Similar immune responses to alpha1-oleate and Bacillus Calmette-Guérin treatment in patients with bladder cancer

BACKGROUND

The molecular content of urine is defined by filtration in the kidneys and by local release from tissues lining the urinary tract. Pathological processes and different therapies change the molecular composition of urine and a variety of markers have been analyzed in patients with bladder cancer. The response to BCG immunotherapy and chemotherapy has been extensively studied and elevated urine concentrations of IL-1RA, IFN-α, IFN-γ TNF-α, and IL-17 have been associated with improved outcome.

METHODS

In this study, the host response to intravesical alpha 1-oleate treatment was characterized in patients with non-muscle invasive bladder cancer by proteomic and transcriptomic analysis.

RESULTS

Proteomic profiling detected a significant increase in multiple cytokines in the treatment group compared to placebo. The innate immune response was strongly activated, including IL-1RA and pro-inflammatory cytokines in the IL-1 family (IL-1α, IL-1β, IL-33), chemokines (MIP-1α, IL-8), and interferons (IFN-α2, IFN-γ). Adaptive immune mediators included IL-12, Granzyme B, CD40, PD-L1, and IL-17D, suggesting broad effects of alpha 1-oleate treatment on the tumor tissues.

CONCLUSIONS

The cytokine response profile in alpha 1-oleate treated patients was similar to that reported in BCG treated patients, suggesting a significant overlap. A reduction in protein levels at the end of treatment coincided with inhibition of cancer-related gene expression in tissue biopsies, consistent with a positive treatment effect. Thus, in addition to killing tumor cells and inducing cell detachment, alpha 1-oleate is shown to activate a broad immune response with a protective potential.

Proximity extension assay proteomics and renal single cell transcriptomics uncover novel urinary biomarkers for active lupus nephritis

OBJECTIVE

To identify urinary biomarkers that can distinguish active renal involvement in Lupus Nephritis (LN), a severe manifestation of systemic lupus erythematosus (SLE).

METHODS

Urine from 117 subjects, comprised of inactive SLE, active non-renal lupus, active LN, and healthy controls, were subjected to Proximity Extension Assay (PEA) based comprehensive proteomics followed by ELISA validation in an independent, ethnically diverse cohort. Proteomic data is also cross-referenced to renal transcriptomic data to elucidate cellular origins of biomarkers.

RESULTS

Systems biology analyses revealed progressive activation of cytokine signaling, chemokine activity and coagulation pathways, with worsening renal disease. In addition to validating 30 previously reported biomarkers, this study uncovers several novel candidates. Following ELISA validation in an independent cohort of different ethnicity, the six most discriminatory biomarkers for active LN were urinary ICAM-2, FABP4, FASLG, IGFBP-2, SELE and TNFSF13B/BAFF, with ROC AUC ≥80%, with most correlating strongly with clinical disease activity. Transcriptomic analyses of LN kidneys mapped the likely origin of these proteins to intra-renal myeloid cells (CXCL16, IL-1RT2, TNFSF13B/BAFF), T/NK cells (FASLG), leukocytes (ICAM2) and endothelial cells (SELE).

CONCLUSION

In addition to confirming the diagnostic potential of urine ALCAM, CD163, MCP1, SELL, ICAM1, VCAM1, NGAL and TWEAK for active LN, this study adds urine ICAM-2, FABP4, FASLG, IGFBP-2, SELE, and TNFSF13B/BAFF as additional markers that warrant systematic validation in larger cross-sectional and longitudinal cohorts.

Corrigendum: Urine L-selectin reflects clinical and histological renal disease activity and treatment response in lupus nephritis across multi-ethnicity

[This corrects the article DOI: 10.3389/fimmu.2023.1200167.].

Urine L-selectin reflects clinical and histological renal disease activity and treatment response in lupus nephritis across multi-ethnicity

Objective

There is an urgent need for novel biomarkers in lupus nephritis (LN). We report a non-invasive urinary biomarker, L-selectin, in two independent multi-ethnic cohorts.

Methods

uL-selectin was tested cross-sectionally in a Chinese cohort (n=255) and a US cohort (n=219) of SLE patients and controls using ELISA. A longitudinal cohort includes 20 active Chinese LN patients.

Results

uL-selectin was significantly increased in active LN patients compared to active non-renal SLE, inactive LN, inactive non-renal SLE, chronic kidney disease patients, and healthy controls. uL-selectin positively correlated with global and renal disease activities as well as histological activity index and chronicity index (CI). Low uL-selectin was an independent predictor for high CI. During follow-up, uL-selectin levels decreased significantly in the complete renal remission group.

Conclusion

uL-selectin is a novel biomarker of disease activity and renal histopathology in LN across multiple ethnicities. It also reflects treatment response in LN patients during follow up.

Integrated genomic, proteomic and cognitive assessment in Duchenne Muscular Dystrophy suggest astrocyte centric pathology

Introduction

Documented Duchenne Muscular Dystrophy (DMD) biomarkers are confined to Caucasians and are poor indicators of cognitive difficulties and neuropsychological alterations.

Materials and methods

This study correlates serum protein signatures with cognitive performance in DMD patients of South Asian origin. Study included 25 DMD patients aged 6-16 years. Cognitive profiles were assessed by Wechsler Intelligence Scale for Children. Serum proteome profiling of 1317 proteins was performed in eight DMD patients and eight age-matched healthy volunteers.

Results

Among the several novel observations we report, better cognitive performance in DMD was associated with increased serum levels of MMP9 and FN1 but decreased Siglec-3, C4b, and C3b. Worse cognitive performance was associated with increased serum levels of LDH-H1 and PDGF-BB but reduced GDF-11, MMP12, TPSB2, and G1B. Secondly, better cognitive performance in Processing Speed (PSI) and Perceptual Reasoning (PRI) domains was associated with intact Dp116, Dp140, and Dp71 dystrophin isoforms while better performance in Verbal Comprehension (VCI) and Working Memory (WMI) domains was associated with intact Dp116 and Dp140 isoforms. Finally, functional pathways shared with Alzheimer's Disease (AD) point towards an astrocyte-centric model for DMD.

Conclusion

Astrocytic dysfunction leading to synaptic dysfunction reported previously in AD may be a common pathogenic mechanism underlying both AD and DMD, linking protein alterations to cognitive impairment. This new insight may pave the path towards novel therapeutic approaches targeting reactive astrocytes.

Quantitative proteomic screening uncovers candidate diagnostic and monitoring serum biomarkers of ankylosing spondylitis

BACKGROUND

We sought to discover serum biomarkers of ankylosing spondylitis (AS) for diagnosis and monitoring disease activity.

METHODS

We studied biologic-treatment-naïve AS and healthy control (HC) patients' sera. Eighty samples matched by age, gender, and race (1:1:1 ratio) for AS patients with active disease, inactive disease, and HC were analyzed with SOMAscan™, an aptamer-based discovery platform. T-tests tests were performed for high/low-disease activity AS patients versus HCs (diagnosis) and high versus low disease activity (Monitoring) in a 2:1 and 1:1 ratio, respectively, to identify differentially expressed proteins (DEPs). We used the Cytoscape Molecular Complex Detection (MCODE) plugin to find clusters in protein-protein interaction networks and Ingenuity Pathway Analysis (IPA) for upstream regulators. Lasso regression analysis was performed for diagnosis.

RESULTS

Of the 1317 proteins detected in our diagnosis and monitoring analyses, 367 and 167 (317 and 59, FDR-corrected q < .05) DEPs, respectively, were detected. MCODE identified complement, IL-10 signaling, and immune/interleukin signaling as the top 3 diagnosis PPI clusters. Complement, extracellular matrix organization/proteoglycans, and MAPK/RAS signaling were the top 3 monitoring PPI clusters. IPA showed interleukin 23/17 (interleukin 22, interleukin 23A), TNF (TNF receptor-associated factor 3), cGAS-STING (cyclic GMP-AMP synthase, Stimulator of Interferon Gene 1), and Jak/Stat (Signal transducer and activator of transcription 1), signaling in predicted upstream regulators. Lasso regression identified a Diagnostic 13-protein model predictive of AS. This model had a sensitivity of 0.75, specificity of 0.90, a kappa of 0.59, and overall accuracy of 0.80 (95% CI: 0.61-0.92). The AS vs HC ROC curve was 0.79 (95% CI: 0.61-0.96).

CONCLUSION

We identified multiple candidate AS diagnostic and disease activity monitoring serum biomarkers using a comprehensive proteomic screen. Enrichment analysis identified key pathways in AS diagnosis and monitoring. Lasso regression identified a multi-protein panel with modest predictive ability.

Comprehensive proteomics and platform validation of urinary biomarkers for bladder cancer diagnosis and staging

BACKGROUND

Bladder cancer (BC) is among the most common cancers diagnosed in men in the USA. The current gold standards for the diagnosis of BC are invasive or lack the sensitivity to correctly identify the disease.

METHODS

An aptamer-based screen analyzed the expression of 1317 proteins in BC compared to urology clinic controls. The top hits were subjected to systems biology analyses. Next, 30 urine proteins were ELISA-validated in an independent cohort of 68 subjects. Three of these proteins were next validated in an independent BC cohort of differing ethnicity.

RESULTS

Systems biology analysis implicated molecular functions related to the extracellular matrix, collagen, integrin, heparin, and transmembrane tyrosine kinase signaling in BC susceptibility, with HNF4A and NFKB1 emerging as key molecular regulators. STEM analysis of the dysregulated pathways implicated a functional role for the immune system, complement, and interleukins in BC disease progression. Of 21 urine proteins that discriminated BC from urology clinic controls (UC), urine D-dimer displayed the highest accuracy (0.96) and sensitivity of 97%. Furthermore, 8 urine proteins significantly discriminated MIBC from NMIBC (AUC = 0.75-0.99), with IL-8 and IgA being the best performers. Urine IgA and fibronectin exhibited the highest specificity of 80% at fixed sensitivity for identifying advanced BC.

CONCLUSIONS

Given the high sensitivity (97%) of urine D-dimer for BC, it may have a role in the initial diagnosis or detection of cancer recurrence. On the other hand, urine IL-8 and IgA may have the potential in identifying disease progression during patient follow-up. The use of these biomarkers for initial triage could have a significant impact as the current cystoscopy-based diagnostic and surveillance approach is costly and invasive when compared to a simple urine test.

Urinary CD163 is a marker of active kidney disease in childhood-onset lupus nephritis

OBJECTIVE

The objective of this study was to evaluate the utility of urine CD163 for detecting disease activity in childhood-onset SLE (cSLE) patients.

METHODS

Sixty consecutive pediatric patients fulfilling four or more ACR criteria for SLE and 20 healthy controls were recruited for testing of urinary CD163 using ELISA. SLE disease activity was assessed using the SLEDAI-2K.

RESULTS

Urine CD163 was significantly higher in patients with active LN than inactive SLE patients and healthy controls, with receiver operating characteristics area under the curve values ranging from 0.93 to 0.96. LN was ascertained by kidney biopsy. Levels of CD163 significantly correlated with the SLEDAI, renal SLEDAI, urinary protein excretion and C3 complement levels. Urine CD163 was also associated with high renal pathology activity index and chronicity index, correlating strongly with interstitial inflammation and interstitial fibrosis based on the examination of concurrent kidney biopsies.

CONCLUSION

Urine CD163 emerges as a promising marker for identifying cSLE patients with active kidney disease. Longitudinal studies are warranted to validate the clinical utility of urine CD163 in tracking kidney disease activity in children with lupus.

Resistin, Elastase, and Lactoferrin as Potential Plasma Biomarkers of Pediatric Inflammatory Bowel Disease Based on Comprehensive Proteomic Screens

Inflammatory bowel disease (IBD) is an immune-mediated chronic inflammation of the intestine, which can present in the form of ulcerative colitis (UC) or as Crohn's disease (CD). Biomarkers are needed for reliable diagnosis and disease monitoring in IBD, especially in pediatric patients. Plasma samples from a pediatric IBD cohort were interrogated using an aptamer-based screen of 1322 proteins. The elevated biomarkers identified using the aptamer screen were further validated by ELISA using an independent cohort of 76 pediatric plasma samples, drawn from 30 CD, 30 UC, and 16 healthy controls. Of the 1322 proteins screened in plasma from IBD patients, 129 proteins were significantly elevated when compared with healthy controls. Of these 15 proteins had a fold change greater than 2 and 28 proteins had a fold change >1.5. Neutrophil and extracellular vesicle signatures were detected among the elevated plasma biomarkers. When seven of these proteins were validated by ELISA, resistin was the only protein that was significantly higher in both UC and CD (p < 0.01), with receiver operating characteristic area under the curve value of 0.82 and 0.77, respectively, and the only protein that exhibited high sensitivity and specificity for both CD and UC. The next most discriminatory plasma proteins were elastase and lactoferrin, particularly for UC, with receiver operating characteristic area under the curve values of 0.74 and 0.69, respectively. We have identified circulating resistin, elastase, and lactoferrin as potential plasma biomarkers of IBD in pediatric patients using two independent diagnostic platforms and two independent patient cohorts.

Exploring urine:serum fractional excretion ratios as potential biomarkers for lupus nephritis

Objectives

The goal of this exploratory study is to determine if urine:serum fractional excretion ratios can outperform the corresponding urinary biomarker proteins in identifying active renal disease in systemic lupus erythematosus (SLE).

Methods

Thirty-six adult SLE patients and twelve healthy controls were examined for serum and urine levels of 8 protein markers, namely ALCAM, calpastatin, hemopexin, peroxiredoxin 6 (PRDX6), platelet factor 4 (PF4), properdin, TFPI and VCAM-1, by ELISA. Fractional excretion of analyzed biomarkers was calculated after normalizing both the urine and serum biomarker levels against creatinine. A further validation cohort of fifty SLE patients was included to validate the initial findings.

Results

The FE ratios of all 8 proteins interrogated outperformed conventional disease activity markers such as anti-dsDNA, C3 and C4 in identifying renal disease activity. All but VCAM-1^FE were superior to the corresponding urine biomarkers levels in differentiating LN activity, exhibiting positive correlation with renal SLEDAI. ALCAM^FE, PF4^FE and properdin^FE ratios exhibited the highest accuracy (AUC>0.9) in distinguishing active LN from inactive SLE. Four of the FE ratios exhibited perfect sensitivity (calpastatin, PRDX6, PF4 and properdin), while ALCAM^FE, PF4^FE and properdin^FE exhibited the highest specificity values for active LN. In addition, several of these novel biomarkers were associated with higher renal pathology activity indices. In the validation cohort ALCAM^FE, PF4^FE and properdin^FE once again exhibited higher accuracy metrics, surpassing corresponding urine and serum biomarkers levels, with ALCAM^FE exhibiting 95% accuracy in distinguishing active LN from inactive SLE.

Conclusions

With most of the tested proteins, urine:serum fractional excretion ratios outperformed corresponding urine and serum protein measurements in identifying active renal involvement in SLE. Hence, this novel class of biomarkers in SLE ought to be systemically evaluated in larger independent cohorts for their diagnostic utility in LN assessment.

Urine ALCAM, PF4 and VCAM-1 Surpass Conventional Metrics in Identifying Nephritis Disease Activity in Childhood-Onset Systemic Lupus Erythematosus

Objectives

Serial kidney biopsy for repeat evaluation and monitoring of lupus nephritis (LN) in childhood-onset Systemic Lupus Erythematosus (cSLE) remains challenging, thus non-invasive biomarkers are needed. Here, we evaluate the performance of ten urine protein markers of diverse nature including cytokines, chemokines, and adhesion molecules in distinguishing disease activity in cSLE.

Methods

Eighty-four pediatric patients meeting ≥4 ACR criteria for SLE were prospectively enrolled for urine assay of 10 protein markers normalized to urine creatinine, namely ALCAM, cystatin-C, hemopexin, KIM-1, MCP-1, NGAL, PF-4, Timp-1, TWEAK, and VCAM-1 by ELISA. Samples from active renal (LN) and active non-renal SLE patients were obtained prior to onset/escalation of immunosuppression. SLE disease activity was evaluated using SLEDAI-2000. 59 patients had clinically-active SLE (SLEDAI score ≥4 or having a flare), of whom 29 patients (34.5%) were classified as active renal, and 30 patients (35.7%) were active non-renal. Twenty-five healthy subjects were recruited as controls.

Results

Urine concentrations of ALCAM, KIM-1, PF4 and VCAM-1 were significantly increased in active LN patients versus active non-renal SLE, inactive SLE and healthy controls. Five urine proteins differed significantly between 2 (hemopexin, NGAL, MCP1) or 3 (Cystatin-C, TWEAK) groups only, with the highest levels detected in active LN patients. Urine ALCAM, VCAM-1, PF4 and hemopexin correlated best with total SLEDAI as well as renal-SLEDAI scores (p < 0.05). Urine ALCAM, VCAM-1 and hemopexin outperformed conventional laboratory measures (anti-dsDNA, complement C3 and C4) in identifying concurrent SLE disease activity among patients (AUCs 0.75, 0.81, 0.81 respectively), while urine ALCAM, VCAM-1 and PF4 were the best discriminators of renal disease activity in cSLE (AUCs 0.83, 0.88, 0.78 respectively), surpassing conventional biomarkers, including proteinuria. Unsupervised Bayesian network analysis based on conditional probabilities re-affirmed urine ALCAM as being most predictive of active LN in cSLE patients.

Conclusion

Urinary ALCAM, PF4, and VCAM-1 are potential biomarkers for predicting kidney disease activity in cSLE and hold potential as surrogate markers of nephritis flares in these patients.

Baseline Elevations of Leukotriene Metabolites and Altered Plasmalogens Are Prognostic Biomarkers of Plaque Progression in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is associated with an increased incidence of acute and chronic cardiovascular disease as compared to the general population. This study uses a comprehensive metabolomic screen of baseline sera from lupus patients to identify metabolites that predict future carotid plaque progression, following 8–9 years of follow-up. Nine patients had SLE without plaque progression, 8 had SLE and went on to develop atherosclerotic plaques (SLE^PP), and 8 patients were controls who did not have SLE. The arachidonic acid pathway metabolites, leukotriene B4 (LTB4) and 5-hydroxyeicosatetraenoic acid (5-HETE), and the oxidized lipids 9/13-hydroxyoctodecadienoic acid (HODE) were found to be significantly altered (p < 0.05 and fold-change >2) in SLE^PP patients compared to SLE patients without plaque progression. SLE^PP patients also exhibited significantly altered levels of branched chain amino acid (BCAA) metabolites and plasmalogens compared to the non-SLE controls. Taken together with the rich literature on these metabolites, these findings suggest that the identified metabolites may not only be prognostic of cardiovascular disease development in SLE patients, but they may also be active drivers of atheroma formation. Early identification of these high risk SLE patients may help institute preventive measures early in the disease course.

Aptamer-based screen of Neuropsychiatric Lupus cerebrospinal fluid reveals potential biomarkers that overlap with the choroid plexus transcriptome

OBJECTIVES

As no gold-standard diagnostic test exists for neuropsychiatric systemic lupus erythematosus (NPSLE), we executed a broad screen of NPSLE cerebrospinal fluid (CSF) using an aptamer-based platform.

METHODS

CSF were obtained from NPSLE patients and subjected to proteomic assay using the aptamer-based screen. Potential biomarkers were identified and validated in independent NPSLE cohorts in comparison with other neurological diseases.

RESULTS

40 proteins out of 1129 screened were elevated in NPSLE CSF. By ELISA validation, CSF Angiostatin, α2-Macroglobulin, DAN, Fibronectin, HCC-1, IgM, Lipocalin 2, M-CSF and SERPING1 were significantly elevated in a predominantly Caucasian NPSLE cohort (n=24), compared to patients with other neurological diseases (n=54), with CSF IgM (AUC=0.95) and M-CSF (AUC=0.91) being the most discriminatory. In a second, Hong Kong NPSLE cohort, CSF IgM (AUC=0.78) and Lipocalin-2 (AUC=0.85) were the most discriminatory. Several CSF proteins exhibited high diagnostic specificity for NPSLE in both cohorts. Elevated CSF C3 was associated with acute confusional state. Eleven molecules elevated in NPSLE CSF exhibited concordant elevation in the choroid plexus, suggesting shared origins.

CONCLUSIONS

CSF Lipocalin-2, M-CSF, IgM and complement C3 emerge as promising CSF biomarkers of NPSLE with diagnostic potential.

Comprehensive aptamer-based screen of 1317 proteins uncovers improved stool protein markers of colorectal cancer

BACKGROUND

To screen and validate novel stool protein biomarkers of colorectal cancer (CRC).

METHODS

A novel aptamer-based screen of 1317 proteins was used to uncover elevated proteins in the stool of patients with CRC, as compared to healthy controls (HCs) in a discovery cohort. Selected biomarker candidates from the discovery cohort were ELISA validated in three independent cross-sectional cohorts comprises 76 CRC patients, 15 adenoma patients, and 63 healthy controls, from two different ethnicities. The expression of the potential stool biomarkers within CRC tissue was evaluated using single-cell RNA-seq datasets.

RESULTS

A total of 92 proteins were significantly elevated in CRC samples as compared to HCs in the discovery cohort. Among Caucasians, the 5 most discriminatory proteins among the 16 selected proteins, ordered by their ability to distinguish CRC from adenoma and healthy controls, were MMP9, haptoglobin, myeloperoxidase, fibrinogen, and adiponectin. Except myeloperoxidase, the others were significantly associated with depth of tumor invasion. The 8 stool proteins with the highest AUC values were also discriminatory in a second cohort of Indian CRC patients. Several of the stool biomarkers elevated in CRC were also expressed within CRC tissue, based on the single-cell RNA-seq analysis.

CONCLUSIONS

Stool MMP9, fibrinogen, myeloperoxidase, and haptoglobin emerged as promising CRC stool biomarkers, outperforming stool Hemoglobin. Longitudinal studies are warranted to assess the clinical utility of these novel biomarkers in early diagnosis of CRC.

Predicting disease course in ulcerative colitis using stool proteins identified through an aptamer-based screen

In the search for improved stool biomarkers for inflammatory bowel disease (IBD), an aptamer-based screen of 1129 stool proteins was conducted using stool samples from an IBD cohort. Here we report that of the 20 proteins subsequently validated by ELISA, stool Ferritin, Fibrinogen, Haptoglobin, Hemoglobin, Lipocalin-2, MMP-12, MMP-9, Myeloperoxidase, PGRP-S, Properdin, Resistin, Serpin A4, and TIMP-1 are significantly elevated in both ulcerative colitis (UC) and Crohn's disease (CD) compared to controls. When tested in a longitudinal cohort of 50 UC patients at 4 time-points, fecal Fibrinogen, MMP-8, PGRP-S, and TIMP-2 show the strongest positive correlation with concurrent PUCAI and PGA scores and are superior to fecal calprotectin. Unlike fecal calprotectin, baseline stool Fibrinogen, MMP-12, PGRP-S, TIMP-1, and TIMP-2 can predict clinical remission at Week-4. Here we show that stool proteins identified using the comprehensive aptamer-based screen are superior to fecal calprotectin alone in disease monitoring and prediction in IBD.

Urine protein biomarkers of bladder cancer arising from 16-plex antibody-based screens

Purpose: The purpose of this study is to identify novel urine protein biomarkers of bladder cancer using a Luminex based screening platform.

Materials and Methods: The current study examines urine samples from 66 subjects, comprised of 31 Urology clinic controls and 35 bladder cancer patients, using a Luminex based screening platform. ELISA validation was carried out for the top 4 prospective urine biomarkers using an independent cohort of 20 Urology clinic controls and 60 bladder cancer (BC) subjects.

Results: Of the 16 proteins screened by Luminex, 10 showed significant elevation in BC compared to the controls. Eight of these urine proteins were able to differentiate BC from control urine with ROC AUC values exceeding 0.70 at p < 0.0001, with specificity values exceeding 0.9. Upon ELISA validation, urine IL-1α, IL-1ra, and IL-8 were able to distinguish control urine from urine drawn from various bladder cancer stages, with IL-8 being the best discriminator. Compared to members of the IL-1 cytokine family, urine IL-8 was also best at discriminating T1 and/or T2–T4 from Ta BC (ROC AUC ≥ 0.83), as well as high grade from low grade BC (ROC AUC ≥ 0.82).

Conclusions: These findings suggest that urine IL-1α, IL-1ra and IL-8 are useful indicators of bladder cancer. Urine IL-8 not only distinguishes bladder cancer from controls, it also discriminates high grade from low grade disease, and the successive clinical stages of bladder cancer. While supportive of previous reports, these findings warrant further analysis in prospective cohorts.

Epigallocatechin-3-Gallate Dampens Non-Alcoholic Fatty Liver by Modulating Liver Function, Lipid Profile and Macrophage Polarization

Epigallocatechin-3-gallate (EGCG) has been shown to attenuate obesity, fatty liver disease, hepatic inflammation and lipid profiles. Here, we validate the efficacy of EGCG in a murine model of non-alcoholic fatty liver disease (NAFLD) and extend the mechanistic insights. NAFLD was induced in mice by a high-fat diet (HFD) with 30% fructose. EGCG was administered at a low dose (25 mg/kg/day, EGCG-25) or high dose (50 mg/kg/day, EGCG-50) for 8 weeks. In HFD-fed mice, EGCG attenuated body and liver weight by ~22% and 47%, respectively, accompanied by ~47% reduction in hepatic triglyceride (TG) accumulation and ~38% reduction in serum cholesterol, resonating well with previous reports in the literature. In EGCG-treated mice, the hepatic steatosis score and the non-alcoholic steatohepatitis activity score were both reduced by ~50% and ~57%, respectively, accompanied by improvements in hepatic inflammation grade. Liver enzymes were improved ~2–3-fold following EGCG treatment, recapitulating previous reports. Hepatic flow cytometry demonstrated that EGCG-fed mice had lower Ly6C⁺, MHCII+ and higher CD206⁺, CD23⁺ hepatic macrophage infiltration, indicating that EGCG impactedM1/M2 macrophage polarization. Our study further validates the salubrious effects of EGCG on NAFLD and sheds light on a novel mechanistic contribution of EGCG, namely hepatic M1-to-M2 macrophage polarization. These findings offer further support for the use of EGCG in human NAFLD.

Targeted urine proteomics in lupus nephritis - a meta-analysis

BACKGROUND

Proteomic approaches are central in biomarker discovery. While mass-spectrometry-based techniques are widely used, novel targeted proteomic platforms have enabled the high-throughput detection of low-abundance proteins in an affinity-based manner. Urine has gained growing attention as an ideal biofluid for monitoring renal disease including lupus nephritis (LN).

METHODS

Pubmed was screened for targeted proteomic studies of LN urine interrogating ≥1000 proteins. Data from the primary studies were combined and a meta-analysis was performed. Shared proteins elevated in active LN across studies were identified, and relevant pathways were elucidated using ingenuity pathway and gene ontology analysis. Urine proteomic data was cross-referenced against renal single-cell RNAseq data from LN kidneys.

RESULTS

Two high-throughput targeted proteomic platforms with capacity to interrogate ≥1000 proteins have been used to investigate LN urine. Twenty-three urine proteins were significantly elevated in both studies, including 10 chemokines, and proteins implicated in angiogenesis, and extracellular matrix turnover. Of these, Cathepsin S, CXCL10, FasL, ferritin, macrophage migration inhibitory factor (MIF), and resistin were also significantly elevated within LN kidneys.

CONCLUSION

Targeted urinary proteomics have uncovered multiple novel biomarkers for LN. Further validation in prospective cohorts and mechanistic studies are warranted to establish their clinical utility.

ALCAM and VCAM-1 as urine biomarkers of activity and long-term renal outcome in systemic lupus erythematosus

OBJECTIVES

We investigated the cell adhesion molecules (CAMs) Vascular CAM 1 (VCAM-1) and Activated Leucocyte CAM (ALCAM) as urinary biomarkers in SLE patients with and without renal involvement.

METHODS

Female SLE patients (n = 111) and non-SLE population-based controls (n = 99) were enrolled. We measured renal activity using the renal domain of the BILAG index and urine (U) and plasma (P) concentrations of soluble (s)VCAM 1 and U-sALCAM using ELISA. U-sCAM levels were next corrected by U-creatinine.

RESULTS

U-sVCAM-1/creatinine and U-sALCAM/creatinine ratios were higher in SLE patients vs non-SLE controls (P < 0.001 for both), as well as in patients with active/low-active (BILAG A-C; n = 11) vs quiescent (BILAG D; n = 19) LN (P = 0.023 and P = 0.001, respectively). U-sALCAM/creatinine but not U-sVCAM-1/creatinine ratios were higher in patients with nephritis history (BILAG A-D; n = 30) vs non-renal SLE (BILAG E; n = 79) (P = 0.014). Patients with baseline U-sVCAM-1/creatinine ratios ≥75th percentile showed a 23-fold increased risk of a deterioration in estimated glomerular filtration rate by ≥25% during a 10-year follow-up (odds ratio: 22.9; 95% CI: 2.8, 189.2; P = 0.004); this association remained significant after adjustments for age, disease duration and organ damage. Traditional markers including anti-dsDNA antibodies did not predict this outcome.

CONCLUSION

While high U-sVCAM-1 levels appear to reflect SLE disease activity, sALCAM might have particular importance in renal SLE. Both U-sVCAM-1 and U-sALCAM showed ability to distinguish SLE patients with active renal involvement from patients with quiescent or no prior nephritis. High U-sVCAM-1 levels may indicate patients at increased risk for long-term renal function loss.

Quantitative planar array screen of 1000 proteins uncovers novel urinary protein biomarkers of lupus nephritis

OBJECTIVE

The goal of these studies is to discover novel urinary biomarkers of lupus nephritis (LN).

METHODS

Urine from systemic lupus erythematosus (SLE) patients was interrogated for 1000 proteins using a novel, quantitative planar protein microarray. Hits were validated in an independent SLE cohort with inactive, active non-renal (ANR) and active renal (AR) patients, in a cohort with concurrent renal biopsies, and in a longitudinal cohort. Single-cell renal RNA sequencing data from LN kidneys were examined to deduce the cellular origin of each biomarker.

RESULTS

Screening of 1000 proteins revealed 64 proteins to be significantly elevated in SLE urine, of which 17 were ELISA validated in independent cohorts. Urine Angptl4 (area under the curve (AUC)=0.96), L-selectin (AUC=0.86), TPP1 (AUC=0.84), transforming growth factor-β1 (TGFβ1) (AUC=0.78), thrombospondin-1 (AUC=0.73), FOLR2 (AUC=0.72), platelet-derived growth factor receptor-β (AUC=0.67) and PRX2 (AUC=0.65) distinguished AR from ANR SLE, outperforming anti-dsDNA, C3 and C4, in terms of specificity, sensitivity and positive predictive value. In multivariate regression analysis, urine Angptl4, L-selectin, TPP1 and TGFβ1 were highly associated with disease activity, even after correction for demographic variables. In SLE patients with serial follow-up, urine L-selectin (followed by urine Angptl4 and TGFβ1) were best at tracking concurrent or pending disease flares. Importantly, several proteins elevated in LN urine were also expressed within the kidneys in LN, either within resident renal cells or infiltrating immune cells, based on single-cell RNA sequencing analysis.

CONCLUSION

Unbiased planar array screening of 1000 proteins has led to the discovery of urine Angptl4, L-selectin and TGFβ1 as potential biomarker candidates for tracking disease activity in LN.

Upregulation of Proinflammatory Bradykinin Peptides in Systemic Lupus Erythematosus and Rheumatoid Arthritis

Our recent study has implicated bradykinin (BK) signaling as being of pathogenic importance in lupus. This study aims to investigate the biomarker potential of BK peptides, BK and BK-des-arg-9, in lupus and other rheumatic autoimmune diseases. Sera from systemic lupus erythematosus (SLE) patients and healthy subjects were screened for BK and BK-des-arg-9 by liquid chromatography-mass spectrometry metabolomics. Serum from 6-mo-old C57BL/6 mice and three murine lupus strains were also screened for the two peptides by metabolomics. Given the promising initial screening results, validation of these two peptides was next conducted using multiple reaction monitoring in larger patient cohorts. In initial metabolomics screening, BK-des-arg-9 was 22-fold higher in SLE serum and 106-fold higher in mouse lupus serum compared with healthy controls. In validation assays using multiple reaction monitoring and quadrupole time-of-flight mass spectrometry, BK and BK-des-arg-9 showed significant elevations in SLE serum compared with controls (p < 0.0001; area under the curve = 0.79-0.88), with a similar but less pronounced increase being noted in rheumatoid arthritis serum. Interestingly, increased renal SLE disease activity index in lupus patients was associated with reduced circulating BK-des-arg-9, and the reasons for this remain to be explored. To sum, increased conversion of BK to the proinflammatory metabolite BK-des-arg-9 appears to be a common theme in systemic rheumatic diseases. Besides serving as an early marker for systemic autoimmunity, independent studies also show that this metabolic axis may also be a pathogenic driver and therapeutic target in lupus.

Comprehensive aptamer-based screening identifies a spectrum of urinary biomarkers of lupus nephritis across ethnicities

Emerging urinary biomarkers continue to show promise in evaluating lupus nephritis (LN). Here, we screen urine from active LN patients for 1129 proteins using an aptamer-based platform, followed by ELISA validation in two independent cohorts comprised of 127 inactive lupus, 107 active LN, 67 active non-renal lupus patients and 74 healthy controls, of three different ethnicities. Urine proteins that best distinguish active LN from inactive disease are ALCAM, PF-4, properdin, and VCAM-1 among African-Americans, sE-selectin, VCAM-1, BFL-1 and Hemopexin among Caucasians, and ALCAM, VCAM-1, TFPI and PF-4 among Asians. Most of these correlate significantly with disease activity indices in the respective ethnic groups, and surpass conventional metrics in identifying active LN, with better sensitivity, and negative/positive predictive values. Several elevated urinary molecules are also expressed within the kidneys in LN, based on single-cell RNAseq analysis. Longitudinal studies are warranted to assess the utility of these biomarkers in tracking lupus nephritis.

Association of Urine sCD163 With Proliferative Lupus Nephritis, Fibrinoid Necrosis, Cellular Crescents and Intrarenal M2 Macrophages

CD163 is a marker for alternatively activated macrophages, which have been implicated in the pathogenesis of lupus nephritis (LN). In our preliminary screening of urine proteins in LN, urine soluble CD163 (sCD163) was significantly elevated in patients with active LN. To evaluate the potential of sCD163 as a biomarker in LN, urine sCD163 was assayed in patients with active LN, active non-renal lupus patients (ANR), inactive SLE and healthy controls (HC), using ELISA and normalized to urine creatinine. The correlation of urine sCD163 with clinical parameters and renal pathological attributes was further investigated in LN patients with concurrent renal biopsies. A total of 228 SLE patients and 56 HC were included from three cohorts. Results demonstrated that urine sCD163 was significantly elevated in active LN when compared with HC, inactive SLE, or ANR in African-American, Caucasian and Asian subjects (all P < 0.001). In LN patients with concurrent renal biopsies, urine sCD163 was significantly increased in patients with proliferative LN when compared with non-proliferative LN (P < 0.001). Urine sCD163 strongly correlated with SLEDAI, rSLEDAI, activity index (AI) of renal pathology, fibrinoid necrosis, cellular crescents, and interstitial inflammation on biopsies (all P < 0.01). Macrophages, particularly M2 macrophages, the predominant cells expressing CD163 within LN kidneys, represented a potential source of elevated urine sCD163, based on single-cell RNA sequencing analysis. To conclude, urine sCD163 discriminated patients with active LN from other SLE patients and was significantly elevated in proliferative LN. It strongly correlated with concurrent AI and several specific pathological attributes, demonstrating its potential in predicting renal pathology.

Low dose Epigallocatechin Gallate Alleviates Experimental Colitis by Subduing Inflammatory Cells and Cytokines, and Improving Intestinal Permeability

Background: In this study, we investigate the impact of epigallocatechin gallate (EGCG), the most abundant and potent catechin in green tea, on a mouse model of inflammatory bowel disease (IBD) and the underlying mechanisms of action. Methods: C57BL/6J mice were subjected to dextran sulfate sodium (DSS)-induced IBD-like disease and then randomly divided into three groups: Model group (MD), low-dose EGCG group (LE, 20 mg/kg/d), and high-dose EGCG group (HE, 50 mg/kg/d). DSS-induced clinical and macroscopic changes were monitored daily. Intestinal permeability was assessed by FITC-Dextran assay. Results: Both high- and low-dose EGCG treatment alleviated clinical manifestations including body weight loss and disease activity index (DAI) of DSS-induced colitis. The DAI score was significantly improved after two days of EGCG treatment. At the end of the study, the macroscopic severity score (MSS) of HE and LE treatment groups were 2.4 ± 1.2, and 2.2 ± 1.0, respectively, significantly lower than that of the controls (5.0 ± 2.1). EGCG treatment also prevented colon shortening, and improved intestinal permeability and histopathological changes. In addition, EGCG treatment attenuated colon inflammation by suppressing colonic levels of pro-inflammatory cytokines IL-6, MCP-1, and TNF-alpha, and inhibited CD3+ T cell and CD68+ macrophage infiltration. Conclusion: EGCG is effective in inflammatory colitis because it reduces cellular and molecular inflammation, and reduces intestinal permeability.

ALCAM and VCAM-1 as potential urinary biomarkers in Caucasian lupus patients

Background

Lupus affects millions of people worldwide and is difficult to diagnose early in patients. By utilizing enzyme-linked immunosorbent assays (ELISA), this study seeks to identify urinary biomarkers that may detect lupus in its earlier stages, allowing for better, earlier treatment regimens.

Methods

197 urine samples from a Swedish SLE cohort were divided into four groups, each matched for demographics: 23 active non-renal SLE samples (SLEDAI&gt;0, rSLEDAI=0), 29 active renal SLE samples (SLEDAI&gt;0, rSLEDAI&gt;0), 46 inactive SLE samples (SLEDAI=0), and 99 healthy controls. These samples were screened for 2 human proteins using ELISA, selected because they exhibited biomarker potential in our earlier screens.

Results

VCAM was noted to be significantly elevated (2-tailed t-test, p&lt;0.0001) in SLE patients compared to healthy controls. More specifically, VCAM was elevated in active renal samples when compared to healthy samples (p&lt;0.0001). An ROC curve shows that VCAM can be used to differentiate between active renal samples and control samples (AUC=0.8889, p-value=0.0250). ALCAM was also elevated (p&lt;0.0001) in SLE patients compared to healthy patients. However, ALCAM was not as highly elevated in active renal samples compared to healthy samples (p&lt;0.001). Additionally, an ROC curve does not show ALCAM strongly differentiating between active renal samples and control samples. Based on these results, VCAM is the more promising biomarker of the two.

Conclusions

Urinary VCAM and ALCAM are both potentially viable biomarkers for lupus that warrant further investigation. Studies are in progress to compare the performance of these urinary markers to conventional yardsticks and their relationship to other clinical parameters.

Hemopexin deficiency prevents joint injury following collagen antibody-induced arthritis

Background

Rheumatoid arthritis is an autoimmune disorder in which the immune system attacks its own tissues, resulting in swelling and inflammation of the joints. Hemopexin (Hx), an acute-phase protein synthesized by hepatocytes in response to proinflammatory cytokines, binds to heme, and controls heme-iron availability in tissues and T lymphocytes. Its absence has been associated with increased inflammatory properties of high-density lipoproteins and the development of autoimmune disease, such as experimental autoimmune encephalomyelitis (EAE). The aim of this study is to investigate the role of Hx in the development of arthritis using the collagen antibody-induced arthritis (CAIA) mouse model.

Methods

CAIA was induced in Hx-deficient (Hx−/−) mice and wild-type (WT) littermates, via i.p injection of antibodies directed against type II collagen, followed by the administration of lipopolysaccharide (LPS). Paw thickness and disease severity was evaluated daily. Blood samples were collected to measure the serum Hx levels using ELISA.

Results

During CAIA, serum Hx level became elevated and remained high. When CAIA was induced in Hx−/− mice, they exhibited reduced arthritis compared to WT mice, as arthritic Hx−/− mice had lower average paw thickness (1.32 ± 0.02 vs 2.67 ± 0.05, 2-tail t test, P &lt; 0.05 ) and reduced arthritis scores ( 2.0 ± 0.5 vs 7.3 ±1.25, 2-tail t test, P &lt; 0.01) at the end of the experiment compared to WT mice. Pathology studies are in progress.

Conclusion

Hx−/− mice are protected from CAIA, with reduced arthritis, indicating a pro-inflammatory role for Hx in the development of arthritis. Further studies are warranted to unravel the pathogenic mechanisms involved and clinical relevance of this molecule.

Epigallocatechin-3-gallate prevents Non-alcoholic fatty liver disease by modulating liver function, lipid profiles and M1/M2 macrophage polarization

Background

Here, we examine the therapeutic efficacy of Epigallocatechin-3-gallate, the most potent catechin in green tea, on nonalcoholic fatty liver disease (NAFLD), a growing epidemic in humans.

Methods

NAFLD was induced by high-fat diet (HFD) with 30% fructose in drinking water for 8 weeks. Mice were divided into 3 groups: model group (MD; no EGCG), low dose EGCG group (LE, 20 mg/kg/d) and high dose EGCG group (HE, 50 mg/kg/d). Liver histology, serum lipid prolife, liver function as well as liver M1/M2 polarization were evaluated.

Results

At the end of the experiment, the mean body weight of LE and HE mice were 39.7g and 45.7g, while it was 51.9g in the MD group (P&lt; 0.05). Similarly, liver weights in the LE and HE groups (means = 1.44g, and 1.68g, respectively) were lower than that in MD (2.94g, P &lt; 0.01). Liver dysfunction observed in the MD group (mean AST=133.2 U/L and ALT=183.4 U/L), was significantly improved in both LE (44.8 U/L, 86.8 U/L, respectively, P &lt; 0.001) and HE groups (83.63 U/L, 117.6 U/L, respectively P &lt; 0.05). Serum cholesterol, HDL, triglyceride levels were increased in the MD group, but lowered in both LE and HE mice (p&lt;0.01). Hepatic FACS, RT-PCR and IHC studies demonstrated that the HE group had lower F4/80+ CD86+ (0.3 ×103 vs 1.5 × 104), F4/80+ MHC II+ (0.7 ×104 vs 1.3 × 104), and higher F4/80+ CD206+(2.96 ×104 vs 0.3 × 104), F4/80+ CD23+ (1.27 ×104 vs 0.65 × 104) hepatic infiltration, accompanied by down-regulated CD68 and up-regulated CD163 mRNA expression.

Conclusion

EGCG subdued NAFLD despite consumption of HDF and high fructose water, marked by improved liver function and serum lipid profile, as well as M1/M2 polarization. EGCG should be investigated as a therapeutic modality in human NAFLD.

Assessing the disease specificity of urinary PF4 for active lupus nephritis

Background

The use of urinary biomarkers is particularly helpful in avoiding invasive procedures such as renal biopsy. We recently observed that urinary Platelet factor 4 (PF4) was elevated in patients with active lupus nephritis compared to patients with inactive lupus or healthy controls. Objective of this study is to assess the specificity of urinary PF4 for lupus nephritis (LN). PF4 is a small cytokine, also known as CXCL-4, known to play a role in inflammation.

Methods

Urinary PF4 level was measured using ELISA in urine samples obtained from 50 chronic kidney disease patient samples comprising of DN (Diabetic Nephropathy) (N = 23), HTN Nephropathy (Hypertensive nephropathy) (N = 6), combination of DN and HTN nephropathy (N = 4), IgA nephropathy (N = 4), FSGS (Focal segmental glomerular sclerosis) (N = 13). As a negative control, urine samples were included from healthy controls, while urine samples from patients with active lupus nephritis were included as a positive control. All results were normalized to urinary creatinine. The urinary PF4 levels in various CKD groups were compared to both negative and positive controls.

Results

Urinary PF4 was significantly elevated (P&lt;0.05) in samples from DN (678±285 pg/mg), FSGS (423±208 pg/mg), and LN (1438±901 pg/mg), compared to healthy controls (11±10 pg/mg). Urine PF4 levels in IgA nephropathy (24±15 pg/mg), HTN nephropathy (38±33), and DN/HTN nephropathy (463±410 pg/mg) were not significantly elevated compared to healthy controls.

Conclusion

PF4, as a urinary biomarker, exhibited significant elevation in patients with DN, FSGS as well as LN when compared to other renal diseases like IgA nephropathy and HTN nephropathy. Hence PF4 may aid in the noninvasive monitoring of DN, FSGS, and LN.

Identification of protein biomarkers in cerebrospinal fluid(CSF) of Neuro Psychiatric SLE(NPSLE) patients using SOMA scan assay

Background

Neurological manifestations of systemic lupus erythematosus (NPSLE) include a wide spectrum of symptoms like seizures, meningitis and psychosis. Clinical diagnosis of NPSLE is challenging due to the lack of objective diagnostic tests. Here, we explore if CSF proteins may have diagnostic value in NPSLE.

Methods

24 CSF samples (8 healthy + 8 neuro controls (NC) + 8 NPSLE) were screened using an aptamer-based platform for about 1100 proteins. A subset of the differentially expressed CSF proteins was selected for validation in two different cohorts, Caucasian controls (N=54) & NPSLE (N= 25) and Chinese controls (N=15) & SLE (N= 17).

Results

The initial aptamer-based screen revealed 8 CSF proteins to be elevated in NPSLE vs healthy, at fold change &gt;2, and p &lt;0.05. All 8 proteins were validated by ELISA. Total IgM, Lipocalin 2, M-CSF were significantly elevated in the CSF of NPSLE when compared to controls, in both Caucasian and Chinese patients (range of fold change: 16–1.2; p &lt; 0.05). CSF HCC-s, DAN and Angiostatin were significantly elevated in Caucasian NPSLE patients only (range of fold change: 2.3–1.8; p &lt; 0.05). Total C3 and albumin in CSF did not show any difference in disease groups in both cohorts, as assayed by ELISA.

Conclusion

Several novel proteins were noted to be elevated in NPSLE CSF, relative to control subjects with other neurological symptoms. Further studies are warranted to establish the specificity of CSF IgM, Lipocalin 2, M-CSF, HCC-s, DAN and Angiostatin for NPSLE and to understand their pathogenic relevance.

Epigallocatechin-3-gallate (EGCG) ameliorates dextran sulfate sodium (DSS) –induced inflammatory bowel disease

Background

Given the potential side effects associated with conventional medical treatment of Inflammatory Bowel Disease (IBD), dietary supplements have been investigated by several groups. We tested if epigallocatechin gallate (EGCG) may be beneficial in IBD.

Methods

36 C57BL/6J mice were subjected to dextran sulfate sodium (DSS)-induced IBD and divided into 3 groups: model group (MD; no EGCG), low dose EGCG group (LE, 20 mg/kg/d) and high dose EGCG group (HE, 50 mg /kg/d).

Results

Both high and low dose EGCG treatment alleviated clinical manifestations of IBD including body weight loss and disease activity index (DAI): HE: 3.3 and LE: 2.8 vs. 8.3 in MD (p &lt; 0.001, n=8–10 mice/group). Macroscopic severity score (MSS) of HE and LE groups were 2.4, and 2.2, respectively, significantly lower than in MD (5.0, P &lt; 0.01). The mean colon length of MD group was 5.8 cm; treatment with EGCG restored colon length (HE: 6.5 cm; LE: 6.4 cm). Intestinal permeability was improved as demonstrated by FITC-Dextran assay (HE: 3.28; LE: 2.85, vs. MD group: 6.69 ng/ml, P &lt; 0.001) .The colitis histology score of HE (1.54) and LE (0.42) groups were significantly lower than that in MD (4.3, P &lt; 0.001). In addition, EGCG treatment reduced colonic levels of pro-inflammatory cytokines: IL-6 (HE: 0.45; LE group: 0.41 vs MD: 0.89 ng/g tissue, P =0.03), MCP-1 (HE: 1.83; LE: 1.87, vs MD: 3.5 ng/g tissue P = 0.01) and TNF-alpha (HE: 8.87; LE: 10 vs MD: 21.7 ng/g tissue, P &lt;0.001). Lower CD3+ T cell and CD68+ macrophage infiltration was also noted in HE and LE mice (P &lt; 0.001), compared to MD controls.

Conclusion

These results underscore the therapeutic potential of EGCG in the treatment of IBD, which appear to be mediated through multiple inflammatory pathways.

Leukocyte Beta-Catenin Expression Is Disturbed in Systemic Lupus Erythematosus

Wnt/β-catenin signaling is relatively understudied in immunity and autoimmunity. β-catenin blocks inflammatory mediators and favors tolerogenic dendritic cell (DC) phenotypes. We show here that leukocytes from lupus-prone mice and SLE patients express diminished β-catenin transcriptional activity, particularly in myeloid cells, although other leukocytes revealed similar trends. Serum levels of DKK-1, an inhibitor under transcriptional control of Wnt/β-catenin, were also decreased in lupus-prone mice. Surprisingly, however, preemptive deletion of β-catenin from macrophages appears to have no effect on lupus development, even in mice with varying genetic loads for lupus. Although myeloid-specific loss of β-catenin does not seem to be important for lupus development, the potential role of this transcription factor in other leukocytes and renal cells remain to be elucidated.

Heightened cleavage of Axl receptor tyrosine kinase by ADAM metalloproteases may contribute to disease pathogenesis in SLE

Systemic lupus erythematosus (SLE) is characterized by antibody-mediated chronic inflammation in the kidney, lung, skin, and other organs to cause inflammation and damage. Several inflammatory pathways are dysregulated in SLE, and understanding these pathways may improve diagnosis and treatment. In one such pathway, Axl tyrosine kinase receptor responds to Gas6 ligand to block inflammation in leukocytes. A soluble form of the Axl receptor ectodomain (sAxl) is elevated in serum from patients with SLE and lupus-prone mice. We hypothesized that sAxl in SLE serum originates from the surface of leukocytes and that the loss of leukocyte Axl contributes to the disease. We determined that macrophages and B cells are a source of sAxl in SLE and in lupus-prone mice. Shedding of the Axl ectodomain from the leukocytes of lupus-prone mice is mediated by the matrix metalloproteases ADAM10 and TACE (ADAM17). Loss of Axl from lupus-prone macrophages renders them unresponsive to Gas6-induced anti-inflammatory signaling in vitro. This phenotype is rescued by combined ADAM10/TACE inhibition. Mice with Axl-deficient macrophages develop worse disease than controls when challenged with anti-glomerular basement membrane (anti-GBM) sera in an induced model of nephritis. ADAM10 and TACE also mediate human SLE PBMC Axl cleavage. Collectively, these studies indicate that increased metalloprotease-mediated cleavage of leukocyte Axl may contribute to end organ disease in lupus. They further suggest dual ADAM10/TACE inhibition as a potential therapeutic modality in SLE.

The association between reduced folate carrier-1 gene 80G/A polymorphism and methotrexate efficacy or methotrexate related-toxicity in rheumatoid arthritis: A meta-analysis

Methotrexate (MTX), the most commonly used anti-rheumatic drug against RA, enters the cell via the action of the reduced folate carrier 1(RFC1). A major polymorphism of the RFC1 gene, 80G/A, has been reported to influence the activity of RFC1, resulting in variable intracellular MTX-polyglutamate (MTX-PG) levels. However, the association studies addressing the RFC1 80G/A polymorphism and MTX efficacy or toxicity in Rheumatoid arthritis (RA) has yielded conflicting results. In the present meta-analysis, we aimed to evaluate the association between the RFC1 80G/A polymorphism and MTX efficacy or toxicity in RA patients. A total 17 studies met our inclusion criteria. Among them, 12 studies with 2049 subjects reported the association between the RFC1 80G/A and MTX response, and 12 studies involving 2627 subjects were on MTX-related toxicity. Meta-analysis revealed significant association between RFC1 80G/A polymorphism and MTX efficacy (odds ratio (OR) for the A allele=1.29, 95% confidence interval (CI) 1.05-1.67, P=0.02; for AA genotype: OR=1.49, 95%CI 1.17-1.907, P=0.001). However, no association could be detected in the analysis of MTX-related toxicity. Stratification by ethnic population also indicated an association between this polymorphism and MTX efficacy in Asian group (P=0.002 for A allele; P=0.003 for AA genotype), but not in the Caucasian group (P=0.15 for A allele; P=0.05 for AA genotype). In both Asian and Caucasian sub-groups, no influence of the RFC1 80G/A polymorphism on MTX toxicity can be detected. In conclusion, the RFC1 G80A polymorphism is associated with responsiveness to MTX therapy, but may not be associated with MTX toxicity in RA patients.

Green Tea Epigallocatechin-3-Gallate Suppresses Autoimmune Arthritis Through Indoleamine-2,3-Dioxygenase Expressing Dendritic Cells and the Nuclear Factor, Erythroid 2-Like 2 Antioxidant Pathway

Background

The activity of one of the major catechins in Green Tea, the polyphenol (−)-epigallocatechin-3-gallate (EGCG), has been shown to have a variety of health benefits. Recent studies suggest that EGCG can modulate both the innate and adaptive arms of the immune system. The goal of the current studies was to examine the immunomodulatory effects and mechanisms of action of EGCG on experimental arthritis in mice.

Methods

EGCG (10 mg/kg) was administered by oral gavage after CIA induction, while control mice were administered phosphate buffered saline (PBS). Disease mechanisms were studied in both groups of mice. Phenotypes were examined using repeated measure analysis of variance (ANOVA) and data from in vitro and ex vivo experiments were analyzed for significance using the Mann-Whitney U test.

Results

EGCG treatment ameliorated clinical symptoms and reduced histological scores in arthritic mice. Serum type-II collagen-specific immunoglobulin (Ig) IgG2a antibodies were significantly lower in EGCG-fed mice compared to PBS-treated mice. EGCG significantly suppressed T cell proliferation and relative frequencies of CD4 T cells, CD8 T cells and B cell subsets including marginal zone B cells, T1 and T2 transitional B cells, while increasing the frequency of CD4⁺ Foxp3⁺ regulatory T cells (Tregs) and indoleamine‐2,3‐dioxygenase (IDO) expression by CD11b⁺ dendritic cells (DC). Splenic CD11b⁺ DC from EGCG fed mice induced an increased frequency of Tregs via an IDO-dependent mechanism in in vitro cultures. Importantly, joint homogenates from EGCG-fed mice exhibited significantly increased levels of Nuclear Factor, Erythroid 2-Like 2 (Nrf-2) and Heme oxygenase-1 (HO-1) compared with PBS-fed mice.

Conclusions

This is the first report of upregulation of the Nrf-2 antioxidant pathway in EGCG-mediated immunoregulation. EGCG ameliorated experimental arthritis in mice by eliciting IDO-producing DCs, increasing frequencies of T regs and inducing the activation of the Nrf-2 antioxidant pathway. It remains to be established whether EGCG is useful for the prevention and treatment of rheumatoid arthritis and other inflammatory disorders.

BANK1 transgenic mice exhibit lupus-associated B cell phenotypes (BA3P.105)

BANK1 is a B-cell adaptor protein that has been implicated in SLE and systemic sclerosis. Previous studies have interpreted that the overexpression of the full length BANK1 isoform plays a pathogenic and the truncated (∆BANK1) version plays a protective role in lupus. However, there is no mechanistic evidence showing that these 2 isoforms can impact lupus development differentially. We have recently generated 2 transgenic strains on the B6 background, BANK1Tg and ∆BANK1Tg, which will be used to address this knowledge gap. The BANK1Tg mice overexpressing the full length Bank1 under the control of CD19 promoter exhibited a dramatic skewing in the splenic B cell population to MZ and B1a cells with a reduction in FO B cells. These mice also exhibited increased plasma cells along with an increased level of total IgM and anti-dsDNA IgG antibodies. Microarray analysis revealed increased transcript levels of several class switched IgG antibodies with a concomitant increase in the level of activation induced deaminase (AID), a master regulator of class switch recombination (CSR). qPCR confirmed higher level of AID and CSR. Interestingly, these phenotypes are observed only in female Tg mice. In contrast, the ∆BANK1Tg mice don’t exhibit the above phenotypes, supporting the hypothesis that the truncated isoform may play a protective role. These studies indicate that the different isoforms of BANK1 observed in humans contribute differentially to the development of B-cell autoimmunity.

Inflammation associated anemia and ferritin as disease markers in SLE

Introduction

In a recent screening to detect biomarkers in systemic lupus erythematosus (SLE), expression of the iron storage protein, ferritin, was increased. Given that proteins that regulate the storage, transfer and release of iron play an important role in inflammation, this study aims to determine the serum and urine levels of ferritin and of the iron transfer protein, transferrin, in lupus patients and to correlate these levels with disease activity, inflammatory cytokine levels and markers of anemia.

Methods

A protein array was utilized to measure ferritin expression in the urine and serum of SLE patients and healthy controls. To confirm these results as well as the role of the iron transfer pathway in SLE, ELISAs were performed to measure ferritin and transferrin levels in inactive or active SLE patients and healthy controls. The relationship between ferritin/transferrin levels and inflammatory markers and anemia was next analyzed.

Results

Protein array results showed elevated ferritin levels in the serum and urine of lupus patients as compared to controls, which were further validated by ELISA. Increased ferritin levels correlated with measures of disease activity and anemia as well as inflammatory cytokine titers. Though active SLE patients had elevated urine transferrin, serum transferrin was reduced.

Conclusion

Urine ferritin and transferrin levels are elevated significantly in SLE patients and correlate with disease activity, bolstering previous reports. Most importantly, these changes correlated with the inflammatory state of the patients and anemia of chronic disease. Taken together, altered iron handling, inflammation and anemia of chronic disease constitute an ominous triad in SLE.

Urine VCAM-1 as a marker of renal pathology activity index in lupus nephritis

Introduction

Although renal pathology is highly predictive of the disease course in lupus nephritis, it cannot be performed serially because of its invasive nature and associated morbidity. The goal of this study is to investigate whether urinary levels of CXC ligand 16 (CXCL16), monocyte chemotactic protein-1 (MCP-1) or vascular cell adhesion molecule-1 (VCAM-1) in patients with lupus nephritis are predictive of particular features of renal pathology in renal biopsies obtained on the day of urine procurement.

Methods

CXCL16, MCP-1, and VCAM-1 levels were measured in urine samples from 74 lupus nephritis patients and 13 healthy volunteers. Of the patients enrolled, 24 patients had a concomitant kidney biopsy performed at the time of urine collection. In addition, patients with other renal diatheses were also included as controls.

Results

All three molecules were elevated in the urine of systemic lupus erythematosus patients, although VCAM-1 (area under curve = 0.92) and MCP-1 (area under curve = 0.87) were best at distinguishing the systemic lupus erythematosus samples from the healthy controls, and were also most strongly associated with clinical disease severity and active renal disease. For patients in whom concurrent renal biopsies had also been performed, urine VCAM-1 exhibited the strongest association with the renal pathology activity index and glomerulonephritis class IV, although it correlated negatively with the chronicity index. Interestingly, urinary VCAM-1 was also elevated in anti-neutrophil cytoplasmic antibodies-associated glomerulonephritis, focal segmental glomerulosclerosis and membranous nephropathy but not in minimal-change disease.

Conclusion

Urinary VCAM-1 emerges as a reliable indicator of the activity:chronicity ratios that mark the underlying renal pathology in lupus nephritis. Since VCAM-1 is involved in the acute phase of inflammation when leukocytic infiltration is ongoing, longitudinal studies are warranted to establish whether tracking urine VCAM-1 levels may help monitor clinical and pathological disease activity over time.

Proteomics in rheumatology: the dawn of a new era

Most rheumatic autoimmune diseases are complex in terms of their genetic origins and underlying pathogenic processes. Non-hypothesis-driven scanning platforms are adding novel insights to our understanding of these multifactorial diseases. This review summarizes the handful of recent proteomic studies that have been executed using samples from patients with rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis, osteoarthritis, or Sjogren's syndrome. The candidate biomarkers that have been uncovered in the reviewed studies have potential applications in diagnosis, prognosis, and theranostics. Though we are at the infancy of the proteomics era in rheumatology, the limited number of molecules uncovered thus far already hold promise. Ongoing research in proteomics holds tremendous potential for shaping how rheumatic diseases are diagnosed, prognosticated, and managed clinically over the coming years.

Urine proteome scans uncover total urinary protease, prostaglandin D synthase, serum amyloid P, and superoxide dismutase as potential markers of lupus nephritis

To identify potential biomarkers in immune-mediated nephritis, urine from mice subjected to an augmented passive model of anti-glomerular basement membrane (GBM)-induced experimental nephritis was resolved using two-dimensional gels. The urinary proteome in these diseased mice was comprised of at least 71 different proteins. Using orthogonal assays, several of these molecules, including serum amyloid P (SAP), PG D synthase, superoxide dismutase, renin, and total protease were validated to be elevated in the urine and kidneys of mice during anti-GBM disease, as well as in mice with spontaneously arising lupus nephritis. Among these, urinary protease was the only marker that appeared to be exclusively renal in origin, whereas the others were partly serum-derived. Longitudinal studies in murine lupus demonstrated that total urinary protease had better predictive value for histologically active nephritis (r = 0.78) compared with proteinuria (r = -0.04), azotemia (r = 0.28), or the other markers examined, whereas urine SAP emerged as the single most predictive marker of histological glomerulonephritis. Collectively, these studies uncover total urinary protease, PG D synthase, SAP, and superoxide dismutase as novel biomarkers of anti-GBM disease and lupus nephritis, with stronger correlation to renal disease compared with currently employed biomarkers. These findings could have important diagnostic and prognostic ramifications in the management of these renal diatheses.