Heparan sulfate expression in the neural crest is essential for mouse cardiogenesis

Area of Science:

• Developmental Biology
• Biochemistry
• Genetics

Background:

• Heparan sulfate (HS) synthesis is crucial for vertebrate development, regulating growth factors and morphogens.
• Disruptions in HS synthesis lead to complex malformations.
• Congenital heart defects are the most common birth defects.

Purpose of the Study:

• To investigate the role of the HS-generating enzyme GlcNAc N-deacetylase/GlcN N-sulfotransferase 1 (NDST1) in vertebrate heart development.
• To elucidate the molecular mechanisms underlying HS-dependent signaling pathways in cardiac development.

Main Methods:

• Targeted disruption of the NDST1 gene in mice.
• Conditional gene targeting using WNT1-Cre/LoxP in neural crest cells (NCCs).
• Analysis of cardiac morphology and molecular signaling (FGF8, ERK phosphorylation).

Main Results:

• NDST1 disruption caused significant heart defects, including VSD, PTA, DORV, and RERSC.
• HS-dependent FGF8/FGFR2c assembly and ERK phosphorylation were reduced in NDST1-deficient cells.
• Impaired HS-dependent NCC development contributed to cardiac anomalies.

Conclusions:

• NDST1 is essential for normal heart development in vertebrates.
• HS-dependent signaling, particularly involving FGF8, is critical for cardiac morphogenesis.
• Defects in HS biosynthesis may be a contributing factor to human congenital heart defects.