title: Spatiotemporal expression of osteopontin in the striatum of rats subjected to the mitochondrial toxin 3-nitropropionic acid correlates with microcalcification.
abstract: Our aim was to elucidate whether osteopontin (OPN) is involved in the onset of mineralisation and progression of extracellular calcification in striatal lesions due to mitochondrial toxin 3-nitropropionic acid exposure. OPN expression had two different patterns when observed using light microscopy. It was either localised to the Golgi complex in brain macrophages or had a small granular pattern scattered in the affected striatum. OPN labelling tended to increase in number and size over a 2-week period following the lesion. Ultrastructural investigations revealed that OPN is initially localised to degenerating mitochondria within distal dendrites, which were then progressively surrounded by profuse OPN on days 7-14. Electron probe microanalysis of OPN-positive and calcium-fixated neurites indicated that OPN accumulates selectively on the surfaces of degenerating calcifying dendrites, possibly via interactions between OPN and calcium. In addition, 3-dimensional reconstruction of OPN-positive neurites revealed that they are in direct contact with larger OPN-negative degenerating dendrites rather than with fragmented cell debris. Our overall results indicate that OPN expression is likely to correlate with the spatiotemporal progression of calcification in the affected striatum, and raise the possibility that OPN may play an important role in the initiation and progression of microcalcification in response to brain insults.
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Tae-Ryong
authors.initials: TR
authors.lastname: Riew
authors.affiliation: Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hong Lim
authors.initials: HL
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Xuyan
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jeong-Heon
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yoo-Jin
authors.initials: YJ
authors.lastname: Shin
authors.affiliation: Gumi Electronics &Information Technology Research Institute, Gumi, Korea.
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, Cell Death Disease Research Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Mun-Yong
authors.initials: MY
authors.lastname: Lee
mesh_terms: D000818:Animals; D002114:Calcinosis / Q000209:etiology / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism* / Q000473:pathology; D003712:Dendrites / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009574:Nitro Compounds / Q000633:toxicity; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism*; D011422:Propionates / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D009574:Nitro Compounds; D011422:Propionates; D053495:Osteopontin; C015392:3-nitropropionic acid