I-B Kinase- Deficiency Attenuates the Development of Angiotensin II-Induced Myocardial Hypertrophy in Mice.

I-B kinase- (IKK) is a member of the IKK complex and a proinflammatory regulator that is active in many diseases. Angiotensin II (Ang II) is a vasoconstricting peptide hormone, and Ang II-induced myocardial hypertrophy is a common cardiovascular disease that can result in heart failure. In this study, we sought to determine the role of IKK in the development of Ang II-induced myocardial hypertrophy in mice. Wild-type (WT) and IKK-knockout (IKK-KO) mice were generated and infused with saline or Ang II for 8 weeks. We found that WT mouse hearts have increased IKK expression after 8 weeks of Ang II infusion. Our results further indicated that IKK-KO mice have attenuated myocardial hypertrophy and alleviated heart failure compared with WT mice. Additionally, Ang II-induced expression of proinflammatory and collagen factors was much lower in the IKK-KO mice than in the WT mice. Apoptosis and pyroptosis were also ameliorated in IKK-KO mice. Mechanistically, IKK bound to extracellular signal-regulated kinase (ERK) and the mitogen-activated protein kinase p38, resulting in MAPK/ERK kinase (MEK) phosphorylation, and IKK deficiency inhibited the phosphorylation of MEK-ERK1/2 and p38 in mouse heart tissues after 8 weeks of Ang II infusion. The findings of our study reveal that IKK plays an important role in the development of Ang II-induced myocardial hypertrophy and may represent a potential therapeutic target for the management of myocardial hypertrophy.