Active Form Of Matrix Metalloproteinase-9 Research Articles

Hyperbaric oxygen therapy accelerates wound healing in diabetic mice by decreasing active matrix metalloproteinase-9.

Diabetic foot ulcers are characterized by hypoxia. For many patients, hyperbaric oxygen (HBO) therapy is the last recourse for saving the limb from amputation, for which the molecular basis is not understood. We previously identified the active form of matrix metalloproteinase-9 (MMP-9) as responsible for diabetic foot ulcer's recalcitrance to healing. Transcription of mmp-9 to the inactive zymogen is upregulated during hypoxia. Activation of the zymogen is promoted by proteases and reactive oxygen species (ROS). We hypothesized that the dynamics of these two events might lead to a lowering of active MMP-9 levels in the wounded tissue. We employed the full-thickness excisional db/db mouse model to study wound healing, and treated the mice to 3.0 atm of molecular oxygen for 90 minutes, 5 days per week for 10 days in an HBO research chamber. Treatment with HBO accelerated diabetic wound healing compared to untreated mice, with more completed and extended reepithelialization. We imaged the wounds for ROS in vivo with a luminol-based probe and found that HBO treatment actually decreases ROS levels. The levels of superoxide dismutase, catalase, and glutathione peroxidase-enzymes that turn over ROS-increased after HBO treatment, hence the observation of decreased ROS. Since ROS levels are lowered, we explored the effect that this would have on activation of MMP-9. Quantitative analysis with an affinity resin that binds and pulls down the active MMPs exclusively, coupled with proteomics, revealed that HBO treatment indeed reduces the active MMP-9 levels. This work for the first time demonstrates that diminution of active MMP-9 is a contributing factor and a mechanism for enhancement of diabetic wound healing by HBO therapy.

Matrix Metalloproteinase-3 (MMP-3) Is an Endogenous Activator of the MMP-9 Secreted by Placental Leukocytes: Implication in Human Labor.

BackgroundThe activity of matrix degrading enzymes plays a leading role in the rupture of the fetal membranes under normal and pathological human labor, and matrix metalloproteinase-9 (MMP-9) it is considered a biomarker of this event. To gain further insight into local MMP-9 origin and activation, in this study we analyzed the contribution of human placental leukocytes to MMP-9 secretion and explored the local mechanisms of the pro-enzyme activation.MethodsPlacental blood leukocytes were obtained from women at term gestation without labor and maintained in culture up to 72 h. MMP-9 activity in the culture supernatants was determined by zymography and using a specific substrate. The presence of a potential pro-MMP-9 activator in the culture supernatants was monitored using a recombinant biotin-labeled human pro-MMP-9. To characterize the endogenous pro-MMP-9 activator, MMP-1, -3, -7 and -9 were measured by multiplex assay in the supernatants, and an inhibition assay of MMP-9 activation was performed using an anti-human MMP-3 and a specific MMP-3 inhibitor. Finally, production of MMP-9 and MMP-3 in placental leukocytes obtained from term pregnancies with and without labor was assessed by immunofluorescence.ResultsPlacental leukocytes spontaneously secreted pro-MMP-9 after 24 h of culture, increasing significantly at 48 h (P≤0.05), when the active form of MMP-9 was detected. Culture supernatants activated the recombinant pro-MMP-9 showing that placental leukocytes secrete the activator. A significant increase in MMP-3 secretion by placental leukocytes was observed since 48 h in culture (P≤0.05) and up to 72 h (P≤0.001), when concentration reached its maximum value. Specific activity of MMP-9 decreased significantly (P≤0.005) when an anti-MMP-3 antibody or a specific MMP-3 inhibitor were added to the culture media. Placental leukocytes from term labor produced more MMP-9 and MMP-3 compared to term non-labor cells.ConclusionsIn this work we confirm that placental leukocytes from human term pregnancies are able to secrete large amounts of MMP-9, and that the production of the enzyme it is enhanced by labor. We also demonstrate for the first time that endogenous MMP-3 plays a major role in MMP-9 activation process. These findings support the contribution of placental leukocytes to create the collagenolytic microenvironment that induces the rupture of the fetal membranes during human labor.

Increased prolyl endopeptidase induces alterations in the expression of neural cell adhesion molecule and its polysialylation in SH-SY5Y neuroblastoma cells in vitro

Development of the nervous system and its structural remodelling in the adult relies on molecules mediating the structural plasticity of neurons, e specially those involved in cell adhesion, cytoskeletal dynamics or synapse formation. Neural cell adhesion molecule (NCAM) is a membrane-associated glycoprotein that can be modified by glycosylation with polysialic acid (PSA), attenuating NCAM-mediated cell interactions, thereby promoting structural plasticity [1]. It has been demonstrated that in conditions of neuroinflammation, NCAM can be cleaved extracellularly by metalloproteinases and other proteolytical enzymes. Prolyl endopeptidase (PREP) is a cytosolic serine protease, and alterations in PREP expression and activity have been associated with neuronal death and neuroinflammation [2]. Since the precise mechanisms and possible partners of PREP in neuroinflammation remain unclear, the aim of this study was to determine whether increased secretion and activation of PREP could impair NCAM expression and its polysialylation. SH-SY5H cell line overexpressing (o/e) PREP was used as an in vitro model for increased PREP expression and extracellular release. When measuring expression levels of NCAM and PSA-NCAM we found remarkable loss in PSA-NCAM and disrupted expression patterns of NCAM compared to wild-type cells. As matrix metalloproteinase 9 (MMP-9) has been indicated in processes regulating shedding of PSA-NCAM, MMP-9 expression level was measured. An increase in the level of the active form of MMP-9 was found, which was counteracted by a specific inhibitor of PREP, KYP-2047. As demonstrated, PREP might have an important role in processes involved in NCAM degradation and polysialylation, thereby inducing progression of pathologies associated with altered neuroplasticity.

Actividad de metaloproteinasa de matriz extracelular-9 en fluido crevicular gingival durante la respuesta reparativa en periodontitis apical asintomática

ObjectiveApical destructive periodontal processes are largely mediated by specific proteases. Evidence supports that the levels of extracellular matrix metalloproteinase-9 (MMP-9) could reflect the presence of asymptomatic apical periodontitis (AAP) in gingival crevicular fluid (GCF). The aim of this study was to evaluate the activity of MMP-9 during reparative response in periapical post endodontic controls between 1 week and 6 months later and in healthy controls. Materials and methodsA prospective study was performed on 28 patients with a diagnosis of AAP. GCF samples were taken from AAP teeth at baseline and post-endodontic controls at 1 week, 1, 3 and 6 months. Additional healthy contralateral controls were obtained, and samples were eluted and analyzed by densitometric scanning and gelatin zymography. ResultsIn patients with asymptomatic apical periodontitis, both the pro form and the active form of MMP-9 were identified. These showed significant increases in post-endodontic controls at three and six months, with signs of periapical repairing. ConclusionsMMP-9 levels significantly increased in teeth diagnosed with AAP during the reparative phase. These results suggest that MMP-9 might be involved in the healing of apical tissues that might be reflected in GCF.

Detection of Active Matrix Metalloproteinase-3 in Serum and Fibroblast-Like Synoviocytes of Collagen-Induced Arthritis Mice

The activity of rheumatoid arthritis (RA) correlates with the expression of proteases. Among several proteases, matrix metalloproteinase-3 (MMP-3) is one of the biological markers used to diagnose RA. The active form of MMP-3 is a key enzyme involved in RA-associated destruction of cartilage and bone. Thus, detection of active MMP-3 in serum or in vivo is very important for early diagnosis of RA. In this study, a soluble MMP-3 probe was prepared to monitor RA progression by detecting expression of active MMP-3 in collagen-induced arthritis (CIA) mice in vivo in both serum and fibroblast-like synoviocytes (FLSs). The MMP-3 probe exhibited strong sensitivity to MMP-3 and moderate sensitivity to MMP-7 at nanomolecular concentrations, but was not sensitive to other MMPs such as MMP-2, MMP-9, and MMP-13. In an optical imaging study, the MMP-3 probe produced early and strong NIR fluorescence signals prior to observation of erythema and swelling in CIA mice. The MMP-3 probe was able to rapidly and selectively detect and monitor active MMP-3 in diluted serum from CIA mice. Furthermore, histological data demonstrated that activated FLSs in arthritic knee joints expressed active MMP-3. Together, our results demonstrated that the MMP-3 probe may be useful for detecting active MMP-3 for diagnosis of RA. More importantly, the MMP-3 probe was able to detect active MMP-3 in diluted serum with high sensitivity. Therefore, the MMP-3 probe developed in this study may be a very promising probe, useful as a biomarker for early detection and diagnosis of RA.

Abstract TMP22: Intravenous Glyburide Treatment is Associated with Reduced Matrix Metalloproteinase-9 in Human Acute Stroke

Background: Elevated matrix metalloproteinase-9 (MMP-9) following acute ischemic stroke is associated with blood-brain barrier breakdown and hemorrhagic conversion. Prior retrospective evidence suggests that sulfonylurea use may be associated with reduced risk of hemorrhagic conversion. We hypothesized that sulfonylureas may reduce MMP-9 level in stroke patients. Methods: Using serial plasma samples from six subjects in the Glyburide Advantage in Malignant Edema and Stroke Pilot trial (GAMES-Pilot), we evaluated the level of MMP-9 in human subjects presenting with large hemispheric stroke who were treated with intravenous glyburide (RP-1127). MMP-9 was measured in a control cohort with large ischemic stroke who were not treated with glyburide. Commercially available ELISA kits and gel zymography were used to measure MMP-9 at baseline and at approximately 48 hours after stroke. GAMES subjects had additional time points analyzed until approximately 84 hours after stroke. Results: Average MMP-9 level in glyburide-treated stroke patients was 47.2 ± 8.0 ng/mL compared to 143.4 ± 60.35 ng/mL in untreated control subjects (p=0.004). Zymography analysis demonstrated a significant decrease in the pro-enzyme but no change in the active form of MMP-9. There was no difference in the level of the MMP-9 specific inhibitor, TIMP-1. No subjects exhibited parenchymal hemorrhagic conversion on 24 hour head CT scan. Conclusions: Glyburide treatment in human stroke patients with large hemispheric stroke is associated reduced level of MMP-9. Elucidating the underlying mechanism of glyburide’s effect on MMP-9 and the risk of hemorrhagic conversion may highlight future directions of therapy, including in combination with intravenous tissue plasminogen activator (IV t-PA).

DJ-1 Cleavage by Matrix Metalloproteinase 3 Mediates Oxidative Stress-Induced Dopaminergic Cell Death

Oxidative stress is commonly implicated in aging and neurodegenerative conditions such as Parkinson's disease (PD). Mutations in DJ-1 are associated with autosomal recessive early-onset PD. We investigated whether DJ-1 can be degraded in oxidative-stressed dopaminergic neuronal cells, leading to loss of its protective role against oxidative stress. We have shown previously and herein that the active form of matrix metalloproteinase-3 (MMP3) was accumulated in dopamine-producing CATH.a cells in the presence of MPP(+). We show that catalytically active MMP3 cleaved DJ-1, and impaired its antioxidant function. In CATH.a cells, both monomeric and dimeric forms of DJ-1 were diminished in the presence of MPP(+), and this was reversed by MMP3 knockdown or inhibition. While DJ-1 expression was decreased in the substantia nigra of mice administered with MPTP, its degradation was largely attenuated in MMP3 knockout mice. The AKT-signaling pathway, thought to mediate the effect of DJ-1 on cell survival, was also altered. MPP(+) caused decrease in both phospho-Thr308 and phospho-Ser473 forms of AKT, and this was restored by NNGH. Our data suggest that DJ-1 is fragmented by the intracellular MMP3 in response to cell stress, abolishing the protective role of DJ-1 against oxidative damage, and this contributes to the pathogenesis of PD.

Role of Hyaluronan-Mediated CD44 Signaling in Head and Neck Squamous Cell Carcinoma Progression and Chemoresistance

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy that may involve the oral cavity, pharynx, larynx, and paranasal sinuses. The mechanisms of tumor progression underlying the clinical behavior of HNSCC remain unclear. CD44 comprises a family of transmembrane receptors that can give rise to multiple CD44 variant isoforms. Hyaluronan (HA), a major extracellular matrix component is the primary ligand for CD44 receptors. HA and CD44 signaling play an important role in HNSCC progression. Several CD44 variant isoforms (including v3-, v6-, and v10-containing isoforms) are associated with advanced disease, possibly through unique growth factor interactions with binding domains in the inserted variant regions of the cytoplasmic domain of CD44. In HNSCC, HA mediates the formation of a complex including CD44 and the epidermal growth factor receptor (EGFR) which is overexpressed in a large proportion of HNSCCs. Downstream effectors under EGFR regulation are activated, promoting promote cell growth and tumor survival. The leukemia-associated Rho-guanine nucleotide exchange factor (LARG) also associates with CD44 and EGFR to promote several Ras and RhoA pathway effectors, leading to cell migration, growth, and tumor survival. The secretion of matrix metalloproteinases, necessary for tumor cell invasion, is also regulated by these HA/CD44-mediated pathways. Finally, EGFR-mediated pathways play major roles in the HA/CD44 promotion of chemoresistance in HNSCC. Understanding HA/CD44-mediated signaling pathways may lead to improved treatment of HNSCC.

5-lipoxygenase inhibitor zileuton attenuates ischemic brain damage: involvement of matrix metalloproteinase 9

Objectives: Cerebral ischemia causes an increased expression and activation of 5-lipoxygenase (5-LOX) and matrix metalloproteinase 9 (MMP-9). Recent works demonstrated that the selective 5-LOX inhibitor zileuton down-regulates MMP-9 expression in vascular diseases and cancer. In the present work, we first studied the neuroprotective effect of zileuton on focal cerebral ischemia in rats and further investigated the effect of zileuton on the expression of 5-LOX and MMP-9 in ischemic brain.Methods: Adult Sprague–Dawley rats underwent permanent middle cerebral artery occlusion (pMCAO). The rats then received treatment with zileuton 5, 10 or 50 mg/kg or vehicle. Cerebral water content and infarct volume were measured 24 hours after pMCAO. Expression of 5-LOX messenger RNA (mRNA) and MMP-9 mRNA were determined by reverse transcription polymerase chain reaction. The levels of the proform and the active form of MMP-9 were detected by gelatin zymography.Results: Oral treatment of zileuton at 10 or 50 mg/kg significantly reduced cerebral water content and infarct volume. It also down-regulated the expression of 5-LOX mRNA and MMP-9 mRNA. Zileuton at 50 mg/kg could inhibit the active form of MMP-9.Conclusion: These results suggest that selective 5-LOX inhibitor zileuton attenuates ischemic brain damage in rats, which may be partly associated with MMP-9 inhibition.

A novel intracellular role of matrix metalloproteinase‐3 during apoptosis of dopaminergic cells

We have previously demonstrated that the active form of matrix metalloproteinase-3 (actMMP-3) is released from dopamine(DA)rgic neurons undergoing apoptosis. Herein, whether actMMP-3 might be generated intracellularly, and if so, whether it is involved in apoptosis of DArgic neurons itself was investigated in primary cultured DArgic neurons of wild-type, MMP-3 knockout animals, and CATH.a cells. During apoptosis, gene expression of MMP-3 is induced, specifically among the various classes of MMPs, generating the proform (55 kDa) which is subsequently cleaved to the catalytically active actMMP-3 (48 kDa) involving a serine protease. Intracellular actMMP-3 activity is directly linked to apoptotic signaling in DArgic cells: (i) Pharmacologic inhibition of enzymatic activity, repression of gene expression by siRNA, and gene deficiency all lead to protection; (ii) pharmacologic inhibition causes attenuation of DNA fragmentation and caspase 3 activation, the indices of apoptosis; and (iii) inhibition of the pro-apoptotic enzyme c-Jun N-terminal protein kinase leads to repression of MMP-3 induction. Under the cell stress condition, MMP-3 is released as actMMP-3 rather than the proform (proMMP-3), and catalytically active MMP-3 added to the medium does not cause cell death. Thus, actMMP-3 seems to have a novel intracellular role in apoptotic DArgic cells and this finding provides an insight into the pathogenesis of Parkinson's disease.

Abstract 1706: Elevation of Pericardial Fluid Active Matrix Metalloproteinase-9 (MMP-9) Level Is Closely Associated With Left Ventricular Remodeling

Background: The development of congestive heart failure (CHF) is associated with left ventricular (LV) remodeling. However, fundamental mechanisms that contribute to this remodeling process remain unclear. The matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) have been demonstrated to play a significant role in tissue remodeling through a number of pathological processes. Objectives: The purpose of this study was to investigate whether MMPs and TIMPs represent autocrine/paracrine factors and are accumulated in pericardial fluid. We previously reported that active MMP-2 levels in pericardial fluid served as more sensitive and accurate indicators of LV remodeling than did active MMP-2 levels in plasma. Methods: We measured the concentrations of the enzyme (active MMP-9) in both plasma and pericardial fluid in 20 patients during coronary artery bypass graft surgery. Results: The active MMP-9 level was significantly higher in pericardial fluid than in plasma (4.68 ± 1.17 vs. 2.58 ± 0.29 ng/ml, p<0.0001). Interestingly, the pericardial fluid levels of active MMP-9 were significantly higher in patients with impaired LV function than in those with normal LV function (5.25 ± 0.57 vs. 2.96 ± 0.65 ng/ml, p<0.0001). Pericardial fluid active MMP-9 levels had closer relations with LVEDVI (r=0.459, p=0.047) and LVESVI (r=0.490, p=0.0321) than did plasma active MMP-9 levels (LVEDVI: r=0.065, p=NS; LVESVI: r=0.254, p=NS). Active MMP-9 levels in pericardial fluid but not in plasma inversely correlated with LV ejection fraction (r=−0.626, p=0.0033). Conclusions: Active MMP-9 levels in pericardial fluid serve as more sensitive and accurate indicators of LV remodeling than did active MMP-9 levels in plasma. Thus, active form of MMP-9 may be also secreted from the heart into the pericardial space with the progression of CHF, and it may have a pathophysiologic role in LV remodeling process as an autocrine/paracrine factor.

Generation of Active-Form of Matrix Metalloproteinase-9 Induced by Hydroxyl Radical: A Possible In Vitro Model for Oxidative Stress-Induced Degradation of Cartilage Matrix in the TMJ

Generation of Active-Form of Matrix Metalloproteinase-9 Induced by Hydroxyl Radical: A Possible In Vitro Model for Oxidative Stress-Induced Degradation of Cartilage Matrix in the TMJ

A pivotal role of matrix metalloproteinase‐3 activity in dopaminergic neuronal degeneration via microglial activation

Recent studies have demonstrated that activated microglia play an important role in dopamine (DA) neuronal degeneration in Parkinson disease (PD) by generating NADPH-oxidase (NADPHO)-derived superoxide. However, the molecular mechanisms that underlie microglial activation in DA cell death are still disputed. We report here that matrix metalloproteinase-3 (MMP-3) was newly induced and activated in stressed DA cells, and the active form of MMP-3 (actMMP-3) was released into the medium. The released actMMP-3, as well as catalytically active recombinant MMP-3 (cMMP-3) led to microglial activation and superoxide generation in microglia and enhanced DA cell death. cMMP-3 caused DA cell death in mesencephalic neuron-glia mixed culture of wild-type (WT) mice, but this was attenuated in the culture of NADPHO subunit null mice (gp91(phox-/-)), suggesting that NADPHO mediated the cMMP-3-induced microglial production of superoxide and DA cell death. Furthermore, in the N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-injected animal model of PD, nigrostriatal DA neuronal degeneration, microglial activation, and superoxide generation were largely attenuated in MMP-3-/- mice. These results indicate that actMMP-3 released from stressed DA neurons is responsible for microglial activation and generation of NADPHO-derived superoxide and eventually enhances nigrostriatal DA neuronal degeneration. Our results could lead to a novel therapeutic approach to PD.

Human urinary bladder cancer T24 cells are susceptible to the Antrodia camphorata extracts

Bladder cancer has been cited to result from the neoplastic lesion with environmental and/or occupational factors identified as causatives. Transitional cell carcinoma (TCC) is the most common type of bladder cancer. Most of the bladder cancer patients die from the invasive, metastatic TCC that has turned out to be resistant to chemotherapy. T24 cells, a cell line established from a human urinary bladder cancer patient, are high-grade and invasive TCC. T24 cells were found very susceptible to ACCE at concentration of 50 μg/mL. MTT assay showed that the cell growth and proliferation were inhibited to 50% of the control when treated with ACCE for 72 h, at which the cell proliferation suppressing rate revealed −4.4×10 3 cells/μg per day. Comparing the expressions of the cell cycle biomarkers Cdc2 and Cyclin B1 by the western blot analysis, a phase G 2M arrest was confirmed. Both the wound scratch assay and the transwell motility assay indicated that ACCE was very effective anti-metastatic against T24 cells. Furthermore, the active form of matrix metalloproteinase-9 (MMP-9) was also found totally suppressed as revealed by zymography at 72 h post-incubation with ACCE, while the light and electron microscopic images have apparently revealed cell membrane damages on T24 cells when treated with ACCE (50 μg/mL). Moreover, both the wound scratch and the transwell assays have demonstrated the migration capability of T24 cells has been significantly retarded to 1.5-fold at same dosage of ACCE used. In conclusion, ACCE is a good anti-cancer agent, being effective in inducing phase G 2M arrest, acting as an anti-proliferative, and an anti-metastatic agent against bladder cancer cell T24 cells.

Matrix Metalloproteinase-3: A Novel Signaling Proteinase from Apoptotic Neuronal Cells That Activates Microglia

Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative human brain disorders. We sought to investigate molecular signaling mechanisms that govern activation of microglia in apoptotic neuronal degeneration. We report here that the active form of matrix metalloproteinase-3 (MMP-3) was released into the serum-deprived media (SDM) of PC12 cells and other media of apoptotic neuronal cells within 2-6 h of treatment of the cells, and SDM and catalytic domain of recombinant MMP-3 (cMMP-3) activated microglia in primary microglia cultures as well as BV2 cells, a mouse microglia cell line. Both SDM and cMMP-3 induced generation of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), IL-1beta, and interleukin-1 receptor antagonist but not IL-12 and inducible nitric oxide synthase, which are readily induced by lipopolysaccharide, in microglia, suggesting that there is a characteristic pattern of microglial cytokine induction by apoptotic neurons. Neither glial cell line-derived neurotrophic factor nor anti-inflammatory cytokines, such as IL-10 and transforming growth factor-beta1, were induced. SDM and cMMP-3 extensively released TNF-alpha from microglia and activated the nuclear factor-kappaB pathway, and these microglial responses were totally abolished by preincubation with an MMP-3 inhibitor, NNGH [N-isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid]. MMP-3-mediated microglial activation mostly depended on ERK (extracellular signal-regulated kinase) phosphorylation but not much on either JNK (c-Jun N-terminal protein kinase) or p38 activation. Conditioned medium of SDM- or cMMP-3-activated BV2 cells caused apoptosis of PC12 cells. These results strongly suggest that the distinctive signal of neuronal apoptosis is the release of active form of MMP-3 that activates microglia and subsequently exacerbates neuronal degeneration. Therefore, the release of MMP-3 from apoptotic neurons may play a major role in degenerative human brain disorders, such as Parkinson's disease.

The pro and the active form of matrix metalloproteinase-9 is increased in serum of patients with amyotrophic lateral sclerosis

Pro and active-matrix metalloproteinase-9 (MMP-9) was measured in sera from patients with amyotrophic lateral sclerosis (ALS), Guillain–Barré syndome (GBS), and healthy subjects. Both forms of MMP-9 were elevated in sera of ALS and GBS patients, compared with healthy controls. It has been postulated that elevated MMP-9 reflects damage to peripheral nerve and muscle. This possibility was investigated in sera, and tissue extracts of sciatic nerves and muscle from mice 5 and 12 days after axotomy of the sciatic nerve. Pro-MMP-9 was elevated in sera and extracts of damaged nerve and muscle, suggesting such damage may be followed by elevated pro-MM9-9 in sera. Active MMP-9 was only elevated in the sera. However, in situ activation of MMP-9 is tightly regulated and localised, and probably difficult to demonstrate by ELISA, resulting in a short half-life active MMP-9, implying any active MMP-9 in the serum may have a more immediate origin than injured muscle or nerve, for example circulating blood cells.

Tissue levels of active matrix metalloproteinase-2 and -9 in colorectal cancer.

The bioactivity of matrix metalloproteinases was studied in tissues from colorectal cancer patients by means of both quantitative gelatin zymography and a fluorometric activity assay. Next to paired samples of tumour tissue and distant normal mucosa (n=73), transitional tissue was analysed from a limited (n=33) number of patients. Broad-spectrum matrix metalloproteinase activity and both the active and latent forms of the gelatinases matrix metalloproteinase-2 and -9 were higher in tumour than in normal mucosa. The ratio's between active and latent forms of matrix metalloproteinase-2 and -9 were highest in tumour tissue and normal mucosa, respectively. Matrix metalloproteinase-2 levels, both active and latent forms, correlated inversely with stage of disease, the tumours without synchronous distant metastases containing significantly (P=0.005) more active matrix metalloproteinase-2 than the others. At much lower levels of activity, the same trend was observed in distant normal mucosa. The level of latent form of matrix metalloproteinase-9 in tumour depended on tumour location. Neither the active form of matrix metalloproteinase-9 nor broad-spectrum matrix metalloproteinase activity in tumour tissue did correlate with any of the clinicopathological parameters investigated. The results demonstrate explicit differences between the activity of matrix metalloproteinase-2 and -9, indicating different roles for both gelatinases in tumour progression. Such data are necessary in order to develop rational anti-cancer therapies based on inhibition of specific matrix metalloproteinases.British Journal of Cancer (2002) 86, 1876–1883. doi:10.1038/sj.bjc.6600366 www.bjcancer.com© 2002 Cancer Research UK

Regulation of matrix metalloproteinases in a model of colonic wound healing in a rabbit.

Matrix metalloproteinases occur in the colon at an anastomosis but not in the normal colon. Matrix metalloproteinase synthesis can be regulated by cytokines, for example interleukin-1 beta and growth factors, such as transforming growth factor beta and basic fibroblast growth factor. The aim of this study was to investigate the regulation of matrix metalloproteinases at an anastomosis by identifying the cell types that synthesize matrix metalloproteinases, examining factors that might regulate their synthesis, determining whether they occur in an active form, and assessing the effect of suture type on these parameters. An anastomosis was formed in the distal colon of rabbits using either polyglactin or polydioxanone and the animals were killed six hours or seven days later. The distribution of matrix metalloproteinases and cytokines and the cell types were assessed by immunohistochemistry. Matrix metalloproteinase-2, matrix metalloproteinase-3, and matrix metalloproteinase-9 were detected also by zymography. Immunohistochemistry showed that matrix metalloproteinases were restricted to the suture line. Although zymography demonstrated that matrix metalloproteinase-2 was present mainly in an active form, matrix metalloproteinase-9 and matrix metalloproteinase-3 were present in the pro-form. The active form of matrix metalloproteinase-3 occurred more often in the polydioxanone-sutured rabbits. With the exception of matrix metalloproteinase-9, the matrix metalloproteinases were synthesized by fibroblasts. Interleukin-1 beta and transforming growth factor beta were more widespread than in the normal colon and were localized adjacent to the matrix metalloproteinases. Basic fibroblast growth factor was also more widespread postoperatively but occurred deeper in the anastomosis than the matrix metalloproteinases. This study has shown that interleukin-1 beta and transforming growth factor beta may regulate the synthesis of the matrix metalloproteinases by fibroblasts and that minor differences that occur in the matrix metalloproteinase profile are dependent on the suture type.

Interleukin-1alpha-dependent regulation of matrix metalloproteinase-9(MMP-9) secretion and activation in the epithelial cells of odontogenic jaw cysts.

Interleukin-1alpha (IL-1alpha) and matrix metalloproteinase-9 (MMP-9) are thought to be involved in odontogenic cyst expansion. In this study, we investigated the effects of IL-1alpha on the secretion and activation of MMP-9 in odontogenic jaw cysts. An active form of MMP-9 was present in odontogenic keratocyst (6 of 8 cases) fluids more frequently than dentigerous cyst (3 of 10 cases) and radicular cyst (3 of 10 cases) fluids, although proMMP-9 was present in all cyst fluids. Odontogenic keratocyst fragments in explant culture secreted a larger amount of IL-1alpha than dentigerous cyst and radicular cyst fragments in explant culture, and spontaneously secreted both proMMP-9 and an active form of MMP-9. The fragments of dentigerous cysts and radicular cysts secreted a small amount of proMMP-9, but no active form of MMP-9. Exogenously added recombinant human IL-1alpha (rhlL-1alpha) increased the secretion and activation of proMMP-9 in the fragments of dentigerous cysts and radicular cysts. The epithelial cells isolated from odontogenic keratocysts secreted IL-1alpha and proMMP-9 without stimulation. Under the cultivation on a fibronectin-coated dish, rhIL-1alpha increased the secretion of proMMP-9 from the epithelial cells in a dose-dependent manner. Moreover, rhIL-1alpha induced the secretion of proMMP-3 and plasminogen activator urokinase (u-PA) from the epithelial cells, and converted the secreted proMMP-3 to the active form in the presence of plasminogen. The secreted proMMP-9 was also activated in the presence of rhIL-1alpha and plasminogen. Hence, our results suggest that IL-1alpha may up-regulate not only proMMP-9 secretion but also proMMP-9 activation by inducing proMMP-3 and u-PA production in the cyst epithelial cells by autocrine/paracrine regulatory mechanisms.

Differential Expression of Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 Protein and mRNA in Epithelial Ovarian Tumors

Objective. Matrix metalloproteinase-9 (MMP-9) can degrade gelatin and type IV collagen and is known to play an important role in tumor cell invasion across the basement membrane. The tissue inhibitor of metalloproteinase-1 (TIMP-1) is able to prevent activation of pro-MMP-9 and forms a 1:1 complex with the active form of MMP-9. The aim of the present study was to investigate the expression of MMP-9 and TIMP-1 in benign, borderline, and invasive epithelial ovarian tumors.Materials and methods. A total of 90 patients with epithelial ovarian tumor were treated at the Brigham and Women's Hospital and were used as the study population. Immunohistochemistry and in situ hybridization were performed to detect protein and mRNA expression of MMP-9 and TIMP-1.Results. In the 90 epithelial ovarian tumors tested, MMP-9 expression in tumor cells was found to be significantly enhanced in serous and mucinous ovarian carcinomas compared with benign and borderline tumors. We also observed the immunostaining of MMP-9 in stromal cells of benign, borderline, and invasive epithelial ovarian tumors. Moreover, the expression levels of TIMP-1 in tumor cells were significantly higher in borderline and invasive ovarian tumors than in benign tumors.Conclusion. Using an in situ hybridization technique, we disclosed a direct correlation between the presence of mRNA and protein expression for both MMP-9 and TIMP-1. The present data suggest that high levels of MMP-9 protein in invasive epithelial ovarian carcinoma are strongly associated with tumor cell invasion. Enhanced expression of TIMP-1 protein in borderline and invasive tumors indicates that endogenous TIMP-1 protein may play a paradoxical role in ovarian tumor progression.