AJP - Renal Physiology, Vol 260, Issue 5 704-F709, Copyright © 1991 by American Physiological Society
Detection of the Na(+)-K(+)-ATPase alpha 3-isoform in multinucleated macrophages
A. Vignery, F. Wang, H. Y. Qian, E. J. Benz Jr and M. Gilmore-Hebert
Department of Orthopedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut 06510.
We previously reported that multinucleated macrophages express a high
concentration of Na(+)-K(+)-ATPases that are concentrated on the
nonadherent domain of their plasma membrane (A. Vignery, T.
Niven-Fairchild, D. H. Ingbar, and M. Caplan. J. Histochem. Cytochem. 37:
1265-1271, 1989). We also showed that an increase in newly synthesized
alpha-subunit occurred during cell culture and multinucleation. We now
present evidence that macrophage multinucleation in vitro is accompanied by
an increased accumulation of Na(+)-K(+)-ATPase alpha-subunit mRNA. Most
interesting is the detection of significant amount of both alpha 1- and
alpha 3-isoform mRNA and peptide in these cells by in situ hybridization,
Northern and Western blot analyses. These qualitative and quantitative
variations in Na(+)-K(+)-ATPase expression suggest that macrophage
multinucleation is accompanied by a coordinated regulation of gene
expression and that multinucleation confers a specific function to
macrophages. Multinucleated macrophages offer a novel model system to
investigate not only the specific function(s) of the alpha 3-isoform but
also the role of the Na(+)-K(+)-ATPase in giant cells and osteoclasts.
