COEXPRESSION OF GFAP AND VIMENTIN IN ASTROCYTES PROLIFERATING IN RESPONSE TO INJURY IN THE MOUSE CEREBRAL HEMISPHERE - A COMBINED AUTORADIOGRAPHIC AND DOUBLE IMMUNOCYTOCHEMICAL STUDY

Authors
Citation
K. Janeczko, COEXPRESSION OF GFAP AND VIMENTIN IN ASTROCYTES PROLIFERATING IN RESPONSE TO INJURY IN THE MOUSE CEREBRAL HEMISPHERE - A COMBINED AUTORADIOGRAPHIC AND DOUBLE IMMUNOCYTOCHEMICAL STUDY, International journal of developmental neuroscience, 11(2), 1993, pp. 139-147
Citations number
22
Categorie Soggetti
Neurosciences
ISSN journal
07365748
Volume
11
Issue
2
Year of publication
1993
Pages
139 - 147
Database
ISI
SICI code
0736-5748(1993)11:2<139:COGAVI>2.0.ZU;2-S
Abstract
Changes in the distribution of proliferating astrocytes expressing gli al fibrillary acidic protein (GFAP) and/or vimentin were examined in t he injured cerebral hemisphere in adult mice. The injury was followed by [H-3]thymidine injections at different time intervals. The brain se ctions were doubly immunostained for GFAP and vimentin and subjected t o autoradiography. In that way three cell types were distinguished imm unocytochemically: (1) astrocytes co-expressing glial fibrillary acidi c protein (GFAP) and vimentin, (2) astrocytes expressing only GFAP and (3) astrocyte-like cells expressing vimentin. Thereafter, numbers of immunopositive and autoradiographically labelled cells and their locat ions within the region of injury were recorded at each stage of the ex periment. Two hours as well as 1 day after the injury proliferation of GFAP-positive astrocytes and of those co-expressing GFAP and vimentin could only be seen as statistically insignificant phenomena. On day 2 the reactive proliferation of each immunocytochemically defined cell type was already maximal, then gradually decreased and its last signs were recorded on day 8. On day 2, among all the proliferating GFAP-pos itive astrocytes, 67.2% were also vimentin-positive. Later, the propor tion declined to 50.7% and 38.5% on days 4 and 8, respectively. The la belled astrocyte-like vimentin-positive cells were located closest to the lesion margins. In comparison, the astrocytes co-expressing GFAP a nd vimentin and those expressing exclusively GFAP, occupied regions pr ogressively farther from the lesion site. At the initial stages of the response to injury, vimentin expression in cells starting their react ive proliferation did not precede the expression of GFAP. This was con sidered as an argument against a hypothesis that reactive astrocyte di vision induces a two-stage increase in the cytoskeletal protein level in which synthesis of vimentin precedes that of GFAP.