Matrix Metalloproteinase-2 And-9 Research Articles

Fibulin 1, targeted by microRNA-24-3p, promotes cell proliferation and migration in vascular smooth muscle cells, contributing to the development of atherosclerosis in APOE-/- mice

Extracellular matrix (ECM) and vascular smooth muscle cells (VSMCs) are the main components of atherosclerosis (AS) plaque. VSMCs participate in plaque formation through phenotypic transformation. The complex interplay between ECM and VSMCs plays vital roles in the progression of AS throughout the disease. An in-depth investigation into the functions of ECM-related molecules in VSMC development might contribute to deciphering the complexity of AS pathogenesis. In this study, the roles and molecular mechanisms of the ECM-related molecule Fibulin-1 (FBLN1) in the development of AS and VSMCs were explored using RNA sequencing, bioinformatics analysis, and cell experiments. Furthermore, the expression of FBLN1, as determined by western blot analysis, immunohistochemistry, and real-time quantitative PCR, was significantly increased in AS vascular samples compared to normal vascular samples. Silencing the FBLN1 through AAV viral injection in mice revealed an improvement in AS. Functional analyses revealed that FBLN1 promoted VSMC proliferation, migration, and wound healing. Combined with RNA sequencing and TargetScan7.2 prediction data, 22 microRNAs (miRNAs) were found to have the potential for direct interaction with the FBLN1 3′UTR in VSMCs. Among these 22 miRNAs, it was demonstrated that microRNA-24-3p (miR-24-3p) could negatively regulate FBLN1 expression by directly binding to the FBLN1 3′UTR. Moreover, miR-24-3p inhibited cell proliferation, migration, and wound healing, and suppressed the expression of Ki67, matrix metalloproteinase-2 and −9 (MMP2/9) by targeting FBLN1 in VSMCs. Meanwhile, inhibition of FBLN1 expression could restrain VSMC phenotypic transformation. In conclusion, miR-24-3p inhibited VSMC proliferation and migration by targeting FBLN1. Additionally, multiple miRNAs with the potential to interact with the FBLN1 3′UTR were identified. These findings might deepen our understanding of ECM gene regulatory networks and the complex etiology of AS.

Association of Zinc Status with Matrix Metalloproteinases, Advanced Glycation End-Products, and Blood Pressure in Patients with Chronic Kidney Disease.

Inflammation, oxidative stress, and hypertension trigger the development of chronic kidney disease (CKD). Zinc is known to have antioxidant and anti-inflammatory properties and a possible role in regulating blood pressure. The aim of this study was to investigate the correlation of serum zinc with matrix metalloproteinase-2 and-9 (MMP-2, MMP-9), advanced glycation end products (AGEs), and blood pressure in patients with CKD. This cross-sectional study included 90 patients with CKD. Serum zinc and the levels of MMP-2, MMP-9, AGEs, and creatinine were measured using validated biochemical methods. Three 24-h food recalls were completed to evaluate dietary zinc intake. Systolic and diastolic blood pressure (SBP, DBP) were measured using a digital sphygmomanometer. Participants' mean age was 60.68 ± 8.81years. The prevalence of zinc deficiency in our participants was 10%. Serum zinc was negatively correlated with MMP-9 (r = - 0.231, p = 0.032) and creatinine (r = - 0.304, p = 0.004). However, after adjusting for confounding variables, the association between serum zinc and MMP-9 was near the significance level (β = - 0.174, p = 0.09) and zinc remained in the model as one of the predictors. Serum zinc was positively correlated with the dietary intake of zinc (r = 0.241, p = 0.025) and estimated glomerular filtration rate (eGFR) (r = 0.259, p = 0.015). In conclusion, our results showed that serum zinc might be one of the predictors of serum MMP-9 in patients with CKD. In addition, serum zinc was positively associated with its dietary intake and eGFR. Future longitudinal studies or clinical trials are required to reveal any causal association between zinc status and profibrotic or inflammatory biomarkers among patients with CKD.

VSMC-specific EP4 deletion exacerbates angiotensin II-induced aortic dissection by increasing vascular inflammation and blood pressure

Prostaglandin E2 (PGE2) plays an important role in vascular homeostasis. Its receptor, E-prostanoid receptor 4 (EP4) is essential for physiological remodeling of the ductus arteriosus (DA). However, the role of EP4 in pathological vascular remodeling remains largely unknown. We found that chronic angiotensin II (AngII) infusion of mice with vascular smooth muscle cell (VSMC)-specific EP4 gene knockout (VSMC-EP4-/-) frequently developed aortic dissection (AD) with severe elastic fiber degradation and VSMC dedifferentiation. AngII-infused VSMC-EP4-/- mice also displayed more profound vascular inflammation with increased monocyte chemoattractant protein-1 (MCP-1) expression, macrophage infiltration, matrix metalloproteinase-2 and -9 (MMP2/9) levels, NADPH oxidase 1 (NOX1) activity, and reactive oxygen species production. In addition, VSMC-EP4-/- mice exhibited higher blood pressure under basal and AngII-infused conditions. Ex vivo and in vitro studies further revealed that VSMC-specific EP4 gene deficiency significantly increased AngII-elicited vasoconstriction of the mesenteric artery, likely by stimulating intracellular calcium release in VSMCs. Furthermore, EP4 gene ablation and EP4 blockade in cultured VSMCs were associated with a significant increase in MCP-1 and NOX1 expression and a marked reduction in α-SM actin (α-SMA), SM22α, and SM differentiation marker genes myosin heavy chain (SMMHC) levels and serum response factor (SRF) transcriptional activity. To summarize, the present study demonstrates that VSMC EP4 is critical for vascular homeostasis, and its dysfunction exacerbates AngII-induced pathological vascular remodeling. EP4 may therefore represent a potential therapeutic target for the treatment of AD.

Zerumbone suppresses the potential of growth and metastasis in hepatoma HepG2 cells via the MAPK signaling pathway.

Zerumbone is an active component of Zingiber zerumbet (L.) Smith and can perform a diverse range of antitumor activities. However, the underlying molecular mechanisms of zerumbone action have not yet been elucidated. The aim of the present study was to investigate the antitumor effects, and the associated molecular mechanisms, of zerumbone in hepatoma HepG2 cells. Treatment with zerumbone markedly induced apoptosis in hepatoma HepG2 cells and suppressed their invasion and metastasis in a dose-dependent manner. Further investigation revealed that treatment with zerumbone led to the dose-dependent induction of apoptosis and cell cycle arrest at G2/M phase in cancer cells. Zerumbone treatment led to the increased expression of p27, cytochrome c, caspase-3 and-9, and Bcl-2-associated X expression, but the decreased expression of cyclin-dependent kinase 1, cyclin B1, B-cell lymphoma-2, focal adhesion kinase, Ras homolog gene family, member A, Rho-associated protein kinase-1, and matrix metalloproteinase-2 and-9 in HepG2 cells. In addition, the phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2, but not C-Jun N-terminal kinase 1/2, was regulated in a dose-dependent manner in response to zerumbone treatment. The results of the current study indicate that zerumbone could be used as potential anticancer agent in for the treatment of hepatoma in the future.

Herbacetin inhibits RANKL-mediated osteoclastogenesis in vitro and prevents inflammatory bone loss in vivo

Herbacetin is an active flavonol (a type of flavonoid) that has various biologic effects such as antioxidant, antitumor, and anti-inflammatory activities. However, one of its novel effects remains to be investigated, that is, the induction of osteoclastogenesis by the receptor activator of nuclear factor-κB ligand (RANKL). In this study, we examined the effects and mechanisms of action of herbacetin on osteoclastogenesis in RANKL-treated bone marrow–derived macrophages (BMMs) and murine macrophage RAW264.7 cells in vitro and on lipopolysaccharide (LPS)-induced bone destruction in vivo. Herbacetin significantly inhibited RANKL-induced osteoclast formation and differentiation in BMMs and RAW264.7 cells in a dose-dependent manner. Moreover, the suppressive effect of herbacetin resulted in a decrease in osteoclast-related genes, including RANK, tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-2 and -9 (MMP-9). Consistent with mRNA results, we confirmed that herbacetin treatment downregulated protein expression of MMP-9 and cathepsin K. Herbacetin also decreased induction of the osteoclastogenic transcription factor c-Fos and nuclear factor of activated T cells c1 (NFATc1) and blocked RANKL-mediated activation of Jun N-terminal kinase (JNK) and nuclear factor-κB. Herbacetin clearly inhibited the bone resorption activity of osteoclasts on plates coated with fluorescein-labeled calcium phosphate. More importantly, the application of herbacetin significantly reduced LPS-induced inflammatory bone loss in mice in vivo. Taken together, our results indicate that herbacetin has potential for use as a therapeutic agent in disorders associated with bone loss.

Upregulated Matrix Metalloproteinase 2/9 Activity in Murine Asthma Detected with Activatable Cell-Penetrating Peptides

RationaleAsthma, an airway inflammatory disease characterized by intermittent airway obstruction, affects more than 300 million people worldwide. Matrix metalloproteinase 2 and 9 (MMP2/9) mRNA and protein levels correlate with asthma pathogenesis; however, the role of MMP2/9 in asthma is not well understood, particularly because previous studies have not evaluated protease activity. We report the application of activatable cell-penetrating peptides (ACPPs), injectable probes that highlight in vivo protease activity, to assess protease activity in murine asthma.MethodsAsthma mice were sensitized (ovalbumin [OVA] + alum in saline [PBS]) and then challenged (OVA in PBS). Age-matched control mice were sensitized but not challenged. The day after the final OVA challenge, ACPPs (cleavable and uncleavable, n = 3-6 mice each) were administered intravenously 6 hr before mice were sacrificed. Lungs were imaged for Cy5 fluorescence (Maestro, CRi). Lung sections (10 μm, 8 images/mouse) were imaged for Cy5 fluorescence on a confocal microscope (5Live, Zeiss) and stained with hematoxylin and eosin.ResultsMMP2/9 activity was > 2-fold higher in lungs from asthma mice than controls (p = 1.8×10−4). The same pattern was observed for ratiometric ACPPs. MMP2/9 activity localized around inflamed airways with 1.6-fold higher ACPP uptake surrounding airways compared to the normal lung parenchyma (p = 0.03). MMP2/9 activity detected by ACPPs co-localized with gelatinase activity measured with in situ DQ gelatin.ConclusionsMMP-activated ACPPs allow for real-time detection of protease activity in a murine asthma model, improving our understanding of protease activation in asthma progression and elucidating novel therapy targets. RationaleAsthma, an airway inflammatory disease characterized by intermittent airway obstruction, affects more than 300 million people worldwide. Matrix metalloproteinase 2 and 9 (MMP2/9) mRNA and protein levels correlate with asthma pathogenesis; however, the role of MMP2/9 in asthma is not well understood, particularly because previous studies have not evaluated protease activity. We report the application of activatable cell-penetrating peptides (ACPPs), injectable probes that highlight in vivo protease activity, to assess protease activity in murine asthma. Asthma, an airway inflammatory disease characterized by intermittent airway obstruction, affects more than 300 million people worldwide. Matrix metalloproteinase 2 and 9 (MMP2/9) mRNA and protein levels correlate with asthma pathogenesis; however, the role of MMP2/9 in asthma is not well understood, particularly because previous studies have not evaluated protease activity. We report the application of activatable cell-penetrating peptides (ACPPs), injectable probes that highlight in vivo protease activity, to assess protease activity in murine asthma. MethodsAsthma mice were sensitized (ovalbumin [OVA] + alum in saline [PBS]) and then challenged (OVA in PBS). Age-matched control mice were sensitized but not challenged. The day after the final OVA challenge, ACPPs (cleavable and uncleavable, n = 3-6 mice each) were administered intravenously 6 hr before mice were sacrificed. Lungs were imaged for Cy5 fluorescence (Maestro, CRi). Lung sections (10 μm, 8 images/mouse) were imaged for Cy5 fluorescence on a confocal microscope (5Live, Zeiss) and stained with hematoxylin and eosin. Asthma mice were sensitized (ovalbumin [OVA] + alum in saline [PBS]) and then challenged (OVA in PBS). Age-matched control mice were sensitized but not challenged. The day after the final OVA challenge, ACPPs (cleavable and uncleavable, n = 3-6 mice each) were administered intravenously 6 hr before mice were sacrificed. Lungs were imaged for Cy5 fluorescence (Maestro, CRi). Lung sections (10 μm, 8 images/mouse) were imaged for Cy5 fluorescence on a confocal microscope (5Live, Zeiss) and stained with hematoxylin and eosin. ResultsMMP2/9 activity was > 2-fold higher in lungs from asthma mice than controls (p = 1.8×10−4). The same pattern was observed for ratiometric ACPPs. MMP2/9 activity localized around inflamed airways with 1.6-fold higher ACPP uptake surrounding airways compared to the normal lung parenchyma (p = 0.03). MMP2/9 activity detected by ACPPs co-localized with gelatinase activity measured with in situ DQ gelatin. MMP2/9 activity was > 2-fold higher in lungs from asthma mice than controls (p = 1.8×10−4). The same pattern was observed for ratiometric ACPPs. MMP2/9 activity localized around inflamed airways with 1.6-fold higher ACPP uptake surrounding airways compared to the normal lung parenchyma (p = 0.03). MMP2/9 activity detected by ACPPs co-localized with gelatinase activity measured with in situ DQ gelatin. ConclusionsMMP-activated ACPPs allow for real-time detection of protease activity in a murine asthma model, improving our understanding of protease activation in asthma progression and elucidating novel therapy targets. MMP-activated ACPPs allow for real-time detection of protease activity in a murine asthma model, improving our understanding of protease activation in asthma progression and elucidating novel therapy targets.

Effect of ultraviolet radiation on the exp ression of p53, matrix metalloproteinase-2 and-9 in actinic keratosis lesions and normal human skin

Objective To estimate the effect of different doses of ultraviolet (UV) radiation on the proliferation of and apoptosis in kertatinocytes,as well as on the expression of p53,matrix metalloproteinase-2 (MMP2) and-9 (MMP9) in actinic keratosis (AK) lesions and normal human skin.Methods Tissue specimens were obtained from the lesions of 20 patients with AK and sun-exposed normal skin of 20 healthy human subjects,and subjected to an air-exposed culture.Each of the specimens was divided into 4 areas to remain untreated (control area) or be irradiated with UV of 5,10 and 20 J/cm2 (irradiated areas) for 4 consecutive days.After another 24-hour culture,the tissue cultures were collected followed by the evaluation of apoptosis in and proliferation of keratinocytes by using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Ki-67 staining,and determination of mRNA and protein expressions of p53,MMP2 and MMP9 by using real time PCR and immunohistochemistry respectively.Results A statistical increase was observed in the percentage of apoptotic cells in the normal skin irradiated with UV of 10 and 20 J/cm2 (46.8％ ± 2.1％ and 56.7％± 2.4％,both P ＜ 0.05) and in the AK lesions irradiated with UV of 20 J/cm2 (43.5％ ± 1.5％,P ＜ 0.05)compared with the corresponding unirradiated tissues.The normal skin showed a higher percentage of apoptotic cells than the lesional skin after irradiation with UV of 10 and 20 J/cm2 (both P ＜ 0.05).The percentage of Ki67-positive cells was significantly decreased in the normal skin after irradiation with UV of 20 J/cm2 (3.34％ ±0.76％,P ＜ 0.05),but experienced no statistical changes in the lesional skin after different doses of UV irradiation (all P ＞ 0.05).There was a statistical elevation in the expression of p53 mRNA (5 J/cm2:1.106 ± 0.025,10 J/cm2: 1.259 ± 0.045,20 J/cm2:1.425 ± 0.053,all P ＜ 0.05) and protein(10 J/cm2:0.1169 ± 0.0032,20 J/cm2:0.1454 ± 0.0047,both P＜ 0.05) in the normal skin,but a statistical reduction in the expression of p53 mRNA(10 J/cm2.0.611 ± 0.050,20 J/cm2:0.578 ± 0.070,both P ＜ 0.05) and protein (20 J/cm2:0.0404 ± 0.0027,P＜ 0.05) in the lesional skin after irradiation compared with the corresponding unirradiated skin tissues.Further more,a statistical increment was observed in MMP2 mRNA and protein expression in normal skin irradiated with UV of 10 J/cm2 (1.086 ± 0.013,0.0843 ± 0.0024,respectively,both P ＜ 0.05) and 20 J/cm2 (1.417 ± 0.036,0.1236 ±0.0042,respectively,both P ＜ 0.05) and in lesional skin irradiated with UV of 20 J/cm2 (1.296 ± 0.028,0.0744± 0.0032,respectively,both P ＜ 0.05),as well as in MMP9 mRNA and protein expression in normal skin irradiated with UV of 20 J/cm2 (1.395 ± 0.026,0.3065 ± 0.0162,respectively,both P ＜ 0.05) and in lesional skin irradiated with UV of 10 J/cm2 (1.298 ± 0.035,0.0992 ± 0.0053,respectively,both P ＜ 0.05) and 20 J/cm2(1.286 ± 0.032,0.1010 ± 0.0063,respectively,both P ＜ 0.05) compared with the corresponding unirradiated tissues.Conclusion Ultraviolet may accelerate the progression of AK by down-regulating p53 expression but up-regulating MMP2 and MMP9 expression. Key words: Actinic keratosis; Ultraviolet rays; Genes,p53; Matrix metalloproteinase 2; Matrix metalloproteinase 9

Tanshinone IIA inhibits atherosclerotic plaque formation by down-regulating MMP-2 and MMP-9 expression in rabbits fed a high-fat diet

Tanshinone IIA (Tan IIA) is one of the major lipophilic components of Salvia miltiorrhiza Bunge (SM) and has an anti-atherosclerotic effect. To investigate the potential mechanism of this effect, we established an atherosclerotic animal model by feeding rabbits a high-fat diet, and Tan IIA was given at different doses. Intimal area of the aorta was measured by image analysis, serum levels of vascular adhesion molecule-1 (VCAM-1) and interleukin (IL-1β) were measured by ELISA, while matrix metalloproteinase-2 and-9 (MMP-2, MMP-9) expression and their activities in atherosclerotic lesions were assessed by Western blotting and zymography respectively. Compared with the control group, the intimal area, serum levels of VCAM-1 and IL-1β, the expression of MMP-2 and MMP-9 as well as their activities were increased significantly in the high-fat fed rabbit group. After Tan IIA administration, all of these parameters were decreased in a dose-dependent manner. Our results show that Tan IIA can inhibit atherosclerotic lesion formation in aorta and down-regulate protein expression and activities of MMP-2 and MMP-9 as well as serum VCAM-1 and IL-1β in rabbits fed a high-fat diet.

Expression and quantitative analysis of matrix metalloproteinase-2 and-9 in human gliomas

The matrix metalloproteinase (MMP) family members catalyze extracellular proteolysis. Recent reports have suggested that expression of MMP-2 and -9 might play a critical role in neoplastic tissue invasion or metastasis. In this study, the relationship between the expression of MMP-2 and -9 and the histological features of tissues from 21 cases of human glioma were investigated. MMP-2 and -9 proteins were detected by immnohistochemical studies. Amplification of MMP-2 and -9 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) assay. MMP-2 and -9 mRNA was measured quantitatively by the real-time RT-PCR method. Immunohistochemically, 38% of the cases were positive for MMP-2. Amplification of MMP-2 mRNA by RT-PCR was detected in 62% of the cases. There was no significant relationship between the expression of MMP-2 protein or mRNA and the biological nature of the tumors, including aggressiveness and histologic classification. The quantity of MMP-2 mRNA was 0.035 +/- 0.113 (MMP-2/GAPDH %), which was significantly elevated in cases of neoplastic dissemination or recurrence (P < 0.05). Tumor cells were immunohistochemically positive for MMP-9 in 81% of the samples. A positive reaction was found not only in neoplastic cells but also in endothelial cells, suggesting that the expression of MMP-9 protein might be associated with tumoral angiogenesis. The expression of mRNA in MMP-9 was detected in 91% of the cases, suggesting a close relationship between expression of MMP-9 and malignancy. The quantity of MMP-9 was 0.097 +/- 0.113 (MMP-9/GAPDH %) in all samples, which was significantly elevated in cases of glioblastoma (P < 0.05). The average Ki-67 labeling index was 8.14 +/- 5.26 in samples from G2 glioma, 19.92 +/- 11.29 in samples from G3 glioma, and 23.52 +/- 10.14 in samples from glioblastoma. All of the cases with elevated indices had recurrence or dissemination. The results of our study suggest that quantity analyses of MMP-2 and -9 mRNA and Ki-67 labeling index should be useful for discerning tumoral behaviors such as invasion, dissemination, and recurrence.

Expression of matrix metalloproteinase-2 and-9 in kidney of diabetic rats

To investigate the expression of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9(MMP-9), transforming growth factor beta(1)(TGF-beta(1)) and IV-collagen (C-IV) in kidneys of diabetic rats. Rat diabetic model was induced by streptozotocin (70 mg/kg), and kidneys were examined pathologically and the expressions of MMP- 2, MMP-9, TGF-beta(1) and C-IV were studied by immunohistochemistry. The results were analyzed by imaging quantitative analysis technique. Immunoreactive MMP-2 and MMP-9 were mainly expressed in the mesangial cells, endothelial cells, parietal layer of Bowman's capsule and tubular cells. The expression of MMP-2 was significantly weaker in the glomeluri of diabetic rats than that of the control animals (P<0.05), while the expression of TGF-beta(1) and C-IV in the glomeluri of diabetic rats was significantly stronger than that of the controls (P%lt;0.05). The expression of MMP-9 didn't show significant different in glomeluri of the two groups (P>0.05). Expression of MMP-2 in glomeluri is decreased in diabetic rats, which may be related to the increased TGF-beta(1) and in turns promote the accumulation of C-IV.

The expression of matrix metalloproteinase-2 and -9 in human gliomas of different pathological grades.

Matrix metalloproteinases (MMPs) have been implicated to play a critical role in glioma invasiveness. In this study, we aimed to investigate the expression of MMP-2 and MMP-9 in human gliomas of different degrees of malignancy, and evaluated the correlation between MMP-2 and MMP-9 expression in gliomas. The samples from 65 cases of glioma were divided into four groups according to the WHO classification: there were 16 cases of grade I, 17 cases of grade II, 20 cases of grade III, and 12 cases of grade IV. Normal brain samples served as the control group, and biopsy specimens were obtained from 8 glioma patients with a needle placed into the adjacent brain 1 cm from the margin after tumor resection. All the samples were stained with hematoxylin and eosin and immunohistochemistry. A computer-aided image-analysis system was employed to measure the integral optical density (IOD) of positive slides. No positive staining was found in the control group. The positive staining was localized in the cytoplasm of glioma cells, the extracellular matrix (ECM), the basement membrane (BM), and the endothelial cells of blood vessels. Positive staining rates increased significantly when the degree of malignancy of gliomas was elevated. The IOD value of MMP-2 and MMP-9 also indicated that the intensity of MMP-2 and MMP-9 expression was elevated significantly with the degree of malignancy of the gliomas. There was a positive correlation between MMP-2 and MMP-9 expression in gliomas. Glioma invasion and angiogenesis were particularly seen in the biopsied tissues, and MMP-9 immunostaining seemed to be much more intense and extensive than MMP-2 immunostaining in these samples. These results suggest that MMP-2 and MMP-9 staining in gliomas is localized in the cytoplasm of tumor cells, BM, and endothelial cells, and that MMP-2 and MMP-9 together play an important role in the invasiveness of gliomas, mediating the degradation of the ECM and angiogenesis. MMP-2 and MMP-9 could be molecular targets in the treatment of malignant glioma.

Matrix metalloproteinase-2 and-9 expression in astrocytic tumors

In this study, we investigated whether the expression of matrix metalloproteinase (MMP)-2 and MMP-9 correlated with invasiveness, proliferative potential, or prognosis in astrocytic tumors. Thirty-seven astrocytic tumors (8 diffuse astrocytomas, 15 anaplastic astrocytomas, and 14 glioblastomas) and three gliomatosis cerebri were investigated immunohistochemically. The invasive glioma group included three cases of gliomatosis cerebri and two of glioblastoma associated with cerebrospinal fluid dissemination. The expression of MMP-2 and MMP-9 was evaluated by assigning an immunohistochemical (IHC) score defined as the sum of expression frequency and intensity. mRNA expression patterns for the MMPs were also evaluated in a reverse transcription-polymerase chain reaction assay. Neither the MMP-2 nor MMP-9 IHC score was related to histological malignancy. The MMP-2 IHC score of the invasive glioma group was significantly higher than those of other kinds of astrocytic tumors. However, the MMP-9 IHC score did not correlate with dissemination among astrocytic tumors. An inverse correlation was observed between the MIB-1 labeling index and the IHC scores of MMP-2, but it was not significant. A Kaplan-Meyer survival analysis revealed no significant relationship between the survival rate and MMP-2 or MMP-9 expression. Our study showed that MMP-2 expression, but not MMP-9 expression, may be associated with invasion in astrocytic tumors.

Zymographic analysis of latent and activated forms of matrix metalloproteinase-2 and -9 in synovial fluid: correlation to polymorphonuclear leukocyte infiltration and in response to infection

Background: Matrix metalloproteinase-2 and-9 (MMP-2, MMP-9), and gelatinase A and B participate in the degradation of the extracellular matrix proteins in a variety of inflammatory connective tissue diseases including arthritis. Methods: Synovial fluid was collected by aseptic aspiration from patients with rheumatoid arthritis (RA), osteoarthritis (OA), gout, infected joint, septic arthritis, and systemic lupus erythematosus (SLE). Synovial fluid was subjected to cell count with polymorphonuclear leukocyte (PMN) differential, Gram staining and culture as necessary. MMP-2 and -9 were characterized by substrate gel electrophoresis (gelatin zymography) to resolve latent and activated ‘partially proteolyzed’ forms. Results: Gelatin zymography revealed that MMP-9 (92, 130, 225 kDa) in synovial fluid was associated with extent of white blood cell infiltration specifically PMNs. In contrast, fibroblast MMP-2 (72 kDa) was present in all synovial fluids irrespective of PMN count. No MMP-9 was detected in the osteoarthritic specimen with low PMN count. Higher PMN count was associated with the presence of activated MMPs, especially in specimens that were confirmed culture positive. Activated synovial fluid MMPs persisted despite resolution of infection. Discussion: Latent and activated MMP-2 and MMP-9 in synovial fluids fluctuate in proportion to PMN infiltration and specifically in response to infection. The presence of activated MMPs post-therapy would suggest that use of specific MMP inhibitors be indicated to eliminate activated MMPs that apparently persist post-infection.