Induction of Cell Migration by Matrix Metalloprotease-2 Cleavage of Laminin-5
Structural changes in the extracellular matrix are necessary for cell migration during tissue remodeling and tumor invasion. Specific cleavage of laminin-5 (Ln-5) by matrix metalloprotease–2 (MMP2) was shown to induce migration of breast epithelial cells. MMP2 cleaved the Ln-5 γ2 subunit at residue 587, exposing a putative cryptic promigratory site on Ln-5 that triggers cell motility. This altered form of Ln-5 is found in tumors and in tissues undergoing remodeling, but not in quiescent tissues. Cleavage of Ln-5 by MMP2 and the resulting activation of the Ln-5 cryptic site may provide new targets for modulation of tumor cell invasion and tissue remodeling. 
Nitric Oxide Activates Metalloprotease Enzymes in Articular Cartilage
Nitric oxide (NO.) is a multifunctional messenger molecule generated by a family of enzymes, collectively termed the nitric oxide synthases. We investigated the role of NO. in the modulation of two metal-dependent proteolytic enzymes (collagenase and stromelysin) which are activated during inflammatory and infective arthritis. The inflammatory mediators interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and the bacterial cell wall fragment endotoxin, induced both nitric oxide synthase activity and stromelysin and collagenase activity in whole cell preparations and in conditioned media from explants of bovine and human cartilage. Both NO2- (the stable end-product of NO.) and metalloprotease activity were inhibited by competitive inhibitors of nitric oxide synthase. The NO. donor, S-nitroso-N-acetyl-D,L-penicillamine (SNAP) also induced metalloprotease activity in a dose-dependent fashion. These data provide evidence that NO. plays a regulatory role in the activation of metal-dependent proteases in articular chondrocytes and cartilage. 
A Novel Proteolytic Cleavage Involved in Notch Signaling: The Role of the Disintegrin-Metalloprotease TACE
The Notch1 receptor is presented at the cell membrane as a heterodimer after constitutive processing by a furin-like convertase. Ligand binding induces the proteolytic release of Notch intracellular domain by a γ-secretase-like activity. This domain translocates to the nucleus and interacts with the DNA-binding protein CSL, resulting in transcriptional activation of target genes. Here we show that an additional processing event occurs in the extracellular part of the receptor, preceding cleavage by the γ-secretase-like activity. Purification of the activity accounting for this cleavage in vitro shows that it is due to TACE (TNFα-converting enzyme), a member of the ADAM (a disintegrin and metalloprotease domain) family of metalloproteases. Furthermore, experiments carried out on TACE−/− bone marrow–derived monocytic precursor cells suggest that this metalloprotease plays a prominent role in the activation of the Notch pathway. 
Characterization of Trypsin-Like Serine Protease from Lethocerus indicus Salivary Venom and its Cytotoxic Effect against Human Epidermoid Carcinoma Cell, A431
Objective: Lethocerus indicus salivary venom characterization and evaluation of extracellular degradation activity and cytotoxic effect against native human collagen type 1 and epidermoid carcinoma cell, A431.
Method: Salivary venom extract was collected from adult insects by injecting 2% pilocarpine of 50 µml. Enzyme presence was detected by the apiZYM assay. The proteolytic activity was tested by the photometric and zymogram methods using specific fluorescent substrates and inhibitors. The cytotoxic activity was determined by the MTT assay and Trypan blue exclusion method. Apoptosis induction was observed using AO/EB staining solution. Digestion of extracellular matrix protein was detected against native human type I collagen.
Result: L. indicus salivary venom presents amylases, proteases, carbohydrases, phosphatases and lipases. Among them, protease enzyme showed highest composition. The highest rate of proteolytic activity observed at pH 8 in 35ºC (100 %). Serine proteases present predominantly in salivary venom. Cysteine and metalloproteases are also detected. The activation energy of salivary venom is 49.86 kJ. Use of serine inhibitor, PMSF inhibited 92.77% which indicated that the maximum activity was due to serine protease. Detection of trypsin-like protease was confirmed by using PMSF and TLCK with specific substrate, BApNA. It shows significant inhibitions, 82% and 78% respectively suggesting maximum influence in salivary venom. Degradation of the fibrillar native state collagen Type I into 8 smaller peptide bands showed it importance in medical application. IC50 concentration of venom that induces cytotoxicity in epidermoid carcinoma cells, A431was 2.3 µg/ml only. It gives prominent apoptotic features such as cytoplasmic membrane blebbing, nuclear contraction, nuclear fragmentation and contact inhibition.
Conclusion: We suggest that further investigation of the venom will lead to identification of active compound in L. indicus salivary venom for its potential use in therapeutic application. 
The Distribution of Matrix Metalloproteinase-2, Tissue Inhibitor of Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-4 in Psoriatic Skin
Aims: To evaluate the appearance and distribution of matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2) and tissue inhibitor of metalloproteinase-4 (TIMP-4) in lesional skin biopsies of psoriasis patients.
Study Design: Observational study.
Place and Duration of Study: Institute of Anatomy and Anthropology and Department of Infectology and Dermatology, RÄ«ga StradiÅ†š University, between September 2013 and June 2014.
Methodology: We included 40 patients (31 men, 9 women; age range 18-70 years) with Psoriasis vulgaris, with present characteristic psoriatic eruptions in typical localization sites and no treatment received. Skin samples were obtained using routine punch biopsy method. 10 clinically healthy skin samples obtained during nevus excision procedure were used as control material. All tissue specimens were stained with hematoxylin and eosin and by immunohistochemistry for MMP-2, TIMP-2 and TIMP-4. The intensity of staining was graded semiquantitatively. Spearman’s rank correlation coefficient was calculated.
Results: In psoriasis patients numerous MMP-2-containing keratinocytes were found in epidermis, MMP-2 positive dermal fibroblasts and inflammatory cells varied from few to abundant. Few epidermal cells and moderate to numerous dermal cells contained TIMP-2. Moderate to numerous epidermal and dermal cells contained TIMP-4. Statistically significant strong positive correlation was found between MMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .878, P = .000). Statistically significant moderate positive correlation was found between TIMP-2 and TIMP-4 in dermis (Spearman’s rank correlation coefficient = .639, P = .000) and between TIMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .564, P = .000).
Conclusion: TIMP-4 seems to be most important inhibitor of psoriatic skin degeneration, richly raised by MMP-2. Its moderate correlation with TIMP-2 proves involvement of other tissue inhibitors in the degeneration inhibition and gives evidence about possible patterning between the tissue inhibitors of metalloproteinases. 
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 Brou, C., Logeat, F., Gupta, N., Bessia, C., LeBail, O., Doedens, J.R., Cumano, A., Roux, P., Black, R.A. and Israël, A., 2000. A novel proteolytic cleavage involved in Notch signaling: the role of the disintegrin-metalloprotease TACE. Molecular cell, 5(2), pp.207-216.
 Debaraj, H., Shantibala, T., K. Lokeshwari, R. and Giri, S. (2014) “Characterization of Trypsin-Like Serine Protease from Lethocerus indicus Salivary Venom and its Cytotoxic Effect against Human Epidermoid Carcinoma Cell, A431”, Biotechnology Journal International, 4(9), pp. 990-1010. doi: 10.9734/BBJ/2014/12217.
 Sidhom, E., Pilmane, M. and Kisis, J. (2015) “The Distribution of Matrix Metalloproteinase-2, Tissue Inhibitor of Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-4 in Psoriatic Skin”, Journal of Advances in Medicine and Medical Research, 8(10), pp. 883-890. doi: 10.9734/BJMMR/2015/18206.