Expression of matrix metalloproteinases and their tissue inhibitor during viral encephalitis

Matrix metalloproteinases (MMPs) participate in remodeling the extracellular matrix and facilitate entry of inflammatory cells into tissues. Infection of the murine central nervous system (CNS) with a neurotropic coronavirus induces encephalitis associated with increased levels of mRNA encoding MMP-3 and MMP-12. Whereas virus-induced MMP-3 expression was restricted to CNS resident astrocytes, MMP-12 mRNA was expressed by both inflammatory cells and CNS resident cells. Immunosuppression increased both MMP-3 and MMP-12 mRNA levels in CNS resident cells, suggesting that the presence of virus rather than inflammation induced protease up-regulation. MMP activity is partially regulated by a small family of genes encoding tissue inhibitors of matrix metalloproteinases (TIMPs); among the TIMPs, only TIMP-1 mRNA expression increased in the CNS following coronavirus infection. During inflammation TIMP-1 mRNA was most prominently expressed by infiltrating cells. By contrast, in the immunosuppressed host TIMP-1 mRNA was expressed by CNS resident cells. Analysis of cytokine and chemokine mRNA induction within the infected CNS of healthy and immunocompromised mice suggested a possible correlation between increased viral replication and increased levels of beta interferon, MMP-3, MMP-12, and TIMP-1 mRNA. CD4+ T cells which localize to the perivascular and subarachnoid spaces were identified as the primary source of TIMP-1 protein. By contrast, protein expression was undetectable in astrocytes or CD8+ T cells, the primary antiviral effectors that localize to the CNS parenchyma in response to infection. These data suggest that in contrast to the results seen with MMPs, inhibition of protease activity via TIMP-1 expression correlates with the differential tissue distribution of T-cell subsets during acute coronavirus-induced encephalitis.     

Structural basis of the matrix metalloproteinases and their physiological inhibitors,the tissue inhibitors of metalloproteinases

The matrix metalloproteinases (MMPs) constitute a family of multidomain zinc endopeptidases with a metzincin-like catalytic domain, which are involved in extracellular matrix degradation but also in a number of other important biological processes. Under healthy conditions, their proteolytic activity is precisely regulated by their main endogenous protein inhibitors, the tissue inhibitors of metalloproteinases. Disruption of this balance results in pathophysiological processes such as arthritis, tumor growth and metastasis, rendering the MMPs attractive targets for inhibition therapy. Knowledge of their tertiary structures is crucial for a full understanding of their functional properties and for rational drug design. Since the first appearance of atomic MMP structures in 1994, a large amount of structural information has become available on the catalytic domains of MMPs and their substrate specificity, interaction with synthetic inhibitors and the TIMPs, the domain organization, and on complex formation with other proteins. This review will outline our current structural knowledge of the MMPs and the TIMPs.     

Effects of hyperinsulinemia on hepatic metalloproteinases and their tissue inhibitors

To gain insight into the pathogenesis of hepatic fibrosis related to insulin resistance, we have examined the effects of euglycemic hyperinsulinemia on three matrix metalloproteinases (MMP-2, MMP-9, and MT1-MMP) and on two major tissue inhibitors of MMPs (TIMP-1 and TIMP-2) in liver of insulin-sensitive and insulin-resistant rats. Four hours of insulin infusion (4.8 mU.kg(-1).min(-1)) without or with lipid-heparin infusion (to produce insulin resistance) decreased hepatic MMP-2 mRNA (by RT-PCR), pro-MMP-2, MMP-2, MMP-9, and MT1-MMP (all by Western blots) and the gelatinolytic activity of MMP-2 (by gelatin zymography) by approximately 60-80%. Hyperinsulinemia ( approximately 1.6 mmol/l) increased TIMP-1 and TIMP-2 concentrations (by ELISA) in insulin-sensitive and insulin-resistant rats. Phosphoinositide 3-kinase was activated by insulin in insulin-sensitive rats and inhibited in insulin-resistant rats. Extracellular signal-regulated kinases 1/2 (ERK1/2) were activated by insulin in insulin-sensitive rats and partially inhibited in insulin-resistant rats; c-jun NH(2)-terminal kinase-1 (JNK1), JNK2/3, or p38 MAPK were only activated by lipid but not by insulin. We conclude that hyperinsulinemia, whether or not associated with insulin resistance, shifts the MMP/TIMP balance toward reduction of extracellular matrix degradation and thus may promote the development of hepatic fibrosis.     

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in the hippocampus of lithium-pilocarpine-induced acute epileptic rats

Molecular Biology Reports - Epilepsy is characterised by abnormal neuronal discharges, including aberrant expression of extracellular matrix (ECM) components and synaptic plasticity stabilisation....     

Structural basis of matrix metalloproteinases and tissue inhibitors of metalloproteinases

The matrix metalloproteinases (MMPs) constitute a family of secreted/cell-surface-anchored multidomain zinc endopeptidases, all of which exhibit a catalytic domain of a common metzincin-like topology, and which are involved in degradation of the extracellular matrix but also in a number of other biologic processes. Normally, the proteolytic activity of the MMPs is precisely regulated by their main endogenous protein inhibitors, in particular the tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in serious diseases such as arthritis, tumor growth, and tumor metastasis, rendering the MMPs attractive targets for inhibition therapy. Knowledge of their tertiary structures is crucial for a full understanding of their functional properties and their associations with dysfunctions. Since the reports of the first atomic structures of MMPs and TIMPs in 1994, considerable structural information has become available about both of these families of substances. Many of the MMP structures have been determined as complexes with synthetic inhibitors, facilitating knowledge-based drug design. This review focuses on the currently available 3D structural information about MMPs and TIMPs.     

Expression of bone morphogenetic proteins, matrix metalloproteinases and inhibitors of matrix metalloproteinases in lung cancers and their prognostic significance

Matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) are one of the molecules that have become a topic of great interest among scientists studying lung cancers. There is a distinct tendency toward higher expression of selected MMP and TIMP in tumor lung tissue. Furthermore, there is a significant correlation between high expression of TIMP-1 or MMP-2 in lung cancer and shortened survival and between high expression of TIMP-1 or MMP-7 in lung cancer and higher stage of disease. There have been only a few articles about the role of bone morphogenetic proteins (BMP) in lung cancer pathogenesis published so far in which BMP-2 or BMP-4 were overexpressed. It was also shown that BMP-2 stimulates tumor growth while BMP-4 inhibits it. This article is mainly concentrated on the expression of MMP, TIMP and BMP in lung cancers, but also it shows the significance of these proteins.     

Temporospatial expression of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in mouse antigen-induced arthritis

Several lines of evidence speak for an important role of matrix metalloproteinases (MMPs) in the development of progressive joint destruction. To better understand the role of MMPs and their tissue inhibitors (TIMPs) in this process, we have used the antigen-induced arthritis model to study the temporospatial expression of several MMPs and TIMPs during the progression of arthritis. Arthritis was induced by a single intra-articular injection of methylated bovine serum albumin (mBSA) into one or both knee joints of adult mice previously immunised against mBSA. Samples were collected at 3, 7, 21 and 42 days after induction of arthritis for histology and RNA extraction, and analysed by Northern hybridisation, histochemistry and immunohistochemistry for production of several MMPs and TIMPs −1, −2 and −3. A systematic analysis of MMP and TIMP mRNA levels in mouse knee joints demonstrated a general upregulation of both MMPs and TIMPs during progression of arthritis. Upregulation of MMP-9, −13 and −14 coincided with the advancement of cartilage degeneration, but the expression patterns of MMP-9 and −13 also followed the course of synovial inflammation. TIMPs were steadily upregulated throughout the examination period. Immunohistochemical localisation of MMPs and TIMPs suggested the synovium to be the major source of MMP and TIMP production in arthritis, although articular cartilage chondrocytes also showed an increased production of both MMPs and TIMPs.     

Highly water-soluble matrix metalloproteinases inhibitors and their effects in a rat adjuvant-induced arthritis model

A new series of succinate-based dual inhibitors against matrix metalloproteinases (MMPs) and tumor necrosis factor alpha converting enzyme (TACE) possessing highly-water solubility was designed, synthesized, and evaluated for enzyme inhibition. Incorporating of acidic or basic functional groups at the P(2)' position afforded sufficient water solubility without significant loss of inhibitory potencies. Compound 18e, which had a guanidino group at the P(2)' position as the basic functional group, exhibited broad inhibition against target enzymes for a relatively long period in rat plasma (beta t(1/2); 2.0h) after sc administration when compared with compounds possessing acidic functional groups (18a and 18b). Consequently, the representative compound 18e together with compound 18b, Marimastat and Trocade were evaluated in the rat adjuvant-induced arthritis model, a model of chronic cartilage destruction. It is concluded that the newly synthesized highly water-soluble compound 18e showed significant activity in suppressing hindpaw swelling and the bone destruction with a minimal administration period (days 3-7).     

Expression of gelatinases and their tissue inhibitors in rat corpus luteum during pregnancy and postpartum

Extensive tissue remodeling occurs in the corpus luteum (CL) during both formation and luteolysis. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are believed to play pivotal roles in these processes. In the present study, to evaluate the potential roles of matrix degrading proteases in luteal development and regression, we examined gelatinases and TIMP-1, -2, -3 mRNA expressions, as well as gelatinase activity in rat CL during pregnancy and postpartum using Northern blot, in situ hybridization, and gelatin zymography, respectively. The results showed that MMP-2 mRNA was only expressed at the early stages of pregnancy; TIMP-2 mRNA was highly expressed at the early and late pregnancy and day 1 postpartum, but could not be detected during the mid-phase of pregnancy; TIMP-3 mRNA expression was abundant during early pregnancy and peaked at day 7, but was absent from other time points examined. MMP-9 and TIMP-1 mRNAs in rat CL were below detectable level in the current study. Furthermore, the active MMP-2 was only present during the early stages of pregnancy, and no MMP-9 activity was observed in the zymogram. Taken together, our results suggest that MMP-2 and TIMP-3 may have functional roles in rat luteal formation, while TIMP-2 may be implicated in both formation and regression of the pregnant CL.     

Temporal study of the activity of matrix metalloproteinases and their endogenous inhibitors during wound healing

The restoration of functional connective tissue is a major goal of the wound healing process. This regenerative event requires the deposition and accumulation of collagenous and noncollagenous matrix molecules as well as the remodelling of extracellular matrix (ECM) by matrix metalloproteinases (MMPs). In this study, we have utilized substrate gel electrophoresis, radiometric enzyme assays, and Western blot analyses to determine the temporal pattern of appearance and activity of active and latent MMPs and their inhibitors during the entire healing process in a partial thickness wound model. Through the use of substrate gel electrophoresis, we studied the appearance of proteolytic bands whose molecular weight was consistent with their being members of the MMP family of enzymes. Proteolytic bands whose molecular weight is consistent with both the active and latent forms of MMP-2 (72 kDa, Type IV gelatinase) were detected in wound fluid of days 1–7 after wounding. The number of active MMP-2 species detectable in wound fluid was greatest during days 4–6 after wounding. The most prominent proteolytic band detected each day migrated with a molecular weight consistent with it being the latent form of MMP-9 (92 kDa, Type V pro-collagenase). In contrast to MMP-2, the active form of this enzyme was never detected. The presence of MMP-1 (interstitial collagenase) was detected by immunoblot in the wound fluid from days 1–6 post-injury. Using a radiometric enzyme assay for collagenase inhibitory activity we have also determined the time course of activity of endogenous matrix metalloproteinase inhibitors. We have correlated these data to the known cellular events occurring in the wound during this time period as well. This study establishes a prototypical pattern of MMP appearance in normal wound healing. It may also provide potential intervention sites for the therapeutic use of inhibitors of aberrant MMP activities which characterize chronic wounds. © 1996 Wiley-Liss, Inc.     

The molecular biology of matrix metalloproteinases and tissue inhibitors of metalloproteinases in inflammatory bowel diseases

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are thought to be predominant proteases and protease inhibitors involved in the pathogenesis of inflammatory bowel diseases (IBD) through their ability to remodel the extracellular matrix (ECM) in response to inflammatory stimuli and by their immunomodulating effects. An imbalance between MMPs and TIMPs has been linked with acute and chronic inflammation and aberrant tissue remodeling, as seen in IBD. Moreover, recurrent phases of tissue destruction and subsequent tissue repair can cause serious complications in IBD patients such as fistulas and fibrosis. The aims of this review are (i) to summarize current literature on genetic association, mRNA, and protein expression studies with regard to MMPs and TIMPs in IBD patients and various animal models, including those with transgenic and knockout mice; (ii) to compare biochemical and molecular biological data in humans with those obtained in animal model studies and (iii) to critically evaluate and translate how this knowledge may be used in practical terms to understand better the pathophysiology and mechanisms operating in IBD and to apply this for improvement of clinical outcomes at diagnostic, prognostic and therapeutic levels.     

Zymographic techniques for the analysis of matrix metalloproteinases and their inhibitors

The balance between matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), is largely responsible for the remodeling of tissues. Deregulation of this balance is a characteristic of extensive tissue degradation in certain degenerative diseases. To analyze the role of MMPs and TIMPs in tissue remodeling under normal and pathological conditions, it is important to have reliable detection methods. This review will focus on zymographical techniques for the analysis of MMPs and TIMPs. MMPs can be analyzed with several zymographical techniques, but substrate zymography is the most commonly used. This technique identifies MMPs by the degradation of their preferential substrate and by their molecular weight. Several substrates that can be used for zymography are described. Reverse zymography, which detects TIMPs by their ability to inhibit MMPs, is also discussed. Finally, in situ zymography is described, which is used to localize MMPs in tissue sections. Common problems encountered during sample preparation, zymography itself and the data analysis are discussed. Hints are given to improve the sensitivity and accuracy of zymographical methods. In conclusion, zymography is a valuable tool for research purposes and for the development of new diagnostic techniques and therapies for pathological conditions such as rheumatoid and osteoarthritis, and tumor progression.     

Expression of insulin-like growth factor-II,matrix metalloproteinases,and their tissue inhibitors as predictive markers in the peripheral blood of HCC patients

Background/aim: Elevated relative expression of insulin-like growth factor-II (IGF-II) was observed in hepatocellular carcinoma (HCC) liver tissues with a role in neovascularization and associated with poor prognosis. IGF-II is influenced by the proteolytic cleavage of IGF-binding protein 3 and by matrix metalloproteinases (MMP), which are further regulated by their tissue inhibitors tissue inhibitor of metalloprotienase-1 (TIMP-1). Our aim is to study new molecular markers for HCC.

Patients/methods: RNA was extracted from the peripheral blood for evaluating the relative expression of IGF-II, MMP-9, and TIMP-1 in correlation with clinical staging of 39 HCC patients and 15 healthy controls using TaqMan real-time PCR.

Results: The relative expression of IGF-II and MMP-9 mRNA were significantly elevated in HCC patients compared with healthy controls; P-value <0.0001 for both. There was a significant correlation between MMP-9 and different HCC stages. On the other hand, TIMP-1 was significantly down-regulated in HCC patients; P?=?0.0003 with the elevation of the IGF-II/TIMP-1 ratio. Significant correlation between TIMP-1 and HCC Stage III and Stage IV was found; P-value?=?0.0138.

Conclusion: These results highlight the importance of profiling the expression of IGF-II, MMP-9, and TIMP-1 in the peripheral blood as prognostic molecular biomarkers in HCC.     

Occurrence and temporal variation in matrix metalloproteinases and their inhibitors during murine secondary palatal morphogenesis

Extracellular matrix (ECM) molecules are known to play a pivotal role in morphogenesis of the secondary palate, and changes in their composition and distribution, not attributable to changes in synthesis, are known to occur during palatogenesis. The present study was undertaken to determine if the enzymes responsible for mediating their degradation, the matrix metalloproteinases (MMP), and their specific inhibitors, the tissue inhibitors of metalloproteinases (TIMP), are temporospatially regulated during murine palatal shelf morphogenesis. Palatal shelves were harvested at gestational days (gd) 12, 13 and 14. MMPs were identified by gelatin zymography, with and without inhibitors, and the identity of specific bands confirmed by Western blot analysis. TIMPs were identified by reverse zymography. MMP and TIMP messages were detected using RT-PCR with specific primers to MMPs 2, 3, 7, 9 and 13 and TIMPs 1 and 2. Zymography revealed bands of molecular weights corresponding to MMPs 2, 7, 9 and 13 at all ages examined; the intensity of these bands increased with developmental age. Western blot analysis established the presence of MMP-3 and its developmental variation in expression. RT-PCR demonstrated the presence of mRNA for all MMPs and TIMP at all sampling times and all but MMP-2 showed developmental variation. Whereas increases in mRNA were detected for MMPs 3, 9, and 13, MMP-7 mRNA decreased between gd 12 and 14. The results of this study demonstrate that MMPs 2, 3, 7, 9 and 13 and TIMPs 1 and 2 and their messages are present during the course of palatal shelf remodelling and that their expression is temporally regulated.     

Expression of matrix metalloproteinases and their tissue inhibitors in the serum and cerebrospinal fluid of patients with HIV-1 infection and syphilis or neurosyphilis

The potential mechanisms for altered matrix metalloproteinase (MMP) or tissue inhibitors of matrix metalloproteinase (TIMP) function in patients with syphilis and HIV-1 co-infection (HIV-S) was unclear. To determine the expression of MMP-2, 9 and TIMP-1, 2, 4 in the serum and cerebrospinal fluid (CSF) of HIV-S patients, a total of 20 HIV-S patients and 8 controls were enrolled in a HIV-1 clinical cohort for diagnosis of neurosyphilis in Taiwan. Serum and CSF concentrations of MMP-2, 9, and TIMP-1, 2, 4 were determined by ELISA. Gelatin zymography was used to detect the expression of MMP-2 and MMP-9 in the CSF. Neurosyphilis was defined as a CSF white blood cell count ≥ 20 cells/μL or a reactive CSF Venereal Disease Research Laboratory (VDRL). All the patients with HIV-S were males. Most (85%) had sex with men (MSM) and serum rapid plasma reagin (RPR) titers of ≥ 1:32. The median age was 35 years (IQR 30-43). The median CD4 T cell counts at the time of the diagnosis of syphilis were 270 cells/μL (IQR 96-484). Ten patients (50%) had neurosyphilis based on a reactive CSF VDRL test (n=8) or increased CSF white cell counts ≥ 20/μL (n=2). The concentrations of CSF MMP-9, TIMP-1, and TIMP-2 were significantly higher in patients with HIV-S than the controls (P<0.05). The CSF TIMP-4 concentrations were significantly lower in those with HIV-S (452 pg/ml) than controls (3101 pg/ml), P<0001. There were no significant differences in serum concentrations between the groups. The only finding that distinguished HIV-1 patients with from those without neurosyphilis is a significant higher expression of CSF MMP-9. In conclusion, the MMP/TIMP system was found to be dysregulated in patients with HIV-S regardless of whether they met the laboratory definition of neurosyphilis. The CSF level of MMP-9 was the only measure that distinguished those with or without neurosyphilis.     

The matrix metalloproteinases and their natural inhibitors: prospects for treating degenerative tissue diseases.

Uncontrolled matrix metalloproteinase activity is thought to be a cause of the tissue damage observed in many disease processes. None of the drugs currently in use can prevent tissue destruction, and strategies for the development of synthetic inhibitors have been hampered by a poor understanding of the biochemistry of matrix metalloproteinases. Recent cDNA cloning efforts and characterization of recombinant human matrix metalloproteinases have permitted structure-function analysis of the enzymes and their inhibitors. Progress in this area should help indicate a route to rational strategies for designing lead therapeutic compounds.