Adhesion molecules in autoimmune disease

L-selectin Promotes Migration, Invasion and Inflammatory Response of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via NF-kB Signaling Pathway

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by chronic inflammation of the synovium and progressive joint damage. Fibroblast-like synoviocytes (FLSs) exhibit excessive proliferative and aggressive phenotypes and play a major role in the pathophysiology of RA. Previous studies have confirmed the pathologic role of L-selectin in cell adhesion and migration. In rheumatoid arthritis models, L-selectin regulates leukocyte homing, which leads to joint inflammation. Moreover, in L-selectin knockout mice, there is a reduction in joint inflammation. However, the associations of L-selectin with FLSs in RA remain unclear. This study aims to reveal the effect of L-selectin on RA-FLSs and to investigate the molecular mechanism of L-selectin in RA. Our findings indicated that L-selectin was significantly expressed in RA synovial tissues and RA-FLSs. L-selectin silencing reduced RA-FLSs migration and invasion and attenuated the secretion of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 in vitro. Moreover, investigations into mechanisms revealed that L-selectin activated the nuclear factor kappa-B (NF-κB) signaling pathway while blocking this signaling pathway could compromise the effects of L-selectin. Finally, in vivo experiments with a collagen-induced arthritis rat model revealed that silencing L-selectin alleviated inflammatory infiltration of the synovium and cartilage destruction, and validated the NF-κB signaling pathways findings observed in vitro. In summary, we show that L-selectin enhances the migration and invasion of RA-FLSs through the activation of NF-κB signaling pathways, ultimately worsening the progression of RA.

Therapeutic Applications of Aggregatibacter actinomycetemcomitans Leukotoxin

Aggregatibacter actinomycetemcomitans is a Gram-negative oral bacterium that has been primarily studied for its role in causing periodontal disease. The bacterium has also been implicated in several systemic diseases such as endocarditis and soft tissue abscesses. Leukotoxin (LtxA) is perhaps the best studied protein virulence factor from A. actinomycetemcomitans. The protein can rapidly destroy white blood cells (WBCs), helping the bacterium to subvert the host immune system. The functional receptor for LtxA is lymphocyte function associated antigen-1 (LFA-1), which is expressed exclusively on the surfaces of WBCs. Bacterial expression and secretion of the protein are highly regulated and controlled by a number of genetic and environmental factors. The mechanism of LtxA action on WBCs varies depending on the type of cell that is being killed, and the protein has been shown to activate numerous cell death pathways in susceptible cells. In addition to serving as an important virulence factor for the bacterium, because of its exquisite specificity and rapid activity, LtxA is also being investigated as a therapeutic agent that may be used to treat diseases such as hematological malignancies and autoimmune/inflammatory diseases. It is our hope that this review will inspire an increased intensity of research related to LtxA and its effect on Aggressive Periodontitis, the disease that led to its initial discovery.

E-Selectin, ICAM-1, and ET-1 Biomarkers Address the Concern of the Challenging Diagnosis of Interstitial Lung Disease in Patients with Autoimmune Diseases

Interstitial lung disease (ILD) constitutes the most critical comorbidity in autoimmune diseases (ADs) and its early diagnosis remains a challenge for clinicians. Accordingly, we evaluated whether E-selectin, ICAM-1, and ET-1, key molecules in endothelial damage, could be useful biomarkers for the detection of AD-ILD+. We recruited patients with rheumatoid arthritis (RA)-ILD+ (n = 21) and systemic sclerosis (SSc)-ILD+ (n = 21). We included comparison groups of patients: RA-ILD- (n = 25), SSc-ILD- (n = 20), and idiopathic pulmonary fibrosis (IPF) (n = 21). Serum levels of these proteins were determined by ELISA. E-selectin, ICAM-1, and ET-1 serum levels were increased in RA-ILD+ and IPF patients in comparison to RA-ILD- patients. Additionally, SSc-ILD+ and IPF patients exhibited higher ICAM-1 levels than those with SSc-ILD-. The ability of E-selectin, ICAM-1, and ET-1 to discriminate RA-ILD+ from RA-ILD- patients, and ICAM-1 to distinguish SSc-ILD+ from SSc-ILD- patients was confirmed using ROC curve analysis. Furthermore, elevated levels of ET-1 and E-selectin correlated with lung function decline in RA-ILD+ and SSc-ILD+ patients, respectively. In conclusion, our findings support the relevant role of E-selectin, ICAM-1, and ET-1 in RA-ILD+ patients as well as of ICAM-1 in SSc-ILD+ patients, constituting potential screening blood biomarkers of ILD in AD. Moreover, this study suggests ET-1 and E-selectin as possible indicators of worsening lung function in RA-ILD+ and SSc-ILD+ patients, respectively.

Altered Expression of Vascular Cell Adhesion Molecule-1 in Oral Lichen Planus

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucocutaneous disease affected by the interaction between keratinocytes and T cells. Recent evidence indicates that vascular cell adhesion molecule-1 (VCAM1) plays a vital role in mediating immune and inflammatory responses. In this study, the expression of VCAM1 in OLP was detected by immunohistochemical staining and its correlations with clinical features were analyzed. The disease severity of OLP was assessed by the reticular, atrophic, and erosive scoring system. We found that VCAM1 was generally localized in the cytoplasm of epithelial cells, and in nucleus, cytoplasm, and extracellular matrix of subepithelial infiltrated cells in superficial layer of lamina propria. Moreover, VCAM1 levels in epithelium and lamina propria of OLP were significantly higher than that in controls, respectively. In addition, VCAM1 level in epithelium was increased compared with that of lamina propria. There were no significant differences for VCAM1 expression between nonerosive and erosive forms of OLP. The expression of VCAM1 in OLP was not associated with the severity of disease, gender, and age. Thus, we speculated that spatial expression differences of VCAM1 in local lesions of OLP may involve the pathogenesis of OLP.

Current experimental methods to investigate the impact of specialized pro-resolving lipid mediators on Sjögren's syndrome

Sjögren's syndrome is a chronic inflammatory autoimmune disease characterized by diminished secretory function of the exocrine glands. Although extensive investigation has been done to understand Sjögren's syndrome, the causes of the disease are as yet unknown and treatments remain largely ineffective, with established therapeutic interventions being limited to use of saliva substitutes with modest effectiveness. A primary feature of Sjögren's syndrome is uncontrolled inflammation of exocrine tissues and previous studies have demonstrated that lipid-based specialized pro-resolving mediators reduce inflammation and restores tissue integrity in salivary glands. However, these studies are limited to a single specialized pro-resolving lipid mediator's family member resolvin D1 or RvD1 and its aspirin-triggered epimer, AT-RvD1. Consequently, additional studies are needed to explore the potential benefits of other members of the specialized pro-resolving lipid mediator's family and related molecules (e.g., additional resolvin subtypes as well as lipoxins, maresins and protectins). In support of this goal, the current review aims to briefly describe the range of current experimental methods to investigate the impact of specialized pro-resolving lipid mediators on Sjögren's syndrome, including both strengths and weaknesses of each approach where this information is known. With this article, the possibilities presented by specialized pro-resolving lipid mediators will be introduced to a wider audience in immunology and practical advice is given to researchers who may wish to take up this work.

Integrin Regulated Autoimmune Disorders: Understanding the Role of Mechanical Force in Autoimmunity

The pathophysiology of autoimmune disorders is multifactorial, where immune cell migration, adhesion, and lymphocyte activation play crucial roles in its progression. These immune processes are majorly regulated by adhesion molecules at cell–extracellular matrix (ECM) and cell–cell junctions. Integrin, a transmembrane focal adhesion protein, plays an indispensable role in these immune cell mechanisms. Notably, integrin is regulated by mechanical force and exhibit bidirectional force transmission from both the ECM and cytosol, regulating the immune processes. Recently, integrin mechanosensitivity has been reported in different immune cell processes; however, the underlying mechanics of these integrin-mediated mechanical processes in autoimmunity still remains elusive. In this review, we have discussed how integrin-mediated mechanotransduction could be a linchpin factor in the causation and progression of autoimmune disorders. We have provided an insight into how tissue stiffness exhibits a positive correlation with the autoimmune diseases’ prevalence. This provides a plausible connection between mechanical load and autoimmunity. Overall, gaining insight into the role of mechanical force in diverse immune cell processes and their dysregulation during autoimmune disorders will open a new horizon to understand this physiological anomaly.

Increase of ALCAM and VCAM-1 in the plasma predicts the Alzheimer's disease

Cell adhesion molecules (CAM) are crucial in several pathological inflammation processes in Alzheimer's disease (AD). However, their potential for clinical diagnostics remains unknown. The present investigation evaluated the clinical significance of ALCAM, VCAM-1, NCAM, and ICAM-1 levels in the plasma of participants with cognitive impairment (44 patients with mild cognitive impairment, 71 patients with Alzheimer's dementia, and 18 patients with other dementia) and 28 controls with normal cognitive ability. We also detected plasma levels of multiple inflammatory factors (IFN-gamma, IL-18, IL-1beta, IL-13, IL-8, IL-7, CCL11, MCP-1, TSLP, IL-10, BDNF, IL-17, IL-5, TREM-1) using Multiplex liquid chip and plasma levels of Abeta1-42 and Abeta1-40 using liquid-phase flow cytometry (FCM). Our findings demonstrated a correlation of ALCAM and VCAM-1 with age, the severity of cognitive decline, and MTA, but no significant difference between groups for NCAM and ICAM-1. ALCAM and VCAM-1 both demonstrated a positive correlation with the degree of atrophy in the medial temporal lobe structure. Further analysis revealed no significant correlation in plasma between VCAM-1, ALCAM and Abeta1-40, Abeta1-42. Nevertheless, there was a significant correlation between VCAM-1, ALCAM and many inflammatory factors. Furthermore, the predictive value of ALCAM and VCAM-1 for AD was assessed using a multi-parameter regression model. ALCAM and VCAM-1 in combination with ApoE4, education, age, and MMSE could predict AD with high precision (AUC=0.891; AIC=146.9) without imaging diagnosis. ALCAM and VCAM-1 combination improved the predictive accuracy significantly. In a nutshell, these findings revealed ALCAM and VCAM-1 as reliable indicators of Alzheimer's disease.

Early Prediction of Clinical Response to Anti-TNF Treatment using Multi-omics and Machine Learning in Rheumatoid Arthritis

Objectives

Advances in immunotherapy by blocking TNF have remarkably improved treatment outcomes for Rheumatoid arthritis (RA) patients. Although treatment specifically targets TNF, the downstream mechanisms of immune suppression are not completely understood. The aim of this study was to detect biomarkers and expression signatures of treatment response to TNF inhibition.

Methods

Peripheral blood mononuclear cells (PBMCs) from 39 female patients were collected before anti-TNF treatment initiation (day 0) and after 3 months. The study cohort included patients previously treated with MTX who failed to respond adequately. Response to treatment was defined based on the EULAR criteria and classified 23 patients as responders and 16 as non-responders. We investigated differences in gene expression in PBMCs, the proportion of cell types and cell phenotypes in peripheral blood using flow cytometry and the level of proteins in plasma. Finally, we used machine learning models to predict non-response to anti-TNF treatment.

Results

The gene expression analysis in baseline samples revealed notably higher expression of the gene EPPK1 in future responders. We detected the suppression of genes and proteins following treatment, including suppressed expression of the T cell inhibitor gene CHI3L1 and its protein YKL-40. The gene expression results were replicated in an independent cohort. Finally, machine learning models mainly based on transcriptomic data showed high predictive utility in classifying non-response to anti-TNF treatment in RA.

Conclusions

Our integrative multi-omics analyses identified new biomarkers for the prediction of response, found pathways influenced by treatment and suggested new predictive models of anti-TNF treatment in RA patients.

Integrin-α9β1 as a Novel Therapeutic Target for Refractory Diseases: Recent Progress and Insights

Integrins refer to heterodimers consisting of subunits α and β. They serve as receptors on cell membranes and interact with extracellular ligands to mediate intracellular molecular signals. One of the least-studied members of the integrin family is integrin-α9β1, which is widely distributed in various human tissues and organs. Integrin-α9β1 regulates the physiological state of cells through a variety of complex signaling pathways to participate in the specific pathological processes of some intractable diseases. In recent years, an increasing amount of research has focused on the role of α9β1 in the molecular mechanisms of different refractory diseases and its promising potential as a therapeutic target. Accordingly, this review introduces and summarizes recent research related to integrin-α9β1, describes the synergistic functions of α9β1 and its corresponding ligands in cancer, autoimmune diseases, nerve injury and thrombosis and, more importantly, highlights the potential of α9β1 as a distinctive target for the treatment of these intractable diseases.

Increased Serum E-Selectin Levels Were Associated with Cognitive Decline in Patients with Stroke

BACKGROUND

Previous studies have reported that patients with stroke have a high incidence of cognitive decline. The aim was to elucidate the association between serum E-selectin levels and cognitive function in stroke patients.

MATERIALS AND METHODS

Serum levels of E-selectin were measured in 322 patients with stroke at baseline. Cox proportional hazard analysis was used to evaluate the predictive value of serum E-selectin for predicting cognitive decline (end point) in patients with stroke.

RESULTS

Multivariate linear regression analysis revealed that serum E-selectin levels were independently associated with MOCA score after adjusting for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and laboratory measurements in patients with stroke at baseline (Sβ= -0.156; 95% CI, - 0.170- - 0.074; P<0.001). The multivariate Cox proportional hazard analysis revealed that serum E-selectin (HR=2.481, 95% CI 1.533-4.327, P-trend <0.001) was an independent prognostic factor for cognitive decline in these patients with stroke during the follow-up period.

CONCLUSION

Our results showed that increased serum E-selectin levels were significantly and independently associated with cognitive decline and had independent predictive value for cognitive decline in patients with stroke. Serum E-selectin might enable early recognition of cognitive decline among stroke patients.

Bile acids modulate colonic MAdCAM-1 expression in a murine model of combined cholestasis and colitis

Primary sclerosing cholangitis (PSC) is a progressive fibrosing cholestatic liver disease that is strongly associated with inflammatory bowel disease (IBD). PSC-associated IBD (PSC-IBD) displays a unique phenotype characterized by right-side predominant colon inflammation and increased risk of colorectal cancer compared to non-PSC-IBD. The frequent association and unique phenotype of PSC-IBD suggest distinctive underlying disease mechanisms from other chronic liver diseases or IBD alone. Multidrug resistance protein 2 knockout (Mdr2-/-) mice develop spontaneous cholestatic liver injury and fibrosis mirroring human PSC. As a novel model of PSC-IBD, we treated Mdr2-/- mice with dextran sulfate sodium (DSS) to chemically induce colitis (Mdr2-/-/DSS). Mdr2-/- mice demonstrate alterations in fecal bile acid composition and enhanced colitis susceptibility with increased colonic adhesion molecule expression, particularly mucosal addressin-cell adhesion molecule 1 (MAdCAM-1). In vitro, ursodeoxycholic acid (UDCA) co-treatment resulted in a dose dependent attenuation of TNF-α-induced endothelial MAdCAM-1 expression. In the combined Mdr2-/-/DSS model, UDCA supplementation attenuated colitis severity and downregulated intestinal MAdCAM-1 expression. These findings suggest a potential mechanistic role for alterations in bile acid signaling in modulating MAdCAM-1 expression and colitis susceptibility in cholestasis-associated colitis. Together, our findings provide a novel model and new insight into the pathogenesis and potential treatment of PSC-IBD.

Genome-wide DNA methylation analysis of Hashimoto's thyroiditis during pregnancy

Hashimoto's thyroiditis (HT) during pregnancy is usually accompanied by an elevation of thyroid‐stimulating hormone and a reduction of serum‐free thyroxine during gestation, which may lead to abortion, preterm delivery, and reduced intellectual function of the offspring. Epigenetic alterations may provide important insights into genetic–environmental interactions in HT. Here, we examined global DNA methylation patterns in patients with HT during pregnancy. DNA was extracted from 13 women with HT during pregnancy (HTDP) and eight healthy pregnant women as a control group. Genome‐wide methylation was detected with the use of an Illumina Human Methylation 850K Beadchip. A total of 652 differentially methylated positions (DMPs) and 27 differentially methylated regions (DMRs) were identified between the HTDP and control groups. GO analysis revealed that DMPs were significantly enriched in 540 GO terms, which included regulation of the differentiation of keratinocytes, T helper cell differentiation, and alpha‐beta T‐cell differentiation. Moreover, significant enrichment of KEGG pathways of the DMPs included mucin‐type O‐glycan biosynthesis, focal adhesion, and the insulin signaling pathway. The GO items associated with DMRs included muscle cell proliferation, response to biotic stimulus, anatomical structure formation involved in morphogenesis, and genes primarily involved in the FoxO signaling pathway. Finally, the DTNA gene was identified as the seed gene of functional epigenetic modules. In summary, the DNA methylation pattern of the HTDP group was distinct from that of the control group, and thus, changes in DNA methylation may influence the development of HT by regulation of the autoimmunity process.

Whole transcriptome approach to evaluate the effect of aluminium hydroxide in ovine encephalon

Aluminium hydroxide adjuvants are crucial for livestock and human vaccines. Few studies have analysed their effect on the central nervous system in vivo. In this work, lambs received three different treatments of parallel subcutaneous inoculations during 16 months with aluminium-containing commercial vaccines, an equivalent dose of aluminium hydroxide or mock injections. Brain samples were sequenced by RNA-seq and miRNA-seq for the expression analysis of mRNAs, long non-coding RNAs and microRNAs and three expression comparisons were made. Although few differentially expressed genes were identified, some dysregulated genes by aluminium hydroxide alone were linked to neurological functions, the lncRNA TUNA among them, or were enriched in mitochondrial energy metabolism related functions. In the same way, the miRNA expression was mainly disrupted by the adjuvant alone treatment. Some differentially expressed miRNAs had been previously linked to neurological diseases, oxidative stress and apoptosis. In brief, in this study aluminium hydroxide alone altered the transcriptome of the encephalon to a higher degree than commercial vaccines that present a milder effect. The expression changes in the animals inoculated with aluminium hydroxide suggest mitochondrial disfunction. Further research is needed to elucidate to which extent these changes could have pathological consequences.

Infection and Inflammation Imaging: Beyond FDG

This review discusses nuclear imaging of inflammation using molecular probes beyond fluoro-d-glucose, is structured by cellular targets, and focuses on those tracers that have been successfully applied clinically.

E-selectin as a prognostic factor of patients hospitalized due to acute inflammatory respiratory diseases: a single institutional study

When examining patients with acute inflammatory respiratory diseases, it is difficult to distinguish between infectious pneumonia and interstitial pneumonia and predict patient prognosis at the beginning of treatment. In this study, we assessed whether endothelial selectin (E-selectin) predicts the outcome of patients with acute inflammatory respiratory diseases. We measured E-selectin serum levels in 101 patients who were admitted to our respiratory care unit between January 2013 and December 2013 because of acute inflammatory respiratory diseases that were eventually diagnosed as interstitial pneumonia (n = 38) and lower respiratory tract infection (n = 63). Seven of these patients (n = 101) died. The pneumonia severity score was significantly higher and the oxygen saturation of arterial blood measured by pulse oximeter (SpO₂)/fraction of inspiratory oxygen (FiO₂) was significantly lower in the deceased patients than in the surviving patients. There were significantly fewer peripheral lymphocytes and significantly higher E-selectin serum levels in the deceased patients than in the surviving patients. In the multiple logistic regression analysis, the E-selectin serum levels and SpO₂/FiO₂ ratio were independent predictive factors of prognosis. The risk of death during acute respiratory disease was determined using a receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) was 0.871 as calculated from the ES, and the cutoff value was 6453.04 pg/ml, with a sensitivity of 1.00 and a specificity of 0.72 (p = 0.0027). E-selectin may be a useful biomarker for predicting the prognosis of patients with acute inflammatory respiratory diseases.

Accelerated Atherosclerosis in Rheumatoid Arthritis: Mechanisms and Treatment

Background:

Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disorder that increases the risk of developing cardiovascular disease. There is accumulating evidence that the RA disease state accelerates the formation of atherosclerotic plaques. Treatments for RA improve joint symptomatology and may reduce inflammation, but consideration of their effects on the cardiovascular system is generally low priority.

Objective:

Since cardiovascular disease is the leading cause of mortality in RA patients, the impact of RA therapies on atherosclerosis is an area in need of attention and the focus of this review.

Results:

The drugs used to treat RA may be analgesics, conventional disease-modifying anti-rheumatic drugs, and/or biologics, including antibodies against the cytokine tumor necrosis factor-α. Pain relievers such as nonselective non-steroidal anti-inflammatory drugs and cyclooxygenase inhibitors may adversely affect lipid metabolism and cyclooxygenase inhibitors have been associated with increased adverse cardiovascular events, such as myocardial infarction and stroke. Methotrexate, the anchor disease-modifying anti-rheumatic drug in RA treatment has multiple atheroprotective advantages and is often combined with other therapies. Biologic inhibitors of tumor necrosis factor-α may be beneficial in preventing cardiovascular disease because tumor necrosis factor-α promotes the initiation and progression of atherosclerosis. However, some studies show a worsening of the lipid profile in RA with blockade of this cytokine, leading to higher total cholesterol and triglycerides.

Conclusion:

Greater understanding of the pharmacologic activity of RA treatments on the atherosclerotic process may lead to improved care, addressing both damages to the joints and heart.

Antibody-Based Tracers for PET/SPECT Imaging of Chronic Inflammatory Diseases

Chronic inflammatory diseases are often progressive, resulting not only in physical damage to patients but also social and economic burdens, making early diagnosis of them critical. Nuclear medicine techniques can enhance the detection of inflammation by providing functional as well as anatomical information when combined with other modalities such as magnetic resonance imaging, computed tomography or ultrasonography. Although small molecules and peptides were mainly used for the treatment and imaging of chronic inflammatory diseases in the past, antibodies and their fragments have also been emerging for chronic inflammatory diseases as they show high specificity to their targets and can have various biological half-lives depending on how they are engineered. In addition, imaging with antibodies or their fragments can visualize the in vivo biodistribution of the probes or help monitor therapeutic responses, thereby providing physicians with a greater understanding of drug behavior in vivo and another means of monitoring their patients. In this review, we introduce various targets and radiolabeled antibody-based probes for the molecular imaging of chronic inflammatory diseases in preclinical and clinical studies. Targets can be classified into three different categories: 1) cell-adhesion molecules, 2) surface markers on immune cells, and 3) cytokines or enzymes. The limitations and future directions of using radiolabeled antibodies for imaging inflammatory diseases are also discussed.

Soluble Vascular Cell Adhesion Molecule-1 Is Associated With Disease Activity in Adult-Onset Minimal Change Disease

BACKGROUND

Cell adhesion molecules have been documented to be elevated in numerous immune inflammatory diseases. Minimal change disease (MCD) is an immune disorder. This study aimed to evaluate whether levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin) reflect disease activity in adult-onset MCD.

METHODS

A sandwich enzyme-linked immunosorbent assay was used to measure the soluble adhesion molecules in 40 patients with nephrotic-range proteinuria and biopsy-proven MCD, obtained at the time of diagnosis and during remission. Thirty-five age- and sex-matched healthy volunteers served as controls.

RESULTS

Patients with MCD during the active stage showed significantly higher levels of sVCAM-1 and sE-selectin when compared to controls. Moreover, sVCAM-1 had significantly positive correlations with both urine protein and serum cholesterol, and was negatively associated with serum albumin. Multiple analyses showed that serum albumin was an independent predictor of sVCAM-1. The correlations between sE-selectin and other clinical parameters were not statistically significant. At follow-up, these markers systematically decreased as the disease went into remission, but the increase in sVCAM-1 persisted even in patients obtaining complete remission for 6 months.

CONCLUSIONS

Patients with active MCD had increased levels of sVCAM-1 and sE-selectin. The correlation between sVCAM-1 and proteinuria, serum albumin and cholesterol and its decline during remission indicate that sVCAM-1 is associated with disease activity.

Chemokine and Adhesion Molecule Profiles in Aqueous Humor of Clinically Quiescent Uveitic Cataracts

PURPOSE

To investigate the chemokine and adhesion molecule profiles in aqueous humor (AH) of eyes with inactive uveitis and their correlations with inflammation relapse after cataract surgery.

METHODS

Patients with inactive uveitis who underwent cataract surgery between July 2014 and January 2016 at our center were included. Undiluted AH samples (100-120 µl) were obtained through lateral corneal incisions during surgery, and concentrations of monocyte chemoattractant protein 1 (MCP-1/CCL2), macrophage inflammatory protein 1 (MIP-1), interleukin 8 (IL-8), regulated on activation, normal T cell expressed and secreted (RANTES/CCL5), soluble vascular cell adhesion molecule (sVCAM) and soluble intercellular adhesion molecule (sICAM) were measured by cytometric bead array (BD Bioscience, San Jose, CA). AH levels of these inflammatory factors were compared between different uveitis entities and non-inflammatory control. Risk factors for postoperative inflammation relapse were also analysed in uveitic eyes.

RESULTS

As compared with the control group, the panuveitis group had significantly higher aqueous concentrations of MCP-1, IL-8, sVCAM, sICAM; the anterior uveitis group had significantly higher concentrations of MCP-1, MIP-1, sVCAM. Uveitic cataracts with postoperative inflammation relapse had significantly higher levels of MCP-1 and IL-8 in AH than those without. And multivariate cox regression analysis revealed that high AH levels of MCP-1 was an independent predictor for postoperative inflammation relapse.

CONCLUSIONS

Clinically quiescent uveitic eyes have elevated levels of chemokines and soluble adhesion molecules in AH, of which MCP-1 is associate with inflammation relapses after cataract surgery.

Relationship between serum vascular cell adhesion molecule-1 and endothelin-1 levels with organ involvement and disease activity in systemic lupus erythematosus patients

Background

Endothelial dysfunction plays an important role in pathogenesis of systemic lupus erythematosus (SLE). Considering the importance of serum soluble vascular cell adhesion molecule-1 as the most abundant of the circulating adhesion molecules increased as a result of endothelial dysfunction and the role of endothelin-1 in pathophysiology of SLE, this study aimed to evaluate serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels in SLE patients compared to healthy subjects.

Methods

In this cross-sectional study, 60 SLE patients according to the Systemic Lupus International Collaborating Clinics classification criteria for SLE and 40 age and sex-matched healthy controls were included. In patients, clinical examination was performed and SLE disease activity index was assessed. Serum endothelin-1 and soluble vascular cell adhesion molecule-1 levels were measured using ELISA kits.

Results

The mean ± standard deviation age of patients and controls was 31.91 ± 7.66 and 33.20 ± 10.08 years, respectively. Compared to healthy controls, serum soluble vascular cell adhesion molecule-1 (1023.8 ± 352.96 vs. 866.06 ± 109.91) and endothelin-1 (77.83 ± 16.27 vs. 54.45 ± 12.01) was significantly higher in SLE patients ( P = 0.003 and P < 0.001, respectively). The most common organs involved in patients were skin, joint and kidney. There were no significant differences in serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels according to organ involvement, activity of disease and the conventional serum markers of disease activity ( P > 0.05). There was no significant correlation between disease activity, organ involvement and negative or positivity of autoantibodies as well as serum complement with endothelin-1 and vascular cell adhesion molecule-1 levels ( P > 0.05).

Conclusions

Although our study revealed higher serum soluble vascular cell adhesion molecule-1 and endothelin-1 levels in SLE patients compared to healthy controls, there were no significant correlations between their serum levels with organ involvement and disease activity.

A Convenient Synthesis of a Lymphocyte Function-Associated Antigen-1 (LFA-1) Antagonist of ‘Compound 4’

The lymphocyte function-associated antigen-1 (LFA-1) antagonist of ‘Compound 4’ was synthesised by a convenient route using cheap, commercially available starting materials and catalysts under mild reaction conditions and by easily handled reactions. The total yield in the preparation of ‘Compound 4’ was more than 38% via Sonogashira coupling of an iodide and an alkyne, reduction of the alkyne catalysed by Raney nickel and later steps involving hydrolysis of an ester, condensation of an acid and an amine and a final hydrolysis of an ester.

sICAM-1, sVCAM-1 and sE-Selectin Levels in Type 1 Diabetes

BACKGROUND/OBJECTIVE

This study was performed to compare soluble levels of adhesion molecules between diabetic patients and controls and to assess their possible association with long-term complications of type 1 diabetes (T1D).

METHODS

Forty-eight patients with T1D and 39 healthy controls were enrolled in this study. The plasma level of adhesion molecules was measured by sandwich enzyme-linked immunosorbent assay technique.

RESULTS

Higher sVCAM 1 (soluble vascular cell adhesion molecule 1) levels correlated with older age of onset of T1D. The plasma level of sICAM 1 (soluble intercellular adhesion molecule 1) was significantly increased, while sE selectin was significantly decreased in patients with T1D, compared to controls. There was no significant relationship between these plasma-level variations and the long-term complications of T1D.

CONCLUSION

Although plasma levels of cell adhesion molecules are different in T1D patients and healthy controls, they might not be good candidate markers for prognosis of disease.

Serum Soluble Vascular Cell Adhesion Molecule-1 Overexpression Is a Disease Marker in Patients with First-Time Diagnosed Antinuclear Antibodies: A Prospective, Observational Pilot Study

Objective

Antinuclear antibodies (ANA) serve as screening tests for connective tissue diseases but have low specificity. In this pilot study, we aimed to identify patients with first-time positive ANA and musculoskeletal complaints and correlate serum soluble vascular adhesion molecules as biomarkers.

Methods

Prospective, observational study with 100 ANA-positive patients, comparing them to age- and gender-matched healthy controls (HC, n = 75), was conducted. Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), endothelial-leukocyte adhesion molecule-1 (sELAM-1), and vascular cell adhesion molecule-1 (sVCAM-1) were measured. A subgroup of patients with systemic sclerosis (SSc) treated with immunosuppressants was followed over 10 months.

Results

Patients belonged to three main entities: rheumatoid arthritis (RA, n = 32), collagen diseases (CD, n = 56) also including systemic sclerosis (SSc, n = 11), and other autoimmune diseases (n = 12). sICAM-1 was similar among groups. sELAM-1 was elevated by 1.9-fold in only in SSc. sVCAM-1 was elevated by 3.1-fold in RA and by 3.3-fold in CD and in other autoimmune diseases by 3.4-fold. Seven SSc patients with immunosuppression had a 2.7-fold increased sVCAM-1 at baseline and reached the levels of healthy controls after 5 months, while CRP, ESR, and clinical parameters remained unchanged.

Conclusion

Our study suggests that sVCAM-1 is a disease marker independent of standard serum parameters in several rheumatic diseases. This study is registered with EU PAS Register number: EUPAS22154.

Text Mining of Rheumatoid Arthritis and Diabetes Mellitus to Understand the Mechanisms of Chinese Medicine in Different Diseases with Same Treatment

OBJECTIVE

To identify the commonalities between rheumatoid arthritis (RA) and diabetes mellitus (DM) to understand the mechanisms of Chinese medicine (CM) in different diseases with the same treatment.

METHODS

A text mining approach was adopted to analyze the commonalities between RA and DM according to CM and biological elements. The major commonalities were subsequently verified in RA and DM rat models, in which herbal formula for the treatment of both RA and DM identified via text mining was used as the intervention.

RESULTS

Similarities were identified between RA and DM regarding the CM approach used for diagnosis and treatment, as well as the networks of biological activities affected by each disease, including the involvement of adhesion molecules, oxidative stress, cytokines, T-lymphocytes, apoptosis, and inflammation. The Ramulus Cinnamomi-Radix Paeoniae Alba-Rhizoma Anemarrhenae is an herbal combination used to treat RA and DM. This formula demonstrated similar effects on oxidative stress and inflammation in rats with collagen-induced arthritis, which supports the text mining results regarding the commonalities between RA and DM.

CONCLUSION

Commonalities between the biological activities involved in RA and DM were identified through text mining, and both RA and DM might be responsive to the same intervention at a specific stage.

Clinical significance of circulating vascular cell adhesion molecule-1 to white matter disintegrity in Alzheimer’s dementia

Endothelial dysfunction leads to worse cognitive performance in Alzheimer’s dementia (AD). While both cerebrovascular risk factors and endothelial dysfunction lead to activation of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin, it is not known whether these biomarkers extend the diagnostic repertoire in reflecting intracerebral structural damage or cognitive performance. A total of 110 AD patients and 50 age-matched controls were enrolled. Plasma levels of VCAM-1, ICAM-1 and E-selectin were measured and correlated with the cognitive performance, white matter macro-structural changes, and major tract-specific fractional anisotropy quantification. The AD patients were further stratified by clinical dementia rating score (mild dementia, n=60; moderate-to-severe dementia, n=50). Compared with the controls, plasma levels of VCAM-1 (p< 0.001), ICAM-1 (p=0.028) and E-selectin (p=0.016) were significantly higher in the patients, but only VCAM-1 levels significantly reflected the severity of dementia (p< 0.001). In addition, only VCAM-1 levels showed an association with macro- and micro- white matter changes especially in the superior longitudinal fasciculus (p< 0.001), posterior thalamic radiation (p=0.002), stria terminalis (p=0.002) and corpus callosum (p=0.009), and were independent of, age and cortical volume. These tracts show significant association with MMSE, short term memory and visuospatial function. Meanwhile, while VCAM-1 level correlated significantly with short-term memory (p=0.026) and drawing (p=0.025) scores in the AD patients after adjusting for age and education, the significance disappeared after adjusting for global FA. Endothelial activation, especially VCAM-1, was of clinical significance in AD that reflects macro- and micro-structural changes and poor short term memory and visuospatial function.

Increased frequency of IL-6-producing non-classical monocytes in neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system that preferentially affects the optic nerves, spinal cord, and area postrema. A series of evidence suggested that B cells play a fundamental role in the pathogenesis of NMOSD. However, there are still gaps left to be answered in NMOSD pathogenesis suggesting the roles of other immune cells. This study aimed to investigate the monocyte inflammatory characteristics, monocyte subset frequency and cytokine production, and cell-surface molecule expression in NMOSD, multiple sclerosis (MS), and healthy controls (HC).

METHODS

Peripheral blood mononuclear cells of 20 aquaporin 4IgG-positive NMOSD patients, 20 MS patients, and 20 healthy controls were collected to analyze the monocyte subsets and to purify monocytes. To mimic the adaptive immunity, we have activated the monocytes using CD40L and IFN-γ to observe the production of cytokines and expression of cell-surface molecules.

RESULTS

NMOSD monocytes showed a remarkable increase in the production of pro-inflammatory cytokines (IL-6, IL-1β) and increased expression of cell-surface molecules (CD80, HLA, ICAM-1, CD16), as well as a decrease in the levels of anti-inflammatory cytokine IL-10, compared to healthy control (HC) monocytes. As expected, MS monocytes also exhibit increased inflammatory cytokine production and increased cell-surface molecule expression compared to HC monocytes. Further analysis of monocyte subsets revealed that NMOSD monocytes have an increased frequency of the non-classical monocyte subset (CD14⁺CD16⁺⁺) and a decreased frequency of the classical monocyte subset (CD14⁺⁺CD16⁺) compared to HC monocytes. This finding was distinctly different from that of MS monocytes, which had an increased intermediate monocyte (CD14⁺CD16⁺) subset. In addition, these NMOSD non-classical monocyte subsets were highly dedicated, IL-6-producing monocytes.

CONCLUSIONS

Increased expression of cell-surface molecules and a reciprocal dysregulation of inflammatory and anti-inflammatory cytokines in NMOSD monocytes suggest an altered monocyte inflammatory response. CD14⁺CD16⁺⁺ non-classical monocyte subset was more abundant in NMOSD monocytes than in HC or MS monocytes, and NMOSD non-classical monocyte subset had dysregulated IL-6 production, a phenotype which has been reported to be highly associated with NMOSD pathogenesis.

Adhesion molecules, mycophenolate mofetil and systemic lupus erythematosus

Mycophenolate mofetil (MMF) has been reproducibly shown to inhibit lymphocyte adhesion and penetration of endothelial cell surfaces. The mechanism is not yet elucidated. In vitro studies on the effects of MMF on cell adhesion molecules (CAM) using human umbilical vein endothelial cells (HUVEC) have shown conflicting results. Different studies have independently shown that MMF increased, decreased or had no effect on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1). Several studies suggest MMF may reduce the endothelial expression of E-selectin. Recent studies have been unable to replicate initial work, which suggested that MMF impaired glycosylation of lymphocyte CAM. The same studies concluded that MMF had no effect on the surface expression of lymphocyte CAM, but altered the binding ability of these molecules. ICAM-1/LFA-1 (lymphocyte function-associated antigen-1), VCAM-1/VLA-4 (very late antigen-4) and P-selectin/PSGL-1 (P-selectin glycoprotein ligand-1) ligand pairs are most likely to be involved. Few in vivo and no conclusive human studies have been carried out. The literature relevant to cell adhesion molecules in systemic lupus erythematosus (SLE) is reviewed in detail.

Adhesion molecules, mycophenolate mofetil and systemic lupus erythematosus

Mycophenolate mofetil (MMF) has been reproducibly shown to inhibit lymphocyte adhesion and penetration of endothelial cell surfaces. The mechanism is not yet elucidated. In vitro studies on the effects of MMF on cell adhesion molecules (CAM) using human umbilical vein endothelial cells (HUVEC) have shown conflicting results. Different studies have independently shown that MMF increased, decreased or had no effect on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1). Several studies suggest MMF may reduce the endothelial expression of E-selectin. Recent studies have been unable to replicate initial work, which suggested that MMF impaired glycosylation of lymphocyte CAM. The same studies concluded that MMF had no effect on the surface expression of lymphocyte CAM, but altered the binding ability of these molecules. ICAM-1/LFA-1 (lymphocyte function-associated antigen-1), VCAM-1/VLA-4 (very late antigen-4) and P-selectin/PSGL-1 (P-selectin glycoprotein ligand-1) ligand pairs are most likely to be involved. Few in vivo and no conclusive human studies have been carried out. The literature relevant to cell adhesion molecules in systemic lupus erythematosus (SLE) is reviewed in detail.

Mechanisms of LtxA (Leukotoxin), a Potent New Anti-Inflammatory Agent for the Treatment of Alopecia Areata

Alopecia areata is an autoimmune condition where activated, pro-inflammatory white blood cells (WBCs) attack the hair follicles, resulting in hair loss. Migration of these activated WBCs from the blood stream and into the follicle tissue requires interaction between the integrin, lymphocyte function-associated antigen-1 (LFA-1) on WBCs, and ICAM-1 on vascular endothelial cells. High levels of active LFA-1 are uniquely expressed on WBCs that are involved in autoimmune and inflammatory conditions. The natural biologic agent LtxA (Leukothera) preferentially targets and depletes disease activated and malignant WBCs by binding to active LFA-1. The experimental drug has demonstrated significant therapeutic efficacy against autoimmune/inflammatory conditions such as psoriasis and allergic asthma in mouse models for these diseases. In addition, when injected into rodents, rhesus macaques, and dogs, LtxA was demonstrated to be physiologically active, biologically specific, and extremely well-tolerated. LFA-1 is an attractive target for therapy because it is only normally present on WBCs and has been shown to be activated and overexpressed on WBCs that are responsible for autoimmune/inflammatory conditions.

Detecting Genetic Associations between ATG5 and Lupus Nephritis by trans-eQTL

Objectives. Numerous loci were identified to perturb gene expression in trans. As elevated ATG5 expression was observed in systemic lupus erythematosus (SLE), the study was conducted to analyze the genome-wide genetic regulatory mechanisms associated with ATG5 expression in a Chinese population with lupus nephritis (LN). Methods. The online expression quantitative trait loci database was searched for trans-expression single nucleotide polymorphisms (trans-eSNPs) of ATG5. Tagging trans-eSNPs were genotyped by a custom-made genotyping chip in 280 patients and 199 controls. For positive findings, clinical information and bioinformation analyses were performed. Results. Four trans-eSNPs were observed to be associated with susceptibility to LN (P < 0.05), including ANKRD50 rs17008504, AGA rs2271100, PAK7 rs6056923, and TET2 rs1391441, while seven other trans-eSNPs showed marginal significant associations (0.05 < P < 0.1). Correlations between the trans-eSNPs and ATG5 expression and different expression levels of ATG5 in SLE patients and controls were validated, and their regulatory effects were annotated. However, no significant associations were observed between different genotypes of trans-eSNPs and severity or outcome of the patients. Conclusion. Using the new systemic genetics approach, we identified 10 loci associated with susceptibility to LN potentially, which may be complementary to future pathway based genetic studies.

The pathogenic role of angiogenesis in rheumatoid arthritis

Angiogenesis is the formation of new capillaries from pre-existing vasculature, which plays a critical role in the pathogenesis of several inflammatory autoimmune diseases such as rheumatoid arthritis (RA), spondyloarthropathies, psoriasis, systemic lupus erythematosus, systemic sclerosis, and atherosclerosis. In RA, excessive migration of circulating leukocytes into the inflamed joint necessitates formation of new blood vessels to provide nutrients and oxygen to the hypertrophic joint. The dominance of the pro-angiogenic factors over the endogenous angiostatic mediators triggers angiogenesis. In this review article, we highlight the underlying mechanisms by which cells present in the RA synovial tissue are modulated to secrete pro-angiogenic factors. We focus on the significance of pro-angiogenic factors such as growth factors, hypoxia-inducible factors, cytokines, chemokines, matrix metalloproteinases, and adhesion molecules on RA pathogenesis. As pro-angiogenic factors are primarily produced from RA synovial tissue macrophages and fibroblasts, we emphasize the key role of RA synovial tissue lining layer in maintaining synovitis through neovascularization. Lastly, we summarize the specific approaches utilized to target angiogenesis. We conclude that the formation of new blood vessels plays an indispensable role in RA progression. However, since the function of several pro-angiogenic mediators is cross regulated, discovering novel approaches to target multiple cascades or selecting an upstream cascade that impairs the activity of a number of pro-angiogenic factors may provide a promising strategy for RA therapy.

Functional knock down of VCAM1 in mice mediated by endoplasmatic reticulum retained intrabodies

Functional knockdowns mediated by endoplasmatic reticulum-retained antibodies (ER intrabodies) are a promising tool for research because they allow functional interference on the protein level. We demonstrate for the first time that ER intrabodies can induce a knock-down phenotype in mice. Surface VCAM1 was suppressed in bone marrow of heterozygous and homozygous ER intrabody mice (iER-VCAM1 mice). iER-VCAM1 mice did not have a lethal phenotype, in contrast to the constitutive knockout of VCAM1, but adult mice exhibited physiological effects in the form of aberrant distribution of immature B-cells in blood and bone marrow. The capability to regulate knock-down strength may spark a new approach for the functional study of membrane and plasma proteins, which may especially be valuable for generating mouse models that more closely resemble disease states than classic knockouts do.

The CO donor CORM-2 inhibits LPS-induced vascular cell adhesion molecule-1 expression and leukocyte adhesion in human rheumatoid synovial fibroblasts

BACKGROUND AND PURPOSE

Infection with Gram-negative bacteria has been recognized as an initiator of rheumatoid arthritis, which is characterized by chronic inflammation and infiltration of immune cells. Carbon monoxide (CO) exhibits anti-inflammatory properties. Here we have investigated the detailed mechanisms of vascular cell adhesion molecule-1 (VCAM-1) expression induced by LPS and if CO inhibited LPS-induced leukocyte adhesion to synovial fibroblasts by suppressing VCAM-1 expression.

EXPERIMENTAL APPROACH

Human rheumatoid arthritis synovial fibroblasts (RASFs) were incubated with LPS and/or the CO-releasing compound CORM-2. Effects of LPS on VCAM-1 levels were determined by analysing mRNA expression, promoter activity, protein expression, and immunohistochemical staining. The molecular mechanisms were investigated by determining the expression, activation, and binding activity of transcriptional factors using target signal antagonists.

KEY RESULTS

CORM-2 significantly inhibited inflammatory responses in LPS-treated RASFs by down-regulating the expression of adhesion molecule VCAM-1 and leukocyte infiltration. The down-regulation of LPS-induced VCAM-1 expression involved inhibition of the expression of phosphorylated-NF-κB p65 and AP-1 (p-c-Jun, c-Jun and c-Fos mRNA levels). These results were confirmed by chromatin immunoprecipitation assay to detect NF-κB and AP-1 DNA binding activity.

CONCLUSIONS AND IMPLICATIONS

LPS-mediated formation of the TLR4/MyD88/TRAF6/c-Src complex regulated NF-κB and MAPKs/AP-1 activation leading to VCAM-1 expression and leukocyte adhesion. CORM-2, which liberates CO to elicit direct biological activities, attenuated LPS-induced VCAM-1 expression by interfering with NF-κB and AP-1 activation, and significantly reduced LPS-induced immune cell infiltration of the synovium.

CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo

Vitiligo is an autoimmune disease of the skin that results in disfiguring white spots. There are no U.S. Food and Drug Administration-approved treatments for vitiligo, and most off-label treatments yield unsatisfactory results. Vitiligo patients have increased numbers of autoreactive, melanocyte-specific CD8(+) T cells in the skin and blood, which are directly responsible for melanocyte destruction. We report that gene expression in lesional skin from vitiligo patients revealed an interferon-γ (IFN-γ)-specific signature, including the chemokine CXCL10. CXCL10 was elevated in both vitiligo patient skin and serum, and CXCR3, its receptor, was expressed on pathogenic T cells. To address the function of CXCL10 in vitiligo, we used a mouse model of disease that also exhibited an IFN-γ-specific gene signature, expression of CXCL10 in the skin, and up-regulation of CXCR3 on antigen-specific T cells. Mice that received Cxcr3(-/-) T cells developed minimal depigmentation, as did mice lacking Cxcl10 or treated with CXCL10-neutralizing antibody. CXCL9 promoted autoreactive T cell global recruitment to the skin but not effector function, whereas CXCL10 was required for effector function and localization within the skin. Surprisingly, CXCL10 neutralization in mice with established, widespread depigmentation induces reversal of disease, evidenced by repigmentation. These data identify a critical role for CXCL10 in both the progression and maintenance of vitiligo and thereby support inhibiting CXCL10 as a targeted treatment strategy.

Cellular adhesion gene SELP is associated with rheumatoid arthritis and displays differential allelic expression

In rheumatoid arthritis (RA), a key event is infiltration of inflammatory immune cells into the synovial lining, possibly aggravated by dysregulation of cellular adhesion molecules. Therefore, single nucleotide polymorphisms of 14 genes involved in cellular adhesion processes (CAST, ITGA4, ITGB1, ITGB2, PECAM1, PTEN, PTPN11, PTPRC, PXN, SELE, SELP, SRC, TYK2, and VCAM1) were analyzed for association with RA. Association analysis was performed consecutively in three European RA family sample groups (Nfamilies = 407). Additionally, we investigated differential allelic expression, a possible functional consequence of genetic variants. SELP (selectin P, CD62P) SNP-allele rs6136-T was associated with risk for RA in two RA family sample groups as well as in global analysis of all three groups (ptotal = 0.003). This allele was also expressed preferentially (p<10-6) with a two- fold average increase in regulated samples. Differential expression is supported by data from Genevar MuTHER (p1 = 0.004; p2 = 0.0177). Evidence for influence of rs6136 on transcription factor binding was also found in silico and in public datasets reporting in vitro data. In summary, we found SELP rs6136-T to be associated with RA and with increased expression of SELP mRNA. SELP is located on the surface of endothelial cells and crucial for recruitment, adhesion, and migration of inflammatory cells into the joint. Genetically determined increased SELP expression levels might thus be a novel additional risk factor for RA.

Large scale analysis of phenotype-pathway relationships based on GWAS results

The widely used pathway-based approach for interpreting Genome Wide Association Studies (GWAS), assumes that since function is executed through the interactions of multiple genes, different perturbations of the same pathway would result in a similar phenotype. This assumption, however, was not systemically assessed on a large scale. To determine whether SNPs associated with a given complex phenotype affect the same pathways more than expected by chance, we analyzed 368 phenotypes that were studied in >5000 GWAS. We found 216 significant phenotype-pathway associations between 70 of the phenotypes we analyzed and known pathways. We also report 391 strong phenotype-phenotype associations between phenotypes that are affected by the same pathways. While some of these associations confirm previously reported connections, others are new and could shed light on the molecular basis of these diseases. Our findings confirm that phenotype-associated SNPs cluster into pathways much more than expected by chance. However, this is true for <20% (70/368) of the phenotypes. Different types of phenotypes show markedly different tendencies: Virtually all autoimmune phenotypes show strong clustering of SNPs into pathways, while most cancers and metabolic conditions, and all electrophysiological phenotypes, could not be significantly associated with any pathway despite being significantly associated with a large number of SNPs. While this may be due to missing data, it may also suggest that these phenotypes could result only from perturbations of specific genes and not from other perturbations of the same pathway. Further analysis of pathway-associated versus gene-associated phenotypes is, therefore, needed in order to understand disease etiology and in order to promote better drug target selection.

Endothelial dysfunction in tristetraprolin-deficient mice is not caused by enhanced tumor necrosis factor-α expression

Cardiovascular events are important co-morbidities in patients with chronic inflammatory diseases like rheumatoid arthritis. Tristetraprolin (TTP) regulates pro-inflammatory processes through mRNA destabilization and therefore TTP-deficient mice (TTP(-/-) mice) develop a chronic inflammation resembling human rheumatoid arthritis. We used this mouse model to evaluate molecular signaling pathways contributing to the enhanced atherosclerotic risk in chronic inflammatory diseases. In the aorta of TTP(-/-) mice we observed elevated mRNA expression of known TTP targets like tumor necrosis factor-α (TNF-α) and macrophage inflammatory protein-1α, as well as of other pro-atherosclerotic mediators, like Calgranulin A, Cathepsin S, and Osteopontin. Independent of cholesterol levels TTP(-/-) mice showed a significant reduction of acetylcholine-induced, nitric oxide-mediated vasorelaxation. The endothelial dysfunction in TTP(-/-) mice was associated with increased levels of reactive oxygen and nitrogen species (RONS), indicating an enhanced nitric oxide inactivation by RONS in the TTP(-/-) animals. The altered RONS generation correlates with increased expression of NADPH oxidase 2 (Nox2) resulting from enhanced Nox2 mRNA stability. Although TNF-α is believed to be a central mediator of inflammation-driven atherosclerosis, genetic inactivation of TNF-α neither improved endothelial function nor normalized Nox2 expression or RONS production in TTP(-/-) animals. Systemic inflammation caused by TTP deficiency leads to endothelial dysfunction. This process is independent of cholesterol and not mediated by TNF-α solely. Thus, other mediators, which need to be identified, contribute to enhanced cardiovascular risk in chronic inflammatory diseases.

G protein-coupled receptor kinase 2 moderates recruitment of THP-1 cells to the endothelium by limiting histamine-invoked Weibel-Palade body exocytosis

BACKGROUND

G protein-coupled receptors (GPCRs) are a major family of signaling molecules, central to the regulation of inflammatory responses. Their activation upon agonist binding is attenuated by GPCR kinases (GRKs), which desensitize the receptors through phosphorylation. G protein-coupled receptor kinase 2(GRK2) down-regulation in leukocytes has been closely linked to the progression of chronic inflammatory disorders such as rheumatoid arthritis and multiple sclerosis. Because leukocytes must interact with the endothelium to infiltrate inflamed tissues, we hypothesized that GRK2 down-regulation in endothelial cells would also be pro-inflammatory.

OBJECTIVES

To determine whether GRK2 down-regulation in endothelial cells is pro-inflammatory.

METHODS

siRNA-mediated ablation of GRK2 in human umbilical vein endothelial cells (HUVECs) was used in analyses of the role of this kinase. Microscopic and biochemical analyses of Weibel-Palade body (WPB) formation and functioning, live cell imaging of calcium concentrations and video analyses of adhesion of monocyte-like THP-1 cells provide clear evidence of GRK2 function in histamine activation of endothelial cells.

RESULTS

G protein-coupled receptor kinase 2 depletion in HUVECs increases WPB exocytosis and P-selectin-dependent adhesion of THP-1 cells to the endothelial surface upon histamine stimulation, relative to controls. Further, live imaging of intracellular calcium concentrations reveals amplified histamine receptor signaling in GRK2-depleted cells, suggesting GRK2 moderates WPB exocytosis through receptor desensitization.

CONCLUSIONS

G protein-coupled receptor kinase 2 deficiency in endothelial cells results in increased pro-inflammatory signaling and enhanced leukocyte recruitment to activated endothelial cells. The ability of GRK2 to modulate initiation of inflammatory responses in endothelial cells as well as leukocytes now places GRK2 at the apex of control of this finely balanced process.

Increased B cell and cytotoxic NK cell proportions and increased T cell responsiveness in blood of natalizumab-treated multiple sclerosis patients

Background

Changes in the blood lymphocyte composition probably both mediate and reflect the effects of natalizumab treatment in multiple sclerosis, with implications for treatment benefits and risks.

Methods

A broad panel of markers for lymphocyte populations, including states of activation and co-stimulation, as well as functional T cell responses to recall antigens and mitogens, were assessed by flow cytometry in 40 patients with relapsing multiple sclerosis before and after one-year natalizumab treatment.

Results

Absolute numbers of all major lymphocyte populations increased after treatment, most markedly for NK and B cells. The fraction of both memory and presumed regulatory B cell subsets increased, as did CD3^-CD56^dim cytotoxic NK cells, whereas CD3^-CD56^bright regulatory NK cells decreased. The increase in cell numbers was further associated with a restored T cell responsiveness to recall antigens and mitogens in functional assays.

Conclusions

Our data confirms that natalizumab treatment increases the number of lymphocytes in blood, likely mirroring the expression of VLA-4 being highest on NK and B cells. This finding supports reduction of lymphocyte extravasation as a main mode of action, although the differential effects on subpopulation composition suggests that cell-signalling may also be affected. The systemic increase in T cell responsiveness reflects the increase in numbers, and while augmenting anti-infectious responses systemically, localized responses may become correspondingly decreased.

Elimination of T cell reactivity to pancreatic β cells and partial preservation of β cell activity by peptide blockade of LFA-1:ICAM-1 interaction in the NOD mouse model

In insulin dependent diabetes mellitus (T1D), self-reactive T cells infiltrate pancreatic islets and induce beta cell destruction and dysregulation of blood glucose. A goal is to control only the self-reactive T cells, leaving the remainder of the T cell population free to protect the host. One approach is blockade of the second signal for T cell activation while allowing the first (antigen-specific) signal to occur. This work proposes that small peptides that block interaction of second signals delivered through the counter receptors LFA-1:ICAM-1 will induce attacking T cells (receiving the antigen signal) to become anergic or undergo apoptosis. In NOD mice, the peptides eliminated T cell reactivity against pancreatic antigens and reduced cellular infiltration into islets, which retained stronger density of insulin staining at five weeks after cessation of therapy. In in vitro studies the peptides induced nonresponsiveness during activation of T cells from mice and from human peripheral blood.

Immunobiology of beta-cell destruction

Type 1 diabetes is a chronic disease characterized by severe insulin deficiency and hyperglycemia, due to autoimmune destruction of pancreatic islets of Langerhans. A susceptible genetic background is necessary, but not sufficient, for the development of the disease. Epidemiological and clinical observations underscore the importance of environmental factors as triggers of type 1 diabetes, currently under investigation. Islet-specific autoantibodies precede clinical onset by months to years and are established tools for risk prediction, yet minor players in the pathogenesis of the disease. Many efforts have been made to elucidate disease-relevant defects in the key immune effectors of islet destruction, from the early failure of specific tolerance to the vicious circle of destructive insulitis. However, the events triggering islet autoimmunity as well as the transition to overt diabetes are still largely unknown, making prevention and treatment strategies still a challenge.

Increased expression of vascular cell adhesion molecule 1 in muscle biopsy samples from juvenile dermatomyositis patients with short duration of untreated disease is regulated by miR-126

OBJECTIVE

To evaluate the effect of duration of untreated disease on vascular cell adhesion molecule 1 (VCAM-1) and microRNA (miRNA) expression in muscle biopsy samples from children with juvenile dermatomyositis (DM) as well as its effect on soluble VCAM-1 (sVCAM-1) and tumor necrosis factor α (TNFα) concentrations in sera from these children.

METHODS

We enrolled 28 untreated children with juvenile DM and 8 pediatric controls. Eleven children with juvenile DM had short duration of untreated disease (symptoms for ≤2 months before muscle biopsy), and 17 had long duration of untreated disease (symptoms for >2 months before muscle biopsy). Vascular structures, characterized by immunofluorescence using antibodies against von Willebrand factor, VCAM-1, and α-smooth muscle actin, were measured for total area and intensity. Circulating sVCAM-1 and TNFα levels were determined in patients with short duration of untreated disease, patients with long duration of untreated disease, and controls. Differential expression of microRNA-126 (miR-126) in muscle biopsy samples from the 2 patient groups and the control group was detected by miRNA expression profiling and confirmed by quantitative reverse transcription-polymerase chain reaction in muscle biopsy samples from the 3 groups.

RESULTS

Juvenile DM patients with short duration of untreated disease had significantly higher total positive area and intensity/high power field of VCAM-1 expression than did juvenile DM patients with long duration of untreated disease (P = 0.043 and P = 0.015, respectively) or controls (P = 0.004 and P = 0.001, respectively). Von Willebrand factor antigen-positive vasculature displayed greater VCAM-1 intensity in patients with short duration of untreated disease than in patients with long duration of untreated disease (P = 0.001). Circulating levels of sVCAM-1 and TNFα were significantly higher in patients with short duration of untreated disease than in controls (P = 0.013 and P = 0.048, respectively). The miRNA miR-126, a negative regulator of VCAM-1 expression, was significantly decreased (3.39-fold; P < 0.006) in patients with short duration of untreated disease compared to controls, while miR-126 expression in patients with long duration of untreated disease did not differ significantly compared to controls.

CONCLUSION

In patients with short duration of untreated disease, miR-126 down-regulation is associated with increased VCAM-1 in both muscle and blood, suggesting that VCAM-1 plays a critical role early in juvenile DM disease pathophysiology, augmented by TNFα.

Endothelial membrane reorganization during leukocyte extravasation

Leukocyte trafficking from the bloodstream to inflamed tissues across the endothelial barrier is an essential response in innate immunity. Leukocyte adhesion, locomotion, and diapedesis induce signaling in endothelial cells and this is accompanied by a profound reorganization of the endothelial cell surfaces that is only starting to be unveiled. Here we review the current knowledge on the leukocyte-mediated alterations of endothelial membrane dynamics and their role in promoting leukocyte extravasation. The formation of protein- and lipid-mediated cell adhesion nanodomains at the endothelial apical surface, the extension of micrometric apical membrane docking structures, which are derived from microvilli and embrace adhered leukocytes, as well as the vesicle-trafficking pathways that are required for efficient leukocyte diapedesis, are discussed. The coordination between these different endothelial membrane-remodeling events probably provides the road map for transmigrating leukocytes to find exit points in the vessel wall, in a context of severe mechanical and inflammatory stress. A better understanding of how vascular endothelial cells respond to immune cell adhesion should enable new therapeutic strategies to be developed that can abrogate uncontrolled leukocyte extravasation in inflammatory diseases.

Lipoxin A4 inhibits immune cell binding to salivary epithelium and vascular endothelium

Lipoxins are formed by leukocytes during cell-cell interactions with epithelial or endothelial cells. Native lipoxin A(4) (LXA(4)) binds to the G protein-coupled lipoxin receptors formyl peptide receptor 2 (FPR2)/ALX and CysLT1. Furthermore, LXA(4) inhibits recruitment of neutrophils, by attenuating chemotaxis, adhesion, and transmigration across vascular endothelial cells. LXA(4) thus appears to serve as an endogenous "stop signal" for immune cell-mediated tissue injury (Serhan CN; Annu Rev Immunol 25: 101-137, 2007). The role of LXA(4) has not been addressed in salivary epithelium, and little is known about its effects on vascular endothelium. Here, we determined that interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) receptor activation in vascular endothelium and salivary epithelium upregulated the expression of adhesion molecules that facilitates the binding of immune cells. We hypothesize that the activation of the ALX/FPR2 and/or CysLT1 receptors by LXA(4) decreases this cytokine-mediated upregulation of cell adhesion molecules that enhance lymphocyte binding to both the vascular endothelium and salivary epithelium. In agreement with this hypothesis, we observed that nanomolar concentrations of LXA(4) blocked IL-1β- and TNF-α-mediated upregulation of E-selectin and intercellular cell adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells (HUVECs). Binding of Jurkat cells to stimulated HUVECs was abrogated by LXA(4). Furthermore, LXA(4) preincubation with human submandibular gland cell line (HSG) also blocked TNF-α-mediated upregulation of vascular cell adhesion molecule-1 (VCAM-1) in these cells, and it reduced lymphocyte adhesion. These findings suggest that ALX/FPR2 and/or CysLT1 receptor activation in endothelial and epithelial cells blocks cytokine-induced adhesion molecule expression and consequent binding of lymphocytes, a critical event in the pathogenesis of Sjögren's syndrome (SS).

Elevated soluble cellular adhesion molecules are associated with increased mortality in a prospective cohort of renal transplant recipients

Background

Increased plasma levels of cellular adhesion molecules (CAMs) have been shown to be predictors of all cause mortality in individuals with chronic renal failure [1,2] and patients with end-stage renal disease receiving haemodialysis [3]. In renal transplant recipients the predictive value of CAMs has not been well characterised. The aim of this study was to assess the relationship between CAMs and all-cause mortality during prospective follow-up of a renal transplant cohort.

Methods

A total of 378 renal transplant recipients were recruited between June 2000 and December 2002. Soluble vascular CAM-1 (VCAM) and soluble intercellular CAM-1 (ICAM) were measured at baseline and prospective follow-up data was collected at a median of 2441 days after enrolment.

Results

In univariate survival analysis the renal transplant recipients with a VCAM or ICAM concentration in the lowest third were significantly more likely to have survived at follow-up (p < 0.001 and p = 0.009 respectively). In multivariate survival analysis VCAM and ICAM remained significant independent predictors of mortality following adjustment for traditional cardiovascular risk factors, hsCRP and estimated GFR (p = 0.030 and p = 0.037 respectively).

Conclusions

The results of this prospective study are the first to show that the CAMs, ICAM and particularly VCAM, are significant independent predictors of mortality in patients with a renal transplant.

Soluble endothelial selectin in acute lung injury complicated by severe pneumonia

BACKGROUND

Pneumonia is still one of the most frequent causes of death in the elderly. Complication of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by pneumonia makes patients very ill due to severe respiratory failure. Biomarkers that can discriminate the presence of complicating ALI/ARDS are required for early detection. The aim of this research was to investigate whether soluble endothelial selectin (sES) could be a biomarker for ALI.

METHODS

Serum sES levels were measured in 27 pneumonia patients, who were enrolled between April 2006 and September 2007. Among these patients, six had ALI or a condition that was clinically comparable to ALI (cALI). All patients who were enrolled were successfully treated and survived.

RESULTS

Circulating sES levels were elevated in pneumonia patients with ALI/cALI, and sES levels decreased following treatment of their pneumonia. Univariate and multivariate logistic regression analyses showed that sES was the only significant factor for identifying complicating ALI/cALI, independently of C-reactive protein (CRP) and lactate dehydrogenase (LDH). By receiver operating characteristic (ROC) curve analysis, the cut-off value for sES was 40.1 ng/mL, with a sensitivity of 0.8 and a specificity of 0.8.

CONCLUSION

sES may be a useful biomarker for discriminating complicating ALI/cALI in patients with severe pneumonia.