Association between Gene Polymorphisms and SNP-SNP Interactions of the Matrix Metalloproteinase 2 Signaling Pathway and the Risk of Vascular Senescence

Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were collected.Fourteen SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic regression.The multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)modeling.Results Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs7201,and MMP2 rs1053605.Carriers of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased risk.CCL2 rs4586 and MMP-2 rs14070 exhibited the most significant interactions.Conclusion CCL2 rs4586,MMP-2 rs14070,MMP-2 rs7201,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.

Placenta-derived mesenchymal stem cells attenuate secondary brain injury after controlled cortical impact in rats by inhibiting matrix metalloproteinases

Background:As a form of biological therapy,placenta-derived mesenchymal stem cells(PDMSCs)exhibit considerable promise in addressing the complex pathological processes of traumaticbrain injury(TBI)due to their multi-target and multi-pathway mode of action.Material&Methods:This study investigates the protective mechanisms and benefits of PDMSCs in mitigating the effects of controlled cortical impact(CCI)in rats and glutamate-induced oxidative stress injury in HT22 cells in vitro.Our primary objective is to provide evidence supporting the clinical application of PDMSCs.Results:In the in vivo arm of our investigation,we observed a swift elevation of matrix metalloproteinase-9(MMP-9)in the proximal cortex of injured brain tissues after CCI.PDMSCs,distinguished by their heightened expression of metalloproteinase tissue inhibitors-1 and-2(TIMP-1 and TIMP-2):were intravenously administered via the caudal vein.This intervention yielded significant reductions in the permeability of the blood-brain barrier(BBB):the extent of brain edema,the levels of inflammatory cytokines IL-1βand TNF-αin damaged brain tissue,and the activation status of microglia in CCI-afflicted rats.In the realm of in vitro experiments,PDMSC-conditioned media demonstrated substantial reductions in mortality rates and cleaved caspase-3 levels in glutamate-induced HT22 cells compared with conventional media.Notably,this advantage was negated upon the introduction of neutralizing antibodies targeting TIMP-1 and TIMP-2.Conclusion:Collectively,our findings underscore the potential of PDMSCs in alleviating oxidative stress injury and secondary brain injury in the pathological process of TBI.

Diagnostic value of matrix metalloproteinases 2, 7 and 9 in urine for early detection of colorectal cancer

BACKGROUND A noninvasive biomarker with high diagnostic performance is urgently needed for the early diagnosis of colorectal cancer(CRC).AIM To evaluate the diagnostic value of matrix metalloproteinases(MMPs)2,7 and 9 in urine for CRC.METHODS Of 59 healthy controls,47 patients with colon polyps and 82 patients with CRC were included in this study.Carcinoembryonic antigen(CEA)in serum and MMP2,MMP7,and MMP9 in urine were detected.The combined diagnostic model of the indicators was established by binary logistic regression.The receiver operating characteristic curve(ROC)of the subjects was used to evaluate the independent and combined diagnostic value of the indicators.RESULTS The MMP2,MMP7,MMP9,and CEA levels in the CRC group differed significantly from levels in the healthy controls(P<0.05).The levels of MMP7,MMP9,and CEA also differed significantly between the CRC group and the colon polyps group(P<0.05).The area under the curve(AUC)distinguishing between the healthy control and the CRC patients using the joint model with CEA,MMP2,MMP7 and MMP9 was 0.977,and the sensitivity and specificity were 95.10%and 91.50%,respectively.For early-stage CRC,the AUC was 0.975,and the sensitivity and specificity were 94.30%and 98.30%,respectively.For advanced stage CRC,the AUC was 0.979,and the sensitivity and specificity were 95.70%and 91.50%,respectively.Using CEA,MMP7 and MMP9 to jointly established a model distinguishing the colorectal polyp group from the CRC group,the AUC was 0.849,and the sensitivity and specificity were 84.10%and 70.20%,respectively.For early-stage CRC,the AUC was 0.818,and the sensitivity and specificity were 76.30%and 72.30%,respectively.For advanced stage CRC,the AUC was 0.875,and the sensitivity and specificity were 81.80%and 72.30%,respectively.CONCLUSION MMP2,MMP7 and MMP 9 may exhibit diagnostic value for the early detection of CRC and may serve as auxiliary diagnostic markers for CRC.

Imbalance of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-1 may contribute to hemorrhage in cerebellar arteriovenous malformations

In this study, we determined the expression levels of matrix metalloproteinase-2 and -9 and matrix metalloproteinase tissue inhibitor-1 and -2 in brain tissues and blood plasma of patients undergoing surgery for cerebellar arteriovenous malformations or primary epilepsy （control group）. Immunohistochemistry and enzyme-linked immunosorbent assay revealed that the expression of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-1 was significantly higher in patients with cerebellar arteriovenous malformations than in patients with primary epilepsy. The ratio of matrix metalloproteinase-9 to matrix metalloproteinase tissue inhibitor-1 was significantly higher in patients with hemorrhagic cerebellar arteriovenous malformations compared with those with non-hemorrhagic malformations. Matrix metalloproteinase-2 and matrix metalloproteinase tissue inhibitor-2 levels were not significantly changed. These findings indicate that an imbalance of matrix metalloproteinase-9 and matrix metalloproteinase tissue inhibitor-I, resulting in a relative overabundance of matrix metalloproteinase-9, might be the underlying mechanism of hemorrhage of cerebellar arteriovenous malformations.

Role of matrix metalloproteinase,tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM:To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1,-2,-3,-9,tissue inhibitors of metalloproteinases (TIMP)-1,-2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD),that may enhance susceptibility and/or disease severity. METHODS:Genomic DNA from 134 Crohn's disease (CD),111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR. RESULTS:The TIMP-1 genotype TT in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%,P=0.018 and 67.9% vs 51.6%,P=0.055,respectively),while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%,P=0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 < P < 0.01). The 5T5T genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during follow-up (91.2% vs 71.8%,P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%,P=0.017). CONCLUSION:Allelic composition at the examinedSNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype,i.e.,fistulizing disease,stricture pathogenesis and first disease localisation. These findings reinforce the important role of these proteins in IBD.

Matrix metalloproteinases and gastrointestinal cancers: Impacts of dietary antioxidants

The process of carcinogenesis is tightly regulated by antioxidant enzymes and matrix degrading enzymes, namely, matrix metalloproteinases(MMPs). Degradation of extracellular matrix(ECM) proteins like collagen, proteoglycan, laminin, elastin and fibronectin is considered to be the prerequisite for tumor invasion and metastasis. MMPs can degrade essentially all of the ECM components and, most MMPs also substantially contribute to angiogenesis, differentiation, proliferation and apoptosis. Hence, MMPs are important regulators of tumor growth both at the primary site and in distant metastases; thus the enzymes are considered as important targets for cancer therapy. The implications of MMPs in cancers are no longer mysterious; however, the mechanism of action is yet to be explained. Herein, our major interest is to clarify how MMPs are tied up with gastrointestinal cancers. Gastrointestinal cancer is a variety of cancer types, including the cancers of gastrointestinal tract and organs, i.e., esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The activity of MMPs is regulated by its endogenous inhibitor tissue inhibitor of metallopro-teinase(TIMP) which bind MMPs with a 1:1 stoichiometry. In addition, RECK(reversion including cysteinerich protein with kazal motifs) is a membrane bound glycoprotein that inhibits MMP-2,-9 and-14. Moreover, α2-macroglobulin mediates the uptake of several MMPs thereby inhibit their activity. Cancerous conditions increase intrinsic reactive oxygen species(ROS) through mitochondrial dysfunction leading to altered protease/anti-protease balance. ROS, an index of oxidative stress is also involved in tumorigenesis by activation of different MAP kinase pathways including MMP induction. Oxidative stress is involved in cancer by changing the activity and expression of regulatory proteins especially MMPs. Epidemiological studies have shown that high intake of fruits that rich in antioxidants is associated with a lower cancer incidence. Evidence indicates that some antioxidants inhibit the growth of malignant cells by inducing apoptosis and inhibiting the activity of MMPs. This review is discussed in six subchapters, as follows.

Doxycycline blocks gastric ulcer by regulating matrix metalloproteinase-2 activity and oxidative stress

AIM: To examine the effect of doxycycline on the activity of matrix metalloproteinases (MMPs) and oxidative stress in gastric tissues of rats following gastric injury.METHODS: Gastric ulcers were generated in rats by administration of 70% ethanol,and activity of doxycycline was tested by administration 30 min prior to ethanol.Similarly,the effect of doxycycline was tested in an indomethacin-induced gastric ulcer model.The activities and expression of MMPs were examined by zymography and Western blot analysis.RESULTS: Gastric injury in rats as judged by elevated ulcer indices following exposure to ulcerogen,either indomethacin or ethanol,was reversed significantly by doxycycline.Indomethacin-induced ulcerated gastric tissues exhibited about 12-fold higher proMMP-9 activity and about 5-fold higher proMMP-3 activity as compared to control tissues.Similarly,ethanol induced about 22-fold and about 6-fold higher proMMP-9 and proMMP-3 activities,respectively,in rat gastric tissues.Both proMMP-9 and MMP-3 activities were markedly decreased by doxycycline in ulcerogen treated rat gastric tissues.In contrast,the reduced MMP-2 activity in ulcerated tissues was increased by doxycycline during ulcer prevention.On the other hand,doxycycline inhibited significantly proMMP-9,-2 and -3 activities in vitro.In addition,doxycycline reduced oxidative load in gastric tissues and scavenged H2O2 in vitro.Our results suggest a novel regulatory role of doxycycline on MMP-2 activity in addition to inhibitory action on MMP-9 and MMP-3 during prevention of gastric ulcers.CONCLUSION: This is the first demonstration of dual action of doxycycline,that is,regulation of MMP activity and reduction of oxidative stress in arresting gastric injury.

Correlation of matrix metalloproteinase－2, －9, tissue inhibitor－1 of matrix metalloproteinase and CD44 variant 6 in head and neck cancer metastasis

This study aimed to explore the molecular mechanism in tumor invasion and metastasis. The expression of matrix metalloproteinase 2, 9 (MMP 2, MMP 9), tissue inhibitor 1 of matrix metalloproteinase (TIMP 1), cell adhesion molecule 44 variant 6 (CD44v6), HER2/neu and p53 was investigated in 154 patients with head and neck squamous cell carcinoma (SCC) by ABC and ImmunoMax immunohistochemical method. Their clinical relevance and correlation were analysed. The expression of MMP 2, MMP 9, TIMP 1, CD44v6, HER2/neu and p53 was found in cancer cells in 87.01%, 85.71%, 68.18%, 98.05%, 55.19% and 50.65% cases respectively. Linear regression and correlation analysis revealed that there was close positive relationship ( P <0.05) between the expression of MMP 2 and MMP 9, TIMP 1 and CD44v6, HER2/neu and MMP 9, MMP 2 and p53. Up regulation of MMP 2 was accompanied by advanced T stage ( P <0.01) . There was also a trend of MMP 2 expression being related with tumor metastasis. Increased expression of HER2/neu was found in patients with tumor recurrence( P <0.05). The expression of TIMP 1 was higher in laryngeal cancer than that in pharyngeal cancer, and higher in keratinizing and non keratinizing SCC than that in basaloid SCC( P <0.05). These findings suggested that MMP 2 and MMP 9, HER2/neu and MMP 9, MMP 2 and p53 had a coordinate function in aggression of tumor; that MMP 2 had a more important function than MMP 9 in tumor invasion and metastasis; and that HER2/neu might serve as a biomarker for poor prognosis in HNSCC.

MATRIX METALLOPROTEINASE AND THEIR INHIBITORS: MOLECULAR ASPECTS OF THEIR ROLES IN THE TUMOR METASTASIS

The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes, whose physiological functions include tissue remo-delling and embryogenesis. The importance of this group of proteins in the processes of tumor invasion and metastasis is now widely acknowledged, and has led to the search for MMP inhibitors for use as anticancer treatments in a clinical setting. The review aims to introduce current research relating to MMPs as well as their native and synthetic inhibitor, with particular emphasis on the molecular aspects of their roles in tumor metastasis.

Inhibition of Metalloproteinase Activity by Chinese Formulations Used to Treat Inflammatory Diseases

Matrix metalloproteinases （MMPs） are known to be involved in a number of pathological processes including cancer, atherosclerosis, arthritis and neurodegenerative disease among others. The drive to develop MMP inhibitors as therapeutics has been put forward for years by pharmaceutical companies as well as academicians. In an attempt to screen for MMP inhibitors from Traditional Chinese Medicines （TCMs） , a number of Chinese formulations used to treat inflammatory diseases such as nephritis and hepatitis have been studied. Strong inhibitory effects of three Chinese formulations toward the activity of MMP-16 have been discovered. These results suggest that these anti-inflammatory medicines contain some unknown MMP inhibitory compound（s） and provide reasonable molecular mechanisms for their theraoeutic effects.

Metalloproteinases as mediators of inflammation and the eyes： molecular genetic underpinnings governing ocular pathophysiology

There are many vision threatening diseases of the eye affecting millions of people worldwide. In this article, we are summarizing potential role of various matrix metalloproteinases （MMPs）; the Zn （2＋）-dependent endoproteases in eye health along with pathogenesis of prominent ocular diseases such as macular degeneration, diabetic retinopathy, and glaucoma via understanding MMPs regulation in affected patients, interactions of MMPs with their substrate molecules, and key regulatory functions of tissue inhibitor of metalloproteinases （TIMPs） towards maintaining overall homeostasis.

Time dependent integration of matrix metalloproteinases and their targeted substrates directs axonal sprouting and synaptogenesis following central nervous system injury

Over the past two decades, many investigators have reported how extracellular matrix molecules act to regulate neuroplasticity. The majority of these studies involve proteins which are targets of matrix metalloproteinases. Importantly, these enzyme/substrate interactions can regulate degenerative and regenerative phases of synaptic plasticity, directing axonal and dendritic reorganization after brain insult. The present review first summarizes literature support for the prominent role of matrix metalloproteinases during neuroregeneration, followed by a discussion of data contrasting adaptive and maladaptive neuroplasticity that reveals time-dependent metalloproteinase/substrate regulation of postinjury synaptic recovery. The potential for these enzymes to serve as therapeutic targets for enhanced neuroplasticity after brain injury is illustrated with experiments demonstrating that metalloproteinase inhibitors can alter adaptive and maladaptive outcome. Finally, the complexity of metalloproteinase role in reactive synaptogenesis is revealed in new studies showing how these enzymes interact with immune molecules to mediate cellular response in the local regenerative environment, and are regulated by novel binding partners in the brain extracellular matrix. Together, these different examples show the complexity with which metalloproteinases are integrated into the process of neuroregeneration, and point to a promising new angle for future studies exploring how to facilitate brain plasticity.

EFFECTS OF GENISTEIN ON INVASION AND MATRIX METALLOPROTEINASE ACTIVITIES OF HT1080 HUMAN FIBROSARCOMA CELLS

Effects of genistein on invasion and matrix metalloproteinase activities were investigated in HT1080 human sarcoma cells.Invasion of HT1080 cells through reconstituted basement membrane was inhibited when the cells were treated with 100 μ mol/L and 200 μ mol/L genistein.At the same concentrations,genistein not only suppressed latent forms of matrix metalloprotinese 2 and 9(MMP 2 and MMP 9) to convert into active forms,but also increase dramatically the tissue inhibitor of metalloproteinase(TIMP 1) mRNA contents and reverse the imbalance of MMPs and TIMPs.However,expressions of MMP 2 and MMP 9 were not significantly affected.Suppression of MMP activation and increase of TIMP 1 expression will decrease matrix degradation by MMPs,and consequently inhibit invasions of the cells.These results emphasized the existence of the imbalance between MMPs and TIMPs in tumor invasion and metastasis formation.The value of genistein as a drug for antiinvasion and anti metastasis chemotherapy was suggested.

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β_1 in Cultured Human RPE Cells

In order to investigate the effects of TGF-β1 on the expression of MMP-2, -9 and TIMP- 1 in human retinal pigment epithelial （RPE） cells, the third-sixth passage cultured RPE cells were treated with TGF-β1 at different concentrations （0.01, 0. 1, 1.0, 10 ng/mL）, the expression of MMP-2, -9 and TIMP-1 mRNA was detected by semi-qudntitative RT-PCR assays. MMP-2, -9 and TIMP-1 mRNA were expressed in the cultured RPE cells. The values of MMP-2/β-actin in the cells treated with 0.1, 1.0, 10 ng/mL TGF-β1 were 1.04±0.04, 1.07±0.02 and 1.11±0.03, respectively, significantly higher than in the control group （0.96±0.03, P〈0. 05-0.01）. The expression of MMP-2 mRNA could be up-regulated by TGF-β, , in a dose-dependent manner. The expression of MMP-9 mRNA in the cultured RPE cells was slightly up-regulated by various TGF-β1 concentrations treatment. The values of TIMP-1/β-actin in the cells treated with 0.01 and 0.1 ng/ mL TGF-β1 were 0.85 ±0.01 and 0.97 ± 0.02 respectively, significantly lower than in the control group （1.07±0.04, P〈0.01）, indicating that the expression of TIMP-1 mRNA was down-regulated by TGF-β1 at low concentrations. But along with the increase of TGF-β1 concentrations （1.0 and 10 ng/mL）, the expression of TIMP-1 mRNA was slightly up-regulated, not significantly different from that in the control group （P〉0.05）. It was concluded that TGF-β1 might play an important role in the up-regulation of the expression of MMP-2 in RPE cells and result in a directional shift in the balance between MMP and TIMP. This may be facilitated for RPE cells to migrate in the pathogenesis of vitreoretinopathy.

Structure,expression,and developmental function of early divergent forms of metalloproteinases in Hydra

Metalloproteinases have a critical role in a broad spectrum of cellular processesranging from the break-down of extracellular matrix to the processing of signaltransduction-related proteins.These hydrolytic functions underlie a variety of mechanisms related to developmental processes as well as disease states.Structural analysis of metalloproteinases from both invertebrate and vertebrate species indicates that these enzymes are highly conserved and arose early during metazoan evolution.In this regard,studies from vari-ous laboratories have reported that a number of classes of metalloproteinases are found in hydra,a member of Cnidaria,the second oldest of existing animal phyla.These studies demonstrate that the hydra genome contains at least three classes of metalloproteinases to include members of the 1)astacin class,2)matrix met-alloproteinase class,and 3)neprilysin class.Functional studies indicate that these metalloproteinases play diverse and important roles in hydra morphogenesis and cell differentiation as well as specialized functions in adult polyps.This article will review the structure,expression,and function of these metalloproteinases in hydra.

Immunohistochemical Studies of the Expression of Matrix Metalloproteinase-2 and Metalloproteinase-9 in Human Prostate Cancer

To study the expression of matrix metalloproteinase 2 and 9 in human prostate cancer, matrix metalloproteinase 2 and 9 were immunohistochemically detected in tissues of prostate cancer and benign prostatic hyperplasia (BPH). Our results showed that matrix metalloproteinase 2 and 9 levels in prostate cancer were much higher than those in tissues of BPH, with the cancer invasion being positively correlated with the expression of the metalloproteinases. It is concluded that matrix metalloproteinase 2 and 9 are better molecular markers, which are of help in the diagnosis and prediction of prognosis of prostate cancer.

Diabetes-related intestinal region-specific thickening of ganglionic basement membrane and regionally decreased matrix metalloproteinase 9 expression in myenteric ganglia

BACKGROUND The importance of the neuronal microenvironment has been recently highlighted in gut region-specific diabetic enteric neuropathy. Regionally distinct thickening of endothelial basement membrane(BM) of intestinal capillaries supplying the myenteric ganglia coincide with neuronal damage in different intestinal segments. Accelerated synthesis of matrix molecules and reduced degradation of matrix components may also contribute to the imbalance of extracellular matrix dynamics resulting in BM thickening. Among the matrix degrading proteinases, matrix metalloproteinase 9(MMP9) and its tissue inhibitor(TIMP1) are essential in regulating extracellular matrix remodelling.AIM To evaluate the intestinal segment-specific effects of diabetes and insulin replacement on ganglionic BM thickness, MMP9 and TIMP1 expression.METHODS Ten weeks after the onset of hyperglycaemia gut segments were taken from the duodenum and ileum of streptozotocin-induced diabetic, insulin-treated diabetic and sex-and age-matched control rats. The thickness of BM surrounding myenteric ganglia was measured by electron microscopic morphometry. Wholemount preparations of myenteric plexus were prepared from the different gut regions for MMP9/TIMP1 double-labelling fluorescent immunohistochemistry. Post-embedding immunogold electron microscopy was applied on ultrathin sections to evaluate the MMP9 and TIMP1 expression in myenteric ganglia and their microenvironment from different gut segments and conditions. The MMP9 and TIMP1 messenger ribonucleic acid(m RNA) level was measured by quantitative polymerase chain reaction.RESULTS Ten weeks after the onset of hyperglycaemia, the ganglionic BM was significantly thickened in the diabetic ileum, while it remained intact in the duodenum. The immediate insulin treatment prevented the diabetes-related thickening of the BM surrounding the ileal myenteric ganglia. Quantification of particle density showed an increasing tendency for MMP9 and a decreasing tendency for TIMP1 from the proximal to the distal small intestine under control conditions. In the diabetic ileum, the number of MMP9-indicating gold particles decreased in myenteric ganglia, endothelial cells of capillaries and intestinal smooth muscle cells, however, it remained unchanged in all duodenal compartments. The MMP9/TIMP1 ratio was also decreased in ileal ganglia only. However, a marked segment-specific induction was revealed in MMP9 and TIMP1 at the m RNA levels.CONCLUSION These findings support that the regional decrease in MMP9 expression in myenteric ganglia and their microenvironment may contribute to extracellular matrix accumulation, resulting in a region-specific thickening of ganglionic BM.

Matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 expression in fibrotic rat liver

INTRODUCTIONLiver fibrosis is an excessive deposition ofextracellular matrix(ECM)resulted from bothincreased synthesis and decreased degradation.Matrix metalloproteinases(MMPs)represent agroup of neutral proteinases with variable

Complex role of matrix metalloproteinases in angiogenesis

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play a significant role in regulating angiogenesis, the process of new blood vessel formation. Interstitial collagenase (MMP-1), 72 kDa gelatinase A/type IV collagenase (MMP-2), and 92 kDa gelatinase B/type IV collagenase (MMP-9) dissolve extracellular matrix (ECM) and may initiate and Promote angiogenesis. TIMP-1, TIMP-2, TIMP-3, and possibly,TIMP-4 inhibit neovascularisation. A new paradigm is emerging that matrilysin (MMP-7), MMP-9, and metalloelastase (MMP-12) may block angiogehesis by converting plasndnogen to angiostatin, which is one of the most potent angiogenesis antagonists. MMPs and TIMPs play a complex role in regulating angiogenesis. An understanding of the biochemical and cellular pathways and mechanisms of angiogenesis will provide importal information to allow the control of angiogenesis, e.g. the stimulation of angiogenesis for coronary collateral circulation formation; while the inhibition for treating arthritis and cancer.

Expression of matrix metalloproteinases 2 and 9 in human gastric cancer and superficial gastritis

AIM:To assess expression of matrix metalloproteinases 2(MMP2)and MMP9 in gastric cancer,superficial gastritis and normal mucosa,and to measure metalloproteinase activity.METHODS:MMP2 and MMP9 mRNA expression was determined by quantitative real-time polymerase chain reaction.Normalization was carried out using three different factors.Proteins were analyzed by quantitative gelatin zymography(qGZ).RESULTS:18S ribosomal RNA(18SRNA)was very highly expressed,while hypoxanthine ribosyltransferase-1(HPRT-1)was moderately expressed.MMP2 was highly expressed,while MMP9 was not detected or lowly expressed in normal tissues,moderately or highly expressed in gastritis and highly expressed in cancer.Relative expression of 18SRNA and HPRT-1 showed no significant differences.Significant differences in MMP2 and MMP9 were found between cancer and normal tissue,but not between gastritis and normal tissue.Absolute quantification of MMP9 echoed this pattern,but differential expression of MMP2 proved conflictive.Analysis by qGZ indicated significant differences between cancer and normal tissue in MMP-2,total MMP-9,250 and 110 kDa bands.CONCLUSION:MMP9 expression is enhanced in gastric cancer compared to normal mucosa;interpretation of differential expression of MMP2 is difficult to establish.