A NOTCH4 intron 28 regulatory element controls arterial specification and lymphoid development from hPSCs

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Hematopoiesis

Background:

• NOTCH signaling is vital for arterial specification and forming hematopoietic stem cells from hemogenic endothelium.
• Understanding NOTCH signaling's role in arterial and lymphoid specification is crucial for regenerative medicine.

Purpose of the Study:

• To investigate NOTCH signaling mechanisms essential for arterial and lymphoid specification.
• To analyze dynamic changes in NOTCH signaling during hematopoietic differentiation.

Main Methods:

• Single-cell multiomics analysis of human pluripotent stem cells (hPSCs) during hematopoietic differentiation.
• Investigated the role of a specific cis-regulatory element (NOTCH4in28) and SOX17 binding in NOTCH4 expression.
• Utilized conventional and conditional iSOX17 hPSCs for genetic manipulation.

Main Results:

• NOTCH signaling and arterial program activation were observed during hemogenic endothelium specification and endothelial-to-hematopoietic transition.
• NOTCH4 expression in arterial endothelium is regulated by the NOTCH4in28 cis-regulatory element via SOX17 binding.
• Deletion of NOTCH4in28 impaired the formation of arterial HE and lymphoid progenitors (T and NK cells).

Conclusions:

• NOTCH4 and its cis-regulatory element NOTCH4in28 are critical for arterial specification.
• The NOTCH4/NOTCH4in28 pathway is important for lymphoid development from hPSCs.
• This study provides insights into the molecular mechanisms governing early hematopoiesis and vascular development.