Tissue inhibitor of metalloproteinase gene from pearl oyster Pinctada martensii participates in nacre formation.

Tissue inhibitors of metalloproteinases (TIMPs) are nature inhibitors of matrix metalloproteinases and play a vital role in the regulation of extracellular matrix turnover, tissue remodeling and bone formation. In this study, the molecular characterization of TIMP and its potential function in nacre formation was described in pearl oyster Pinctada martensii. The cDNA of TIMP gene in P. martensii (Pm-TIMP) was 901 bp long, containing a 5' untranslated region (UTR) of 51 bp, a 3' UTR of 169 bp, and an open reading fragment (ORF) of 681 bp encoding 226 amino acids with an estimated molecular mass of 23.37 kDa and a theoretical isoelectric point of 5.42; The predicted amino acid sequence had a signal peptide, 13 cysteine residues, a N-terminal domain and a C-terminal domain, similar to that from other species. Amino acid multiple alignment showed Pm-TIMP had the highest (41%) identity to that from Crassostrea gigas. Tissue expression analysis indicated Pm-TIMP was highly expressed in nacre formation related-tissues, including mantle and pearl sac. After decreasing Pm-TIMP gene expression by RNA interference (RNAi) technology in the mantle pallium, the inner nacreous layer of the shells showed a disordered growth. These results indicated that the obtained Pm-TIMP in this study participated in nacre formation.

Matrix metalloproteinases and their tissue inhibitors in cuprizone-induced demyelination and remyelination of brain white and gray matter.

Apart from their involvement in the pathogenesis of demyelinating diseases such as multiple sclerosis, there is emerging evidence that matrix metalloproteinases (MMPs) also promote remyelination. We investigated region-specific expression patterns of 11 MMPs and 4 tissueinhibitors of metalloproteinases (TIMPs) in the cuprizone murine demyelination model. Messenger RNA (mRNA) was extracted at different time points of exposure to cuprizone from microdissected samples of corpus callosum, cortex, and ex vivo isolated microglia and analyzedusing quantitative reverse transcription-polymerase chain reaction.Matrix metalloproteinase 12 and TIMP-1 mRNA were significantly upregulated versus age-matched controls in both areas during demyelination and remyelination. Matrix metalloproteinases 3, 11, and 14 mRNA were upregulated only in white matter during remyelination. Matrix metalloproteinase 24 mRNA was downregulated during both demyelination and remyelination. To identify potential cellular sources of the MMPs and TIMPs, we isolated microglia and detected high MMP-12and TIMP-2 mRNA upregulation at the peak of demyelination.By immunohistochemistry, MMP-3 protein was localized in astrocytes and MMP-12 was identified in microglia, astrocytes, and cells of oligodendrocyte lineage. These findings suggest that MMPs and TIMPs have roles in the regulation of demyelination and remyelination in thismodel. Moreover, differences in the expression levels of these genesbetween white and gray matter reveal region-specific molecularmechanisms.

Collagenases in cancer.

Three mammalian collagenases (MMP-1, MMP-8, and MMP-13) belong to family of matrix metalloproteinases and are the principal secreted endopeptidases capable of cleaving collagenous extracellular matrix. In addition to fibrillar collagens, collagenases can cleave several other matrix and non-matrix proteins including growth factors, and this way regulate cell growth and survival. Collagenases are important proteolytic tools for extracellular matrix remodeling during organ development and tissue regeneration, but they also apparently play important roles in many pathological situations and tumor progression and metastasis. Because of their potentially destructive characteristics the expression and activity of collagenases are strictly controlled. Synthesis of collagenases is regulated by extracellular signals via cellular signal transduction pathways at transcriptional and post-transcriptional level. Collagenases are synthesized as inactive pro-forms, and once activated, their activity is inhibited by specific tissue inhibitors of metalloproteinases, TIMPs, as well as by non-specific proteinase inhibitors. In this review we discuss the current view on the role of collagenases in tumor growth, invasion, and metastasis, as a basis for their feasibility in diagnosis and prognostication, as well as therapeutic targets in cancer patients.

The TIMPs tango with MMPs and more in the central nervous system.

The matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular proteases that have been implicated in CNS development and disease. Crucial homeostatic regulation of MMPs is mediated through the expression and actions of the tissue inhibitors of metalloproteinases (TIMPs). Although the TIMPs are recognized inhibitors of the MMPs, recent studies have revealed that these proteins also can exhibit biological activities that are distinct from their interactions with or inhibition of the MMPs. With our understanding of the roles of the TIMPs in the CNS continuously emerging, this review examines the current state of knowledge regarding the multifarious and novel functions of this family of proteins, with particular attention to their increasing potential in the development, plasticity, and pathology of the CNS.

Expression pattern of metalloproteinases and tissue inhibitors of matrix-metalloproteinases in cycling human endometrium.

The cyclic growth, differentiation, and cell death of endometrium represents the most dynamic example of steroid-driven tissue turnover in human adults. Key effectors in these processes-matrix metalloproteinases (MMPs) and their specific inhibitors (TIMPs)-are regulated by ovarian steroids and, locally, by cytokines. We used reverse transcription-polymerase chain reaction to evaluate the expression of both transcriptionally regulated molecules such as estrogen receptor-alpha, progesterone receptor, and prolactin and a large array of MMPs and TIMPs (MMP-1, -2, -3, -7, -8, -9, -11, -12, -19, -26, MT1-MMP, MT2-MMP, MT3-MMP, TIMP-1, -2, -3). Altogether, three distinct patterns of MMP and two patterns of TIMP expression were detected in cycling endometrium: 1). MMPs restricted to the menstrual period (MMPs-1, -3, -8, -9, -12); 2). MMPs and TIMPs expressed throughout the cycle (MMP-2, MT1-MMP, MT2-MMP, MMP-19, TIMP-1, and TIMP-2); 3). MMPs predominantly expressed during the proliferative phase (MMP-7, MMP-11, MMP-26, and MT3-MMP); and 4). TIMP-3, which, contrary to the other TIMPs, shows significant modulations, with maximum expression during the late secretory and menstrual phases. These specific patterns of MMP expression associated with each phase of the cycle may point to specific roles in the processes of menstruation, housekeeping activities, angiogenesis, tissue growth, and extracellular matrix remodeling.

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.

MMPs and TIMPs--an historical perspective.

There are currently 25 known vertebrate matrix metalloproteinases (MMPs) and 4 tissue inhibitors of metalloproteinases (TIMPs). This article reviews these proteases from an historical perspective in terms of who discovered each protein, when the sequence was established, when action on protein substrates was demonstrated, and what names have been used. A similar approach is taken for the TIMPS, and their multiple functions in addition to protease inhibition are emphasized. MMPs from invertebrates, plants, and bacteria are also discussed. This review is an outgrowth and update of a chapter by the same name originally published in Matrix Metalloproteinase Protocols, pp. 1-23, edited by I. M. Clark and published by Humana Press in 2001.

Human endothelial gelatinases and angiogenesis.

Endothelial cell invasion is an essential event during angiogenesis (formation of new blood vessels). The process involves the degradation of the basement membrane and the underlying interstitium. The matrix metalloproteinase (MMP) family is considered to be primarily responsible for matrix degradation. Two members of the family, gelatinase A and B play an important role in angiogenesis. This review outlines recent findings on their regulation in human endothelial cells. Latent gelatinase B is secreted from endothelial cells. This enzyme can also accumulate in the cytosol as an active enzyme, free of TIMP-1. In contrast, latent gelatinase A is constitutively secreted from the cells. Unlike other MMPs, gelatinase A activation occurs on the cell membrane and is mediated by MT1-MMP. A number of physiological activators have recently been described. These include thrombin and activated protein C, both of which activate gelatinase A independent of the MT1-MMP pathway. These new findings may lead to therapeutic interventions for the treatment of angiogenic-dependent diseases such as cancer and arthritis.

[Recent progress of matrix metalloproteinase (MMP) research and its clinical application for cancer therapy].

The matrix metalloproteinases (MMPs) are a family of secreted and membrane-bound zinc-endopeptidases. These enzymes are capable of degrading the extracellular matrix, including collagens, laminin, proteoglycan and fibronectin. In some human cancers, a positive correlation has been demonstrated between MMP expression and the likelihood of developing metastasis. An imbalance between MMPs and the tissues inhibitor of metalloproteinases (TIMPs) may play a significant role in the invasive phenotype of cancers. Although TIMPs have been shown to inhibit tumor metastasis in some in vivo models, they are not suitable for pharmacologic applications due to their short half-life in vivo and large molecular size. In this paper, recent advances in MMP research and reports of clinical applications of synthetic MMP inhibitors for cancer patients are reviewed.