Tead1 is required for perinatal cardiomyocyte proliferation.

Area of Science:

• Cardiovascular Biology
• Developmental Biology
• Molecular Cardiology

Background:

• Adult heart size depends on cardiomyocyte number and size, established during early development.
• The Hippo kinase pathway regulates cardiomyocyte proliferation, with Tead1 as a key downstream factor.
• The specific role of Tead1 in perinatal cardiomyocyte proliferation remains unclear.

Purpose of the Study:

• To investigate the role of the transcription factor Tead1 in perinatal cardiomyocyte proliferation.
• To determine the consequences of Tead1 deletion in cardiomyocytes during the perinatal period.

Main Methods:

• Generation of cardiomyocyte-specific perinatal Tead1 knockout mice (Tead1-cKO) using Myh6-Cre.
• Analysis of Tead1-cKO mice for lethality, cardiac function, and cardiomyocyte proliferation.
• In vitro studies using HL-1 cardiac cell line to confirm cell-autonomous Tead1 function.

Main Results:

• Perinatal deletion of Tead1 resulted in lethal dilated cardiomyopathy by postnatal day 9.
• Tead1-deficient cardiomyocytes exhibited significantly decreased proliferation during the critical postnatal period.
• Tead1 deficiency led to reduced levels of cell cycle-promoting proteins in cardiomyocytes.
• Cell-autonomous function of Tead1 is required for normal cardiomyocyte proliferation.

Conclusions:

• Tead1 plays a critical, non-redundant role in regulating cardiomyocyte proliferation during the perinatal period.
• Tead1 is essential for maintaining cardiomyocyte cell cycle progression by controlling key regulatory proteins.
• Disruption of Tead1 function leads to impaired heart development and dilated cardiomyopathy.