Journal articles on the topic 'Extracellular proteolysi'
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Kakurina, Gelena Valer'evna, Irina Viktorovna Kondakova, and Evgeniy Lkhamatsyrenovich Choynzonov. "Degradome Components in Progression of Squamous Cell Carcinoma of the Head and Neck." Annals of the Russian academy of medical sciences 70, no. 6 (December 6, 2015): 684–93. http://dx.doi.org/10.15690/vramn563.
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The process of tumor progression is closely related to the intracellular, extracellular and intramembranous proteolysis. Many studies indicate that the proteases function as part of an extensive multidirectional network of proteolytic interactions. Disturbance of strictly controlled equilibrium of the proteolytic system is described in a number of diseases, including cancer. The paper presents a review of the available data concerning the contribution of intracellular, extracellular and intramembrane proteolysis to the process of squamous cell head and neck carcinoma. Specific mechanisms of interaction of different proteolytic systems in cancer progression both in general and in squamous cell head and neck carcinoma remain underinvestigated. The versatility of functions and complexity of the relationships between proteolytic systems highlights the importance of studying the participation of all degradome components in tumor progression that may clarify the multi-link complex mechanisms of carcinogenesis of squamous cell head and neck carcinoma and to identify markers of progression and/or a targets for therapeutic intervention.
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Weaver, T. E., and J. A. Whitsett. "Processing of hydrophobic pulmonary surfactant protein B in rat type II cells." American Journal of Physiology-Lung Cellular and Molecular Physiology 257, no. 2 (August 1, 1989): L100—L108. http://dx.doi.org/10.1152/ajplung.1989.257.2.l100.
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The amino acid sequence of surfactant protein B (SP-B), derived from human genomic and cDNA sequences, indicates that the active polypeptide is contained within the sequence of a preproprotein of 381 residues. Synthesis of mature SP-B, which requires proteolytic processing at both the NH2- and COOH-termini of the proprotein, was studied in primary cultures of rat alveolar type II epithelial cells. Type II cells were pulse labeled with [35S]methionine-cysteine for 15-30 min and chased for 0-18 h. SP-B proprotein (Mr = 42,000) accumulated in the medium at early time points but declined at later time points suggesting extracellular proteolysis of the proprotein. In contrast, surfactant protein A (SP-A), another surfactant protein, continued to accumulate extracellularly during this time period. A proteolytic fragment of SP-B (Mr = 25,000) accumulated in the medium with a slightly slower time course, consistent with extracellular proteolysis of the proprotein. Intracellular processing of SP-B was also detected. SP-B polypeptides of Mr 8,000 and 12,000 were detected intracellularly and in the medium at late time points. These forms of SP-B (Mr = 8,000 and 12,000) comigrated in two-dimensional isoelectric-focusing sodium dodecyl sulfate-polyacrylamide gel electrophoresis with mature SP-B isolated from rat alveolar lavage fluid. The mature form of SP-B (Mr = 8,000), but not the Mr 42,000 and 25,000 SP-B precursors, was also detected in lamellar bodies isolated from rat lung homogenates. These experiments demonstrate complete proteolytic processing of prepro-SP-B to the alveolar Mr 8,000 form by type II epithelial cells in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hintermann, Edith, Susan Kinder Haake, Urs Christen, Andrew Sharabi, and Vito Quaranta. "Discrete Proteolysis of Focal Contact and Adherens Junction Components in Porphyromonas gingivalis-Infected Oral Keratinocytes: a Strategy for Cell Adhesion and Migration Disabling." Infection and Immunity 70, no. 10 (October 2002): 5846–56. http://dx.doi.org/10.1128/iai.70.10.5846-5856.2002.
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ABSTRACT Adhesive interactions of cells are critical to tissue integrity. We show that infection with Porphyromonas gingivalis, a major pathogen in the periodontal disease periodontitis, interferes with both cell-matrix and cell-cell adhesion in the oral keratinocyte cell line HOK-16. Thus, infected cells showed reduced adhesion to extracellular matrix, changes in morphology from spread to rounded, and impaired motility on purified matrices in Transwell migration assays and scratch assays. Western blot analysis of P. gingivalis-challenged HOK-16 cells revealed proteolysis of focal contact components (e.g., focal adhesion kinase), adherens junction proteins (e.g., catenins), and adhesion signaling molecules (e.g., the tyrosine kinase SRC). Proteolysis was selective, since important components of adherens junctions (E-cadherin) or signaling molecules (extracellular signal-regulated kinases ERK1/2) were not degraded. The virulence factors gingipains, cysteine proteinases expressed by P. gingivalis, are likely responsible for this proteolytic attack, since they directly digested specific proteins in pull-down experiments, and their proteolytic activity was blocked by the cysteine proteinase inhibitor N-α-p-tosyl-l-lysine chloromethyl ketone and also by a caspase inhibitor. Proteolysis was strain dependent, such that ATCC 33277 and 381 had high proteolytic potential, whereas W50 showed almost no proteolytic activity. These findings may help explain the formation of gingival pockets between cementum and periodontal epithelium, a hallmark of periodontitis. Furthermore, they illustrate a new pathogenetic paradigm of infection whereby bacteria may disrupt the integrity of epithelia.
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Perregaux, David G., and Christopher A. Gabel. "Post-Translational Processing of Murine IL-1: Evidence that ATP-Induced Release of IL-1α and IL-1β Occurs via a Similar Mechanism." Journal of Immunology 160, no. 5 (March 1, 1998): 2469–77. http://dx.doi.org/10.4049/jimmunol.160.5.2469.
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Abstract In response to LPS, peritoneal macrophages produce IL-1, but, for the most part, newly synthesized cytokine molecules remain cell associated. Externalization and proteolytic processing of pro-IL-1β can be initiated by extracellular ATP. In this study, kinetics and inhibitor sensitivity of the stimulus-coupled mechanism were investigated with [35S]methionine-labeled macrophages. Optimal ATP concentrations required to promote cytokine post-translational processing suggest the involvement of a P2Z type of receptor. Proteolysis of pro-IL-1β initiates within 7.5 min of ATP addition; 17-kDa mature IL-1β is observed first intracellularly and subsequently extracellularly. In contrast, ATP-treated cells do not contain 17-kDa IL-1α. Macrophages exposed to ATP continuously or only for a 15-min pulse release IL-1α, IL-1β, and lactate dehydrogenase (LDH). Proteolytic maturation of IL-1β exceeds that of IL-1α in both formats, but pulsed cells process the externalized cytokines more efficiently. Ethacrynic acid and DIDS (4,4′-diisothiocyanato-stilbene-2,2′-disulfonic acid) block ATP-induced proteolysis of pro-IL-1β and prevent release of pro-IL-1α/β and LDH; they do not inhibit ATP-induced K+ (86Rb+) efflux. Ethacrynic acid inhibits release of both forms of IL-1 with a similar concentration dependence; within the arrested cells, procytokines accumulate in a Triton-insoluble fraction. An IL-1β-converting enzyme inhibitor blocks proteolysis of IL-1β, but it does not prevent release of pro-IL-1α, pro-IL-1β, or LDH. These results indicate that ATP stimulates externalization of both IL-1α and IL-1β. The ATP-induced cytokine release mechanism is accompanied by cell death and requires activity of an anion transport inhibitor-sensitive component, but this pathway operates independently of cytokine proteolytic processing.
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Petushkova, Anastasiia I., and Andrey A. Zamyatnin. "Redox-Mediated Post-Translational Modifications of Proteolytic Enzymes and Their Role in Protease Functioning." Biomolecules 10, no. 4 (April 23, 2020): 650. http://dx.doi.org/10.3390/biom10040650.
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Proteolytic enzymes play a crucial role in metabolic processes, providing the cell with amino acids through the hydrolysis of multiple endogenous and exogenous proteins. In addition to this function, proteases are involved in numerous protein cascades to maintain cellular and extracellular homeostasis. The redox regulation of proteolysis provides a flexible dose-dependent mechanism for proteolytic activity control. The excessive reactive oxygen species (ROS) and reactive nitrogen species (RNS) in living organisms indicate pathological conditions, so redox-sensitive proteases can swiftly induce pro-survival responses or regulated cell death (RCD). At the same time, severe protein oxidation can lead to the dysregulation of proteolysis, which induces either protein aggregation or superfluous protein hydrolysis. Therefore, oxidative stress contributes to the onset of age-related dysfunction. In the present review, we consider the post-translational modifications (PTMs) of proteolytic enzymes and their impact on homeostasis.
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Toe, Cui Jin, Hooi Ling Foo, Teck Chwen Loh, Rosfarizan Mohamad, Raha Abdul Rahim, and Zulkifli Idrus. "Extracellular Proteolytic Activity and Amino Acid Production by Lactic Acid Bacteria Isolated from Malaysian Foods." International Journal of Molecular Sciences 20, no. 7 (April 10, 2019): 1777. http://dx.doi.org/10.3390/ijms20071777.
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Amino acids (AAs) are vital elements for growth, reproduction, and maintenance of organisms. Current technology uses genetically engineered microorganisms for AAs production, which has urged the search for a safer food-grade AA producer strain. The extracellular proteolytic activities of lactic acid bacteria (LAB) can be a vital tool to hydrolyze extracellular protein molecules into free AAs, thereby exhibiting great potential for functional AA production. In this study, eight LAB isolated from Malaysian foods were determined for their extracellular proteolytic activities and their capability of producing AAs. All studied LAB exhibited versatile extracellular proteolytic activities from acidic to alkaline pH conditions. In comparison, Pediococcus pentosaceus UP-2 exhibited the highest ability to produce 15 AAs extracellularly, including aspartate, lysine, methionine, threonine, isoleucine, glutamate, proline, alanine, valine, leucine, tryptophan, tyrosine, serine, glycine, and cystine, followed by Pediococcus pentosaceus UL-2, Pediococcus acidilactici UB-6, and Pediococcus acidilactici UP-1 with 11 to 12 different AAs production detected extracellularly. Pediococcus pentosaceus UL-6 demonstrated the highest increment of proline production at 24 h of incubation. However, Pediococcus acidilactici UL-3 and Lactobacillus plantarum I-UL4 exhibited the greatest requirement for AA. The results of this study showed that different LAB possess different extracellular proteolytic activities and potentials as extracellular AA producers.
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Campbell, E. J., E. K. Silverman, and M. A. Campbell. "Elastase and cathepsin G of human monocytes. Quantification of cellular content, release in response to stimuli, and heterogeneity in elastase-mediated proteolytic activity." Journal of Immunology 143, no. 9 (November 1, 1989): 2961–68. http://dx.doi.org/10.4049/jimmunol.143.9.2961.
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Abstract Human peripheral blood monocytes contain human leukocyte elastase (HLE) and cathepsin G (CG), serine proteinases originally described in azurophil granules of polymorphonuclear neutrophils (PMN). Immunoreactive HLE and CG of freshly harvested monocytes have been quantified in this study; to begin to elucidate potential roles for these enzymes in extracellular events, release in response to stimuli has been measured, along with proteolytic activity of monocytes toward surface-bound proteins. Our results indicate that whole-cell extracts of monocytes contain approximately 6% of the amount of HLE as do extracts of comparable numbers of PMN. In response to PMA in vitro, monocytes released 39 to 53% of their content of HLE and CG within 60 min, a fractional release greater than that of PMN. Furthermore, when phorbol-stimulated monocytes were adherent to a fibronectin-coated surface, extensive HLE-mediated proteolysis of the surface-bound protein was observed. Proteolysis by such cells in the presence of proteinase inhibitors was of considerable interest, since a subpopulation (15 to 20% of the total) expressed marked but localized proteolytic activity, possibly escaping inhibition through contact-mediated mechanisms. These data indicate that a subpopulation of freshly harvested monocytes is rich in HLE and CG (serine proteinases traditionally associated with PMN), can promptly release HLE and CG in response to stimuli, and can utilize HLE for extracellular proteolysis. Monocyte-derived serine proteinases may participate in extracellular events formerly associated with PMN-derived HLE and CG.
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Lockwood, Thomas D. "Redox-dependent and redox-independent subcomponents of protein degradation in perfused myocardium." American Journal of Physiology-Endocrinology and Metabolism 276, no. 5 (May 1, 1999): E945—E954. http://dx.doi.org/10.1152/ajpendo.1999.276.5.e945.
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The integration of proteolytic pathways with metabolism was investigated in perfused rat myocardium. After a 10-min incorporation period, the minute-to-minute release of [3H]leucine from myocardial proteins was measured in nonrecirculating effluent perfusate. The nontoxic pro-oxidant probe diamide (100 μM) or a supraphysiological concentration of the endogenous oxidative metabolite dehydroascorbic acid (200 μM) reversibly inhibited 75% of myocardial proteolysis consisting of several known subcomponents (redox dependent); however, 25% of proteolysis was diamide insensitive (redox independent). Decrease in extracellular glucose concentration from 10 to 0.1 mM strongly increased the potencies of minimally effective concentrations of diamide (10 μM) or dehydroascorbic acid (15 μM) by ∼10-fold to the respective potencies maximally inhibiting proteolysis. The reversal of diamide action was also strongly dependent on the perfusate glucose concentration observed at 0.1, 0.2, 1.0 and 10 mM glucose. Proteolytic inhibition caused by diamide (100 μM) was not accompanied by change in basal tissue ATP content of 5 μmol/g wet wt. Conversely, nearly lethal 60% ATP depletion caused by sodium azide (0.4 mM) was not accompanied by change in total [3H]leucine release. Results indicate that a large proteolytic subcomponent (75%) is maintained by redox chains fed by glucose; however, there is no apparent linkage of this proteolysis to short-term ATP fluctuations. A distinct major proteolytic subcomponent (25%) does not vary in response to experimental intervention in either ATP content or redox chains.
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Chirkin, A. A., O. M. Balaeva-Tikhomirova, V. V. Dolmatova, and I. O. Semenov. "Molecular-structural homology of proteolytic enzymеs in the studying of proteolysis mechanism and its regulation." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 57, no. 2 (June 3, 2021): 206–17. http://dx.doi.org/10.29235/1561-8331-2021-57-2-206-217.
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The actual problem of experimental medicine is the substantiation of new model organisms that meet modern requirements of bioethics, cost and conditions of detention. The aim of this work was a comparative analysis of the homology degree of proteolytic enzymes in humans and pulmonary freshwater mollusks. The homology of enzymes in nucleotide sequences in humans and pulmonary freshwater mollusks in the analysis of unregulated proteolysis is 66–68 %; regulated proteolysis – 69–76 %; ubiquitin-like modifiers – 78–83 %; extracellular enzymes – 67–76 %; and intracellular enzymes – 65–72 %. The evolutionary conservatism of proteolytic enzymes and the presence of an open blood circulation, which allows the substances under study to be delivered from the hemolymph directly to target cells, make it possible to use these animals as cheap and convenient test organisms. The practical importance of a sufficiently high homology degree of proteolytic enzymes in humans and pulmonary freshwater mollusks justifies the expediency of forming mollusk aquaculture to obtain proteolytic enzyme protein preparations from their tissues within the framework of the tasks of biopharmaceuticals, cosmetics and the food industry.
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Mineur, Pierre, Alain C. Colige, Christophe F. Deroanne, Johanne Dubail, Frédéric Kesteloot, Yvette Habraken, Agnès Noël, et al. "Newly identified biologically active and proteolysis-resistant VEGF-A isoform VEGF111 is induced by genotoxic agents." Journal of Cell Biology 179, no. 6 (December 17, 2007): 1261–73. http://dx.doi.org/10.1083/jcb.200703052.
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Ultraviolet B and genotoxic drugs induce the expression of a vascular endothelial growth factor A (VEGF-A) splice variant (VEGF111) encoded by exons 1–4 and 8 in many cultured cells. Although not detected in a series of normal human and mouse tissue, VEGF111 expression is induced in MCF-7 xenografts in nude mice upon treatment by camptothecin. The skipping of exons that contain proteolytic cleavage sites and extracellular matrix–binding domains makes VEGF111 diffusible and resistant to proteolysis. Recombinant VEGF111 activates VEGF receptor 2 (VEGF-R2) and extracellularly regulated kinase 1/2 in human umbilical vascular endothelial cells and porcine aortic endothelial cells expressing VEGF-R2. The mitogenic and chemotactic activity and VEGF111's ability to promote vascular network formation during embyonic stem cell differentiation are similar to those of VEGF121 and 165. Tumors in nude mice formed by HEK293 cells expressing VEGF111 develop a more widespread network of numerous small vessels in the peritumoral tissue than those expressing other isoforms. Its potent angiogenic activity and remarkable resistance to proteolysis makes VEGF111 a potential adverse factor during chemotherapy but a beneficial therapeutic tool for ischemic diseases.
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Moradian-Oldak, J., N. Gharakhanian, and I. Jimenez. "Limited Proteolysis of Amelogenin: Toward Understanding the Proteolytic Processes in Enamel Extracellular Matrix." Connective Tissue Research 43, no. 2 (April 1, 2002): 450–55. http://dx.doi.org/10.1080/713713519.
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Moradian-Oldak, J., N. Gharakhanian, and I. Jimenez. "Limited Proteolysis of Amelogenin: Toward Understanding the Proteolytic Processes in Enamel Extracellular Matrix." Connective Tissue Research 43, no. 2-3 (January 2002): 450–55. http://dx.doi.org/10.1080/03008200290000835.
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Weeks, Amy M., James R. Byrnes, Irene Lui, and James A. Wells. "Mapping proteolytic neo-N termini at the surface of living cells." Proceedings of the National Academy of Sciences 118, no. 8 (February 3, 2021): e2018809118. http://dx.doi.org/10.1073/pnas.2018809118.
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N terminomics is a powerful strategy for profiling proteolytic neo-N termini, but its application to cell surface proteolysis has been limited by the low relative abundance of plasma membrane proteins. Here we apply plasma membrane-targeted subtiligase variants (subtiligase-TM) to efficiently and specifically capture cell surface N termini in live cells. Using this approach, we sequenced 807 cell surface N termini and quantified changes in their abundance in response to stimuli that induce proteolytic remodeling of the cell surface proteome. To facilitate exploration of our datasets, we developed a web-accessible Atlas of Subtiligase-Captured Extracellular N Termini (ASCENT; http://wellslab.org/ascent). This technology will facilitate greater understanding of extracellular protease biology and reveal neo-N termini biomarkers and targets in disease.
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Gold, L. I., R. Schwimmer, and J. P. Quigley. "Human plasma fibronectin as a substrate for human urokinase." Biochemical Journal 262, no. 2 (September 1, 1989): 529–34. http://dx.doi.org/10.1042/bj2620529.
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An early event in malignant transformation is the increased expression of proteases, such as plasminogen activator, which can degrade surrounding extracellular matrices, thereby conferring an advantage for tumour cell invasion and metastasis. The present studies provide evidence that plasma fibronectin (Fn), which is a component of the extracellular matrix, is a direct substrate for the plasminogen activator urokinase (UK). Human plasma Fn was incubated with human UK under plasminogen-free conditions. Fn cleavage was both time- and dose-dependent and was evident within 30 min. The proteolytic digestion was limited and complete within 12 h at an enzyme/substrate ratio of 1:20. Analysis of the final proteolytic digestion products demonstrated the disappearance of the native dimeric 440 kDa structure of Fn with the concomitant appearance of three proteolytic fragments of 210, 200 and 25 kDa. Since two large fragments of similar size to the 220 kDa monomeric chains of Fn were obtained following proteolysis, it is proposed that UK cleaves Fn at two sites, one towards the N-terminal and one close to the C-terminal, but N-terminal to its interchain disulphide bonds. These studies suggest that the local proteolytic digestion and release of Fn from the extracellular matrix by tumour cells possessing high levels of UK may involve the direct proteolytic breakdown of Fn by UK.
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Stalboerger, Paul, Carmelo Panetta, Robert Simari, and Noel Caplice. "Plasmin Proteolysis of Endothelial Cell and Vessel Wall Associated Tissue Factor Pathway Inhibitor." Thrombosis and Haemostasis 86, no. 09 (2001): 923–28. http://dx.doi.org/10.1055/s-0037-1616151.
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SummaryPlasmin is an important protease that mediates clot fibrinolysis and vessel wall extracellular matrix proteolysis. Recently, in vitro studies have suggested that plasmin can cleave and inactivate recombinant TFPI, a major inhibitor of TF-mediated coagulation. We hypothesized that such an interaction may occur in vascular cells expressing TFPI, or in the vessel wall, with implications for thrombolysis. In a series of experiments, we examined the effects of plasmin on cell surface and extracellular matrix (ECM) associated TFPI in endothelial cells (EC) in culture and on EC and smooth muscle cells (SMC) in the vessel wall. Plasmin (0.2 μM) decreased cell surface and matrix associated TFPI activity in cultured endothelial cells by 77 ± 5 % and 69 ± 6% respectively (p < 0.01). Plasminogen, the proenzyme form of plasmin had no such effect on cell surface TFPI or matrix TFPI. Cell surface TFPI antigen measured by fluorescence activated cell sorter (FACS) was also significantly reduced by plasmin. Proteolysis of conditioned medium TFPI was suggested by loss of a ~45kD TFPI on Western Blot analysis following plasmin treatment. Plasmin also proteolysed a ~45kD TFPI protein in the intact ECM of EC, an effect which was inhibited by preincubation with aprotinin, a plasmin inhibitor. Incubation of similar concentrations of plasmin, with homogenates of normal vessel decreased a ~45kD TFPI immunoreactive band on Western blot analysis. Plasmin also decreased surface TFPI activity on frozen sections of normal vessel as measured by an amidolytic assay. Finally, plasmin treatment of atherosclerotic plaque sections caused complete removal of TFPI immunoreactivity associated with luminal EC and intimal SMC, when compared to control treated plaque (n = 3). Together these data suggest that plasmin proteolyses the majority of EC-associated (surface and matrix) TFPI and may remove TFPI from the luminal surface and intima of the vessel wall. TFPI proteolysis in cultured EC was associated with significant reduction in TFPI anticoagulant activity. These data provide evidence that plasmin degradation of TFPI occurs in vascular cells and in the vessel wall and may have implications for rethrombosis following thrombolysis in vivo.
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Pepper, Michael. "Extracellular Proteolysis and Angiogenesis." Thrombosis and Haemostasis 86, no. 07 (2001): 346–55. http://dx.doi.org/10.1055/s-0037-1616232.
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SummaryExtracellular proteolysis is an absolute requirement for new blood vessel formation, a process known as angiogenesis. This review will examine the role of the matrix metalloproteinase and plasminogen activator/plasmin systems during angiogenesis. Extracellular proteolysis has also been implicated in the generation of molecules with angioregulatory activity. These include, but are not limited to, angiostatin and endostatin. However, despite an abundance of data on their bioactivity, the molecular mechanisms by which these molecules achieve their effects are unknown. Anti-proteolysis, particularly in the context of angiogenesis, has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization.
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MacLennan, P. A., A. McArdle, and R. H. Edwards. "Effects of calcium on protein turnover of incubated muscles from mdx mice." American Journal of Physiology-Endocrinology and Metabolism 260, no. 4 (April 1, 1991): E594—E598. http://dx.doi.org/10.1152/ajpendo.1991.260.4.e594.
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Mdx mice have a genetic defect similar to that which causes Duchenne muscular dystrophy in humans. The influence of calcium on muscle protein metabolism of mdx and wild type (C57BL/10) mice was examined in vitro. Incubation of mdx muscles in a medium containing calcium at a concentration of 2.0 mM (but not 0.2 mM) resulted in proteolytic rates that were greater than those of C57BL/10 muscles. At 2.0 mM extracellular calcium, mdx muscle proteolysis was attenuated by thiol protease inhibitors but not by the weak base methylamine. Protein synthetic rates were higher in incubated mdx muscles than in incubated C57BL/10 muscles, but no effect of extracellular calcium concentration was observed in either strain. These data suggest that mdx mice have an abnormality of muscle calcium handling, which results in activation of nonlysosomal proteolytic processes but does not exert acute effects on protein synthetic rate.
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Friedl, Peter, and Katarina Wolf. "Proteolytic and non-proteolytic migration of tumour cells and leucocytes." Biochemical Society Symposia 70 (September 1, 2003): 277–85. http://dx.doi.org/10.1042/bss0700277.
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The migration of different cell types, such as leucocytes and tumour cells, involves cellular strategies to overcome the physical resistance of three-dimensional tissue networks, including proteolytic degradation of extracellular matrix (ECM) components. High-resolution live-cell imaging techniques have recently provided structural and biochemical insight into the differential use of matrix-degrading enzymes in the migration processes of different cell types within the three-dimensional ECM. Proteolytic migration is achieved by slow-moving cells, such as fibroblasts and mesenchymally moving tumour cells, by engaging matrix metalloproteinases, cathepsins and serine proteases at the cell surface in a focalized manner ('pericellular proteolysis'), while adhesion and migratory traction are provided by integrins. Pericellular breakdown of ECM components generates localized matrix defects and remodelling along migration tracks. In contrast with tumour cells, constitutive non-proteolytic migration is used by rapidly moving T lymphocytes. This migration type does not generate proteolytic matrix remodelling, but rather depends on shape change to allow cells to glide and squeeze through gaps and trails present in connective tissues. In addition, constitutive proteolytic migration can be converted into non-proteolytic movement by protease inhibitors. After the simultaneous inhibition of matrix metalloproteinases, serine/threonine proteases and cysteine proteases in tumour cells undergoing proteolysis-dependent movement, a fundamental adaptation towards amoeboid movement is able to sustain non-proteolytic migration in these tumour cells (the mesenchymal-amoeboid transition). Instead of using proteases for matrix degradation, the tumour cells use leucoyte-like strategies of shape change and squeezing through matrix gaps along tissue scaffolds. The diversity of protease function in cell migration by different cell types highlights response diversity and molecular adaptation of cell migration upon pharmacotherapeutic protease inhibitor treatment.
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Kugaevskaya, E. V., O. S. Timoshenko, T. A. Gureeva, and N. I. Solovieva. "The Role of Stromal Proteolytic Systems in Cancer Progression (Review)." General Reanimatology 15, no. 5 (November 9, 2019): 106–26. http://dx.doi.org/10.15360/1813-9779-2019-5-106-126.
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Oncological diseases belong to life-threatening pathologies being the second most frequent cause of morbidity and mortality after cardiovascular diseases. Clarification of carcinogenesis mechanisms makes it possible to expand the stock of tools available for prevention of critical illness accompanying this pathological condition.Nowadays, proteolytic systems of tumor microenvironment (ТМЕ) are regarded as key regulators of a tumor progression including tumor growth, invasion and metastazing. The review discusses ТМЕ structure and role in cancer progression.Recent data decipher the role of proteolytic systems in the interaction stromal cells with tumor cells in different types of cancer in humans. The most known proteolytic systems contributed to cancer progression are matrix metalloproteinase system (MMP), urokinase-type plasminogen activator system (uPA-system), various cathepsins, granzymes, and elastase. Inhibition of extracellular proteolysis in the course of an oncological process is considered an effective approach to cancer therapy.
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Greco, Maria Raffaella, Loredana Moro, Stefania Forciniti, Khalid Alfarouk, Stefania Cannone, Rosa Angela Cardone, and Stephan Joel Reshkin. "Integrin-Linked Kinase Links Integrin Activation to Invadopodia Function and Invasion via the p(T567)-Ezrin/NHERF1/NHE1 Pathway." International Journal of Molecular Sciences 22, no. 4 (February 22, 2021): 2162. http://dx.doi.org/10.3390/ijms22042162.
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Tumor cell invasion depends largely on degradation of the extracellular matrix (ECM) by protease-rich structures called invadopodia, whose formation and activity requires the convergence of signaling pathways engaged in cell adhesion, actin assembly, membrane regulation and ECM proteolysis. It is known that β1-integrin stimulates invadopodia function through an invadopodial p(T567)-ezrin/NHERF1/NHE1 signal complex that regulates NHE1-driven invadopodia proteolytic activity and invasion. However, the link between β1-integrin and this signaling complex is unknown. In this study, in metastatic breast (MDA-MB-231) and prostate (PC-3) cancer cells, we report that integrin-linked kinase (ILK) integrates β1-integrin with this signaling complex to regulate invadopodia activity and invasion. Proximity ligation assay experiments demonstrate that, in invadopodia, ILK associates with β1-integrin, NHE1 and the scaffold proteins p(T567)-ezrin and NHERF1. Activation of β1-integrin increased both invasion and invadopodia activity, which were specifically blocked by inhibition of either NHE1 or ILK. We conclude that ILK integrates β1-integrin with the ECM proteolytic/invasion signal module to induce NHE1-driven invadopodial ECM proteolysis and cell invasion.
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Aguilera-Toro, Miguel, Søren Drud-Heydary Nielsen, Martin Laage Kragh, Yinghua Xiao, Lisbeth Truelstrup Hansen, Valentin Rauh, Lars Wiking, Nina Aagaard Poulsen, and Lotte Bach Larsen. "Peptidomic Fingerprints of Stored UHT Milk Inoculated with Protease Extracts from Different Pseudomonas Strains Relative to aprX Expression and Visible Spoilage." Dairy 4, no. 1 (January 9, 2023): 83–97. http://dx.doi.org/10.3390/dairy4010005.
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Lately, concern about the protease AprX produced by Pseudomonas has increased in the dairy industry due to its ability to survive UHT treatment and spoil UHT milk. Efficient prediction methods for UHT milk spoilage are currently lacking, mainly due to high diversity in proteolytic potential between Pseudomonas strains. The present study aimed to gain more insight into the variability between Pseudomonas strains regarding proteolytic potential by comparing their proteolytic capability with their aprX expression levels and differences in peptide formation. The variability in aprX expression levels in four Pseudomonas strains were related to physical stability, milk proteolysis and peptidomic cleavage patterns of milk proteins in a storage experiment of UHT milk inoculated with protease extracellular extracts and stored for 45 days at 20 °C. A positive relationship was observed between the relative expression of aprX and milk proteolysis during storage, with the strain Pseudomonas panacis DSM 18529 showing the highest level in both parameters. This strain was the only strain to show visual gelation, which occurred after 21 days. The peptide formation analysis showed a similar protein hydrolysis pattern between strains and high hydrolysis of αs1-caseins during long-term spoilage putatively due to the activity of AprX was observed.
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Kovács, Hajnal A., Enikő Lázár, György Várady, Gábor Sirokmány, and Miklós Geiszt. "Characterization of the Proprotein Convertase-Mediated Processing of Peroxidasin and Peroxidasin-like Protein." Antioxidants 10, no. 10 (September 30, 2021): 1565. http://dx.doi.org/10.3390/antiox10101565.
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Peroxidasin (PXDN) and peroxidasin-like protein (PXDNL) are members of the peroxidase-cyclooxygenase superfamily. PXDN functions in basement membrane synthesis by forming collagen IV crosslinks, while the function of PXDNL remains practically unknown. In this work, we characterized the post-translational proteolytic processing of PXDN and PXDNL. Using a novel knock-in mouse model, we demonstrate that the proteolytic cleavage of PXDN occurs in vivo. With the help of furin-specific siRNA we also demonstrate that the proprotein-convertase, furin participates in the proteolytic processing of PXDN. Furthermore, we demonstrate that only the proteolytically processed PXDN integrates into the extracellular matrix, highlighting the importance of the proteolysis step in PXDN’s collagen IV-crosslinking activity. We also provide multiple lines of evidence for the importance of peroxidase activity in the proteolytic processing of PXDN. Finally, we show that PXDNL does not undergo proteolytic processing, despite containing sequence elements efficiently recognized by proprotein convertases. Collectively, our observations suggest a previously unknown protein quality control during PXDN synthesis and the importance of the peroxidase activity of PXDN in this process.
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Campbell, Kenneth L., Nurit Haspel, Cassandra Gath, Nuzulul Kurniatash, Indira (Nouduri) Akkiraju, Naomi Stuffers, and Uma Vadher. "Protein hormone fragmentation in intercellular signaling: hormones as nested information systems." Biology of Reproduction 104, no. 4 (January 5, 2021): 887–901. http://dx.doi.org/10.1093/biolre/ioaa234.
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Abstract This study explores the hypothesis that protein hormones are nested information systems in which initial products of gene transcription, and their subsequent protein fragments, before and after secretion and initial target cell action, play additional physiological regulatory roles. The study produced four tools and key results: (1) a problem approach that proceeds, with examples and suggestions for in vivo organismal functional tests for peptide–protein interactions, from proteolytic breakdown prediction to models of hormone fragment modulation of protein–protein binding motifs in unrelated proteins; (2) a catalog of 461 known soluble human protein hormones and their predicted fragmentation patterns; (3) an analysis of the predicted proteolytic patterns of the canonical protein hormone transcripts demonstrating near-universal persistence of 9 ± 7 peptides of 8 ± 8 amino acids even after cleavage with 24 proteases from four protease classes; and (4) a coincidence analysis of the predicted proteolysis locations and the 1939 exon junctions within the transcripts that shows an excess (P < 0.001) of predicted proteolysis within 10 residues, especially at the exonal junction (P < 0.01). It appears all protein hormone transcripts generate multiple fragments the size of peptide hormones or protein–protein binding domains that may alter intracellular or extracellular functions by acting as modulators of metabolic enzymes, transduction factors, protein binding proteins, or hormone receptors. High proteolytic frequency at exonal junctions suggests proteolysis has evolved, as a complement to gene exon fusion, to extract structures or functions within single exons or protein segments to simplify the genome by discarding archaic one-exon genes.
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Cai, Fang, Carrie B. Adrion, and James E. Keller. "Comparison of Extracellular and Intracellular Potency of Botulinum Neurotoxins." Infection and Immunity 74, no. 10 (October 2006): 5617–24. http://dx.doi.org/10.1128/iai.00552-06.
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ABSTRACT Levels of botulinum neurotoxin (BoNT) proteolytic activity were compared using a cell-free assay and living neurons to measure extracellular and intracellular enzymatic activity. Within the cell-free reaction model, BoNT serotypes A and E (BoNT/A and BoNT/E, respectively) were reversibly inhibited by chelating Zn2+ with N,N,N′,N′-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN). BoNT/E required relatively long incubation with TPEN to achieve total inhibition, whereas BoNT/A was inhibited immediately upon mixing. When naïve Zn2+-containing BoNTs were applied to cultured neurons, the cellular action of each BoNT was rapidly inhibited by subsequent addition of TPEN, which is membrane permeable. Excess Zn2+ added to the culture medium several hours after poisoning fully restored intracellular toxin activity. Unlike TPEN, EDTA irreversibly inhibited both BoNT/A and -E within the cell-free in vitro reaction. Excess Zn2+ did not reactivate the EDTA-treated toxins. However, application of EDTA-treated BoNT/A or -E to cultured neurons demonstrated normal toxin action in terms of both blocking neurotransmission and SNAP-25 proteolysis. Different concentrations of EDTA produced toxin preparations with incrementally reduced in vitro proteolytic activities, which, when applied to living neurons showed undiminished cellular potency. This suggests that EDTA renders the BoNT proteolytic domain conformationally inactive when tested with the cell-free reaction, but this change is corrected during entry into neurons. The effect of EDTA is unrelated to Zn2+ because TPEN could be applied to living cells before or after poisoning to produce rapid and reversible inhibition of both BoNTs. Therefore, bound Zn2+ is not required for toxin entry into neurons, and removal of Zn2+ from cytosolic BoNTs does not irreversibly alter toxin structure or function. We conclude that EDTA directly alters both BoNTs in a manner that is independent of Zn2+.
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Liou, T. G., and E. J. Campbell. "Quantum proteolysis resulting from release of single granules by human neutrophils: a novel, nonoxidative mechanism of extracellular proteolytic activity." Journal of Immunology 157, no. 6 (September 15, 1996): 2624–31. http://dx.doi.org/10.4049/jimmunol.157.6.2624.
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Abstract Proteinase inhibitors confine the activity of proteolytic enzymes of inflammatory cells, but fail to protect substrates in the immediate pericellular zone. We report quantitative imaging that demonstrates discrete, evanescent, quantized proteolytic events attributable to the release of single azurophil granules from neutrophils. The images provide information about the dynamics of this nonequilibrium system, which is characterized by overwhelmingly high local concentrations of enzymes that rapidly dissipate. With physiologic concentrations of extracellular human leukocyte elastase inhibitors (32.8 microM), the radii of the unit proteolytic events are 1.32 microm (approximately 8 times the radius of the azurophil granule) and are inversely and nonlinearly related to the concentration of proteinase inhibitor that is present in the bathing medium. We have obtained identical results with alpha1-antitrypsin, alpha2m, recombinant secretory leukocyte proteinase inhibitor, and ICI 200,355, and we have found that phagocyte-derived oxidants are not required for the genesis of this catalytic activity. Our results reveal that the enzyme:inhibitor ratio is the primary delimiter of quantized proteolysis in the local microenvironment.
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Baracos, V., R. E. Greenberg, and A. L. Goldberg. "Influence of calcium and other divalent cations on protein turnover in rat skeletal muscle." American Journal of Physiology-Endocrinology and Metabolism 250, no. 6 (June 1, 1986): E702—E710. http://dx.doi.org/10.1152/ajpendo.1986.250.6.e702.
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When rat muscles were incubated in Ca2+-free media, their rates of protein break-down were significantly lower than in complete medium (2.58 mM Ca2+). Dantrolene and 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester, inhibitors of Ca2+ release from the sarcoplasmic reticulum, also reduced muscle proteolysis. When Ca2+ was added (up to 5.16 mM), proteolysis increased progressively up to 70% in the intact soleus and extensor digitorum longus muscles and up to 300% in the cut diaphragm preparation. Addition of Ca2+ did not affect the muscles' ATP or phosphocreatine content and increased protein synthesis slightly or not at all. Sr2+, Ba2+, and Mn2+ also increased proteolysis, but were less effective than Ca2+. Mg2+ inhibited the enhancement of proteolysis by Ca2+. This stimulation by Ca2+ was not affected by inhibitors of voltage-dependent Ca2+ channels, calmodulin, metalloendoproteases, microfilament or microtubule formation, or mersalyl. High Ca2+ levels also increased prostaglandin (PG) E2 production, although a rise in PGE2 did not appear essential for the increased proteolysis. The proteolysis induced by Ca2+ was prevented in muscles treated with Ep-475 or leupeptin. By contrast, these inhibitors of thiol proteases did not affect protein breakdown in Ca2+-free medium. Thus extracellular Ca2+ activates and Mg2+ inhibits a proteolytic pathway involving thiol proteases.
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Akassoglou, Katerina, Keith W. Kombrinck, Jay L. Degen, and Sidney Strickland. "Tissue Plasminogen Activator–Mediated Fibrinolysis Protects against Axonal Degeneration and Demyelination after Sciatic Nerve Injury." Journal of Cell Biology 149, no. 5 (May 29, 2000): 1157–66. http://dx.doi.org/10.1083/jcb.149.5.1157.
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Tissue plasminogen activator (tPA) is a serine protease that converts plasminogen to plasmin and can trigger the degradation of extracellular matrix proteins. In the nervous system, under noninflammatory conditions, tPA contributes to excitotoxic neuronal death, probably through degradation of laminin. To evaluate the contribution of extracellular proteolysis in inflammatory neuronal degeneration, we performed sciatic nerve injury in mice. Proteolytic activity was increased in the nerve after injury, and this activity was primarily because of Schwann cell–produced tPA. To identify whether tPA release after nerve damage played a beneficial or deleterious role, we crushed the sciatic nerve of mice deficient for tPA. Axonal demyelination was exacerbated in the absence of tPA or plasminogen, indicating that tPA has a protective role in nerve injury, and that this protective effect is due to its proteolytic action on plasminogen. Axonal damage was correlated with increased fibrin(ogen) deposition, suggesting that this protein might play a role in neuronal injury. Consistent with this idea, the increased axonal degeneration phenotype in tPA- or plasminogen-deficient mice was ameliorated by genetic or pharmacological depletion of fibrinogen, identifying fibrin as the plasmin substrate in the nervous system under inflammatory axonal damage. This study shows that fibrin deposition exacerbates axonal injury, and that induction of an extracellular proteolytic cascade is a beneficial response of the tissue to remove fibrin. tPA/plasmin-mediated fibrinolysis may be a widespread protective mechanism in neuroinflammatory pathologies.
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Campbell, E. J., and M. A. Campbell. "Pericellular proteolysis by neutrophils in the presence of proteinase inhibitors: effects of substrate opsonization." Journal of Cell Biology 106, no. 3 (March 1, 1988): 667–76. http://dx.doi.org/10.1083/jcb.106.3.667.
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Inflammatory cells are capable of degrading extracellular matrix macromolecules in vivo in the presence of proteinase inhibitors. We and others have hypothesized that such proteolysis is permitted in large part by mechanisms operative in the immediate pericellular environment, especially at zones of contact between inflammatory cells and insoluble matrix components. To further test this hypothesis in vitro, we have used a model system in which viable polymorphonuclear neutrophils (PMN) are allowed to contact a surface coated with proteinase-sensitive substrate, and in which PMN interaction with the surface can be modulated. We have evaluated proteolysis of the surface-bound protein in the presence and absence of proteinase inhibitors. Our results were: (a) In the presence (but not in the absence) of proteinase inhibitors, proteolysis was confined to sharply marginated zones subjacent to the cells; (b) opsonization of the surface enhanced spreading of the PMN, (c) opsonization diminished the effectiveness of alpha-1-proteinase inhibitor (alpha-1-PI) and alpha-2-macroglobulin as inhibitors of proteolysis of surface-bound protein; (d) anti-oxidants did not alter the effectiveness of alpha-1-PI in inhibiting proteolysis of opsonized substrate by PMN; and (e) PMN could restrict entry of alpha-1-PI into zones of contact with opsonized surfaces. We conclude that: (a) In the presence of proteinase inhibitors, PMN can express sharply marginated and exclusively pericellular proteolytic activity; (b) locally high proteinase concentrations and/or exclusion of proteinase inhibitors from pericellular microenvironments may be important mechanisms for pericellular matrix degradation by PMN; and (c) these observations may have general relevance to extracellular matrix remodeling by a variety of inflammatory and other cell types.
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Bozdagi, Ozlem, Vanja Nagy, Kimberly T. Kwei, and George W. Huntley. "In Vivo Roles for Matrix Metalloproteinase-9 in Mature Hippocampal Synaptic Physiology and Plasticity." Journal of Neurophysiology 98, no. 1 (July 2007): 334–44. http://dx.doi.org/10.1152/jn.00202.2007.
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Extracellular proteolysis is an important regulatory nexus for coordinating synaptic functional and structural plasticity, but the identity of such proteases is incompletely understood. Matrix metalloproteinases (MMPs) have well-known, mostly deleterious roles in remodeling after injury or stroke, but their role in nonpathological synaptic plasticity and function in intact adult brains has not been extensively investigated. Here we address the role of MMP-9 in hippocampal synaptic plasticity using both gain- and loss-of-function approaches in urethane-anesthetized adult rats. Acute blockade of MMP-9 proteolytic activity with inhibitors or neutralizing antibodies impairs maintenance, but not induction, of long-term potentiation (LTP) at synapses formed between Schaffer-collaterals and area CA1 dendrites. LTP is associated with significant increases in levels of MMP-9 and proteolytic activity within the potentiated neuropil. By introducing a novel application of gelatin-substrate zymography in vivo, we find that LTP is associated with significantly elevated numbers of gelatinolytic puncta in the potentiated neuropil that codistribute with immunolabeling for MMP-9 and for markers of synapses and dendrites. Such increases in proteolytic activity require NMDA receptor activation. Exposing intact area CA1 neurons to recombinant-active MMP-9 induces a slow synaptic potentiation that mutually occludes, and is occluded by, tetanically evoked potentiation. Taken together, our data reveal novel roles for MMP-mediated proteolysis in regulating nonpathological synaptic function and plasticity in mature hippocampus.
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Bhattacharya, Sarbani, Victoria A. Ploplis, and Francis J. Castellino. "Bacterial Plasminogen Receptors Utilize Host Plasminogen System for Effective Invasion and Dissemination." Journal of Biomedicine and Biotechnology 2012 (2012): 1–19. http://dx.doi.org/10.1155/2012/482096.
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In order for invasive pathogens to migrate beyond the site of infection, host physiological barriers such as the extracellular matrix, the basement membrane, and encapsulating fibrin network must be degraded. To circumvent these impediments, proteolytic enzymes facilitate the dissemination of the microorganism. Recruitment of host proteases to the bacterial surface represents a particularly effective mechanism for enhancing invasiveness. Plasmin is a broad spectrum serine protease that degrades fibrin, extracellular matrices, and connective tissue. A large number of pathogens express plasminogen receptors which immobilize plasmin(ogen) on the bacterial surface. Surface-bound plasminogen is then activated by plasminogen activators to plasmin through limited proteolysis thus triggering the development of a proteolytic surface on the bacteria and eventually assisting the spread of bacteria. The host hemostatic system plays an important role in systemic infection. The interplay between hemostatic processes such as coagulation and fibrinolysis and the inflammatory response constitutes essential components of host defense and bacterial invasion. The goal of this paper is to highlight mechanisms whereby pathogenic bacteria, by engaging surface receptors, utilize and exploit the host plasminogen and fibrinolytic system for the successful dissemination within the host.
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Rifkin, D. B., D. Moscatelli, J. Bizik, N. Quarto, F. Blei, P. Dennis, R. Flaumenhaft, and P. Mignatti. "Growth factor control of extracellular proteolysis." Cell Differentiation and Development 32, no. 3 (December 1990): 313–18. http://dx.doi.org/10.1016/0922-3371(90)90045-x.
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Osmolovskiy, Alexander A., Laura Schmidt, Anastasia V. Orekhova, Sergey K. Komarevtsev, Valeriana G. Kreyer, Sergey V. Shabunin, and Nikolay S. Egorov. "Action of Extracellular Proteases of Aspergillus flavus and Aspergillus ochraceus Micromycetes on Plasma Hemostasis Proteins." Life 11, no. 8 (August 2, 2021): 782. http://dx.doi.org/10.3390/life11080782.
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In this study, we investigated the properties of proteolytic enzymes of two species of Aspergillus, Aspergillus flavus 1 (with a high degree of pathogenicity) and Aspergillus ochraceus L-1 (a conditional pathogen), and their effects on various components of the hemostasis system (in vitro) in the case of their penetration into the bloodstream. We showed that micromycete proteases were highly active in cleaving both globular (albuminolysis) and fibrillar (fibrin) proteins, and, to varying degrees, they could coagulate the plasma of humans and animals (due to proteolysis of factors of the blood coagulation cascade) but were not able to coagulate fibrinogen. The proteases of both Aspergillus fully hydrolyzed thrombi in 120–180 min. Micromycetes did not show hemolytic activity but were able to break down hemoglobin.
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Christiaens, Valerie, Ilse Scroyen, and H. Roger Lijnen. "Role of proteolysis in development of murine adipose tissue." Thrombosis and Haemostasis 99, no. 02 (2008): 290–94. http://dx.doi.org/10.1160/th07-10-0589.
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SummaryObesity is a common disorder, and related diseases such as diabetes, atherosclerosis, hypertension, cardiovascular disease and cancer are a major cause of mortality and morbidity inWesterntype societies. Development of obesity is associated with extensive modifications in adipose tissue involving adipogenesis, angiogenesis and extracellular matrix proteolysis. The fibrinolytic (plasminogen/plasmin) and matrix metalloproteinase (MMP) systems cooperate in these processes. A nutritionally induced obesity model in transgenic mice has been used extensively to study the role of the fibrinolytic and MMP systems in the development of obesity. These studies support a role of both systems in adipogenesis and obesity, and suggest that modulation of proteolytic activity may affect development of adipose tissue.
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Birkedal-Hansen, H. "Proteolytic remodeling of extracellular matrix." Current Opinion in Cell Biology 7, no. 5 (1995): 728–35. http://dx.doi.org/10.1016/0955-0674(95)80116-2.
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Aoki, Shigeji, Shoko Ito-Kuwa, Kenjirou Nakamura, Joji Kato, Kazunori Ninomiya, and Valerio Vidotto. "Extracellular proteolytic activity ofCryptococcus neoformans." Mycopathologia 128, no. 3 (December 1994): 143–50. http://dx.doi.org/10.1007/bf01138475.
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Kuz'min, P. N. "XYLOTROPHIC FUNGUS Trichoderma atroviride: CULTIVATION, EXTRACELLULAR HYDROLYTIC AND ANTIMICROBIAL ACTIVITY." Biotechnologia Acta 14, no. 3 (June 2021): 46–53. http://dx.doi.org/10.15407/biotech14.03.046.
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Xylotrophic fungi are well known by their ability to excrete enzymes into environment. These fungi have important biotechnological potential and some of them produce industrial enzymes. Besides, xylotrophic fungal species have recently attracted a lot of attention among researchers as a source of antibacterial drugs. Aim. To analyze the effect of the carbon source in the culture medium, as well as the conditions of deep cultivation on the mycelium yield, proteolytic, cellulolytic and antimicrobial activity of the culture liquid of Trichoderma atroviride. Methods. Deep culture methods were used, partial purification was carried out with salting and subsequent dialysis, the cellulolytic activity was determined spectrophotometrically, antimicrobial activity was determined using the disc diffusion technique. Statistical analysis was performed using STATISTICA 6.0 software. Results. The highest cellulolytic activity (0.50±0.03 units/ml), mycelium yield and the smallest colony diameter were detected when cellulose was used as a carbon source. However, the highest proteolytic activity of the culture liquid was observed with glucose as a carbon source. The optimal temperature range for hydrolase activity was shown to be in the range of 25-30 °C. In comparison with Pleurotus ostreatus, the culture liquid of T. atroviride not only has more pronounced antimicrobial activity, but also inhibits the growth of Candida albicans. Conclusions. The culture liquid of isolated strain T. atroviride is a promising source of hydrolytic enzymes that can be used in organic farming and industry. The purified preparation obtained from the culture liquid of T. atroviride showed significant antimicrobial activity and can be successfully used for drug development in the future.
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Niland, Stephan, Andrea Ximena Riscanevo, and Johannes Andreas Eble. "Matrix Metalloproteinases Shape the Tumor Microenvironment in Cancer Progression." International Journal of Molecular Sciences 23, no. 1 (December 23, 2021): 146. http://dx.doi.org/10.3390/ijms23010146.
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Cancer progression with uncontrolled tumor growth, local invasion, and metastasis depends largely on the proteolytic activity of numerous matrix metalloproteinases (MMPs), which affect tissue integrity, immune cell recruitment, and tissue turnover by degrading extracellular matrix (ECM) components and by releasing matrikines, cell surface-bound cytokines, growth factors, or their receptors. Among the MMPs, MMP-14 is the driving force behind extracellular matrix and tissue destruction during cancer invasion and metastasis. MMP-14 also influences both intercellular as well as cell–matrix communication by regulating the activity of many plasma membrane-anchored and extracellular proteins. Cancer cells and other cells of the tumor stroma, embedded in a common extracellular matrix, interact with their matrix by means of various adhesive structures, of which particularly invadopodia are capable to remodel the matrix through spatially and temporally finely tuned proteolysis. As a deeper understanding of the underlying functional mechanisms is beneficial for the development of new prognostic and predictive markers and for targeted therapies, this review examined the current knowledge of the interplay of the various MMPs in the cancer context on the protein, subcellular, and cellular level with a focus on MMP14.
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ELIAS, C. G. R., F. M. PEREIRA, B. A. SILVA, C. S. ALVIANO, R. M. A. SOARES, and A. L. S. SANTOS. "Leishmanolysin (gp63 metallopeptidase)-like activity extracellularly released byHerpetomonas samuelpessoai." Parasitology 132, no. 1 (September 21, 2005): 37–47. http://dx.doi.org/10.1017/s0031182005008802.
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In previous studies, we showed thatHerpetomonas samuelpessoaiproduced a large amount of a surface-located metallopeptidase that presented similar biochemical properties to that of gp63 fromLeishmaniaspp., which is a well-known virulence factor expressed by these digenetic parasites. The present study aims to identify the proteolytic activity released by livingH. samuelpessoaicells. In this context, the parasites were incubated in phosphate buffer up to 4 h, and the supernatants were obtained by centrifugation and filtration steps and were then applied on SDS–PAGE to determine the secretory protein profile and on gelatin-SDS–PAGE to identify the proteolytic activity. The results demonstrated thatH. samuelpessoaisecreted at least 12 polypeptides and an extracellular peptidase of 66 kDa. This enzyme had its activity diminished by 1,10-phenanthroline, EDTA and EGTA. This metallopeptidase was active in a broad spectrum of pH, showing maximum activity at pH 6·0 at 37 °C. Casein was also cleaved by this secretory proteolytic enzyme, while bovine serum albumin and haemoglobin were not degraded under these conditions. Fluorescence microscopy and flow cytometry using anti-gp63 antibody against leishmanolysin ofL. amazonensisdemonstrated the presence of similar molecules on the cell-surface ofH. samuelpessoai. Moreover, immunoblot analysis showed the presence of a reactive polypeptide in the cellular extract and in the supernatant fluid ofH. samuelpessoai, which suggests immunological similarities between these two distinct trypanosomatids. The zinc-metallopeptidase inhibitor 1,10-phenanthroline was able to inhibit the secretion of the 66 kDa metallopeptidase in a dose-dependent manner, while the phospholipase C inhibitor (p-CMPS) did not alter the secretion pattern. Additionally, anti-cross-reacting determinant (CRD) antibody failed to recognize any secreted polypeptide fromH. samuelpessoai. Collectively, these results suggest that the gp63-like molecule was released from theH. samuelpessoaisurface by proteolysis instead of phospholipolysis, in a similar mechanism to that observed inLeishmania.
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Pidard, D., P. Renesto, M. C. Berndt, S. Rabhi, K. J. Clemetson, and M. Chignard. "Neutrophil proteinase cathepsin G is proteolytically active on the human platelet glycoprotein Ib-IX receptor: characterization of the cleavage sites within the glycoprotein Ibα subunit." Biochemical Journal 303, no. 2 (October 15, 1994): 489–98. http://dx.doi.org/10.1042/bj3030489.
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The proteolytic activity of the neutrophil serine-proteinase cathepsin G (CG) on platelet adherence receptors, the glycoprotein (GP) Ib-IX complex and the integrin alpha IIb beta 3, has been investigated. In the range 50 to 200 nmol/l, CG is a potent platelet agonist which induces shape change, granule exocytosis and aggregation. Investigation of the proteolysis of the receptors' subunits during the course of platelet activation by CG was performed by immunoblot analysis of platelet proteins using a panel of specific antibodies. Exposure of platelets for 3 min at 37 degrees C to CG at a concentration that induces full cell activation resulted in an extensive cleavage of the N-terminal region of the extracellular domain of GPIb alpha, the largest (relative molecular mass, M(r), 143,000) of the three subunits constituting the GPIb-IX complex. In contrast, no detectable proteolytic modification of the two other subunits, GPIb beta and GPIX, was detected. Similarly, we observed that neither of the two subunits of the alpha IIb beta 3 receptor were proteolytically modified by CG. Cleavage of GPIb alpha by CG leaves a remnant of the polypeptide chain with M(r) approx. 106,000 in the plasma membrane, while releasing into the extracellular milieu the N-terminal domain with M(r) in the range 40,000 to 46,000. N-terminal sequencing of the CG-derived fragments of GPIb alpha indicated that the Leu275-Tyr276 peptide bond was the primary cleavage site for this proteinase. Proteolysis of GPIb alpha was already detectable at concentrations of CG as low as 25 nmol/l, while with 200 nmol/l the cleavage was detected as soon as 10 s after exposure of platelets to the proteinase. Comparison of the kinetics and concentration dependency for the proteolysis of GPIb alpha and for the activation of platelets by CG showed that cleavage of the GPIb-IX receptor is an early event that accompanies exocytosis and aggregation. Quantitative evaluation of the conversion of GPIb alpha into its membrane fragment indicated that, under optimal conditions, a maximum of approx. 50% of the total GPIb alpha can be affected by proteolysis. However, this proteolysis was > 90% complete when platelets were in the presence of the potent antagonist prostacyclin, suggesting that cellular redistribution of the GPIb-IX receptor may also occur during activation by CG. These results thus indicate that the very early phase of platelet activation by CG is accompanied by extensive modifications in the structure and expression of the GPIb-IX receptor, an effect that might be of functional significance for the interaction of platelets with the vessel wall.
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Saksela, O., and D. B. Rifkin. "Release of basic fibroblast growth factor-heparan sulfate complexes from endothelial cells by plasminogen activator-mediated proteolytic activity." Journal of Cell Biology 110, no. 3 (March 1, 1990): 767–75. http://dx.doi.org/10.1083/jcb.110.3.767.
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Cultured bovine capillary endothelial (BCE) cells synthesize heparan sulfate proteoglycans (HSPG), which are both secreted into the culture medium and deposited in the cell layer. The nonsoluble HSPGs can be isolated as two predominant species: a larger 800-kD HSPG, which is recovered from preparations of extracellular matrix, and a 250-kD HSPG, which is solubilized by nonionic detergent extraction of the cells. Both HSPG species bind bFGF. 125I-bFGF bound to BCE cell cultures is readily released by either heparinase or plasmin. When released by plasmin, the growth factor is recovered from the incubation medium as a complex with the partly degraded high molecular mass HSPG. Endogenous bFGF activity is released by a proteolytic treatment of cultured BCE cells. The bFGF-binding HSPGs are also released when cultures are incubated with the inactive proenzyme plasminogen. Under such experimental conditions, the release of the extracellular proteoglycans can be enhanced by treating the cells either with bFGF, which increases the plasminogen activating activity expressed by the cells, or decreased by treating the cells with transforming growth factor beta, which decreases the plasminogen activating activity of the cells. Specific immune antibodies raised against bovine urokinase also block the release of HSPG from BCE cell cultures. We propose that this plasminogen activator-mediated proteolysis provides a mechanism for the release of biologically active bFGF-HSPG complexes from the extracellular matrix and that bFGF release can be regulated by the balance between factors affecting the pericellular proteolytic activity.
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Satala, Dorota, Grazyna Bras, Andrzej Kozik, Maria Rapala-Kozik, and Justyna Karkowska-Kuleta. "More than Just Protein Degradation: The Regulatory Roles and Moonlighting Functions of Extracellular Proteases Produced by Fungi Pathogenic for Humans." Journal of Fungi 9, no. 1 (January 15, 2023): 121. http://dx.doi.org/10.3390/jof9010121.
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Extracellular proteases belong to the main virulence factors of pathogenic fungi. Their proteolytic activities plays a crucial role in the acquisition of nutrients from the external environment, destroying host barriers and defenses, and disrupting homeostasis in the human body, e.g., by affecting the functions of plasma proteolytic cascades, and playing sophisticated regulatory roles in various processes. Interestingly, some proteases belong to the group of moonlighting proteins, i.e., they have additional functions that contribute to successful host colonization and infection development, but they are not directly related to proteolysis. In this review, we describe examples of such multitasking of extracellular proteases that have been reported for medically important pathogenic fungi of the Candida, Aspergillus, Penicillium, Cryptococcus, Rhizopus, and Pneumocystis genera, as well as dermatophytes and selected endemic species. Additional functions of proteinases include supporting binding to host proteins, and adhesion to host cells. They also mediate self-aggregation and biofilm formation. In addition, fungal proteases affect the host immune cells and allergenicity, understood as the ability to stimulate a non-standard immune response. Finally, they play a role in the proper maintenance of cellular homeostasis. Knowledge about the multifunctionality of proteases, in addition to their canonical roles, greatly contributes to an understanding of the mechanisms of fungal pathogenicity.
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Braun, Peter, Arjan de Groot, Wilbert Bitter, and Jan Tommassen. "Secretion of Elastinolytic Enzymes and Their Propeptides by Pseudomonas aeruginosa." Journal of Bacteriology 180, no. 13 (July 1, 1998): 3467–69. http://dx.doi.org/10.1128/jb.180.13.3467-3469.1998.
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ABSTRACT Elastase of Pseudomonas aeruginosa is synthesized as a preproenzyme. The signal sequence is cleaved off during transport across the inner membrane and, in the periplasm, proelastase is further processed. We demonstrate that the propeptide and the mature elastase are both secreted but that the propeptide is degraded extracellularly. In addition, reduction of the extracellular proteolytic activity led to the accumulation of unprocessed forms of LasA and LasD in the extracellular medium, which shows that these enzymes are secreted in association with their propeptides. Furthermore, a hitherto undefined protein with homology to a Streptomyces griseusaminopeptidase accumulated under these conditions.
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Sachs, Benjamin D., George S. Baillie, Julianne R. McCall, Melissa A. Passino, Christian Schachtrup, Derek A. Wallace, Allan J. Dunlop, et al. "p75 neurotrophin receptor regulates tissue fibrosis through inhibition of plasminogen activation via a PDE4/cAMP/PKA pathway." Journal of Cell Biology 177, no. 6 (June 18, 2007): 1119–32. http://dx.doi.org/10.1083/jcb.200701040.
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Clearance of fibrin through proteolytic degradation is a critical step of matrix remodeling that contributes to tissue repair in a variety of pathological conditions, such as stroke, atherosclerosis, and pulmonary disease. However, the molecular mechanisms that regulate fibrin deposition are not known. Here, we report that the p75 neurotrophin receptor (p75NTR), a TNF receptor superfamily member up-regulated after tissue injury, blocks fibrinolysis by down-regulating the serine protease, tissue plasminogen activator (tPA), and up-regulating plasminogen activator inhibitor-1 (PAI-1). We have discovered a new mechanism in which phosphodiesterase PDE4A4/5 interacts with p75NTR to enhance cAMP degradation. The p75NTR-dependent down-regulation of cAMP results in a decrease in extracellular proteolytic activity. This mechanism is supported in vivo in p75NTR-deficient mice, which show increased proteolysis after sciatic nerve injury and lung fibrosis. Our results reveal a novel pathogenic mechanism by which p75NTR regulates degradation of cAMP and perpetuates scar formation after injury.
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Chang, Hao, Philip M. Smallwood, John Williams, and Jeremy Nathans. "Intramembrane Proteolysis of Astrotactins." Journal of Biological Chemistry 292, no. 8 (January 18, 2017): 3506–16. http://dx.doi.org/10.1074/jbc.m116.768077.
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Astrotactins are vertebrate-specific membrane proteins implicated in neuron-glia interactions during central nervous system development and in hair follicle polarity during skin development. By studying epitope-tagged derivatives of mouse astrotactin-2 (Astn2) produced in transfected cells, we determined that the amino and carboxyl termini reside in the extracellular space and are initially linked by two transmembrane segments and a single cytoplasmic domain. We further show that Astn2 undergoes proteolytic cleavage in the second transmembrane domain (TM2) and that a disulfide bond holds the resulting two fragments together. Recombinant Astn1 also undergoes TM2 cleavage, as does Astn2 isolated from mouse cerebellum. Astn2 intramembrane proteolysis is insensitive to replacement of TM2 by the transmembrane domain of CD74 or by 21 alanines. However, replacement of TM2 by the transmembrane domain of CD4, the asialoglycoprotein receptor, or the transferrin receptor eliminates intramembrane proteolysis, as does leucine substitution of residues that overlap or are immediately upstream of the cleavage site. Replacement of the transmembrane domain of CD74 or the asialoglycoprotein receptor with Astn2 TM2 leads to the appearance of a carboxyl-terminal fragment consistent with intramembrane proteolysis. These experiments define a highly unusual transmembrane topology for the astrotactins, reveal intramembrane proteolysis as a feature of astrotactin maturation, and constrain the substrate sequences that are permissive for cleavage of one type 2 transmembrane segment.
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Alfano, Daniela, Paola Franco, Immacolata Vocca, Nadia Gambi, Viviana Pisa, Alessandro Mancini, Mario Caputi, Maria Carriero, Ingram Iaccarino, and Maria Stoppelli. "The urokinase plasminogen activator and its receptor." Thrombosis and Haemostasis 93, no. 02 (2005): 205–11. http://dx.doi.org/10.1160/th04-09-0592.
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SummaryThe urinary-type plasminogen activator, or uPA, controls matrix degradation through the conversion of plasminogen into plasmin and is regarded as the critical trigger for plasmin generation during cell migration and invasion, under physiological and pathological conditions (such as cancer metastasis).The proteolytic activity of uPA is responsible for the activation or release of several growth factors and modulates the cell survival/apoptosis ratio through the dynamic control of cell-matrix contacts. The urokinase receptor (uPAR), binding to the EGF-like domain of uPA, directs membrane-associated extracellular proteolysis and signals through transmembrane proteins, thus regulating cell migration, adhesion and cytoskeletal status. However, recent evidence highlights an intricate relationship linking the uPA/uPAR system to cell growth and apoptosis.
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Quesnel, Agathe, George S. Karagiannis, and Panagiota S. Filippou. "Extracellular proteolysis in glioblastoma progression and therapeutics." Biochimica et Biophysica Acta (BBA) - Reviews on Cancer 1874, no. 2 (December 2020): 188428. http://dx.doi.org/10.1016/j.bbcan.2020.188428.
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Sappino, A. P., R. Madani, J. Huarte, D. Belin, J. Z. Kiss, A. Wohlwend, and J. D. Vassalli. "Extracellular proteolysis in the adult murine brain." Journal of Clinical Investigation 92, no. 2 (August 1, 1993): 679–85. http://dx.doi.org/10.1172/jci116637.
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Li, Sining, Shanhu Tang, Qiang He, Jiangxiao Hu, and Jing Zheng. "Changes in Proteolysis in Fermented Milk Produced by Streptococcus thermophilus in Co-Culture with Lactobacillus plantarum or Bifidobacterium animalis subsp. lactis During Refrigerated Storage." Molecules 24, no. 20 (October 15, 2019): 3699. http://dx.doi.org/10.3390/molecules24203699.
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Proteolysis in fermented milk, a complex and dynamic process, depends on the starter cultures used. This study aimed to evaluate the influence of Lactobacillus plantarum or Bifidobacterium animalis subsp. lactis, or both, co-fermented with Streptococcus thermophilus, on the changes in the proteolysis profile of fermented milk during 21-day storage at 4 °C, including the pH value, proteolytic degree, protease activity, aminopeptidase activity, free amino acid content, and electrophoresis performance. The results showed that the treatments with co-cultures exhibited a higher amount of free amino groups and neutral protease activity at an extracellular level, whereas lower pH values and aminopeptidase activities towards the six substrates at an intracellular level than the ones with a single-strain of S. thermophilus over the refrigerated storage were observed. In co-fermentation with S. thermophilus, B. animalis subsp. lactis did not significantly affect the concentrations of most free amino acids, while contributions of L. plantarum were found. Electrophoresis indicated that the mixed starters, especially the co-cultures containing L. plantarum, showed a stronger degradation for caseins than the pure S. thermophilus culture. These findings suggest that culture combinations may influence the proteolysis characteristics of the fermented products, and probiotic cultures must be carefully chosen for fermented production.
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Pepper, M. S., D. Belin, R. Montesano, L. Orci, and J. D. Vassalli. "Transforming growth factor-beta 1 modulates basic fibroblast growth factor-induced proteolytic and angiogenic properties of endothelial cells in vitro." Journal of Cell Biology 111, no. 2 (August 1, 1990): 743–55. http://dx.doi.org/10.1083/jcb.111.2.743.
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Tightly controlled proteolytic degradation of the extracellular matrix by invading microvascular endothelial cells is believed to be a necessary component of the angiogenic process. We have previously demonstrated the induction of plasminogen activators (PAs) in bovine microvascular endothelial (BME) cells by three agents that induce angiogenesis in vitro: basic FGF (bFGF), PMA, and sodium orthovanadate. Surprisingly, we find that these agents also induce plasminogen activator inhibitor-1 (PAI-1) activity and mRNA in BME cells. We also find that transforming growth factor-beta 1 (TGF-beta 1), which in vitro modulates a number of endothelial cell functions relevant to angiogenesis, also increases both PAI-1 and urokinase-type PA (u-PA) mRNA. Thus, production of both proteases and protease inhibitors is increased by angiogenic agents and TGF-beta 1. However, the kinetics and amplitude of PAI-1 and u-PA mRNA induction by these agents are strikingly different. We have used the ratio of u-PA:PAI-1 mRNA levels as an indicator of proteolytic balance. This ratio is tilted towards enhanced proteolysis in response to bFGF, towards antiproteolysis in response to TGF-beta 1, and is similar to that in untreated cultures when the two agents are added simultaneously. Using an in vitro angiogenesis assay in three-dimensional fibrin gels, we find that TGF-beta 1 inhibits the bFGF-induced formation of tube-like structures, resulting in the formation of solid endothelial cell cords within the superficial parts of the gel. These results suggest that a net positive proteolytic balance is required for capillary lumen formation. A novel perspective is provided on the relationship between extracellular matrix invasion, lumen formation, and net proteolytic balance, thereby reflecting the interplay between angiogenesis-modulating cytokines such as bFGF and TGF-beta 1.
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Alele, Jimmy, Jing Jiang, Jeffrey F. Goldsmith, Xiaoyong Yang, Hiralal G. Maheshwari, Roy A. Black, Gerhard Baumann, and Stuart J. Frank. "Blockade of Growth Hormone Receptor Shedding by a Metalloprotease Inhibitor*." Endocrinology 139, no. 4 (April 1, 1998): 1927–35. http://dx.doi.org/10.1210/endo.139.4.5906.
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Abstract GH, an important growth-promoting and metabolic hormone, exerts its biological effects by interacting with cell surface GH receptors (GHRs). The GHR is a single membrane-spanning protein that binds GH via its extracellular domain. The high affinity GH-binding protein (GHBP), which corresponds to a soluble form of the GHR extracellular domain, carries a substantial fraction of the GH in the circulation of various species and probably has a role in modulation of the hormone’s bioavailability. Although in rodents, it is believed that the GHBP is largely derived by translation of an alternatively spliced GHR messenger RNA, in humans and rabbits, proteolytic cleavage of the membrane-anchored receptor releases the GHR extracellular domain, which is believed to thereby become the GHBP. In this study, we used human IM-9 lymphocytes and GHR antibodies to study this proteolytic shedding of the GHBP. As determined by immunoblotting with anti-GHR cytoplasmic domain serum, addition of phorbol 12-myristate 13-acetate (PMA; 1μ g/ml) to serum-starved cells led to rapid loss (roughly 60% decline after 1 h; t1/2 = ∼5 min) of mature GHRs (115–140 kDa) from either total cell or detergent-soluble extracts. Loss of full-length GHRs was accompanied by accumulation of four proteins (65–68 kDa), each reactive with the cytoplasmically directed antiserum. The pattern of appearance of these GHR ctyoplasmic domain proteins, the electrophoretic and immunological characteristics of which are similar to those of a recombinant rabbit GHR mutant that lacks the extracellular domain, was such that progressively faster migrating forms were evident between 5–60 min of PMA exposure. Treatment with N-ethylmaleimide (NEM; 5 mm), an agent known to cause GHBP shedding from IM-9 cells, promoted a similar rapid loss of full-length GHRs and an accumulation of GHR cytoplasmic domain remnant proteins. PMA-induced, but not NEM-induced, GHR proteolysis was blocked by the protein kinase C inhibitor, GF109203X. Both PMA- and NEM-induced receptor proteolysis were, however, inhibited by the metalloprotease inhibitor, Immunex Compound 3 (minimum effective concentration, 10 μm). Notably, PMA and NEM also promoted shedding of GHBP into the conditioned medium of the cells, as determined by a chromatographic [125I]human GH binding assay; this GHBP shedding was also inhibited by Immunex Compound 3. These results strongly implicate a member(s) of the metalloprotease family as a potential GHBP-generating enzyme.