Signal transduction by serine proteinases in astrocytes: Regulation of proliferation, morphologic changes, and survival via proteinase-activated receptors

2003 ◽  
Vol 60 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Hong Wang ◽  
Georg Reiser
Keyword(s):  
Signal Transduction ◽  
Serine Proteinases ◽  
Regulation Of Proliferation ◽  
Proteinase Activated Receptors ◽  
Morphologic Changes

Proteinase-mediated cell signalling: targeting proteinase-activated receptors (PARs) by kallikreins and more

2006 ◽  
Vol 387 (6) ◽  
pp. 677-685 ◽  
Author(s):  
Katerina Oikonomopoulou ◽  
Kristina K. Hansen ◽  
Mahmoud Saifeddine ◽  
Nathalie Vergnolle ◽  
Illa Tea ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Physiological Responses ◽  
Cell Signalling ◽  
Target Cells ◽  
Serine Proteinases ◽  
Catalytic Domains ◽  
Proteinase Activated Receptors ◽  
G Protein Coupled ◽  
Unique Mechanism ◽  
Receptor Family

AbstractSerine proteinases, like trypsin, can play a hormone-like role by triggering signal transduction pathways in target cells. In many respects these hormone-like actions of proteinases can now be understood in terms of the pharmacodynamics of the G protein-coupled ‘receptor’ responsible for the cellular actions of thrombin (proteinase-activated receptor-1, or PAR1). PAR1, like the other three members of this receptor family (PAR2, PAR3and PAR4), has a unique mechanism of activation involving the proteolytic unmasking of an N-terminally tethered sequence that can activate the receptor. The selective activation of each PAR by short synthetic peptides representing these sequences has demonstrated that PAR1, PAR2and PAR4play important roles in regulating physiological responses ranging from vasoregulation and cell growth to inflammation and nociception. We hypothesise that the tissue kallikreins may regulate signal transduction via the PARs. Although PARs can account for many of their biological actions, kallikreins may also cause effects by mechanisms not involving the PARs. For instance, trypsin activates the insulin receptor and thrombin can act via a mechanism involving its non-catalytic domains. Based on the data we summarise, we propose that the kallikreins, like thrombin and trypsin, must now be considered as important ‘hormonal’ regulators of tissue function.

scholarly journals Prostatic trypsin-like kallikrein-related peptidases (KLKs) and other prostate-expressed tryptic proteinases as regulators of signalling via proteinase-activated receptors (PARs)

2008 ◽  
Vol 389 (6) ◽  
Author(s):  
Andrew J. Ramsay ◽  
Janet C. Reid ◽  
Mark N. Adams ◽  
Hemamali Samaratunga ◽  
Ying Dong ◽  
...  
Keyword(s):  
Serine Proteinase ◽  
Cellular Responses ◽  
Serine Proteinases ◽  
Inhibitory Mechanisms ◽  
Lysine Residues ◽  
Proteinase Activated Receptors ◽  
A Site ◽  
Potential Interactions ◽  
G Protein Coupled ◽  
Serine Proteinase Activity

AbstractThe prostate is a site of high expression of serine proteinases including members of the kallikrein-related peptidase (KLK) family, as well as other secreted and membrane-anchored serine proteinases. It has been known for some time that members of this enzyme family elicit cellular responses by acting directly on cells. More recently, it has been recognised that for serine proteinases with specificity for cleavage after arginine and lysine residues (trypsin-like or tryptic enzymes) these cellular responses are often mediated by cleavage of members of the proteinase-activated receptor (PAR) family – a four member sub-family of G protein-coupled receptors. Here, we review the expression of PARs in prostate, the ability of prostatic trypsin-like KLKs and other prostate-expressed tryptic enzymes to cleave PARs, as well as the prostate cancer-associated consequences of PAR activation. In addition, we explore the dysregulation of trypsin-like serine proteinase activity through the loss of normal inhibitory mechanisms and potential interactions between these dysregulated enzymes leading to aberrant PAR activation, intracellular signalling and cancer-promoting cellular changes.

scholarly journals Induction of Tumor Necrosis Factor (TNF) Release from Subtypes of T Cells by Agonists of Proteinase Activated Receptors

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Haiwei Yang ◽  
Tao Li ◽  
Jifu Wei ◽  
Huiyun Zhang ◽  
Shaoheng He
Keyword(s):  
T Cells ◽  
Tumor Necrosis ◽  
Proteinase Inhibitors ◽  
Human Peripheral Blood ◽  
Fold Increase ◽  
The Body ◽  
Serine Proteinases ◽  
Proteinase Activated Receptors ◽  
Culture Supernatants ◽  
Necrosis Factor

Serine proteinases have been recognized as playing an important role in inflammation via proteinase activated receptors (PARs). However, little is known about the influence of serine proteinases and PARs on TNF secretion from highly purified T cells. We challenged T cells from human peripheral blood with serine proteinases and agonist peptides of PARs and measured the levels of TNF in culture supernatants by ELISA. The results showed that thrombin and trypsin, but not tryptase, stimulated approximately up to 2.5-fold increase in TNF release from T cells following 16 h incubation. Proteinase inhibitors and PAR-1 antagonist SCH 79797 almost completely abolished thrombin- and trypsin-induced TNF release from T cells. Agonist peptides of PAR-1, but not PAR-2 induced TNF release from T cells. Moreover, trypsin- and thrombin-induced upregulated expression of TNF was observed in CD4+, IL-4+, or CD25+ T cells, but not in IFN+ or IL-17+ T cells. The signaling pathways MAPK/ERK and PI3K/Akt are involved in the thrombin- and trypsin-induced TNF release from T cells. In conclusion, thrombin and trypsin can induce TNF release from IL-4+ and CD25+ T cells through activation of PAR-1 and therefore contribute to regulation of immune response and inflammation of the body.

Morphologic alterations in bacteroides fragilis following single and combinant beta-lactam exposure

1986 ◽  
Vol 44 ◽  
pp. 304-305
Author(s):  
Michael P. Goheen ◽  
Charles E. Edmiston
Keyword(s):  
Bacteroides Fragilis ◽  
Synergistic Activity ◽  
Beta Lactam ◽  
Clinical Strains ◽  
Drug Activity ◽  
Obligate Anaerobic ◽  
Morphologic Changes

The synergistic activity of antimicrobial combinants against aerobic and facultative microorganisms has been well documented. in comparison, few studies have been performed using obligate anaerobic isolates and antimicrobial combinants. For this study clinical strains of Bacteroides fragilis(BF) were selected to investigate both single/combinant drug activity and cellular morphologic changes when BF is exposed to Imipenem (I), Piperacillin (P), Cefpimizole (C), Imipenem/Piperacillin (I+P), and Imipenem/Cefpimizole (I+C).

Ultrastructural aspects of olfactory signal transduction and its development

1994 ◽  
Vol 52 ◽  
pp. 142-143
Author(s):  
Bert Ph. M. Menco
Keyword(s):  
Signal Transduction ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Freeze Substitution ◽  
Luminal Surface ◽  
Tissue Sections ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Olfactory Signal ◽  
Odor Molecule

Vertebrate olfactory receptor cells are specialized neurons that have numerous long tapering cilia. The distal parts of these cilia line the interface between the external odorous environment and the luminal surface of the olfactory epithelium. The length and number of these cilia results in a large surface area that presumably increases the chance that an odor molecule will meet a receptor cell. Advanced methods of cryoprepration and immuno-gold labeling were particularly useful to preserve the delicate ultrastructural and immunocytochemical features of olfactory cilia required for localization of molecules involved in olfactory signal-transduction. We subjected olfactory tissues to freeze-substitution in acetone (unfixed tissues) or methanol (fixed tissues) followed by low temperature embedding in Lowicryl K11M for that purpose. Tissue sections were immunoreacted with several antibodies against proteins that are presumably important in olfactory signal-transduction.

Signal-regulated oxidation of proteins via MICAL

2020 ◽  
Vol 48 (2) ◽  
pp. 613-620
Author(s):  
Clara Ortegón Salas ◽  
Katharina Schneider ◽  
Christopher Horst Lillig ◽  
Manuela Gellert
Keyword(s):  
Signal Transduction ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Redox Regulation ◽  
Signal Transduction Pathways ◽  
Cellular Functions ◽  
Intracellular Signals ◽  
Amino Acid Side Chains ◽  
Specific Receptors ◽  
Sulfur Containing

Processing of and responding to various signals is an essential cellular function that influences survival, homeostasis, development, and cell death. Extra- or intracellular signals are perceived via specific receptors and transduced in a particular signalling pathway that results in a precise response. Reversible post-translational redox modifications of cysteinyl and methionyl residues have been characterised in countless signal transduction pathways. Due to the low reactivity of most sulfur-containing amino acid side chains with hydrogen peroxide, for instance, and also to ensure specificity, redox signalling requires catalysis, just like phosphorylation signalling requires kinases and phosphatases. While reducing enzymes of both cysteinyl- and methionyl-derivates have been characterised in great detail before, the discovery and characterisation of MICAL proteins evinced the first examples of specific oxidases in signal transduction. This article provides an overview of the functions of MICAL proteins in the redox regulation of cellular functions.

Specificity of receptor-mediated signal transduction by E. coli type its heat-labile toxin

2001 ◽  
Vol 120 (5) ◽  
pp. A700-A700
Author(s):  
S WIMERMACKIN ◽  
R HOLMES ◽  
A WOLF ◽  
W LENCER ◽  
M JOBLING
Keyword(s):  
Signal Transduction ◽  
E Coli ◽  
Heat Labile
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