TRANSFORMATION OF CULTURED HUMAN MONOCYTES BY PEROXIDIZED LOW-DENSITY-LIPOPROTEIN

To study the roles of peroxidized low-density lipoprotein (pox-LDL) du ring the formation of foam cells from human monocytes, monocytes isola ted from normal human blood were incubated with RPMI alone, normal low -density lipoprotein (n-LDL) and copper pox-LDL, The concentrations of total cholesterol (TCH) and lipid peroxide in the human monocyte medi um did not change significantly after incubation with RPMI medium alon e or n-LDL, but those of TCH decreased slightly after incubation with pox-LDL for 24 h, Triglyceride (TC) concentrations in the culture medi um of human monocytes decreased after incubation with all above substa nces, Ultrastructural studies showed that the monocytes changed to mac rophages after incubation with RPMI alone or n-LDL and to foam cells a fter incubation with pox-LDL for 48 h. We conclude that TGs may be met abolized for ATP production by human monocytes. The energy may play a role in the transformation of monocytes to macrophages, and pox-LDL ca n induce transformation of monocyte-derived macrophages to foam cells.