Enhanced Expression Of Matrix Metalloproteinase-9 Research Articles

Gold Nanoparticles Inhibit PMA-Induced MMP-9 Expression via microRNA-204-5p Upregulation and Deactivation of NF-κBp65 in Breast Cancer Cells.

Breast cancer (BC) is the most common malignancy in females globally. Matrix metalloproteinase-9 (MMP-9) is crucial to the invasion, progression and spread of BC. Gold nanoparticles (AuNPs) have an anti-tumorigenic role, but their therapeutic role in microRNAs (miRNAs) regulation has not been explored. This study determined the potential of AuNPs against MMP-9 overexpression/production and miRNA-204-5p regulation in BC cells. AuNPs were newly engineered, and their stability was analyzed using the zeta potential, polydispersity index, surface-plasmon-resonance peak and transmission electron microscopy. A bioinformatics algorithm was used to predict the pairing of miRNA in the 3'untranslated-region (3'UTR) of MMP-9 mRNA. TaqMan assays were carried out to quantify miRNA and mRNA, whereas MMP-9-specific immunoassays and gelatin zymography were used to determine protein secretion and activity. The binding of miRNA in MMP-9 mRNA 3'UTR was verified by luciferase reporter clone assays and transfection with anti-miRNAs. In addition, NF-κBp65 activity was determined and confirmed with parthenolide treatment. Engineered AuNPs were highly stable and spherical in shape, with a mean size of 28.3 nm. Tested in MCF-7 BC cells, microRNA-204-5p directly regulates MMP-9. AuNPs inhibit PMA-induced MMP-9 mRNA and protein via hsa-miR-204-5p upregulation. Anti-miR-204 transfected MCF-7 cells demonstrated enhanced MMP-9 expression (p < 0.001), while AuNPs treatment attenuated MMP-9 expression in a dose-dependent manner (p < 0.05). Moreover, AuNPs also inhibit PMA-induced NF-κBp65 activation in anti-hsa-miR-204 transfected MCF-7 cells. Engineered AuNPs were stable and non-toxic to BC cells. AuNPs inhibit PMA-induced MMP-9 expression, production and activation via NF-κBp65 deactivation and hsa-miR-204-5p upregulation. These novel therapeutic potentials of AuNPs on stimulated BC cells provide novel suggestions that AuNPs inhibit carcinogenic activity via inverse regulation of microRNAs.

Matrix Metalloproteinase-9 Expression is Enhanced by Ischemia and Tissue Plasminogen Activator and Induces Hemorrhage, Disability and Mortality in Experimental Stroke

Matrix metalloproteinase-9 (MMP-9) degrades collagen and other cellular matrix proteins. After acute ischemic stroke, increased MMP-9 levels are correlated with hemorrhage, lack of reperfusion and stroke severity. Nevertheless, definitive data that MMP-9 itself causes poor outcomes in ischemic stroke are limited. In a model of experimental ischemic stroke with reperfusion, we examined whether ischemia and recombinant tissue plasminogen activator (r-tPA) therapy affected MMP-9 expression, and we used specific inhibitors to test if MMP-9 affects brain injury and recovery. After stroke, MMP-9 expression increased significantly in the ischemic vs. non-ischemic hemisphere of the brain (p < 0.001). MMP-9 expression in the ischemic, but not the non-ischemic hemisphere, was further increased by r-tPA treatment (p < 0.001). To determine whether MMP-9 expression contributed to stroke outcomes after r-tPA treatment, we tested three different antibody MMP-9 inhibitors. When compared to treatment with r-tPA and saline, treatment with r-tPA and MMP-9 antibody inhibitors significantly reduced brain hemorrhage by 11.3 to 38.6-fold (p < 0.01), brain swelling by 2.8 to 4.3-fold (p < 0.001) and brain infarction by 2.5 to 3.9-fold (p < 0.0001). Similarly, when compared to treatment with r-tPA and saline, treatment with r-tPA and an MMP-9 antibody inhibitor significantly improved neurobehavioral outcomes (p < 0.001), decreased weight loss (p < 0.001) and prolonged survival (p < 0.01). In summary, both prolonged ischemia and r-tPA selectively enhanced MMP-9 expression in the ischemic hemisphere. When administered with r-tPA, specific MMP-9 inhibitors markedly reduced brain hemorrhage, swelling, infarction, disability and death, which suggests that blocking the deleterious effects of MMP-9 may improve outcomes after ischemic stroke.

BRD4 Phosphorylation Regulates HPV E2-Mediated Viral Transcription, Origin Replication, and Cellular MMP-9 Expression

Post-translational modification can modulate protein conformation and alter binding partner recruitment within gene regulatory regions. Here, we report that bromodomain-containing protein 4 (BRD4), a transcription co-factor and chromatin regulator, uses aphosphorylation-induced switch mechanism to recruit E2 protein encoded by cancer-associated human papillomavirus (HPV) to viral early gene andcellular matrix metalloproteinase-9 (MMP-9) promoters. Enhanced MMP-9 expression, induced upon keratinocyte differentiation, occurs via BRD4-dependent recruitment of active AP-1 and NF-κB to their target sequences. This is triggered by replacement of AP-1 family members JunB and JunD by c-Jun and by re-localization of NF-κB from the cytoplasm to the nucleus. In addition, BRD4 phosphorylation is critical for E2- and origin-dependent HPV DNA replication. A class of phospho-BRD4-targeting compounds, distinct from the BET bromodomain inhibitors, effectively blocks BRD4 phosphorylation-specific functions in transcription and factor recruitment.

Effects of Tissue Factor, PAR-2 and MMP-9 Expression on Human Breast Cancer Cell Line MCF-7 Invasion

This study aimed to explore the expression of tissue factor (TF), protease activated receptor-2 (PAR-2), and matrix metalloproteinase-9 (MMP-9) in the MCF-7 breast cancer cell line and influence on invasiveness. Stable MCF-7 cells transfected with TF cDNA and with TF ShRNA were established. TF, PAR-2, and MMP-9 protein expression was analyzed using indirect immunofluorescence and invasiveness was evaluated using a cell invasion test. Effects of an exogenous PAR-2 agonist were also examined. TF protein expression significantly differed between the TF cDNA and TF ShRNA groups. MMP-9 protein expression was significantly correlated with TF protein expression, but PAR-2 protein expression was unaffected. The PAR- 2 agonist significantly enhanced MMP-9 expression and slightly increased TF and PAR-2 expression in the TF ShRNA group, but did not significantly affect protein expression in MCF-7 cells transfected with TF cDNA. TF and MMP-9 expression was positively correlated with the invasiveness of tumor cells. TF, PAR-2, and MMP-9 affect invasiveness of MCF-7 cells. TF may increase MMP-9 expression by activating PAR-2.

MDM2 Promotes Invasion and Metastasis in Invasive Ductal Breast Carcinoma by Inducing Matrix Metalloproteinase-9

The molecular mechanisms that underpin invasive ductal breast cancer (IDC) invasion and metastasis are incompletely understood. The oncogene, mouse double minute 2 (MDM2), has been implicated in the pathogenesis of numerous cancers, where it stimulates the expression of matrix metalloproteinase 9 (MMP9), an important enzyme in the breakdown of the extracellular matrix. However, its role in breast cancer remains poorly understood. This study assessed the clinical significance of MDM2 expression in IDC and used in vitro expression assays to determine the molecular roles of MDM2. Immunohistochemical staining for MMP9 and MDM2 was performed using archived tumor blocks from 321 women who underwent surgical resection for IDC at the First Affiliated Hospital of Nanjing Medical University, China between January 2002 and December 2003. MCF-7 and MDA-MD-231 cell lines were transfected with siRNA targeted against MDM2, or MDM2 was overexpressed using transiently expressed vectors. The invasion, cell migration and proteolytic capabilities of cells that over- or underexpressed MDM2 was then assessed and compared against control cells, in addition to the consequent effects on MMP9 expression using RT-PCR. In vivo, 54.9% and 49.6% of samples were positive for MMP9 and MDM2 expression, respectively, and their expression was significantly correlated (r2 = 0.171, P = 0.012). Moreover, MDM2 expression was markedly correlated with disease-free survival (HR 2.56, 95% CI 1.02–6.40, P = 0.038). In vitro, MDM2 overexpression significantly enhanced cell invasion, migration and proteolysis compared with control cells, and the converse effects were observed after MDM2-siRNA treatment. MDM2 overexpression induced MMP9 expression in a dose-dependent manner. Taken together, these results suggest that high levels of MDM2 are associated with a poorer prognosis in IDC. This might result from increased tumor invasiveness due to enhanced MMP9 expression causing increased extracellular matrix breakdown.

Hepatitis B virus X protein stabilizes amplified in breast cancer 1 protein and cooperates with it to promote human hepatocellular carcinoma cell invasiveness

Chronic infection of hepatitis B virus (HBV) is closely associated with the development of human hepatocellular carcinoma (HCC). HBV X protein (HBx) plays a key role in the progression of HCC. We recently found that amplified in breast cancer 1 (AIB1) protein is overexpressed in 68% of human HCC specimens and promotes HCC progression by enhancing cell proliferation and invasiveness. Given that both HBx and AIB1 play important oncogenic roles in HCC, we aimed to determine whether they could cooperatively promote human HCC development. Herein, we show that HBx-positive HCC tissues had a higher level of AIB1 protein, compared to HBx-negative HCC tissues. A positive correlation between HBx protein level and AIB1 protein level was established in HCC specimens. Without affecting its messenger RNA level, HBx induced a significant increase of the protein level of AIB1, which correlated with a significant extension of the half-life of AIB1 protein. Mechanistically, HBx could interact with AIB1 to prevent the interaction between envelope protein 3 ubiquitin ligase F-box and WD repeat domain containing 7 (Fbw7)α and AIB1, then inhibited the Fbw7α-mediated ubiquitination and degradation of AIB1. In addition, reporter assays and chromatin immunoprecipitation assays revealed that both HBx and AIB1 were recruited to matrix metalloproteinase-9 (MMP-9) promoter to enhance MMP-9 promoter activity cooperatively. Consistently, HBx and AIB1 cooperatively enhanced MMP-9 expression in HepG2 cells, which, in turn, increased cell-invasive ability. Our study demonstrates that HBx can stabilize AIB1 protein and cooperate with it to promote human HCC cell invasiveness, highlighting the essential role of the cross-talk between HBx and AIB1 in HBV-related HCC progression.

Effect of epidermal growth factor on the expression of matrix metalloproteinase-9 and the signalling pathways involved in the trophoblast cell line JEG-3

To investigate the effect of epidermal growth factor (EGF) on the expression of Matrix metalloproteinase-9 (MMP-9) and the signalling pathways involved in the trophoblast cell line JEG-3. The JEG-3 trophoblast cell line was used in this study. (1) JEG-3 cells were cultured with various concentrations of EGF (0, 1, 10, 20 ng/ml) for 24 hours and the expression of MMP-9 was tested by western blotting and reverse transcription PCR (RT-PCR). (2) Western blotting and RT-PCR were also used to investigate the expression of MMP-9 expression after incubation for 0, 4, 12 and 24 hours with EGF treatment (10 ng/ml) in JEG-3 cells. (3) According to the different added ingredients, JEG-3 cells were divided into some groups: control group (without EGF), EGF group (exposure to 10 ng/ml EGF), EGF+ inhibitors group (exposure to 10 ng/ml EGF+ 20 ng/ml SB203580 or exposure to 10 ng/ml EGF+ 10 ng/ml U0126), inhibitors group (exposure to 20 ng/ml SB203580 or exposure to 10 ng/ml U0126). Western blotting were used to investigate the expression levels of MMP-9, nuclear factor kappa B (NF-κB), p38MAPK, phospho-p38MAPK (p-p38MAPK), extracellular-signal regulated kinase (ERK) and phospho-ERK (p-ERK) protein in JEG-3 cells after incubation for 24 hours. (1) The profiles of MMP-9 mRNA were increased by various concentrations of EGF (0, 1, 10, 20 ng/ml) in JEG-3 cells after 24 h-culture. The expression of MMP-9 mRNA in JEG-3 cells exposure at 1 ng/ml of EGF (0.567±0.056), 10 ng/ml of EGF (1.392±0.133), 20 ng/ml of EGF (1.971±0.067) were significantly higher respectively (P<0.05), compared with 0 ng/ml of EGF treatment (0.166±0.015). Similarly, MMP-9 mRNAs were also increased with the increasing incubation time. Compared to EGF (10 ng/ml) stimulation for 0 h (0.253±0.044), the MMP-9 mRNA profiles were 0.470±0.026, 1.061±0.115, 1.453±0.180 for 4, 12 and 24 hours, respectively (P<0.05). (2) In accordance to the mRNA profiles, the expression of MMP-9 protein was also increased by different concentrations of EGF (0, 1, 10, 20 ng/ml) in JEG-3 cells after 24 h-culture. The abundance of MMP-9 protein in the three groups was 0.043±0.012, 0.085±0.008, 0.142±0.015, with a significantly higher expression, compared with 0 ng/ml of EGF treatment (0.004±0.001, P<0.05) respectively. Similarly, MMP-9 proteins were also increased with the increasing incubation time. Compared to EGF (10 ng/ml) stimulation for 0 h (0.030±0.009), the profiles of MMP-9 protein were 0.137±0.010, 0.240±0.010, 1.240±0.061 for 4, 12 and 24 hours, respectively (P<0.05). (3) Both p38MAPK and ERK signalling pathways were activated by EGF in JEG-3 cells. The expression of p-p38MAPK was significantly higher (without or with 10 ng/ml EGF, 234.1±4.1 vs. 260.9±2.5, P<0.05), however, the p38MAPK inhibitor SB203580 markedly suppressed the increase in p-p38MAPK content induced by EGF (227.9±2.4 vs. 260.9±2.5, P<0.05). Similarly, the expression of p-ERK was significantly higher with EGF treatment (812.2±3.5) vs. without EGF group (453.4±5.8) (P<0.05), while the ERK inhibitor U0126 significantly inhibited the increased p-ERK content in response to EGF treatment (71.0±1.2 vs. 812.2±3.5, P<0.05). (4) The p38MAPK inhibitor SB203580 significantly reduced the expression of EGF-induced MMP-9 (0.645±0.270 vs. 1.476±0.452, P<0.05) and NF-κB (0.530±0.026 vs. 0.959±0.017, P<0.05). (5) The ERK inhibitor U0126 also significantly reduced the expression of EGF-induced MMP-9 (0.623±0.030 vs. 2.112±0.056, P<0.05) and NF-κB (0.325±0.082 vs. 0.939±0.153, P<0.05). EGF induced the expression of MMP-9 in a time and dose-dependant manner in JEG-3 cells. EGF enhanced MMP-9 expression through the activation of p38MAPK and ERK signalling pathways in JEG-3 cells.

Rac1-mediated Mitochondrial H2O2 Generation Regulates MMP-9 Gene Expression in Macrophages via Inhibition of SP-1 and AP-1

Aberrant matrix deposition is a hallmark of pulmonary fibrosis and is characterized by an imbalance between matrix deposition and degradation. We have previously shown that mice harboring a conditional deletion of the GTP-binding protein, Rac1, in macrophages are protected from asbestos-induced pulmonary fibrosis. To investigate the contribution of aberrant matrix degradation, we addressed the role of Rac1 in regulating expression of macrophage-specific MMP-9 (matrix metalloproteinase-9). We found that MMP-9 gene transcription was significantly greater in Rac1 null macrophages. Deletion and mutational analysis of the MMP-9 promoter revealed that both SP-1 and AP-1 are essential for MMP-9 transcription. Overexpression of constitutive active Rac1 (V12) revealed that H(2)O(2) was derived from the mitochondria. Rac1-induced H(2)O(2) generation down-regulated MMP-9 gene transcription, whereas catalase overexpression in WT cells enhanced MMP-9 expression. SP-1 interacted directly with both c-Jun and c-Fos, and H(2)O(2) decreased this binding, suggesting that SP-1 and AP-1 function cooperatively to regulate MMP-9 transcription. Rac1-mediated H(2)O(2) inhibited the ERK MAPK, which was essential for activation of SP-1 and AP-1. ERK activation and MMP-9 expression were recovered by overexpressing catalase or transfecting siRNA for the mitochondrial iron-sulfur protein, Rieske. These observations were recapitulated in vivo. MMP-9 mRNA was higher in alveolar macrophages isolated from Rac1 null mice and wild type mice given catalase. Rac1 regulates MMP-9 transcription via mitochondrial H(2)O(2) generation, providing a potential mechanism by which Rac1 null mice fail to develop pulmonary fibrosis.

Induction of Neutrophil Gelatinase-Associated Lipocalin in Vascular Injury via Activation of Nuclear Factor-κB

Neutrophil gelatinase-associated lipocalin (NGAL) has recently emerged as an important modulator of cell homeostasis. Elevated plasma NGAL levels, possibly because of activation of blood leukocytes, are associated with atherosclerosis. However, little is known about induction of NGAL expression in blood vessels. Using a rat carotid artery injury model, we found that NGAL was highly induced in the intima after angioplasty but was attenuated by adenovirus-mediated expression of a dominant-negative mutant of inhibitor of nuclear factor (NF)-kappaB kinase beta (dnIKKbeta). Expression of NGAL mRNA and protein was also up-regulated in an NF-kappaB-dependent manner in rat and human vascular smooth muscle cells (SMCs) in response to interleukin-1beta stimulation. Rat SMC-produced NGAL was present as mono- and homomeric forms in the cytosol and in a complex containing matrix metalloproteinase-9 (MMP-9) after secretion. In agreement with levels of NGAL, proteolytic activity of MMP-9 was markedly high in the intima of injured vessels and in the culture supernatant of activated intimal SMCs but was reduced in the vessels transduced with dnIKKbeta. The present study reveals a previously unrecognized vascular response to an-gioplastic injury, characterized by NF-kappaB-dependent expression of NGAL in vascular SMCs. Further-more, SMC-produced NGAL interacts with MMP-9, a mechanism by which NGAL may modulate MMP-9 proteolytic activity in the vascular repair process.