Matrix metalloproteinase 9 (MMP-9/gelatinase B) proteolytically cleaves ICAM-1 and participates in tumor cell resistance to natural killer cell-mediated cytotoxicity.

Shedding of intercellular adhesion molecule 1 (ICAM-1) is believed to play a role in tumor cell resistance to cell-mediated cytotoxicity. However, the mechanism whereby ICAM-1 is shed from the surface of tumor cells remains unclear. In this study, we have addressed the possibility that matrix metalloproteinases are implicated in ICAM-1 shedding. Our observations suggest a functional relationship between ICAM-1 and matrix metalloproteinase 9 (MMP-9) whereby ICAM-1 provides a cell surface docking mechanism for proMMP-9, which, upon activation, proteolytically cleaves the extracellular domain of ICAM-1 leading to its release from the cell surface. MMP-9-dependent shedding of ICAM-1 is found to augment tumor cell resistance to natural killer (NK) cell-mediated cytotoxicity. Taken together, our observations propose a mechanism for ICAM-1 shedding from the cell surface and provide support for MMP involvement in tumor cell evasion of immune surveillance.

Recruitment of Matrix Metalloproteinase-9 (MMP-9) to the Fibroblast Cell Surface by Lysyl Hydroxylase 3 (LH3) Triggers Transforming Growth Factor-β (TGF-β) Activation and Fibroblast Differentiation.

Solid tumor growth triggers a wound healing response. Similar to wound healing, fibroblasts in the tumor stroma differentiate into myofibroblasts (also referred to as cancer-associated fibroblasts) primarily, but not exclusively, in response to transforming growth factor-β (TGF-β). Myofibroblasts in turn enhance tumor progression by remodeling the stroma. Among proteases implicated in stroma remodeling, matrix metalloproteinases (MMPs), including MMP-9, play a prominent role. Recent evidence indicates that MMP-9 recruitment to the tumor cell surface enhances tumor growth and invasion. In the present work, we addressed the potential relevance of MMP-9 recruitment to and activity at the surface of fibroblasts. We show that recruitment of MMP-9 to the fibroblast cell surface occurs through its fibronectin-like (FN) domain and that the molecule responsible for the recruitment is lysyl hydroxylase 3 (LH3). Functional assays suggest that both pro- and active MMP-9 trigger α-smooth muscle actin expression in cultured fibroblasts, reflecting myofibroblast differentiation, possibly as a result of TGF-β activation. Moreover, the recombinant FN domain inhibited both MMP-9-induced TGF-β activation and α-smooth muscle actin expression by displacing MMP-9 from the fibroblast cell surface. Together our results uncover LH3 as a new docking receptor of MMP-9 on the fibroblast cell surface and demonstrate that the MMP-9 FN domain is essential for the interaction. They also show that the recombinant FN domain inhibits MMP-9-induced TGF-β activation and fibroblast differentiation, providing a potentially attractive therapeutic reagent toward attenuating tumor progression where MMP-9 activity is strongly implicated.

Angiotensin II induces NF-κB, JNK and p38 MAPK activation in monocytic cells and increases matrix metalloproteinase-9 expression in a PKC- andRho kinase-dependent manner

Angiotensin II (ANG II), the main effector of the renin-angiotensin system, is implicated in endothelial permeability, recruitment and activation of the immune cells, and also vascular remodeling through induction of inflammatory genes. Matrix metalloproteinases (MMPs) are considered to be important inflammatory factors. Elucidation of ANG II signaling pathways and of possible cross-talks between their components is essential for the development of efficient inhibitory medications. The current study investigates the inflammatory signaling pathways activated by ANG II in cultures of human monocytic U-937 cells, and the effects of specific pharmacological inhibitors of signaling intermediates on MMP-9 gene (MMP-9) expression and activity. MMP-9 expression was determined by real-time PCR and supernatants were analyzed for MMP-9 activity by ELISA and zymography methods. A multi-target ELISA kit was employed to evaluate IκB, NF-κB, JNK, p38, and STAT3 activation following treatments. Stimulation with ANG II (100 nM) significantly increased MMP-9 expression and activity, and also activated NF-κB, JNK, and p38 by 3.8-, 2.8- and 2.2-fold, respectively (P < 0.01). ANG II-induced MMP-9 expression was significantly reduced by 75 and 67%, respectively, by co-incubation of the cells with a selective inhibitor of protein kinase C (GF109203X, 5 µM) or of rho kinase (Y-27632, 15 µM), but not with inhibitors of phosphoinositide 3-kinase (wortmannin, 200 nM), tyrosine kinases (genistein, 100 µM) or of reactive oxygen species (α-tocopherol, 100 µM). Thus, protein kinase C and Rho kinase are important components of the inflammatory signaling pathways activated by ANG II to increase MMP-9 expression in monocytic cells. Both signaling molecules may constitute potential targets for effective management of inflammation.

Matrix metalloproteinase-9 expression in pterygium

OBJETIVO: Avaliar a expressão da metaloprotease de matriz (MMP)-9 nos pterígios. MÉTODOS: Foi realizado na Faculdade de Medicina de Botucatu estudo prospectivo, aleatório, com o intuito de avaliar a expressão da metaloprotease de matriz na cápsula de Tenon normal e de pterígios primários e recidivados, usando o método da imuno-histoquímica e o sistema computadorizado de análise de imagem. Os resultados foram avaliados estatisticamente. RESULTADOS: A expressão da metaloprotease de matriz foi semelhante na cápsula de Tenon normal e nos pterígios primários e recidivados. CONCLUSÃO: A expressão da metaloprotease de matriz na cápsula de Tenon normal e nos pterígios primários ou recidivados é semelhante, o que nos leva a concluir que esta metaloprotease de matriz não esteja envolvida na gênese ou na recidiva do pterígio.

Genetic Variants in Matrix Metalloproteinase-9 Gene Modify Metalloproteinase-9 Levels in Black Subjects

Altered matrix metalloproteinases (MMPs) levels are involved in cardiovascular diseases and increased MMP-9 levels enhance the cardiovascular risk in apparently healthy subjects. We investigated the effects of MMP-9 gene polymorphisms and haplotypes on the circulating MMP-9 levels in healthy black subjects and the effects of an MMP-2 polymorphism on the plasma MMP-2 concentrations. We studied 190 healthy subjects, nonsmokers, self-reported as blacks (18-63 years). Genotypes for the MMP-2 C-1306T polymorphism and the MMP-9 C-1562T, 90(CA)(14-24) and Q279R polymorphisms (rs243865, rs3918242, rs2234681, and rs17576, respectively) were determined by TaqMan (R) Allele Discrimination assay and real-time polymerase chain reaction or restriction fragment length polymorphism. Alleles for the 90(CA)(14-24) polymorphism were grouped as low (L) when there were < 21 and high (H) when there were >= 21 CA repeats. The plasma levels of MMP-2 and MMP-9 were determined by gelatin zymography. The software PHASE 2.1 was used to estimate the haplotypes frequencies. Although we found no effects of the MMP-9 C-1562T or the Q279R polymorphisms on MMP-9 levels, higher MMP-9 levels were associated with the HH genotype for the -90(CA)(14-24) polymorphism compared with the HL or LL genotypes. Lower MMP-9 levels were found in carriers of the CRL haplotype (combining the C, R, and L alleles for the MMP-9 polymorphisms) compared with the CRH haplotype. Consistent with this finding, the CRL haplotype was more commonly found in subjects with low MMP-9 levels. The MMP-2 C-1306T polymorphism had no effects on the plasma MMP-2 levels. Our results show that MMP-9 genetic variations modify MMP-9 levels in black subjects and may offer biochemical evidence implicating MMP-9 in the pathogenesis of cardiovascular diseases in blacks.

Specific matrix metalloproteinase 9 (MMP-9) haplotype affect the circulating MMP-9 levels in women with migraine

We investigated whether three relevant polymorphisms (C-1562T, microsatellite - 90(CA)(14-24), and Q279R) in the MMP-9 gene, or MMP-9 haplotypes, are associated with migraine and affect MMP-9 and tissue inhibitor of MMPs (TIMP)-1 levels in patients with migraine. We studied 102 healthy women (controls) and 187 women with migraine (141 without aura - MWA, and 46 with aura - MA). Patients with MWA had higher plasma MMP-9 concentrations than patients with MA. Patients with MA had the highest TIMP-1 and lowest MMP-9/TIMP-1 ratios. The MMP-9 "C L Q" haplotype was associated with higher plasma MMP-9 concentrations in migraine patients. (C) 2012 Elsevier B.V. All rights reserved.

Imbalanced matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 activities in patients with thromboangiitis obliterans

The pathogenic mechanisms of thromboangiitis obliterans (TAO) are not entirely known and the imbalance of matrix metalloproteinases (MMPs) plays a role in vascular diseases. We evaluated the MMP-2 and MMP-9 circulating levels and their endogenous tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in TAO patients with clinical manifestations. The study included 20 TAO patients (n = 10 female, n = 10 male) aged 38-59 years under clinical follow-up. The patients were classified into two groups: (1) TAO former smokers (n = 11) and (2) TAO active smokers (n = 9); the control group included normal volunteer non-smokers (n = 10) and active smokers without peripheral artery disease (n = 10). Patient plasma samples were used to analyze MMP-2 and MMP-9 levels using zymography, and TIMP-1 and TIMP-2 concentrations were determined by enzyme-linked immunosorbent assays. The analysis of MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios (which were used as indices of net MMP-2 and MMP-9 activity, respectively) showed significantly higher MMP-9/TIMP-1 ratios in TAO patients (p < 0.05). We found no significant differences in MMP-2/TIMP-2 ratios (p > 0.05). We found higher MMP-9 levels and decreased levels of TIMP-1 in the TAO groups (active smokers and former smokers), especially in active smokers compared with the other groups (all p < 0.05). MMP-2 and TIMP-2 were not significantly different in patients with TAO as compared to the control group (p > 0.05). In conclusion, our results showed increased MMP-9 and reduced TIMP-1 activity in TAO patients, especially in active smokers compared with non-TAO patients. These data suggest that smoke compounds could activate MMP-9 production or inhibit TIMP-1 activity.

Matrix metalloproteinase-9 polymorphisms affect plasma MMP-9 levels and antihypertensive therapy responsiveness in hypertensive disorders of pregnancy

Abnormal matrix metalloproteinase (MMP)-9 levels may have a role in hypertensive disorders of pregnancy. We examined whether MMP-9 genetic polymorphisms (g.-1562C>T and g.-90(CA)(13-25)) modify plasma MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 levels and the responses to antihypertensive therapy in 214 patients with preeclampsia (PE), 185 patients with gestational hypertension (GH) and a control group of 214 healthy pregnant (HP). Alleles for the g.-90(CA)(13-25) polymorphism were grouped L (low) (<21 CA repeats) or H (high) (>= 21 CA repeats). Plasma MMP-9 and TIMP-1 concentrations were measured by enzyme-linked immunosorbent assay. Plasma MMP-9 concentrations were not affected by genotypes or haplotypes in HP and PE groups, except for the g.-90(CA)(13-25) polymorphism: GH patients with the LH genotype for this polymorphism have higher MMP-9 levels than those with other genotypes. The T allele for the g.-1562C>T polymorphism and the H4 haplotype (combining T and H alleles) are associated with GH and lack of responsiveness to antihypertensive therapy in GH. The H2 haplotype (combining C and H alleles) was associated with lack of responsiveness to antihypertensive therapy in PE, but not in GH. In conclusion, our results show that MMP-9 genetic variants are associated with GH and suggest that MMP-9 haplotypes affect the responsiveness to antihypertensive therapy in hypertensive disorders of pregnancy. The Pharmacogenomics Journal (2012) 12, 489-498; doi: 10.1038/tpj.2011.31; published online 19 July 2011

Matrix metalloproteinase-9 genetic variations affect MMP-9 levels in obese children

Objective: Matrix metalloproteinase-9 (MMP-9) is involved in the atherosclerotic process and functional polymorphisms in the MMP-9 gene affect MMP-9 expression/activity, and are associated with cardiovascular diseases. However, no study has tested the hypothesis that functional MMP-9 polymorphisms could affect MMP-9 levels in obese children. We investigated whether three MMP-9 gene polymorphisms (C-1562T (rs3918242), 90(CA)((14-24)) (rs2234681) and Q279R (rs17576)), or haplotypes, affect MMP-9 levels in obese children. Methods: We studied 175 healthy control children and 127 obese children. Plasma MMP-9, tissue inhibitor of MMPs (TIMP)-1 and adiponectin concentrations were measured using enzyme-linked immunosorbent assay. Results: We found similar MMP-9 genotypes, allelic and haplotypes distributions in the two study groups (P > 0.05). However, we found lower plasma MMP-9 concentrations in obese subjects carrying the CC or the QQ genotypes for the C-1562T and the Q279R polymorphisms, respectively, in obese children compared with children with the other genotypes, or with non-obese children with the same genotypes (all P < 0.05). Moreover, we found lower MMP-9 levels and lower MMP-9/TIMP-1 ratios (which reflect net MMP-9 activity) in obese children carrying the H2 haplotype (which combines the C, H and Q alleles for the three polymorphisms, respectively) when compared with obese children carrying the other haplotypes, or with non-obese children carrying the same haplotype (P < 0.05). Conclusions: Our findings show that MMP-9 genotypes and haplotypes affect MMP-9 levels in obese children and adolescents, and suggest that genetic factors may modify relevant pathogenetic mechanisms involved in the development of cardiovascular complications associated with obesity in childhood. International Journal of Obesity (2012) 36, 69-75; doi:10.1038/ijo.2011.169; published online 16 August 2011

Regulation der Phorbolester-induzierten Matrix-Metalloproteinase-9-Expression in humanen Brustkrebszelllinien durch Stickstoffmonoxid

Das Hauptziel dieser Arbeit war die Identifizierung der Regulationsebenen auf denen die TPA-induzierte Matrix-Metalloproteinase-9 (MMP-9) durch das nitrose Gas Stickstoffmonoxid (NO) in MCF-7-Zellen verändert wird. Dabei konnte sowohl mit Hilfe der Zymographie als auch mit einem MMP-9-Aktivitäts-ELISA gezeigt werden, dass die extrazellulären MMP-9-Spiegel durch die Behandlung der Zellen mit NO reduziert werden. Gleichzeitig zeigte sich auch eine durch NO bedingte Abnahme der intrazellulären MMP-9-Spiegel, wie mit Hilfe von Western-Blot-Analyse nachgewiesen werden konnte. Experimente mit dem Proteasominhibitor Lactacystin und dem Proteinsynthesehemmstoff Cycloheximid ließen darüber hinaus eine NO-bedingte Veränderung der MMP-9-Proteinstabilität ausschließen. Im Gegensatz dazu konnte mittels der metabolischen Markierung mit radioaktiv markiertem Methionin und Cystein gezeigt werden, dass die Proteinneusynthese der MMP-9 durch eine Behandlung der Zellen mit NO stark beeinträchtigt wird. In Übereinstimmung mit diesen Daten finden sich reduzierte MMP-9-mRNA-Spiegel auch in der polysomalen Zellfraktion von MCF-7-Zellen. Wie mit Hilfe des Transkriptionshemmstoffes Actinomycin D und durch Reportergenstudien mit hybriden MMP-9-Promotorkonstrukten gezeigt werden konnte, ist die NO-induzierte Reduktion der MMP-9-mRNA-Spiegel nicht auf eine Verringerung der MMP-9-mRNA-Stabilität zurückzuführen. Reportergenstudien mit einem 670bp langen Promotorfragment des 5’flankierenden Bereichs des humanen MMP-9-Gens zeigten jedoch auf, dass der hemmende Effekt des NOs zum Teil auf eine NO-vermittelte Abnahme der TPA-induzierten MMP-9-Promotoraktivität zurückgeführt werden kann. Demzufolge wurde in den nachfolgenden Experimenten nach den für die MMP-9-Expression notwendigen und von NO modulierten Transkriptionsfaktoren in MCF-7-Zellen gesucht. Anhand von Western-Blot-Analysen und Gelshiftanalysen konnte gezeigt werden, dass die Aktivität des Transkriptionsfaktors AP-1 in MCF-7-Zellen durch NO gehemmt wird, während weder die Expressionspiegel noch die Bindungsaffinität der Transkriptionsfaktoren NFκB und Sp1 durch die NO-Behandlung verändert sind. Weiterhin konnte unter Verwendung von pharmakologischen Inhibitoren der MAPK-Signalwege mit Hilfe der Western-Blot-Analyse nachgewiesen werden, dass MAPK-vermittelte Signalwege zwar für die Induktion der MMP-9-Expression essenziell sind, diese jedoch nicht von NO beeinflusst sind. Im Unterschied hierzu konnte mit Hilfe eines PKC-Aktivitätsassays gezeigt werden, dass die Gesamtaktivität von PKCs nach Behandlung von MCF-7-Zellen mit NO signifikant gehemmt ist. Zusammenfassend zeigen diese Untersuchungen, dass die NO-vermittelte Hemmung der TPA-induzierten MMP-9-Expression in MCF-7-Zellen im Wesentlichen auf eine NO-abhängige Reduktion der Protein-Kinase-C-Aktivität und einer daraus resultierenden Aktivitätshemmung des Transkriptionsfaktors AP-1 zurückgeführt werden kann.

Tenascin-C and matrix metalloproteinase-9 levels in crevicular fluid of teeth and implants

The role of and interaction between bacterial infection and biomechanical impact in the development of peri-implant inflammatory processes is not clear.

Matrix metalloproteinase-9 in pneumococcal meningitis: activation via an oxidative pathway

In experimental bacterial meningitis, matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) contribute to brain damage. MMP-9 increases in cerebrospinal fluid (CSF) during bacterial meningitis and is associated with the brain damage that is a consequence of the disease. This study assesses the origin of MMP-9 in bacterial meningitis and how ROS modulate its activity. Rat brain-slice cultures and rat polymorphonuclear cells (PMNs) that had been challenged with capsule-deficient heat-inactivated Streptococcus pneumoniae R6 (hiR6) released MMP-9. Coincubation with either catalase, with the myeloperoxidase inhibitor azide, or with the hypochlorous acid scavenger methionine almost completely prevented activation, but not the release, of MMP-9, in supernatants of human PMNs stimulated with hiR6. Thus, in bacterial meningitis, both brain-resident cells and invading PMNs may act as sources of MMP-9, and stimulated PMNs may activate MMP-9 via an ROS-dependent pathway. MMP-9 activation by ROS may represent a target for therapeutic intervention in bacterial meningitis.

Levels of matrix metalloproteinase-9 within cerebrospinal fluid in a rabbit model of coccidioidal meningitis and vasculitis.

Matrix metalloproteinase (MMP)-9 is produced by the central nervous system and inflammatory cells in a variety of inflammatory conditions in both animals and humans. MMP-9 promotes inflammation, breakdown of the blood-brain barrier, and vasculitis. Because vasculitis is seen frequently in patients with coccidioidal meningitis (CM), this study evaluated the presence of MMP-9 within the cerebrospinal fluid (CSF) of rabbits infected intracisternally with Coccidioides immitis arthroconidia. Infected rabbits demonstrated systemic and neurological sequelae to infection, including CSF pleocytosis. Levels of MMP-9 within CSF were assayed by use of zymography and compared with MMP-2 levels, which served as an internal control. Elevated levels of MMP-9 were detectable by day 3, continued to increase through day 10, and declined by day 15 after infection. MMP-9 may contribute to inflammation and vasculitis in this animal model. Future work can focus on evaluation of MMP inhibitors, to gain a better perspective of the role of this MMP in CM.

Activation of matrix metalloproteinase -9 (MMP-9) by heregulin in human breast cancer cells involves multiple signaling pathways

Matrix metalloproteinase-9 (MMP-9) plays an important role in tumor invasion and angiogenesis. Secretion of MMP-9 has been reported in various cancer types including lung cancer, brain cancer, colon cancer, and breast cancer. Heregulin is a growth factor that regulates growth and differentiation of normal breast cells as well as mammary tumor cells. To study the role of heregulin in breast cancer metastasis, we tested whether heregulin may regulate MMP-9 secretion. By screening a panel of breast cancer cell line for their ability to respond to heregulin and produce MMP-9, we have found that MMP-9 secretion can be induced by heregulin-β1 in two breast cancer cell lines, SKBr3 and MCF-7. In both cell lines, increase of MMP-9 activity as shown by zymography was accompanied by increased protein level as well as mRNA level of MMP-9. Using a reporter luciferase assay, we have identified that proximal −670bp promoter of MMP-9 had similar activity to a 2.2kb MMP-9 promoter in response to heregulin stimulation. Heregulin treatment of SKBr3 and MCF-7 activated multiple signaling pathways inside cells. These include the Erk pathway, the p38 kinase pathway, PKC pathway, and PI-3K pathway. To examine which pathways are involved in MMP-9 activation by heregulin, we have used a panel of chemical inhibitors to specifically inhibit each one of these pathways. Ro-31-8220 (PKC inhibitor) and SB203580 (p38 kinase inhibitor) completely blocked heregulin activation of MMP-9. On the other hand, PD098059 (MEK-1 inhibitor) partially blocked MMP-9 activation, whereas PI-3K inhibitor, wortmannin, had no effect. Therefore, at least three signaling pathways are involved in activation of MMP-9 by heregulin. Since MMP-9 is tightly associated with metastatic potential, our study also suggests that heregulin may enhance breast tumor metastasis through induction of MMP-9 expression. ^

Regulation of matrix metalloproteinase-9 and inhibition of tumor invasion by the membrane-anchored glycoprotein RECK

A human fibroblast cDNA expression library was screened for cDNA clones giving rise to flat colonies when transfected into v-Ki-ras-transformed NIH 3T3 cells. One such gene, RECK, encodes a membrane-anchored glycoprotein of about 110 kDa with multiple epidermal growth factor-like repeats and serine-protease inhibitor-like domains. While RECK mRNA is expressed in various human tissues and untransformed cells, it is undetectable in tumor-derived cell lines and oncogenically transformed cells. Restored expression of RECK in malignant cells resulted in suppression of invasive activity with concomitant decrease in the secretion of matrix metalloproteinase-9 (MMP-9), a key enzyme involved in tumor invasion and metastasis. Moreover, purified RECK protein was found to bind to, and inhibit the proteolytic activity of, MMP-9. Thus, RECK may link oncogenic signals to tumor invasion and metastasis.