TCF7L1 Accelerates Smooth Muscle Cell Phenotypic Switching and Aggravates Abdominal Aortic Aneurysms

Phenotypic switching of vascular smooth muscle cells is a central process in abdominal aortic aneurysm (AAA) pathology. We found that knockdown TCF7L1 (transcription factor 7-like 1), a member of the TCF/LEF (T cell factor/lymphoid enhancer factor) family of transcription factors, inhibits vascular smooth muscle cell differentiation. This study hints at potential interventions to maintain a normal, differentiated smooth muscle cell state, thereby eliminating the pathogenesis of AAA. In addition, our study provides insights into the potential use of TCF7L1 as a biomarker for AAA.

Cardiac Nuclear High-Mobility Group Box 1 Ameliorates Pathological Cardiac Hypertrophy by Inhibiting DNA Damage Response

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HMGB1 is a DNA-binding protein associated with nuclear homeostasis and DNA repair.

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Decreased nuclear HMGB1 expression is observed in human failing hearts, which is associated with cardiomyocyte hypertrophy and fibrosis.

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Cardiac nuclear HMGB1 overexpression ameliorates Ang II–induced pathological cardiac remodeling by inhibiting cardiomyocyte DNA damage and following ataxia telangiectasia mutated activation in mice.

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Ataxia telangiectasia mutated inhibitor treatment provided a cardioprotective effect on Ang II–induced cardiac remodeling in mice.

High-mobility group box 1 (HMGB1) is a deoxyribonucleic acid (DNA)–binding protein associated with DNA repair. Decreased nuclear HMGB1 expression and increased DNA damage response (DDR) were observed in human failing hearts. DNA damage and DDR as well as cardiac remodeling were suppressed in cardiac-specific HMGB1 overexpression transgenic mice after angiotensin II stimulation as compared with wild-type mice. In vitro, inhibition of HMGB1 increased phosphorylation of extracellular signal-related kinase 1/2 and nuclear factor kappa B, which was rescued by DDR inhibitor treatment. DDR inhibitor treatment provided a cardioprotective effect on angiotensin II–induced cardiac remodeling in mice.