Increased cysteine-protease activity in fecal supernatants from constipated IBS-C patients leads to occludin enzymatic degradation in colonic mucosa

2011 ◽  
Vol 49 (05) ◽  
Author(s):  
R Róka ◽  
A Annaházi ◽  
V Bezirard ◽  
H Eutamene ◽  
L Ferrier ◽  
...  
2011 ◽  
Vol 140 (5) ◽  
pp. S-151-S-152
Author(s):  
Anita Annahazi ◽  
Valérie Bézirard ◽  
Mathilde Leveque ◽  
Helene Eutamene ◽  
Laurent Ferrier ◽  
...  

2007 ◽  
Vol 46 (6) ◽  
pp. 1260-1266 ◽  
Author(s):  
Said Abisi ◽  
Kevin G. Burnand ◽  
Matthew Waltham ◽  
Julia Humphries ◽  
Peter R. Taylor ◽  
...  

2005 ◽  
Vol 73 (2) ◽  
pp. 859-864 ◽  
Author(s):  
Björn Zimmerlein ◽  
Hae-Sun Park ◽  
Shaoying Li ◽  
Andreas Podbielski ◽  
P. Patrick Cleary

ABSTRACT The streptococcal pyrogenic exotoxin B (SpeB) is an important virulence factor of group A streptococci (GAS) with cysteine protease activity. Maturation of SpeB to a proteolytically active form was suggested to be dependent on cell-wall-anchored M1 protein, the major surface protein of GAS (M. Collin and A. Olsén, Mol. Microbiol. 36:1306-1318, 2000). Collin and Olsén showed that mutant GAS strains expressing truncated M protein secrete a conformationally different form of unprocessed SpeB with no proteolytic activity. Alternatively, we hypothesized that a truncated M protein may interfere with processing of this secreted protease, and therefore we tested cysteine protease activity in genetically defined mutant strains that express either no M protein or membrane-anchored M protein with an in-frame deletion of the AB repeat region. Measurements of SpeB activity by cleavage of a substrate n-benzoyl-Pro-Phe-Arg-p-nitroanilide hydrochloride showed that the proteolytic activities in culture supernatants of both mutants were similar to those from the wild-type strain. In addition, Western blot analysis of culture supernatants showed that SpeB expression and processing to a mature form was unaffected by either deletion mutation. Therefore, we conclude that M protein is not required for maturation of the streptococcal cysteine protease SpeB.


2014 ◽  
Vol 63 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Hideo Iida ◽  
Toshiro Takai ◽  
Yusuke Hirasawa ◽  
Seiji Kamijo ◽  
Sakiko Shimura ◽  
...  

2007 ◽  
Vol 3 (10) ◽  
pp. 668-677 ◽  
Author(s):  
Galia Blum ◽  
Georges von Degenfeld ◽  
Milton J Merchant ◽  
Helen M Blau ◽  
Matthew Bogyo

2019 ◽  
Vol 38 (4) ◽  
pp. S250
Author(s):  
C. Morrone ◽  
N. Smirnova ◽  
N. Kneidinger ◽  
H. Schiller ◽  
O. Eickelberg ◽  
...  

2005 ◽  
Vol 386 (9) ◽  
Author(s):  
Vivian Hook ◽  
Thomas Toneff ◽  
Matthew Bogyo ◽  
Doron Greenbaum ◽  
Katalin F. Medzihradszky ◽  
...  

AbstractThe regulated secretory pathway of neurons is the major source of extracellular Aβ that accumulates in Alzheimer's disease (AD). Extracellular Aβ secreted from that pathway is generated by β-secretase processing of amyloid precursor protein (APP). Previously, cysteine protease activity was demonstrated as the major β-secretase activity in regulated secretory vesicles of neuronal chromaffin cells. In this study, the representative cysteine protease activity in these secretory vesicles was purified and identified as cathepsin B by peptide sequencing. Immunoelectron microscopy demonstrated colocalization of cathepsin B with Aβ in these vesicles. The selective cathepsin B inhibitor, CA074, blocked the conversion of endogenous APP to Aβ in isolated regulated secretory vesicles. In chromaffin cells, CA074Me (a cell permeable form of CA074) reduced by about 50% the extracellular Aβ released by the regulated secretory pathway, but CA074Me had no effect on Aβ released by the constitutive pathway. Furthermore, CA074Me inhibited processing of APP into the COOH-terminal β-secretase-like cleavage product. These results provide evidence for cathepsin B as a candidate β-secretase in regulated secretory vesicles of neuronal chromaffin cells. These findings implicate cathepsin B as β-secretase in the regulated secretory pathway of brain neurons, suggesting that inhibitors of cathepsin B may be considered as therapeutic agents to reduce Aβ in AD.


2012 ◽  
Vol 27 (2) ◽  
pp. 803-810 ◽  
Author(s):  
Madasu Yadaiah ◽  
Babu Sudhamalla ◽  
P. Nageswara Rao ◽  
Karnati R. Roy ◽  
Dasari Ramakrishna ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document