INTRANUCLEAR UBIQUITIN-IMMUNOPOSITIVE STRUCTURES OF THE HUMAN SUBSTANTIA NIGRA NEURONS
I.P. Grigoriev,1 D.E. Korzhevskii, E.G. Sukhorukova, V.V. Gusel'nikova, O.V. Kirik
Institute of Experimental Medicine, St. Petersburg, 197376;
1 e-mail: ipg-iem@yandex.ru
Marinesco bodies were discovered in the human substantia nigra neurons in 1902. However, relationships these intranuclear inclusions with other cell nuclear structures remains
obscured yet. The aim of the present study was to investigate morphological and cytochemical peculiarities of these ubiquitin-immunopositive intranuclear bodies in neurons of the
human substantia nigra and the character of their relationships with the nucleolus using light microscopy, immunocytochemistry, and confocal laser microscopy. It has been
established that up to 20 % of the neurons of the substantia nigra contain ubiquitin-immunopositive Marinesco bodies. Only a third of them were closely adjacent to the
nucleolus. Using a method of silver impregnation of argentophilic proteins associated with nuclear organizer, the lack of the argentophilic proteins typical for the nucleolus has been
shown in the Marinesco bodies. We have found some specific ubiquitin-positive structures in the nuclei of neurons in addition to Marinesco bodies. These structures having less than
1 mkm in size are supposedly the initial forms of the Marinesco bodies. Confocal laser microscopy has revealed two types of the ubiquitin-immuno-positive intranuclear bodies - with
high and low immunofluorescence, while the latter shows heterogeneity in distribution of the immunopositive product. With the use of a fluorescent dye SYTOX Green, the presence
of DNA has been revealed in the Marinesco bodies. The absence of the peripheral zone of heterochromatin and poor perception of toluidine blue in combination with the DNA presence
and loss of argentophilic proteins strongly suggest significant structural and chemical differences between Marinesco bodies and nucleoli and argue against the view that the revealed
bodies may be changed nucleoli.
Key words:
Marinesco bodies, ubiquitin, cell nucleus, cell nucleolus, substantia nigra
| Back
| Contents
| Home EN |
|
