SEARCH · PubMed Health

Results for “Matrix Metalloproteinase 2”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 73 records · Page 4Linked to original sources

PubMedDate not supplied

Expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinase 1 and 2 in inflammation-induced corneal neovascularization.

PURPOSE: Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) have been linked to the angiogenic process in general. In order to understand the potential roles of MMP-2, MMP-9 and TIMPs in the corneal neovascularization process, we examined the expression and activities of MMP-2, MMP-9 and TIMPs during the course of cauterization-induced corneal neovascularization in a rat model. METHODS: Neovascularization of rat corneas was induced by silver nitrate cauterization. The expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 was examined by immunohistochemistry and RT-PCR. The protein activities of MMPs and TIMPs were compared in pre- and postcauterization corneas by gelatin zymography and reverse zymography, respectively. RESULTS: MMP-2, TIMP-1 and TIMP-2 immunoreactivities were expressed in normal corneas, predominantly in the corneal epithelium. After injury, immunoreactivities of both MMPs and TIMPs were increased, notably in the healing corneal epithelium, infiltrating inflammatory cells, stromal fibroblasts and ingrowing vascular endothelial cells. The increase in gross MMP-2 enzymatic activity paralleled the maximal vascular ingrowth on day 4, while the gross MMP-9 enzymatic activity rose immediately on day 1, then decreased steadily, which paralleled the magnitude of inflammatory cell infiltration. The immunoreactivity of MMPs/TIMPs decreased significantly 2 weeks after cauterization. On day 35, MMP-2, TIMP-1 and TIMP-2 staining was seen only in corneal epithelium and vascular endothelial cells. Both the RT-PCR and reverse zymography results revealed a more constant expression of TIMP-2, while the TIMP-1 expression appeared to be more inducible. CONCLUSION: MMPs as well as TIMPs were upregulated in cauterization-induced corneal neovascularization, suggesting that both may participate in extracellular matrix remodeling in the corneal wound healing, inflammation and neovascularization processes.

Animals↗

PubMed2006

The involvement of matrix metalloproteinases 2 and 9 in rat retinal ischemia.

BACKGROUND: The involvement of matrix metalloproteinases (MMPs) in ischemic tissue damage and remodeling has been reported by many investigators. Our study was designed to investigate the involvement of MMPs and of tissue inhibitors of metalloproteinases (TIMPs) in rat retinal ischemic injury, the effect of nitric oxide synthase (NOS) inhibitors on MMPs' activity in this model and whether minocycline (an MMP inhibitor) is protective in retinal ischemia. METHODS: Ninety-four rats were used in the study. Ischemia was induced by 90 min elevation of intraocular pressure. MMPs' activities and the effect of NOS inhibitors [aminoguanidine (AG) or N-nitro-L-arginine (NNA)] and minocycline on MMPs' activities were assessed by zymography and TIMPs expression by Western analysis. Morphological damage was quantified by morphometry of hematoxylin and eosin-stained retinal sections. RESULTS: Retinal extracts exhibited activities of proMMP-9 and proMMP-2. The activity of proMMP-9 increased immediately post ischemia (PI) and peaked to 4.6 times that of normal untreated controls in ischemic retinas and to 2.6 times that of controls in retinas of fellow sham-treated eyes at 24 h PI. The relative amount of TIMP-1 increased to 1.9-fold following ischemia and 2.5-fold in fellow sham-treated eyes at 24 h PI. ProMMP-2 activity increased more than two-fold immediately, at 24 h and at 48 h PI in ischemic retinas, and insignificantly in fellow sham-treated eyes. Treatment with 25 mg/kg AG or NNA caused a non-significant increase in proMMP-9 activity at 24 h PI (3.7- and 2.9-fold, respectively, p>0.6). There was no effect of AG or NNA on the activity of proMMP-2. Minocycline significantly attenuated the retinal ischemic damage, primarily by partially preserving ganglion cells and the inner plexiform layer. Minocyline (0.5 mg/ml or 5 mg/ml) inhibited MMPs' activities in ischemic retinal extracts in vitro. CONCLUSIONS: MMPs participated in morphological ischemic damage to rat retina. Treatment with minocycline dramatically attenuated damage to the retina.

Animals↗

PubMed1999

Expression of matrix metalloproteinase 2 (MMP-2), membrane-type 1 MMP and tissue inhibitor of metalloproteinase 2 and activation of proMMP-2 in pancreatic duct adenocarcinomas in hamsters treated with N-nitrosobis(2-oxopropyl)amine.

In order to assess the significance of changes in metalloproteinase activity in pancreatic carcinogenesis, the expression of matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9, respectively), tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and membrane-type 1 MMP (MT1-MMP) and MT2-MMP in ductal lesions in a rapid-production model for pancreatic duct carcinomas (PCs) in hamsters initiated with N-nitrosobis(2-oxopropyl)amine (BOP) and in subcutaneous transplantable tumors of hamster pancreatic duct carcinoma (HPDs) was investigated. Northern analysis revealed MMP-2, MMP-9, TIMP-2 and MT1-MMP mRNAs to be overexpressed in PCs. Immunohistochemically, elevated levels of MMP-2 were apparent in early duct epithelial hyperplasias and staining increased from atypical hyperplasias to carcinomas. Gelatin zymography demonstrated clear activation of proMMP-2 but not proMMP-9 in both of primary and HPD tumors, the MT1-MMP mRNA level and proMMP-2 activation being significantly correlated (r = 0.893, P < 0.001). In our rapid production model, 0.1 and 0.2% OPB-3206, an inhibitor of MMPs, given in the diet after two cycles of augmentation pressures for 48 days decreased the incidence and number of carcinomas. Gelatin zymography demonstrated that OPB-3206 inhibited activation of proMMP-2 in pancreatic cancer tissues. These results indicate that overexpression of MMP-2, TIMP-2 and MT1-MMP, and cell surface activation of proMMP-2 by MT1-MMP, are involved in the development of PCs, and that MMP-2 expression at the protein level appears in the early phase of pancreatic duct carcinogenesis. OPB-3206 may be a candidate chemopreventive agent for pancreatic ductal adenocarcinomas.

Adenocarcinoma↗

PubMed2003

Matrix metalloproteinase 2 and 9 activity in patients with colorectal cancer liver metastasis.

BACKGROUND: Matrix metalloproteinases (MMPs) have been reported to play an important role in tumour cell invasion and metastasis. The bioactivity of MMPs in liver metastasis from colorectal cancer was investigated and correlated with clinicopathological variables. METHOD: Thirty-two patients underwent resection of colorectal cancer liver metastases. Latent and active forms of MMP were measured in tissue extracts, by means of quantitative gelatin zymography and a fluorometric activity assay. RESULTS: Broad-spectrum MMP activity, and levels of both active and latent forms of MMP-2 and MMP-9, were higher in tissues containing metastatic tumour than in normal liver tissue. Median metastatic to normal tissue ratios were 15.0 and 17.6 for active and proMMP-2 respectively, and those for active and proMMP-9 were 6.2 and 2.9. The ratios of active to latent enzyme were higher in metastatic tissue than in normal tissue. Lowered MMP-2 activity was associated with large metastatic lesions and increased proMMP-9 levels with preoperative chemotherapy. Both MMP-2 and MMP-9 activity were linked unfavourably to early recurrent disease. CONCLUSION: These data suggest a role for MMPs in colorectal cancer liver metastasis, but indicate different roles for individual MMPs.

Colorectal Neoplasms↗

PubMed1999

Matrix metalloproteinase 2 (gelatinase A) is related to migration of keratinocytes.

The role of matrix metalloproteinases (MMPs) in cell migration was studied by measuring cell growth, migration, and production of MMP-2 and -9 in oral mucosal and skin keratinocytes cultured in the presence of synthetic MMP inhibitors. MMP-2 was the major gelatinolytic MMP produced by these cells while MMP-9 was produced at a low basal level. Inhibitor effects on MMP-9 production were therefore studied in keratinocytes stimulated by tumor necrosis factor alpha (TNFalpha). Tetracycline analogues at concentrations that inhibited the production of MMP-2 but not MMP-9 were able to drastically inhibit migration of both mucosal and skin keratinocytes. Tetracycline analogues also inhibited keratinocyte growth, an effect not found for the other inhibitors tested. Heterocyclic carbonate-derived compounds (LWs) that inhibited MMP-9 but not MMP-2 production had no effect on cell migration. Batimastat, a potent MMP inhibitor, did not have any effect on MMP production or cell growth but did inhibit keratinocyte migration. Tumor growth factor beta (TGFbeta) increased keratinocyte migration as well as both cell-associated and secreted MMP-2 production in wounded cell cultures. The secreted enzyme was partially converted into an active form. In this model batimastat totally blocked TGFbeta-promoted keratinocyte migration. Immunostaining of keratinocytes advancing into the wound revealed that MMP-2 was localized in extracellular matrix contactlike structures against the endogenously produced laminin-5-rich matrix. MMP-9 was localized diffusely along the cell membranes. Using in situ hybridization we observed that in chronically inflamed human gingiva MMP-2 is expressed in epithelium extending into subepithelial connective tissue. These results suggest that MMP-2 plays a specific role in epithelial migration, possibly by detaching the advancing cells from the pericellular matrix or by activating other MMPs.

Cell Adhesion Molecules↗

PubMed2001

Increased expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinases 1 and 2 correlate with poor prognostic variables in renal cell carcinoma.

PURPOSE: Matrix metalloproteinases (MMPs) degrade components of the extracellular matrix and are implicated in tissue remodeling and tumor infiltration. Tissue inhibitor of metalloproteinases (TIMPs) inhibit enzymes of the MMP family and preserve stromal integrity, thus inhibiting tumor migration. Although numerous studies on several human carcinomas have demonstrated a role for MMPs in tumor metastasis and patient survival, their prognostic role in patients with renal cell carcinoma (RCC) has not been well defined. More importantly, the recently documented paradoxical functions of TIMPs have not been characterized in these neoplasms. EXPERIMENTAL DESIGN: Five-microm, formalin-fixed, paraffin-embedded tissue sections from 153 RCCs were immunostained using specific antibodies against MMP2, MMP9, (Novocastra, Burlingame, CA) TIMP1, and TIMP2 (NeoMarkers, Fremont, CA) proteins. Immunostaining was semiquantitatively scored based on intensity and distribution, and results were correlated with histological and prognostic variables. RESULTS: The rates of increased expression of MMPs and TIMPs in RCC were as follows: MMP2, 67%; MMP9, 43%; TIMP1, 46%; and TIMP2, 73%. Each of these four markers individually correlated with histological tumor type with a vast majority of papillary and sarcomatoid RCCs expressing these proteins as compared with clear cell tumors (P range, 0.0001-0.003). Significant coexpression of MMPs and TIMPs was observed (P = 0.0001). Increased immunoreactivity for each of these proteins correlated with high tumor grade (P range, 0.0001-0.01). On univariate analysis, expression of each of these markers correlated with shortened survival (P range, 0.004-0.05). On multivariate analysis, including tumor grade, stage, and all four markers, only advanced stage (P = 0.047) and increased TIMP1 expression (P = 0.007) independently predicted shortened survival. CONCLUSION: Increased expression of MMP2, MMP9, TIMP1, and TIMP2 proteins in RCCs correlate with poor prognostic variables including shortened patient survival. The paradoxical poor prognostic implication of TIMP overexpression complements the recently documented dual function of TIMPs and warrants further investigation.

Carcinoma, Renal Cell↗

PubMed2005

Difference in progesterone-receptor isoforms ratio between early and late first-trimester human trophoblast is associated with differential cell invasion and matrix metalloproteinase 2 expression.

The expression profile of the progesterone-receptor isoforms and progesterone regulation of matrix metalloproteinase 2 (MMP2) were investigated in early and late first-trimester trophoblast cells. Human trophoblast cells were obtained from legal abortions (6-12 wk of gestation). Purity of 95-98% was verified using immunohistochemistry with specific antibodies. Evaluation of cell count was performed with XTT Reagent kit, and invasion was tested using Matrigel invasion assay. Zymography was used to detect proteolytic activity, and Western blot immunoassay was used to study protein concentration. Gene expression of PGRB, PGR, and MMP2 was studied using reverse transcription-polymerase chain reaction with the housekeeping gene GAPDH used for normalization. Promoter activity was determined using luciferase reporter assay. Differential progesterone-receptor profile was documented with the dominance of PGRB in early trophoblast and the dominance of PGRA in late trophoblast. This differential profile is compatible with the inverse effect of progesterone on the two cell populations, decreasing invasion and gelatinase expression in the early first-trimester trophoblast and increasing invasion and gelatinase expression in the late first-trimester trophoblast. A decrease in MMP2 promoter activity in early trophoblast cells exposed to progesterone suggests that MMP2 expression is regulated by progesterone at the transcriptional level as well. Early trophoblast cells transfected with expressing vector for PGR encoding PGRA revealed less MMP2 activity and reversal of its response to progesterone similar to the effect observed in late trophoblast cells.

Embryo Implantation↗

PubMed2001

Serum levels of matrix metalloproteinase 2 in patients with breast cancer.

Matrix metalloproteinases (MMPs) have been reported to be associated with invasive and metastatic behaviors of human malignant tumors. However, there is still limited knowledge about the role of matrix metalloproteinases-2 (MMP-2) in breast cancer. This study was designed with the aim to elucidate the possible relationship between the preoperative circulating MMP-2 and breast cancer. Fifty-seven consecutive patients with invasive breast cancer undergoing surgery were prospectively included and evaluated. Venous blood samples were collected before the surgery. Sera were obtained by centrifugation, and stored at -70 degrees C until assayed. The control group consisted of 12 patients with benign breast tumor (six with fibrocystic disease and six with fibroadenoma). Serum concentrations of MMP-2 were measured by the quantitative sandwich enzyme immunoassay technique. The data on primary tumor stage, age, estrogen receptor, lymph node status, and TNM staging were reviewed and recorded. The mean value of serum MMP-2 in patients with invasive breast cancer was 694.3+/-140.5 ng/ml and those of control group were 593.3+/-134.0 ng/ml and the difference was significant (P=0.026). Furthermore, there were significantly higher serum levels of MMP-2 in the patients with more advanced primary tumor staging (P=0.005), in the patients with more advanced lymph node status(P=0.011) and in the patients with more advanced TNM staging (P<0.001). In multivariate analysis, TNM staging (P<0.001) appeared as independent factor regarding the significant higher serum levels of MMP-2. Patients with more advanced TNM staging were shown to have higher serum MMP-2 levels. Thus preoperative serum MMP-2 levels might reflect the severity of invasive breast cancer and deserve further evaluation.

Adult↗

PubMed2003

Role of matrix metalloproteinases 2 and 9 in determination of invasive potential of pancreatic tumors.

Our findings indicate that expression of matrix metalloproteinase-2 is an important prognostic marker of invasive potential of pancreatic tumors. Expression of this marker in neuroendocrine tumors (particularly in gastrinomas) can be used as a differential diagnostic criterion characterizing more malignant phenotype of tumors with the presence of ductal component. On the contrary, weak expression matrix metalloproteinase-9 is characteristic of less invasive phenotype of tumor cells (neuroendocrine and solid pseudopapillary tumors, mucinous cystadenomas). Co-expression of matrix metalloproteinases 2 and 9 is an unfavorable prognostic sign.

Adenocarcinoma↗

PubMed1998

Matrix metalloproteinases 2 and 9 in canine rheumatoid arthritis.

Matrix metalloproteinases (MMPs) are considered important mediators of tissue damage in joint diseases. The levels of MMPs 2 and 9 were measured in samples of synovial fluid from 20 joints in seven dogs with rheumatoid arthritis by gelatin zymography. The results were compared with the actual gelatinolytic activity of the fluid measured in a gelatin-degradation ELISA. The gelatinolytic activity in synovial fluid from arthritic joints was markedly greater than that in fluid from disease-free joints. The zymographic activity attributable to MMP-9 (identified by Western blotting) was absent from synovial fluid from control joints but prominent in fluid from arthritic joints, and in these joints the presence of a 75 kDa form of MMP-9 was correlated with the gelatinolytic activity of the fluid measured by the ELISA (r = 0.81, P < 0.05). Synovial fluid from one dog with rheumatoid arthritis was examined before and after treatment with corticosteroids. After treatment its zymographic pattern had returned to normal.

Adrenal Cortex Hormones↗

PubMed2002

Matrix metalloproteinases 2 and 9 work in concert to produce aortic aneurysms.

Matrix metalloproteinases (MMPs) 9 and 2 are increased in human abdominal aortic aneurysm (AAA) tissue, but their precise role and potential interaction remain unclear. Experimental induction of aortic aneurysms in mice genetically deficient in these peptidases could provide new insight into AAA pathogenesis. Mice deficient in the expression of MMP-9 (MMP-9KO) or MMP-2 (MMP-2KO) and their corresponding wild-type background mice (WT) underwent AAA induction by abluminal application of calcium chloride (CaCl(2)). No aneurysm formation was observed at 10 weeks after treatment in either the MMP-9KO or the MMP-2KO mice, whereas the corresponding WT mice showed an average 74% and 52% increase in aortic diameter, respectively. Reinfusion of competent macrophages from the corresponding WT strains into knockout mice resulted in reconstitution of AAA in MMP-9KO but not MMP-2KO mice. These findings suggest that macrophage-derived MMP-9 and mesenchymal cell MMP-2 are both required and work in concert to produce AAA.

Animals↗

PubMed1998

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in loose artificial hip joints.

The role of extracellular matrix metalloproteinase enzymes and the tissue inhibitors of metalloproteinase in the periprostetic connective tissue matrix of loose artificial hip joints is reviewed. In the periprosthetic granulomatous interface connective tissues between bone and implants and inner cellular regenerating pseudocapsular tissues, matrix metalloproteinase 1, matrix metalloproteinase 2, matrix metalloproteinase 3, matrix metalloproteinase-9, and membrane type 1 matrix metalloproteinase enzymes can be shown in the light of immunohistochemistry, enzyme activity analysis, and messenger ribonucleic acid levels. Tissue inhibitors of metalloproteinase 1 and tissue inhibitors of metalloproteinase 2 also are found in the corresponding tissues. Analysis of matrix metalloproteinase and tissue inhibitors of metalloproteinase interaction shows imbalance between the enzymes and the endogenous inhibitors in favor of matrix metalloproteinase. This induces pathologic connective tissue remodeling in the interface and pseudocapsule. The data suggest that matrix metalloproteinase and tissue inhibitors of metalloproteinase system participate in the extracellular matrix degradation and tissue remodeling in artificial hip joints, and may contribute to the periprosthetic weakening, implant loosening, and osteolysis around implants. More evidence for their active involvement is sought by intervention studies with type specific matrix metalloproteinase inhibitors.

Animals↗

PubMed1998

SPARC/osteonectin induces matrix metalloproteinase 2 activation in human breast cancer cell lines.

Activation of the matrix metalloproteinase 2 (MMP-2) has been shown to play a major role in the proteolysis of extracellular matrix (ECM) associated with tumor invasion. Although the precise mechanism of this activation remains elusive, levels of the membrane type 1-MMP (MT1-MMP) at the cell surface and of the tissue inhibitor of MMP-2 (TIMP-2) appear to be two important determinants. Induction of MMP-2 activation in cells cultivated on collagen type I gels indicated that the ECM is important in the regulation of this process. In this study, we show that SPARC/osteonectin, a small ECM-associated matricellular glycoprotein, can induce MMP-2 activation in two invasive breast cancer cell lines (MDA-MB-231 and BT549) but not in a noninvasive counterpart (MCF-7), which lacks MT1-MMP. Using a set of peptides from different regions of SPARC, we found that peptide 1.1 (corresponding to the NH2-terminal region of the protein) contained the activity that induced MMP-2 activation. Despite the requirement for MT1-MMP, seen in MCF-7 cells transfected with MT1-MMP, the activation of MMP-2 by SPARC peptide 1.1 was not associated with increased steady-state levels of MT1-MMP mRNA or protein in either MT1-MMP-transfected MCF-7 cells or constitutively expressing MDA-MB-231 and BT549 cells. We did, however, detect decreased levels of TIMP-2 protein in the media of cells incubated with peptide 1.1 or recombinant SPARC; thus, the induction of MMP-2 activation by SPARC might be due in part to a diminution of TIMP-2 protein. We conclude that SPARC, and specifically its NH2-terminal domain, regulates the activation of MMP-2 at the cell surface and is therefore likely to contribute to the proteolytic pathways associated with tumor invasion.

Amino Acid Sequence↗

PubMed2004

Differential alterations in the expression and activity of matrix metalloproteinases 2 and 9 after transient cerebral ischemia in mice.

Abnormal expression and activity of matrix metalloproteinases (MMPs) may contribute to the pathophysiology of cerebral disease such as ischemic injury. In this study, we compared the cellular localization, expression, and activity of MMP-2 and -9 in relation to the evolution of neuronal damage 24 and 72 h after transient global ischemia. In response to ischemia, there was a generalized increase in cellular MMP-2 immunoreactivity at 24-h reperfusion (in neurons, glia and vessels) whereas at 72-h reperfusion the increase in MMP-2 was predominantly in glia. These glial alterations contributed to a significant increase in pro MMP-2 levels in ischemic regions (P < 0.01) as measured by zymography. In contrast, MMP-9 was predominantly upregulated in neurons and this was significantly different to shams at 24- and 72-h reperfusion after ischemia (P < 0.05). Notably, a dramatic increase in proteolytic activity in neurons was observed 24 h after ischemia and this response was absent at 72 h post-ischemia. The present data are supportive of a role for MMPs in contributing to neuronal injury after ischemia.

Animals↗

PubMed2005

Matrix metalloproteinase 2 may be a marker of microangiopathy in children and adolescents with type 1 diabetes mellitus.

Matrix metalloproteinases (MMPs) 2 and 9 are responsible for extracellular matrix breakdown and their abnormal circulating levels may pre-date clinical evidence of diabetic angiopathy. We detected by ELISA, plasma MMP-2 and MMP-9 levels and associated activity in 25 children and adolescents with T1DM. Thirteen male and 12 female patients were evaluated at the clinical diagnosis and onset of T1DM and again at a 5-year follow-up. Twelve patients had developed microangiopathic complications at the follow-up evaluation. MMP-2 and MMP-9 levels and activity were detected in samples obtained at T1DM diagnosis and at the 5-year follow-up. As controls, 19 healthy subjects who were the same age as the patients were also evaluated at baseline and again after 5 years. MMP-2 levels and activity were significantly higher in the patients than in the controls at disease onset. This was particularly evident when patients who developed microangiopathic complications were compared to controls and patients without complications. At the 5-year follow-up, a significant increase in MMP-2 levels and a significant decrease in MMP-2 activity were found only in the control group compared to the baseline levels. MMP-2 levels and activity were higher in patients with microangiopathy. MMP-9 levels and activity were increased in all groups compared to baseline levels. MMP-9 levels were lower in patients with microangiopathy compared to controls, but no difference was found between the two patient groups. It is well known that MMP-9 is an index of the severity and stability of macroangiopathy while our results allow us to postulate that MMP-2 may be a marker of microangiopathy.

Adolescent↗

PubMed2004

Growth hormone replacement decreases plasma levels of matrix metalloproteinases (2 and 9) and vascular endothelial growth factor in growth hormone-deficient individuals.

BACKGROUND: Matrix metalloproteinases (MMP) are implicated in cardiovascular disease. Growth hormone (GH) deficiency is associated with increased cardiovascular mortality. We assessed whether GH replacement, in GH-deficient adults, has any effect on plasma levels of MMP-2 and MMP-9 and on vascular endothelial growth factor (VEGF), known to activate MMPs. METHODS AND RESULTS: The study comprised 66 GH-deficient adults, 37.8+/-14.7 years of age (37 female). Plasma MMP-2 and MMP-9, VEGF, and insulin-like growth factor-1 (IGF-1) were measured at baseline (V1), at 12 months (V2), and at 24 months of GH treatment (V3). IGF-1 levels rose under GH replacement (mean+/-SD): V1, 151.6+/-91.9 microg/mL; V2, 270.2+/-114.8 microg/mL; and V3, 266.2+/-109.8 (V1 versus V2; P<0.001: V2 versus V3; P=0.76). MMP-9 exhibited the most pronounced and sustained decline from 1248.0+/-651.1 ng/mL at V1, 949.2+/-457.7 ng/mL at V2, and 760.8+/-386.1 ng/mL at V3 (P<0.001 at all time points). A similar pattern was detected for VEGF levels: 358.5+/-209.0 pg/mL at V1, 310.6+/-225.7 pg/mL at V2 (P<0.001), and 283.7+/-202.7 pg/mL at V3 (V2 versus V3; P=0.005). MMP-2 demonstrated a significant decline initially from V1 to V2 (1134.4+/-217.8 ng/mL versus 1074.5+/-203.0 ng/mL, respectively; P=0.031), reaching a plateau at V3 (1072.3+/-220.2 ng/mL) (V2 versus V3; P=0.93). A negative relation existed between MMP-9 versus IGF-1 and MMP-2 versus IGF-1 (P<0.001 and P=0.007, respectively) as well as between VEGF and IGF-1 (P<0.001). CONCLUSIONS: These changes in MMPs and VEGF may contribute to the anticipated reduction in vascular mortality in hypopituitary adults receiving GH replacement.

Adult↗

PubMed2004

Platelet-activating factor (PAF) induces activation of matrix metalloproteinase 2 activity and vascular endothelial cell invasion and migration.

Tumor-induced angiogenic responses lead to complex phenotypic changes in vascular endothelial cells, which must coordinate the expression of both proteases and protease inhibitors prior to the proliferation and invasion of surrounding stroma. Matrix metalloproteinase 2 (MMP2), which degrades Type IV collagen, is produced as proMMP2. proMMP2 is activated in part through its interactions with membrane Type 1 MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase 2 (TIMP2). In this study, we demonstrate that platelet-activating factor (PAF) is a potent inducer of human umbilical vein endothelial cell (HUVEC) migration and invasion, which is attenuated by PAF receptor antagonists, and that PAF receptor antagonists inhibit the migration and invasion of HUVEC mediated by medium conditioned by a prostatic carcinoma cell line. We confirm that PAF receptor antagonists inhibit proliferation of HUVEC grown in rich growth medium. We show that PAF increases mRNA levels for MT1-MMP and TIMP2, followed by increased temporal conversion of latent proMMP2 to MMP2. Finally, we demonstrate that the ratio of MT1-MMP to TIMP2 in membrane preparations from PAF-stimulated HUVEC is 1.6:1, approximating the hypothesized ideal ratio of 2:1 necessary for the conversion of proMMP2 to MMP2. Our data support the involvement of PAF in vascular endothelial cell migration and invasion.

Adenocarcinoma↗

PubMed2000

Thrombospondin type 1 repeats interact with matrix metalloproteinase 2. Regulation of metalloproteinase activity.

Thrombospondins are thought to function as inhibitors of angiogenesis. However, the mechanism(s) of this activity is not well understood. In this study, we have used the yeast two-hybrid system to identify proteins that interact with the thrombospondins 1 (TSP1) and 2 (TSP2) properdin-like type 1 repeats (TSR). One of the proteins identified that interacted with both TSR was matrix metalloproteinase 2 (MMP2). The isolated MMP2 cDNA clone encoded amino acid residues 237-633, which include the fibronectin-like gelatin binding region flanking the catalytic center and the carboxyl hemopexin-like region. Further testing of this clone demonstrated that the TSR interacted with the NH(2)-terminal region of the MMP2 that contains the catalytic domain. The protein interaction observed in yeast was further demonstrated by immunoprecipitation and Western blotting using purified intact TSP1, TSP2, MMP2, and MMP9. Although MMP2 interacted with TSP1 and TSP2 via its gelatin-binding domain or a closely mapping site, neither TSP1 nor TSP2 was degraded by MMP2 in vitro. Tissue culture and in vitro assays demonstrated that the presence of purified TSR and intact TSP1 resulted in inhibition of MMP activity. The ability of TSP1 to inhibit MMP3-dependent activation of pro-MMP9 and thrombin-induced activation of pro-MMP2 suggests that the TSPs may inhibit MMP activity by preventing activation of the MMP2 and MMP9 zymogens.

Animals↗