Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Matrix”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66Linked to original sources
PubMed1993

Effects of exogenous hyaluronic acid and serum on matrix organization and stability in the mouse cumulus cell-oocyte complex.

Compact cumulus cell-oocyte complexes (COCs) isolated from preovulatory mouse follicles undergo expansion in vitro when high levels of hyaluronic acid (HA) are synthesized and organized into an extracellular matrix. We studied the effects of fetal bovine serum (FBS) and of exogenous HA and HA-oligomers on the expansion process. Maximum retention of HA in the COC matrix, and hence complete COC expansion, occurs when 1% FBS is continuously present during the first 18 h of culture. Irrespective of the culture time, HA synthesized when serum is absent is primarily in the medium, whereas HA synthesized when serum is present is primarily in the cell matrix. These findings support the hypothesis that the serum factor, identified as an inter-alpha-trypsin inhibitor by Chen et al. (Chen, L., Mao, S. J., and Larsen, W. J. (1992) J. Biol. Chem. 267, 12380-12386), is a structural component of the matrix. Addition of exogenous HA or of HA oligomers of decasaccharide size (GlcUA-GlcNAc)5 or larger effectively displaces endogenously synthesized HA from the matrix into the medium, thereby preventing COC expansion. Addition of exogenous chondroitin sulfate affects neither matrix organization nor COC expansion, thus indicating specificity of the binding of some structural component(s) to HA. Fully expanded COCs disassemble when cultured longer than 18 h, a process which occurs also in vivo and which correlates with loss of oocyte fertilizability both in vivo and in vitro. This process involves release of macromolecular HA from the matrix into the medium, with loss of 50% of the HA in the first 8 h of incubation after full expansion. The release is not facilitated when HA oligomers, long enough to prevent matrix formation, are added to the culture medium after the COCs are fully expanded. This suggests that cooperative binding to HA of either the serum factor, an endogenously synthesized factor(s), or both is required to stabilize the fully expanded COC matrix.

Animals↗
PubMed2000

Inactive matrix metalloproteinase 2 is a normal constituent of human glomerular basement membrane. An immuno-electron microscopic study.

Remodelling of the extracellular matrix requires tight control not only of matrix synthesis, but also of matrix degradation. Control of matrix degradation is achieved mainly through the matrix metalloproteinase (MMP) enzymes. In the glomerulus, MMP-2 and MMP-9 are believed to be particularly important, as they have activity against type IV collagen. This study has demonstrated by immuno-electron microscopy that most of the immunoreactivity for MMP-2 in the normal glomerulus is located within the glomerular basement membranes and mesangial matrix. mRNA for MMP-2 is also detectable in normal glomeruli, but the other main gelatinase, MMP-9, could not be localized by immuno-electron microscopy. In the normal glomerulus, it seemed likely that MMP-2 is present in an inactive form. To confirm this, in situ zymography was carried out using frozen sections of normal kidney. Baseline activity of normal kidney was relatively weak, but this was dramatically increased by chemical activation of metalloproteinases. The results imply that MMP-2, in an inactive form, is a normal constituent of the extracellular matrix and glomerular basement membranes. Activation would presumably render the matrix 'self-degrading'; membrane-bound MMPs (MT-MMPs) seem particularly likely to be involved in leukocyte penetration of basement membranes in inflammation.

Basement Membrane↗
PubMed2001

Up-regulated expression of the phosphodiesterase nucleotide pyrophosphatase family member PC-1 is a marker and pathogenic factor for knee meniscal cartilage matrix calcification.

OBJECTIVE: Elevated cartilage inorganic pyrophosphate (PPi) production and PPi-generating nucleoside triphosphate pyrophosphohydrolase (NTPPPH) activity are strongly linked with aging-related cartilage calcification in meniscal and articular cartilages. We hypothesized that there were divergent relationships of 3 NTPPPH isozymes with cartilage matrix calcification and sought to identify them. METHODS: We studied knee medial meniscal expression in situ of 3 NTPPPH isozymes of the phosphodiesterase nucleotide pyrophosphatase (PDNP) family: plasma cell membrane glycoprotein 1 (PC-1, or PDNP1), autotaxin (ATX, or PDNP2), and B10/PDNP3. We also used complementary DNA transfection to assess differential functions in matrix calcification of each NTPPPH isozyme in vitro in meniscal cells. RESULTS: We observed diffuse cell-associated ATX and B10/PDNP3 expression in central (chondrocytic) and, to a lesser degree, peripheral (fibroblastic) regions of normal, degenerative uncalcified, and degenerative calcified menisci. In contrast, PC-1 expression was only robust at sites of apoptotic cells and calcification in central regions of degenerative menisci. Only PC-1 was abundant at the perimeter of meniscal cells and in association with meniscal cell-derived matrix vesicles (MVs). Because each PDNP-family isozyme was expressed by cells near calcifications, we transfected the isozymes in nonadherent knee meniscal cells cultured with ascorbic acid, beta-glycerophosphate, and dexamethasone supplementation to stimulate them to calcify the matrix. PC-1, but not ATX or B10/PDNP3, consistently promoted increased MV NTPPPH, MV-associated PPi, and extracellular PPi. PC-1 also increased matrix calcification (with hydroxyapatite crystals) by meniscal cells. ATX uniquely induced alkaline phosphatase activity, but promoted only moderately increased matrix calcification. CONCLUSION: We identified divergent effects of 3 PDNP-family NTPPPH isozymes on meniscal cell matrix calcification. Increased expression of PC-1 is both a marker and a potential pathogenic factor for knee meniscal cartilage matrix calcification.

Aging↗
PubMed1994

Elastic extracellular matrix of the embryonic chick heart: an immunohistological study using laser confocal microscopy.

The "elastic matrix" constitutes a specialized component of the extracellular matrix which confers resiliency to tissues and organs subjected to repeated deformations. The role of the elastic matrix in living organisms appears to be of key importance since diseases characterized by expression of defective inherited genes which encode components of the elastic matrix lead to premature death. While the elastic matrix of adult organs has received a great deal of attention, little is known about when it first appears in embryonic tissues or its possible role in developing organs. In the present study we have performed an immunohistochemical study of the distribution of elastin and three additional components often associated with elastic matrices in adult tissues (i.e., fibrillin, emilin, and type VI collagen) during the development of the chicken embryonic heart. The three-dimensional arrangement of these components was established through the observation of whole-amount specimens with scanning laser confocal microscopy. Our results revealed three different periods of heart development regarding the composition of the elastic matrix. Prior to stage 21 the embryonic heart lacks elastin but exhibits a matrix scaffold of fibrillin and emilin associated with the endocardium and the developing cardiac jelly. Between stages 22 and 29 the heart shows a transient elastic scaffold in the outflow tract which contains elastin, fibrillin, and emilin. Elastin-positive fibrillar material is also observed during these stages in the base of the atrioventricular cushion adjacent to the myocardial wall. In addition, emilin-positive material appears to be associated with the zones of formation of ventricular trabeculae. Collagen type VI was not detected during these early stages. From stage 30 to stage 40 a progressive modification of the pattern of distribution of elastin, fibrillin, emilin, and collagen type VI is observed in association with the formation of the definitive four-chambered heart. The distribution of the elastic scaffold in the outflow tract appears to be rearranged and becomes restricted to the roots of the main arteries. Each of the components studied here is also deposited at increasing levels in the developing valvular apparatus including the valve leaflets and the chordae tendinea. The components are also present in the subendocardial space where they form aligned fibrillar tracts, an arrangement suggestive of a role in ventricular contractile function. The epicardium constitutes an additional region of elastic matrix deposition during these later stages and contains elastic, fibrillin, and collagen type VI.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1993

Immunolocalization of noncollagenous bone matrix proteins in lumbar vertebrae from intact and surgically menopausal cynomolgus monkeys.

The noncollagenous matrix proteins, composing about 10% of the organic matrix of bone, are considered important for cell matrix organization and regulation of mineralization in bone. In the present study, seven of the major noncollagenous bone matrix proteins were localized immunohistochemically in serial sections of lumbar vertebrae from 24 (12 intact and 12 ovariectomized) adult female cynomolgus monkeys (Macaca fascicularis). Osteocalcin was the only protein restricted to bone cells and mineralized bone matrix. Bone sialoprotein was present in both bone and calcified cartilage, and all the other proteins were distributed in soft tissues as well as bone. Staining for both osteocalcin and bone sialoprotein was present diffusely throughout the bone matrix, but osteonectin, osteopontin, matrix gla protein, decorin, and biglycan staining was concentrated along bone surfaces. Osteoid was negative for osteocalcin and bone sialoprotein, but all other proteins had areas of positive immunostaining within osteoid. All proteins except biglycan exhibited strong immunostaining of a subset of active osteoblasts, suggesting that they may be markers of osteoblast maturity or state of activation. The pattern of immunostaining in intact and surgically menopausal monkeys was similar, except that staining for matrix proteins concentrated along bone surfaces appeared to be more widely distributed in the surgically menopausal monkeys, probably due to the higher rate of bone formation in these animals.

Animals↗
PubMed2003

Endothelial cell-matrix interactions.

Dynamic interactions between endothelial cells and components of their surrounding extracellular matrix are necessary for the invasion, migration, and survival of endothelial cells during angiogenesis. These interactions are mediated by matrix receptors that initiate intracellular signaling cascades in response to binding to specific extracellular matrix molecules. The interactions between endothelial cells and their environment are also modulated by enzymes that degrade different matrix components and thus enable endothelial invasion. Recent reports on gene targeting in mice have confirmed the role of two classes of matrix receptors, integrins and cell surface heparan sulfate proteoglycans, and a group of matrix degrading proteolytic enzymes, matrix metalloproteinases, in angiogenesis. The significance of endothelial cell-matrix interactions is further supported by several ongoing clinical trials that analyze the effects of drugs blocking this interaction on angiogenesis-dependent growth of human tumors.

Animals↗
PubMed1997

Interaction of matrix metalloproteinases-2 and -9 with pregnancy zone protein and alpha2-macroglobulin.

The binding of matrix metalloproteinases-2 and -9 to pregnancy zone protein and alpha2-macroglobulin was studied. The binding was demonstrated by formation of dimeric as well as tetrameric complexes of pregnancy zone protein and by the formation of alpha2-macroglobulin complexes with fast and intermediate mobility in native gel electrophoresis. The complex formation was confirmed by the use of 125I-labeled matrix metalloproteinase-2. The cleavage sites in the "bait" regions following formation of high-molecular-weight complexes of matrix metalloproteinases with the alpha-macroglobulins were determined by protein sequence analysis. Pregnancy zone protein was cleaved at Thr693-Tyr694 and alpha2-macroglobulin at Gly679-Leu680 and Arg696-Leu697 by matrix metalloproteinase-2. Matrix metalloproteinase-9 cleaved alpha2-macroglobulin at the same site as matrix metalloproteinase-2, but cleavage of pregnancy zone protein was at Leu753-Ser754. The sequences of the bands, visualized in the SDS gel, of approximately 90 and 165 kDa or higher molecular weight complexes were the same. This indicates that the matrix metalloproteinases cleaved the inhibitors with or without binding to them. The present results suggest that matrix metalloproteinases-2 and -9 may interact with pregnancy zone protein and alpha2-macroglobulin in vivo.

Animals↗
PubMed2002

Modeling extracellular matrix degradation balance with proteinase/transglutaminase cycle.

Extracellular matrix mass balance is implied in many physiological and pathological events, such as metastasis dissemination. Widely studied, its destructive part is mainly catalysed by extracellular proteinases. Conversely, the properties of the constructive part are less obvious, cellular neo-synthesis being usually considered as its only element. In this paper, we introduce the action of transglutaminase in a mathematical model for extracellular matrix remodeling. This extracellular enzyme, catalysing intermolecular protein cross-linking, is considered here as a reverse proteinase as far as the extracellular matrix physical state is concerned. The model is based on a proteinase/transglutaminase cycle interconverting insoluble matrix and soluble proteolysis fragments, with regulation of cellular proteinase expression by the fragments. Under "closed" (batch) conditions, i.e. neglecting matrix influx and fragment efflux from the system, the model is bistable, with reversible hysteresis. Extracellular matrix proteins concentration abruptly switches from low to high levels when transglutaminase activity exceeds a threshold value. Proteinase concentration usually follows the reverse complementary kinetics, but can become apparently uncoupled from extracellular matrix concentration for some parameter values. When matrix production by the cells and fragment degradation are taken into account, the dynamics change to sustained oscillations because of the emergence of a stable limit cycle. Transitions out of and into oscillation areas are controlled by the model parameters. Biological interpretation indicates that these oscillations could represent the normal homeostatic situation, whereas the other exhibited dynamics can be related to pathologies such as tumor invasion or fibrosis. These results allow to discuss the insights that the model could contribute to the comprehension of these complex biological events.

Animals↗
PubMed1993

Development of a novel human extracellular matrix for quantitation of the invasiveness of human cells.

During the crucial stages of tumor cell invasion and metastasis, neoplastic cells must traverse extracellular matrices for their migration to distant sites. Because basement membranes (BM) serve as a critical barrier to such passages, most previous in vitro assay models have utilized either an intact BM or a reconstituted rodent or avian BM-matrix to study this process. We have created a gel-like extracellular matrix derived from human amnions which contained type IV collagen, laminin, entactin, tenascin and heparan sulfate proteoglycan. This matrix, which we called Amgel, was used to study selected steps of invasion including cell attachment to matrix, degradation of it by proteolytic enzymes and movement of human tumor cells through matrix defects. An efficient tumor invasion assay system was developed utilizing filter-supported uniform coatings of this matrix in chambers. Human tumor cells (HT-1080 fibrosarcoma and RL-95 adenocarcinoma), when seeded onto Amgel-coated membranes, attached to matrix within 2 h and initiated a time-dependent migration and invasion process, as verified by biochemical analysis and both light and electron microscopy. In an optimized invasion assay 12-15% of tumor cells completely traversed the matrix during a 72-h period with > 90% viability. In contrast to these highly-invasive cells, normal human foreskin fibroblasts and normal human endometrial stromal cells exhibited minimal migration/matrix penetration during the same time period. When the Amgel-selected tumor cells (i.e. those penetrating the barrier) were isolated, subcultured, and re-exposed to Amgel, they had heightened invasiveness (2-3-fold) as compared to the parental cells. Thus, this improved 'all human' system for quantitating the invasive ability of tumor cells may provide a valuable tool in dissecting out the mechanistic underpinnings of human metastasis. In addition, this assay has the ability to screen agents which have potential anti-invasive and by extension anti-metastatic, activity or chemotactic properties.

Basement Membrane↗
PubMed2005

Matrix metalloproteinase induction in post-transplant obliterative bronchiolitis.

BACKGROUND: Epithelial cell injury, inflammation, fibrosis, and airway obliteration are associated in post-transplant obliterative bronchiolitis. Fibrosis is a consequence of fibroblastic activity and of collagen deposition after disturbances in the balance of protein formation and degradation. Proteolytic enzymes such as the matrix metalloproteinases mediate degradation. To assess matrix metalloproteinases during obliterative bronchiolitis development, we studied porcine, heterotopic bronchial allografts. METHODS: A total of 119 allografts or autografts were harvested serially at 3 to 60 days after transplantation and processed for histology and in situ hybridization for matrix metalloproteinases 2 and 9. Immunocytochemistry for vimentin and alpha-smooth-muscle-cell actin was performed with specific antibodies. RESULTS: Implants had initial ischemic injury to airway epithelium and to the bronchial wall. Recovery was rapid in autografts and in immunosuppressed allografts. In matrix metalloproteinase-2 mRNA activity in fibroblasts, correlation with endothelial expression and expression in macrophages occurred during intense fibroproliferation. We observed intense matrix metalloproteinase-9 positivity during onset of inflammation and fibroproliferation in endothelial cells (p < 0.01), fibroblasts (p < 0.05), macrophages (p < 0.05), and lymphocytes (p < 0.05). Matrix metalloproteinase-9 mRNA activity in fibroblasts correlated with that in endothelial and inflammatory cells and also proved predictive of early obliteration. CONCLUSIONS: Matrix metalloproteinase-2, and especially matrix metalloproteinase-9, gene activity was associated with onset of inflammation and fibroblastic proliferation in allografts, predicting early obliteration. Although this may be the case in the model described, its role in human-allograft post-transplant obliterative bronchiolitis requires further supportive data.

Animals↗
PubMed2005

Cell transplantation preserves matrix homeostasis: a novel paracrine mechanism.

OBJECTIVES: Cell transplantation prevents chamber dilatation, but the underlying molecular mechanisms remain undefined. Structural cardiac remodeling involves matrix degradation from an imbalance of matrix metalloproteinases (MMP) relative to endogenous tissue inhibitors of metalloproteinases (TIMP). We aimed to determine the capacity of cell transplantation to alter extracellular matrix in the failing heart and, in so doing, identify novel paracrine molecular mediators underlying the beneficial effects of cell transplantation on chamber dilatation. METHODS: Smooth muscle cells were transplanted to the dilating left ventricle of cardiomyopathic hamsters (CTX, n = 15) compared with age-matched media-injected cardiomyopathic (CON, n = 15) and normal hamsters (n = 7). After 5 weeks, left ventricular volume was measured by computerized planimetry. Fibrillar collagen was examined by confocal microscopy. Matrix homeostasis was quantified by measuring MMP/TIMP expression/activity relative to myocardial collagen synthesis (14C-proline uptake). RESULTS: Left ventricular dilatation was attenuated in CTX hearts (P = .02). CTX restored perimysial collagen fiber content and architecture to normal levels. TIMP-2 and TIMP-3 expression were enhanced in CTX (TIMP-2, 195% +/- 42% of CON, P = .02; TIMP-3, 118% +/- 3% of CON, P = .002), and correspondingly, gelatinase MMP-2 activity was reduced (P < .05). The TIMP:MMP ratio was increased in CTX hearts (TIMP-2 to MMP-2, 410% +/- 134% of CON, P = .04, and TIMP-3 to MMP-9, 205% +/- 47% of CON, P = .03), reflecting a reduced capacity for matrix degradation. Collagen synthesis was equivalent (CTX vs CON), suggesting that restored matrix architecture was a function of attenuated matrix degradation. CONCLUSIONS: These data provide the first evidence that cell transplantation limits ventricular dilatation in the failing heart through a paracrine-mediated mechanism that preserves extracellular matrix homeostasis.

Animals↗
PubMed2004

COMP mutations, chondrocyte function and cartilage matrix.

Cartilage oligomeric matrix protein (COMP) is a large extracellular pentameric glycoprotein found in the territorial matrix surrounding chondrocytes. More than 60 unique COMP mutations have been identified as causing two skeletal dysplasias, pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED/EDM1). Recent studies demonstrate that calcium-binding and calcium induced protein folding differ between wild type and mutant COMP proteins and abnormal processing of the mutant COMP protein causes the characteristic large lamellar appearing rough endoplasimic reticulum (rER) cisternae phenotype observed in PSACH and EDMI growth plate chondrocytes. To understand the cellular events leading to this intracellular phenotype, PSACH chondrocytes with a G427E, D469del and D511Y mutations were grown in 3-D culture to produce cartilage nodules. Each nodule was assessed for the appearance and accumulation of cartilage-specific proteins within the rER and for matrix protein synthesis. All three COMP mutations were associated with accumulation of COMP in the rER cisternae by 4 weeks in culture, and by 8 weeks the majority of chondrocytes had the characteristic cellular phenotype. Mutations in COMP also affect the secretion of type IX collagen and matrilin-3 (MATN3) but not the secretion of aggrecan and type II collagen. COMP, type IX collagen and MATN3 were dramatically reduced in the PSACH matrices, and the distribution of these proteins in the matrix was diffuse. Ultrastructural analysis shows that the type II collagen present in the PSACH matrix does not form organized fibril bundles and, overall, the matrix is disorganized. The combined absence of COMP, type IX collagen and MATN3 causes dramatic changes in the matrix and suggests that these proteins play important roles in matrix assembly.

Calcium↗
PubMed2000

Reduction of matrix metalloproteinase-9 activity by the selective phosphodiesterase 4 inhibitor, RP 73-401 in sensitized mice.

Matrix metalloproteinases are particularly potent in degrading basement membrane collagen and other extracellular matrix components. We have investigated the effects of a selective phosphodiesterase 4 inhibitor, RP 73-401 [N-(3, 5-dichloropyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamide], on gelatinase (matrix metalloproteinase-2 and matrix metalloproteinase-9) activity in ovalbumin-sensitized and -challenged mice. Twenty-four hours after the last challenge, matrix metalloproteinase activity was evaluated in the bronchoalveolar lavage fluids by a zymography technique, and a significant increase in matrix metalloproteinase-9, but not matrix metalloproteinase-2, activity was noted. When administered orally (0.3-3 mg/kg) 1 h before each ovalbumin challenge, the selective phosphodiesterase 4 inhibitor, RP 73-401, significantly reduced this increased matrix metalloproteinase-9 activity in bronchoalveolar lavage fluids. Our data suggest that RP 73-401 may modulate tissue remodelling associated with lung inflammatory processes including asthma.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

Immunolocalization and quantification of noncollagenous bone matrix proteins in methylmethacrylate-embedded adult human bone in combination with histomorphometry.

The noncollagenous proteins (NCPs) in the bone matrix comprise growth factors with distinct cellular effects and a series of proteins with less clear biological actions. In order to understand the role of these proteins in bone metabolism and in bone diseases, it is crucial to determine their localization and quantity in normal and pathological bone. We have developed an immunohistochemical method to detect osteopontin, osteocalcin, bone sialoprotein, osteonectin, decorin, biglycan, and the growth factors transforming growth factor-beta, insulin-like growth factor-I, and bone morphogenetic protein-2 both in bone matrix and in bone cells of adult human bone embedded in methylmethacrylate. Immunohistochemistry and standard bone histomorphometry in adjacent sections allows the localization of the proteins to metabolically active sites in bone. The protocol works with several fixatives and with bone specimens obtained and embedded to over 20 years ago. Most importantly, we developed a procedure to specifically stain the mineralized matrix green in combination with a red staining of the NCPs. Using digital image analysis it is possible to quantify the relative amounts of NCPs (microm2 NCP area/microm2 mineralized matrix area). Within one biopsy of normal bone cut at four different heights (at a distance of 100 microm), two adjacent sections were stained either for osteopontin or osteonectin. Thirty trabecular and 20 cortical microscopic fields were measured, and the NCP:mineralized matrix ratio was calculated. Stepwise analysis of the standard error of the mean of the NCP:mineralized matrix ratios showed that measuring about 50 microscopic fields is sufficient to obtain representative data with a small confidence interval. In conclusion, the present procedure enables to quantify NCPs and to relate their presence to metabolically active sites in bone. The quantification provides the opportunity to monitor differences in distribution (e.g., cortical vs. trabecular) and differences between normal and pathological conditions and to assess changes in matrix composition during treatment. This can be done by reanalyzing bone biopsies obtained in the past, e.g., during clinical trials. Therefore, the present technique will be a valuable tool for the study of noncollagenous bone matrix proteins in human bone.

Adult↗
PubMedDate not supplied

Developmental differences in the expression and modulation of extracellular matrix proteases and inhibitors in mouse skin fibroblasts.

To investigate developmental differences in the wound repair process between fetal and adult skin fibroblasts, we studied the expression of plasminogen activator, plasminogen activator inhibitor, matrix metalloproteinase, and tissue inhibitor of metalloproteinase in E-15, E-17, newborn and adult mouse skin fibroblasts cultured within three dimensional matrices of either collagen or fibrin. Fibrin overlay and reverse overlay analyses revealed that mouse skin fibroblasts secreted tissue plasminogen activator and type1 plasminogen activator inhibitor. However, only E-15 and E-17 fibroblasts secreted the active form of tissue plasminogen activator, while in newborn and adult fibroblasts tissue plasminogen activator was conjugated to type1 plasminogen activator inhibitor. Only adult fibroblasts expressed a high level of active type1 plasminogen activator inhibitor. Gelatin zymography revealed that the predominant matrix metalloproteinase secreted by all the mouse fibroblasts was gelatinase A (matrix metalloproteinase -2). Matrix metalloproteinase -2 was partially activated in the adult fibroblasts cultured within a collagen matrix. The tissue inhibitor of metalloproteinase-2 was expressed by all fibroblasts, but levels were highest in the newborn and adult fibroblasts. When E-15 fibroblasts were cultured within a fibrin matrix, tissue plasminogen activator was downregulated. Transforming growth factor-betadownregulated tissue plasminogen activator while upregulating type1 plasminogen activator inhibitor, and platelet-derived growth factor enhanced tissue plasminogen activator expression in E-15 fibroblasts. Therefore, plasminogen activator and its inhibitor, and matrix metalloproteinase and its associated tissue inhibitor are differentially expressed in fetal and adult fibroblasts, and their expression is controlled by extracellular matrix components and growth factors present in wounds.

Animals↗
PubMed2003

Increased matrix metalloproteinase activity after canine cardiopulmonary bypass is suppressed by a nitric oxide scavenger.

OBJECTIVES: We tested whether nitric oxide scavenging with a ruthenium-based compound (AMD6221) would improve hemodynamics and alter nitric oxide synthase and matrix metalloproteinase activities in a canine model of cardiopulmonary bypass. METHODS: Dogs were randomized to either cardiopulmonary bypass (n = 12) or control (n = 12) groups. They were further randomized to receive a continuous infusion of AMD6221 or placebo. Cardiopulmonary bypass was maintained for 90 minutes, and then, 4 hours later, dogs were killed. Cardiac, lung, and brain sections were snap frozen in liquid nitrogen for determination of nitric oxide synthase, matrix metalloproteinase 2, and matrix metalloproteinase 9 activities. RESULTS: After cardiopulmonary bypass, 3 of 6 placebo-treated (cardiopulmonary bypass-placebo) and 0 of 6 AMD6221-treated (cardiopulmonary bypass-6221) animals required phenylephrine infusion to maintain a predetermined blood pressure (P <.05). Total fluid administration was lower in the cardiopulmonary bypass-6221 group compared with that in the cardiopulmonary bypass-placebo group (983 +/- 134 vs 1617 +/- 254 mL, respectively; P <.005). After cardiopulmonary bypass, matrix metalloproteinase 2 and matrix metalloproteinase 9 activities in the lung, left ventricle, and left atrium were decreased in the cardiopulmonary bypass-6221 group compared with that in the cardiopulmonary bypass-placebo group (P <.05). Ca(2+)-independent nitric oxide synthase activity and matrix metalloproteinase 2 activity in the brain were also lower (P <.05) in the cardiopulmonary bypass-SCV group. Finally, neutrophil expression of CD18, an adhesion complex, was lower at 4 hours after cardiopulmonary bypass in the cardiopulmonary bypass-6221 group compared with that in the cardiopulmonary bypass-placebo group (38 +/- 27 vs 81 +/- 11; P <.05). CONCLUSIONS: We found that (1) infusion of an nitric oxide scavenger, AMD6221, was associated with improved predefined hemodynamics; (2) cardiopulmonary bypass increased activities of Ca(2+)-independent nitric oxide synthase and matrix metalloproteinases in multiple organs; and (3) AMD6221 could ameliorate the increased generation of nitric oxide and increased matrix metalloproteinase activities.

Animals↗
PubMed2006

Analysis of two polymorphisms in the promoter region of matrix metalloproteinase 1 and 3 genes in women with endometriosis.

BACKGROUND: Matrix metalloproteinases are a family of proteolytic enzymes that can degrade extracellular matrix components and have been implicated in connective tissue remodeling associated with cancer invasion and metastasis. These proteins are also involved in the invasive events underlying endometriotic lesion formation and aggressive behavior. Given the established genetic background of endometriosis, the aim of this study was to examine the potential impact of two polymorphisms in the gene promoter region of two of these enzymes, matrix metalloproteinases 1 and 3, on predisposition and severity of the disease. METHODS: Genomic DNA was obtained from 56 Italian Caucasian women with a surgical diagnosis of endometriosis and a control group of 71 age-matched Caucasian healthy female blood donors. In control women, endometriosis was ruled out by evaluation of the medical history, gynecologic examinations, and ultrasound scanning. Two polymorphisms have been specifically investigated: 1. a single insertion polymorphism (2G) in the matrix metalloproteinase-1 promoter region known to elevate transcriptional level of matrix metalloproteinase-1; and 2. a single insertion/deletion polymorphism (5A/6A) located in the promoter of the matrix metalloproteinase-3 gene with functional significance in the regulation of its expression. Genotypes were determined by PCR amplification and sequence analysis. RESULTS: Allele and genotype frequencies of both polymorphisms did not significantly differ between endometriosis and control groups. Moreover, no significant difference for both polymorphisms was observed in relation to the clinical stage and recurrence status of the disease. CONCLUSIONS: This is the first study that has evaluated the possibility that gene variants of matrix metalloproteinases might be involved in the susceptibility to endometriosis. However, these results suggest that matrix metalloproteinases 1 and 3 promoter polymorphism do not constitute an important factor for the genetic predisposition to endometriosis and its invasive behavior in the Italian population.

Adult↗
PubMed2005

High rate of joint capsule matrix turnover in chronic human elbow contractures.

The joint capsule is a key component in posttraumatic joint contractures. The capsule is described as thickened, but little data exist supporting the observation. Our hypotheses were that mRNA levels of (1) collagen; (2) decorin and biglycan; (3) matrix metalloproteinases; and (4) tissue inhibitors of matrix metalloproteinases were significantly elevated in anterior joint capsules obtained from 11 patients having surgery for posttraumatic contractures when compared with nine elbows, from organ donors, that were free of contractures. Reverse transcription-polymerase chain reaction was used to evaluate mRNA expression normalized to a housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase. In the joint capsules of the patients with elbow contractures, relative mRNA levels were increased for: collagen Types I, III, and V (1.5-2.5 times); biglycan (1.5 times); and matrix metalloproteinases-1, -2, -9, -13, and -15 (1.6-3.9 times). In contrast, expression of tissue inhibitors of matrix metalloproteinases-1, -2, and -4 were decreased (1/3-3/4 times) in the capsules of patients with contractures. There was no difference between the groups in relative mRNA expression for decorin, matrix metalloproteinases-8, -14 and -16, and tissue inhibitor of matrix metalloproteinase-3. The results indicate that joint capsule matrix molecule mRNA levels are altered in the chronic stages of posttraumatic elbow contractures in humans, potentially creating an environment with high matrix turnover rates.

Adolescent↗