V. Fitzgerald et al., MOLECULAR-SPECIES OF SPHINGOMYELIN IN SPHINGOMYELINASE-SENSITIVE AND SPHINGOMYELINASE-RESISTANT POOLS OF HL-60 CELLS, Lipids, 30(9), 1995, pp. 805-809
This study of sphingomyelin molecular species in undifferentiated and
differentiated (granulocytic form) HL-60 cells demonstrated only minor
differences in the distribution of species between the sphingomyelina
se-sensitive and sphingomyelinase-resistant pools of sphingomyelin in
these cells. The two most prominent species of sphingosine present in
both the undifferentiated and differentiated cells were those containi
ng 16:0 (slightly higher in the sphingomyelinase-resistant membranes)
and 24:1 N-acyl moieties. Cell differentiation exerted little effect o
n the distribution of molecular species of sphingomyelin between the s
phingomyelinase-sensitive and sphingomyelinase-resistant pools in HL-6
0 cells, although the levels of N-palmitoyl sphinganine were significa
ntly lower and the N-nervonoyl sphingosine higher in both pools from t
he differentiated cells. Our results indicate the same species of sphi
ngomyelin, available at both the outer layer of the plasma membrane an
d inner layer of the plasma membrane (plus intracellular membranes) of
HL-60 cells, serve as-precursors for generation of the ceramides that
participate in signal transduction processes initiated by cell activa
tion.