Differences in definitive endoderm induction approaches using growth factors and small molecules

Area of Science:

• Stem cell biology
• Developmental biology
• Regenerative medicine

Background:

• Definitive endoderm (DE) is a critical early stage in human pluripotent stem cell (hPSC) differentiation towards hepatocyte-like cells.
• Developing robust human liver cell models is essential for pharmaceutical research and drug development.
• Numerous protocols exist for DE induction from hPSCs, necessitating comparative analysis.

Purpose of the Study:

• To evaluate and compare the efficiency and specificity of various published protocols for DE induction from hPSCs.
• To identify optimal conditions for generating DE cells suitable for subsequent differentiation and applications.
• To optimize a 6-day protocol for DE generation.

Main Methods:

• Two hPSC lines (induced and embryonic) were differentiated to DE on Matrigel.
• Combinations of growth factors (Activin A, Wnt-3a) and small molecules (sodium butyrate, IDE 1) were tested.
• Dynamic changes in cell morphology and expression of pluripotency, DE, and germ layer markers were monitored over 6 days.

Main Results:

• Activin A was identified as essential for DE differentiation.
• Wnt-3a and sodium butyrate were found to be dispensable for DE induction.
• Sodium butyrate induced rapid differentiation but caused significant cell death, hindering further applications.
• IDE 1 did not induce DE as previously reported.
• An effective 6-day protocol for DE generation was established.

Conclusions:

• Activin A is the key factor for successful DE induction from hPSCs.
• The tested combinations of Wnt-3a and sodium butyrate are not optimal for generating sufficient DE cells.
• The developed 6-day protocol provides an effective method for obtaining DE cells for downstream applications in liver cell modeling.