SciCombinator

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Concept: Matrix metalloproteinase

172

Infection with Wuchereria bancrofti can cause severe disease characterized by subcutaneous fibrosis and extracellular matrix remodeling. Matrix metalloproteinases (MMPs) are a family of enzymes governing extracellular remodeling by regulating cellular homeostasis, inflammation, and tissue reorganization, while tissue-inhibitors of metalloproteinases (TIMPs) are endogenous regulators of MMPs. Homeostatic as well as inflammation-induced balance between MMPs and TIMPs is considered critical in mediating tissue pathology.

Concepts: Inflammation, Extracellular matrix, Infection, Matrix metalloproteinase, Diethylcarbamazine, Filariasis, Wuchereria bancrofti, Tissue inhibitor of metalloproteinases

167

Tissue inhibitors of metalloproteinases (TIMPs) while originally characterized as inhibitors of matrix metalloproteinases (MMPs) have recently been shown to have a wide range of functions that are independent of their MMP inhibitory properties. Tissue inhibitor of metalloproteinases-3 (TIMP-3) is a potent inhibitor of VEGF-mediated angiogenesis and neovascularization through its ability to block the binding of VEGF to its receptor VEGFR-2. To identify and characterize the anti-angiogenic domain of TIMP-3, structure function analyses and synthetic peptide studies were performed using VEGF-mediated receptor binding, signaling, migration and proliferation. In addition, the ability of TIMP-3 peptides to inhibit CNV in a mouse model was evaluated. We demonstrate that the anti-angiogenic property resides in the COOH-terminal domain of TIMP-3 protein which can block the binding of VEGF specifically to its receptor VEGFR-2, but not to VEGFR-1 similar to the full-length wild-type protein. Synthetic peptides corresponding to putative loop 6 and tail region of TIMP-3 have anti-angiogenic properties as determined by inhibition of VEGF binding to VEGFR-2, VEGF-induced phosphorylation of VEGFR-2 and downstream signaling pathways as well as endothelial cell proliferation and migration in response to VEGF. In addition, we show that intravitreal administration of TIMP-3 peptide could inhibit the size of laser-induced choroidal neovascularization lesions in mice. Thus, we have identified TIMP-3 peptides to be efficient inhibitors of angiogenesis and have a potential to be used therapeutically in diseases with increased neovascularization.

Concepts: Protein, Signal transduction, Angiogenesis, Peptide, Enzyme inhibitor, Inhibitor, Matrix metalloproteinase, Tissue inhibitor of metalloproteinases

167

Synthetic inhibitors of matrix metalloproteinases (MMPs) designed previously as well as tissue inhibitors of metalloproteinases (TIMPs) lack enzyme selectivity, which has been a major obstacle for developing the inhibitors into safe and effective MMP-targeted drugs. Here we designed a fusion protein named APP-IP-TIMP-2, in which the ten amino acid residues sequence of APP-derived MMP-2-selective inhibitory peptide (APP-IP) is added to the N terminus of TIMP-2. The APP-IP and TIMP-2 regions of the fusion protein are designed to interact with the active site and the hemopexin-like domain of MMP-2, respectively. The reactive site of the TIMP-2 region, which has broad specificity against MMPs, is blocked by the APP-IP adduct. The recombinant APP-IP-TIMP-2 showed strong inhibitory activity toward MMP-2 (Ki(app) = 0.68 pM), whereas its inhibitory activity toward MMP-1, MMP-3, MMP-7, MMP-8, MMP-9 or MT1-MMP was six orders of magnitude or more weaker (IC(50) > 1 μM). The fusion protein inhibited the activation of pro-MMP-2 in the concanavalin A-stimulated HT1080 cells, degradation of type IV collagen by the cells, and the migration of the stimulated cells. As compared with the decapeptide APP-IP (t1/2 = 30 min), APP-IP-TIMP-2 (t1/2 > 96 h) showed much longer half-life in cultured tumor cells. Therefore, the fusion protein may be a useful tool to evaluate contributions of proteolytic activity of MMP-2 in various pathophysiological processes. It may also be developed as an effective anti-tumor drug that has restricted side effects.

Concepts: Protein, Amino acid, Acid, Collagen, Peptide, Matrix metalloproteinase, Glycine, Tissue inhibitor of metalloproteinases

166

To investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-κB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9).

Concepts: In vitro, Inhibitor, Matrix metalloproteinase, Caffeic acid, Metalloproteinase, MMP2, MMP9, EC 3.4.24

164

Proteolytic activity of cell surface-associated MT1-MMP (MMP-14) is directly related to cell migration, invasion and metastasis. MT1-MMP is regulated as a proteinase by activation and conversion of the latent proenzyme into the active enzyme, and also via inhibition by tissue inhibitors of MMPs (TIMPs) and self-proteolysis. MT1-MMP is also regulated as a membrane protein through its internalization and recycling. Routine immunohistochemistry, flow cytometry, reverse transcription-PCR and immunoblotting methodologies do not allow quantitative imaging and assessment of the cell-surface levels of the active, TIMP-free MT1-MMP enzyme. Here, we developed a fluorescent reporter prototype that targets the cellular active MT1-MMP enzyme alone. The reporter (MP-3653) represents a liposome tagged with a fluorochrome and functionalized with a PEG chain spacer linked to an inhibitory hydroxamate warhead. Our studies using the MP-3653 reporter and its inactive derivative demonstrated that MP-3653 can be efficiently used not only to visualize the trafficking of MT1-MMP through the cell compartment, but also to quantify the femtomolar range amounts of the cell surface-associated active MT1-MMP enzyme in multiple cancer cell types, including breast carcinoma, fibrosarcoma and melanoma. Thus, the levels of the naturally expressed, fully functional, active cellular MT1-MMP enzyme are roughly equal to 1x105 molecules/cell, while these levels are in a 1x106 range in the cells with the enforced MT1-MMP expression. We suggest that the reporter we developed will contribute to the laboratory studies of MT1-MMP and then, ultimately, to the design of novel, more efficient prognostic approaches and personalized cancer therapies.

Concepts: Protein, Gene expression, Cancer, Breast cancer, Metastasis, Lung cancer, Protease, Matrix metalloproteinase

29

The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors) have been discussed toward cosmeceutical application. In addition, atopic dermatitis and the possible role of matrix metalloproteinase (MMP) in skin-related diseases have been explored extensively for cosmeceutical products. The proper development of marine algae compounds will be helpful in cosmeceutical product development and in the development of the cosmeceutical industry.

Concepts: Algae, Cosmetics, Matrix metalloproteinase, Active ingredient, Food and Drug Administration, Seaweed, Algaculture, Cosmeceutical

29

Disruption of the blood-brain barrier (BBB) is a serious complication frequently encountered in neurodegenerative disorders. Infantile neuronal ceroid lipofuscinosis (INCL) is a devastating childhood neurodegenerative lysosomal storage disorder caused by palmitoyl-protein thioesterase-1 (PPT1) deficiency. It remains unclear whether BBB is disrupted in INCL and if so, what might be the molecular mechanism(s) of this complication. We previously reported that the Ppt1-knockout (Ppt1-KO) mice that mimic INCL manifest high levels of oxidative stress and neuroinflammation. Recently, it has been reported that CD4(+) T-helper 17 (T(H)17) lymphocytes may mediate BBB disruption and neuroinflammation, although the precise molecular mechanism(s) remain unclear. We sought to determine: (i) whether the BBB is disrupted in Ppt1-KO mice, (ii) if so, do T(H)17-lymphocytes underlie this complication, and (iii) how might T(H)17 lymphocytes breach the BBB. Here, we report that the BBB is disrupted in Ppt1-KO mice and that T(H)17 lymphocytes producing IL-17A mediate disruption of the BBB by stimulating production of matrix metalloproteinases (MMPs), which degrade the tight junction proteins essential for maintaining BBB integrity. Importantly, dietary supplementation of resveratrol (RSV), a naturally occurring antioxidant/anti-inflammatory polyphenol, markedly reduced the levels of T(H)17 cells, IL-17A and MMPs, and elevated the levels of tight junction proteins, which improved the BBB integrity in Ppt1-KO mice. Intriguingly, we found that RSV suppressed the differentiation of CD4(+) T lymphocytes to IL-17A-positive T(H)17 cells. Our findings uncover a mechanism by which T(H)17 lymphocytes mediate BBB disruption and suggest that small molecules such as RSV that suppress T(H)17 differentiation are therapeutic targets for neurodegenerative disorders such as INCL.

Concepts: Protein, Antioxidant, Lysosomal storage disease, B cell, Matrix metalloproteinase, Neuronal ceroid lipofuscinosis, Batten disease, Lipofuscin

28

Matrix metalloproteinases (MMPs) are expressed in Dupuytren’s contracture and play a role in matrix remodeling. We tested the role of tension on contractility and MMP expression in Dupuytren’s nodule and cord cells. Cells were subjected to pre-determined loading patterns of known repeatable magnitudes (static load, unloading, and overloading) and tested for MMP gene expression (MMP-1, -2, -9, -13, and TIMP-1, -2) and force generation using a tension-culture force monitor. Matrix remodeling was assessed by addition of cytochalasin D and residual matrix tension was quantified. Nodule compared to cord and control cells demonstrate greater force generation and remodeling (p < 0.05). Nodule cells subjected to a reduced load and overloading led to threefold increase of MMP-1, -2, and -9 compared to static load, whilst cord and control cells only showed a twofold increase of MMP-9. Nodule cells subjected to overloading showed a twofold increase in TIMP-2 expression, whilst cord and control cells showed a twofold increase in TIMP-1 expression. Nodule cells differ from cord cells by increased force generation in response to changes in the mechanical environment and related MMP/TIMP-mediated matrix remodeling. In turn this may lead to permanent matrix shortening and digital contracture. Interventional therapies should be aimed at nodule cells to prevent contraction and subsequent permanent matrix remodeling. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 328-334, 2013.

Concepts: DNA, Gene, Cell nucleus, Gene expression, Bacteria, Organism, Matrix metalloproteinase, Dupuytren's contracture

28

Toxoplasma gondii is a zoonotic parasite and its infection in human can induce toxoplasmic encephalitis in immune disorders. In this study, astroglia were infected with the TS-4 strain of T. gondii tachyzoite in vitro to investigate the changes of matrix metalloproteinase (MMP)-2, MMP-9 and their substrate fibronectin. MMP-2 and MMP-9 were significantly increased at 1h, 6h and 12h post-infection (PI) in the cell homogenates, and increased at 6h, 12h, 24h and 48h PI in the cell-cultured supernatants. Fibronectin degradation also occurred at the same time points. In addition, immunocytochemistry showed that MMP-2 and MMP-9 localized in the cytoplasm, and confocal scanning laser microscopy revealed co-labeled patterns of MMP-2 and MMP-9 with fibronectin. MMP-2 and MMP-9 interacted with fibronectin, respectively. These results suggest that MMP-2 and MMP-9 induction from astroglia may contribute to extracellular matrix (ECM) degradation occurring in toxoplasmosis. Thus, we hypothesize that MMP-2 and MMP-9 cleave fibronectin and may contribute to the astroglia reaction and leukocyte migration to the sites of T. gondii replication during toxoplasmic encephalitis.

Concepts: Extracellular matrix, Apicomplexa, Rat, Matrix metalloproteinase, Toxoplasmosis, Toxoplasma gondii

28

The Achilles tendon has a high incidence of rupture, and the healing process leads to a disorganized extracellular matrix (ECM) with a high rate of injury recurrence. To evaluate the effects of different conditions of low-level laser (LLL) application on partially tenotomized tendons, adult male rats were divided into the following groups: G1, intact; G2, injured; G3, injured + LLL therapy (LLLT; 4 J/cm(2) continuous); G4, injured + LLLT (4 J/cm(2), 20 Hz); G5, injured; G6, injured + LLLT (4 J/cm(2) continuous); and G7, injured + LLLT (4 J/cm(2), 20 Hz until the 7th day and 2 kHz from 8 to 14 days). G2, G3, and G4 were euthanized 8 days after injury, and G5, G6, and G7 were euthanized on the 15th day. The quantification of hydroxyproline (HOPro) and non-collagenous protein (NCP), zymography for matrix metalloproteinase (MMP)-2 and MMP-9, and Western blotting (WB) for collagen types I and III were performed. HOPro levels showed a significant decrease in all groups (except G7) when compared with G1. The NCP level increased in all transected groups. WB for collagen type I showed an increase in G4 and G7. For collagen type III, G4 presented a higher value than G2. Zymography for MMP-2 indicated high values in G4 and G7. MMP-9 increased in both treatment groups euthanized at 8 days, especially in G4. Our results indicate that the pulsed LLLT improved the remodeling of the ECM during the healing process in tendons through activation of MMP-2 and stimulation of collagen synthesis.

Concepts: Collagen, Extracellular matrix, Cartilage, Matrix metalloproteinase, Tendon, Achilles tendon, Tendons, Type-I collagen