Discovery of a new RNA-containing nuclear structure in UVC-induced apoptotic cells by integrated laser electron microscopy.

Détails

ID Serval
serval:BIB_072260182E0C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Discovery of a new RNA-containing nuclear structure in UVC-induced apoptotic cells by integrated laser electron microscopy.
Périodique
Biology of the Cell
Auteur(s)
Karreman M.A., Agronskaia A.V., Verkleij A.J., Cremers F.F., Gerritsen H.C., Humbel B.M.
ISSN
1768-322X (Electronic)
ISSN-L
0248-4900
Statut éditorial
Publié
Date de publication
2009
Volume
101
Numéro
5
Pages
287-299
Langue
anglais
Résumé
BACKGROUND INFORMATION: Treatment of cells with UVC radiation leads to the formation of DNA cross-links which, if not repaired, can lead to apoptosis. gamma-H2AX and cleaved caspase 3 are proteins formed during UVC-induced DNA damage and apoptosis respectively. The present study sets out to identify early morphological markers of apoptosis using a new method of correlative microscopy, ILEM (integrated laser electron microscopy). Cleaved caspase 3 and gamma-H2AX were immunofluorescently labelled to mark the cells of interest. These cells were subsequently searched in the fluorescence mode of the ILEM and further analysed at high resolution with TEM (transmission electron microscopy).
RESULTS: Following the treatment of HUVECs (human umbilical vein endothelial cells) with UVC radiation, in the majority of the cells gamma-H2AX was formed, whereas only in a subset of cells caspase 3 was activated. In severely damaged cells with high levels of gamma-H2AX a round, electron-dense nuclear structure was found, which was hitherto not identified in UV-stressed cells. This structure exists only in nuclei of cells containing cleaved caspase 3 and is present during all stages of the apoptotic process. Energy-loss imaging showed that the nuclear structure accumulates phosphorus, indicating that it is rich in nucleic acids. Because the nuclear structure did not label for DNA and was not affected by regressive EDTA treatment, it is suggested that the UV-induced nuclear structure contains a high amount of RNA.
CONCLUSIONS: Because the UV-induced nuclear structure was only found in cells labelled for cleaved caspase 3 it is proposed as an electron microscopic marker for all stages of apoptosis. Such a marker will especially facilitate the screening for early apoptotic cells, which lack the well-known hallmarks of apoptosis within a cell population. It also raises new questions on the mechanisms involved in the UV-induced apoptotic pathway.
Mots-clé
Apoptosis/radiation effects, Biological Markers/analysis, Caspase 3/analysis, Caspase 3/radiation effects, Cell Nucleus/chemistry, Cell Nucleus/radiation effects, Cells, Cultured, Endothelial Cells/cytology, Endothelial Cells/radiation effects, Fluorescent Antibody Technique, Histones/analysis, Histones/radiation effects, Humans, Microscopy, Confocal/instrumentation, Microscopy, Confocal/methods, Microscopy, Electron/instrumentation, Microscopy, Electron/methods, RNA/analysis, Ultraviolet Rays
Pubmed
Web of science
Création de la notice
28/02/2012 19:40
Dernière modification de la notice
03/03/2018 13:27
Données d'usage