Carboxy derivatized glucosamine is a potent inhibitor of matrix metalloproteinase-9 in HT1080 cells

Experimental evidences have confirmed that matrix metalloproteinases (MMPs) play a fundamental role in a wide variety of pathologic conditions and recent advances in medicinal chemistry approach to the design of MMP inhibitors with desired structural and functional properties. Among MMPs, MMP-9 has demonstrated to play a major role in the establishment of metastases and it is substantially increased in the majority of malignant tumors. Inhibition of MMP-9 is thought to have a therapeutic benefit to cancer. Results of this study present a novel synthetic MMP-9 inhibitor that downregulates MMP-9 expression level in HT1080, human fibrosarcoma cells.     

Carbamylated albumin is a potent inhibitor of polymorphonuclear neutrophil respiratory burst

Carbamylation is a post-translational modification of proteins characterized by the binding of cyanate to amino groups, increased in renal failure. Pathophysiological consequences of carbamylation and adverse effects of carbamylated proteins on cell functions are poorly understood. We studied the influence of carbamylated albumin on polymorphonuclear neutrophil (PMN) O(2)(-) production. Carbamylated albumin significantly decreased O(2)(-) production in PMNs stimulated by type I collagen, but not by phorbol 12-myristate 13-acetate or tumor necrosis factor-alpha. This effect was related to inhibition of p(125)FAK phosphorylation. Such an alteration of neutrophil oxidative functions might explain characteristic complications of renal failure, such as increased occurrence of inflammation or infections.     

Dynamic alterations of connexin43, matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 during ventricular fibrillation in canine

The aim of this study is to investigate the dynamic alterations of cardiac connexin 43 (Cx43), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in the setting of different ventricular fibrillation (VF) duration. In this study, thirty-two dogs were randomly divided into sham control group, 8-min VF group, 12-min VF group, and 30-min VF group. Cx43 and phosphorylated Cx43 (p-Cx43) in tissues were detected by western blot and immunofluorescence analysis. MMP-2 and TIMP-2 were detected by western blot and immunohistochemistry analysis. The results showed that Cx43 levels in three VF groups were significantly decreased compared with sham control group. p-Cx43 levels in 12-min and 30-min VF groups were significantly reduced compared with sham control group. The ratio of p-Cx43/Cx43 was also decreased in VF groups. Compared with sham controls, no significant difference was observed between the sham control group and 8-min VF group in MMP-2 level, but MMP-2 level increased in 12-min and 30-min VF groups. The ratios of MMP-2/TIMP-2 were higher in VF groups, and were correlated with the duration of VF. A remarkable correlation was observed between the ratio of p-Cx43/Cx43 and MMP-2/TIMP-2 (r = ?0.93, P < 0.01). In conclusion, the alteration of Cx43 and/or p-Cx43 levels and the imbalance of MMP-2 and TIMP-2 may contribute to the initiation and/or persistence of VF. Maneuvers managed to modulate Cx43 level or normalize the balance of MMP-2/TIMP-2 are promising to ameliorate prognosis of VF.     

Interleukin 15 stimulates production of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 by human peripheral blood mononuclear cells

In peripheral blood mononuclear cells (PBMC), matrix metalloproteinase (MMP)-9 mediates the extravasation of immune cells and may be involved in tissue destruction during inflammation. We investigated the effect of the pro-inflammatory cytokines interleukin (IL-)12 and 15 on the secretion of MMP-9 in PBMC. IL-15, but not IL-12, induces MMP-9 in PBMC and in T cells. Moreover, the combination of IL-15 and IL-2 had an additive effect. In contrast, both IL-12 and IL-15 induced the release of tissue inhibitor of metalloproteinases (TIMP)-1. IL-15 led to a dose-dependent increase of the MMP-9/TIMP-1 ratio as a measure for increased proteolytic capacity. We conclude that IL-15 mediates its effects in inflammation in part through MMP-9.     

Inhibition of apoptosis of activated hepatic stellate cells by tissue inhibitor of metalloproteinase-1 is mediated via effects on matrix metalloproteinase inhibition: implications for reversibility of liver fibrosis.

The activated hepatic stellate cell (HSC) is central to liver fibrosis as the major source of collagens I and III and the tissue inhibitors of metalloproteinase-1 (TIMP-1). During spontaneous recovery from liver fibrosis, there is a decrease of TIMP expression, an increase in collagenase activity, and increased apoptosis of HSC, highlighting a potential role for TIMP-1 in HSC survival. In this report, we use tissue culture and in vivo models to demonstrate that TIMP-1 directly inhibits HSC apoptosis. TIMP-1 demonstrated a consistent, significant, and dose-dependent antiapoptotic effect for HSC activated in tissue culture and stimulated to undergo apoptosis by serum deprivation, cycloheximide exposure, and nerve growth factor stimulation. A nonfunctional mutated TIMP-1 (T2G mutant) in which all other domains are conserved did not inhibit apoptosis, indicating that inhibition of apoptosis was mediated through MMP inhibition. Synthetic MMP inhibitors also inhibited HSC apoptosis. Studies of experimental liver cirrhosis demonstrated that persistent expression of TIMP-1 mRNA determined by PCR correlated with persistence of activated HSC quantified by alpha smooth muscle actin staining, while in fibrosis, loss of activated HSC correlated with a reduction in TIMP-1 mRNA. We conclude that TIMP-1 inhibits apoptosis of activated HSC via MMP inhibition.     

Matrix metalloproteinase-9,-3 and tissue inhibitor of matrix metalloproteinase-1 in colorectal cancer: relationship to clinicopathological variables

The balance between matrix metalloproteinases (MMPs) and their physiological tissue inhibitors of matrix metalloproteinases (TIMPs) is crucial in tumour invasion and progression. The aim of this study was to investigate the levels of MMP-9, MMP-3 and TIMP-1 in colorectal cancer (CRC) and to evaluate these proteinases and their inhibitor with respect to clinicopathological variables. Activities of pro- and active MMP-9 were measured in paired tumour and distant normal tissue specimens from 43 patients with CRC using gelatin zymography. ELISA was employed for the determination of MMP-9, MMP-3 and TIMP-1 protein expressions. The activity levels of pro- and active MMP-9 and protein expression levels of MMP-9, MMP-3 and TIMP-1 were higher in tumour tissues than in the corresponding normal tissues; the differences being significant for all (p < 0.05), except TIMP-1. Similarly, active MMP-9/proMMP-9 and the ratio of protein expression level of MMP-9-TIMP-1 were found to be significantly higher in tumour tissues ( p < 0.01). Among all the clinicopathological variables investigated, significant correlations were found between MMP-9 and presence of perineural invasion, MMP-3 and lymph node status, TIMP-1 and tumour differentiation, MMP-9/TIMP-1 ratio and histological types ( p < 0.05). In conclusion, MMP-3 was not as notably increased as MMP-9 in tumour tissues. However, different roles may be attributed to MMP-9 and MMP-3 in CRC development and progression. Additionally, assessment of TIMP-1 in relation to MMPs appeared to be crucial in CRC studies to provide a basis for the re-evaluation of the clinical usefulness of TIMP-1 in colorectal cancer.     

Cerulenin is a potent inhibitor of antigen processing by antigen-presenting cells

Cerulenin is an antibiotic that inhibits eukaryotic lipid and sterol synthesis and blocks lipid modification of proteins. The effect of cerulenin on the ability of accessory cells to present antigen to T cells was investigated. This antibiotic strongly inhibits the ability of accessory cells to present antigen to murine T-T hybrids. This effect is observed for multiple distinct antigens including L-glutamic acid60-L-alanine30-L-tyrosine10, bovine insulin, L-glutamic acid56-L-lysine35-L-phenylalanine9, and ovalbumen. Presentation by both macrophage and B lymphoblastoid cell lines is inhibited. The ability to effectively pulse these cells with antigen is inhibited but not the ability of these same cells to present antigen that they have previously processed. Furthermore, this inhibition is selective as it can occur without significant inhibition of the antigen-presenting cell protein or DNA synthesis. Cerulenin does not inhibit antigen uptake or catabolism as assessed with labeled antigen. By these criteria this drug is shown to interfere with an antigen-processing step. The ability of cerulenin to block processing was compared with other known inhibitors. Although cerulenin was effective with all antigens tested, at least one inhibitor was not. Taken together, these results suggest that the effect of cerulenin may define a distinct step in antigen processing and provides evidence that some other processing events are not universally required. The ability of cerulenin to interfere with antigen processing is discussed in the context of the known actions of this antibiotic and events of antigen processing and presentation.     

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 are key regulators of extracellular matrix degradation by mouse embryos

Embryo implantation in humans and rodents is a highly invasive yet tightly controlled process involving extracellular matrix (ECM) degradation. Matrix metalloproteinase 9 (MMP-9) has been implicated as the major facilitator of this ECM degradation. MMP-9 is expressed by the embryo's trophoblast cells, whereas tissue inhibitor of metalloproteinases 3 (TIMP-3) is expressed by the maternal uterine cells immediately adjacent to the trophoblast. We examined the functional roles of MMP-9 and TIMP-3 during in vitro ECM degradation by mouse embryos. Blastocysts were treated with either MMP-9 antisense or sense oligonucleotides and incubated on an ECM gel. The extent of ECM degradation exhibited by the blastocysts due to proteinase secretion was quantified. Embryos exposed to MMP-9 antisense oligonucleotides exhibited reduced ECM-degrading activity as compared with controls, and this reduced activity was correlated with the level of MMP-9 secreted by the embryos. The functional role of TIMP-3 was then examined by incubating blastocysts on an ECM gel that had been impregnated with various amounts of TIMP-3. In a dose-dependent manner, increases in TIMP-3 resulted in a reduction in ECM degradation and were correlated with diminished MMP-9 activity. These results provide important functional evidence that in vitro ECM degradation is regulated by embryo-derived MMP-9 and ECM-derived TIMP-3.     

Circulating beta-chemokines and matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 system in hemodialyzed patients--role of oxidative stress

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), beta-chemokines, increased oxidative stress (SOX) and inflammation have been implicated as important factors in atherosclerosis and vascular remodeling. We hypothesized the possible roles of beta-chemokines [monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory proteins (MIP-1alpha, MIP-1beta) and regulated upon activation, normal T-cell expressed and secreted (RANTES)] as regulators of the metabolism of the vascular extracellular matrix in conditions of increased SOX in hemodialysis (HD) patients. We compared pre-dialysis levels of MMP-9/TIMP-1 system, beta-chemokines, Cu/Zn superoxide dismutase (Cu/Zn SOD) as a marker of SOX and C-reactive protein (CRP) as a marker of inflammation in HD patients with and without cardiovascular disease (CVD) to those of controls. HD patients, particularly those with CVD, showed a significant increase in values of Cu/Zn SOD, CRP, TIMP-1, TIMP-1/MMP-9 ratio, MCP-1 and MIP-1beta, whereas RANTES levels were lower than in the controls. The levels of MIP-1alpha as well as MMP-9 in all HD groups were similar to the controls. The positive correlations were observed between the MMP-9/TIMP-1 system and beta-chemokines, SOX and inflammation in whole HD group and in the subgroup with CVD. Multivariate analysis showed that the duration of dialysis followed by Cu/Zn SOD, MIP-1alpha and beta levels were the significant positive predictors of TIMP-1. In conclusion, our data show that MMP-9/TIMP-1 system and beta-chemokines could cooperate in conditions of elevated SOX, which ultimately predisposes hemodialysis patients to accelerated atherosclerosis.     

Enamel matrix derivative is a potent inhibitor of breast cancer cell attachment to bone

This study examined whether enamel matrix derivative (EMD) inhibits the adhesion of cancer cells to bone. A typical breast cancer cell line, MCF-7, was used. Conditioned human osteosarcoma cell (Saos-2) medium was used as extracellular bone matrix (ECBM) to measure cell attachment. MCF-7 cells were incubated on ECBM-coated culture plates with or without soluble EMD, Arg-Gly-Asp (RGD) sequence blocking peptides, recombinant bone sialoprotein (rBSP), or specific integrin antibodies, and the attached cells were quantified using toluidine blue staining. EMD markedly reduced the attachment of MCF-7 cells to ECBM in a dose-dependent manner. An RGD peptide (GRGDSP) and recombinant BSP inhibited cell attachment to the same degree as EMD. Similarly, anti-alphavbeta3 integrin antibody strongly reduced cell attachment, whereas anti-alphavbeta5 and anti-beta1 integrin antibodies had less marked effects on cell attachment. These results show that EMD inhibits MCF-7 cell attachment to a bone matrix and that it might be useful as an anti-adhesive agent for breast cancer cells to bone in vivo.     

Identification of novel, exosite-binding matrix metalloproteinase-13 inhibitor scaffolds

Matrix metalloproteinase-13 (MMP-13) has been implicated as the protease responsible for collagen degradation in cartilage during osteoarthritis (OA). Compounds that inhibit the metalloproteinase at the Zn binding site typically lack specificity among MMP family members. Analogs of the low-micromolar lead MMP-13 inhibitor 4, discovered through high-throughput screening, were synthesized to investigate structure-activity relationships in this inhibitor series. Systematic modifications of 4 led to the discovery of MMP-13 inhibitors 20 and 24 which are more selective than 4 against other MMPs. Compound 20 is also approximately fivefold more potent as an MMP-13 inhibitor than the original HTS-derived lead compound 4.     

Plasma concentrations of matrix metalloproteinase-2, tissue inhibitor of metalloproteinase-1 and osteopontin reflect severity of heart failure in DOCA-salt hypertensive rat

The matrix metalloproteinases (MMPs) and their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs) play a key role in extracellular matrix maintenance and are altered in the failing heart, both in experimental models and in chronic end-stage heart failure in humans. As the common diagnostic markers of heart failure, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) primarily reflect increased pressure loading, determination of soluble, heart-derived MMPs and TIMPs in plasma, as well as the determination of the emerging fibrosis marker osteopontin (OPN) might be valuable tools for detecting heart fibrosis. In this study the effect of spironolactone treatment on plasma MMP-2, TIMP-1 and OPN levels was assessed in a heart failure animal model. Unilaterally nephrectomized Sprague Dawley rats received subcutaneous injection of 100 mg deoxycorticosterone acetate (DOCA) once a week and 1% (w/v) NaCl in drinking water. Blood pressure was monitored weekly and blood samples were collected after 1, 2 and 4 weeks. After 6 weeks, left ventricular contractility (LVC) and heart weight-to-body weight ratio (HW/BW) were assessed. DOCA treatment increased plasma MMP-2, TIMP-1 and OPN concentrations. Alterations of plasma marker levels were correlated with changes of HW/BW and paralleled impaired LVC. Furthermore, beneficial effects of spironolactone treatment were observed. In DOCA-salt hypertensive rats, plasma concentrations of MMP-2, TIMP-1 and OPN reflected heart failure associated with haemodynamic, functional and morphological changes. Based on these findings, it appears reasonable to use plasma markers of fibrosis to monitor the development of heart failure.     

Genistein, a soy isoflavone, is a potent alpha-glucosidase inhibitor.

Genistein is an isoflavone that is known to be contained in soybean. It was proved that genistein plays a pivotal role in homeostasis in the human body. In the course of screening for useful alpha-glucosidase inhibitors, we isolated and identified genistein as a candidate for alpha-glucosidase inhibitor from fermentation broths of a Streptomyces sp. Genistein was shown to be a reversible, slow-binding, non-competitive inhibitor of yeast alpha-glucosidase with a K(i) value of 5.7x10(-8) M when the enzyme mixture was pretreated with genistein. These results show a possibility that genistein could be a useful tool for metabolic disorders.     

Identification,purification and partial characterization of tissue inhibitor of matrix metalloproteinase-2 in bovine pulmonary artery smooth muscle

Bovine pulmonary artery smooth muscle possesses the tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) as revealed by Western immunoblot study of its cytosol fraction with bovine polyclonal TIMP-2 antibody. This potent polypeptide inhibitor of matrix metalloproteinases (MMPs) was purified to homogeneity from cytosol fraction of bovine pulmonary artery smooth muscle. This inhibitor was purified by ammonium sulfate precipitation followed by gelatin sepharose and lentil lectin sepharose affinity chromatography and continuous elution electrophoresis by Prep Cell Model 491 (Bio-Rad, USA). SDS-PAGE revealed that the inhibitor has an apparent molecular mass of 21 kDa and was confirmed as TIMP-2 by (i) Western immunoblot assay using bovine polyclonal TIMP-2 antibody; and also by (ii) amino terminal amino acid sequence analysis of the purified inhibitor is found to be identical with TIMP-2 obtained from other sources. The purified 21 kDa inhibitor was found to be active against matrix metalloproteinase-2 (MMP-2, 72 kDa gelatinase) and matrix metalloproteinase-9 (MMP-9, 92 kDa gelatinase), the ambient MMPs in the pulmonary artery smooth muscle. The inhibitor was also found to be sensitive to the activated 72 kDa gelatinase-TIMP-2 complex and also active human interstitial collagenase. By contrast, it was found to be insensitive to the serine proteases: trypsin and plasmin. The inhibitor was heat and acid resistant and it had the sensitivity to trypsin degradation and reduction-alkylation. Treatment of the inhibitor with hydrogen peroxide, superoxide generating system (hypoxanthine plus xanthine oxidase) and peroxynitrite inactivated the inhibitor.     

Mast cell tissue inhibitor of metalloproteinase-1 is cleaved and inactivated extracellularly by alpha-chymase

We previously reported that mast cell alpha-chymase cleaves and activates progelatinase B (progel B). Outside of cells, progel B is complexed with tissue inhibitor of metalloproteinase (TIMP)-1, which hinders zymogen activation and inhibits activity of mature forms. The current work demonstrates that dog BR mastocytoma cells, HMC-1 cells, and murine bone marrow-derived mast cells secrete TIMP-1 whose electrophoretic profile in supernatants suggests degranulation-dependent proteolysis. Alpha-chymase cleaves uncomplexed TIMP-1, reducing its ability to inhibit gel B, whereas tryptase has no effect. Sequencing of TIMP-1's alpha-chymase-mediated cleavage products reveals hydrolysis at Phe(12)-Cys(13) and Phe(23)-Val(24) in loop 1 and Phe(101)-Val(102) and Trp(105)-Asn(106) in loop 3 of the NH(2)-terminal domain. TIMP-1 in a ternary complex with progel B and neutrophil gelatinase-associated lipocalin is also susceptible to alpha-chymase cleavage, yielding products like those resulting from processing of free TIMP-1. Thus, alpha-chymase cleaves free and gel B-bound TIMP-1. Incubation of the progel B-TIMP-1-neutrophil gelatinase-associated lipocalin complex with alpha-chymase increases gel B activity 2- to 5-fold, suggesting that alpha-chymase activates progel B whether it exists as free monomer or as a complex with TIMP-1. Furthermore, inhibition of alpha-chymase blocks degranulation-induced TIMP-1 processing (absent in alpha-chymase-deficient HMC-1 cells). Purified alpha-chymase processes TIMP-1 in BR supernatants, generating products like those induced by degranulation. In summary, these results suggest that controlled exocytosis of mast cell alpha-chymase activates progel B even in the presence of TIMP-1. This is the first identification of a protease that overcomes inhibition by bound TIMP-1 to activate progel B without involvement of other proteases.