title: Gelatinase activity imaged by activatable cell-penetrating peptides in cell-based and in vivo models of stroke.
abstract: Matrix metalloproteinases (MMPs), particularly gelatinases (MMP-2/-9), are involved in neurovascular impairment after stroke. Detection of gelatinase activity in vivo can provide insight into blood-brain barrier disruption, hemorrhage, and nerve cell injury or death. We applied gelatinase-activatable cell-penetrating peptides (ACPP) with a cleavable l-amino acid linker to examine gelatinase activity in primary neurons in culture and ischemic mouse brain in vivo We found uptake of Cy5-conjugated ACPP (ACPP-Cy5) due to gelatinase activation both in cultured neurons exposed to n-methyl-d-aspartate and in mice after cerebral ischemia. Fluorescence intensity was significantly reduced when cells or mice were treated with MMP inhibitors or when a cleavage-resistant ACPP-Cy5 was substituted. We also applied an ACPP dendrimer (ACPPD) conjugated with multiple Cy5 and/or gadolinium moieties for fluorescence and magnetic resonance imaging (MRI) in intact animals. Fluorescence analysis showed that ACPPD was detected in sub-femtomole range in ischemic tissues. Moreover, MRI and inductively coupled plasma mass spectrometry revealed that ACPPD produced quantitative measures of gelatinase activity in the ischemic region. The resulting spatial pattern of gelatinase activity and neurodegeneration were very similar. We conclude that ACPPs are capable of tracing spatiotemporal gelatinase activity in vivo, and will therefore be useful in elucidating mechanisms of gelatinase-mediated neurodegeneration after stroke.
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri at Columbia, USA.|Center for Translational Neuroscience, University of Missouri at Columbia, USA.
authors.forename: Shanyan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri at Columbia, USA.|Center for Translational Neuroscience, University of Missouri at Columbia, USA.|Truman VA Hospital Research Service.
authors.forename: Jiankun
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Pharmacology, University of California San Diego School of Medicine, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Pharmacology, University of California San Diego School of Medicine, USA.
authors.forename: Emilia S
authors.initials: ES
authors.lastname: Olson
authors.affiliation: Truman VA Hospital Research Service.|Department of Radiology, University of Missouri at Columbia, USA.
authors.forename: Quan-Yu
authors.initials: QY
authors.lastname: Cai
authors.affiliation: Truman VA Hospital Research Service.|Department of Radiology, University of Missouri at Columbia, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri at Columbia, USA.|Center for Translational Neuroscience, University of Missouri at Columbia, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: Research Reactor Center, University of Missouri at Columbia, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Guthrie
authors.affiliation: Research Reactor Center, University of Missouri at Columbia, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Robertson
authors.affiliation: Department of Neurosciences, University of California San Diego School of Medicine, USA.|Scintillon Institute Neurodegenerative Disease Center, USA.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Lipton
authors.affiliation: Truman VA Hospital Research Service.|Department of Radiology, University of Missouri at Columbia, USA.
authors.forename: Lixin
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Pharmacology, University of California San Diego School of Medicine, USA.|Howard Hughes Medical Institute, University of California San Diego School of Medicine, USA.
authors.forename: Roger Y
authors.initials: RY
authors.lastname: Tsien
authors.affiliation: Department of Pathology and Anatomical Sciences, University of Missouri at Columbia, USA guze@health.missouri.edu.|Center for Translational Neuroscience, University of Missouri at Columbia, USA.|Truman VA Hospital Research Service.
authors.forename: Zezong
authors.initials: Z
authors.lastname: Gu
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging; D002232:Carbocyanines / Q000737:chemistry; D057846:Cell-Penetrating Peptides / Q000737:chemistry*; D002478:Cells, Cultured; D018093:Gelatinases / Q000032:analysis* / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D015335:Molecular Probes / Q000737:chemistry; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000209:etiology; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D002232:Carbocyanines; D057846:Cell-Penetrating Peptides; D015335:Molecular Probes; C085321:cyanine dye 5; D018093:Gelatinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9
keywords: Focal ischemia; MRI; matrix proteins; molecular imaging; neurodegeneration