The adipocyte: relationships between proliferation and adipose cell differentiation.
The differentiation of adipose precursor cells can be divided into early and late events. Growth arrest at the G1/S boundary triggers the activation of early genes, i.e., pOb24 and lipoprotein lipase; the expression of both genes is primarily regulated at a transcriptional level. The expression of late markers, which lead to terminal differentiation and accumulation of neutral lipids, takes place after a limited number of mitoses of early-marker-expressing cells. Only terminal differentiation requires the presence of growth hormone and triiodothyronine as obligatory hormones and insulin as a modulating hormone, and results in the formation of triacylglycerol-filled, non-dividing cells. It appears that terminal differentiation involves the cyclic AMP pathway, the diacylglycerol pathway, and a third pathway triggered by insulinlike growth factor-I and insulin. It is thus proposed that a combination of mitogenic-adipogenic signals is required to trigger terminal differentiation of preadipose cells.
Ailhaud
G
G
Centre de Biochimie du CNRS, Laboratoire de Biologie du Développment du Tissu, Adipeux, Faculté des Sciences, Nice, France.
Amri
E
E
Bardon
S
S
Barcellini-Couget
S
S
Bertrand
B
B
Catalioto
R M
RM
Dani
C
C
Djian
P
P
Doglio
A
A
Forest
C
C
D000273:Adipose Tissue / Q000166:cytology*; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D000242:Cyclic AMP / Q000502:physiology; D005786:Gene Expression Regulation; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics; D006133:Growth Substances / Q000502:physiology; D006801:Humans; D008071:Lipoprotein Lipase / Q000235:genetics
D006133:Growth Substances; D000242:Cyclic AMP; D005993:Glycerolphosphate Dehydrogenase; D008071:Lipoprotein Lipase