Soluble and catalytically active endothelin converting enzyme-1 is present in cerebrospinal fluid of subarachnoid hemorrhage patients.

Endothelin converting Enzyme-1 (ECE-1) is essential for the production of Endothelin-1 (ET-1), which is associated with vasospasm following subarachnoid hemorrhage (SAH). We have previously demonstrated the presence of a catalytically active soluble form of ECE-1 in the media of endothelial cells. We aimed to determine if this form of ECE-1 exists in vivo, in cerebrospinal fluid (CSF) of SAH patients. We examined CSF taken from SAH subjects for the presence of soluble ECE-1 using a bradykinin based quenched fluorescent substrate assay. We obtained further confirmation by characterizing the CSF mediated cleavage products of BigET-1 and BigET18₋34 (6 µg/ml) using mass spectrometry. The specificity of cleavage was confirmed using the ECE-1 inhibitor CGS35066 5 nmol/L. SAH CSF samples had mean ECE-1 activity of 0.127 ± 0.037 µmols of substrate cleaved/µl of CSF/24 h. The C-terminal peptides generated upon the cleavage of BigET-1 and BigET18₋34 were detected 48 h after incubation of these substrates with CSF. Cleavage of these substrates was inhibited by CGS35066. Results of Western blots also produced strong evidence for the presence of truncated soluble ECE-1 in CSF. These results strongly suggest the presence of a truncated but catalytically active form of ECE-1 in the CSF of SAH subjects. Further studies are necessary to determine the biological significance of soluble ECE-1 in CSF of SAH subjects, including an association with vasospasm after SAH.

Cerebrospinal fluid proteomic analysis reveals dysregulation of methionine aminopeptidase-2 expression in human and mouse neurofibromatosis 1-associated glioma.

Individuals affected with the neurofibromatosis 1 (NF1) tumor predisposition syndrome are prone to the development of multiple nervous system tumors, including optic pathway gliomas (OPG). The NF1 tumor suppressor gene product, neurofibromin, functions as a Ras GTPase-activating protein, and has been proposed to regulate cell growth by inhibiting Ras activity. Recent studies from our laboratory have shown that neurofibromin also regulates the mammalian target of rapamycin activity in a Ras-dependent fashion, and that the rapamycin-mediated mammalian target of rapamycin inhibition ameliorates the Nf1-/- astrocyte growth advantage. Moreover, Nf1-deficient astrocytes exhibit increased protein translation. As part of a larger effort to identify protein markers for NF1-associated astrocytomas that could be exploited for therapeutic drug design, we did an objective proteomic analysis of the cerebrospinal fluid from genetically engineered Nf1 mice with optic glioma. One of the proteins found to be increased in the cerebrospinal fluid of OPG-bearing mice was the eukaryotic initiation factor-2alpha binding protein, methionine aminopeptidase 2 (MetAP2). In this study, we show that Nf1 mouse OPGs and NF1-associated human astrocytic tumors, but not sporadic pilocytic or other low-grade astrocytomas, specifically expressed high levels of MetAP2. In addition, we show that Nf1-deficient astrocytes overexpress MetAP2 in vitro and in vivo, and that treatment with the MetAP2 inhibitor fumagillin significantly reduces Nf1-/- astrocyte proliferation in vitro. These observations suggest that MetAP2 is regulated by neurofibromin, and that MetAP2 inhibitors could be potentially employed to treat NF1-associated tumor proliferation.

Cerebrospinal fluid biomarkers in experimental spinal nerve root injury.

STUDY DESIGN: Cerebrospinal fluid biomarkers were evaluated in a setup using established pig models to mimic clinical disc herniation. OBJECTIVES: To investigate biomarkers for nerve tissue injury, inflammation, and pain in cerebrospinal fluid after mechanical compression and/or nucleus pulposus application to spinal nerve roots. SUMMARY OF BACKGROUND DATA: The association between mechanical compression, biochemical effects of nucleus pulposus, and nerve root injury in degenerative disc disorders is incompletely investigated. METHODS: The unilateral S1 nerve root was exposed in 20 pigs. The animals were divided into four groups (n = 5 each): 1) slow-onset mechanical compression with an ameroid constrictor; 2) autologous nucleus pulposus application; 3) mechanical compression plus nucleus pulposus; and 4) sham operation. After 1 week, 6 mL of cerebrospinal fluid was collected, and four structural nerve proteins, neurofilaments, S-100, glial fibrillary acidic protein, neuron-specific enolase, the proinflammatory cytokine interleukin-8, the neurotransmitter nociceptin, and substance P endopeptidase activity were analyzed using immunoassays. RESULTS: The concentration of neurofilament was increased in the mechanical compression group (17.0 microg/L +/- 5.0) and in the mechanical compression plus nucleus pulposus group (19.8 +/- 12.1 microg/L) compared with the sham group (0.9 +/- 0.9 microg/L) and the nucleus pulposus group (0.4 +/- 0.1 microg/L) (P < 0.01 for both). The concentration of nociceptin was increased significantly in the mechanical compression group (24.0 +/- 8.6 fm/mL) and in the mechanical compression plus nucleus pulposus group (31.2 +/- 6.6 fm/mL) compared with the sham group (7.0 +/- 1.3 fm/mL) (P < 0.05 and P < 0.01, respectively). A correlation was found between concentrations of neurofilament and nociceptin (r = 0.50, P < 0.05). There were no intergroup differences regarding glial fibrillary acidic protein, neuron-specific enolase, S-100, interleukin-8, or substance P endopeptidase activity. CONCLUSIONS: The present study demonstrates increased concentrations of neurofilament and nociceptin in cerebrospinal fluid after nerve root compression. A simultaneous application of nucleus pulposus did not increase the response.

Regulators of the neuropeptide-degrading enzyme, EC 3.4.24.15 (thimet oligopeptidase), in cerebrospinal fluid.

Endopeptidase EC 3.4.24.15 (EP 24.15; thimet oligopeptidase) is a soluble metalloendopeptidase implicated in the metabolism of a number of neuropeptides, including neurotensin, gonadotropin-releasing hormone, and opioid peptides. We have shown previously that thiol reducing agents, such as dithiothreitol, activate EP 24.15 by mediating the conversion of inactive multimeric forms to active monomers and that this conversion involves the disruption of intermolecular disulfide bonds involving cysteine residues 246, 248, and 253. We have identified two components of cerebrospinal fluid that activate recombinant EP 24.15, but have no effect on a thiol-independent cysteine mutant form of the enzyme. The low molecular weight (<10 kDa) component co-elutes with glutathione by reversed-phase HPLC, whereas the high molecular weight component (>50 kDa) is sensitive to digestion with trypsin, suggesting it is proteinaceous in nature. These results suggest that EP 24.15 activity in the brain may be modulated by factors released into cerebrospinal fluid.

ADAM-10 and ADAM-17 in the inflamed human CNS.

Inflammatory demyelinating disorders of the CNS, such as multiple sclerosis (MS), are mediated, at least in part, by various cytokines and proteases. In the present study, we investigated the expression of A disintegrin and metalloproteinase (ADAM)-17, an important sheddase for various proteins, including tumor necrosis factor-alpha (TNF-alpha), and the p75- and p55-TNF receptors, as well as ADAM-10, a protease implicated in myelin degradation, in post mortem CNS tissue samples from patients with MS, and normal brain tissue (as control) by immunohistochemistry. ADAM-10 was found to be expressed by astrocytes in all MS and control sections studied; however, in some MS sections, perivascular macrophages were determined as an additional cellular source as well. ADAM-17 could be observed exclusively in acute and chronic active MS plaques and localized to invading T lymphocytes. The staining pattern of ADAM-17 in MS plaques was mirrored in distribution and extent by the pattern obtained with an antibody against the p75-TNF-receptor (TNFR-2), whereas TNF-alpha was found to be expressed primarily by perivascular macrophages. In studying cerebrospinal fluid (CSF) samples from MS patients, we were able to detect increased protein levels of ADAM-17 as compared with noninflammatory controls. In addition, increased levels of soluble TNFR-2 could be measured, suggestive of an active shedding process mediated by ADAM-17. The stimulation of peripheral blood mononuclear cells (PBMC) obtained from MS patients and healthy individuals corroborated these findings by revealing expression of ADAM-17 by T lymphocytes and ADAM-10 by macrophages in vitro. Our results indicate that ADAM-10 is expressed constitutively by astrocytes in the normal and inflamed human CNS. In contrast, under inflammatory conditions, ADAM-10, expressed by perivascular macrophages, and ADAM-17, expressed by invading T cells, may actively contribute to the pathogenesis of inflammatory disorders of the CNS.

[alpha]-Secretase ADAM10 as well as [alpha]APPs is reduced in platelets and CSF of Alzheimer disease patients.

BACKGROUND: Members of membrane-bound disintegrin metalloproteinases (ADAMs) were shown to be capable of cleaving amyloid precursor protein (APP) at the alpha-cleavage site in different cell systems. One of the candidate alpha-secretases identified in this family is ADAM10. The present study addresses the following major questions: 1) Are the levels of an alpha-secretase candidate (i.e., ADAM10) reduced in accessible cells of Alzheimer Disease (AD) patients? 2) Are ADAM10 levels in the peripheral cells of AD patients related to a concomitant decrease in alpha APPs? MATERIALS AND METHODS: Western Blot analysis of ADAM10 is performed on platelet homogenates from 33 sporadic AD patients and on 26 age-matched control subjects. Moreover, the levels of alpha-secretase metabolite (alpha APPs) are tested both in platelets and cerebrospinal fluid (CSF) of the same pool of subjects by means of Western blot with a specific antibody. RESULTS: A significant decrease of platelet ADAM10 levels is observed in patients affected by probable AD when compared to control subjects and this is paralleled by a reduced level of alpha APPs released from platelets. Moreover, in the same pool of AD patients, alpha APPs levels were reduced concomitantly in CSF. CONCLUSIONS: ADAM10 is expressed in platelets. A reduced level of ADAM10 is observed in platelets obtained from AD patients compared to age-matched controls. Further, in the same pool of AD patients, a qualitatively and quantitatively similar decrease in alpha APPs is present both in thrombin-activated platelets and CSF, thus suggesting that alterations of APP processing might occur both in the neuronal compartment and peripheral cells.

Neuropeptidases regulating gonadal function.

The generation and metabolism of bioactive peptides involves a series of highly ordered proteolytic events. This post-translational processing can occur either within the cell, at the cell surface or after secretion. In the central nervous system a number of extracellular peptidases have been implicated in the regulated processing of peptides, particularly in the regulation of neuroendocrine function. The aim of this study has been to identify the peptidases involved in the metabolism of gonadotropin-releasing hormone (GnRH) and to characterize the factors and the mechanisms by which the activity of these peptidases are regulated. We have shown that both prolylendopeptidase and the thimet oligopeptidase EC 3.4. 24.15 are involved in GnRH metabolism and that both oestrogen and thiol-based reductants could be involved in the physiological regulation of their activities.

Incremento de la actividad metaloproteinásica y de sus inhibidores en el líquido cefalorraquídeo, en pacientes con paraparesia espástica tropical / Increased activity of matrix metalloproteinases and their tissue inhibitors in cerebrospinal fluid of patients with HTLV-1 associated tropical spastic paraparesis

Background: Proteolytic modifications of neuronal surfaces and the surrounding extracellular matrix are very important in neuronal development and regeneration. Increased activity of matrix metalloproteinases (MMPs) and their tissue inhibitors, due to secretion by macrophages and lymphocytes, occur in inflammatory processes that disrupt the blood brain barrier. However, neurons and microglia can also secrete these enzymes. Aim: To identify the type of MMP present in the cerebrospinal fluid (CSF) and changes in the expression of tissue inhibitors of metalloproteinases (TIMPs) in patients with HTLV-1 associated tropical spastic paraparesis. Patients and methods: CSF samples from 12 patients with HTLV-1 associated tropical spastic paraparesis and 12 healthy controls were obtained by an atraumatic lumbar puncture. The presence of MMPs was measured by zymography and the relative amounts of TIMPs were measured by immunowestern blot. Results: In the CSF of both controls and patients, a similar gelatinolytic band corresponding to proMMP-2 (latent form) was observed. In 83.3 percent of patients with HTLV 1 associated tropical spastic paraparesis, the MMP-9 was also present. TIMP-1, TIMP-2 and TIMP-3 were elevated 2.24 ñ 0.72, 3.85 ñ 1.38 and 5.89 ñ 3.4 fold, respectively, in the CSF of patients as compared to controls. Conclusions: Patients with HTLV-1 associated tropical spastic paraparesis have elevated activity of MMP-9 and levels of TIMPs in the CSF, when compared to healthy controls

Cerebrospinal fluid levels of MMP-2, 7, and 9 are elevated in association with human immunodeficiency virus dementia.

Pathological evidence suggests that alterations of the blood-brain barrier (BBB) may occur in association with human immunodeficiency virus (HIV) dementia (HIVD). Increased BBB permeability could contribute to the development of dementia by facilitating the entry of activated and infected monocytes, as well as potentially toxic serum proteins, into the central nervous system. One mechanism by which BBB permeability may be altered is through increased activity of select matrix metalloproteinases (MMPs). In the present study, we examined the possibility that MMPs that target critical BBB proteins, including laminin, entactin, and collagen type IV, are elevated in the cerebrospinal fluid (CSF) of patients with HIVD. We also examined the possibility that such MMPs could be produced by brain-derived cells, and that MMP production by these cells might be increased by tumor necrosis factor-alpha, an inflammatory cytokine that is produced by HIV-infected monocytes/microglia and is elevated in HIVD. By using western blot and enzyme-linked immunosorbent assay, we observed that CSF levels of pro-MMP-2 and pro-MMP-7 were increased in association with HIVD. In addition, through the use of gelatin substrate zymography, a sensitive functional assay for MMP-2 and MMP-9, we observed that MMP-2 or pro-MMP-9 activity was more frequently detectable in the CSF of individuals with HIV dementia (9/16) than in the CSF from either nondemented seropositive (2/11) or seronegative (0/11) controls. Although the presence of MMPs in the serum could contribute to elevated levels in the CSF, we also show that brain-derived cells release MMP-2, 7, and 9, and that such release is increased after their stimulation with tumor necrosis factor-alpha. Together, these results suggest that elevated CSF levels of select MMPs may reflect immune activation within the central nervous system. They also suggest that further studies may be warranted to determine whether these proteins may play a role in the development of symptomatic neurological disease.

Differential expression of matrix metalloproteinases in bacterial meningitis.

Matrix metalloproteinases (MMPs) are implicated in the pathogenesis of various inflammatory diseases of the central nervous system. Evidence is accumulating that gelatinase B (MMP-9) might be involved in the pathogenesis of meningitis, but the spectrum of different MMPs involved in the inflammatory reaction of this disease has not been determined. We investigated the temporal and spatial mRNA expression pattern of gelatinase B in experimental meningococcal meningitis in rats. In contrast to controls, increased mRNA levels with peak values 6 h after injection with menigococci were found in brain specimens of the animals. Elevated MMP-9 mRNA expression was accompanied by enhanced proteolytic activity, as demonstrated by gelatin zymography, and positive immunoreactivity. The mRNA expression pattern of six other MMPs was investigated. Collagenase-3 and stromelysin-1 mRNAs were also found to be upregulated. In contrast, mRNA levels for gelatinase A, matrilysin, stromelysin-2 and stromelysin-3 remained unchanged. As evidenced by significantly increased intracranial pressure and by leakage of intravenously injected Evans blue through the blood vessel walls into the brain parenchyma, the animals injected with meningococci revealed signs of blood-brain barrier disruption. Augmented proteolytic activity of MMP-9 could also be demonstrated in CSF samples obtained from patients with bacterial meningitis, underlining the clinical relevance of our experimental findings. Our data indicate that gelatinase B, collagenase-3 and stromelysin-1 are selectively upregulated in bacterial meningitis and thus may contribute to the pathogenesis of this infectious disease of the central nervous system.

Experimental pneumococcal meningitis in rabbits: the increase of matrix metalloproteinase-9 in cerebrospinal fluid correlates with leucocyte invasion.

Gelatinolytic activity of matrix metalloproteinases (MMPs), particularly MMP-9 and MMP-2, was studied by quantitative zymography in a rabbit model of bacterial meningitis during 24 h after inoculation with Streptococcus pneumoniae. In cerebrospinal fluid (CSF), MMP-2 was constitutively present and its level did not change during the experiment. In contrast, MMP-9, hardly detectable in CSF of healthy animals, increased dramatically. The increase of MMP-9 was correlated with both, an increase of CSF cell count and of total protein concentration. Intrathecal production of MMP-9 and MMP-2 was demonstrated by zymography of equal amounts of total protein from CSF and serum. Homogenates, prepared from various cortical regions of infected rabbits did not show increase of MMP activities. On the other hand, leucocytes isolated from CSF expressed high levels of MMP-9 suggesting a significant contribution of these cells to the elevation of MMP-9 activity in this body fluid.

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in HTLV-I-associated myelopathy.

Matrix metalloproteinases (MMPs) have been reported to be involved in inflammatory disorders of the central nervous system (CNS). However, little is known about the role of MMPs in the pathogenesis of HTLV-I-associated myelopathy (HAM)/Tropical spastic paraparesis (TSP). To address this issue, we examined the tissue expression and localization of MMPs and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs) in the spinal cord lesions of HAM/TSP using immunohistochemistry. In addition, the blood and cerebrospinal fluid (CSF) levels of MMPs and TIMPs of the patients with HAM/TSP were determined using sandwich enzyme immunoassays (SIA) and gelatin zymography. Immunohistochemical studies revealed that collagen IV and decorin immunoreactivity on the basement membrane of CNS parenchymal vessels was partially disrupted where inflammatory mononuclear cells infiltrated in active-chronic lesions of HAM/TSP. In these lesions, MMP-2 (gelatinase A) was immunostained mainly on the surface of foamy macrophages and lymphocytes, whereas MMP-9 (gelatinase B) expression was positive in the intravascular and perivascular mononuclear cells but not on foamy macrophages. In contrast, inactive chronic lesions of the spinal cords of the HAM/TSP contained fewer MMP-2-positive or MMP-9-positive mononuclear cells than active-chronic lesions. Many parenchymal vessels had thickened vascular walls which showed increased immunoreactivity to decorin. SIA revealed that production levels of MMP-2 and MMP-9 in both blood and CSF were higher in the patients with HAM/TSP than those in non-inflammatory other neurological disease controls (ONDs). Using zymography, proMMP-9 was detected more frequently in the CSF of patients with HAM/TSP than those in ONDs. Taken together, our data indicate that MMP-2 and MMP-9 may play an important role in the blood-brain barrier breakdown and tissue remodeling in the CNS of HAM/TSP.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in viral meningitis: upregulation of MMP-9 and TIMP-1 in cerebrospinal fluid.

A hallmark of viral meningitis is the invasion of monocytes, lymphocytes and, in the initial phase of the disease, neutrophils into the subarachnoidal space. By their degradation of different macromolecular components in the extracellular connective tissue, matrix metalloproteinases (MMPs) may be essential for the breakdown of the vessel wall in the meninges and the choroid plexus. In this study, the occurrence of MMP-1, MMP-2, MMP-3 and MMP-9 and the two tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2, was monitored in the cerebrospinal fluid (CSF) from patients with viral meningitis. Of the proteinases, MMP-9 was found in 13 of 39 (33%) patients, but not in controls; the levels being correlated with the neutrophil cell number in CSF. The CSF concentration of TIMP-1 was increased three-fold compared to the control group (median 233 ng/ml; range 9.4-1252.5 ng/ml) and was correlated to the levels of total protein in CSF. Of the other MMPs and TIMPs assayed, MMP-2 and TIMP-2 were constitutively expressed and not upregulated in viral meningitis. High levels of MMP-9 and MMP-2, as measured by ELISA, was associated with high proteolytic activity detected in CSF by zymography. In conclusion, invasion of the leukocytes into the CSF compartment in viral meningitis may involve MMP-9, its proteolytic effect likely being controlled by expression of TIMP-1.

Specific matrix metalloproteinase profiles in the cerebrospinal fluid correlated with the presence of malignant astrocytomas, brain metastases, and carcinomatous meningitis.

BACKGROUND: Detection in tumor tissue of specific matrix metalloproteinases (MMPs), particularly gelatinases A and B, correlates with the grade and aggressiveness of primary and metastatic brain tumors. The ability to detect these enzymes in the cerebrospinal fluid (CSF) would be a minimally invasive method of evaluating brain tumors. METHODS: CSF from 66 patients with white blood cell counts of < or = 5 microL were analyzed for the presence of gelatinolytic activity by zymography. Twenty-nine patients had malignant astrocytomas, 10 had brain metastases from systemic malignancies, 4 had systemic cancer not involving the central nervous system, 4 had nonmalignant neurologic diseases, and 19 were healthy controls. Fifteen CSF samples had positive cytologies. The zymographic results were retrospectively correlated with clinical information and CSF cytologic data. RESULTS: CSF from all patients with malignant astrocytomas or brain metastases contained precursor gelatinase A (pMMP2) and precursor gelatinase B (pMMP9), whereas control CSF contained only pMMP2. All patients with positive CSF cytologies had activated MMP2. A similar correlation was observed between the presence of activated MMP9 and positive CSF cytology. CONCLUSIONS: The precursor and activated forms of gelatinases A and B can be detected in the CSF of patients with primary and metastatic brain tumors. The distribution of gelatinase activity in CSF distinguishes patients with malignant gliomas or brain metastases from those without brain tumors, and distinguishes patients with meningeal carcinomatosis from those without CSF spread of tumor, regardless of their brain tumor status. Analysis of MMPs in the CSF may be a sensitive technique for diagnosing CNS tumors and provide an early indication of tumor recurrence. This technique may also provide longitudinal information that would be useful in evaluating ongoing treatment and predicting tumor behavior.

Matrix metalloproteinases in the cerebrospinal fluid of patients with Lyme neuroborreliosis.

Neurologic manifestations of Lyme disease include meningitis, encephalopathy, and cranial and peripheral neuropathy. There are no sensitive markers for neuroborreliosis, and diagnosis is often based on clinical presentation and cerebrospinal fluid (CSF) abnormalities, including intrathecal antibody production. Matrix metalloproteinase (MMP) activity in CSF was compared in patients with neuroborreliosis, patients with diverse neurologic disorders, and healthy controls. The CSF of 17 of 18 healthy subjects and 33 of 37 patients with neurologic symptoms and normal CSF and imaging studies contained only MMP2. The CSF of several patients with neurologic disorders contained MMP2, MMP9, and gelatinolytic activity at 130 and 250 kDa. The 130-kDa MMP was found without the 92-kDa MMP9 in the CSF of 11 (79%) of 14 patients with neuroborreliosis and only 7 (6%) of 118 control patients (P < .001). This pattern of CSF gelatinase activity may be a useful marker for neuroborreliosis.

Purification of substance P endopeptidase (SPE) activity in human spinal cord and subsequent comparative studies with SPE in cerebrospinal fluid and with chymotrypsin.

An enzyme activity capable of hydrolysing the neuroactive undecapeptide substance P (SP) between its Phe7-Phe8 residues was purified from the membrane-bound fraction of human spinal cords. The enzyme preparation yielded was compared with a previously described SP-hydrolysing enzyme from human cerebrospinal fluid (CSF) with regard to inhibition profile, protein chemical properties and kinetics. In addition, the results were compared with those of bovine pancreatic chymotrypsin (a serine protease that cleaves the carboxy-terminal side preferentially at hydrophobic amino acids). The SP peptidase activity was extracted from human spinal cords with 1% Triton X-100 in 20 mM Tris-HCI pH 7.8. After ion exchange chromatography (DEAE-Sepharose) where the enzyme activity was separated from other proteins by gradient elution, the pooled enzyme fraction was further purified by molecular sieving (Sephadex G-50). The enzyme activity was finally recovered by HPLC molecular sieving (Superdex 75 HR 10/30) using a new preparative system, AKTA-purifier, controlled by UNICORN software version 2.20.

Elevated cerebrospinal fluid level of substance P and decreased undecapeptidase activity at term pregnancy.

This paper reports a study of substance P and its converting enzyme substance P endopeptidase (SPE) in cerebrospinal fluid (CSF) collected from women at term pregnancy. A method was developed to assess the CSF levels of substance P itself with minimum contribution from prestages or fragments of the undecapetide. The measured activity was compared with that detected in CSF from control, non-pregnant, non-puerperal women. The result indicates a significant increase in substance P-like immunoreactivity at term pregnancy (19.9 +/- 3.9 fmol/ml, n = 10) compared with that of control subjects (12.3 +/- 2.8 fmol/ml, n = 9; P < 0.001). This elevation was suggested to reflect an increased activity in spinal sensory neurons at this stage of pregnancy. The activity of SPE was assessed by measuring the product substance P1-7 by a radioimmunoassay specific for this fragment. It was found that the enzyme activity was significantly decreased in CSF from pregnant women (11.2 +/- 0.71 pmol/h.ml), compared with control samples (18.4 +/- 0.73 pmol/h.ml; P < 0.05). Moreover, a significant negative correlation was found to exist between the level of substance P and the activity of SPE (P < 0.05, r2 = 0.65), suggesting that the enzyme may be involved in a mechanism regulating the level of substance P concentration.

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.

Increased cerebrospinal fluid concentration of aspartate but decreased concentration of nitric oxide breakdown products in women experiencing visceral pain during active labour.

The aim of the present study was to investigate some putative neurotransmitters involved in nociception and pain in parturients during active labour experiencing intense visceral pain. The concentration of the excitatory amino acid aspartate was significantly increased, and there was a tendency for an increase in glutamate, in lumbar cerebrospinal fluid (CSF) of parturients in active vaginal labour compared with control patients without pain subjected to elective caesarean section. The CSF concentration of the nitric oxide breakdown product nitrate was significantly decreased in parturients compared with control patients and healthy volunteers. No significant differences in the concentrations of substance P, substance P-endopeptidase or met-enkephalin were detected between parturients and controls. Our data suggest a paradoxical negative relationship between CSF concentrations of excitatory amino acids and nitric oxide in labour pain. The mechanisms behind this finding is unclear at present.

Effect of steroids on CSF matrix metalloproteinases in multiple sclerosis: relation to blood-brain barrier injury.

Contrast-enhanced MRI in patients with MS shows that increased permeability of the blood-brain barrier (BBB) commonly occurs. The changes in capillary permeability often precede T2-weighted MRI evidence of tissue damage. In animal studies, intracerebral injection of the matrix metalloproteinase (MMP) 72-kDa type IV collagenase (gelatinase A) opens the BBB by disrupting the basal lamina around capillaries. Steroids affect production of endogenous MMPs and tissue inhibitors to metalloproteinases (TIMPs). To determine the role of MMP activity in BBB damage during acute exacerbations of MS, we measured MMPs in the CSF of patients with MS. Patients (n = 7) given steroids to treat an acute episode of MS had CSF sampled before and after 3 days of methylprednisolone (1 g/day). Patients had a graded neurologic examination and gadolinium-enhanced MRI before treatment. CSF studies included total protein, cell count, and a demyelinating profile. We measured levels of MMPs, urokinase-type plasminogen activator (uPA), and TIMPs by zymography, reverse zymography, and Western blots. The MMP, 92-kDa type IV collagenase (gelatinase B), fell from 216 +/- 70 before steroids to 54 +/- 26 relative lysis zone units (p < 0.046) after treatment. Similarly, uPA dropped from 3880 +/- 800 to 2655 +/- 353 (p < 0.03). Four patients with gadolinium enhancement on MRI had the most pronounced drop in gelatinase B and uPA. Western immunoblots showed an increase in a complex of gelatinase B and TIMPs after treatment, suggesting an increase in a TIMP (p < 0.05). Reverse zymography of CSF samples showed that steroids increased a TIMP with a molecular weight similar to that of mouse TIMP-3 (p = 0.053). Our results suggest that increased gelatinase B is associated with an open BBB on MRI. Steroids may improve capillary function by reducing activity of gelatinase B and uPA and increasing levels of TIMPs.