Matrix Metalloproteinase Matrilysin Research Articles

Functional characterization of neostatins, the MMP-derived, enzymatic cleavage products of type XVIII collagen

Several anti-angiogenic factors are derived from proteolytic processing of large molecules including endostatin from type XVIII collagen and angiostatin from plasminogen. In previous studies we showed that neostatin-7, the C-terminal 28 kDa endostatin-spanning proteolytic fragment, is generated from the proteolytic action of matrix metalloproteinase matrilysin (MMP)-7 on type XVIII collagen. Now, we report a second member of the neostatin family of proteins, neostatin-14. Given the small quantities of neostatin-7 and -14 generated by the breakdown of naturally occurring collagen XVIII (using MMP-7 and -14, respectively), we used two other approaches to characterize the anti-angiogenic properties of these molecules: murine recombinant neostatin in vitro, and gene therapy. We demonstrate that murine recombinant neostatin-7 inhibits calf pulmonary artery endothelial cell proliferation and that microinjection of neostatin-7 and neostatin-14 naked DNA into the corneal stroma of mice results in significant reduction of basic fibroblast growth factor-induced corneal neovascularization. These results provide supportive evidence of the possible anti-angiogenic effect of neostatins.

Pharmacological inhibition of FGF receptor signaling inhibits LNCaP prostate tumor growth, promatrilysin, and PSA expression.

Previously we have shown that the matrix metalloproteinase matrilysin (MMP-7) is overexpressed in human prostate cancers compared with normal epithelium. However, the mechanism for this overexpression is not understood. Human prostate fibroblasts have been shown to express certain fibroblast growth factors (FGFs), including FGF-1. Evidence from our laboratory and others has indicated that FGFs can regulate the expression of certain matrix metalloproteinases, including matrilysin. The goal of this study was to determine whether pharmacological inhibition of FGFR signaling would alter LNCaP tumor growth as well as expression of promatrilysin when LNCaP cells were co-injected subcutaneously with human prostate fibroblasts into athymic nude mice. For these inhibitor studies, AG1-X2 beads were coated with the pharmacological FGFR inhibitor SU5402 and were co-injected along with LNCaP and human prostate fibroblast cells (PF). Mice injected with LNCaP/PF and LNCaP/PF/beads alone demonstrated significant tumor growth, whereas mice injected with LNCaP/PF/SU5402-coated beads showed a significant decrease in tumor volume and weight. Immunohistochemical analysis showed that significant promatrilysin expression in tumors was inhibited by the FGFR inhibitor SU5402. Serum prostate-specific antigen (PSA) and promatrilysin levels were measured by enzyme-linked immunosorbent assay. The mice injected with LNCaP/PF and LNCaP/PF/beads expressed promatrilysin and serum PSA levels that were inhibited by co-injecting with SU5402. Therefore, pharmacological inhibition of FGF receptor signaling results in a decrease in the growth of LNCaP tumors generated subcutaneously by co-injecting LNCaP cells and human prostate fibroblasts. The inhibition in tumor growth was correlated with a decrease in tumor promatrilysin expression and a decrease in serum promatrilysin and PSA.

The expression of matrix metalloproteinase matrilysin indicates the degree of inflammation in ulcerative colitis.

Any alteration in the synthesis and breakdown of the extracellular matrix is important in tissue remodeling during inflammation and wound healing. The degradation of the extracellular matrix components is regulated by a cascade of matrix metalloproteinases (MMPs). The present study attempted to assess the relationship between MMPs and the degree of inflammation in ulcerative colitis. The expression of MMPs, including MMP-1, -2, -3, -7 (matrilysin), and -9, and that of their inhibitors (tissue inhibitor of metalloproteinases [TIMP]-1 and -2) were analyzed immunohistochemically by using 52 formalin-fixed and paraffin-embedded specimens from patients with ulcerative colitis who had undergone a biopsy or surgery. It was observed that MMP-1, -2, and -9, and the TIMPs were expressed in stromal cells, MMP-3 was expressed in both the epithelial cells and stromal components, and matrilysin was expressed only in the epithelial cells on the edge of ulcers. The expression of the MMPs was increased compared with that of the TIMPs. The frequency of matrilysin expression was increased corresponding to the severity of the inflammation. Matrilysin was also expressed in epithelial cells with dysplasia and cancer. Matrilysin expression could be an important marker of activity and could be used for the prediction of subsequent transformation in patients with ulcerative colitis.

Association of matrilysin expression with progression and poor prognosis in human pancreatic adenocarcinoma

The matrix metalloproteinase matrilysin has been implicated in the progression of gastrointestinal and other cancers. The aim of this study was to determine whether matrilysin has clinicopathological and prognostic significance in pancreatic carcinoma. Using immunohistochemistry, we analyzed 39 pancreatic adenocarcinoma tissues for expression of matrilysin. The results were matched with clinicopathological characteristics and patient survival. The relationship of matrilysin expression with p53 expression or cellular proliferation determined by Ki-67 expression was also investigated. Sections with immunostaining signals in more than 30% of carcinoma cells at the invasive front, which were observed in 25 (64%) cases, were judged to be positive for matrilysin. Matrilysin positivity was significantly correlated with infiltrating growth pattern, lymph node metastasis, and postoperative recurrence. Expression of matrilysin was not correlated with either Ki-67 or p53 expression. Patients with matrilysin-positive carcinoma had a significantly shorter overall survival time than did those with matrilysin-negative carcinoma. Our results suggest that matrilysin plays a key role in the progression of pancreatic carcinoma.

Hypochlorous acid oxygenates the cysteine switch domain of pro-matrilysin (MMP-7). A mechanism for matrix metalloproteinase activation and atherosclerotic plaque rupture by myeloperoxidase.

Myeloperoxidase uses hydrogen peroxide (H2O2) to generate hypochlorous acid (HOCl), a potent cytotoxic oxidant. We demonstrate that HOCl regulates the activity of matrix metalloproteinase-7 (MMP-7, matrilysin) in vitro, suggesting that this oxidant activates MMPs in the artery wall. Indeed, both MMP-7 and myeloperoxidase were colocalized to lipid-laden macrophages in human atherosclerotic lesions. A highly conserved domain called the cysteine switch has been proposed to regulate MMP activity. When we exposed a synthetic peptide that mimicked the cysteine switch to HOCl, HPLC analysis showed that the thiol residue reacted rapidly, generating a near-quantitative yield of products. Tandem mass spectrometric analysis identified the products as sulfinic acid, sulfonic acid, and a dimer containing a disulfide bridge. In contrast, the peptide reacted slowly with H2O2, and the only product was the disulfide. Moreover, HOCl markedly activated pro-MMP-7, an MMP expressed at high levels in lipid-laden macrophages in vivo. Tandem mass spectrometric analysis of trypsin digests revealed that the thiol residue of the enzyme's cysteine switch domain had been converted to sulfinic acid. Thiol oxidation was associated with autolytic cleavage of pro-MMP-7, strongly suggesting that oxygenation activates the latent enzyme. In contrast, H2O2 failed to oxidize the thiol residue of the protein or activate the enzyme. Thus, HOCl activates pro-MMP-7 by converting the thiol residue of the cysteine switch to sulfinic acid. This activation mechanism is distinct from the well-studied proteolytic cleavage of MMP pro-enzymes. Our observations raise the possibility that HOCl generated by myeloperoxidase contributes to MMP activation, and therefore to plaque rupture, in the artery wall. HOCl and other oxidants might regulate MMP activity by the same mechanism in a variety of inflammatory conditions.

Association of matrilysin mRNA expression with K-ras mutations and progression in pancreatic ductal adenocarcinomas.

The matrix metalloproteinase matrilysin has been implicated in the progression of gastrointestinal and other cancers. The aim of this study was to examine matrilysin mRNA expression and determine whether it is correlated with K-ras mutations and/or progression of pancreatic carcinoma. Using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we analyzed 11 pancreatic cancer cell lines and 70 pancreatic adenocarcinoma tissues for matrilysin mRNA expression. The results were correlated with clinicopathological characteristics and K-ras mutations. Significant amounts of matrilysin mRNA were detected in six of the eight cell lines with K-ras mutations but not in the three cell lines with wild-type K-ras. Matrilysin mRNA was detected in 57 (81.4% ) of the 70 tumor tissues and in all of the eight liver metastases, but not in any of the adjacent non-tumorous tissues. Matrilysin expression was significantly correlated with the size of tumor, tumor spreading, lymph node metastasis, advanced pathologic tumor-node- metastasis stage and K-ras mutations. The relative amounts of matrilysin mRNA in tumor tissues increased with increase in tumor stage and were highest in liver metastatic tumor tissues. Our results suggest that matrilysin, the expression of which is correlated with K-ras mutations, plays a key role in tumor growth and progression of pancreatic carcinoma.

The PEA3 subfamily of Ets transcription factors synergizes with beta-catenin-LEF-1 to activate matrilysin transcription in intestinal tumors.

The matrix metalloproteinase matrilysin (MMP-7) is expressed in the tumor cells of a majority of mouse intestinal and human colonic adenomas. We showed previously that matrilysin is a target gene of beta-catenin-Tcf, the transcription factor complex whose activity is thought to play a crucial role in the initiation of intestinal tumorigenesis. Here we report that overexpression of a stable mutant form of beta-catenin alone was not sufficient to effect expression of luciferase from a matrilysin promoter-luciferase reporter plasmid. However, cotransfection of the reporter with an expression vector encoding the PEA3 Ets transcription factor, or its close relatives ER81 and ERM, increased luciferase expression and rendered the promoter responsive to beta-catenin-LEF-1 as well as to the AP-1 protein c-Jun. Other Ets proteins could not substitute for the PEA3 subfamily. Luciferase activity was induced up to 250-fold when PEA3, c-Jun, beta-catenin, and LEF-1 were coexpressed. This combination of transcription factors was also sufficient to induce expression of the endogenous matrilysin gene. Furthermore, all matrilysin-expressing benign intestinal tumors of the Min mouse expressed a member of the PEA3 subfamily, as did all human colon tumor cell lines examined. These data suggest that the expression of members of the PEA3 subfamily, in conjunction with the accumulation of beta-catenin in these tumors, leads to coordinate upregulation of matrilysin gene transcription, contributing to gastrointestinal tumorigenesis.

Matrilysin [MMP-7] Expression Selects for Cells with Reduced Sensitivity to Apoptosis

The matrix metalloproteinase matrilysin (MMP-7) has been demonstrated to contribute to tumor development. We have shown previously that members of the TNF family of apoptosis-inducing proteins are substrates for this enzyme, resulting in increased death pathway signaling. The goal of the current study was to reconcile the proapoptotic and tumor-promoting functions of matrilysin. In the human HBL100 and murine NMuMG cell lines that represent early stages of tumor progression and that express both Fas ligand and its receptor, exposure to matrilysin results in cell death that can be blocked by FasL neutralizing antibodies. Constitutive expression of matrilysin in these cell lines selects for cells with reduced sensitivity to Fas-mediated apoptosis as demonstrated both with a receptor-activating antibody and with in vitro activated splenocytes. Matrilysin-expressing cells are also significantly less sensitive to chemical inducers of apoptosis. We propose that the expression of matrilysin that has been reported at early stages in various tumor types can act to select cells with a significantly decreased chance of removal due to immune surveillance. As a result, these cells are more likely to acquire additional genetic modifications and develop further as tumors.

The metalloproteinase matrilysin proteolytically generates active soluble Fas ligand and potentiates epithelial cell apoptosis

Background: The Fas ligand/Fas receptor (FasL/Fas) system is an important mediator of apoptosis in the immune system where the juxtaposition of cells expressing the cell-surface ligand induces the apoptotic pathway in Fas-expressing lymphocytes. The FasL/Fas system has also been shown to be involved in apoptosis in epithelial tissues, including the involuting rodent prostate. FasL can be shed through the action of an hitherto unidentified metalloproteinase to yield soluble FasL (sFasL), although the biological activity of sFasL has been disputed.Results: Here we report that the matrix metalloproteinase matrilysin can process recombinant and cell-associated FasL to sFasL, and that matrilysin-generated sFasL was effective at inducing apoptosis in a target epithelial cell population. In the involuting mouse prostate, FasL and matrilysin colocalized to the cell surface in a restricted population of epithelial cells. Mice deficient in matrilysin demonstrated a 67% reduction in the apoptotic index in the involuting prostate compared with wild-type animals, implicating matrilysin in this FasL-mediated process.Conclusions:The results show that a functional form of sFasL was generated by the action of the metalloproteinase matrilysin, and suggest that matrilysin cleavage of FasL is an important mediator of epithelial cell apoptosis.

Differential expression of matrilysin and cyclooxygenase-2 in intestinal and colorectal neoplasms

Both the matrix metalloproteinase matrilysin and the prostaglandin H synthase cyclooxygenase-2 (Cox-2), are thought to play key roles in colorectal carcinogenesis. These enzymes are overexpressed in 85-90% of human colorectal cancers. Furthermore, mice carrying an adenomatous polyposis coli germline mutation that are also nullizygous for either matrilysin or Cox-2 display a significant reduction in tumor multiplicity. To determine if there is a direct link between matrilysin and Cox-2, their expression was characterized in two mouse models of intestinal carcinogenesis and in human colorectal tumor samples. Both matrilysin and Cox-2 expression was increased in the mouse models and in the human colorectal cancers; however, immunohistochemistry and in situ hybridization indicated that their localization within the tumors was different. In the mouse models, Cox-2 was expressed in the superficial stroma, whereas matrilysin expression was localized exclusively to the neoplastic epithelium. In contrast, in human colorectal cancers, both Cox-2 and matrilysin were expressed in the neoplastic epithelium. Although over 80% of the specimens expressed both matrilysin and Cox-2, the levels and localization of matrilysin and Cox-2 expression were distinct. Cox-2 expression was strongest in well-differentiated areas, and matrilysin immunostaining was strongest in the more dysplastic and invasive regions of the tumor. These results indicate that these two important modulators of colorectal tumorigenesis are differentially expressed and imply that the therapeutic benefit may be improved by combination therapy utilizing selective Cox-2 and matrilysin inhibitors.

Matrix metalloproteinase matrilysin (MMP-7) participates in the progression of human gastric and esophageal cancers.

Matrilysin is one of matrix metalloproteinases, which is supposed to have a specific role in tumor progression. Expression of matrilysin was investigated in gastric and esophageal cancers by an immunohistochemical examination. Matrilysin was expressed in all esophageal squamous cell carcinomas (13/13) and in the majority of gastric adenocarcinomas (31/35, 89%). The positive staining was observed in tumor cells of cancerous tissues. In gastric cancers, there were significant statistical correlations between matrilysin expression at the invasive front and nodal metastasis or advanced stage. These results suggest that overexpression of matrilysin has an important role in the progression of upper gastrointestinal cancers.

Matrilysin activity in the rat uterus during the oestrous cycle and implantation.

The objective of this study was to follow changes in the activity of the small matrix metalloproteinase matrilysin (MMP-7) in the rat uterus during the oestrous cycle and embryo implantation. Matrilysin was extracted from rat uteri, partially purified and separated into active and latent forms. The two forms of the enzyme were quantified at all stages of the oestrous cycle and after oestradiol and progesterone treatment. The activity was also measured during the first 7 days of pregnancy. Both latent and active forms of MMP-7 reached a peak during the pro-oestrous stage of the cycle; the concentrations were three times higher than at dioestrus and metoestrus. In rats treated with 0.1 mg oestradiol at metoestrus, both latent and active forms of the enzyme increased by more than two-fold after 24 h. In rats treated at pro-oestrus with 0.4 mg progesterone, there was a 70% increase in latent MMP-7, but no change in the active form. The highest concentrations of MMP-7 were observed on the first day of pregnancy. Between days 3 and 7 of pregnancy, the concentrations were relatively constant and comparable to the low concentrations at dioestrus. Enzyme activities were not different at implantation sites compared with remote sites.

Overexpression of the matrix metalloproteinase matrilysin results in premature mammary gland differentiation and male infertility.

To examine the role of matrilysin (MAT), an epithelial cell-specific matrix metalloproteinase, in the normal development and function of reproductive tissues, we generated transgenic animals that overexpress MAT in several reproductive organs. Three distinct forms of human MAT (wild-type, active, and inactive) were placed under the control of the murine mammary tumor virus promoter/enhancer. Although wild-type, active, and inactive forms of the human MAT protein could be produced in an in vitro culture system, mutations of the MAT cDNA significantly decreased the efficiency with which the MAT protein was produced in vivo. Therefore, animals carrying the wild-type MAT transgene that expressed high levels of human MAT in vivo were further examined. Mammary glands from female transgenic animals were morphologically normal throughout mammary development, but displayed an increased ability to produce beta-casein protein in virgin animals. In addition, beginning at approximately 8 mo of age, the testes of male transgenic animals became disorganized with apparent disintegration of interstitial tissue that normally surrounds the seminiferous tubules. The disruption of testis morphology was concurrent with the onset of infertility. These results suggest that overexpression of the matrix-degrading enzyme MAT alters the integrity of the extracellular matrix and thereby induces cellular differentiation and cellular destruction in a tissue-specific manner.

Cleavage of β4 Integrin by Matrilysin

Overexpression of the matrix metalloproteinase matrilysin and the absence of β4 integrin are two features characteristic of human prostate carcinoma. In the following study we demonstrate that the β4 integrin, but not the α6 or β1 integrin subunits, is cleaved by matrilysinin vitro.A specific fragment of 90 kDa is generated using matrilysin, which is not observed with other proteases. Two putative cleavage sites for matrilysin within the extracellular domain of the β4 integrin at residues 107 (isoleucine, prior to the ligand-binding region) and 417 (leucine, prior to cysteine-rich region) are identified by sequence comparisons with known matrilysin substrates. The selective cleavage of the β4 integrin by matrilysin may partly explain the loss of β4 integrin expression in invasive prostate carcinoma.

Matrix Metalloproteinase Matrilysin Is Constitutively Expressed in Adult Human Exocrine Epithelium

The proteolytic activity of matrix metalloproteinases is involved in normal and disease-related remodeling processes. One member of this family, matrilysin, can degrade a wide spectrum of connective tissue proteins, suggesting that this enzyme is involved in numerous and diverse biologic processes. In fact, recent studies have shown that matrilysin is expressed in developing hair follicles and glands. Using in situ hybridization and immunohistochemistry, we examined the sites of matrilysin expression in normal and diseased adult skin. In normal mature skin, matrilysin mRNA and protein was strongly and consistently expressed in ductal cells and in some secretory cells of all eccrine and apocrine glands and was not found in any other cell type. A similar tissue distribution was also found in numerous benign inflammatory skin lesions, and prominent expression of matrilysin mRNA and protein was also found in glandular disorders such as axillary hidradenitis and sweat gland tumors. These findings indicate that matrilysin is a constitutive product of the epithelium of dermal glands and that its expression may not be related to a disease-specific or remodeling process. Because of its extensive expression in dermal glands, we assessed whether matrilysin might be produced by all exocrine glands. Indeed, we detected matrilysin mRNA and immunoreactive protein in the ductal and glandular epithelium of mammary and parotid glands, pancreas, liver, prostate, and the serous acini of peribronchial glands of the lung. Thus, our findings indicate that matrilysin is constitutively produced by exocrine epithelial cells throughout the body. Because of its broad catalytic activity, we speculate matrilysin may participate in the normal function of exocrine glands by preventing glandular obstruction.

The metalloproteinase matrilysin is preferentially expressed by epithelial cells in a tissue-restricted pattern in the mouse.

To explore the role of the matrix metalloproteinase matrilysin (MAT) in normal tissue remodeling, we cloned the murine homologue of MAT from postpartum uterus using RACE polymerase chain reaction and examined its pattern of expression in embryonic, neonatal, and adult mice. The murine coding sequence and the corresponding predicted protein sequence were found to be 75% and 70% identical to the human sequences, respectively, and organization of the six exons comprising the gene is similar to the human gene. Northern analysis and in situ hybridization revealed that MAT is expressed in the normal cycling, pregnant, and postpartum uterus, with levels of expression highest in the involuting uterus at early time points (6 h to 1.5 days postpartum). The mRNA was confined to epithelial cells lining the lumen and some glandular structures. High constitutive levels of MAT transcripts were also detected in the small intestine, where expression was localized to the epithelial Paneth cells at the base of the crypts. Similarly, MAT expression was found in epithelial cells of the efferent ducts, in the initial segment and cauda of the epididymis, and in an extra-hepatic branch of the bile duct. MAT transcripts were detectable only by reverse transcription-polymerase chain reaction in the colon, kidney, lung, skeletal muscle, skin, stomach, juvenile uterus, and normal, lactating, and involuting mammary gland, as was expression primarily late in embryogenesis. Analysis of MAT expression during postnatal development indicated that although MAT is expressed in the juvenile small intestine and reproductive organs, the accumulation of significant levels of MAT mRNA appears to correlate with organ maturation. These results show that MAT expression is restricted to specific organs in the mouse, where the mRNA is produced exclusively by epithelial cells, and suggest that in addition to matrix degradation and remodeling, MAT may play an important role in the differentiated function of these organs.

Expression of matrix metalloproteinase matrilysin (MMP-7) was induced by activated Ki-ras via AP-1 activation in SW1417 colon cancer cells.

The matrix metalloproteinase matrilysin (MMP-7) is a member of the matrix metalloproteinase gene family, which is believed to play an important role in tumor invasion and metastasis. We have previously found that matrilysin mRNA is specifically expressed in colorectal cancers and adenomas and that its message is localized in the tumor cells themselves. We examined the effects of activated Ki-ras oncogene on the expression of matrilysin in colon cancer cells. We showed that both mRNA and the enzymatic activity of matrilysin were induced by the introduction of activated Ki-ras into SW1417 colon cancer cells. To understand the mechanisms regulating this induction, we analyzed alterations of AP-1 activity induced by activated Ki-ras, using the chloramphenicol acetyltransferase assay. AP-1 activity in SW1417 cells expressing activated Ki-ras was higher than that in control cells. The gel-shift assay also showed higher levels of AP-1 binding protein in SW1417 cells expressing activated Ki-ras than those in control cells. Our results suggest that activated Ki-ras may play a role in inducing expression of matrilysin through an AP-1-dependent pathway in colon cancer cells.

Polyamine-dependent expression of the matrix metalloproteinase matrilysin in a human colon cancer-derived cell line.

Matrilysin, which is a member of the matrix metalloproteinase family and is implicated in colon cancer invasion, is expressed in human colon adenocarcinoma-derived SW1116 cells. We investigated the effect of alpha-difluoromethylornithine (DFMO) on matrilysin expression in this cell line because others have shown that DFMO can inhibit invasion and carcinogenesis in epithelial tissues, including the colon, in experimental models. DFMO reduced extracellular levels of matrilysin protein after 4 d of treatment. Intracellular levels of matrilysin protein were minimally affected by DFMO treatment. The decrease in extracellular matrilysin protein levels caused by DFMO was not a consequence of lowered steady-state levels of matrilysin mRNA. After 4 d of exposure, the amount of this transcript was higher in DFMO-treated cells than in untreated cultures, whereas the mRNA stabilities were similar. These data show that polyamine depletion by DFMO can suppress the expression of matrilysin, a gene product thought to be involved in tumor invasion. The decrease in extracellular matrilysin protein caused by DFMO treatment appears to be due to a posttranscriptional mechanism, although transcription of this gene also seems to be affected by polyamines in SW1116 cells.

Structure and expression of the human gene for the matrix metalloproteinase matrilysin.

Matrilysin, a member of the matrix metalloproteinase family, is structurally different from the other matrix metalloproteinases by virtue of the absence of a conserved COOH-terminal protein domain. In addition, matrilysin mRNA is regulated in a specific and distinct manner in normal and malignant tissues. Analysis of the genomic structure of the human matrilysin gene revealed that the organization of the first five exons is highly conserved among the different members of the matrix metalloproteinase family, but that matrilysin contains an atypical sixth exon. The promoter region of the matrilysin gene has several features that are conserved among several other matrix metalloproteinase family members, including the presence of TATA, AP-1, and PEA3 elements. Comparison of the expression of the human matrilysin promoter with rat stromelysin promoter/chloramphenicol acetyltransferase constructs in HeLa cells revealed that constructs containing AP-1 and PEA3 elements respond similarly to epidermal growth factor and tumor promoter (12-O-tetradecanoyl-phorbol-13-acetate) induction, but that the addition of upstream stromelysin sequences results in an increased transcriptional activity not observed with upstream matrilysin sequences. The similarities and differences observed between the promoters of matrilysin and the other metalloproteinases may provide insights into the molecular mechanisms that regulate the expression of this family of enzymes as a whole and the factors that distinguish the expression patterns of individual family members.