High-resolution wide-field surface plasmon microscopy.

This paper describes the application of a Köhler illuminated high-resolution wide-field microscope using surface plasmons to provide the image contrast. The response of the microscope to a grating structure in both the Fourier and the image planes is presented to demonstrate image formation by surface waves. The effect of spatial filtering in the back focal (Fourier) plane to enhance image contrast is described. We also discuss how the surface wave contrast mechanism affects the imaging performance of the microscope and discuss factors that can be expected to lead to even greater improvements in lateral resolution and sensitivity.

IFN-beta1a may increase serum levels of TIMP-1 in patients with relapsing-remitting multiple sclerosis.

Serum levels of matrix metalloprotease-9 (MMP-9) and tissue inhibitor of MMP-1 (TIMP-1) were measured monthly in 7 patients with relapsing-remitting multiple sclerosis (MS) 6 months before and 6 months during treatment with weekly intramuscular (i.m.) injections of interferon-beta1a (IFN-beta1a) 30 microg. Within-patient median MMP-9 levels were unchanged on treatment. Within-patient median TIMP-1 levels were higher during months 1-6 (771.5 ng/ml) and during months 4, 5, and 6 of treatment (793 ng/ml) compared with 6 months pretreatment (414 ng/ml) (respectively, p = 0.10, p = 0.047; Wilcoxon signed-rank test). These preliminary data suggest that IFN-beta1a therapy may increase TIMP-1 levels.

Serum MMP-9 and TIMP-1 levels are related to MRI activity in relapsing multiple sclerosis.

OBJECTIVE: To 1) compare monthly serum levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of MMP-type 1 (TIMP-1) in patients with relapsing-remitting MS (RRMS) versus healthy controls and 2) determine the relationship among monthly serum levels of MMP-9 and TIMP-1 and MRI activity. BACKGROUND: Activated T-cells and macrophages secrete MMPs that may facilitate their migration across vascular subendothelial basement membranes into the CNS. The serum concentration of MMP-9 is reported to be higher in patients with RRMS than healthy controls. METHODS: Monthly evaluations including gadolinium-enhanced (Gd+) brain MRI and measures of serum MMP-9 and TIMP-1 were performed for up to 15 months in 24 patients with RRMS and for up to 4 months in 10 controls. RESULTS: Serum MMP-9 but not TIMP-1 levels are elevated in RRMS patients compared to healthy controls (p = 0.025, p = 0.61). In a univariate analysis, high MMP-9 and low TIMP-1 levels precede appearance of new Gd+ lesions (respectively; odds ratio = 3.3, p = 0.008; odds ratio = 2.2, p = 0.086). In a multivariate analysis, in comparison to months when MMP-9 is low and TIMP-1 high, MRI scans obtained the month following high MMP-9 and low TIMP-1 serum concentrations are more likely to report new Gd+ lesions (p = 0.0006, odds ratio = 21.5). CONCLUSION: An increase in the activity of matrix metalloproteinase-9 (MMP-9) relative to tissue inhibitor of MMP-type 1 (TIMP-1) may be related to formation of new MS lesions, suggesting that serum levels of MMP-9 and TIMP-1 may be surrogate markers of disease activity in relapsing-remitting MS.

Serum gelatinase B, TIMP-1 and TIMP-2 levels in multiple sclerosis. A longitudinal clinical and MRI study.

Metalloproteinases have been implicated in the pathogenesis of multiple sclerosis. We report longitudinal serum levels of gelatinase B and of the tissue inhibitors of matrix metalloproteinases (TIMP), TIMP-1 and TIMP-2, in 21 patients with relapsing multiple sclerosis. Patients had monthly clinical and gadolinium-enhanced MRI follow-up for 10 months. Longitudinal samples in nine healthy controls and cross-sectional samples from 12 patients with inflammatory CNS disease and 15 patients with other neurological diseases were used for comparison. Average serum gelatinase B, TIMP-1 and TIMP-2 levels were significantly higher in multiple sclerosis patients and those with other neurological diseases than in healthy controls. In the patients with multiple sclerosis, gelatinase B levels were significantly higher during clinical relapse compared with periods of clinical stability. Multiple sclerosis patients with high mean serum gelatinase B levels had significantly more T1-weighted gadolinium-enhancing MRI lesions than those with mean levels within the control range. TIMP-1 levels were not different during relapse and between relapses. There was a trend for TIMP-2 levels to be lower during relapse compared with non-relapse periods. For similar levels of serum gelatinase B, associated TIMP-1 levels were significantly lower and TIMP-2 levels significantly higher in multiple sclerosis patients compared with the inflammatory CNS control group. We propose that an abnormality in the inhibitory response to metalloproteinases may play an aetiological role in the chronicity of multiple sclerosis.

Matrix metalloproteinase-9 (gelatinase B) is selectively elevated in CSF during relapses and stable phases of multiple sclerosis.

Matrix metalloproteinases (MMPs) are a family of endopeptidases capable of enzymatic digestion of subendothelial basement membrane and other components of the extracellular matrix. Expression of MMP-2, -3, -7 and -9 is increased around multiple sclerosis plaques and in brain tissue in experimental allergic encephalomyelitis. To measure quantitatively the expression of these MMPs and their endogenous inhibitors (TIMP-1 and -2), we analysed samples from 52 patients with relapsing-remitting and primary progressive multiple sclerosis by ELISA (enzyme-linked immunosorbent assay) and substrate-gel electrophoresis (zymography). MMP-9 was increased over controls in 100% of relapsing-remitting multiple sclerosis cases, with similar levels detected in relapses and clinically stable phases of disease. In primary progressive multiple sclerosis, MMP-9 was increased in 57% of CSF samples, but concentrations were below those encountered in the relapsing-remitting form. The selective upregulation of MMP-9 suggests that T-cells and macrophages invading the brain parenchyma and the CSF space are the predominant source of MMP-9 in multiple sclerosis. TIMPs and other MMPs (MMP-2 and -3) were not upregulated or not detectable (MMP-7) in CSF of patients with relapsing-remitting and primary progressive multiple sclerosis. The sustained increase of MMP-9 in clinically stable multiple sclerosis supports the concept that multiple sclerosis is associated with ongoing proteolysis that may result in progressive tissue damage. The selective inhibition of MMP-9 could be a useful approach for the prevention of disease progression in multiple sclerosis.

Matrix metalloproteinase expression during experimental autoimmune encephalomyelitis and effects of a combined matrix metalloproteinase and tumour necrosis factor-alpha inhibitor.

Matrix metalloproteinases (MMPs) are a large family of Zn2+ endopeptidases that are expressed in inflammatory conditions and are capable of degrading connective tissue macromolecules. MMP-like enzymes are also involved in the processing of a variety of cell surface molecules including the pro-inflammatory cytokine TNF-alpha. MMPs and TNF-alpha have both been implicated in the pathology associated with neuro-inflammatory diseases (NIDs), particularly multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). We have shown that BB-1101, a broad spectrum hydroxamic acid-based combined inhibitor of MMP activity and TNF processing, reduces the clinical signs and weight loss in an acute EAE model in Lewis rats. However, little is known about which MMPs are involved in the neuroinflammatory process. In order to determine the optimum inhibitory profile for an MMP inhibitor in the treatment of NID, we investigated the profile of MMP expression and activity during EAE. The development of disease symptoms was associated with a 3-fold increase in MMP activity in the cerebrospinal fluid (CSF), which could be inhibited by treatment with BB-1101, and an increase in 92 kDa gelatinase activity detected by gelatin substrate zymography. Quantitative PCR analysis of normal and EAE spinal cord revealed the expression of at least seven MMPs. Of these, matrilysin showed the most significant change, being elevated over 500 fold with onset of clinical symptoms and peaking at maximum disease severity. Of the other six MMPs detected, 92 kDa gelatinase showed a modest 5 fold increase which peaked at the onset of clinical signs and then declined during the most severe phase of the disease. Matrilysin was localised by immunohistochemistry to the invading macrophages within the inflammatory lesions of the spinal cord. Matrilysin's potent broad spectrum proteolytic activity and its localisation to inflammatory lesions in the CNS suggest this enzyme could be particularly involved in the pathological processes associated with neuro-inflammatory disease.