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MMP
Terms modified by MMP Selected AbstractsCardioprotection of bradykinin at reperfusion involves transactivation of the epidermal growth factor receptor via matrix metalloproteinase-8ACTA PHYSIOLOGICA, Issue 4 2009C. Methner Abstract Aim:, The endogenous autacoid bradykinin (BK) reportedly reduces myocardial infarct size when given exogenously at reperfusion. Muscarinic and opioid G-protein-coupled receptors are equally protective and have been shown to couple through a matrix metalloproteinase (MMP)-dependent transactivation of the epidermal growth factor receptor (EGFR). Here we test whether BK protects the rat heart through the EGFR by an MMP-dependent pathway. Methods:, Infarct size was measured in isolated perfused rat hearts undergoing 30 min regional ischaemia followed by 120 min reperfusion. In additional studies HL-1 cardiomyocytes were loaded with tetramethylrhodamine ethyl to measure their mitochondrial membrane potential (,m). Adding the calcium ionophore calcimycin, causes ,m-collapse presumably due to calcium-induced mitochondrial permeability transition. Results:, As expected, BK (100 nmol L,1) started 5 min prior to reperfusion reduced infarct size from 38.9 ± 2.0% of the ischaemic zone in control hearts to 22.2 ± 3.3% (P < 0.001). Co-infusing the EGFR inhibitor AG1478, the broad-spectrum MMP-inhibitor GM6001, or a highly selective MMP-8 inhibitor abolished BK's protection, thus suggesting an MMP-8-dependent EGFR transactivation in the signalling. Eighty minutes of exposure to calcimycin reduced the mean cell fluorescence to 37.4 ± 1.8% of untreated cells while BK could partly preserve the fluorescence and, hence, protect the cells (50.5 ± 2.3%, P < 0.001). The BK-induced mitochondrial protection could again be blocked by AG1478, GM6001 and MMP-8 inhibitor. Finally, Western blotting revealed that BK's protection was correlated with increased phosphorylation of EGFR and its downstream target Akt. Conclusion:, These results indicate that BK at reperfusion triggers its protective signalling pathway through MMP-8-dependent transactivation of the EGFR. [source] Serum Iron and Matrix Metalloproteinase-9 Variations in Limbs Affected by Chronic Venous Disease and Venous Leg UlcersDERMATOLOGIC SURGERY, Issue 6 2005Paolo Zamboni MD Background. Severe chronic venous disease (CVD) is characterized by both dermal hemosiderin accumulation and matrix metalloproteinase (MMP) hyperactivation. The iron-driven pathway is one of the recognized mechanisms of MMP hyperactivation. Objective. To investigate the potential consequences of leg hemosiderin deposits on both iron metabolism and activation of MMPs. Methods. We contemporaneously assessed the following in the serum of the arm and ankle veins of 30 patients (C4,6) with CVD and 14 normal subjects: ferritin, transferrin, iron, percentage of transferrin iron binding capacity (%TIBC), and MMP-9. Optical microscopy examinations with Perls' staining of chronic wounds were also performed. Results. Histology consistently revealed iron deposits. Serum ferritin, iron, and %TIBC were significantly increased in the legs affected by severe CVD compared with the arm of the same subjects or the controls. In addition, iron and %TIBC were significantly elevated in the legs of ulcer patients. The rate of activation of MMP-9 was significantly elevated in CVD. Conclusions. The increased iron deposition in legs affected by CVD seems to be more instable in ulcer patients, leading to iron release in the serum of the affected leg. Our data suggest the iron-driven pathway as a further mechanism for MMP hyperexpression leading to tissue lesion. [source] Matrix metalloproteinases mediate the dismantling of mesenchymal structures in the tadpole tail during thyroid hormone-induced tail resorptionDEVELOPMENTAL DYNAMICS, Issue 3 2002Jae-Chang Jung Abstract It has been suggested that a family of tissue remodelling enzymes called matrix metalloproteinases (MMPs) play a causal role in the process of tail resorption during thyroid hormone-induced metamorphosis of the anuran tadpole; however, this hypothesis has never been directly substantiated. We cloned two new Xenopus MMPs, gelatinase A (MMP-2) and MT3-MMP (MMP-16), and the MMP inhibitor TIMP-2. These clones were used along with several others to perform a comprehensive expression study. We show that all MMPs and TIMP-2 are dramatically induced in the resorbing tail during spontaneous metamorphosis and are spatially coexpressed, primarily in the remodelling mesenchymal tissues. By Northern blotting, we show that all the examined MMPs/TIMP-2 are also induced by treatment of organ-cultured tails with thyroid hormone (T3). Using the organ culture model, we provide the first direct evidence that MMPs are required for T3 -induced tail resorption by showing that a synthetic inhibitor of MMP activity/expression can specifically retard the resorption process. By gelatin zymography, we also show T3 induction of a fifth MMP, preliminarily identified as gelatinase B (GelB; MMP-9). Moreover, T3 not only induces MMP/TIMP expression but also MMP activation, and we provide evidence that TIMP-2 participates in the latter process. These findings suggest that MMPs and TIMPs act in concert to effect the dismantling of mesenchymal structures during T3 -induced metamorphic tadpole tail resorption. © 2002 Wiley-Liss, Inc. [source] What role do extracellular matrix changes contribute to the cardiovascular disease burden of diabetes mellitus?DIABETIC MEDICINE, Issue 12 2005M. H. Tayebjee Abstract Matrix metalloproteinases (MMP) and their inhibitors (TIMP) are central factors in the control of extracellular matrix turnover. They are important in normal physiology and also during a range of pathological states. In this review, we have systematically identified clinical articles relevant to cardiovascular disease in diabetes from the last 10 years. Our aim was to outline the structure, function and regulation of metalloproteinases and their key roles in cardiomyopathy and vasculopathy in diabetes. We also explore the effects of drug intervention on both human subjects with diabetes and experimental animal models. The modulation of MMP and TIMP activity using drugs that affect the expression and function of these proteins may provide us with new ways to treat this serious and disabling disease, and we explore potential mechanisms and treatments. [source] Protective effect of CPUX1, a progesterone, on hydrogen peroxide-induced oxidative damage in PC12 cells,DRUG DEVELOPMENT RESEARCH, Issue 8 2008Bian-sheng Ji Abstract The protective effect of CPUX1, a novel progesterone analog, on hydrogen peroxide (H2O2)-induced oxidative damage was investigated in rat pheochromocytoma (PC12) cells. Following the exposure of PC12 cells to H2O2, there was a reduction in cell survival and activities of superoxide dismutase (SOD) and mitochondrial membrane potential (MMP) accompanied by increased levels of lactate dehydrogenase (LDH) release, malondialdehyde (MDA) production, and intracellular reactive oxygen species (ROS) and intracellular [Ca2+]i levels. Preincubation of cells with CPUX1 prior to H2O2 exposure attenuated all these changes mentioned and had a protective effect against H2O2 -induced toxicity in PC12 cells, indicating that the compound may have potential therapeutic benefit for CNS disorders influenced by oxidative damage. Drug Dev Res 69: 2008 ©2008 Wiley-Liss, Inc. [source] Equine laminitis: glucose deprivation and MMP activation induce dermo-epidermal separation in vitroEQUINE VETERINARY JOURNAL, Issue 3 2004K. R. French Summary Reasons for performing study: Acute laminitis is characterised by hoof lamellar dermal-epidermal separation at the basement membrane (BM) zone. Hoof lamellar explants cultured in vitro can also be made to separate at the basement membrane zone and investigating how this occurs may give insight into the poorly understood pathophysiology of laminitis. Objectives: To investigate why glucose deprivation and metalloproteinase (MMP) activation in cultured lamellar explants leads to dermo-epidermal separation. Methods: Explants, cultured without glucose or with the MMP activator p -amino-phenol-mercuric acetate (APMA), were subjected to tension and processed for transmission electron microscopy (TEM). Results: Without glucose, or with APMA, explants under tension separated at the dermo-epidermal junction. This in vitro separation occurred via 2 different ultrastructural processes. Lack of glucose reduced hemidesmosomes (HDs) numbers until they disappeared and the basal cell cytoskeleton collapsed. Anchoring filaments (AFs), connecting the basal cell plasmalemma to the BM, were unaffected although they failed under tension. APMA activation of constituent lamellar MMPs did not affect HDs but caused AFs to disappear, also leading to dermo-epidermal separation under tension. Conclusions: Natural laminitis may occur in situations where glucose uptake by lamellar basal cells is compromised (e.g. equine Cushing's disease, obesity, hyperlipaemia, ischaemia and septicaemia) or when lamellar MMPs are activated (alimentary carbohydrate overload). Potential relevance: Therapies designed to facilitate peripheral glucose uptake and inhibit lamellar MMP activation may prevent or ameliorate laminitis. [source] Serum markers of lamellar basement membrane degradation and lamellar histopathological changes in horses affected with laminitisEQUINE VETERINARY JOURNAL, Issue 6 2000P. J. JOHNSON Summary In order better to evaluate the extent to which degradation of the lamellar basement membrane (LBM) by matrix metalloproteinases (MMP) occurs in equine laminitis, we determined the concentration of type IV collagen and laminin in normal and laminitic horses, using specific immunoassays. Blood samples were obtained from both the jugular and the cephalic veins of horses (n = 10) before and after the induction of acute alimentary laminitis by carbohydrate overload. Jugular and cephalic venous blood samples were also obtained from horses affected with naturally occurring laminitis (n = 16) and nonlaminitic controls (n = 8). The serum collagen IV concentration was not changed following the induction of laminitis in the experimental group. Serum collagen IV concentration was increased in jugular venous blood obtained from cases of naturally occurring laminitis (mean ± s.e. 218.04 ± 18.59 ng/ml) compared with nonlaminitic controls (157.50 ± 10.93 ng/ml) (P<0.05). Serum collagen IV concentration was also increased in jugular venous blood obtained from severely laminitic horses (219.50 ± 18.18 ng/ml) compared with nonlaminitic controls (157.50 ± 10.93 ng/ml) (P<0.05). A difference in serum concentration of collagen IV was not identified based on chronicity of naturally occurring laminitis. Serum laminin concentration did not differ between laminitic and nonlaminitic horses. Differences in serum laminin concentration were not identified based on sampling location (jugular orcephalic vein), severity of laminitic pain, or chronicity of spontaneous laminitis. In conclusion, the circulating concentration of collagen IV was increased in horses affected with naturally occurring laminitis. The potential role for serum collagen IV assay for characterisation of equine laminitis warrants further investigation. [source] 8-isoprostane increases scavenger receptor A and matrix metalloproteinase activity in THP-1 macrophages, resulting in long-lived foam cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2004H. Scholz Abstract Background, Oxidative stress is a key factor in atherogenesis, in which it is closely associated with the inflammation and formation of bioactive lipids. Although 8-isoprostane is regarded as a reliable marker of oxidative stress in vivo, the pathogenic role of this F2 -isoprostane in atherogenesis is far from clear. Based on the important role of foam cells in the initiation and progression of atherosclerosis we hereby examined the ability of 8-isoprostane to modulate oxidized (ox)LDL-induced foam cell formation and the function of these cells, particularly focusing on the effect on matrix degradation. Methods and results, 8-isoprostane (10 µM) augmented the oxLDL-induced (20 µg mL,1) lipid accumulation of THP-1 macrophages evaluated by Oil-Red-O staining and lipid mass quantification (colourimetric assay). Additionally, 8-isoprostane induced the expression of the scavenger receptor A type 1 (MSR-1) [mRNA and protein level], assessed by RT-PCR and Western blotting, respectively. Moreover, 8-isoprostane counteracted the oxLDL-induced apoptosis of these cells, involving both mitochondrial-protective and caspase-suppressive mechanisms. Along with these changes, 8-isoprostane increased the oxLDL-induced gene expression of matrix metalloproteinase (MMP)-9 and its endogenous inhibitor [i.e. tissue inhibitor of MMP (TIMP)-1] accompanied by enhanced total MMP activity. Conclusions, We show that 8-isoprostane increases foam cell formation at least partly by enhancing MSR-1 expression and by inhibiting apoptosis of these cells, inducing long-lived foam cells with enhanced matrix degrading capacity. Our findings further support a role for 8-isoprostane not only as a marker of oxidative stress in patients with atherosclerotic disorders, but also as a mediator in atherogenesis and plaque destabilization. [source] Increased myocardial matrix metalloproteinases in hypoxic newborn pigs during resuscitation: effects of oxygen and carbon dioxideEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2004W. B. Borke Abstract Background, Perinatal asphyxia is associated with cardiac dysfunction, and it is important to prevent further tissue injury during resuscitation. There is increasing evidence that myocardial matrix metalloproteinases (MMPs) are involved in myocardial hypoxaemia,reoxygenation injury. Objective, To assess MMPs and antioxidant capacity in newborn pigs after global ischaemia and subsequent resuscitation with ambient air or 100% O2 at different PaCO2 -levels. Methods, Newborn pigs (12,36 h of age) were resuscitated for 30 min by ventilation with 21% or 100% O2 at different PaCO2 levels after a hypoxic insult, and thereafter observed for 150 min. In myocardial tissue extracts, MMPs were analyzed by gelatin zymography and broad matrix-degrading capacity (total MMP). Total endogenous antioxidant capacity in myocardial tissue extracts was measured by the oxygen radical absorbance capacity (ORAC) assay. Results, Matrix metalloproteinase-2 more than doubled from baseline values (P < 0·001), and was higher in piglets resuscitated with 100% O2 than with ambient air (P = 0·012). The ORAC value was considerably decreased (P < 0·001). In piglets with elevated PaCO2, total MMP-activity in the right ventricle was more increased than in the left ventricle (P = 0·008). In the left ventricle, total MMPactivity was higher in the piglets with low PaCO2 than in the piglets with elevated PaCO2 (P = 0·013). Conclusion, In hypoxaemia-reoxygenation injury the MMP-2 level was highly increased and was most elevated in the piglets resuscitated with 100% O2. Antioxidant capacity was considerably decreased. Assessed by total MMP-activity, elevated PaCO2 during resuscitation might protect the left ventricle, and probably increase right ventricle injury of the myocardium. [source] Hypoxia suppresses the production of matrix metalloproteinases and the migration of humanmonocyte-derived dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2005Wenli Zhao Abstract As most solid tumors are hypoxic, dendritic cells (DC) in solid tumors are also exposed to hypoxia. While many adaptation responses of tumor cells to hypoxia are known, it is yet to be determined how hypoxia affects the functions of DC. To explore the effects of hypoxia on the functions of DC, we compared the expression of surface markers, cytokines, chemokine receptors and matrix metalloproteinases (MMP) of human monocyte-derived DC (hmDC) differentiated under hypoxia to those differentiated under normoxia. Both groups of hmDC expressed similar levels of surface markers and cytokines. However, expression of MMP-9 and membrane type-1-MMP, as well as migrating activity, was significantly suppressed in hmDC differentiated under hypoxia compared with their normoxia counterparts. We also demonstrated that trichostatin A restored the production of MMP-9 in hmDC, under hypoxia. Collectively, our findings show that a hypoxic microenvironment suppresses the production of MMP in hmDC, most probably through the deacetylation of promoter regions of MMP, thus suppressing the migrating activity of hmDC. Our results suggest that the hypoxic microenvironment in solid tumor tissues may suppress the function of DC. [source] Analysis of mitochondria by capillary electrophoresis: cardiolipin levels decrease in response to carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazoneEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2010Wenfeng Zhao Abstract Cardiolipin is an important phospholipid present in the inner membrane of mitochondria. It plays a critical role in adenosine triphosphate (ATP) synthesis mediated by oxidative phosphorylation. Exposure of HepG2 cells to carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP) caused the inhibition of ATP synthesis and the depolarization of mitochondria. Capillary electrophoresis with laser-induced fluorescence (CE-LIF) analysis of fluorescent mitochondrion-selective probe 10-N-nonyl acridine orange (NAO) labeled mitochondria was employed to in situ estimate the cardiolipin levels under FCCP-induced de-energization of mitochondria. NAO, stoichiometriclly bound to cardiolipin at a 1:1 or 2:1 molar ratio (NAO/cardiolipin), emitted green and red fluorescence, respectively. Green fluorescence was chosen for cardiolipin content analysis because it was more intense than red fluorescence. A significant decrease in the cardiolipin content, up to 11% of the control, was evident when the ATP content and mitochondrial membrane potential (MMP) correspondingly decreased. These related findings suggested that CE-LIF may provide a sensitive strategy to determine cardiolipin content in response to exposure to chemical uncouplers. This reinforces the hypothesis that alterations in ATP synthesis and MMP have a close association with cardiolipin content, which correlated tightly with mitochondrial membrane assembly and activity. [source] The effects of natalizumab on inflammatory mediators in multiple sclerosis: prospects for treatment-sensitive biomarkersEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2009M. Khademi Background:, Natalizumab affects systemic cytokine expressions and clinical course in relapsing,remitting multiple sclerosis (RRMS). We analyzed levels of inflammatory cytokines in cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMCs), levels of matrix metalloproteinase (MMP)-9 and osteopontin (OPN) in CSF, and clinical outcome measures in 22 natalizumab-treated RRMS patients. Methods:, mRNA levels of cytokines in cells were detected with real-time RT-PCR. Protein levels of OPN and MMP-9 were measured by ELISA. Results:, Natalizumab reduced CSF cell counts (P < 0.0001). Tumor necrosis factor (TNF) and interferon-, (IFN-,) mRNAs were significantly increased in PBMCs. In contrast, expressions of IFN-, and interleukin (IL)-23 were decreased but IL-10 increased in the CSF cells. OPN and MMP-9 were reduced in the CSF. Patients being in remission at baseline showed the same deviations of mediators as those in relapse after natalizumab treatment. The open label clinical outcome measures were either stable or improved during therapy. Conclusions:, Natalizumab attenuates pro-inflammatory mediators intrathecally and the reduced pro-inflammatory milieu may allow increased production of the anti-inflammatory mediator IL-10. The increased systemic cytokines may impede the improvement of certain clinical measures like fatigue. The affected mediators seem to be sensitive to an immune-modifying treatment which could be used as biomarkers for this therapy. [source] Matrix metalloproteinases 2 and 9 in human atherosclerotic and non-atherosclerotic cerebral aneurysmsEUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2006J. Caird Matrix metalloproteinases 2 and 9 (MMP 2 and -9) have been implicated in the pathogenesis of atherosclerosis and aneurysm formation. The goal of the study was to establish the role of these metalloproteinases in both human atherosclerotic and non-atherosclerotic cerebral aneurysms. Eleven cerebral aneurysms (four atherosclerotic, seven non-atherosclerotic) were immunohistochemically stained for MMP 2 and -9. As controls, atherosclerotic and normal Circle of Willis arteries were similarly immunostained. All specimens were retrieved at autopsy and were paraffin-embedded. In order to evaluate the real MMP 2 and -9 activities, gelatin zymography was also performed in only two available specimens of non-atherosclerotic intracranial aneurysms, because of the relative unavailability of fresh intracranial aneurysm tissue (i.e. reluctance to excise the aneurysm fundus at surgery). Our data establish that MMP 2 and -9 were expressed minimally or not at all in normal Circle of Willis arteries but were strongly expressed in medial smooth muscle cells of atherosclerotic Circle of Willis arteries. In the aneurysm group, both MMP 2 and -9 were strongly expressed in the atherosclerotic aneurysms, but MMP 2 alone was detected in the non-atherosclerotic aneurysms. Zymography revealed a weak enzyme activity correlating to MMP 9 standard recombinant protein. MMP 2 activity was not demonstrated in either specimen. This study shows that the expression of MMP 2 and -9 is associated with atherosclerosis, be it in aneurysmal or non-aneurysmal cerebral vessels but MMP 2 appears to be specifically expressed in aneurysms devoid of atherosclerosis perhaps suggesting a pathogenic role for MMP 2 in the alteration of the extracellular matrix of cerebral arteries during aneurysm formation. [source] Activation of gelatinolytic/collagenolytic activity in dentin by self-etching adhesivesEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2006Yoshihiro Nishitani Mild acids are known to activate dentin matrix metalloproteinase (MMPs). All self-etching dental adhesives are acidic (pH 1.5,2.7) and may activate dentin MMPs. The purpose of this study was to compare the ability of several all-in-one adhesives to activate gelatinolytic and collagenolytic activities in powdered mineralized dentin. Powdered dentin made from human teeth was mixed with all-in-one adhesives (Clearfil Tri-S Bond, G-Bond, Adper Prompt L-Pop) or a self-etching primer (Clearfil SE Bond primer) for varying times and then the reaction was stopped by extracting the adhesives using acetone. Fresh untreated mineralized dentin powder had a gelatinolytic activity of 3.31 ± 0.39 relative fluorescent units (RFU) per mg dry weight (24 h) that increased, over storage time, to 87.5 RFU mg,1 (24 h) after 6,8 wk. When fresh powder was treated with acidic Tri-S Bond, the gelatinolytic activity increased from 3.24 ± 0.70 RFU mg,1 to >,112.5 RFU mg,1 (24 h) after 20 min and then remained unchanged. Monomers with lower pH values produced less activity. There was a significant, direct correlation between gelatinolytic activity and pH, with Tri-S giving the highest activity. Coating dentin powder with Tri-S resin prevented fluorescent substrates from gaining access to the enzyme, even though it activated the enzyme. In conclusion, self-etch adhesives may activate latent MMP and increase the activity to near-maximum levels and contribute to the degradation of resin,dentin bonds over time. [source] District magnitude, electoral formula, and the number of partiesEUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 2 2001KENNETH BENOIT Duverger's propositions concerning the psychological and mechanical consequences of electoral rules have previously been examined mainly through the lens of district magnitude, comparing the properties of single,member district plurality elections with those of multimember proportional representation elections. The empirical consequences of multimember plurality (MMP) rules, on the other hand, have received scant attention. Theory suggests that the effect of district magnitude on the number and concentration of parties will differ with regard to whether the allocation rules are plurality,based or proportional. I test this theory by drawing on a uniquely large,sample dataset where district magnitude and electoral formula vary but the basic universe of political parties is held constant, applying regression analysis to data from several thousand Hungarian local bodies elected in 1994 consisting of municipal councils, county councils, and mayors. The results indicate that omitting the variable of electoral formula has the potential to cause significant bias in estimates of Duvergerian consequences of district magnitude. In addition, the analysis of multi,member plurality elections from the local election dataset reveals counter,intuitively that candidate and party entry may increase with district magnitude under MMP, suggesting important directions for future investigation of MMP rules. [source] Incorporating power system security into market-clearing of day-ahead joint energy and reserves auctionsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2010J. Aghaei Abstract This paper is intended to introduce a technique for incorporating system security into the clearing of day-ahead joint electricity markets, with particular emphasis on the voltage stability. A Multiobjective Mathematical Programming (MMP) formulation is implemented for provision of ancillary services (Automatic Generation Control or AGC, spinning, non-spinning, and operating reserves) as well as energy in simultaneous auctions by pool-based aggregated market scheme. In the proposed market-clearing structure, the security problem, as an important responsibility of ISO, is addressed and a nonlinear model is formulated and used as the extra objective functions of the optimization problem. Thus, in the MMP formulation of the market-clearing process, the objective functions (including augmented generation offer cost, overload index, voltage drop index, and loading margin) are optimized while meeting AC power flow constraints, system reserve requirements, and lost opportunity cost (LOC) considerations. The IEEE 24-bus Reliability Test System (RTS 24-bus) is used to demonstrate the performance of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd. [source] In vitro induction of matrix metalloproteinase-2 and matrix metalloproteinase-9 expression in keratinocytes by boron and manganeseEXPERIMENTAL DERMATOLOGY, Issue 8 2004Nathalie Chebassier Abstract:, Matrix metalloproteinase (MMP)-2 and MMP-9 are involved in keratinocyte migration and granulation tissue remodeling during wound healing. Thermal water cures are sometimes proposed as complementary treatment for accelerating healing of wounds resulting from burns and/or surgery, but their mechanisms of action remain unknown. Some thermal waters are rich in trace elements such as boron and manganese. Interestingly, clinical studies have shown the beneficial effects of trace elements such as boron and manganese for human wound healing. To try to specify the role of trace elements in cutaneous healing, the present study investigated the effects of these trace elements on the production of MMP-2 and MMP-9 by normal human keratinocytes cultured in vitro. Immunohistochemistry and Western blot showed that intracellular MMP-9 expression in keratinocytes was induced when incubated for 6 h with boron at 10 µg/ml or manganese at 0.2 µg/ml. Moreover, gelatin zymography on keratinocyte supernatants showed an increase of gelatinase secretion after 24 h of incubation of keratinocytes with boron or manganese, regardless of concentration. Gelatinase secretion was not associated with keratinocyte proliferation induced by trace elements. Thus, our results suggest that boron and manganese could play a role in the clinical efficiency of thermal water on wound healing. [source] Golgi reassembly stacking protein 55 interacts with membrane-type (MT) 1-matrix metalloprotease (MMP) and furin and plays a role in the activation of the MT1-MMP zymogenFEBS JOURNAL, Issue 15 2010Christian Roghi Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a proteinase involved in the remodelling of extracellular matrix and the cleavage of a number of substrates. MT1-MMP is synthesized as a zymogen that requires intracellular post-translational cleavage to gain biological activity. Furin, a member of the pro-protein convertase family, has been implicated in the proteolytic removal of the MT1-MMP prodomain sequence. In the present study, we demonstrate a role for the peripheral Golgi matrix protein GRASP55 in the furin-dependent activation of MT1-MMP. MT1-MMP and furin were found to co-localize with Golgi reassembly stacking protein 55 (GRASP55). Further analysis revealed that GRASP55 associated with the cytoplasmic domain of both proteases and that the LLY573 motif in the MT1-MMP intracellular domain was crucial for the interaction with GRASP55. Overexpression of GRASP55 was found to enhance the formation of a complex between MT1-MMP and furin. Finally, we report that disruption of the interaction between GRASP55 and furin led to a reduction in pro-MT1-MMP activation. Taken together, these data suggest that GRASP55 may function as an adaptor protein coupling MT1-MMP with furin, thus leading to the activation of the zymogen. Structured digital abstract ,,MINT-7897990: Furin (uniprotkb:P09958) and GRASP55 (uniprotkb:Q9H8Y8) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897801: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with MT2-MMP (uniprotkb:P51511) by two hybrid (MI:0018) ,,MINT-7897821: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with MT3-MMP (uniprotkb:P51512) by two hybrid (MI:0018) ,,MINT-7897577: GRASP55 (uniprotkb:Q9R064) and MT1-MMP (uniprotkb:P50281) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897366: MT1-MMP (uniprotkb:P50281) physically interacts (MI:0915) with GRASP55 (uniprotkb:Q9H8Y8) by anti bait coimmunoprecipitation (MI:0006) ,,MINT-7897617, MINT-7897659, MINT-7897681, MINT-7897702, MINT-7897725, MINT-7898032, MINT-7898011, MINT-7897907, MINT-7897884: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with MT1-MMP (uniprotkb:P50281) by two hybrid (MI:0018) ,,MINT-7898002: MT1-MMP (uniprotkb:P50281) physically interacts (MI:0914) with Furin (uniprotkb:P09958) by anti bait coimmunoprecipitation (MI:0006) ,,MINT-7897500: MT1-MMP (uniprotkb:P50281) and Giantin (uniprotkb:Q14789) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897750, MINT-7897394: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with MT1-MMP (uniprotkb:P50281) by anti tag coimmunoprecipitation (MI:0007) ,,MINT-7897562: MT1-MMP (uniprotkb:P50281) and GRASP55 (uniprotkb:Q9H8Y8) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897512: TGN46 (uniprotkb:O43493) and MT1-MMP (uniprotkb:P50281) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897921, MINT-7897975: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with Furin (uniprotkb:P09958) by two hybrid (MI:0018) ,,MINT-7898052, MINT-7897410: MT1-MMP (uniprotkb:P50281) physically interacts (MI:0915) with GRASP55 (uniprotkb:Q9R064) by anti bait coimmunoprecipitation (MI:0006) ,,MINT-7897951: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with PC7 (uniprotkb:Q16549) by two hybrid (MI:0018) ,,MINT-7897866: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with MT5-MMP (uniprotkb:Q9Y5R2) by two hybrid (MI:0018) ,,MINT-7897633: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with TGFA (uniprotkb:P01135) by two hybrid (MI:0018) ,,MINT-7897551: GRASP55 (uniprotkb:Q9H8Y8) and Giantin (uniprotkb:Q14789) colocalize (MI:0403) by fluorescence microscopy (MI:0416) ,,MINT-7897938: GRASP55 (uniprotkb:Q9R064) physically interacts (MI:0915) with PC5/6B (uniprotkb:Q04592) by two hybrid (MI:0018) [source] The role of exon 5 in fibroblast collagenase (MMP-1) substrate specificity and inhibitor selectivityFEBS JOURNAL, Issue 6 2001Vera Knäuper Interstitial collagen is degraded by members of the matrix metalloproteinase (MMP) family, including MMP-1. Previous work has shown that the region of MMP-1 coded for by exon 5 is implicated both in substrate specificity and inhibitor selectivity. We have constructed a chimeric enzyme, the exon 5 chimera, consisting primarily of MMP-1, with the region coded for by exon 5 replaced with the equivalent region of MMP-3, a noncollagenolytic MMP. Unlike MMP-3, the exon 5 chimera is capable of cleaving type I collagen, but the activity is only 2.2% of trypsin-activated MMP-1. ,Superactivation' of the chimera has no discernible effect, suggesting that the salt bridge formed in ,superactive' MMP-1 is not present. The kinetics for exon 5 chimera cleavage of two synthetic substrates display an MMP-3 phenotype, however, cleavage of gelatin is slightly impaired as compared to the parent enzymes. The Kiapp values for the exon 5 chimera complexed with synthetic inhibitors and N-terminal TIMP-2 also show a more MMP-3-like behaviour. However, the kon values for N-terminal TIMP-1 and N-terminal TIMP-2 are more comparable to those for MMP-1. These data show that the region of MMP-1 coded for by exon 5 is involved in both substrate specificity and inhibitor selectivity and the structural basis for our findings is discussed. [source] Thioredoxin alters the matrix metalloproteinase/tissue inhibitors of metalloproteinase balance and stimulates human SK-N-SH neuroblastoma cell invasionFEBS JOURNAL, Issue 2 2001Antonietta R. Farina Thioredoxin (Trx) inhibited tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 activity with an approximate IC50 of 0.3 µm, matrix metalloproteinase (MMP)-2 activity with an approximate IC50 of 2 µm but did not inhibit MMP-9 activity. This differential capacity of Trx to inhibit TIMP and MMP activity resulted in the promotion of MMP-2 and MMP-9 activity in the presence of molar TIMP excess. Inhibition of TIMP and MMP-2 activity by Trx was dependent upon thioredoxin reductase (TrxR), was abolished by Trx catalytic site mutation and did not result from TIMP or MMP-2 degradation. HepG2 hepatocellular carcinoma cells induced to secrete Trx inhibited TIMP activity in the presence of TrxR. SK-N-SH neuroblastoma cells secreted TrxR, which inhibited TIMP and MMP-2 activity in the presence of Trx. Trx stimulated SK-N-SH invasive capacity in vitro in the absence of exogenous TrxR. This study therefore identifies a novel extracellular role for the thioredoxin/thioredoxin reductase redox system in the differential inhibition of TIMP and MMP activity and provides a novel mechanism for altering the TIMP/MMP balance that is of potential relevance to tumor invasion. [source] Cloning of MMP-26FEBS JOURNAL, Issue 11 2000A novel matrilysin-like proteinase A cDNA encoding a novel human matrix metalloproteinase (MMP), named MMP-26, was cloned from fetal cDNA. The deduced 261-amino-acid sequence is homologous to macrophage metalloelastase (51.8% identity). It includes only the minimal characteristic features of the MMP family: a signal peptide, a prodomain and a catalytic domain. As with MMP-7, this new MMP does not comprise the hemopexin domain, which is believed to be involved in substrate recognition. A study of MMP-26 mRNA steady states levels reveals, among the tissue examined, a specific expression in placenta. MMP-26 mRNA could also be detected in several human cell lines such as HEK 293 kidney cells and HFB1 lymphoma cells. Recombinant MMP-26 was produced in mammalian cells and used to demonstrate a proteolytic activity of the enzyme on gelatin and ,-casein. [source] Microglial expression of ,v,3 and ,v,5 integrins is regulated by cytokines and the extracellular matrix: ,5 Integrin null microglia show no defects in adhesion or MMP-9 expression on vitronectinGLIA, Issue 7 2009Richard Milner Abstract As the primary immune effector cells in the CNS, microglia play a central role in regulating inflammation. The extracellular matrix (ECM) protein vitronectin is a strong inducer of microglial activation, switching microglia from a resting into an activated potentially destructive phenotype. As the activating effect of vitronectin is mediated by ,v integrins, the aim of the current study was to evaluate the requirement of the ,v,5 integrin in mediating microglial adhesion and activation to vitronectin, by studying these events in ,5 integrin-null murine microglia. Surprisingly, ,5 integrin null microglia were not defective in adhesion to vitronectin. Further analysis showed that microglia express the ,v,3 integrin, in addition to ,v,5. Flow cytometry revealed that microglial ,v integrin expression is regulated by cytokines and ECM proteins. ,v,3 integrin expression was downregulated by IFN-,, TNF, LPS, and TGF-,1. ,v,5 expression was also reduced by IFN-,, TNF, and LPS, but strongly increased by the antiactivating factors TGF-,1 and laminin. Gel zymography revealed that ,5 integrin null microglia showed no deficiency in their expression of matrix metalloproteinase (MMP)-9 in response to vitronectin. Taken together, these data show that microglia express two different ,v integrins, ,v,3 and ,v,5, and that expression of these integrins is independently regulated by cytokines and ECM proteins. Furthermore, it reveals that the ,v,5 integrin is not essential for mediating microglial adhesion and MMP-9 expression in response to vitronectin. © 2008 Wiley-Liss, Inc. [source] Decreased hepatic nitric oxide production contributes to the development of rat sinusoidal obstruction syndromeHEPATOLOGY, Issue 4 2003Laurie D. Deleve M.D., Ph.D. This study examined the role of decreased nitric oxide (NO) in the microcirculatory obstruction of hepatic sinusoidal obstruction syndrome (SOS). SOS was induced in rats with monocrotaline. Monocrotaline caused hepatic vein NO to decrease by 30% at 24 hours and by 70% at 72 hours; this decrease persisted throughout late SOS. NG -nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase, exacerbated monocrotaline toxicity, whereas V-PYRRO/NO, a liver-selective NO donor prodrug, restored NO levels, preserved sinusoidal endothelial cell (SEC) integrity and sinusoidal perfusion as assessed by in vivo microscopy and electron microscopy, and prevented clinical and histologic evidence of SOS. NO production in vitro by SEC and Kupffer cells, the 2 major liver cell sources of NO, decreases largely in parallel with loss of cell viability after exposure to monocrotaline. Increased matrix metalloproteinase (MMP) activity increases early on in SOS and this increase in activity has been implicated in initiating SOS. Infusion of V-PYRRO-NO prevented the monocrotaline-induced increase in MMP-9. In conclusion, decreased hepatic NO production contributes to the development of SOS. Infusion of an NO donor preserves SEC integrity and prevents development of SOS. These findings show that a decrease in NO contributes to SOS by allowing up-regulation of MMP activity, loss of sinusoidal integrity, and subsequent disruption of sinusoidal perfusion. (Hepatology 2003;38:900,908). [source] Tissue inhibitor of metalloproteinases-1 attenuates spontaneous liver fibrosis resolution in the transgenic mouseHEPATOLOGY, Issue 4 2002Hitoshi Yoshiji It has been suggested that the tissue inhibitor of metalloproteinases-1 (TIMP-1) is involved in spontaneous resolution of liver fibrosis. The aim of this study was to investigate whether TIMP-1 altered spontaneous resolution of liver fibrosis in conjunction with matrix metalloproteinases (MMP) inhibition and hepatic stellate cell (HSC) activation. The livers of liver-targeted TIMP-1 transgenic (TIMP-Tg) and control hybrid (Cont) mice were harvested at 0, 3, 7, and 28 days following spontaneous recovery from CCl4 -induced liver fibrosis. The extent of fibrosis resolution, MMP expression, ,-smooth-muscle actin (,-SMA) positive cells, and procollagen-(I) messenger RNA (mRNA) in the liver were assessed at the respective periods in both groups. We also examined the effect of TIMP-1 on HSC apoptosis. The TIMP-Tg mice showed significantly attenuated resolution of spontaneous liver fibrosis compared with the Cont mice. The hydroxyproline content, number of ,-SMA positive cells, and procollagen-(I) mRNA rapidly decreased with time in the Cont mice, whereas these markers were little changed in TIMP-Tg mice. The level of the active form of metalloproteinases-2 (MMP-2) in the TIMP-Tg mice was less than that in the Cont mice. TIMP-1 markedly decreased the nonparenchyma apoptotic cells in the liver fibrosis resolution model, and it also inhibited HSC apoptosis associated with suppression of caspase-3 activity in vitro. In conclusion, TIMP-1 significantly attenuated spontaneous resolution of liver fibrosis by the combination of a net reduction of the MMP activity and suppression of apoptosis in HSC. [source] Effect of tauroursodeoxycholic acid on endoplasmic reticulum stress,induced caspase-12 activationHEPATOLOGY, Issue 3 2002Qing Xie Activation of death receptors and mitochondrial damage are well-described common apoptotic pathways. Recently, a novel pathway via endoplasmic reticulum (ER) stress has been reported. We assessed the role of tauroursodeoxycholic acid (TUDCA) in inhibition of caspase-12 activation and its effect on calcium homeostasis in an ER stress-induced model of apoptosis. The human liver-derived cell line, Huh7, was treated with thapsigargin (TG) to induce ER stress. Typical morphologic changes of ER stress preceded development of apoptotic changes, including DNA fragmentation and cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP), as well as activation of caspase-3 and -7. Elevation of intracellular calcium levels without loss of mitochondrial membrane potential (MMP) was shown using Fluo-3/Fura-red labeling and flow cytometry, and confirmed by induction of Bip/GRP78, a calcium-dependent chaperon of ER lumen. These changes were accompanied by procaspase-12 processing. TUDCA abolished TG-induced markers of ER stress; reduced calcium efflux, induction of Bip/GRP78, and caspase-12 activation; and subsequently inhibited activation of effector caspases and apoptosis. In conclusion, we propose that mitochondria play a secondary role in ER-mediated apoptosis and that TUDCA prevents apoptosis by blocking a calcium-mediated apoptotic pathway as well as caspase-12 activation. This novel mechanism of TUDCA action suggests new intervention methods for ER stress-induced liver disease. [source] Autocrine motility factor enhances hepatoma cell invasion across the basement membrane through activation of ,1 integrinsHEPATOLOGY, Issue 1 2001Takuji Torimura Autocrine motility factor/phosphohexose isomerase (AMF/PHI) is a cytokine that is linked to tumor invasion and metastasis. In hepatocellular carcinoma (HCC) tissues, hepatoma cells produce AMF/PHI and its receptor, Mr 78,000 glycoprotein (gp78), is strongly detected in hepatoma cells invading into the stroma and tumor thrombi in the portal vein. Here, we investigated the mechanism of hepatoma cell invasion through Matrigel induced by AMF/PHI using 3 hepatoma cell lines. Production of AMF/PHI, phosphorylation of MEK1/2, and Rho activity were investigated by immunoblotting. Expression of AMF/PHI and gp78 was observed by confocal fluorescence microscopy. The influence of AMF/PHI on activated integrin ,1 subunit expression was evaluated by flow cytometry. Changes in invasion, adhesion, and motility induced by AMF/PHI were evaluated using chemoinvasion, adhesion, and phagokinetic track motility assays. The effect of AMF/PHI on matrix metalloproteinase (MMP) secretion was evaluated by gelatin zymography. Hepatoma cells produced AMF/PHI and expressed gp78. Although AMF/PHI was ubiquitously detected, gp78 was strongly expressed in migrating cells. AMF/PHI induced up-regulation of activated integrin ,1 subunit expression. AMF/PHI stimulated hepatoma cell invasion through Matrigel, and stimulated the adhesion, motility, and MMP-2 secretion of hepatoma cells. The latter effects were suppressed by the function-blocking antibody for integrin ,1 subunit. AMF/PHI also enhanced Rho activity and the phosphorylation of MEK1 and MEK 2. Our results indicate that AMF/PHI enhances hepatoma cell invasion through Matrigel in an autocrine manner by stimulating the adhesion, motility, and MMP-2 secretion of these cells through activation of ,1 integrins. [source] Critical Role of Reactive Oxygen Species and Mitochondrial Permeability Transition in Microcystin-Induced Rapid Apoptosis in Rat HepatocytesHEPATOLOGY, Issue 3 2000Wen-Xing Ding Microcystin-LR (M-LR) is a specific hepatotoxin. At present, the exact toxic mechanism of its action remains unclear though apoptosis is believed to be involved. This study was designed to investigate the role of reactive oxygen species (ROS) and mitochondrial permeability transition (MPT) in the M-LR,induced apoptotic process. Morphologic changes such as cell shrinkage, externalization of cell membrane phosphatidylserine, DNA fragmentation, and nuclear condensation suggest that M-LR causes rapid apoptosis in hepatocytes. Confocal microscopy revealed that M-LR exposure led to the onset of MPT and mitochondrial depolarization, evidenced by (1) redistribution of calcein fluorescence from cytosol to mitochondria, and (2) loss of mitochondrial tetramethyrhodamine methyl ester (TMRM) fluorescence; both occurred before apoptosis. Moreover, there was a significant and rapid increase of ROS level before the onset of MPT and loss of MMP, indicating a critical role of ROS in M-LR,induced apoptosis. Deferoxamine (DFO), an iron chelator, prevented the increase of ROS production, delayed the onset of MPT, and, subsequently, cell death. In addition, a specific MPT inhibitor, cyclosporin A (CsA), blocked the M-LR,induced ROS formation, onset of MPT, and mitochondrial depolarization as well as cell death. Thus, we conclude that the M-LR,induced ROS formation leads to the onset of MPT and apoptosis. [source] Lipoxin A4 inhibited hepatocyte growth factor-induced invasion of human hepatoma cellsHEPATOLOGY RESEARCH, Issue 9 2009Xiao-Yan Zhou Aim:, Inflammation is a critical component of tumor progression. Lipoxin A4 (LXA4) has been approved for potent anti-inflammatory properties. Recently, it was reported that LXA4 repressed the expression and activity of cyclooxygenase-2 (COX-2), which is essential for invasion. However, there are few reports dealing with its effects on cancer. To explore whether LXA4 regulate invasion, the effects of LXA4 and its receptor agonist BML-111 on hepatocyte growth factor (HGF)-induced invasion of hepatoma cells and the possible mechanisms were researched. Methods:, Lipoxin A4 receptor (ALX) expression in HepG2 cells were measured through reverse transcription polymerase chain reaction and western blot. Cytotoxicity of LXA4 and BML-111 to HepG2 cells was detected by MTT and (3H)-TdR incorporation assay. Cell migration and invasion assays were performed using a Boyden chemotaxis chamber. COX-2 expression was detected by real-time polymerase chain reaction and western blot, respectively. Moreover, the expressions of matrix metalloproteinases (MMP)-2, MMP-9, I,B, and nuclear factor-,B (NF-,B) p65 were observed via western blot, and NF-,B transcriptional activity was tested by transfections and luciferase activities assay. Results:, ALX expression was detected in HepG2 cells, and suitable concentrations of LXA4 and BML-111 had no cytotoxicity to cells. LXA4 and BML-111 inhibited HGF-induced migration and invasion; downregulated COX-2, MMP-2 and -9; restrained HGF-induced I,B, degradation, NF-,B translocation and the transcriptional activity of NF-,B in HepG2 cells. Furthermore, exogenous PGE2 could reverse the inhibitory effects of LXA4 also BML-111 on HGF-induced invasion and migration partially. Conclusion:, LXA4 inhibited HGF-induced invasion of HepG2 cells through NF-,B/COX-2 signaling pathway partially. [source] Matrix metalloproteinase inhibitor, CTS-1027, attenuates liver injury and fibrosis in the bile duct-ligated mouseHEPATOLOGY RESEARCH, Issue 8 2009Alisan Kahraman Aim:, Excessive matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of acute and chronic liver injury. CTS-1027 is an MMP inhibitor, which has previously been studied in humans as an anti-arthritic agent. Thus, our aim was to assess if CTS-1027 is hepato-protective and anti-fibrogenic during cholestatic liver injury. Methods:, C57/BL6 mice were subjected to bile duct ligation (BDL) for 14 days. Either CTS-1027 or vehicle was administered by gavage. Results:, BDL mice treated with CTS-1027 demonstrated a threefold reduction in hepatocyte apoptosis as assessed by the TUNEL assay or immunohistochemistry for caspase 3/7-positive cells as compared to vehicle-treated BDL animals (P < 0.01). A 70% reduction in bile infarcts, a histological indicator of liver injury, was also observed in CTS-1027-treated BDL animals. These differences could not be ascribed to differences in cholestasis as serum total bilirubin concentrations were nearly identical in the BDL groups of animals. Markers for stellate cell activation (,-smooth muscle actin) and hepatic fibrogenesis (collagen 1) were reduced in CTS-1027 versus vehicle-treated BDL animals (P < 0.05). Overall animal survival following 14 days of BDL was also improved in the group receiving the active drug (P < 0.05). Conclusion:, The BDL mouse, liver injury and hepatic fibrosis are attenuated by treatment with the MMP inhibitor CTS-1027. This drug warrants further evaluation as an anti-fibrogenic drug in hepatic injury. [source] Expression of c-MET, low-molecular-weight cytokeratin, matrix metalloproteinases-1 and -2 in spinal chordomaHISTOPATHOLOGY, Issue 5 2009Takahiko Naka Aims:, In skull base chordoma, c-MET expression has been reported to correlate with younger patient age and favourable prognosis; however, it also contributes to tumour invasiveness, especially in recurrent lesions, suggesting variable roles for c-MET according to clinical status. The aim of this study was to investigate the significance of c-MET expression in spinal chordoma, which affects patients who are 10,20 years older than those with skull base chordoma. Methods and results:, Using immunohistochemical techniques, the expression of c-MET and its ligand, hepatocyte growth factor (HGF) was investigated in 34 primary spinal chordomas and compared with other clinicopathological parameters. Expression of c-MET and HGF was observed in 85.3 and 21.7% of lesions, respectively. c-MET expression correlated with the expression of an epithelial marker, low-molecular-weight cytokeratin (CAM5.2). Lesions with higher c-MET expression showed significantly stronger expression of proteinases, including matrix metalloproteinase (MMP)-1 and MMP-2. However, c-MET expression was not associated with patient age, proliferative ability estimated by MIB-1 labelling index, or prognosis. Conclusions:, c-MET expression was observed in most spinal chordomas and correlated with the expression of CAM5.2, suggesting a relationship to an epithelial phenotype. [source] | |||||||||||||||||||||||||||||||||||||