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.

[Targeting B cells in multiple sclerosis. Current concepts and strategies]

Multiple sclerosis (MS) is a chronic inflammatory demyelinating autoimmune disease of the CNS and a leading cause of lasting neurological disability in younger adults. In the last decade our knowledge of its immunopathogenesis expanded vastly. It is now widely appreciated that B cells are key players in the autoreactive immune network. They exert far more functions than merely being the precursors of antibody-producing plasma cells. B cells act as efficient antigen-presenting cells and may stimulate an autoreactive immune response through secretion of proinflammatory cytokines. It is thus only logical to test therapeutic strategies targeting B cells in MS. Rituximab is a depleting chimeric monoclonal antibody directed against CD20 and expressed on developing, naïve, and memory B cells but not stem or plasma cells. Several smaller studies have been conducted that led to a placebo controlled, double blind phase II study on efficacy which was reported recently. The results are very promising, meeting not only the primary endpoint of reduction of the surrogate MRI marker of contrast-enhancing lesions but also showing a reduction in clinical relapse rate of patients treated with rituximab. This review discusses the role of autoreactive B cells in the context of MS, analyzes the B-cell-depleting treatment studies reported, and provides information on planned and future B-cell-directed therapeutic strategies in MS.

[Choice of early and escalation treatment options for multiple sclerosis]

Recent advances in understanding of the immunopathogenesis of multiple sclerosis (MS) have led to the development of new treatment options. To date several immunomodulatory agents have been licensed for the treatment of relapsing-remitting MS. However, some debate remains on the optimal time point for initiating therapy. While there is general consensus on the benefit of an early treatment start, the issues of how to define "early MS" and how to identify patients with a "benign" disease course have not yet been finally addressed. Further open questions include the situations of treatment failure and therapeutic escalation. Here we summarize available data from studies on early treatment with immunomodulatory drugs for a first demyelinating event, also referred to as clinically isolated syndrome. Furthermore, options for the escalation of immunomodulatory therapy will be discussed, e.g. with the recently licensed monoclonal antibody natalizumab.

[Update on pathophysiologic and immunotherapeutic approaches for the treatment of multiple sclerosis]

Multiple sclerosis (MS) is a chronic disabling disease with significant implications for patients and society. The individual disease course is difficult to predict due to the heterogeneity of clinical presentation and of radiologic and pathologic findings. Although its etiology still remains unknown, the last decade has brought considerable understanding of the underlying pathophysiology of MS. In addition to its acceptance as a prototypic inflammatory autoimmune disorder, recent data reveal the importance of primary and secondary neurodegenerative mechanisms such as oligodendrocyte death, axonal loss, and ion channel dysfunction. The deepened understanding of its immunopathogenesis and the limited effectiveness of currently approved disease-modifying therapies have led to a tremendous number of trials investigating potential new drugs. Emerging treatments take into account the different immunopathological mechanisms and strategies, to protect against axonal damage and promote remyelination. This review provides a compilation of novel immunotherapeutic strategies and recently uncovered aspects of known immunotherapeutic agents. The pathogenetic rationale of these novel drugs for the treatment of MS and accompanying preclinical and clinical data are highlighted.

[Revision of McDonald's new diagnostic criteria for multiple sclerosis]

In 2001, an international panel suggested new diagnostic criteria for multiple sclerosis (MS). These criteria integrate clinical, imaging (MRI), and paraclinical results in order to facilitate diagnosis. Since then, these so-called McDonald criteria have been broadly accepted and widely propagated. In the meantime a number of publications have dealt with the sensitivity and specificity for MS diagnosis and with implementing these new criteria in clinical practice. Based on these empirical values and newer data on MS, an international expert group recently proposed a revision of the criteria. Substantial changes affect (1) MRI criteria for the dissemination of lesions over time, (2) the role of spinal cord lesions in the MRI and (3) diagnosis of primary progressive MS. In this article we present recent experiences with the McDonald and revised criteria.

Immunotherapeutic approaches in MS: update on pathophysiology and emerging agents or strategies 2006

Multiple sclerosis (MS) is a chronic disabling disease with significant implications for patients and society. The individual disease course is difficult to predict due to the heterogeneity of clinical presentation as well as radiological and pathological findings. Although its etiology still remains unknown, the last decade has generated considerable success in understanding the underlying pathophysiology of MS. In addition to its view as a prototypic inflammatory autoimmune disorder, recent data support the importance of primary and secondary neurodegenerative mechanisms such as oligodendrocyte death, axonal loss and ion channel dysfunction. The deepened understanding of the immunopathogenesis as well as the limited effectiveness of the currently approved disease modifying therapies have led to a tremendous number of trials investigating potentially new drug targets. Emerging treatments take into account the different immunopathological mechanisms as well as strategies to protect against axonal damage or to promote remyelination. This review provides a compilation of novel immunotherapeutic strategies or new aspects of known immunotherapeutic agents which have evolved recently. The pathogenetic rationale of these novel drug targets for the treatment of MS as well as accompanying preclinical and clinical data are highlighted.

Expression of CD28-related costimulatory molecule and its ligand in inflammatory neuropathies

BACKGROUND

Activation of effector T lymphocytes, mediated in part by costimulatory molecules, is an important mechanism in the pathogenesis of immune-mediated diseases of the peripheral nervous system (PNS).

OBJECTIVE

To analyze the expression and distribution pattern of the inducible costimulator (ICOS), a recently identified costimulatory molecule implicated in T-cell activation, and its unique ligand (ICOS-L), in inflammatory disorders of the PNS.

METHODS

We studied RNA and protein expression in sural nerve biopsy specimens from patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and vasculitic neuropathy (VN) vs patients with hereditary neuropathies (HNs) serving as a noninflammatory control using reverse-transcriptase PCR and immunohistochemistry. In addition, in vitro analysis was performed by flow cytometry.

RESULTS

ICOS and ICOS-L mRNA was found to be significantly upregulated in samples from patients with GBS, CIDP, and VN compared to HNs. Immunohistochemistry identified T lymphocytes as the cellular source of ICOS, whereas macrophages expressed the corresponding ligand ICOS-L. Further analysis revealed that the distribution of ICOS-expressing T cells did not differ between acute and chronic inflamed PNS diseases. Correspondingly, the expression pattern of ICOS-L was similar in the inflamed tissues but differed significantly when compared to HNs.

CONCLUSIONS

Inducible costimulator, expressed by T lymphocytes, and inducible costimulator ligand, expressed by macrophages within the peripheral nerve, might not only be relevant in inducing an acute immune response but might also be critically involved in perpetuating inflammation in chronically immune-mediated disorders of the peripheral nervous system.

[Plasma exchange as a therapeutic option in neurological disorders]

Plasma exchange is a therapeutic procedure commonly used in various neurological disorders. Here we review its current role as a treatment option in diseases of the central and peripheral nervous system.

[Acute disseminated encephalomyelitis. Pathogenesis, diagnosis, treatment, and prognosis]

Acute disseminated encephalomyelitis (ADEM) is typically a monophasic, demyelinating disease of the CNS that predominantly affects children. Typically, its clinical symptoms follow an infection or vaccination. In this regard, numerous viral and bacterial pathogens as well as several vaccinations have been associated with ADEM. Studies from animal models suggest that primary and secondary autoimmune responses may contribute to CNS inflammation and demyelination in ADEM. The diagnosis of ADEM is strongly suggested by a close temporal relationship between a viral infection or immunization and the onset of neurologic symptoms, and it is supported by extensive, multifocal, subcortical white-matter disease on brain magnetic resonance imaging. While mild lymphocytic pleocytosis and elevated proteins are detectable in the CSF in ADEM, oligoclonal bands are not always present. Treatment of this disorder consists of anti-inflammatory and immunosuppressive therapies, and the prognosis is generally considered favorable.

Blockade von Adhäsionsmolekülen mit Natalizumab in der Therapie der Multiplen Sklerose

Natalizumab is a humanized, monoclonal antibody, that inhibits adhesion molecules (alpha(4)-integrins) on the surface of immune cells. These adhesion molecules are important for binding of lymphocytes to endothelial cells of blood vessels and infiltration of inflammatory cells into tissues. Natalizumab is currently being tested in large clinical trials for the treatment of multiple sclerosis (MS) and other autoimmune diseases (inflammatory bowel diseases, rheumatoid arthritis). After demonstrating the safety and potential effectiveness of natalizumab in MS therapy during shorter treatment periods (</=6 months) in clinical phase I and II studies, two ongoing large, double-blinded, placebo-controlled phase III trials (named AFFIRM and SENTINEL) are evaluating its efficacy for patients with relapsing-remitting MS in respect to primary clinical endpoints (relapse rate, disease progression). Based a 1-year interim analysis of these studies, natalizumab was recently authorized by the U.S. Food and Drug Administration for treatment in reducing the frequency of clinical surges in multiple sclerosis, and an application was also made for its use in Europe. After more than 2 years of combined natalizumab (Tysabri) and interferon beta-1a (Avonex) therapy in the so-called Sentinel Study, there was one unexpected death and one appearance of progressive multifocal leukoencephalopathy. As a result, in February 2005 the manufacturers (Biogen/Elan) stopped all running studies of natalizumab and removed the drug from the market. New studies are underway to gain more understanding and especially to determine the risk to patients treated in the Sentinel Study. This article summarizes and updates the results of previous and ongoing natalizumab trials in the context of MS.

Statine zur Behandlung von Erkrankungen des zentralen Nervensystems

3-Hydroxy-3-methyglutaryl coenzyme A (HMG-CoA) reductase inhibitors, "statins," are widely used oral cholesterol-lowering drugs. Statins competitively inhibit HMG-CoA reductase, the enzyme that catalyzes conversion of HMG-CoA to L-mevalonate, a key intermediate in cholesterol synthesis. Certain metabolites of L-mevalonate are also involved in posttranslational modifications of specific proteins with cell proliferation and differentiation properties. Thus, statins have important biologic effects beyond their cholesterol-reducing properties. Here we discuss recent experimental and clinical data that may support a potential role for statins in the treatment of three central nervous system (CNS) neurological diseases: Multiple sclerosis (MS), Alzheimer's disease (AD), and ischemic stroke. Despite their considerable pathogenic differences, in animal models of these disorders statins have shown beneficial effects. In both stroke and AD cohort studies suggest a beneficial treatment effect in humans; in MS, results from small open-label studies look encouraging. Multicenter, randomized, placebo-controlled clinical trials are in the planning or recruiting stage to evaluate the therapeutic effects of statins in all three disorders.

[Multiple sclerosis: potential therapeutic options and update of ongoing studies]

The therapeutic options for the treatment of multiple sclerosis (MS) have experienced enormous progress over recent years. Despite these encouraging developments, available therapies are only partially effective, and the ultimate goal of curing MS is still far from being attained. The improved understanding of the cellular and molecular mechanisms of MS (immune) pathogenesis together with recent shifts in paradigms led to a variety of new therapeutic targets and approaches. In addition to modulation of the inflammatory process, therapeutic approaches focussing on active neuroprotection, remyelinization, and regeneration have become increasingly important. Based on current concepts of the MS pathogenesis, this article summarizes new therapeutic approaches. Substances and strategies currently tested in clinical trials are reviewed.

Jean-Martin Charcot im Spiegel der deutschen Nervenheilkunde

Jean-Martin Charcot (1825-1893), well known as the founder of modern neurology, was the most celebrated neurologist in the nineteenth century. His international success stemmed not only from mastery descriptions of various neurological disorders but also from his many contacts with scientists all over the world. The aim of this article is to review Charcot's ambivalent relationship to German neuropsychiatry of the time and to examine the German reception of his personality and work. Wilhelm Erb, Ludwig Hirt, Ernst von Leyden, Max Nonne, Adolph Strümpell, and other German physicians cultivated -to varying degrees - professional contacts with Charcot and, based on the fascination of his personality and significance of his work, were long and intensively influenced by the Salpêtrière school. The extent of their admiration became apparent in 1882 by the award of an honorary doctorate to Charcot by the University of Würzburg. Along with increasingly severe criticism of Charcot's research on hysteria and hypnosis, most German neuropsychiatrists became estranged, without neglecting his importance to the development of neurology in Germany.

Mitoxantron zur Therapie der Multiplen Sklerose

The recent publication of the MIMS study (Mitoxantrone in multiple sclerosis), approval by local health authorities, and the recommendation by the MS Therapy Consensus Group (MSTCG) support the use of mitoxantrone in patients with active multiple sclerosis. This review provides an outline of relevant preclinical and clinical studies, discusses relevant side effects of the compound, and compares its use with other therapeutic approaches to this crippling disorder.