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Glucose intake induces an increase in activator protein 1 and early growth response 1 binding activities, in the expression of tissue factor and matrix metalloproteinase in mononuclear cells, and in plasma tissue factor and matrix metalloproteinase concentrations.

BACKGROUND: Glucose intake has been shown to cause an increase in intranuclear nuclear factor-kappa B and a decrease in inhibitor kappa B that are consistent with a proinflammatory effect. We investigated the effect of glucose intake on 2 other proinflammatory transcription factors, activator protein 1 (AP-1) and early growth response 1 (Egr-1), and on the genes regulated by them, ie, the genes for matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9) and tissue factor (TF), respectively. OBJECTIVE: The objective of the study was to ascertain whether the intake of 75 g glucose induces an increase in AP-1, Egr-1, and the genes regulated by them. DESIGN: Eight healthy subjects were given 75 g glucose dissolved in 300 mL water to drink. Blood samples were collected before and 1, 2, and 3 h after glucose intake. Four weeks later, the same subjects were given 300 mL water sweetened with saccharine, and blood samples were collected at the same time points. Mononuclear cells (MNCs) were separated, and nuclear fractions were isolated. RESULTS: AP-1 and Egr-1 binding activities were significantly higher 1 and 2 h after glucose intake and then decreased toward the baseline by 3 h. The expression of MMP-2 and TF in MNC homogenates also was significantly higher at 2 and 3 h. Plasma concentrations of MMP-2 were significantly higher at 3 h, whereas those of MMP-9 were significantly higher at 1, 2, and 3 h. In addition, TF was significantly higher at 2 and 3 h. Intake of saccharine-sweetened water had no significant effect on the inflammatory mediators measured in this study. CONCLUSION: Glucose induces proinflammatory changes, including increases in AP-1, Egr-1, MMPs, and TF, the factors that regulate processes that are potentially relevant to atherosclerotic plaque rupture and thrombosis.

Adult↗

Progesterone analogues similarly modulate endometrial matrix metalloproteinase-1 and matrix metalloproteinase-3 and their inhibitor in a model for long-term contraceptive effects.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in normal menstruation, while MMP-1 and MMP-3 production by human endometrial stromal cells (HESCs) is repressed in vitro by progesterone. We postulated that the repression by synthetic progestins of MMP production from HESCs may not be fully maintained in the long term, and that this may account for the disturbed uterine bleeding patterns in women using long-acting progestins. In this study, a long-term HESC culture model was established to compare the effects of natural progesterone and a number of synthetic analogues (ORG2058, medroxyprogesterone acetate, norethindrone acetate, levonorgestrel and drospirenone) on the production by these cells of MMP-1 and MMP-3 and TIMP-1. Zymographic and enzyme-linked immunosorbent analysis of culture medium after 2 weeks showed that both natural progesterone and all of the synthetic progestins tested maintained a significant inhibition of MMP-1 and MMP-3 production. Production of mRNA for MMP-1 and MMP-3 was also suppressed by all progestins, while TIMP production was increased. Thus, menstrual bleeding disturbances which occur during the use of synthetic progestins is not likely to result directly from changes in the effect of long-term progestin exposure on MMP-1 or MMP-3 or TIMP-1 production by HESCs.

Adult↗

Secretion of matrix metalloproteinase-2, matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases into the intrauterine compartments during early pregnancy.

Matrix metalloproteinases (MMPs) are important enzymes in tissue remodelling, a key event for the development of the fetal membranes and placenta and establishing the feto-maternal interface during early pregnancy. This study has examined the secretion of the gelatinases, MMP-2 (72 kDa) and MMP-9 (92 kDa), and the endogenous tissue inhibitors of metalloproteinases (TIMPs) into extra-embryonic coelomic and amniotic fluids, the two principal intra-uterine compartments of the first trimester, and compared them to amniotic fluid collected later in gestation. In extra-embryonic coelomic fluid, gelatin zymography demonstrated that MMP-2 (72 kDa) was the predominant gelatinase, with some MMP-9 present. A broad range of TIMPs corresponding to TIMP-1 and TIMP-2, glycosylated and unglycosylated TIMP-3 and TIMP-4 was detected in this compartment by reverse zymography and immunoblot analyses. There was little gelatinase or TIMP activity in amniotic fluid in the first trimester. In amniotic fluid from the second trimester after fusion of the membranes obliterating the extra-embryonic coelom, and at term elective caesarean section, MMP-2 is the predominant gelatinase present, with a broad spectrum of TIMPs. These findings demonstrate that predominantly MMP-2 and also MMP-9, regulated by a range of TIMPs, are involved in intra-uterine tissue remodelling during the establishment of pregnancy.

Adult↗

Reduction of serum matrix metalloproteinase 1 and matrix metalloproteinase 3 in rheumatoid arthritis patients following anti-tumour necrosis factor-alpha (cA2) therapy.

Matrix metalloproteinase (MMP)-1 and MMP-3 levels were measured in serum samples from rheumatoid arthritis (RA) patients undergoing a double-blinded placebo-controlled trial with the chimaeric anti-tumour necrosis factor (TNF)-alpha antibody cA2. Both MMP-1 (P < 0.015), but to a larger extent MMP-3 (P < 0.001) levels were elevated in all RA patients prior to the commencement of the trial compared with normal control sera. Following cA2 therapy, MMP-1 and MMP-3 levels were assessed in the placebo, and 1 and 10 mg/kg cA2-treated groups at 7, 14, 21 and 28 days. In both the 1 and the 10 mg/kg cA2-treated groups, a significant decrease in serum MMP-3 levels at all time points was observed, reducing maximally to 41% of pre-infusion values at day 7. MMP-1 levels were also reduced, but less dramatically than MMP-3, to 85% of pre-infusion values after 14 days in the 10 mg/kg cA2 treated group. In a separate non-placebo-controlled study, we also evaluated the tissue inhibitor of metalloproteinase (TIMP)-1 levels in plasma following cA2 infusion. Pre-infusion TIMP-1 levels were above the normal control range, but were significantly reduced (P < 0.035) 14 days after infusion to 72% of pre-infusion values. This study confirms previous reports that MMP-3 levels are elevated and correlate with measures of inflammation in RA, and furthermore demonstrate that serum MMP-3 and MMP-1 levels are downmodulated following anti-TNF-alpha antibody therapy. Whilst serum MMP-3 levels correlated with C-reactive protein (CRP) both prior to and following anti-TNF-alpha antibody therapy, it remains to be demonstrated that serum MMP-3 and/or MMP-1 levels reflect the cartilage and bone resorptive processes which are evident in this disease.

Antibodies, Monoclonal↗

Histologic features of venous invasion, expression of vascular endothelial growth factor and matrix metalloproteinase-2 and matrix metalloproteinase-9, and the relation with liver metastasis in pancreatic cancer.

INTRODUCTION: Pancreatic cancer frequently is associated with venous invasion and hematogenous metastasis. AIMS: To determine morphologic features of invaded veins, intratumoral vascular composition, the correlation with liver metastasis, and expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2 and MMP-9, and the mechanism of development of hematogenous metastasis. METHODOLOGY: We examined 32 patients with resected pancreatic cancer: 18 had postoperative liver metastasis, and 14 had no liver metastasis. Specimens were examined to determine the composition of veins and microvessels by staining of victoria-blue and CD34. We also investigated expression of VEGF, MMP-2, and MMP-9 by immunohistochemical staining. RESULTS: Venous invasion was detected in 31 of 32 patients. Invaded venous densities of middle- and large-sized veins were significantly higher in patients with liver metastasis than in those with nonliver metastasis, and they were related to MMP-2 and MMP-9 overexpression. Invaded veins with fragmentation of the lumen through cancer cells were considered to be an intravasation of cancer (destroyed type vein), and their numbers were significantly related to liver metastasis, and MMP-2 and MMP-9 overexpression. CONCLUSION: In conclusion, almost all the patients with pancreatic cancer showed venous invasion, indicating that invasion into large veins and destroyed type veins could be a risk factor for liver metastasis and that increased expression MMP-2 and MMP-9 were related to such invasion.

Adult↗

Interactions of immature human mast cells with extracellular matrix: expression of specific adhesion receptors and their role in cell binding to matrix proteins.

Interactions of cells with their extracellular matrix (ECM) are central to tissue-specific migration, localization, and function of migratory cells. Since mast cells circulate as immature precursor cells and home to tissues in a characteristic distribution, with increases in various disease states, we used the immature human mast cell line HMC-1 as a model to investigate the poorly understood mast cell-ECM interactions in humans. Functional adhesion studies showed that HMC-1 cells spontaneously adhere to fibronectin and laminin (80% at 6 and 12 microgram/ml, respectively) and to collagen type I and III (50% at 20 microgram/ml), whereas binding to vitronectin and collagen type IV required cell activation by phorbol myristate acetate. HMC-1 cells did not adhere to hyaluronic acid. Moreover, both fibronectin and laminin supported pronounced cytoplasmatic spreading with formation of isolated lamellipodia, whereas these cells exhibited a round cell shape on collagen and vitronectin, as shown by scanning electron microscopy. On flow cytometric analysis, HMC-1 cells expressed several adhesion molecules including the integrins beta 1, alpha 2 through alpha 6, alpha v, and alpha v beta 5, as well as CD44. Adhesion to fibronectin and vitronectin was found to be divalent cation- and arginine-glycine-aspartic acid-dependent, and could be blocked by antibodies to beta 1 or alpha 5, and alpha v or alpha v beta 5, respectively. In contrast, binding to laminin and collagen could not be blocked by monoclonal antibodies to any of the cell surface adhesion receptors expressed. Our results show that immature mast cells are able to modify their adhesive behavior in response to various ECM proteins and activating stimuli, and that this phenomenon is partly integrin mediated. These findings may be important for our understanding of the mechanisms leading to tissue-specific localization of mast cells.

Cell Adhesion↗

In vitro induction of matrix metalloproteinase-2 and matrix metalloproteinase-9 expression in keratinocytes by boron and manganese.

Matrix metalloproteinase (MMP)-2 and MMP-9 are involved in keratinocyte migration and granulation tissue remodeling during wound healing. Thermal water cures are sometimes proposed as complementary treatment for accelerating healing of wounds resulting from burns and/or surgery, but their mechanisms of action remain unknown. Some thermal waters are rich in trace elements such as boron and manganese. Interestingly, clinical studies have shown the beneficial effects of trace elements such as boron and manganese for human wound healing. To try to specify the role of trace elements in cutaneous healing, the present study investigated the effects of these trace elements on the production of MMP-2 and MMP-9 by normal human keratinocytes cultured in vitro. Immunohistochemistry and Western blot showed that intracellular MMP-9 expression in keratinocytes was induced when incubated for 6 h with boron at 10 micro g/ml or manganese at 0.2 micro g/ml. Moreover, gelatin zymography on keratinocyte supernatants showed an increase of gelatinase secretion after 24 h of incubation of keratinocytes with boron or manganese, regardless of concentration. Gelatinase secretion was not associated with keratinocyte proliferation induced by trace elements. Thus, our results suggest that boron and manganese could play a role in the clinical efficiency of thermal water on wound healing.

Blotting, Western↗

Levels of matrix metalloproteinases-8 and -9 with simultaneous presence of periodontal pathogens in gingival crevicular fluid as well as matrix metalloproteinase-9 and cholesterol in blood.

BACKGROUND AND OBJECTIVES: To investigate the levels of matrix metalloproteinase (MMP) -8 and -9 with the simultaneous presence of periodontal pathogens in gingival crevicular fluid (GCF) as well as MMP-9 and cholesterol in blood. Although bacterial pathogens are required to initiate the periodontal disease process, in some individuals the reaction to bacteria may lead to an excessive host response, resulting in a general inflammatory response. METHODS: MMP-9 and lipids were analyzed from the blood samples of 33 subjects with a 16-year history and oral health records of periodontal disease as well as from 31 periodontally healthy controls. Information was obtained on education, body mass index, and family history of atherosclerosis. GCF was taken to determine MMP-8 and MMP-9 levels, and bacterial samples were simultaneously collected for polymerase chain reaction assessment of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythia, and Treponema denticola. Analysis of variance, chi-squared test, and multiple logistic regression analysis were used to analyze the results. RESULTS: Demographic data showed significant differences between patients and controls in smoking (P < 0.01), body mass index (P < 0.05), family history of atherosclerotic disease (P < 0.01), and education (P < 0.01). Significant differences were also observed in oral health data, in the detection of P. gingivalis (P < 0.001), P. intermedia (P < 0.01), P. nigrescens (P < 0.001), and T. forsythia (P < 0.001) and in the levels of MMP-8 and MMP-9 in GCF between patients and controls. T. forsythia[odds ratio(OR) 10.1; P = 0.001] and age (OR 5.54; P = 0.008) appeared to be the main independent predictors for high MMP-8 in GCF. Patients had significantly higher total cholesterol (P < 0.01), low-density lipoprotein cholesterol (P = 0.05), and triglycerides (P < = 0.01) than controls. Plasma levels of MMP-9 were significantly higher in patients than in controls (P = 0.001). CONCLUSIONS: Specific periodontal microorganisms appeared to induce host response, with increased release of MMP-8 and MMP-9 in gingival pockets as well as of MMP-9 in plasma, possibly triggering its up-regulation in blood.

Analysis of Variance↗

Different roles for matrix metalloproteinase-2 and matrix metalloproteinase-9 in the pathogenesis of cardiac allograft rejection.

Recent studies have shown an increased expression of several matrix metalloproteinases (MMP) during cardiac, renal and pulmonary allograft rejection. To further define the roles of MMP-2 and MMP-9 in the pathogenesis of cardiac allograft rejection, BALB/c cardiac allografts were transplanted into MMP-2-deficient (-/-) and MMP-9-/- mice. Allografts rejected by wild-type mice revealed a significant increase in MMP-2 and MMP-9 expression. MMP-2-deficiency significantly prolonged allograft survival time. Functioning allografts harvested from MMP-2-/- mice showed lower cellular infiltration and fibrosis than rejected allografts harvested from MMP-2+/+ mice at the same time. In contrast, MMP-9-deficiency significantly decreased allograft survival time. Functioning allografts harvested from MMP-9+/+ mice showed lower cellular infiltration and fibrosis than rejected allografts harvested from MMP-9-/- mice at the same time. MMP-2-/- recipients showed decreased T-cell alloreactivity mediated by a defect in dendritic cell stimulatory and T-cell responsive capacities. In contrast, MMP-9-/- recipients showed increased T-cell alloreactivity mediated by a significant increased in dendritic cell stimulatory and T-cell responsive capacities. These results indicate that MMP2 and MMP-9 play significantly different roles in the process of cardiac allograft rejection.

Animals↗

Selective spatiotemporal induction of matrix metalloproteinase-2 and matrix metalloproteinase-9 transcription after myocardial infarction.

Myocardial remodeling after myocardial infarction (MI) is associated with increased levels of the matrix metalloproteinases (MMPs). Levels of two MMP species, MMP-2 and MMP-9, are increased after MI, and transgenic deletion of these MMPs attenuates post-MI left ventricular (LV) remodeling. This study characterized the spatiotemporal patterns of gene promoter induction for MMP-2 and MMP-9 after MI. MI was induced in transgenic mice in which the MMP-2 or MMP-9 promoter sequence was fused to the beta-galactosidase reporter, and reporter level was assayed up to 28 days after MI. Myocardial localization with respect to cellular sources of MMP-2 and MMP-9 promoter induction was examined. After MI, LV diameter increased by 70% (P < 0.05), consistent with LV remodeling. beta-Galactosidase staining in MMP-2 reporter mice was increased by 1 day after MI and increased further to 64 +/- 6% of LV epicardial area by 7 days after MI (P < 0.05). MMP-2 promoter activation occurred in fibroblasts and myofibroblasts in the MI region. In MMP-9 reporter mice, promoter induction was detected after 3 days and peaked at 7 days after MI (53 +/- 6%, P < 0.05) and was colocalized with inflammatory cells at the peri-infarct region. Although MMP-2 promoter activation was similarly distributed in the MI and border regions, activation of the MMP-9 promoter was highest at the border between the MI and remote regions. These unique findings visually demonstrated that activation of the MMP-2 and MMP-9 gene promoters occurs in a distinct spatial relation with reference to the MI region and changes in a characteristic time-dependent manner after MI.

Animals↗

Expression of the extracellular matrix proteins collagen I, collagen III and fibronectin and matrix metalloproteinase-1 and -13 in the skin of patients with inguinal hernia.

Although abnormal collagen metabolism has been ascribed an important role in the high recurrence rates after surgical hernia repair, knowledge on tissue sampled in the region affected by inguinal hernias is poor. In the present study, we determined collagen type I and type III in the skin of adult patients with indirect and direct inguinal hernias by both immunohistochemistry and Western blot analysis. In addition, we quantified the immunohistochemical expression of fibronectin and matrix metalloproteinase (MMP)-1 and -13. The results indicated that the ratio of collagen type I/III was significantly decreased in the skin of patients with either indirect (n = 9) or direct hernia (n = 7), with a concomitant increase in collagen type III (p < 0.001 vs. controls, n = 7, without affection of the inguinal region). There was no significant difference between patients with indirect and direct hernia (p > 0.05). MMP-13 was not expressed in any of the skin samples investigated, whereas MMP-1 was found in the epidermis. Fibronectin was predominantly detected at the epidermal-dermal junction. MMP-1, MMP-13 and fibronectin levels were significantly different between patients and controls (p > 0. 05). We conclude that in contrast to the unchanged expression of fibronectin and MMP-1 and MMP-13, the decreased ratios of collagen tpye I/III with the basically increased amount of collagen type III could be of significant importance for the pathophysiology of hernias. The specific ratio collagen I/III probably reflects the altered structural integrity and mechanical stability of the connective tissue in both indirect and direct hernias. Moreover, our findings stress that hernias should be regarded as the manifestation of a systemic disease in the inguinal region with a genetic background, explaining the high recurrence rates after repeated suture repair, as well as the usefulness of surgical meshes in this clinical setting.

Aged↗

Expression of matrix metalloproteinases and tissue inhibitor of matrix metalloproteinases in non-small-cell lung cancer.

Expression of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 was studied in non-small-cell lung cancer (NSCLC). Activity of MMP-2 and MMP-9 by gelatin zymography and expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNAs were examined in 11 lung cancer cell lines which included six small-cell lung cancer (SCLC) cell lines. Localization of MMP-2, MMP-9, TIMP-1, and TIMP-2 was examined by immunohistochemistry in 43 resected NSCLC (22 adenocarcinomas, 17 squamous cell carcinomas, 4 large cell carcinomas) using specific anti-human monoclonal antibodies. Expression of MMP-2 mRNA was detected in 5 (100%), MMP-9 in 1 (20%), TIMP-1 in 4 (80%), and TIMP-2 in 5 (100%) of 5 NSCLC cell lines examined. MMP-2 gelatinolytic activity also was detected in all five NSCLC cell lines, whereas MMP-9 activity was detected in only one cell line. In 43 patients, MMP-2, MMP-9, TIMP-1, and TIMP-2 immunoreactivity was demonstrated in 19 (44%), 9 (21%), 15 (35%), and 29 (67%) excised tumors, respectively. All stromal fibroblasts in tumor samples stained positive for MMP-2. There was a correlation between TIMP-2 immunoreactivity and disease stage (42% stage I versus 88% stages II, III, and IV) (p = 0.0024). Both cancer cell lines and NSCLC tumor samples frequently expressed MMP-2, MMP-9, TIMP-1, and TIMP-2; MMP-2 in particular was highly expressed in malignant cells and surrounding fibroblasts. These findings suggest that MMP-2 plays a more important role in invasion of NSCLC than MMP-9 and that TIMP-2 may have clinical relevance in NSCLC.

Adenocarcinoma↗

Renal matrix metalloproteinase activity is unaffected by experimental ischemia-reperfusion injury and matrix metalloproteinase inhibition does not alter outcome of renal function.

BACKGROUND: Ischemia-reperfusion injury can lead to organ damage, such as delayed graft function in kidney transplantation. Reactive oxygen species that play a key role in this disorder may directly activate latent matrix metalloproteinases (MMP). In the kidney, little is known about the role of MMP in ischemia-reperfusion. Therefore, the aim of our study was to analyze activity/expression of MMP and to assess their functional role by the use of the MMP inhibitor BB-94 (Batimastat). METHODS: Renal ischemia was induced by left renal pedicle occlusion for 60 min, preceded by right nephrectomy. Thirty-two female Sprague-Dawley rats were analyzed: sham-operated rats (n = 8), treated sham-operated rats (n = 4), ischemic rats (n = 12), and treated ischemic rats (n = 8). Batimastat therapy (30 mg/kg body weight/day) was initiated 2 days prior to induction of ischemia. Animals were sacrificed 12 h (n = 8) and 24 h (n = 24) after ischemia for analyses of MMP activity/expression and of plasma creatinine levels. RESULTS: We found no evidence for an alteration in the activity or expression of MMP as a result of renal ischemia-reperfusion. Importantly, plasma creatinine levels significantly increased to a mean of 374 +/- 61 micromol/l in ischemic rats after 24 h, almost identical to the BB-94-treated ischemic rats (384 +/- 36 micromol/l). The creatinine levels in sham-operated rats remained within normal limits. CONCLUSION: MMP play no role during the early phase of experimental renal ischemia-reperfusion injury.

Animals↗

Novel conformation-specific antibodies against matrix gamma-carboxyglutamic acid (Gla) protein: undercarboxylated matrix Gla protein as marker for vascular calcification.

OBJECTIVE: Matrix gamma-carboxyglutamic acid (Gla) protein (MGP), a vitamin K-dependent protein, is a potent in vivo inhibitor of arterial calcification. We hypothesized that low endogenous production of MGP and impaired carboxylation of MGP may contribute to the development or the progression of vascular disease. METHODS AND RESULTS: Novel conformation-specific antibodies against MGP were used for immunohistochemistry of healthy and sclerotic arteries. In healthy arteries, MGP was mainly displayed around the elastin fibers in the tunica media. The staining colocalized with that for carboxylated MGP, whereas undercarboxylated MGP (ucMGP) was not detected. In atherosclerotic arteries, ucMGP was found in the intima, where it was associated with vesicular structures. In Mönckeberg's sclerosis of the media, ucMGP was localized around all areas of calcification. The results indicate that ucMGP is strongly associated with vascular calcification of different etiologies. In a separate study, serum MGP concentrations in a cohort of 172 subjects who had undergone percutaneous coronary intervention were significantly reduced compared with an apparently healthy population. CONCLUSIONS: These data show that impaired carboxylation of MGP is associated with intimal and medial vascular calcification and suggest the essentiality of the vitamin K modification to the function of MGP as an inhibitor of ectopic calcification.

Antibody Specificity↗

Donor spontaneous intracerebral hemorrhage is associated with systemic activation of matrix metalloproteinase-2 and matrix metalloproteinase-9 and subsequent development of coronary vasculopathy in the heart transplant recipient.

BACKGROUND: Matrix metalloproteinase (MMP)-2 and MMP-9 have been shown to play a role in the progression of hemorrhagic stroke. We hypothesized that donor intracerebral hemorrhage (ICH) is associated with activation of the metalloproteinases before transplantation that play a key role in the subsequent development of transplant vasculopathy. METHODS AND RESULTS: We evaluated mRNA expressions of MMP-2 and MMP-9 in donor spleen lymphocytes (before transplantation) and in heart biopsies at 1 week after transplantation in 20 recipients from ICH donors and 20 recipients from trauma donors. Patients underwent serial coronary intravascular ultrasound, and interstitial myocardial fibrosis was quantified at 1 year. The baseline characteristics were similar except for increased donor age in the ICH group. Heart biopsies from the ICH group showed significant increased expression of MMP-2 (17-fold, P<0.0001) and MMP-9 (20-fold, P<0.0001) compared with the trauma group. Furthermore, the ICH group showed 1.8-fold (P=0.016) increased mRNA expression of MMP-2 and 1.7-fold (P=0.015) increased mRNA expression of MMP-9 in the donor spleen lymphocytes, suggesting the presence of systemic activation of metalloproteinases before transplantation. At 1 year, the ICH group showed increased myocardial fibrosis and accelerated coronary vasculopathy. Using multivariate regression analysis, MMP-9 was found to be associated with increased risk for vasculopathy independent of donor age (OR, 2.41; P=0.01; 95% CI, 1.24 to 4.69). CONCLUSIONS: This is the first report to describe systemic activation of MMP-2 and MMP-9 in donors with intracerebral hemorrhage and subsequent development of allograft vasculopathy.

Adult↗

Differences in matrix metalloproteinase-1 and matrix metalloproteinase-12 transcript levels among carotid atherosclerotic plaques with different histopathological characteristics.

BACKGROUND AND PURPOSE: Previous studies have shown that atherosclerotic lesions express a number of matrix metalloproteinases (MMPs). Here we investigated whether transcript levels of MMP-1, -3, -7, -9, and -12 in carotid atherosclerotic plaques were correlated with histological features and clinical manifestations. METHODS: Atherosclerotic plaques (n=50) removed from patients undergoing carotid endarterectomy were classified histologically using a system proposed by Virmani et al, and MMP-1, -3, -7, -9, and -12 transcript levels in these tissues were quantified by real-time reverse-transcriptase polymerase chain reaction. RESULTS: Compared to plaques with a thick fibrous cap, those with a thin cap had a 7.8-fold higher MMP-1 transcript level (P=0.006). MMP-3, -7, and -12 were 1.5-fold, 1.8-fold, and 2.1-fold, respectively, higher in thin cap plaques, but the differences did not reach statistical significance. MMP-12 transcript levels were significantly increased in ruptured plaques compared with lesions without cap disruption (P=0.001). MMP-9 transcript levels were similar among the different types of lesion. MMP-1 and -12 transcript levels were significantly higher in plaques from patients with amaurosis fugax, than in those from asymptomatic patients (P=0.029 and P=0.008 for MMP-1 and MMP-12, respectively), than in those from patients with stroke (P=0.027 and P=0.001, respectively), and than in those from patients with transient ischemic attack (P=0.046 and P=0.008, respectively). CONCLUSIONS: These data support a role of MMP-1 and -12 in determining atherosclerotic plaque stability.

Aged↗

Local IL-13 gene transfer prior to immune-complex arthritis inhibits chondrocyte death and matrix-metalloproteinase-mediated cartilage matrix degradation despite enhanced joint inflammation.

During immune-complex-mediated arthritis (ICA), severe cartilage destruction is mediated by Fcgamma receptors (FcgammaRs) (mainly FcgammaRI), cytokines (e.g. IL-1), and enzymes (matrix metalloproteinases (MMPs)). IL-13, a T helper 2 (Th2) cytokine abundantly found in synovial fluid of patients with rheumatoid arthritis, has been shown to reduce joint inflammation and bone destruction during experimental arthritis. However, the effect on severe cartilage destruction has not been studied in detail. We have now investigated the role of IL-13 in chondrocyte death and MMP-mediated cartilage damage during ICA. IL-13 was locally overexpressed in knee joints after injection of an adenovirus encoding IL-13 (AxCAhIL-13), 1 day before the onset of arthritis; injection of AxCANI (an empty adenoviral construct) was used as a control. IL-13 significantly increased the amount of inflammatory cells in the synovial lining and the joint cavity, by 30% to 60% at day 3 after the onset of ICA. Despite the enhanced inflammatory response, chondrocyte death was diminished by two-thirds at days 3 and 7. The mRNA level of FcgammaRI, a receptor shown to be crucial in the induction of chondrocyte death, was significantly down-regulated in synovium. Furthermore, MMP-mediated cartilage damage, measured as neoepitope (VDIPEN) expression using immunolocalization, was halved. In contrast, mRNA levels of MMP-3, -9, -12, and -13 were significantly higher and IL-1 protein, which induces production of latent MMPs, was increased fivefold by IL-13. This study demonstrates that IL-13 overexpression during ICA diminished both chondrocyte death and MMP-mediated VDIPEN expression, even though joint inflammation was enhanced.

Adenoviridae↗

L-arginine attenuates acute pulmonary embolism-induced increases in lung matrix metalloproteinase-2 and matrix metalloproteinase-9.

STUDY OBJECTIVES: To evaluate the effects of L-arginine on acute pulmonary embolism (APE)-induced pulmonary hypertension and increases in lung matrix metalloproteinase (MMP)-2 and MMP-9 activities. DESIGN: Prospective trial. SETTING: University laboratory. INTERVENTIONS: Using an isolated lung perfusion rat model of APE, we examined whether L-arginine (0, 0.5, 3, and 10 mmol/L; five to seven rats per group) attenuates the pulmonary hypertension induced by the injection of 6.6 mg/kg of 300 microm microspheres into the pulmonary artery. In a second series of experiments (6 to 11 rats per group), we investigated whether nonselective inhibition of nitric oxide (NO) synthases with N(G)-nitro-L-arginine methyl ester (L-NAME; 4 mmol/L) decreases the effects produced by L-arginine. Lung MMP-2 and MMP-9 activities were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis gelatin zymography. RESULTS: L-arginine at 0.5, 3, and 10 mmol/L attenuated APE-induced pulmonary hypertension by 25 to 42% (all p < 0.05). The protective effect of L-arginine was completely reversed by inhibition of NO synthesis with L-NAME. APE was associated with increased lung MMP-2 and MMP-9 activities (both p < 0.05). While L-arginine at 0.5 mmol/L produced no effect on MMPs, L-arginine 3 at mmol/L and 10 mmol/L attenuated the increases in MMP-2 and MMP-9 activities after APE (both p < 0.05). CONCLUSIONS: L-arginine attenuates APE-induced pulmonary hypertension through mechanisms involving increased NO synthesis and maybe attenuation of lung MMP-2 and MMP-9 activities.

Animals↗