Induction of matrix metalloproteinase-2 and -9 via Erk1/2-NF-κB pathway in human astroglia infected with Toxoplasma gondii

Matrix metalloproteinase (MMP)-2 and MMP-9 can cleave fibronectin, allowing leukocyte migration to the site of Toxoplasma gondii infection during toxoplasmic encephalitis. The aim of this study was to investigate the association between extracellular signal-regulated kinase (Erk)1/2-nuclear factor (NF)-κB pathway and MMP-2/-9 expression in astroglia infected with T. gondii tachyzoite in vitro. Our results showed that phosphorylated (p)-Erk1/2 transiently increased 1 h post-infection (PI) and p-NF-κB significantly increased from 1 h PI to 12 h PI in cell homogenates. NF-κB was bound directly to oligonucleotides containing putative NF-κB binding sites for the MMP-9 promoter. Additionally, expression of p-NF-κB, MMP-2, and MMP-9 was significantly decreased by MG132, an indirect NF-κB inhibitor. Treatment with PD98059, an Erk kinase inhibitor, efficiently reduced p-Erk1/2, p-NF-κB, MMP-2, and MMP-9 expression. These results suggest that suppression of the Erk1/2-NF-κB signaling pathway causes reductions in MMP-2 and MMP-9 activities in astroglia response to T. gondii infection. Thus, inhibiting this signaling intermediate involved in MMP-2 and MMP-9 expression may be a potential method for controlling inflammatory development of T. gondii-induced encephalitis.     

Rosiglitazone uppresses lipopolysaccharide-induced matrix metalloproteinase-2 activity in rat aortic endothelial cells via rasMEK1/2 signaling

ix metalloproteinase(MMPs) plays a key role in the pathogenesis of chronic inflammatory disease,such as atherosclerosis.Among MMPs,MMP-2 is regarded as a major proteinase in atherosclerotic plaque lesions.Peroxisome proliferator activated receptor-gamma(PPARg) ameliorates oxidative stress and the inflammatory response.The aim of the present study was to evaluate the effect of Rosiglitazone on Lipopolysaccharide(LPS)-induced MMP-2 activation as well as its possible mechanism.LPS-induced MMP-2 activity was inhibited by Rosiglitazone(PPARg agonist) in the rat aortic endothelial cells(RAEC).LPS-induced MMP-2 activation was diminished no matter exposure to NF-kB Activation Inhibitor II(JSH-23)or Ras inhibitor,farnesylthiosalicylic acid(FTS). Further study shows that LPS-induced activation of Phospho-Rho A and Phospho-MEKl/2 were significantly inhibited by Rosiglitazone.The activation of NF-kB p65 in the nuclear extract of cells was also significantly suppressed by Rosiglitazone, moreover,the expression of NF-κB p65 was partly activated by GW9662(PPARg antagonist).NF-kB DNA binding activity was also demolished by Rosiglitazone.In summary,our data showed that PPARg agonist,Rosiglitazone suppresses LPS-activated MMP-2 secretion via Ras-MEK1/2 signaling pathways and NF-kB activation.PPARg agonist and Ras-MEK1/2 pathway may be another potential therapeutic target for the disease induced by chronic inflammation.     

Collagenase-3 (MMP-13) expression by inflamed mucosa in inflammatory bowel disease

OBJECTIVE: To determine whether the expression of collagenase-3 (MMP-13) in biopsies from patients with inflammatory bowel disease is correlated with histological inflammation parameters. MATERIAL AND METHODS: Fifty-nine patients with inflammatory bowel disease were included in the study. The control group comprised 20 patients free of inflammatory disease and ten patients with acute diverticulitis. MMP-13 expression was determined by immunohistochemical staining and the specimens were assigned a histological inflammation score. RESULTS: It was found that 62.8% of patients with ulcerative colitis (UC) and 54.1% of patients with Crohn's disease (CD) showed MMP-13-positive immunostaining in biopsies from affected areas. MMP-13-positive staining was more intense in ulcerated colonic mucosa. A positive and significant correlation was found between MMP-13 expression and the histological inflammation scores in mucosal samples from patients with CD (r = 0.74, p < 0.0001) or UC (r = 0.62, p < 0.0001). However, no MMP-13-positive immunostaining was found in either the biopsy specimens of the control group or those biopsies taken from patients with UC or CD in microscopically confirmed non-affected areas of the colonic mucosa. Similarly, colonic mucosa samples of the 10 patients with acute diverticulitis did not show immunostaining for MMP-13. CONCLUSIONS: Our findings demonstrating the absence of MMP-13 expression in non-inflamed colonic mucosa or in acute diverticulitis, as well as a positive correlation between elevated MMP-13 expression and histological criteria of inflammation in patients with inflammatory bowel diseases (CD and UC) suggest a role of the protease in the pathogenesis of these latter processes.     

细胞外调节蛋白激酶在1型糖尿病颈动脉内皮及炎症表达中的作用

目的探讨细胞外调节蛋白激酶(ERK)在1型糖尿病小鼠颈动脉内皮功能紊乱及炎症表达中的作用。方法选择C57BL/6野生型雄性小鼠8只为对照组,同窝INS2~(AKITA)雄性小鼠16只分为1型糖尿病组和干预组,每组8只,分别腹腔注射0.1%DMSO 50μl/d;PD98059 10 mg/(kg·d),连续8周。检测血糖及NO、内皮素1水平,凝胶电泳迁移率实验检测颈动脉NO、一氧化氮合酶(NOS)、髓过氧化物酶(MPO)水平及信号转导与转录活化因子3(STAT-3)活性,Western blot检测ERK和基质金属蛋白酶9(MMP-9)蛋白表达,免疫组织化学检测颈动脉内皮MMP-9阳性表达。结果与对照组比较,1型糖尿病组血清内皮素1和颈动脉MPO明显增高,血清和颈动脉NO、NOS明显减低(P<0.05);ERK和MMP-9蛋白表达、颈动脉STAT-3活性及颈动脉内皮MMP-9阳性表达明显增高(P<0.05)。与1型糖尿病组比较,干预组上述各项均明显变化,差异有统计学意义(P<0.05)。结论 ERK信号途径可通过STAT-3参与1型糖尿病小鼠颈动脉内皮功能紊乱及MMP-9等炎性因子表达。     

Dominant-negative E-cadherin inhibits the invasiveness of inflammatory breast cancer cells in vitro

E-cadherin is a transmembrane glycoprotein which mediates epithelial cell-to-cell adhesion function as a tumor suppressor and frequently loss of expression in a wide spectrum of human cancer. However, recent studies demonstrated that E-cadherin was always over-expressed in inflammatory breast cancer (IBC) specimen and cell lines, which is a clinical extreme malignancy of breast cancer. It is hypothesized that the gain and not the loss of the E-cadherin axis contributes to the IBC unique phenotype. To test this assumption, we generated dominant negative mutant E-cadherin high-expression inflammatory breast cancer cells by introduced dominant negative mutant E-cadherin (H-2kd-E-cad) cDNA into human IBC SUM149 cells. Our studies demonstrated that the ability of invasion of SUM149 cells was significantly inhibited by H-2kd-E-cad via down-regulation of MMP-1 and MMP-9 expression. The underlying signal pathway of MAPK phosphorylated Erk 1/2(P44/42) in H-2kd-E-cad-transfected SUM149 cells was significantly down-regulated compared to parental and mock contrast. Our studies provided further functional evidence as the gain of E-cadherin expression dedicated to the IBC malignant phenotype and the blockage of MAPK/Erk activation maybe a promising therapeutic target.Hui-Ming Dong and Gang Liu contributed equally to this work.     

Production of matrix metalloproteinases in human cultured mast cells: involvement of protein kinase C-mitogen activated protein kinase kinase-extracellular signal-regulated kinase pathway.

BACKGROUND: Matrix metalloproteinases (MMPs) have been reported to play crucial roles in the migration of inflammatory cells through basement membrane components. To confirm the role of mast cells as a source of MMPs, we investigated the production of MMP and its pathway in human cultured mast cells (HCMC). We also investigated the production of tissue inhibitors of metalloproteinase (TIMPs). METHODS: HCMC was stimulated with phorbor 12-miristate 13-acetate (PMA) and/or calcium ionophore A23187 (A23187), and the resulting MMP production was evaluated by gelatin zymography and western blotting. Expression of MMP and TIMP mRNA was also examined. Granulocyte macrophage-colony stimulating factor (GM-CSF) was measured by ELISA and activation of extracellular signal-regulated kinase (ERK) was evaluated by western blotting. RESULTS: We detected the de novo synthesis of MMP-9 in HCMC after stimulation with PMA and found that the synthesis was mediated through protein kinase C-mitogen activated protein kinase kinase (MEK)-ERK pathway. The MMP-9 production induced by PMA was suppressed by simultaneous treatment with A23187, whereas GM-CSF production was potentiated. We also detected the expression of mRNA for membrane-type 1 (MT1)-MMP, TIMP-1 and TIMP-2 after stimulation with PMA. Glucocorticoids and flavonoids inhibited MMP-9 production, and TIMPs and MMP inhibitors inhibited the gelatinolytic activity of mast cell-derived MMP-9. Furthermore, phenylmethylsulfonyl fluoride, a protease inhibitor, inhibited the conversion from proMMP-9 to active MMP-9. CONCLUSIONS: These results suggest that the human mast cell is a leading member of MMP production, and the production, activation and activity are controllable by pharmacological agents.     

PGE2-induced metalloproteinase-9 is essential for dendritic cell migration

Following antigen acquisition and maturation, dendritic cells (DCs) disengage from the extracellular matrix, cross basement membranes, and travel to draining lymph nodes to activate T cells. CCR7 expression is necessary but not sufficient for the directional migration of DCs. Prostaglandin E2 (PGE2), present in inflammatory sites, induces DC migration, presumably by enacting a migration-permissive gene expression program. Since regulation of DC migration is highly important for their use in vaccination and therapy, we examined the PGE2-induced changes in the expression of metalloproteinases (MMPs). Our results indicate that PGE2 significantly up-regulates MMP-9 expression, induces both secreted and membrane-bound MMP-9, and that in turn, DC-derived MMP-9 is essential for DC chemotaxis in response to the CCR7 ligand CCL19, Matrigel migration, and in vivo migration in both wild-type and MMP-9-deficient hosts. We conclude that DCs matured within inflammatory sites require both CCR7 and PGE2-induced MMP-9 for their directional migration to draining lymph nodes.     

Differential Expression of Three Matrix Metalloproteinases, MMP-19, MMP-26, and MMP-28, in Normal and Inflamed Intestine and Colon Cancer

Several matrix metalloproteinases (MMPs) have been implicated in intestinal inflammation, mucosal wound healing, and cancer progression. The purpose of this study was to examine the cellular location and putative function of MMP-19, MMP-26 (matrilysin-2), and MMP-28 (epilysin), in normal, inflammatory, and malignant conditions of the intestine. Peroperative tissue specimens from patients with ulcerative colitis (UC) (n = 16) and archival tissue samples of ischemic colitis (n = 9), Crohn's disease (n = 7), UC (n = 8), colon cancer (n = 20), and healthy intestine (n = 5) were examined using immunohistochemical analyses with polyclonal antibodies. Unlike many classical MMPs, MMP-19, MMP-26, and MMP-28 were all expressed in normal intestine. In inflammatory bowel disease (IBD), MMP- 19 was expressed in nonmigrating enterocytes and shedding epithelium. MMP-26 was detected in migrating enterocytes, unlike MMP-28. In colon carcinomas, MMP-19 and MMP-28 expression was downregulated in tumor epithelium. Staining for MMP-26 revealed a meshwork-like pattern between cancer islets, which was absent from most dedifferentiated areas. Our results suggest that MMP-19 is involved in epithelial proliferation and MMP-26 in enterocyte migration, while MMP-28 expression is not associated with inflammatory and destructive changes seen in IBD. In contrast to many previously characterized MMPs, MMP-19 and MMP-28 are downregulated during malignant transformation of the colon and may play a prominent role in tissue homeostasis.     

Expression of matrix metalloproteinases in vasculitic neuropathy

The aim of this study was to investigate the expression pattern and cellular source of matrix metalloproteinases (MMP) in vasculitic neuropathy. Matrix metalloproteinases are endopeptidases degrading components of extracellular matrix proteins, and they have been implicated in the pathogenesis of inflammatory demyelination. They are induced by cytokines, secreted by inflammatory cells, and enhance T cell migration. Vasculitic neuropathy occurs as a component of systemic vasculitis or as an isolated angiitis of the peripheral nervous system, and T cell-mediated inflammation is detected in its pathogenesis. Nerve biopsy sections of eight patients with nonsystemic vasculitic neuropathy (NSVN) and four with systemic vasculitic neuropathy were examined for the presence of CD4+, CD8+, and CD68+ cells and immunohistochemically for MMP-2 and MMP-9 expression. Nerve biopsies of eight patients with noninflammatory neuropathy were used as a control group. Semiquantitative polymerase chain reaction analysis was performed to detect MMP-2 and MMP-9 mRNA. The predominant cells were CD8+ and CD68+ T cells. Expression of MMP-9, but not MMP-2, was increased in perivascular inflammatory infiltrate in nerve tissues of vasculitic neuropathy patients. This MMP-9 expression correlated positively with immunostaining of CD8+ T cells. No difference was detected between immunostaining patterns of nonsystemic and systemic vasculitic neuropathies with the antibodies used, except in MMP-9 immunostaining, which was found to be enhanced in NSVN group. Polymerase chain reaction analysis revealed elevated mRNA levels of MMP-9 and MMP-2 compared with controls, but this did not reach statistical significance. Our results imply a pathogenic role for MMP-9 secreted from CD8+ cells in vasculitic neuropathy.     

Increased acinar damage of salivary glands of patients with Sjögren's syndrome is paralleled by simultaneous imbalance of matrix metalloproteinase 3/tissue inhibitor of metalloproteinases 1 and matrix metalloproteinase 9/tissue inhibitor of metalloproteinases 1 ratios

OBJECTIVE: Previous findings in labial salivary glands (LSGs) from patients with Sj?gren's syndrome (SS) suggest that increased activity and expression of matrix metalloproteinase 9 (MMP-9) and MMP-3 trigger the destruction of acinar structures in these glands. Tissue inhibitors of matrix metalloproteinases (TIMPs) tightly control MMP activity, and TIMP expression is an important modulator of effects attributed to MMPs. This study was undertaken to investigate the correlation between the balance of MMPs/TIMPs in the LSGs of SS patients and the degree of inflammatory infiltration and acinar structure integrity. METHODS: Three groups of SS patients classified according to focus score and residual tissue were studied. The expression of MMP-2, MMP-3, MMP-9, TIMP-1, and TIMP-2 was examined at the messenger RNA and protein levels. The ratio of MMP/TIMP expression (R value) was calculated. Focus score and acinar structure were evaluated by histologic analysis. RESULTS: In SS patients the MMP-3/TIMP-1 ratio was higher than 1 and the MMP-9/TIMP-1 ratio was much higher than 1 whereas the MMP-2/TIMP-2 ratio nearly equaled 1, suggesting elevated proteolytic activity due mainly to MMP-9. R values were independent of the focus score of inflammatory cells, but correlated well with the dramatic changes observed in morphologic integrity of acini, as revealed mainly by the lack of nuclear polarity. Acinar changes were more evident when R values for both MMP-9/TIMP-1 and MMP-3/TIMP-1 were higher. CONCLUSION: This study provides evidence that an altered balance between MMPs and their inhibitors is associated with acinar damage. Since salivary gland acinar cells express both MMPs and TIMPs, these cells may play an important role in extracellular matrix destruction and in the LSG pathophysiology in SS.     

肿瘤坏死因子样凋亡的微弱诱导剂诱导成纤维样滑膜细胞合成基质金属蛋白酶-1机制的研究

目的 通过研究p38丝裂原活化蛋白激酶(MAPK)信号通路在肿瘤坏死因子样凋亡的微弱诱导剂(TWEAK)诱导类风湿关节炎(RA)成纤维样滑膜细胞(FLS)合成基质金属蛋白酶(MMP)-1过程中的作用,探讨TWEAK参与RA发病的机制.方法 将重组TWEAK与FLS共培养,对经或未经SB203580预处理的FLS,应用酶联免疫吸附试验(ELISA)法检测细胞培养液中MMP-1水平;应用Western-blot法检测FLS中p-p38MAPK和P65的表达.结果 100 ng/ml的TWEAK能够明显诱导RAFLS合成MMP-1;SB203580能够部分抑制TWEAK诱导RA FLS合成的MMP-1;TWEAK作用于RAFLS,能够使D38MAPK磷酸化,并使细胞核内P65蛋白表达增加.结论 TWEAK诱导RA FLS合成MMP-1过程中,p38MAPK信号通路处于激活状态,并诱导核因子(NF)-κB的表达.     

Adenovirus mediated intra-articular expression of collagenase-3 (MMP-13) induces inflammatory arthritis in mice

OBJECTIVES: To better understand the role of collagenase-3 (MMP-13) in joint inflammation by investigating the consequences of transient overexpression of human collagenase-3 (matrix metalloproteinase-13 (MMP-13)), introduced by adenoviral gene delivery, in the mouse knee joint. METHODS: A single dose (5x10(7) pfu) of recombinant adenovirus coding either for beta-galactosidase (RAdLacZ) or human MMP-13 (RAdMMP-13) was injected intra-articularly into the knee joint of adult mice. The joints were analysed at frequent intervals up to 4 weeks by histology, immunohistochemistry, and RNA analysis. RESULTS: When RAdLacZ reporter virus was used, adenoviruses efficiently infected synovial cells, chondrocytes of articular cartilage, and hypertrophic chondrocytes of the growth plate. The infection was transient as no reporter gene activity was detected 3 weeks after the injection. After RAdMMP-13 injection into the knee joints, expression of human MMP-13 in joint tissues resulted in an arthritis characterised by recruitment of inflammatory cells and increased production of cytokines and chemokines, synovial hyperplasia, and pannus formation. After the loss of MMP-13 transgene expression at 3 weeks, these inflammatory changes began to diminish. CONCLUSIONS: MMP-13 has a role in the onset of inflammatory reaction in synovium. However, damage to articular cartilage was only rarely detected after the short term overexpression of MMP-13.     

Metalloproteinases and tissue inhibitors of metalloproteinases in exudative pleural effusions.

The aim of this study was to assess the expression of several metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in exudative pleural effusions, and their relationship with inflammatory and fibrinolytic mediators in parapneumonic effusions. The study included 51 parapneumonic effusions (30 empyema or complicated parapneumonic, 21 noncomplicated parapneumonic), 28 tuberculous, 30 malignant and 30 transudates. Inflammatory markers (tumour necrosis factor-alpha, interleukin-8, polymorphonuclear elastase), fibrinolytic system variables (tissue plasminogen activator (PA), urokinase PA (u-PA), plasminogen activation inhibitor (PAI)-1, PAI-2), and several MMPs (MMP-1, MMP-2, MMP-8, MMP-9) and TIMPs (TIMP-1, TIMP-2) were determined by ELISA in plasma and pleural fluid. Elevated MMP-2 and TIMP-1 concentrations were observed in all the pleural fluid samples studied. The group of empyema or complicated parapneumonic effusions showed higher MMP-1, MMP-8 and MMP-9 concentrations than the remaining exudates. There was no correlation between MMP and TIMP levels in plasma and pleural fluid in this group of effusions. In parapneumonic effusions, MMP-1, MMP-8 and MMP-9 showed a positive correlation with the inflammatory markers and with u-PA and PAI-1. Moreover, there was a relationship between MMP-8 concentration in pleural fluid and pleural thickening at the end of treatment. In conclusion, elevated metalloproteinase-1, -8 and -9 expression was found in parapneumonic pleural effusions. These metalloproteinases could be implicated in the local inflammatory response existing in this group of effusions.