Adipogenic effect of alcohol on human bone marrow-derived mesenchymal stem cells.
BACKGROUND
In addition to a decrease in bone mass in alcoholics their osteopenic skeletons show an increase in bone marrow adiposity. Human bone marrow mesenchymal stem cells (hMSC) in vivo differentiate into several phenotypes including osteogenic and adipogenic cells, both of which remain as resident populations of bone marrow. In vitro, the lineage commitment and differentiation of hMSC toward the adipogenic pathway can be promoted by alcohol.


METHODS
Human male and female mesenchymal stem cells from joint replacement surgery were cultured. Cells were grouped as: 1) Control (no additions to the culture medium), 2) EtOH (50 mm alcohol added to the culture medium), 3) OS (osteogenic inducers added to the culture medium), and 4) OS + EtOH (osteogenic inducers and 50 mm alcohol added to the culture medium). Cultures stained with Nile Red confirmed the development of differentiated adipocytes. Population analysis was performed using fluorescence-activated cell sorting. Gene expression of early, middle, late, and terminal differentiation stage markers (PPAR)gamma2, lipoprotein lipase, adipsin, leptin, and adipocyte P2 (aP2)] was studied by Northern hybridization, and protein synthesis of aP2 was determined by Western analysis.


RESULTS
Nile red staining confirmed increased adipocyte development 10 days after the onset of treatment with 50 mm alcohol and osteogenic induction. By day 21 the number of adipocytes increased to 13.6% of the total population. Alcohol up-regulated the gene expression of PPARgamma2 whereas no up-regulation was observed for the other genes. Protein production of aP2 was significantly increased in hMSC cells by culture in the presence of alcohol.


CONCLUSIONS
The data suggest that alcohol's adipogenic effect on cultured hMSC is through up-regulation of PPARgamma2 at the point of lineage commitment as well as through enhancement of lipid transport and storage through increased aP2 synthesis. The alcohol-induced expression and synthesis changes account for the increased Nile red staining of cultured hMSC.
Wezeman
Frederick H
FH
Department of Orthopaedic Surgery and Rehabilitation and the Alcohol Research Program, Loyola University Stritch School of Medicine, Maywood, Illinois 60153, USA. fwezema@lumc.edu
Gong
Zhaodi
Z
D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism; D008875:Middle Aged
D000431:Ethanol