Role of endothelin-converting enzyme, chymase and neutral endopeptidase in the processing of big ET-1, ET-1(1-21) and ET-1(1-31) in the trachea of allergic mice

2002 ◽  
Vol 103 (s2002) ◽  
pp. 353S-356S ◽  
Author(s):  
Benjamin A. DE CAMPO ◽  
Roy G. GOLDIE ◽  
Arco Y. JENG ◽  
Peter J. HENRY

The present study examined the roles of endothelin-converting enzyme (ECE), neutral endopeptidase (NEP) and mast cell chymase as processors of the endothelin (ET) analogues ET-1(1–21), ET-1(1–31) and big ET-1 in the trachea of allergic mice. Male CBA/CaH mice were sensitized with ovalbumin (10µg) delivered intraperitoneal on days 1 and 14, and exposed to aerosolized ovalbumin on days 14, 25, 26 and 27 (OVA mice). Mice were killed and the trachea excised for histological analysis and contraction studies on day 28. Tracheae from OVA mice had 40% more mast cells than vehicle-sensitized mice (sham mice). Ovalbumin (10µg/ml) induced transient contractions (15±3% of the Cmax) in tracheae from OVA mice. The ECE inhibitor CGS35066 (10µM) inhibited contractions induced by big ET-1 (4.8-fold rightward shift of dose-response curve; P<0.05), but not those induced by either ET-1(1–21) or ET-1(1–31). The chymase inhibitors chymostatin (10µM) and Bowman-Birk inhibitor (10µM) had no effect on contractions induced by any of the ET analogues used. The NEP inhibitor CGS24592 (10µM) inhibited contractions induced by ET-1(1–31) (6.2-fold rightward shift; P<0.05) but not ET-1(1–21) or big ET-1. These data suggest that big ET-1 is processed predominantly by a CGS35066-sensitive ECE within allergic airways rather than by mast cell-derived proteases such as chymase. If endogenous ET-1(1–31) is formed within allergic airways, it is likely to undergo further conversion by NEP to more active products.

2003 ◽  
Vol 81 (6) ◽  
pp. 503-510 ◽  
Author(s):  
P D'Orléans-Juste ◽  
M Plante ◽  
J C Honoré ◽  
E Carrier ◽  
J Labonté

The endothelin-converting enzyme (ECE) is the main enzyme responsible for the genesis of the potent pressor peptide endothelin-1 (ET-1). It is suggested that the ECE is pivotal in the genesis of ET-1, considering that the knockout of both genes generates the same lethal developments during the embryonic stage. Several isoforms of the ECE have been disclosed, namely ECE-1, ECE-2, and ECE-3. Within each of the first two groups, several sub-isoforms derived through splicing of single genes have also been identified. In this review, the characteristics of each sub-isoform for ECE-1 and 2 will be discussed. It is important to mention that the ECE is, however, not the sole enzyme involved in the genesis of endothelins. Indeed, other moieties, such as chymase and matrix metalloproteinase II, have been suggested to be involved in the production of ET intermediates, such as ET-1 (1–31) and ET-1 (1–32), respectively. Other enzymes, such as the neutral endopeptidase 24–11, is curiously not only involved in the degradation and inactivation of ET-1, but is also responsible for the final production of the peptide via the hydrolysis of ET-1 (1–31). In this review, we will attempt to summarize, through the above-mentioned characteristics, the current wisdom on the role of these different enzymes in the genesis and termination of effect of the most potent pressor peptide reported to date.Key words: endothelin converting enzyme, endothelin-1, isoforms, human, inhibitors, chymase, ET-1 (1–31).


Allergy ◽  
2021 ◽  
Author(s):  
Lea Pohlmeier ◽  
Sanchaita Sriwal Sonar ◽  
Hans‐Reimer Rodewald ◽  
Manfred Kopf ◽  
Luigi Tortola

1984 ◽  
Vol 62 (6) ◽  
pp. 734-737 ◽  
Author(s):  
F. Shanahan ◽  
J. A. Denburg ◽  
J. Bienenstock ◽  
A. D. Befus

Increasing evidence for the existence of inter- and intra-species mast cell heterogeneity has expanded the potential biological role of this cell. Early studies suggesting that mast cells at mucosal sites differ morphologically and histochemically from connective tissue mast cells have been confirmed using isolated intestinal mucosal mast cells in the rat and more recently in man. These studies also established that mucosal mast cells are functionally distinct from connective tissue mast cells. Thus, mucosal and connective tissue mast cells differ in their responsiveness to a variety of mast cell secretagogues and antiallergic agents. Speculation about the therapeutic use of antiallergic drugs in disorders involving intestinal mast cells cannot, therefore, be based on extrapolation from studies of their effects on mast cells from other sites. Regulatory mechanisms for mast cell secretion may also be heterogeneous since mucosal mast cells differ from connective tissue mast cells in their response to a variety of physiologically occurring regulatory peptides. The development of techniques to purify isolated mast cell sub-populations will facilitate future analysis of the biochemical basis of the functional heterogeneity of mast cells.


1996 ◽  
Vol 80 (4) ◽  
pp. 1322-1330 ◽  
Author(s):  
M. Longphre ◽  
L. Y. Zhang ◽  
J. R. Harkema ◽  
S. R. Kleeberger

Ozone (O3) exposure produces inflammation in the airways of humans and animal models. However, the mechanism by which O3 affects these changes is uncertain. Mast cells are strategically located below the epithelium of the airways and are capable of releasing a number of proinflammatory mediators. We tested the hypothesis that mast cells contribute to inflammation, epithelial sloughing, and epithelial proliferation in the nasal and terminal bronchiolar murine airways after O3 exposure. Mast cell-sufficient (+/+), mast cell-deficient (W/Wv), and mast cell-repleted [bone marrow-transplanted (BMT) W/Wv] mice were exposed to 2 ppm O3 or filtered air for 3 h. Nasal and bronchoalveolar lavage fluids were collected 6 and 24 h after exposure. Differential cell counts and protein content of the lavage fluids were used as indicators of inflammation and permeability changes in the airways. O3-induced epithelial injury was assessed by light microscopy, and O3-induced DNA synthesis in airway epithelium was estimated by using a 5-bromo-2′-deoxyuridine-labeling index in the nasal and terminal bronchiolar epithelia. Relative to air control mice, O3 caused significant increases in inflammation, epithelial injury, and epithelial DNA synthesis in +/+ mice. There was no significant effect of O3 exposure on any measured parameter in the W/Wv mice. To further assess the role of mast cells in O3-induced epithelial damage, mast cells were restored in W/Wv mice by BMT from +/+ congeners. Relative to sham-transplanted W/Wv mice, O3 caused significant increases in epithelial damage and DNA synthesis as well as inflammatory indicators in BMT W/Wv mice. These observations are consistent with the hypothesis that mast cells significantly modulate the inflammatory and proliferative responses of the murine airways to O3.


2018 ◽  
Vol 11 (556) ◽  
pp. eaao4354 ◽  
Author(s):  
Ivana Halova ◽  
Monika Bambouskova ◽  
Lubica Draberova ◽  
Viktor Bugajev ◽  
Petr Draber

Chemotaxis of mast cells is one of the crucial steps in their development and function. Non–T cell activation linker (NTAL) is a transmembrane adaptor protein that inhibits the activation of mast cells and B cells in a phosphorylation-dependent manner. Here, we studied the role of NTAL in the migration of mouse mast cells stimulated by prostaglandin E2 (PGE2). Although PGE2 does not induce the tyrosine phosphorylation of NTAL, unlike IgE immune complex antigens, we found that loss of NTAL increased the chemotaxis of mast cells toward PGE2. Stimulation of mast cells that lacked NTAL with PGE2 enhanced the phosphorylation of AKT and the production of phosphatidylinositol 3,4,5-trisphosphate. In resting NTAL-deficient mast cells, phosphorylation of an inhibitory threonine in ERM family proteins accompanied increased activation of β1-containing integrins, which are features often associated with increased invasiveness in tumors. Rescue experiments indicated that only full-length, wild-type NTAL restored the chemotaxis of NTAL-deficient cells toward PGE2. Together, these data suggest that NTAL is a key inhibitor of mast cell chemotaxis toward PGE2, which may act through the RHOA/ERM/β1-integrin and PI3K/AKT axes.


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