Changes of serum sICAM-1 and MMP-9 induced by rIFNbeta-1b treatment in relapsing-remitting MS

Targeting cytokine networks in neuroinflammatory diseases

In neuroinflammatory diseases, systemic (blood-borne) leukocytes invade the central nervous system (CNS) and lead to tissue damage. A causal relationship between neuroinflammatory diseases and dysregulated cytokine networks is well established across several preclinical models. Cytokine dysregulation is also observed as an inadvertent effect of cancer immunotherapy, where it often leads to neuroinflammation. Neuroinflammatory diseases can be separated into those in which a pathogen is at the centre of the immune response and those of largely unknown aetiology. Here, we discuss the pathophysiology, cytokine networks and therapeutic landscape of 'sterile' neuroinflammatory diseases such as multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), neurosarcoidosis and immune effector cell-associated neurotoxicity syndrome (ICANS) triggered by cancer immunotherapy. Despite successes in targeting cytokine networks in preclinical models of neuroinflammation, the clinical translation of targeting cytokines and their receptors has shown mixed and often paradoxical responses.

Influence of Anticoagulants and Heparin Contaminants on the Suitability of MMP-9 as a Blood-Derived Biomarker

In contrast to other common anticoagulants such as citrate and low-molecular-weight heparin (LMWH), high-molecular-weight heparin (HMWH) induces the expression of matrix metalloproteinase (MMP)-9, which is also measured as a biomarker for stroke in blood samples. Mechanistically, HMWH-stimulated T cells produce cytokines that induce monocytic MMP-9 expression. Here, the influence of further anticoagulants (Fondaparinux, Hirudin, and Alteplase) and the heparin-contaminating glycosaminoglycans (GAG) hyaluronic acid (HA), dermatan sulfate (DS), chondroitin sulfate (CS), and over-sulfated CS (OSCS) on MMP-9 was analyzed to assess its suitability as a biomarker under various conditions. Therefore, starved Jurkat T cells were stimulated with anticoagulants/contaminants. Subsequently, starved monocytic THP-1 cells were incubated with the conditioned Jurkat supernatant, and MMP-9 mRNA levels were monitored (quantitative (q)PCR). Jurkat-derived mediators secreted in response to anticoagulants/contaminants were also assessed (proteome profiler array). The supernatants of HMWH-, Hirudin-, CS-, and OSCS-treated Jurkat cells comprised combinations of activating mediators and led to a significant (in the case of OSCS, dramatic) MMP-9 induction in THP-1. HA induced MMP-9 only in high concentrations, while LMWH, Fondaparinux, Alteplase, and DS had no effect. This indicates that depending on molecular weight and charge (but independent of anticoagulant activity), anticoagulants/contaminants provoke the expression of T-cell-derived cytokines/chemokines that induce monocytic MMP-9 expression, thus potentially impairing the diagnostic validity of MMP-9.

TLR3 Ligand PolyI:C Prevents Acute Pancreatitis Through the Interferon-β/Interferon-α/β Receptor Signaling Pathway in a Caerulein-Induced Pancreatitis Mouse Model

Acute pancreatitis (AP) is a common and devastating inflammatory disorder of the pancreas. However, there are still no effective treatments available for the disease. Therefore, it is important to discover new therapeutic targets and strategies for better treatment and prognosis of AP patients. Toll-like receptor 3 (TLR3) ligand polyI:C is a double-stranded RNA mimic that can be used as an immune stimulant. Our current study indicates that polyI:C exerted excellent anti-inflammatory effects in a caerulein-induced AP mouse model and taurocholate-induced pancreatic acinar cell line injury model. We found that polyI:C triggers type I interferon (IFN) production and downstream IFN-α/β receptor (IFNAR)-dependent signaling, which play key roles in protecting the pancreas from inflammatory injury. Knockout of IFN-β and IFNAR in mice abolished the preventive effects of polyI:C on caerulein-induced AP symptoms, which include pancreatic edema, neutrophil infiltration, the accumulation of reactive oxygen species (ROS), and inflammatory gene expression. Treating pancreatic acinar 266-6 cells with an IFNAR inhibitor, which blocks the interaction between type I IFN and IFNAR, diminishes the downregulation of oxidative stress by polyI:C. Additionally, a subsequent transcriptome analysis on the role of polyI:C in treating pancreatitis suggested that chemotaxis of neutrophils and the production of ROS were inhibited by polyI:C in the pancreases damaged by caerulein injection. Thus, polyI:C may act as a type I IFN inducer to alleviate AP, and it has the potential to be a promising therapeutic agent used at the early stages of AP.

Dynamic changes of MMP-9 plasma levels correlate with JCV reactivation and immune activation in natalizumab-treated multiple sclerosis patients

The aim of the study was to investigate the changes of matrix metalloproteinase (MMP)-2 and MMP-9 plasma levels during natalizumab treatment and their correlation with JC virus (JCV) reactivation and T-lymphocyte phenotypic modifications in peripheral blood samples from 34 relapsing-remitting multiple sclerosis (RRMS) patients. MMP-9 levels were assessed by zymography in plasma samples. JCV-DNA was detected through quantitative real time PCR in plasma samples. T-lymphocyte phenotype was assessed with flow cytometry. MMP-9 plasma levels resulted increased from 12 to 24 natalizumab infusions. Stratifying plasma samples according to JCV-DNA detection, MMP-9 plasma levels were significantly increased in JCV-DNA positive than JCV-DNA negative samples. MMP-9 plasma levels resulted positively correlated with JCV viral load. CD4 immune senescence, CD8 immune activation and CD8 effector percentages were positively correlated to MMP-9 plasma levels, whereas a negative correlation between CD8 naïve percentages and MMP-9 plasma levels was found. Our data indicate an increase of MMP-9 plasma levels between 12 and 24 natalizumab infusions and a correlation with JCV-DNA detection in plasma, T-lymphocyte immune activation and senescence. These findings could contribute to understand PML pathogenesis under natalizumab treatment, suggesting a potential role of MMP-9 as a predictive marker of PML in RRMS patients.

Fluid biomarker and electrophysiological outcome measures for progressive MS trials

Progressive multiple sclerosis (MS) is characterized by insidious clinical worsening that is difficult to accurately quantify and predict. Biofluid markers and electrophysiological measures are potential candidate outcome measures in clinical trials, allowing the quantification of nervous damage occurring in the disease. Neurofilaments are highly specific neuronal proteins. They may have come closest to such applications by their higher concentrations repeatedly demonstrated in cerebrospinal fluid (CSF) in all stages of MS, during relapses, their responsiveness to disease-modifying treatments in relapsing and progressive MS and their associations with measures of inflammatory and degenerative magnetic resonance imaging (MRI) outcomes. Digital single-molecule array (Simoa) technology improves accuracy of bioassays in the quantification of neurofilament light chain (NfL) in serum and plasma. NfL seems to mark a common final path of neuroaxonal injury independent of specific causal pathways. CSF and blood levels of NfL are highly correlated across various diseases including MS, suggesting that blood measurements may be useful in assessing response to treatment and predicting future disease activity. Other biomarkers like matrix metalloproteinases, chemokines, or neurotrophic factors have not been studied to a similar extent. Such measures, especially in blood, need further validation to enter the trial arena or clinical practice. The broadening armamentarium of highly sensitive assay technologies in the future may shed even more light on patient heterogeneity and mechanisms leading to disability in MS. Evoked potentials (EPs) are used in clinical practice to measure central conduction of central sensorimotor pathways. They correlate with and predict the severity of clinical involvement of their corresponding function. Their validation for use in multicenter studies is still lacking, with the exception of visual EPs. If further validated, EPs and fluid biomarkers would represent useful outcome measures for clinical trials, being related to specific mechanisms of the ongoing pathologic changes.

Multiple sclerosis: Association of gelatinase B/matrix metalloproteinase-9 with risk and clinical course the disease

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and axonal degeneration of the central nervous system and a leading cause of disability in young adults. The matrix metalloproteinases in general and specially gelatinase B/metalloproteinase-9 (MMP-9) plays a role in the pathogenesis of multiple sclerosis.

OBJECTIVE

To investigate the presence of the MMP-9 -1562C/T polymorphism in a Portuguese population of MS patients and assess its impact in susceptibility and course of the disease. The relation of MMP-9 serum levels with the polymorphism and with clinical and therapeutic factors will also be assessed.

METHODS

Our study included 355 Caucasian individuals distributed as MS patients (n=169) and controls (n=186). Samples were genotyped for -1562C/T polymorphism by PCR-RFLP analysis. MMP-9 concentration in serum was analyzed using a commercially available enzyme-linked immunosorbent assay.

RESULTS

A significant increase in T-allele frequency was found in female MS patients, but not in the total patient population. No association between the presence of the polymorphism and disease progression was found. MMP-9 serum concentrations were increased in patients, and although not influenced by the -1562C/T polymorphism, were modified by INF-beta therapy.

CONCLUSION

Although we did not find an association of this polymorphism with disease susceptibility or prognosis, MMP-9 appears to be a good therapeutic response marker for multiple sclerosis.

Marine pharmacology: therapeutic targeting of matrix metalloproteinases in neuroinflammation

Alterations in matrix metalloproteinase (MMP) expression and activity are recognized as key pathogenetic events in several neurological disorders. This evidence makes MMPs possible therapeutic targets. The search for substances that can inhibit MMPs is moving progressively toward the screening of natural products. In particular, marine bioprospecting could be promising for the discovery of marine natural products with anti-MMP activities. Despite recent advances in this field, the possibility of using marine MMP inhibitors (MMPIs) for the treatment of neuroinflammation is still under-investigated. Here, we review the latest findings in this promising research field and the potential that marine MMPIs can have in the management and treatment of various neurological diseases.

Brain endothelial dysfunction in cerebral adrenoleukodystrophy

See Aubourg (doi:10.1093/awv271) for a scientific commentary on this article.X-linked adrenoleukodystrophy is caused by mutations in the ABCD1 gene leading to accumulation of very long chain fatty acids. Its most severe neurological manifestation is cerebral adrenoleukodystrophy. Here we demonstrate that progressive inflammatory demyelination in cerebral adrenoleukodystrophy coincides with blood-brain barrier dysfunction, increased MMP9 expression, and changes in endothelial tight junction proteins as well as adhesion molecules. ABCD1, but not its closest homologue ABCD2, is highly expressed in human brain microvascular endothelial cells, far exceeding its expression in the systemic vasculature. Silencing of ABCD1 in human brain microvascular endothelial cells causes accumulation of very long chain fatty acids, but much later than the immediate upregulation of adhesion molecules and decrease in tight junction proteins. This results in greater adhesion and transmigration of monocytes across the endothelium. PCR-array screening of human brain microvascular endothelial cells after ABCD1 silencing revealed downregulation of both mRNA and protein levels of the transcription factor c-MYC (encoded by MYC). Interestingly, MYC silencing mimicked the effects of ABCD1 silencing on CLDN5 and ICAM1 without decreasing the levels of ABCD1 protein itself. Together, these data demonstrate that ABCD1 deficiency induces significant alterations in brain endothelium via c-MYC and may thereby contribute to the increased trafficking of leucocytes across the blood-brain barrier as seen in cerebral adrenouleukodystrophy.

Genome-wide gene expression analysis of peripheral leukocytes in relation to the male predominance of Guillain-Barre syndrome: differential gene expression between male and female patients

BACKGROUND

Guillain-Barre syndrome (GBS) fulfils most of the clinical features of an autoimmune disease except for its male predominance. No previous studies have evaluated the differential genome-wide expression between male and female GBS patients.

OBJECTIVE

This study sought to identify differences between male and female GBS patients in the gene expression profiles of peripheral leukocytes.

METHODS

We downloaded gene chip data-sets pertaining to peripheral leukocyte samples from GBS patients using the gene expression omnibus (submitted by Chang et al.) and applied hierarchical cluster analysis to detect whether there was a gender difference in genome-wide gene expression levels. Then, we identified the sexually differentially expressed genes using a bioinformatic approach and applied enrichment analysis to the gene ontology and Kyoto Encyclopaedia of Genes and Genomes terms to identify significant pathways related to these genes.

RESULTS

We observed gender stratification among GBS patients. Twenty genes were expressed more highly in male patients and were enriched for functions, such as macrophage differentiation, leukocyte migration, bladder cancer, pathogenic Escherichia coli infection. In female patients, 62 genes were more highly expressed and were enriched for responses to viral infection and defence, retinoic acid-inducible gene I (RIG-I)-like receptors, cytoplasmic DNA sensing. Matrix metalloproteinase 9 (MMP9) seem to play an important role in the male predominance of GBS.

CONCLUSIONS

This study demonstrated gender differences in the genome-wide gene expression of patients with GBS. Bioinformatic approaches offer new means for identifying candidate genes and pathways relevant to the pathophysiology of GBS.

The role of fractalkine (CX3CL1) in regulation of CD4(+) cell migration to the central nervous system in patients with relapsing-remitting multiple sclerosis

Fractalkine (CX3CL1) levels are increased in the cerebrospinal fluid (CSF) of patients with clinically isolated syndrome (CIS), as well as in the CSF and serum samples from patients with relapsing-remitting multiple sclerosis (RRMS). A higher percentage of circulating CD4(+) T-cells expressed its surface receptor (CX3CR1) and intracellular adhesion molecule (ICAM-1) in RRMS patients in comparison to healthy controls (HCs). The CX3CR1(+)ICAM-1(+)CD4(+) T-cells are enriched in the CSF of the RRMS patients. In vitro migration studies revealed that CD4(+) T-cells, which migrated toward a CX3CL1 gradient, expressed higher levels of ICAM-1 than non-migrating cells. CX3CL1 significantly increased IFN-γ and TNF-α gene expression and IFN-γ secretion by CD4(+) T-cells derived from the RRMS patients. CX3CL1 upregulated ICAM-1 expression on the surface of RRMS patient-derived but not HC-derived CD4(+) T-cells. Thus, CX3CL1 induces recruitment of CX3CR1(+)ICAM-1(+)CD4(+) T-cells into the central nervous system (CNS) during the early inflammatory response in MS.

Heterogeneity of serum gelatinases MMP-2 and MMP-9 isoforms and charge variants

The matrix metalloproteinases (MMPs) gelatinase A (MMP-2) and gelatinase B (MMP-9) are mediators of brain injury in multiple sclerosis (MS) and valuable biomarkers of disease activity. We applied bidimensional zymography (2-DZ) as an extension of classic monodimensional zymography (1-DZ) to analyse the complete pattern of isoforms and post-translational modifications of both MMP-9 and MMP-2 present in the sera of MS patients. The enzymes were separated on the basis of their isoelectric points (pI) and apparent molecular weights (Mw) and identified both by comparison with standard enzyme preparations and by Western blot analysis. Two MMP-2 isoforms, and at least three different isoforms and two different states of organization of MMP-9 (the multimeric MMP-9 and the N-GAL-MMP-9 complex) were observed. In addition, 2-DZ revealed for the first time that all MMP-9 and MMP-2 isoforms actually exist in the form of charge variants: four or five variants in the NGAL complex, more charge variants in the case of MMP-9; and five to seven charge variants for MMP-2. Charge variants were also observed in recombinant enzymes and, after concentration, also in sera from healthy individuals. Sialylation (MMP-9) and phosphorylation (MMP-2) contributed to molecular heterogeneity. The detection of charge variants of MMP-9 and MMP-2 in MS serum samples illustrates the power of 2-DZ and demonstrates that in previous studies MMP mixtures, rather than single molecules, were analysed. These observations open perspectives for better diagnosis and prognosis of many diseases and need to be critically interpreted when applying other methods for MS and other diseases.

The significance of matrix metalloproteinases in the immunopathogenesis and treatment of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). The major pathological outcomes of the disease are the loss of blood-brain barrier (BBB) integrity and the development of reactive astrogliosis and MS plaque. For the disease to occur, the non-resident cells must enter into the immune-privileged CNS through a breach in the relatively impermeable BBB. It has been demonstrated that matrix metalloproteinases (MMPs) play an important role in the immunopathogenesis of MS, in part through the disruption of the BBB and the recruitment of inflammatory cells into the CNS. Moreover, MMPs can also enhance the cleavage of myelin basic protein (MBP) and the demyelination process. Regarding the growing data on the roles of MMPs and their tissue inhibitors (TIMPs) in the pathogenesis of MS, this review discusses the role of different types of MMPs, including MMP-2, -3, -7, -9, -12 and -25, in the immunopathogenesis and treatment of MS.

Matrix metalloproteinases and their pathological upregulation in multiple sclerosis: an overview

Matrix metalloproteinases (MMPs) are a family of extracellular proteases associated with extracellular matrix remodeling. They are involved in many physiological and reparative processes. MMPs can break down all extracellular constituents; therefore, their expression is very tightly regulated and their abnormal activity or over production has been linked to many diseases including multiple sclerosis (MS) which is a leading cause of non-traumatic disability in young adults in North America. Recently many studies, both in animals and humans, have been conducted to better elucidate the underlying causes, mechanisms and pathophysiology of MS. In this review, we discuss the potential role of pathological upregulation of MMPs in MS and future challenges which if properly addressed might help in development of potential cure for this disease.

The role of microglia and matrix metalloproteinases involvement in neuroinflammation and gliomas

Matrix metalloproteinases (MMPs) are involved in the pathogenesis of neuroinflammatory diseases (such as multiple sclerosis) as well as in the expansion of malignant gliomas because they facilitate penetration of anatomical barriers (such as the glia limitans) and migration within the neuropil. This review elucidates pathomechanisms and summarizes the current knowledge of the involvement of MMPs in neuroinflammation and glioma, invasion highlighting microglia as major sources of MMPs. The induction of expression, suppression, and multiple pathways of function of MMPs in these scenarios will also be discussed. Understanding the induction and action of MMPs might provide valuable information and reveal attractive targets for future therapeutic strategies.

Inhibition of myelin-cleaving poteolytic activities by interferon-beta in rat astrocyte cultures. Comparative analysis between gelatinases and calpain-II

Background

Proteolytic enzymes have been implicated in the pathogenesis of Multiple Sclerosis (MS) for both their ability to degrade myelin proteins and for their presence in MS plaques.In this study we investigated whether interferon-beta (IFN-β) could differently modulate the activity and the expression of proteolytic activities against myelin basic protein (MBP) present in lipopolysaccharide (LPS)-activated astrocytes.

Methodology/Principal Findings

Rat astrocyte cultures were activated with LPS and simultaneously treated with different doses of IFN-β. To assess the presence of MBP-cleaving proteolytic activity, culture supernatants and cellular extracts collected from astrocytes were incubated with exogenous MBP. A MBP-degrading activity was found in both lysates and supernatants from LPS-activated astrocytes and was dose-dependently inhibited by IFN-β. The use of protease inhibitors as well as the zymographic analysis indicated the presence of calpain II (CANP-2) in cell lysates and gelatinases A (MMP-2) and B (MMP-9) in cell supernatants. RT-PCR revealed that the expression of CANP-2 as well as of MMP-2 and MMP-9 was increased in LPS-activated astrocytes and was dose-dependently inhibited by IFN-β treatment. The expression of calpastatin, the natural inhibitor of CANPs, was not affected by IFN-β treatment. By contrast, decreased expression of TIMP-1 and TIMP-2, the natural inhibitors of MMP-9 and MMP-2, respectively, was observed in IFN-β-treated astrocytes compared to LPS-treated cells. The ratio enzyme/inhibitor indicated that the effect of IFN-β treatment is more relevant to CANP-2 than on MMPs.

Conclusions/ Significance

These results suggest that the neuroinflammatory damage during MS involves altered balance between multiple proteases and their inhibitors and indicate that IFN-β is effective in regulating different enzymatic systems involved in MS pathogenesis.

On the roles of polyvalent binding in immune recognition: perspectives in the nanoscience of immunology and the immune response to nanomedicines

Immunology often conveys the image of large molecules, either in the soluble state or in the membrane of leukocytes, forming multiple contacts with a target for actions of the immune system. Avidity names the ability of a polyvalent molecule to form multiple connections of the same kind with ligands tethered to the same surface. Polyvalent interactions are vastly stronger than their monovalent equivalent. In the present review, the functional consequences of polyvalent interactions are explored in a perspective of recent theoretical advances in understanding the thermodynamics of such binding. From insights on the structural biology of soluble pattern recognition molecules as well as adhesion molecules in the cell membranes or in their proteolytically shed form, this review documents the prominent role of polyvalent interactions in making the immune system a formidable barrier to microbial infection as well as constituting a significant challenge to the application of nanomedicines.

Type I interferon and pattern recognition receptor signaling following particulate matter inhalation

Background

Welding, a process that generates an aerosol containing gases and metal-rich particulates, induces adverse physiological effects including inflammation, immunosuppression and cardiovascular dysfunction. This study utilized microarray technology and subsequent pathway analysis as an exploratory search for markers/mechanisms of in vivo systemic effects following inhalation. Mice were exposed by inhalation to gas metal arc – stainless steel (GMA-SS) welding fume at 40 mg/m³ for 3 hr/d for 10 d and sacrificed 4 hr, 14 d and 28 d post-exposure. Whole blood cells, aorta and lung were harvested for global gene expression analysis with subsequent Ingenuity Pathway Analysis and confirmatory qRT-PCR. Serum was collected for protein profiling.

Results

The novel finding was a dominant type I interferon signaling network with the transcription factor Irf7 as a central component maintained through 28 d. Remarkably, these effects showed consistency across all tissues indicating a systemic type I interferon response that was complemented by changes in serum proteins (decreased MMP-9, CRP and increased VCAM1, oncostatin M, IP-10). In addition, pulmonary expression of interferon α and β and Irf7 specific pattern recognition receptors (PRR) and signaling molecules (Ddx58, Ifih1, Dhx58, ISGF3) were induced, an effect that showed specificity when compared to other inflammatory exposures. Also, a canonical pathway indicated a coordinated response of multiple PRR and associated signaling molecules (Tlr7, Tlr2, Clec7a, Nlrp3, Myd88) to inhalation of GMA-SS.

Conclusion

This methodological approach has the potential to identify consistent, prominent and/or novel pathways and provides insight into mechanisms that contribute to pulmonary and systemic effects following toxicant exposure.

The effects of omega-3 Fatty acids on matrix metalloproteinase-9 production and cell migration in human immune cells: implications for multiple sclerosis

In multiple sclerosis (MS), compromised blood-brain barrier (BBB) integrity contributes to inflammatory T cell migration into the central nervous system. Matrix metalloproteinase-9 (MMP-9) is associated with BBB disruption and subsequent T cell migration into the CNS. The aim of this paper was to evaluate the effects of omega-3 fatty acids on MMP-9 levels and T cell migration. Peripheral blood mononuclear cells (PBMC) from healthy controls were pretreated with two types of omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Cell supernatants were used to determine MMP-9 protein and activity levels. Jurkat cells were pretreated with EPA and DHA and were added to fibronectin-coated transwells to measure T cell migration. EPA and DHA significantly decreased MMP-9 protein levels, MMP-9 activity, and significantly inhibited human T cell migration. The data suggest that omega-3 fatty acids may benefit patients with multiple sclerosis by modulating immune cell production of MMP-9.

Differential gene expression and translational approaches to identify biomarkers of interferon beta activity in multiple sclerosis

More than 16 years ago human interferon-β-1b (IFN-β-1β) was shown to be effective in the treatment of the relapsing-remitting form of multiple sclerosis (MS). Over time, IFN-β has been demonstrated to be both a safe and effective treatment. However, the mechanism of action of IFN-β in MS remains unknown. To better understand the mechanism of action of IFN-β, considerable effort has been made in transcriptional profiling of peripheral blood mononuclear cells collected from MS patients. IFN-β is known to induce a large number of genes that play an important role in regulating responses to viral infection, immune modulation, and cell proliferation. Identifying differentially induced genes that are linked to the beneficial effects observed during treatment is under active investigation. IFN biomarkers in MS patients have been proposed but have not been clearly confirmed in independent studies or consistently correlated with clinical measures of disease progression. Organizing single genes or gene signatures grouped according to molecular mechanisms meaningful in MS may help to link IFN activity measurements to clinical outcomes. In this review, IFN activity measurements will be discussed with a specific emphasis on what is known about differential gene expression and treatment effects in MS.

CD46 plasticity and its inflammatory bias in multiple sclerosis

Known as a link to the adaptive immune system, a complement regulator, a "pathogen magnet" and more recently as an inducer of autophagy, CD46 is the human receptor that refuses to be put in a box. This review summarizes the current roles of CD46 during immune responses and highlights the role of CD46 as both a promoter and attenuator of the immune response. In patients with multiple sclerosis (MS), CD46 responses are overwhelmingly pro-inflammatory with notable defects in cytokine and chemokine production. Understanding the role of CD46 as an inflammatory regulator is a distant goal considering the darkness in which its regulatory mechanisms reside. Further research into the regulation of CD46 expression through its internalization and processing will undoubtedly extend our knowledge of how the balance is tipped in favor of inflammation in MS patients.

Clinical effects and tolerability of high-dose, high-frequency recombinant interferon beta-1a in patients with multiple sclerosis: maximizing therapy through long-term adherence

IMPORTANCE OF THE FIELD

High-dose, high-frequency IFN beta-1a in multiple sclerosis (MS) can prevent lesion formation, decrease the frequency/severity of relapses and delay progression of disability, with a proven safety profile. Rates of non-adherence are high. There are drugs under investigation that may have greater efficacy and different safety profiles from existing therapies.

AREAS COVERED IN THIS REVIEW

Evidence supporting the efficacy of IFN beta-1a, factors contributing to non-adherence, and strategies to combat non-adherence. It is hoped that these strategies, coupled with future advances in pharmacogenetics, might lead to better outcomes. The PubMed database was searched using the terms "multiple sclerosis" and "interferon beta-1a", for papers published between 1998 and 2010. Relevant manuscripts and pivotal papers from clinical trials were cited. Searches of abstracts from congresses were also performed to obtain recent findings.

WHAT THE READER WILL GAIN

An overview of early pivotal trials, comparative studies with other treatments, and recent studies assessing the development of this therapy.

TAKE HOME MESSAGE

Long-term treatment with IFN beta-1a has benefits in MS and a good safety profile. Although adherence outside of clinical trials can be poor, injection devices, better tolerated drug formulations and education regarding treatment expectations are some of the strategies employed to help patients to adhere to treatment in the hope of improving outcomes.

Alterations in serum MMP-8, MMP-9, IL-12p40 and IL-23 in multiple sclerosis patients treated with interferon-β1b

Background: Interferon-β1b (IFN-β1b), an effective treatment for multiple sclerosis (MS), lessens disease severity in MS patients. However, the mechanisms of its immunoregulatory and anti-inflammatory effects in MS remain only partially understood. Matrix metalloproteinases (MMP) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are involved in blood brain barrier disruption and formation of MS lesions. Th1/Th17 cytokines e.g. interleukins IL-12p40, IL-17, and IL-23, are associated with MS disease activity and are significant players in pathogenesis of MS.

Objective: During a 1-year prospective study, we serially measured serum MMP-8, MMP-9, TIMP-1, IL-12p40, IL-17, and IL-23 in 24 patients with relapsing—remitting MS. We compared the results to clinical course and to brain magnetic resonance imaging. IFN-β1b decreased serum MMP-8 and MMP-9 (not TIMP-1).

Results: The sustained treatment with IFN-β1b attenuated the pro-inflammatory environment by significantly reducing the serum IL-12p40, IL-23, and showed a trend for decreasing IL-17. Decreased serum MMP-8, MMP-9, IL-12 and IL-23 levels were correlated with a decrease in the number of contrast-enhanced T2-weighted lesions.

Conclusion: Early treatment of MS with IFN-β1b may stabilize clinical disease by attenuating levels of inflammatory cytokines and MMPs. Serial measurement of inflammatory mediators may serve as sensitive markers to gauge therapeutic responses to IFN-β1b during the first year of treatment.

Complementary and alternative medicine for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic disabling disease of the CNS that affects people during early adulthood. Despite several US FDA-approved medications, the treatment options in MS are limited. Many people with MS explore complementary and alternative medicine (CAM) treatments to help control their MS and treat their symptoms. Surveys suggest that up to 70% of people with MS have tried one or more CAM treatment for their MS. People with MS using CAM generally report deriving some benefit from the therapies. The CAM therapies most frequently used include diet, omega-3 fatty acids and antioxidants. There is very limited research evaluating the safety and effectiveness of CAM in MS. The most promising among CAM therapies that warrant further investigation are a low-fat diet, omega-3 fatty acids, lipoic acid and vitamin D supplementation as potential anti-inflammatory and neuroprotective agents in both relapsing and progressive forms of MS. There is very limited research evaluating the safety and effectiveness of CAM in MS. However, in recent years, the NIH and the National MS Society have been actively supporting the research in this very important area.

High-dose, high-frequency recombinant interferon beta-1a in the treatment of multiple sclerosis

BACKGROUND

There is at present no cure for multiple sclerosis (MS), and existing therapies are designed primarily to prevent lesion formation, decrease the rate and severity of relapses and delay the resulting disability by reducing levels of inflammation.

OBJECTIVE

The aim of this review was to assess the treatment of relapsing MS with particular focus on subcutaneous (s.c.) interferon (IFN) beta-1a.

METHOD

The literature on IFN beta-1a therapy of MS was reviewed based on a PubMed search (English-language publications from 1990) including its pharmacodynamics and pharmacokinetics, clinical efficacy in relapsing MS as shown in placebo-controlled studies and in comparative trials, efficacy in secondary progressive MS, safety and tolerability, and the impact of neutralizing antibodies.

CONCLUSION

The literature suggests that high-dose, high-frequency s.c. IFN beta-1a offers an effective option for treating patients with relapsing MS, with proven long-term safety and tolerability, and has a favourable benefit-to-risk ratio compared with other forms of IFN beta.

Regulation of matrix metalloproteinases and their inhibitors by interferon-beta: a longitudinal study in multiple sclerosis patients

BACKGROUND

Matrix metalloproteinases (MMPs) represent a large family of proteolytic enzymes, with some members being implicated in the immunopathogenesis of multiple sclerosis (MS). Interferon (IFN)-beta is one of the current mainstays in MS therapy and known to downregulate the expression of MMP-9. However, only sparse information is available on the effects of IFN-beta on the other 20 members of the MMP family.

METHODS

This is a longitudinal analysis on the RNA expression pattern of all known MMPs and their endogenous inhibitors before and after 1 and 6 months of IFN-beta therapy. RNA expression levels were assessed in peripheral venous blood cells from 14 MS patients and 8 matched controls by real time-PCR.

RESULTS

RNA expression levels before treatment differed in part in MS patients compared to healthy controls (MMP-9, MMP-14, MMP-19, TIMP-1, TIMP-2). Some of the MMPs responded to therapy specifically (MMP-8, MMP-9, MMP-19), whereas others remained unchanged over time.

CONCLUSIONS

These data suggest that MMPs may differ in their expression levels in MS patients and that this group of enzymes is differentially regulated during the treatment with IFN-beta in MS for at least 6 months.

Omega-3 fatty acid supplementation decreases matrix metalloproteinase-9 production in relapsing-remitting multiple sclerosis

OBJECTIVES

The primary objective was to evaluate the effect of omega-3 fatty acids (omega-3 FA) on matrix metalloproteinase-9 (MMP-9) production by immune cells in multiple sclerosis (MS). Quality of life, fatty acid levels, and safety were also evaluated.

MATERIALS AND METHODS

Ten participants with relapsing-remitting MS (RRMS) received omega-3 FA supplementation (9.6g/day fish oil) in an open-label study. Participants were evaluated at four time points, baseline, after 1 month of omega-3 FA supplementation, after 3 months of omega-3 FA supplementation, and after a 3-month wash out.

RESULTS

Immune cell secretion of MMP-9 decreased by 58% after 3 months of omega-3 FA supplementation when compared with baseline levels (p<0.01). This effect was coupled with a significant increase in omega-3 FA levels in red blood cell membranes.

CONCLUSIONS

Omega-3 FA significantly decreased MMP-9 levels in RRMS and may act as an immune-modulator that has potential therapeutic benefit in MS patients.

Kallikreins are associated with secondary progressive multiple sclerosis and promote neurodegeneration

Tissue kallikrein KLK1 and the kallikrein-related peptidases KLK2-15 are a subfamily of serine proteases that have defined or proposed roles in a range of central nervous system (CNS) and non-CNS pathologies. To further understand their potential activity in multiple sclerosis (MS), serum levels of KLK1, 6, 7, 8 and 10 were determined in 35 MS patients and 62 controls by quantitative fluorometric ELISA. Serum levels were then correlated with Expanded Disability Status Scale (EDSS) scores determined at the time of serological sampling or at last clinical follow-up. Serum levels of KLK1 and KLK6 were elevated in MS patients (p<or=0.027), with highest levels associated with secondary progressive disease. Elevated KLK1 correlated with higher EDSS scores at the time of serum draw and KLK6 with future EDSS worsening in relapsing remitting patients (p<or=0.007). Supporting the concept that KLK1 and KLK6 promote degenerative events associated with progressive MS, exposure of murine cortical neurons to either kallikrein promoted rapid neurite retraction and neuron loss. These novel findings suggest that KLK1 and KLK6 may serve as serological markers of progressive MS and contribute directly to the development of neurological disability by promoting axonal injury and neuron cell death.

The multiple sclerosis degradome: enzymatic cascades in development and progression of central nervous system inflammatory disease

An array of studies implicate different classes of protease and their endogenous inhibitors in multiple sclerosis (MS) pathogenesis based on expression patterns in MS lesions, sera, and/or cerebrospinal fluid (CSF). Growing evidence exists regarding their mechanistic roles in inflammatory and neurodegenerative aspects of this disease. Proteolytic events participate in demyelination, axon injury, apoptosis, and development of the inflammatory response including immune cell activation and extravasation, cytokine and chemokine activation/inactivation, complement activation, and epitope spreading. The potential significance of proteolytic activity to MS therefore relates not only to their potential use as important biomarkers of disease activity, but additionally as prospective therapeutic targets. Experimental data indicate that understanding the net physiological consequence of altered protease levels in MS development and progression necessitates understanding protease activity in the context of substrates, endogenous inhibitors, and proteolytic cascade interactions, which together make up the MS degradome. This review will focus on evidence regarding the potential physiologic role of those protease families already identified as markers of disease activity in MS; that is, the metallo-, serine, and cysteine proteases.

Cleavage of myelin associated glycoprotein by matrix metalloproteinases

Derivative myelin associated glycoprotein (dMAG) results from proteolysis of transmembrane MAG and can inhibit axonal growth. We have tested the ability of certain matrix metalloproteinases (MMPs) elevated with inflammatory and demyelinating diseases to cleave MAG. We show MMP-2, MMP-7 and MMP-9, but not MMP-1, cleave recombinant human MAG. Cleavage by MMP-7 occurs at Leu 509, just distal to the transmembrane domain and, to a lesser extent, at Met 234. We also show that MMP-7 cleaves MAG expressed on the external surface of CHO cells, releasing fragments that accumulate in the medium over periods of up to 48 h or more and that are able to inhibit outgrowth by dorsal root ganglion (DRG) neurons. We conclude that MMPs may have the potential both to disrupt MAG dependent axon-glia communication and to generate bioactive fragments that can inhibit neurite growth.

Pharmacokinetics and pharmacodynamics of the interferon-betas, glatiramer acetate, and mitoxantrone in multiple sclerosis

Five disease-modifying agents are currently approved for long-term treatment of multiple sclerosis (MS), namely three interferon-beta preparations, glatiramer acetate, and mitoxantrone(1). Pharmacokinetics describes the fate of drugs in the human body by studying their absorption, distribution, metabolism and excretion. Pharmacodynamics is dedicated to the mechanisms of action of drugs. The understanding of the pharmacokinetics and pharmacodynamics of the approved disease-modifying agents against MS is of importance as it might contribute to the development of future derivatives with a potentially higher efficacy and a more favourable safety profile. This article reviews data thus far present both on the pharmacokinetics as well as on the putative mechanisms of action of the interferon-betas, glatiramer acetate, and mitoxantrone in the immunopathogenesis of MS.

Elevation of matrix metalloproteinases (MMPs) in multiple sclerosis and impact of immunomodulators

The matrix metalloproteinases (MMPs) are implicated in the pathology of multiple sclerosis (MS). This review summarizes the consequences of upregulation of MMP members in MS as well as in an animal model of the disease, experimental autoimmune encephalomyelitis (EAE). The pathogenic roles of MMPs are considered, especially in the transmigration of leukocytes into the CNS. We review the evidence that interferon-beta, an immunomodulator that is commonly used in MS, affects MMP expression in the disease. The potential of minocycline as a therapy in MS, based on its activity as an MMP inhibitor, is discussed. Besides affecting MMPs, minocycline may have other actions that help account for its possible utility in MS.

Inhibitory effect of polyunsaturated fatty acids on MMP-9 release from microglial cells--implications for complementary multiple sclerosis treatment

We investigated whether polyunsaturated fatty acids (PUFA), which might be a useful complementary therapy among patients with multiple sclerosis (MS), are able to modulate matrix metalloproteinase (MMP) production in microglial cultures. MMPs are myelinotoxic factors. Primary cultures of rat microglia were treated with different doses of omega-3 (omega-3) PUFA or purified fish oil, containing a mixture of omega-3 and omega-6 PUFA, and simultaneously activated by exposure to lipopolysaccharide (LPS). Culture supernatants were subjected to zymography and Western blot analysis for the assessment of MMP-2 and MMP-9 levels. Increased amounts of MMP-9, but not of the constitutively expressed MMP-2, were observed in supernatants from LPS-treated microglia in comparison with non-treated control cells. The treatment with both omega-3 PUFA and fish oil dose-dependently inhibited the LPS-induced production of MMP-9. Our results suggest that a low fat diet supplemented with omega-3 PUFA may become recommended for the well being of MS patients under therapy.

Once-weekly 22microg subcutaneous IFN-beta-1a in secondary progressive MS: a 3-year follow-up study on brain MRI measurements and serum MMP-9 levels

OBJECTIVE

To study the effect of weekly injected subcutaneous interferon (IFN)-beta-1a 22 microg on the extent of brain lesions on magnetic resonance imaging (MRI) and the level of serum matrix metalloproteinase (MMP)-9 in patients with secondary progressive multiple sclerosis (SPMS).

SUBJECTS AND METHODS

All the 28 Finnish patients participating in the Nordic multicentre trial on the clinical efficacy of weekly IFN-beta-1a (Rebif) 22 microg in SPMS were studied neurologically and by volumetric MRI during a 3-year follow-up. The levels of MMP-9 in serum were measured over the 3-year study.

RESULTS

There was no obvious effect on the number of contrast medium-enhancing lesions, the volume of T1 or T2 lesions or level of serum MMP-9, nor was any effect detected on the relapse rate and the Expanded Disability Status Scale (EDSS). Brain atrophy progression was not affected by the treatment.

CONCLUSION

The lack of effect on MRI, clinical outcomes or the levels of MMP-9 indicates that subcutaneous administration of low-dose low-frequency IFN-beta-1a is insufficient in controlling either the inflammatory constitutes or the neurodegenerative changes of advanced SPMS.

Effect of immunomodulation with human interferon-beta on early functional recovery from experimental spinal cord injury

STUDY DESIGN

Electron and light microscopic changes, neutrophil infiltration, and lipid peroxidation in the spinal cord and early neurologic examination were studied in rats.

OBJECTIVE

To examine the effects of immunomodulator treatment with recombinant human interferon-beta after spinal cord contusion injury.

SUMMARY OF BACKGROUND DATA

Immunomodulator treatment with interferon-beta has been the subject of extensive studies, but mainly in relation to multiple sclerosis. Recently, it was reported that interferon-beta possessed significant neuroprotection after experimental transient ischemic stroke. However, to our knowledge, there have been no previous reports about the neuroprotective effect of interferon-beta after spinal cord injury.

METHODS

Rats were randomly allocated into 5 groups. Group 1 was control and after clinical examination, normal spinal cord samples were obtained. Group 2 was introduced 50 g/cm contusion injury. Group 3 was vehicle, immediately after trauma 1 mL of physiologic saline was injected. Group 4 was given 30 mg/kg methylprednisolone sodium succinate intraperitoneally immediately after trauma. Group 5 was given 1 x 10(7) IU interferon-beta immediately and 0.5 x 10(7) IU interferon-beta 4 hours after trauma. Animals were examined by inclined plane and Basso-Beattie-Bresnahan scale 24 hours after trauma. Spinal cord samples obtained following clinical evaluations. Neutrophil infiltration was evaluated by myeloperoxidase activity and lipid peroxidation was estimated by thiobarbituric acid test. Electron and light microscopic results were also performed to determine the effects of interferon-beta on tissue structure.

RESULTS

Interferon-beta treatment improved neurologic outcome, which was supported by decreased myeloperoxidase activity and lipid peroxidation. Electron and light microscopic results also showed preservation of tissue structure in the treatment group.

CONCLUSIONS

Immunomodulator treatment with interferon-beta possesses obvious neuroprotection after acute contusion injury to the rat spinal cord.

Immunopathogenesis of multiple sclerosis

Multiple sclerosis (MS) is considered an immune-mediated disorder in which immune cells cross the blood-brain barrier to enter the central nervous system (CNS) wherein they augment the neuropathology of the disease. This chapter discusses the role of various immune cell types that contribute to the development and progression of MS. Specifically, the role of T cells, antigen-presenting cells, and components of the innate immune system such as macrophages, B cells, and the complement system are discussed. The involvement of CNS-specific cells such as microglia, astrocytes, and neurons in MS are discussed and the immunosuppressive role of regulatory T cells is considered. We introduce the involvement of chemokines and matrix metalloproteinases which helps recruit immune cells into the CNS in MS. Although the causes of MS are unknown, various factors such as genetic influences, environmental effects, and involvement of infectious agents as potential contributors to MS immune dysfunctions are also considered. With this background, we discuss the mechanisms of the immunomodulators that are used to treat MS.

Increased Soluble 4-1BB Ligand (4-1BBL) Levels in Peripheral Blood of Patients with Multiple Sclerosis

4-1BB ligand (4-1BBL; CD137L) is a member of the tumour necrosis factor superfamily expressed primarily on antigen presenting cells such as B cells, macrophages and dendritic cells. Its engagement with the receptor 4-1BB (CD137) has been shown to promote T-cell activation and regulate proliferation and survival of T cells. The role of the costimulatory molecule in multiple sclerosis (MS) remains unclear. In this study, the expression of 4-1BBL and soluble 4-1BBL (s4-1BBL) protein levels were analysed in peripheral blood of MS patients. Compared with healthy controls, MS patients had an increase in both plasma s4-1BBL protein levels and expression of 4-1BBL in CD14(+) monocytes. In contrast, myelin basic protein-reactive T-cell proliferation was not found to be inhibited by the use of an anti-4-1BBL antibody. The elevated s4-1BBL protein levels in the MS patients may function as a self-regulatory mechanism of 4-1BB/4-1BBL interaction and costimulation.

Anti-inflammatory properties of Type I interferons

The notion that Type I interferons (interferon-alpha and -beta) possess anti-inflammatory potential is supported by data from clinical application in multiple sclerosis, by studies on cultured immune-competent cells and by investigation of experimental diseases in whole animals. These observations deserve the attention of virologists for their potential role in the pathogenesis and clinical management of virus infections.

Mechanisms of action for treatments in multiple sclerosis: Does a heterogeneous disease demand a multi-targeted therapeutic approach?

The etiology of multiple sclerosis (MS) is incompletely understood, and evidence suggests there may be more than one underlying cause in this disorder. Furthermore, this complex and heterogeneous autoimmune disease shows a high degree of clinical variability between patients. Therefore, in the absence of a single therapeutic target for MS, it is difficult to apply conventional drug design strategies in the search for new treatments. We review the potential mechanisms of action of several effective therapies for MS that are currently available or in development. The effects of each treatment are described in terms of their actions on key processes in a five-step model of MS pathogenesis. Conventional immunosuppressants targeting intracellular ligands (e.g. mitoxantrone) have broad cytotoxic effects on B cells, T cells, and macrophages. This suppresses the pathogenic immune response in MS with high efficacy but is also associated with high toxicity, limiting the long-term use of these agents. Monoclonal antibodies (e.g. natalizumab and alemtuzumab) are a new generation of immunosuppressants that act on immune-cell surface ligands. These agents have narrower immunosuppressive actions and different safety profiles compared with conventional immunosuppressants. Immunomodulators (interferon-beta and glatiramer acetate), which shift the immune balance toward an anti-inflammatory response, are at the frontline of treatments for MS. Immunomodulators have targeted actions on the immune system, but affect a greater number of immunopathogenic processes than monoclonal antibodies. Given the inherent heterogeneity of MS, such treatments, which act at many levels of the disease, may achieve the best clinical results. Using our understanding of the interplay between mechanism of action and clinical effects in MS therapies may help us to better design and select new treatments for the future.

Serum MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in multiple sclerosis: relationships with different magnetic resonance imaging measures of disease activity during IFN-beta-1a treatment

Matrix metalloproteinase-9 (MMP-9) is involved in blood-brain barrier (BBB) disruption in active multiple sclerosis (MS), while MMP-2 seems to be associated with the chronic progressive phase of the disease. Recombinant interferon beta-1a (rIFNbeta-1a) is effective in restoring the BBB. We studied the relationships between serum MMP-9, MMP-2, TIMP-1 and TIMP-2 and different magnetic resonance imaging (MRI) measures of disease activity in MS patients during treatment with rIFNbeta-1a. Twenty-one relapsing-remitting (RR) MS patients underwent longitudinally simultaneous blood withdrawals and MRI (before and after standard dose (SD) and triple dose (TD) of gadolinium (Gd)) examinations before and during 48 weeks of rIFNbeta-1a (Rebif 22 mcg three times a week) treatment. Serum MMP-9, MMP-2, TIMP-1 and TIMP-2 were measured, MMP-9 to TIMP-1 and MMP-2 to TIMP-2 ratios were calculated and the numbers of Gd-SD, Gd-TD, new-Gd-SD, new-Gd-TD and new-T2 lesions counted. Serum MMP-9/TIMP-1 ratio (P < 0.0001), as well as the numbers of 'active' lesions (P ranging from 0.0004 to 0.005) decreased during treatment Moreover, serum MMP-9/TIMP-1 ratio proved to be a good positive predictor (estimate = 0.85; P < 0.05) of the numbers of MRI Gd-TD active lesions. These data confirm that serum MMP-9/TMIP-1 ratio may be viewed as a reliable marker and may be predictive of MRI activity in RR MS.

Dopamine fails to regulate activation of peripheral blood lymphocytes from multiple sclerosis patients: effects of IFN-beta

The neurotransmitter dopamine counteracts T cell functions through its specific receptor subtype D5R but favors T cell proliferation and adhesion when acting on D3R. We found diminished mRNA and protein levels of D5R, but not of D3R, in peripheral blood mononuclear cells (PBMCs) from untreated multiple sclerosis (MS) patients. Dopamine reduced T cell proliferation, secretion of interferon-gamma (IFN-gamma), and production of matrix metalloproteinase-9 (MMP-9) mRNA in PBMCs from controls but not from MS patients. By contrast, reduced levels of D3R and renewed dopamine-associated regulatory functions were found in PBMCs from IFN-beta treated MS patients. Failure of the dopaminergic system of lymphocytes may lessen the threshold of T cell activation and sustain the pathogenic cascade of MS.

Lipoic acid in multiple sclerosis: a pilot study

Lipoic acid (LA) is an antioxidant that suppresses and treats an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis. The purpose of this study was to determine the pharmacokinetics (PK), tolerability and effects on matrix metalloproteinase-9 (MMP-9) and soluble intercellular adhesion molecule-1 (sICAMP-1) of oral LA in patients with MS. Thirty-seven MS subjects were randomly assigned to one of four groups: placebo, LA 600 mg twice a day, LA 1200 mg once a day and LA 1200 mg twice a day. Subjects took study capsules for 14 days. We found that subjects taking 1200 mg LA had substantially higher peak serum LA levels than those taking 600 mg and that peak levels varied considerably among subjects. We also found a significant negative correlation between peak serum LA levels and mean changes in serum MMP-9 levels (T = -0.263, P =0.04). There was a significant dose response relationship between LA and mean change in serum sICAM-1 levels (P =0.03). We conclude that oral LA is generally well tolerated and appears capable of reducing serum MMP-9 and sICAM-1 levels. LA may prove useful in treating MS by inhibiting MMP-9 activity and interfering with T-cell migration into the CNS.

The Role of Metalloproteinases in Corona Virus Infection

Infection with neurotropic strains of mouse hepatitis virus (MHV) results in rapid leukocyte infiltration into the central nervous system (CNS). The inflammatory response controls virus replication but fails to mediate sterile clearance. The persistence of viral RNA and inflammatory cells within the CNS is associated with the development of ongoing demyelination. Matrix metalloproteinases (MMPs) are a family of proteases involved in degradation of the extracellular matrix (ECM). During inflammatory responses MMPs are thought to play a significant role in breaking down the basement membrane surrounding blood vessels as well as parenchymal ECM thereby facilitating leukocyte infiltration. MMPs have also been associated with activation of chemokines and perhaps more significantly the degradation of myelin proteins and generation of autoantigens. Recent examination of MMP expression during MHV infection suggests that MMP-3, -9 and -12 are involved in the inflammatory response. The proinflammatory effects of these MMPs are likely tempered by induction of tissue inhibiter of metalloproteinase-1 expression.

ICAM G241A polymorphism and soluble ICAM-1 serum levels: evidence for an active immune process in schizophrenia

OBJECTIVES

We have previously reported reduced serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in schizophrenic patients. A single-nucleotide polymorphism (SNP) of the ICAM-1 gene was described at position 241. The G-->A SNP results in a nonsynonymous amino acid exchange of the ICAM-1 protein, and the A allele was shown to be also associated with several immunological disorders like rheumatoid arthritis.

METHODS

We investigated 70 schizophrenic patients and 128 unrelated healthy control persons regarding the relationship between the serum levels of sICAM-1 and the ICAM-1 G214A polymorphism.

RESULTS

We were able to replicate our previous finding of reduced sICAM-1 levels in schizophrenia. Healthy control persons carrying the polymorphic A allele showed markedly lower sICAM-1 serum levels than carriers of the homozygous GG wild type (p < 0.004). In contrast, no significant difference in the sICAM-1 serum levels were seen regarding the G241A genotype distribution in schizophrenic patients.

CONCLUSION

We hypothesize that the biochemical effect of the G241A SNP is masked in schizophrenic patients, indicating a disease-related mechanism leading to reduced levels of sICAM-1 in schizophrenia.