Demonstration of elevated levels of active cathepsin S in dextran sulfate sodium colitis using a new activatable probe. Issue 11 (24th August 2015)

• Record Type: Journal Article
• Authors: Barlow, N.; Nasser, Y.; Zhao, P.; Sharma, N.; Guerrero‐Alba, R.; Edgington‐Mitchell, L. E.; Lieu, T.; Veldhuis, N. A.; Poole, D. P.; Conner, J. W.; Lindström, E.; Craig, A. W.; Graham, B.; Vanner, S. J.; Bunnett, N. W.
• Is Part Of: Neurogastroenterology & motility. Volume 27:Issue 11(2015:Nov.)
• Page Start: 1675
• Page End: 1680
• Publication Date: 2015-08-24
• Subjects: Gastrointestinal system -- Motility -- Periodicals; Gastrointestinal system -- Innervation -- Periodicals; 616.33
• DOI: 10.1111/nmo.12656
• Languages: English
• ISSNs: 1350-1925

Abstract

<abstract abstract-type="main" id="nmo12656-abs-0001"> <title>Abstract</title> <sec id="nmo12656-sec-0001" sec-type="section"> <title>Background</title> <p>Proteases play a major role in inflammatory diseases of the gastrointestinal tract. Activatable probes are a major technological advance, enabling sensitive detection of active proteases in tissue samples. Our aim was to synthesize an activatable probe for cathepsin S and validate its use in a mouse model of colitis.</p> </sec> <sec id="nmo12656-sec-0002" sec-type="section"> <title>Methods</title> <p>We designed and synthesized a new fluorescent activatable probe, NB200, for the detection of active cathepsin S. Colitis was induced in C57BL/6 mice by the administration of 3% dextran sulfate sodium (DSS). Homogenized mouse colons, with or without the addition of the specific cathepsin S inhibitor MV026031, were incubated with NB200 in a fluorescent plate reader.</p> </sec> <sec id="nmo12656-sec-0003" sec-type="section"> <title>Key Results</title> <p>NB200 selectively detected purified cathepsin S and not other common inflammatory proteases. Homogenates of colon from mice with DSS colitis induced a significant fluorescent increase when compared to control animals (control <italic>vs</italic> DSS:<italic> p</italic> < 0.05 at 200 min and <italic>p</italic> < 0.01 at 220–240 min), indicating cathepsin S activation. The cathepsin S inhibitor abolished this increase in fluorescence (DSS <italic>vs</italic> DSS + MV026031: <italic>p</italic> < 0.05 at 140 min, <italic>p</italic> < 0.01 at 180 min, <italic>p</italic> < 0.001 at 200–240 min), which confirms cathepsin S activation. Cathepsin S activity correlated with the disease activity index (Spearman <italic>r</italic> = 0.77, <italic>p</italic> = 0.017).</p> </sec> <sec id="nmo12656-sec-0004" sec-type="section"> <title>Conclusions & Inferences</title> <p>Our investigation has demonstrated the utility of activatable probes for detecting protease activity in intestinal inflammation. Panels of such probes may allow 'signature' protease profiles to be established for a range of inflammatory diseases and disorders.</p> </sec> </abstract>