p130/p107 expression distinguishes adipogenic potential in primary myoblasts based on age.
Recent investigations have provided significant evidence that many mesodermally derived tissues contain stem cell-like precursors capable of being stimulated to undergo differentiation into a variety of cellular lineages. We have recently reported that primary myoblasts isolated from 23-month-old mice have an increased adipogenic potential when compared to their 8-month-old counterparts. To further characterize the degree of adipocyte differentiation in these myoblasts, we examined early and late markers of adipocyte differentiation. Within the first 24h of adipocyte differentiation, expression of p130 and p107, two members of the retinoblastoma tumor suppressor gene family, are regulated and this event is an important one early in adipogenesis. Consistent with the increased adipogenic potential of the older myoblasts and in contrast to the younger cells, the p130:p107 pattern of expression is very similar to that observed in adipogenesis where there is a transient increase in p107 expression accompanied by a decrease in p130 expression. Interestingly, while these older cells accumulated lipid and expressed genes associated with lipid metabolism, they failed to express adipsin and leptin, two well-established markers of terminal adipocyte differentiation. These results suggest that older myoblasts are capable of initiating and progressing through the adipogenic program to a point where they express genes associated with lipid metabolism, but do not reach a terminally differentiated state. This finding may have important metabolic implications in the aging population.
Department of Pediatrics/Division of Neonatology, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, 4301 West Markham Street, Slot 512-B, 72205, Little Rock, AR, USA.
Yu
Y
Guan
Jane M
JM
Taylor-Jones
Charlotte A
CA
Peterson
Robert E
RE
McGehee
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism; D000375:Aging; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D002478:Cells, Cultured; D006728:Hormones / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D008808:Mice, Inbred CBA; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011506:Proteins; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology
D015415:Biomarkers; D006728:Hormones; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; C489485:Rbl1 protein, mouse; C493838:Rbl2 protein, mouse; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130