title: Characterizing Cathepsin Activity and Macrophage Subtypes in Excised Human Carotid Plaques.
abstract: OBJECTIVE
  Atherosclerosis is a leading cause of mortality worldwide, contributing to both strokes and heart attacks. Macrophages are key players in atherogenesis, promoting vascular inflammation and arterial remodeling through cysteine cathepsin proteases. We used a cathepsin-targeted activity-based probe in human carotid plaque to assess its diagnostic potential and evaluate macrophage subtypes ex vivo.
  
  
  METHODS
  Carotid plaque specimens surgically removed during endarterectomy from 62 patients (age range, 38% female, 28% symptomatic) were graded pathologically as either stable (Grade 1) or unstable (Grade 2 or 3). A cathepsin activity-based probe was used to quantify individual cathepsins in plaque tissue and macrophage subtypes.
  
  
  RESULTS
  Cathepsin B and S activities were increased in unstable carotid plaques. They were quantified using the probe to biochemically investigate individual cathepsins (Cathepsin B and S: 0.97 and 0.90 for grade 3 versus 0.51 and 0.59 for grade 1; P=0.006 and P=0.03 arbitrary units (AU), respectively). Higher cathepsin activity was observed in carotid plaques from symptomatic patients (Cathepsin B and S: 0.65 and 0.77 for asymptomatic, 0.99 and 1.17 for symptomatic; P=0.008 and P=0.005 AU, respectively). Additionally, it was demonstrated that M2 macrophages from unstable plaques express cathepsin activity 5-fold higher than M2 macrophages from stable plaques (25.52 versus 5.22; P=0.008 AU).
  
  
  CONCLUSIONS
  Targeting cathepsin activity in human carotid plaques may present a novel diagnostic tool for characterizing high-risk plaques. Novel cathepsin activity patterns within plaques and macrophage subpopulations suggest their involvement in the transition to active disease.
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Ihab
authors.initials: I
authors.lastname: Abd-Elrahman
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Karen
authors.initials: K
authors.lastname: Meir
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Hisanori
authors.initials: H
authors.lastname: Kosuge
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Yael
authors.initials: Y
authors.lastname: Ben-Nun
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Tommy
authors.initials: T
authors.lastname: Weiss Sadan
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Chen
authors.initials: C
authors.lastname: Rubinstein
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Samet
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.).
authors.forename: Michael V
authors.initials: MV
authors.lastname: McConnell
authors.affiliation: From the Institute of Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel (I.A.-E., Y.B.-N., T.W.S., G.B.); Department of Pathology (K.M.) and Department of Vascular Surgery (C.R., Y.S.), Hadassah Medical Center, Jerusalem, 9112001, Israel; and Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA (H.K., M.V.M.). galiabl@ekmd.huji.ac.il.
authors.forename: Galia
authors.initials: G
authors.lastname: Blum
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002403:Cathepsins / Q000378:metabolism*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000378:metabolism* / Q000473:pathology / Q000601:surgery
chemical_list: D002403:Cathepsins
keywords: activity-based probe; atherosclerosis; cathepsins; macrophages; optical imaging