|Cancer||Cell death||Cell cycle||Cytoskeleton||Exo/endocytosis||Differentiation||Division||Organelles||Signalling||Stem cells||Trafficking|
Cell Biology International (1998) 22, 351357 (Printed in Great Britain)
MULTINUCLEATION AND PRESERVATION OF NUCLEOLAR INTEGRITY OF MACROPHAGES
KENJI SORIMACHIab,f1, HONAMI NAORAb, KAZUMI AKIMOTOc, AKIRA NIWAa and HIROTO NAORAb
aDepartment of Microbiology, Dokkyo University School of Medicine, Mibu, Tochigi, 321-02, Japan
cLaboratory of Molecular and Cellular Biology, Dokkyo University School of Medicine, Mibu, Tochigi, 321-02, Japan
bResearch School of Biological Sciences, The Australian National University, Canberra, A.C.T. 2601, Australia
Rat bone marrow-derived macrophages formed multinucleated giant cells spontaneously when cultured in slide glass chambers or when induced with the polyanion acetyl lignin. Nuclei in such cells tended to cluster in distinct rings. DNA fragmentation appeared to occur in multinucleated cells, as detected by 3′ end-labeling. Southern blot analyses, using probes specific for nucleolar and non-nucleolar genes, indicated that chromatin DNA was fragmented whereas nucleolar DNA was relatively intact. Autoradiography revealed preservation, in multinucleated cells, of nucleoli into which radiolabeled uridine was incorporated. Multinucleated macrophages appeared to eventually fragment. Preserved integrity of nucleoli seems to be a feature of macrophage multinucleation, a process which apparently culminates in cell death.
Key words: macrophages, multinucleation, nucleolar DNA, chromatin DNA.
f1*To whom correspondence should be addressed.