Oral Presentation The Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2013

Role of amino acids in self-renewal and directed differentiation of MESCS  – An in vivo model for embryo development (#153)

Tanya A Saraogi 1 , Margot L Day 1 , Michael B Morris 1
  1. University of Sydney, Sydney, NSW, Australia

Stem cells are an important in vivo model for embryo development. Our lab and others have shown that several amino acids can function as signalling molecules which regulate stem-cell differentiation. L-Proline (L-Pro) together with the cytokine leukaemia inhibitory factor (LIF) induces mouse embryonic stem cell (mESCs) proliferation and formation of a distinct pluripotent cell population 1 2 3 - early primitive ectoderm-like (EPL) cells which have the characteristics of embryonic primitive ectoderm. On the other hand, self-renewal of mESCs depends on another amino acid, L-Threonine (L-Thr), which controls the G1-to-S phase transition via Akt and MAPK signalling pathways; these pathways are important during early embryo development. Our aim is to determine whether mESC self-renewal and rate of differentiation is dependent on the concentration of specific amino acids. mESCs were cultured in medium containing LIF ± different concentrations of L-Proline or L-Threonine. Cell type was identified by marker analysis using qPCR. Our results showed that higher concentrations of L-Pro prolonged the expression of markers of primitive ectoderm and accelerated Primitive Streak formation compared to lower concentrations. On the other hand, increased concentration of L-Thr sustained self-renewal of mESCs even when the concentration of LIF was reduced from 1000 U/mL to 330 U/mL. Our results indicate that amino acids can act like growth factors in combination with the cytokine LIF to affect the self-renewal and differentiation properties of mESCs in a concentration-dependent manner. These data provide evidence for the role of these amino acids in cell differentiation during early embryo development.

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