998 resultados para COLLAGENASE-2 MMP-8


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The type IV collagenases/gelatinases matrix metalloproteinase-2 (MMP-2) and MMP-9 play a variety of important roles in both physiological and pathological processes and are regulated by various growth factors, including transforming growth factor-β1 (TGF-β1), in several cell types. Previous studies have suggested that cellular control of one or both collagenases can occur through direct transcriptional mechanisms and/or after secretion through proenzyme processing and interactions with metalloproteinase inhibitors. Using human prostate cancer cell lines, we have found that TGF-β1 induces the MMP-9 proenzyme; however, this induction does not result from direct effects on gene transcription but, instead, through a protein synthesis–requiring process leading to increased MMP-9 mRNA stability. In addition, we have examined levels of TGF-β1 regulation of MMP-2 in one prostate cancer cell line and found that TGF-β1 induces higher secreted levels of this collagenase through increased stability of the secreted 72-kDa proenzyme. These results identify two novel nontranscriptional pathways for the cellular regulation of MMP-9 and MMP-2 collagenase gene expression and activities.

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Metalloproteinases, especially metal loprotemase-2 (MMP-2), are known for their role in the degradation of the extracellular matrix. Nevertheless, a thorough understanding of MMP-2 expression in neoplastic lesions of the uterine cervix has yet to be accomplished. This study aimed to analyze the MMP-2 expression in cervical intraepithelial neoplasia III (CIN3) and in cervical squamous cell carcinoma, in tumor cells and adjacent stromal cells. MMP-2 expression was assessed by an immunohistochernical technique. MMP-2 expression was greater in the stromal cells of invasive carcinomas than in CIN3 (p < 0.0001). MMP-2 expression in stromal cells correlates with the clinical stage, gradually increasing as the tumor progresses (p = 0.04). This study corroborates that stromal cells play an important role in tumor invasion and progression, mediated by the progressive enhancement of MMP-2 expression from CIN3 to advanced invasive tumor. The intense MMP-2 expression most probably is associated with poor tumor prognosis.

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Mercury (Hg) exposure causes health problems that may result from increased oxidative stress and matrix metalloproteinase (MMP) levels. We investigated whether there is an association between the circulating levels of MMP-2, MMP-9, their endogenous inhibitors (the tissue inhibitors of metalloproteinases; TIMPs) and the circulating Hg levels in 159 subjects environmentally exposed to Hg. Blood and plasma Hg were determined by inductively coupled plasma-mass spectrometry (ICP-MS). MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA respectively. Thiobarbituric acid-reactive species (TBARS) were measured in plasma to assess oxidative stress. Selenium (Se) levels were determined by ICP-MS because it is an antioxidant. The relations between bioindicators of Hg and the metalloproteinases levels were examined using multivariate regression models. While we found no relation between blood or plasma Hg and MMP-9, plasma Hg levels were negatively associated with TIMP-1 and TIMP-2 levels, and thereby with increasing MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios, thus indicating a positive association between plasma Hg and circulating net MMP-9 and MMP-2 activities. These findings provide a new insight into the possible biological mechanisms of Hg toxicity, particularly in cardiovascular diseases.

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Objectives: To develop an index for the ratio of metalloproteinase 2 (MMP-2) to its tissue inhibitor (TIMP-2) in immunostained medullary thyroid carcinoma specimens and to correlate it with clinical and pathologic prognostic factors. Metalloproteinases, enzymes related to the degradation of the extracellular matrix, take part in carcinogenesis and have been associated with the prognosis of neoplasias. Nevertheless, medullary carcinoma is rarely considered in research analysis. Researchers tend to favor the ratio of enzymes to their inhibitors over the absolute concentrations of these enzymes. Design: Retrospective study of surgical samples. Setting: Head and Neck Surgery and Endocrinology Departments, Universidade de Sao Paulo Medical School Hospital. Patients: Surgical specimens from 33 patients who had been observed for a mean of 76.8 months (range, 4-201 months) were immunohistochemically stained for MMP-2 and TIMP-2. Only patients whose clinical and pathologic data were complete and whose specimens were preserved were included in the study. Main Outcome Measures: The ratio between the expressions of MMP-2 and TIMP-2 was based on a staining index (immunostaining extent and intensity) of each of the markers. Results: Proportionally large expressions of TIMP-2 over MMP-2 correlated with low occurrences of positive findings on initial cervical examination for the presence of thyroid nodules and/or lymphadenopathy (P = .02) and cervical lymph node metastases (P < .001), conditions correlated with prognosis. A correlation with cure at the end of follow-up (P = .01) was also observed. (P < .05 was considered statistically significant.) Conclusion: The ratio of MMP-2 to TIMP-2 expression is an additional and novel prognostic predictor of the outcome of medullary carcinoma treated surgically.

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Objectives: To compare the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and the MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in preeclampsia and gestational hypertension with those found in normotensive pregnancies. Design and methods: We studied 83 pregnant women (30 healthy pregnant women with uncomplicated pregnancies, 26 with gestational hypertension, and 27 with preeclampsia) and 30 healthy nonpregnant women in a cross-sectional study. MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively. Results: We found higher plasma pro-MMP-9 levels, and higher pro-MMP-9/TIMP-1 ratios in women with gestational hypertension (95%-CI: 1.031 to 2.357, and 0.012 to 0.031, respectively), but not with preeclampsia, compared with those found in normotensive pregnant women (95%-CI: 0.810 to 1.350, and 0.006 to 0.013, respectively; both P<0.05). We found no significant differences in pro-MMP-2 levels (P>0.05). Conclusions: The higher net MMP-9 (but not MMP-2) activity in gestational hypertension compared with normotensive pregnancy suggests that MMP-9 plays a role in the pathophysiology of gestational hypertension. Conversely, the lack of such alterations in preeclampsia is consistent with the notion that different pathophysiological mechanisms are involved in these hypertensive disorders. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

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MMPs are endopeptidases that play a pivotal role in ECM turnover. RECK is a single membrane-anchored MMP-regulator. Here, we evaluated the temporal and spatial expression of MMP-2, MMP-9, and RECK during alveolar bone regeneration. The maxillary central incisor of Wistar rats was extracted and the animals were killed at 1, 3, 7, 10, 14, 21, 28, and 42 days post-operatively (n = 3/period). The hemimaxillae were collected, demineralized and embedded in paraffin. Immunohistochemical analysis was performed by the immunoperoxidase technique with polyclonal antibodies. On day 1, polymorphonuclear cells in the blood clot presented mild immunolabeling for MMPs. During bone remodeling, osteoblasts facing new bone showed positive staining for gelatinases and RECK in all experimental periods. MMPs were also found in the connective tissue and endothelial cells. Our results show for the first time that inactive and/or active forms of MMP-2, MMP-9 and RECK are differentially expressed by osteogenic and connective cells during several events of alveolar bone regeneration. This may be important for the replacement of the blood clot by connective tissue, and in the formation, maturation and remodeling of new bone.

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The bone formation executed by osteoblasts represents an interesting research field both for basic and applied investigations. The goal of this work was to evaluate the molecular mechanisms involved during osteoblast differentiation in vitro. Accordingly, we demonstrated that, during the osteoblastic differentiation, TIMP-2 and RECK presented differential expressions, where RECK expression was downregulated from the 14th day in contrast with an increase in TIMP-2. Concomitantly, our results showed a temporal regulation of two major signaling cascades during osteoblast differentiation: proliferation cascades in which RECK, PI3 K, and GSK-3 beta play a pivotal role and latter, differentiation cascades with participation of Ras, Rho, Rac-1, PKC alpha/beta, and TIMP-2. Furthermore, we observed that phosphorylation level of paxillin was downregulated while FAK(125) remained unchangeable, but active during extracellular matrix (ECM) remodeling. Concluding, our results provide evidences that RECK and TIMP-2 are involved in the control of ECM remodeling in distinct phases of osteoblast differentiation by modulating MMP activities and a multitude of signaling proteins governs these events.

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Anti-angiogenic therapies are currently in cancer clinical trials, but to date there are no established tests for evaluating the angiogenic status of a patient. We measured 11 circulating angiogenesis-associated molecules in cancer patients before and after local treatment. The purpose of our study was to screen for possible relationships among the different molecules and between individual molecules and tumor burden. We measured VEGF-A, PlGF, SCF, MMP-9, EDB+ -fibronectin, sVEGFR-2, sVEGFR-1, salphaVbeta3, sTie-2, IL-8 and CRP in the blood of 22 healthy volunteers, 17 early breast, 17 early colorectal, and 8 advanced sarcoma/melanoma cancer patients. Breast cancer patients had elevated levels of VEGF-A and sTie-2, colorectal cancer patients of VEGF-A, MMP-9, sTie-2, IL-8 and CRP, and melanoma/sarcoma patients of sVEGFR-1. salphaVbeta3 was decreased in colorectal cancer patients. A correlation between VEGF-A and MMP-9 was found. After tumor removal, MMP-9 and salphaVbeta3 significantly decreased in breast and CRP in colorectal cancer, whereas sVEGFR-1 increased in colorectal cancer patients. In sarcoma/melanoma patients treated regionally with TNF and chemotherapy we observed a rise in VEGF-A, SCF, VEGFR-2, MMP-9, Tie-2 and CRP, a correlation between CRP and IL-8, and a decreased in sVEGFR-1 levels. In conclusion, among all factors measured, only VEGF-A and MMP-9 consistently correlated to each other, elevated CRP levels were associated with tumor burden, whereas sVEGF-R1 increased after tumor removal in colorectal cancer. Treatment with chemotherapy and TNF induced changes consistent with an angiogenic switch. These results warrant a prospective study to compare the effect of surgical tumor removal vs. chemotherapy on some of these markers and to evaluate their prognostic/predictive value.

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The [3+4] cycloaddition between furan and the oxyallyl cation generated from 1-bromo-1-phenylpropan-2-one (4), resulted in the formation of 2-phenyl-8-oxabicyclo[3.2.1]oct-6-en-3-one (5) in 30% yield. This compound was further converted into 2-phenyl-6,7-exo-isopropylidenedioxi-8-oxabicyclo[3.2.1]oct-2-ene (13) in 35.4% yield. The selective effect of compound (13) and its isomer 3-phenyl-6,7-exo-isopropylidenedioxi-8-oxabicyclo[3.2.1]oct -2-ene (1a) on the radicle growth of Sorghum bicolor L. (sorghum) and Cucumis sativus L. (cucumber) were evaluated. For both plants, compound 13 showed to be more potent than its isomer 1a.

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Bonding, photochemical and electrochemical properties of the clusters [Ru-3(CO)(8)(mu-CO)(2)(alpha-diimine)] (alpha-diimine=2,2'-bipyridine (1), 4,4'-dimethyl-2,2'-bipyridine (2) and 2,2'-bipyrimidine (3)) are strongly influenced by the presence of bridging carbonyl ligands. Irradiation at 471 nm initially results in the population of a sigma(Ru-3)pi*(alpha-diimine) excited state. From this state, fast decay takes place to the optically hardly directly accessible pi(Ru/mu-CO) pi*(alpha-diimine) lowest excited state. These assignments agree with theoretical (TD-DFT) results, resonance Raman and picosecond time-resolved infrared spectra. The involvement of the bridging carbonyl ligands in the electron transfer increases the energetic barrier for the formation of open-structure photoproducts such as biradicals and zwitterions. Zwitterions were therefore only obtained in strongly coordinating media such as pyridine at 250 K. The bridging carbonyl ligands also stabilize the radical anions produced upon one-electron reduction of the clusters [Ru-3(CO)(8)(mu-CO)(2)(alpha-diimine)] and observed with cyclic voltammetry, EPR and IR spectroelectrochemistry (for alpha-diimine=2,2'-bipyrimidine). In contrast, open-triangle intermediates formed along the reduction path to [Ru(CO)(2)(alpha-diimine)](n) and [Ru-2(CO)(8)](2-) are more reactive than their triosmium analogues.

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Background: Diabetes and periodontitis produce a protein discharge that can be reflected in saliva. This study evaluates the salivary concentrations of interleukin (IL)-6, matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in patients with periodontitis with type 2 diabetes. Methods: Whole saliva samples were obtained from 90 subjects who were divided into four groups: healthy (control; n = 22), untreated periodontitis (UPD; n = 24), diabetes mellitus (DM; n = 20), and UPD + DM (n = 24) groups. Clinical and metabolic data were recorded. Salivary IL-6, MMP-8, and OPG concentrations were determined by a standard enzyme-linked immunosorbent assay. Results: The UPD and UPD + DM groups exhibited higher salivary IL-6 than the control and DM groups (P <0.01). The salivary MMP-8 concentrations in all diseased groups (UPD, DM, and UPD + DM) were higher than in the control group (P <0.01). The salivary OPG concentrations in the DM group were higher than in the UPD and control groups (P<0.05). In the UPD + DM group, salivary IL-6 was correlated with glycated hemoglobin (HbA1c) levels (r = 0.60; P<0.05). The regression analysis indicated that the number of remaining teeth, clinical attachment level, and IL-6 might have influenced the HbA1c levels in patients with diabetes. Conclusions: Salivary 1L-6 concentrations were elevated in patients with periodontitis with or without diabetes. Salivary MMP-8 and OPG concentrations were elevated regardless of periodontal inflammation in patients with diabetes. Therefore, periodontitis and diabetes are conditions that may interfere with protein expression and should be considered when using saliva for diagnoses. J Periodontol 2010;81:384-391.

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Este estudo teve como objetivo avaliar a expressão das metaloproteinases 2 (MMP-2) e 9 (MMP-9) em próstatas caninas normais e com desordens proliferativas, verificando o papel dessas enzimas na remodelação da matriz extracelular (MEC) e no processo de invasão tecidual. Um total de 355 amostras prostáticas foram obtidas, sendo 36 (10,1%) normais, 46 (13,0%) com hiperplasia prostática benigna (HPB), 128 (36,1%) com atrofia inflamatória proliferativa (PIA), 74 (20,8%) com neoplasia intraepitelial prostática (PIN) e 71 (20,0%) com carcinoma prostático (CP). Houve diferença de imunomarcação citoplasmática para MMP-2 e MMP-9 entre o epitélio acinar e o estroma periacinar, quanto aos diferentes diagnósticos. Observou-se correlação entre a expressão de MMP-2 e MMP-9 em relação ao número de células marcadas no epitélio acinar e estroma periacinar, bem como para a intensidade de marcação das células estromais periacinares em próstatas caninas com PIA. Conclui-se que há variação na expressão de MMP-2 e MMP-9 em próstatas caninas de acordo com a lesão, com menor expressão em próstatas caninas normais e com HPB, e maior naquelas com PIA, PIN e CP. Ainda, o microambiente inflamatório na PIA influencia a atividade de ambas as enzimas.

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The initial events in prostatic morphogenesis involve cell proliferation, epithelial canalization and outgrowth toward the stroma. We have hypothesized that stromal rearrangement takes place at the sites of epithelial growth and branching and that this rearrangement involves the action of gelatinases matrix metalloproteinase (MMP)-2 and MMP-9. Thus, the purpose of the present study was to characterize structural aspects of epithelial growth during the first week of postnatal development of the rat ventral prostate and to investigate the expression, localization and activity of MMP-2 and MMP-9 during this period by histological, ultrastructural and immunocytochemical analysis, in addition to gel zymography, in situ zymography and Western blotting. An increasing complexity of prostatic architeture was observed within the first postnatal week. Concurrently, the stroma became more organized and some cells differentiated into smooth muscle cells. Reticulin fibers appeared in a basket-like arrangement around both growing tips and epithelial sprouts, associated with a fainter staining for laminin. MMP-2 and MMP-9 activities were detected. MMP-2/MMP-9 expression decreased during the first week. Developing epithelial cords showed strong and difuse gelatinolytic activity. This activity coincided with the distribution of MMP-2 as determined by immunocytochemistry. on the other hand, MMP-9 was rather concentrated at the epithelial tips. These results suggest that gelatinolytic activity (with contribution of both MMP-2 and MMP-9) in the epithelium and at the epithelium-stroma interface are at least in part responsible for the tissue remodeling that allows epithelial growth and its projection into the surrounding stroma.