Uptake of the aromatic retinoids Ro 10-9359 (etretinate) and Ro 10-1670 (acitretin), its main metabolite, delivered to cultured human fibroblasts by serum proteins. Lack of evidence for perturbation of LDL catabolism.
Etretinate or acitretin are efficiently delivered to cultured human fibroblasts in the presence of low density lipoproteins, high density lipoproteins or human serum albumin. In contrast to acitretin, delivery of etretinate to fibroblasts is more efficiently achieved with human serum albumin than with lipoproteins. The uptake of etretinate and acitretin via low density lipoproteins delivery, does not take place via the low density lipoprotein-receptor endocytotic pathway but mostly through a passive exchange with the plasma membrane. However, in contrast to acitretin, the exchange of etretinate seems to occur alter binding of etretinate-loaded low density lipoproteins to the apolipoprotein B receptors. No differences are observed in binding, internalization and degradation of native, etretinate-loaded low density lipoproteins and acitretin-loaded low density lipoproteins, suggesting that the presence of these retinoids in low density lipoproteins does not alter their processing by the cells. Furthermore, the presence of these retinoids in the cells does not notably affect, under our experimental conditions, the catabolism of native low density lipoproteins.
Carillet
V
V
Laboratoire de Dermatologie, INSERM U. 312, Hôpital Henri Mondor, Créteil, France.
Morlière
P
P
Mazière
J C
JC
Hüppe
G
G
Santus
R
R
Dubertret
L
L
D017255:Acitretin; D001667:Binding, Competitive; D001692:Biological Transport; D002478:Cells, Cultured; D005050:Etretinate / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000097:blood / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000097:blood / Q000378:metabolism*; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D014212:Tretinoin / Q000031:analogs & derivatives* / Q000378:metabolism
D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D012709:Serum Albumin; D014212:Tretinoin; D005050:Etretinate; D017255:Acitretin