Tension Force Downregulates Matrix Metalloproteinase Expression and Upregulates the Expression of Their Inhibitors through MAPK Signaling Pathways in MC3T3-E1 cells

Objective: Matrix metalloproteinases (MMPs), produced by osteoblasts, catalyze the turnover of extracellular matrix (ECM) molecules in osteoid, and the regulation of MMP activity depends on interactions between MMPs and tissue inhibitors of metalloproteinases (TIMPs). We focused on the degradation process of ECM in osteoid that was exposed to mechanical strain, and conducted an in vitro study using MC3T3-E1 osteoblastic cells to examine the effects of tension force (TF) on the expression of MMPs and TIMPs, and activation of mitogen-activated protein kinase (MAPK) pathways.Design: Cells were incubated on flexible-bottomed culture plates and stimulated with or without cyclic TF for 24 hours. The expression of MMPs and TIMPs was examined at mRNA and protein levels by real-time RT-PCR and Western blotting, respectively. The phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38 MAPK, and stress-activated protein kinases/c-jun N-terminal kinases (SAPK/JNK) were examined by Western blotting.Results: TF decreased the expression of MMP-1, -3, -13 and phosphorylated ERK1/2. In contrast, TF increased the expression of TIMP-2, -3 and phosphorylated SAPK/JNK. The expression of MMP-2, -14, TIMP-1, -4 and phosphorylated p38 MAPK was unaffected by TF. MMP-1, -3 and -13 expression decreased in cells treated with the ERK inhibitor PD98059 compared with untreated control cells. The JNK inhibitor SP600125 inhibited the TF-induced upregulation of TIMP-2 and -3.Conclusions: The results suggest that TF suppresses the degradation process that occurs during ECM turnover in osteoid via decreased production of MMP-1, -3 and -13, and increased production of TIMP-2 and -3 through the MAPK signaling pathways in osteoblasts.     

Expression of metalloproteinases and its inhibitor in later stage of rabbit neointima development

Neointima formation after arterial de-endothelialization refers not only to smooth muscle cell (SMC) migration and proliferation, but also involves extracellular matrix (ECM) metabolism. Most studies regarding the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in neointima have focused on the early phase of vascular remodeling. In this study, we examined the expression of MMP and TIMP in rabbit aortic neointima at a relatively late stage of lesion development, between 4 and 12 weeks after initial de-endothelialization. Northern blot analysis revealed expression of steady-state MMP-9 mRNA was increased up to the 4th week and MMP-2 mRNA to the 12th week after de-endothelialization. In situ hybridization shown that MMP positive cells were predominantly distributed in arterial neointima. Expression of TIMP-1 mRNA was continuously up-regulated up to the 12th week and TIMP-1 positive cells, primarily SMCs, were also localized to the neointimal tissue. Alteration at mRNA level was accompanied by that at protein level, as assessed by SDS-PAGE zymography for MMPs and immunoblotting for TIMP-1. The profile of alteration at protein level correlated well with that at mRNA level. These data suggest that synthesis of MMPs and TIMP is a prolonged process and arterial SMC is a major source of MMP production in arterial neointima. Enhanced synthesis of MMPs and TIMPs at late stage of neointimal development may contribute to arterial ECM metabolism.     

Expression and Roles of MMP-2, MMP-9, MMP-13, TIMP-1, and TIMP-2 in Allergic Nasal Mucosa

Purpose

Allergic rhinitis (AR) and asthma share many characteristics, but structural changes are observed far less often in AR. Matrix metalloproteinases (MMPs) constitute a family of Zn-dependent endopeptidases that can decompose the extracellular matrix and basement membrane, and regulate cell infiltration. We analyzed the expression of MMPs and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), in allergic nasal mucosa after nasal allergen challenge (NAC) and determined their relationship to inflammatory cells.

Methods

Nasal mucosa specimens were obtained at surgery performed for hypertrophied turbinates. We performed NAC with house dust mite (HDM) allergen disks and control disks, and took biopsies at 30 minutes, 6 hours, and 12 hours after NAC. Cells expressing MMP-2, MMP-9, MMP-13, TIMP-1, and TIMP-2, as well as eosinophils and mast cells, were analyzed immunohistochemically. The MMPs and TIMPs in allergic nasal mucosa were quantified using enzyme-linked immunosorbent assays.

Results

At 30 minutes post-NAC, HDM-exposed nasal mucosa exhibited significantly more MMP-2+, MMP-9+, MMP-13+, TIMP-1+, and TIMP-2+ cells compared with control mucosa, and the numbers of MMP-9+ and TIMP-1+ cells correlated strongly with the number of mast cells. At 6 hours post-NAC, the numbers of MMP+ and TIMP+ cells did not differ significantly between HDM-exposed mucosa and control mucosa, but the ratios of MMP+ cells to TIMP+ cells were higher in HDM-exposed mucosa. At 12 hours post-NAC, the number of MMP-13+ cells tended to be higher in HDM-exposed mucosa and was strongly correlated with the number of eosinophils. Quantitatively, the levels of MMP-2 and MMP-13 were significantly higher than the MMP-9 level, and the TIMP-2 level was significantly higher than the TIMP-1 level in allergic nasal mucosa.

Conclusions

We demonstrated increased expression of MMP-2, MMP-9, and MMP-13 in allergic nasal mucosa, high MMPs-to-TIMP-1 ratios, and a strong correlation between MMP-9 and mast cells and between MMP-13 and eosinophils. The imbalance between MMPs and TIMPs may contribute to the migration of inflammatory cells such as eosinophils and mast cells to the nasal mucosa of AR patients, suggesting a possible active role of MMPs in AR.     

基质金属蛋白酶及其组织抑制因子在人前列腺组织及各种类型前列腺细胞中的表达

目的：研究基质金属蛋白酶（MMPs）及其组织抑制因子（TIMPs）在人前列腺组织及各种类型细胞中的表达。方法： 用半定量RT－PCR的方法，对癌变和非癌变部分的前列腺组织、原代培养的平滑肌细胞、成纤维细胞、上皮细胞以及4种前列腺上皮细胞系（BPH－1、LNCaP、DU－145和PC－3）中MMP2、MMP7和MMP9、膜型基质金属蛋白酶1和3（MT1－MMP和MT3－MMP）及其组织抑制因子1和2（TIMP－1和TIMP－2）的mRNA 水平进行了测定。结果：MMP-2主要在前列腺基质细胞中表达；MMP-7和MMP-9则在前列腺上皮细胞中有较高的表达；MT1-MMP、MT3-MMP、TIMP-1和TIMP-2在前列腺基质细胞和上皮细胞中均有表达，但MT1-MMP和MT3-MMP在成纤维细胞中的表达量较高；另外，各种基质金属蛋白酶及其组织抑制因子在各种前列腺细胞系中也存在差异表达。结论： MMPs和TIMPs在前列腺组织及其各种类型细胞中的差异表达提示：它们可能在前列腺癌的转移中起着不同的作用。     

Immunohistochemical study of metalloproteinases and their tissue inhibitors in the lungs of patients with diffuse alveolar damage and idiopathic pulmonary fibrosis.

Immunohistochemical and confocal microscopic studies of the localization of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and type IV collagen were made in lung tissues from patients with normal pulmonary histology (n = 3), diffuse alveolar damage (n = 14), and idiopathic pulmonary fibrosis (n = 12). Pretreatment with pepsin revealed otherwise undetectable MMP- and TIMP-immunoreactive sites. In normal lung, MMP-2, MMP-9, TIMP-1, and TIMP-2 were localized in ciliated cells, endothelial cells, pneumocytes, macrophages, and smooth muscle cells; fibroblasts showed a strong reaction only for MMP-2. Only TIMP-2 showed co-localization with type IV collagen. Myofibroblasts and epithelial cells expressed increased reactivity for MMPs and TIMPs in both disorders. The reactivities for MMPs and TIMPs were stronger in diffuse alveolar damage. MMP-2 showed focal co-localization in capillary endothelial and disrupted epithelial basement membranes, suggesting activation of collagenolysis. A protective effect against this lysis was suggested by the extensive co-localization of TIMP-2 with type IV collagen and fibrillar collagens. Alveolar buds showed increased reactivity for MMPs and TIMPs in their lining epithelial cells, myofibroblasts, and their basement membranes; however, their matrices were mostly unreactive. These findings emphasize the complexity of the roles of MMPs and TIMPs in collagen turnover in diffuse alvcolar damage and idiopathic pulmonary fibrosis.     

Expression of matrix metalloproteinases, tissue inhibitors of metalloproteinase, collagens, and Ki67 antigen in pleural malignant mesothelioma: an immunohistochemical and electron microscopic study

Because matrix metalloproteinases (MMPs) degrade extracellular matrix, including basement membrane, and because tissue inhibitors of MMP (TIMPs) suppress MMP activities, MMPs and TIMPs are considered to play important roles in invasion and metastasis in many malignancies. We examined immunohistochemically the expression of MMPs (MMP-1, -2, -3, -7, and -9), TIMPs (TIMP-1 and -2), and collagens (types I, III, and IV) in 16 patients with pleural malignant mesothelioma (PMM; 8 with the epithelial, 4 with the sarcomatous, and 4 with the biphasic type). Electron microscopy revealed that the tumor cells in all types possessed the characteristics of malignant mesotheliomas, including numerous microvilli and moderate amounts of intermediate filaments. Basement lamina was present only focally. The proliferative Ki67 index was at a high level, compared with values reported in various other malignancies. Positive staining for MMP-1 was observed in most tumor cells in all 16 patients (100%). MMP-2 was expressed in most tumor cells in 2 patients (13%). In contrast, MMP-3, -7, and -9 were not detected in any PMM. TIMP-1 and TIMP-2 were expressed in 3 patients (19%) and 2 patients (13%), respectively. The stromal cells were simultaneously positive for MMPs or TIMPs in the patients whose tumor parenchymal cells were positive for each enzyme. These results indicate that the expression of MMP-1 and MMP-2 may be related to PMM invasion and spread. In particular, as MMP-1 was overexpressed in contrast to the lower expression of TIMP-1, MMP-1 is strongly suggested to play an important role in PMM invasion by degrading the tumor stroma. In spite of general agreement that epithelial-type PMM has a better prognosis than other types, there was no significant difference in the Ki67 index among the histological types of PMM.     

Increased matrix metalloproteinases as possible cause of osseoarticular tissue destruction in long-term haemodialysis and β2-microglobulin amyloidosis

Immunolocalization of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in periarticular tissues of ₂-microglobulin amyloidosis patients was investigated. MMP-1 (interstitial collagenase) the most strongly expressed of the MMPs, was localized in the synovial lining cells, mesenchymal cells in granulation tissue and nodular amyloid deposits, and chondrocytes within areas of cartilage erosion. Expression of MMP-1 was correlated with the degree of macrophage infiltration and synovial cell hyperplasia, but it was not correlated with the degree of amyloid deposition or haemodialysis period. Expression of MMP-1 appeared more intense than that of TIMP-1 and TIMP-2 in highly inflammatory cases. MMP-2 was mildly expressed in the interstitial fibroblasts and MMP-3 was faintly stained in the extracellular matrix of the synovial membrane. MMP-9 (gelatinase B) was found to be strongly positive in the osteoclasts which increased in the progressing osteolytic lesion from the destructive arthropathy. These results suggest involvement of MMPs in inflammation with an imbalance between expression of MMPs and TIMPs being closely related to pathogenesis of the destructive arthropathy.     

MMP-2, MMP-9 and their inhibitors TIMP-2 and TIMP-1 production by human monocytes in vitro in the presence of different forms of hydroxyapatite particles

After calcium-phosphates biomaterials based implantation like hydroxyapatite (HA) coating, particles are released in the periprosthetic tissues. Wear-debris induced fibrous membranes contain macrophage subsets that can produce metalloproteinases (MMPs), which are considered to be key enzymes in extra-cellular matrix turnover. Tissue inhibitors of metalloproteinases (TIMPs) are important regulator of MMPs activity. Interleukin-1 mainly produced by monocytes can also regulate MMPs production. In the present work, we have evaluated the effect of HA particles characteristics (size, shape and sintering temperature) on the MMP-2, -9 and their respective inhibitors TIMP-2, -1 production. Our results demonstrate that sintering temperature (that modify crystal size and surface area) have little effect on MMPs and TIMPs production. Non-phagocytable particles induced more MMP-9, although phagocytable particles induced more IL-1beta release. The shape of the particles was the most important factor since needle-shaped particles induced the most significant up-regulated expression of MMPs and IL-1beta.     

Progesterone receptor modulator CDB-2914 induces extracellular matrix metalloproteinase inducer in cultured human uterine leiomyoma cells

Effects of progesterone receptor modulator CDB-2914 on the expression of the extracellular matrix (ECM) components were examined in cultured human uterine leiomyoma and myometrial cells. ECM metalloproteinase inducer (EMMPRIN), matrix metalloproteinases (MMPs), tissue inhibitors of MMP (TIMPs) and collagen levels were assessed by Western blot analysis, MMP activity assay and real-time RT-PCR. RNA interference (RNAi) of EMMPRIN was performed using small interfering mRNA. In cultured leiomyoma cells, CDB-2914 treatment at concentrations greater than or equal to 10(-8) M significantly increased EMMPRIN, MMP-1 and MMP-8 protein contents and MMP-1, MMP-2, MMP-3 and MMP-9 mRNA levels, and activity of MMP-1, MMP-2, MMP-3 and MMP-9 in the medium. TIMP-1 and TIMP-2 were significantly decreased at mRNA and protein levels by CDB-2914 treatment at concentrations > or =10(-7) M in these cells. CDB-2914 treatment decreased types I and III collagen protein contents. However, CDB-2914 treatment did not affect the ECM component expression in cultured myometrial cells. RNAi of EMMPRIN abrogated CDB-2914-mediated both induction of MMPs and reduction of TIMPs and collagens in cultured leiomyoma cells. These results suggest that CDB-2914 modulates the expression of EMMPRIN, MMPs, TIMPs and collagens in cultured leiomyoma cells without comparable effects on myometrial cells.     

Overexpression of tissue inhibitor of metalloproteinases-3 in intestinal and cutaneous lesions of graft-versus-host disease.

Matrix metalloproteinases (MMPs) have been implicated in the pathobiology of various T-cell-mediated inflammatory disorders of the intestine and skin. Their synthetic inhibitor has been shown to prevent lethal acute graft-versus-host disease in animal models. We intended to determine the expression of MMPs 1, 3, 7, 9, 10, 12, and 19 and tissue inhibitors of metalloproteinases (TIMPs) 1 and 3 in intestinal and cutaneous lesions of patients suffering from graft-versus-host disease after bone marrow transplantation. In situ hybridizations for MMPs 1, 3, 7, 10, and 12 as well as TIMPs 1 and 3 were performed using (35)S-labeled cRNA probes on intestinal (n = 13) and cutaneous specimens (n = 9) from patients with graft-versus-host disease. Immunohistochemical stainings were carried out to localize MMP-9, MMP-19, TIMP-3, and TGF-beta1 proteins, and TUNEL staining, to detect apoptotic cells. TIMP-3 mRNA and protein were detected in cutaneous lesions in areas with vacuolar degeneration of the basal epidermal layer in all skin samples, and they colocalized with apoptotic keratinocytes and partly with staining for TGF-beta. None of the MMPs examined were overexpressed in skin lesions. Signals for MMP-1 and MMP-3 mRNA was found in 10/13 and 5/13 intestinal biopsies, respectively. In the gut, MMP-19-positive epithelial cells, particularly in the crypts, were found in 10/13 samples. Expression of MMPs 7, 9, 10, and 12 was absent or very low. TIMPs 1 and 3 were expressed by stromal cells in 12/13 and 10/13 gut samples, respectively. Whereas TIMP-1 was expressed particularly by subepithelial cells where epithelium had shed away, TIMP-3 was detected in deeper areas. We conclude that MMPs are differentially regulated in the skin and gut lesions of graft-versus-host disease. In agreement with previous data on cancer cells, TIMP-3, induced by TGF-beta1, may contribute to the apoptosis of keratinocytes in cutaneous graft-versus-host disease lesions, leading to typical histopathological changes. We also conclude that MMPs play a less important role as effector molecules in intestinal graft-versus-host disease than in celiac or inflammatory bowel disease.     

Differential modulation of proliferation, matrix metalloproteinase expression and invasion of human head and neck squamous carcinoma cells by c-erbB ligands

Evidence suggests that there is an association between the abnormal expression of members of the c-erbB receptor tyrosine kinase family and poor prognosis in head and neck squamous cell carcinomas (HNSCC). Until now, the relative contributions of different c-erbB ligands to HNSCC progression have not been clearly defined. In this paper we examined the effects of ligands with different c-erbB receptor specificities in terms of their stimulation of HNSCC proliferation, expression of matrix metalloproteinases (MMPs) and invasion. Heregulin-beta1 (HRG-β1; selective c-erbB3/B4 ligand) was found to stimulate proliferation in the majority of cell lines, whereas epidermal growth factor (EGF; EGFR ligand) and betacellulin (BTC; EGFR/B4 ligand) induced variable responses. All three ligands up-regulated multiple MMPs including collagenases, stromelysins, matrilysin and gelatinase B (MMP-9) but had minimal or no effects on gelatinase A (MMP-2), MT1-MMP and tissue inhibitors of MMPs (TIMPs). MMP-9 mRNA was induced to a higher level than other MMPs, although with slower kinetics. HRG-β1 was less active than EGF and BTC at the optimal concentration (relative potency of EGF:BTC:HRG = 3:4:1). In vitro invasion through Matrigel was also increased by all three ligands in proportion to their MMP up-regulation. A specific anti-EGFR monoclonal antibody (mAb ICR62) inhibited MMP up-regulation, migration and invasion induced by all three ligands, whereas an anti-c-erbB-2 mAb ICR12 inhibited mitogenic and motogenic responses following ligand stimulation but had no effect on MMP expression. These results suggest that c-erbB ligands may differentially potentiate the invasive phenotype of HNSCC via co-operative induction of cell proliferation, migration and proteolysis. The EGFR signalling pathway appears to be the dominant component controlling the proteolytic and invasive phenotype in HNSCC, whereas the c-erbB-2 signalling pathway is responsible, in part, for the mitogenic and motogenic effects of ligands. This revised version was published online in July 2006 with corrections to the Cover Date.     

Gelatinase-B (Matrix Metalloproteinase-9; MMP-9) secretion is involved in the migratory phase of human and murine muscle cell cultures

The remodelling of connective tissue components is a fundamental requirement for a number of pivotal processes in cell biology. These may include myoblast migration and fusion during development and regeneration. In other systems, similar biological processes are facilitated by secretion of the matrix metalloproteinases (MMPs), especially the gelatinases. This study investigated the activity of the gelatinases MMP-2 and 9 by zymography on cell conditioned media in cultures of cells derived from explants of the human masseter muscle and in the murine myoblast cell-line C2C12. Expression of MMP-9 by western blotting and TIMP-1, the major inhibitor of MMPs, by northern blotting, during all phases of myoblast proliferation, migration, alignment and fusion, was also measured. Irrespective of the origin of the cultures, MMP-9 activity was secreted only by single cell and pre-fusion cultures whilst MMP-2 activity was secreted at all stages as well as by myotubes. The loss of MMP-9 activity was due to the loss of MMP-9 protein expression. TIMP-1 mRNA was not detectable at the single cell stage but its expression increased as cells progressed through the pre-fusion and post-fusion stages to reach a maximal in myotube containing cultures. Migration of cells derived from human masseter muscle was inhibited, using a specific anti-MMP-9 blocking monoclonal antibody (6-6B). These data are consistent with the concept that regulation of matrix turnover via MMP-9 may be involved in the events leading to myotube formation, including migration. Loss of expression of this enzyme and expression of TIMP-1 mRNA is associated with myotube containing cultures. Consequently, the ratio between MMPs and TIMPs maybe important in determining myoblast migration and differentiation.     

Expression and prognostic significance of matrix metalloproteinases and their tissue inhibitors in primary neuroendocrine carcinoma of the skin

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been implicated in the development and progression of many tumors, but data for primary neuroendocrine carcinoma (PNC) of the skin are lacking. The aim of the study was to assess the expression of MMPs and TIMPs in PNC and to evaluate their prognostic significance. Expression of MMP-1, MMP-2, MMP-3, MMP-9, MMP-11, MMP-13, and MMP-14 and TIMP-1, TIMP-2, and TIMP-3 was evaluated by immunohistochemistry on 23 samples of PNC of the skin. The results were matched with clinical features and patient survival. In the 23 specimens of PNC, high (>20% of positive neoplastic cells) MMP-1 expression was found in 13 (56.5%) cases. MMP-2 was evidenced in 12 (52.1%) cases, 8 (34.7%) of which showed high expression in neoplastic cells. MMP-3 was detected in 11 cases (47.8%), with high expression in 9 (39.1%) of them. High MMP-9 expression was observed in 3 (13%) cases, whereas high MMP-14 expression was detected in 11 (47.8%) specimens. Expression of TIMP-1 by neoplastic cells was found in 8 (34.7%) cases, with high expression in 3 cases, whereas high TIMP-3 expression was detected in 21 (91.3%) cases. No immunoreactivity for MMP-11, MMP-13, or TIMP-2 was found. Statistical analysis failed to identify a significant correlation between MMP/TIMP expression and clinical parameters. By univariate analysis, stage >I (P = 0.01), high expression of MMP-1 (P = 0.04) and MMP-3 (P = 0.01) resulted significant negative prognostic factors, whereas by multivariate analysis, stage was the only factor that affected survival (P = 0.02). Our results suggest that MMP-1 and MMP-3 may influence the invasive and metastatic potential of PNCs. It is conceivable that future attempts to specifically block MMP-1 and MMP-3 activity may provide a novel means to inhibit invasiveness and distant spread in selected patients with PNC.     

Differential expression of matrix metalloproteinases and their inhibitors in non-small cell lung cancer

In a comprehensive immunohistochemical study of the expression of ten metalloproteinases (MMPs) and their four inhibitors (TIMPs) in 115 non-small cell lung carcinomas (NSCLCs), the findings have been correlated with the histological and clinical features of the tumours. All MMPs and TIMPs were expressed in tumours, with frequencies ranging from 41% for MMP-2 to 68% for MMP-13. Stromal immunoreactivity ranged from 6% for TIMP-4 to 87% for MMP-13. In some tumours, an overexpression of these proteins, as revealed by stronger staining in cancer cells than in adjacent normal bronchial epithelium, was also observed. The frequency ranged from 1% for MMP-3 to 28% for MMP-13. Compared with squamous cell carcinoma (SqCC), adenocarcinoma (AdC) more frequently overexpressed MMP-1, -11, -13, -14, and TIMP-2, and TIMP-1 and/or TIMP-2 overexpression positively correlated with more advanced stage disease. None of the MMP or TIMP expression correlated with the ras genotype of the tumours. The higher frequency of MMP overexpression in AdC than in SqCC may relate to the greater tendency of the former for systemic metastasis. The association of TIMP-1 overexpression with more advanced disease may suggest a role in prognosis.     

Protein expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinase 1 and 2 in papillary thyroid carcinomas

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play an important role in tumor invasion and metastasis. There have been only a few studies on the protein expression of MMPs and TIMPs in thyroid carcinomas. Therefore, we investigated the protein expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in 86 papillary thyroid carcinomas using immunohistochemistry, semiquantitative scoring morphometry of immunohistochemistry, gelatin zymography, and western blotting. We also examined the correlations between the immunohistochemical scores and several clinicopathological parameters. The immunoreactivities of MMP-2, MMP-9, TIMP-1, and TIMP-2 were largely located in the tumor cells or non-tumor follicular cells and to a much lesser extent in the fibroblasts and endothelial cells in the tumor and non-tumor regions. Compared with non-tumor regions, these four proteins tended to be overexpressed in the tumor cells; the overexpression was found in 64 of 86 (74%), 80 of 86 (93%), 79 of 86 (92%), and 64 of 86 (74%) cases for MMP-2, MMP-9, TIMP-1, and TIMP-2, respectively. Gelatin zymography showed distinct bands of MMP-2 and MMP-9 in tumor extracts but vague bands in non-tumor extracts. Western blotting revealed the specific bands of MMP-2 and MMP-9 in both tumor and non-tumor extracts. Morphometric scoring revealed that high expression of these proteins significantly correlated with large tumor size, presence of lymph node metastasis, high clinical stage, high intrathyroidal invasion, and high vascular invasion. These data suggest that MMP-2, MMP-9, TIMP-1, and TIMP-2 proteins and activities are increased in tumors cells of papillary thyroid carcinomas and that they play an important role in the invasion and metastasis of papillary thyroid carcinomas.     

Metalloproteinases and their Tissue Inhibitors in Multiple Sclerosis

Matrix metalloproteinases (MMPs) comprise a family of proteolytic enzymes. MMPs are capable of disrupting the blood-brain barrier (BBB), mediating the destruction of extracellular matrix and myelin components. MMPs are also involved in the processing of a variety of cell surface molecules, including the proinflammatory cytokine TNF-alpha. Each of these mechanisms are thought to be important in the pathogenesis of multiple sclerosis (MS). We investigated mRNA expression of MMP-3, MMP-9 and two tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in parallel in blood mononuclear cells (MNC) from patients with MS and controls, using in situ hybridization. Numbers of MMP-9 mRNA-expressing cells in blood were higher in patients with MS compared to other neurological diseases (OND), other inflammatory neurological diseases (OIND) and healthy subjects (P<0.0001 for all comparisons). Patients with MS had also higher levels of MMP-3 and TIMP-1 mRNA expressing blood MNC compared to patients with OND and healthy subjects. A positive correlation was observed for MMP-9 and TIMP-1 mRNA expression in MS. These results demonstrate that MMPs and TIMPs are upregulated in MS and may contribute to the pathogenesis of the disease.