TAB3 defect induces augmented cardioprotection loss from ischemic injury

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Cellular Biology

Background:

• Transforming growth factor β-activated kinase-binding protein 3 (TAB3) is implicated in various diseases, but its role in cardiac function remains unclear.
• Investigating TAB3's function in the heart is crucial for understanding ischemic heart disease pathogenesis.

Purpose of the Study:

• To elucidate the role of TAB3 in the context of ischemic heart disease.
• To determine the effects of TAB3 deficiency on cardiomyocyte apoptosis, proliferation, and angiogenesis.

Main Methods:

• In vitro studies involved isolating cardiomyocytes from TAB3 knockout (KO) and wild-type (WT) mice to assess apoptosis, proliferation, and tube formation.
• In vivo studies utilized a myocardial infarction (MI) model in TAB3 KO and WT mice, followed by echocardiography, hemodynamic testing, and histological analysis.
• Protein expression changes were analyzed using quantitative real-time polymerase chain reaction and immunoblotting.

Main Results:

• TAB3 deficiency led to increased cardiomyocyte apoptosis, decreased proliferation, and impaired angiogenesis in both in vitro and in vivo models.
• TAB3 knockout mice exhibited worse cardiac function, larger infarct sizes, and altered expression of key proteins including active-caspase-3, NF-κB/p65, Akt, Bcl-2/Bax, and VEGF.
• Histological assessments confirmed increased apoptosis, reduced proliferation, and neovascularization in TAB3-deficient hearts.

Conclusions:

• The absence of TAB3 exacerbates myocardial injury and dysfunction in ischemic heart disease.
• TAB3 plays a protective role in the heart, and its deficiency is detrimental to cardiac recovery post-ischemia.