Biomedical subjects

L M Matrisian

Publications and source records attributed to L M Matrisian.

At least 91 records · Page 5Linked to original sources

PubMed1992

Negative regulation of gene expression by TGF-beta.

Stromelysin gene expression is transcriptionally activated by a number of growth factors (e.g., EGF and PDGF), tumor promoters (e.g., TPA), and oncogenes (e.g., ras, src) through an AP-1-dependent mechanism. TGF-beta repression of stromelysin induction is mediated at the level of transcription by an element located at position -709 in the rat stromelysin promoter referred to as the TGF-beta inhibitory element (TIE). A TIE-binding protein complex is induced by treatment of rat fibroblasts with TGF-beta. This protein complex contains the protooncogene c-fos, and induction of c-fos by TGF-beta is required for the repressive effects of TGF-beta on stromelysin gene expression. Interestingly, c-fos induction is also required for stimulation of stromelysin expression by EGF in rat fibroblasts. Preliminary studies suggest that differential regulation of members of the jun family of early-response genes may explain this apparent paradox and determine whether stromelysin is induced or repressed by growth factors. TGF-beta stimulation therefore initiates a cascade of events that results in a specific pattern of gene expression: the direct stimulation of early-response genes can lead to subsequent induction or repression of other genes. Growth factor regulation of matrix metalloproteinases appears to play a role in embryonic development in the morphogenesis of the murine lung. Treatment of embryonic lungs in organ culture with the growth factors EGF or TGF-alpha results in stimulation of growth and inhibition of branching morphogenesis. A similar inhibition of branching was observed when these lung rudiments were treated with the matrix metalloproteinase collagenase. Most interestingly, the effects of EGF and TGF-alpha can be completely reversed by the tissue inhibitor of metalloproteinases, TIMP. TGF-beta has the opposite effect on growth of murine lung rudiments--growth is inhibited in a dose-dependent manner. This example illustrates a potential role for growth factor regulation of matrix-degrading metalloproteinases in complex developmental processes.

Animals↗

PubMed1992

Developing in a family way. Transforming Growth Factor Type beta and Related Proteins in Development: the Sixth Molecular, Cellular and Developmental Biology/Iowa State University Symposium, Ames, IA, USA September 20-23, 1991.

We are left with the impression that members of the TGF-beta family are critically positioned in a cascade of events regulating complex developmental processes. Roberts described the TGF-betas as providing the cells with cues to their temporal positions in a developmental program, that is, telling the cells "where they were, where they are, and where they're going." The broad diversity of cellular and tissue responses to TGF-betas and the widespread expression of their receptors suggest the TGF-betas may act as a "common currency," enabling diverse cell types to communicate with each other. Other members of the family are more restricted in their expression and the expression of their receptors, and may have a more limited and well-defined developmental role. The complex regulation of the members of the TGF-beta family is consistent with their importance as directors and coordinators of complicated physiological processes such as those occurring in the development of multicellular organisms. Their expression is highly regulated at the transcriptional and post-transcriptional levels, and their localization and activation can be affected by binding proteins and matrix proteins. We still have much to learn about the receptors for this family of growth factors, but the recent cloning of the activin and TGF-beta receptors and the discovery of their enzymatic nature has dramatically opened the way for future studies to resolve the signal transduction pathway(s) used by members of this family.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

The role of C-Fos in growth factor regulation of stromelysin/transin gene expression.

Expression of the rat stromelysin (transin) gene is stimulated by growth factors such as epidermal growth factor (EGF) and platelet-derived growth factor (PDGF), and inhibited by transforming growth factor-beta (TGF beta). Stimulation by both EGF and PDGF requires the presence of factors that recognize the AP-1 binding site in the stromelysin promoter, but PDGF stimulation requires induction of the protooncogene c-fos, while EGF acts through a FOS-independent pathway. The FOS-independent pathway appears to involve protein kinase C (PKC), since EGF, but not PDGF, requires activated protein kinase C to stimulate stromelysin expression. TGF beta inhibition of stromelysin gene expression requires an upstream sequence, referred to as the TGF beta inhibitory element (TIE). FOS is also a part of a protein complex that binds to the TIE. The protooncogene FOS is therefore involved in both stimulation and inhibition of stromelysin gene expression.

3T3 Cells↗

PubMed1991

Mutational analysis of the transin (rat stromelysin) autoinhibitor region demonstrates a role for residues surrounding the "cysteine switch".

The family of mammalian extracellular matrix metalloproteases (MMPs) are secreted by cells in an inactive (latent) proenzyme form. A highly conserved amino acid sequence, PRCGVPDV, is found near the COOH-terminal end of the pro-domain of these MMPs and believed to act as an "autoinhibitor." Recent studies (Springman, E. B., Angleton, E. L., Birkedal-Hansen, H., and Wart, H. E. V. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 364-368) indicate the Cys of this sequence ligands to the active-site zinc keeping the proenzyme in an inactive state, and mutational analysis (Sanchez-Lopez, R., Nicholson, R., Gesnel, M. C., Matrisian, L. M., and Breathnach, R. (1988) J. Biol. Chem. 263, 11892-11899) suggests that the conserved residues surrounding this Cys are required for latency. We have constructed 16 new site-directed mutations of the PRCGVPDV autoinhibitor region of the MMP transin (rat stromelysin) and tested whether these mutant enzymes are produced in a latent or activated form. We find that the conserved Arg as well as the Cys are essential for maintaining latency. The Cys cannot be replaced by other zinc-liganding amino acids, and the Arg cannot be replaced by Lys. Residues immediately surrounding the Cys are sensitive to even conservative amino acid substitutions. We show that a synthetic peptide PRCGVPDV is capable of acting as a weak inhibitor of transin and that replacement of the Cys with a Ser abolishes inhibition by the peptide. A review of the current knowledge of MMP substrate specificity in combination with these new results suggests that the PRCGVPDV sequence does not inhibit activity by mimicking the known substrates of the protease.

Amino Acid Sequence↗

PubMed1991

Expression and localization of the matrix metalloproteinase pump-1 (MMP-7) in human gastric and colon carcinomas.

The expression of members of the family of matrix-degrading metalloproteinases (MMPs) is believed to contribute to the complex process of invasion and metastasis. In this study, specific cDNA probes for three members of the stromelysin subfamily of MMPs--stromelysin (MMP-3), stromelysin-2 (MMP-10), and pump-1 (MMP-7)--were used to examine the expression of these three different MMPs in human gastric and colonic carcinomas and in adjacent normal mucosa. The expression of pump-1 mRNA in malignant colon and stomach samples was striking. In a total of 10 gastric carcinoma samples examined, eight (80%) expressed pump-1 transcripts; similarly, 6 of 8 (75%) colon carcinoma samples were also positive. Stromelysin and stromelysin-2 mRNAs were not detected in any of these samples. Expression of the MMPs examined was not detected in any of the adjacent, grossly normal tissue samples. Using in situ hybridization and affinity purified anti-pump-1 antibodies, the expression of pump-1 mRNA and protein was localized to tumor cells and was not detected in stromal or lymphocytic cells. This data suggests that the inappropriate expression of pump-1 by malignant cells may contribute to the neoplastic phenotype.

Carcinoma↗

PubMed1991

The role of the matrix metalloproteinase stromelysin in the progression of squamous cell carcinomas.

The expression of the metalloproteinase stromelysin correlates with the progression of chemically induced squamous cell carcinomas. We demonstrate that the expression of activated stromelysin in papilloma-derived cells enhances in vitro cell invasion. We also demonstrate that the Ha-ras oncogene induces the transcription of the stromelysin gene through an AP-1 dependent pathway. The hypothesis is that alterations in oncogenes and suppressor genes influence stromelysin expression and thus influence subsequent steps of tumor invasion and metastasis.

Carcinoma, Squamous Cell↗

PubMed1991

EGF and TGF alpha influence in vitro lung development by the induction of matrix-degrading metalloproteinases.

Remodeling of the extracellular matrix by matrix-degrading metalloproteinases (MMPs) has been implicated in the early morphogenesis of branched organs. Growth factors such as EGF and TGF alpha are known to regulate the expression of MMPs in a variety of systems. We therefore examined the effects of EGF, TGF alpha, and collagenase upon in vitro branching of the embryonic lung. Lung rudiments from 11.5 day post coitum mice underwent extensive growth and repetitive branching during a 3-day period in organ culture. Lungs treated with EGF or TGF alpha were larger than controls, yet displayed fewer branches along with markedly dilated end buds which lacked clefts, indicating that these growth factors inhibit normal lung branching. Addition of purified mammalian collagenase to lung cultures similarly inhibited epithelial branching and produced end bud enlargement. In addition, gelatin-substrate enzymography of the conditioned medium from EGF- and TGF alpha-treated lungs revealed a marked induction of a metalloproteinase activity which most likely corresponds to the 72kDa type IV collagenase/gelatinase which degrades basement membrane collagens. Lungs maintained in the presence of both TGF alpha and TIMP, a specific inhibitor of MMPs, branched repeatedly and displayed normal, narrow end buds as seen with controls, suggesting that TIMP is capable of preventing or reversing the observed growth factor mediated effects upon lung branching. Taken together, these results provide evidence that the growth factors EGF and TGF alpha guide lung development, at least in part, by inducing the expression of matrix-degrading metalloproteinases.

Animals↗

PubMed1990

Rat collagenase. Cloning, amino acid sequence comparison, and parathyroid hormone regulation in osteoblastic cells.

We have isolated clones for rat collagenase from a rat osteoblastic cell cDNA library. These clones have been sequenced and the amino acids deduced. The calculated molecular weight is 51,352 for the proenzyme and 42,229 for the active enzyme. The deduced amino acid sequence was compared to those previously reported for: 1) human collagenase, 2) rat transin 1 (stromelysin), 3) human stromelysin, and 4) rabbit collagenase. The number of amino acids conserved was 47, 47, 50, and 47%, respectively. We also compared the collagenase mRNA and protein in different rat cells (osteoblast, uterine smooth muscle, synovial fibroblast) and determined that in rat uterine cells the message is slightly larger, although collagenase protein in all three cell types was identical in size. Parathyroid hormone dramatically induces the 2.9-kilobase collagenase mRNA in the rat osteoblastic cells, UMR 106-01. Nuclear run-on studies in UMR 106-01 cells demonstrated a 4-8-fold induction in the rate of synthesis of collagenase mRNA at 2 and 4 after parathyroid hormone treatment, with steady state levels of mRNA increased 100-fold at 4 h. Thus, parathyroid hormone regulation of the collagenase gene in UMR 106-01 cells is in part transcriptional.

Amino Acid Sequence↗

PubMed1990

TGF-beta 1 inhibition of transin/stromelysin gene expression is mediated through a Fos binding sequence.

Transforming growth factor beta 1 (TGF-beta 1) inhibits the growth factor and oncogene induction of transin/stromelysin, a secreted matrix-degrading metalloprotease. We demonstrate that a 10 bp element in the transin promoter is required for the TGF-beta 1 inhibitory effects and that this sequence is conserved in the promoter regions of several other TGF-beta 1-inhibited genes. The TGF-beta 1 inhibitory element (TIE) specifically binds a nuclear protein complex from TGF-beta 1-stimulated rat fibroblasts. Interestingly, this complex contained the c-fos proto-oncogene product, Fos, and induction of Fos expression was required for the inhibitory effect of TGF-beta 1 on transin gene expression. These results suggest that TGF-beta 1 inhibition of gene expression is mediated by the binding of a Fos-containing protein complex to the TIE promoter sequences.

Animals↗

PubMed1990

Stromelysin in tumor progression and metastasis.

There are several characteristics of stromelysin that suggest that expression of this enzyme may play an important role in tumor invasion and metastasis; the stromelysin gene is expressed in response to stimulation by oncogenes and tumor promoters, and the protein product of this gene is a metalloproteinase capable of degrading multiple components of the extracellular matrix. Experimental evidence to support this hypothesis has been derived from several animal model systems, in which a positive correlation has been observed between stromelysin expression and tumor progression and metastasis. In addition, in vivo experiments in which the levels of TIMP, the tissue inhibitor of metalloproteinases, were altered also strongly suggest a causal role for metalloproteinases in tumor metastases. The expression of active stromelysin in tumor cells requires the fulfillment of several criteria, and this multistep process is reminiscent of the molecular events that are currently understood to contribute to tumor progression and carcinogenesis. Expression of stromelysin mRNA requires both a stimulus, a step which may correspond to the activation of an oncogene in multistep carcinogenesis, as well as the lifting of transcriptional repression, which may correspond to the loss of tumor suppressor function. Both positive and negative modulation of stromelysin transcription appear to utilize pathways that involve the protooncogenes c-fos and/or c-jun. The expression of active stromelysin enzyme also requires conversion of the proenzyme to an active form, and a proper balance between the expression of inhibitors and the levels of active enzyme. The multiple levels of stromelysin regulation support the concept of multistep carcinogenesis and may provide a tool for further understanding of the molecular nature of the events that lead to tumor progression, invasion, and metastasis.

Animals↗

PubMed1990

Metalloproteinases and their inhibitors in matrix remodeling.

The matrix metalloproteinases are a tightly regulated family of enzymes that degrade extracellular matrix and basement membrane components. Recent evidence suggests that these proteases and their specific inhibitors play important roles in normal developmental processes and in pathological conditions. Interestingly, experiments designed to improve our understanding of metalloproteinase regulation have also resulted in new insights into mechanisms by which growth factors and proto-oncogenes may regulate biological processes.

Amino Acid Sequence↗

PubMed1990

Growth factor-regulated proteases and extracellular matrix remodeling during mammalian development.

Although specific details may vary from system to system, some general concepts have emerged from studies of the regulation of ECM components, proteases, and protease inhibitors by growth factors. Growth factors may be divided into those that enhance matrix synthesis and inhibit matrix degradation and those that stimulate protease production and result in a general degradation of ECM. These relationships are illustrated in Fig. 3. In general, growth factors such as EGF, PDGF, bFGF, and IL-1 induce genes for ECM-degrading proteinases and their activators (e.g., metalloproteinases and PAs). This concerted release of proteases results in the degradation of the many components of basement membranes or ECM. Other growth factors (e.g., the TGF-beta family) stimulate the synthesis of ECM structural proteins (e.g., collagens and fibronectin), elevate levels of inhibitors of proteases (e.g., TIMP and PAI-1), and repress expression of the matrix-degrading metalloproteinases and PA. The overall result is systems in which such a relationship seems very likely. Direct evidence should become available within the next few years now that the technology exists to correlate spatial and temporal expression of growth factors with expression of ECM-associated proteases and inhibitors and to misregulate this expression in specific ways, for example, in transgenic mice. Future studies involving the use of model systems in which complex tissue interactions and organogenesis can be followed in culture should also provide the opportunity to examine cause-and-effect relationships between growth factors and ECM-modulating proteins.

Animals↗

PubMed1990

Epidermal growth factor stimulation of stromelysin mRNA in rat fibroblasts requires induction of proto-oncogenes c-fos and c-jun and activation of protein kinase C.

Stromelysin (transin) is a secreted metalloprotease that is transcriptionally induced by a variety of growth factors and oncogenes. We examined the necessity of specific secondary (protein kinase C) and tertiary (c-fos and c-jun protein products) messengers in the transactivation of stromelysin gene expression by epidermal growth factor (EGF). Rat-1 fibroblasts exposed to antisense c-fos DNA or RNA demonstrated that c-fos expression was necessary for complete EGF induction of stromelysin expression. Similar results demonstrating the necessity of c-jun protein in the EGF induction of stromelysin were obtained. We also demonstrated that protein kinase C activation is required for the EGF induction of stromelysin, since phorbol ester desensitization of C kinase proteins abolished the ability of EGF to induce stromelysin mRNA, protein, and promoter activity. In reconstitution experiments, neither c-fos, c-jun, nor C kinase activation alone induced significant stromelysin expression. Overexpression of c-fos and c-jun was able to induce stromelysin to a level similar to that of the growth factor, and stimulation of protein kinase C activity augmented this induction. The data suggest that the EGF induction of stromelysin in rat fibroblasts procedes through a pathway involving c-fos, c-jun, and protein kinase C.

Animals↗

PubMed1990

Altered regulation of protein disulfide isomerase in cells resistant to the growth-inhibitory effects of transforming growth factor beta 1.

A murine keratinocyte cell line that is resistant to the growth-inhibitory effects of transforming growth factor beta 1 (TGF beta 1) was examined for differential gene expression patterns that may be related to the mechanism of the loss of TGF beta 1 responsiveness. Cells that were resistant to the growth-inhibitory effects of TGF beta 1 (KCR cells) were derived from K-ras-transformed BALB/MK keratinocytes (KC cells). Using a subtractive hybridization procedure with KC and KCR mRNAs, we isolated a complementary DNA clone for murine protein disulfide isomerase (PDI). The mRNA for PDI is inhibited by TGF beta 1 treatment in the parental KC cells, but not in the TGF beta 1-resistant KCR cells. Similar PDI down-regulation also occurs in other TGF beta-sensitive cells, but not in a human pancreatic carcinoma cell line which is insensitive to the growth-inhibitory effects of TGF beta 1. The results suggest that misregulation of PDI, an important component of co- and posttranslational modification systems, may be involved in the mechanism by which some cells escape from the growth-inhibitory effects of TGF beta 1.

Animals↗

PubMed1990

Stromelysin/transin and tumor progression.

Transin is an oncogene-inducible protein which has been shown to be the rat homologue of an extracellular matrix-degrading metalloproteinase known as stromelysin. The activity of transin/stromelysin is regulated at several levels: (1) at the transcriptional level, it is positively regulated by oncogenes, tumor promoters, and certain growth factors, and is negatively regulated by several agents including glucocorticoids and transforming growth factor-beta; (2) the protease activity is produced by processing of an inactive precursor form to an active enzyme; and (3) total protease activity is modulated by activity of tissue inhibitors of metalloproteinases (TIMPs). The association of transin/stromelysin expression with tumor progression suggests that it plays an important role in cancer.

Amino Acid Sequence↗

PubMed1988

Growth factors regulate transin gene expression by c-fos-dependent and c-fos-independent pathways.

The rapid induction of the proto-oncogene c-fos by growth factors and other bioactive agents, and the recent evidence that the c-fos protein (Fos) is associated with transcriptional complexes, suggests that Fos may represent an integral part of an intracellular messenger pathway that triggers changes in gene expression and ultimately phenotypic alterations. This report examines the role of c-fos in growth factor stimulation of transin, a matrix-degrading secreted metalloproteinase. Platelet-derived growth factor (PDGF) stimulation of transin RNA was blocked by a selective reduction in Fos synthesis with antisense c-fos mRNA, whereas epidermal growth factor (EGF) stimulation of transin occurred despite an equivalent inhibition of Fos levels. The stimulatory effect of both PDGF and EGF on transin transcription involved factors recognizing the sequence TGAGTCA, which is found in the transin promoter and is reported to be a binding site for the transcriptional factor Jun/AP-1 and for associated Fos and Fos-related complexes. Thus both Fos-dependent and Fos-independent pathways exist for growth factor regulation of gene expression, and both effects may be mediated through the same cis-acting transcription element.

Animals↗

PubMed1988

Transforming growth factor beta 1 and cAMP inhibit transcription of epidermal growth factor- and oncogene-induced transin RNA.

Transin mRNA encodes a secreted metalloprotease which is transcriptionally induced in Rat-1 cells by epidermal growth factor (EGF) and a number of oncogenes. A role for transin in tumor progression is suggested by its overexpression in malignant and metastatic tumors compared to their benign counterparts. In an effort to elucidate mechanisms by which elevated transin expression may be inhibited, it has been determined that both transforming growth factor type beta 1 (TGF beta 1) and increased levels of intracellular cyclic 5'-adenosine monophosphate (cAMP) inhibit EGF and oncogene induction of transin mRNA. The inhibition of transin mRNA occurred at the level of transcription as demonstrated by nuclear run-on assays. EGF binding studies in Rat-1 cells showed no significant effect of cAMP or TGF beta 1 on EGF receptor number or affinity. We have also examined the effects of cAMP and TGF beta 1 on oncogene-induced transin using Rat-1 cells transformed by temperature-sensitive mutants of v-src and K-ras oncogenes. Both inhibitors prevented the induction of transin RNA as well as decreased the levels of transin once elevated at the permissive temperature. Despite the similarities in the actions of TGF beta 1 and cAMP on transin gene expression, TGF beta 1 treatment did not significantly elevate intracellular cAMP levels, thus making it unlikely that cAMP is a second messenger system for TGF beta 1 action. These studies suggest that the inhibitory effects of cAMP and TGF beta 1 occur by distinct pathways at the level of gene regulation.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1988

Structure-function relationships in the collagenase family member transin.

We have developed a system for studying the proteinase activity of a collagenase family member, transin. Cos cells transfected with a vector designed to direct synthesis of a secretable fusion protein between staphylococcal protein A and transin secrete a latent proteinase, activable by 4-aminophenylmercuric acetate, which binds to IgG-Sepharose. Treatment with 4-aminophenylmercuric acetate leads to cleavage of the fusion protein and elution of the active proteinase transin. Based on results obtained with this system we propose that transin comprises an N-terminal proteinase domain and an independent C-terminal hemopexin-like domain. The latter domain is not required for binding of inhibitors or for maintenance of transin in its inactive form. The sequence PRCGVPDV is present in the proenzyme forms of collagenase family proteinases just upstream from the N termini of the active enzymes. We show that mutations within this sequence lead to transin variants with a much increased tendency to undergo spontaneous activation. Finally, we show that mutations within a region of transin having sequence similarity to the zinc-binding site of bacterial metalloproteinases inactivate the proteinase activity of transin, lending support to the notion that this region represents part of transin's active site.

Amino Acid Sequence↗