Comparative immunohistochemical study of glial filament proteins (glial fibrillary acidic protein and vimentin) in goldfish, octopus, and snail

Abstract

Glial fibrillary acidic protein (GFAP) and vimentin proteins are known to be component proteins of glial filaments in the CNS of many vertebrates. The nature of the filaments present in the glial cells of the goldfish optic tectum and in the CNS of two members of the Mollusca (Helix pomatia and Octopus vulgaris) were investigated using immunocytochemical localization of monoclonal antibodies to GFAP and vimentin. Immunoblots visualized by the alkaline phosphatase method showed cross-reactive protein bands to GFAP and vimentin antibodies in total brain homogenates of the goldfish, octopus, and snail. Immunofluorescence staining of the goldfish optic tectum showed GFAP immunoreactivity, primarily in the ependymal cell processes. Immunogold labelling at the ultrastructural level verified that GFAP antibodies were bound to glial filaments. Immunolabelling of the optic lobe of Octopus vulgaris and the cerebral ganglia of Helix pomatia suggests that a protein exhibiting antigenic properties similar to GFAP is a component protein in the filaments of the protoplasmic and filamentous glia randomly distributed throughout the CNS. Unlike anti-GFAP antibodies, which stained relatively specific to filaments, vimentin staining in the CNS tissues of the three organisms studied did not appear to be exclusive to filamentous structures. As vimentin protein has been shown, in previous studies as well as our own, to exist in many tissue types, this suggests that it does not appear to be confined to glial filaments but is shared with other subcellular components. The proteins GFAP and vimentin which are thought to be well conserved in vertebrate evolution also appear to be expressed in the nervous system of some lower organisms.

Glial fibrillary acidic protein and vimentin immunoreactivity of astroglial cells in the central nervous system of adult Podarcis sicula (Squamata, Lacertidae)

“…Nevertheless vimentin is still expressed in the ependymal cells of some regions of adult CNS in mammals (Chouaf et al 1989 ;Oudega & Marani, 1991 ;Yamada et al 1992), birds (Alvarez-Buylla et al 1987 ;Kalman et al 1998), reptiles (Lauro et al 1991 ; present study), amphibians (Zamora & Mutin, 1988 ;Lauro et al 1991 ;Lazzari et al 1997) and fish (Cardone & Roots, 1990 ;Rubio et al 1992 ;Bodega et al 1993).…”

“…Even though vimentin has been found in immature cells of the astroglial lineage in mammals (Elmquist et al 1994 ;Pulido-Caballero et al 1994) and reptiles (Monzon-Mayor et al 1990 ;Yanes et al 1990), it is still present in adult glial cells in teleosts and amphibians (Zamora & Mutin, 1988 ;Cardone & Roots, 1990 ;Rubio et al 1992 ;Lazzari et al 1997). Furthermore, vimentin is highly conserved in phylogenesis as suggested by the cross reaction of antibodies produced against mammalian vimentin with the corresponding protein in birds and amphibians (Bennett et al 1978 ;Szaro & Gainer, 1988 ;Zamora & Mutin, 1988 ;Bodega et al 1994).…”

Glial fibrillary acidic protein (GFAP)‐like immunoreactivity in the visual system of the crab Ucides cordatus (Crustacea, Decapoda)

“…Accordingly, GFAP-like immunoreactivity has been shown in enteric glia (Jessen and Mirsky, 1980), Schwann cells of unmyelinated peripheral nerve fibers (Yen and Fields, 1981;Dahl et al, 1982), lens epithelium (Hatfield et al, 1984), and Kupffer cells in the liver (Gard et al, 1985), among others. Filaments of morphological structure similar to the intermediate glial filament have been reported in the glial cells of many mammals, birds, reptiles, fishes (Dahl et al, 1985), and in some invertebrates such as annelids and mollusks (see Radojcic and Pentreath, 1979;Cardone and Roots, 1990;Riehl and Schlue, 1998;Dos Santos et al, 2002).…”

“…Because of the main role that has been attributed to GFAP in astrocytes, as a cytoskeleton stabilizer (see Rutka et al, 1997), and to the presence of this protein in few invertebrates (see Radojcic and Pentreath, 1979;Cardone and Roots, 1990, Riehl and Schlue, 1998, Dos Santos et al, 2002, we wanted to search for the presence of GFAP-like proteins in crustaceans.…”

Development of vimentin and glial fibrillary acidic protein immunoreactivities in the brain of gray mullet (Chelon labrosus), an advanced teleost

“…These cells have been classically studied with metallic impregnation (see Lara et al, 1995) and electron microscopy Maxwell, 1966, 1967;Tapp, 1973;Laufer and Vanegas, 1974;Peter and Nagahama, 1976;Roots, 1978;Stevenson and Yoon, 1982;Díaz-Regueira et al, 1993). Immunocytochemical studies of ependymal and radial glia cells of bony fishes reported the presence of both GFAP (Onteniente et al, 1983;Anderson et al, 1984;Raamsdonk et al, 1984;Dahl et al, 1985;Levine, 1989;Nona et al, 1989;Cardone and Roots, 1990;Rubio et al, 1992;Díaz-Regueira et al, 1993;Ká lmá n, 1998;Kawai et al, 2001; Ká lmá n and Ari, 2002) and Vim (Cardone and Roots, 1990;Rubio et al, 1992;Díaz-Regueira et al, 1993;De Guevara et al, 1994;Cerdà et al, 1998). By using NADPH-diaphorase histochemistry, Ma (1993) described the regional distribution of tanycytes in the adult brain of the sunfish (Lepomis sp.).…”