Apolipoprotein D transcription occurs specifically in nonproliferating quiescent and senescent fibroblast cultures.
We studied apolipoprotein D (apoD) mRNA in primary cultures of human diploid fibroblasts (HDF). In early-passage HDF no apoD mRNA was detected in replicating cells in sparse culture, but the gene was expressed in quiescent cells in confluent and in serum-starved cultures. In contrast, late-passage HDF expressed apoD mRNA in sparse culture, but the level increased after attainment of confluence. Thus fibroblasts, the common cell-type expressing apoD mRNA in vivo, express this characteristic following growth-arrest. The same pattern of activation was found in another fibroblast cell line deficient in apoB/E (LDL) receptors, excluding a role for cellular cholesterol delivery by the LDL-receptor pathway controlling apoD expression.
Département des sciences biologiques, Université du Québec à Montréal, Canada.
P R
PR
Provost
Y L
YL
Marcel
R W
RW
Milne
P K
PK
Weech
E
E
Rassart
D001053:Apolipoproteins / Q000235:genetics*; D053399:Apolipoproteins D; D015152:Blotting, Northern; D002455:Cell Division; D002460:Cell Line; D016922:Cellular Senescence; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
D001053:Apolipoproteins; D053399:Apolipoproteins D; D012333:RNA, Messenger