Supplementation-dependent differences in the rates of embryonic stem cell self-renewal, differentiation, and apoptosis.
Although it is known that leukemia inhibitory factor (LIF) supports the derivation and expansion of murine embryonic stem (ES) cells, it is unclear whether this is due to inhibitory effects of LIF on ES cell differentiation or stimulatory effects on ES cell survival and proliferation. Using an ES cell line transgenic for green fluorescent protein (GFP) expression under control of the Oct4 promoter, we were able to simultaneously track the responses of live Oct4-GFP-positive (ES) and -negative (differentiated) fractions to LIF, serum, and other growth factors. Our findings show that, in addition to inhibiting differentiation of undifferentiated cells, the administration of LIF resulted in a distinct dose-dependent survival and proliferation advantage, thus enabling the long-term propagation of undifferentiated cells. Competitive responses from the differentiated cell fraction could only be elicited upon addition of serum, fibroblast growth factor-4 (FGF-4), or insulin-like growth factor-1 (IGF-1). The growth factors did not induce additional differentiation of ES cells, but rather they significantly improved the proliferation of already differentiated cells. Our analyses show that, by adjusting culture conditions, including the type and amount of growth factors or cytokines present, the frequency of media exchange, and the presence or absence of serum, we could selectively and specifically alter the survival, proliferation, and differentiation dynamics of the two subpopulations, and thus effectively control population outputs. Our findings therefore have important applications in engineering stem cell culture systems to predictably generate desired stem cells or their derivatives for various regenerative therapies.
Viswanathan
Sowmya
S
Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada.
Benatar
Tania
T
Mileikovsky
Maria
M
Lauffenburger
Douglas A
DA
Nagy
Andras
A
Zandstra
Peter W
PW
D017209:Apoptosis / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015850:Interleukin-6 / Q000494:pharmacology*; D053605:Leukemia Inhibitory Factor; D050814:Octamer Transcription Factor-3; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D023822:Tissue Engineering / Q000379:methods*; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D050814:Octamer Transcription Factor-3; D011994:Recombinant Proteins; D014157:Transcription Factors