CSB329H1 Lecture Notes - Lecture 7: Inner Cell Mass, Cytokine, Endoderm
9 May 2018
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Lecture 7(a): Embryonic Stem Cells
Embryonic Stem Cells:
• Originate in the early stage of development; soon after the first cell specification occurs
Mouse Blastocyst:
• Collection of cell stained in green are expressed OCT4 transcription factor
o Compact area of the blastocyst known as the inner cell mass
ð Inner cell mass consists of pluripotent embryonic stem cells which will
give rise to the entire embryo proper
o Cells surrounding the inner cell mass will give rise to extra
embryonic tissue
§ Pluripotent – have the capacity to give rise to all cell types making the embryo
Promise of Stem Cell Research:
• Can allow us to study the process of cell differentiation
o Stem cells have to self-renew and differentiation; observing how they differentiate in
culture will allow us to study their process
§ Embryonic stem cells differentiation into the three germ layers
• Toxicity Testing:
o Potential drug that may be useful for cardiac arrest; ensure that the drug does not have
unexpected toxicity effect by studying them in a simplified system
§ ‘organ on a chip’ – different layers of differentiated cells; instead of doing it
on animal models
Cardiomyocytes:
• Embryonic stem cells are capable of differentiating into cardiomyocytes in culture
o Will not be able to differentiate to complete mature cardiomyocytes but are capable
of beating spontaneously in culture (in synchrony) via pacemaker cell
§ Can be used to study how cardiac cells respond to drugs to treat damaged
heart tissue after cardiac arrest
Mouse Life Cycle:
• Fertilized egg will begin to undergo cleavage and first divisions occur
o Several cell divisions later, an early blastocyst will form which contains the inner
mass cells; pluripotent embryonic stem cells
§ Late blastocyst/post-implantation, pluripotent stem cells = epiblast
• Naïve pluripotent stem cells = inner mass cells
• Primed stem cells = epiblast
o Both are pluripotent, but different inner regulatory
network & rely on different external cues for maintenance
ð Human ESC = Epiblast | iPSC = Inner mass cells
Document Summary
Lecture 7(a): embryonic stem cells: originate in the early stage of development; soon after the first cell specification occurs. Mouse blastocyst: collection of cell stained in green are expressed oct4 transcription factor, compact area of the blastocyst known as the inner cell mass. Inner cell mass consists of pluripotent embryonic stem cells which will give rise to the entire embryo proper: cells surrounding the inner cell mass will give rise to extra embryonic tissue. Pluripotent have the capacity to give rise to all cell types making the embryo. Promise of stem cell research: can allow us to study the process of cell differentiation, stem cells have to self-renew and differentiation; observing how they differentiate in culture will allow us to study their process. Embryonic stem cells differentiation into the three germ layers: toxicity testing, potential drug that may be useful for cardiac arrest; ensure that the drug does not have unexpected toxicity effect by studying them in a simplified system.
