Mesodermal expression of Moz is necessary for cardiac septum development

Area of Science:

• Developmental Biology
• Genetics
• Cardiovascular Research

Background:

• Ventricular septal defects (VSDs) are common congenital heart defects, often linked to syndromes like DiGeorge and Holt-Oram.
• These syndromes involve haploinsufficiency of T-box transcription factors TBX1 and TBX5.
• The histone acetyltransferase MOZ (MYST3/KAT6A) is essential for TBX1 and TBX5 gene expression, and its loss causes VSDs.

Purpose of the Study:

• To investigate the tissue-specific role of MOZ in cardiac development.
• To determine if MOZ is required in the mesoderm for proper heart formation.
• To elucidate the molecular mechanisms underlying VSDs in MOZ-deficient models.

Main Methods:

• Utilized Mesp1-cre to achieve mesoderm-specific deletion of the Moz gene in mice.
• Assessed cardiac development and phenotype in genetically modified mice.
• Quantified the expression levels of MOZ-dependent genes, including Tbx1 and Tbx5.

Main Results:

• Mesodermal deletion of Moz resulted in a high incidence of VSDs and overriding aorta.
• Significant downregulation of MOZ-dependent Tbx1 and Tbx5 expression was observed.
• These findings implicate MOZ's role in activating mesodermal Tbx1 and Tbx5.

Conclusions:

• MOZ is required in the mesoderm for normal heart development.
• Loss of MOZ in mesodermal cells leads to VSDs through impaired activation of Tbx1 and Tbx5.
• This study clarifies the molecular pathogenesis of VSDs associated with MOZ deficiency.