title: Multiple therapeutic effects of progranulin on experimental acute ischaemic stroke.
abstract: In the central nervous system, progranulin, a glycoprotein growth factor, plays a crucial role in maintaining physiological functions, and progranulin gene mutations cause TAR DNA-binding protein-43-positive frontotemporal lobar degeneration. Although several studies have reported that progranulin plays a protective role against ischaemic brain injury, little is known about temporal changes in the expression level, cellular localization, and glycosylation status of progranulin after acute focal cerebral ischaemia. In addition, the precise mechanisms by which progranulin exerts protective effects on ischaemic brain injury remains unknown. Furthermore, the therapeutic potential of progranulin against acute focal cerebral ischaemia, including combination treatment with tissue plasminogen activator, remains to be elucidated. In the present study, we aimed to determine temporal changes in the expression and localization of progranulin after ischaemia as well as the therapeutic effects of progranulin on ischaemic brain injury using in vitro and in vivo models. First, we demonstrated a dynamic change in progranulin expression in ischaemic Sprague-Dawley rats, including increased levels of progranulin expression in microglia within the ischaemic core, and increased levels of progranulin expression in viable neurons as well as induction of progranulin expression in endothelial cells within the ischaemic penumbra. We also demonstrated that the fully glycosylated mature secretory isoform of progranulin (∼88 kDa) decreased, whereas the glycosylated immature isoform of progranulin (58-68 kDa) markedly increased at 24 h and 72 h after reperfusion. In vitro experiments using primary cells from C57BL/6 mice revealed that the glycosylated immature isoform was secreted only from the microglia. Second, we demonstrated that progranulin could protect against acute focal cerebral ischaemia by a variety of mechanisms including attenuation of blood-brain barrier disruption, neuroinflammation suppression, and neuroprotection. We found that progranulin could regulate vascular permeability via vascular endothelial growth factor, suppress neuroinflammation after ischaemia via anti-inflammatory interleukin 10 in the microglia, and render neuroprotection in part by inhibition of cytoplasmic redistribution of TAR DNA-binding protein-43 as demonstrated in progranulin knockout mice (C57BL/6 background). Finally, we demonstrated the therapeutic potential of progranulin against acute focal cerebral ischaemia using a rat autologous thrombo-embolic model with delayed tissue plasminogen activator treatment. Intravenously administered recombinant progranulin reduced cerebral infarct and oedema, suppressed haemorrhagic transformation, and improved motor outcomes (P = 0.007, 0.038, 0.007 and 0.004, respectively). In conclusion, progranulin may be a novel therapeutic target that provides vascular protection, anti-neuroinflammation, and neuroprotection related in part to vascular endothelial growth factor, interleukin 10, and TAR DNA-binding protein-43, respectively.
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kanazawa
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Kawamura
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Minami
authors.initials: M
authors.lastname: Miura
authors.affiliation: 2 Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Misaki
authors.initials: M
authors.lastname: Koyama
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Toriyabe
authors.affiliation: 3 Department of Centre for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Hironaka
authors.initials: H
authors.lastname: Igarashi
authors.affiliation: 3 Department of Centre for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakada
authors.affiliation: 2 Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Masugi
authors.initials: M
authors.lastname: Nishihara
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan.
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nishizawa
authors.affiliation: 1 Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan t-shimo@bri.niigata-u.ac.jp.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shimohata
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002545:Brain Ischemia / Q000378:metabolism; D004195:Disease Models, Animal; D005455:Fluorescent Antibody Technique; D000077155:Granulins; D015151:Immunoblotting; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D000077153:Progranulins; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020521:Stroke / Q000378:metabolism* / Q000473:pathology*
chemical_list: D000077155:Granulins; C120204:Grn protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins
keywords: IL10; TDP-43; VEGF; cerebral ischaemia; progranulin