Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Matrix Metalloproteinases”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed2004

Renal expression of matrix metalloproteinases in human ANCA-associated glomerulonephritis.

BACKGROUND: Expression of matrix metalloproteinases (MMPs) by infiltrating and intrinsic renal cells is increased in inflammatory conditions, and may correlate with disease activity of glomerulonephritis. We analysed renal expression of MMPs, tissue inhibitor of metalloproteinase-1 (TIMP-1) and markers of neutrophil and monocyte infiltration in renal biopsies of patients with active anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. METHODS: Immunohistochemical expression of MMP-2, -3, -9, TIMP-1, the neutrophil- and monocyte-derived MMP activators cathepsin G, neutrophil elastase and myeloperoxidase (MPO), and the monocyte marker CD14 was determined in renal biopsies of active proteinase 3 (PR3)-ANCA (n = 7) and MPO-ANCA (n = 6) associated glomerulonephritis, and in normal renal tissue (n = 4). Double labelling experiments of MMPs and TIMP-1 were performed with MPO and CD68, labelling neutrophils and macrophages. RESULTS: MMP-2-, MMP-3-, MMP-9- and TIMP-1-positive cells were detected in ANCA-associated glomerulonephritis in glomeruli with active inflammation (cellular crescents or fibrinoid necrosis), only occasionally in normal appearing glomeruli, and not in sclerotic glomeruli and positive cells were found in the tubulo-interstitium. MMPs and TIMP-1 were expressed predominantly by MPO-and CD68-positive cells. In normal renal tissue, no expression was detected, with the exception of weak mesangial staining for MMP-2. In ANCA-associated glomerulonephritis, glomerular MMP-2, -9 and TIMP-1 correlated with glomerular cathepsin G expression, while the number of MMP-9-expressing cells per glomerulus correlated with the percentage of crescentic glomeruli. Tubulo-interstitial expression of MMPs correlated with all markers of neutrophil and monocyte infiltration, and interstitial MMP-9 and TIMP-1 expression correlated with renal function at the time of renal biopsy. CONCLUSIONS: Expression of glomerular and interstitial MMP-2, -3, -9 and TIMP-1 is increased in active ANCA-associated glomerulonephritis and correlates with inflammatory activity.

Adult↗
PubMed2006

Therapeutic implications of the specific inhibition of causative matrix metalloproteinases in experimental colitis induced by dextran sulphate sodium.

Extracellular matrix dynamics, crucial for tissue remodelling, are highly regulated by a cascade of matrix metalloproteinases (MMPs) during inflammation and wound healing processes in inflammatory bowel disease (IBD). Contrary to expectations, there are limited reports to date that MMP inhibitors have some beneficial therapeutic effects in experimental colitis models. Furthermore, clinical trials of MMP inhibitors against certain tumours have failed to show any therapeutic benefit. One major reason for this lack of success may be the apparent uncertainty about the precise spectrum of inhibitory activity required. Since tumour necrosis factor alpha (TNFalpha), a key mediator in colonic inflammation, promotes MMP production in a dose-dependent manner, the therapeutic success of anti-TNFalpha agents against IBD motivated us to re-evaluate the therapeutic potential of MMP inhibition. First, using a quantitative polymerase chain reaction (PCR), western blotting, and zymography, we determined which MMPs were relevant to experimental colitis induced in mice by dextran sulphate sodium. Next, we examined a distinct role for MAPK and NFkappaB signalling pathways in the regulation of the expression of these MMP genes. Finally, we examined whether transcriptional regulation of these MMPs, either indirectly using inhibitors of MAPK and/or NFkappaB signalling pathways or directly using siRNA directed against these MMPs, contributes to the prevention of colitis. Changes in the expression level of colonic MMP-3 and MMP-10 preceded the clinical course of colitis. Colitis improved in mice that received these signal inhibitors, together with suppression of MMP expression. Moreover, siRNA that targeted MMP-3 and MMP-10 effectively reduced both the transcription of these MMPs and the severity of colitis. We conclude that MMP-3 and MMP-10 play a causal role in excess tissue destruction in colitis. Specific inhibition of these MMPs should provide novel therapeutics against IBD.

Animals↗
PubMed2006

Porphyromonas gingivalis affects host collagen degradation by affecting expression, activation, and inhibition of matrix metalloproteinases.

OBJECTIVE: Studies have shown that Porphyromonas gingivalis and host matrix metalloproteinases (MMPs) play important roles in the tissue destruction associated with periodontal disease. It is still unclear which MMPs or their inhibitors are regulated by P. gingivalis at the transcriptional and/or at the protein levels. Therefore, this study was conducted to determine what effects P. gingivalis supernatant has on the collagen degrading ability of human gingival fibroblasts (HGFs) and how it regulates the activation, mRNA expression, and inhibition of MMPs. METHODS: Culture supernatant from P. gingivalis ATCC 33277 was added to HGFs cultured in six-well plates coated with Type I collagen. At certain time intervals, the cell conditioned media was collected for zymography and/or western blot analyses to determine the MMP and tissue inhibitor of MMPs (TIMP) protein levels. The cells were then removed and the collagen cleavage visualized by Coomassie blue staining. The mRNA expression of multiple MMPs and TIMPs by the treated and untreated HGFs was determined by reverse transcription-polymerase chain reaction. RESULTS: The collagen in the six-well plates was degraded more rapidly by the HGFs treated with 10% v/v P. gingivalis supernatant. More active MMP-1, MMP-2, MMP-3, and MMP-14 were detected in the conditioned media from the HGFs treated with the P. gingivalis supernatant. TIMP-1, but not TIMP-2, was decreased in the presence of the P. gingivalis supernatant. MMP-1 mRNA expression by the treated HGFs increased more than two-fold over the untreated HGFs. MMP-3 mRNA was unchanged, MMP-2 mRNA had a slight increase, MMP-14 mRNA decreased, and MMP-15 increased. MMP-12 mRNA was induced in the P. gingivalis treated HGFs. TIMP-1 and TIMP-2 mRNA had a slight increase with P. gingivalis treatment. CONCLUSION: Porphyromonas gingivalis increased the collagen degrading ability of HGFs, in part, by increasing MMP activation and by lowering the TIMP-1 protein level, as well as by affecting the mRNA expression of multiple MMPs and TIMPs.

Cells, Cultured↗
PubMed1995

Leukemic cells (HL-60) produce a novel extracellular matrix-degrading proteinase that is not inhibited by tissue inhibitors of matrix metalloproteinases (TIMPs).

In addition to the known 94-kd gelatinase (matrix metalloproteinase 9, MMP-9), HL-60 leukemia cells release a hither-to undescribed 45-kd metalloproteinase into the culture medium. This enzyme cleaves the synthetic substrate Pro-Gln-Gly-Ile-Ala-Gly-Gln-Arg, which represents the cleavage site for collagenases in collagen type I not between isoleucine and alanine--the typical cleavage site for collagenases--but between alanine and glycine. The enzymatic activity was purified through a combination of zinc-chelate-Sepharose column chromatography, precipitation with Fractogel TSK-AF Red and gelatin-Sepharose, and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Microsequence analysis of the NH2-terminus of the purified 45-kd proteinase revealed the sequence Asp-Ile-Ser-Lys-Tyr-Thr-Thr-Thr-, which could not be found in other proteins when searched in several protein data bases. Incubation of the enzyme immobilized on nitrocellulose membranes with polyclonal antibodies to collagenase and stromelysin or gelatinases revealed no cross-reactivity. The proteolytic activity was not increased by treatment with trypsin, 8M urea, acid, or organomercurials. The proteinase, which was inhibited by chemical inhibitors of metalloproteinases, such as phenanthrolene or EDTA, is able to degrade several matrix constituents, such as collagen type IV, fibronectin, gelatin, and proteoglycans. In contrast to all known MMPs, the proteolytic activity of the 45-kd enzyme was not abolished upon incubation with recombinant tissue inhibitors of matrix metalloproteinases (TIMP) 1 or 2. Thus, the novel enzyme may influence extracellular matrix (ECM) turnover in vivo because its activity is not influenced by specific inhibitors of MMPs.

Amino Acid Sequence↗
PubMed2004

The relative contribution of cysteine proteinases and matrix metalloproteinases to the resorption process in osteoclasts derived from long bone and scapula.

It has been suggested that functional heterogeneity exists between osteoclasts from different bone sites. This could be exploited to design therapeutics that would selectively inhibit bone resorption only at compromised sites. To further investigate the existence of functional differences between osteoclasts from different bone sites we assessed whether osteoclasts isolated from intramembranous bone differ from osteoclasts isolated from endochondral bone in the extent that they utilize cysteine proteinases and matrix metalloproteinases to degrade the organic matrix of bone. The differential involvement of the two classes of proteases was assessed by analyzing dose-dependent effects of the matrix metalloproteinase inhibitor, CT-1746, and of the cathepsin inhibitor, E64, on bone resorption. Osteoclasts isolated from the scapula (intramembranous) and long bones (endochondral) of newborn New Zealand white rabbits were seeded on cortical bovine bone slices in the presence or absence of inhibitors. Resorptive activity was evaluated by measuring the number and area of resorption pits and by measuring the release of collagen degradation products in the culture medium. In the absence of inhibitors, scapular osteoclasts and long bone osteoclasts had similar activity based on these criteria. The resorptive activity of scapular osteoclasts was inhibited to a greater extent by the MMP inhibitor CT-1746 than by the cysteine proteinase inhibitor E64. Conversely, resorption by osteoclasts derived from long bones was inhibited to a greater degree by the cysteine proteinase inhibitor. These results strongly suggest that there are functional differences between dispersed osteoclasts derived from the scapula and long bones, with scapular osteoclasts utilizing matrix metalloproteinases to a greater extent than cysteine proteinases and long bone osteoclasts using cysteine proteinases to a greater extent than matrix metalloproteinases.

Amides↗
PubMedDate not supplied

Prognostic significance of matrix metalloproteinase expression in colorectal carcinomas.

The matrix metalloproteinases (MMPs) are a family of enzymes that degrade the extracellular matrix (ECM) and are considered to be important in neoplastic cell invasion and metastasis. Structural changes in the extracellular matrix are necessary for cell migration during tissue remodeling and neoplastic cell invasion. Histochemical expression of MMP-2, -3, -9, -10, and -13 was observed in 19 human colorectal carcinomas (CCs) employing an indirect alkaline phosphatase (AP) conjugated antigen detection technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin (SL), types 1 (MMP-3) and 2 (MMP-10), share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in all CC cases observed, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells, and the staining intensity was also the strongest possible (A,B). Weak (surrounding anywhere between 10% and 90% of the neoplastically transformed cells, and of strong A,B intensity) expression of MMP-2 (gelatinase A) and MMP-9 (gelatinase B), two cytokine-induced MMPs, was also observed in CCs. Expression of collagenase-3 (MMP-13), an endopeptidase characterized by a potent degrading activity against a wide spectrum of substrates, was not defined in the CCs cases observed by us. It is clear that the activation of MMPs and their inhibitors occurs in a very well orchestrated manner. The necessity of these same enzymes for the extravasation and infiltration of lymphocytes into regions of chronic local inflammation, as associated with neoplastically transformed masses of cells, may aid the transformed cells which have already acquired a metastatic immunophenotype to enter the peripheral circulation. Further characterization of the expression and utilization of MMPs and their inhibitors in the progression of solid human neoplasms should lead to the development of novel anti-cancer therapies.

Adenocarcinoma↗
PubMed1999

Invasiveness of hepatocellular carcinoma cell lines: contribution of membrane-type 1 matrix metalloproteinase.

Intrahepatic metastasis is one of the malignant features of hepatocellular carcinoma (HCC). Matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (u-PA)/plasmin, are known to be associated with the invasive properties of various types of tumor cells. In this study, we examined which proteinases play a role in the metastatic invasion of human HCC cell lines. JHH-5 and JHH-6 cells constitutively expressed mRNAs for both membrane-type 1 matrix metalloproteinase (MT1-MMP) and u-PA and invaded through reconstituted MATRIGEL in vitro, whereas JHH-7 cells expressed u-PA mRNA but not MT1-MMP and did not invade. However, hepatocyte growth factor (HGF) induced MT1-MMP expression on the surface of JHH-7 cells and markedly increased invasiveness of JHH-7 in a concentration-dependent manner. Moreover, cleavage activity for pro-MMP-2 was induced in HGF-treated JHH-7 cells. MMP inhibitor, rather than serine proteinase inhibitor, potently inhibited HCC cell invasion. Intrahepatic injection of HCC cell lines into athymic nude mice caused visible intrahepatic metastases in vivo. Moreover, JHH-7 tumors showed expression of MT1-MMP mRNA, while in vitro cultured JHH-7 cells did not. These findings suggest that MT1-MMP plays an important role in the invasive properties of HCC cells, and that HGF modifies the invasive properties of noninvasive HCC cells.

Animals↗
PubMed1996

Matrix metalloproteinase-7 expression in gastric carcinoma.

BACKGROUND/AIMS: Matrix metalloproteinase-7 (MMP-7) belongs to the same family as matrix degrading metalloproteinase (MMPs) that may play an important part in cancer cell invasion and metastasis. This study reports on the MMP-7 mRNA expression level both in human gastric carcinomas and the normal gastric mucosa. METHODS: From fresh specimens of 47 surgical pairs of primary gastric carcinomas and corresponding normal tissue specimens, cDNA was obtained by reverse transcription (RT) and thereafter MMP-7 mRNAs were detected by means of a polymerase chain reaction. The tumour/normal (T/N) ratio of MMP-7 expression was calculated after correcting for glyceraldehyde-3-phosphate dehydrogenase as an internal control. RESULTS: The expression corrected levels of MMP-7 mRNA of the tumour was greater than that of the normal mucosa in 41 of 47 cases (87%). The 13 cases whose T/N ratio was more than 2.1 showed a deeper invasion of the gastric wall, and more frequent lymphatic or vascular permeations than the 34 cases whose T/N ratio was less than 2.0. An immunohistochemical study showed that MMP-7 was predominantly expressed in the cancer cells, weakly expressed in normal epithelial cells, and not expressed in the surrounding stromal cells. CONCLUSIONS: These findings suggest that the overexpression of MMP-7 may thus play an important part in tumour invasion in gastric carcinomas while, in addition, MMP-7 may also prove to be a useful marker for determining the biological aggressiveness of gastric carcinoma.

Aged↗
PubMed2006

Expression of matrix metalloproteinases in benign and malignant follicular thyroid lesions.

AIMS: To examine expression of matrix metalloproteinases (MMPs) and related proteins in follicular thyroid lesions (FTLs) and to determine their usefulness for differential diagnosis of FTLs, particularly between minimally invasive carcinoma and adenoma. METHODS AND RESULTS: Six widely invasive follicular carcinomas (WIFCs), 15 minimally invasive follicular carcinomas (MIFCs), 19 follicular adenomas (FAs) and 10 adenomatous goitres (AGs) were analysed immunohistochemically for MMP-1, MMP-2, MMP-7, MMP-9, membrane-type 1-MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). MMP-1 was positive in all FTLs. MMP-2 and MMP-7 were positive in more than 80% of WIFC and MIFC cases, whereas they were negative in all FA and AG cases except one MMP-2+ FA (P < 0.001). MMP-9 stained positive significantly more in MIFC than FA or AG cases (P < 0.05, respectively). The positivity of MT1-MMP and TIMP-2 was different among some of the FTLs, but with no significant difference between MIFC and FA cases. In-situ hybridization of MMP-2 and MMP-7 mRNA in selected cases demonstrated the expression of these enzymes in the tumour cells as well as in some stromal cells. CONCLUSIONS: Our results confirm MMP expression mainly in malignant FTLs and suggest that MMP-2 and MMP-7 may be useful markers to distinguish MIFC from FA.

Adenocarcinoma, Follicular↗
PubMed1999

Purification of aminophenyl mercuryacetate-activated human matrix metalloproteinase 1 and removal of the organomercurial in a single-step chromatography.

Matrix metalloproteinases are secreted from different cells as inactive zymogens. For their activation in vitro organomercurials may be used, the presence of which, however, can falsify activity assays and modulate the effects of the proteases in subsequent investigations. Here, we demonstrate the binding of human matrix metalloproteinase 1 to a thiophilic resin (mercaptoethylquinazolinedione derivatized agarose) and take advantage of this thiophilic interaction for the purification of organomercurial activated matrix metalloproteinase 1 from the supernatant of a thyroid carcinoma cell line in connection with the simultaneous removal of the activator.

Chromatography, Affinity↗
PubMed2005

Impaired alveolization in mice deficient in membrane-type matrix metalloproteinase 1 (MT1-MMP).

To clarify the involvement of membrane-type matrix metalloproteinase 1 (MT1-MMP) in lung organogenesis, we studied the lung morphology of 13-day-old MT1-MMP null mice. The lung architecture in MT1-MMP null mice was abnormal, and the airspace compartments were characterized by smooth walls and larger size. Most of the compartment wall consisted of one or two layers of cells and interstitial connective tissue that was thicker than that of normal alveoli. The wall frequently had capillaries on both sides of the interstitial connective tissue. These findings indicate that the lung in MT1-MMP null mice at 13 days of age is comparable to that of neonatal mice, i.e., it represents the stage before alveolization, suggesting that the generation of a large respiratory surface - the final process of lung development - is impaired in MT1-MMP null mice. Moreover, a zymography assay revealed decreased activity of matrix metalloproteinase 2 (MMP-2) in MT1-MMP null mice, suggesting that activation of pro-MMP-2 by MT1-MMP is critical in this process.

Animals↗
PubMed1998

Expression of membrane-type matrix metalloproteinase-1 in human pancreatic adenocarcinomas.

The expression of a new type of matrix metalloproteinase, membrane-type matrix metalloproteinase-1 (MT-MMP-1), was examined in 24 cases of primary pancreatic adenocarcinomas and 9 cases of secondary liver tumors derived from pancreatic adenocarcinomas, using a non-radioactive in situ hybridization and immunohistochemical methods. Out of 24 cases of primary pancreatic adenocarcinomas, 18 showed positive expression of MT-MMP-1 transcripts in cancer cells and 20 of 24 showed positive expression in the tumor stromal cells. The immunoreactivity of the gene products for MT-MMP-1 was demonstrated to be almost the same, as shown by in situ hybridization in these 24 cases. In particular, both the staining intensity for MT-MMP-1 transcripts and the immunoreactivity of the gene products in the tumor stromal cells of mucinous cystadenocarcinomas were significantly weaker than those of common-type ductal adenocarcinomas among the 24 cases. All of the 9 cases of secondary liver tumors derived from pancreatic adenocarcinomas showed positive expression for MT-MMP- transcripts but less immunoreactivity for the gene products. These results suggest that MT-MMP-1 is transcribed and translated in both cancer cells and the tumor stromal cells in human pancreatic adenocarcinomas. Furthermore, considering that common-type ductal adenocarcinoma of the pancreas usually shows a strong desmoplastic reaction, while mucinous cystadenocarcinoma typically does not, MT-MMP-1 expressed in the tumor stromal cells of common-type adenocarcinomas may be involved in processes leading to the desmoplastic reaction.

Adenocarcinoma↗
PubMed2001

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.

Animals↗
PubMed1996

Cleavage of structural components of mammalian vitreous by endogenous matrix metalloproteinase-2

Our goal was to determine if the major endogenous vitreous matrix metalloproteinase (MMP-2) could digest known collagenous components of the vitreous body. Matrix metalloproteinase-2 and its associated inhibitors were isolated from porcine vitreous by affinity column chromatography. The inhibitors were inactivated by chemical modification with dithiothreitol and iodoacetamide. The latent MMP-2 was then activated with the organo-mercurial, p-aminophenyl mercuric acetate (APMA). Bovine vitreous fibrillar collagens (types II, V/XI and IX) were isolated by pepsin extraction and differential salt precipitation. Intact type IX collagen was purified by selective salt precipitation followed by ion exchange and size exclusion chromatography. These isolated collagens were incubated for 6 to 24 h with different concentrations of activated MMP-2, and the extent of collagen degradation was analyzed. Activated MMP-2 was also introduced into freshly isolated vitreous gels and the degree of liquefaction was determined. Our results showed that the activated MMP-2 has no apparent effect upon type II collagen but can degrade type V/XI collagen and type IX collagen fragments (COL2 and COL2 + COL3). In addition, when the type IX collagen was in the intact helical form, MMP-2 appeared to selectively digest alpha3 (IX) chains. This suggested that vitreous MMP-2 preferentially cleaved certain vitreous collagen chains into large fragments than small peptides. MMP-2 also disrupted the vitreous gel in vitro, releasing proteins but not hexuronic acid or sulfated glycosaminoglycans into the liquefied supernatant. We conclude that MMP-2 activity should be considered as a potential mechanism of vitreous liquefaction that is seen in aging and various pathological states. Keywords: matrix metalloproteinase; type II collagen; type IX collagen; type V/XI collagen; vitreous; pig

Journal Article↗
PubMed2004

Increased tissue microarray matrix metalloproteinase expression favors proteolysis in thoracic aortic aneurysms and dissections.

BACKGROUND: Little information is available regarding the role of matrix metalloproteinases (MMPs) in thoracic aortic aneurysms and dissections. We applied tissue microarray analysis to determine MMP profiles in a large group of surgically resected thoracic aneurysms and dissections. METHODS: Specimens from 47 patients undergoing a variety of surgical procedures for thoracic aneurysm (n = 30) and dissection (n = 17) were included. Expression of MMP-1, MMP-2, and MMP-9 and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were assessed by aortic tissue microarray immunostaining. Matrix metalloproteinase and TIMP expression in aortic tissue was compared with seven control aortic specimens, free of any vascular disease. RESULTS: Expression of MMP-1 and MMP-9 was significantly increased in aneurysm and aortic dissection patients compared with control specimens (p < 0.05). Expression of TIMP-2 was significantly increased in the entire patient group, compared with control specimens (p < 0.05). Aortic dissection patients had higher MMP-2 and MMP-9 expression than aortic aneurysm patients in areas of disease. Compared with control patients, the MMP-9 to TIMP-1 ratio (a relative index of proteolytic state) was increased in both the aortic aneurysm and dissection groups (p < 0.05). CONCLUSIONS: The increased MMP expression in aortic aneurysms and dissections indicates a metamorphosis in the aneurysm wall toward increased proteolysis compared with the normal aorta. Furthermore, we find even higher MMP-2 and MMP-9 presence in aortic dissection. In both aneurysms and dissections, this transformation to a proteolytic state likely plays an important pathophysiologic role in the development and progression of the aortic disease. The recognition of this pathophysiologic mechanism raises the potential for drug therapy to interrupt the cascade of events.

Aged↗
PubMed2002

The promoter polymorphism of the matrix metalloproteinase 3 (MMP-3) gene in women with ovarian cancer.

Matrix metalloproteinases (MMPs) comprise family proteolytic enzymes that degrade extracellular matrix components and therefore play an important role in tumour cell invasion and cancer metastasis. Overexpression of matrix metalloproteinase 3 (MMP-3 or stromelysin 1) gene has been demonstrated in various types of cancers and high level of MMP-3 protein in tumour is a poor prognostic factor for patients. The insertion (6A)/deletion (5A) polymorphism (5A/6A polymorphism) located at the promoter of the MMP-3 gene may have functional significance in the regulation of its expression. In the present work the distribution of genotypes and frequencies of alleles of the 5A/6A polymorphism in subjects with ovarian cancer were investigated. Paraffin embedded tumour tissues were obtained from 100 women with ovarian cancer. The genotypes of 5A/6A polymorphism were determined by PCR amplification using the allele specific primers. The distribution of the genotypes of the 5A/6A polymorphism in both control and patients did not differ significantly (p > 0.05) from those predicted by the Hardy-Weinberg distribution. Additionally, there were no significant differences (p > 0.05) in genotype distributions and allele frequencies between subgroups assigned to histological stage. The results suggest that the 5A/6A polymorphism of MMP-3 gene may not be linked with appearance and development to ovarian cancer.

Aged↗
PubMedDate not supplied

Expression of matrix metalloproteinases in spontaneous regression of liver fibrosis.

BACKGROUND/AIMS: Spontaneous regression of liver fibrosis would depend on the degradation of the excessive matrix in the liver. In this study, we tried to determine the kinetics of the expression of genes for matrix metalloproteinase-2 and -13. METHODOLOGY: Liver fibrosis induced by carbon tetrachloride was resolved after withdrawal of this toxin. Histological staining for fibrous septa and determination of liver collagen content were used to evaluate the extent of liver fibrosis. Expression in liver of matrix metalloproteinase-2 and -13 was determined by reverse transcription-polymerase chain reaction. RESULTS: The fibrous septa became thinner and interrupted and liver fibrosis resolved rapidly within 10 days. Expression of matrix metalloproteinase-2 and -13 was elevated to 2.5- and 8.7-fold, respectively, at peak fibrosis. The former was maintained at 88%-76% and the later dropped rapidly to 30%-20% in the recovery periods. CONCLUSIONS: Resolution of liver fibrosis began within 10 days but only to 70%. Gene expression kinetics suggested metalloproteinase-13 might play a more important role in the resolution because it surged more markedly at peak fibrosis and returned to nearly basal levels in the recovery periods in parallel with liver collagen content.

Animals↗
PubMed2002

Balance between activation and inhibition of matrix metalloproteinase-2 (MMP-2) is altered in colorectal tumors compared to normal colonic epithelium.

Matrix metalloproteinase-2 (MMP-2) is overexpressed in human cancers and facilitates tumor growth and metastasis. It is synthesized as an inactive proenzyme that is activated by membrane-type matrix metalloproteinase-1 (MT1-MMP) and inhibited by tissue inhibitor of metalloproteinase-2 (TIMP-2). We hypothesized that there is an imbalance between the expression of TIMP-2 and the expression of MMP-2 and MT1-MMP that favors activation of MMP-2 in malignant colon tumors compared to normal colonic tissue. Specimens of colon tumors and of adjacent normal mucosa were obtained from 22 patients at the time of surgical resection. MMP-2, MT1-MMP, and TIMP-2 RNA transcripts were measured in each sample using a quantitative reverse transcriptase polymerase chain reaction assay. We observed that MMP-2 RNA levels were significantly elevated in tumors compared to normal tissue (P = 0.039). In addition, the TIMP-2:MMP-2 ratio was twofold lower (P = 0.001) and the TIMP-2:MT1-MMP ratio was 1.5-fold lower (P = 0.003) in tumors compared to normal mucosa. These results suggest that the balance between genes that activate and inhibit MMP-2 is shifted toward activation in colon tumors. The abnormal expression of gene products that regulate MMP-2 activity may be an important early step in the malignant transformation of colon cancer and may provide a useful target for new chemoprevention and adjuvant treatment strategies.

Colon↗