Cell growth-promoting activity of tissue inhibitor of metalloproteinases-2 (TIMP-2)

Prognostic significance of matrix metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 expression in prostate cancer

Matrix metalloproteinases (MMPs) are proteolytic enzymes capable of degrading the structural support network for normal and malignant cells, promoting neoplastic cell invasion and metastasis. Tissue inhibitors of metalloproteinases (TIMPs) maintain connective tissue integrity by modulating MMP activity. Formalin-fixed paraffin-embedded tissue sections from 138 prostatic adenocarcinomas (PACs) were immunostained by a combined automated/manual method using monoclonal antibodies against MMP2 and TIMP2. Immunoreactivity was semiquantitatively scored based on stain intensity and distribution, and results were correlated with Gleason grade, pathologic stage, ploidy status, and disease recurrence. One hundred five of 138 (76%) and 113/138 (82%) PACs expressed MMP2 and TIMP2, respectively. Co-expression was observed in 94/138 (68%) of PACs (P =.01), correlated with advanced tumor stage (P =.05), and tended to be associated with disease recurrent cases (P =.07). TIMP2 expression individually correlated with advanced tumor stage (P =.04) and reached near significance with disease recurrence (P =.06). MMP2 expression was also more frequent in recurrent PACs, although this value did not reach statistical significance (P =.07). However, on multivariate analysis, only pathologic stage (P =.009) and ploidy status (P =.03) independently predicted disease recurrence. In conclusion, MMP2 and TIMP2 are co-expressed in a majority of PACs and correlate with prognostic variables. Interestingly, contrary to the previously documented anti-tumor effects of TIMPs, TIMP2 expression appears to have a tumor-promoting role in PACs and warrants further investigation.

In vitro production of bovine embryos and their application for embryo transfer

This review introduces newly developed serum-free media (IVD101 and IVMD101), that are effective for producing high yields of transferable embryos of good quality from in vitro-matured and -fertilized oocytes. Both serum-free media produced better results than serum-containing medium, including increased rates of blastocyst formation, post-thaw embryo viability, and pregnancy after transfer. In addition, reduced risks of calf mortality and large calf syndrome were also observed for the serum-free-derived embryos. Serum-derived embryos contained a large number of lipid droplets and immature mitochondria in their cytoplasm that may account for the lower production of transferable embryos and poor embryo quality. A non-invasive technique using scanning electrochemical microscopy was successful in quantitatively measuring oxygen consumption of single embryos. This technique may prove to be reliable for predicting embryo viability and subsequent developmental ability.

Increased matrix metalloproteinase-9 with elastolysis in nocturnal asthma

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) is capable of degrading elastin, whereas tissue inhibitor of metalloproteinase-1 (TIMP-1) can inhibit MMP-9 activity. We observed reduced airway tissue elastin volume density in six subjects with nocturnal asthma (NA) as compared with seven subjects with nonnocturnal asthma (NNA) and seven normal controls (NL) when endobronchial biopsies were evaluated morphometrically at 4:00 PM and 4:00 AM.

OBJECTIVE

We hypothesized that increased metalloproteinases and decreased tissue inhibitors of metalloproteinases in the airways of subjects with NA may be responsible for reduced elastin volume density.

METHODS

Ten additional subjects with NA, 10 subjects with NNA, and 7 normal control subjects underwent bronchoscopy with bronchoalveolar lavage at 4:00 PM and 4:00 AM. Levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined in bronchoalveolar lavage by enzyme-linked immunosorbent assay.

RESULTS

There was a fourfold circadian increase in bronchoalveolar lavage levels of MMP-9, and there was a twofold increase in MMP-9:TIMP-1 ratio in NA subjects from 4:00 PM to 4:00 AM. There were no circadian changes in the NNA and NL subjects. At 4:00 AM, MMP-9 levels and the MMP-9:TIMP-1 ratio were highest in NA subjects. At 4:00 PM, no significant group differences were observed. The MMP-9 levels positively correlated with the overnight fall in forced expiratory volume in 1 second and the MMP-9/TIMP-1 ratio negatively correlated with the 4:00 AM % predicted forced expiratory volume in 1 second.

CONCLUSIONS

Our results from these two pilot studies suggest that increased MMP-9 and decreased TIMP-1 at night in NA may lead to reduced elastin density.

Utilization of a novel recombinant myoglobin fusion protein expression system to characterize the tissue inhibitor of metalloproteinase (TIMP)-4 and TIMP-2 C-terminal domain and tails by mutagenesis. The importance of acidic residues in binding the MMP-2 hemopexin C-domain

Tissue inhibitor of metalloproteinase (TIMP)-4 binds pro-matrix metalloproteinase (MMP)-2 and efficiently inhibits MT1-MMP, but unlike TIMP-2 neither forms a trimolecular complex nor supports pro-MMP-2 activation. To investigate the structural and functional differences between these two TIMPs, the C-terminal domains (C-TIMP-4 and C-TIMP-2) were expressed independently from their N domains and mutations were introduced into the C-terminal tails. Myoglobin was used as a novel recombinant fusion protein partner because spectroscopic measurement of the heme Soret absorbance at 408 nm readily enabled calculation of the molar equivalent of the red-colored recombinant protein, even in complex protein mixtures. Both C-TIMP-4 and C-TIMP-2 bound pro-MMP-2 and blocked concanavalin A-induced cellular activation of the enzyme. Measurement of k(on) rates revealed that the inhibition of MMP-2 by TIMP-4 is preceded by a C domain docking interaction, but in contrast to TIMP-2, this is not enhanced by a C-terminal tail interaction and so occurs at a slower rate. Indeed, the binding stability of C-TIMP-4 was unaltered by deletion of the C-terminal tail, but replacement with the tail of TIMP-2 increased its affinity for pro-MMP-2 by approximately 2-fold, as did substitution with the TIMP-2 C-terminal tail acidic residues in the tail of C-TIMP-4 (V193E/Q194D). Conversely, substitution of the C-terminal tail of C-TIMP-2 with that of TIMP-4 reduced pro-MMP-2 binding by approximately 75%, as did reduction of its acidic character by mutation to the corresponding TIMP-4 amino acid residues (E192V/D193Q). Together, this shows the importance of Glu(192) and Asp(193) in TIMP-2 binding to pro-MMP-2; the lack of these acidic residues in the TIMP-4 C-terminal tail, which reduces the stability of complex formation with the MMP-2 hemopexin C domain, probably precludes TIMP-4 from supporting the activation of pro-MMP-2.

Matrix metalloproteinase-9 is necessary for the regulation of smooth muscle cell replication and migration after arterial injury

Matrix metalloproteinases (MMPs) and, in particular, MMP-9 are important for smooth muscle cell (SMC) migration into the intima. In this study, we sought to determine whether MMP-9 is critical for SMC migration and for the formation of a neointima by using mice in which the gene was deleted (MMP-9(-/-) mice). A denuding injury to the arteries of wild-type mice promoted the migration of medial SMCs into the neointima at 6 days, and a large neointimal lesion was observed after 28 days. In wild-type arteries, medial SMC replication was approximately 8% at day 4, 6% at day 6, and 4% at day 8 and had further decreased to 1% at day 14. Intimal cell replication was 65% at 8 days and had decreased to approximately 10% at 14 days after injury. In MMP-9(-/-) arteries, SMC replication was significantly lower at day 8. In addition, SMC migration and arterial lesion growth were significantly impaired in MMP-9(-/-) arteries. SMCs, isolated from MMP-9(-/-) mouse arteries, showed an impairment of migration and replication in vitro. Thus, our present data indicate that MMP-9 is critical for the development of arterial lesions by regulating both SMC migration and proliferation.

Expression of MMP-2, MMP-9, and MMP-1 and their endogenous counterregulators TIMP-1 and TIMP-2 in postmortem brain tissue of Parkinson's disease

We investigated the levels and tissue localization of matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) in postmortem brain tissue from Parkinson's disease (PD) and age-matched control cases. Using zymography, we found reduced MMP-2 levels in PD cases in the substantia nigra as compared to controls; levels of MMP-2 were not significantly changed in the cortex and the hippocampus. MMP-9 levels were unchanged in the investigated brain regions. Immunohistochemically, MMP-2 was localized primarily in astrocytes and microglia cells, whereas MMP-9 was predominantly neuronal. Levels of TIMP-1, an endogenous tissue inhibitor of MMPs, were significantly elevated in the substantia nigra, but not in the cortex and hippocampus. TIMP-2 levels were unchanged in PD. To investigate whether increased TIMP-1 levels in the substantia nigra might be due to increased MMP-1 expression, we measured MMP-1 levels using Western blots. MMP-1 levels were unchanged in PD cases compared to controls. Together, these data show alterations of MMP-2 and TIMP-1 in the substantia nigra of PD, consistent with the possibility that alterations in MMPs/TIMPs may contribute to disease pathogenesis.

Metalloproteinase inhibitors: biological actions and therapeutic opportunities

Tissue inhibitors of metalloproteinases (TIMPs) are the major cellular inhibitors of the matrix metalloproteinase (MMP) sub-family, exhibiting varying efficacy against different members, as well as different tissue expression patterns and modes of regulation. Other proteins have modest inhibitory activity against some of the MMPs, including domains of netrins, the procollagen C-terminal proteinase enhancer (PCPE), the reversion-inducing cysteine-rich protein with Kazal motifs (RECK), and tissue factor pathway inhibitor (TFPI-2), but their physiological significance is not at all clear. Alpha2-macroglobulin, thrombospondin-1 and thrombospondin-2 can bind to some MMPs and act as agents for their removal from the extracellular environment. In contrast, few effective inhibitors of other members of the metzincin family, the astacins or the distintegrin metalloproteinases, ADAMs have been identified. Many of these MMP inhibitors, including the TIMPs, possess other biological activities which may not be related to their inhibitory capacities. These need to be thoroughly characterized in order to allow informed development of MMP inhibitors as potential therapeutic agents. Over activity of MMPs has been implicated in many diseases, including those of the cardiovascular system, arthritis and cancer. The development of synthetic small molecule inhibitors has been actively pursued for some time, but the concept of the use of the natural inhibitors, such as the TIMPs, in gene based therapies is being assessed in animal models and should provide useful insights into the cell biology of degradative diseases.

Secretory leukocyte protease inhibitor mediates proliferation of human endometrial epithelial cells by positive and negative regulation of growth-associated genes

Secretory leukocyte protease inhibitor (SLPI) inhibits chymotrypsin, trypsin, elastase, and cathepsin G. This protein also exhibits proliferative effects, although little is known about the molecular mechanisms underlying this activity. We have generated SLPI-ablated epithelial sublines by stably transfecting the Ishikawa human endometrial cell line with an antisense human SLPI RNA expression vector. We demonstrate a positive correlation between cellular SLPI production and proliferation. We further show that Ishikawa sublines expressing low to undetectable SLPI have correspondingly increased and decreased expression, respectively, of transforming growth factor-beta 1 and cyclin D1 genes, relative to parental cells. SLPI selectively increased cyclin D1 gene expression, with the effect occurring in part at the level of promoter activity. Cellular SLPI levels negatively influenced the anti-proliferative and pro-apoptotic insulin-like growth factor-binding protein-3 expression. We also identified lysyl oxidase, a phenotypic inhibitor of the ras oncogenic pathway and a tumor suppressor, as SLPI-repressed gene, whose expression is up-regulated by transforming growth factor-beta1. Our results suggest that SLPI acts at the node(s) of at least three major interacting growth inhibitory pathways. Because expression of SLPI is generally high in epithelial cells exhibiting abnormal proliferation such as in carcinomas, SLPI may define a novel pathway by which cellular growth is modulated.

Both tissue inhibitors of metalloproteinases-1 (TIMP-1) and TIMP-2 activate Ras but through different pathways

Tissue inhibitors of metalloproteinases-1 (TIMP-1) and TIMP-2 have growth-stimulating activity for a wide range of cell types. Ras, which comprises a family of three members, i.e, Ha-Ras, Ki-Ras, and H-Ras, is known to participate in growth control in all its facets, including cell proliferation, transformation, differentiation, and apoptosis. In this study, we tested the hypothesis that Ras might be involved in the cell growth-promoting activity of TIMPs. Using MG-63 human osteosarcoma cells, we demonstrated that both TIMP-1 and TIMP-2 caused an increase in the Ras-GTP level in a dose-dependent manner. Our previous results indicated that TIMP-1 activity is mediated through the tyrosine kinase (TYK)/mitogen-activated protein kinase (MAPK) pathway. Here, we demonstrated that Ras activation by TIMP-1 was inhibited by a specific TYK inhibitor, herbimycin A, suggesting that the TYK/MAPK signaling pathway was involved in Ras activation by TIMP-1. However, the activation of Ras by TIMP-2 was inhibited by an inhibitor specific for cyclic AMP-dependent protein kinase (PKA), H89, suggesting the involvement of the PKA-mediated pathway. Furthermore, TIMP-2 promoted the formation of a complex between Ras-GTP and phosphoinositide 3-kinase.

Enhanced mRNA expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in breast carcinomas is correlated with adverse prognosis

Tissue inhibitor of metalloproteinase-1 (TIMP-1) has emerged as a multifunctional protein with the contrasting activities of inhibiting tissue-degrading enzymes and promoting cellular growth. In an attempt to elucidate the clinical significance of TIMP-1 in breast cancer, the expression of TIMP-1 mRNA was evaluated in 117 invasive breast carcinomas by mRNA in situ hybridization, in correlation with clinicopathological parameters, immunohistochemical prognostic factors (Ki-67, c-erb-B-2, bcl-2) and clinical outcome. TIMP-1 was detected in stromal cells in areas within the tumours and at the tumour margin. High TIMP-1 mRNA expression in the marginal portion of the tumours was significantly correlated with lymph node metastasis (p<0.05) and c-erbB-2 expression (p<0.05). On the other hand, increased TIMP-1 mRNA expression within the tumours showed a statistically significant correlation with ER detection (p<0.01). Multivariate analysis revealed worse survival for patients with high TIMP-1 mRNA expression in the marginal portion of the tumours; the subgroup of these patients co-expressing high levels of TIMP-1 mRNA within the tumours as well had even worse survival (p=0.042). In conclusion, our data support the multifunctional role of TIMP-1, particularly its growth-promoting activity, on the basis of its significant correlation with lymph node metastasis and adverse prognosis. In addition to the latter property, a probable association of TIMP-1 with tumour cell differentiation is suggested by its topographical correlation with ER detection.

Interactions of cytokines, growth factors, and the extracellular matrix in the cellular biology of uterine leiomyomata

OBJECTIVE

To review the available information regarding the role of cytokines, growth factors, and the extracellular matrix in the pathophysiology of uterine leiomyomata and to integrate this information in a suggested model of disease at the cellular level.

DESIGN

A thorough literature and MEDLINE search was conducted to identify the relevant studies in the English literature published between January, 1966 and October, 2001. A model of disease at the cellular level was developed using the most likely cytokines to be involved in the pathogenesis of leiomyomata as determined by our assessment of the available literature.

RESULT(S)

A number of cytokines and growth factors, including transforming growth factor-beta (TGF-beta), epidermal growth factor, monocyte chemotactic protein-1, insulin-like growth factors 1 and 2, prolactin, parathyroid-hormone-related peptide, basic fibroblast growth factor, platelet-derived growth factor, interleukin-8, and endothelin, have been investigated in myometrium and leiomyoma. Among these cytokines, TGF-beta appears to be the only growth factor that has been shown to be overexpressed in leiomyoma vs. myometrium, be hormonally-regulated both in vivo and in vitro, and be both mitogenic and fibrogenic in these tissues. In addition to the cytokines, extracellular matrix components such as collagen, fibronectin, proteoglycans, matrix metalloproteinases, and tissue inhibitors of metalloproteinases seem to play pivotal roles in the pathogenesis of leiomyomata.

CONCLUSION(S)

We believe that, given the extent and depth of the current research on the cellular biology of leiomyomata, the cellular mechanisms responsible in the pathogenesis of leiomyomata will be identified clearly within the foreseeable future. This will enable researchers to develop therapy directed against the molecules and mechanisms at the cellular level.

Inhibition of apoptosis in rat mesangial cells by tissue inhibitor of metalloproteinase-1

BACKGROUND

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an important inhibitor of extracellular matrix degradation. Recently, it was reported that TIMP-1 also could inhibit apoptosis in B type lymphocyte. This study was designed to examine the effects of TIMP-1 on mesangial cell apoptosis.

METHODS

The full-length cDNA of TIMP-1 was cloned and used to construct two recombinant vectors, TIMP-1S and TIMP-1AS, encoding sense TIMP-1 and antisense TIMP-1, respectively. The vectors were transfected into rat mesangial cells (RMC) and their expressions detected by Northern and Western blotting. Apoptosis was induced by serum deprivation, and was monitored for DNA fragmentation by TUNEL assay and DNA laddering. In addition, the expression of endogenous TIMP-1, matrix metalloprotein-2 (MMP-2), and MMP-9, as well as apoptosis-related genes Bcl-2 and Bax were investigated.

RESULTS

TIMP-1AS transfection induced a suppression of TIMP-1 expression accompanied by an earlier onset of apoptosis, and TIMP-1S transfection induced TIMP-1 over-expression accompanied by a much later onset of apoptosis. A neutralizing antibody of TIMP-1 restored the sensitivity of TIMP-1S-transfected RMC to serum deprivation, but a synthetic matrix metalloproteinase inhibitor BB-94 did not influence the sensitivity of TIMP-1S-transfected RMC to serum deprivation. Finally, TIMP-1 over-expression inhibited the expression of Bax but with no effect on the expression of Bcl-2.

CONCLUSION

TIMP-1 inhibits the serum deprivation-induced apoptosis in RMC, in which Bax might be involved.

Marrow matrix metalloproteinases (MMPs) and tissue inhibitors of MMP in acute leukaemia: potential role of MMP-9 as a surrogate marker to monitor leukaemic status in patients with acute myelogenous leukaemia

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were demonstrated to have important implications in the progression and invasiveness of many malignant disorders. In contrast, the biological significance of these molecules in human leukaemias is not clear. We determined the levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in the bone marrow of 37 patients with acute myelogenous leukaemia (AML) and 18 patients with acute lymphoblastic leukaemia (ALL) before chemotherapy. Nineteen bone marrow donors served as normal controls. After chemotherapy, sequential measurements were done during the course in 19 AML patients. The levels of TIMP-1 and TIMP-2 were significantly higher and MMP-9 levels were significantly lower in the AML and ALL patients than in the normal controls. MMP-2 levels were higher in ALL, but not AML patients, compared with controls. Moreover, the levels of marrow MMP-2 and MMP-9 did not parallel the numbers of leukaemic blasts in the peripheral blood. MMP-9 levels were significantly lower in the AML patients who achieved a complete remission (CR) than in those who did not (8.71 +/- 8.15 ng/ml vs 26.13 +/- 27.75 ng/ml, P < 0.05). The AML patients with lower MMP-9 levels (< or = 4.4 ng/ml) tended to have longer survival time than those with higher levels (> 12 months vs 4 months, P = 0.12). In addition, MMP-9 levels in the AML patients at CR rose to the same range as the controls, but dropped again at relapse, demonstrating a close relationship of marrow MMP-9 with disease status of AML. Therefore, we conclude that the level of marrow MMP-9 may be a useful surrogate marker for monitoring disease status in AML and propose it as a potential prognostic factor.

Matrix metalloproteinases in disease and repair processes in the anterior segment

The pathogenesis of many anterior segment disorders and ocular complications following surgery are secondary to the wound healing response. The extent of clinical damage observed is closely related to the amount of scarring and tissue contraction. Matrix metalloproteinases (MMPs) are a family of enzymes that play a vital role in all stages of the wound healing process. They degrade all extracellular matrix components and also have the ability to synthesize collagen and extracellular matrix members, and are therefore important in the remodeling of a wound. Overexpression of MMPs results in excessive extracellular matrix degradation, leading to tissue destruction and loss of organ function. In the case of the anterior segment, this may mean the loss of visual function. This review focuses on the role MMPs have in the development of various anterior segment disorders. The importance of MMPs in the wound healing response and its potential modulation to manipulate the scarring response is being recognized, and current developments will be described.

Up-regulation of MMP-8 and MMP-9 activity in the BALB/c mouse spinal cord correlates with the severity of experimental autoimmune encephalomyelitis

Induction of EAE can be inhibited or repressed by administration of soluble metalloproteinase inhibitors. We studied the matrix metalloproteinase (MMP) and their tissue inhibitor (TIMP) expression pattern in experimental autoimmune encephalomyelitis (EAE) of the resistant Th2 prone BALB/c mouse, where the disease can be induced with ultrasound-emulsified antigen/adjuvant (son-ag), but not with conventional technique (syr-ag). We found highly elevated expression of MMP-8 (neutrophil collagenase) mRNA and protein in diseased son-ag challenged mice, colocalizing to neutrophil infiltrates found in brain and extensively in the spinal cord submeningeal space. MMP-8 expression has not been found previously in sensitive mouse strains. The infiltrates stained positive also for MMP-9 protein, and brain homogenates from corresponding mice showed MMP-9 activity during overt disease (days 12-16 post-immunization). TIMP-1 gene expression could be detected in CNS samples from diseased son-ag challenged mice but not in syr-ag or control mice, and the TIMP-1 protein colocalized with GFAP-staining. In contrast, in syr-ag mice both TIMP-2 and TIMP-3 gene expression in the spinal cords was elevated. The results show that sonication, but not extrusion, creates an adjuvant formula potent in activating the matrix metalloproteinase cascade similar to sensitive mouse strains, strongly implicating their role in EAE induction in this Th2 prone strain. The study provides the basis for establishment of MMP-specific therapy in this model.

Tissue inhibitor of metalloproteinase-3 induces a Fas-associated death domain-dependent type II apoptotic pathway

Tissue inhibitors of metalloproteinases (TIMPs) are important regulators of matrix metalloproteinase (MMP) and adamalysin metalloproteinase activity. We previously reported that overexpression of TIMP-3 inhibits MMPs and induces apoptotic cell death in a variety of cell types and demonstrated that apoptosis is mediated through the N terminus of TIMP-3, which harbors the MMP inhibitory domain. However, little is known about the mechanisms underlying TIMP-3-induced apoptosis. Here we demonstrate that overexpression of TIMP-3 induced activation of initiator caspase-8 and -9 and promoted caspase-mediated cleavage of the death substrates poly(ADP-ribose) polymerase and focal adhesion kinase. Furthermore, TIMP-3 induced mitochondrial activation as demonstrated by loss of mitochondrial membrane potential and release of cytochrome c. Intervention studies demonstrated that overexpression of Bcl-2, the anti-apoptotic mitochondrial membrane protein, or CrmA, a viral serpin inhibitor of caspase-8, completely inhibited TIMP-3-induced apoptosis. Furthermore, a dominant-negative Fas-associated death domain mutant inhibited TIMP-3-induced death substrate cleavage and apoptotic death. Taken together, these results indicate that TIMP-3 overexpression induces a type II apoptotic pathway initiated via a Fas-associated death domain-dependent mechanism.

Complex roles of tissue inhibitors of metalloproteinases in cancer

Matrix metalloproteinases (MMPs) is tightly associated with extracellular matrix (ECM) turnover, which plays a very active role in tumor invasion and metastasis. Tissue inhibitors of metalloproteinases (TIMPs) plays a critical role in the homeostasis of ECM by regulating the activity of MMPs. TIMPs are well-known for their ability to inhibit MMP activity thereby inhibiting tumor growth and metastasis. However, many evidences suggest that TIMPs are multifunctional proteins, which regulate cell proliferation, apoptosis, proMMP-2 activation, and angiogenesis. These effects may be through MMP-dependent or MMP-independent pathways. Recent data indicate that TIMPs have many paradoxical roles in tumorigenesis. In particular, both inhibitory effect and stimulatory effect on tumorigenesis have been demonstrated in many animal models in which TIMPs were overexpressed in cancer cells or in mice. Elevated TIMP levels are reported in association with cancer progression and identified as poor prognostic indicators in several human tumor types. Herein, we review the complex roles of TIMPs in cancer growth and metastasis.

Presence of active gelatinases in endometrial carcinoma and correlation of matrix metalloproteinase expression with increasing tumor grade and invasion

BACKGROUND

The actions of the extracellular-matrix degrading enzymes, matrix metalloproteinases (MMPs), are implicated in tumorigenesis. The cellular localization of MMP-2, MMP-9, membrane type 1 (MT1)-MMP, tissue inhibitors of metalloproteinases (TIMPs) 1-3, and the presence of active gelatinases were investigated in endometrial carcinoma.

METHODS

Endometrial carcinomas were grouped according to histologic grade (Grades 1-3), depth of myometrial invasion (0, < 50%, > 50%) and the presence of vascular/lymphatic invasion. Twenty-nine endometrial carcinoma biopsies were investigated immunohistochemically to determine the tissue localization of MMP-2 (gelatinase A), MMP-9 (gelatinase B), MT1-MMP, and TIMPs 1-3. In situ hybridization was performed to localize MMP-2 and MMP-9 mRNA. The presence of active gelatinases was assessed using in situ zymography.

RESULTS

Epithelial tumor cells were the main site of MMP-2, MMP-9, and MT1-MMP protein. Variable stromal cell localization was also observed, particularly in areas adjacent to tumor nests. Semiquantitative analysis revealed increases in MMP-9 and MMP-2 but not MT1-MMP staining scores in tumor epithelial cells in the transition from histologic Grade 1 to Grades 2 and 3. Matrix metalloproteinase-9 and MT1-MMP staining scores in tumor cells were significantly associated with the presence of myometrial invasion and vascular/lymphatic invasion, while MMP-2 did not correlate with these factors. In addition, MT1-MMP was co-localized with MMP-2, supporting its role in the activation of proMMP-2. Tumor cells from all histologic grades stained intensely for TIMP-2 and TIMP-3 proteins, while variable stromal staining was observed. In Grade 1 carcinomas TIMP-1 was predominantly immunolocalized to the stromal compartment with variable tumor cell localization being observed in Grades 2 and 3 carcinomas. Matrix metalloproteinase-9 and MMP-2 mRNAs were predominantly observed in tumor epithelial cells as well as in the stroma to varying degrees. In situ zymography revealed active forms of gelatinases at the cellular surface and in association with tumor epithelial cells within endometrial carcinoma tissues.

CONCLUSIONS

These data suggest that increasing expression of MMPs and endometrial carcinoma progression are closely related. Active gelatinases are present in endometrial carcinoma, resulting in alterations to the microenvironment that promote tumor invasion and metastasis.

Control of extracellular matrix homeostasis of normal cartilage by a TGFbeta autocrine pathway. Validation of flow cytometry as a tool to study chondrocyte metabolism in vitro

OBJECTIVE

To validate flow cytometry as an experimental technique for the study of the homeostasis of the extracellular matrix (ECM) of human articular cartilage.

METHODS

Given the established insights in the relation between the transforming growth factor (TGF)-beta type II Receptor (TGF-betaRII)/TGF-beta auto/paracrine pathway, the intracellular levels of matrix metalloproteinases (MMPs) and their natural inhibitors (TIMPs), and the accumulation of ECM molecules in the ECM of articular cartilage, this metabolic pathway was used as a reference model to fulfill the objective. Chondrocytes were liberated from visually intact femoral condyle cartilage and cultured in gelled agarose to maintain their differentiated phenotype. After 2 weeks of culture, the chondrocytes were isolated from the agarose and flow cytometry was used to analyse the expression of TGF-betaRII on the plasmamembrane, the expression of TGFbeta1, MMP-1, MMP-3, TIMP-1 and TIMP-3 inside the cells, as well as the amounts of aggrecan, type II collagen and hyaluronan in the cell-associated matrix (CAM). The expression of the different substances was analysed with flow cytometry and reported as mean fluorescence intensity (MFI), which is due to the binding of FITC-labeled antibodies to their specific antigens. In addition, the effects of exogenous TGFbeta1 on the expression of these proteins was investigated on chondrocytes cultured in serum-free media. Enzyme Linked Immunosorbent Assay (ELISA) was performed to evaluate the MMP-1, MMP-3, TIMP-1 and MMP-1/TIMP-1 complex in the culture medium collected after the last 3 days of the culture period. The correlations between the data were analysed with the Spearman's test.

RESULTS

Exogenous TGF-beta1 increased the accumulation of aggrecan and hyaluronan in the CAM of chondrocytes and down-regulated the intracellular levels of MMP-1 and -3. TIMP-1 and -3 were increased after exposure to TGF-beta1. Baseline expression of TGF-betaRII on the plasmamembrane of normal human articular chondrocytes significantly correlated with the intracellular levels of TGFbeta1, TIMP-1 and TIMP-3. TGFbeta1 was correlated with TIMP-1, TIMP-3 and MMP-1. Aggrecan in the CAM was inversely correlated with the ratio of MMP-1 to TIMPs. In addition, there were correlations between TIMP-1 and TIMP-3, aggrecan and hyaluronan. ELISA also revealed the correlation between MMP-1 and TIMP-1 secreted by the chondrocytes into the nutrient medium. MMP-1/TIMP-1 complex was hardly found in the medium.

CONCLUSIONS

Some aspects of ECM metabolism of normal cartilage were evaluated by flow cytometry. Chondrocytes from normal human cartilage, when cultured in gelled agarose, showed correlations between the expression of TGF-betaRII/TGF-beta1 and the intracellular levels of TIMPs, indicating that TGF-beta autocrine pathway may contribute to homeostasis of the ECM in the normal cartilage. The relations between MMPs, TIMPs and the ECM molecules support that a physiological balance between MMPs and TIMPs results in a well-controlled matrix turnover in normal cartilage.

New functions for the matrix metalloproteinases in cancer progression

Matrix metalloproteinases (MMPs) have long been associated with cancer-cell invasion and metastasis. This provided the rationale for clinical trials of MMP inhibitors, unfortunately with disappointing results. We now know, however, that the MMPs have functions other than promotion of invasion, have substrates other than components of the extracellular matrix, and that they function before invasion in the development of cancer. With this knowledge in hand, can we rethink the use of MMP inhibitors in the clinic?

Proteolysis of the abdominal aortic aneurysm wall and the association with rupture

PURPOSE

to investigate proteolysis of the abdominal aortic aneurysm (AAA) wall and the association with rupture.

METHODS

levels of matrix metalloproteinases (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinases (TIMP-1 and TIMP-2) were measured in the walls of medium-sized (5-7 cm in diameter) ruptured AAA (rAAA) (n =30) and large (> or = 7 cm in diameter) asymptomatic AAA (aAAA) (n=30).

RESULTS

MMP-2 levels (median, range) were significantly higher in the walls of large aAAA (165 ng/g AAA tissue, 50-840) than from medium-sized rAAA (110 ng/g AAA tissue, 47-547, p=0.007). MMP-9 levels were significantly higher in the walls of medium-sized rAAA (107 ng/g AAA tissue, 19-582) than from large aAAA (55 ng/g AAA tissue, 11-278, p=0.012). TIMP-1 and TIMP-2 levels were equivalent. There was a positive correlation between MMP-2 and the diameter of aAAA (r=0.54, p=0.002), but a negative correlation with MMP-9 (r= -0.44, p=0.017). No significant correlations were found between aAAA diameter and TIMP-1 or TIMP-2.

CONCLUSION

AAA rupture is associated with higher levels of MMP-9. There is no association with TIMP-1 or TIMP-2 levels. MMP-2 levels are positively, whereas MMP-9 levels are negatively, correlated with aAAA size. MMP-9 may play a role in the progression towards rupture, whereas MMP-2 may play a role in expansion.

Relaxin increases secretion of tissue inhibitor of matrix metalloproteinase-1 and -2 during uterine and cervical growth and remodeling in the pig

Remodeling of reproductive organs during pregnancy requires degradation and resynthesis of structural barriers to cell invasion. Matrix metalloproteinases (MMPs) are enzymes that break down components of the extracellular matrix (ECM) and are essential for tissue remodeling processes. Tissue inhibitors of metalloproteinases (TIMPs) are important regulators of MMP activity. In the pig, relaxin stimulates growth and remodeling of the uterus and cervix during pregnancy, effects that include the ability to alter elements of the ECM. Therefore, the objective of this study was to determine whether relaxin alters the production and/or activity of TIMP-1 and TIMP-2 in the porcine uterus or cervix. The growth-promoting effects of relaxin were elicited by administering relaxin to prepubertal gilts every 6 h for 54 h. Expression of TIMP-1 and TIMP-2 was characterized by immunoblotting. Total enzyme activity was measured using an MMP-specific fluorescent substrate assay. TIMP-1 and TIMP-2 proteins were present in the uterus and cervix of control and relaxin-treated pigs, and both proteins were increased by relaxin in the uterine flushes and tissues (P < 0.05). Inhibitor activity in uterine tissue extracts and uterine flushes from relaxin-treated animals was greater than that in controls; however, this activity was restricted to inhibition of MMP-2. In the uterine cervix, relaxin enhanced expression of TIMP-1 and TIMP-2 (P < 0.05), whereas expression of both TIMP proteins was similar in the vaginal cervix of control and relaxin-treated animals. Likewise, inhibitor activity against MMP-2 in the uterine cervix was enhanced in response to relaxin (P < 0.05). In contrast, inhibitor activity was attenuated in extracts from the vaginal cervix (P < 0.05). This study highlights the complex nature of MMP/TIMP regulation during reproductive tissue growth and suggests that TIMP-1 and TIMP-2 may be involved in other aspects of the growth process. These data support a role for relaxin in regulating the activity of TIMPs during growth and remodeling of reproductive connective tissue.

Evaluation of extracellular matrix proteins and tissue inhibitor of matrix metalloproteinases-2 on bovine inner cell mass outgrowth in vitro

Effects of extracellular matrix proteins and tissue inhibitor of matrix metalloproteinases-2 (TIMP-2) on bovine inner cell mass (ICM) outgrowth and proteinase production in vitro were determined. Inner cell masses were isolated immunosurgically from day 7 embryos (day 0 = onset of estrus) and cultured for 96 h. In experiment 1, cellular outgrowth and gelatinase production were evaluated for ICM cultured on collagen IV, fibronectin, or laminin. More (P < 0.05) ICM generated cellular outgrowth on fibronectin (71%). compared with collagen IV (0%) or laminin (15%). Inner cell mass and outgrowth areas were greatest (P < 0.05) on fibronectin after 96 h of culture, compared with laminin. Although the incidence of cellular outgrowth on laminin was limited, numbers of cells in outgrowths supported by laminin were similar (P > 0.10) to fibronectin except at 72 h of culture, where more (P < 0.05) cells were in laminin than in fibronectin outgrowths. Gelatinase activity was not detected in conditioned medium. In experiment 2, cellular outgrowth and plasminogen activator production by ICM cultured on fibronectin in medium containing 0 or 10 microg/ml TIMP-2 were evaluated. Inner cell mass and outgrowth areas, and numbers of cells in outgrowths were greater (P < 0.05) in 10 compared with 0 microg/ml TIMP-2 at 96 h of culture. Mean plasminogen activator activity in conditioned medium from ICM cultured in 10 microg/ml TIMP-2 was greater (P < 0.05) compared with 0 microg/ml TIMP-2 (16.2 +/- 4.8 versus 6.7 +/- 1.4 x 10(-3) IU/ml, respectively). These results demonstrate that cellular outgrowth from bovine ICM is supported by fibronectin and is stimulated by TIMP-2.

Correlation of tissue inhibitor of metalloproteinase-2 with proliferative activity and patients' survival in breast cancer

Tissue inhibitors of metalloproteinases (TIMPs) are endogenous regulators of matrix metalloproteinases (MMPs). They are believed to possess several distinct cellular functions, particularly the contradictory activities of inhibiting MMPs and promoting tumor cell growth. Immunohistochemistry was performed to detect TIMP-2 protein in 136 infiltrative breast carcinomas. TIMP-2 protein was analyzed in parallel with clinicopathologic features (tumor size, histologic type, nuclear and histologic grade, stage), patients' overall survival and ER, PR, Ki-67, topo IIalpha, c-erbB-2, p53 and bcl-2 proteins. Statistical analysis was performed using univariate and multivariate models analysis. Immunoreactivity for TIMP-2 was observed in cancer cells and stromal fibroblasts in 106 (77.94%) and 104 (76.47%) of 136 cases, respectively. TIMP-2 protein expression in stromal fibroblasts showed a statistically significant inverse correlation with tumor size (P =.014). An inverse correlation was also observed between TIMP-2 epithelial immunoreactivity and nuclear and histologic grade (P =.036 and P =.007, respectively). TIMP-2 protein reactivity showed statistically significant positive associations with topo IIalpha and bcl-2 in stromal and cancer cells, respectively (P =.032 and P =.001, respectively). TIMP-2 protein expression in cancer and stromal cells was associated with better patients' overall survival (P =.002 and P =.038, respectively). When evaluated by the Cox's proportional hazard regression model, this association was further established, but only as far as TIMP-2 expression in tumor epithelium was concerned (P =.019). Our results support the multifunctional potential of TIMP-2 through its correlation on the one hand to a favorable outcome, due to its MMP inhibitory activity and on the other to topo IIalpha contributing to its growth factor activity.

Tissue inhibitor of metalloproteinases 1 is an autocrine and paracrine survival factor, with additional immune-regulatory functions, expressed by Hodgkin/Reed-Sternberg cells

Tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2 are proteins with proteinase-inhibiting and cytokine properties. TIMP-1 is active primarily in B cells and B-cell lymphomas, whereas TIMP-2 expression is restricted to T cells. The expression of TIMP-1 and TIMP-2 in lymph nodes from patients with Hodgkin disease (HD) and in Hodgkin-derived cell lines was investigated. In situ hybridization showed TIMP-1 RNA expression in 3% to 80% of Hodgkin/Reed-Sternberg (H/R-S) cells from 14 of 15 patients, with results in one patient being at the lowest detection limit; no expression of TIMP-2 in H/R-S cells; and only weak expression of TIMP-2 in reactive lymphoid tissue. Production of TIMP-1 protein by H/R-S cells was accordingly found on immunohistochemical analysis of lymph nodes from patients with HD. There was only low expression of matrix metalloproteinase (MMP)-2, which is mainly inhibited by TIMP-2; no expression of MMP-1 and MMP-3 in reactive lymphoid tissue; and no expression of these MMPs in H/R-S cells. Thus, TIMP-1 expression in lymph nodes was not correlated with metalloproteinase expression. Five of 7 Hodgkin-derived cell lines expressed TIMP-1 at the protein level. Only one of these cell lines expressed TIMP-2, at the lowest detection limit. TIMP-1 levels in plasma from patients with HD were within the same range as those in plasma from healthy controls. Recombinant human TIMP-1 inhibited induced cell death in Hodgkin-derived cell lines in vitro. TIMP-1 and TIMP-2 inhibited T-cell cytotoxicity against autologous cells presenting tumor-associated antigens and in allogeneic mixed lymphocyte cultures. Thus, TIMP-1, aside from its role in proteinase equilibrium, is an autocrine and paracrine survival factor for H/R-S cells and an immunosuppressive protein expressed in Hodgkin lymphomas.

Regulation of hepatic fibrosis and extracellular matrix genes by the th response: new insight into the role of tissue inhibitors of matrix metalloproteinases

Hepatic fibrosis is the hallmark of Schistosoma mansoni infection and often results in portal hypertension and bleeding from esophageal varices. The fibrotic process is highly dependent on type 2 cytokines, yet their role in the regulation of extracellular matrix remodeling genes remains largely unknown. Here, we examined the expression of matrix metalloproteases (MMP) -2, -3, -9, -12, and -13 and their inhibitors, tissue inhibitor of metalloproteases (TIMP) -1, -2, and -3, in the livers of infected mice and correlated their expression profiles with fibrosis and type 2 cytokine production. Expression of MMP-2, -3, -9, -12, and -13 and of TIMP-1 and -2 mRNA rapidly increased at the onset of egg laying in infected mice, while TIMP-3 was unchanged. Because TIMP are presumed to be important regulators of the extracellular matrix, and their expression correlated with the development of fibrosis, we studied their role in fibrogenesis by infecting TIMP-1- and TIMP-2-deficient mice. Strikingly, our data revealed no role for TIMP-1 or -2 in the fibrotic pathology induced by S. mansoni eggs. Because of these findings, we infected IL-10/IFN-gamma-deficient mice that develop an exaggerated fibrotic response to determine whether changes in type 2 cytokine dominance influence the pattern of MMP and TIMP expression. Fibrosis and type 2 cytokine production correlated with increased MMP-2/MMP-9 vs TIMP-1/TIMP-2 expression. These data, in addition to our knockout studies, demonstrate that TIMP-1/TIMP-2 play no essential role in fibrogenesis in schistosomiasis. Indeed, our findings suggest that inhibiting profibrotic cytokines or specific MMP may be a more effective strategy to ameliorate fibrotic pathology.

Adenovirus-based overexpression of tissue inhibitor of metalloproteinases 1 reduces tissue damage in the joints of tumor necrosis factor alpha transgenic mice

OBJECTIVE

Rheumatoid arthritis is a prototype of a destructive inflammatory disease. Inflammation triggered by the overexpression of tumor necrosis factor alpha (TNFalpha) is a driving force of this disorder and mediates tissue destruction. Since matrix metalloproteinases (MMPs) are among the molecules activated by TNFalpha, we hypothesized that overexpression of their natural inhibitor, tissue inhibitor of metalloproteinases 1 (TIMP-1), in TNFalpha transgenic mice could inhibit the development of destructive arthritis.

METHODS

Systemic treatment was carried out by replication-defective adenoviral vectors for TIMP-1, beta-galactosidase, or phosphate buffered saline (PBS), which were applied once at the onset of arthritis. Clinical, serologic, radiologic, and histologic outcomes were assessed 18 days after the treatment.

RESULTS

The AdTIMP-1 group showed significantly reduced paw swelling and increased grip strength compared with the 2 control groups, whereas total body weight, TNFalpha, and interleukin-6 levels were similar in all 3 groups. Radiographic assessment revealed a significant reduction of joint destruction in the AdTIMP-1 group; this was confirmed by histologic analyses showing reduced formation of pannus and erosions in the AdTIMP-1 group compared with the AdLacZ and PBS control groups. The formation of arthritis-specific autoantibodies to heterogeneous nuclear RNP A2 was not observed in the AdTIMP-1 group but was present in the 2 control groups.

CONCLUSION

These results indicate a central role of MMPs in TNFalpha-mediated tissue damage in vivo and a promising therapeutic role for TIMP-1.

Tissue inhibitor of metalloproteinases 1 and 2 directly stimulate the bone-resorbing activity of isolated mature osteoclasts

Tissue inhibitor metalloproteinases 1 (TIMP-1) and 2 have been reported to inhibit bone resorption. However, here, we report the direct action of both TIMP-1 and TIMP-2 on isolated rabbit mature osteoclasts to stimulate their bone-resorbing activity at significantly lower concentrations (approximately ng/ml) than those (approximately microg/ml) required for the inhibition of bone resorption. The cell population used in this study consisted of a mature osteoclast population with >95% purity. TIMP-1 (approximately 50 ng/ml) and TIMP-2 (approximately 8-10 ng/ml) increased the pit area excavated by the isolated mature osteoclasts. The stimulatory effects of TIMPs were abolished by simultaneous addition of anti-TIMP antibodies. At higher concentrations, the stimulation of bone resorption decreased reversely to the control level. The magnitude of the stimulatory effect of TIMP-2 was more than that of TIMP-1. Metalloproteinase inhibitors such as BE16627B and R94138 could not replace TIMPs with respect to the bone-resorbing activity, suggesting that the osteoclast-stimulating activity of TIMPs was independent of the inhibitory activity on matrix metalloproteinases (MMPs). TIMPs stimulated tyrosine phosphorylation of cellular proteins in the isolated mature osteoclasts. Both herbimycin A, an inhibitor of tyrosine kinases, and PD98059 and U0126, inhibitors of mitogen-activated protein kinase (MAPK), completely blocked the TIMP-induced stimulation of osteoclastic bone-resorbing activity. On the plasma membrane of osteoclasts, some TIMP-2-binding proteins were detected by a cross-linking experiment. These findings show that TIMPs directly stimulate the bone-resorbing activity of isolated mature osteoclasts at their physiological concentrations and that the stimulatory action of TIMPs is likely to be independent of their activities as inhibitors of MMPs.

Differential growth regulation in human melanoma cell lines by TIMP-1 and TIMP-2

We investigated the role of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in the growth regulation. Primary (PM-WK and KHm-4), recurrent primary (RPM-EP and RPM-MC), lymph node metastatic (MM-AN, MM-BP and MM-RU), and a visceral metastatic (MM-LH) melanoma cell lines were used. Reverse transcriptase-coupled polymerase chain reaction and Western blotting revealed that all expressed and produced TIMP-1 and TIMP-2 except for PM-WK, which neither expressed nor produced TIMP-1. TIMP-1 and TIMP-2 secretion levels were measured by enzyme-linked immunosorbent assay in supernatants of cells. We found that the TIMP-1 production level was correlated with the cell migration rate. Moreover, TIMP-1 enhanced the cell migration of PM-WK. The growth of the primary melanoma cell lines was stimulated by TIMP-1 and inhibited by TIMP-2. In contrast, the growth of the visceral metastatic melanoma cell line was stimulated by TIMP-2.

Phenotypic alterations in Caki-1 cells as a consequence of TIMP-1 overexpression

Maintenance of the extracellular matrix (ECM) is important for tissue integrity and cellular physiology. Normal ECM turnover is regulated by a balance between matrix metalloproteinases and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). In metastasis, this balance favours increased ECM degradation. The objective of this study was to determine the effects of TIMP-1 overexpression on the metastatic process. To this end, we stably transfected a renal carcinoma cell line, Caki-1, with TIMP-1, using a pRc/CMV expression plasmid and LIPOFECTAMINE transfection reagent. The resultant clones displayed increased adhesion on the ECM substratum, including collagen type IV and laminin, and altered invasive capacity through fibronectin and Matrigel, dependent upon the level of TIMP-1 expression. These changes were not due to altered integrin expression, as assessed by flow cytometry. As well as protease inhibitory activity, TIMPs can influence cell proliferation and cell survival. The TIMP-1 clones displayed no changes in proliferation under normal growth conditions, compared with Caki-1 cells. However, under reduced serum conditions, the TIMP-1 clones had a greater percentage of cells in both S (P<0.05) and G(2)/M (P<0.005) phases and less cells in G(0)/G(1) (P<0.001) of the cell cycle than Caki-1 cells. The results confirm a dual role for TIMP-1 in invasion and metastasis, and provide further clues behind the molecular mechanisms in these processes.

Matrix metalloproteinase inhibition after myocardial infarction: a new approach to prevent heart failure?

Increased activity of matrix metalloproteinases (MMPs) has been implicated in numerous disease processes, including tumor growth and metastasis, arthritis, and periodontal disease. It is now becoming increasingly clear that extracellular matrix degradation by MMPs is also involved in the pathogenesis of cardiovascular disease, including atherosclerosis, restenosis, dilated cardiomyopathy, and myocardial infarction. Administration of synthetic MMP inhibitors in experimental animal models of these cardiovascular diseases significantly inhibits the progression of, respectively, atherosclerotic lesion formation, neointima formation, left ventricular remodeling, pump dysfunction, and infarct healing. This review focuses on the role of MMPs in cardiovascular disease, in particular myocardial infarction and the subsequent progression to heart failure. MMPs, which are present in the myocardium and capable of degrading all the matrix components of the heart, are the driving force behind myocardial matrix remodeling. The recent finding that acute pharmacological inhibition of MMPs or deficiency in MMP-9 attenuates left ventricular dilatation in the infarcted mouse heart led to the proposal that MMP inhibitors could be used as a potential therapy for patients at risk for the development of heart failure after myocardial infarction. Although these promising results encourage the design of clinical trials with MMP inhibitors, there are still several unresolved issues. This review describes the biology of MMPs and discusses new insights into the role of MMPs in several cardiovascular diseases. Attention will be paid to the central role of the plasminogen system as an important activator of MMPs in the remodeling process after myocardial infarction. Finally, we speculate on the use of MMP inhibitors as potential therapy for heart failure.

Inhibition of Wilms' tumor growth by intramuscular administration of tissue inhibitor of metalloproteinases-4 plasmid DNA

Extracellular matrix (ECM) degrading matrix metalloproteinases (MMPs) lead to ECM turnover, a key event in cancer growth and progression. The tissue inhibitors of matrix metalloproteinases (TIMPs) limit the activity of MMPs, which suggests their use for cancer gene therapy. Here we report that systemic administration of naked TIMP-4 DNA significantly inhibited Wilms' tumor growth in nude mice. TIMP-4, whose expression was lost in Wilms' tumor, inhibited the growth of G401 Wilms' tumor cells at a concentration lower than those required for MMP inhibition. This inhibition was associated with internalization of exogenous recombinant TIMP-4. Electroporation-mediated intramuscular injection of TIMP-4 expression plasmid resulted in sustained plasma TIMP-4 levels and significant tumor suppression. Our data demonstrate a tumor suppressive effect of TIMP-4 against Wilms' tumor and the potential utility of intramuscular delivery of TIMP gene for treatment of kidney derived cancers.

Differential expression and localization of TIMP-1 and TIMP-4 in human gliomas

Studies have suggested that an imbalance of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to the malignant phenotype of gliomas. In this study, we have undertaken a detailed analysis of expression of the TIMP family in normal human brain and malignant gliomas at both the mRNA and protein level. Reverse transcription-PCR (RT-PCR) analyses of total RNA from surgical tumour specimens revealed unique expression patterns for the 4 members of the TIMP family, with TIMP-1 and -4 showing positive and negative correlations, respectively, with glioma malignancy. By RT-PCR, TIMP-2 and TIMP-3 expression did not change with tumour grade. In situ hybridization localized TIMP-1 to glial tumour cells and also to the surrounding tumour vasculature. TIMP-4 transcripts were predominantly localized to tumour cells, though minor expression was found in vessels. Recombinant TIMP-4 reduced invasion of U251 glioma cells through Matrigel, and U87 clones overexpressing TIMP-4 showed reduced invasive capacity in vitro. TIMP-4, but not TIMP-1, blocked Membrane Type-1-MMP-mediated progelatinase-A (MMP-2) activation in human umbilical vein endothelial cells. The differential expression and localization of individual TIMPs may contribute to the pathophysiology of human malignant gliomas, particularly with regard to tumour vascularization.

Increased expression of the Zn-finger transcription factor BTEB1 in human endometrial cells is correlated with distinct cell phenotype, gene expression patterns, and proliferative responsiveness to serum and TGF-beta1

Basic transcription element binding (BTEB, also designated BTEB1) protein is a member of the Sp-family of GC-box binding transcription factors that exhibit distinct patterns of expression in many cell types and tissues. A role for BTEB1 in the regulation of cell growth and gene transcription has been invoked, but little is known about the molecular mechanisms underlying these activities. The present study examined the functional consequences of high and low BTEB1 expression in the human endometrial carcinoma cell line Hec-1-A, by deriving stable clonal lines that expressed sense (S) and anti-sense (As) rat BTEB1 constructs. Clonal S lines, with BTEB1 mRNA and protein levels higher than in corresponding parent (N) and As lines, displayed enhanced DNA synthesis upon 3[H]-thymidine incorporation, in serum-containing but not in serum-free medium, and increased cell cycle kinetics, concomitant with the induction in expression of the genes for the cell cycle-associated components cyclin D1, PCNA, cyclin-dependent kinase (Cdk) inhibitor p21, and Cdk2. Compared to N and As lines, S lines also had diminished ability to grow in multi-layers and exhibited increased mRNA levels for plasminogen activator inhibitor-1 (PAI-1), secretory leukocyte protease inhibitor (SLPI), and tissue inhibitor of metalloproteinases (TIMP)-2. In serum-free medium, S, but not N nor As lines, had enhanced DNA synthesis with transforming growth factor (TGF)-beta1, albeit all lines demonstrated similar responses to insulin-like growth factor-I and to epidermal growth factor, respectively. The higher DNA synthesis in S relative to N and As, lines upon exogenous TGF-beta1 addition, was observed in concert with increased expression of cyclins D1 and E and p21, genes. Moreover, S and As lines had increased mRNA levels for TIMP-1, TIMP-2, PAI-1, and beta-catenin, and diminished SLPI, and to a lesser extent, Cdk4 mRNA levels, with TGF-beta1 treatment. These results suggest that BTEB1 may mediate cell growth, in part, by modulating gene expression levels of distinct cell cycle and growth-associated proteins. The correlation between serum- and TGF-beta1 induction of DNA synthesis with increased BTEB1 expression further suggests that BTEB1 may constitute an important downstream regulatory component of various signaling pathways utilized by serum-associated and other growth factors in endometrial epithelial cells.

Selective induction of tissue inhibitor of metalloproteinase-1 in bleomycin-induced pulmonary fibrosis

Tissue inhibitors of metalloproteinases (TIMPs) are multifunctional proteins that have the capacity to modify cellular activities and to modulate matrix turnover. We demonstrate that TIMP-1 messenger RNA (mRNA) and protein expression are selectively and markedly increased in a murine model of bleomycin-induced pulmonary fibrosis. Northern analysis showed that lung steady-state TIMP-1 mRNA levels increased 14-fold after bleomycin administration compared with control mice. Expression of the genes for TIMP-2, TIMP-3, and interstitial collagenase (matrix metalloproteinase-13) was unaltered in the injured lung. In situ hybridization demonstrated that TIMP-1 gene induction was spatially restricted to areas of lung injury. Metalloproteinase inhibitory activity of relative molecular mass of ~ 21 to 28 kD, corresponding to the molecular weights for TIMP-1 and TIMP-2, was identified in lung extracts of bleomycin-injured mice by reverse zymography. Western analysis demonstrated that TIMP-1 protein levels in bronchoalveolar lavage fluid (BALF) of bleomycin-treated mice increased 220- and 151-fold at Days 4 and 28, respectively, compared with control mice. TIMP-2 immunoreactive protein in the BALF increased 20- and 103-fold relative to controls at Days 4 and 28, respectively. These results demonstrate that TIMP-1 gene expression is selectively increased, and that the expression of TIMP-1 and TIMP-2 is differentially regulated in bleomycin-induced pulmonary fibrosis. The profound and durable increase in TIMP-1 and TIMP-2 proteins suggests an important regulatory role for these antiproteases in the inflammatory and fibrotic responses to bleomycin-induced lung injury.

Expression of MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2 mRNA in valvular lesions of the heart

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play an important role in several diseases. This study was undertaken to investigate the mRNA synthesis of MMP2, MMP9, membrane-type 1 (MT1)-MMP, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 by in situ hybridization in a set of heart mitral and aortic valves operatively removed due to degenerative or inflammatory valvular diseases. The material consisted of 21 valves, eight with endocarditis and 13 with a degenerative valvular disease. The samples were studied by in situ hybridization with specific probes for MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2. Synthesis of MMP2 mRNA was found in seven valves, five with endocarditis and two with degenerative valvular disease. Signals for MMP9 mRNA were found in two cases with endocarditis and five cases with degenerative valvular disease. No signal for MT1-MMP mRNA was found in the lesions. TIMP1 mRNA, on the other hand, was found in 17 cases, both endocarditis and degenerative valvular disease. TIMP2 mRNA was found in three cases of endocarditis. The signals for MMP2, MMP9, TIMP1, and TIMP2 mRNA were localized in endothelial cells and in fibroblast-like cells expressing alpha-smooth muscle actin, thus showing myofibroblast-type differentiation. The results show that matrix metalloproteinases MMP2 and MMP9, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 mRNAs are synthesized in diseased valves and suggest that they may contribute to matrix remodelling in valvular disease.

Tissue inhibitor of matrix metalloproteinase-3 expression in the mouse uterus during implantation and artificially induced decidualization

During implantation in mice, tissue inhibitor of matrix metalloproteinases-3 is believed to play a key role in inhibiting matrix metalloproteinase activity associated with embryo invasion and tissue remodeling. The first objective of this study was to quantitatively compare the steady-state mRNA levels of tissue inhibitors of matrix metalloproteinases between segments of the mouse uterus undergoing decidualization compared to those that are not during early pregnancy plus oil-induced decidualization. Steady-state tissue inhibitor of metalloproteinase-3 mRNA levels were significantly greater in implantation compared to interimplantation areas on days 6 and 7 of pregnancy and in stimulated compared to nonstimulated uterine horns at 48 and 72 hr after artificial induction of decidualization. Steady-state tissue inhibitor of metalloproteinase-1 mRNA levels were significantly greater in implantation compared to interimplantation areas on days 5-8 of pregnancy and in stimulated compared to nonstimulated uterine horns at 24, 48, and 72 hr after oil stimulation. Therefore, the steady-state mRNA levels of tissue inhibitors of metalloproteinase-1 and -3 increased in the uterus during decidualization. The second objective of this study was to determine if transforming growth factor-beta1 influences tissue inhibitors of metalloproteinase mRNA concentrations in mouse endometrial stromal cells. As determined by Northern blot analyses, transforming growth factor beta1 significantly increased tissue inhibitors of matrix metalloproteinases-1 and -3 mRNA levels in cultured mouse endometrial stromal cells isolated from uteri sensitized for decidualization. On the other hand, interleukin-1, epidermal growth factor, and leukemia inhibitory factor had no effect. The results of this study further characterize the tissue inhibitor of metalloproteinase expression in the uterus during implantation and artificially induced decidualization and the potential control of their expression in the stroma by transforming growth factor.

Distinct expression patterns and levels of enzymatic activity of matrix metalloproteinases and their inhibitors in primary brain tumors

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been implicated in the immense invasive potential and neovascularization of primary brain tumors. We investigated the gene expression profiles of MMPs 1, 2, 3, 7, 9, 12, 13, 14, 16 and of TIMPs 1, 2, 3, and 4 in various primary brain tumors (astrocytoma WHO grade I-III, glioblastoma, PNET, ependymoma III and oligoastrocytoma II) using novel RNase protection assay probe sets. In addition, we determined the level and cellular source of gelatinolytic activity and localized gelatinase B and TIMP-1 RNA. Distinct expression patterns of the MMP and TIMP genes were found in the various brain tumors tested. While the WHO grade I and II tumors had MT1/MT3 ratios below 1, the malignant (grade III and IV) tumors had ratios above 1. Strong expression of TIMP-1 RNA was observed in all malignant tumors and in grade I pilocytic astrocytomas and localized to the walls of neovessels. Quantitative analysis of enzymatic activity in the soluble fraction of protein extracts revealed that in most tumors gelatinases remained in the inactive pro-form. In situ zymography revealed net gelatinolytic activity in neurons of normal brain and in tumor cells and vessel walls of all tumors tested. Immunohistochemistry demonstrated that gelatinase B was localized to vessel walls, to neutrophils in areas of hemorrhage, and in glioblastomas to macrophages. Together these data demonstrate that the different primary brain tumors show distinct regulation of MMP and TIMP genes. The localization of the soluble gelatinase B indicates an association with neovascularization, whereas membrane-bound MMPs may account for the invasive potential of the glial tumor cells.

Significance of matrix metalloproteinases and tissue inhibitors of metalloproteinase expression in the recurrence of superficial transitional cell carcinoma of the bladder

PURPOSE

We determined whether expression levels of matrix metalloproteinase (MMP)-2, MMP-9, membrane-type MMP-1 (MT1-MMP), tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 messenger (m) RNA in superficial transitional cell carcinoma of the bladder may be used as predictors of tumor recurrence.

MATERIALS AND METHODS

Total RNA was extracted from 51 superficial transitional cell carcinomas of the bladder, and expression levels of MMP-2, MMP-9, MT1-MMP, TIMP-1 and TIMP-2 messenger mRNA in these specimens were measured by Northern blot analysis. Results were evaluated in regard to tumor recurrence.

RESULTS

Mean MMP-9 and TIMP-2 mRNA expression in the tumors of patients with recurrence were 2.5 and 3-fold higher, respectively, than in those of patients without recurrence despite no significant differences in MMP-2, MT1-MMP or TIMP-1 expression. The recurrence-free survival rate of patients with elevated MMP-9 and TIMP-2 mRNA expression was significantly lower than that of patients with normal MMP-9 and TIMP-2 expression, respectively. In addition, Cox's multivariate analysis revealed that elevated MMP-9 and TIMP-2 were strongly associated with a high incidence of intravesical recurrence of superficial bladder cancer.

CONCLUSIONS

These results indicate that MMP-9 and TIMP-2 are strongly expressed in the tumors of patients with recurrence compared with those without recurrence and elevated MMP-9 and TIMP-2 may be used as predictors of recurrence in patients with superficial transitional cell carcinoma.

Matrix metalloproteinases in cancer invasion, metastasis and angiogenesis

Matrix metalloproteinases (MMPs) are a family of proteinases that play an important role in cancer as well as in numerous other diseases. In this article, we summarize the current views on the role of MMPs in cancer with respect to invasion, metastasis and angiogenesis. A positive correlation between tumor progression and the expression of multiple MMP family members in tumor tissues has been demonstrated in numerous human and animal studies. It has been assumed that cancer cells are responsible for producing the MMPs in human tumors. However, recent evidence suggests that tumor cells have docking sites that bind stromal-cell-secreted MMPs. Furthermore, the role of MMPs produced by endothelial cells, especially MMP-2 and MT1-MMP, appear to be crucial for tumor angiogenesis, which is a requirement for cancer growth and dissemination.

Acute exercise induced changes in rat skeletal muscle mRNAs and proteins regulating type IV collagen content

This experiment tested the hypothesis that running-induced damage to rat skeletal muscle causes changes in synthesis and degradation of basement membrane type IV collagen and to proteins regulating its degradation. Samples from soleus muscle and red and white parts of quadriceps femoris muscle (MQF) were collected 6 h or 1, 2, 4, or 7 days after downhill running. Increased muscle beta-glucuronidase activity indicated greater muscle damage in the red part of MQF than in the white part of MQF or soleus. In the red part of MQF, type IV collagen expression was upregulated at the pretranslational level and the protein concentration decreased, whereas matrix metalloproteinase-2 (MMP-2), a protein that degrades type IV collagen, and tissue inhibitor of metalloproteinase-2 (TIMP-2), a protein that inhibits degradation, were increased in parallel both at mRNA and protein levels. Type IV collagen mRNA level increased in the white part of MQF and soleus muscle. The protein concentration increased in the white part of MQF and was unchanged in soleus muscle. MMP-2 and TIMP-2 changed only slightly in the white part of MQF and soleus muscle. The changes seem to depend on the severity of myofiber injury and thus probably reflect reorganization of basement membrane compounds.

Inhibition of ADAMTS4 (aggrecanase-1) by tissue inhibitors of metalloproteinases (TIMP-1, 2, 3 and 4)

ADAMTS4 (aggrecanase-1) is considered to play a key role in the degradation of aggrecan in arthritides. The inhibitory activity of tissue inhibitors of metalloproteinases (TIMPs) to ADAMTS4 was examined in an assay using aggrecan substrate. Among the four TIMPs, TIMP-3 inhibited the activity most efficiently with an IC(50) value of 7.9 nM, which was at least 44-fold lower than that of TIMP-1 (350 nM) and TIMP-2 (420 nM) and >250-fold less than that of TIMP-4 (2 microM for 35% inhibition). These results suggest that TIMP-3 is a potent inhibitor against the aggrecanase activity of ADAMTS4 in vivo.

Proteases in invasion: matrix metalloproteinases

The role of proteases in general, and the matrix metalloproteinases in particular, in tumor invasion and metastasis is well established. However, the classic view that these enzymes simply provide a mechanism for the breakdown of connective tissue barriers has been challenged. This overview summarizes recent evidence to support the changing view of the role of matrix metalloproteinases in cancer progression. First we briefly review the central role of cell invasion in cancer progression and also the matrix metalloproteinase family members. We then focus on the emerging roles for these enzymes in cancer progression, including the role of matrix metalloproteinases in cell proliferation and release of growth factors, cell migration and in modification of the extracellular matrix to reveal cryptic sites that alter cell behaviour.

Tissue inhibitor of metalloproteinases 1 regulation of interleukin-10 in B-cell differentiation and lymphomagenesis

Tissue inhibitors of metalloproteinases (TIMPs), first described as specific inhibitors of matrix metalloproteinases, have recently been shown to exert growth factor activities. It was previously demonstrated that TIMP-1 inhibits apoptosis in germinal center B cells and induces further differentiation. Interleukin-10 (IL-10) is reported as a vital factor for the differentiation and survival of germinal center B cells and is also a negative prognostic factor in non-Hodgkin lymphoma (NHL). However, the mechanism of IL-10 activity in B cells and the regulation of its expression are not well understood. IL-10 has been shown to up-regulate TIMP-1 in tissue macrophages, monocytes, and prostate cancer cell lines, but IL-10 modulation of TIMP-1 in B cells and the effect of TIMP-1 on IL-10 expression has not been previously studied. It was found that TIMP-1 expression regulates IL-10 levels in B cells and that TIMP-1 mediates specific B-cell differentiation steps. TIMP-1 inhibition of apoptosis is not IL-10 dependent. TIMP-1 expression in B-cell NHL correlates closely with IL-10 expression and with high histologic grade. Thus, TIMP-1 regulates IL-10 expression in B-cell NHL and, through the inhibition of apoptosis, appears responsible for the negative prognosis associated with IL-10 expression in these tumors.

Role of human airway smooth muscle in altered extracellular matrix production in asthma

1. The underlying abnormality in asthma is not fully understood; however, inflammation, airway remodelling and bronchial hyperresponsiveness are key factors. The plasma exudate from the microvascular leakage plays a significant role in remodelling, which includes extracellular matrix (ECM) protein deposition/breakdown and airway smooth muscle (ASM) hyperplasia/hypertrophy. 2. The ECM is an intricate network of macromolecules that forms the 'scaffolding' of the airways. This scaffolding not only acts as mechanical support that plays a crucial role in the maintenance of airway function and structure, but it is also a dynamic and complex network that has the potential to influence cellular function, including migration, differentiation and proliferation of a number of cell types. 3. In asthmatic airways, the profile of ECM proteins is altered. The deposition of collagen I, III, V, fibronectin, tenascin, hyaluronan, versican and laminin alpha2/beta2 is increased, whereas the deposition of collagen IV and elastin is decreased. 4. This imbalance in the ECM profile within the asthmatic airway could be due to: (i) increased de novo synthesis of ECM proteins; (ii) decreased activity of its degrading enzymes, namely matrix metalloproteinases (MMP); or (iii) upregulation of the tissue-specific inhibitors of metalloproteinases (TIMP). 5. One of the characteristic features of asthma is an increase in the amount of ASM within the airways. The ECM proteins/MMP/TIMP in and around the smooth muscle may play a contributory role in this increased growth. 6. The role of current asthma treatments in the prevention or reversal of airway ECM changes is an area that has only recently become of interest, with the majority of the in vivo work focusing on the effects of corticosteroids. 7. The evidence presented in this review indicates that the ASM may influence its own environment/proliferation through the production of ECM proteins, MMP and TIMP. Further studies are needed to fully understand the role of the ASM in the production of ECM proteins, MMP and TIMP andtheir potential influence in the mechanisms underlying asthma.

Tissue inhibitor of metalloproteinases-2 (TIMP-2) suppresses TKR-growth factor signaling independent of metalloproteinase inhibition

The tissue inhibitors of metalloproteinases (TIMPs) block matrix metalloproteinase (MMP)-mediated increases in cell proliferation, migration, and invasion that are associated with extracellular matrix (ECM) turnover. Here we demonstrate a direct role for TIMP-2 in regulating tyrosine kinase-type growth factor receptor activation. We show that TIMP-2 suppresses the mitogenic response to tyrosine kinase-type receptor growth factors in a fashion that is independent of MMP inhibition. The TIMP-2 suppression of mitogenesis is reversed by the adenylate cyclase inhibitor SQ22536, and implicates cAMP as the second messenger in these effects. TIMP-2 neither altered the release of transforming growth factor alpha from the cell surface, nor epidermal growth factor (EGF) binding to the cognate receptor, EGFR. TIMP-2 binds to the surface of A549 cells in a specific and saturable fashion (K(d) = 147 pm), that is not competed by the synthetic MMP inhibitor BB-94 and is independent of MT-1-MMP. TIMP-2 induces a decrease in phosphorylation of EGFR and a concomitant reduction in Grb-2 association. TIMP-2 prevents SH2-protein-tyrosine phosphatase-1 (SHP-1) dissociation from immunoprecipitable EGFR complex and a selective increase in total SHP-1 activity. These studies represent a new functional paradigm for TIMP-2 in which TIMP suppresses EGF-mediated mitogenic signaling by short-circuiting EGFR activation.

Cloning and characterization of tissue inhibitor of metalloproteinase-3 (TIMP-3) from shark, Scyliorhinus torazame

We cloned the full-length cDNA encoding TIMP-3 from the cartilage of cloudy dogfish, Scyliorhinus torazame. The entire open reading frame was composed of 645 nucleotides and 214 residues including 12 conserved cysteines and asparagine-184, a putative site for N-linked sugars. It showed about 72% identity to those of other species based on the deduced amino acid sequence. The mRNA of shark TIMP-3 were expressed abundantly in brain and cartilage tissues. To investigate the roles of shark TIMP-3, an expression vector was constructed and transfected into HT1080 human fibrosarcoma cells. Overexpression of shark TIMP-3 reduced the activity of MMP-2 in gelatin zymography. Through human Alu PCR based CAM assay, we also confirmed that shark TIMP-3 transfected HT1080 cells had less intravasation effects.

Alpha-1-antitrypsin stimulates fibroblast proliferation and procollagen production and activates classical MAP kinase signalling pathways

Connective tissue formation at sites of tissue repair is regulated by matrix protein synthesis and degradation, which in turn is controlled by the balance between proteases and antiproteases. Recent evidence has suggested that antiproteases may also exert direct effects on cell function, including influencing cell migration and proliferation. The antiprotease, alpha1-antitrypsin, is the major circulating serine protease inhibitor which protects tissues from neutrophil elastase attack. Its deficiency is associated with the destruction of connective tissue in the lung and the development of emphysema, whereas accumulation of mutant alpha1-antitrypsin within hepatocytes often leads to liver fibrosis. In this study, we report that alpha1antitrypsin, at physiologically relevant concentrations, promotes fibroblast proliferation, with maximal stimulatory effects of 118 +/- 2% (n=6, P < 0.02) above media controls for cells exposed to 60 microM. We further show that alpha1antitrypsin also stimulates fibroblast procollagen production, independently of its effects on cell proliferation, with values maximally increased by 34 +/- 3% (n = 6, P < 0.01) above media controls at 30 microM. Finally, mechanistic studies to examine the mechanism by which alpha1-antitrypsin acts, showed that alpha1-antitrypsin induced the rapid activation of p42MAPK and p44MAPK (also known as ERK1/2) and that the specific MEK1 inhibitor PD98059 totally blocked alpha1-antitrypsin's mitogenic effects. These results support the hypothesis that alpha1-antitrypsin may play a role in influencing tissue repair in vivo by directly stimulating fibroblast proliferation and extracellular matrix production via classical mitogen-activated signalling pathways.