MAB3306 Sigma-AldrichAnti-MMP-3 Antibody, cross reacts w/hMMP-10, clone 55-2A4

Recent data have shown that abnormal subchondral bone remodeling plays an important role in osteoarthritis (OA) onset and progression, and it was suggested that abnormal mechanical pressure applied to the articulation was responsible for these metabolic changes. This study was undertaken to evaluate the effects of cyclic compression on osteoblasts from OA subchondral bone.

Neonatal mice developed neurological disease and pulmonary dysfunction after an infection with a mouse-adapted human Enterovirus 71 (EV71) strain MP4. However, the hallmark of severe human EV71 infection, pulmonary edema (PE), was not evident.To test whether EV71-induced PE required a proinflammatory cytokine response, exogenous pro-inflammatory cytokines were administered to EV71-infected mice during the late stage of infection.After intracranial infection of EV71/MP4, 7-day-old mice developed hind-limb paralysis, pulmonary dysfunction, and emphysema. A transient increase was observed in serum IL-6, IL-10, IL-13, and IFN-γ, but not noradrenaline. At day 3 post infection, treatment with IL-6, IL-13, and IFN-γ provoked mild PE and severe emphysema that were accompanied by pulmonary dysfunction in EV71-infected, but not herpes simplex virus-1 (HSV-1)-infected control mice. Adult mice did not develop PE after an intracerebral microinjection of EV71 into the nucleus tractus solitarii (NTS). While viral antigen accumulated in the ventral medulla and the NTS of intracerebrally injected mice, neuronal loss was observed in the ventral medulla only.Exogenous IL-6, IL-13, and IFN-γ treatment could induce mild PE and exacerbate pulmonary abnormality of EV71-infected mice. However, other factors such as over-activation of the sympathetic nervous system may also be required for the development of classic PE symptoms.

In this study we tested the effectiveness of a formaldehyde-inactivated EV71 vaccine and its compatibility for co-immunization with a pentavalent vaccine that contained inactivated poliovirus (PV) vaccine. The inactivated EV71 vaccine (C2 genogroup) elicited an antibody response which broadly neutralized homologous and heterologous genogroups, including B4, C4, and B5. Pups from vaccinated dams were resistant to the EV71 challenge and had a high survival rate and a low tissue viral burden when compared to those from non-vaccinated counterparts. Co-immunization with pentavalent and inactivated EV71 vaccines elicited antibodies against the major components of the pentavalent vaccine including the PV, Bordetella pertussis, Haemophilus influenzae type b, diphtheria toxoid, and tetanus toxoid at the same levels as in mice immunized with pentavalent vaccine alone. Likewise, EV71 neutralizing antibody titers were comparable between EV71-vaccinated mice and mice co-immunized with the two vaccines. These results indicate that formaldehyde-inactivated whole virus EV71 vaccine is feasible for designing multivalent vaccines.Copyright © 2011 Elsevier Ltd. All rights reserved.

A number of lines of evidence suggest that senescence of normal human diploid fibroblasts (HDFs) in culture is relevant to the process of aging in vivo. Using normal human skin diploid fibroblasts, we examine the changes in genes and proteins following treatment with a mild dose of H2O2, which induces premature senescence. Multidimensional Protein Identification Technology (MudPIT) in combination with mass spectrometry analyses of whole cell lysates from HDFs detected 65 proteins in control group, 48 proteins in H2O2-treated cells and 109 proteins common in both groups. In contrast, cDNA microarray analyses show 173 genes up-regulated and 179 genes down-regulated upon H2O2 treatment. Both MudPIT and cDNA microarray analyses indicate that H2O2 treatment caused elevated levels of thioredoxin reductase 1. Semi-quantitative RT-PCR and Western-blot were able to verify the finding. Out of a large number of genes or proteins detected, only a small fraction shows the overlap between the outcomes of microarray versus proteomics. The low overlap suggests the importance of considering proteins instead of transcripts when investigating the gene expression profile altered by oxidative stress.

Papillary thyroid cancers (PTC) are associated with nonoverlapping mutations of genes coding for mitogen-activated protein kinase signaling effectors (i.e., the TK receptors RET or NTRK and the signaling proteins RAS and BRAF). We examined the pattern of gene expression after activation of these oncoproteins in thyroid PCCL3 cells, with the goal of identifying pathways or gene subsets that may account for the phenotypic differences observed in human cancers. We hybridized cDNA from cells treated with or without doxycycline to induce expression of BRAF(V600E), RET/PTC3, or RET/PTC3 with small interfering RNA-mediated knockdown of BRAF, respectively, to slides arrayed with a rat 70-mer oligonucleotide library consisting of 27,342 oligos. Among the RET/PTC3-induced genes, 2,552 did not require BRAF as they were similarly regulated by RET/PTC3 with or without BRAF knockdown and not by expression of BRAF(V600E). Immune response and IFN-related genes were highly represented in this group. About 24% of RET/PTC3-regulated genes were BRAF dependent, as they were similarly modified by RET/PTC3 and BRAF(V600E) but not in cells expressing RET/PTC3 with knockdown of BRAF. A gene cluster coding for components of the mitochondrial electron transport chain pathway was down-regulated in this group, potentially altering regulation of cell viability. Metalloproteinases were also preferentially induced by BRAF, particularly matrix metalloproteinase 3 (MMP3), MMP9, and MMP13. Accordingly, conditional expression of BRAF was associated with markedly increased invasion into Matrigel compared with cells expressing RET/PTC3. The preferential induction of MMPs by BRAF could explain in part the more invasive behavior of thyroid cancers with BRAF mutations.

Three members of the SIBLING family of integrin-binding phosphoglycoproteins (bone sialoprotein, BSP; osteopontin, OPN; and dentin matrix protein-1, DMP1) were recently shown to bind with high affinity (nM) and to activate 3 different matrix metalloproteinases (MMP-2, MMP-3, and MMP-9, respectively) in vitro. The current study was designed to document the possible biological relevance of the SIBLING-MMP activation pathway in vivo by showing that these 3 SIBLINGs and their known MMP partners are co-expressed in normal adult tissue. BSP, OPN, and DMP1 were invariably co-expressed with their partner MMPs in salivary glands of humans and mice. The 2 SIBLING proteins without known MMP partners, dentin sialophosphoprotein (DSPP) and matrix extracellular phosphoglycoprotein (MEPE), were also expressed in salivary glands. Expression of all SIBLINGs in this normal, non-mineralizing epithelial tissue suggests that they serve at least one function in vivo other than directly promoting matrix mineralization--a function we hypothesize involves local activation of MMPs.

BACKGROUND AND PURPOSE: Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade the extracellular matrix and are implicated in numerous pathological conditions including atherosclerosis, inflammation, and tumor growth and metastasis. In the brain, the endothelial cell wall, strengthened by tight junctions, defines the blood-brain barrier (BBB). The extracellular matrix molecules constitute the basement membrane underlying the vasculature and play a critical role in maintaining the integrity of the BBB. After focal stroke, there is a breakdown of the BBB with an associated increase in vascular permeability, inflammatory cell influx, and neuronal cell death. The present study was designed to investigate the effects of MMP expression after stroke. METHODS: Focal stroke was produced by permanent middle cerebral artery occlusion (MCAO) in the rat, and MMP protein expression was measured by Western blot and zymogram analysis over a time course ranging from 6 hours to 30 days (n=32). Immunohistochemistry at 1 and 5 days (n=8 and 6, respectively) was also utilized to characterize the expression of several MMPs and related proteins after stroke, including their cellular source. To test the hypothesis that early increased MMP-9 expression is involved in ischemic brain injury, a neutralizing monoclonal antibody directed against MMP-9 was administered intravenously (n=7 per group) 1 hour before MCAO, and infarct size was measured 24 hours later. RESULTS: MMP expression increased progressively over time after stroke. After 12 hours, significant (P<0.05) MMP-9 activity was observed that reached maximum levels by 24 hours (P<0.001), then persisted for 5 days at this level and returned to basal (zero) levels by 15 days. On the basis of morphological criteria, MMP-9 appeared to stain with endothelial cells and neutrophils identified both within and at the periphery of the infarct within 24 hours of focal ischemia. After 5 days, MMP-9 appeared to stain with macrophages present within the infarcted brain. MMP-2 activity was significantly (P<0.001) increased by 24 hours and was maximum after 5 days following MCAO. MMP-2 appeared to stain with macrophages present within the infarcted region. Unlike MMP-9 and MMP-2, tissue inhibitor of metalloproteinase-1 was identified at comparable levels in both control and ischemic tissue after MCAO. MMP-1 and MMP-3 could not be detected in the brain after focal stroke. When an MMP-9-neutralizing monoclonal antibody was administered systemically, animals exhibited significantly reduced infarct size (ie, a 30% reduction compared with non-immune antibody controls; P<0.05). CONCLUSIONS: These results demonstrate that early increased MMP-9 expression in endothelial cells and infiltrating neutrophils is a significant response to cerebral focal ischemia and that selective inhibition of MMP-9 activity can significantly reduce brain injury after stroke.

The role of matrix metalloproteinases (MMP's) and their inhibitor, tissue inhibitor of metalloproteinases-1 (TIMP-1), in human brain tumor invasion was investigated. Gelatinolytic activity was assayed via gelatin zymography, and four MMP's (MMP-1, MMP-2, MMP-3, and MMP-9) and TIMP-1 were immunolocalized in human brain tumors and in normal brain tissues using monoclonal antibodies. The tissue was surgically removed from 44 patients: glioblastoma (five cases), anaplastic astrocytoma (six cases), astrocytoma (four cases), metastatic tumor (six cases), neurinoma (10 cases), meningioma (10 cases), and normal brain tissue (three cases). Glioblastomas, anaplastic astrocytomas, and metastatic tumors showed high gelatinolytic activity and positive immunostaining for MMP's; TIMP-1 was also expressed in these tumors, but some tumor cells were negative for the antibody. Astrocytomas had low gelatinolytic activity and the tumor cells showed no immunoreactivity for MMP's and TIMP-1. Although neurinomas and meningiomas had only moderate proteinase activity and exhibited positive immunoreactivity for MMP-9, intense expression of TIMP-1 was simultaneously observed in these tumor cells. These findings suggest that MMP's play an important role in human brain tumor invasion, probably due to an imbalance between the production of MMP's and TIMP-1 by the tumor cells.

The stromelysin-2 (SL-2) gene is transcriptionally active in normal human keratinocytes and encodes a secreted, catalytically competent but latent matrix metalloproteinase. Phorbolester induction resulted in the emergence of SL-2 (but not SL-1 transcripts), whereas the opposite was true for human mucosal fibroblasts. Expression of keratinocyte SL-2 was also induced by the two keratinocyte growth factors, transforming growth factor-alpha and epidermal growth factor, by the proinflammatory cytokine, tumor necrosis factor-alpha, but, somewhat surprisingly, not by interleukin-1 beta. The latent SL-2 proenzyme was isolated from 12-O-tetradecanoylphorbol-13-acetate-induced keratinocytes by immunoaffinity chromatography using a cross-reactive antibody raised against human SL-1. This procedure led to the recovery of a single M(r) 54,000 molecular species at a level of approximately 0.2 microgram/ml of culture medium. Amino-terminal sequencing identified the protein as SL-2 and verified the predicted signal sequence cleavage site. Conformational activation of latent SL-2 precursor by SDS gave rise to a full-length, uncleaved (M(r) 54,000) active form and at the same time exposed a cryptic thiol group. By contrast, organomercurial activation resulted in autolytic truncation of the molecule with loss of M(r) approximately 10,000 propeptide. SL-2 shared with (human fibroblast) SL-1 the ability to cleave casein, to "superactivate" fibroblast type procollagenase, and to form apparently binary, SDS-resistant complexes with tissue inhibitor of metalloproteinases-1.

A one-step sandwich enzyme immunoassay (EIA) for matrix metalloproteinase 3 (MMP-3; stromelysin-1) was developed. The assay system used two simultaneous immunoreactions using a solid phase monoclonal antibody and a horseradish peroxidase-labeled monoclonal antibody (Fab'). The sensitivity of the assay system was 20 micrograms/l and linearity was obtained between 31 and 500 micrograms/l. The EIA system was capable of measuring both precursor and active forms of MMP-3 as well as the forms of MMP-3 complexed with tissue inhibitors of metalloproteinases. MMP-3 levels as measured by this assay are significantly higher in the sera of patients with rheumatoid arthritis as compared to those of healthy subjects and patients with osteoarthritis. Immunoblot analyses showed that in the sera and synovial fluids of patients with rheumatoid arthritis, MMP-3 is present in the 59- and 57-kDa precursor forms.