A subpopulation of reactive astrocytes at affected neuronal perikarya after hypophysectomy in adult rats.
Intermediate filaments (IFs) of nestin and vimentin are expressed in immature astrocytes. In this study, we examined the re-expression of these early glial traits in rat reactive astrocytes in affected neuronal perikarya in supraoptic (SON) and paraventricular (PVN) nuclei induced by hypophysectomy. Double-labeling immunofluorescence confocal laser microscopy demonstrated that by 7 days post-lesion, both nestin and vimentin were present intensely in hypertrophied GFAP-IR reactive astrocytes in the area of hypophysectomized magnocellular neurons in SON and PVN, while nestin and vimentin are absent in the normal or sham-operated animals. As the gliotic reaction progressed, the morphology of nestin or vimentin-positive reactive astrocytes in SON but not PVN changed from stellate form at 7 days to thin and elongated shape, morphologically compatible with radial glia during development, at 14 days post-lesion. By 28 days post-lesion, while vimentin-IR persisted in reactive astrocytes in SON and PVN, nestin-IR could hardly be detected. The spatiotemporal pattern of nestin-IR and/or vimentin-IR in reactive astrocytes suggests astrocytes attempt to revert to a more primitive glia form indicated by changes in morphology and phenotype following hypophysectomy, which may contribute to neuronal trophism and plasticity in the lesioned HNS favoring neuronal maintenance and fiber outgrowth.
Yuan
Qiuju
Q
Department of Anatomy, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
Scott
David E
DE
So
Kwok-Fai
KF
Wu
Wutian
W
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism; D001253:Astrocytes / Q000145:classification* / Q000378:metabolism*; D001973:Bromodeoxyuridine / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007016:Hypophysectomy; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000166:cytology; D013997:Time Factors; D014746:Vimentin / Q000378:metabolism
D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D014746:Vimentin; D001127:Arginine Vasopressin; D001973:Bromodeoxyuridine