Atf3 Deficiency Promotes Mesodermal Commitment and Enhances Endothelial Differentiation in Embryonic Stem Cells.

Area of Science:

• Stem cell biology
• Vascular biology
• Molecular and developmental biology

Background:

• Endothelial cell (EC) damage is central to ischemic diseases.
• Cell therapies for endothelial repair are promising but face procurement challenges.
• The role of Atf3 (activating transcription factor 3) in EC differentiation from stem cells is unclear.

Purpose of the Study:

• To investigate the role of Atf3 in embryonic stem cell differentiation into ECs.
• To elucidate the molecular mechanisms by which Atf3 influences EC development.

Main Methods:

• CRISPR-Cas9 was used to knockout Atf3 (Atf3KO) in mouse embryonic stem cells.
• EC differentiation was induced using embryoid body formation and attachment.
• EC marker expression, EC function (LDL uptake, NO production), and signaling pathways were analyzed.

Main Results:

• Atf3KO significantly upregulated progenitor and mesoderm cell markers.
• Mature EC markers increased by day 9 post-differentiation.
• Atf3KO enhanced EC function and activated the Rap1 signaling pathway.

Conclusions:

• Atf3 knockout directs stem cells toward the mesodermal lineage, promoting EC development.
• Activation of the Rap1 signaling pathway by Atf3KO is crucial for EC maturation.
• Atf3 plays a key regulatory role in early vascular endothelial development.