Analysis of surface protein expression in human bone marrow stromal cells: new aspects of culture-induced changes, inter-donor differences and intracellular expression.
The most widely used technique for isolation of human bone marrow stromal cells (hBMSCs) from bone marrow includes density gradient centrifugation, recovery of the mononuclear cell population, and subsequent isolation of hBMSCs by virtue of their plastic adherence. During subsequent in vitro cultivation, they may lose their original characteristics since in vitro the stem cell niche cannot yet be properly mimicked. To further characterize these culture-induced changes in regard to mRNA and extra- and intracellular protein expression, as well as potential differences between hBMSCs from different donors, we investigated a panel of CD antigens for their presence on in vitro cultured hBMSCs. Interestingly, after culture-induced downregulation of their extracellular expression, both CD146 and CD271 persist intracellularly, which hints at the possibility that culture-induced changes may be reversed by appropriate stimuli. Further, CD34-a protein whose expression on hBMSCs is still controversial-is expressed at the intracellular level in hBMSCs of all donors independently of passage number. CD34 mRNA levels are significantly higher in female than in male donors. In summary, we further elucidate phenotypical changes induced by in vitro culture of hBMSCs, highlight interindividual differences in the phenotype of these cells and for the first time show the intracellular expression of CD34.
1 Department of Orthopaedic Trauma, Hannover Medical School , Hannover, Germany .
Luisa Marilena
LM
Schäck
Sandra
S
Noack
Ramona
R
Weist
Michael
M
Jagodzinski
Christian
C
Krettek
Manuela
M
Buettner
Andrea
A
Hoffmann
D015703:Antigens, CD / Q000096:biosynthesis; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics; D003470:Culture Media; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D014019:Tissue Donors
D015703:Antigens, CD; D003470:Culture Media; D008565:Membrane Proteins