N Barlow1, Y Nasser2, P Zhao1, N Sharma3, R Guerrero-Alba2, L E Edgington-Mitchell1, T Lieu1, N A Veldhuis1, D P Poole1,4, J W Conner1, E Lindström5, A W Craig3, B Graham1, S J Vanner2, N W Bunnett1. 1. Monash Institute of Pharmaceutical Sciences Parkville Australia, Parkville, Vic., Australia. 2. Gastrointestinal Diseases Research Unit, Division of Gastroenterology, Queen's University, Kingston, ON, Canada. 3. Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada. 4. Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Vic., Australia. 5. Medivir AB, Huddinge, Sweden.
Abstract
BACKGROUND: 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. METHODS: 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. KEY RESULTS: 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 vs DSS: p < 0.05 at 200 min and p < 0.01 at 220-240 min), indicating cathepsin S activation. The cathepsin S inhibitor abolished this increase in fluorescence (DSS vs DSS + MV026031: p < 0.05 at 140 min, p < 0.01 at 180 min, p < 0.001 at 200-240 min), which confirms cathepsin S activation. Cathepsin S activity correlated with the disease activity index (Spearman r = 0.77, p = 0.017). CONCLUSIONS & INFERENCES: 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.
BACKGROUND: 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. METHODS: 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. KEY RESULTS: 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 vs DSS: p < 0.05 at 200 min and p < 0.01 at 220-240 min), indicating cathepsin S activation. The cathepsin S inhibitor abolished this increase in fluorescence (DSS vs DSS + MV026031: p < 0.05 at 140 min, p < 0.01 at 180 min, p < 0.001 at 200-240 min), which confirms cathepsin S activation. Cathepsin S activity correlated with the disease activity index (Spearman r = 0.77, p = 0.017). CONCLUSIONS & INFERENCES: 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.
Authors: Rocco Latorre; Alan Hegron; Chloe J Peach; Shavonne Teng; Raquel Tonello; Jeffri S Retamal; Rafael Klein-Cloud; Diana Bok; Dane D Jensen; Lena Gottesman-Katz; Jeanette Rientjes; Nicholas A Veldhuis; Daniel P Poole; Brian L Schmidt; Charalabos H Pothoulakis; Carl Rankin; Ying Xie; Hon Wai Koon; Nigel W Bunnett Journal: Proc Natl Acad Sci U S A Date: 2022-02-08 Impact factor: 12.779