Rearrangement of nuclear ribonucleoproteins and extrusion of nucleolus-like bodies during apoptosis induced by hypertonic stress.
Short-term hypertonic (HT) stress induces apoptotic cell death in human EUE cells in culture, as observed by electron microscopy, agarose-gel electrophoresis of low-molecular-weight DNA, DNA flow cytometry and annexin-V-propidium iodide double-staining. During HT-induced apoptosis, nuclear ribonucleoprotein (RNP)-containing structures undergo rearrangement, with the formation of Heterogeneous Ectopic RNP-Derived Structures (HERDS) which pass into the cytoplasm, as already reported for other examples of spontaneous and drug-induced apoptosis. Of special interest was the observation that nucleolus-like bodies (NLBs) which resemble morphologically nuclear functional nucleoli may be extruded into the cytoplasm of apoptotic cells and are observed inside the cytoplasmic fragments blebbing-out at the cell surface; these NLBs still contain immunodetectable nucleolar proteins (such as fibrillarin). This is an additional example of RNP-containing structures of nuclear origin which are extruded from the nucleus, in an almost "native" form, during apoptosis.
Pellicciari
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Dipartimento di Biologia Animale and Centro di Studio per l'Istochimica del CNR, University of Pavia, Italy. pelli@unipv.it
Bottone
M G
MG
Scovassi
A I
AI
Martin
T E
TE
Biggiogera
M
M
D017209:Apoptosis / Q000502:physiology*; D002466:Cell Nucleolus / Q000502:physiology / Q000648:ultrastructure; D002467:Cell Nucleus / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D004847:Epithelial Cells / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D006982:Hypertonic Solutions
D006982:Hypertonic Solutions