 of the 25 studies validated their results for a selected number of biomarkers in an independent cohort, resulting in the validation of 28 candidate biomarkers. It is noteworthy that 11 candidate biomarkers were identified in more than one study. A significant number of potential proteomic biomarkers that are related to a number of aspects of SLE have been identified using mass spectrometry proteomic approaches. However, further studies are required to assess the utility of these biomarkers in routine clinical practice.

Identifying the association between interleukin-6 and lichen planus: A meta-analysis

Numerous studies have examined the association between interleukin-6 and the pathogenesis of lichen planus (LP)/oral LP (OLP) in various populations; however, there is a lack of systematic analysis. The aim of the present study was to assess this association more precisely, thus a meta-analysis was performed. Case-control studies, which were published up to December 2015, were obtained from PubMed, Embase and the China National Knowledge Infrastructure databases. Data were extracted and pooled mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Ultimately, eight studies were included, comprising 299 LP/OLP cases and 231 control subjects. Overall, the pooled MD for IL-6 was 16.24 (95% CI, 9.84-22.64; I²=99% for heterogeneity). In the subgroup analysis by ethnicity, a significant increase of the IL-6 expression level was identified among Asian individuals, but not in Caucasian individuals. Thus, IL-6 may be significant in the pathogenesis of LP. However, further studies are required to validate these associations.

Cis- and Trans-gnetin H from Paeonia suffruticosa suppress inhibitor kappa B kinase phosphorylation in LPS-stimulated human THP-1 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The inflammatory response is an important mechanism in host defense; however, overstimulation and chronic inflammation are involved in many important human diseases. Currently, tumor necrosis factor-alpha blockers such as infliximab and adalimumab along with methotrexate are used in cases of severe and chronic disease. However, there are severe side effects and limitations associated with these treatments. Cis- and trans-gnetin H are compounds isolated from the seeds of Paeonia suffruticosa, a medicinal plant used in traditional Chinese medicine for the treatment of many conditions, including inflammatory diseases. In this study, we investigated possible anti-inflammatory mechanisms of cis- and trans-gnetin H against LPS-stimulated human THP-1 cells.

MATERIAL AND METHODS

PMA-differentiated THP-1 cells were pretreated with increasing concentrations of cis- and trans-gnetin H with or without LPS. Following treatment, cytotoxicity and the TNF-α, IL-1β, and IL-8 response were measured. We also characterized the nuclear translocation of NF-κB subunit p65 (RelA) by immunofluorescence and then investigated NF-κB activation by measuring the phosphorylation of NF-κB mediators, IKK-β, IκB α, and p65 by western blotting.

RESULTS

We found that cis- and trans-gnetin H significantly inhibited the cytokine response in a concentration-dependent manner without affecting cell viability. Cis- and trans-gnetin H effectively inhibited nuclear translocation of p65 and phosphorylation of IKK-β, IκB α, and p65. While both compounds showed promising anti-inflammatory effects, trans-gnetin H was determined to be more effective in suppressing cytokine responses.

CONCLUSION

We demonstrated that cis- and trans-gnetin H suppress cytokine response in LPS-stimulated THP-1 cells by preventing activation of key signaling molecules, IKK-β, IκB α, and p65, involved in the NF-κB pathway and suggest the use of cis- and trans-gnetin H in potential therapies for conditions and diseases associated with chronic inflammation.

Adipokines, tumor necrosis factor and its receptors in female patients with systemic lupus erythematosus

OBJECTIVES

To analyze the association of adipokines and tumor necrosis factor α (TNFα) and its receptors with characteristics of systemic lupus erythematosus (SLE) and to investigate the correlation between adipokines and the TNF system.

METHODS

One hundred and thirty-six SLE women, aged ≥18 years old, were assessed. TNFα, soluble TNFα receptors 1 (sTNFR1) and 2 (sTNFR2) and adipokines were analyzed by ELISA kits.

RESULTS

The median (IQR) of age was 41.5 (33.0-49.7) years old and of disease duration 11.3 (7.8-15.8) years. The median (IQR) of disease activity was 0 (0-4) and of damage index was 2 (1-3). Higher levels of sTNFR1 and sTNFR2 were associated with nephritis (p < 0.001 for both), and sTNFR1 (p = 0.025) and TNFα (p = 0.014) were positively associated with arthritis. Higher sTNFR1 levels were found in participants that were not using antimalarial drugs (p = 0.04). Independent correlation was found between sTNFR1 (β = 0.253; p = 0.003) and sTNFR2 (β = 0.297; p < 0.001) levels and disease activity and damage index (sTNFR1: β = 0.367; p < 0.001; sTNFR2: β = 0.335; p < 0.001). Higher adiponectin levels were independently associated with nephritis (p = 0.009) and antimalarial drugs use (p = 0.015). There was a positive correlation between leptin and sTNFR2 levels (p = 0.002) and between resistin levels and sTNFR1 (p < 0.001) and sTNFR2 (p < 0.001).

CONCLUSION

The correlation between adipokines and TNF system allows a better understanding of the role of adipokines in the inflammatory response in SLE patients.

Drugs in early clinical development for Systemic Lupus Erythematosus

INTRODUCTION

While immunosuppressive therapy has positively impacted the prognosis of systemic lupus erythematosus (SLE), many patients still do not respond to traditional therapy. Thus, active SLE disease remains a significant problem. Furthermore, conventional immunosuppressive treatments for SLE are associated a high risk of side effects. These issues call for improvement in our current therapeutic armamentarium.

AREAS COVERED

In this review, the authors highlight the recent developments in therapies for SLE, and present an overview of drugs which are in early clinical development for SLE. There are many new therapeutic approaches being developed, including those focused on B-cell targets, T-cell downregulation, co-stimulatory blockade, anti-cytokine agents, and kinase inhibition, and Toll-like receptor inhibition. They also discuss peptide therapy as a potential method to re-establish immune tolerance, and some of the challenges ahead in developing and testing novel agents for SLE.

EXPERT OPINION

Many novel agents are currently in development for SLE, but this encouraging news is tempered by several disappointments in clinical trials and provides a timely moment to reflect on the future of therapeutic development in SLE. It seems likely that biological heterogeneity between patients is a major contributor to difficulty in drug design in SLE.

Diagnostic value of progranulin in patients with lupus nephritis and its correlation with disease activity

The aim of this study was to explore whether progranulin (PGRN) can be a useful marker not only for accurate diagnosis of patients with active lupus nephritis (LN), but also for prediction of the disease activity in this population. A total of 154 LN patients were enrolled in this study, 76 of which were diagnosed as having active LN and 78 as having stable LN. Additionally, 71 age-matched non-LN patients were enrolled as controls. The serum and urine PGRN levels of each study population were measured using the enzyme-linked immunosorbent assay method. The diagnostic performance of both indicators and their correlation with the disease activity of LN were systematically investigated using receiver operating characteristic (ROC) analysis and correlation analysis. The active LN population had significantly higher serum and urine PGRN levels than the other two populations. ROC analysis further demonstrated that these two indicators, particularly in combination, appear to have a strong performance in discriminating active LN patients from the rest of the LN population. In the active LN population, serum and urine PGRN levels were not only significantly correlated with SLEDAI score, rSLEDAI score, and activity index, but also had a considerable association with several key markers reflecting the disease activity of LN, including serum levels of complement component 3 and ds-DNA. Nevertheless, neither of the two indicators were correlated with the pathological classification of LN, chronicity index, serum creatinine level, and 24-h urine protein levels. Our findings demonstrate that PGRN may have great potential as a diagnostic factor for active LN and as a predictor for its disease activity.

Assessment of TNFA polymorphisms at positions -857 and -863 in Polish peptic ulcer patients

PURPOSE

Peptic ulceration connected with chronic inflammation in gastrointestinal mucosa could be induced by Helicobacter pylori infection. Tumor necrosis factor alpha (TNF-α) encoded by TNFA gene is a key mediator in the inflammation process. There are several polymorphisms in the promoter of TNFA influencing its transcriptional activity. -857C>T (rs1799724) and -863C>A (rs1800630) substitutions may be responsible for increased TNFA transcription and TNF-α production. The association of these two polymorphisms with peptic ulceration and the development of H. pylori infection in peptic ulcer patients in Poles were evaluated.

MATERIAL AND METHODS

Polymorphisms were assessed by PCR-RFLP in 203 peptic ulcer patients. H. pylori infection was confirmed by rapid urease test. The results of genotyping were compared with those obtained for 248 healthy Polish individuals.

RESULTS

There were no significant differences in genotype and allele frequencies for both investigated polymorphisms between peptic ulcer patients and healthy individuals. No associations between frequencies of particular genotypes and alleles for both SNPs and the presence of H. pylori infection in peptic ulcer patients and in subgroups of peptic ulcer women and men were confirmed.

CONCLUSIONS

The investigated SNPs are not risk factors for peptic ulcer development. They are not risk factors for H. pylori infection in ulcer patients.

Depressive symptoms are associated with tumor necrosis factor alpha in systemic lupus erythematosus

BACKGROUND

Tumor necrosis factor alpha (TNF-α) is deeply related to pathogenesis of neurodevelopmental disorders, especially depression. The aim of this study was to explore potential relationships between sera TNF-α levels and mood and anxiety disorders in systemic lupus erythematosus (SLE) patients.

METHODS

We included 153 consecutive SLE patients (women 148; median age 30; range 10-62) and 40 (women 37; mean age 28.5; range 12-59) age- and sex-matched healthy controls. Mood and anxiety disorders were determined through Beck Depression and Beck Anxiety Inventory. SLE patients were further assessed for clinical and laboratory SLE manifestations. TNF-α levels were measured by enzyme-linked immunosorbent assay using commercial kits.

RESULTS

Depressive symptoms were identified in 70 (45.7 %) SLE patients and in 10 (25 %) healthy controls (p < 0.001). Anxiety symptoms were identified in 93 (60.7 %) SLE patients and in 16 controls (40 %) (p < 0.001). Sera TNF-α levels were increased in SLE patients with depressive symptoms (p < 0.001) and with anxiety symptoms (p = 0.014). A direct correlation between the severity of depressive symptoms and sera TNF-α levels (r = 0.22; p = 0.003) was observed. TNF-α levels were significantly increased in patients with active disease (p = 0.012). In addition, we observed a correlation between sera TNF-α levels and disease activity (r = 0.28; p = 0.008). In the multivariate analysis, sera TNF-α levels were independently associated with depressive symptoms (t = 3.28; 95 % CI 1.08-2.2; p = 0.002).

CONCLUSIONS

Sera TNF-α levels are increased in SLE patients with mood and anxiety disorders. In SLE, sera TNF-α levels are independently associated with mood disorders. The etiology of mood disorders is still debated in SLE, but our findings suggest the presence of immunological basis for depression in SLE.

Differential changes in gene expression in human neutrophils following TNF-α stimulation: Up-regulation of anti-apoptotic proteins and down-regulation of proteins involved in death receptor signaling

Responses of human neutrophils to TNF‐α are complex and multifactorial. Exposure of human neutrophils to TNF‐α in vitro primes the respiratory burst, delays apoptosis and induces the expression of several genes including chemokines, and TNF‐α itself. This study aimed to determine the impact of TNF‐α exposure on the expression of neutrophil genes and proteins that regulate apoptosis. Quantitative PCR and RNA‐Seq, identified changes in expression of several apoptosis regulating genes in response to TNF‐α exposure. Up‐regulated genes included TNF‐α itself, and several anti‐apoptotic genes, including BCL2A1, CFLAR (cFLIP) and TNFAIP3, whose mRNA levels increased above control values by between 4‐20 fold (n = 3, P < 0.05). In contrast, the expression of pro‐apoptotic genes, including CASP8, FADD and TNFRSF1A and TNFRSF1B, were significantly down‐regulated following TNF‐α treatment. These changes in mRNA levels were paralleled by decreases in protein levels of caspases 8 and 10, TRADD, FADD, TNFRSF1A and TNFRSF1B, and increased cFLIP protein levels, as detected by western blotting. These data indicate that when neutrophils are triggered by TNF‐α exposure, they undergo molecular changes in transcriptional expression to up‐regulate expression of specific anti‐apoptotic proteins and concomitantly decrease expression of specific proteins involved in death receptor signaling which will alter their function in TNF‐α rich environments.

PTPN22 Variant R620W Is Associated With Reduced Toll-like Receptor 7-Induced Type I Interferon in Systemic Lupus Erythematosus

OBJECTIVE

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is associated with an increased risk of systemic lupus erythematosus (SLE). PTPN22 encodes Lyp, and a disease-associated coding variant bears an R620W substitution (LypW). LypW carriage is associated with impaired production of type I interferon (IFN) by myeloid cells following Toll-like receptor (TLR) engagement. The aim of this study was to investigate the effects of LypW carriage on TLR signaling in patients with SLE.

METHODS

Plasma IFNα concentrations and whole-blood IFN gene scores were compared in SLE patients who were LypW carriers and those who were noncarriers. TLR-7 agonist R848-stimulated IFNα and tumor necrosis factor levels, IFN-dependent gene expression, and STAT-1 activation were determined in peripheral blood mononuclear cells (PBMCs) and/or plasmacytoid dendritic cells (PDCs) obtained from these patients. The effect of LypW expression on the systemic type I IFN response to R848 stimulation in vivo was assessed in transgenic mice.

RESULTS

Plasma IFNα levels and whole-blood IFN gene signatures were comparable in SLE patients who were LypW carriers and those who were noncarriers. However, PBMCs from LypW carriers produced less IFNα and showed reduced IFN-dependent gene up-regulation and STAT-1 activation after R848 stimulation. The frequency of PDCs producing IFNα2 and the per-cell IFNα2 levels were significantly reduced in LypW carriers. LypW-transgenic mice displayed reduced TLR-7-induced circulating type I IFN responses.

CONCLUSION

PDCs from SLE patients carrying the disease-associated PTPN22 variant LypW showed a reduced capacity for TLR-7 agonist-induced type I IFN production, even though LypW carriers displayed systemic type I IFN activation comparable with that observed in noncarriers. LypW carriage identifies SLE patients who may harbor defects in TLR- and PDC-dependent host defense or antiinflammatory functions.

Pathogenic Inflammation and Its Therapeutic Targeting in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE, lupus) is a highly complex and heterogeneous autoimmune disease that most often afflicts women in their child-bearing years. It is characterized by circulating self-reactive antibodies that deposit in tissues, including skin, kidneys, and brain, and the ensuing inflammatory response can lead to irreparable tissue damage. Over many years, clinical trials in SLE have focused on agents that control B- and T-lymphocyte activation, and, with the single exception of an agent known as belimumab which targets the B-cell survival factor BAFF, they have been disappointing. At present, standard therapy for SLE with mild disease is the agent hydroxychloroquine. During disease flares, steroids are often used, while the more severe manifestations with major organ involvement warrant potent, broad-spectrum immunosuppression with cyclophosphamide or mycophenolate. Current treatments have severe and dose-limiting toxicities and thus a more specific therapy targeting a causative factor or signaling pathway would be greatly beneficial in SLE treatment. Moreover, the ability to control inflammation alongside B-cell activation may be a superior approach for disease control. There has been a recent focus on the innate immune system and associated inflammation, which has uncovered key players in driving the pathogenesis of SLE. Delineating some of these intricate inflammatory mechanisms has been possible with studies using spontaneous mouse mutants and genetically engineered mice. These strains, to varying degrees, exhibit hallmarks of the human disease and therefore have been utilized to model human SLE and to test new drugs. Developing a better understanding of the initiation and perpetuation of disease in SLE may uncover suitable novel targets for therapeutic intervention. Here, we discuss the involvement of inflammation in SLE disease pathogenesis, with a focus on several key proinflammatory cytokines and myeloid growth factors, and review the known outcomes or the potential for targeting these factors in SLE.

Regulation of PGE2 signaling pathways and TNF-alpha signaling pathways on the function of bone marrow-derived dendritic cells and the effects of CP-25

This study was to investigate PGE2 and TNF-alpha signaling pathway involving in the maturation and activation of bone marrow dendritic cells (DCs) and the effect of CP-25. Bone marrow DCs were isolated and stimulated by PGE2 and TNF-alpha respectively. The markers of maturation and activation expressed on DCs, such as CD40, CD80, CD83, CD86, MHC-II, and the ability of antigen uptake of DCs were analyzed by flow cytometry. The proliferation of T cells co-cultured with DCs, the signaling pathways of PGE2-EP4-cAMP and TNF-alpha-TRADD-TRAF2-NF-κB in DCs were analyzed. The results showed that both PGE2 and TNF-alpha up-regulated the expressions of CD40, CD80, CD83, CD86, and MHC-II, decreased the antigen uptake of DCs, and DCs stimulated by PGE2 or TNF-alpha could increase T cell proliferation. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased significantly the expressions of CD40, CD80, CD83, CD86 and MHC-II, increased the antigen uptake of DCs, and suppressed T cell proliferation induced by DCs. PGE2 increased the expressions of EP4, NF-κB and down-regulated cAMP level of DCs. TNF-alpha could also up-regulate TNFR1, TRADD, TRAF2, and NF-κB expression of DCs. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) decreased the expressions of EP4 and NF-κB, increased cAMP level in DCs stimulated by PGE2. CP-25 (10(-5), 10(-6), and 10(-7)mol/l) also could down-regulate significantly TNFR1, TRADD, TRAF2, and NF-κB expression in DCs stimulated by TNF-alpha. These results demonstrate that PGE2 and TNF-alpha could enhance DCs functions by mediating PGE2-EP4-cAMP pathway, TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathway respectively. CP-25 might inhibit the function of DCs through regulating PGE2-EP4-cAMP and TNF-alpha-TNFR1-TRADD-TRAF2-NF-κB pathways.

Endotoxin tolerance in monocytes can be mitigated by α2-interferon

Endotoxin tolerance is characterized by diminished expression of inflammatory cytokines after sequential exposure to Toll-like receptor stimuli. Many mechanisms contribute to tolerance; however, chromatin remodeling appears to be the most significant regulator. The type II interferon, IFN-γ, has been recognized as being able to reverse or abrogate the establishment of tolerance. Type I interferons have not been investigated previously, and they bind a distinct receptor. We found that α2-interferon was able to abrogate or diminish tolerance by endotoxin, as defined by measuring mRNA levels at recognized tolerance targets. We also found that α2-interferon treatment during tolerization was associated with increased H3K4me3 and H3K4me2 levels at promoters of tolerance targets in THP1 cells. These marks were normalized after exposure of the cells to α2-interferon. Interferon regulatory factor 1 is a transcription factor activated and induced by types I and II interferons. We found recruitment of this transcription factor paralleled tolerance and inhibition of tolerance at target genes. Therefore, there are at least 2 distinct pathways by which endotoxin tolerance may be mitigated. A type I interferon, in spite of binding to a different receptor, was just as able to inhibit tolerance as the type II interferon and also appeared to act by modifying chromatin at tolerance target genes.

Genetics and novel aspects of therapies in systemic lupus erythematosus

Autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and inflammatory bowel disease, have complex pathogeneses and the factors which cause these disorders are not well understood. But all have in common that they arise from a dysfunction of the immune system, interpreting self components as foreign antigens. Systemic lupus erythematosus (SLE) is one of these complex inflammatory disorders that mainly affects women and can lead to inflammation and severe damage of virtually any tissue and organ. Recently, the application of advanced techniques of genome-wide scanning revealed more genetic information about SLE than previously possible. These case-control or family-based studies have provided evidence that SLE susceptibility is based (with a few exceptions) on an individual accumulation of various risk alleles triggered by environmental factors and also help to explain the discrepancies in SLE susceptibility between different populations or ethnicities. Moreover, during the past years new therapies (autologous stem cell transplantation, B cell depletion) and improved conventional treatment options (corticosteroids, traditional and new immune-suppressants like mycophenolate mofetile) changed the perspective in SLE therapeutic approaches. Thus, this article reviews genetic aspects of this autoimmune disease, summarizes clinical aspects of SLE and provides a general overview of conventional and new therapeutic approaches in SLE.

Increased expression of TLR2 in CD4(+) T cells from SLE patients enhances immune reactivity and promotes IL-17 expression through histone modifications

The innate immune system has been shown to play an important pathologic role in systemic lupus erythematosus (SLE). TLR2, a PRR, recognizes exogenous PAMPs, and endogenous damage-associated molecular patterns and has been implicated in the initiation and maintenance of the perpetuated inflammatory reactions in autoimmune diseases. Here, we report increased expression of TLR2 in CD4(+) and CD8(+) T cells, CD19(+) B cells, and CD14(+) monocytes from SLE patients. Conventional treatment, such as hydroxychloroquine and corticosteroids, showed no effect on TLR2 expression in CD4(+) T cells from SLE patients. In vitro stimulation of TLR2 in CD4(+) T cells from SLE patients increased CD40L and CD70 expression, as well as secretion of IL-6, IL-17A, IL-17F, and TNF-α, while Foxp3 transcription decreased. This effect was reversed by TLR2 siRNA. Moreover, TLR2 activation upregulated H3K4 tri-methylation and H4 acetylation levels while downregulated H3K9 tri-methylation level in the IL-17A promoter region. In addition, it also increased H4 acetylation levels and decreased H3K9 tri-methylation levels in the IL-17F promoter region. In summary, our findings demonstrate that increased expression of TLR2 contributes to immune reactivity and promotes IL-17A and IL-17F expression through histone modifications in SLE.

Tumor necrosis factor-alpha single nucleotide polymorphisms in juvenile systemic lupus erythematosus

BACKGROUND

Juvenile systemic lupus erythematosus (JSLE) is a multi-system autoimmune disorder of unknown origin. Given the importance of the contribution of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), towards the pathogenesis of JSLE, this study was performed to assess TNFA gene polymorphisms in a case-control study.

METHODS

Fifty nine patients with JSLE were enrolled in this study as case group and compared with healthy control subjects. The frequency of alleles, genotypes, and haplotypes of TNFA single-nucleotide polymorphisms (SNPs) at positions -308 and -238 were evaluated, using polymerase chain reaction with sequence-specific primers method.

RESULTS

The G allele at position -238 in TNFA promoter region was significantly more frequent in patients with JSLE than in the healthy controls (P value<0.001), while the frequency of A allele at the same position was significantly lower than controls. Furthermore, a significant positive association for G/G genotype at the same position was detected in patients' group compared with control subjects (P value<0.001). The GA haplotype of TNFA (positions -308, -238) was significantly less frequent in case group than in controls (P value<0.001), while GG was the most frequent haplotype for TNFA in the patient group, compared to controls (P value<0.01).

CONCLUSIONS

Pro-inflammatory cytokine gene polymorphisms may influence susceptibility to JSLE. Particular TNFA gene variants are associated with JSLE and could be used as a genetic marker for susceptibility to JSLE.

TNF-308 G/A polymorphism and risk of systemic lupus erythematosus in the Polish population

OBJECTIVES

Numerous studies have been performed with TNF-α-308 G/A (rs1800629) single nuclear polymorphism (SNP) to evaluate the risk of SLE in various ethnicities. However, the significance of TNF-α-308 G/A in both clinical and laboratory studies of the disease remains unclear.

METHODS

Using a high-resolution melting curve analysis, we assessed the prevalence of TNF-α-308 G/A SNP in SLE patients (n = 262) and controls (n = 528) in a Polish population. We also assessed the contribution of this SNP to various clinical symptoms and the presence of autoantibodies in SLE patients.

RESULTS

The p-value obtained using a χ(2) test for the trend of TNF-α-308 G/A was statistically significant (ptrend = 0.0297). However, using logistic regression analysis for the presence of the HLA-DRB1*03:01 haplotype, we observed that the TNF-α-308 G/A SNP may be the DRB1*03:01-dependent risk factor of SLE in the Polish population. There was a significant contribution of TNF-α-308 A/A and A/G genotypes to arthritis OR = [2.692 (1.503-4.822, p = 0.0007, pcorr = 0.0119)] as well as renal SLE manifestation OR = [2.632 (1.575-4.397, p = 0.0002, pcorr = 0.0034)]. There was a significant association between TNF-α-308 A/A and A/G genotypes and the presence of anti-Ro antibodies (Ab) OR = 3.375(1.711-6.658, p = 0.0003, pcorr = 0.0051). However, the logistic regression analysis revealed that only renal manifestations and the presence of anti-anti-Ro antibodies remained significant after adjustment to the presence of the HLA-DRB1*03:01 haplotype.

CONCLUSION

Our studies indicate that the TNF-α-308 G/A polymorphism may be a DRB1*03:01 haplotype-dependent genetic risk factor for SLE. However, this SNP was independently associated with renal manifestations and production of anti-Ro Ab.

Association of lymphotoxin alpha polymorphism with systemic lupus erythematosus and rheumatoid arthritis: a meta-analysis

AIM

The aim of this study was to perform a meta-analysis of eligible studies to derive precise estimation of the associations of lymphotoxin alpha (LTA) 252 A>G polymorphism (rs909253) with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) risk.

METHOD

Data were collected from the following electronic databases, including EMBASE, PubMed and China National Knowledge Infrastructure (CNKI). A total of 19 studies (13 studies involving 1346 SLE patients and 1951 controls, six studies involving 1079 RA patients and 1057 controls) were included.

RESULTS

This meta-analysis showed no evidence of significant association of the A allele with SLE susceptibility (odds ratio [OR] 1.26; 95% confidence interval [CI] 0.98-1.62, P = 0.073), but it showed a weaker association under an additive model (OR 1.63, 95%CI 1.01-2.65, P = 0.047). Stratification by ethnicity indicated that the variant A allele carriers increased the risk of SLE in Asians (OR 1.91, 95%CI 1.44-2.53, P < 0.001). However, we failed to reveal any association between LTA gene 252 A>G polymorphism and RA risk under all models (for A vs. G: OR 1.02, 95%CI 0.79-1.33, P = 0.853; for AA + AG vs. GG: OR 0.86, 95%CI 0.52-1.41, P = 0.542; for AA vs. AG + GG: OR 1.19, 95%CI 0.80-1.78, P = 0.394, for AA vs. GG: OR 1.03, 95%CI 0.58-1.84, P = 0.919). Similar results were obtained in the subgroup analysis based on ethnicity.

CONCLUSION

The present study suggests that LTA 252 A>G polymorphism is associated with SLE susceptibility in Asians, and there is no significant association between LTA 252 A>G polymorphism and RA.

Association of TNF-α with impaired migration capacity of mesenchymal stem cells in patients with systemic lupus erythematosus

Previous studies indicated that bone marrow mesenchymal stem cells (BMSCs) from patients with systemic lupus erythematosus (SLE) exhibited impaired capacities of proliferation, differentiation, and immune modulation. Considering that migration capacity is important for the exertion of BMSCs functions, the defects in migration might contribute to BMSCs dysfunction in SLE patients. In this study, we showed that the migration capacity of SLE BMSCs was remarkably impaired in comparison with those of healthy controls. Increased tumor necrosis factor α (TNF-α) in SLE serum significantly inhibited the migration capacity and in vivo homing capacity of SLE BMSCs via a specific TNF receptor I (TNFRI) manner, in which decreased HGF mRNA production caused by the activation of I kappa B kinase beta (IKK-β) pathway is partially involved. To our knowledge, this is the first report to discuss the possible mechanisms for impaired migration of BMSCs in SLE patients. Our results suggest that inhibition of TNF-α pathway might be helpful for accelerating BMSCs migration to the inflammatory microenvironment in SLE patients, thereby having a potential role in SLE treatment.

The effect of the autoimmunity-associated gene, PTPN22, on a BXSB-derived model of lupus

A single nucleotide polymorphism in PTPN22 is linked to increased disease susceptibility in a range of autoimmune diseases including systemic lupus erythematosus (SLE). PTPN22 encodes the Lyp phosphatase that dampens TCR signaling and is necessary for signaling downstream of toll-like receptors in myeloid cells. To understand these dual functions in disease, we examined the impact of deficiency in PTPN22 on a spontaneous murine model of SLE. Male PTPN22 KO mice carrying BXSB chromosome 1 and the Yaa disease accelerating factor developed disease at a similar rate and severity as PTPN22 WT. In contrast, although female mice showed no differences in survival in the absence of PTPN22, autoantibody production was significantly increased and splenic populations associated with pathogenesis in this model were expanded in the PTPN22 KO group. These findings support the notion that when coupled with other predisposing autoimmunity genes, PTPN22 deficiency contributes to a predisposition to lupus pathogenesis.

Tumor necrosis factor-α 238 G/A polymorphism and risk of hepatocellular carcinoma: evidence from a meta-analysis

BACKGROUND

Tumor necrosis factor-α (TNF-α) plays a very important role in the development and progression of cancer. Many epidemiological studies have evaluated associations between the TNF-α 238 G/A polymorphism and hepatocellular carcinoma (HCC) risk, but the published data are inconclusive. Therefore, we performed the present meta-analysis.

METHODS

Electronic searches of several databases were conducted for all publications on the association between TNF-α 238 G/A polymorphism and HCC through July 2012. Asummary odds ratio (OR) with its 95% confidence interval (CI) were calculated to evaluate the strength of this association.

RESULTS

Eleven case-control studies with a total of 1,572 HCC cases and 1,875 controls were finally included in this meta-analysis. Overall, the TNF-α 238 G/A polymorphism was significantly associated with increased risk of hepatocellular carcinoma in three genetic comparison models (For A versus G: OR 1.32, 95%CI 1.04-1.69, P = 0.02, I2 = 40%; for AG versus GG: OR 1.32, 95%CI 1.02-1.71, P = 0.03, I2 = 40%; for AA/AG versus GG: OR 1.33, 95%CI 1.03-1.72, P = 0.03, I2 = 41%) when all studies were pooled. Subgroup analysis by ethnicity further showed that there was a significant association between the TNF-α 238 G/A polymorphism and risk of HCC in Asians under three genetic comparison models (For A versus G: OR 1.30, 95%CI 1.00-1.68, P = 0.05, I2 = 45% for AA/AG versus GG: OR 1.31, 95%CI 1.00-1.71, P = 0.05, I2 = 46%).

CONCLUSIONS

This meta-analysis provided convincing evidence that the TNF-α 238 G/A polymorphism is associated with increased susceptibility to HCC. However, more well-designed studies with large sample size are needed to validate this association in Caucasians.

Pathogenesis and potential therapeutic targets in systemic lupus erythematosus: from bench to bedside

Systemic lupus erythematosus (SLE) is considered an autoimmune disease with multiorgan involvement. Many advances have been made during the last decade regarding inflammatory pathways, genetic and epigenetic alterations, adaptive and innate immune system mechanisms specifically involved in SLE pathogenesis. Apoptosis has been proposed as an important player in SLE pathogenesis more than a decade ago. However, only recently new key apoptotic pathways have been investigated and the link between apoptotic debris containing autoantigens, innate immunity and ongoing inflammation has been further elucidated. Better understanding of cellular mechanisms and involved cytokines contributed to the development of new biological drugs specifically addressed for SLE therapy.

Macrophage migration inhibitory factor: association of -794 CATT5-8 and -173 G>C polymorphisms with TNF-α in systemic lupus erythematosus

Macrophage migration inhibitory factor (MIF) is an upstream immunoregulatory cytokine associated with the pathogenesis of autoimmune inflammatory diseases. There is evidence that MIF functions in a positive feedback loop with TNF-α that could perpetuate the inflammatory process in systemic lupus erythematosus (SLE). In this case-control study we investigated whether commonly occurring functional MIF polymorphisms are associated with SLE as well as with MIF and TNF-α serum levels in a Mexican-Mestizo population. Genotyping of the -794 CATT5-8 (rs5844572) and -173 G>C (rs755622) MIF polymorphisms was performed by PCR and PCR-RFLP, respectively in 186 SLE patients and 200 healthy subjects. MIF and TNF-α serum levels were determined by ELISA. A significant increase of MIF and TNF-α levels was found in SLE patients. According to a genetic model, we found a significant association of genotypes carrying the -794 CATT7 and -173(∗)C risk alleles with susceptibility to SLE and with a significant increase of TNF-α. In conclusion, MIF gene polymorphisms are associated with SLE susceptibility and with an increase of TNF-α serum levels in a Mexican-Mestizo population.